Commit d199c96d by Alan Stern ensured that low speed and full speed
devices below a high speed hub without a transaction translator (TT) would
never get enumerated. Simplify the check for a TT in the xHCI virtual
device allocation to only check if the usb_device references a parent's
TT.
Make sure not to set the TT information on LS/FS devices directly
connected to the roothub. The xHCI host doesn't really have a TT, and the
host will throw an error when those virtual device TT fields are set for a
device connected to the roothub. We need this check because the xHCI
driver will shortly register two roothubs: a USB 2.0 roothub and a USB 3.0
roothub.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
The USB core only allows up to 31 (USB_MAXCHILDREN) ports under a roothub.
The xHCI driver keeps track of which ports are suspended, which ports have
a suspend change bit set, and what time the port will be done resuming.
It keeps track of the first two by setting a bit in a u32 variable,
suspended_ports or port_c_suspend. The xHCI driver currently assumes we
can have up to 256 ports under a roothub, so it allocates an array of 8
u32 variables for both suspended_ports and port_c_suspend. It also
allocates a 256-element array to keep track of when the ports will be done
resuming.
Since we can only have 31 roothub ports, we only need to use one u32 for
each of the suspend state and change variables. We simplify the bit math
that's trying to index into those arrays and set the correct bit, if we
assume wIndex never exceeds 30. (wIndex is zero-based after it's
decremented from the value passed in from the USB core.) Finally, we
change the resume_done array to only hold 31 elements.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Andiry Xu <andiry.xu@amd.com>
Functions that are not used outsde of the module they are defined
should be marked as static.
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
There is no point in casting to (void *) when setting up xhci->ir_set
as it only makes us lose __iomem annotation and makes sparse unhappy.
OTOH we do need to cast to (void *) when calculating xhci->dba from
offset, but since it is IO memory we need to annotate it as such.
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
xhci->ir_set points to __iomem region, but xhci_print_ir_set accepts
plain struct xhci_intr_reg * causing multiple sparse warning at call
sites and inside the fucntion when we try to read that memory.
Instead of adding __iomem qualifier to the argument let's rework the
function so it itself gets needed register set from xhci and prints
it.
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Fix two bugs with the port array setup.
The first bug will only show up with broken xHCI hosts with Extended
Capabilities registers that have duplicate port speed entries for the same
port. The idea with the original code was to set the port_array entry to
-1 if the duplicate port speed entry said the port was a different speed
than the original port speed entry. That would mean that later, the port
would not be exposed to the USB core. Unfortunately, I forgot a continue
statement, and the port_array entry would just be overwritten in the next
line.
The second bug would happen if there are conflicting port speed registers
(so that some entry in port_array is -1), or one of the hardware port
registers was not described in the port speed registers (so that some
entry in port_array is 0). The code that sets up the usb2_ports array
would accidentally claim those ports. That wouldn't really cause any
user-visible issues, but it is a bug.
This patch should go into the stable trees that have the port array and
USB 3.0 port disabling prevention patches.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
An xHCI host controller contains USB 2.0 and USB 3.0 ports, which can
occur in any order in the PORTSC registers. We cannot read the port speed
bits in the PORTSC registers at init time to determine the port speed,
since those bits are only valid when a USB device is plugged into the
port.
Instead, we read the "Supported Protocol Capability" registers in the xHC
Extended Capabilities space. Those describe the protocol, port offset in
the PORTSC registers, and port count. We use those registers to create
two arrays of pointers to the PORTSC registers, one for USB 3.0 ports, and
another for USB 2.0 ports. A third array keeps track of the port protocol
major revision, and is indexed with the internal xHCI port number.
This commit is a bit big, but it should be queued for stable because the "Don't
let the USB core disable SuperSpeed ports" patch depends on it. There is no
other way to determine which ports are SuperSpeed ports without this patch.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Don Zickus <dzickus@redhat.com>
Cc: stable@kernel.org
USB2.0 spec 9.6.6 says: For all endpoints, bit 10..0 specify the maximum
packet size(in bytes).
So the wMaxPacketSize mask should be 0x7ff rather than 0x3ff.
This patch should be queued for the stable tree. The bug in
xhci_endpoint_init() was present as far back as 2.6.31, and the bug in
xhci_get_max_esit_payload() was present when the function was introduced
in 2.6.34.
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
This patch implements xHCI bus suspend/resume function hook.
In the patch it goes through all the ports and suspend/resume
the ports if needed.
If any port is in remote wakeup, abort bus suspend as what ehci/ohci do.
Signed-off-by: Libin Yang <libin.yang@amd.com>
Signed-off-by: Crane Cai <crane.cai@amd.com>
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit implements port remote wakeup.
When a port is in U3 state and resume signaling is detected from a device,
the port transitions to the Resume state, and the xHC generates a Port Status
Change Event.
