All other AER-related log messages use the PCI device, e.g.,
"pci 0000:00:1c.0", not the PCIe service device, e.g.,
"aer 0000:00:1c.0:pcie02".
Change the probe error messages to match the rest and include a little
context.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Remove the unused DRIVER_VERSION, DRIVER_AUTHOR, and DRIVER_DESC macros.
The author information is already included in a comment above.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
0516c8bcd2 ("PCI: PCIe portdrv: Simplily probe callback of service
drivers") removed the "id" argument of aer_probe() but neglected to remove
the kernel-doc comment. Update the comment.
[bhelgaas: changelog]
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Save the position of the error reporting capability so it doesn't need to
be rediscovered during error handling.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Lukas Wunner <lukas@wunner.de>
Per the PCI Firmware spec, r3.0, sec 4.5.1, on ACPI systems, the OS must
not use AER unless _OSC is present and _OSC grants AER control to the OS.
The aerdriver.forceload kernel parameter was a way to enable Linux AER
support on ACPI systems that lack _OSC or fail to grant control the the OS.
Enabling Linux AER support when the firmware doesn't want us to is a recipe
for problems, e.g., the firmware might be handling AER itself.
Remove the aerdriver.forceload kernel parameter and related supporting
code.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This code is not being built as a module by anyone:
obj-$(CONFIG_PCIEAER) += aerdriver.o
aerdriver-objs := aerdrv_errprint.o aerdrv_core.o aerdrv.o
drivers/pci/pcie/aer/Kconfig:config PCIEAER
drivers/pci/pcie/aer/Kconfig: bool "Root Port Advanced Error Reporting support"
Remove uses of MODULE_DESCRIPTION(), MODULE_AUTHOR(), MODULE_LICENSE(),
etc., so that when reading the driver there is no doubt it is builtin-only.
The information is preserved in comments at the top of the file.
Note that for non-modular code, module_init() translates to
device_initcall().
[bhelgaas: changelog]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Tom Long Nguyen <tom.l.nguyen@intel.com>
A Root Port's AER structure (rpc) contains a queue of events. aer_irq()
enqueues AER status information and schedules aer_isr() to dequeue and
process it. When we remove a device, aer_remove() waits for the queue to
be empty, then frees the rpc struct.
But aer_isr() references the rpc struct after dequeueing and possibly
emptying the queue, which can cause a use-after-free error as in the
following scenario with two threads, aer_isr() on the left and a
concurrent aer_remove() on the right:
Thread A Thread B
-------- --------
aer_irq():
rpc->prod_idx++
aer_remove():
wait_event(rpc->prod_idx == rpc->cons_idx)
# now blocked until queue becomes empty
aer_isr(): # ...
rpc->cons_idx++ # unblocked because queue is now empty
... kfree(rpc)
mutex_unlock(&rpc->rpc_mutex)
To prevent this problem, use flush_work() to wait until the last scheduled
instance of aer_isr() has completed before freeing the rpc struct in
aer_remove().
I reproduced this use-after-free by flashing a device FPGA and
re-enumerating the bus to find the new device. With SLUB debug, this
crashes with 0x6b bytes (POISON_FREE, the use-after-free magic number) in
GPR25:
pcieport 0000:00:00.0: AER: Multiple Corrected error received: id=0000
Unable to handle kernel paging request for data at address 0x27ef9e3e
Workqueue: events aer_isr
GPR24: dd6aa000 6b6b6b6b 605f8378 605f8360 d99b12c0 604fc674 606b1704 d99b12c0
NIP [602f5328] pci_walk_bus+0xd4/0x104
[bhelgaas: changelog, stable tag]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org
One PCI bus reset function to rule them all.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CONFIG_HOTPLUG is going away as an option so __devexit_p, __devint,
__devinitdata, __devinitconst, and _devexit are no longer needed.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pci/stephen-const:
make drivers with pci error handlers const
scsi: make pci error handlers const
netdev: make pci_error_handlers const
PCI: Make pci_error_handlers const
Since pci_error_handlers is just a function table make it const.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Linas Vepstas <linasvepstas@gmail.com>
Introduce an inline function pci_pcie_type(dev) to extract PCIe
device type from pci_dev->pcie_flags_reg field, and prepare for
removing pci_dev->pcie_type.
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Move the evaluation of acpi_pci_osc_control_set() (to request control of
PCI Express native features) into acpi_pci_root_add() to avoid calling
it many times for the same root complex with the same arguments.
Additionally, check if all of the requisite _OSC support bits are set
before calling acpi_pci_osc_control_set() for a given root complex.
