staging: zcache: fix a compile warning

Fix:

drivers/staging/zcache/zcache-main.c: In function ‘zcache_comp_op’:
drivers/staging/zcache/zcache-main.c:112:2: warning: ‘ret’ may be used uninitial

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: zcache: mark zbud_init/zcache_comp_init as __init

These functions are called only when system is initializing, so mark __init
for them to free memory

Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: zcache: cleanup zbud_init

Need not set global parameters to 0

Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: zcache: optimize zcache_do_preload

zcache_do_preload is called in zcache_put_page where IRQ is disabled, so, need
not care preempt

Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: zcache: cleanup zcache_do_preload and zcache_put_page

Cleanup the code for zcache_do_preload and zcache_put_page

Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: zcache: cleanup the code between tmem_obj_init and tmem_obj_find

tmem_obj_find and insertion tmem-obj have the some logic, we can integrate
the code

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
msm: msm_fb: remove mmio access through mmap

Disable access to mm io and add
appropriate range checks to ensure valid accesses
through framebuffer mmap. This prevents illegal
access into memory.

Signed-off-by: Manoj Rao <manojraj@codeaurora.org>
Signed-off-by: Shalabh Jain <shalabhj@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
workqueue: drop CPU_DYING notifier operation

Workqueue used CPU_DYING notification to mark GCWQ_DISASSOCIATED.
This was necessary because workqueue's CPU_DOWN_PREPARE happened
before other DOWN_PREPARE notifiers and workqueue needed to stay
associated across the rest of DOWN_PREPARE.

After the previous patch, workqueue's DOWN_PREPARE happens after
others and can set GCWQ_DISASSOCIATED directly.  Drop CPU_DYING and
let the trustee set GCWQ_DISASSOCIATED after disabling concurrency
management.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
workqueue: ROGUE workers are UNBOUND workers

Currently, WORKER_UNBOUND is used to mark workers for the unbound
global_cwq and WORKER_ROGUE is used to mark workers for disassociated
per-cpu global_cwqs.  Both are used to make the marked worker skip
concurrency management and the only place they make any difference is
in worker_enter_idle() where WORKER_ROGUE is used to skip scheduling
idle timer, which can easily be replaced with trustee state testing.

This patch replaces WORKER_ROGUE with WORKER_UNBOUND and drops
WORKER_ROGUE.  This is to prepare for removing trustee and handling
disassociated global_cwqs as unbound.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
workqueue: use mutex for global_cwq manager exclusion

POOL_MANAGING_WORKERS is used to ensure that at most one worker takes
the manager role at any given time on a given global_cwq.  Trustee
later hitched on it to assume manager adding blocking wait for the
bit.  As trustee already needed a custom wait mechanism, waiting for
MANAGING_WORKERS was rolled into the same mechanism.

Trustee is scheduled to be removed.  This patch separates out
MANAGING_WORKERS wait into per-pool mutex.  Workers use
mutex_trylock() to test for manager role and trustee uses mutex_lock()
to claim manager roles.

gcwq_claim/release_management() helpers are added to grab and release
manager roles of all pools on a global_cwq.  gcwq_claim_management()
always grabs pool manager mutexes in ascending pool index order and
uses pool index as lockdep subclass.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
cpuidle: add checks to avoid NULL pointer dereference

The existing check for dev == NULL in __cpuidle_register_device() is
rendered useless because dev is dereferenced before the check itself.
Moreover, correctly speaking, it is the job of the callers of this
function, i.e., cpuidle_register_device() & cpuidle_enable_device() (which
also happen to be exported functions) to ensure that
__cpuidle_register_device() is called with a non-NULL dev.

So add the necessary dev == NULL checks in the two callers and remove the
(useless) check from __cpuidle_register_device().

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
cpuidle: move field disable from per-driver to per-cpu

Andrew J.Schorr raises a question.  When he changes the disable setting on
a single CPU, it affects all the other CPUs.  Basically, currently, the
disable field is per-driver instead of per-cpu.  All the C states of the
same driver are shared by all CPU in the same machine.

The patch changes the `disable' field to per-cpu, so we could set this
separately for each cpu.

Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
Reported-by: Andrew J.Schorr <aschorr@telemetry-investments.com>
Reviewed-by: Yanmin Zhang <yanmin_zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
PM / cpuidle: Add driver reference counter

Add a reference counter for the cpuidle driver, so that it can't
be unregistered when it is in use.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
PM / Domains: Rework default domain power off governor function, v2

The existing default domain power down governor function for PM
domains, default_power_down_ok(), is supposed to check whether or not
the PM QoS latency constraints of the devices in the domain will be
violated if the domain is turned off by pm_genpd_poweroff().
However, the computations carried out by it don't reflect the
definition of the PM QoS latency constrait in
Documentation/ABI/testing/sysfs-devices-power.

