libahci_platform: Fail when PHY required but PHY support disabled

ahci_platform_get_resources handles resource management for
platform AHCI drivers, including getting a possible PHY
from the device tree. Since not all drivers need a PHY, it
ignores -ENODEV and -ENOSYS from devm_get_phy. However, when
the PHY subsystem is mistakenly disabled, -ENOSYS can be
returned even when a PHY is needed.

This patch modifies the -ENOSYS case to check if a "phys"
device tree node exists. If it exists, then clearly the PHY
subsystem is mistakenly disabled and the driver cannot work,
ahci_platform_get_resources will fail and propagate the error.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
PCI: Fix unaligned access in AF transaction pending test

pci_wait_for_pending() uses word access, so we shouldn't be passing
an offset that is only byte aligned.  Use the control register offset
instead, shifting the mask to match.

Fixes: d0b4cc4e3270 ("PCI: Wrong register used to check pending traffic")
Fixes: 157e876ffe0b ("PCI: Add pci_wait_for_pending() (refactor pci_wait_for_pending_transaction())
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
CC: stable@vger.kernel.org	# v3.14+
cgroup: fix broken css_has_online_children()

After running:

  # mount -t cgroup cpu xxx /cgroup && mkdir /cgroup/sub && \
    rmdir /cgroup/sub && umount /cgroup

I found the cgroup root still existed:

  # cat /proc/cgroups
  #subsys_name    hierarchy       num_cgroups     enabled
  cpuset  0       1       1
  cpu     1       1       1
  ...

It turned out css_has_online_children() is broken.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Sigend-off-by: Tejun Heo <tj@kernel.org>
ahci: imx: manage only sata_ref_clk in imx_sata_enable[disable]

Doing suspend/resume on imx6q and imx53 boards with no SATA disk
attached will trigger the following warning.

------------[ cut here ]------------
WARNING: CPU: 0 PID: 661 at drivers/ata/libahci.c:224 ahci_enable_ahci+0x74/0x8)
Modules linked in:
CPU: 0 PID: 661 Comm: sh Tainted: G        W     3.15.0-rc5-next-20140521-000027
Backtrace:
[<80011c90>] (dump_backtrace) from [<80011e2c>] (show_stack+0x18/0x1c)
 r6:803a22f4 r5:00000000 r4:00000000 r3:00000000
[<80011e14>] (show_stack) from [<80661e60>] (dump_stack+0x88/0xa4)
[<80661dd8>] (dump_stack) from [<80028fdc>] (warn_slowpath_common+0x70/0x94)
 r5:00000009 r4:00000000
[<80028f6c>] (warn_slowpath_common) from [<80029024>] (warn_slowpath_null+0x24/)
 r8:808f68c4 r7:00000000 r6:00000000 r5:00000000 r4:e0810004
[<80029000>] (warn_slowpath_null) from [<803a22f4>] (ahci_enable_ahci+0x74/0x80)
[<803a2280>] (ahci_enable_ahci) from [<803a2324>] (ahci_reset_controller+0x24/0)
 r8:ddcd9410 r7:80351178 r6:ddcd9444 r5:dde8b850 r4:e0810000 r3:ddf35e90
[<803a2300>] (ahci_reset_controller) from [<803a2c68>] (ahci_platform_resume_ho)
 r7:80351178 r6:ddcd9444 r5:dde8b850 r4:ddcd9410
[<803a2c30>] (ahci_platform_resume_host) from [<803a38f0>] (imx_ahci_resume+0x2)
 r5:00000000 r4:ddcd9410
[<803a38c4>] (imx_ahci_resume) from [<803511ac>] (platform_pm_resume+0x34/0x54)
....

The reason is that the SATA controller has no working clock at this
point, and thus ahci_enable_ahci() fails to enable the controller.  In
case that there is no SATA disk attached, the imx_sata_disable() gets
called in ahci_imx_error_handler(), and both sata_clk and sata_ref_clk
will be disabled there.  Because all the imx_sata_enable() calls
afterward will return immediately due to imxpriv->no_device check, the
SATA controller working clock sata_clk will never get any chance to be
enabled again.

