linux-stable.git/arch/powerpc/platforms, branch linux-4.7.y

powerpc/pseries: use pci_host_bridge.release_fn() to kfree(phb)

2016-10-16T15:50:36+00:00

commit 2dd9c11b9d4dfbd6c070eab7b81197f65e82f1a0 upstream.

This patch leverages 'struct pci_host_bridge' from the PCI subsystem
in order to free the pci_controller only after the last reference to
its devices is dropped (avoiding an oops in pcibios_release_device()
if the last reference is dropped after pcibios_free_controller()).

The patch relies on pci_host_bridge.release_fn() (and .release_data),
which is called automatically by the PCI subsystem when the root bus
is released (i.e., the last reference is dropped).  Those fields are
set via pci_set_host_bridge_release() (e.g. in the platform-specific
implementation of pcibios_root_bridge_prepare()).

It introduces the 'pcibios_free_controller_deferred()' .release_fn()
and it expects .release_data to hold a pointer to the pci_controller.

The function implictly calls 'pcibios_free_controller()', so an user
must *NOT* explicitly call it if using the new _deferred() callback.

The functionality is enabled for pseries (although it isn't platform
specific, and may be used by cxl).

Details on not-so-elegant design choices:

 - Use 'pci_host_bridge.release_data' field as pointer to associated
   'struct pci_controller' so *not* to 'pci_bus_to_host(bridge->bus)'
   in pcibios_free_controller_deferred().

   That's because pci_remove_root_bus() sets 'host_bridge->bus = NULL'
   (so, if the last reference is released after pci_remove_root_bus()
   runs, which eventually reaches pcibios_free_controller_deferred(),
   that would hit a null pointer dereference).

   The cxl/vphb.c code calls pci_remove_root_bus(), and the cxl folks
   are interested in this fix.

Test-case #1 (hold references)

  # ls -ld /sys/block/sd* | grep -m1 0021:01:00.0
  <...> /sys/block/sdaa -> ../devices/pci0021:01/0021:01:00.0/<...>

  # ls -ld /sys/block/sd* | grep -m1 0021:01:00.1
  <...> /sys/block/sdab -> ../devices/pci0021:01/0021:01:00.1/<...>

  # cat >/dev/sdaa & pid1=$!
  # cat >/dev/sdab & pid2=$!

  # drmgr -w 5 -d 1 -c phb -s 'PHB 33' -r
  Validating PHB DLPAR capability...yes.
  [  594.306719] pci_hp_remove_devices: PCI: Removing devices on bus 0021:01
  [  594.306738] pci_hp_remove_devices:    Removing 0021:01:00.0...
  ...
  [  598.236381] pci_hp_remove_devices:    Removing 0021:01:00.1...
  ...
  [  611.972077] pci_bus 0021:01: busn_res: [bus 01-ff] is released
  [  611.972140] rpadlpar_io: slot PHB 33 removed

  # kill -9 $pid1
  # kill -9 $pid2
  [  632.918088] pcibios_free_controller_deferred: domain 33, dynamic 1

Test-case #2 (don't hold references)

  # drmgr -w 5 -d 1 -c phb -s 'PHB 33' -r
  Validating PHB DLPAR capability...yes.
  [  916.357363] pci_hp_remove_devices: PCI: Removing devices on bus 0021:01
  [  916.357386] pci_hp_remove_devices:    Removing 0021:01:00.0...
  ...
  [  920.566527] pci_hp_remove_devices:    Removing 0021:01:00.1...
  ...
  [  933.955873] pci_bus 0021:01: busn_res: [bus 01-ff] is released
  [  933.955977] pcibios_free_controller_deferred: domain 33, dynamic 1
  [  933.955999] rpadlpar_io: slot PHB 33 removed

Suggested-By: Gavin Shan 
Signed-off-by: Mauricio Faria de Oliveira 
Reviewed-by: Gavin Shan 
Reviewed-by: Andrew Donnellan 
Tested-by: Andrew Donnellan  # cxl
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc/powernv: Fix corrupted PE allocation bitmap on releasing PE

2016-09-24T08:09:27+00:00

commit caa58f808834fca9a4443233fd09df5ab639690d upstream.

In pnv_ioda_free_pe(), the PE object (including the associated PE
number) is cleared before resetting the corresponding bit in the
PE allocation bitmap. It means PE#0 is always released to the bitmap
wrongly.

This fixes above issue by caching the PE number before the PE object
is cleared.

Fixes: 1e9167726c41 ("powerpc/powernv: Use PE instead of number during setup and release"
Signed-off-by: Gavin Shan 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/powernv : Drop reference added by kset_find_obj()

2016-09-24T08:09:27+00:00

commit a9cbf0b2195b695cbeeeecaa4e2770948c212e9a upstream.

In a situation, where Linux kernel gets notified about duplicate error log
from OPAL, it is been observed that kernel fails to remove sysfs entries
(/sys/firmware/opal/elog/0xXXXXXXXX) of such error logs. This is because,
we currently search the error log/dump kobject in the kset list via
'kset_find_obj()' routine. Which eventually increment the reference count
by one, once it founds the kobject.

