Commit Graph

1034 Commits

Author SHA1 Message Date
Linus Torvalds 5cbb3d216e Merge branch 'akpm' (patches from Andrew Morton)
Merge first patch-bomb from Andrew Morton:
 "Quite a lot of other stuff is banked up awaiting further
  next->mainline merging, but this batch contains:

   - Lots of random misc patches
   - OCFS2
   - Most of MM
   - backlight updates
   - lib/ updates
   - printk updates
   - checkpatch updates
   - epoll tweaking
   - rtc updates
   - hfs
   - hfsplus
   - documentation
   - procfs
   - update gcov to gcc-4.7 format
   - IPC"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (269 commits)
  ipc, msg: fix message length check for negative values
  ipc/util.c: remove unnecessary work pending test
  devpts: plug the memory leak in kill_sb
  ./Makefile: export initial ramdisk compression config option
  init/Kconfig: add option to disable kernel compression
  drivers: w1: make w1_slave::flags long to avoid memory corruption
  drivers/w1/masters/ds1wm.cuse dev_get_platdata()
  drivers/memstick/core/ms_block.c: fix unreachable state in h_msb_read_page()
  drivers/memstick/core/mspro_block.c: fix attributes array allocation
  drivers/pps/clients/pps-gpio.c: remove redundant of_match_ptr
  kernel/panic.c: reduce 1 byte usage for print tainted buffer
  gcov: reuse kbasename helper
  kernel/gcov/fs.c: use pr_warn()
  kernel/module.c: use pr_foo()
  gcov: compile specific gcov implementation based on gcc version
  gcov: add support for gcc 4.7 gcov format
  gcov: move gcov structs definitions to a gcc version specific file
  kernel/taskstats.c: return -ENOMEM when alloc memory fails in add_del_listener()
  kernel/taskstats.c: add nla_nest_cancel() for failure processing between nla_nest_start() and nla_nest_end()
  kernel/sysctl_binary.c: use scnprintf() instead of snprintf()
  ...
2013-11-13 15:45:43 +09:00
Linus Torvalds 9bc9ccd7db Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "All kinds of stuff this time around; some more notable parts:

   - RCU'd vfsmounts handling
   - new primitives for coredump handling
   - files_lock is gone
   - Bruce's delegations handling series
   - exportfs fixes

  plus misc stuff all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (101 commits)
  ecryptfs: ->f_op is never NULL
  locks: break delegations on any attribute modification
  locks: break delegations on link
  locks: break delegations on rename
  locks: helper functions for delegation breaking
  locks: break delegations on unlink
  namei: minor vfs_unlink cleanup
  locks: implement delegations
  locks: introduce new FL_DELEG lock flag
  vfs: take i_mutex on renamed file
  vfs: rename I_MUTEX_QUOTA now that it's not used for quotas
  vfs: don't use PARENT/CHILD lock classes for non-directories
  vfs: pull ext4's double-i_mutex-locking into common code
  exportfs: fix quadratic behavior in filehandle lookup
  exportfs: better variable name
  exportfs: move most of reconnect_path to helper function
  exportfs: eliminate unused "noprogress" counter
  exportfs: stop retrying once we race with rename/remove
  exportfs: clear DISCONNECTED on all parents sooner
  exportfs: more detailed comment for path_reconnect
  ...
2013-11-13 15:34:18 +09:00
Cody P Schafer ec778edf97 bitops/find: clarify and extend documentation
Add return value documentation and clarify the units of the @size
parameter.

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:22 +09:00
Linus Torvalds c2d3306991 Merge tag 'gpio-v3.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO changes from Linus Walleij:
 "Here is the bulk of GPIO changes for the v3.13 development cycle.

  I've got ACKs for the things that affect other subsystems (or it's my
  own subsystem, like pinctrl).  Most of that pertain to an attempt from
  my side to consolidate and get rid of custom GPIO implementations in
  the ARM tree.  I will continue doing this.

  The main change this time is the new GPIO descriptor API, background
  for this can be found in Corbet's summary from this january in LWN:

    http://lwn.net/Articles/533632/

  Summary:

   - Merged the GPIO descriptor API from Alexandre Courbot.  This is a
     first step toward trying to get rid of the global GPIO numberspace
     for the future.

   - Add an API so that driver can flag that a certain GPIO line is
     being used by a irqchip backend for generating IRQs, so that we can
     enforce checks, like not allowing users to switch that line to an
     output at runtime, since this makes no sense.  Implemented
     corresponding calls in a few select drivers.

   - ACPI GPIO cleanups, refactorings and switch to using the
     descriptor-based interface.