For USB3 port, software write a '0' to the PLS field to complete the resume
signaling. For USB2 port, the resume should be signaling for at least 20ms,
irq handler set a timer for port remote wakeup, and then finishes process in
hub_control GetPortStatus.
Some codes are borrowed from EHCI code.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add software trigger USB device suspend resume function hook.
Do port suspend & resume in terms of xHCI spec.
Port Suspend:
Stop all endpoints via Stop Endpoint Command with Suspend (SP) flag set.
Place individual ports into suspend mode by writing '3' for Port Link State
(PLS) field into PORTSC register. This can only be done when the port is in
Enabled state. When writing, the Port Link State Write Strobe (LWS) bit shall
be set to '1'.
Allocate an xhci_command and stash it in xhci_virt_device to wait completion for
the last Stop Endpoint Command. Use the Suspend bit in TRB to indicate the Stop
Endpoint Command is for port suspend. Based on Sarah's suggestion.
Port Resume:
Write '0' in PLS field, device will transition to running state.
Ring an endpoints' doorbell to restart it.
Ref: USB device remote wake need another patch to implement. For details of
how USB subsystem do power management, please see:
Documentation/usb/power-management.txt
Signed-off-by: Crane Cai <crane.cai@amd.com>
Signed-off-by: Libin Yang <libin.yang@amd.com>
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add a pointer to udev in struct xhci_virt_device. When allocate a new
virt_device, make the pointer point to the corresponding udev.
Modify xhci_check_args(), check if virt_dev->udev matches the target udev,
to make sure command is issued to the right device.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that the event handler functions no longer use xhci_set_hc_event_deq()
to update the event ring dequeue pointer, that function is not used by
anything in xhci-ring.c. Move that function into xhci-mem.c and make it
static.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
I've been using perf to measure the top symbols while transferring 1GB of data
on a USB 3.0 drive with dd. This is using the raw disk with /dev/sdb, with a
block size of 1K.
During performance testing, the top symbol was xhci_triad_to_transfer_ring(), a
function that should return immediately if streams are not enabled for an
endpoint. It turned out that the functions to find the endpoint ring was
defined in xhci-mem.c and used in xhci-ring.c and xhci-hcd.c. I moved a copy of
xhci_triad_to_transfer_ring() and xhci_urb_to_transfer_ring() into xhci-ring.c
and declared them static. I also made a static version of
xhci_urb_to_transfer_ring() in xhci.c.
This improved throughput on a 1GB read of the raw disk with dd from
186MB/s to 195MB/s, and perf reported sampling the xhci_triad_to_transfer_ring()
0.06% of the time, rather than 9.26% of the time.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Isochronous endpoint needs a bigger size of transfer ring. Isochronous URB
consists of multiple packets, each packet needs a isoc td to carry, and
there will be multiple trbs inserted to the ring at one time. One segment
is too small for isochronous endpoints, and it will result in
room_on_ring() check failure and the URB is failed to enqueue.
Allocate bigger ring for isochronous endpoint. 8 segments should be enough.
This will be replaced with dynamic ring expansion in the future.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add urb_priv data structure to xHCI driver. This structure allows multiple
xhci TDs to be linked to one urb, which is essential for isochronous
transfer. For non-isochronous urb, only one TD is needed for one urb;
for isochronous urb, the TD number for the urb is equal to
urb->number_of_packets.
The length field of urb_priv indicates the number of TDs in the urb.
The td_cnt field indicates the number of TDs already processed by xHC.
When td_cnt matches length, the urb can be given back to usbcore.
When an urb is dequeued or cancelled, add all the unprocessed TDs to the
endpoint's cancelled_td_list. When process a cancelled TD, increase
td_cnt field. When td_cnt equals urb_priv->length, giveback the
cancelled urb.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds mechanism to process Missed Service Error Event.
Sometimes the xHC is unable to process the isoc TDs in time, it will
generate Missed Service Error Event. In this case some TDs on the ring are
not processed and missed. When encounter a Missed Servce Error Event, set
the skip flag of the ep, and process the missed TDs until reach the next
processed TD, then clear the skip flag.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The bmAttributes field of the SuperSpeed Endpoint Companion Descriptor has
different meanings, depending on the endpoint type. If the endpoint is
isochronous, the bmAttributes field is the maximum number of packets
within a service interval that this endpoint supports. If the endpoint is
bulk, it's the number of stream IDs this endpoint supports.
Only set the Mult field of the xHCI endpoint context using the
bmAttributes field if the endpoint is isochronous, and the device is a
SuperSpeed device.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When a configured device is reset, the control endpoint's ring is reused.
If control transfers to the device were issued before the device is reset,
the dequeue pointer will be somewhere in the middle of the ring. If the
device is then issued an address with the set address command, the xHCI
driver must provide a valid input context for control endpoint zero.
