msm: lpm_levels: update suspend stats counters and time

suspend stats in the debug pm stats are not getting updated as
suspend stats in the suspend wake path is missing. This change
will add and update the suspend stats in the suspend wake path.

Signed-off-by: Anil kumar mamidala <amami@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
msm: lpm_levels: fix incorrect mode select with next event time

Based on the next event timer value the best power mode will get
selected but there is a mismatch in calculation of selecting
the best mode. This change will fix that and selects the correct
mode based on the next wakeup time.

Signed-off-by: Anil kumar mamidala <amami@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
msm: lpm_levels: fix driver compilation issue

Assigning an unsinged long value to unsinged int is not
correct and it cause driver compilation failure. Fix by
assigning a proper value.

Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
msm: lpm_levels: Perform system_unprepare only system low power mode

system_unprepare() needs to execute operations related to system
unprepare only when the CPU subsystem was scheduled for a system low
power mode by the last core that went down. On the last core down, its
possible that residency conditions for system low power mode weren't met
and the system was never programmed to enter a low power mode. In these
scenarios, the system_unprepare() needn't execute any of the unprepare
functionalities.

Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
msm: lpm_levels: return new idle level to cpuidle framework

Need to return the new idle level to cpuidle framework
but just returned input value argument 'index' which is
not used actually at lpm_cpu_power_select().

Signed-off-by: Anil kumar mamidala <amami@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
timekeeping: Add persistent_clock_exist flag

In current kernel, there are several places which need to check
whether there is a persistent clock for the platform. Current check
is done by calling the read_persistent_clock() and validating its
return value.

So one optimization is to do the check only once in timekeeping_init(),
and use a flag persistent_clock_exist to record it.

v2: Add a has_persistent_clock() helper function, as suggested by John.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
 timekeeping: Correct run-time detection of persistent_clock.

Since commit 31ade30, timekeeping_init()
checks for presence of persistent clock by attempting to read a non-zero
time value. This is an issue on platforms where persistent_clock (instead
is implemented as a free-running counter (instead of an RTC) starting
from zero on each boot and running during suspend. Examples are some ARM
platforms (e.g. PandaBoard).

An attempt to read such a clock during timekeeping_init() may return zero
value and falsely declare persistent clock as missing. Additionally, in
the above case suspend times may be accounted twice (once from
timekeeping_resume() and once from rtc_resume()), resulting in a gradual
drift of system time.

This patch does a run-time correction of the issue by doing the same check
during timekeeping_suspend().

A better long-term solution would have to return error when trying to read
non-existing clock and zero when trying to read an uninitialized clock, but
that would require changing all persistent_clock implementations.

This patch addresses the immediate breakage, for now.

Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org>
[jstultz: Tweaked commit message and subject]
Signed-off-by: John Stultz <john.stultz@linaro.org>

BackPort by Dorimanx.
time: create __getnstimeofday for WARNless calls

Expose getnstimeofday logic that returns
an error instead of a WARN. This can be detected and the timestamp can
be zeroed out.

Reported-by: Doug Anderson <dianders@chromium.org>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
timekeeping: Add suspend and resume of clock event devices

Some clock event devices, for example such that belong to PM domains,
need to be handled in a spcial way during the timekeeping suspend
and resume (which takes place in the system core, or "syscore",
stages of system power transitions) in analogy with clock sources.

Introduce .suspend() and .resume() callbacks for clock event devices
that will be executed by timekeeping_suspend/_resume(), respectively,
next the the clock sources' .suspend() and .resume() callbacks.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
time: Move timekeeper structure to timekeeper_internal.h for vsyscall changes

We're going to need to access the timekeeper in update_vsyscall,
so make the structure available for those who need it.

Cc: Tony Luck <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>