Enable pipe flag.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Reclaim RAM from loggers
lib/memcopy: use glibc version

the kernel's memcpy and memmove is very inefficient. But the glibc version is
quite fast, in some cases it is 10 times faster than the kernel version. So I
introduce some memory copy macros and functions of the glibc to improve the
kernel version's performance.

The strategy of the memory functions is:
1. Copy bytes until the destination pointer is aligned.
2. Copy words in unrolled loops.  If the source and destination are not
   aligned in the same way, use word memory operations, but shift and merge
   two read words before writing.
3. Copy the few remaining bytes.

Signed-off-by: Miao Xie <miaox*******>
Signed-off-by: faux123 <reioux@gmail.com>
lib/string: use glibc version

the performance of memcpy and memmove of the general version is very
inefficient, this patch improved them.

Signed-off-by: Miao Xie <miaox*******>
Signed-off-by: faux123 <reioux@gmail.com>
Add /dev/frandom
workqueues: Introduce new flag WQ_POWER_EFFICIENT for power oriented workqueues

Adapted for 3.4 from lsk-v3.10

Workqueues can be performance or power-oriented. Currently, most workqueues are
bound to the CPU they were created on. This gives good performance (due to cache
effects) at the cost of potentially waking up otherwise idle cores (Idle from
scheduler's perspective. Which may or may not be physically idle) just to
process some work. To save power, we can allow the work to be rescheduled on a
core that is already awake.

Workqueues created with the WQ_UNBOUND flag will allow some power savings.
However, we don't change the default behaviour of the system.  To enable
power-saving behaviour, a new config option CONFIG_WQ_POWER_EFFICIENT needs to
be turned on. This option can also be overridden by the
workqueue.power_efficient boot parameter.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>

Conflicts:
	include/linux/workqueue.h
	kernel/workqueue.c

Conflicts:
	include/linux/workqueue.h
	kernel/workqueue.c

Conflicts:
	kernel/workqueue.c
workqueue: Add system wide power_efficient workqueues

Adapted for 3.4 from lsk-v3.10

This patch adds system wide workqueues aligned towards power saving. This is
done by allocating them with WQ_UNBOUND flag if 'wq_power_efficient' is set to
'true'.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>

Conflicts:
	include/linux/workqueue.h

Conflicts:
	include/linux/workqueue.h
block: queue work on power efficient wq

Adapted for 3.4 from lsk-v3.10

Block layer uses workqueues for multiple purposes. There is no real dependency
of scheduling these on the cpu which scheduled them.

On a idle system, it is observed that and idle cpu wakes up many times just to
service this work. It would be better if we can schedule it on a cpu which the
scheduler believes to be the most appropriate one.

This patch replaces normal workqueues with power efficient versions.

Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
PHYLIB: queue work on system_power_efficient_wq

Adapted for 3.4 from lsk-v3.10

Phylib uses workqueues for multiple purposes. There is no real dependency of
scheduling these on the cpu which scheduled them.

On a idle system, it is observed that and idle cpu wakes up many times just to
service this work. It would be better if we can schedule it on a cpu which the
scheduler believes to be the most appropriate one.

This patch replaces system_wq with system_power_efficient_wq for PHYLIB.

Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
ASoC: pcm: Use the power efficient workqueue for delayed powerdown

Adapted for 3.4 from lsk-v3.10

There is no need to use a normal per-CPU workqueue for delayed power downs
as they're not timing or performance critical and waking up a core for them
would defeat some of the point.

Signed-off-by: Mark Brown <broonie@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
regulator: core: Use the power efficient workqueue for delayed powerdown

There is no need to use a normal per-CPU workqueue for delayed power downs
as they're not timing or performance critical and waking up a core for them
would defeat some of the point.

Signed-off-by: Mark Brown <broonie@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Liam Girdwood <liam.r.girdwood@intel.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
ASoC: jack: Use power efficient workqueue

The accessory detect debounce work is not performance sensitive so let
the scheduler run it wherever is most efficient rather than in a per CPU
workqueue by using the system power efficient workqueue.

