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  1. 18 6月, 2014 2 次提交
    • B
      PCI: pciehp: Compute timeout from hotplug command start time · 40b96083
      由 Bjorn Helgaas 提交于 
      If we issue a hotplug command, go do something else, then come back and
wait for the command to complete, we don't have to wait the whole timeout
period, because some of it elapsed while we were doing something else.

Keep track of the time we issued the command, and wait only until the
timeout period from that point has elapsed.

For controllers with errata like Intel CF118, we previously timed out
before issuing the second hotplug command:

  At time T1 (during boot):
    - Write DLLSCE, ABPE, PDCE, etc. to Slot Control
  At time T2 (hotplug event):
    - Wait for command completion (CC) in Slot Status
    - Timeout at T2 + 1 second because CC is never set in Slot Status
    - Write PCC, PIC, etc. to Slot Control

With this change, we wait until T1 + 1 second instead of T2 + 1 second.
If the hotplug event is more than 1 second after the boot-time
initialization, we won't wait for the timeout at all.

We still emit a "Timeout on hotplug command" message if it timed out; we
should see this on the first hotplug event on every controller with this
erratum, as well as on real errors on controllers without the erratum.

Link: http://www.intel.com/content/www/us/en/processors/xeon/xeon-e7-v2-spec-update.html
Tested-by: Rajat Jain <rajatxjain@gmail.com>	(IDT 807a controller)
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
      40b96083
    • B
      PCI: pciehp: Wait for hotplug command completion lazily · 3461a068
      由 Bjorn Helgaas 提交于 
      Previously we issued a hotplug command and waited for it to complete.  But
there's no need to wait until we're ready to issue the *next* command.  The
next command will probably be much later, so the first one may have already
completed and we may not have to actually wait at all.

Because of hardware errata, some controllers generate command completion
events for some commands but not others.  In the case of Intel CF118 (see
spec update reference), the controller indicates command completion only
for Slot Control writes that change the value of the following bits:

  Power Controller Control
  Power Indicator Control
  Attention Indicator Control
  Electromechanical Interlock Control

Changes to other bits, e.g., the interrupt enable bits, do not cause the
Command Completed bit to be set.  Controllers from AMD and Nvidia are
reported to have similar errata.

These errata cause timeouts when pcie_enable_notification() enables
interrupts.  Previously that timeout occurred at boot-time.  With this
change, the timeout occurs later, when we change the state of the slot
power, indicators, or interlock.  This speeds up boot but causes a timeout
at the first hotplug event on the slot.  Subsequent events don't timeout
because only the first (boot-time) hotplug command updates Slot Control
without touching the power/indicator/interlock controls.

Link: http://www.intel.com/content/www/us/en/processors/xeon/xeon-e7-v2-spec-update.html
Tested-by: Rajat Jain <rajatxjain@gmail.com>	(IDT 807a controller)
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
      3461a068
  3. 17 6月, 2014 1 次提交
  5. 11 6月, 2014 2 次提交
  7. 25 4月, 2014 1 次提交
  9. 20 2月, 2014 1 次提交
  11. 12 2月, 2014 4 次提交
  13. 11 2月, 2014 2 次提交
  15. 16 12月, 2013 7 次提交
  17. 15 12月, 2013 1 次提交
  19. 15 11月, 2013 1 次提交
  21. 15 8月, 2013 1 次提交
  23. 04 7月, 2013 1 次提交
  25. 13 1月, 2013 1 次提交
    • Y
      PCI: pciehp: Use per-slot workqueues to avoid deadlock · c2be6f93
      由 Yijing Wang 提交于 
      When we have a hotplug-capable PCIe port with a second hotplug-capable
PCIe port below it, removing the device below the upstream port causes
a deadlock.

The deadlock happens because we use the pciehp_wq workqueue to run
pciehp_power_thread(), which uses pciehp_disable_slot() to remove devices
below the upstream port.  When we remove the downstream PCIe port, we call
pciehp_remove(), the pciehp driver's .remove() method.  That calls
flush_workqueue(pciehp_wq), which deadlocks because the
pciehp_power_thread() work item is still running.

This patch avoids the deadlock by creating a workqueue for every PCIe port
and removing the single shared workqueue.

Here's the call path that leads to the deadlock:

  pciehp_queue_pushbutton_work
    queue_work(pciehp_wq)                   # queue pciehp_power_thread
    ...

  pciehp_power_thread
    pciehp_disable_slot
      remove_board
	pciehp_unconfigure_device
	  pci_stop_and_remove_bus_device
	    ...
	      pciehp_remove                 # pciehp driver .remove method
		pciehp_release_ctrl
		  pcie_cleanup_slot
		    flush_workqueue(pciehp_wq)

This is fairly urgent because it can be caused by simply unplugging a
Thunderbolt adapter, as reported by Daniel below.

[bhelgaas: changelog]
Reference: http://lkml.kernel.org/r/CAMVG2ssiRgcTD1bej2tkUUfsWmpL5eNtPcNif9va2-Gzb2u8nQ@mail.gmail.comReported-and-tested-by: NDaniel J Blueman <daniel@quora.org>
Reviewed-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org
      c2be6f93
  27. 24 8月, 2012 1 次提交
  29. 13 7月, 2012 1 次提交
  31. 15 2月, 2012 5 次提交
  33. 07 1月, 2012 1 次提交
  35. 06 12月, 2011 1 次提交
  37. 12 11月, 2011 2 次提交
  39. 08 11月, 2011 1 次提交
  41. 23 7月, 2011 1 次提交
  43. 18 10月, 2010 1 次提交
    • T
      pciehp: update workqueue usage · a827ea30
      由 Tejun Heo 提交于 
      * Rename pciehp_wq to pciehp_ordered_wq and add non-ordered pciehp_wq
  which is used instead of the system workqueue.  This is to remove
  the use of flush_scheduled_work() which is deprecated and scheduled
  for removal.

* With cmwq in place, there's no point in creating workqueues lazily.
  Create both pciehp_wq and pciehp_ordered_wq upfront.

* Include workqueue.h from pciehp.h.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
      a827ea30
  45. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      由 Tejun Heo 提交于 
      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: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6