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Merge branch 'master' of /home/cbou/linux-2.6 

Conflicts:

	drivers/power/Kconfig
	drivers/power/Makefile
hifive-unleashed-5.1
Anton Vorontsov 2008-07-30 02:05:23 +04:00
parent fece418418 6e86841d05
commit 9fec6060d9
9844 changed files with 689683 additions and 529487 deletions
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13
.gitignore vendored
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@ -3,6 +3,10 @@
# subdirectories here. Add them in the ".gitignore" file
# in that subdirectory instead.
#
# NOTE! Please use 'git-ls-files -i --exclude-standard'
# command after changing this file, to see if there are
# any tracked files which get ignored after the change.
#
# Normal rules
#
.*
@ -18,18 +22,21 @@
*.lst
*.symtypes
*.order
*.elf
*.bin
*.gz
#
# Top-level generic files
#
tags
TAGS
vmlinux*
!vmlinux.lds.S
vmlinux
System.map
Module.markers
Module.symvers
!.gitignore
!.mailmap
#
# Generated include files
@ -52,8 +59,8 @@ series
# cscope files
cscope.*
ncscope.*
*.orig
*.rej
*~
\#*#

16
CREDITS
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@ -317,6 +317,14 @@ S: 2322 37th Ave SW
S: Seattle, Washington 98126-2010
S: USA
N: Muli Ben-Yehuda
E: mulix@mulix.org
E: muli@il.ibm.com
W: http://www.mulix.org
D: trident OSS sound driver, x86-64 dma-ops and Calgary IOMMU,
D: KVM and Xen bits and other misc. hackery.
S: Haifa, Israel
N: Johannes Berg
E: johannes@sipsolutions.net
W: http://johannes.sipsolutions.net/
@ -2611,8 +2619,9 @@ S: Perth, Western Australia
S: Australia
N: Miguel Ojeda Sandonis
E: maxextreme@gmail.com
W: http://maxextreme.googlepages.com/
E: miguel.ojeda.sandonis@gmail.com
W: http://miguelojeda.es
W: http://jair.lab.fi.uva.es/~migojed/
D: Author of the ks0108, cfag12864b and cfag12864bfb auxiliary display drivers.
D: Maintainer of the auxiliary display drivers tree (drivers/auxdisplay/*)
S: C/ Mieses 20, 9-B
@ -3343,8 +3352,7 @@ S: Spain
N: Linus Torvalds
E: torvalds@linux-foundation.org
D: Original kernel hacker
S: 12725 SW Millikan Way, Suite 400
S: Beaverton, Oregon 97005
S: Portland, Oregon 97005
S: USA
N: Marcelo Tosatti

2
Documentation/00-INDEX
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@ -361,8 +361,6 @@ telephony/
- directory with info on telephony (e.g. voice over IP) support.
time_interpolators.txt
- info on time interpolators.
tipar.txt
- information about Parallel link cable for Texas Instruments handhelds.
tty.txt
- guide to the locking policies of the tty layer.
uml/

34
Documentation/ABI/testing/sysfs-block
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@ -26,3 +26,37 @@ Description:
I/O statistics of partition <part>. The format is the
same as the above-written /sys/block/<disk>/stat
format.
What: /sys/block/<disk>/integrity/format
Date: June 2008
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Metadata format for integrity capable block device.
E.g. T10-DIF-TYPE1-CRC.
What: /sys/block/<disk>/integrity/read_verify
Date: June 2008
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Indicates whether the block layer should verify the
integrity of read requests serviced by devices that
support sending integrity metadata.
What: /sys/block/<disk>/integrity/tag_size
Date: June 2008
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Number of bytes of integrity tag space available per
512 bytes of data.
What: /sys/block/<disk>/integrity/write_generate
Date: June 2008
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Indicates whether the block layer should automatically
generate checksums for write requests bound for
devices that support receiving integrity metadata.

35
Documentation/ABI/testing/sysfs-bus-css 100644
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@ -0,0 +1,35 @@
What: /sys/bus/css/devices/.../type
Date: March 2008
Contact: Cornelia Huck <cornelia.huck@de.ibm.com>
linux-s390@vger.kernel.org
Description: Contains the subchannel type, as reported by the hardware.
This attribute is present for all subchannel types.
What: /sys/bus/css/devices/.../modalias
Date: March 2008
Contact: Cornelia Huck <cornelia.huck@de.ibm.com>
linux-s390@vger.kernel.org
Description: Contains the module alias as reported with uevents.
It is of the format css:t<type> and present for all
subchannel types.
What: /sys/bus/css/drivers/io_subchannel/.../chpids
Date: December 2002
Contact: Cornelia Huck <cornelia.huck@de.ibm.com>
linux-s390@vger.kernel.org
Description: Contains the ids of the channel paths used by this
subchannel, as reported by the channel subsystem
during subchannel recognition.
Note: This is an I/O-subchannel specific attribute.
Users: s390-tools, HAL
What: /sys/bus/css/drivers/io_subchannel/.../pimpampom
Date: December 2002
Contact: Cornelia Huck <cornelia.huck@de.ibm.com>
linux-s390@vger.kernel.org
Description: Contains the PIM/PAM/POM values, as reported by the
channel subsystem when last queried by the common I/O
layer (this implies that this attribute is not neccessarily
in sync with the values current in the channel subsystem).
Note: This is an I/O-subchannel specific attribute.
Users: s390-tools, HAL

4
Documentation/ABI/testing/sysfs-class-bdi
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@ -14,6 +14,10 @@ MAJOR:MINOR
non-block filesystems which provide their own BDI, such as NFS
and FUSE.
MAJOR:MINOR-fuseblk
Value of st_dev on fuseblk filesystems.
default
The default backing dev, used for non-block device backed

20
Documentation/ABI/testing/sysfs-dev 100644
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@ -0,0 +1,20 @@
What: /sys/dev
Date: April 2008
KernelVersion: 2.6.26
Contact: Dan Williams <dan.j.williams@intel.com>
Description: The /sys/dev tree provides a method to look up the sysfs
path for a device using the information returned from
stat(2). There are two directories, 'block' and 'char',
beneath /sys/dev containing symbolic links with names of
the form "<major>:<minor>". These links point to the
corresponding sysfs path for the given device.
Example:
$ readlink /sys/dev/block/8:32
../../block/sdc
Entries in /sys/dev/char and /sys/dev/block will be
dynamically created and destroyed as devices enter and
leave the system.
Users: mdadm <linux-raid@vger.kernel.org>

24
Documentation/ABI/testing/sysfs-devices-memory 100644
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@ -0,0 +1,24 @@
What: /sys/devices/system/memory
Date: June 2008
Contact: Badari Pulavarty <pbadari@us.ibm.com>
Description:
The /sys/devices/system/memory contains a snapshot of the
internal state of the kernel memory blocks. Files could be
added or removed dynamically to represent hot-add/remove
operations.
Users: hotplug memory add/remove tools
https://w3.opensource.ibm.com/projects/powerpc-utils/
What: /sys/devices/system/memory/memoryX/removable
Date: June 2008
Contact: Badari Pulavarty <pbadari@us.ibm.com>
Description:
The file /sys/devices/system/memory/memoryX/removable
indicates whether this memory block is removable or not.
This is useful for a user-level agent to determine
identify removable sections of the memory before attempting
potentially expensive hot-remove memory operation
Users: hotplug memory remove tools
https://w3.opensource.ibm.com/projects/powerpc-utils/

127
Documentation/ABI/testing/sysfs-firmware-acpi
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@ -29,46 +29,46 @@ Description:
$ cd /sys/firmware/acpi/interrupts
$ grep . *
error:0
ff_gbl_lock:0
ff_pmtimer:0
ff_pwr_btn:0
ff_rt_clk:0
ff_slp_btn:0
gpe00:0
gpe01:0
gpe02:0
gpe03:0
gpe04:0
gpe05:0
gpe06:0
gpe07:0
gpe08:0
gpe09:174
gpe0A:0
gpe0B:0
gpe0C:0
gpe0D:0
gpe0E:0
gpe0F:0
gpe10:0
gpe11:60
gpe12:0
gpe13:0
gpe14:0
gpe15:0
gpe16:0
gpe17:0
gpe18:0
gpe19:7
gpe1A:0
gpe1B:0
gpe1C:0
gpe1D:0
gpe1E:0
gpe1F:0
gpe_all:241
sci:241
error: 0
ff_gbl_lock: 0 enable
ff_pmtimer: 0 invalid
ff_pwr_btn: 0 enable
ff_rt_clk: 2 disable
ff_slp_btn: 0 invalid
gpe00: 0 invalid
gpe01: 0 enable
gpe02: 108 enable
gpe03: 0 invalid
gpe04: 0 invalid
gpe05: 0 invalid
gpe06: 0 enable
gpe07: 0 enable
gpe08: 0 invalid
gpe09: 0 invalid
gpe0A: 0 invalid
gpe0B: 0 invalid
gpe0C: 0 invalid
gpe0D: 0 invalid
gpe0E: 0 invalid
gpe0F: 0 invalid
gpe10: 0 invalid
gpe11: 0 invalid
gpe12: 0 invalid
gpe13: 0 invalid
gpe14: 0 invalid
gpe15: 0 invalid
gpe16: 0 invalid
gpe17: 1084 enable
gpe18: 0 enable
gpe19: 0 invalid
gpe1A: 0 invalid
gpe1B: 0 invalid
gpe1C: 0 invalid
gpe1D: 0 invalid
gpe1E: 0 invalid
gpe1F: 0 invalid
gpe_all: 1192
sci: 1194
sci - The total number of times the ACPI SCI
has claimed an interrupt.
@ -89,6 +89,13 @@ Description:
error - an interrupt that can't be accounted for above.
invalid: it's either a wakeup GPE or a GPE/Fixed Event that
doesn't have an event handler.
disable: the GPE/Fixed Event is valid but disabled.
enable: the GPE/Fixed Event is valid and enabled.
Root has permission to clear any of these counters. Eg.
# echo 0 > gpe11
@ -97,3 +104,43 @@ Description:
None of these counters has an effect on the function
of the system, they are simply statistics.
Besides this, user can also write specific strings to these files
to enable/disable/clear ACPI interrupts in user space, which can be
used to debug some ACPI interrupt storm issues.
Note that only writting to VALID GPE/Fixed Event is allowed,
i.e. user can only change the status of runtime GPE and
Fixed Event with event handler installed.
Let's take power button fixed event for example, please kill acpid
and other user space applications so that the machine won't shutdown
when pressing the power button.
# cat ff_pwr_btn
0
# press the power button for 3 times;
# cat ff_pwr_btn
3
# echo disable > ff_pwr_btn
# cat ff_pwr_btn
disable
# press the power button for 3 times;
# cat ff_pwr_btn
disable
# echo enable > ff_pwr_btn
# cat ff_pwr_btn
4
/*
* this is because the status bit is set even if the enable bit is cleared,
* and it triggers an ACPI fixed event when the enable bit is set again
*/
# press the power button for 3 times;
# cat ff_pwr_btn
7
# echo disable > ff_pwr_btn
# press the power button for 3 times;
# echo clear > ff_pwr_btn /* clear the status bit */
# echo disable > ff_pwr_btn
# cat ff_pwr_btn
7

71
Documentation/ABI/testing/sysfs-firmware-memmap 100644
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@ -0,0 +1,71 @@
What: /sys/firmware/memmap/
Date: June 2008
Contact: Bernhard Walle <bwalle@suse.de>
Description:
On all platforms, the firmware provides a memory map which the
kernel reads. The resources from that memory map are registered
in the kernel resource tree and exposed to userspace via
/proc/iomem (together with other resources).
However, on most architectures that firmware-provided memory
map is modified afterwards by the kernel itself, either because
the kernel merges that memory map with other information or
just because the user overwrites that memory map via command
line.
kexec needs the raw firmware-provided memory map to setup the
parameter segment of the kernel that should be booted with
kexec. Also, the raw memory map is useful for debugging. For
that reason, /sys/firmware/memmap is an interface that provides
the raw memory map to userspace.
The structure is as follows: Under /sys/firmware/memmap there
are subdirectories with the number of the entry as their name:
/sys/firmware/memmap/0
/sys/firmware/memmap/1
/sys/firmware/memmap/2
/sys/firmware/memmap/3
...
The maximum depends on the number of memory map entries provided
by the firmware. The order is just the order that the firmware
provides.
Each directory contains three files:
start : The start address (as hexadecimal number with the
'0x' prefix).
end : The end address, inclusive (regardless whether the
firmware provides inclusive or exclusive ranges).
type : Type of the entry as string. See below for a list of
valid types.
So, for example:
/sys/firmware/memmap/0/start
/sys/firmware/memmap/0/end
/sys/firmware/memmap/0/type
/sys/firmware/memmap/1/start
...
Currently following types exist:
- System RAM
- ACPI Tables
- ACPI Non-volatile Storage
- reserved
Following shell snippet can be used to display that memory
map in a human-readable format:
-------------------- 8< ----------------------------------------
#!/bin/bash
cd /sys/firmware/memmap
for dir in * ; do
start=$(cat $dir/start)
end=$(cat $dir/end)
type=$(cat $dir/type)
printf "%016x-%016x (%s)\n" $start $[ $end +1] "$type"
done
-------------------- >8 ----------------------------------------

6
Documentation/ABI/testing/sysfs-kernel-mm 100644
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@ -0,0 +1,6 @@
What: /sys/kernel/mm
Date: July 2008
Contact: Nishanth Aravamudan <nacc@us.ibm.com>, VM maintainers
Description:
/sys/kernel/mm/ should contain any and all VM
related information in /sys/kernel/.

15
Documentation/ABI/testing/sysfs-kernel-mm-hugepages 100644
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@ -0,0 +1,15 @@
What: /sys/kernel/mm/hugepages/
Date: June 2008
Contact: Nishanth Aravamudan <nacc@us.ibm.com>, hugetlb maintainers
Description:
/sys/kernel/mm/hugepages/ contains a number of subdirectories
of the form hugepages-<size>kB, where <size> is the page size
of the hugepages supported by the kernel/CPU combination.
Under these directories are a number of files:
nr_hugepages
nr_overcommit_hugepages
free_hugepages
surplus_hugepages
resv_hugepages
See Documentation/vm/hugetlbpage.txt for details.

38
Documentation/CodingStyle
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@ -474,25 +474,29 @@ make a good program).
So, you can either get rid of GNU emacs, or change it to use saner
values. To do the latter, you can stick the following in your .emacs file:
(defun linux-c-mode ()
"C mode with adjusted defaults for use with the Linux kernel."
(interactive)
(c-mode)
(c-set-style "K&R")
(setq tab-width 8)
(setq indent-tabs-mode t)
(setq c-basic-offset 8))
(defun c-lineup-arglist-tabs-only (ignored)
"Line up argument lists by tabs, not spaces"
(let* ((anchor (c-langelem-pos c-syntactic-element))
(column (c-langelem-2nd-pos c-syntactic-element))
(offset (- (1+ column) anchor))
(steps (floor offset c-basic-offset)))
(* (max steps 1)
c-basic-offset)))
This will define the M-x linux-c-mode command. When hacking on a
module, if you put the string -*- linux-c -*- somewhere on the first
two lines, this mode will be automatically invoked. Also, you may want
to add
(add-hook 'c-mode-hook
(lambda ()
(let ((filename (buffer-file-name)))
;; Enable kernel mode for the appropriate files
(when (and filename
(string-match "~/src/linux-trees" filename))
(setq indent-tabs-mode t)
(c-set-style "linux")
(c-set-offset 'arglist-cont-nonempty
'(c-lineup-gcc-asm-reg
c-lineup-arglist-tabs-only))))))
(setq auto-mode-alist (cons '("/usr/src/linux.*/.*\\.[ch]$" . linux-c-mode)
auto-mode-alist))
to your .emacs file if you want to have linux-c-mode switched on
automagically when you edit source files under /usr/src/linux.
This will make emacs go better with the kernel coding style for C
files below ~/src/linux-trees.
But even if you fail in getting emacs to do sane formatting, not
everything is lost: use "indent".

4
Documentation/DMA-API.txt
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@ -298,10 +298,10 @@ recommended that you never use these unless you really know what the
cache width is.
int
dma_mapping_error(dma_addr_t dma_addr)
dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
int
pci_dma_mapping_error(dma_addr_t dma_addr)
pci_dma_mapping_error(struct pci_dev *hwdev, dma_addr_t dma_addr)
In some circumstances dma_map_single and dma_map_page will fail to create
a mapping. A driver can check for these errors by testing the returned

9
Documentation/DMA-attributes.txt
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@ -22,3 +22,12 @@ ready and available in memory. The DMA of the "completion indication"
could race with data DMA. Mapping the memory used for completion
indications with DMA_ATTR_WRITE_BARRIER would prevent the race.
DMA_ATTR_WEAK_ORDERING
----------------------
DMA_ATTR_WEAK_ORDERING specifies that reads and writes to the mapping
may be weakly ordered, that is that reads and writes may pass each other.
Since it is optional for platforms to implement DMA_ATTR_WEAK_ORDERING,
those that do not will simply ignore the attribute and exhibit default
behavior.

38
Documentation/DocBook/gadget.tmpl
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@ -524,6 +524,44 @@ These utilities include endpoint autoconfiguration.
<!-- !Edrivers/usb/gadget/epautoconf.c -->
</sect1>
<sect1 id="composite"><title>Composite Device Framework</title>
<para>The core API is sufficient for writing drivers for composite
USB devices (with more than one function in a given configuration),
and also multi-configuration devices (also more than one function,
but not necessarily sharing a given configuration).
There is however an optional framework which makes it easier to
reuse and combine functions.
</para>
<para>Devices using this framework provide a <emphasis>struct
usb_composite_driver</emphasis>, which in turn provides one or
more <emphasis>struct usb_configuration</emphasis> instances.
Each such configuration includes at least one
<emphasis>struct usb_function</emphasis>, which packages a user
visible role such as "network link" or "mass storage device".
Management functions may also exist, such as "Device Firmware
Upgrade".
</para>
!Iinclude/linux/usb/composite.h
!Edrivers/usb/gadget/composite.c
</sect1>
<sect1 id="functions"><title>Composite Device Functions</title>
<para>At this writing, a few of the current gadget drivers have
been converted to this framework.
Near-term plans include converting all of them, except for "gadgetfs".
</para>
!Edrivers/usb/gadget/f_acm.c
!Edrivers/usb/gadget/f_serial.c
</sect1>
</chapter>
<chapter id="controllers"><title>Peripheral Controller Drivers</title>

82
Documentation/DocBook/kernel-locking.tmpl
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@ -219,10 +219,10 @@
</para>
<sect1 id="lock-intro">
<title>Three Main Types of Kernel Locks: Spinlocks, Mutexes and Semaphores</title>
<title>Two Main Types of Kernel Locks: Spinlocks and Mutexes</title>
<para>
There are three main types of kernel locks. The fundamental type
There are two main types of kernel locks. The fundamental type
is the spinlock
(<filename class="headerfile">include/asm/spinlock.h</filename>),
which is a very simple single-holder lock: if you can't get the
@ -239,14 +239,6 @@
can't sleep (see <xref linkend="sleeping-things"/>), and so have to
use a spinlock instead.
</para>
<para>
The third type is a semaphore
(<filename class="headerfile">include/linux/semaphore.h</filename>): it
can have more than one holder at any time (the number decided at
initialization time), although it is most commonly used as a
single-holder lock (a mutex). If you can't get a semaphore, your
task will be suspended and later on woken up - just like for mutexes.
</para>
<para>
Neither type of lock is recursive: see
<xref linkend="deadlock"/>.
@ -278,7 +270,7 @@
</para>
<para>
Semaphores still exist, because they are required for
Mutexes still exist, because they are required for
synchronization between <firstterm linkend="gloss-usercontext">user
contexts</firstterm>, as we will see below.
</para>
@ -289,18 +281,17 @@
<para>
If you have a data structure which is only ever accessed from
user context, then you can use a simple semaphore
(<filename>linux/linux/semaphore.h</filename>) to protect it. This
is the most trivial case: you initialize the semaphore to the number
of resources available (usually 1), and call
<function>down_interruptible()</function> to grab the semaphore, and
<function>up()</function> to release it. There is also a
<function>down()</function>, which should be avoided, because it
user context, then you can use a simple mutex
(<filename>include/linux/mutex.h</filename>) to protect it. This
is the most trivial case: you initialize the mutex. Then you can
call <function>mutex_lock_interruptible()</function> to grab the mutex,
and <function>mutex_unlock()</function> to release it. There is also a
<function>mutex_lock()</function>, which should be avoided, because it
will not return if a signal is received.
</para>
<para>
Example: <filename>linux/net/core/netfilter.c</filename> allows
Example: <filename>net/netfilter/nf_sockopt.c</filename> allows
registration of new <function>setsockopt()</function> and
<function>getsockopt()</function> calls, with
<function>nf_register_sockopt()</function>. Registration and
@ -515,7 +506,7 @@
<listitem>
<para>
If you are in a process context (any syscall) and want to
lock other process out, use a semaphore. You can take a semaphore
lock other process out, use a mutex. You can take a mutex
and sleep (<function>copy_from_user*(</function> or
<function>kmalloc(x,GFP_KERNEL)</function>).
</para>
@ -662,7 +653,7 @@
<entry>SLBH</entry>
<entry>SLBH</entry>
<entry>SLBH</entry>
<entry>DI</entry>
<entry>MLI</entry>
<entry>None</entry>
</row>
@ -692,8 +683,8 @@
<entry>spin_lock_bh</entry>
</row>
<row>
<entry>DI</entry>
<entry>down_interruptible</entry>
<entry>MLI</entry>
<entry>mutex_lock_interruptible</entry>
</row>
</tbody>
@ -703,6 +694,31 @@
</sect1>
</chapter>
<chapter id="trylock-functions">
<title>The trylock Functions</title>
<para>
There are functions that try to acquire a lock only once and immediately
return a value telling about success or failure to acquire the lock.
They can be used if you need no access to the data protected with the lock
when some other thread is holding the lock. You should acquire the lock
later if you then need access to the data protected with the lock.
</para>
<para>
<function>spin_trylock()</function> does not spin but returns non-zero if
it acquires the spinlock on the first try or 0 if not. This function can
be used in all contexts like <function>spin_lock</function>: you must have
disabled the contexts that might interrupt you and acquire the spin lock.
</para>
<para>
<function>mutex_trylock()</function> does not suspend your task
but returns non-zero if it could lock the mutex on the first try
or 0 if not. This function cannot be safely used in hardware or software
interrupt contexts despite not sleeping.
</para>
</chapter>
<chapter id="Examples">
<title>Common Examples</title>
<para>
@ -1285,7 +1301,7 @@ as Alan Cox says, <quote>Lock data, not code</quote>.
<para>
There is a coding bug where a piece of code tries to grab a
spinlock twice: it will spin forever, waiting for the lock to
be released (spinlocks, rwlocks and semaphores are not
be released (spinlocks, rwlocks and mutexes are not
recursive in Linux). This is trivial to diagnose: not a
stay-up-five-nights-talk-to-fluffy-code-bunnies kind of
problem.
@ -1310,7 +1326,7 @@ as Alan Cox says, <quote>Lock data, not code</quote>.
<para>
This complete lockup is easy to diagnose: on SMP boxes the
watchdog timer or compiling with <symbol>DEBUG_SPINLOCKS</symbol> set
watchdog timer or compiling with <symbol>DEBUG_SPINLOCK</symbol> set
(<filename>include/linux/spinlock.h</filename>) will show this up
immediately when it happens.
</para>
@ -1533,7 +1549,7 @@ the amount of locking which needs to be done.
<title>Read/Write Lock Variants</title>
<para>
Both spinlocks and semaphores have read/write variants:
Both spinlocks and mutexes have read/write variants:
<type>rwlock_t</type> and <structname>struct rw_semaphore</structname>.
These divide users into two classes: the readers and the writers. If
you are only reading the data, you can get a read lock, but to write to
@ -1656,7 +1672,7 @@ the amount of locking which needs to be done.
#include &lt;linux/slab.h&gt;
#include &lt;linux/string.h&gt;
+#include &lt;linux/rcupdate.h&gt;
#include &lt;linux/semaphore.h&gt;
#include &lt;linux/mutex.h&gt;
#include &lt;asm/errno.h&gt;
struct object
@ -1888,7 +1904,7 @@ machines due to caching.
</listitem>
<listitem>
<para>
<function> put_user()</function>
<function>put_user()</function>
</para>
</listitem>
</itemizedlist>
@ -1902,13 +1918,13 @@ machines due to caching.
<listitem>
<para>
<function>down_interruptible()</function> and
<function>down()</function>
<function>mutex_lock_interruptible()</function> and
<function>mutex_lock()</function>
</para>
<para>
There is a <function>down_trylock()</function> which can be
There is a <function>mutex_trylock()</function> which can be
used inside interrupt context, as it will not sleep.
<function>up()</function> will also never sleep.
<function>mutex_unlock()</function> will also never sleep.
</para>
</listitem>
</itemizedlist>
@ -1998,7 +2014,7 @@ machines due to caching.
<para>
Prior to 2.5, or when <symbol>CONFIG_PREEMPT</symbol> is
unset, processes in user context inside the kernel would not
preempt each other (ie. you had that CPU until you have it up,
preempt each other (ie. you had that CPU until you gave it up,
except for interrupts). With the addition of
<symbol>CONFIG_PREEMPT</symbol> in 2.5.4, this changed: when
in user context, higher priority tasks can "cut in": spinlocks

28
Documentation/DocBook/kgdb.tmpl
View File

@ -72,7 +72,7 @@
kgdb is a source level debugger for linux kernel. It is used along
with gdb to debug a linux kernel. The expectation is that gdb can
be used to "break in" to the kernel to inspect memory, variables
and look through a cal stack information similar to what an
and look through call stack information similar to what an
application developer would use gdb for. It is possible to place
breakpoints in kernel code and perform some limited execution
stepping.
@ -84,17 +84,18 @@
runs an instance of gdb against the vmlinux file which contains
the symbols (not boot image such as bzImage, zImage, uImage...).
In gdb the developer specifies the connection parameters and
connects to kgdb. Depending on which kgdb I/O modules exist in
the kernel for a given architecture, it may be possible to debug
the test machine's kernel with the development machine using a
rs232 or ethernet connection.
connects to kgdb. The type of connection a developer makes with
gdb depends on the availability of kgdb I/O modules compiled as
builtin's or kernel modules in the test machine's kernel.
</para>
</chapter>
<chapter id="CompilingAKernel">
<title>Compiling a kernel</title>
<para>
To enable <symbol>CONFIG_KGDB</symbol>, look under the "Kernel debugging"
and then select "KGDB: kernel debugging with remote gdb".
To enable <symbol>CONFIG_KGDB</symbol> you should first turn on
"Prompt for development and/or incomplete code/drivers"
(CONFIG_EXPERIMENTAL) in "General setup", then under the
"Kernel debugging" select "KGDB: kernel debugging with remote gdb".
</para>
<para>
Next you should choose one of more I/O drivers to interconnect debugging
@ -221,7 +222,7 @@
</para>
<para>
IMPORTANT NOTE: Using this option with kgdb over the console
(kgdboc) or kgdb over ethernet (kgdboe) is not supported.
(kgdboc) is not supported.
</para>
</sect1>
</chapter>
@ -247,18 +248,11 @@
(gdb) target remote /dev/ttyS0
</programlisting>
<para>
Example (kgdb to a terminal server):
Example (kgdb to a terminal server on tcp port 2012):
</para>
<programlisting>
% gdb ./vmlinux
(gdb) target remote udp:192.168.2.2:6443
</programlisting>
<para>
Example (kgdb over ethernet):
</para>
<programlisting>
% gdb ./vmlinux
(gdb) target remote udp:192.168.2.2:6443
(gdb) target remote 192.168.2.2:2012
</programlisting>
<para>
Once connected, you can debug a kernel the way you would debug an