The original code would give the hardware the original input context,
which had a dequeue pointer set to the top of the ring. This would cause
the host to re-execute any control transfers until it reached the ring's
enqueue pointer. When issuing a set address command for a device that has
just been configured and then reset, use the control endpoint's enqueue
pointer as the hardware's dequeue pointer.
Assumption: All control transfers will be completed or cancelled before
the set address command is issued to the device. If there are any
outstanding control transfers, this code will not work.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1375) eliminates the usb_host_ss_ep_comp structure used
for storing a dynamically-allocated copy of the SuperSpeed endpoint
companion descriptor. The SuperSpeed descriptor is placed directly in
the usb_host_endpoint structure, alongside the standard endpoint
descriptor.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix usb sparse warnings:
drivers/usb/host/isp1362-hcd.c:2220:50: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:43:24: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:49:24: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:161:24: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:198:16: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:319:31: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:1231:33: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-pci.c:177:23: warning: non-ANSI function declaration of function 'xhci_register_pci'
drivers/usb/host/xhci-pci.c:182:26: warning: non-ANSI function declaration of function 'xhci_unregister_pci'
drivers/usb/host/xhci-ring.c:342:32: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:525:34: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1009:32: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1031:32: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1041:16: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1096:30: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1100:27: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:224:27: warning: symbol 'xhci_alloc_container_ctx' was not declared. Should it be static?
drivers/usb/host/xhci-mem.c:242:6: warning: symbol 'xhci_free_container_ctx' was not declared. Should it be static?
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Lothar Wassmann <LW@KARO-electronics.de>
Signed-off By: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Much of the xHCI driver code assumes that endpoints only have one ring.
Now an endpoint can have one ring per enabled stream ID, so correct that
assumption. Use functions that translate the stream_id field in the URB
or the DMA address of a TRB into the correct stream ring.
Correct the polling loop to print out all enabled stream rings. Make the
URB cancellation routine find the correct stream ring if the URB has
stream_id set. Make sure the URB enqueueing routine does the same. Also
correct the code that handles stalled/halted endpoints.
Check that commands and registers that can take stream IDs handle them
properly. That includes ringing an endpoint doorbell, resetting a
stalled/halted endpoint, and setting a transfer ring dequeue pointer
(since that command can set the dequeue pointer in a stream context or an
endpoint context).
Correct the transfer event handler to translate a TRB DMA address into the
stream ring it was enqueued to. Make the code to allocate and prepare TD
structures adds the TD to the right td_list for the stream ring. Make
sure the code to give the first TRB in a TD to the hardware manipulates
the correct stream ring.
When an endpoint stalls, store the stream ID of the stream ring that
stalled in the xhci_virt_ep structure. Use that instead of the stream ID
in the URB, since an URB may be re-used after it is given back after a
non-control endpoint stall.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add support for allocating streams for USB 3.0 bulk endpoints. See
Documentation/usb/bulk-streams.txt for more information about how and why
you would use streams.
When an endpoint has streams enabled, instead of having one ring where all
transfers are enqueued to the hardware, it has several rings. The ring
dequeue pointer in the endpoint context is changed to point to a "Stream
Context Array". This is basically an array of pointers to transfer rings,
one for each stream ID that the driver wants to use.
The Stream Context Array size must be a power of two, and host controllers
can place a limit on the size of the array (4 to 2^16 entries). These
two facts make calculating the size of the Stream Context Array and the
number of entries actually used by the driver a bit tricky.
Besides the Stream Context Array and rings for all the stream IDs, we need
one more data structure. The xHCI hardware will not tell us which stream
ID a transfer event was for, but it will give us the slot ID, endpoint
index, and physical address for the TRB that caused the event. For every
endpoint on a device, add a radix tree to map physical TRB addresses to
virtual segments within a stream ring.
Keep track of whether an endpoint is transitioning to using streams, and
don't enqueue any URBs while that's taking place. Refuse to transition an
endpoint to streams if there are already URBs enqueued for that endpoint.
We need to make sure that freeing streams does not fail, since a driver's
disconnect() function may attempt to do this, and it cannot fail.
Pre-allocate the command structure used to issue the Configure Endpoint
command, and reserve space on the command ring for each stream endpoint.
This may be a bit overkill, but it is permissible for the driver to
allocate all streams in one call and free them in multiple calls. (It is
not advised, however, since it is a waste of resources and time.)
Even with the memory and ring room pre-allocated, freeing streams can
still fail because the xHC rejects the configure endpoint command. It is
valid (by the xHCI 0.96 spec) to return a "Bandwidth Error" or a "Resource
Error" for a configure endpoint command. We should never see a Bandwidth
Error, since bulk endpoints do not effect the reserved bandwidth. The
host controller can still return a Resource Error, but it's improbable
since the xHC would be going from a more resource-intensive configuration
(streams) to a less resource-intensive configuration (no streams).
