loop: use aio to perform io on the underlying file

This uses the new kernel aio interface to process loopback IO by
submitting concurrent direct aio.  Previously loop's IO was serialized
by synchronous processing in a thread.

The aio operations specify the memory for the IO with the bio_vec arrays
directly instead of mappings of the pages.

The use of aio operations is enabled when the backing file supports the
read_iter, write_iter and direct_IO methods.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
modified for Mako from LKML reference

Signed-off-by: faux123 <reioux@gmail.com> (reverted from commit ae664431ddcffe3db567b80c61991c635fde304c)
msm: hotplug: Add MSM Hotplug driver
msm: mdss: Adding lcd notifier

Supports notifier for start&end of LCD power on&off

Change-Id: Idaa685a2c554286da5f764519305d830c4d1a1bd
Signed-off-by: Se Hun Kim <sean2.kim@lge.com>
Signed-off-by: Jongrak Kwon <jongrak.kwon@lge.com>
Signed-off-by: Devin Kim <dojip.kim@lge.com>
msm: hotplug: Max 1036MHz during screen off
msm: hotplug: Remove spinlock in load stats

It's too expensive and not nessecary.
msm: hotplug: Stop hotplug work a tad later
msm: hotplug: Schedule suspend/resume work

Dennis is right, this is the proper way to suspend and resume.
msm: hotplug: Increase down lock duration and janitize
msm: hotplug: Use high-priority workqueue
msm: hotplug: Add input boost handler

Add an input handler to hotplug additional cpus. Down lock will
take care of keeping the cpu boosted.
msm: hotplug: Add minimum interval for input boost
msm: hotplug: Remove deprecated msm_cpufreq_set_freq_limits
msm: hotplug: Cleanup hotplugging routines

Remove paroid atomic operations that were causing issues.
cpufreq: add new routine cpufreq_verify_within_cpu_limits()

Most of the users of cpufreq_verify_within_limits() calls it for
limiting with min/max from policy->cpuinfo. We can make that code
simple by introducing another routine which will do this for them
automatically.

This patch adds another routine cpufreq_verify_within_cpu_limits()
and updates others to use it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
msm: hotplug: Optimize hotplugging routines

- Power down the slowest cpu
- Move checks from callback to calling function
- Clean it up a bit
msm: hotplug: Add pm ops
msm: hotplug: Fix symbol export
msm: hotplug: Fixup sysfs interface

* Use proper return values
* Fix store_down_lock_duration()
* Add some more checks
* Cleanup some mess
msm: hotplug: Update threshold values and down lock duration

* Power up additional cpus earlier
* Power down cpus later
* Keep cpus online at least 5 seconds
msm: hotplug: Revert to original thresholds
msm: hotplug: Consider load instead of frequency for slowest cpu