Add a boot option to disable firmware first mode for corrected errors.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Pull x86 debug update from Ingo Molnar:
"Two small changes: a documentation update and a constification"
* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, early-printk: Update earlyprintk documentation (and kill x86 copy)
x86: Constify a few items
Documentation/kernel-parameters.txt and
Documentation/x86/x86_64/boot-options.txt contain virtually
identical text describing earlyprintk.
This consolidates the two copies and updates the documentation a
bit. No one ever documented the:
earlyprintk=serial,0x1008,115200
syntax, nor mentioned that ARM is now a supported earlyprintk
arch.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rob Landley <rob@landley.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave@sr71.net>
Link: http://lkml.kernel.org/r/20130410210338.E2930E98@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 microcode loading update from Peter Anvin:
"This patchset lets us update the CPU microcode very, very early in
initialization if the BIOS fails to do so (never happens, right?)
This is handy for dealing with things like the Atom erratum where we
have to run without PSE because microcode loading happens too late.
As I mentioned in the x86/mm push request it depends on that
infrastructure but it is otherwise a standalone feature."
* 'x86/microcode' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/Kconfig: Make early microcode loading a configuration feature
x86/mm/init.c: Copy ucode from initrd image to kernel memory
x86/head64.c: Early update ucode in 64-bit
x86/head_32.S: Early update ucode in 32-bit
x86/microcode_intel_early.c: Early update ucode on Intel's CPU
x86/tlbflush.h: Define __native_flush_tlb_global_irq_disabled()
x86/microcode_intel_lib.c: Early update ucode on Intel's CPU
x86/microcode_core_early.c: Define interfaces for early loading ucode
x86/common.c: load ucode in 64 bit or show loading ucode info in 32 bit on AP
x86/common.c: Make have_cpuid_p() a global function
x86/microcode_intel.h: Define functions and macros for early loading ucode
x86, doc: Documentation for early microcode loading
Pull x86 mm changes from Peter Anvin:
"This is a huge set of several partly interrelated (and concurrently
developed) changes, which is why the branch history is messier than
one would like.
The *really* big items are two humonguous patchsets mostly developed
by Yinghai Lu at my request, which completely revamps the way we
create initial page tables. In particular, rather than estimating how
much memory we will need for page tables and then build them into that
memory -- a calculation that has shown to be incredibly fragile -- we
now build them (on 64 bits) with the aid of a "pseudo-linear mode" --
a #PF handler which creates temporary page tables on demand.
This has several advantages:
1. It makes it much easier to support things that need access to data
very early (a followon patchset uses this to load microcode way
early in the kernel startup).
2. It allows the kernel and all the kernel data objects to be invoked
from above the 4 GB limit. This allows kdump to work on very large
systems.
3. It greatly reduces the difference between Xen and native (Xen's
equivalent of the #PF handler are the temporary page tables created
by the domain builder), eliminating a bunch of fragile hooks.
The patch series also gets us a bit closer to W^X.
Additional work in this pull is the 64-bit get_user() work which you
were also involved with, and a bunch of cleanups/speedups to
__phys_addr()/__pa()."
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (105 commits)
x86, mm: Move reserving low memory later in initialization
x86, doc: Clarify the use of asm("%edx") in uaccess.h
x86, mm: Redesign get_user with a __builtin_choose_expr hack
x86: Be consistent with data size in getuser.S
x86, mm: Use a bitfield to mask nuisance get_user() warnings
x86/kvm: Fix compile warning in kvm_register_steal_time()
x86-32: Add support for 64bit get_user()
x86-32, mm: Remove reference to alloc_remap()
x86-32, mm: Remove reference to resume_map_numa_kva()
x86-32, mm: Rip out x86_32 NUMA remapping code
x86/numa: Use __pa_nodebug() instead
x86: Don't panic if can not alloc buffer for swiotlb
mm: Add alloc_bootmem_low_pages_nopanic()
x86, 64bit, mm: hibernate use generic mapping_init
x86, 64bit, mm: Mark data/bss/brk to nx
x86: Merge early kernel reserve for 32bit and 64bit
x86: Add Crash kernel low reservation
x86, kdump: Remove crashkernel range find limit for 64bit
memblock: Add memblock_mem_size()
x86, boot: Not need to check setup_header version for setup_data
...
