Commit Graph

33 Commits

Author SHA1 Message Date
Keith Busch
c4eed62a21 PCI/ERR: Use slot reset if available
The secondary bus reset may have link side effects that a hotplug capable
port may incorrectly react to.  Use the slot specific reset for hotplug
ports, fixing the undesirable link down-up handling during error
recovering.

Signed-off-by: Keith Busch <keith.busch@intel.com>
[bhelgaas: fold in
https://lore.kernel.org/linux-pci/20180926152326.14821-1-keith.busch@intel.com
for issue reported by Stephen Rothwell <sfr@canb.auug.org.au>]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>
2018-09-21 12:18:10 -05:00
Lukas Wunner
81c4b5bf30 PCI: hotplug: Constify hotplug_slot_ops
Hotplug drivers cannot declare their hotplug_slot_ops const, making them
attractive targets for attackers, because upon registration of a hotplug
slot, __pci_hp_initialize() writes to the "owner" and "mod_name" members
in that struct.

Fix by moving these members to struct hotplug_slot and constify every
driver's hotplug_slot_ops except for pciehp.

pciehp constructs its hotplug_slot_ops at runtime based on the PCIe
port's capabilities, hence cannot declare them const.  It can be
converted to __write_rarely once that's mainlined:
http://www.openwall.com/lists/kernel-hardening/2016/11/16/3

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>  # drivers/pci/hotplug/rpa*
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # drivers/platform/x86
Cc: Len Brown <lenb@kernel.org>
Cc: Scott Murray <scott@spiteful.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Oliver OHalloran <oliveroh@au1.ibm.com>
Cc: Gavin Shan <gwshan@linux.vnet.ibm.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Corentin Chary <corentin.chary@gmail.com>
Cc: Darren Hart <dvhart@infradead.org>
2018-09-18 17:52:15 -05:00
Bjorn Helgaas
43b90eaed5 Merge branch 'pci/misc'
- use PCI_EXP_DEVCTL2_COMP_TIMEOUT in rapidio/tsi721 (Bjorn Helgaas)

  - remove possible NULL pointer dereference in of_pci_bus_find_domain_nr()
    (Shawn Lin)

  - report quirk timings with dev_info (Bjorn Helgaas)

  - report quirks that take longer than 10ms (Bjorn Helgaas)

  - add and use Altera Vendor ID (Johannes Thumshirn)

  - tidy Makefiles and comments (Bjorn Helgaas)

* pci/misc:
  PCI: Always define the of_node helpers
  PCI: Tidy comments
  PCI: Tidy Makefiles
  mcb: Add Altera PCI ID to mcb-pci
  PCI: Add Altera vendor ID
  PCI: Report quirks that take more than 10ms
  PCI: Report quirk timings with pci_info() instead of pr_debug()
  PCI: Fix NULL pointer dereference in of_pci_bus_find_domain_nr()
  rapidio/tsi721: use PCI_EXP_DEVCTL2_COMP_TIMEOUT macro
2018-04-04 13:27:45 -05:00
Jay Fang
1acfb9b7ee PCI: Add decoding for 16 GT/s link speed
PCIe 4.0 defines the 16.0 GT/s link speed.  Links can run at that speed
without any Linux changes, but previously their sysfs "max_link_speed" and
"current_link_speed" files contained "Unknown speed", not the expected
"16.0 GT/s".

Add decoding for the new 16 GT/s link speed.

Signed-off-by: Jay Fang <f.fangjian@huawei.com>
[bhelgaas: add PCI_EXP_LNKCAP2_SLS_16_0GB]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Dongdong Liu <liudongdong3@huawei.com>
2018-03-21 16:23:55 -05:00
Bjorn Helgaas
df62ab5e0f PCI: Tidy comments
Remove pointless comments that tell us the file name, remove blank line
comments, follow multi-line comment conventions.  No functional change
intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-03-19 14:20:43 -05:00
Bjorn Helgaas
7328c8f48d PCI: Add SPDX GPL-2.0 when no license was specified
b24413180f ("License cleanup: add SPDX GPL-2.0 license identifier to
files with no license") added SPDX GPL-2.0 to several PCI files that
previously contained no license information.

