Pull CRIS updates from Jesper Nilsson:
"Mostly removal of old cruft of which we can use a generic version, or
fixes for code not commonly run in the cris port, but also additions
to enable some good debug"

* tag 'cris-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris: (25 commits)
CRISv10: delete unused lib/dmacopy.c
CRISv10: delete unused lib/old_checksum.c
CRIS: fix switch_mm() lockdep splat
CRISv32: enable LOCKDEP_SUPPORT
CRIS: add STACKTRACE_SUPPORT
CRISv32: annotate irq enable in idle loop
CRISv32: add support for irqflags tracing
CRIS: UAPI: use generic types.h
CRIS: UAPI: use generic shmbuf.h
CRIS: UAPI: use generic msgbuf.h
CRIS: UAPI: use generic socket.h
CRIS: UAPI: use generic sembuf.h
CRIS: UAPI: use generic sockios.h
CRIS: UAPI: use generic auxvec.h
CRIS: UAPI: use generic headers via Kbuild
CRIS: UAPI: fix elf.h export
CRIS: don't make asm/elf.h depend on asm/user.h
CRIS: UAPI: fix ptrace.h
CRISv32: Squash compile warnings for axisflashmap
CRISv32: Add GPIO driver to the default configs
...

rq_data_dir() returns either READ or WRITE (0 == READ, 1 == WRITE), not
a boolean value.

Now, admittedly the "!= 0" doesn't really change the value (0 stays as
zero, 1 stays as one), but it's not only redundant, it confuses gcc, and
causes gcc to warn about the construct

switch (rq_data_dir(req)) {
case READ:
...
case WRITE:
...

that we have in a few drivers.

Now, the gcc warning is silly and stupid (it seems to warn not about the
switch value having a different type from the case statements, but about
_any_ boolean switch value), but in this case the code itself is silly
and stupid too, so let's just change it, and get rid of warnings like
this:

drivers/block/hd.c: In function ‘hd_request’:
drivers/block/hd.c:630:11: warning: switch condition has boolean value [-Wswitch-bool]
switch (rq_data_dir(req)) {

The odd '!= 0' came in when "cmd_flags" got turned into a "u64" in
commit 5953316dbf90 ("block: make rq->cmd_flags be 64-bit") and is
presumably because the old code (that just did a logical 'and' with 1)
would then end up making the type of rq_data_dir() be u64 too.

But if we want to retain the old regular integer type, let's just cast
the result to 'int' rather than use that rather odd '!= 0'.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This file is never built.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>

Fix up the writeback plugging introduced in commit d353d7587d02
("writeback: plug writeback at a high level") that then caused problems
due to the unplug happening with a spinlock held.

* writeback-plugging:
writeback: plug writeback in wb_writeback() and writeback_inodes_wb()
Revert "writeback: plug writeback at a high level"

This file is never built.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>

I didn't notice this when merging the thermal code from Zhang, but his
merge (commit 5a924a07f882: "Merge branches 'thermal-core' and
'thermal-intel' of .git into next") of the thermal-core and
thermal-intel branches was wrong.

In thermal-core, commit 17e8351a7739 ("thermal: consistently use int for
temperatures") converted the thermal layer to use "int" for
temperatures.

But in parallel, in the thermal-intel branch commit d0a12625d2ff
("thermal: Add Intel PCH thermal driver") added support for the intel
PCH thermal sensor using the old interfaces that used "unsigned long"
pointers.

This resulted in warnings like this:

drivers/thermal/intel_pch_thermal.c:184:14: warning: initialization from incompatible pointer type [-Wincompatible-pointer-types]
.get_temp = pch_thermal_get_temp,
^
drivers/thermal/intel_pch_thermal.c:184:14: note: (near initialization for ‘tzd_ops.get_temp’)
drivers/thermal/intel_pch_thermal.c:186:19: warning: initialization from incompatible pointer type [-Wincompatible-pointer-types]
.get_trip_temp = pch_get_trip_temp,
^
drivers/thermal/intel_pch_thermal.c:186:19: note: (near initialization for ‘tzd_ops.get_trip_temp’)

This fixes it.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We had to revert the pluggin in writeback_sb_inodes() because the
wb->list_lock is held, but we could easily plug at a higher level before
taking that lock, and unplug after releasing it. This does that.

Chris will run performance numbers, just to verify that this approach is
comparable to the alternative (we could just drop and re-take the lock
around the blk_finish_plug() rather than these two commits.

I'd have preferred waiting for actual performance numbers before picking
one approach over the other, but I don't want to release rc1 with the
known "sleeping function called from invalid context" issue, so I'll
pick this cleanup version for now. But if the numbers show that we
really want to plug just at the writeback_sb_inodes() level, and we
should just play ugly games with the spinlock, we'll switch to that.