4
Documentation/DocBook/procfs-guide.tmpl
View File

@ -29,12 +29,12 @@
<revhistory>
<revision>
<revnumber>1.0&nbsp;</revnumber>
<revnumber>1.0</revnumber>
<date>May 30, 2001</date>
<revremark>Initial revision posted to linux-kernel</revremark>
</revision>
<revision>
<revnumber>1.1&nbsp;</revnumber>
<revnumber>1.1</revnumber>
<date>June 3, 2001</date>
<revremark>Revised after comments from linux-kernel</revremark>
</revision>

63
Documentation/DocBook/uio-howto.tmpl
View File

@ -21,6 +21,18 @@
</affiliation>
</author>
<copyright>
<year>2006-2008</year>
<holder>Hans-Jürgen Koch.</holder>
</copyright>
<legalnotice>
<para>
This documentation is Free Software licensed under the terms of the
GPL version 2.
</para>
</legalnotice>
<pubdate>2006-12-11</pubdate>
<abstract>
@ -29,6 +41,12 @@
</abstract>
<revhistory>
<revision>
<revnumber>0.5</revnumber>
<date>2008-05-22</date>
<authorinitials>hjk</authorinitials>
<revremark>Added description of write() function.</revremark>
</revision>
<revision>
<revnumber>0.4</revnumber>
<date>2007-11-26</date>
@ -57,20 +75,9 @@
</bookinfo>
<chapter id="aboutthisdoc">
<?dbhtml filename="about.html"?>
<?dbhtml filename="aboutthis.html"?>
<title>About this document</title>
<sect1 id="copyright">
<?dbhtml filename="copyright.html"?>
<title>Copyright and License</title>
<para>
Copyright (c) 2006 by Hans-Jürgen Koch.</para>
<para>
This documentation is Free Software licensed under the terms of the
GPL version 2.
</para>
</sect1>
<sect1 id="translations">
<?dbhtml filename="translations.html"?>
<title>Translations</title>
@ -189,6 +196,30 @@ interested in translating it, please email me
represents the total interrupt count. You can use this number
to figure out if you missed some interrupts.
</para>
<para>
For some hardware that has more than one interrupt source internally,
but not separate IRQ mask and status registers, there might be
situations where userspace cannot determine what the interrupt source
was if the kernel handler disables them by writing to the chip's IRQ
register. In such a case, the kernel has to disable the IRQ completely
to leave the chip's register untouched. Now the userspace part can
determine the cause of the interrupt, but it cannot re-enable
interrupts. Another cornercase is chips where re-enabling interrupts
is a read-modify-write operation to a combined IRQ status/acknowledge
register. This would be racy if a new interrupt occurred
simultaneously.
</para>
<para>
To address these problems, UIO also implements a write() function. It
is normally not used and can be ignored for hardware that has only a
single interrupt source or has separate IRQ mask and status registers.
If you need it, however, a write to <filename>/dev/uioX</filename>
will call the <function>irqcontrol()</function> function implemented
by the driver. You have to write a 32-bit value that is usually either
0 or 1 to disable or enable interrupts. If a driver does not implement
<function>irqcontrol()</function>, <function>write()</function> will
return with <varname>-ENOSYS</varname>.
</para>
<para>
To handle interrupts properly, your custom kernel module can
@ -362,6 +393,14 @@ device is actually used.
<function>open()</function>, you will probably also want a custom
<function>release()</function> function.
</para></listitem>
<listitem><para>
<varname>int (*irqcontrol)(struct uio_info *info, s32 irq_on)
</varname>: Optional. If you need to be able to enable or disable
interrupts from userspace by writing to <filename>/dev/uioX</filename>,
you can implement this function. The parameter <varname>irq_on</varname>
will be 0 to disable interrupts and 1 to enable them.
</para></listitem>
</itemizedlist>
<para>

4
Documentation/HOWTO
View File

@ -358,7 +358,7 @@ Here is a list of some of the different kernel trees available:
- pcmcia, Dominik Brodowski <linux@dominikbrodowski.net>
git.kernel.org:/pub/scm/linux/kernel/git/brodo/pcmcia-2.6.git
- SCSI, James Bottomley <James.Bottomley@SteelEye.com>
- SCSI, James Bottomley <James.Bottomley@hansenpartnership.com>
git.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6.git
- x86, Ingo Molnar <mingo@elte.hu>
@ -377,7 +377,7 @@ Bug Reporting
bugzilla.kernel.org is where the Linux kernel developers track kernel
bugs. Users are encouraged to report all bugs that they find in this
tool. For details on how to use the kernel bugzilla, please see:
http://test.kernel.org/bugzilla/faq.html
http://bugzilla.kernel.org/page.cgi?id=faq.html
The file REPORTING-BUGS in the main kernel source directory has a good
template for how to report a possible kernel bug, and details what kind

39
Documentation/IRQ-affinity.txt
View File

@ -1,17 +1,26 @@
ChangeLog:
Started by Ingo Molnar <mingo@redhat.com>
Update by Max Krasnyansky <maxk@qualcomm.com>
SMP IRQ affinity, started by Ingo Molnar <mingo@redhat.com>
SMP IRQ affinity
/proc/irq/IRQ#/smp_affinity specifies which target CPUs are permitted
for a given IRQ source. It's a bitmask of allowed CPUs. It's not allowed
to turn off all CPUs, and if an IRQ controller does not support IRQ
affinity then the value will not change from the default 0xffffffff.
Here is an example of restricting IRQ44 (eth1) to CPU0-3 then restricting
the IRQ to CPU4-7 (this is an 8-CPU SMP box):
/proc/irq/default_smp_affinity specifies default affinity mask that applies
to all non-active IRQs. Once IRQ is allocated/activated its affinity bitmask
will be set to the default mask. It can then be changed as described above.
Default mask is 0xffffffff.
Here is an example of restricting IRQ44 (eth1) to CPU0-3 then restricting
it to CPU4-7 (this is an 8-CPU SMP box):
[root@moon 44]# cd /proc/irq/44
[root@moon 44]# cat smp_affinity
ffffffff
[root@moon 44]# echo 0f > smp_affinity
[root@moon 44]# cat smp_affinity
0000000f
@ -21,17 +30,27 @@ PING hell (195.4.7.3): 56 data bytes
--- hell ping statistics ---
6029 packets transmitted, 6027 packets received, 0% packet loss
round-trip min/avg/max = 0.1/0.1/0.4 ms
[root@moon 44]# cat /proc/interrupts | grep 44:
44: 0 1785 1785 1783 1783 1
1 0 IO-APIC-level eth1
[root@moon 44]# cat /proc/interrupts | grep 'CPU\|44:'
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7
44: 1068 1785 1785 1783 0 0 0 0 IO-APIC-level eth1
As can be seen from the line above IRQ44 was delivered only to the first four
processors (0-3).
Now lets restrict that IRQ to CPU(4-7).
[root@moon 44]# echo f0 > smp_affinity
[root@moon 44]# cat smp_affinity
000000f0
[root@moon 44]# ping -f h
PING hell (195.4.7.3): 56 data bytes
..
--- hell ping statistics ---
2779 packets transmitted, 2777 packets received, 0% packet loss
round-trip min/avg/max = 0.1/0.5/585.4 ms
[root@moon 44]# cat /proc/interrupts | grep 44:
44: 1068 1785 1785 1784 1784 1069 1070 1069 IO-APIC-level eth1
[root@moon 44]#
[root@moon 44]# cat /proc/interrupts | 'CPU\|44:'
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7
44: 1068 1785 1785 1783 1784 1069 1070 1069 IO-APIC-level eth1
This time around IRQ44 was delivered only to the last four processors.
i.e counters for the CPU0-3 did not change.

4
Documentation/Intel-IOMMU.txt
View File

@ -48,7 +48,7 @@ IOVA generation is pretty generic. We used the same technique as vmalloc()
but these are not global address spaces, but separate for each domain.
Different DMA engines may support different number of domains.
We also allocate gaurd pages with each mapping, so we can attempt to catch
We also allocate guard pages with each mapping, so we can attempt to catch
any overflow that might happen.
@ -112,4 +112,4 @@ TBD
- For compatibility testing, could use unity map domain for all devices, just
provide a 1-1 for all useful memory under a single domain for all devices.
- API for paravirt ops for abstracting functionlity for VMM folks.
- API for paravirt ops for abstracting functionality for VMM folks.

3
Documentation/RCU/NMI-RCU.txt
View File

@ -93,6 +93,9 @@ Since NMI handlers disable preemption, synchronize_sched() is guaranteed
not to return until all ongoing NMI handlers exit. It is therefore safe
to free up the handler's data as soon as synchronize_sched() returns.
Important note: for this to work, the architecture in question must
invoke irq_enter() and irq_exit() on NMI entry and exit, respectively.
Answer to Quick Quiz

108
Documentation/RCU/RTFP.txt
View File

@ -52,6 +52,10 @@ of each iteration. Unfortunately, chaotic relaxation requires highly
structured data, such as the matrices used in scientific programs, and
is thus inapplicable to most data structures in operating-system kernels.
In 1992, Henry (now Alexia) Massalin completed a dissertation advising
parallel programmers to defer processing when feasible to simplify
synchronization. RCU makes extremely heavy use of this advice.
In 1993, Jacobson [Jacobson93] verbally described what is perhaps the
simplest deferred-free technique: simply waiting a fixed amount of time
before freeing blocks awaiting deferred free. Jacobson did not describe
@ -138,6 +142,13 @@ blocking in read-side critical sections appeared [PaulEMcKenney2006c],
Robert Olsson described an RCU-protected trie-hash combination
[RobertOlsson2006a].
2007 saw the journal version of the award-winning RCU paper from 2006
[ThomasEHart2007a], as well as a paper demonstrating use of Promela
and Spin to mechanically verify an optimization to Oleg Nesterov's
QRCU [PaulEMcKenney2007QRCUspin], a design document describing
preemptible RCU [PaulEMcKenney2007PreemptibleRCU], and the three-part
LWN "What is RCU?" series [PaulEMcKenney2007WhatIsRCUFundamentally,
PaulEMcKenney2008WhatIsRCUUsage, and PaulEMcKenney2008WhatIsRCUAPI].
Bibtex Entries
@ -202,6 +213,20 @@ Bibtex Entries
,Year="1991"
}
@phdthesis{HMassalinPhD
,author="H. Massalin"
,title="Synthesis: An Efficient Implementation of Fundamental Operating
System Services"
,school="Columbia University"
,address="New York, NY"
,year="1992"
,annotation="
Mondo optimizing compiler.
Wait-free stuff.
Good advice: defer work to avoid synchronization.
"
}
@unpublished{Jacobson93
,author="Van Jacobson"
,title="Avoid Read-Side Locking Via Delayed Free"
@ -635,3 +660,86 @@ Revised:
"
}
@unpublished{PaulEMcKenney2007PreemptibleRCU
,Author="Paul E. McKenney"
,Title="The design of preemptible read-copy-update"
,month="October"
,day="8"
,year="2007"
,note="Available:
\url{http://lwn.net/Articles/253651/}
[Viewed October 25, 2007]"
,annotation="
LWN article describing the design of preemptible RCU.
"
}
########################################################################
#
# "What is RCU?" LWN series.
#
@unpublished{PaulEMcKenney2007WhatIsRCUFundamentally
,Author="Paul E. McKenney and Jonathan Walpole"
,Title="What is {RCU}, Fundamentally?"
,month="December"
,day="17"
,year="2007"
,note="Available:
\url{http://lwn.net/Articles/262464/}
[Viewed December 27, 2007]"
,annotation="
Lays out the three basic components of RCU: (1) publish-subscribe,
(2) wait for pre-existing readers to complete, and (2) maintain
multiple versions.
"
}
@unpublished{PaulEMcKenney2008WhatIsRCUUsage
,Author="Paul E. McKenney"
,Title="What is {RCU}? Part 2: Usage"
,month="January"
,day="4"
,year="2008"
,note="Available:
\url{http://lwn.net/Articles/263130/}
[Viewed January 4, 2008]"
,annotation="
Lays out six uses of RCU:
1. RCU is a Reader-Writer Lock Replacement
2. RCU is a Restricted Reference-Counting Mechanism
3. RCU is a Bulk Reference-Counting Mechanism
4. RCU is a Poor Man's Garbage Collector
5. RCU is a Way of Providing Existence Guarantees
6. RCU is a Way of Waiting for Things to Finish
"
}
@unpublished{PaulEMcKenney2008WhatIsRCUAPI
,Author="Paul E. McKenney"
,Title="{RCU} part 3: the {RCU} {API}"
,month="January"
,day="17"
,year="2008"
,note="Available:
\url{http://lwn.net/Articles/264090/}
[Viewed January 10, 2008]"
,annotation="
Gives an overview of the Linux-kernel RCU API and a brief annotated RCU
bibliography.
"
}
@article{DinakarGuniguntala2008IBMSysJ
,author="D. Guniguntala and P. E. McKenney and J. Triplett and J. Walpole"
,title="The read-copy-update mechanism for supporting real-time applications on shared-memory multiprocessor systems with {Linux}"
,Year="2008"
,Month="April"
,journal="IBM Systems Journal"
,volume="47"
,number="2"
,pages="@@-@@"
,annotation="
RCU, realtime RCU, sleepable RCU, performance.
"
}

89
Documentation/RCU/checklist.txt
View File

@ -13,10 +13,13 @@ over a rather long period of time, but improvements are always welcome!
detailed performance measurements show that RCU is nonetheless
the right tool for the job.
The other exception would be where performance is not an issue,
and RCU provides a simpler implementation. An example of this
situation is the dynamic NMI code in the Linux 2.6 kernel,
at least on architectures where NMIs are rare.
Another exception is where performance is not an issue, and RCU
provides a simpler implementation. An example of this situation
is the dynamic NMI code in the Linux 2.6 kernel, at least on
architectures where NMIs are rare.
Yet another exception is where the low real-time latency of RCU's
read-side primitives is critically important.
1. Does the update code have proper mutual exclusion?
@ -39,9 +42,10 @@ over a rather long period of time, but improvements are always welcome!
2. Do the RCU read-side critical sections make proper use of
rcu_read_lock() and friends? These primitives are needed
to suppress preemption (or bottom halves, in the case of
rcu_read_lock_bh()) in the read-side critical sections,
and are also an excellent aid to readability.
to prevent grace periods from ending prematurely, which
could result in data being unceremoniously freed out from
under your read-side code, which can greatly increase the
actuarial risk of your kernel.
As a rough rule of thumb, any dereference of an RCU-protected
pointer must be covered by rcu_read_lock() or rcu_read_lock_bh()
@ -54,15 +58,30 @@ over a rather long period of time, but improvements are always welcome!
be running while updates are in progress. There are a number
of ways to handle this concurrency, depending on the situation:
a. Make updates appear atomic to readers. For example,
a. Use the RCU variants of the list and hlist update
primitives to add, remove, and replace elements on an
RCU-protected list. Alternatively, use the RCU-protected
trees that have been added to the Linux kernel.
This is almost always the best approach.
b. Proceed as in (a) above, but also maintain per-element
locks (that are acquired by both readers and writers)
that guard per-element state. Of course, fields that
the readers refrain from accessing can be guarded by the
update-side lock.
This works quite well, also.
c. Make updates appear atomic to readers. For example,
pointer updates to properly aligned fields will appear
atomic, as will individual atomic primitives. Operations
performed under a lock and sequences of multiple atomic
primitives will -not- appear to be atomic.
This is almost always the best approach.
This can work, but is starting to get a bit tricky.
b. Carefully order the updates and the reads so that
d. Carefully order the updates and the reads so that
readers see valid data at all phases of the update.
This is often more difficult than it sounds, especially
given modern CPUs' tendency to reorder memory references.
@ -123,18 +142,22 @@ over a rather long period of time, but improvements are always welcome!
when publicizing a pointer to a structure that can
be traversed by an RCU read-side critical section.
5. If call_rcu(), or a related primitive such as call_rcu_bh(),
is used, the callback function must be written to be called
from softirq context. In particular, it cannot block.
5. If call_rcu(), or a related primitive such as call_rcu_bh() or
call_rcu_sched(), is used, the callback function must be
written to be called from softirq context. In particular,
it cannot block.
6. Since synchronize_rcu() can block, it cannot be called from
any sort of irq context.
any sort of irq context. Ditto for synchronize_sched() and
synchronize_srcu().
7. If the updater uses call_rcu(), then the corresponding readers
must use rcu_read_lock() and rcu_read_unlock(). If the updater
uses call_rcu_bh(), then the corresponding readers must use
rcu_read_lock_bh() and rcu_read_unlock_bh(). Mixing things up
will result in confusion and broken kernels.
rcu_read_lock_bh() and rcu_read_unlock_bh(). If the updater
uses call_rcu_sched(), then the corresponding readers must
disable preemption. Mixing things up will result in confusion
and broken kernels.
One exception to this rule: rcu_read_lock() and rcu_read_unlock()
may be substituted for rcu_read_lock_bh() and rcu_read_unlock_bh()
@ -143,9 +166,9 @@ over a rather long period of time, but improvements are always welcome!
such cases is a must, of course! And the jury is still out on
whether the increased speed is worth it.
8. Although synchronize_rcu() is a bit slower than is call_rcu(),
it usually results in simpler code. So, unless update
performance is critically important or the updaters cannot block,
8. Although synchronize_rcu() is slower than is call_rcu(), it
usually results in simpler code. So, unless update performance
is critically important or the updaters cannot block,
synchronize_rcu() should be used in preference to call_rcu().
An especially important property of the synchronize_rcu()
@ -187,23 +210,23 @@ over a rather long period of time, but improvements are always welcome!
number of updates per grace period.
9. All RCU list-traversal primitives, which include
list_for_each_rcu(), list_for_each_entry_rcu(),
rcu_dereference(), list_for_each_rcu(), list_for_each_entry_rcu(),
list_for_each_continue_rcu(), and list_for_each_safe_rcu(),
must be within an RCU read-side critical section. RCU
must be either within an RCU read-side critical section or
must be protected by appropriate update-side locks. RCU
read-side critical sections are delimited by rcu_read_lock()
and rcu_read_unlock(), or by similar primitives such as
rcu_read_lock_bh() and rcu_read_unlock_bh().
Use of the _rcu() list-traversal primitives outside of an
RCU read-side critical section causes no harm other than
a slight performance degradation on Alpha CPUs. It can
also be quite helpful in reducing code bloat when common
code is shared between readers and updaters.
The reason that it is permissible to use RCU list-traversal
primitives when the update-side lock is held is that doing so
can be quite helpful in reducing code bloat when common code is
shared between readers and updaters.
10. Conversely, if you are in an RCU read-side critical section,
you -must- use the "_rcu()" variants of the list macros.
Failing to do so will break Alpha and confuse people reading
your code.
and you don't hold the appropriate update-side lock, you -must-
use the "_rcu()" variants of the list macros. Failing to do so
will break Alpha and confuse people reading your code.
11. Note that synchronize_rcu() -only- guarantees to wait until
all currently executing rcu_read_lock()-protected RCU read-side
@ -230,6 +253,14 @@ over a rather long period of time, but improvements are always welcome!
must use whatever locking or other synchronization is required
to safely access and/or modify that data structure.
RCU callbacks are -usually- executed on the same CPU that executed
the corresponding call_rcu(), call_rcu_bh(), or call_rcu_sched(),
but are by -no- means guaranteed to be. For example, if a given
CPU goes offline while having an RCU callback pending, then that
RCU callback will execute on some surviving CPU. (If this was
not the case, a self-spawning RCU callback would prevent the
victim CPU from ever going offline.)
14. SRCU (srcu_read_lock(), srcu_read_unlock(), and synchronize_srcu())
may only be invoked from process context. Unlike other forms of
RCU, it -is- permissible to block in an SRCU read-side critical

48
Documentation/RCU/torture.txt
View File

@ -10,23 +10,30 @@ status messages via printk(), which can be examined via the dmesg
command (perhaps grepping for "torture"). The test is started
when the module is loaded, and stops when the module is unloaded.
However, actually setting this config option to "y" results in the system
running the test immediately upon boot, and ending only when the system
is taken down. Normally, one will instead want to build the system
with CONFIG_RCU_TORTURE_TEST=m and to use modprobe and rmmod to control
the test, perhaps using a script similar to the one shown at the end of
this document. Note that you will need CONFIG_MODULE_UNLOAD in order
to be able to end the test.
CONFIG_RCU_TORTURE_TEST_RUNNABLE
It is also possible to specify CONFIG_RCU_TORTURE_TEST=y, which will
result in the tests being loaded into the base kernel. In this case,
the CONFIG_RCU_TORTURE_TEST_RUNNABLE config option is used to specify
whether the RCU torture tests are to be started immediately during
boot or whether the /proc/sys/kernel/rcutorture_runnable file is used
to enable them. This /proc file can be used to repeatedly pause and
restart the tests, regardless of the initial state specified by the
CONFIG_RCU_TORTURE_TEST_RUNNABLE config option.
You will normally -not- want to start the RCU torture tests during boot
(and thus the default is CONFIG_RCU_TORTURE_TEST_RUNNABLE=n), but doing
this can sometimes be useful in finding boot-time bugs.
MODULE PARAMETERS
This module has the following parameters:
nreaders This is the number of RCU reading threads supported.
The default is twice the number of CPUs. Why twice?
To properly exercise RCU implementations with preemptible
read-side critical sections.
irqreaders Says to invoke RCU readers from irq level. This is currently
done via timers. Defaults to "1" for variants of RCU that
permit this. (Or, more accurately, variants of RCU that do
-not- permit this know to ignore this variable.)
nfakewriters This is the number of RCU fake writer threads to run. Fake
writer threads repeatedly use the synchronous "wait for
@ -37,6 +44,16 @@ nfakewriters This is the number of RCU fake writer threads to run. Fake
to trigger special cases caused by multiple writers, such as
the synchronize_srcu() early return optimization.
nreaders This is the number of RCU reading threads supported.
The default is twice the number of CPUs. Why twice?
To properly exercise RCU implementations with preemptible
read-side critical sections.
shuffle_interval
The number of seconds to keep the test threads affinitied
to a particular subset of the CPUs, defaults to 3 seconds.
Used in conjunction with test_no_idle_hz.
stat_interval The number of seconds between output of torture
statistics (via printk()). Regardless of the interval,
statistics are printed when the module is unloaded.
@ -44,10 +61,11 @@ stat_interval The number of seconds between output of torture
be printed -only- when the module is unloaded, and this
is the default.
shuffle_interval
The number of seconds to keep the test threads affinitied
to a particular subset of the CPUs, defaults to 5 seconds.
Used in conjunction with test_no_idle_hz.
stutter The length of time to run the test before pausing for this
same period of time. Defaults to "stutter=5", so as
to run and pause for (roughly) five-second intervals.
Specifying "stutter=0" causes the test to run continuously
without pausing, which is the old default behavior.
test_no_idle_hz Whether or not to test the ability of RCU to operate in
a kernel that disables the scheduling-clock interrupt to

62
Documentation/RCU/whatisRCU.txt
View File

@ -1,3 +1,11 @@
Please note that the "What is RCU?" LWN series is an excellent place
to start learning about RCU:
1. What is RCU, Fundamentally? http://lwn.net/Articles/262464/
2. What is RCU? Part 2: Usage http://lwn.net/Articles/263130/
3. RCU part 3: the RCU API http://lwn.net/Articles/264090/
What is RCU?
RCU is a synchronization mechanism that was added to the Linux kernel
@ -772,26 +780,18 @@ Linux-kernel source code, but it helps to have a full list of the
APIs, since there does not appear to be a way to categorize them
in docbook. Here is the list, by category.
Markers for RCU read-side critical sections:
rcu_read_lock
rcu_read_unlock
rcu_read_lock_bh
rcu_read_unlock_bh
srcu_read_lock
srcu_read_unlock
RCU pointer/list traversal:
rcu_dereference
list_for_each_rcu (to be deprecated in favor of
list_for_each_entry_rcu)
list_for_each_entry_rcu
list_for_each_continue_rcu (to be deprecated in favor of new
list_for_each_entry_continue_rcu)
hlist_for_each_entry_rcu
RCU pointer update:
list_for_each_rcu (to be deprecated in favor of
list_for_each_entry_rcu)
list_for_each_continue_rcu (to be deprecated in favor of new
list_for_each_entry_continue_rcu)
RCU pointer/list update:
rcu_assign_pointer
list_add_rcu
@ -799,16 +799,36 @@ RCU pointer update:
list_del_rcu
list_replace_rcu
hlist_del_rcu
hlist_add_after_rcu
hlist_add_before_rcu
hlist_add_head_rcu
hlist_replace_rcu
list_splice_init_rcu()
RCU grace period:
RCU: Critical sections Grace period Barrier
rcu_read_lock synchronize_net rcu_barrier
rcu_read_unlock synchronize_rcu
call_rcu
bh: Critical sections Grace period Barrier
rcu_read_lock_bh call_rcu_bh rcu_barrier_bh
rcu_read_unlock_bh
sched: Critical sections Grace period Barrier
[preempt_disable] synchronize_sched rcu_barrier_sched
[and friends] call_rcu_sched
SRCU: Critical sections Grace period Barrier
srcu_read_lock synchronize_srcu N/A
srcu_read_unlock
synchronize_net
synchronize_sched
synchronize_rcu
synchronize_srcu
call_rcu
call_rcu_bh
See the comment headers in the source code (or the docbook generated
from them) for more information.