Signed-off-by: Mark Brown <broonie@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
deadline: Allow 0ms deadline latency, increase the read speed

Change a timer compare from after to after-equals, thus allowing
0 timeout and making deadline schedule FIFO.

Signed-off-by: xiaobing tu <xiaobing.tu@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: flar2 <asegaert@gmail.com>

Conflicts:
	block/deadline-iosched.c

Conflicts:
	block/deadline-iosched.c
cpufreq: Break out early when frequency equals target_freq

Many drivers keep frequencies in frequency table in ascending
or descending order. When governor tries to change to policy->min
or policy->max respectively then the cpufreq_frequency_table_target
could return on first iteration. This will save some iteration cycles.

So, break out early when a frequency in cpufreq_frequency_table
equals to target one.

Testing this during kernel compilation using ondemand governor
with a frequency table in ascending order, the
cpufreq_frequency_table_target returned early on the first
iteration at about 30% of times called.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
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>
block: Adding ROW scheduling algorithm

This patch adds the implementation of a new scheduling algorithm - ROW.
The policy of this algorithm is to prioritize READ requests over WRITE
as much as possible without starving the WRITE requests.

Change-Id: I4ed52ea21d43b0e7c0769b2599779a3d3869c519
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: ROW: Correct minimum values of ROW tunable parameters

The ROW scheduling algorithm exposes several tunable parameters.
This patch updates the minimum allowed values for those parameters.

Change-Id: I5ec19d54b694e2e83ad5376bd99cc91f084967f5
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: ROW: Fix forced dispatch

This patch fixes forced dispatch in the ROW scheduling algorithm.
When the dispatch function is called with the forced flag on, we
can't delay the dispatch of the requests that are in scheduler queues.
Thus, when dispatch is called with forced turned on, we need to cancel
idling, or not to idle at all.

Change-Id: I3aa0da33ad7b59c0731c696f1392b48525b52ddc
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: 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>

row: Adding support for reinsert already dispatched req

Add support for reinserting already dispatched request back to the
schedulers internal data structures.
The request will be reinserted back to the queue (head) it was
dispatched from as if it was never dispatched.

Change-Id: I70954df300774409c25b5821465fb3aa33d8feb5
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block:row: fix idling mechanism in ROW

This patch addresses the following issues found in the ROW idling
mechanism:
1. Fix the delay passed to queue_delayed_work (pass actual delay
   and not the time when to start the work)
2. Change the idle time and the idling-trigger frequency to be
   HZ dependent (instead of using msec_to_jiffies())
3. Destroy idle_workqueue() in queue_exit

Change-Id: If86513ad6b4be44fb7a860f29bd2127197d8d5bf
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

cfq-iosched: Fix null pointer dereference

NULL pointer dereference can happen in cfq_choose_cfqg()
when there are no cfq groups to select other than the
current serving group. Prevent this by adding a NULL
check before dereferencing.

Unable to handle kernel NULL pointer dereference at virtual address
[<c02502cc>] (cfq_dispatch_requests+0x368/0x8c0) from
[<c0243f30>] (blk_peek_request+0x220/0x25c)
[<c0243f30>] (blk_peek_request+0x220/0x25c) from
[<c0243f74>] (blk_fetch_request+0x8/0x1c)
[<c0243f74>] (blk_fetch_request+0x8/0x1c) from
[<c041cedc>] (mmc_queue_thread+0x58/0x120)
[<c041cedc>] (mmc_queue_thread+0x58/0x120) from
[<c00ad310>] (kthread+0x84/0x90)
[<c00ad310>] (kthread+0x84/0x90) from
[<c000eeac>] (kernel_thread_exit+0x0/0x8)

CRs-Fixed: 416466
Change-Id: I1fab93a4334b53e1d7c5dcc8f93cff174bae0d5e
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>

row: Add support for urgent request handling

This patch adds support for handling urgent requests.
ROW queue can be marked as "urgent" so if it was un-served in last
dispatch cycle and a request was added to it - it will trigger
issuing an urgent-request-notification to the block device driver.
The block device driver may choose at stop the transmission of current
ongoing request to handle the urgent one. Foe example: long WRITE may
be stopped to handle an urgent READ. This decreases READ latency.