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With lockdep support implemented on CRISv32, we get the following splat.
switch_mm() can be called both from the scheduler() (with interrupts
disabled) and from flush_old_exec (via activate_mm()), with interrupts
enabled. Fix it by disabling interrupts in activate_mm(), similar to
powerpc and hexagon.

t======================================================
[ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ]
3.19.0-08802-g20bc9f1-dirty #323 Not tainted
------------------------------------------------------
init/1 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
(mmu_context_lock){+.+...}, at: [<c0009290>] switch_mm+0x22/0xc6

and this task is already holding:
(&rq->lock){-.-.-.}, at: [<c01a0756>] __schedule+0x5e/0x648
which would create a new lock dependency:
(&rq->lock){-.-.-.} -> (mmu_context_lock){+.+...}

but this new dependency connects a HARDIRQ-irq-safe lock:
(&rq->lock){-.-.-.}
... which became HARDIRQ-irq-safe at:
[<c002b03c>] scheduler_tick+0x28/0x5e
[<c0007c6c>] timer_interrupt+0x4e/0x6a
[<c0043ac4>] handle_irq_event_percpu+0x54/0x13c
[<c004343c>] generic_handle_irq+0x2a/0x36

to a HARDIRQ-irq-unsafe lock:
(mmu_context_lock){+.+...}
... which became HARDIRQ-irq-unsafe at:
... [<c0039e60>] __lock_acquire+0x8f8/0x1d9c
[<c0009290>] switch_mm+0x22/0xc6
[<c009c260>] flush_old_exec+0x500/0x5d4
[<c00da4c6>] load_elf_phdrs+0x7a/0x84
[<c00dbdb0>] load_elf_binary+0x21c/0x13b4
[<c009cdb6>] do_execve+0x22/0x2c
[<c001dcf2>] ____call_usermodehelper+0x0/0x154
[<c000581e>] ret_from_kernel_thread+0xe/0x14

other info that might help us debug this:

Possible interrupt unsafe locking scenario:

CPU0 CPU1
---- ----
lock(mmu_context_lock);
local_irq_disable();
lock(&rq->lock);
lock(mmu_context_lock);
<Interrupt>
lock(&rq->lock);

*** DEADLOCK ***

1 lock held by init/1:
#0: (&rq->lock){-.-.-.}, at: [<c01a0756>] __schedule+0x5e/0x648

Call Trace:
[<c019fe9e>] printk+0x0/0x4e
[<c00368f8>] print_shortest_lock_dependencies+0x0/0x15c
[<c0048628>] print_stack_trace+0x0/0x88
[<c0038912>] __lock_is_held+0x3e/0x5e
[<c003b894>] lock_acquire+0x8a/0xcc
[<c01a50c4>] _raw_spin_lock+0x44/0x7a
[<c0009290>] switch_mm+0x22/0xc6
[<c01a06f8>] __schedule+0x0/0x648
[<c01a0d76>] schedule+0x36/0x7c
[<c0037d04>] trace_hardirqs_on+0x0/0x1e
[<c0004e18>] do_work_pending+0x30/0xd4
[<c000591a>] _work_pending+0xe/0x12

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>

Merge fourth patch-bomb from Andrew Morton:

- sys_membarier syscall

- seq_file interface changes

- a few misc fixups

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
revert "ocfs2/dlm: use list_for_each_entry instead of list_for_each"
mm/early_ioremap: add explicit #include of asm/early_ioremap.h
fs/seq_file: convert int seq_vprint/seq_printf/etc... returns to void
selftests: enhance membarrier syscall test
selftests: add membarrier syscall test
sys_membarrier(): system-wide memory barrier (generic, x86)
MODSIGN: fix a compilation warning in extract-cert

This reverts commit d353d7587d02116b9732d5c06615aed75a4d3a47.

Doing the block layer plug/unplug inside writeback_sb_inodes() is
broken, because that function is actually called with a spinlock held:
wb->list_lock, as pointed out by Chris Mason.

Chris suggested just dropping and re-taking the spinlock around the
blk_finish_plug() call (the plgging itself can happen under the
spinlock), and that would technically work, but is just disgusting.

We do something fairly similar - but not quite as disgusting because we
at least have a better reason for it - in writeback_single_inode(), so
it's not like the caller can depend on the lock being held over the
call, but in this case there just isn't any good reason for that
"release and re-take the lock" pattern.

[ In general, we should really strive to avoid the "release and retake"
pattern for locks, because in the general case it can easily cause
subtle bugs when the caller caches any state around the call that
might be invalidated by dropping the lock even just temporarily. ]

But in this case, the plugging should be easy to just move up to the
callers before the spinlock is taken, which should even improve the
effectiveness of the plug. So there is really no good reason to play
games with locking here.

I'll send off a test-patch so that Dave Chinner can verify that that
plug movement works. In the meantime this just reverts the problematic
commit and adds a comment to the function so that we hopefully don't
make this mistake again.

Reported-by: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Now that we have stack tracing and irq flags tracing support,
we can also enable lockdep support

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>

Newer bitfiles needs the reduced clk even for SMP builds

Cc: <stable@vger.kernel.org> #4.2
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Revert commit f83c7b5e9fd6 ("ocfs2/dlm: use list_for_each_entry instead
of list_for_each").

list_for_each_entry() will dereference its `pos' argument, which can be
NULL in dlm_process_recovery_data().

Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Reported-by: Fengguang Wu <fengguang.wu@gmail.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull btrfs cleanups and fixes from Chris Mason:
"These are small cleanups, and also some fixes for our async worker
thread initialization.

I was having some trouble testing these, but it ended up being a
combination of changing around my test servers and a shiny new
schedule while atomic from the new start/finish_plug in
writeback_sb_inodes().