72
Documentation/SubmittingPatches
View File

@ -327,6 +327,52 @@ Some people also put extra tags at the end. They'll just be ignored for
now, but you can do this to mark internal company procedures or just
point out some special detail about the sign-off.
If you are a subsystem or branch maintainer, sometimes you need to slightly
modify patches you receive in order to merge them, because the code is not
exactly the same in your tree and the submitters'. If you stick strictly to
rule (c), you should ask the submitter to rediff, but this is a totally
counter-productive waste of time and energy. Rule (b) allows you to adjust
the code, but then it is very impolite to change one submitter's code and
make him endorse your bugs. To solve this problem, it is recommended that
you add a line between the last Signed-off-by header and yours, indicating
the nature of your changes. While there is nothing mandatory about this, it
seems like prepending the description with your mail and/or name, all
enclosed in square brackets, is noticeable enough to make it obvious that
you are responsible for last-minute changes. Example :
Signed-off-by: Random J Developer <random@developer.example.org>
[lucky@maintainer.example.org: struct foo moved from foo.c to foo.h]
Signed-off-by: Lucky K Maintainer <lucky@maintainer.example.org>
This practise is particularly helpful if you maintain a stable branch and
want at the same time to credit the author, track changes, merge the fix,
and protect the submitter from complaints. Note that under no circumstances
can you change the author's identity (the From header), as it is the one
which appears in the changelog.
Special note to back-porters: It seems to be a common and useful practise
to insert an indication of the origin of a patch at the top of the commit
message (just after the subject line) to facilitate tracking. For instance,
here's what we see in 2.6-stable :
Date: Tue May 13 19:10:30 2008 +0000
SCSI: libiscsi regression in 2.6.25: fix nop timer handling
commit 4cf1043593db6a337f10e006c23c69e5fc93e722 upstream
And here's what appears in 2.4 :
Date: Tue May 13 22:12:27 2008 +0200
wireless, airo: waitbusy() won't delay
[backport of 2.6 commit b7acbdfbd1f277c1eb23f344f899cfa4cd0bf36a]
Whatever the format, this information provides a valuable help to people
tracking your trees, and to people trying to trouble-shoot bugs in your
tree.
13) When to use Acked-by: and Cc:
@ -482,7 +528,33 @@ See more details on the proper patch format in the following
references.
16) Sending "git pull" requests (from Linus emails)
Please write the git repo address and branch name alone on the same line
so that I can't even by mistake pull from the wrong branch, and so
that a triple-click just selects the whole thing.
So the proper format is something along the lines of:
"Please pull from
git://jdelvare.pck.nerim.net/jdelvare-2.6 i2c-for-linus
to get these changes:"
so that I don't have to hunt-and-peck for the address and inevitably
get it wrong (actually, I've only gotten it wrong a few times, and
checking against the diffstat tells me when I get it wrong, but I'm
just a lot more comfortable when I don't have to "look for" the right
thing to pull, and double-check that I have the right branch-name).
Please use "git diff -M --stat --summary" to generate the diffstat:
the -M enables rename detection, and the summary enables a summary of
new/deleted or renamed files.
With rename detection, the statistics are rather different [...]
because git will notice that a fair number of the changes are renames.
-----------------------------------
SECTION 2 - HINTS, TIPS, AND TRICKS

11
Documentation/accounting/delay-accounting.txt
View File

@ -11,6 +11,7 @@ the delays experienced by a task while
a) waiting for a CPU (while being runnable)
b) completion of synchronous block I/O initiated by the task
c) swapping in pages
d) memory reclaim
and makes these statistics available to userspace through
the taskstats interface.
@ -41,7 +42,7 @@ this structure. See
include/linux/taskstats.h
for a description of the fields pertaining to delay accounting.
It will generally be in the form of counters returning the cumulative
delay seen for cpu, sync block I/O, swapin etc.
delay seen for cpu, sync block I/O, swapin, memory reclaim etc.
Taking the difference of two successive readings of a given
counter (say cpu_delay_total) for a task will give the delay
@ -94,7 +95,9 @@ CPU count real total virtual total delay total
7876 92005750 100000000 24001500
IO count delay total
0 0
MEM count delay total
SWAP count delay total
0 0
RECLAIM count delay total
0 0
Get delays seen in executing a given simple command
@ -108,5 +111,7 @@ CPU count real total virtual total delay total
6 4000250 4000000 0
IO count delay total
0 0
MEM count delay total
SWAP count delay total
0 0
RECLAIM count delay total
0 0

8
Documentation/accounting/getdelays.c
View File

@ -196,14 +196,18 @@ void print_delayacct(struct taskstats *t)
" %15llu%15llu%15llu%15llu\n"
"IO %15s%15s\n"
" %15llu%15llu\n"
"MEM %15s%15s\n"
"SWAP %15s%15s\n"
" %15llu%15llu\n"
"RECLAIM %12s%15s\n"
" %15llu%15llu\n",
"count", "real total", "virtual total", "delay total",
t->cpu_count, t->cpu_run_real_total, t->cpu_run_virtual_total,
t->cpu_delay_total,
"count", "delay total",
t->blkio_count, t->blkio_delay_total,
"count", "delay total", t->swapin_count, t->swapin_delay_total);
"count", "delay total", t->swapin_count, t->swapin_delay_total,
"count", "delay total",
t->freepages_count, t->freepages_delay_total);
}
void task_context_switch_counts(struct taskstats *t)

15
Documentation/accounting/taskstats-struct.txt
View File

@ -6,7 +6,7 @@ This document contains an explanation of the struct taskstats fields.
There are three different groups of fields in the struct taskstats:
1) Common and basic accounting fields
If CONFIG_TASKSTATS is set, the taskstats inteface is enabled and
If CONFIG_TASKSTATS is set, the taskstats interface is enabled and
the common fields and basic accounting fields are collected for
delivery at do_exit() of a task.
2) Delay accounting fields
@ -24,6 +24,10 @@ There are three different groups of fields in the struct taskstats:
4) Per-task and per-thread context switch count statistics
5) Time accounting for SMT machines
6) Extended delay accounting fields for memory reclaim
Future extension should add fields to the end of the taskstats struct, and
should not change the relative position of each field within the struct.
@ -164,4 +168,13 @@ struct taskstats {
__u64 nvcsw; /* Context voluntary switch counter */
__u64 nivcsw; /* Context involuntary switch counter */
5) Time accounting for SMT machines
__u64 ac_utimescaled; /* utime scaled on frequency etc */
__u64 ac_stimescaled; /* stime scaled on frequency etc */
__u64 cpu_scaled_run_real_total; /* scaled cpu_run_real_total */
6) Extended delay accounting fields for memory reclaim
/* Delay waiting for memory reclaim */
__u64 freepages_count;
__u64 freepages_delay_total;
}

10
Documentation/arm/Interrupts
View File

@ -138,14 +138,8 @@ So, what's changed?
Set active the IRQ edge(s)/level. This replaces the
SA1111 INTPOL manipulation, and the set_GPIO_IRQ_edge()
function. Type should be one of the following:
#define IRQT_NOEDGE (0)
#define IRQT_RISING (__IRQT_RISEDGE)
#define IRQT_FALLING (__IRQT_FALEDGE)
#define IRQT_BOTHEDGE (__IRQT_RISEDGE|__IRQT_FALEDGE)
#define IRQT_LOW (__IRQT_LOWLVL)
#define IRQT_HIGH (__IRQT_HIGHLVL)
function. Type should be one of IRQ_TYPE_xxx defined in
<linux/irq.h>
3. set_GPIO_IRQ_edge() is obsolete, and should be replaced by set_irq_type.

4
Documentation/auxdisplay/cfag12864b
View File

@ -3,7 +3,7 @@
===================================
License: GPLv2
Author & Maintainer: Miguel Ojeda Sandonis <maxextreme@gmail.com>
Author & Maintainer: Miguel Ojeda Sandonis
Date: 2006-10-27
@ -22,7 +22,7 @@ Date: 2006-10-27
1. DRIVER INFORMATION
---------------------
This driver support one cfag12864b display at time.
This driver supports a cfag12864b LCD.
---------------------

2
Documentation/auxdisplay/cfag12864b-example.c
View File

@ -4,7 +4,7 @@
* Description: cfag12864b LCD userspace example program
* License: GPLv2
*
* Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
* Author: Copyright (C) Miguel Ojeda Sandonis
* Date: 2006-10-31
*
* This program is free software; you can redistribute it and/or modify

4
Documentation/auxdisplay/ks0108
View File

@ -3,7 +3,7 @@
==========================================
License: GPLv2
Author & Maintainer: Miguel Ojeda Sandonis <maxextreme@gmail.com>
Author & Maintainer: Miguel Ojeda Sandonis
Date: 2006-10-27
@ -21,7 +21,7 @@ Date: 2006-10-27
1. DRIVER INFORMATION
---------------------
This driver support the ks0108 LCD controller.
This driver supports the ks0108 LCD controller.
---------------------

327
Documentation/block/data-integrity.txt 100644
View File

@ -0,0 +1,327 @@
----------------------------------------------------------------------
1. INTRODUCTION
Modern filesystems feature checksumming of data and metadata to
protect against data corruption. However, the detection of the
corruption is done at read time which could potentially be months
after the data was written. At that point the original data that the
application tried to write is most likely lost.
The solution is to ensure that the disk is actually storing what the
application meant it to. Recent additions to both the SCSI family
protocols (SBC Data Integrity Field, SCC protection proposal) as well
as SATA/T13 (External Path Protection) try to remedy this by adding
support for appending integrity metadata to an I/O. The integrity
metadata (or protection information in SCSI terminology) includes a
checksum for each sector as well as an incrementing counter that
ensures the individual sectors are written in the right order. And
for some protection schemes also that the I/O is written to the right
place on disk.
Current storage controllers and devices implement various protective
measures, for instance checksumming and scrubbing. But these
technologies are working in their own isolated domains or at best
between adjacent nodes in the I/O path. The interesting thing about
DIF and the other integrity extensions is that the protection format
is well defined and every node in the I/O path can verify the
integrity of the I/O and reject it if corruption is detected. This
allows not only corruption prevention but also isolation of the point
of failure.
----------------------------------------------------------------------
2. THE DATA INTEGRITY EXTENSIONS
As written, the protocol extensions only protect the path between
controller and storage device. However, many controllers actually
allow the operating system to interact with the integrity metadata
(IMD). We have been working with several FC/SAS HBA vendors to enable
the protection information to be transferred to and from their
controllers.
The SCSI Data Integrity Field works by appending 8 bytes of protection
information to each sector. The data + integrity metadata is stored
in 520 byte sectors on disk. Data + IMD are interleaved when
transferred between the controller and target. The T13 proposal is
similar.
Because it is highly inconvenient for operating systems to deal with
520 (and 4104) byte sectors, we approached several HBA vendors and
encouraged them to allow separation of the data and integrity metadata
scatter-gather lists.
The controller will interleave the buffers on write and split them on
read. This means that the Linux can DMA the data buffers to and from
host memory without changes to the page cache.
Also, the 16-bit CRC checksum mandated by both the SCSI and SATA specs
is somewhat heavy to compute in software. Benchmarks found that
calculating this checksum had a significant impact on system
performance for a number of workloads. Some controllers allow a
lighter-weight checksum to be used when interfacing with the operating
system. Emulex, for instance, supports the TCP/IP checksum instead.
The IP checksum received from the OS is converted to the 16-bit CRC
when writing and vice versa. This allows the integrity metadata to be
generated by Linux or the application at very low cost (comparable to
software RAID5).
The IP checksum is weaker than the CRC in terms of detecting bit
errors. However, the strength is really in the separation of the data
buffers and the integrity metadata. These two distinct buffers much
match up for an I/O to complete.
The separation of the data and integrity metadata buffers as well as
the choice in checksums is referred to as the Data Integrity
Extensions. As these extensions are outside the scope of the protocol
bodies (T10, T13), Oracle and its partners are trying to standardize
them within the Storage Networking Industry Association.
----------------------------------------------------------------------
3. KERNEL CHANGES
The data integrity framework in Linux enables protection information
to be pinned to I/Os and sent to/received from controllers that
support it.
The advantage to the integrity extensions in SCSI and SATA is that
they enable us to protect the entire path from application to storage
device. However, at the same time this is also the biggest
disadvantage. It means that the protection information must be in a
format that can be understood by the disk.
Generally Linux/POSIX applications are agnostic to the intricacies of
the storage devices they are accessing. The virtual filesystem switch
and the block layer make things like hardware sector size and
transport protocols completely transparent to the application.
However, this level of detail is required when preparing the
protection information to send to a disk. Consequently, the very
concept of an end-to-end protection scheme is a layering violation.
It is completely unreasonable for an application to be aware whether
it is accessing a SCSI or SATA disk.
The data integrity support implemented in Linux attempts to hide this
from the application. As far as the application (and to some extent
the kernel) is concerned, the integrity metadata is opaque information
that's attached to the I/O.
The current implementation allows the block layer to automatically
generate the protection information for any I/O. Eventually the
intent is to move the integrity metadata calculation to userspace for
user data. Metadata and other I/O that originates within the kernel
will still use the automatic generation interface.
Some storage devices allow each hardware sector to be tagged with a
16-bit value. The owner of this tag space is the owner of the block
device. I.e. the filesystem in most cases. The filesystem can use
this extra space to tag sectors as they see fit. Because the tag
space is limited, the block interface allows tagging bigger chunks by
way of interleaving. This way, 8*16 bits of information can be
attached to a typical 4KB filesystem block.
This also means that applications such as fsck and mkfs will need
access to manipulate the tags from user space. A passthrough
interface for this is being worked on.
----------------------------------------------------------------------
4. BLOCK LAYER IMPLEMENTATION DETAILS
4.1 BIO
The data integrity patches add a new field to struct bio when
CONFIG_BLK_DEV_INTEGRITY is enabled. bio->bi_integrity is a pointer
to a struct bip which contains the bio integrity payload. Essentially
a bip is a trimmed down struct bio which holds a bio_vec containing
the integrity metadata and the required housekeeping information (bvec
pool, vector count, etc.)
A kernel subsystem can enable data integrity protection on a bio by
calling bio_integrity_alloc(bio). This will allocate and attach the
bip to the bio.
Individual pages containing integrity metadata can subsequently be
attached using bio_integrity_add_page().
bio_free() will automatically free the bip.
4.2 BLOCK DEVICE
Because the format of the protection data is tied to the physical
disk, each block device has been extended with a block integrity
profile (struct blk_integrity). This optional profile is registered
with the block layer using blk_integrity_register().
The profile contains callback functions for generating and verifying
the protection data, as well as getting and setting application tags.
The profile also contains a few constants to aid in completing,
merging and splitting the integrity metadata.
Layered block devices will need to pick a profile that's appropriate
for all subdevices. blk_integrity_compare() can help with that. DM
and MD linear, RAID0 and RAID1 are currently supported. RAID4/5/6
will require extra work due to the application tag.
----------------------------------------------------------------------
5.0 BLOCK LAYER INTEGRITY API
5.1 NORMAL FILESYSTEM
The normal filesystem is unaware that the underlying block device
is capable of sending/receiving integrity metadata. The IMD will
be automatically generated by the block layer at submit_bio() time
in case of a WRITE. A READ request will cause the I/O integrity
to be verified upon completion.
IMD generation and verification can be toggled using the
/sys/block/<bdev>/integrity/write_generate
and
/sys/block/<bdev>/integrity/read_verify
flags.
5.2 INTEGRITY-AWARE FILESYSTEM
A filesystem that is integrity-aware can prepare I/Os with IMD
attached. It can also use the application tag space if this is
supported by the block device.
int bdev_integrity_enabled(block_device, int rw);
bdev_integrity_enabled() will return 1 if the block device
supports integrity metadata transfer for the data direction
specified in 'rw'.
bdev_integrity_enabled() honors the write_generate and
read_verify flags in sysfs and will respond accordingly.
int bio_integrity_prep(bio);
To generate IMD for WRITE and to set up buffers for READ, the
filesystem must call bio_integrity_prep(bio).
Prior to calling this function, the bio data direction and start
sector must be set, and the bio should have all data pages
added. It is up to the caller to ensure that the bio does not
change while I/O is in progress.
bio_integrity_prep() should only be called if
bio_integrity_enabled() returned 1.
int bio_integrity_tag_size(bio);
If the filesystem wants to use the application tag space it will
first have to find out how much storage space is available.
Because tag space is generally limited (usually 2 bytes per
sector regardless of sector size), the integrity framework
supports interleaving the information between the sectors in an
I/O.
Filesystems can call bio_integrity_tag_size(bio) to find out how
many bytes of storage are available for that particular bio.
Another option is bdev_get_tag_size(block_device) which will
return the number of available bytes per hardware sector.
int bio_integrity_set_tag(bio, void *tag_buf, len);
After a successful return from bio_integrity_prep(),
bio_integrity_set_tag() can be used to attach an opaque tag
buffer to a bio. Obviously this only makes sense if the I/O is
a WRITE.
int bio_integrity_get_tag(bio, void *tag_buf, len);
Similarly, at READ I/O completion time the filesystem can
retrieve the tag buffer using bio_integrity_get_tag().
6.3 PASSING EXISTING INTEGRITY METADATA
Filesystems that either generate their own integrity metadata or
are capable of transferring IMD from user space can use the
following calls:
struct bip * bio_integrity_alloc(bio, gfp_mask, nr_pages);
Allocates the bio integrity payload and hangs it off of the bio.
nr_pages indicate how many pages of protection data need to be
stored in the integrity bio_vec list (similar to bio_alloc()).
The integrity payload will be freed at bio_free() time.
int bio_integrity_add_page(bio, page, len, offset);
Attaches a page containing integrity metadata to an existing
bio. The bio must have an existing bip,
i.e. bio_integrity_alloc() must have been called. For a WRITE,
the integrity metadata in the pages must be in a format
understood by the target device with the notable exception that
the sector numbers will be remapped as the request traverses the
I/O stack. This implies that the pages added using this call
will be modified during I/O! The first reference tag in the
integrity metadata must have a value of bip->bip_sector.
Pages can be added using bio_integrity_add_page() as long as
there is room in the bip bio_vec array (nr_pages).
Upon completion of a READ operation, the attached pages will
contain the integrity metadata received from the storage device.
It is up to the receiver to process them and verify data
integrity upon completion.
6.4 REGISTERING A BLOCK DEVICE AS CAPABLE OF EXCHANGING INTEGRITY
METADATA
To enable integrity exchange on a block device the gendisk must be
registered as capable:
int blk_integrity_register(gendisk, blk_integrity);
The blk_integrity struct is a template and should contain the
following:
static struct blk_integrity my_profile = {
.name = "STANDARDSBODY-TYPE-VARIANT-CSUM",
.generate_fn = my_generate_fn,
.verify_fn = my_verify_fn,
.get_tag_fn = my_get_tag_fn,
.set_tag_fn = my_set_tag_fn,
.tuple_size = sizeof(struct my_tuple_size),
.tag_size = <tag bytes per hw sector>,
};
'name' is a text string which will be visible in sysfs. This is
part of the userland API so chose it carefully and never change
it. The format is standards body-type-variant.
E.g. T10-DIF-TYPE1-IP or T13-EPP-0-CRC.
'generate_fn' generates appropriate integrity metadata (for WRITE).
'verify_fn' verifies that the data buffer matches the integrity
metadata.
'tuple_size' must be set to match the size of the integrity
metadata per sector. I.e. 8 for DIF and EPP.
'tag_size' must be set to identify how many bytes of tag space
are available per hardware sector. For DIF this is either 2 or
0 depending on the value of the Control Mode Page ATO bit.
See 6.2 for a description of get_tag_fn and set_tag_fn.
----------------------------------------------------------------------
2007-12-24 Martin K. Petersen <martin.petersen@oracle.com>

67
Documentation/bt8xxgpio.txt 100644
View File

@ -0,0 +1,67 @@
===============================================================
== BT8XXGPIO driver ==
== ==
== A driver for a selfmade cheap BT8xx based PCI GPIO-card ==
== ==
== For advanced documentation, see ==
== http://www.bu3sch.de/btgpio.php ==
===============================================================
A generic digital 24-port PCI GPIO card can be built out of an ordinary
Brooktree bt848, bt849, bt878 or bt879 based analog TV tuner card. The
Brooktree chip is used in old analog Hauppauge WinTV PCI cards. You can easily
find them used for low prices on the net.
The bt8xx chip does have 24 digital GPIO ports.
These ports are accessible via 24 pins on the SMD chip package.
==============================================
== How to physically access the GPIO pins ==
==============================================
The are several ways to access these pins. One might unsolder the whole chip
and put it on a custom PCI board, or one might only unsolder each individual
GPIO pin and solder that to some tiny wire. As the chip package really is tiny
there are some advanced soldering skills needed in any case.
The physical pinouts are drawn in the following ASCII art.
The GPIO pins are marked with G00-G23
G G G G G G G G G G G G G G G G G G
0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
---------------------------------------------------------------------------
--| ^ ^ |--
--| pin 86 pin 67 |--
--| |--
--| pin 61 > |-- G18
--| |-- G19
--| |-- G20
--| |-- G21
--| |-- G22
--| pin 56 > |-- G23
--| |--
--| Brooktree 878/879 |--
--| |--
--| |--
--| |--
--| |--
--| |--
--| |--
--| |--
--| |--
--| |--
--| |--
--| |--
--| |--
--| |--
--| O |--
--| |--
---------------------------------------------------------------------------
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
^
This is pin 1

5
Documentation/cciss.txt
View File

@ -21,6 +21,11 @@ This driver is known to work with the following cards:
* SA E200
* SA E200i
* SA E500
* SA P212
* SA P410
* SA P410i
* SA P411
* SA P812
Detecting drive failures:
-------------------------

8
Documentation/cgroups.txt
View File

@ -310,8 +310,8 @@ and then start a subshell 'sh' in that cgroup:
cd /dev/cgroup
mkdir Charlie
cd Charlie
/bin/echo 2-3 > cpus
/bin/echo 1 > mems
/bin/echo 2-3 > cpuset.cpus
/bin/echo 1 > cpuset.mems
/bin/echo $$ > tasks
sh
# The subshell 'sh' is now running in cgroup Charlie
@ -390,6 +390,10 @@ If you have several tasks to attach, you have to do it one after another:
...
# /bin/echo PIDn > tasks
You can attach the current shell task by echoing 0:
# echo 0 > tasks
3. Kernel API
=============

8
Documentation/controllers/devices.txt
View File

@ -13,7 +13,7 @@ either an integer or * for all. Access is a composition of r
The root device cgroup starts with rwm to 'all'. A child device
cgroup gets a copy of the parent. Administrators can then remove
devices from the whitelist or add new entries. A child cgroup can
never receive a device access which is denied its parent. However
never receive a device access which is denied by its parent. However
when a device access is removed from a parent it will not also be
removed from the child(ren).
@ -29,7 +29,11 @@ allows cgroup 1 to read and mknod the device usually known as
echo a > /cgroups/1/devices.deny
will remove the default 'a *:* mrw' entry.
will remove the default 'a *:* rwm' entry. Doing
echo a > /cgroups/1/devices.allow
will add the 'a *:* rwm' entry to the whitelist.
3. Security

3
Documentation/controllers/memory.txt
View File

@ -242,8 +242,7 @@ rmdir() if there are no tasks.
1. Add support for accounting huge pages (as a separate controller)
2. Make per-cgroup scanner reclaim not-shared pages first
3. Teach controller to account for shared-pages
4. Start reclamation when the limit is lowered
5. Start reclamation in the background when the limit is
4. Start reclamation in the background when the limit is
not yet hit but the usage is getting closer
Summary

10
Documentation/cpu-freq/governors.txt
View File

@ -122,21 +122,13 @@ around '10000' or more.
show_sampling_rate_(min|max): the minimum and maximum sampling rates
available that you may set 'sampling_rate' to.
up_threshold: defines what the average CPU usaged between the samplings
up_threshold: defines what the average CPU usage between the samplings
of 'sampling_rate' needs to be for the kernel to make a decision on
whether it should increase the frequency. For example when it is set
to its default value of '80' it means that between the checking
intervals the CPU needs to be on average more than 80% in use to then
decide that the CPU frequency needs to be increased.
sampling_down_factor: this parameter controls the rate that the CPU
makes a decision on when to decrease the frequency. When set to its
default value of '5' it means that at 1/5 the sampling_rate the kernel
makes a decision to lower the frequency. Five "lower rate" decisions
have to be made in a row before the CPU frequency is actually lower.
If set to '1' then the frequency decreases as quickly as it increases,
if set to '2' it decreases at half the rate of the increase.
ignore_nice_load: this parameter takes a value of '0' or '1'. When
set to '0' (its default), all processes are counted towards the
'cpu utilisation' value. When set to '1', the processes that are

20
Documentation/cpusets.txt
View File

@ -154,13 +154,15 @@ browsing and modifying the cpusets presently known to the kernel. No
new system calls are added for cpusets - all support for querying and
modifying cpusets is via this cpuset file system.
The /proc/<pid>/status file for each task has two added lines,
The /proc/<pid>/status file for each task has four added lines,
displaying the tasks cpus_allowed (on which CPUs it may be scheduled)
and mems_allowed (on which Memory Nodes it may obtain memory),
in the format seen in the following example:
in the two formats seen in the following example:
Cpus_allowed: ffffffff,ffffffff,ffffffff,ffffffff
Cpus_allowed_list: 0-127
Mems_allowed: ffffffff,ffffffff
Mems_allowed_list: 0-63
Each cpuset is represented by a directory in the cgroup file system
containing (on top of the standard cgroup files) the following
@ -199,7 +201,7 @@ using the sched_setaffinity, mbind and set_mempolicy system calls.
The following rules apply to each cpuset:
- Its CPUs and Memory Nodes must be a subset of its parents.
- It can only be marked exclusive if its parent is.
- It can't be marked exclusive unless its parent is.
- If its cpu or memory is exclusive, they may not overlap any sibling.
These rules, and the natural hierarchy of cpusets, enable efficient
@ -345,7 +347,7 @@ is modified to perform an inline check for this PF_SPREAD_PAGE task
flag, and if set, a call to a new routine cpuset_mem_spread_node()
returns the node to prefer for the allocation.
Similarly, setting 'memory_spread_cache' turns on the flag
Similarly, setting 'memory_spread_slab' turns on the flag
PF_SPREAD_SLAB, and appropriately marked slab caches will allocate
pages from the node returned by cpuset_mem_spread_node().
@ -542,7 +544,10 @@ otherwise initial value -1 that indicates the cpuset has no request.
2 : search cores in a package.
3 : search cpus in a node [= system wide on non-NUMA system]
( 4 : search nodes in a chunk of node [on NUMA system] )
( 5~ : search system wide [on NUMA system])
( 5 : search system wide [on NUMA system] )
The system default is architecture dependent. The system default
can be changed using the relax_domain_level= boot parameter.
This file is per-cpuset and affect the sched domain where the cpuset
belongs to. Therefore if the flag 'sched_load_balance' of a cpuset
@ -709,7 +714,10 @@ Now you want to do something with this cpuset.
In this directory you can find several files:
# ls
cpus cpu_exclusive mems mem_exclusive mem_hardwall tasks
cpu_exclusive memory_migrate mems tasks
cpus memory_pressure notify_on_release
mem_exclusive memory_spread_page sched_load_balance
mem_hardwall memory_spread_slab sched_relax_domain_level
Reading them will give you information about the state of this cpuset:
the CPUs and Memory Nodes it can use, the processes that are using