Change-Id: I84954c13f5e3b1b5caeadc9fe1f9aa21208cb35e
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: row: Add some debug information on ROW queues

1. Add a counter for number of requests on queue.
2. Add function to print queues status (number requests
   currently on queue and number of already dispatched requests
   in current dispatch cycle).

Change-Id: I1e98b9ca33853e6e6a8ddc53240f6cd6981e6024
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: row: Insert dispatch_quantum into struct row_queue

There is really no point in keeping the dispatch quantum
of a queue outside of it. By inserting it to the row_queue
structure we spare extra level in accessing it.

Change-Id: Ic77571818b643e71f9aafbb2ca93d0a92158b199
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: row: fix sysfs functions - idle_time conversion

idle_time was updated to be stored in msec instead of jiffies.
So there is no need to convert the value when reading from user or
displaying the value to him.

Change-Id: I58e074b204e90a90536d32199ac668112966e9cf
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: row: Aggregate row_queue parameters to one structure

Each ROW queues has several parameters which default values are defined
in separate arrays. This patch aggregates all default values into one
array.
The values in question are:
 - is idling enabled for the queue
 - queue quantum
 - can the queue notify on urgent request

Change-Id: I3821b0a042542295069b340406a16b1000873ec6
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: row: Dispatch requests according to their io-priority

This patch implements "application-hints" which is a way the issuing
application can notify the scheduler on the priority of its request.
This is done by setting the io-priority of the request.
This patch reuses an already existing mechanism of io-priorities developed
for CFQ. Please refer to kernel/Documentation/block/ioprio.txt for
usage example and explanations.

Change-Id: I228ec8e52161b424242bb7bb133418dc8b73925a
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: row: Idling mechanism re-factoring

At the moment idling in ROW is implemented by delayed work that uses
jiffies granularity which is not very accurate. This patch replaces
current idling mechanism implementation with hrtime API, which gives
nanosecond resolution (instead of jiffies).

Change-Id: I86c7b1776d035e1d81571894b300228c8b8f2d92
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: row: Don't notify URGENT if there are un-completed urgent req

When ROW scheduler reports to the block layer that there is an urgent
request pending, the device driver may decide to stop the transmission
of the current request in order to handle the urgent one. If the current
transmitted request is an urgent request - we don't want it to be
stopped.
Due to the above ROW scheduler won't notify of an urgent request if
there are urgent requests in flight.

Change-Id: I2fa186d911b908ec7611682b378b9cdc48637ac7
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: row: Update initial values of ROW data structures

This patch sets the initial values of internal ROW
parameters.

Change-Id: I38132062a7fcbe2e58b9cc757e55caac64d013dc
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
[smuckle@codeaurora.org: ported from msm-3.7]
Signed-off-by: Steve Muckle <smuckle@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: row: Re-design urgent request notification mechanism

When ROW scheduler reports to the block layer that there is an urgent
request pending, the device driver may decide to stop the transmission
of the current request in order to handle the urgent one. This is done
in order to reduce the latency of an urgent request. For example:
long WRITE may be stopped to handle an urgent READ.

This patch updates the ROW URGENT notification policy to apply with the
below:

- Don't notify URGENT if there is an un-completed URGENT request in driver
- After notifying that URGENT request is present, the next request
  dispatched is the URGENT one.
- At every given moment only 1 request can be marked as URGENT.
  Independent of it's location (driver or scheduler)

Other changes to URGENT policy:
- Only READ queues are allowed to notify of an URGENT request pending.

CR fix:
If a pending urgent request (A) gets merged with another request (B)
A is removed from scheduler queue but is not removed from
rd->pending_urgent_rq.

CRs-Fixed: 453712
Change-Id: I321e8cf58e12a05b82edd2a03f52fcce7bc9a900
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: row: Prevent starvation of regular priority by high priority

At the moment all REGULAR and LOW priority requests are starved as long as
there are HIGH priority requests to dispatch.
This patch prevents the above starvation by setting a starvation limit the
REGULAR\LOW priority requests can tolerate.