If the xHC returns a Resource Error, the endpoint will be stuck with
streams and will be unusable for drivers. It's an unavoidable consequence
of broken host controller hardware.
Includes bug fixes from the original patch, contributed by
John Youn <John.Youn@synopsys.com> and Andy Green <AGreen@PLXTech.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
For periodic endpoints, we must let the xHCI hardware know the maximum
payload an endpoint can transfer in one service interval. The xHCI
specification refers to this as the Maximum Endpoint Service Interval Time
Payload (Max ESIT Payload). This is used by the hardware for bandwidth
management and scheduling of packets.
For SuperSpeed endpoints, the maximum is calculated by multiplying the max
packet size by the number of bursts and the number of opportunities to
transfer within a service interval (the Mult field of the SuperSpeed
Endpoint companion descriptor). Devices advertise this in the
wBytesPerInterval field of their SuperSpeed Endpoint Companion Descriptor.
For high speed devices, this is taken by multiplying the max packet size by the
"number of additional transaction opportunities per microframe" (the high
bits of the wMaxPacketSize field in the endpoint descriptor).
For FS/LS devices, this is just the max packet size.
The other thing we must set in the endpoint context is the Average TRB
Length. This is supposed to be the average of the total bytes in the
transfer descriptor (TD), divided by the number of transfer request blocks
(TRBs) it takes to describe the TD. This gives the host controller an
indication of whether the driver will be enqueuing a scatter gather list
with many entries comprised of small buffers, or one contiguous buffer.
It also takes into account the number of extra TRBs you need for every TD.
This includes No-op TRBs and Link TRBs used to link ring segments
together. Some drivers may choose to chain an Event Data TRB on the end
of every TD, thus increasing the average number of TRBs per TD. The Linux
xHCI driver does not use Event Data TRBs.
In theory, if there was an API to allow drivers to state what their
bandwidth requirements are, we could set this field accurately. For now,
we set it to the same number as the Max ESIT payload.
The Average TRB Length should also be set for bulk and control endpoints,
but I have no idea how to guess what it should be.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A SuperSpeed interrupt or isochronous endpoint can define the number of
"burst transactions" it can handle in a service interval. This is
indicated by the "Mult" bits in the bmAttributes of the SuperSpeed
Endpoint Companion Descriptor. For example, if it has a max packet size
of 1024, a max burst of 11, and a mult of 3, the host may send 33
1024-byte packets in one service interval.
We must tell the xHCI host controller the number of multiple service
opportunities (mults) the device can handle when the endpoint is
installed. We do that by setting the Mult field of the Endpoint Context
before a configure endpoint command is sent down. The Mult field is
invalid for control or bulk SuperSpeed endpoints.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
The xHCI hardware can only handle polling intervals that are a power of
two. When we add a new endpoint during a bandwidth allocation, and the
polling interval is rounded down to a power of two, print the original
polling interval in the endpoint descriptor.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It's really the wireless speed, so rename the thing to make
more sense. Based on a recommendation from David Vrabel
Cc: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The xhci_command structure is the basic structure for issuing commands to
the xHCI hardware. It contains a struct completion (so that the issuing
function can wait on the command), command status, and a input context
that is used to pass information to the hardware. Not all commands need
the input context, so make it optional to allocate. Allow
xhci_free_container_ctx() to be passed a NULL input context, to make
freeing the xhci_command structure simple.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Refactor out the code to cache or free endpoint rings from recently
dropped or disabled endpoints. This code will be used by a new function
to reset a device and disable all endpoints except control endpoint 0.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When a driver wants to switch to a different alternate setting for an
interface, the USB core will (soon) check whether there is enough
bandwidth. Once the new alternate setting is installed in the xHCI
hardware, the USB core will send a USB_REQ_SET_INTERFACE control
message. That can fail in various ways, and the USB core needs to be
able to reinstate the old alternate setting.
With the old code, reinstating the old alt setting could fail if the
there's not enough memory to allocate new endpoint rings. Keep
around a cache of (at most 31) endpoint rings for this case. When we
successfully switch the xHCI hardware to the new alt setting, the old
alt setting's rings will be stored in the cache. Therefore we'll
always have enough rings to satisfy a conversion back to a previous
device setting.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It's not surprising that the transfer request buffer (TRB) physical to
virtual address translation function has bugs in it, since I wrote most of
it at 4am last October. Add a test suite to check the TRB math. This
runs at memory initialization time, and causes the driver to fail to load
if the TRB math fails.
Please excuse the excessively long lines in the test vectors; they can't
really be made shorter and still be readable.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In order to giveback a canceled URB, we must ensure that the xHCI
hardware will not access the buffer in an URB. We can't modify the
buffer pointers on endpoint rings without issuing and waiting for a stop
endpoint command. Since URBs can be canceled in interrupt context, we
can't wait on that command. The old code trusted that the host
controller would respond to the command, and would giveback the URBs in
the event handler. If the hardware never responds to the stop endpoint
command, the URBs will never be completed, and we might hang the USB
subsystem.