26
Documentation/cputopology.txt
View File

@ -14,9 +14,8 @@ represent the thread siblings to cpu X in the same physical package;
To implement it in an architecture-neutral way, a new source file,
drivers/base/topology.c, is to export the 4 attributes.
If one architecture wants to support this feature, it just needs to
implement 4 defines, typically in file include/asm-XXX/topology.h.
The 4 defines are:
For an architecture to support this feature, it must define some of
these macros in include/asm-XXX/topology.h:
#define topology_physical_package_id(cpu)
#define topology_core_id(cpu)
#define topology_thread_siblings(cpu)
@ -25,17 +24,10 @@ The 4 defines are:
The type of **_id is int.
The type of siblings is cpumask_t.
To be consistent on all architectures, the 4 attributes should have
default values if their values are unavailable. Below is the rule.
1) physical_package_id: If cpu has no physical package id, -1 is the
default value.
2) core_id: If cpu doesn't support multi-core, its core id is 0.
3) thread_siblings: Just include itself, if the cpu doesn't support
HT/multi-thread.
4) core_siblings: Just include itself, if the cpu doesn't support
multi-core and HT/Multi-thread.
So be careful when declaring the 4 defines in include/asm-XXX/topology.h.
If an attribute isn't defined on an architecture, it won't be exported.
To be consistent on all architectures, include/linux/topology.h
provides default definitions for any of the above macros that are
not defined by include/asm-XXX/topology.h:
1) physical_package_id: -1
2) core_id: 0
3) thread_siblings: just the given CPU
4) core_siblings: just the given CPU

153
Documentation/edac.txt
View File

@ -222,74 +222,9 @@ both csrow2 and csrow3 are populated, this indicates a dual ranked
set of DIMMs for channels 0 and 1.
Within each of the 'mc','mcX' and 'csrowX' directories are several
Within each of the 'mcX' and 'csrowX' directories are several
EDAC control and attribute files.
============================================================================
DIRECTORY 'mc'
In directory 'mc' are EDAC system overall control and attribute files:
Panic on UE control file:
'edac_mc_panic_on_ue'
An uncorrectable error will cause a machine panic. This is usually
desirable. It is a bad idea to continue when an uncorrectable error
occurs - it is indeterminate what was uncorrected and the operating
system context might be so mangled that continuing will lead to further
corruption. If the kernel has MCE configured, then EDAC will never
notice the UE.
LOAD TIME: module/kernel parameter: panic_on_ue=[0|1]
RUN TIME: echo "1" >/sys/devices/system/edac/mc/edac_mc_panic_on_ue
Log UE control file:
'edac_mc_log_ue'
Generate kernel messages describing uncorrectable errors. These errors
are reported through the system message log system. UE statistics
will be accumulated even when UE logging is disabled.
LOAD TIME: module/kernel parameter: log_ue=[0|1]
RUN TIME: echo "1" >/sys/devices/system/edac/mc/edac_mc_log_ue
Log CE control file:
'edac_mc_log_ce'
Generate kernel messages describing correctable errors. These
errors are reported through the system message log system.
CE statistics will be accumulated even when CE logging is disabled.
LOAD TIME: module/kernel parameter: log_ce=[0|1]
RUN TIME: echo "1" >/sys/devices/system/edac/mc/edac_mc_log_ce
Polling period control file:
'edac_mc_poll_msec'
The time period, in milliseconds, for polling for error information.
Too small a value wastes resources. Too large a value might delay
necessary handling of errors and might loose valuable information for
locating the error. 1000 milliseconds (once each second) is the current
default. Systems which require all the bandwidth they can get, may
increase this.
LOAD TIME: module/kernel parameter: poll_msec=[0|1]
RUN TIME: echo "1000" >/sys/devices/system/edac/mc/edac_mc_poll_msec
============================================================================
'mcX' DIRECTORIES
@ -392,7 +327,7 @@ Sdram memory scrubbing rate:
'sdram_scrub_rate'
Read/Write attribute file that controls memory scrubbing. The scrubbing
rate is set by writing a minimum bandwith in bytes/sec to the attribute
rate is set by writing a minimum bandwidth in bytes/sec to the attribute
file. The rate will be translated to an internal value that gives at
least the specified rate.
@ -537,7 +472,6 @@ Channel 1 DIMM Label control file:
motherboard specific and determination of this information
must occur in userland at this time.
============================================================================
SYSTEM LOGGING
@ -570,7 +504,6 @@ error type, a notice of "no info" and then an optional,
driver-specific error message.
============================================================================
PCI Bus Parity Detection
@ -604,6 +537,74 @@ Enable/Disable PCI Parity checking control file:
echo "0" >/sys/devices/system/edac/pci/check_pci_parity
Parity Count:
'pci_parity_count'
This attribute file will display the number of parity errors that
have been detected.
============================================================================
MODULE PARAMETERS
Panic on UE control file:
'edac_mc_panic_on_ue'
An uncorrectable error will cause a machine panic. This is usually
desirable. It is a bad idea to continue when an uncorrectable error
occurs - it is indeterminate what was uncorrected and the operating
system context might be so mangled that continuing will lead to further
corruption. If the kernel has MCE configured, then EDAC will never
notice the UE.
LOAD TIME: module/kernel parameter: edac_mc_panic_on_ue=[0|1]
RUN TIME: echo "1" > /sys/module/edac_core/parameters/edac_mc_panic_on_ue
Log UE control file:
'edac_mc_log_ue'
Generate kernel messages describing uncorrectable errors. These errors
are reported through the system message log system. UE statistics
will be accumulated even when UE logging is disabled.
LOAD TIME: module/kernel parameter: edac_mc_log_ue=[0|1]
RUN TIME: echo "1" > /sys/module/edac_core/parameters/edac_mc_log_ue
Log CE control file:
'edac_mc_log_ce'
Generate kernel messages describing correctable errors. These
errors are reported through the system message log system.
CE statistics will be accumulated even when CE logging is disabled.
LOAD TIME: module/kernel parameter: edac_mc_log_ce=[0|1]
RUN TIME: echo "1" > /sys/module/edac_core/parameters/edac_mc_log_ce
Polling period control file:
'edac_mc_poll_msec'
The time period, in milliseconds, for polling for error information.
Too small a value wastes resources. Too large a value might delay
necessary handling of errors and might loose valuable information for
locating the error. 1000 milliseconds (once each second) is the current
default. Systems which require all the bandwidth they can get, may
increase this.
LOAD TIME: module/kernel parameter: edac_mc_poll_msec=[0|1]
RUN TIME: echo "1000" > /sys/module/edac_core/parameters/edac_mc_poll_msec
Panic on PCI PARITY Error:
@ -614,21 +615,13 @@ Panic on PCI PARITY Error:
error has been detected.
module/kernel parameter: panic_on_pci_parity=[0|1]
module/kernel parameter: edac_panic_on_pci_pe=[0|1]
Enable:
echo "1" >/sys/devices/system/edac/pci/panic_on_pci_parity
echo "1" > /sys/module/edac_core/parameters/edac_panic_on_pci_pe
Disable:
echo "0" >/sys/devices/system/edac/pci/panic_on_pci_parity
Parity Count:
'pci_parity_count'
This attribute file will display the number of parity errors that
have been detected.
echo "0" > /sys/module/edac_core/parameters/edac_panic_on_pci_pe

131
Documentation/fb/sh7760fb.txt 100644
View File

@ -0,0 +1,131 @@
SH7760/SH7763 integrated LCDC Framebuffer driver
================================================
0. Overwiew
-----------
The SH7760/SH7763 have an integrated LCD Display controller (LCDC) which
supports (in theory) resolutions ranging from 1x1 to 1024x1024,
with color depths ranging from 1 to 16 bits, on STN, DSTN and TFT Panels.
Caveats:
* Framebuffer memory must be a large chunk allocated at the top
of Area3 (HW requirement). Because of this requirement you should NOT
make the driver a module since at runtime it may become impossible to
get a large enough contiguous chunk of memory.
* The driver does not support changing resolution while loaded
(displays aren't hotpluggable anyway)
* Heavy flickering may be observed
a) if you're using 15/16bit color modes at >= 640x480 px resolutions,
b) during PCMCIA (or any other slow bus) activity.
* Rotation works only 90degress clockwise, and only if horizontal
resolution is <= 320 pixels.
files: drivers/video/sh7760fb.c
include/asm-sh/sh7760fb.h
Documentation/fb/sh7760fb.txt
1. Platform setup
-----------------
SH7760:
Video data is fetched via the DMABRG DMA engine, so you have to
configure the SH DMAC for DMABRG mode (write 0x94808080 to the
DMARSRA register somewhere at boot).
PFC registers PCCR and PCDR must be set to peripheral mode.
(write zeros to both).
The driver does NOT do the above for you since board setup is, well, job
of the board setup code.
2. Panel definitions
--------------------
The LCDC must explicitly be told about the type of LCD panel
attached. Data must be wrapped in a "struct sh7760fb_platdata" and
passed to the driver as platform_data.
Suggest you take a closer look at the SH7760 Manual, Section 30.
(http://documentation.renesas.com/eng/products/mpumcu/e602291_sh7760.pdf)
The following code illustrates what needs to be done to
get the framebuffer working on a 640x480 TFT:
====================== cut here ======================================
#include <linux/fb.h>
#include <asm/sh7760fb.h>
/*
* NEC NL6440bc26-01 640x480 TFT
* dotclock 25175 kHz
* Xres 640 Yres 480
* Htotal 800 Vtotal 525
* HsynStart 656 VsynStart 490
* HsynLenn 30 VsynLenn 2
*
* The linux framebuffer layer does not use the syncstart/synclen
* values but right/left/upper/lower margin values. The comments
* for the x_margin explain how to calculate those from given
* panel sync timings.
*/
static struct fb_videomode nl6448bc26 = {
.name = "NL6448BC26",
.refresh = 60,
.xres = 640,
.yres = 480,
.pixclock = 39683, /* in picoseconds! */
.hsync_len = 30,
.vsync_len = 2,
.left_margin = 114, /* HTOT - (HSYNSLEN + HSYNSTART) */
.right_margin = 16, /* HSYNSTART - XRES */
.upper_margin = 33, /* VTOT - (VSYNLEN + VSYNSTART) */
.lower_margin = 10, /* VSYNSTART - YRES */
.sync = FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,
.vmode = FB_VMODE_NONINTERLACED,
.flag = 0,
};
static struct sh7760fb_platdata sh7760fb_nl6448 = {
.def_mode = &nl6448bc26,
.ldmtr = LDMTR_TFT_COLOR_16, /* 16bit TFT panel */
.lddfr = LDDFR_8BPP, /* we want 8bit output */
.ldpmmr = 0x0070,
.ldpspr = 0x0500,
.ldaclnr = 0,
.ldickr = LDICKR_CLKSRC(LCDC_CLKSRC_EXTERNAL) |
LDICKR_CLKDIV(1),
.rotate = 0,
.novsync = 1,
.blank = NULL,
};
/* SH7760:
* 0xFE300800: 256 * 4byte xRGB palette ram
* 0xFE300C00: 42 bytes ctrl registers
*/
static struct resource sh7760_lcdc_res[] = {
[0] = {
.start = 0xFE300800,
.end = 0xFE300CFF,
.flags = IORESOURCE_MEM,
},
[1] = {
.start = 65,
.end = 65,
.flags = IORESOURCE_IRQ,
},
};
static struct platform_device sh7760_lcdc_dev = {
.dev = {
.platform_data = &sh7760fb_nl6448,
},
.name = "sh7760-lcdc",
.id = -1,
.resource = sh7760_lcdc_res,
.num_resources = ARRAY_SIZE(sh7760_lcdc_res),
};
====================== cut here ======================================

44
Documentation/fb/tridentfb.txt
View File

@ -3,11 +3,25 @@ Tridentfb is a framebuffer driver for some Trident chip based cards.
The following list of chips is thought to be supported although not all are
tested:
those from the Image series with Cyber in their names - accelerated
those with Blade in their names (Blade3D,CyberBlade...) - accelerated
the newer CyberBladeXP family - nonaccelerated
those from the TGUI series 9440/96XX and with Cyber in their names
those from the Image series and with Cyber in their names
those with Blade in their names (Blade3D,CyberBlade...)
the newer CyberBladeXP family
Only PCI/AGP based cards are supported, none of the older Tridents.
All families are accelerated. Only PCI/AGP based cards are supported,
none of the older Tridents.
The driver supports 8, 16 and 32 bits per pixel depths.
The TGUI family requires a line length to be power of 2 if acceleration
is enabled. This means that range of possible resolutions and bpp is
limited comparing to the range if acceleration is disabled (see list
of parameters below).
Known bugs:
1. The driver randomly locks up on 3DImage975 chip with acceleration
enabled. The same happens in X11 (Xorg).
2. The ramdac speeds require some more fine tuning. It is possible to
switch resolution which the chip does not support at some depths for
older chips.
How to use it?
==============
@ -17,12 +31,11 @@ video=tridentfb
The parameters for tridentfb are concatenated with a ':' as in this example.
video=tridentfb:800x600,bpp=16,noaccel
video=tridentfb:800x600-16@75,noaccel
The second level parameters that tridentfb understands are:
noaccel - turns off acceleration (when it doesn't work for your card)
accel - force text acceleration (for boards which by default are noacceled)
fp - use flat panel related stuff
crt - assume monitor is present instead of fp
@ -31,21 +44,24 @@ center - for flat panels and resolutions smaller than native size center the
image, otherwise use
stretch
memsize - integer value in Kb, use if your card's memory size is misdetected.
memsize - integer value in KB, use if your card's memory size is misdetected.
look at the driver output to see what it says when initializing.
memdiff - integer value in Kb,should be nonzero if your card reports
more memory than it actually has.For instance mine is 192K less than
memdiff - integer value in KB, should be nonzero if your card reports
more memory than it actually has. For instance mine is 192K less than
detection says in all three BIOS selectable situations 2M, 4M, 8M.
Only use if your video memory is taken from main memory hence of
configurable size.Otherwise use memsize.
If in some modes which barely fit the memory you see garbage at the bottom
this might help by not letting change to that mode anymore.
configurable size. Otherwise use memsize.
If in some modes which barely fit the memory you see garbage
at the bottom this might help by not letting change to that mode
anymore.
nativex - the width in pixels of the flat panel.If you know it (usually 1024
800 or 1280) and it is not what the driver seems to detect use it.
bpp - bits per pixel (8,16 or 32)
mode - a mode name like 800x600 (as described in Documentation/fb/modedb.txt)
bpp - bits per pixel (8,16 or 32)
mode - a mode name like 800x600-8@75 as described in
Documentation/fb/modedb.txt
Using insane values for the above parameters will probably result in driver
misbehaviour so take care(for instance memsize=12345678 or memdiff=23784 or

100
Documentation/feature-removal-schedule.txt
View File

@ -47,6 +47,30 @@ Who: Mauro Carvalho Chehab <mchehab@infradead.org>
---------------------------
What: old tuner-3036 i2c driver
When: 2.6.28
Why: This driver is for VERY old i2c-over-parallel port teletext receiver
boxes. Rather then spending effort on converting this driver to V4L2,
and since it is extremely unlikely that anyone still uses one of these
devices, it was decided to drop it.
Who: Hans Verkuil <hverkuil@xs4all.nl>
Mauro Carvalho Chehab <mchehab@infradead.org>
---------------------------
What: V4L2 dpc7146 driver
When: 2.6.28
Why: Old driver for the dpc7146 demonstration board that is no longer
relevant. The last time this was tested on actual hardware was
probably around 2002. Since this is a driver for a demonstration
board the decision was made to remove it rather than spending a
lot of effort continually updating this driver to stay in sync
with the latest internal V4L2 or I2C API.
Who: Hans Verkuil <hverkuil@xs4all.nl>
Mauro Carvalho Chehab <mchehab@infradead.org>
---------------------------
What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
When: November 2005
Files: drivers/pcmcia/: pcmcia_ioctl.c
@ -138,24 +162,6 @@ Who: Kay Sievers <kay.sievers@suse.de>
---------------------------
What: find_task_by_pid
When: 2.6.26
Why: With pid namespaces, calling this funciton will return the
wrong task when called from inside a namespace.
The best way to save a task pid and find a task by this
pid later, is to find this task's struct pid pointer (or get
it directly from the task) and call pid_task() later.
If someone really needs to get a task by its pid_t, then
he most likely needs the find_task_by_vpid() to get the
task from the same namespace as the current task is in, but
this may be not so in general.
Who: Pavel Emelyanov <xemul@openvz.org>
---------------------------
What: ACPI procfs interface
When: July 2008
Why: ACPI sysfs conversion should be finished by January 2008.
@ -222,13 +228,6 @@ Who: Thomas Gleixner <tglx@linutronix.de>
---------------------------
What: i2c-i810, i2c-prosavage and i2c-savage4
When: May 2008
Why: These drivers are superseded by i810fb, intelfb and savagefb.
Who: Jean Delvare <khali@linux-fr.org>
---------------------------
What (Why):
- include/linux/netfilter_ipv4/ipt_TOS.h ipt_tos.h header files
(superseded by xt_TOS/xt_tos target & match)
@ -289,6 +288,14 @@ Who: Glauber Costa <gcosta@redhat.com>
---------------------------
What: old style serial driver for ColdFire (CONFIG_SERIAL_COLDFIRE)
When: 2.6.28
Why: This driver still uses the old interface and has been replaced
by CONFIG_SERIAL_MCF.
Who: Sebastian Siewior <sebastian@breakpoint.cc>
---------------------------
What: /sys/o2cb symlink
When: January 2010
Why: /sys/fs/o2cb is the proper location for this information - /sys/o2cb
@ -299,8 +306,41 @@ Who: ocfs2-devel@oss.oracle.com
---------------------------
What: asm/semaphore.h
When: 2.6.26
Why: Implementation became generic; users should now include
linux/semaphore.h instead.
Who: Matthew Wilcox <willy@linux.intel.com>
What: SCTP_GET_PEER_ADDRS_NUM_OLD, SCTP_GET_PEER_ADDRS_OLD,
SCTP_GET_LOCAL_ADDRS_NUM_OLD, SCTP_GET_LOCAL_ADDRS_OLD
When: June 2009
Why: A newer version of the options have been introduced in 2005 that
removes the limitions of the old API. The sctp library has been
converted to use these new options at the same time. Any user
space app that directly uses the old options should convert to using
the new options.
Who: Vlad Yasevich <vladislav.yasevich@hp.com>
---------------------------
What: CONFIG_THERMAL_HWMON
When: January 2009
Why: This option was introduced just to allow older lm-sensors userspace
to keep working over the upgrade to 2.6.26. At the scheduled time of
removal fixed lm-sensors (2.x or 3.x) should be readily available.
Who: Rene Herman <rene.herman@gmail.com>
---------------------------
What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS
(in net/core/net-sysfs.c)
When: After the only user (hal) has seen a release with the patches
for enough time, probably some time in 2010.
Why: Over 1K .text/.data size reduction, data is available in other
ways (ioctls)
Who: Johannes Berg <johannes@sipsolutions.net>
---------------------------
What: CONFIG_NF_CT_ACCT
When: 2.6.29
Why: Accounting can now be enabled/disabled without kernel recompilation.
Currently used only to set a default value for a feature that is also
controlled by a kernel/module/sysfs/sysctl parameter.
Who: Krzysztof Piotr Oledzki <ole@ans.pl>

9
Documentation/filesystems/Locking
View File

@ -92,7 +92,6 @@ prototypes:
void (*destroy_inode)(struct inode *);
void (*dirty_inode) (struct inode *);
int (*write_inode) (struct inode *, int);
void (*put_inode) (struct inode *);
void (*drop_inode) (struct inode *);
void (*delete_inode) (struct inode *);
void (*put_super) (struct super_block *);
@ -115,7 +114,6 @@ alloc_inode: no no no
destroy_inode: no
dirty_inode: no (must not sleep)
write_inode: no
put_inode: no
drop_inode: no !!!inode_lock!!!
delete_inode: no
put_super: yes yes no
@ -512,6 +510,7 @@ prototypes:
void (*close)(struct vm_area_struct*);
int (*fault)(struct vm_area_struct*, struct vm_fault *);
int (*page_mkwrite)(struct vm_area_struct *, struct page *);
int (*access)(struct vm_area_struct *, unsigned long, void*, int, int);
locking rules:
BKL mmap_sem PageLocked(page)
@ -519,6 +518,7 @@ open: no yes
close: no yes
fault: no yes
page_mkwrite: no yes no
access: no yes
->page_mkwrite() is called when a previously read-only page is
about to become writeable. The file system is responsible for
@ -527,6 +527,11 @@ taking to lock out truncate, the page range should be verified to be
within i_size. The page mapping should also be checked that it is not
NULL.
->access() is called when get_user_pages() fails in
acces_process_vm(), typically used to debug a process through
/proc/pid/mem or ptrace. This function is needed only for
VM_IO | VM_PFNMAP VMAs.
================================================================================
Dubious stuff

10
Documentation/filesystems/bfs.txt
View File

@ -26,11 +26,11 @@ You can simplify mounting by just typing:
this will allocate the first available loopback device (and load loop.o
kernel module if necessary) automatically. If the loopback driver is not
loaded automatically, make sure that your kernel is compiled with kmod
support (CONFIG_KMOD) enabled. Beware that umount will not
deallocate /dev/loopN device if /etc/mtab file on your system is a
symbolic link to /proc/mounts. You will need to do it manually using
"-d" switch of losetup(8). Read losetup(8) manpage for more info.
loaded automatically, make sure that you have compiled the module and
that modprobe is functioning. Beware that umount will not deallocate
/dev/loopN device if /etc/mtab file on your system is a symbolic link to
/proc/mounts. You will need to do it manually using "-d" switch of
losetup(8). Read losetup(8) manpage for more info.
To create the BFS image under UnixWare you need to find out first which
slice contains it. The command prtvtoc(1M) is your friend:

4
Documentation/filesystems/configfs/configfs_example.c
View File

@ -279,7 +279,7 @@ static struct config_item *simple_children_make_item(struct config_group *group,
simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL);
if (!simple_child)
return NULL;
return ERR_PTR(-ENOMEM);
config_item_init_type_name(&simple_child->item, name,
@ -366,7 +366,7 @@ static struct config_group *group_children_make_group(struct config_group *group
simple_children = kzalloc(sizeof(struct simple_children),
GFP_KERNEL);
if (!simple_children)
return NULL;
return ERR_PTR(-ENOMEM);
config_group_init_type_name(&simple_children->group, name,