That one only hits on btrfs raid5/6 or MD raid10, and if I wasn't
changing a bunch of things in my test setup at once it would have been
really clear. Fix for writeback_sb_inodes() on the way as well"

* 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: cleanup: remove unnecessary check before btrfs_free_path is called
btrfs: async_thread: Fix workqueue 'max_active' value when initializing
btrfs: Add raid56 support for updating num_tolerated_disk_barrier_failures in btrfs_balance
btrfs: Cleanup for btrfs_calc_num_tolerated_disk_barrier_failures
btrfs: Remove noused chunk_tree and chunk_objectid from scrub_enumerate_chunks and scrub_chunk
btrfs: Update out-of-date "skip parity stripe" comment

Add stacktrace support, which is required for lockdep and tracing. The
stack tracing simply looks at all kernel text symbols found on the
stack, similar to the trap stack dumping code, which can also be
converted to use this.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>

Pull NTB fixes from Jon Mason:
"NTB bug and documentation fixes, new device IDs, performance
improvements, and adding a mailing list to MAINTAINERS for NTB"

* tag 'ntb-4.3' of git://github.com/jonmason/ntb:
NTB: Fix range check on memory window index
NTB: Improve index handling in B2B MW workaround
NTB: Fix documentation for ntb_peer_db_clear.
NTB: Fix documentation for ntb_link_is_up
NTB: Use unique DMA channels for TX and RX
NTB: Remove dma_sync_wait from ntb_async_rx
NTB: Clean up QP stats info
NTB: Make the transport list in order of discovery
NTB: Add PCI Device IDs for Broadwell Xeon
NTB: Add flow control to the ntb_netdev
NTB: Add list to MAINTAINERS

Commit 6b0f68e32ea8 ("mm: add utility for early copy from unmapped ram")
introduces a function copy_from_early_mem() into mm/early_ioremap.c
which itself calls early_memremap()/early_memunmap(). However, since
early_memunmap() has not been declared yet at this point in the .c file,
nor by any explicitly included header files, we are depending on a
transitive include of asm/early_ioremap.h to declare it, which is
fragile.

So instead, include this header explicitly.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull Ceph update from Sage Weil:
"There are a few fixes for snapshot behavior with CephFS and support
for the new keepalive protocol from Zheng, a libceph fix that affects
both RBD and CephFS, a few bug fixes and cleanups for RBD from Ilya,
and several small fixes and cleanups from Jianpeng and others"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
ceph: improve readahead for file holes
ceph: get inode size for each append write
libceph: check data_len in ->alloc_msg()
libceph: use keepalive2 to verify the mon session is alive
rbd: plug rbd_dev->header.object_prefix memory leak
rbd: fix double free on rbd_dev->header_name
libceph: set 'exists' flag for newly up osd
ceph: cleanup use of ceph_msg_get
ceph: no need to get parent inode in ceph_open
ceph: remove the useless judgement
ceph: remove redundant test of head->safe and silence static analysis warnings
ceph: fix queuing inode to mdsdir's snaprealm
libceph: rename con_work() to ceph_con_workfn()
libceph: Avoid holding the zero page on ceph_msgr_slab_init errors
libceph: remove the unused macro AES_KEY_SIZE
ceph: invalidate dirty pages after forced umount
ceph: EIO all operations after forced umount

We need not check path before btrfs_free_path() is called because
path is checked in btrfs_free_path().

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Use a call to local_irq_enable() instead of incline asm so that the
irqsoff latency tracer knows that interrupts are enabled here.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>

Pull more input updates from Dmitry Torokhov:
"Second round of updates for the input subsystem.

This introduces two brand new touchscreen drivers (Colibri and
imx6ul_tsc), some small driver fixes, and we are no longer report
errors from evdev_flush() as users do not really have a way of
handling errors, error codes that we were returning were not on the
list of errors supposed to be returned by close(), and errors were
causing issues with one of older versions of systemd"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: imx_keypad - remove obsolete comment
Input: touchscreen - add imx6ul_tsc driver support
Input: Add touchscreen support for Colibri VF50
Input: i8042 - lower log level for "no controller" message
Input: evdev - do not report errors form flush()
Input: elants_i2c - extend the calibration timeout to 12 seconds
Input: sparcspkr - fix module autoload for OF platform drivers
Input: regulator-haptic - fix module autoload for OF platform driver
Input: pwm-beeper - fix module autoload for OF platform driver
Input: ab8500-ponkey - Fix module autoload for OF platform driver
Input: cyttsp - remove unnecessary MODULE_ALIAS()
Input: elan_i2c - add ACPI ID "ELAN1000"

The range check must exclude the upper bound.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

The seq_<foo> function return values were frequently misused.

See: commit 1f33c41c03da ("seq_file: Rename seq_overflow() to
seq_has_overflowed() and make public")

All uses of these return values have been removed, so convert the
return types to void.

Miscellanea:

o Move seq_put_decimal_<type> and seq_escape prototypes closer the
other seq_vprintf prototypes
o Reorder seq_putc and seq_puts to return early on overflow
o Add argument names to seq_vprintf and seq_printf
o Update the seq_escape kernel-doc
o Convert a couple of leading spaces to tabs in seq_escape

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull GFS2 updates from Bob Peterson:
"Here is a list of patches we've accumulated for GFS2 for the current
upstream merge window. This time we've only got six patches, many of
which are very small:

- three cleanups from Andreas Gruenbacher, including a nice cleanup
of the sequence file code for the sbstats debugfs file.