Implement a watchdog timer that is spawned whenever a stop endpoint
command is queued. If a stop endpoint command event is found on the
event ring during an interrupt, we need to stop the watchdog timer with
del_timer(). Since del_timer() can fail if the timer is running and
waiting on the xHCI lock, we need a way to signal to the timer that
everything is fine and it should exit. If we simply clear
EP_HALT_PENDING, a new stop endpoint command could sneak in and set it
before the watchdog timer can grab the lock.
Instead we use a combination of the EP_HALT_PENDING flag and a counter
for the number of pending stop endpoint commands
(xhci_virt_ep->stop_cmds_pending). If we need to cancel the watchdog
timer and del_timer() succeeds, we decrement the number of pending stop
endpoint commands. If del_timer() fails, we leave the number of pending
stop endpoint commands alone. In either case, we clear the
EP_HALT_PENDING flag.
The timer will decrement the number of pending stop endpoint commands
once it obtains the lock. If the timer is the tail end of the last stop
endpoint command (xhci_virt_ep->stop_cmds_pending == 0), and the
endpoint's command is still pending (EP_HALT_PENDING is set), we assume
the host is dying. The watchdog timer will set XHCI_STATE_DYING, try to
halt the xHCI host, and give back all pending URBs.
Various other places in the driver need to check whether the xHCI host
is dying. If the interrupt handler ever notices, it should immediately
stop processing events. The URB enqueue function should also return
-ESHUTDOWN. The URB dequeue function should simply return the value
of usb_hcd_check_unlink_urb() and the watchdog timer will take care of
giving the URB back. When a device is disconnected, the xHCI hardware
structures should be freed without issuing a disable slot command (since
the hardware probably won't respond to it anyway). The debugging
polling loop should stop polling if the host is dying.
When a device is disconnected, any pending watchdog timers are killed
with del_timer_sync(). It must be synchronous so that the watchdog
timer doesn't attempt to access the freed endpoint structures.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The scratchpad_free() function uses xhci->page_size to free some memory
with pci_free_consistent(). However, the page_size is set to zero before
the call, causing kernel oopses on driver unload. Call scratchpad_free()
before setting xhci->page_size to zero.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Acked-by: John Youn <John.Youn@synopsys.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
If the xHCI driver fails during the memory initialization, xhci->ir_set
may not be a valid pointer. Check that it points to valid DMA'able memory
before writing to that address during the memory freeing process.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When setting up a slot context for an address device command, set the
multi-TT field if this is a low or full speed device under a HS hub with
multiple transaction translators.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The xHCI driver needs to set the route string in the slot context of all
devices, not just SuperSpeed devices. The route string concept was added
in the USB 3.0 specification, section 10.1.3.2. Each hub in the topology
is expected to have no more than 15 ports in order for the route string of
a device to be unique. SuperSpeed hubs are restricted to only having 15
ports, but FS/LS/HS hubs are not. The xHCI specification says that if the
port number the device is under is greater than 15, that portion of the
route string shall be set to 15.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some commands to the xHCI hardware cannot be allowed to fail due to out of
memory issues or the command ring being full.
Add a way to reserve a TRB on the command ring, and make all command
queueing functions indicate whether they are using a reserved TRB.
Add a way to pre-allocate all the memory a command might need. A command
needs an input context, a variable to store the status, and (optionally) a
completion for the caller to wait on. Change all code that assumes the
input device context, status, and completion for a command is stored in
the xhci virtual USB device structure (xhci_virt_device).
Store pending completions in a FIFO in xhci_virt_device. Make the event
handler for a configure endpoint command check to see whether a pending
command in the list has completed. We need to use separate input device
contexts for some configure endpoint commands, since multiple drivers can
submit requests at the same time that require a configure endpoint
command.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The xhci_ring structure contained information that is really related to an
endpoint, not a ring. This will cause problems later when endpoint
streams are supported and there are multiple rings per endpoint.
Move the endpoint state and cancellation information into a new virtual
endpoint structure, xhci_virt_ep. The list of TRBs to be cancelled should
be per endpoint, not per ring, for easy access. There can be only one TRB
that the endpoint stopped on after a stop endpoint command (even with
streams enabled); move the stopped TRB information into the new virtual
endpoint structure. Also move the 31 endpoint rings and temporary ring
storage from the virtual device structure (xhci_virt_device) into the
virtual endpoint structure (xhci_virt_ep).