137
Documentation/filesystems/ext4.txt
View File

@ -13,72 +13,93 @@ Mailing list: linux-ext4@vger.kernel.org
1. Quick usage instructions:
===========================
- Grab updated e2fsprogs from
ftp://ftp.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs-interim/
This is a patchset on top of e2fsprogs-1.39, which can be found at
- Compile and install the latest version of e2fsprogs (as of this
writing version 1.41) from:
http://sourceforge.net/project/showfiles.php?group_id=2406
or
ftp://ftp.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs/
- It's still mke2fs -j /dev/hda1
or grab the latest git repository from:
- mount /dev/hda1 /wherever -t ext4dev
git://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git
- To enable extents,
- Create a new filesystem using the ext4dev filesystem type:
mount /dev/hda1 /wherever -t ext4dev -o extents
# mke2fs -t ext4dev /dev/hda1
- The filesystem is compatible with the ext3 driver until you add a file
which has extents (ie: `mount -o extents', then create a file).
Or configure an existing ext3 filesystem to support extents and set
the test_fs flag to indicate that it's ok for an in-development
filesystem to touch this filesystem:
NOTE: The "extents" mount flag is temporary. It will soon go away and
extents will be enabled by the "-o extents" flag to mke2fs or tune2fs
# tune2fs -O extents -E test_fs /dev/hda1
If the filesystem was created with 128 byte inodes, it can be
converted to use 256 byte for greater efficiency via:
# tune2fs -I 256 /dev/hda1
(Note: we currently do not have tools to convert an ext4dev
filesystem back to ext3; so please do not do try this on production
filesystems.)
- Mounting:
# mount -t ext4dev /dev/hda1 /wherever
- When comparing performance with other filesystems, remember that
ext3/4 by default offers higher data integrity guarantees than most. So
when comparing with a metadata-only journalling filesystem, use `mount -o
data=writeback'. And you might as well use `mount -o nobh' too along
with it. Making the journal larger than the mke2fs default often helps
performance with metadata-intensive workloads.
ext3/4 by default offers higher data integrity guarantees than most.
So when comparing with a metadata-only journalling filesystem, such
as ext3, use `mount -o data=writeback'. And you might as well use
`mount -o nobh' too along with it. Making the journal larger than
the mke2fs default often helps performance with metadata-intensive
workloads.
2. Features
===========
2.1 Currently available
* ability to use filesystems > 16TB
* ability to use filesystems > 16TB (e2fsprogs support not available yet)
* extent format reduces metadata overhead (RAM, IO for access, transactions)
* extent format more robust in face of on-disk corruption due to magics,
* internal redunancy in tree
2.1 Previously available, soon to be enabled by default by "mkefs.ext4":
* dir_index and resize inode will be on by default
* large inodes will be used by default for fast EAs, nsec timestamps, etc
* improved file allocation (multi-block alloc)
* fix 32000 subdirectory limit
* nsec timestamps for mtime, atime, ctime, create time
* inode version field on disk (NFSv4, Lustre)
* reduced e2fsck time via uninit_bg feature
* journal checksumming for robustness, performance
* persistent file preallocation (e.g for streaming media, databases)
* ability to pack bitmaps and inode tables into larger virtual groups via the
flex_bg feature
* large file support
* Inode allocation using large virtual block groups via flex_bg
* delayed allocation
* large block (up to pagesize) support
* efficent new ordered mode in JBD2 and ext4(avoid using buffer head to force
the ordering)
2.2 Candidate features for future inclusion
There are several under discussion, whether they all make it in is
partly a function of how much time everyone has to work on them:
* Online defrag (patches available but not well tested)
* reduced mke2fs time via lazy itable initialization in conjuction with
the uninit_bg feature (capability to do this is available in e2fsprogs
but a kernel thread to do lazy zeroing of unused inode table blocks
after filesystem is first mounted is required for safety)
* improved file allocation (multi-block alloc, delayed alloc; basically done)
* fix 32000 subdirectory limit (patch exists, needs some e2fsck work)
* nsec timestamps for mtime, atime, ctime, create time (patch exists,
needs some e2fsck work)
* inode version field on disk (NFSv4, Lustre; prototype exists)
* reduced mke2fs/e2fsck time via uninitialized groups (prototype exists)
* journal checksumming for robustness, performance (prototype exists)
* persistent file preallocation (e.g for streaming media, databases)
There are several others under discussion, whether they all make it in is
partly a function of how much time everyone has to work on them. Features like
metadata checksumming have been discussed and planned for a bit but no patches
exist yet so I'm not sure they're in the near-term roadmap.
Features like metadata checksumming have been discussed and planned for
a bit but no patches exist yet so I'm not sure they're in the near-term
roadmap.
The big performance win will come with mballoc, delalloc and flex_bg
grouping of bitmaps and inode tables. Some test results available here:
The big performance win will come with mballoc and delalloc. CFS has
been using mballoc for a few years already with Lustre, and IBM + Bull
did a lot of benchmarking on it. The reason it isn't in the first set of
patches is partly a manageability issue, and partly because it doesn't
directly affect the on-disk format (outside of much better allocation)
so it isn't critical to get into the first round of changes. I believe
Alex is working on a new set of patches right now.
- http://www.bullopensource.org/ext4/20080530/ffsb-write-2.6.26-rc2.html
- http://www.bullopensource.org/ext4/20080530/ffsb-readwrite-2.6.26-rc2.html
3. Options
==========
@ -139,8 +160,16 @@ commit=nrsec (*) Ext4 can be told to sync all its data and metadata
Setting it to very large values will improve
performance.
barrier=1 This enables/disables barriers. barrier=0 disables
it, barrier=1 enables it.
barrier=<0|1(*)> This enables/disables the use of write barriers in
the jbd code. barrier=0 disables, barrier=1 enables.
This also requires an IO stack which can support
barriers, and if jbd gets an error on a barrier
write, it will disable again with a warning.
Write barriers enforce proper on-disk ordering
of journal commits, making volatile disk write caches
safe to use, at some performance penalty. If
your disks are battery-backed in one way or another,
disabling barriers may safely improve performance.
orlov (*) This enables the new Orlov block allocator. It is
enabled by default.
@ -214,9 +243,11 @@ stripe=n Number of filesystem blocks that mballoc will try
to use for allocation size and alignment. For RAID5/6
systems this should be the number of data
disks * RAID chunk size in file system blocks.
delalloc (*) Deferring block allocation until write-out time.
nodelalloc Disable delayed allocation. Blocks are allocation
when data is copied from user to page cache.
Data Mode
---------
=========
There are 3 different data modes:
* writeback mode
@ -228,10 +259,10 @@ typically provide the best ext4 performance.
* ordered mode
In data=ordered mode, ext4 only officially journals metadata, but it logically
groups metadata and data blocks into a single unit called a transaction. When
it's time to write the new metadata out to disk, the associated data blocks
are written first. In general, this mode performs slightly slower than
writeback but significantly faster than journal mode.
groups metadata information related to data changes with the data blocks into a
single unit called a transaction. When it's time to write the new metadata
out to disk, the associated data blocks are written first. In general,
this mode performs slightly slower than writeback but significantly faster than journal mode.
* journal mode
data=journal mode provides full data and metadata journaling. All new data is
@ -239,7 +270,8 @@ written to the journal first, and then to its final location.
In the event of a crash, the journal can be replayed, bringing both data and
metadata into a consistent state. This mode is the slowest except when data
needs to be read from and written to disk at the same time where it
outperforms all others modes.
outperforms all others modes. Curently ext4 does not have delayed
allocation support if this data journalling mode is selected.
References
==========
@ -248,7 +280,8 @@ kernel source: <file:fs/ext4/>
<file:fs/jbd2/>
programs: http://e2fsprogs.sourceforge.net/
http://ext2resize.sourceforge.net
useful links: http://fedoraproject.org/wiki/ext3-devel
http://www.bullopensource.org/ext4/
http://ext4.wiki.kernel.org/index.php/Main_Page
http://fedoraproject.org/wiki/Features/Ext4

114
Documentation/filesystems/gfs2-glocks.txt 100644
View File

@ -0,0 +1,114 @@
Glock internal locking rules
------------------------------
This documents the basic principles of the glock state machine
internals. Each glock (struct gfs2_glock in fs/gfs2/incore.h)
has two main (internal) locks:
1. A spinlock (gl_spin) which protects the internal state such
as gl_state, gl_target and the list of holders (gl_holders)
2. A non-blocking bit lock, GLF_LOCK, which is used to prevent other
threads from making calls to the DLM, etc. at the same time. If a
thread takes this lock, it must then call run_queue (usually via the
workqueue) when it releases it in order to ensure any pending tasks
are completed.
The gl_holders list contains all the queued lock requests (not
just the holders) associated with the glock. If there are any
held locks, then they will be contiguous entries at the head
of the list. Locks are granted in strictly the order that they
are queued, except for those marked LM_FLAG_PRIORITY which are
used only during recovery, and even then only for journal locks.
There are three lock states that users of the glock layer can request,
namely shared (SH), deferred (DF) and exclusive (EX). Those translate
to the following DLM lock modes:
Glock mode | DLM lock mode
------------------------------
UN | IV/NL Unlocked (no DLM lock associated with glock) or NL
SH | PR (Protected read)
DF | CW (Concurrent write)
EX | EX (Exclusive)
Thus DF is basically a shared mode which is incompatible with the "normal"
shared lock mode, SH. In GFS2 the DF mode is used exclusively for direct I/O
operations. The glocks are basically a lock plus some routines which deal
with cache management. The following rules apply for the cache:
Glock mode | Cache data | Cache Metadata | Dirty Data | Dirty Metadata
--------------------------------------------------------------------------
UN | No | No | No | No
SH | Yes | Yes | No | No
DF | No | Yes | No | No
EX | Yes | Yes | Yes | Yes
These rules are implemented using the various glock operations which
are defined for each type of glock. Not all types of glocks use
all the modes. Only inode glocks use the DF mode for example.
Table of glock operations and per type constants:
Field | Purpose
----------------------------------------------------------------------------
go_xmote_th | Called before remote state change (e.g. to sync dirty data)
go_xmote_bh | Called after remote state change (e.g. to refill cache)
go_inval | Called if remote state change requires invalidating the cache
go_demote_ok | Returns boolean value of whether its ok to demote a glock
| (e.g. checks timeout, and that there is no cached data)
go_lock | Called for the first local holder of a lock
go_unlock | Called on the final local unlock of a lock
go_dump | Called to print content of object for debugfs file, or on
| error to dump glock to the log.
go_type; | The type of the glock, LM_TYPE_.....
go_min_hold_time | The minimum hold time
The minimum hold time for each lock is the time after a remote lock
grant for which we ignore remote demote requests. This is in order to
prevent a situation where locks are being bounced around the cluster
from node to node with none of the nodes making any progress. This
tends to show up most with shared mmaped files which are being written
to by multiple nodes. By delaying the demotion in response to a
remote callback, that gives the userspace program time to make
some progress before the pages are unmapped.
There is a plan to try and remove the go_lock and go_unlock callbacks
if possible, in order to try and speed up the fast path though the locking.
Also, eventually we hope to make the glock "EX" mode locally shared
such that any local locking will be done with the i_mutex as required
rather than via the glock.
Locking rules for glock operations:
Operation | GLF_LOCK bit lock held | gl_spin spinlock held
-----------------------------------------------------------------
go_xmote_th | Yes | No
go_xmote_bh | Yes | No
go_inval | Yes | No
go_demote_ok | Sometimes | Yes
go_lock | Yes | No
go_unlock | Yes | No
go_dump | Sometimes | Yes
N.B. Operations must not drop either the bit lock or the spinlock
if its held on entry. go_dump and do_demote_ok must never block.
Note that go_dump will only be called if the glock's state
indicates that it is caching uptodate data.
Glock locking order within GFS2:
1. i_mutex (if required)
2. Rename glock (for rename only)
3. Inode glock(s)
(Parents before children, inodes at "same level" with same parent in
lock number order)
4. Rgrp glock(s) (for (de)allocation operations)
5. Transaction glock (via gfs2_trans_begin) for non-read operations
6. Page lock (always last, very important!)
There are two glocks per inode. One deals with access to the inode
itself (locking order as above), and the other, known as the iopen
glock is used in conjunction with the i_nlink field in the inode to
determine the lifetime of the inode in question. Locking of inodes
is on a per-inode basis. Locking of rgrps is on a per rgrp basis.