- a patch from Ben Hutchings that changes statistics variables from
signed to unsigned.

- two patches from me that increase GFS2's glock scalability by
switching from a conventional hash table to rhashtable"

* tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: A minor "sbstats" cleanup
gfs2: Fix a typo in a comment
gfs2: Make statistics unsigned, suitable for use with do_div()
GFS2: Use resizable hash table for glocks
GFS2: Move glock superblock pointer to field gl_name
gfs2: Simplify the seq file code for "sbstats"

When readahead encounters file holes, osd reply returns error -ENOENT,
finish_read() skips adding pages to the the page cache. So readahead
does not work for file holes. The fix is adding zero pages to the
page cache when -ENOENT is returned.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

At initializing time, for threshold-able workqueue, it's max_active
of kernel workqueue should be 1 and grow if it hits threshold.

But due to the bad naming, there is both 'max_active' for kernel
workqueue and btrfs workqueue.
So wrong value is given at workqueue initialization.

This patch fixes it, and to avoid further misunderstanding, change the
member name of btrfs_workqueue to 'current_active' and 'limit_active'.

Also corresponding comment is added for readability.

Reported-by: Alex Lyakas <alex.btrfs@zadarastorage.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Add support irqflags tracing, which is required for things like lockdep
and ftrace.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>

Pull more power management and ACPI updates from Rafael Wysocki:
"These are mostly fixes and cleanups on top of the previous PM+ACPI
pull request (cpufreq core and drivers, cpuidle, generic power domains
framework). Some of them didn't make to that pull request and some
fix issues introduced by it.

The only really new thing is the support for suspend frequency in the
cpufreq-dt driver, but it is needed to fix an issue with Exynos
platforms.

Specifics:

- build fix for the new Mediatek MT8173 cpufreq driver (Guenter
Roeck).

- generic power domains framework fixes (power on error code path,
subdomain removal) and cleanup of a deprecated API user (Geert
Uytterhoeven, Jon Hunter, Ulf Hansson).

- cpufreq-dt driver fixes including two fixes for bugs related to the
new Operating Performance Points Device Tree bindings introduced
recently (Viresh Kumar).

- suspend frequency support for the cpufreq-dt driver (Bartlomiej
Zolnierkiewicz, Viresh Kumar).

- cpufreq core cleanups (Viresh Kumar).

- intel_pstate driver fixes (Chen Yu, Kristen Carlson Accardi).

- additional sanity check in the cpuidle core (Xunlei Pang).

- fix for a comment related to CPU power management (Lina Iyer)"

* tag 'pm+acpi-4.3-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
intel_pstate: fix PCT_TO_HWP macro
intel_pstate: Fix user input of min/max to legal policy region
PM / OPP: Return suspend_opp only if it is enabled
cpufreq-dt: add suspend frequency support
cpufreq: allow cpufreq_generic_suspend() to work without suspend frequency
PM / OPP: add dev_pm_opp_get_suspend_opp() helper
staging: board: Migrate away from __pm_genpd_name_add_device()
cpufreq: Use __func__ to print function's name
cpufreq: staticize cpufreq_cpu_get_raw()
PM / Domains: Ensure subdomain is not in use before removing
cpufreq: Add ARM_MT8173_CPUFREQ dependency on THERMAL
cpuidle/coupled: Add sanity check for safe_state_index
PM / Domains: Try power off masters in error path of __pm_genpd_poweron()
cpufreq: dt: Tolerance applies on both sides of target voltage
cpufreq: dt: Print error on failing to mark OPPs as shared
cpufreq: dt: Check OPP count before marking them shared
kernel/cpu_pm: fix cpu_cluster_pm_exit comment

Prepare second round of input updates for 4.3 merge window.

Check that b2b_mw_idx is in range of the number of memory windows when
initializing the device. The workaround is considered to be in effect
only if the device b2b_idx is exactly UINT_MAX, instead of any index
past the last memory window.

Only print B2B MW workaround information in debugfs if the workaround is
in effect.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

Update the membarrier syscall self-test to match the membarrier
interface. Extend coverage of the interface. Consider ENOSYS as a
"SKIP" test, since it is a valid configuration, but does not allow
testing the system call.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Pranith Kumar <bobby.prani@gmail.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull sound fixes from Takashi Iwai:
"A collection of small fixes since the last update: the HD-audio quirks
as usual with a USB-audio fix and a trivial fix for the old sparc
driver"

* tag 'sound-fix-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: usb-audio: Change internal PCM order
ALSA: hda - Fix white noise on Dell M3800
ALSA: hda - Use ALC880_FIXUP_FUJITSU for FSC Amilo M1437
ALSA: hda - Enable headphone jack detect on old Fujitsu laptops
ALSA: sparc: amd7930: Fix module autoload for OF platform driver
ALSA: hda - Add some FIXUP quirks for white noise on Dell laptop.

It seems cleaner to avoid the temporary value here.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

Signed-off-by: Yan, Zheng <zyan@redhat.com>

Code for updating fs_info->num_tolerated_disk_barrier_failures in
btrfs_balance() lacks raid56 support.

Reason:
Above code was wroten in 2012-08-01, together with
btrfs_calc_num_tolerated_disk_barrier_failures()'s first version.

Then, btrfs_calc_num_tolerated_disk_barrier_failures() got updated
later to support raid56, but code in btrfs_balance() was not
updated together.