Pull trivial tree from Jiri Kosina:
"Assorted tiny fixes queued in trivial tree"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (22 commits)
DocBook: update EXPORT_SYMBOL entry to point at export.h
Documentation: update top level 00-INDEX file with new additions
ARM: at91/ide: remove unsused at91-ide Kconfig entry
percpu_counter.h: comment code for better readability
x86, efi: fix comment typo in head_32.S
IB: cxgb3: delay freeing mem untill entirely done with it
net: mvneta: remove unneeded version.h include
time: x86: report_lost_ticks doesn't exist any more
pcmcia: avoid static analysis complaint about use-after-free
fs/jfs: Fix typo in comment : 'how may' -> 'how many'
of: add missing documentation for of_platform_populate()
btrfs: remove unnecessary cur_trans set before goto loop in join_transaction
sound: soc: Fix typo in sound/codecs
treewide: Fix typo in various drivers
btrfs: fix comment typos
Update ibmvscsi module name in Kconfig.
powerpc: fix typo (utilties -> utilities)
of: fix spelling mistake in comment
h8300: Fix home page URL in h8300/README
xtensa: Fix home page URL in Kconfig
...
OVMF (an implementation of UEFI based on TianoCore used in virtual
environments) now has the ability to boot Linux natively; this is used
for "qemu -kernel" and similar things in a UEFI environment.
Accordingly, assign it a bootloader ID.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Now 64bit entry is fixed on 0x200, can not be changed anymore.
Update the comments to reflect that.
Also put info about it in boot.txt
-v2: fix some grammar error
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-27-git-send-email-yinghai@kernel.org
Cc: Rob Landley <rob@landley.net>
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Define the 2.12 bzImage boot protocol: add xloadflags and additional
fields to allow the command line, initramfs and struct boot_params to
live above the 4 GiB mark.
The xloadflags now communicates if this is a 64-bit kernel with the
legacy 64-bit entry point and which of the EFI handover entry points
are supported.
Avoid adding new read flags to loadflags because of claimed
bootloaders testing the whole byte for == 1 to determine bzImageness
at least until the issue can be researched further.
This is based on patches by Yinghai Lu and David Woodhouse.
Originally-by: Yinghai Lu <yinghai@kernel.org>
Originally-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1359058816-7615-26-git-send-email-yinghai@kernel.org
Cc: Rob Landley <rob@landley.net>
Cc: Gokul Caushik <caushik1@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joe Millenbach <jmillenbach@gmail.com>
'report_lost_ticks' parameter has been removed back in 2007 through
1489939f0a ("time: x86_64: convert x86_64 to use GENERIC_TIME").
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Pull small x86 fixes from Peter Anvin:
"A collection of very small fixes, mostly pure documentation."
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, doc: Document that bootloader ID 4 is used also by iPXE
x86, doc: Add a formal bootloader ID for kexec-tools
x86, 8042: Enable A20 using KBC to fix S3 resume on some MSI laptops
Add bootloader id D for kexec-tools (it is kexec-tools, not the kexec
system call, that builds the data structures, therefore it is
kexec-tools which is the "bootloader" for this purpose.)
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/50C95832.5030306@zytor.com
Fixes some minor issues in the x86 boot documentation.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Rob Landley <rob@landley.net>
Link: http://lkml.kernel.org/r/20121026031702.GA23828@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The ACPI spec doesn't provide for a way for the bios to pass down
recommended thresholds to the OS on a _per-bank_ basis. This patch adds
a new boot option, which if passed, tells Linux to use CMCI thresholds
set by the bios.
As fail-safe, we initialize threshold to 1 if some banks have not been
initialized by the bios and warn the user.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Pul x86/efi changes from Ingo Molnar:
"This tree adds an EFI bootloader handover protocol, which, once
supported on the bootloader side, will make bootup faster and might
result in simpler bootloaders.
The other change activates the EFI wall clock time accessors on x86-64
as well, instead of the legacy RTC readout."
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, efi: Handover Protocol
x86-64/efi: Use EFI to deal with platform wall clock
Assign a bootloader ID for Sebastian Plotz' "Minimal Linux Bootloader"
(http://sebastian-plotz.blogspot.de). Sebastian has agreed to make
this the pilot for the use of extended boot loader IDs, so this is
assigned version ID 0x11 (avoid assigning 0x10 for now to catch bugs
with people putting E in the primary ID but leaving the extended ID as
zero.)
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Sebastian Plotz <sebastian-plotz@web.de>
Link: http://lkml.kernel.org/n/tip-nq318h0okuaem8x9dpv9854k@git.kernel.org
As things currently stand, traditional EFI boot loaders and the EFI
boot stub are carrying essentially the same initialisation code
required to setup an EFI machine for booting a kernel. There's really
no need to have this code in two places and the hope is that, with
this new protocol, initialisation and booting of the kernel can be
left solely to the kernel's EFI boot stub. The responsibilities of the
boot loader then become,
o Loading the kernel image from boot media
File system code still needs to be carried by boot loaders for the
scenario where the kernel and initrd files reside on a file system
that the EFI firmware doesn't natively understand, such as ext4, etc.
o Providing a user interface
Boot loaders still need to display any menus/interfaces, for example
to allow the user to select from a list of kernels.