Add SPDX GPL-2.0 to all other PCI files that did not contain any license
information and hence were under the default GPL version 2 license of the
kernel.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-26 11:45:16 -06:00
Peter Zijlstra
2c935bc572 locking/atomic, kref: Add kref_read()
Since we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages.

Kills two anti-patterns:

	atomic_read(&kref->refcount)
	kref->refcount.counter

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14 11:37:18 +01:00
Yijing Wang
017ffe64e8 PCI: Hold pci_slot_mutex while searching bus->slots list
Previously, pci_setup_device() and similar functions searched the
pci_bus->slots list without any locking.  It was possible for another
thread to update the list while we searched it.

Add pci_dev_assign_slot() to search the list while holding pci_slot_mutex.

[bhelgaas: changelog, fold in CONFIG_SYSFS fix]
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-07-30 16:19:53 -05:00
Yijing Wang
6754676297 PCI: Protect pci_bus->slots with pci_slot_mutex, not pci_bus_sem
Rajat Jain reported a deadlock when PCIe hot-add and AER recovery happen at
the same time:

thread 1:

  pciehp_enable_slot
    pciehp_configure_device
      pci_bus_add_devices
        pci_bus_add_device
          device_attach
            device_lock(dev)                       # acquire device lock
            ...
            pciehp_probe
              init_slot
                pci_hp_register
                  pci_create_slot
                    down_write(pci_bus_sem)        # deadlock here

thread 2:

  aer_isr_one_error
    aer_process_err_device
      do_recovery
        broadcast_error_message(..., report_error_detected)
          pci_walk_bus(..., cb=report_error_detected, ...)
            down_read(&pci_bus_sem)                # acquire pci_bus_sem
            report_error_detected(dev)             # cb()
              device_lock(dev)                     # deadlock here

Previously, the bus->devices and bus->slots list were protected by
pci_bus_sem.  In pci_create_slot(), we held it for writing so we could
add to the bus->slots list.

Add a new local pci_slot_mutex to protect bus->slots.  Hold pci_bus_sem for
reading while searching the bus->devices list.

[bhelgaas: changelog]
Link: http://lkml.kernel.org/r/CAA93t1qpPqbih+UB0McA_d_+2rVaNkXsinAUxYzK9+JXSS+L-g@mail.gmail.com
Reported-by: Rajat Jain <rajatja@google.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-07-30 15:49:10 -05:00
Rusty Russell
58f86cc89c VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms.
Summary of http://lkml.org/lkml/2014/3/14/363 :

  Ted: module_param(queue_depth, int, 444)
  Joe: 0444!
  Rusty: User perms >= group perms >= other perms?
  Joe: CLASS_ATTR, DEVICE_ATTR, SENSOR_ATTR and SENSOR_ATTR_2?

Side effect of stricter permissions means removing the unnecessary
S_IFREG from several callers.

Note that the BUILD_BUG_ON_ZERO((perm) & 2) test was removed: a fair
number of drivers fail this test, so that will be the debate for a
future patch.

Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> for drivers/pci/slot.c
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-03-24 12:21:00 +10:30
Stephen Hemminger
4ab4467606 PCI: Remove unused pci_renumber_slot()
My philosophy is unused code is dead code.  And dead code is subject to bit
rot and is a likely source of bugs.  Use it or lose it.

This reverts part of f46753c5e3 ("PCI: introduce pci_slot") and
d25b7c8d6b ("PCI: rename pci_update_slot_number to pci_renumber_slot"),
removing this interface:

    pci_renumber_slot()

[bhelgaas: split to separate patch, add historical link from Alex]
Link: http://lkml.kernel.org/r/20081009043140.8678.44164.stgit@bob.kio
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Chiang <achiang@canonical.com>
2014-01-13 11:14:44 -07:00
Bjorn Helgaas
f7625980f5 PCI: Fix whitespace, capitalization, and spelling errors
Fix whitespace, capitalization, and spelling errors.  No functional change.
I know "busses" is not an error, but "buses" was more common, so I used it
consistently.