References: https://bugzilla.kernel.org/show_bug.cgi?id=20232
Reported-by: Ozan Caglayan <ozan@pardus.org.tr>
Tested-by: Ozan Caglayan <ozan@pardus.org.tr>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
There is a design issue related to PCIe AER and _OSC that the BIOS
may be asked to grant control of the AER service even if some
Hardware Error Source Table (HEST) entries contain information
meaning that the BIOS really should control it. Namely,
pcie_port_acpi_setup() calls pcie_aer_get_firmware_first() that
determines whether or not the AER service should be controlled by
the BIOS on the basis of the HEST information for the given PCIe
port. The BIOS is asked to grant control of the AER service for
a PCIe Root Complex if pcie_aer_get_firmware_first() returns 'false'
for at least one root port in that complex, even if all of the other
root ports' HEST entries have the FIRMWARE_FIRST flag set (and none
of them has the GLOBAL flag set). However, if the AER service is
controlled by the kernel, that may interfere with the BIOS' handling
of the error sources having the FIRMWARE_FIRST flag. Moreover,
there may be PCIe endpoints that have the FIRMWARE_FIRST flag set in
HEST and are attached to the root ports in question, in which case it
also may be unsafe to ask the BIOS for control of the AER service.
For this reason, introduce a function checking if there's at least
one PCIe-related HEST entry with the FIRMWARE_FIRST flag set and
disable the native AER service altogether if this function returns
'true'.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Introduce a function allowing the caller to check whether to try to
enable PCIe AER.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Skip zero-ing in aer_alloc_rpc() since it is allocated by kzalloc().
The closing comment marker "*/" is recommended for kernel-doc comments.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
I noticed that when I inject a fatal error to an endpoint via
aer-inject, aer_root_reset() is called as reset_link for a
downstream port at upstream of the endpoint:
pcieport 0000:00:06.0: AER: Uncorrected (Fatal) error received: id=5401
:
pcieport 0000:52:02.0: Root Port link has been reset
It externally appears to be working, but internally issues some
accesses to PCI_ERR_ROOT_COMMAND/STATUS registers that is for
root port so not available on downstream port.
This patch introduces default_downstream_reset_link that is
a version of aer_root_reset() with no accesses to root port's
register. It is used for downstream ports that has no reset_link
function its specific.
This patch also updates related description in pcieaer-howto.txt.
Some minor fixes are included.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Make it clear that we only interest in 2 *_RCV bits.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
These functions are only called from init/remove path of aerdrv,
so move them from aerdrv_core.c to aerdrv.c, to make them static.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This cleanup solves some minor naming issues by removing unuseful
function aer_delete_rootport() and by renaming disable_root_aer()
to aer_disable_rootport().
- Inconsistent location of alloc & free:
The struct rpc is allocated in aer_alloc_rpc() at aerdrv.c
while it is implicitly freed in aer_delete_rootport() at
aerdrv_core.c.
- Inconsistent function name:
It makes a bit confusion that aer_delete_rootport() is seemed
to be paired with aer_enable_rootport(), i.e. there is neither
"add" against "delete" nor "disable" against "enable".
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
While testing completion timeouts I found that hardware was not recovering.
It looks like the hot reset was never being propagated to the endpoint
devices on the bus due to the fact that we were clearing the bit too
quickly.
The documentation I have states that we should be transmitting hot reset
TS1s for 2ms. To achieve this I have added a 2ms delay from the time we
set the secondary bus reset bit to the time we clear it. In addition I
changed the define used for the secondary bus reset bit to match the
register define that was being used.
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
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>
Remove 'port_type' field in struct pcie_port_data(), because we can
get port type information from struct pci_dev. With this change, this
patch also does followings:
- Remove struct pcie_port_data because it no longer has any field.
- Remove portdrv private definitions about port type (PCIE_RC_PORT,
PCIE_SW_UPSTREAM_PORT and PCIE_SW_DOWNSTREAM_PORT), and use generic
definitions instead.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Use pcie_cap() instead of pci_find_capability() to get PCIe capability
offset in PCIe AER driver. This avoids unnecessary search in PCI
configuration space.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
PCI: Prevent AER driver from being loaded on non-root port PCIE devices
PCI: get larger bridge ranges when space is available
PCI: pci.c: fix kernel-doc notation
PCI quirk: TI XIO200a erroneously reports support for fast b2b transfers
PCI PM: Read device power state from register after updating it
PCI: remove pci_assign_resource_fixed()
PCI: PCIe portdrv: remove "-driver" from driver name
After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
A bug was seen on boards using a PLX 8518 switch device which advertises
AER on each of it's transparent bridges. The AER driver was loaded for
each bridge and this driver tried to access the AER source ID register
whenever an interrupt occured on the shared PCI INTX lines. The source
ID register does not exist on non root port PCIE device's which
advertise AER and trying to access this register causes a unsupported
request error on the bridge. Thus, when the next interrupt occurs,
another error is found and the non existent source ID register is
accessed again, and so it goes on.
The result is a spammed dmesg with unsupported request PCI express
errors on the bridge device that the AER driver is loaded against.
Reported-by: Malcolm Crossley <malcolm.crossley2@gefanuc.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: Malcolm Crossley <malcolm.crossley2@gefanuc.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
When booting with pci=nomsi aer causes lost interrupts and
lockdep inversions.
