arm: atomic.h: defined relaxed atomic_read

Defining relaxed version of atomic read as cpu_relaxed_read_atomic.

bug 1440421

Signed-off-by: Sumit Singh <sumsingh@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
arm: asm: relaxed.h: defined relaxed.h

Defined a new header file relaxed.h, which uses generic
definitions of some macros used by arm64 for improving
power efficiency.

bug 1440421

Signed-off-by: Sumit Singh <sumsingh@nvidia.com>
Reviewed-on: http://git-master/r/398766
(cherry picked from commit a96e59b1959f3ee216503b4f9df3cb75f7093ed6)
Reviewed-on: http://git-master/r/422211
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
sched: defining relaxed version of idle_cpu

Defining relaxed version of idle_cpu, which uses
macro cpu_relaxed_read_long, that will be used to
enhance power efficiency.

bug 1440421

Signed-off-by: Sumit Singh <sumsingh@nvidia.com>
Reviewed-by: Sri Krishna Chowdary <schowdary@nvidia.com>
Reviewed-by: Alexander Van Brunt <avanbrunt@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
asm-generic: relaxed.h: defined relaxed.h

Defined a new header file relaxed.h, which contains basic
macros which will be used for improving power efficiency for
arm64.

bug 1440421

Signed-off-by: Sumit Singh <sumsingh@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
llist: defining relaxed version of llist_empty

Defining relaxed version of llist_empty as llist_empty_relaxed,
which will be used for power-optimization.

bug 1440421

Signed-off-by: Sumit Singh <sumsingh@nvidia.com>
Reviewed-by: Sri Krishna Chowdary <schowdary@nvidia.com>
Reviewed-by: Alexander Van Brunt <avanbrunt@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
asm-generic: processor.h: adding new header file

Defining a new header file and adding architecture
independent macros. Using these macros we are optimizing
power usage on ARM64.

bug 1440421

Signed-off-by: Sumit Singh <sumsingh@nvidia.com>
Reviewed-by: Alexander Van Brunt <avanbrunt@nvidia.com>
Reviewed-by: Sri Krishna Chowdary <schowdary@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
ARM: including asm-generic/processor.h

Here we are including asm-generic/processor.h
because it has defined some generic macros which
can be used by any architecture for optimaztion
of power usage.

bug 1440421

Change-Id: I39db944d348b3dad9235b76d8c7ea3867c0006ce
Signed-off-by: Sumit Singh <sumsingh@nvidia.com>
Reviewed-by: Alexander Van Brunt <avanbrunt@nvidia.com>
Reviewed-by: Peng Du <pdu@nvidia.com>
Reviewed-by: Sri Krishna Chowdary <schowdary@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
cpu: enhance power efficiency

Here we are trying to reduce power usage through the
use of macros cpu_relaxed_read and relaxed version of
idle_cpu().

Bug 1440421

Signed-off-by: Sumit Singh <sumsingh@nvidia.com>
Reviewed-by: Sri Krishna Chowdary <schowdary@nvidia.com>
Reviewed-by: Alexander Van Brunt <avanbrunt@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
seqlock: enhance power efficiency

Trying to improve the power efficiency in linux/seqlock.h,
using macros cpu_relaxed_read and cpu_read_relax.

Bug 1440421

Signed-off-by: Sumit Singh <sumsingh@nvidia.com>
Reviewed-by: Sri Krishna Chowdary <schowdary@nvidia.com>
Reviewed-by: Alexander Van Brunt <avanbrunt@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
mutex: save power with better cpu_relax

Use cpu_relaxed_read and cpu_read_relax to allow more architectures to be able
to "relax" instead of busy spinning.

Bug 1440421

Signed-off-by: Alex Van Brunt <avanbrunt@nvidia.com>
Reviewed-by: Sumit Singh <sumsingh@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
sched: Trying to reduce power usage

Using macros cpu_relaxed_read, cpu_relaxed_read_long and
cpu_read_relax in core.c to improve power efficiency.

Bug 1440421

Signed-off-by: Sumit Singh <sumsingh@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Tested-by: Bharat Nihalani <bnihalani@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
hrtimer: enhance power efficiency

Defining relaxed version of hrtimer_callback_running(),
which will be used to improve power efficiency through
the use of macro cpu_relaxed_read_long.

Bug 1440421

Signed-off-by: Sumit Singh <sumsingh@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
smp: enhance power efficiency

Here we are trying to reduce power usage through the
use of macros cpu_relaxed_read_short and cpu_relaxed_read.

Bug 1440421

Signed-off-by: Sumit Singh <sumsingh@nvidia.com>
Reviewed-by: Sri Krishna Chowdary <schowdary@nvidia.com>
Reviewed-by: Alexander Van Brunt <avanbrunt@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
kernel/smp.c: use '|=' for csd_lock

csd_lock() uses assignment to data->flags rather than |=.  That is not
buggy at present because only one bit (CSD_FLAG_LOCK) is defined in
call_single_data.flags.

But it will become buggy if we later add another flag, so fix it now.

Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
kernel/smp.c: cleanups

We sometimes use "struct call_single_data *data" and sometimes "struct
call_single_data *csd".  Use "csd" consistently.

We sometimes use "struct call_function_data *data" and sometimes "struct
call_function_data *cfd".  Use "cfd" consistently.

Also, avoid some 80-col layout tricks.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
arch: arm: lib: optimize memcpy for cortex-A15

The LDRD/STRD instruction is faster than LDM/STM on Cortex-A15.
Also optimized preload cache size for Cortex-A15.

Added USE_LDRDSTRD_OVER_LDMSTM to turn on LDRD/STRD optimization.
Added ARM_PLD_SIZE, default 32. Should set to 64 for Cortex-A15.

Bug 1185248

Signed-off-by: Chandler Zhang <chazhang@nvidia.com>
Reviewed-by: Krishna Reddy <vdumpa@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
arch: arm: lib: optimize memcpy for cortex-A15

* Apply to memutils we ported from msm8960pro

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
sched: Force sleep on consecutive sched_yields

If a task sched_yields to itself continuously, force the task to
sleep in sched_yield. This will lower the CPU load of this task
thereby lowering the cpu frequency and improving power.

Added a stat variable to track how many times we sleep due these
consecutive sched_yields. Also added sysctl knobs to control the number
of consecutive sched_yields before which the sleep kicks in and the
duration fo the sleep in us.

Bug 1424617

Signed-off-by: Sai Gurrappadi <sgurrappadi@nvidia.com>
Reviewed-by: Wen Yi <wyi@nvidia.com>
Reviewed-by: Peter Zu <pzu@nvidia.com>
Reviewed-by: Diwakar Tundlam <dtundlam@nvidia.com>
[neo: Include cleanups by @Dorimanx . Thanks.]
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
ARM: cleanup undefined instruction entry code

We don't need to keep reloading the thread into into r10 - we can do
this once and keep the value cached in the register.  Also, schedule
some instructions better so that the pipeline doesn't stall after a
load in the neon code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
ARM: mm: Remove unnecessary CMO in Cortex A15 startup

Cortex-A15 flush L2 cache after reset, there is no need to do this
in software, if L2 is already invalidated in bootloader and
cache is disabled. For secondary startup, there is no reason to
flush L2 as well.

This change assumes the setup code is always entered as the result
of CPU reset.

Signed-off-by: Bo Yan <byan@nvidia.com>
Reviewed-by: Mrutyunjay Sawant <msawant@nvidia.com>
Tested-by: Mrutyunjay Sawant <msawant@nvidia.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>