103
Documentation/filesystems/nfs-rdma.txt
View File

@ -5,7 +5,7 @@
################################################################################
Author: NetApp and Open Grid Computing
Date: April 15, 2008
Date: May 29, 2008
Table of Contents
~~~~~~~~~~~~~~~~~
@ -60,16 +60,18 @@ Installation
The procedures described in this document have been tested with
distributions from Red Hat's Fedora Project (http://fedora.redhat.com/).
- Install nfs-utils-1.1.1 or greater on the client
- Install nfs-utils-1.1.2 or greater on the client
An NFS/RDMA mount point can only be obtained by using the mount.nfs
command in nfs-utils-1.1.1 or greater. To see which version of mount.nfs
you are using, type:
An NFS/RDMA mount point can be obtained by using the mount.nfs command in
nfs-utils-1.1.2 or greater (nfs-utils-1.1.1 was the first nfs-utils
version with support for NFS/RDMA mounts, but for various reasons we
recommend using nfs-utils-1.1.2 or greater). To see which version of
mount.nfs you are using, type:
> /sbin/mount.nfs -V
$ /sbin/mount.nfs -V
If the version is less than 1.1.1 or the command does not exist,
then you will need to install the latest version of nfs-utils.
If the version is less than 1.1.2 or the command does not exist,
you should install the latest version of nfs-utils.
Download the latest package from:
@ -77,22 +79,33 @@ Installation
Uncompress the package and follow the installation instructions.
If you will not be using GSS and NFSv4, the installation process
can be simplified by disabling these features when running configure:
If you will not need the idmapper and gssd executables (you do not need
these to create an NFS/RDMA enabled mount command), the installation
process can be simplified by disabling these features when running
configure:
> ./configure --disable-gss --disable-nfsv4
$ ./configure --disable-gss --disable-nfsv4
For more information on this see the package's README and INSTALL files.
To build nfs-utils you will need the tcp_wrappers package installed. For
more information on this see the package's README and INSTALL files.
After building the nfs-utils package, there will be a mount.nfs binary in
the utils/mount directory. This binary can be used to initiate NFS v2, v3,
or v4 mounts. To initiate a v4 mount, the binary must be called mount.nfs4.
The standard technique is to create a symlink called mount.nfs4 to mount.nfs.
or v4 mounts. To initiate a v4 mount, the binary must be called
mount.nfs4. The standard technique is to create a symlink called
mount.nfs4 to mount.nfs.
NOTE: mount.nfs and therefore nfs-utils-1.1.1 or greater is only needed
This mount.nfs binary should be installed at /sbin/mount.nfs as follows:
$ sudo cp utils/mount/mount.nfs /sbin/mount.nfs
In this location, mount.nfs will be invoked automatically for NFS mounts
by the system mount commmand.
NOTE: mount.nfs and therefore nfs-utils-1.1.2 or greater is only needed
on the NFS client machine. You do not need this specific version of
nfs-utils on the server. Furthermore, only the mount.nfs command from
nfs-utils-1.1.1 is needed on the client.
nfs-utils-1.1.2 is needed on the client.
- Install a Linux kernel with NFS/RDMA
@ -156,8 +169,8 @@ Check RDMA and NFS Setup
this time. For example, if you are using a Mellanox Tavor/Sinai/Arbel
card:
> modprobe ib_mthca
> modprobe ib_ipoib
$ modprobe ib_mthca
$ modprobe ib_ipoib
If you are using InfiniBand, make sure there is a Subnet Manager (SM)
running on the network. If your IB switch has an embedded SM, you can
@ -166,7 +179,7 @@ Check RDMA and NFS Setup
If an SM is running on your network, you should see the following:
> cat /sys/class/infiniband/driverX/ports/1/state
$ cat /sys/class/infiniband/driverX/ports/1/state
4: ACTIVE
where driverX is mthca0, ipath5, ehca3, etc.
@ -174,10 +187,10 @@ Check RDMA and NFS Setup
To further test the InfiniBand software stack, use IPoIB (this
assumes you have two IB hosts named host1 and host2):
host1> ifconfig ib0 a.b.c.x
host2> ifconfig ib0 a.b.c.y
host1> ping a.b.c.y
host2> ping a.b.c.x
host1$ ifconfig ib0 a.b.c.x
host2$ ifconfig ib0 a.b.c.y
host1$ ping a.b.c.y
host2$ ping a.b.c.x
For other device types, follow the appropriate procedures.
@ -202,11 +215,11 @@ NFS/RDMA Setup
/vol0 192.168.0.47(fsid=0,rw,async,insecure,no_root_squash)
/vol0 192.168.0.0/255.255.255.0(fsid=0,rw,async,insecure,no_root_squash)
The IP address(es) is(are) the client's IPoIB address for an InfiniBand HCA or the
cleint's iWARP address(es) for an RNIC.
The IP address(es) is(are) the client's IPoIB address for an InfiniBand
HCA or the cleint's iWARP address(es) for an RNIC.
NOTE: The "insecure" option must be used because the NFS/RDMA client does not
use a reserved port.
NOTE: The "insecure" option must be used because the NFS/RDMA client does
not use a reserved port.
Each time a machine boots:
@ -214,43 +227,45 @@ NFS/RDMA Setup
For InfiniBand using a Mellanox adapter:
> modprobe ib_mthca
> modprobe ib_ipoib
> ifconfig ib0 a.b.c.d
$ modprobe ib_mthca
$ modprobe ib_ipoib
$ ifconfig ib0 a.b.c.d
NOTE: use unique addresses for the client and server
- Start the NFS server
If the NFS/RDMA server was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in kernel config),
load the RDMA transport module:
If the NFS/RDMA server was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in
kernel config), load the RDMA transport module:
> modprobe svcrdma
$ modprobe svcrdma
Regardless of how the server was built (module or built-in), start the server:
Regardless of how the server was built (module or built-in), start the
server:
> /etc/init.d/nfs start
$ /etc/init.d/nfs start
or
> service nfs start
$ service nfs start
Instruct the server to listen on the RDMA transport:
> echo rdma 2050 > /proc/fs/nfsd/portlist
$ echo rdma 2050 > /proc/fs/nfsd/portlist
- On the client system
If the NFS/RDMA client was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in kernel config),
load the RDMA client module:
If the NFS/RDMA client was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in
kernel config), load the RDMA client module:
> modprobe xprtrdma.ko
$ modprobe xprtrdma.ko
Regardless of how the client was built (module or built-in), issue the mount.nfs command:
Regardless of how the client was built (module or built-in), use this
command to mount the NFS/RDMA server:
> /path/to/your/mount.nfs <IPoIB-server-name-or-address>:/<export> /mnt -i -o rdma,port=2050
$ mount -o rdma,port=2050 <IPoIB-server-name-or-address>:/<export> /mnt
To verify that the mount is using RDMA, run "cat /proc/mounts" and check the
"proto" field for the given mount.
To verify that the mount is using RDMA, run "cat /proc/mounts" and check
the "proto" field for the given mount.
Congratulations! You're using NFS/RDMA!

106
Documentation/filesystems/omfs.txt 100644
View File

@ -0,0 +1,106 @@
Optimized MPEG Filesystem (OMFS)
Overview
========
OMFS is a filesystem created by SonicBlue for use in the ReplayTV DVR
and Rio Karma MP3 player. The filesystem is extent-based, utilizing
block sizes from 2k to 8k, with hash-based directories. This
filesystem driver may be used to read and write disks from these
devices.
Note, it is not recommended that this FS be used in place of a general
filesystem for your own streaming media device. Native Linux filesystems
will likely perform better.
More information is available at:
http://linux-karma.sf.net/
Various utilities, including mkomfs and omfsck, are included with
omfsprogs, available at:
http://bobcopeland.com/karma/
Instructions are included in its README.
Options
=======
OMFS supports the following mount-time options:
uid=n - make all files owned by specified user
gid=n - make all files owned by specified group
umask=xxx - set permission umask to xxx
fmask=xxx - set umask to xxx for files
dmask=xxx - set umask to xxx for directories
Disk format
===========
OMFS discriminates between "sysblocks" and normal data blocks. The sysblock
group consists of super block information, file metadata, directory structures,
and extents. Each sysblock has a header containing CRCs of the entire
sysblock, and may be mirrored in successive blocks on the disk. A sysblock may
have a smaller size than a data block, but since they are both addressed by the
same 64-bit block number, any remaining space in the smaller sysblock is
unused.
Sysblock header information:
struct omfs_header {
__be64 h_self; /* FS block where this is located */
__be32 h_body_size; /* size of useful data after header */
__be16 h_crc; /* crc-ccitt of body_size bytes */
char h_fill1[2];
u8 h_version; /* version, always 1 */
char h_type; /* OMFS_INODE_X */
u8 h_magic; /* OMFS_IMAGIC */
u8 h_check_xor; /* XOR of header bytes before this */
__be32 h_fill2;
};
Files and directories are both represented by omfs_inode:
struct omfs_inode {
struct omfs_header i_head; /* header */
__be64 i_parent; /* parent containing this inode */
__be64 i_sibling; /* next inode in hash bucket */
__be64 i_ctime; /* ctime, in milliseconds */
char i_fill1[35];
char i_type; /* OMFS_[DIR,FILE] */
__be32 i_fill2;
char i_fill3[64];
char i_name[OMFS_NAMELEN]; /* filename */
__be64 i_size; /* size of file, in bytes */
};
Directories in OMFS are implemented as a large hash table. Filenames are
hashed then prepended into the bucket list beginning at OMFS_DIR_START.
Lookup requires hashing the filename, then seeking across i_sibling pointers
until a match is found on i_name. Empty buckets are represented by block
pointers with all-1s (~0).
A file is an omfs_inode structure followed by an extent table beginning at
OMFS_EXTENT_START:
struct omfs_extent_entry {
__be64 e_cluster; /* start location of a set of blocks */
__be64 e_blocks; /* number of blocks after e_cluster */
};
struct omfs_extent {
__be64 e_next; /* next extent table location */
__be32 e_extent_count; /* total # extents in this table */
__be32 e_fill;
struct omfs_extent_entry e_entry; /* start of extent entries */
};
Each extent holds the block offset followed by number of blocks allocated to
the extent. The final extent in each table is a terminator with e_cluster
being ~0 and e_blocks being ones'-complement of the total number of blocks
in the table.
If this table overflows, a continuation inode is written and pointed to by
e_next. These have a header but lack the rest of the inode structure.

77
Documentation/filesystems/proc.txt
View File

@ -296,6 +296,7 @@ Table 1-4: Kernel info in /proc
uptime System uptime
version Kernel version
video bttv info of video resources (2.4)
vmallocinfo Show vmalloced areas
..............................................................................
You can, for example, check which interrupts are currently in use and what
@ -380,28 +381,35 @@ i386 and x86_64 platforms support the new IRQ vector displays.
Of some interest is the introduction of the /proc/irq directory to 2.4.
It could be used to set IRQ to CPU affinity, this means that you can "hook" an
IRQ to only one CPU, or to exclude a CPU of handling IRQs. The contents of the
irq subdir is one subdir for each IRQ, and one file; prof_cpu_mask
irq subdir is one subdir for each IRQ, and two files; default_smp_affinity and
prof_cpu_mask.
For example
> ls /proc/irq/
0 10 12 14 16 18 2 4 6 8 prof_cpu_mask
1 11 13 15 17 19 3 5 7 9
1 11 13 15 17 19 3 5 7 9 default_smp_affinity
> ls /proc/irq/0/
smp_affinity
The contents of the prof_cpu_mask file and each smp_affinity file for each IRQ
is the same by default:
smp_affinity is a bitmask, in which you can specify which CPUs can handle the
IRQ, you can set it by doing:
> cat /proc/irq/0/smp_affinity
> echo 1 > /proc/irq/10/smp_affinity
This means that only the first CPU will handle the IRQ, but you can also echo
5 which means that only the first and fourth CPU can handle the IRQ.
The contents of each smp_affinity file is the same by default:
> cat /proc/irq/0/smp_affinity
ffffffff
It's a bitmask, in which you can specify which CPUs can handle the IRQ, you can
set it by doing:
The default_smp_affinity mask applies to all non-active IRQs, which are the
IRQs which have not yet been allocated/activated, and hence which lack a
/proc/irq/[0-9]* directory.
> echo 1 > /proc/irq/prof_cpu_mask
This means that only the first CPU will handle the IRQ, but you can also echo 5
which means that only the first and fourth CPU can handle the IRQ.
prof_cpu_mask specifies which CPUs are to be profiled by the system wide
profiler. Default value is ffffffff (all cpus).
The way IRQs are routed is handled by the IO-APIC, and it's Round Robin
between all the CPUs which are allowed to handle it. As usual the kernel has
@ -550,6 +558,49 @@ VmallocTotal: total size of vmalloc memory area
VmallocUsed: amount of vmalloc area which is used
VmallocChunk: largest contigious block of vmalloc area which is free
..............................................................................
vmallocinfo:
Provides information about vmalloced/vmaped areas. One line per area,
containing the virtual address range of the area, size in bytes,
caller information of the creator, and optional information depending
on the kind of area :
pages=nr number of pages
phys=addr if a physical address was specified
ioremap I/O mapping (ioremap() and friends)
vmalloc vmalloc() area
vmap vmap()ed pages
user VM_USERMAP area
vpages buffer for pages pointers was vmalloced (huge area)
N<node>=nr (Only on NUMA kernels)
Number of pages allocated on memory node <node>
> cat /proc/vmallocinfo
0xffffc20000000000-0xffffc20000201000 2101248 alloc_large_system_hash+0x204 ...
/0x2c0 pages=512 vmalloc N0=128 N1=128 N2=128 N3=128
0xffffc20000201000-0xffffc20000302000 1052672 alloc_large_system_hash+0x204 ...
/0x2c0 pages=256 vmalloc N0=64 N1=64 N2=64 N3=64
0xffffc20000302000-0xffffc20000304000 8192 acpi_tb_verify_table+0x21/0x4f...
phys=7fee8000 ioremap
0xffffc20000304000-0xffffc20000307000 12288 acpi_tb_verify_table+0x21/0x4f...
phys=7fee7000 ioremap
0xffffc2000031d000-0xffffc2000031f000 8192 init_vdso_vars+0x112/0x210
0xffffc2000031f000-0xffffc2000032b000 49152 cramfs_uncompress_init+0x2e ...
/0x80 pages=11 vmalloc N0=3 N1=3 N2=2 N3=3
0xffffc2000033a000-0xffffc2000033d000 12288 sys_swapon+0x640/0xac0 ...
pages=2 vmalloc N1=2
0xffffc20000347000-0xffffc2000034c000 20480 xt_alloc_table_info+0xfe ...
/0x130 [x_tables] pages=4 vmalloc N0=4
0xffffffffa0000000-0xffffffffa000f000 61440 sys_init_module+0xc27/0x1d00 ...
pages=14 vmalloc N2=14
0xffffffffa000f000-0xffffffffa0014000 20480 sys_init_module+0xc27/0x1d00 ...
pages=4 vmalloc N1=4
0xffffffffa0014000-0xffffffffa0017000 12288 sys_init_module+0xc27/0x1d00 ...
pages=2 vmalloc N1=2
0xffffffffa0017000-0xffffffffa0022000 45056 sys_init_module+0xc27/0x1d00 ...
pages=10 vmalloc N0=10
1.3 IDE devices in /proc/ide
----------------------------
@ -880,7 +931,7 @@ group_prealloc max_to_scan mb_groups mb_history min_to_scan order2_req
stats stream_req
mb_groups:
This file gives the details of mutiblock allocator buddy cache of free blocks
This file gives the details of multiblock allocator buddy cache of free blocks
mb_history:
Multiblock allocation history.
@ -1423,7 +1474,7 @@ used because pages_free(1355) is smaller than watermark + protection[2]
normal page requirement. If requirement is DMA zone(index=0), protection[0]
(=0) is used.
zone[i]'s protection[j] is calculated by following exprssion.
zone[i]'s protection[j] is calculated by following expression.
(i < j):
zone[i]->protection[j]

10
Documentation/filesystems/relay.txt
View File

@ -294,6 +294,16 @@ user-defined data with a channel, and is immediately available
(including in create_buf_file()) via chan->private_data or
buf->chan->private_data.
Buffer-only channels
--------------------
These channels have no files associated and can be created with
relay_open(NULL, NULL, ...). Such channels are useful in scenarios such
as when doing early tracing in the kernel, before the VFS is up. In these
cases, one may open a buffer-only channel and then call
relay_late_setup_files() when the kernel is ready to handle files,
to expose the buffered data to the userspace.
Channel 'modes'
---------------

1
Documentation/filesystems/sysfs-pci.txt
View File

@ -36,6 +36,7 @@ files, each with their own function.
local_cpus nearby CPU mask (cpumask, ro)
resource PCI resource host addresses (ascii, ro)
resource0..N PCI resource N, if present (binary, mmap)
resource0_wc..N_wc PCI WC map resource N, if prefetchable (binary, mmap)
rom PCI ROM resource, if present (binary, ro)
subsystem_device PCI subsystem device (ascii, ro)
subsystem_vendor PCI subsystem vendor (ascii, ro)

6
Documentation/filesystems/sysfs.txt
View File

@ -248,6 +248,7 @@ The top level sysfs directory looks like:
block/
bus/
class/
dev/
devices/
firmware/
net/
@ -274,6 +275,11 @@ fs/ contains a directory for some filesystems. Currently each
filesystem wanting to export attributes must create its own hierarchy
below fs/ (see ./fuse.txt for an example).
dev/ contains two directories char/ and block/. Inside these two
directories there are symlinks named <major>:<minor>. These symlinks
point to the sysfs directory for the given device. /sys/dev provides a
quick way to lookup the sysfs interface for a device from the result of
a stat(2) operation.
More information can driver-model specific features can be found in
Documentation/driver-model/.

164
Documentation/filesystems/ubifs.txt 100644
View File

@ -0,0 +1,164 @@
Introduction
=============
UBIFS file-system stands for UBI File System. UBI stands for "Unsorted
Block Images". UBIFS is a flash file system, which means it is designed
to work with flash devices. It is important to understand, that UBIFS
is completely different to any traditional file-system in Linux, like
Ext2, XFS, JFS, etc. UBIFS represents a separate class of file-systems
which work with MTD devices, not block devices. The other Linux
file-system of this class is JFFS2.
To make it more clear, here is a small comparison of MTD devices and
block devices.
1 MTD devices represent flash devices and they consist of eraseblocks of
rather large size, typically about 128KiB. Block devices consist of
small blocks, typically 512 bytes.
2 MTD devices support 3 main operations - read from some offset within an
eraseblock, write to some offset within an eraseblock, and erase a whole
eraseblock. Block devices support 2 main operations - read a whole
block and write a whole block.
3 The whole eraseblock has to be erased before it becomes possible to
re-write its contents. Blocks may be just re-written.
4 Eraseblocks become worn out after some number of erase cycles -
typically 100K-1G for SLC NAND and NOR flashes, and 1K-10K for MLC
NAND flashes. Blocks do not have the wear-out property.
5 Eraseblocks may become bad (only on NAND flashes) and software should
deal with this. Blocks on hard drives typically do not become bad,
because hardware has mechanisms to substitute bad blocks, at least in
modern LBA disks.
It should be quite obvious why UBIFS is very different to traditional
file-systems.
UBIFS works on top of UBI. UBI is a separate software layer which may be
found in drivers/mtd/ubi. UBI is basically a volume management and
wear-leveling layer. It provides so called UBI volumes which is a higher
level abstraction than a MTD device. The programming model of UBI devices
is very similar to MTD devices - they still consist of large eraseblocks,
they have read/write/erase operations, but UBI devices are devoid of
limitations like wear and bad blocks (items 4 and 5 in the above list).
In a sense, UBIFS is a next generation of JFFS2 file-system, but it is
very different and incompatible to JFFS2. The following are the main
differences.
* JFFS2 works on top of MTD devices, UBIFS depends on UBI and works on
top of UBI volumes.
* JFFS2 does not have on-media index and has to build it while mounting,
which requires full media scan. UBIFS maintains the FS indexing
information on the flash media and does not require full media scan,
so it mounts many times faster than JFFS2.
* JFFS2 is a write-through file-system, while UBIFS supports write-back,
which makes UBIFS much faster on writes.
Similarly to JFFS2, UBIFS supports on-the-flight compression which makes
it possible to fit quite a lot of data to the flash.
Similarly to JFFS2, UBIFS is tolerant of unclean reboots and power-cuts.
It does not need stuff like ckfs.ext2. UBIFS automatically replays its
journal and recovers from crashes, ensuring that the on-flash data
structures are consistent.
UBIFS scales logarithmically (most of the data structures it uses are
trees), so the mount time and memory consumption do not linearly depend
on the flash size, like in case of JFFS2. This is because UBIFS
maintains the FS index on the flash media. However, UBIFS depends on
UBI, which scales linearly. So overall UBI/UBIFS stack scales linearly.
Nevertheless, UBI/UBIFS scales considerably better than JFFS2.
The authors of UBIFS believe, that it is possible to develop UBI2 which
would scale logarithmically as well. UBI2 would support the same API as UBI,
but it would be binary incompatible to UBI. So UBIFS would not need to be
changed to use UBI2
Mount options
=============
(*) == default.
norm_unmount (*) commit on unmount; the journal is committed
when the file-system is unmounted so that the
next mount does not have to replay the journal
and it becomes very fast;
fast_unmount do not commit on unmount; this option makes
unmount faster, but the next mount slower
because of the need to replay the journal.
Quick usage instructions
========================
The UBI volume to mount is specified using "ubiX_Y" or "ubiX:NAME" syntax,
where "X" is UBI device number, "Y" is UBI volume number, and "NAME" is
UBI volume name.
Mount volume 0 on UBI device 0 to /mnt/ubifs:
$ mount -t ubifs ubi0_0 /mnt/ubifs
Mount "rootfs" volume of UBI device 0 to /mnt/ubifs ("rootfs" is volume
name):
$ mount -t ubifs ubi0:rootfs /mnt/ubifs
The following is an example of the kernel boot arguments to attach mtd0
to UBI and mount volume "rootfs":
ubi.mtd=0 root=ubi0:rootfs rootfstype=ubifs
Module Parameters for Debugging
===============================
When UBIFS has been compiled with debugging enabled, there are 3 module
parameters that are available to control aspects of testing and debugging.
The parameters are unsigned integers where each bit controls an option.
The parameters are:
debug_msgs Selects which debug messages to display, as follows:
Message Type Flag value
General messages 1
Journal messages 2
Mount messages 4
Commit messages 8
LEB search messages 16
Budgeting messages 32
Garbage collection messages 64
Tree Node Cache (TNC) messages 128
LEB properties (lprops) messages 256
Input/output messages 512
Log messages 1024
Scan messages 2048
Recovery messages 4096
debug_chks Selects extra checks that UBIFS can do while running:
Check Flag value
General checks 1
Check Tree Node Cache (TNC) 2
Check indexing tree size 4
Check orphan area 8
Check old indexing tree 16
Check LEB properties (lprops) 32
Check leaf nodes and inodes 64
debug_tsts Selects a mode of testing, as follows:
Test mode Flag value
Force in-the-gaps method 2
Failure mode for recovery testing 4
For example, set debug_msgs to 5 to display General messages and Mount
messages.
References
==========
UBIFS documentation and FAQ/HOWTO at the MTD web site:
http://www.linux-mtd.infradead.org/doc/ubifs.html
http://www.linux-mtd.infradead.org/faq/ubifs.html

8
Documentation/filesystems/vfat.txt
View File

@ -96,6 +96,14 @@ shortname=lower|win95|winnt|mixed
emulate the Windows 95 rule for create.
Default setting is `lower'.
tz=UTC -- Interpret timestamps as UTC rather than local time.
This option disables the conversion of timestamps
between local time (as used by Windows on FAT) and UTC
(which Linux uses internally). This is particuluarly
useful when mounting devices (like digital cameras)
that are set to UTC in order to avoid the pitfalls of
local time.
<bool>: 0,1,yes,no,true,false
TODO

10
Documentation/filesystems/vfs.txt
View File

@ -143,7 +143,7 @@ struct file_system_type {
The get_sb() method has the following arguments:
struct file_system_type *fs_type: decribes the filesystem, partly initialized
struct file_system_type *fs_type: describes the filesystem, partly initialized
by the specific filesystem code
int flags: mount flags
@ -205,7 +205,6 @@ struct super_operations {
void (*dirty_inode) (struct inode *);
int (*write_inode) (struct inode *, int);
void (*put_inode) (struct inode *);
void (*drop_inode) (struct inode *);
void (*delete_inode) (struct inode *);
void (*put_super) (struct super_block *);
@ -246,9 +245,6 @@ or bottom half).
inode to disc. The second parameter indicates whether the write
should be synchronous or not, not all filesystems check this flag.
put_inode: called when the VFS inode is removed from the inode
cache.
drop_inode: called when the last access to the inode is dropped,
with the inode_lock spinlock held.
@ -899,9 +895,9 @@ struct dentry_operations {
iput() yourself
d_dname: called when the pathname of a dentry should be generated.
Usefull for some pseudo filesystems (sockfs, pipefs, ...) to delay
Useful for some pseudo filesystems (sockfs, pipefs, ...) to delay
pathname generation. (Instead of doing it when dentry is created,
its done only when the path is needed.). Real filesystems probably
it's done only when the path is needed.). Real filesystems probably
dont want to use it, because their dentries are present in global
dcache hash, so their hash should be an invariant. As no lock is
held, d_dname() should not try to modify the dentry itself, unless

1360
Documentation/ftrace.txt 100644
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135
Documentation/gpio.txt
View File

@ -347,15 +347,12 @@ necessarily be nonportable.
Dynamic definition of GPIOs is not currently standard; for example, as
a side effect of configuring an add-on board with some GPIO expanders.
These calls are purely for kernel space, but a userspace API could be built
on top of them.
GPIO implementor's framework (OPTIONAL)
=======================================
As noted earlier, there is an optional implementation framework making it
easier for platforms to support different kinds of GPIO controller using
the same programming interface.
the same programming interface. This framework is called "gpiolib".
As a debugging aid, if debugfs is available a /sys/kernel/debug/gpio file
will be found there. That will list all the controllers registered through
@ -392,11 +389,21 @@ either NULL or the label associated with that GPIO when it was requested.
Platform Support
----------------
To support this framework, a platform's Kconfig will "select HAVE_GPIO_LIB"
To support this framework, a platform's Kconfig will "select" either
ARCH_REQUIRE_GPIOLIB or ARCH_WANT_OPTIONAL_GPIOLIB
and arrange that its <asm/gpio.h> includes <asm-generic/gpio.h> and defines
three functions: gpio_get_value(), gpio_set_value(), and gpio_cansleep().
They may also want to provide a custom value for ARCH_NR_GPIOS.
ARCH_REQUIRE_GPIOLIB means that the gpio-lib code will always get compiled
into the kernel on that architecture.
ARCH_WANT_OPTIONAL_GPIOLIB means the gpio-lib code defaults to off and the user
can enable it and build it into the kernel optionally.
If neither of these options are selected, the platform does not support
GPIOs through GPIO-lib and the code cannot be enabled by the user.
Trivial implementations of those functions can directly use framework
code, which always dispatches through the gpio_chip:
@ -439,4 +446,120 @@ becomes available. That may mean the device should not be registered until
calls for that GPIO can work. One way to address such dependencies is for
such gpio_chip controllers to provide setup() and teardown() callbacks to
board specific code; those board specific callbacks would register devices
once all the necessary resources are available.
once all the necessary resources are available, and remove them later when
the GPIO controller device becomes unavailable.
Sysfs Interface for Userspace (OPTIONAL)
========================================
Platforms which use the "gpiolib" implementors framework may choose to
configure a sysfs user interface to GPIOs. This is different from the
debugfs interface, since it provides control over GPIO direction and
value instead of just showing a gpio state summary. Plus, it could be
present on production systems without debugging support.
Given approprate hardware documentation for the system, userspace could
know for example that GPIO #23 controls the write protect line used to
protect boot loader segments in flash memory. System upgrade procedures
may need to temporarily remove that protection, first importing a GPIO,
then changing its output state, then updating the code before re-enabling
the write protection. In normal use, GPIO #23 would never be touched,
and the kernel would have no need to know about it.
Again depending on appropriate hardware documentation, on some systems
userspace GPIO can be used to determine system configuration data that
standard kernels won't know about. And for some tasks, simple userspace
GPIO drivers could be all that the system really needs.
Note that standard kernel drivers exist for common "LEDs and Buttons"
GPIO tasks: "leds-gpio" and "gpio_keys", respectively. Use those
instead of talking directly to the GPIOs; they integrate with kernel
frameworks better than your userspace code could.
Paths in Sysfs
--------------
There are three kinds of entry in /sys/class/gpio:
- Control interfaces used to get userspace control over GPIOs;
- GPIOs themselves; and
- GPIO controllers ("gpio_chip" instances).
That's in addition to standard files including the "device" symlink.
The control interfaces are write-only:
/sys/class/gpio/
"export" ... Userspace may ask the kernel to export control of
a GPIO to userspace by writing its number to this file.
Example: "echo 19 > export" will create a "gpio19" node
for GPIO #19, if that's not requested by kernel code.
"unexport" ... Reverses the effect of exporting to userspace.
Example: "echo 19 > unexport" will remove a "gpio19"
node exported using the "export" file.
GPIO signals have paths like /sys/class/gpio/gpio42/ (for GPIO #42)
and have the following read/write attributes:
/sys/class/gpio/gpioN/
"direction" ... reads as either "in" or "out". This value may
normally be written. Writing as "out" defaults to
initializing the value as low. To ensure glitch free
operation, values "low" and "high" may be written to
configure the GPIO as an output with that initial value.
Note that this attribute *will not exist* if the kernel
doesn't support changing the direction of a GPIO, or
it was exported by kernel code that didn't explicitly
allow userspace to reconfigure this GPIO's direction.
"value" ... reads as either 0 (low) or 1 (high). If the GPIO
is configured as an output, this value may be written;
any nonzero value is treated as high.
GPIO controllers have paths like /sys/class/gpio/chipchip42/ (for the
controller implementing GPIOs starting at #42) and have the following
read-only attributes:
/sys/class/gpio/gpiochipN/
"base" ... same as N, the first GPIO managed by this chip
"label" ... provided for diagnostics (not always unique)
"ngpio" ... how many GPIOs this manges (N to N + ngpio - 1)
Board documentation should in most cases cover what GPIOs are used for
what purposes. However, those numbers are not always stable; GPIOs on
a daughtercard might be different depending on the base board being used,
or other cards in the stack. In such cases, you may need to use the
gpiochip nodes (possibly in conjunction with schematics) to determine
the correct GPIO number to use for a given signal.
Exporting from Kernel code
--------------------------
Kernel code can explicitly manage exports of GPIOs which have already been
requested using gpio_request():
/* export the GPIO to userspace */
int gpio_export(unsigned gpio, bool direction_may_change);
/* reverse gpio_export() */
void gpio_unexport();
After a kernel driver requests a GPIO, it may only be made available in
the sysfs interface by gpio_export(). The driver can control whether the
signal direction may change. This helps drivers prevent userspace code
from accidentally clobbering important system state.
This explicit exporting can help with debugging (by making some kinds
of experiments easier), or can provide an always-there interface that's
suitable for documenting as part of a board support package.

3
Documentation/hwmon/adt7473
View File

@ -69,7 +69,8 @@ point2: Set the pwm speed at a higher temperature bound.
The ADT7473 will scale the pwm between the lower and higher pwm speed when
the temperature is between the two temperature boundaries. PWM values range
from 0 (off) to 255 (full speed).
from 0 (off) to 255 (full speed). Fan speed will be set to maximum when the
temperature sensor associated with the PWM control exceeds temp#_max.
Notes
-----

37
Documentation/hwmon/ibmaem 100644
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@ -0,0 +1,37 @@
Kernel driver ibmaem
======================
Supported systems:
* Any recent IBM System X server with Active Energy Manager support.
This includes the x3350, x3550, x3650, x3655, x3755, x3850 M2,
x3950 M2, and certain HS2x/LS2x/QS2x blades. The IPMI host interface
driver ("ipmi-si") needs to be loaded for this driver to do anything.
Prefix: 'ibmaem'
Datasheet: Not available
Author: Darrick J. Wong
Description
-----------
This driver implements sensor reading support for the energy and power
meters available on various IBM System X hardware through the BMC. All
sensor banks will be exported as platform devices; this driver can talk
to both v1 and v2 interfaces. This driver is completely separate from the
older ibmpex driver.
The v1 AEM interface has a simple set of features to monitor energy use.
There is a register that displays an estimate of raw energy consumption
since the last BMC reset, and a power sensor that returns average power
use over a configurable interval.
The v2 AEM interface is a bit more sophisticated, being able to present
a wider range of energy and power use registers, the power cap as
set by the AEM software, and temperature sensors.
Special Features
----------------
The "power_cap" value displays the current system power cap, as set by
the Active Energy Manager software. Setting the power cap from the host
is not currently supported.

33
Documentation/hwmon/sysfs-interface
View File

@ -2,17 +2,12 @@ Naming and data format standards for sysfs files
------------------------------------------------
The libsensors library offers an interface to the raw sensors data
through the sysfs interface. See libsensors documentation and source for
further information. As of writing this document, libsensors
(from lm_sensors 2.8.3) is heavily chip-dependent. Adding or updating
support for any given chip requires modifying the library's code.
This is because libsensors was written for the procfs interface
older kernel modules were using, which wasn't standardized enough.
Recent versions of libsensors (from lm_sensors 2.8.2 and later) have
support for the sysfs interface, though.
The new sysfs interface was designed to be as chip-independent as
possible.
through the sysfs interface. Since lm-sensors 3.0.0, libsensors is
completely chip-independent. It assumes that all the kernel drivers
implement the standard sysfs interface described in this document.
This makes adding or updating support for any given chip very easy, as
libsensors, and applications using it, do not need to be modified.
This is a major improvement compared to lm-sensors 2.
Note that motherboards vary widely in the connections to sensor chips.
There is no standard that ensures, for example, that the second
@ -35,19 +30,17 @@ access this data in a simple and consistent way. That said, such programs
will have to implement conversion, labeling and hiding of inputs. For
this reason, it is still not recommended to bypass the library.
If you are developing a userspace application please send us feedback on
this standard.
Note that this standard isn't completely established yet, so it is subject
to changes. If you are writing a new hardware monitoring driver those
features can't seem to fit in this interface, please contact us with your
extension proposal. Keep in mind that backward compatibility must be
preserved.
Each chip gets its own directory in the sysfs /sys/devices tree. To
find all sensor chips, it is easier to follow the device symlinks from
/sys/class/hwmon/hwmon*.
Up to lm-sensors 3.0.0, libsensors looks for hardware monitoring attributes
in the "physical" device directory. Since lm-sensors 3.0.1, attributes found
in the hwmon "class" device directory are also supported. Complex drivers
(e.g. drivers for multifunction chips) may want to use this possibility to
avoid namespace pollution. The only drawback will be that older versions of
libsensors won't support the driver in question.
All sysfs values are fixed point numbers.
There is only one value per file, unlike the older /proc specification.

47
Documentation/i2c/busses/i2c-i810
View File

@ -1,47 +0,0 @@
Kernel driver i2c-i810
Supported adapters:
* Intel 82810, 82810-DC100, 82810E, and 82815 (GMCH)
* Intel 82845G (GMCH)
Authors:
Frodo Looijaard <frodol@dds.nl>,
Philip Edelbrock <phil@netroedge.com>,
Kyösti Mälkki <kmalkki@cc.hut.fi>,
Ralph Metzler <rjkm@thp.uni-koeln.de>,
Mark D. Studebaker <mdsxyz123@yahoo.com>
Main contact: Mark Studebaker <mdsxyz123@yahoo.com>
Description
-----------
WARNING: If you have an '810' or '815' motherboard, your standard I2C
temperature sensors are most likely on the 801's I2C bus. You want the
i2c-i801 driver for those, not this driver.
Now for the i2c-i810...
The GMCH chip contains two I2C interfaces.
The first interface is used for DDC (Data Display Channel) which is a
serial channel through the VGA monitor connector to a DDC-compliant
monitor. This interface is defined by the Video Electronics Standards
Association (VESA). The standards are available for purchase at
http://www.vesa.org .
The second interface is a general-purpose I2C bus. It may be connected to a
TV-out chip such as the BT869 or possibly to a digital flat-panel display.
Features
--------
Both busses use the i2c-algo-bit driver for 'bit banging'
and support for specific transactions is provided by i2c-algo-bit.
Issues
------
If you enable bus testing in i2c-algo-bit (insmod i2c-algo-bit bit_test=1),
the test may fail; if so, the i2c-i810 driver won't be inserted. However,
we think this has been fixed.

23
Documentation/i2c/busses/i2c-prosavage
View File

@ -1,23 +0,0 @@
Kernel driver i2c-prosavage
Supported adapters:
S3/VIA KM266/VT8375 aka ProSavage8
S3/VIA KM133/VT8365 aka Savage4
Author: Henk Vergonet <henk@god.dyndns.org>
Description
-----------
The Savage4 chips contain two I2C interfaces (aka a I2C 'master' or
'host').
The first interface is used for DDC (Data Display Channel) which is a
serial channel through the VGA monitor connector to a DDC-compliant
monitor. This interface is defined by the Video Electronics Standards
Association (VESA). The standards are available for purchase at
http://www.vesa.org . The second interface is a general-purpose I2C bus.
Usefull for gaining access to the TV Encoder chips.

26
Documentation/i2c/busses/i2c-savage4
View File

@ -1,26 +0,0 @@
Kernel driver i2c-savage4
Supported adapters:
* Savage4
* Savage2000
Authors:
Alexander Wold <awold@bigfoot.com>,
Mark D. Studebaker <mdsxyz123@yahoo.com>
Description
-----------
The Savage4 chips contain two I2C interfaces (aka a I2C 'master'
or 'host').
The first interface is used for DDC (Data Display Channel) which is a
serial channel through the VGA monitor connector to a DDC-compliant
monitor. This interface is defined by the Video Electronics Standards
Association (VESA). The standards are available for purchase at
http://www.vesa.org . The DDC bus is not yet supported because its register
is not directly memory-mapped.
The second interface is a general-purpose I2C bus. This is the only
interface supported by the driver at the moment.

2
Documentation/i2c/chips/max6875
View File

@ -49,7 +49,7 @@ $ modprobe max6875 force=0,0x50
The MAX6874/MAX6875 ignores address bit 0, so this driver attaches to multiple
addresses. For example, for address 0x50, it also reserves 0x51.
The even-address instance is called 'max6875', the odd one is 'max6875 subclient'.
The even-address instance is called 'max6875', the odd one is 'dummy'.