Bump the boot protocol number because we added the 'handover_offset'
field to indicate the location of the handover protocol entry point.
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Acked-and-Tested-by: Matthew Garrett <mjg@redhat.com>
Link: http://lkml.kernel.org/r/1342689828-16815-1-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Since we can't expect every user to read the EFI boot stub code it
seems prudent to have a couple of paragraphs explaining what it is and
how it works.
The "initrd=" option in particular is tricky because it only
understands absolute EFI-style paths (backslashes as directory
separators), and until now this hasn't been documented anywhere. This
has tripped up a couple of users.
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1331907517-3985-4-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Commit 3ae36655b9 (x86-64: Rework vsyscall
emulation and add vsyscall= parameter) removed the special use of the
0xcc IDT vector.
Remove it from Documentation/x86/entry_64.txt also.
Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Acked-by: Andy Lutomirski <luto@MIT.EDU>
Link: http://lkml.kernel.org/r/1313447210-9149-1-git-send-email-cesarb@cesarb.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-64, vdso: Do not allocate memory for the vDSO
clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG option
x86, vdso: Drop now wrong comment
Document the vDSO and add a reference parser
ia64: Replace clocksource.fsys_mmio with generic arch data
x86-64: Move vread_tsc and vread_hpet into the vDSO
clocksource: Replace vread with generic arch data
x86-64: Add --no-undefined to vDSO build
x86-64: Allow alternative patching in the vDSO
x86: Make alternative instruction pointers relative
x86-64: Improve vsyscall emulation CS and RIP handling
x86-64: Emulate legacy vsyscalls
x86-64: Fill unused parts of the vsyscall page with 0xcc
x86-64: Remove vsyscall number 3 (venosys)
x86-64: Map the HPET NX
x86-64: Remove kernel.vsyscall64 sysctl
x86-64: Give vvars their own page
x86-64: Document some of entry_64.S
x86-64: Fix alignment of jiffies variable
The real-mode kernel header init_size field is located at 0x260 per the field
listing in th e"REAL-MODE KERNEL HEADER" section. It is listed as 0x25c in
the "DETAILS OF HEADER FIELDS" section, which overlaps with pref_address.
Correct the details listing to 0x260.
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Link: http://lkml.kernel.org/r/541cf88e2dfe5b8186d8b96b136d892e769a68c1.1310441260.git.dvhart@linux.intel.com
CC: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This file only contains code relevant for the northbridge
gart in AMD processors. This patch renames the file to
represent this fact in the filename.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
The oops=panic cmdline option is not x86 specific, move it to generic code.
Update documentation.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This integrates the XZ decompression code to the x86 pre-boot code.
mkpiggy.c is updated to reserve about 32 KiB more buffer safety margin for
kernel decompression. It is done unconditionally for all decompressors to
keep the code simpler.
The XZ decompressor needs around 30 KiB of heap, so the heap size is
increased to 32 KiB on both x86-32 and x86-64.
Documentation/x86/boot.txt is updated to list the XZ magic number.
With the x86 BCJ filter in XZ, XZ-compressed x86 kernel tends to be a few
percent smaller than the equivalent LZMA-compressed kernel.
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alain Knaff <alain@knaff.lu>
Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
IRQ stacks provide much better safety against unexpected stack use from
interrupts, at the minimal downside of slightly higher memory usage.
Enable irq stacks also for the default 8k stack on 32-bit kernels to
minimize the problem of stack overflows through interrupt activity.
This is what the 64-bit kernel and various other architectures already do.
Signed-off-by: Christoph Hellwig <hch@lst.de>
LKML-Reference: <20100628121554.GA6605@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add support for saving OFW's cif, and later calling into it to run OFW
commands. OFW remains resident in memory, living within virtual range
0xff800000 - 0xffc00000. A single page directory entry points to the
pgdir that OFW actually uses, so rather than saving the entire page
table, we grab and install that one entry permanently in the kernel's
page table.
This is currently only used by the OLPC XO. Note that this particular
calling convention breaks PAE and PAT, and so cannot be used on newer
x86 hardware.