Fix:
Merge above similar code to a common function:
btrfs_get_num_tolerated_disk_barrier_failures()
and make it support both case.

It can fix this bug with a bonus of cleanup, and make these code
never in above no-sync state from now on.

Suggested-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

CRIS' types.h is functionally identical to the asm-generic version.

Effective diff:

+#ifndef _ASM_GENERIC_TYPES_H
+#define _ASM_GENERIC_TYPES_H
+
#include <asm-generic/int-ll64.h>
+
+#endif

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>

Pull SCSI target updates from Nicholas Bellinger:
"Here are the outstanding target-pending updates for v4.3-rc1.

Mostly bug-fixes and minor changes this round. The fallout from the
big v4.2-rc1 RCU conversion have (thus far) been minimal.

The highlights this round include:

- Move sense handling routines into scsi_common code (Sagi)

- Return ABORTED_COMMAND sense key for PI errors (Sagi)

- Add tpg_enabled_sendtargets attribute for disabled iscsi-target
discovery (David)

- Shrink target struct se_cmd by rearranging fields (Roland)

- Drop iSCSI use of mutex around max_cmd_sn increment (Roland)

- Replace iSCSI __kernel_sockaddr_storage with sockaddr_storage (Andy +
Chris)

- Honor fabric max_data_sg_nents I/O transfer limit (Arun + Himanshu +
nab)

- Fix EXTENDED_COPY >= v4.1 regression OOPsen (Alex + nab)"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (37 commits)
target: use stringify.h instead of own definition
target/user: Fix UFLAG_UNKNOWN_OP handling
target: Remove no-op conditional
target/user: Remove unused variable
target: Fix max_cmd_sn increment w/o cmdsn mutex regressions
target: Attach EXTENDED_COPY local I/O descriptors to xcopy_pt_sess
target/qla2xxx: Honor max_data_sg_nents I/O transfer limit
target/iscsi: Replace __kernel_sockaddr_storage with sockaddr_storage
target/iscsi: Replace conn->login_ip with login_sockaddr
target/iscsi: Keep local_ip as the actual sockaddr
target/iscsi: Fix np_ip bracket issue by removing np_ip
target: Drop iSCSI use of mutex around max_cmd_sn increment
qla2xxx: Update tcm_qla2xxx module description to 24xx+
iscsi-target: Add tpg_enabled_sendtargets for disabled discovery
drivers: target: Drop unlikely before IS_ERR(_OR_NULL)
target: check DPO/FUA usage for COMPARE AND WRITE
target: Shrink struct se_cmd by rearranging fields
target: Remove cmd->se_ordered_id (unused except debug log lines)
target: add support for START_STOP_UNIT SCSI opcode
target: improve unsupported opcode message
...

* pm-cpu:
kernel/cpu_pm: fix cpu_cluster_pm_exit comment

* pm-cpuidle:
cpuidle/coupled: Add sanity check for safe_state_index

* pm-domains:
staging: board: Migrate away from __pm_genpd_name_add_device()
PM / Domains: Ensure subdomain is not in use before removing
PM / Domains: Try power off masters in error path of __pm_genpd_poweron()

Prepare first round of input updates for 4.3 merge window.

Since commit 81e8f2bc (Input: imx_keypad - add pm suspend and resume
support) the imx_keypad driver supports power management, so let's remove
the obsolete comment.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

The documentation should say "peer" not "local" when referring to the
peer doorbell register.

Reported-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

Add a self test for the membarrier system call.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull drm fixes from Dave Airlie:
"Just a bunch of fixes to squeeze in before -rc1:

- three nouveau regression fixes

- one qxl regression fix

- a bunch of i915 fixes

... and some core displayport/atomic fixes"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/nouveau/device: enable c800 quirk for tecra w50
drm/nouveau/clk/gt215: Unbreak engine pausing for GT21x/MCP7x
drm/nouveau/gr/nv04: fix big endian setting on gr context
drm/qxl: validate monitors config modes
drm/i915: Allow DSI dual link to be configured on any pipe
drm/i915: Don't try to use DDR DVFS on CHV when disabled in the BIOS
drm/i915: Fix CSR MMIO address check
drm/i915: Limit the number of loops for reading a split 64bit register
drm/i915: Fix broken mst get_hw_state.
drm/i915: Pass hpd_status_i915[] to intel_get_hpd_pins() in pre-g4x
uapi/drm/i915_drm.h: fix userspace compilation.
drm/i915: Always mark the object as dirty when used by the GPU
drm/dp: Add dp_aux_i2c_speed_khz module param to set the assume i2c bus speed
drm/dp: Adjust i2c-over-aux retry count based on message size and i2c bus speed
drm/dp: Define AUX_RETRY_INTERVAL as 500 us
drm/atomic: Fix bookkeeping with TEST_ONLY, v3.

New PCMs will now be added to the end of the chip's PCM list instead of to the
front. This changes the way streams are combined so that the first capture
stream will now be merged with the first playback stream instead of the last.

This fixes a problem with ASUS U7. Cards with one playback stream and cards
without capture streams should be unaffected by this change.

