timer: Don't reinitialize the cpu base lock during CPU_UP_PREPARE

An inactive timer's base can refer to a offline cpu's base.

In the current code, cpu_base's lock is blindly reinitialized
each time a CPU is brought up. If a CPU is brought online
during the period that another thread is trying to modify an
inactive timer on that CPU with holding its timer base lock,
then the lock will be reinitialized under its feet. This leads
to following SPIN_BUG().

<0> BUG: spinlock already unlocked on CPU#3, kworker/u:3/1466
<0> lock: 0xe3ebe000, .magic: dead4ead, .owner: kworker/u:3/1466,
 .owner_cpu: 1
<4> [<c0013dc4>] (unwind_backtrace+0x0/0x11c) from [<c026e794>]
(do_raw_spin_unlock+0x40/0xcc)
<4> [<c026e794>] (do_raw_spin_unlock+0x40/0xcc) from [<c076c160>]
(_raw_spin_unlock+0x8/0x30)
<4> [<c076c160>] (_raw_spin_unlock+0x8/0x30) from [<c009b858>]
(mod_timer+0x294/0x310)
<4> [<c009b858>] (mod_timer+0x294/0x310) from [<c00a5e04>]
(queue_delayed_work_on+0x104/0x120)
<4> [<c00a5e04>] (queue_delayed_work_on+0x104/0x120) from [<c04eae00>]
(sdhci_msm_bus_voting+0x88/0x9c)
<4> [<c04eae00>] (sdhci_msm_bus_voting+0x88/0x9c) from [<c04d8780>]
(sdhci_disable+0x40/0x48)
<4> [<c04d8780>] (sdhci_disable+0x40/0x48) from [<c04bf300>]
(mmc_release_host+0x4c/0xb0)
<4> [<c04bf300>] (mmc_release_host+0x4c/0xb0) from [<c04c7aac>]
(mmc_sd_detect+0x90/0xfc)
<4> [<c04c7aac>] (mmc_sd_detect+0x90/0xfc) from [<c04c2504>]
(mmc_rescan+0x7c/0x2c4)
<4> [<c04c2504>] (mmc_rescan+0x7c/0x2c4) from [<c00a6a7c>]
(process_one_work+0x27c/0x484)
<4> [<c00a6a7c>] (process_one_work+0x27c/0x484) from [<c00a6e94>]
(worker_thread+0x210/0x3b0)
<4> [<c00a6e94>] (worker_thread+0x210/0x3b0) from [<c00aad9c>]
(kthread+0x80/0x8c)
<4> [<c00aad9c>] (kthread+0x80/0x8c) from [<c000ea80>]
(kernel_thread_exit+0x0/0x8)

As an example, this particular crash occurred when CPU #3 is executing
mod_timer() on an inactive timer whose base is refered to offlined CPU #2.
The code locked the timer_base corresponding to CPU #2. Before it could
proceed, CPU #2 came online and reinitialized the spinlock corresponding
to its base. Thus now CPU #3 held a lock which was reinitialized. When
CPU #3 finally ended up unlocking the old cpu_base corresponding to CPU #2,
we hit the above SPIN_BUG().

CPU #0			CPU #3				       CPU #2
------			-------				       -------
.....			 ......				      <Offline>
			mod_timer()
			 lock_timer_base
			  spin_lock_irqsave(&base->lock)

cpu_up(2)		 .....				        ......
							 init_timers_cpu()
.....		 	 spin_unlock_irqrestore(&base->lock)     ......
			   <spin_bug>

Allocation of per_cpu timer vector bases is done only once under
"tvec_base_done[]" check. In the current code, spinlock_initialization
of base->lock isn't under this check. When a CPU is up each time the base
lock is reinitialized. Move base spinlock initialization under the check.

CRs-Fixed: 471127
Change-Id: I73b48440fffb227a60af9180e318c851048530dd
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>
Merge "timer: Don't reinitialize the cpu base lock during CPU_UP_PREPARE"
msm: kgsl: Don't hold process list global mutex in process private create

Don't hold process list global mutex for long. Instead make
use of process specific spin_lock() to serialize access
to process private structure while creating it. Holding
process list global mutex could lead to deadlocks as other
functions depend on it.

CRs-fixed: 480732
Change-Id: Id54316770f911d0e23384f54ba5c14a1c9113680
Signed-off-by: Harsh Vardhan Dwivedi <hdwivedi@codeaurora.org>
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>
msm8974: mhl_sii8334: init chip in D3

MHL Tx chipset is set to low power during chip
initialization. In open-drain mode, mhl tx releases
the upstream HPD line. Set ID and data lines by
default in USB mode during initial power state.
Delay setting the chipset into low power mode until
MHL HPD STAT interrupt has occurred, this is the true
reflection of hpd state. This change also sets the hardware
to mirror cbus hpd state in driver.