So, unless we decrement the reference count by one after it found the kobject,
we would not be able to release the kobject properly later.

This patch adds the 'kobject_put()' which was missing earlier.

Signed-off-by: Mukesh Ojha 
Reviewed-by: Vasant Hegde 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'powerpc-4.7-3Michael Ellerman:' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2016-06-10T19:23:49+00:00

Pull powerpc fixes from
 - ptrace: Fix out of bounds array access warning from Khem Raj
 - pseries: Fix PCI config address for DDW from Gavin Shan
 - pseries: Fix IBM_ARCH_VEC_NRCORES_OFFSET since POWER8NVL was added
   from Michael Ellerman
 - of: fix autoloading due to broken modalias with no 'compatible' from
   Wolfram Sang
 - radix: Fix always false comparison against MMU_NO_CONTEXT from Aneesh
   Kumar K.V
 - hash: Compute the segment size correctly for ISA 3.0 from Aneesh
   Kumar K.V
 - nohash: Fix build break with 64K pages from Michael Ellerman

* tag 'powerpc-4.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/nohash: Fix build break with 64K pages
  powerpc/mm/hash: Compute the segment size correctly for ISA 3.0
  powerpc/mm/radix: Fix always false comparison against MMU_NO_CONTEXT
  of: fix autoloading due to broken modalias with no 'compatible'
  powerpc/pseries: Fix IBM_ARCH_VEC_NRCORES_OFFSET since POWER8NVL was added
  powerpc/pseries: Fix PCI config address for DDW
  powerpc/ptrace: Fix out of bounds array access warning

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-06-08T03:41:36+00:00

Pull vfs fixes from Al Viro:
 "Fixes for crap of assorted ages: EOPENSTALE one is 4.2+, autofs one is
  4.6, d_walk - 3.2+.

  The atomic_open() and coredump ones are regressions from this window"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  coredump: fix dumping through pipes
  fix a regression in atomic_open()
  fix d_walk()/non-delayed __d_free() race
  autofs braino fix for do_last()
  fix EOPENSTALE bug in do_last()

coredump: fix dumping through pipes

2016-06-08T02:07:09+00:00

The offset in the core file used to be tracked with ->written field of
the coredump_params structure. The field was retired in favour of
file->f_pos.

However, ->f_pos is not maintained for pipes which leads to breakage.

Restore explicit tracking of the offset in coredump_params. Introduce
->pos field for this purpose since ->written was already reused.

Fixes: a00839395103 ("get rid of coredump_params->written").

Reported-by: Zbigniew Jędrzejewski-Szmek 
Signed-off-by: Mateusz Guzik 
Reviewed-by: Omar Sandoval 
Signed-off-by: Al Viro

Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux

2016-06-07T23:24:44+00:00

Pull clk fixes from Stephen Boyd:
 "This finally removes the CLK_IS_ROOT flag by picking up the last few
  stragglers that didn't get merged by anyone this time around.

  Better to do it now than wait for another one to pop up.  There's also
  a minor maintainers update and a Kconfig fix"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: nxp: Select MFD_SYSCON for creg driver
  MAINTAINERS: Add file patterns for clock device tree bindings
  clk: Remove CLK_IS_ROOT flag
  clk: microchip: Remove CLK_IS_ROOT
  powerpc/512x: clk: Remove CLK_IS_ROOT
  vexpress/spc: Remove CLK_IS_ROOT

powerpc/pseries: Fix PCI config address for DDW

2016-06-06T01:51:42+00:00

In commit 8445a87f7092 "powerpc/iommu: Remove the dependency on EEH
struct in DDW mechanism", the PE address was replaced with the PCI
config address in order to remove dependency on EEH. According to PAPR
spec, firmware (pHyp or QEMU) should accept "xxBBSSxx" format PCI config
address, not "xxxxBBSS" provided by the patch. Note that "BB" is PCI bus
number and "SS" is the combination of slot and function number.

This fixes the PCI address passed to DDW RTAS calls.

Fixes: 8445a87f7092 ("powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism")
Cc: stable@vger.kernel.org # v3.4+
Reported-by: Guilherme G. Piccoli 
Signed-off-by: Gavin Shan 
Tested-by: Guilherme G. Piccoli 
Signed-off-by: Michael Ellerman

powerpc/512x: clk: Remove CLK_IS_ROOT

2016-06-01T21:51:41+00:00

This flag is a no-op now (see commit 47b0eeb3dc8a "clk: Deprecate
CLK_IS_ROOT", 2016-02-02) so remove it.

Cc: Gerhard Sittig 
Signed-off-by: Stephen Boyd

powerpc/pseries/eeh: Refactor the configure_bridge RTAS tokens

2016-05-30T03:50:12+00:00

The RTAS calls "ibm,configure-pe" and "ibm,configure-bridge" perform the
same actions, however the former can skip configuration if unnecessary.
The existing code treats them as different tokens even though only one
will ever be called.  Refactor this by making a single token that is
assigned during init.

Signed-off-by: Russell Currey 
Acked-by: Gavin Shan 
Signed-off-by: Michael Ellerman