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Set the max packet size for the default control endpoint on high speed
devices to be 64 bytes. High speed devices always have a max packet size
of 64 bytes. There's no use setting it to eight for the initial 8 byte
descriptor fetch and then issuing (and waiting for) an evaluate context
command to update it to 64 bytes for the subsequent control transfers.
The USB core guesses that the max packet size on a full speed control
endpoint is 64 bytes, and then updates it after the first 8-byte
descriptor fetch. Change the initial setup for the xHCI internal
representation of the full speed device to have a 64 byte max packet size.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Refactor out the code issue, wait for, and parse the event completion code
for a configure endpoint command. Modify it to support the evaluate
context command, which has a very similar submission process. Add
functions to copy parts of the output context into the input context
(which will be used in the evaluate context command).
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Different sections of the xHCI 0.95 specification had opposing
requirements for the chain bit in a link transaction request buffer (TRB).
The chain bit is used to designate that adjacent TRBs are all part of the
same scatter gather list that should be sent to the device. Link TRBs can
be in the middle, or at the beginning or end of these chained TRBs.
Sections 4.11.5.1 and 6.4.4.1 both stated the link TRB "shall have the
chain bit set to 1", meaning it is always chained to the next TRB.
However, section 4.6.9 on the stop endpoint command has specific cases for
what the hardware must do for a link TRB with the chain bit set to 0. The
0.96 specification errata later cleared up this issue by fixing the
4.11.5.1 and 6.4.4.1 sections to state that a link TRB can have the chain
bit set to 1 or 0.
The problem is that the xHCI cancellation code depends on the chain bit of
the link TRB being cleared when it's at the end of a TD, and some 0.95
xHCI hardware simply stops processing the ring when it encounters a link
TRB with the chain bit cleared.
Allow users who are testing 0.95 xHCI prototypes to set a module parameter
(link_quirk) to turn on this link TRB work around. Cancellation may not
work if the ring is stopped exactly on a link TRB with chain bit set, but
cancellation should be a relatively uncommon case.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Adds support for controllers that use 64-byte contexts. The following context
data structures are affected by this: Device, Input, Input Control, Endpoint,
and Slot. To accommodate the use of either 32 or 64-byte contexts, a Device or
Input context can only be accessed through functions which look-up and return
pointers to their contained contexts.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sure the xHCI output device context is 64-byte aligned. Previous
code was using the same structure for both the output device context and
the input control context. Since the structure had 32 bytes of flags
before the device context, the output device context wouldn't be 64-byte
aligned. Define a new structure to use for the output device context and
clean up the debugging for these two structures.
The copy of the device context in the input control context does *not*
need to be 64-byte aligned.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Allocates and initializes the scratchpad buffer array (XHCI 4.20). This is an
array of 64-bit DMA addresses to scratch pages that the controller may use
during operation. The number of pages is specified in the "Max Scratchpad
Buffers" field of HCSPARAMS2. The DMA address of this array is written into
slot 0 of the DCBAA.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is a work around for a bug in the SuperSpeed Endpoint Companion Descriptor
parsing code. It fails in some corner cases, which means ep->ss_ep_comp may be
NULL.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The xHCI host controller can be programmed to retry a transfer a certain number
of times per endpoint before it passes back an error condition to the host
controller driver. The xHC will return an error code when the error count
transitions from 1 to 0. Programming an error count of 3 means the xHC tries
the transfer 3 times, programming it with a 1 means it tries to transfer once,
and programming it with 0 means the HW tries the transfer infinitely.
We want isochronous transfers to only be tried once, so set the error count to
one.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are several xHCI data structures that use two 32-bit fields to
represent a 64-bit address. Since some architectures don't support 64-bit
PCI writes, the fields need to be written in two 32-bit writes. The xHCI
specification says that if a platform is incapable of generating 64-bit
writes, software must write the low 32-bits first, then the high 32-bits.
Hardware that supports 64-bit addressing will wait for the high 32-bit
write before reading the revised value, and hardware that only supports
32-bit writes will ignore the high 32-bit write.
Previous xHCI code represented 64-bit addresses with two u32 values. This
lead to buggy code that would write the 32-bits in the wrong order, or
forget to write the upper 32-bits. Change the two u32s to one u64 and
create a function call to write all 64-bit addresses in the proper order.
This new function could be modified in the future if all platforms support
64-bit writes.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Narrow down time spent holding the xHCI spinlock so that it's only used to
protect the xHCI rings, not as mutual exclusion. Stop allocating memory
while holding the spinlock and calling xhci_alloc_virt_device() and
xhci_endpoint_init().