Signed-off-by: Andres Salomon <dilinger@queued.net>
LKML-Reference: <20100618174653.7755a39a@dev.queued.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Now that numa=fake=<size>[MG] is implemented, it is possible to remove
configurable node size support. The command-line parsing was already
broken (numa=fake=*128, for example, would not work) and since fake nodes
are now interleaved over physical nodes, this support is no longer
required.
Signed-off-by: David Rientjes <rientjes@google.com>
LKML-Reference: <alpine.DEB.2.00.1002151343080.26927@chino.kir.corp.google.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
numa=fake=N specifies the number of fake nodes, N, to partition the
system into and then allocates them by interleaving over physical nodes.
This requires knowledge of the system capacity when attempting to
allocate nodes of a certain size: either very large nodes to benchmark
scalability of code that operates on individual nodes, or very small
nodes to find bugs in the VM.
This patch introduces numa=fake=<size>[MG] so it is possible to specify
the size of each node to allocate. When used, nodes of the size
specified will be allocated and interleaved over the set of physical
nodes.
FAKE_NODE_MIN_SIZE was also moved to the more-appropriate
include/asm/numa_64.h.
Signed-off-by: David Rientjes <rientjes@google.com>
LKML-Reference: <alpine.DEB.2.00.1002151342510.26927@chino.kir.corp.google.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Add missing information about requirements of using the EHCI usb debug
controller as well as to mention you can use a debug controller other
than the first one in the system.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Sarah Sharp <sarah.a.sharp@intel.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (38 commits)
x86: Move get/set_wallclock to x86_platform_ops
x86: platform: Fix section annotations
x86: apic namespace cleanup
x86: Distangle ioapic and i8259
x86: Add Moorestown early detection
x86: Add hardware_subarch ID for Moorestown
x86: Add early platform detection
x86: Move tsc_init to late_time_init
x86: Move tsc_calibration to x86_init_ops
x86: Replace the now identical time_32/64.c by time.c
x86: time_32/64.c unify profile_pc
x86: Move calibrate_cpu to tsc.c
x86: Make timer setup and global variables the same in time_32/64.c
x86: Remove mca bus ifdef from timer interrupt
x86: Simplify timer_ack magic in time_32.c
x86: Prepare unification of time_32/64.c
x86: Remove do_timer hook
x86: Add timer_init to x86_init_ops
x86: Move percpu clockevents setup to x86_init_ops
x86: Move xen_post_allocator_init into xen_pagetable_setup_done
...
Fix up conflicts in arch/x86/include/asm/io_apic.h
x86 bootprotocol 2.07 has introduced hardware_subarch ID in the boot
parameters provided by FW. We use it to identify Moorestown platforms.
[ tglx: Cleanup and paravirt fix ]
Signed-off-by: Jacob Pan <jacob.jun.pan@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch adds kernel configuration and boot support for Intel Trusted
Execution Technology (Intel TXT).
Intel's technology for safer computing, Intel Trusted Execution
Technology (Intel TXT), defines platform-level enhancements that
provide the building blocks for creating trusted platforms.
Intel TXT was formerly known by the code name LaGrande Technology (LT).
Intel TXT in Brief:
o Provides dynamic root of trust for measurement (DRTM)
o Data protection in case of improper shutdown
o Measurement and verification of launched environment
Intel TXT is part of the vPro(TM) brand and is also available some
non-vPro systems. It is currently available on desktop systems based on
the Q35, X38, Q45, and Q43 Express chipsets (e.g. Dell Optiplex 755, HP
dc7800, etc.) and mobile systems based on the GM45, PM45, and GS45
Express chipsets.
For more information, see http://www.intel.com/technology/security/.
This site also has a link to the Intel TXT MLE Developers Manual, which
has been updated for the new released platforms.
A much more complete description of how these patches support TXT, how to
configure a system for it, etc. is in the Documentation/intel_txt.txt file
in this patch.
This patch provides the TXT support routines for complete functionality,
documentation for TXT support and for the changes to the boot_params structure,
and boot detection of a TXT launch. Attempts to shutdown (reboot, Sx) the system
will result in platform resets; subsequent patches will support these shutdown modes
properly.
Documentation/intel_txt.txt | 210 +++++++++++++++++++++
Documentation/x86/zero-page.txt | 1
arch/x86/include/asm/bootparam.h | 3
arch/x86/include/asm/fixmap.h | 3
arch/x86/include/asm/tboot.h | 197 ++++++++++++++++++++
arch/x86/kernel/Makefile | 1
arch/x86/kernel/setup.c | 4
arch/x86/kernel/tboot.c | 379 +++++++++++++++++++++++++++++++++++++++
security/Kconfig | 30 +++
9 files changed, 827 insertions(+), 1 deletion(-)
Signed-off-by: Joseph Cihula <joseph.cihula@intel.com>
Signed-off-by: Shane Wang <shane.wang@intel.com>
Signed-off-by: Gang Wei <gang.wei@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
exception.txt only explains the code on x86, so it's better to
move it into Documentation/x86 directory.