Exception added for M-Audio Audiophile USB (tm) since it seems to have a fix to
swap capture stream numbering in alsa-lib conf/cards/USB-audio.conf

Signed-off-by: Johan Rastén <johan@oljud.se>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

Only ->alloc_msg() should check data_len of the incoming message
against the preallocated ceph_msg, doing it in the messenger is not
right. The contract is that either ->alloc_msg() returns a ceph_msg
which will fit all of the portions of the incoming message, or it
returns NULL and possibly sets skip, signaling whether NULL is due to
an -ENOMEM. ->alloc_msg() should be the only place where we make the
skip/no-skip decision.

I stumbled upon this while looking at con/osd ref counting. Right now,
if we get a non-extent message with a larger data portion than we are
prepared for, ->alloc_msg() returns a ceph_msg, and then, when we skip
it in the messenger, we don't put the con/osd ref acquired in
ceph_con_in_msg_alloc() (which is normally put in process_message()),
so this also fixes a memory leak.

An existing BUG_ON in ceph_msg_data_cursor_init() ensures we don't
corrupt random memory should a buggy ->alloc_msg() return an unfit
ceph_msg.

While at it, I changed the "unknown tid" dout() to a pr_warn() to make
sure all skips are seen and unified format strings.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>

1: Use ARRAY_SIZE(types) to replace a static-value variant:
int num_types = 4;

2: Use 'continue' on condition to reduce one level tab
if (!XXX) {
code;
...
}
->
if (XXX)
continue;
code;
...

3: Put setting 'num_tolerated_disk_barrier_failures = 2' to
(num_tolerated_disk_barrier_failures > 2) condition to make
make logic neat.
if (num_tolerated_disk_barrier_failures > 0 && XXX)
num_tolerated_disk_barrier_failures = 0;
else if (num_tolerated_disk_barrier_failures > 1) {
if (XXX)
num_tolerated_disk_barrier_failures = 1;
else if (XXX)
num_tolerated_disk_barrier_failures = 2;
->
if (num_tolerated_disk_barrier_failures > 0 && XXX)
num_tolerated_disk_barrier_failures = 0;
if (num_tolerated_disk_barrier_failures > 1 && XXX)
num_tolerated_disk_barrier_failures = ;
if (num_tolerated_disk_barrier_failures > 2 && XXX)
num_tolerated_disk_barrier_failures = 2;

4: Remove comment of:
num_mirrors - 1: if RAID1 or RAID10 is configured and more
than 2 mirrors are used.
which is not fit with code.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

CRIS' shmbuf.h is equivalent to the asm-generic verison.

Effective diff:

-#ifndef _CRIS_SHMBUF_H
-#define _CRIS_SHMBUF_H
+#ifndef __ASM_GENERIC_SHMBUF_H
+#define __ASM_GENERIC_SHMBUF_H
+
+#include <asm/bitsperlong.h>

struct ipc64_perm shm_perm;
size_t shm_segsz;
__kernel_time_t shm_atime;
+#if __BITS_PER_LONG != 64
unsigned long __unused1;
+#endif
__kernel_time_t shm_dtime;
+#if __BITS_PER_LONG != 64
unsigned long __unused2;
+#endif
__kernel_time_t shm_ctime;
+#if __BITS_PER_LONG != 64
unsigned long __unused3;
+#endif
__kernel_pid_t shm_cpid;
__kernel_pid_t shm_lpid;
- unsigned long shm_nattch;
- unsigned long __unused4;
- unsigned long __unused5;
+ __kernel_ulong_t shm_nattch;
+ __kernel_ulong_t __unused4;
+ __kernel_ulong_t __unused5;
};

struct shminfo64 {
- unsigned long shmmax;
- unsigned long shmmin;
- unsigned long shmmni;
- unsigned long shmseg;
- unsigned long shmall;
- unsigned long __unused1;
- unsigned long __unused2;
- unsigned long __unused3;
- unsigned long __unused4;
+ __kernel_ulong_t shmmax;
+ __kernel_ulong_t shmmin;
+ __kernel_ulong_t shmmni;
+ __kernel_ulong_t shmseg;
+ __kernel_ulong_t shmall;
+ __kernel_ulong_t __unused1;
+ __kernel_ulong_t __unused2;
+ __kernel_ulong_t __unused3;
+ __kernel_ulong_t __unused4;
};

#endif

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>

Pull second round of SCSI updates from James Bottomley:
"There's one late arriving patch here (added today), fixing a build
issue which the scsi_dh patch set in here uncovered. Other than that,
everything has been incubated in -next and the checkers for a week.

The major pieces of this patch are a set patches facilitating better
integration between scsi and scsi_dh (the device handling layer used
by multi-path; all the dm parts are acked by Mike Snitzer).

This also includes driver updates for mp3sas, scsi_debug and an
assortment of bug fixes"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (50 commits)
scsi_dh: fix randconfig build error
scsi: fix scsi_error_handler vs. scsi_host_dev_release race
fcoe: Convert use of __constant_htons to htons
mpt2sas: setpci reset kernel oops fix
pm80xx: Don't override ts->stat on IO_OPEN_CNX_ERROR_HW_RESOURCE_BUSY
lpfc: Fix possible use-after-free and double free in lpfc_mbx_cmpl_rdp_page_a2()
bfa: Fix incorrect de-reference of pointer
bfa: Fix indentation
scsi_transport_sas: Remove check for SAS expander when querying bay/enclosure IDs.
scsi_debug: resp_request: remove unused variable
scsi_debug: fix REPORT LUNS Well Known LU
scsi_debug: schedule_resp fix input variable check
scsi_debug: make dump_sector static
scsi_debug: vfree is null safe so drop the check
scsi_debug: use SCSI_W_LUN_REPORT_LUNS instead of SAM2_WLUN_REPORT_LUNS;
scsi_debug: define pr_fmt() for consistent logging
mpt2sas: Refcount fw_events and fix unsafe list usage
mpt2sas: Refcount sas_device objects and fix unsafe list usage
scsi_dh: return SCSI_DH_NOTCONN in scsi_dh_activate()
scsi_dh: don't allow to detach device handlers at runtime
...