Signed-off-by: Marta Rybczynska <rybczynska@gmail.com> (pci_reset_bridge_secondary_bus())
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-11-14 11:28:18 -07:00
Bjorn Helgaas
9fc9eea09f PCI: Warn about failures instead of "must_check" functions
These places capture return values to avoid "must_check" warnings,
but we didn't *do* anything with the return values, which causes
"set but not used" warnings.  We might as well do something instead
of just trying to evade the "must_check" warnings.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-04-17 10:21:12 -06:00
Paul Gortmaker
eefa9cfc89 pci: add module.h to files implicitly relying on its presence.
These were getting module.h implicitly from device.h but we want
to clean that up, so we fix it here to avoid things like:

pci/slot.c: In function ‘pci_hp_create_module_link’:
pci/slot.c:383: error: ‘module_kset’ undeclared (first use in this function)

Similarly, rpadlpar_core.c is modular, so add module.h to its includes.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:23 -04:00
Stephen Hemminger
17134d9673 PCI: bus speed strings should be const
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-08-31 15:28:00 -07:00
Jesse Barnes
3be434f024 Revert "PCI: create function symlinks in /sys/bus/pci/slots/N/"
This reverts commit 75568f8094.

Since they're just a convenience anyway, remove these symlinks since
they're causing duplicate filename errors in the wild.

Acked-by: Alex Chiang <achiang@canonical.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-06-11 13:08:37 -07:00
Alex Chiang
75568f8094 PCI: create function symlinks in /sys/bus/pci/slots/N/
Create convenience symlinks in sysfs, linking slots to device
functions, and vice versa. These links make it easier for users to
figure out which devices actually live in what slots.

For example:

sapphire:/sys/bus/pci/slots # ls
1  10  2  3  4  5  6  7  8  9

sapphire:/sys/bus/pci/slots # ls -l 3
total 0
-r--r--r-- 1 root root 65536 Aug 18 14:10 address
lrwxrwxrwx 1 root root     0 Aug 18 14:10 function0 ->
../../../../devices/pci0000:23/0000:23:01.0
lrwxrwxrwx 1 root root     0 Aug 18 14:10 function1 ->
../../../../devices/pci0000:23/0000:23:01.1

sapphire:/sys/bus/pci/slots # ls -l 3/function0/slot
lrwxrwxrwx 1 root root 0 Aug 18 14:13 3/function0/slot ->
../../../bus/pci/slots/3

The original form of this patch was written by Matthew Wilcox,
and was enhanced to include links from the sysfs slots/ directory
pointing back at the device functions.

Cc: willy@linux.intel.com
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-05-11 12:01:07 -07:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
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>
2010-03-30 22:02:32 +09:00
Emese Revfy
52cf25d0ab Driver core: Constify struct sysfs_ops in struct kobj_type
Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:49 -08:00
Matthew Wilcox
9dfd97fe12 PCI: Add support for reporting PCIe 3.0 speeds
Add the 8.0 GT/s speed.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-02-22 16:15:19 -08:00
Matthew Wilcox
45b4cdd57e PCI: Add support for AGP in cur/max bus speed
Take advantage of some gaps in the table to fit in support for AGP speeds.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-02-22 16:15:19 -08:00
Matthew Wilcox
3749c51ac6 PCI: Make current and maximum bus speeds part of the PCI core
Move the max_bus_speed and cur_bus_speed into the pci_bus.  Expose the
values through the PCI slot driver instead of the hotplug slot driver.
Update all the hotplug drivers to use the pci_bus instead of their own
data structures.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-02-22 16:15:17 -08:00
Randy Dunlap
503998ca4a PCI: fix kernel-doc warnings
Add documentation for missing parameters in PCI hotplug code.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-29 12:13:56 -07:00
Kenji Kaneshige
c825bc94c8 PCI hotplug: create symlink to hotplug driver module
Create symbolic link to hotplug driver module in the PCI slot
directory (/sys/bus/pci/slots/<SLOT#>). In the past, we need to load
hotplug drivers one by one to identify the hotplug driver that handles
the slot, and it was very inconvenient especially for trouble shooting.
With this change, we can easily identify the hotplug driver.

Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reviewed-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-16 14:30:11 -07:00
Randy Dunlap
cffb2fafb7 docbooks: add/fix PCI kernel-doc
Add drivers/pci/*.c source files to DocBook/kernel-api.tmpl
and update those pci/*.c source files that need kernel-doc fixes.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-04-22 14:49:33 -07:00
Alex Chiang
6279504141 PCI: enhance physical slot debug information
Convert usages of pr_debug to dev_dbg and add physical slot name.

Note that we use dev_dbg on the struct pci_bus and still manually
print out the PCI slot number (instead of calling dev_dbg on a
pci_dev) because a struct pci_bus with empty physical slots will
not have any pci_devs.

Reviewed-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-03-19 19:29:30 -07:00
Alex Chiang
3b5dd45e94 PCI: stop leaking 'slot_name' in pci_create_slot
In pci_create_slot(), the local variable 'slot_name' is allocated by
make_slot_name(), but never freed. We never use it after passing it to
the kobject core, so we should free it upon function exit.

Cc: stable@kernel.org
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-12-09 14:36:03 -08:00
Alex Chiang
0ad772ec46 PCI, PCI Hotplug: introduce slot_name helpers
In preparation for cleaning up the various hotplug drivers
such that they don't have to manage their own 'name' parameters
anymore, we provide the following convenience functions:

	pci_slot_name()
	hotplug_slot_name()

These helpers will be used by individual hotplug drivers.

Cc: kristen.c.accardi@intel.com
Cc: matthew@wil.cx
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-10-22 16:42:40 -07:00
Alex Chiang
5fe6cc6068 PCI: prevent duplicate slot names
Prevent callers of pci_create_slot() from registering slots with
duplicate names. This condition occurs most often when PCI hotplug
drivers are loaded on platforms with broken firmware that assigns
identical names to multiple slots.

We now rename these duplicate slots on behalf of the user.

If firmware assigns the name N to multiple slots, then:

	The first registered slot is assigned N
	The second registered slot is assigned N-1
	The third registered slot is assigned N-2
	etc.

This is the permanent fix mentioned in earlier commits d6a9e9b4 and
167e782e (shpchp/pciehp: Rename duplicate slot name...).

We take advantage of the new 'hotplug' parameter in pci_create_slot()
to prevent a slot create/rename race between hotplug drivers and
detection drivers.

	Scenario A:
	hotplug driver                  detection driver
	--------------                  ----------------
	pci_create_slot(hotplug=set)
					pci_create_slot(hotplug=NULL)

The hotplug driver creates the slot with its desired name, and then
releases the semaphore. Now, the detection driver tries to create
the same slot, but it already exists. We don't care about renaming,
so return the existing slot.

	Scenario B:
	hotplug driver                  detection driver
	--------------                  ----------------
					pci_create_slot(hotplug=NULL)
	pci_create_slot(hotplug=set)

The detection driver creates the slot with name "X". Then the hotplug
driver tries to create the same slot, but wants the name "Y" instead.
We detect that we're trying to create the same slot and that we also
want a rename, so rename the slot to "Y" and return.

	Scenario C:
	hotplug driver                  hotplug driver
	--------------                  ----------------
	pci_create_slot(hotplug=set)
					pci_create_slot(hotplug=set)

Two separate hotplug drivers are attempting to claim the slot and
are passing valid hotplug_slot args to pci_create_slot(). We detect
that the slot already has a ->hotplug callback, prevent a rename,
and return -EBUSY.