This is a regression caused by commit 90870d79d4f2 (ahci-imx: Port to
library-ised ahci_platform).  Before the commit, only sata_ref_clk is
managed by the driver in enable/disable function.  But after the commit,
all the clocks are enabled/disabled in a row by ahci platform helpers
ahci_platform_enable[disable]_clks.  Since ahb_clk is a bus clock which
does not have gate at all, and i.MX low-power hardware module already
manages sata_clk across suspend/resume cycle, the only clock that needs
to be managed by software is sata_ref_clk.

So instead of using ahci_platform_enable[disable]_clks to manage all
the clocks in a row from imx_sata_enable[disable], we should manage
only sata_ref_clk in there.

Reported-by: Fabio Estevam <fabio.estevam@freescale.com>
Fixes: 90870d79d4f2 (ahci-imx: Port to library-ised ahci_platform)
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
f2fs: fix to report newly allocate region as extent

Previous get_block in f2fs didn't report the newly allocated region which has
NEW_ADDR.
For reader, it should not report, but fiemap needs this.
So, this patch introduces two get_block sharing core function.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs: recover fallocated data and its i_size together

This patch arranges the f2fs_locks to cover the fallocated data and its i_size.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs: fix not to allocate unnecessary blocks during fallocate

This patch fixes the fallocate bug like below. (See xfstests/255)

In fallocate(fd, 0, 20480),
expand_inode_data processes
	for (index = pg_start; index <= pg_end; index++) {
		f2fs_reserve_block();
		...
	}

So, even though fallocate requests 20480, 5 blocks, f2fs allocates 6 blocks
including pg_end.
So, this patch adds one condition to avoid block allocation.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
workqueue: fix dev_set_uevent_suppress() imbalance

Uevents are suppressed during attributes registration, but never
restored, so kobject_uevent() does nothing.

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 226223ab3c4118ddd10688cc2c131135848371ab
ahci: disable ncq feature for hisilicon sata

NCQ feature is unsupported on hisilicon sata controller, so disable
it.  This version of IP is used by hip04 and hix5hd2 soc.

tj: "|=" was replaced with "=" for no reason.  Restored "|=".

Signed-off-by: Kefeng Wang <kefeng.wang@linaro.org>
Sigend-off-by: Tejun Heo <tj@kernel.org>
ata: ahci_imx: warn when disabling ahci link

When the AHCI link is disabled, it can't be re-enabled except by
resetting the entire SoC.  Rather than doing this silently print
some kernel messages to inform the user, along with how to avoid
this.

tj: Put a long printf format string on a single line.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Tejun Heo <tj@kernel.org>
cpuset,mempolicy: fix sleeping function called from invalid context

When runing with the kernel(3.15-rc7+), the follow bug occurs:
[ 9969.258987] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586
[ 9969.359906] in_atomic(): 1, irqs_disabled(): 0, pid: 160655, name: python
[ 9969.441175] INFO: lockdep is turned off.
[ 9969.488184] CPU: 26 PID: 160655 Comm: python Tainted: G       A      3.15.0-rc7+ #85
[ 9969.581032] Hardware name: FUJITSU-SV PRIMEQUEST 1800E/SB, BIOS PRIMEQUEST 1000 Series BIOS Version 1.39 11/16/2012
[ 9969.706052]  ffffffff81a20e60 ffff8803e941fbd0 ffffffff8162f523 ffff8803e941fd18
[ 9969.795323]  ffff8803e941fbe0 ffffffff8109995a ffff8803e941fc58 ffffffff81633e6c
[ 9969.884710]  ffffffff811ba5dc ffff880405c6b480 ffff88041fdd90a0 0000000000002000
[ 9969.974071] Call Trace:
[ 9970.003403]  [<ffffffff8162f523>] dump_stack+0x4d/0x66
[ 9970.065074]  [<ffffffff8109995a>] __might_sleep+0xfa/0x130
[ 9970.130743]  [<ffffffff81633e6c>] mutex_lock_nested+0x3c/0x4f0
[ 9970.200638]  [<ffffffff811ba5dc>] ? kmem_cache_alloc+0x1bc/0x210
[ 9970.272610]  [<ffffffff81105807>] cpuset_mems_allowed+0x27/0x140
[ 9970.344584]  [<ffffffff811b1303>] ? __mpol_dup+0x63/0x150
[ 9970.409282]  [<ffffffff811b1385>] __mpol_dup+0xe5/0x150
[ 9970.471897]  [<ffffffff811b1303>] ? __mpol_dup+0x63/0x150
[ 9970.536585]  [<ffffffff81068c86>] ? copy_process.part.23+0x606/0x1d40
[ 9970.613763]  [<ffffffff810bf28d>] ? trace_hardirqs_on+0xd/0x10
[ 9970.683660]  [<ffffffff810ddddf>] ? monotonic_to_bootbased+0x2f/0x50
[ 9970.759795]  [<ffffffff81068cf0>] copy_process.part.23+0x670/0x1d40
[ 9970.834885]  [<ffffffff8106a598>] do_fork+0xd8/0x380
[ 9970.894375]  [<ffffffff81110e4c>] ? __audit_syscall_entry+0x9c/0xf0
[ 9970.969470]  [<ffffffff8106a8c6>] SyS_clone+0x16/0x20
[ 9971.030011]  [<ffffffff81642009>] stub_clone+0x69/0x90
[ 9971.091573]  [<ffffffff81641c29>] ? system_call_fastpath+0x16/0x1b