Signed-off-by: David Disseldorp <ddiss@suse.de>
Acked-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

* pm-cpufreq:
intel_pstate: fix PCT_TO_HWP macro
intel_pstate: Fix user input of min/max to legal policy region
cpufreq-dt: add suspend frequency support
cpufreq: allow cpufreq_generic_suspend() to work without suspend frequency
cpufreq: Use __func__ to print function's name
cpufreq: staticize cpufreq_cpu_get_raw()
cpufreq: Add ARM_MT8173_CPUFREQ dependency on THERMAL
cpufreq: dt: Tolerance applies on both sides of target voltage
cpufreq: dt: Print error on failing to mark OPPs as shared
cpufreq: dt: Check OPP count before marking them shared

cpu_cluster_pm_exit() must be sent after cpu_cluster_pm_enter() has been
sent for the cluster and before any cpu_pm_exit() notifications are sent
for any CPU.

Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Since we are using cpuidle_driver::safe_state_index directly as the
target state index, it is better to add the sanity check at the point
of registering the driver.

Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The named genpd APIs are deprecated. Hence convert the board staging
code from using genpd names to DT node paths.

For now this supports PM domains with "#power-domain-cells = <0>" only.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Bit 2 of the mode byte has dual meaning: it can disable reporting of
gestures when touchpad works in Relative mode or normal Absolute mode,
or it can enable so called Extended W-Mode when touchpad uses enhanced
Absolute mode (W-mode). The extended W-Mode confuses our driver and
causes missing button presses on some Thinkpads (x250, T450s), so let's
make sure we do not enable it.

Also, according to the spec W mode "... bit is defined only in Absolute
mode on pads whose capExtended capability bit is set. In Relative mode and
in TouchPads without this capability, the bit is reserved and should be
left at 0.", so let's make sure we respect this requirement as well.

Reported-by: Nick Bowler <nbowler@draconx.ca>
Suggested-by: Gabor Balla <gaborwho@gmail.com>
Tested-by: Gabor Balla <gaborwho@gmail.com>
Tested-by: Nick Bowler <nbowler@draconx.ca>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

When driver is in IAP mode ic_type query may return 0xff. However
iap_version will always be valid, so let's use it to determine parameters
of the firmware that the controller is supposed to accept.

Signed-off-by: Duson Lin <dusonlin@emc.com.tw>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Freescale i.MX6UL contains a internal touchscreen controller,
this patch add a driver to support this controller.

Signed-off-by: Haibo Chen <haibo.chen@freescale.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

There was a copy and paste error in the documentation for
ntb_link_is_up. The long description was mistakenly copied from
ntb_link_set_trans.

This adds the appropriate long description for ntb_link_is_up.

Reported-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

Here is an implementation of a new system call, sys_membarrier(), which
executes a memory barrier on all threads running on the system. It is
implemented by calling synchronize_sched(). It can be used to
distribute the cost of user-space memory barriers asymmetrically by
transforming pairs of memory barriers into pairs consisting of
sys_membarrier() and a compiler barrier. For synchronization primitives
that distinguish between read-side and write-side (e.g. userspace RCU
[1], rwlocks), the read-side can be accelerated significantly by moving
the bulk of the memory barrier overhead to the write-side.

The existing applications of which I am aware that would be improved by
this system call are as follows:

* Through Userspace RCU library (http://urcu.so)
- DNS server (Knot DNS) https://www.knot-dns.cz/
- Network sniffer (http://netsniff-ng.org/)
- Distributed object storage (https://sheepdog.github.io/sheepdog/)
- User-space tracing (http://lttng.org)
- Network storage system (https://www.gluster.org/)
- Virtual routers (https://events.linuxfoundation.org/sites/events/files/slides/DPDK_RCU_0MQ.pdf)
- Financial software (https://lkml.org/lkml/2015/3/23/189)

Those projects use RCU in userspace to increase read-side speed and
scalability compared to locking. Especially in the case of RCU used by
libraries, sys_membarrier can speed up the read-side by moving the bulk of
the memory barrier cost to synchronize_rcu().

* Direct users of sys_membarrier
- core dotnet garbage collector (https://github.com/dotnet/coreclr/issues/198)

Microsoft core dotnet GC developers are planning to use the mprotect()
side-effect of issuing memory barriers through IPIs as a way to implement
Windows FlushProcessWriteBuffers() on Linux. They are referring to
sys_membarrier in their github thread, specifically stating that
sys_membarrier() is what they are looking for.