Cc: kristen.c.accardi@intel.com
Cc: matthew@wil.cx
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-10-22 16:42:39 -07:00
Alex Chiang
828f37683e PCI: update pci_create_slot() to take a 'hotplug' param
Slot detection drivers can co-exist with hotplug drivers. The names
of the detected/claimed slots may be different depending on module
load order.

For legacy reasons, we need to allow hotplug drivers to override
the slot name if a detection driver is loaded first (and they find
the same slots).

Creating and overriding slot names should be an atomic operation,
otherwise you get a locking nightmare as various drivers race to
call pci_create_slot().

pci_create_slot() is already serialized by grabbing the pci_bus_sem.

We update the API and add a 'hotplug' param, which is:

	set if the caller is a hotplug driver
	NULL if the caller is a detection driver

pci_create_slot() does not actually use the 'hotplug' parameter in this
patch. A later patch will add the logic that uses it.

Cc: kristen.c.accardi@intel.com
Cc: matthew@wil.cx
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-10-22 16:42:38 -07:00
Alex Chiang
d25b7c8d6b PCI: rename pci_update_slot_number to pci_renumber_slot
The GPL exported symbol pci_update_slot_number has been renamed to
pci_renumber_slot. Some of the safety checks were unnecessary and
were removed.

Cc: kristen.c.accardi@intel.com
Cc: matthew@wil.cx
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-10-22 16:42:37 -07:00
Alex Chiang
cef354db0d PCI: connect struct pci_dev to struct pci_slot
The introduction of struct pci_slot (f46753c5e3)
added a struct pci_slot pointer to struct pci_dev, but we forgot to
associate the two.

Connect the two structs together; the interesting portions of the object
lifetimes are:

	- when a new pci_slot is created, connect it to the appropriate
	  pci_dev's. A single pci_slot may be associated with multiple
	  pci_dev's, e.g. any multi-function PCI device.

	- when a pci_slot is released, look for all the pci_dev's it was
	  associated with, and set their pci_slot pointers to NULL

	- when a pci_dev is created, look for slots to associate with.

Note -- when a pci_dev is released, we don't need to do any bookkeeping,
since pci_slot's do not have pointers to pci_dev's.

Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-10-20 10:53:52 -07:00
Alex Chiang
f46753c5e3 PCI: introduce pci_slot
Currently, /sys/bus/pci/slots/ only exposes hotplug attributes when a
hotplug driver is loaded, but PCI slots have attributes such as address,
speed, width, etc.  that are not related to hotplug at all.

Introduce pci_slot as the primary data structure and kobject model.
Hotplug attributes described in hotplug_slot become a secondary
structure associated with the pci_slot.

This patch only creates the infrastructure that allows the separation of
PCI slot attributes and hotplug attributes.  In this patch, the PCI
hotplug core remains the only user of this infrastructure, and thus,
/sys/bus/pci/slots/ will still only become populated when a hotplug
driver is loaded.

A later patch in this series will add a second user of this new
infrastructure and demonstrate splitting the task of exposing pci_slot
attributes from hotplug_slot attributes.

  - Make pci_slot the primary sysfs entity. hotplug_slot becomes a
    subsidiary structure.
    o pci_create_slot() creates and registers a slot with the PCI core
    o pci_slot_add_hotplug() gives it hotplug capability

  - Change the prototype of pci_hp_register() to take the bus and
    slot number (on parent bus) as parameters.

  - Remove all the ->get_address methods since this functionality is
    now handled by pci_slot directly.

[achiang@hp.com: rpaphp-correctly-pci_hp_register-for-empty-pci-slots]
Tested-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: make headers_check happy]
[akpm@linux-foundation.org: nuther build fix]
[akpm@linux-foundation.org: fix typo in #include]
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Cc: Greg KH <greg@kroah.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Len Brown <lenb@kernel.org>
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-06-10 14:37:03 -07:00