   - Support for the TPS80036 Palmas GPIO variant.

   - A new driver for the Broadcom Kona GPIO SoC IP block.

   - Device tree support for the PCF857x driver.

   - A set of ARM GPIO refactorings with the goal of getting rid of a
     bunch of custom GPIO implementations from the arch/arm/* tree:

     * Move the IOP GPIO driver to the GPIO subsystem and fix all users
       to use the gpiolib API for accessing GPIOs.  Delete the old
       custom GPIO implementation.

     * Delete the unused custom PXA GPIO implemention.

     * Convert all users of the IXP4 custom GPIO implementation to use
       gpiolib and delete the custom implementation.

     * Delete the custom Gemini GPIO implementation, also completely
       unused.

   - Various cleanups and renamings"

* tag 'gpio-v3.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (85 commits)
  gpio: gpio-mxs: Remove unneeded dt checks
  gpio: pl061: don't depend on CONFIG_ARM
  gpio: bcm-kona: add missing .owner to struct gpio_chip
  gpiolib: provide a declaration of seq_file in gpio/driver.h
  gpiolib: include gpio/consumer.h in of_gpio.h for desc_to_gpio()
  gpio: provide stubs for devres gpio functions
  gpiolib: devres: add missing headers
  gpiolib: make GPIO_DEVRES depend on GPIOLIB
  gpiolib: devres: fix devm_gpiod_get_index()
  gpiolib / ACPI: document the GPIO descriptor based interface
  gpiolib / ACPI: allow passing GPIOF_ACTIVE_LOW for GpioInt resources
  gpiolib / ACPI: add ACPI support for gpiod_get_index()
  gpiolib / ACPI: convert to gpiod interfaces
  gpiolib: add gpiod_get() and gpiod_put() functions
  gpiolib: port of_ functions to use gpiod
  gpiolib: export descriptor-based GPIO interface
  Fixup "MAINTAINERS: GPIO-INTEL-MID: add maintainer"
  gpio: bcm281xx: Don't print addresses of GPIO area in probe()
  gpio: tegra: use new gpio_lock_as_irq() API
  gpio: rcar: Include linux/of.h header
  ...
2013-11-12 15:50:46 +09:00
Linus Torvalds 8a5dc585d5 Merge tag 'pinctrl-for-v3.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull pin control updates from Linus Walleij:
 "Main pin control pull request for the v3.13 cycle.

  The changes hitting arch/blackfin are ACKed by the Blackfin
  maintainer, and the device tree bindings are ACKed to the extent
  possible by someone from the device tree maintainers group.

   - Blackfin ADI pin control driver, we move yet another architecture
     under this subsystem umbrella.

   - Incremental updates to the Renesas Super-H PFC pin control driver.
     New subdriver for the r8a7791 SoC.

   - Non-linear GPIO ranges from the gpiolib side of things, this
     enabled simplified device tree bindings by referring entire groups
     of pins on some pin controller to act as back-end for a certain
     GPIO-chip driver.

   - Add the Abilis TB10x pin control driver used on the ARC
     architecture.  Also the corresponding GPIO driver is merged through
     this tree, so the ARC has full support for pins and GPIOs after
     this.

   - Subdrivers for Freescale i.MX1, i.MX27 and i.MX50 pin controller
     instances.  The i.MX1 and i.MX27 is an entirely new family
     (silicon) of controllers whereas i.MX50 is a variant of the
     previous supported controller.

   - Then the usual slew of fixes, cleanups and incremental updates"

The ARC DT changes are apparently still pending, that hopefully gets
sorted out in a timely manner.

* tag 'pinctrl-for-v3.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (48 commits)
  pinctrl: imx50: add pinctrl support code for the IMX50 SoC
  pinctrl: at91: copy define to driver
  pinctrl: remove minor dead code
  pinctrl: imx: fix using pin->input_val wrongly
  pinctrl: imx1: fix return value check in imx1_pinctrl_core_probe()
  gpio: tb10x: fix return value check in tb10x_gpio_probe()
  gpio: tb10x: use module_platform_driver to simplify the code
  pinctrl: imx27: imx27 pincontrol driver
  pinctrl: imx1 core driver
  pinctrl: sh-pfc: r8a7791 PFC support
  sh-pfc: r8a7778: Add CAN pin groups
  gpio: add TB10x GPIO driver
  pinctrl: at91: correct a few typos
  pinctrl: mvebu: remove redundant of_match_ptr
  pinctrl: tb10x: use module_platform_driver to simplify the code
  pinctrl: tb10x: fix the error handling in tb10x_pinctrl_probe()
  pinctrl: add documentation for pinctrl_get_group_pins()
  pinctrl: rockchip: emulate both edge triggered interrupts
  pinctrl: rockchip: add rk3188 specifics
  pinctrl: rockchip: remove redundant check
  ...
2013-11-12 15:40:03 +09:00
Al Viro ce39596048 constify copy_siginfo_to_user{,32}()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:29 -05:00
Alexandre Courbot 79a9becda8 gpiolib: export descriptor-based GPIO interface
This patch exports the gpiod_* family of API functions, a safer
alternative to the legacy GPIO interface. Differences between the gpiod
and legacy gpio APIs are:

- gpio works with integers, whereas gpiod operates on opaque handlers
  which cannot be forged or used before proper acquisition
- gpiod get/set functions are aware of the active low state of a GPIO
- gpio consumers should now include <linux/gpio/consumer.h> to access
  the new interface, whereas chips drivers will use
  <linux/gpio/driver.h>

The legacy gpio API is now built as inline functions on top of gpiod.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-10-19 23:24:45 +02:00
Christian Ruppert 586a87e6ed pinctrl/gpio: non-linear GPIO ranges accesible from gpiolib
This patch adds the infrastructure required to register non-linear gpio
ranges through gpiolib and the standard GPIO device tree bindings.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-10-16 15:33:50 +02:00
Linus Walleij 263c43a447 Merge tag 'v3.12-rc4' into devel
Linux 3.12-rc4
2013-10-16 10:05:53 +02:00
Linus Walleij d468bf9eca gpio: add API to be strict about GPIO IRQ usage
It is currently often possible in many GPIO drivers to request
a GPIO line to be used as IRQ after calling gpio_to_irq() and,
as the gpiolib is not aware of this, set the same line to
output and start driving it, with undesired side effects.

As it is a bogus usage scenario to request a line flagged as
output to used as IRQ, we introduce APIs to let gpiolib track
the use of a line as IRQ, and also set this flag from the
userspace ABI.

The API is symmetric so that lines can also be flagged from
.irq_enable() and unflagged from IRQ by .irq_disable().
The debugfs file is altered so that we see if a line is
reserved for IRQ.

Cc: Enric Balletbo i Serra <eballetbo@gmail.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-10-16 09:59:54 +02:00
Ingo Molnar 37bf06375c Merge tag 'v3.12-rc4' into sched/core
Merge Linux v3.12-rc4 to fix a conflict and also to refresh the tree
before applying more scheduler patches.

Conflicts:
	arch/avr32/include/asm/Kbuild

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:36:13 +02:00
David Miller 2679494246 mm: Fix generic hugetlb pte check return type.
The include/asm-generic/hugetlb.h stubs that just vector huge_pte_*()
calls to the pte_*() implementations won't work in certain situations.

x86 and sparc, for example, return "unsigned long" from the bit
checks, and just go "return pte_val(pte) & PTE_BIT_FOO;"

But since huge_pte_*() returns 'int', if any high bits on 64-bit are
relevant, they get chopped off.

The net effect is that we can loop forever trying to COW a huge page,
because the huge_pte_write() check signals false all the time.

Reported-by: Gurudas Pai <gurudas.pai@oracle.com>
Tested-by: Gurudas Pai <gurudas.pai@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: David Rientjes <rientjes@google.com>
2013-10-02 20:02:35 -04:00
Andrew Morton 2a156a6b52 include/asm-generic/vtime.h: avoid zero-length file
patch(1) can't handle zero-length files - it appears to simply not create
the file, so my powerpc build fails.

Put something in here to make life easier.

Cc: Hugh Dickins <hughd@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30 14:31:02 -07:00
Peter Zijlstra 75f93fed50 sched: Revert need_resched() to look at TIF_NEED_RESCHED
Yuanhan reported a serious throughput regression in his pigz
benchmark. Using the ftrace patch I found that several idle
paths need more TLC before we can switch the generic
need_resched() over to preempt_need_resched.

The preemption paths benefit most from preempt_need_resched and
do indeed use it; all other need_resched() users don't really
care that much so reverting need_resched() back to
tif_need_resched() is the simple and safe solution.

Reported-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: lkp@linux.intel.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20130927153003.GF15690@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-28 10:04:47 +02:00
Peter Zijlstra 1a338ac32c sched, x86: Optimize the preempt_schedule() call
Remove the bloat of the C calling convention out of the
preempt_enable() sites by creating an ASM wrapper which allows us to
do an asm("call ___preempt_schedule") instead.

calling.h bits by Andi Kleen

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-tk7xdi1cvvxewixzke8t8le1@git.kernel.org
[ Fixed build error. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-25 14:23:07 +02:00
Peter Zijlstra bdb4380658 sched: Extract the basic add/sub preempt_count modifiers
Rewrite the preempt_count macros in order to extract the 3 basic
preempt_count value modifiers:

  __preempt_count_add()
  __preempt_count_sub()

and the new:

  __preempt_count_dec_and_test()

And since we're at it anyway, replace the unconventional
$op_preempt_count names with the more conventional preempt_count_$op.