Programming the chip using i2c-dev

10
Documentation/i2c/chips/pca9539
View File

@ -7,7 +7,7 @@ drivers/gpio/pca9539.c instead.
Supported chips:
* Philips PCA9539
Prefix: 'pca9539'
Addresses scanned: 0x74 - 0x77
Addresses scanned: none
Datasheet:
http://www.semiconductors.philips.com/acrobat/datasheets/PCA9539_2.pdf
@ -23,6 +23,14 @@ The input sense can also be inverted.
The 16 lines are split between two bytes.
Detection
---------
The PCA9539 is difficult to detect and not commonly found in PC machines,
so you have to pass the I2C bus and address of the installed PCA9539
devices explicitly to the driver at load time via the force=... parameter.
Sysfs entries
-------------

12
Documentation/i2c/chips/pcf8574
View File

@ -4,13 +4,13 @@ Kernel driver pcf8574
Supported chips:
* Philips PCF8574
Prefix: 'pcf8574'
Addresses scanned: I2C 0x20 - 0x27
Addresses scanned: none
Datasheet: Publicly available at the Philips Semiconductors website
http://www.semiconductors.philips.com/pip/PCF8574P.html
* Philips PCF8574A
Prefix: 'pcf8574a'
Addresses scanned: I2C 0x38 - 0x3f
Addresses scanned: none
Datasheet: Publicly available at the Philips Semiconductors website
http://www.semiconductors.philips.com/pip/PCF8574P.html
@ -38,12 +38,10 @@ For more informations see the datasheet.
Accessing PCF8574(A) via /sys interface
-------------------------------------
! Be careful !
The PCF8574(A) is plainly impossible to detect ! Stupid chip.
So every chip with address in the interval [20..27] and [38..3f] are
detected as PCF8574(A). If you have other chips in this address
range, the workaround is to load this module after the one
for your others chips.
So, you have to pass the I2C bus and address of the installed PCF857A
and PCF8574A devices explicitly to the driver at load time via the
force=... parameter.
On detection (i.e. insmod, modprobe et al.), directories are being
created for each detected PCF8574(A):

9
Documentation/i2c/chips/pcf8575
View File

@ -40,12 +40,9 @@ Detection
---------
There is no method known to detect whether a chip on a given I2C address is
a PCF8575 or whether it is any other I2C device. So there are two alternatives
to let the driver find the installed PCF8575 devices:
- Load this driver after any other I2C driver for I2C devices with addresses
in the range 0x20 .. 0x27.
- Pass the I2C bus and address of the installed PCF8575 devices explicitly to
the driver at load time via the probe=... or force=... parameters.
a PCF8575 or whether it is any other I2C device, so you have to pass the I2C
bus and address of the installed PCF8575 devices explicitly to the driver at
load time via the force=... parameter.
/sys interface
--------------

127
Documentation/i2c/fault-codes 100644
View File

@ -0,0 +1,127 @@
This is a summary of the most important conventions for use of fault
codes in the I2C/SMBus stack.
A "Fault" is not always an "Error"
----------------------------------
Not all fault reports imply errors; "page faults" should be a familiar
example. Software often retries idempotent operations after transient
faults. There may be fancier recovery schemes that are appropriate in
some cases, such as re-initializing (and maybe resetting). After such
recovery, triggered by a fault report, there is no error.
In a similar way, sometimes a "fault" code just reports one defined
result for an operation ... it doesn't indicate that anything is wrong
at all, just that the outcome wasn't on the "golden path".
In short, your I2C driver code may need to know these codes in order
to respond correctly. Other code may need to rely on YOUR code reporting
the right fault code, so that it can (in turn) behave correctly.
I2C and SMBus fault codes
-------------------------
These are returned as negative numbers from most calls, with zero or
some positive number indicating a non-fault return. The specific
numbers associated with these symbols differ between architectures,
though most Linux systems use <asm-generic/errno*.h> numbering.
Note that the descriptions here are not exhaustive. There are other
codes that may be returned, and other cases where these codes should
be returned. However, drivers should not return other codes for these
cases (unless the hardware doesn't provide unique fault reports).
Also, codes returned by adapter probe methods follow rules which are
specific to their host bus (such as PCI, or the platform bus).
EAGAIN
Returned by I2C adapters when they lose arbitration in master
transmit mode: some other master was transmitting different
data at the same time.
Also returned when trying to invoke an I2C operation in an
atomic context, when some task is already using that I2C bus
to execute some other operation.
EBADMSG
Returned by SMBus logic when an invalid Packet Error Code byte
is received. This code is a CRC covering all bytes in the
transaction, and is sent before the terminating STOP. This
fault is only reported on read transactions; the SMBus slave
may have a way to report PEC mismatches on writes from the
host. Note that even if PECs are in use, you should not rely
on these as the only way to detect incorrect data transfers.
EBUSY
Returned by SMBus adapters when the bus was busy for longer
than allowed. This usually indicates some device (maybe the
SMBus adapter) needs some fault recovery (such as resetting),
or that the reset was attempted but failed.
EINVAL
This rather vague error means an invalid parameter has been
detected before any I/O operation was started. Use a more
specific fault code when you can.
One example would be a driver trying an SMBus Block Write
with block size outside the range of 1-32 bytes.
EIO
This rather vague error means something went wrong when
performing an I/O operation. Use a more specific fault
code when you can.
ENODEV
Returned by driver probe() methods. This is a bit more
specific than ENXIO, implying the problem isn't with the
address, but with the device found there. Driver probes
may verify the device returns *correct* responses, and
return this as appropriate. (The driver core will warn
about probe faults other than ENXIO and ENODEV.)
ENOMEM
Returned by any component that can't allocate memory when
it needs to do so.
ENXIO
Returned by I2C adapters to indicate that the address phase
of a transfer didn't get an ACK. While it might just mean
an I2C device was temporarily not responding, usually it
means there's nothing listening at that address.
Returned by driver probe() methods to indicate that they
found no device to bind to. (ENODEV may also be used.)
EOPNOTSUPP
Returned by an adapter when asked to perform an operation
that it doesn't, or can't, support.
For example, this would be returned when an adapter that
doesn't support SMBus block transfers is asked to execute
one. In that case, the driver making that request should
have verified that functionality was supported before it
made that block transfer request.
Similarly, if an I2C adapter can't execute all legal I2C
messages, it should return this when asked to perform a
transaction it can't. (These limitations can't be seen in
the adapter's functionality mask, since the assumption is
that if an adapter supports I2C it supports all of I2C.)
EPROTO
Returned when slave does not conform to the relevant I2C
or SMBus (or chip-specific) protocol specifications. One
case is when the length of an SMBus block data response
(from the SMBus slave) is outside the range 1-32 bytes.
ETIMEDOUT
This is returned by drivers when an operation took too much
time, and was aborted before it completed.
SMBus adapters may return it when an operation took more
time than allowed by the SMBus specification; for example,
when a slave stretches clocks too far. I2C has no such
timeouts, but it's normal for I2C adapters to impose some
arbitrary limits (much longer than SMBus!) too.

99
Documentation/i2c/functionality
View File

@ -51,26 +51,38 @@ A few combinations of the above flags are also defined for your convenience:
the transparent emulation layer)
ALGORITHM/ADAPTER IMPLEMENTATION
--------------------------------
ADAPTER IMPLEMENTATION
----------------------
When you write a new algorithm driver, you will have to implement a
function callback `functionality', that gets an i2c_adapter structure
pointer as its only parameter:
When you write a new adapter driver, you will have to implement a
function callback `functionality'. Typical implementations are given
below.
struct i2c_algorithm {
/* Many other things of course; check <linux/i2c.h>! */
u32 (*functionality) (struct i2c_adapter *);
}
A typical SMBus-only adapter would list all the SMBus transactions it
supports. This example comes from the i2c-piix4 driver:
A typically implementation is given below, from i2c-algo-bit.c:
static u32 bit_func(struct i2c_adapter *adap)
static u32 piix4_func(struct i2c_adapter *adapter)
{
return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
I2C_FUNC_PROTOCOL_MANGLING;
return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_BLOCK_DATA;
}
A typical full-I2C adapter would use the following (from the i2c-pxa
driver):
static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
I2C_FUNC_SMBUS_EMUL includes all the SMBus transactions (with the
addition of I2C block transactions) which i2c-core can emulate using
I2C_FUNC_I2C without any help from the adapter driver. The idea is
to let the client drivers check for the support of SMBus functions
without having to care whether the said functions are implemented in
hardware by the adapter, or emulated in software by i2c-core on top
of an I2C adapter.
CLIENT CHECKING
@ -78,36 +90,33 @@ CLIENT CHECKING
Before a client tries to attach to an adapter, or even do tests to check
whether one of the devices it supports is present on an adapter, it should
check whether the needed functionality is present. There are two functions
defined which should be used instead of calling the functionality hook
in the algorithm structure directly:
check whether the needed functionality is present. The typical way to do
this is (from the lm75 driver):
/* Return the functionality mask */
extern u32 i2c_get_functionality (struct i2c_adapter *adap);
/* Return 1 if adapter supports everything we need, 0 if not. */
extern int i2c_check_functionality (struct i2c_adapter *adap, u32 func);
This is a typical way to use these functions (from the writing-clients
document):
int foo_detect_client(struct i2c_adapter *adapter, int address,
unsigned short flags, int kind)
static int lm75_detect(...)
{
/* Define needed variables */
/* As the very first action, we check whether the adapter has the
needed functionality: we need the SMBus read_word_data,
write_word_data and write_byte functions in this example. */
if (!i2c_check_functionality(adapter,I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_WRITE_BYTE))
goto ERROR0;
/* Now we can do the real detection */
ERROR0:
/* Return an error */
(...)
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA))
goto exit;
(...)
}
Here, the lm75 driver checks if the adapter can do both SMBus byte data
and SMBus word data transactions. If not, then the driver won't work on
this adapter and there's no point in going on. If the check above is
successful, then the driver knows that it can call the following
functions: i2c_smbus_read_byte_data(), i2c_smbus_write_byte_data(),
i2c_smbus_read_word_data() and i2c_smbus_write_word_data(). As a rule of
thumb, the functionality constants you test for with
i2c_check_functionality() should match exactly the i2c_smbus_* functions
which you driver is calling.
Note that the check above doesn't tell whether the functionalities are
implemented in hardware by the underlying adapter or emulated in
software by i2c-core. Client drivers don't have to care about this, as
i2c-core will transparently implement SMBus transactions on top of I2C
adapters.
CHECKING THROUGH /DEV
@ -116,19 +125,19 @@ CHECKING THROUGH /DEV
If you try to access an adapter from a userspace program, you will have
to use the /dev interface. You will still have to check whether the
functionality you need is supported, of course. This is done using
the I2C_FUNCS ioctl. An example, adapted from the lm_sensors i2cdetect
program, is below:
the I2C_FUNCS ioctl. An example, adapted from the i2cdetect program, is
below:
int file;
if (file = open("/dev/i2c-0",O_RDWR) < 0) {
if (file = open("/dev/i2c-0", O_RDWR) < 0) {
/* Some kind of error handling */
exit(1);
}
if (ioctl(file,I2C_FUNCS,&funcs) < 0) {
if (ioctl(file, I2C_FUNCS, &funcs) < 0) {
/* Some kind of error handling */
exit(1);
}
if (! (funcs & I2C_FUNC_SMBUS_QUICK)) {
if (!(funcs & I2C_FUNC_SMBUS_QUICK)) {
/* Oops, the needed functionality (SMBus write_quick function) is
not available! */
exit(1);

81
Documentation/i2c/smbus-protocol
View File

@ -1,5 +1,6 @@
SMBus Protocol Summary
======================
The following is a summary of the SMBus protocol. It applies to
all revisions of the protocol (1.0, 1.1, and 2.0).
Certain protocol features which are not supported by
@ -8,6 +9,7 @@ this package are briefly described at the end of this document.
Some adapters understand only the SMBus (System Management Bus) protocol,
which is a subset from the I2C protocol. Fortunately, many devices use
only the same subset, which makes it possible to put them on an SMBus.
If you write a driver for some I2C device, please try to use the SMBus
commands if at all possible (if the device uses only that subset of the
I2C protocol). This makes it possible to use the device driver on both
@ -15,7 +17,12 @@ SMBus adapters and I2C adapters (the SMBus command set is automatically
translated to I2C on I2C adapters, but plain I2C commands can not be
handled at all on most pure SMBus adapters).
Below is a list of SMBus commands.
Below is a list of SMBus protocol operations, and the functions executing
them. Note that the names used in the SMBus protocol specifications usually
don't match these function names. For some of the operations which pass a
single data byte, the functions using SMBus protocol operation names execute
a different protocol operation entirely.
Key to symbols
==============
@ -35,17 +42,16 @@ Count (8 bits): A data byte containing the length of a block operation.
[..]: Data sent by I2C device, as opposed to data sent by the host adapter.
SMBus Write Quick
=================
SMBus Quick Command
===================
This sends a single bit to the device, at the place of the Rd/Wr bit.
There is no equivalent Read Quick command.
A Addr Rd/Wr [A] P
SMBus Read Byte
===============
SMBus Receive Byte: i2c_smbus_read_byte()
==========================================
This reads a single byte from a device, without specifying a device
register. Some devices are so simple that this interface is enough; for
@ -55,17 +61,17 @@ the previous SMBus command.
S Addr Rd [A] [Data] NA P
SMBus Write Byte
================
SMBus Send Byte: i2c_smbus_write_byte()
========================================
This is the reverse of Read Byte: it sends a single byte to a device.
See Read Byte for more information.
This operation is the reverse of Receive Byte: it sends a single byte
to a device. See Receive Byte for more information.
S Addr Wr [A] Data [A] P
SMBus Read Byte Data
====================
SMBus Read Byte: i2c_smbus_read_byte_data()
============================================
This reads a single byte from a device, from a designated register.
The register is specified through the Comm byte.
@ -73,30 +79,30 @@ The register is specified through the Comm byte.
S Addr Wr [A] Comm [A] S Addr Rd [A] [Data] NA P
SMBus Read Word Data
====================
SMBus Read Word: i2c_smbus_read_word_data()
============================================
This command is very like Read Byte Data; again, data is read from a
This operation is very like Read Byte; again, data is read from a
device, from a designated register that is specified through the Comm
byte. But this time, the data is a complete word (16 bits).
S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
SMBus Write Byte Data
=====================
SMBus Write Byte: i2c_smbus_write_byte_data()
==============================================
This writes a single byte to a device, to a designated register. The
register is specified through the Comm byte. This is the opposite of
the Read Byte Data command.
the Read Byte operation.
S Addr Wr [A] Comm [A] Data [A] P
SMBus Write Word Data
=====================
SMBus Write Word: i2c_smbus_write_word_data()
==============================================
This is the opposite operation of the Read Word Data command. 16 bits
This is the opposite of the Read Word operation. 16 bits
of data is written to a device, to the designated register that is
specified through the Comm byte.
@ -113,8 +119,8 @@ S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A]
S Addr Rd [A] [DataLow] A [DataHigh] NA P
SMBus Block Read
================
SMBus Block Read: i2c_smbus_read_block_data()
==============================================
This command reads a block of up to 32 bytes from a device, from a
designated register that is specified through the Comm byte. The amount
@ -124,8 +130,8 @@ S Addr Wr [A] Comm [A]
S Addr Rd [A] [Count] A [Data] A [Data] A ... A [Data] NA P
SMBus Block Write
=================
SMBus Block Write: i2c_smbus_write_block_data()
================================================
The opposite of the Block Read command, this writes up to 32 bytes to
a device, to a designated register that is specified through the
@ -134,10 +140,11 @@ Comm byte. The amount of data is specified in the Count byte.
S Addr Wr [A] Comm [A] Count [A] Data [A] Data [A] ... [A] Data [A] P
SMBus Block Process Call
========================
SMBus Block Write - Block Read Process Call
===========================================
SMBus Block Process Call was introduced in Revision 2.0 of the specification.
SMBus Block Write - Block Read Process Call was introduced in
Revision 2.0 of the specification.
This command selects a device register (through the Comm byte), sends
1 to 31 bytes of data to it, and reads 1 to 31 bytes of data in return.
@ -159,13 +166,16 @@ alerting device's address.
Packet Error Checking (PEC)
===========================
Packet Error Checking was introduced in Revision 1.1 of the specification.
PEC adds a CRC-8 error-checking byte to all transfers.
PEC adds a CRC-8 error-checking byte to transfers using it, immediately
before the terminating STOP.
Address Resolution Protocol (ARP)
=================================
The Address Resolution Protocol was introduced in Revision 2.0 of
the specification. It is a higher-layer protocol which uses the
messages above.
@ -177,14 +187,17 @@ require PEC checksums.
I2C Block Transactions
======================
The following I2C block transactions are supported by the
SMBus layer and are described here for completeness.
They are *NOT* defined by the SMBus specification.
I2C block transactions do not limit the number of bytes transferred
but the SMBus layer places a limit of 32 bytes.
I2C Block Read
==============
I2C Block Read: i2c_smbus_read_i2c_block_data()
================================================
This command reads a block of bytes from a device, from a
designated register that is specified through the Comm byte.
@ -203,8 +216,8 @@ S Addr Wr [A] Comm1 [A] Comm2 [A]
S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P
I2C Block Write
===============
I2C Block Write: i2c_smbus_write_i2c_block_data()
==================================================
The opposite of the Block Read command, this writes bytes to
a device, to a designated register that is specified through the
@ -212,5 +225,3 @@ Comm byte. Note that command lengths of 0, 2, or more bytes are
supported as they are indistinguishable from data.
S Addr Wr [A] Comm [A] Data [A] Data [A] ... [A] Data [A] P

281
Documentation/i2c/upgrading-clients 100644
View File

@ -0,0 +1,281 @@
Upgrading I2C Drivers to the new 2.6 Driver Model
=================================================
Ben Dooks <ben-linux@fluff.org>
Introduction
------------
This guide outlines how to alter existing Linux 2.6 client drivers from
the old to the new new binding methods.
Example old-style driver
------------------------
struct example_state {
struct i2c_client client;
....
};
static struct i2c_driver example_driver;
static unsigned short ignore[] = { I2C_CLIENT_END };
static unsigned short normal_addr[] = { OUR_ADDR, I2C_CLIENT_END };
I2C_CLIENT_INSMOD;
static int example_attach(struct i2c_adapter *adap, int addr, int kind)
{
struct example_state *state;
struct device *dev = &adap->dev; /* to use for dev_ reports */
int ret;
state = kzalloc(sizeof(struct example_state), GFP_KERNEL);
if (state == NULL) {
dev_err(dev, "failed to create our state\n");
return -ENOMEM;
}
example->client.addr = addr;
example->client.flags = 0;
example->client.adapter = adap;
i2c_set_clientdata(&state->i2c_client, state);
strlcpy(client->i2c_client.name, "example", I2C_NAME_SIZE);
ret = i2c_attach_client(&state->i2c_client);
if (ret < 0) {
dev_err(dev, "failed to attach client\n");
kfree(state);
return ret;
}
dev = &state->i2c_client.dev;
/* rest of the initialisation goes here. */
dev_info(dev, "example client created\n");
return 0;
}
static int __devexit example_detach(struct i2c_client *client)
{
struct example_state *state = i2c_get_clientdata(client);
i2c_detach_client(client);
kfree(state);
return 0;
}
static int example_attach_adapter(struct i2c_adapter *adap)
{
return i2c_probe(adap, &addr_data, example_attach);
}
static struct i2c_driver example_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "example",
},
.attach_adapter = example_attach_adapter,
.detach_client = __devexit_p(example_detach),
.suspend = example_suspend,
.resume = example_resume,
};
Updating the client
-------------------
The new style binding model will check against a list of supported
devices and their associated address supplied by the code registering
the busses. This means that the driver .attach_adapter and
.detach_adapter methods can be removed, along with the addr_data,
as follows:
- static struct i2c_driver example_driver;
- static unsigned short ignore[] = { I2C_CLIENT_END };
- static unsigned short normal_addr[] = { OUR_ADDR, I2C_CLIENT_END };
- I2C_CLIENT_INSMOD;
- static int example_attach_adapter(struct i2c_adapter *adap)
- {
- return i2c_probe(adap, &addr_data, example_attach);
- }
static struct i2c_driver example_driver = {
- .attach_adapter = example_attach_adapter,
- .detach_client = __devexit_p(example_detach),
}
Add the probe and remove methods to the i2c_driver, as so:
static struct i2c_driver example_driver = {
+ .probe = example_probe,
+ .remove = __devexit_p(example_remove),
}
Change the example_attach method to accept the new parameters
which include the i2c_client that it will be working with:
- static int example_attach(struct i2c_adapter *adap, int addr, int kind)
+ static int example_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
Change the name of example_attach to example_probe to align it with the
i2c_driver entry names. The rest of the probe routine will now need to be
changed as the i2c_client has already been setup for use.
The necessary client fields have already been setup before
the probe function is called, so the following client setup
can be removed:
- example->client.addr = addr;
- example->client.flags = 0;
- example->client.adapter = adap;
-
- strlcpy(client->i2c_client.name, "example", I2C_NAME_SIZE);
The i2c_set_clientdata is now:
- i2c_set_clientdata(&state->client, state);
+ i2c_set_clientdata(client, state);
The call to i2c_attach_client is no longer needed, if the probe
routine exits successfully, then the driver will be automatically
attached by the core. Change the probe routine as so:
- ret = i2c_attach_client(&state->i2c_client);
- if (ret < 0) {
- dev_err(dev, "failed to attach client\n");
- kfree(state);
- return ret;
- }
Remove the storage of 'struct i2c_client' from the 'struct example_state'
as we are provided with the i2c_client in our example_probe. Instead we
store a pointer to it for when it is needed.
struct example_state {
- struct i2c_client client;
+ struct i2c_client *client;
the new i2c client as so:
- struct device *dev = &adap->dev; /* to use for dev_ reports */
+ struct device *dev = &i2c_client->dev; /* to use for dev_ reports */
And remove the change after our client is attached, as the driver no
longer needs to register a new client structure with the core:
- dev = &state->i2c_client.dev;
In the probe routine, ensure that the new state has the client stored
in it:
static int example_probe(struct i2c_client *i2c_client,
const struct i2c_device_id *id)
{
struct example_state *state;
struct device *dev = &i2c_client->dev;
int ret;
state = kzalloc(sizeof(struct example_state), GFP_KERNEL);
if (state == NULL) {
dev_err(dev, "failed to create our state\n");
return -ENOMEM;
}
+ state->client = i2c_client;
Update the detach method, by changing the name to _remove and
to delete the i2c_detach_client call. It is possible that you
can also remove the ret variable as it is not not needed for
any of the core functions.
- static int __devexit example_detach(struct i2c_client *client)
+ static int __devexit example_remove(struct i2c_client *client)
{
struct example_state *state = i2c_get_clientdata(client);
- i2c_detach_client(client);
And finally ensure that we have the correct ID table for the i2c-core
and other utilities:
+ struct i2c_device_id example_idtable[] = {
+ { "example", 0 },
+ { }
+};
+
+MODULE_DEVICE_TABLE(i2c, example_idtable);
static struct i2c_driver example_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "example",
},
+ .id_table = example_ids,
Our driver should now look like this:
struct example_state {
struct i2c_client *client;
....
};
static int example_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct example_state *state;
struct device *dev = &client->dev;
state = kzalloc(sizeof(struct example_state), GFP_KERNEL);
if (state == NULL) {
dev_err(dev, "failed to create our state\n");
return -ENOMEM;
}
state->client = client;
i2c_set_clientdata(client, state);
/* rest of the initialisation goes here. */
dev_info(dev, "example client created\n");
return 0;
}
static int __devexit example_remove(struct i2c_client *client)
{
struct example_state *state = i2c_get_clientdata(client);
kfree(state);
return 0;
}
static struct i2c_device_id example_idtable[] = {
{ "example", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, example_idtable);
static struct i2c_driver example_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "example",
},
.id_table = example_idtable,
.probe = example_probe,
.remove = __devexit_p(example_remove),
.suspend = example_suspend,
.resume = example_resume,
};

69
Documentation/i2c/writing-clients
View File

@ -25,14 +25,29 @@ routines, and should be zero-initialized except for fields with data you
provide. A client structure holds device-specific information like the
driver model device node, and its I2C address.
/* iff driver uses driver model ("new style") binding model: */
static struct i2c_device_id foo_idtable[] = {
{ "foo", my_id_for_foo },
{ "bar", my_id_for_bar },
{ }
};
MODULE_DEVICE_TABLE(i2c, foo_idtable);
static struct i2c_driver foo_driver = {
.driver = {
.name = "foo",
},
/* iff driver uses driver model ("new style") binding model: */
.id_table = foo_ids,
.probe = foo_probe,
.remove = foo_remove,
/* if device autodetection is needed: */
.class = I2C_CLASS_SOMETHING,
.detect = foo_detect,
.address_data = &addr_data,
/* else, driver uses "legacy" binding model: */
.attach_adapter = foo_attach_adapter,
@ -173,10 +188,9 @@ handle may be used during foo_probe(). If foo_probe() reports success
(zero not a negative status code) it may save the handle and use it until
foo_remove() returns. That binding model is used by most Linux drivers.
Drivers match devices when i2c_client.driver_name and the driver name are
the same; this approach is used in several other busses that don't have
device typing support in the hardware. The driver and module name should
match, so hotplug/coldplug mechanisms will modprobe the driver.
The probe function is called when an entry in the id_table name field
matches the device's name. It is passed the entry that was matched so
the driver knows which one in the table matched.
Device Creation (Standard driver model)
@ -207,6 +221,31 @@ in the I2C bus driver. You may want to save the returned i2c_client
reference for later use.
Device Detection (Standard driver model)
----------------------------------------
Sometimes you do not know in advance which I2C devices are connected to
a given I2C bus. This is for example the case of hardware monitoring
devices on a PC's SMBus. In that case, you may want to let your driver
detect supported devices automatically. This is how the legacy model
was working, and is now available as an extension to the standard
driver model (so that we can finally get rid of the legacy model.)
You simply have to define a detect callback which will attempt to
identify supported devices (returning 0 for supported ones and -ENODEV
for unsupported ones), a list of addresses to probe, and a device type
(or class) so that only I2C buses which may have that type of device
connected (and not otherwise enumerated) will be probed. The i2c
core will then call you back as needed and will instantiate a device
for you for every successful detection.
Note that this mechanism is purely optional and not suitable for all
devices. You need some reliable way to identify the supported devices
(typically using device-specific, dedicated identification registers),
otherwise misdetections are likely to occur and things can get wrong
quickly.
Device Deletion (Standard driver model)
---------------------------------------
@ -559,7 +598,6 @@ SMBus communication
in terms of it. Never use this function directly!
extern s32 i2c_smbus_write_quick(struct i2c_client * client, u8 value);
extern s32 i2c_smbus_read_byte(struct i2c_client * client);
extern s32 i2c_smbus_write_byte(struct i2c_client * client, u8 value);
extern s32 i2c_smbus_read_byte_data(struct i2c_client * client, u8 command);
@ -568,30 +606,31 @@ SMBus communication
extern s32 i2c_smbus_read_word_data(struct i2c_client * client, u8 command);
extern s32 i2c_smbus_write_word_data(struct i2c_client * client,
u8 command, u16 value);
extern s32 i2c_smbus_read_block_data(struct i2c_client * client,
u8 command, u8 *values);
extern s32 i2c_smbus_write_block_data(struct i2c_client * client,
u8 command, u8 length,
u8 *values);
extern s32 i2c_smbus_read_i2c_block_data(struct i2c_client * client,
u8 command, u8 length, u8 *values);
These ones were removed in Linux 2.6.10 because they had no users, but could
be added back later if needed:
extern s32 i2c_smbus_read_block_data(struct i2c_client * client,
u8 command, u8 *values);
extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client * client,
u8 command, u8 length,
u8 *values);
These ones were removed from i2c-core because they had no users, but could
be added back later if needed:
extern s32 i2c_smbus_write_quick(struct i2c_client * client, u8 value);
extern s32 i2c_smbus_process_call(struct i2c_client * client,
u8 command, u16 value);
extern s32 i2c_smbus_block_process_call(struct i2c_client *client,
u8 command, u8 length,
u8 *values)
All these transactions return -1 on failure. The 'write' transactions
return 0 on success; the 'read' transactions return the read value, except
for read_block, which returns the number of values read. The block buffers
need not be longer than 32 bytes.
All these transactions return a negative errno value on failure. The 'write'
transactions return 0 on success; the 'read' transactions return the read
value, except for block transactions, which return the number of values
read. The block buffers need not be longer than 32 bytes.
You can read the file `smbus-protocol' for more information about the
actual SMBus protocol.

8
Documentation/ia64/kvm.txt
View File

@ -50,9 +50,9 @@ Note: For step 2, please make sure that host page size == TARGET_PAGE_SIZE of qe
/usr/local/bin/qemu-system-ia64 -smp xx -m 512 -hda $your_image
(xx is the number of virtual processors for the guest, now the maximum value is 4)
5. Known possibile issue on some platforms with old Firmware.
5. Known possible issue on some platforms with old Firmware.
If meet strange host crashe issues, try to solve it through either of the following ways:
In the event of strange host crash issues, try to solve it through either of the following ways:
(1): Upgrade your Firmware to the latest one.
@ -65,8 +65,8 @@ index 0b53344..f02b0f7 100644
mov ar.pfs = loc1
mov rp = loc0
;;
- srlz.d // seralize restoration of psr.l
+ srlz.i // seralize restoration of psr.l
- srlz.d // serialize restoration of psr.l
+ srlz.i // serialize restoration of psr.l
+ ;;
br.ret.sptk.many b0
END(ia64_pal_call_static)

137
Documentation/ia64/paravirt_ops.txt 100644
View File

@ -0,0 +1,137 @@
Paravirt_ops on IA64
====================
21 May 2008, Isaku Yamahata <yamahata@valinux.co.jp>
Introduction
------------
The aim of this documentation is to help with maintainability and/or to
encourage people to use paravirt_ops/IA64.
paravirt_ops (pv_ops in short) is a way for virtualization support of
Linux kernel on x86. Several ways for virtualization support were
proposed, paravirt_ops is the winner.
On the other hand, now there are also several IA64 virtualization
technologies like kvm/IA64, xen/IA64 and many other academic IA64
hypervisors so that it is good to add generic virtualization
infrastructure on Linux/IA64.
What is paravirt_ops?
---------------------
It has been developed on x86 as virtualization support via API, not ABI.
It allows each hypervisor to override operations which are important for
hypervisors at API level. And it allows a single kernel binary to run on
all supported execution environments including native machine.
Essentially paravirt_ops is a set of function pointers which represent
operations corresponding to low level sensitive instructions and high
level functionalities in various area. But one significant difference
from usual function pointer table is that it allows optimization with
binary patch. It is because some of these operations are very
performance sensitive and indirect call overhead is not negligible.
With binary patch, indirect C function call can be transformed into
direct C function call or in-place execution to eliminate the overhead.
Thus, operations of paravirt_ops are classified into three categories.
- simple indirect call
These operations correspond to high level functionality so that the
overhead of indirect call isn't very important.
- indirect call which allows optimization with binary patch
Usually these operations correspond to low level instructions. They
are called frequently and performance critical. So the overhead is
very important.
- a set of macros for hand written assembly code
Hand written assembly codes (.S files) also need paravirtualization
because they include sensitive instructions or some of code paths in
them are very performance critical.
The relation to the IA64 machine vector
---------------------------------------
Linux/IA64 has the IA64 machine vector functionality which allows the
kernel to switch implementations (e.g. initialization, ipi, dma api...)
depending on executing platform.
We can replace some implementations very easily defining a new machine
vector. Thus another approach for virtualization support would be
enhancing the machine vector functionality.
But paravirt_ops approach was taken because
- virtualization support needs wider support than machine vector does.
e.g. low level instruction paravirtualization. It must be
initialized very early before platform detection.
- virtualization support needs more functionality like binary patch.
Probably the calling overhead might not be very large compared to the
emulation overhead of virtualization. However in the native case, the
overhead should be eliminated completely.
A single kernel binary should run on each environment including native,
and the overhead of paravirt_ops on native environment should be as
small as possible.
- for full virtualization technology, e.g. KVM/IA64 or
Xen/IA64 HVM domain, the result would be
(the emulated platform machine vector. probably dig) + (pv_ops).
This means that the virtualization support layer should be under
the machine vector layer.
Possibly it might be better to move some function pointers from
paravirt_ops to machine vector. In fact, Xen domU case utilizes both
pv_ops and machine vector.
IA64 paravirt_ops
-----------------
In this section, the concrete paravirt_ops will be discussed.
Because of the architecture difference between ia64 and x86, the
resulting set of functions is very different from x86 pv_ops.
- C function pointer tables
They are not very performance critical so that simple C indirect
function call is acceptable. The following structures are defined at
this moment. For details see linux/include/asm-ia64/paravirt.h
- struct pv_info
This structure describes the execution environment.
- struct pv_init_ops
This structure describes the various initialization hooks.
- struct pv_iosapic_ops
This structure describes hooks to iosapic operations.
- struct pv_irq_ops
This structure describes hooks to irq related operations
- struct pv_time_op
This structure describes hooks to steal time accounting.
- a set of indirect calls which need optimization
Currently this class of functions correspond to a subset of IA64
intrinsics. At this moment the optimization with binary patch isn't
implemented yet.
struct pv_cpu_op is defined. For details see
linux/include/asm-ia64/paravirt_privop.h
Mostly they correspond to ia64 intrinsics 1-to-1.
Caveat: Now they are defined as C indirect function pointers, but in
order to support binary patch optimization, they will be changed
using GCC extended inline assembly code.
- a set of macros for hand written assembly code (.S files)
For maintenance purpose, the taken approach for .S files is single
source code and compile multiple times with different macros definitions.
Each pv_ops instance must define those macros to compile.
The important thing here is that sensitive, but non-privileged
instructions must be paravirtualized and that some privileged
instructions also need paravirtualization for reasonable performance.
Developers who modify .S files must be aware of that. At this moment
an easy checker is implemented to detect paravirtualization breakage.
But it doesn't cover all the cases.
Sometimes this set of macros is called pv_cpu_asm_op. But there is no
corresponding structure in the source code.
Those macros mostly 1:1 correspond to a subset of privileged
instructions. See linux/include/asm-ia64/native/inst.h.
And some functions written in assembly also need to be overrided so
that each pv_ops instance have to define some macros. Again see
linux/include/asm-ia64/native/inst.h.
Those structures must be initialized very early before start_kernel.
Probably initialized in head.S using multi entry point or some other trick.
For native case implementation see linux/arch/ia64/kernel/paravirt.c.

2
Documentation/input/cs461x.txt
View File

@ -31,7 +31,7 @@ The driver works with ALSA drivers simultaneously. For example, the xracer
uses joystick as input device and PCM device as sound output in one time.
There are no sound or input collisions detected. The source code have
comments about them; but I've found the joystick can be initialized
separately of ALSA modules. So, you canm use only one joystick driver
separately of ALSA modules. So, you can use only one joystick driver
without ALSA drivers. The ALSA drivers are not needed to compile or
run this driver.

2
Documentation/input/gameport-programming.txt
View File

@ -1,5 +1,3 @@
$Id: gameport-programming.txt,v 1.3 2001/04/24 13:51:37 vojtech Exp $
Programming gameport drivers
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1
Documentation/input/input.txt
View File

@ -1,7 +1,6 @@
Linux Input drivers v1.0
(c) 1999-2001 Vojtech Pavlik <vojtech@ucw.cz>
Sponsored by SuSE
$Id: input.txt,v 1.8 2002/05/29 03:15:01 bradleym Exp $
----------------------------------------------------------------------------
0. Disclaimer

2
Documentation/input/joystick-api.txt
View File

@ -5,8 +5,6 @@
7 Aug 1998
$Id: joystick-api.txt,v 1.2 2001/05/08 21:21:23 vojtech Exp $
1. Initialization
~~~~~~~~~~~~~~~~~