The cause is that cpuset_mems_allowed() try to take
mutex_lock(&callback_mutex) under the rcu_read_lock(which was hold in
__mpol_dup()). And in cpuset_mems_allowed(), the access to cpuset is
under rcu_read_lock, so in __mpol_dup, we can reduce the rcu_read_lock
protection region to protect the access to cpuset only in
current_cpuset_is_being_rebound(). So that we can avoid this bug.

This patch is a temporary solution that just addresses the bug
mentioned above, can not fix the long-standing issue about cpuset.mems
rebinding on fork():

"When the forker's task_struct is duplicated (which includes
 ->mems_allowed) and it races with an update to cpuset_being_rebound
 in update_tasks_nodemask() then the task's mems_allowed doesn't get
 updated. And the child task's mems_allowed can be wrong if the
 cpuset's nodemask changes before the child has been added to the
 cgroup's tasklist."

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable <stable@vger.kernel.org>
crypto: sha512_ssse3 - fix byte count to bit count conversion

Byte-to-bit-count computation is only partly converted to big-endian and is
mixing in CPU-endian values. Problem was noticed by sparce with warning:

  CHECK   arch/x86/crypto/sha512_ssse3_glue.c
arch/x86/crypto/sha512_ssse3_glue.c:144:19: warning: restricted __be64 degrades to integer
arch/x86/crypto/sha512_ssse3_glue.c:144:17: warning: incorrect type in assignment (different base types)
arch/x86/crypto/sha512_ssse3_glue.c:144:17:    expected restricted __be64 <noident>
arch/x86/crypto/sha512_ssse3_glue.c:144:17:    got unsigned long long

Cc: <stable@vger.kernel.org>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
i2c: mux: pca954x: fix dependencies

This driver causes the following randconfig build error:

drivers/i2c/muxes/i2c-mux-pca954x.c: In function ‘pca954x_probe’:
drivers/i2c/muxes/i2c-mux-pca954x.c:204:2: error: implicit declaration
of function ‘devm_gpiod_get’ [-Werror=implicit-function-declaration]
  gpio = devm_gpiod_get(&client->dev, "reset");
  ^
drivers/i2c/muxes/i2c-mux-pca954x.c:204:7: warning: assignment makes
pointer from integer without a cast [enabled by default]
  gpio = devm_gpiod_get(&client->dev, "reset");
       ^
drivers/i2c/muxes/i2c-mux-pca954x.c:206:3: error: implicit declaration
of function ‘gpiod_direction_output’
[-Werror=implicit-function-declaration]
   gpiod_direction_output(gpio, 0);
   ^
cc1: some warnings being treated as errors
make[3]: *** [drivers/i2c/muxes/i2c-mux-pca954x.o] Error 1

This is because it is getting compiled without gpiolib, so
introduce an explicit dependency.

Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c: sun6i-p2wi: Remove duplicate inclusion of module.h

module.h was included twice.