Change-Id: Ibe24207982c2c55d75c0b0230f67e013d1106017
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: row: Update sysfs functions

All ROW (time related) configurable parameters are stored in ms so there
is no need to convert from/to ms when reading/updating them via sysfs.

Change-Id: Ib6a1de54140b5d25696743da944c076dd6fc02ae
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: row: Fix starvation tolerance values

The current starvation tolerance values increase the boot time
since high priority SW requests are delayed by regular priority requests.
In order to overcome this, increase the starvation tolerance values.

Change-Id: I9947fca9927cbd39a1d41d4bd87069df679d3103
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
Signed-off-by: Maya Erez <merez@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>

block: Remove "requeuing urgent req" error messages

It is possible for URGENT request to be requeued/reinserted if it was
fetched during the creation of a packed list. This end case is rare and is
not handled at the moment.
This patch changes the messages notifying of the above to debug level
(instead of error) in order to clear the dmesg log.

Change-Id: Ie8bc067e61559a6f702077b95c5dbcc426404232
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: row-iosched idling triggered by readahead pages

In the current implementation idling is triggered only by request
insertion frequency. This heuristic is not very accurate and may hit
random requests that shouldn't trigger idling. This patch uses the
PG_readahead flag in struct page's flags, which indicates that the page
is part of a readahead window, to start idling upon dispatch of a request
associated with a readahead page.

The above readehead flag is used together with the existing
insertion-frequency trigger. The frequency timer will catch read requests
which are not part of a readahead window, but are still part of a
sequential stream (and therefore dispatched in small time intervals).

Change-Id: Icb7145199c007408de3f267645ccb842e051fd00
Signed-off-by: Lee Susman <lsusman@codeaurora.org>

block: row: change hrtimer_cancel to hrtimer_try_to_cancel

Calling hrtimer_cancel with interrupts disabled can result in a livelock.
When flushing plug list in the block layer interrupts are disabled and an
hrtimer is used when adding requests from that plug list to the scheduler.
In this code flow, if the hrtimer (which is used for idling) is set, it's
being canceled by calling hrtimer_cancel. hrtimer_cancel will perform
the following in an endless loop:
1. try cancel the timer
2. if fails - rest_cpu
the cancellation can fail if the timer function already started. Since
interrupts are disabled it can never complete.
This patch reduced the number of times the hrtimer lock is taken while
interrupts are disabled by calling hrtimer_try_co_cancel. the later will
try to cancel the timer just once and return with an error code if fails.

CRs-fixed: 499887
Change-Id: I25f79c357426d72ad67c261ce7cb503ae97dc7b9
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: Add URGENT request notification support to CFQ scheduler

When the scheduler reports to the block layer that there is an urgent
request pending, the device driver may decide to stop the transmission
of the current request in order to handle the urgent one. This is done
in order to reduce the latency of an urgent request. For example:
long WRITE may be stopped to handle an urgent READ.

Change-Id: I3072b8a1423870fed9c04c28d93caaf9557a7b89
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

block: row: Remove warning massage from add_request

Regular priority queues is marked as "starved" if it skipped a dispatch
due to being empty. When a new request is added to a "starved" queue
it will be marked as urgent.
The removed WARN_ON was warning about an impossible case when a regular
priority (read) queue was marked as starved but wasn't empty. This is
a possible case due to the bellow:
If the device driver fetched a read request that is pending for
transmission and an URGENT request arrives, the fetched read will be
reinserted back to the scheduler. Its possible that the queue it will be
reinserted to was marked as "starved" in the meanwhile due to being empty.

CRs-fixed: 517800
Change-Id: Iaae642ea0ed9c817c41745b0e8ae2217cc684f0c
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
block: row: add magic values.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
blx: Battery Life eXtender (BLX)

This is a simple port of Ezekeel's BLX mod to the Nexus 4.
See this thread for more information: http://forum.xda-developers.com/showthread.php?t=1257497
Let's keep the same sysfs implementation so that apps, such as Trickster MOD, can support this.

Conflicts:
	drivers/misc/Kconfig
	drivers/misc/Makefile
blx: Change the max charge to 100
lm3530: Add a toggle for the CABC PWM