So check if MSIs are not disabled before initializing the aer
driver.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This is used by PCIE AER error injection to fake an PCI AER interrupt.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Implement pm object for the PCI Express port driver in order to use
the new power management framework and reduce the code size.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The PCI Express port driver uses 'struct pcie_port_service_id' for
matching port service devices and drivers, but this structure
contains fields that duplicate information from the port device
itself (vendor, device, subvendor, subdevice) and fields that are not
used by any existing port service driver (class, class_mask,
drvier_data). Also, both existing port service drivers (AER and
PCIe HP) don't even use the vendor and device fields for device
matching. Therefore 'struct pcie_port_service_id' can be removed
altogether and the only useful members of it (port_type, service) can
be introduced directly into the port service device and port service
driver structures. That simplifies the code quite a bit and reduces
its size.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The second argument of the ->probe() callback in
struct pcie_port_service_driver is unnecessary and never used.
Remove it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Remove some open coded (and buggy) versions of pci_find_ext_capability
in favor of the real routine in the PCI core.
Tested-by: Tomasz Czernecki <czernecki@gmail.com>
Acked-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
While refreshing my physical PCI slot series against upstream, I
noticed a few simple sparse/compile warnings that were easy to
fix.
Fix the following sparse warnings in PCIe:
drivers/pci/pcie/aer/aerdrv.c:86:6: warning: symbol 'pci_no_aer'
was not declared. Should it be static?
drivers/pci/pcie/portdrv_bus.c:21:17: warning: symbol
'pcie_port_bus_type' was not declared. Should it be static?
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
For cases in which CONFIG_PCIEAER=y (such as distro kernels), allow users
to disable PCIE Advanced Error Reporting by using "pci=noaer" on the
kernel command line.
This can be used to work around hardware or (kernel) software problems.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Transform some calls to kmalloc/memset to a single kzalloc (or kcalloc).
Here is a short excerpt of the semantic patch performing
this transformation:
@@
type T2;
expression x;
identifier f,fld;
expression E;
expression E1,E2;
expression e1,e2,e3,y;
statement S;
@@
x =
- kmalloc
+ kzalloc
(E1,E2)
... when != \(x->fld=E;\|y=f(...,x,...);\|f(...,x,...);\|x=E;\|while(...) S\|for(e1;e2;e3) S\)
- memset((T2)x,0,E1);
@@
expression E1,E2,E3;
@@
- kzalloc(E1 * E2,E3)
+ kcalloc(E1,E2,E3)
[akpm@linux-foundation.org: get kcalloc args the right way around]
Signed-off-by: Yoann Padioleau <padator@wanadoo.fr>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Bryan Wu <bryan.wu@analog.com>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Dave Airlie <airlied@linux.ie>
Acked-by: Roland Dreier <rolandd@cisco.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Acked-by: Pierre Ossman <drzeus-list@drzeus.cx>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Greg KH <greg@kroah.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix following section mismatch warning (when compiled with CONFIG_HOTPLUG=n):
WARNING: drivers/pci/built-in.o - Section mismatch: reference to .init.text:aer_probe from .data between 'aerdrv' (at offset 0x1608) and 'aer_error_handlers'
Warning was fixed by renaming aerdrv to aerdriver so we pass the whitelist.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Run this:
#!/bin/sh
for f in $(grep -Erl "\([^\)]*\) *k[cmz]alloc" *) ; do
echo "De-casting $f..."
perl -pi -e "s/ ?= ?\([^\)]*\) *(k[cmz]alloc) *\(/ = \1\(/" $f
done
And then go through and reinstate those cases where code is casting pointers
to non-pointers.
And then drop a few hunks which conflicted with outstanding work.
Cc: Russell King <rmk@arm.linux.org.uk>, Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Greg KH <greg@kroah.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Karsten Keil <kkeil@suse.de>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Steven French <sfrench@us.ibm.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Pass the work_struct pointer to the work function rather than context data.
The work function can use container_of() to work out the data.
For the cases where the container of the work_struct may go away the moment the
pending bit is cleared, it is made possible to defer the release of the
structure by deferring the clearing of the pending bit.
To make this work, an extra flag is introduced into the management side of the
work_struct. This governs auto-release of the structure upon execution.
Ordinarily, the work queue executor would release the work_struct for further
scheduling or deallocation by clearing the pending bit prior to jumping to the
work function. This means that, unless the driver makes some guarantee itself
that the work_struct won't go away, the work function may not access anything
else in the work_struct or its container lest they be deallocated.. This is a
problem if the auxiliary data is taken away (as done by the last patch).
However, if the pending bit is *not* cleared before jumping to the work
function, then the work function *may* access the work_struct and its container
with no problems. But then the work function must itself release the
work_struct by calling work_release().
In most cases, automatic release is fine, so this is the default. Special
initiators exist for the non-auto-release case (ending in _NAR).
Signed-Off-By: David Howells <dhowells@redhat.com>
Bjorn Helgaas