The USB core should have locking in it to prevent device state to be
manipulated by more than one kernel thread. E.g. you can't free a device
while you're in the middle of setting a new configuration. So removing
the locks from the sections where xhci_alloc_dev() and
xhci_reset_bandwidth() touch xHCI's representation of the device should be
OK.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
xhci-mem.c includes calls to dma_pool_alloc() and other functions defined
in linux/dmapool.h. Make sure to include that header file.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Differentiate between SuperSpeed endpoint companion descriptor and the
wireless USB endpoint companion descriptor. Make all structure names for
this descriptor have "ss" (SuperSpeed) in them. David Vrabel asked for
this change in http://marc.info/?l=linux-usb&m=124091465109367&w=2
Reported-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make all globally visible functions start with xhci_ and mark functions as
static if they're only called within the same C file. Fix some long lines
while we're at it.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The 0.95 xHCI spec says that if the xHCI HW support 64-bit addressing, you
must write the whole 64-bit address as one atomic operation, or write the
low 32 bits, and then the high 32 bits. I had the register writes
swapped in some places.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Turns out someone never built this code on a 64bit platform.
Someone owes me a beer...
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add URB cancellation support to the xHCI host controller driver. This
currently supports cancellation for endpoints that do not have streams
enabled.
An URB is represented by a number of Transaction Request Buffers (TRBs),
that are chained together to make one (or more) Transaction Descriptors
(TDs) on an endpoint ring. The ring is comprised of contiguous segments,
linked together with Link TRBs (which may or may not be chained into a TD).
To cancel an URB, we must stop the endpoint ring, make the hardware skip
over the TDs in the URB (either by turning them into No-op TDs, or by
moving the hardware's ring dequeue pointer past the last TRB in the last
TD), and then restart the ring.
There are times when we must drop the xHCI lock during this process, like
when we need to complete cancelled URBs. We must ensure that additional
URBs can be marked as cancelled, and that new URBs can be enqueued (since
the URB completion handlers can do either). The new endpoint ring
variables cancels_pending and state (which can only be modified while
holding the xHCI lock) ensure that future cancellation and enqueueing do
not interrupt any pending cancellation code.
To facilitate cancellation, we must keep track of the starting ring
segment, first TRB, and last TRB for each URB. We also need to keep track
of the list of TDs that have been marked as cancelled, separate from the
list of TDs that are queued for this endpoint. The new variables and
cancellation list are stored in the xhci_td structure.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Allow device drivers to submit URBs to bulk endpoints on devices under an
xHCI host controller. Share code between the control and bulk enqueueing
functions when it makes sense.
To get the best performance out of bulk transfers, SuperSpeed devices must
have the bMaxBurst size copied from their endpoint companion controller
into the xHCI device context. This allows the host controller to "burst"
up to 16 packets before it has to wait for the device to acknowledge the
first packet.
The buffers in Transfer Request Blocks (TRBs) can cross page boundaries,
but they cannot cross 64KB boundaries. The buffer must be broken into
multiple TRBs if a 64KB boundary is crossed.
The sum of buffer lengths in all the TRBs in a Transfer Descriptor (TD)
cannot exceed 64MB. To work around this, the enqueueing code must enqueue
multiple TDs. The transfer event handler may incorrectly give back the
URB in this case, if it gets a transfer event that points somewhere in the
first TD. FIXME later.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Since the xHCI host controller hardware (xHC) has an internal schedule, it
needs a better representation of what devices are consuming bandwidth on
the bus. Each device is represented by a device context, with data about
the device, endpoints, and pointers to each endpoint ring.
We need to update the endpoint information for a device context before a
new configuration or alternate interface setting is selected. We setup an
input device context with modified endpoint information and newly
allocated endpoint rings, and then submit a Configure Endpoint Command to
the hardware.
The host controller can reject the new configuration if it exceeds the bus
bandwidth, or the host controller doesn't have enough internal resources
for the configuration. If the command fails, we still have the older
device context with the previous configuration. If the command succeeds,
we free the old endpoint rings.
The root hub isn't a real device, so always say yes to any bandwidth
changes for it.
The USB core will enable, disable, and then enable endpoint 0 several
times during the initialization sequence. The device will always have an
endpoint ring for endpoint 0 and bandwidth allocated for that, unless the
device is disconnected or gets a SetAddress 0 request. So we don't pay
attention for when xhci_check_bandwidth() is called for a re-add of
endpoint 0.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Allow device drivers to enqueue URBs to control endpoints on devices under
an xHCI host controller. Each control transfer is represented by a
series of Transfer Descriptors (TDs) written to an endpoint ring. There
is one TD for the Setup phase, (optionally) one TD for the Data phase, and
one TD for the Status phase.
Enqueue these TDs onto the endpoint ring that represents the control
endpoint. The host controller hardware will return an event on the event
ring that points to the (DMA) address of one of the TDs on the endpoint
ring. If the transfer was successful, the transfer event TRB will have a
completion code of success, and it will point to the Status phase TD.
Anything else is considered an error.