Make default_power_down_ok() follow the definition of the PM QoS
latency constrait.  In particular, make it only take latencies into
account, because it doesn't matter how much time has elapsed since
the domain's devices were suspended for the computation.

Remove the break_even_ns and power_off_time fields from
struct generic_pm_domain, because they are not necessary any more.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
PM / Domains: Rework default device stop governor function, v2

The existing default device stop governor function for PM domains,
default_stop_ok(), is supposed to check whether or not the device's
PM QoS latency constraint will be violated if the device is stopped
by pm_genpd_runtime_suspend().  However, the computations carried out
by it don't reflect the definition of the PM QoS latency constrait in
Documentation/ABI/testing/sysfs-devices-power.

Make default_stop_ok() follow the definition of the PM QoS latency
constrait.  In particular, make it take the device's start and stop
latencies correctly.

Add a new field, effective_constraint_ns, to struct gpd_timing_data
and use it to store the difference between the device's PM QoS
constraint and its resume latency for use by the device's parent
(the effective_constraint_ns values for the children are used for
computing the parent's one along with its PM QoS constraint).

Remove the break_even_ns field from struct gpd_timing_data, because
it's not used any more.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
PM / Runtime: Remove device fields related to suspend time, v2

After the previous changes in default_stop_ok() and
default_power_down_ok() for PM domains, there are two fields in
struct dev_pm_info that aren't necessary any more,  suspend_time
and max_time_suspended_ns.

Remove those fields along with all of the code that accesses them,
which simplifies the runtime PM framework quite a bit.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
PM / Domains: Make device removal more straightforward

The removal of a device from a PM domain doesn't have to browse
the domain's device list, because it can check directly if the
device belongs to the given domain.  Moreover, it should clear
the domain_data pointer in dev->power.subsys_data, because
dev_pm_put_subsys_data(dev) may not remove dev->power.subsys_data
and the stale domain data pointer may cause problems to happen.

Rework pm_genpd_remove_device() taking the above observations into
account.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
PM / Domains: Cache device stop and domain power off governor results, v3

The results of the default device stop and domain power off governor
functions for generic PM domains, default_stop_ok() and
default_power_down_ok(), depend only on the timing data of devices,
which are static, and on their PM QoS constraints.  Thus, in theory,
these functions only need to carry out their computations, which may
be time consuming in general, when it is known that the PM QoS
constraint of at least one of the devices in question has changed.

Use the PM QoS notifiers of devices to implement that.  First,
introduce new fields, constraint_changed and max_off_time_changed,
into struct gpd_timing_data and struct generic_pm_domain,
respectively, and register a PM QoS notifier function when adding
a device into a domain that will set those fields to 'true' whenever
the device's PM QoS constraint is modified.  Second, make
default_stop_ok() and default_power_down_ok() use those fields to
decide whether or not to carry out their computations from scratch.

The device and PM domain hierarchies are taken into account in that
and the expense is that the changes of PM QoS constraints of
suspended devices will not be taken into account immediately, which
isn't guaranteed anyway in general.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
PM / Domains: Fix link checking when add subdomain

Current pm_genpd_add_subdomain() will allow duplicated link between
master and slave domain.  This patch fixed it.

Because when current pm_genpd_add_subdomain() checks whether the link
between the master and slave generic PM domain already exists,
slave_links instead of master_links of master domain is used.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
PM / Domains: Make it possible to add devices to inactive domains

The generic PM domains core code currently requires domains to be in
the "power on" state for adding devices to them, but this limitation
turns out to be inconvenient in some situations, so remove it.

For this purpose, make __pm_genpd_add_device() set the device's
need_restore flag if the domain is in the "power off" state, so that
the device's "restore state" (usually .runtime_resume()) callback
is executed when it is resumed after the domain has been turned on.
If the domain is in the "power on" state, the device's need_restore
flag will be cleared by __pm_genpd_add_device(), so that its "save
state" (usually .runtime_suspend()) callback is executed when the
domain is about to be turned off.  However, since that default
behavior need not be always desirable, add a helper function
pm_genpd_dev_need_restore() allowing a device's need_restore flag
to be set/unset at any time.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>