Since these basic operators are equivalent to the previous _notrace()
variants, do away with the _notrace() versions.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-ewbpdbupy9xpsjhg960zwbv8@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-25 14:07:54 +02:00
Peter Zijlstra 0102874755 sched: Create more preempt_count accessors
We need a few special preempt_count accessors:
 - task_preempt_count() for when we're interested in the preemption
   count of another (non-running) task.
 - init_task_preempt_count() for properly initializing the preemption
   count.
 - init_idle_preempt_count() a special case of the above for the idle
   threads.

With these no generic code ever touches thread_info::preempt_count
anymore and architectures could choose to remove it.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-jf5swrio8l78j37d06fzmo4r@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-25 14:07:52 +02:00
Peter Zijlstra a787870924 sched, arch: Create asm/preempt.h
In order to prepare to per-arch implementations of preempt_count move
the required bits into an asm-generic header and use this for all
archs.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-h5j0c1r3e3fk015m30h8f1zx@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-25 14:07:50 +02:00
Linus Torvalds 64c353864e Merge branch 'for-v3.12' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping
Pull DMA mapping update from Marek Szyprowski:
 "This contains an addition of Device Tree support for reserved memory
  regions (Contiguous Memory Allocator is one of the drivers for it) and
  changes required by the KVM extensions for PowerPC architectue"

* 'for-v3.12' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
  ARM: init: add support for reserved memory defined by device tree
  drivers: of: add initialization code for dma reserved memory
  drivers: of: add function to scan fdt nodes given by path
  drivers: dma-contiguous: clean source code and prepare for device tree
2013-09-09 10:26:33 -07:00
Linus Torvalds 6832d9652f Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timers/nohz changes from Ingo Molnar:
 "It mostly contains fixes and full dynticks off-case optimizations, by
  Frederic Weisbecker"

* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  nohz: Include local CPU in full dynticks global kick
  nohz: Optimize full dynticks's sched hooks with static keys
  nohz: Optimize full dynticks state checks with static keys
  nohz: Rename a few state variables
  vtime: Always debug check snapshot source _before_ updating it
  vtime: Always scale generic vtime accounting results
  vtime: Optimize full dynticks accounting off case with static keys
  vtime: Describe overriden functions in dedicated arch headers
  m68k: hardirq_count() only need preempt_mask.h
  hardirq: Split preempt count mask definitions
  context_tracking: Split low level state headers
  vtime: Fix racy cputime delta update
  vtime: Remove a few unneeded generic vtime state checks
  context_tracking: User/kernel broundary cross trace events
  context_tracking: Optimize context switch off case with static keys
  context_tracking: Optimize guest APIs off case with static key
  context_tracking: Optimize main APIs off case with static key
  context_tracking: Ground setup for static key use
  context_tracking: Remove full dynticks' hacky dependency on wide context tracking
  nohz: Only enable context tracking on full dynticks CPUs
  ...
2013-09-04 09:36:54 -07:00
Linus Torvalds b854e4de0b Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "Main RCU changes this cycle were:

   - Full-system idle detection.  This is for use by Frederic
     Weisbecker's adaptive-ticks mechanism.  Its purpose is to allow the
     timekeeping CPU to shut off its tick when all other CPUs are idle.

   - Miscellaneous fixes.

   - Improved rcutorture test coverage.

   - Updated RCU documentation"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
  nohz_full: Force RCU's grace-period kthreads onto timekeeping CPU
  nohz_full: Add full-system-idle state machine
  jiffies: Avoid undefined behavior from signed overflow
  rcu: Simplify _rcu_barrier() processing
  rcu: Make rcutorture emit online failures if verbose
  rcu: Remove unused variable from rcu_torture_writer()
  rcu: Sort rcutorture module parameters
  rcu: Increase rcutorture test coverage
  rcu: Add duplicate-callback tests to rcutorture
  doc: Fix memory-barrier control-dependency example
  rcu: Update RTFP documentation
  nohz_full: Add full-system-idle arguments to API
  nohz_full: Add full-system idle states and variables
  nohz_full: Add per-CPU idle-state tracking
  nohz_full: Add rcu_dyntick data for scalable detection of all-idle state
  nohz_full: Add Kconfig parameter for scalable detection of all-idle state
  nohz_full: Add testing information to documentation
  rcu: Eliminate unused APIs intended for adaptive ticks
  rcu: Select IRQ_WORK from TREE_PREEMPT_RCU
  rculist: list_first_or_null_rcu() should use list_entry_rcu()
  ...
2013-09-04 08:17:12 -07:00
Ingo Molnar 7d992feb76 Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:

"
 * Update RCU documentation.  These were posted to LKML at
   https://lkml.org/lkml/2013/8/19/611.