Signed-off-by: Sachin Kamat <sachin.kamat@samsung.com>
Acked-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
cgroup: fix mount failure in a corner case

  # cat test.sh
  #! /bin/bash

  mount -t cgroup -o cpu xxx /cgroup
  umount /cgroup

  mount -t cgroup -o cpu,cpuacct xxx /cgroup
  umount /cgroup
  # ./test.sh
  mount: xxx already mounted or /cgroup busy
  mount: according to mtab, xxx is already mounted on /cgroup

It's because the cgroupfs_root of the first mount was under destruction
asynchronously.

Fix this by delaying and then retrying mount for this case.

v3:
- put the refcnt immediately after getting it. (Tejun)

v2:
- use percpu_ref_tryget_live() rather that introducing
  percpu_ref_alive(). (Tejun)
- adjust comment.

tj: Updated the comment a bit.

Cc: <stable@vger.kernel.org> # 3.15
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
kernfs: introduce kernfs_pin_sb()

kernfs_pin_sb() tries to get a refcnt of the superblock.

This will be used by cgroupfs.

v2:
- make kernfs_pin_sb() return the superblock.
- drop kernfs_drop_sb().

tj: Updated the comment a bit.

[ This is a prerequisite for a bugfix. ]
Cc: <stable@vger.kernel.org> # 3.15
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
cgroup: fix a race between cgroup_mount() and cgroup_kill_sb()

We've converted cgroup to kernfs so cgroup won't be intertwined with
vfs objects and locking, but there are dark areas.

Run two instances of this script concurrently:

    for ((; ;))
    {
    	mount -t cgroup -o cpuacct xxx /cgroup
    	umount /cgroup
    }

After a while, I saw two mount processes were stuck at retrying, because
they were waiting for a subsystem to become free, but the root associated
with this subsystem never got freed.

This can happen, if thread A is in the process of killing superblock but
hasn't called percpu_ref_kill(), and at this time thread B is mounting
the same cgroup root and finds the root in the root list and performs
percpu_ref_try_get().

To fix this, we try to increase both the refcnt of the superblock and the
percpu refcnt of cgroup root.

v2:
- we should try to get both the superblock refcnt and cgroup_root refcnt,
  because cgroup_root may have no superblock assosiated with it.
- adjust/add comments.

tj: Updated comments.  Renamed @sb to @pinned_sb.

Cc: <stable@vger.kernel.org> # 3.15
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
cpuset: break kernfs active protection in cpuset_write_resmask()

Writing to either "cpuset.cpus" or "cpuset.mems" file flushes
cpuset_hotplug_work so that cpu or memory hotunplug doesn't end up
migrating tasks off a cpuset after new resources are added to it.

As cpuset_hotplug_work calls into cgroup core via
cgroup_transfer_tasks(), this flushing adds the dependency to cgroup
core locking from cpuset_write_resmak().  This used to be okay because
cgroup interface files were protected by a different mutex; however,
8353da1f91f1 ("cgroup: remove cgroup_tree_mutex") simplified the
cgroup core locking and this dependency became a deadlock hazard -
cgroup file removal performed under cgroup core lock tries to drain
on-going file operation which is trying to flush cpuset_hotplug_work
blocked on the same cgroup core lock.

The locking simplification was done because kernfs added an a lot
easier way to deal with circular dependencies involving kernfs active
protection.  Let's use the same strategy in cpuset and break active
protection in cpuset_write_resmask().  While it isn't the prettiest,
this is a very rare, likely unique, situation which also goes away on
the unified hierarchy.

The commands to trigger the deadlock warning without the patch and the
lockdep output follow.

 localhost:/ # mount -t cgroup -o cpuset xxx /cpuset
 localhost:/ # mkdir /cpuset/tmp
 localhost:/ # echo 1 > /cpuset/tmp/cpuset.cpus
 localhost:/ # echo 0 > cpuset/tmp/cpuset.mems
 localhost:/ # echo $$ > /cpuset/tmp/tasks
 localhost:/ # echo 0 > /sys/devices/system/cpu/cpu1/online