To explain the benefit of this scheme, let's introduce two example threads:

Thread A (non-frequent, e.g. executing liburcu synchronize_rcu())
Thread B (frequent, e.g. executing liburcu
rcu_read_lock()/rcu_read_unlock())

In a scheme where all smp_mb() in thread A are ordering memory accesses
with respect to smp_mb() present in Thread B, we can change each
smp_mb() within Thread A into calls to sys_membarrier() and each
smp_mb() within Thread B into compiler barriers "barrier()".

Before the change, we had, for each smp_mb() pairs:

Thread A Thread B
previous mem accesses previous mem accesses
smp_mb() smp_mb()
following mem accesses following mem accesses

After the change, these pairs become:

Thread A Thread B
prev mem accesses prev mem accesses
sys_membarrier() barrier()
follow mem accesses follow mem accesses

As we can see, there are two possible scenarios: either Thread B memory
accesses do not happen concurrently with Thread A accesses (1), or they
do (2).

1) Non-concurrent Thread A vs Thread B accesses:

Thread A Thread B
prev mem accesses
sys_membarrier()
follow mem accesses
prev mem accesses
barrier()
follow mem accesses

In this case, thread B accesses will be weakly ordered. This is OK,
because at that point, thread A is not particularly interested in
ordering them with respect to its own accesses.

2) Concurrent Thread A vs Thread B accesses

Thread A Thread B
prev mem accesses prev mem accesses
sys_membarrier() barrier()
follow mem accesses follow mem accesses

In this case, thread B accesses, which are ensured to be in program
order thanks to the compiler barrier, will be "upgraded" to full
smp_mb() by synchronize_sched().

* Benchmarks

On Intel Xeon E5405 (8 cores)
(one thread is calling sys_membarrier, the other 7 threads are busy
looping)

1000 non-expedited sys_membarrier calls in 33s =3D 33 milliseconds/call.

* User-space user of this system call: Userspace RCU library

Both the signal-based and the sys_membarrier userspace RCU schemes
permit us to remove the memory barrier from the userspace RCU
rcu_read_lock() and rcu_read_unlock() primitives, thus significantly
accelerating them. These memory barriers are replaced by compiler
barriers on the read-side, and all matching memory barriers on the
write-side are turned into an invocation of a memory barrier on all
active threads in the process. By letting the kernel perform this
synchronization rather than dumbly sending a signal to every process
threads (as we currently do), we diminish the number of unnecessary wake
ups and only issue the memory barriers on active threads. Non-running
threads do not need to execute such barrier anyway, because these are
implied by the scheduler context switches.

Results in liburcu:

Operations in 10s, 6 readers, 2 writers:

memory barriers in reader: 1701557485 reads, 2202847 writes
signal-based scheme: 9830061167 reads, 6700 writes
sys_membarrier: 9952759104 reads, 425 writes
sys_membarrier (dyn. check): 7970328887 reads, 425 writes

The dynamic sys_membarrier availability check adds some overhead to
the read-side compared to the signal-based scheme, but besides that,
sys_membarrier slightly outperforms the signal-based scheme. However,
this non-expedited sys_membarrier implementation has a much slower grace
period than signal and memory barrier schemes.

Besides diminishing the number of wake-ups, one major advantage of the
membarrier system call over the signal-based scheme is that it does not
need to reserve a signal. This plays much more nicely with libraries,
and with processes injected into for tracing purposes, for which we
cannot expect that signals will be unused by the application.

An expedited version of this system call can be added later on to speed
up the grace period. Its implementation will likely depend on reading
the cpu_curr()->mm without holding each CPU's rq lock.

This patch adds the system call to x86 and to asm-generic.

[1] http://urcu.so

membarrier(2) man page:

MEMBARRIER(2) Linux Programmer's Manual MEMBARRIER(2)

NAME
membarrier - issue memory barriers on a set of threads

SYNOPSIS
#include <linux/membarrier.h>

int membarrier(int cmd, int flags);

DESCRIPTION
The cmd argument is one of the following:

MEMBARRIER_CMD_QUERY
Query the set of supported commands. It returns a bitmask of
supported commands.

MEMBARRIER_CMD_SHARED
Execute a memory barrier on all threads running on the system.
Upon return from system call, the caller thread is ensured that
all running threads have passed through a state where all memory
accesses to user-space addresses match program order between
entry to and return from the system call (non-running threads
are de facto in such a state). This covers threads from all pro=E2=80=90
cesses running on the system. This command returns 0.

The flags argument needs to be 0. For future extensions.

All memory accesses performed in program order from each targeted
thread is guaranteed to be ordered with respect to sys_membarrier(). If
we use the semantic "barrier()" to represent a compiler barrier forcing
memory accesses to be performed in program order across the barrier,
and smp_mb() to represent explicit memory barriers forcing full memory
ordering across the barrier, we have the following ordering table for
each pair of barrier(), sys_membarrier() and smp_mb():

The pair ordering is detailed as (O: ordered, X: not ordered):

barrier() smp_mb() sys_membarrier()
barrier() X X O
smp_mb() X O O
sys_membarrier() O O O

RETURN VALUE
On success, these system calls return zero. On error, -1 is returned,
and errno is set appropriately. For a given command, with flags
argument set to 0, this system call is guaranteed to always return the
same value until reboot.

ERRORS
ENOSYS System call is not implemented.

EINVAL Invalid arguments.

Linux 2015-04-15 MEMBARRIER(2)

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Nicholas Miell <nmiell@comcast.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Pranith Kumar <bobby.prani@gmail.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>