1
Documentation/input/joystick-parport.txt
View File

@ -2,7 +2,6 @@
(c) 1998-2000 Vojtech Pavlik <vojtech@ucw.cz>
(c) 1998 Andree Borrmann <a.borrmann@tu-bs.de>
Sponsored by SuSE
$Id: joystick-parport.txt,v 1.6 2001/09/25 09:31:32 vojtech Exp $
----------------------------------------------------------------------------
0. Disclaimer

1
Documentation/input/joystick.txt
View File

@ -1,7 +1,6 @@
Linux Joystick driver v2.0.0
(c) 1996-2000 Vojtech Pavlik <vojtech@ucw.cz>
Sponsored by SuSE
$Id: joystick.txt,v 1.12 2002/03/03 12:13:07 jdeneux Exp $
----------------------------------------------------------------------------
0. Disclaimer

1
Documentation/ioctl-number.txt
View File

@ -117,6 +117,7 @@ Code Seq# Include File Comments
<mailto:natalia@nikhefk.nikhef.nl>
'c' 00-7F linux/comstats.h conflict!
'c' 00-7F linux/coda.h conflict!
'c' 80-9F asm-s390/chsc.h
'd' 00-FF linux/char/drm/drm/h conflict!
'd' 00-DF linux/video_decoder.h conflict!
'd' F0-FF linux/digi1.h

7
Documentation/ioctl/hdio.txt
View File

@ -508,12 +508,13 @@ HDIO_DRIVE_RESET execute a device reset
error returns:
EACCES Access denied: requires CAP_SYS_ADMIN
ENXIO No such device: phy dead or ctl_addr == 0
EIO I/O error: reset timed out or hardware error
notes:
Abort any current command, prevent anything else from being
queued, execute a reset on the device, and issue BLKRRPART
ioctl on the block device.
Execute a reset on the device as soon as the current IO
operation has completed.
Executes an ATAPI soft reset if applicable, otherwise
executes an ATA soft reset on the controller.

4
Documentation/ioctl/ioctl-decoding.txt
View File

@ -1,6 +1,6 @@
To decode a hex IOCTL code:
Most architecures use this generic format, but check
Most architectures use this generic format, but check
include/ARCH/ioctl.h for specifics, e.g. powerpc
uses 3 bits to encode read/write and 13 bits for size.
@ -18,7 +18,7 @@ uses 3 bits to encode read/write and 13 bits for size.
7-0 function #
So for example 0x82187201 is a read with arg length of 0x218,
So for example 0x82187201 is a read with arg length of 0x218,
character 'r' function 1. Grepping the source reveals this is:
#define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct dirent [2])

2
Documentation/iostats.txt
View File

@ -143,7 +143,7 @@ disk and partition statistics are consistent again. Since we still don't
keep record of the partition-relative address, an operation is attributed to
the partition which contains the first sector of the request after the
eventual merges. As requests can be merged across partition, this could lead
to some (probably insignificant) innacuracy.
to some (probably insignificant) inaccuracy.
Additional notes
----------------

6
Documentation/isdn/README.mISDN 100644
View File

@ -0,0 +1,6 @@
mISDN is a new modular ISDN driver, in the long term it should replace
the old I4L driver architecture for passiv ISDN cards.
It was designed to allow a broad range of applications and interfaces
but only have the basic function in kernel, the interface to the user
space is based on sockets with a own address family AF_ISDN.

24
Documentation/kbuild/kconfig-language.txt
View File

@ -377,27 +377,3 @@ config FOO
limits FOO to module (=m) or disabled (=n).
Build limited by a third config symbol which may be =y or =m
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A common idiom that we see (and sometimes have problems with) is this:
When option C in B (module or subsystem) uses interfaces from A (module
or subsystem), and both A and B are tristate (could be =y or =m if they
were independent of each other, but they aren't), then we need to limit
C such that it cannot be built statically if A is built as a loadable
module. (C already depends on B, so there is no dependency issue to
take care of here.)
If A is linked statically into the kernel image, C can be built
statically or as loadable module(s). However, if A is built as loadable
module(s), then C must be restricted to loadable module(s) also. This
can be expressed in kconfig language as:
config C
depends on A = y || A = B
or for real examples, use this command in a kernel tree:
$ find . -name Kconfig\* | xargs grep -ns "depends on.*=.*||.*=" | grep -v orig

22
Documentation/kdump/kdump.txt
View File

@ -65,26 +65,26 @@ Install kexec-tools
2) Download the kexec-tools user-space package from the following URL:
http://www.kernel.org/pub/linux/kernel/people/horms/kexec-tools/kexec-tools-testing.tar.gz
http://www.kernel.org/pub/linux/kernel/people/horms/kexec-tools/kexec-tools.tar.gz
This is a symlink to the latest version, which at the time of writing is
20061214, the only release of kexec-tools-testing so far. As other versions
are released, the older ones will remain available at
http://www.kernel.org/pub/linux/kernel/people/horms/kexec-tools/
This is a symlink to the latest version.
Note: Latest kexec-tools-testing git tree is available at
The latest kexec-tools git tree is available at:
git://git.kernel.org/pub/scm/linux/kernel/git/horms/kexec-tools-testing.git
git://git.kernel.org/pub/scm/linux/kernel/git/horms/kexec-tools.git
or
http://www.kernel.org/git/?p=linux/kernel/git/horms/kexec-tools-testing.git;a=summary
http://www.kernel.org/git/?p=linux/kernel/git/horms/kexec-tools.git
More information about kexec-tools can be found at
http://www.kernel.org/pub/linux/kernel/people/horms/kexec-tools/README.html
3) Unpack the tarball with the tar command, as follows:
tar xvpzf kexec-tools-testing.tar.gz
tar xvpzf kexec-tools.tar.gz
4) Change to the kexec-tools directory, as follows:
cd kexec-tools-testing-VERSION
cd kexec-tools-VERSION
5) Configure the package, as follows:
@ -109,7 +109,7 @@ There are two possible methods of using Kdump.
2) Or use the system kernel binary itself as dump-capture kernel and there is
no need to build a separate dump-capture kernel. This is possible
only with the architecutres which support a relocatable kernel. As
of today i386 and ia64 architectures support relocatable kernel.
of today, i386, x86_64 and ia64 architectures support relocatable kernel.
Building a relocatable kernel is advantageous from the point of view that
one does not have to build a second kernel for capturing the dump. But

99
Documentation/kernel-doc-nano-HOWTO.txt
View File

@ -1,6 +1,105 @@
kernel-doc nano-HOWTO
=====================
How to format kernel-doc comments
---------------------------------
In order to provide embedded, 'C' friendly, easy to maintain,
but consistent and extractable documentation of the functions and
data structures in the Linux kernel, the Linux kernel has adopted
a consistent style for documenting functions and their parameters,
and structures and their members.
The format for this documentation is called the kernel-doc format.
It is documented in this Documentation/kernel-doc-nano-HOWTO.txt file.
This style embeds the documentation within the source files, using
a few simple conventions. The scripts/kernel-doc perl script, some
SGML templates in Documentation/DocBook, and other tools understand
these conventions, and are used to extract this embedded documentation
into various documents.
In order to provide good documentation of kernel functions and data
structures, please use the following conventions to format your
kernel-doc comments in Linux kernel source.
We definitely need kernel-doc formatted documentation for functions
that are exported to loadable modules using EXPORT_SYMBOL.
We also look to provide kernel-doc formatted documentation for
functions externally visible to other kernel files (not marked
"static").
We also recommend providing kernel-doc formatted documentation
for private (file "static") routines, for consistency of kernel
source code layout. But this is lower priority and at the
discretion of the MAINTAINER of that kernel source file.
Data structures visible in kernel include files should also be
documented using kernel-doc formatted comments.
The opening comment mark "/**" is reserved for kernel-doc comments.
Only comments so marked will be considered by the kernel-doc scripts,
and any comment so marked must be in kernel-doc format. Do not use
"/**" to be begin a comment block unless the comment block contains
kernel-doc formatted comments. The closing comment marker for
kernel-doc comments can be either "*/" or "**/".
Kernel-doc comments should be placed just before the function
or data structure being described.
Example kernel-doc function comment:
/**
* foobar() - short function description of foobar
* @arg1: Describe the first argument to foobar.
* @arg2: Describe the second argument to foobar.
* One can provide multiple line descriptions
* for arguments.
*
* A longer description, with more discussion of the function foobar()
* that might be useful to those using or modifying it. Begins with
* empty comment line, and may include additional embedded empty
* comment lines.
*
* The longer description can have multiple paragraphs.
**/
The first line, with the short description, must be on a single line.
The @argument descriptions must begin on the very next line following
this opening short function description line, with no intervening
empty comment lines.
Example kernel-doc data structure comment.
/**
* struct blah - the basic blah structure
* @mem1: describe the first member of struct blah
* @mem2: describe the second member of struct blah,
* perhaps with more lines and words.
*
* Longer description of this structure.
**/
The kernel-doc function comments describe each parameter to the
function, in order, with the @name lines.
The kernel-doc data structure comments describe each structure member
in the data structure, with the @name lines.
The longer description formatting is "reflowed", losing your line
breaks. So presenting carefully formatted lists within these
descriptions won't work so well; derived documentation will lose
the formatting.
See the section below "How to add extractable documentation to your
source files" for more details and notes on how to format kernel-doc
comments.
Components of the kernel-doc system
-----------------------------------
Many places in the source tree have extractable documentation in the
form of block comments above functions. The components of this system
are:

8
Documentation/kernel-docs.txt
View File

@ -715,14 +715,14 @@
* Name: "Gary's Encyclopedia - The Linux Kernel"
Author: Gary (I suppose...).
URL: http://www.lisoleg.net/cgi-bin/lisoleg.pl?view=kernel.htm
Keywords: links, not found here?.
URL: http://slencyclopedia.berlios.de/index.html
Keywords: linux, community, everything!
Description: Gary's Encyclopedia exists to allow the rapid finding
of documentation and other information of interest to GNU/Linux
users. It has about 4000 links to external pages in 150 major
categories. This link is for kernel-specific links, documents,
sites... Look there if you could not find here what you were
looking for.
sites... This list is now hosted by developer.Berlios.de,
but seems not to have been updated since sometime in 1999.
* Name: "The home page of Linux-MM"
Author: The Linux-MM team.

147
Documentation/kernel-parameters.txt
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@ -87,7 +87,8 @@ parameter is applicable:
SH SuperH architecture is enabled.
SMP The kernel is an SMP kernel.
SPARC Sparc architecture is enabled.
SWSUSP Software suspend is enabled.
SWSUSP Software suspend (hibernation) is enabled.
SUSPEND System suspend states are enabled.
TS Appropriate touchscreen support is enabled.
USB USB support is enabled.
USBHID USB Human Interface Device support is enabled.
@ -147,10 +148,16 @@ and is between 256 and 4096 characters. It is defined in the file
default: 0
acpi_sleep= [HW,ACPI] Sleep options
Format: { s3_bios, s3_mode, s3_beep }
Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, old_ordering }
See Documentation/power/video.txt for s3_bios and s3_mode.
s3_beep is for debugging; it makes the PC's speaker beep
as soon as the kernel's real-mode entry point is called.
s4_nohwsig prevents ACPI hardware signature from being
used during resume from hibernation.
old_ordering causes the ACPI 1.0 ordering of the _PTS
control method, wrt putting devices into low power
states, to be enforced (the ACPI 2.0 ordering of _PTS is
used by default).
acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Format: { level | edge | high | low }
@ -271,6 +278,17 @@ and is between 256 and 4096 characters. It is defined in the file
aic79xx= [HW,SCSI]
See Documentation/scsi/aic79xx.txt.
amd_iommu= [HW,X86-84]
Pass parameters to the AMD IOMMU driver in the system.
Possible values are:
isolate - enable device isolation (each device, as far
as possible, will get its own protection
domain)
amd_iommu_size= [HW,X86-64]
Define the size of the aperture for the AMD IOMMU
driver. Possible values are:
'32M', '64M' (default), '128M', '256M', '512M', '1G'
amijoy.map= [HW,JOY] Amiga joystick support
Map of devices attached to JOY0DAT and JOY1DAT
Format: <a>,<b>
@ -295,7 +313,7 @@ and is between 256 and 4096 characters. It is defined in the file
when initialising the APIC and IO-APIC components.
apm= [APM] Advanced Power Management
See header of arch/i386/kernel/apm.c.
See header of arch/x86/kernel/apm_32.c.
arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
Format: <io>,<irq>,<nodeID>
@ -398,9 +416,6 @@ and is between 256 and 4096 characters. It is defined in the file
cio_ignore= [S390]
See Documentation/s390/CommonIO for details.
cio_msg= [S390]
See Documentation/s390/CommonIO for details.
clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
[Deprecated]
Forces specified clocksource (if available) to be used
@ -563,6 +578,8 @@ and is between 256 and 4096 characters. It is defined in the file
debug_objects [KNL] Enable object debugging
debugpat [X86] Enable PAT debugging
decnet.addr= [HW,NET]
Format: <area>[,<node>]
See also Documentation/networking/decnet.txt.
@ -602,6 +619,29 @@ and is between 256 and 4096 characters. It is defined in the file
See drivers/char/README.epca and
Documentation/digiepca.txt.
disable_mtrr_cleanup [X86]
enable_mtrr_cleanup [X86]
The kernel tries to adjust MTRR layout from continuous
to discrete, to make X server driver able to add WB
entry later. This parameter enables/disables that.
mtrr_chunk_size=nn[KMG] [X86]
used for mtrr cleanup. It is largest continous chunk
that could hold holes aka. UC entries.
mtrr_gran_size=nn[KMG] [X86]
Used for mtrr cleanup. It is granularity of mtrr block.
Default is 1.
Large value could prevent small alignment from
using up MTRRs.
mtrr_spare_reg_nr=n [X86]
Format: <integer>
Range: 0,7 : spare reg number
Default : 1
Used for mtrr cleanup. It is spare mtrr entries number.
Set to 2 or more if your graphical card needs more.
disable_mtrr_trim [X86, Intel and AMD only]
By default the kernel will trim any uncacheable
memory out of your available memory pool based on
@ -641,7 +681,7 @@ and is between 256 and 4096 characters. It is defined in the file
elanfreq= [X86-32]
See comment before function elanfreq_setup() in
arch/i386/kernel/cpu/cpufreq/elanfreq.c.
arch/x86/kernel/cpu/cpufreq/elanfreq.c.
elevator= [IOSCHED]
Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
@ -689,6 +729,12 @@ and is between 256 and 4096 characters. It is defined in the file
floppy= [HW]
See Documentation/floppy.txt.
force_pal_cache_flush
[IA-64] Avoid check_sal_cache_flush which may hang on
buggy SAL_CACHE_FLUSH implementations. Using this
parameter will force ia64_sal_cache_flush to call
ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
gamecon.map[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
support via parallel port (up to 5 devices per port)
@ -719,9 +765,6 @@ and is between 256 and 4096 characters. It is defined in the file
hd= [EIDE] (E)IDE hard drive subsystem geometry
Format: <cyl>,<head>,<sect>
hd?= [HW] (E)IDE subsystem
hd?lun= See Documentation/ide/ide.txt.
highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
size of <nn>. This works even on boxes that have no
highmem otherwise. This also works to reduce highmem
@ -734,8 +777,22 @@ and is between 256 and 4096 characters. It is defined in the file
hisax= [HW,ISDN]
See Documentation/isdn/README.HiSax.
hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
hugepagesz= [HW,IA-64,PPC] The size of the HugeTLB pages.
hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
On x86-64 and powerpc, this option can be specified
multiple times interleaved with hugepages= to reserve
huge pages of different sizes. Valid pages sizes on
x86-64 are 2M (when the CPU supports "pse") and 1G
(when the CPU supports the "pdpe1gb" cpuinfo flag)
Note that 1GB pages can only be allocated at boot time
using hugepages= and not freed afterwards.
default_hugepagesz=
[same as hugepagesz=] The size of the default
HugeTLB page size. This is the size represented by
the legacy /proc/ hugepages APIs, used for SHM, and
default size when mounting hugetlbfs filesystems.
Defaults to the default architecture's huge page size
if not specified.
i8042.direct [HW] Put keyboard port into non-translated mode
i8042.dumbkbd [HW] Pretend that controller can only read data from
@ -782,7 +839,7 @@ and is between 256 and 4096 characters. It is defined in the file
See Documentation/ide/ide.txt.
idle= [X86]
Format: idle=poll or idle=mwait
Format: idle=poll or idle=mwait, idle=halt, idle=nomwait
Poll forces a polling idle loop that can slightly improves the performance
of waking up a idle CPU, but will use a lot of power and make the system
run hot. Not recommended.
@ -790,6 +847,9 @@ and is between 256 and 4096 characters. It is defined in the file
to not use it because it doesn't save as much power as a normal idle
loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
as idle=poll.
idle=halt. Halt is forced to be used for CPU idle.
In such case C2/C3 won't be used again.
idle=nomwait. Disable mwait for CPU C-states
ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
Claim all unknown PCI IDE storage controllers.
@ -1094,9 +1154,6 @@ and is between 256 and 4096 characters. It is defined in the file
mac5380= [HW,SCSI] Format:
<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
mac53c9x= [HW,SCSI] Format:
<num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
machvec= [IA64] Force the use of a particular machine-vector
(machvec) in a generic kernel.
Example: machvec=hpzx1_swiotlb
@ -1166,7 +1223,7 @@ and is between 256 and 4096 characters. It is defined in the file
or
memmap=0x10000$0x18690000
memtest= [KNL,X86_64] Enable memtest
memtest= [KNL,X86] Enable memtest
Format: <integer>
range: 0,4 : pattern number
default : 0 <disable>
@ -1185,6 +1242,14 @@ and is between 256 and 4096 characters. It is defined in the file
mga= [HW,DRM]
mminit_loglevel=
[KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
parameter allows control of the logging verbosity for
the additional memory initialisation checks. A value
of 0 disables mminit logging and a level of 4 will
log everything. Information is printed at KERN_DEBUG
so loglevel=8 may also need to be specified.
mousedev.tap_time=
[MOUSE] Maximum time between finger touching and
leaving touchpad surface for touch to be considered
@ -1208,6 +1273,11 @@ and is between 256 and 4096 characters. It is defined in the file
mtdparts= [MTD]
See drivers/mtd/cmdlinepart.c.
mtdset= [ARM]
ARM/S3C2412 JIVE boot control
See arch/arm/mach-s3c2412/mach-jive.c
mtouchusb.raw_coordinates=
[HW] Make the MicroTouch USB driver use raw coordinates
('y', default) or cooked coordinates ('n')
@ -1234,6 +1304,13 @@ and is between 256 and 4096 characters. It is defined in the file
This usage is only documented in each driver source
file if at all.
nf_conntrack.acct=
[NETFILTER] Enable connection tracking flow accounting
0 to disable accounting
1 to enable accounting
Default value depends on CONFIG_NF_CT_ACCT that is
going to be removed in 2.6.29.
nfsaddrs= [NFS]
See Documentation/filesystems/nfsroot.txt.
@ -1496,6 +1573,9 @@ and is between 256 and 4096 characters. It is defined in the file
Use with caution as certain devices share
address decoders between ROMs and other
resources.
norom [X86-32,X86_64] Do not assign address space to
expansion ROMs that do not already have
BIOS assigned address ranges.
irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
assigned automatically to PCI devices. You can
make the kernel exclude IRQs of your ISA cards
@ -1525,6 +1605,8 @@ and is between 256 and 4096 characters. It is defined in the file
This is normally done in pci_enable_device(),
so this option is a temporary workaround
for broken drivers that don't call it.
skip_isa_align [X86] do not align io start addr, so can
handle more pci cards
firmware [ARM] Do not re-enumerate the bus but instead
just use the configuration from the
bootloader. This is currently used on
@ -1569,6 +1651,10 @@ and is between 256 and 4096 characters. It is defined in the file
Format: { parport<nr> | timid | 0 }
See also Documentation/parport.txt.
pmtmr= [X86] Manual setup of pmtmr I/O Port.
Override pmtimer IOPort with a hex value.
e.g. pmtmr=0x508
pnpacpi= [ACPI]
{ off }
@ -1677,6 +1763,10 @@ and is between 256 and 4096 characters. It is defined in the file
Format: <reboot_mode>[,<reboot_mode2>[,...]]
See arch/*/kernel/reboot.c or arch/*/kernel/process.c
relax_domain_level=
[KNL, SMP] Set scheduler's default relax_domain_level.
See Documentation/cpusets.txt.
reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
reservetop= [X86-32]
@ -1969,6 +2059,9 @@ and is between 256 and 4096 characters. It is defined in the file
snd-ymfpci= [HW,ALSA]
softlockup_panic=
[KNL] Should the soft-lockup detector generate panics.
sonypi.*= [HW] Sony Programmable I/O Control Device driver
See Documentation/sonypi.txt
@ -2033,6 +2126,12 @@ and is between 256 and 4096 characters. It is defined in the file
tdfx= [HW,DRM]
test_suspend= [SUSPEND]
Specify "mem" (for Suspend-to-RAM) or "standby" (for
standby suspend) as the system sleep state to briefly
enter during system startup. The system is woken from
this state using a wakeup-capable RTC alarm.
thash_entries= [KNL,NET]
Set number of hash buckets for TCP connection
@ -2060,13 +2159,6 @@ and is between 256 and 4096 characters. It is defined in the file
<deci-seconds>: poll all this frequency
0: no polling (default)
tipar.timeout= [HW,PPT]
Set communications timeout in tenths of a second
(default 15).
tipar.delay= [HW,PPT]
Set inter-bit delay in microseconds (default 10).
tmscsim= [HW,SCSI]
See comment before function dc390_setup() in
drivers/scsi/tmscsim.c.
@ -2100,6 +2192,10 @@ and is between 256 and 4096 characters. It is defined in the file
Note that genuine overcurrent events won't be
reported either.
unknown_nmi_panic
[X86-32,X86-64]
Set unknown_nmi_panic=1 early on boot.
usbcore.autosuspend=
[USB] The autosuspend time delay (in seconds) used
for newly-detected USB devices (default 2). This
@ -2110,6 +2206,9 @@ and is between 256 and 4096 characters. It is defined in the file
usbhid.mousepoll=
[USBHID] The interval which mice are to be polled at.
add_efi_memmap [EFI; x86-32,X86-64] Include EFI memory map in
kernel's map of available physical RAM.
vdso= [X86-32,SH,x86-64]
vdso=2: enable compat VDSO (default with COMPAT_VDSO)
vdso=1: enable VDSO (default)

2
Documentation/keys.txt
View File

@ -864,7 +864,7 @@ payload contents" for more information.
request_key_with_auxdata() respectively.
These two functions return with the key potentially still under
construction. To wait for contruction completion, the following should be
construction. To wait for construction completion, the following should be
called:
int wait_for_key_construction(struct key *key, bool intr);

2
Documentation/kobject.txt
View File

@ -305,7 +305,7 @@ should not be manipulated by any other user.
A kset keeps its children in a standard kernel linked list. Kobjects point
back to their containing kset via their kset field. In almost all cases,
the kobjects belonging to a ket have that kset (or, strictly, its embedded
the kobjects belonging to a kset have that kset (or, strictly, its embedded
kobject) in their parent.
As a kset contains a kobject within it, it should always be dynamically

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