 * Miscellaneous fixes.  These were posted to LKML at
   https://lkml.org/lkml/2013/8/19/619.

 * Full-system idle detection.  This is for use by Frederic
   Weisbecker's adaptive-ticks mechanism.  Its purpose is
   to allow the timekeeping CPU to shut off its tick when
   all other CPUs are idle.  These were posted to LKML at
   https://lkml.org/lkml/2013/8/19/648.

 * Improve rcutorture test coverage.  These were posted to LKML at
   https://lkml.org/lkml/2013/8/19/675.
"

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-03 07:41:11 +02:00
Martin Schwidefsky 0944fe3f4a s390/mm: implement software referenced bits
The last remaining use for the storage key of the s390 architecture
is reference counting. The alternative is to make page table entries
invalid while they are old. On access the fault handler marks the
pte/pmd as young which makes the pte/pmd valid if the access rights
allow read access. The pte/pmd invalidations required for software
managed reference bits cost a bit of performance, on the other hand
the RRBE/RRBM instructions to read and reset the referenced bits are
quite expensive as well.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-08-29 13:20:11 +02:00
Marek Szyprowski a254738039 drivers: dma-contiguous: clean source code and prepare for device tree
This patch cleans the initialization of dma contiguous framework. The
all-in-one dma_declare_contiguous() function is now separated into
dma_contiguous_reserve_area() which only steals the the memory from
memblock allocator and dma_contiguous_add_device() function, which
assigns given device to the specified reserved memory area. This improves
the flexibility in defining contiguous memory areas and assigning device
to them, because now it is possible to assign more than one device to
the given contiguous memory area. Such split in initialization procedure
is also required for upcoming device tree support.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Tomasz Figa <t.figa@samsung.com>
2013-08-27 09:18:29 +02:00
Linus Torvalds 2b047252d0 Fix TLB gather virtual address range invalidation corner cases
Ben Tebulin reported:

 "Since v3.7.2 on two independent machines a very specific Git
  repository fails in 9/10 cases on git-fsck due to an SHA1/memory
  failures.  This only occurs on a very specific repository and can be
  reproduced stably on two independent laptops.  Git mailing list ran
  out of ideas and for me this looks like some very exotic kernel issue"

and bisected the failure to the backport of commit 53a59fc67f ("mm:
limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT").

That commit itself is not actually buggy, but what it does is to make it
much more likely to hit the partial TLB invalidation case, since it
introduces a new case in tlb_next_batch() that previously only ever
happened when running out of memory.

The real bug is that the TLB gather virtual memory range setup is subtly
buggered.  It was introduced in commit 597e1c3580 ("mm/mmu_gather:
enable tlb flush range in generic mmu_gather"), and the range handling
was already fixed at least once in commit e6c495a96c ("mm: fix the TLB
range flushed when __tlb_remove_page() runs out of slots"), but that fix
was not complete.

The problem with the TLB gather virtual address range is that it isn't
set up by the initial tlb_gather_mmu() initialization (which didn't get
the TLB range information), but it is set up ad-hoc later by the
functions that actually flush the TLB.  And so any such case that forgot
to update the TLB range entries would potentially miss TLB invalidates.

Rather than try to figure out exactly which particular ad-hoc range
setup was missing (I personally suspect it's the hugetlb case in
zap_huge_pmd(), which didn't have the same logic as zap_pte_range()
did), this patch just gets rid of the problem at the source: make the
TLB range information available to tlb_gather_mmu(), and initialize it
when initializing all the other tlb gather fields.

This makes the patch larger, but conceptually much simpler.  And the end
result is much more understandable; even if you want to play games with
partial ranges when invalidating the TLB contents in chunks, now the
range information is always there, and anybody who doesn't want to
bother with it won't introduce subtle bugs.

Ben verified that this fixes his problem.

Reported-bisected-and-tested-by: Ben Tebulin <tebulin@googlemail.com>
Build-testing-by: Stephen Rothwell <sfr@canb.auug.org.au>
Build-testing-by: Richard Weinberger <richard.weinberger@gmail.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-16 08:52:46 -07:00