Change-Id: I65e0b4c1a3e6a4eadd20cbc46c5209d748aacd13
Signed-off-by: Manoj Rao <manojraj@codeaurora.org>
netlink: use kfree_rcu() in netlink_release()

On some suspend/resume operations involving wimax device, we have
noticed some intermittent memory corruptions in netlink code.

Stéphane Marchesin tracked this corruption in netlink_update_listeners()
and suggested a patch.

It appears netlink_release() should use kfree_rcu() instead of kfree()
for the listeners structure as it may be used by other cpus using RCU
protection.

netlink_release() must set to NULL the listeners pointer when
it is about to be freed.

Also have to protect netlink_update_listeners() and
netlink_has_listeners() if listeners is NULL.

Add a nl_deref_protected() lockdep helper to properly document which
locks protects us.

CRs-Fixed: 484684
Change-Id: I4d65f8787d33a5d220b08686887ef205337cd6c3
Reported-by: Jonathan Kliegman <kliegs@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stéphane Marchesin <marcheu@google.com>
Cc: Sam Leffler <sleffler@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-commit: 6d772ac5578f711d1ce7b03535d1c95bffb21dff
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
Merge "msm: kgsl: Don't hold process list global mutex in process private create"
Merge "msm8974: mhl_sii8334: init chip in D3"
Merge "netlink: use kfree_rcu() in netlink_release()"
msm: camera: Enhance CCI error handling

Handle all error interrupts in CCI by calling HALT followed by RESET
on corresponding CCI MASTER. Validate queue before performing I2C
read and write to ensure that queue is empty.

Change-Id: I336e6563e7430b50d41311c0e275315e87e82174
Signed-off-by: Sreesudhan Ramakrish Ramkumar <srramku@codeaurora.org>
(cherry picked from commit a1806d83f530728b967da33f541248c419115c1f)
msm: mdss: add DSI state machine

Maintain state of DSI panel, and avoid performing some operations
depending on the the current state.

Change-Id: Id8c2cc30e5058dea7585cc9d06b2ab11368bc337
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>
(cherry picked from commit 4805d08acd82d427b40a5ddfcfd1a2fb84528e43)
rtc: qpnp-rtc: Remove enable operation for RTC peripheral

As RTC is already enabled from trustzone removing enable operation
from RTC driver.

Change-Id: I1891d2f35a9e595d30a1965d4cf20aedaf83d7d5
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>
(cherry picked from commit 36568b82c9c049395c3b6760ccce6933d4608670)
workqueue: skip nr_running sanity check in worker_enter_idle() if trustee is active

worker_enter_idle() has WARN_ON_ONCE() which triggers if nr_running
isn't zero when every worker is idle.  This can trigger spuriously
while a cpu is going down due to the way trustee sets %WORKER_ROGUE
and zaps nr_running.

It first sets %WORKER_ROGUE on all workers without updating
nr_running, releases gcwq->lock, schedules, regrabs gcwq->lock and
then zaps nr_running.  If the last running worker enters idle
inbetween, it would see stale nr_running which hasn't been zapped yet
and trigger the WARN_ON_ONCE().

Fix it by performing the sanity check iff the trustee is idle.

Change-Id: I54465b67d76bfaff3138963153256cde48add673
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Git-commit: 544ecf310f0e7f51fa057ac2a295fc1b3b35a9d3
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
(cherry picked from commit 8a85eb91e3e84af18d9611fe38a8e7c66b70670a)
workqueue: don't use WQ_HIGHPRI for unbound workqueues

Unbound wqs aren't concurrency-managed and try to execute work items
as soon as possible.  This is currently achieved by implicitly setting
%WQ_HIGHPRI on all unbound workqueues; however, WQ_HIGHPRI
implementation is about to be restructured and this usage won't be
valid anymore.

Add an explicit chain-wakeup path for unbound workqueues in
process_one_work() instead of piggy backing on %WQ_HIGHPRI.

Change-Id: Iecd17a9935ee28f856d8b726bb4c296762922bed
Signed-off-by: Tejun Heo <tj@kernel.org>
Git-commit: 974271c485a4d8bb801decc616748f90aafb07ec
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
(cherry picked from commit 5b92cea36d8328c17380d7997744284707134397)
workqueue: factor out worker_pool from global_cwq

Move worklist and all worker management fields from global_cwq into
the new struct worker_pool.  worker_pool points back to the containing
gcwq.  worker and cpu_workqueue_struct are updated to point to
worker_pool instead of gcwq too.

This change is mechanical and doesn't introduce any functional
difference other than rearranging of fields and an added level of
indirection in some places.  This is to prepare for multiple pools per
gcwq.

v2: Comment typo fixes as suggested by Namhyung.