This should work for control endpoints besides the default endpoint, but
that hasn't been tested.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
xHCI needs to get a "Slot ID" from the host controller and allocate other
data structures for every USB device. Make usb_alloc_dev() and
usb_release_dev() allocate and free these device structures. After
setting up the xHC device structures, usb_alloc_dev() must wait for the
hardware to respond to an Enable Slot command. usb_alloc_dev() fires off
a Disable Slot command and does not wait for it to complete.
When the USB core wants to choose an address for the device, the xHCI
driver must issue a Set Address command and wait for an event for that
command.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
xHCI host controllers can optionally implement a no-op test. This
simple test ensures the OS has correctly setup all basic data structures
and can correctly respond to interrupts from the host controller
hardware.
There are two rings exercised by the no-op test: the command ring, and
the event ring.
The host controller driver writes a no-op command TRB to the command
ring, and rings the doorbell for the command ring (the first entry in
the doorbell array). The hardware receives this event, places a command
completion event on the event ring, and fires an interrupt.
The host controller driver sees the interrupt, and checks the event ring
for TRBs it can process, and sees the command completion event. (See
the rules in xhci-ring.c for who "owns" a TRB. This is a simplified set
of rules, and may not contain all the details that are in the xHCI 0.95
spec.)
A timer fires every 60 seconds to debug the state of the hardware and
command and event rings. This timer only runs if
CONFIG_USB_XHCI_HCD_DEBUGGING is 'y'.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Instead of keeping a "frame list" like older host controllers, the xHCI
host controller keeps internal representations of the USB devices, with a
transfer ring per endpoint. The host controller queues Transfer Request
Blocks (TRBs) to the endpoint ring, and then "rings the doorbell" for that
device. The host controller processes the transfer, places a transfer
completion event on the event ring, and interrupts the system.
The device context base address array must be allocated by the xHCI host
controller driver, along with the device contexts it points to.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Allocate basic xHCI host controller data structures. For every xHC, there
is a command ring, an event ring, and a doorbell array.
The doorbell array is used to notify the host controller that work has
been enqueued onto one of the rings. The host controller driver enqueues
commands on the command ring. The HW enqueues command completion events
on the event ring and interrupts the system (currently using PCI
interrupts, although the xHCI HW will use MSI interrupts eventually).
All rings and the doorbell array must be allocated by the xHCI host
controller driver.
Each ring is comprised of one or more segments, which consists of 16-byte
Transfer Request Blocks (TRBs) that can be chained to form a Transfer
Descriptor (TD) that represents a multiple-buffer request. Segments are
linked into a ring using Link TRBs, which means they are dynamically
growable.
The producer of the ring enqueues a TD by writing one or more TRBs in the
ring and toggling the TRB cycle bit for each TRB. The consumer knows it
can process the TRB when the cycle bit matches its internal consumer cycle
state for the ring. The consumer cycle state is toggled an odd amount of
times in the ring.
An example ring (a ring must have a minimum of 16 TRBs on it, but that's
too big to draw in ASCII art):
chain cycle
bit bit
------------------------
| TD A TRB 1 | 1 | 1 |<------------- <-- consumer dequeue ptr
------------------------ | consumer cycle state = 1
| TD A TRB 2 | 1 | 1 | |
------------------------ |
| TD A TRB 3 | 0 | 1 | segment 1 |
------------------------ |
| TD B TRB 1 | 1 | 1 | |
------------------------ |
| TD B TRB 2 | 0 | 1 | |
------------------------ |
| Link TRB | 0 | 1 |----- |
------------------------ | |
| |
chain cycle | |
bit bit | |
------------------------ | |
| TD C TRB 1 | 0 | 1 |<---- |
------------------------ |
| TD D TRB 1 | 1 | 1 | |
------------------------ |
| TD D TRB 2 | 1 | 1 | segment 2 |
------------------------ |
| TD D TRB 3 | 1 | 1 | |
------------------------ |
| TD D TRB 4 | 1 | 1 | |
------------------------ |
| Link TRB | 1 | 1 |----- |
------------------------ | |
| |
chain cycle | |
bit bit | |
------------------------ | |
| TD D TRB 5 | 1 | 1 |<---- |
------------------------ |
| TD D TRB 6 | 0 | 1 | |
------------------------ |
| TD E TRB 1 | 0 | 1 | segment 3 |
------------------------ |
| | 0 | 0 | | <-- producer enqueue ptr
------------------------ |
| | 0 | 0 | |
------------------------ |
| Link TRB | 0 | 0 |---------------
------------------------
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add PCI initialization code to take control of the xHCI host controller
away from the BIOS, halt, and reset the host controller. The xHCI spec
says that BIOSes must give up the host controller within 5 seconds.
Add some host controller glue functions to handle hardware initialization
and memory allocation for the host controller. The current xHCI
prototypes use PCI interrupts, but the xHCI spec requires MSI-X
interrupts. Add code to support MSI-X interrupts, but use the PCI
interrupts for now.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
