Fix
block: add latest ROW I/O scheduler from CAF msm-3.4
together with following prerequisites

block: Add API for urgent request handling
This patch add support in block & elevator layers for handling
urgent requests. The decision if a request is urgent or not is taken
by the scheduler. Urgent request notification is passed to the underlying
block device driver (eMMC for example). Block device driver may decide to
interrupt the currently running low priority request to serve the new
urgent request. By doing so READ latency is greatly reduced in read&write
collision scenarios.

Note that if the current scheduler doesn't implement the urgent request
mechanism, this code path is never activated.

Change-Id: I8aa74b9b45c0d3a2221bd4e82ea76eb4103e7cfa
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
____________

block: Add support for reinsert a dispatched req
Add support for reinserting a dispatched request back to the
scheduler's internal data structures.
This capability is used by the device driver when it chooses to
interrupt the current request transmission and execute another (more
urgent) pending request. For example: interrupting long write in order
to handle pending read. The device driver re-inserts the
remaining write request back to the scheduler, to be rescheduled
for transmission later on.

Add API for verifying whether the current scheduler
supports reinserting requests mechanism. If reinsert mechanism isn't
supported by the scheduler, this code path will never be activated.

Change-Id: I5c982a66b651ebf544aae60063ac8a340d79e67f
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
______________

block: urgent request: remove unnecessary urgent marking
An urgent request is marked by the scheduler in rq->cmd_flags with the
REQ_URGENT flag. There is no need to add an additional marking by
the block layer.

Change-Id: I05d5e9539d2f6c1bfa80240b0671db197a5d3b3f
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
__________________

block: add REQ_URGENT to request flags
This patch adds a new flag to be used in cmd_flags field of struct request
for marking request as urgent.
Urgent request is the one that should be given priority currently handled
(regular) request by the device driver. The decision of a request urgency
is taken by the scheduler.

Change-Id: Ic20470987ef23410f1d0324f96f00578f7df8717
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
___________________

block: urgent request: Update dispatch_urgent in case of requeue/reinsert
The block layer implements a mechanism for verifying that the device
driver won't be notified of an URGENT request if there is already an
URGENT request in flight. This is due to the fact that interrupting an
URGENT request isn't efficient.
This patch fixes the above described mechanism in case the URGENT request
was returned back to the block layer from some reason: by requeue or
reinsert.

CRs-fixed: 473376, 473036, 471736
Change-Id: Ie8b8208230a302d4526068531616984825f1050d
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
_____________________

block: urgent: Fix dispatching of URGENT mechanism
There are cases when blk_peek_request is called not from blk_fetch_request
thus the URGENT request may be started but the flag q->dispatched_urgent is
not updated.

Change-Id: I4fb588823f1b2949160cbd3907f4729767932e12
CRs-fixed: 471736
CRs-fixed: 473036
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
___________________

mm: pass readahead info down to the i/o scheduler
Some i/o schedulers (i.e. row-iosched, cfq-iosched) deploy an idling
algorithm in order to be better synced with the readahead algorithm.
Idling is a prediction algorithm for incoming read requests.

In this patch we mark pages which are part of a readahead window, by
setting a newly introduced flag. With this flag, the i/o scheduler can
identify a request which is associated with a readahead page. This
enables the i/o scheduler's idling mechanism to be en-sync with the
readahead mechanism and, in turn, can increase read throughput.

Change-Id: I0654f23315b6d19d71bcc9cc029c6b281a44b196
Signed-off-by: Lee Susman <lsusman@codeaurora.org>
Enable ROW-Scheduler
msm: cpufreq: Initialize cpufreq driver early at boot
cpufreq: Manage only online cpus

cpufreq core doesn't manage offline cpus and if driver->init() has returned
mask including offline cpus, it may result in unwanted behavior by cpufreq core
or governors.

We need to get only online cpus in this mask. There are two places to fix this
mask, cpufreq core and cpufreq driver. It makes sense to do this at common place
and hence is done in core.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Notify governors when cpus are hot-[un]plugged
Because cpufreq core and governors worry only about the online cpus, if a cpu is
hot [un]plugged, we must notify governors about it, otherwise be ready to expect
something unexpected.

We already have notifiers in the form of CPUFREQ_GOV_START/CPUFREQ_GOV_STOP, we
just need to call them now.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Save user policy min/max instead of policy min/max during hotplug

When a CPU is hotplugged off, various fields of the policy are saved so
that they can be restored when the CPU is hotplugged back in.

The existing code saves the policy min/max field during hotplug remove and
restores it into user policy min/max during hotplug add. This results in
the loss of the user policy min/max values across a hotplug remove/add.

Fix it by saving the user policy min/max instead of policy min/max during
hotplug remove. During a hotplug add, after user policy min/max is
restored, the policy min/max is already recomputed. So, there's no risk of
going beyound any limits imposed by the CPUFREQ_ADJUST/INCOMPATIBLE
notifiers.

Change-Id: Ib8e09fa324c1f80f095c5754b5dcf2685e8e4a66
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
msm: cpufreq: Always update frequency limits when core is online

Remove condition in msm_cpufreq_init() so that when cpu is set to
online, it will call set_cpu_freq() and update the frequency limits.

CRs-Fixed: 462816
Change-Id: I40ac33c9cb4b42590a83f9d61b74f23379f5642e
Signed-off-by: Jennifer Liu <chihning@codeaurora.org>
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>
msm: cpufreq: Relax constraints on "msm-cpufreq" workqueue

This workqueue is not used in memory reclaim paths, so the
WQ_MEM_RECLAIM flag is not needed. Additionally, there is no
need to restrict the queue to having one in-flight work item.
Remove these constraints.

Change-Id: I9edde40917d3ec885ce061133de20680634321d0
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
msm: cpufreq: Ensure cpufreq change happens on corresponding CPU

Checking the cpus_allowed mask of the current thread before changing the
frequency doesn't guarantee that the rest of the execution will continue on
the same CPU. The only way to guarantee this is to schedule a work on the
specific CPU and also prevent hotplug  of that CPU (already done by
existing code).

Change-Id: I51a02fcc777a47d3c16f2d83c47e96f2c59f7ae6
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
msm: cpufreq: Move cpu_frequency_* trace points from acpuclock to cpufreq

acpuclock is not used on newer targets, so move the trace points
in it up to the generic msm cpufreq driver. Also drop the use of
the 'trace_cpu_frequency' entirely, since it's already present in
generic cpufreq code.

As a side effect of this change, these trace events will no longer
track cpu frequency changes from the power-collapse path. Only
frequency changes coming from cpufreq will be tracked.

CRs-Fixed: 535512
Change-Id: Ib69d92f5d3209a7e36be678997b79bcdac92f953
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
msm: makefile: we don't need these in mako

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
defconfig: Fix for SCSI