Change-Id: Iefae84798c2af580f425b92ed79117935d99f21f
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Git-commit: bd7bdd43dcb81bb08240b9401b36a104f77dc135
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
(cherry picked from commit e3676a67902c18021bd571aa3fcefc74b377b65f)
workqueue: use @pool instead of @gcwq or @cpu where applicable

Modify all functions which deal with per-pool properties to pass
around @pool instead of @gcwq or @cpu.

The changes in this patch are mechanical and don't caues any
functional difference.  This is to prepare for multiple pools per
gcwq.

Change-Id: I4be6727e1cce6f9aa2a0057b96bdc725c84f1ea8
Signed-off-by: Tejun Heo <tj@kernel.org>
Git-commit: 63d95a9150ee3bbd4117fcd609dee40313b454d9
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
(cherry picked from commit ae73f6e6eae63e64d552227a109b6ccb802cdd04)
workqueue: separate out worker_pool flags

GCWQ_MANAGE_WORKERS, GCWQ_MANAGING_WORKERS and GCWQ_HIGHPRI_PENDING
are per-pool properties.  Add worker_pool->flags and make the above
three flags per-pool flags.

The changes in this patch are mechanical and don't caues any
functional difference.  This is to prepare for multiple pools per
gcwq.

Change-Id: I1824fd1c509d8ac6b0619536621a22b15b316256
Signed-off-by: Tejun Heo <tj@kernel.org>
Git-commit: 11ebea50dbc1ade5994b2c838a096078d4c02399
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
(cherry picked from commit 1ab4f069d6d1255625a42209a42cf9d6773480d9)
workqueue: introduce NR_WORKER_POOLS and for_each_worker_pool()

Introduce NR_WORKER_POOLS and for_each_worker_pool() and convert code
paths which need to manipulate all pools in a gcwq to use them.
NR_WORKER_POOLS is currently one and for_each_worker_pool() iterates
over only @gcwq->pool.

Note that nr_running is per-pool property and converted to an array
with NR_WORKER_POOLS elements and renamed to pool_nr_running.  Note
that get_pool_nr_running() currently assumes 0 index.  The next patch
will make use of non-zero index.

The changes in this patch are mechanical and don't caues any
functional difference.  This is to prepare for multiple pools per
gcwq.

v2: nr_running indexing bug in get_pool_nr_running() fixed.

v3: Pointer to array is stupid.  Don't use it in get_pool_nr_running()
    as suggested by Linus.

Change-Id: I46e9488601d764d25e4a6c707de129ab68f7064c
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: 4ce62e9e30cacc26885cab133ad1de358dd79f21
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
(cherry picked from commit ca6a47d36f578a3c9ae47037413abca8319fd99f)
workqueue: reimplement WQ_HIGHPRI using a separate worker_pool

WQ_HIGHPRI was implemented by queueing highpri work items at the head
of the global worklist.  Other than queueing at the head, they weren't
handled differently; unfortunately, this could lead to execution
latency of a few seconds on heavily loaded systems.

Now that workqueue code has been updated to deal with multiple
worker_pools per global_cwq, this patch reimplements WQ_HIGHPRI using
a separate worker_pool.  NR_WORKER_POOLS is bumped to two and
gcwq->pools[0] is used for normal pri work items and ->pools[1] for
highpri.  Highpri workers get -20 nice level and has 'H' suffix in
their names.  Note that this change increases the number of kworkers
per cpu.

POOL_HIGHPRI_PENDING, pool_determine_ins_pos() and highpri chain
wakeup code in process_one_work() are no longer used and removed.

This allows proper prioritization of highpri work items and removes
high execution latency of highpri work items.

v2: nr_running indexing bug in get_pool_nr_running() fixed.

v3: Refreshed for the get_pool_nr_running() update in the previous
    patch.

Change-Id: Id843c0a425f51f84083786fbf413d999d35771b7
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Josh Hunt <joshhunt00@gmail.com>
LKML-Reference: <CAKA=qzaHqwZ8eqpLNFjxnO2fX-tgAOjmpvxgBFjv6dJeQaOW1w@mail.gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Git-commit: 3270476a6c0ce322354df8679652f060d66526dc
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
(cherry picked from commit f2a9a769bf4fa185757115007bf94c36c2f29aca)
msm: rpm-smd: Configure WQ for higer priority

When the workqueue runs at a lower priority, it gets starved by higher
priority threads. Bump the WQ priority to high to ensure rpm smd work
queue gets a fair chance

Change-Id: I06b864611cf45afe6931d6030327806032894663
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
(cherry picked from commit e0eccf8f6dece61cdb639c4b43374c34c3acf3ea)
msm: cpufreq: Configure WQ for higer priority

When the workqueue runs at a lower priority, it gets starved by higher
priority threads. Bump the WQ priority to high to ensure cpufreq work
queue gets a fair scheduling chance

Change-Id: I9e994da94a347dceb884e72ec3dd3da468a4471d
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
(cherry picked from commit c0a082fec5b016f0e2ea8b454de901d184401d9a)