  ======================================================
  [ INFO: possible circular locking dependency detected ]
  3.16.0-rc1-0.1-default+ #7 Not tainted
  -------------------------------------------------------
  kworker/1:0/32649 is trying to acquire lock:
   (cgroup_mutex){+.+.+.}, at: [<ffffffff8110e3d7>] cgroup_transfer_tasks+0x37/0x150

  but task is already holding lock:
   (cpuset_hotplug_work){+.+...}, at: [<ffffffff81085412>] process_one_work+0x192/0x520

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #2 (cpuset_hotplug_work){+.+...}:
  ...
  -> #1 (s_active#175){++++.+}:
  ...
  -> #0 (cgroup_mutex){+.+.+.}:
  ...

  other info that might help us debug this:

  Chain exists of:
    cgroup_mutex --> s_active#175 --> cpuset_hotplug_work

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(cpuset_hotplug_work);
				 lock(s_active#175);
				 lock(cpuset_hotplug_work);
    lock(cgroup_mutex);

   *** DEADLOCK ***

  2 locks held by kworker/1:0/32649:
   #0:  ("events"){.+.+.+}, at: [<ffffffff81085412>] process_one_work+0x192/0x520
   #1:  (cpuset_hotplug_work){+.+...}, at: [<ffffffff81085412>] process_one_work+0x192/0x520

  stack backtrace:
  CPU: 1 PID: 32649 Comm: kworker/1:0 Not tainted 3.16.0-rc1-0.1-default+ #7
 ...
  Call Trace:
   [<ffffffff815a5f78>] dump_stack+0x72/0x8a
   [<ffffffff810c263f>] print_circular_bug+0x10f/0x120
   [<ffffffff810c481e>] check_prev_add+0x43e/0x4b0
   [<ffffffff810c4ee6>] validate_chain+0x656/0x7c0
   [<ffffffff810c53d2>] __lock_acquire+0x382/0x660
   [<ffffffff810c57a9>] lock_acquire+0xf9/0x170
   [<ffffffff815aa13f>] mutex_lock_nested+0x6f/0x380
   [<ffffffff8110e3d7>] cgroup_transfer_tasks+0x37/0x150
   [<ffffffff811129c0>] hotplug_update_tasks_insane+0x110/0x1d0
   [<ffffffff81112bbd>] cpuset_hotplug_update_tasks+0x13d/0x180
   [<ffffffff811148ec>] cpuset_hotplug_workfn+0x18c/0x630
   [<ffffffff810854d4>] process_one_work+0x254/0x520
   [<ffffffff810875dd>] worker_thread+0x13d/0x3d0
   [<ffffffff8108e0c8>] kthread+0xf8/0x100
   [<ffffffff815acaec>] ret_from_fork+0x7c/0xb0

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Li Zefan <lizefan@huawei.com>
Tested-by: Li Zefan <lizefan@huawei.com>
core: fix typo in percpu read_mostly section

This fixes a typo that named the read_mostly section of percpu as
readmostly. It works fine with SMP because the linker script specifies
.data..percpu..readmostly. However, UP kernel builds don't have percpu
sections defined and the non-percpu version of the section is called
data..read_mostly, so .data..readmostly will float around and may break
things unexpectedly.

Looking at the original change that introduced data..percpu..readmostly
(commit c957ef2c59e952803766ddc22e89981ab534606f), it looks like this
was the original intention.

Tested: Built UP kernel and confirmed the sections got merged.

- Before the patch:
$ objdump -h vmlinux.o  | grep '\.data\.\.read.*mostly'
38 .data..read_mostly 00004418  0000000000000000  0000000000000000  00431ac0  2**6
50 .data..readmostly 00000014  0000000000000000  0000000000000000  00444000  2**3

- After the patch:
$ objdump -h vmlinux.o  | grep '\.data\.\.read.*mostly'
38 .data..read_mostly 00004438  0000000000000000  0000000000000000  00431ac0  2**6

Signed-off-by: Zhengyu He <hzy@google.com>
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
kbuild: Do not print the build directory with make -s

Commit c2e28dc9 (kbuild: Print the name of the build directory) prints
the name of the build directory for O= builds, but we should not be
doing this in make -s mode, so that commands like

  make -s O=<dir> kernelrelease

can be used by scripts. This matches the behavior of make itself, where
the -s option implies --no-print-directory.

Signed-off-by: Michal Marek <mmarek@suse.cz>