And also rename it to exception-tables.txt which looks much
more reasonable.
This patch is on top of the previous one.
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch introduces three boot options (no_cmci, dont_log_ce
and ignore_ce) to control handling for corrected errors.
The "mce=no_cmci" boot option disables the CMCI feature.
Since CMCI is a new feature so having boot controls to disable
it will be a help if the hardware is misbehaving.
The "mce=dont_log_ce" boot option disables logging for corrected
errors. All reported corrected errors will be cleared silently.
This option will be useful if you never care about corrected
errors.
The "mce=ignore_ce" boot option disables features for corrected
errors, i.e. polling timer and cmci. All corrected events are
not cleared and kept in bank MSRs.
Usually this disablement is not recommended, however it will be
a help if there are some conflict with the BIOS or hardware
monitoring applications etc., that clears corrected events in
banks instead of OS.
[ And trivial cleanup (space -> tab) for doc is included. ]
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
LKML-Reference: <4A30ACDF.5030408@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (22 commits)
x86: fix system without memory on node0
x86, mm: Fix node_possible_map logic
mm, x86: remove MEMORY_HOTPLUG_RESERVE related code
x86: make sparse mem work in non-NUMA mode
x86: process.c, remove useless headers
x86: merge process.c a bit
x86: use sparse_memory_present_with_active_regions() on UMA
x86: unify 64-bit UMA and NUMA paging_init()
x86: Allow 1MB of slack between the e820 map and SRAT, not 4GB
x86: Sanity check the e820 against the SRAT table using e820 map only
x86: clean up and and print out initial max_pfn_mapped
x86/pci: remove rounding quirk from e820_setup_gap()
x86, e820, pci: reserve extra free space near end of RAM
x86: fix typo in address space documentation
x86: 46 bit physical address support on 64 bits
x86, mm: fault.c, use printk_once() in is_errata93()
x86: move per-cpu mmu_gathers to mm/init.c
x86: move max_pfn_mapped and max_low_pfn_mapped to setup.c
x86: unify noexec handling
x86: remove (null) in /sys kernel_page_tables
...
On Intel platforms machine check exceptions are always broadcast to
all CPUs. This patch makes the machine check handler synchronize all
these machine checks, elect a Monarch to handle the event and collect
the worst event from all CPUs and then process it first.
This has some advantages:
- When there is a truly data corrupting error the system panics as
quickly as possible. This improves containment of corrupted
data and makes sure the corrupted data never hits stable storage.
- The panics are synchronized and do not reenter the panic code
on multiple CPUs (which currently does not handle this well).
- All the errors are reported. Currently it often happens that
another CPU happens to do the panic first, but reports useless
information (empty machine check) because the real error
happened on another CPU which came in later.
This is a big advantage on Nehalem where the 8 threads per CPU
lead to often the wrong CPU winning the race and dumping
useless information on a machine check. The problem also occurs
in a less severe form on older CPUs.
- The system can detect when no CPUs detected a machine check
and shut down the system. This can happen when one CPU is so
badly hung that that it cannot process a machine check anymore
or when some external agent wants to stop the system by
asserting the machine check pin. This follows Intel hardware
recommendations.
- This matches the recommended error model by the CPU designers.
- The events can be output in true severity order
- When a panic happens on another CPU it makes sure to be actually
be able to process the stop IPI by enabling interrupts.
The code is extremly careful to handle timeouts while waiting
for other CPUs. It can't rely on the normal timing mechanisms
(jiffies, ktime_get) because of its asynchronous/lockless nature,
so it uses own timeouts using ndelay() and a "SPINUNIT"
The timeout is configurable. By default it waits for upto one
second for the other CPUs. This can be also disabled.
From some informal testing AMD systems do not see to broadcast
machine checks, so right now it's always disabled by default on
non Intel CPUs or also on very old Intel systems.
Includes fixes from Ying Huang
Fixed a "ecception" in a comment (H.Seto)
Moved global_nwo reset later based on suggestion from H.Seto
v2: Avoid duplicate messages
[ Impact: feature, fixes long standing problems. ]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Document that check_interval set to 0 means no polling.
Noticed by Hidetoshi Seto
Also add a reference from boot options to the sysfs tunables
Acked-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>