cpufreq: Fix policy getting stuck when user & kernel min/max don't overlap

Every __cpufreq_set_policy starts with checking the new policy min/max has
some overlap with the current policy min/max. This works out fine until we
end up with the policy min/max being set to a range that doesn't overlap
with the user policy min/max. Once we get into this situation, the check at
the start of __cpufreq_set_policy fails and prevents us from getting out of
this state.

This only happens when one of the CPUFREQ_ADJUST/CPUFREQ_INCOMPATIBLE
notifiers called inside __cpufreq_set_policy pick a min/max outside the
range of user policy min/max.

The real intent of the check at the start of __cpufreq_set_policy is to
make sure userspace can't set user policy min > user policy max. Since
__cpufreq_set_policy always gets called only with current user policy
min/max except when the actual user space policy min/max is changed, we can
fix the issue by simply checking the new policy min/max against current
user policy min/max.

Change-Id: Iaac805825e64d7985c41fb9052bd96baacdf3d6f
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
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.

tj: Updated config description and comments.  Renamed
    CONFIG_WQ_POWER_EFFICIENT to CONFIG_WQ_POWER_EFFICIENT_DEFAULT.

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>
(cherry picked from commit cee22a15052faa817e3ec8985a28154d3fabc7aa)
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Luis Cruz <ljc2491@gmail.com>
Signed-off-by: poondog <markj338@gmail.com>

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'.

tj: updated comments a bit.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
(cherry picked from commit 0668106ca3865ba945e155097fb042bf66d364d3)
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Luis Cruz <ljc2491@gmail.com>
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>
(cherry picked from commit 695588f9454bdbc7c1a2fbb8a6bfdcfba6183348)
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Luis Cruz <ljc2491@gmail.com>
Signed-off-by: poondog <markj338@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>
(cherry picked from commit d4e1a73acd4e894f8332f2093bceaef585cfab67)
Signed-off-by: Luis Cruz <ljc2491@gmail.com>
Signed-off-by: poondog <markj338@gmail.com>
ASoC: jack: Use power efficient workqueue

Adapted for 3.4 from lsk-v3.10

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>
(cherry picked from commit e6058aaadcd473e5827720dc143af56aabbeecc7)
Signed-off-by: Luis Cruz <ljc2491@gmail.com>
Signed-off-by: poondog <markj338@gmail.com>
regulator: core: 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>
Acked-by: Liam Girdwood <liam.r.girdwood@intel.com>
(cherry picked from commit 070260f07c7daec311f2466eb9d1df475d5a46f8)
Signed-off-by: Luis Cruz <ljc2491@gmail.com>
Signed-off-by: poondog <markj338@gmail.com>
LIB: use generic strnlen_user and strncpy_from_user functions
(Chad Goodman)

Conflicts:
	arch/arm/Kconfig
	lib/Makefile

Conflicts:
	arch/arm/Kconfig
ASM: word-at-a-time: make the interfaces truly generic
(Chad Goodman)

Signed-off-by: poondog <markj338@gmail.com>
ARM: dcache: select DCACHE_WORD_ACCESS for little-endian ARMv6+ CPUs
(Chad Goodman)

Signed-off-by: poondog <markj338@gmail.com>
ARM: 7927/1: dcache: select DCACHE_WORD_ACCESS for big-endian CPUs

With commit 11ec50caedb5 ("word-at-a-time: provide generic big-endian
zero_bytemask implementation"), the asm-generic word-at-a-time code now
provides a zero_bytemask implementation, allowing us to make use of
DCACHE_WORD_ACCESS on big-endian CPUs, providing our
load_unaligned_zeropad function is endianness-clean.

This patch reworks the load_unaligned_zeropad fixup code to work for
both big- and little-endian CPUs, then removes the !CPU_BIG_ENDIAN check
when selecting DCACHE_WORD_ACCESS.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Async I/O latency to a ssd greatly increased, 34% gain (Creds: kleikamp)
Disable Gentle Fair Sleepers

Better UI response
net/ipv4/tcp_output.c: conflicting types for 'tcp_write_xmit'

uses:
     static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
instead of
     static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,

refers to: https://bitbucket.org/AOSPA-hybrid/kernel_lge_msm8974/commits/3ead69fd1889fb7a214eb8685ecf89e9d71ff2a6

Signed-off-by: Andre Saddler <dresadd09691@gmail.com>
ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) optimizations

Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
assumptions about the implementation of memset and similar functions.
The current ARM optimized memset code does not return the value of
its first argument, as is usually expected from standard implementations.

For instance in the following function:

void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
	waiter->magic = waiter;
	INIT_LIST_HEAD(&waiter->list);
}

compiled as:

800554d0 <debug_mutex_lock_common>:
800554d0:       e92d4008        push    {r3, lr}
800554d4:       e1a00001        mov     r0, r1
800554d8:       e3a02010        mov     r2, #16 ; 0x10
800554dc:       e3a01011        mov     r1, #17 ; 0x11
800554e0:       eb04426e        bl      80165ea0 <memset>
800554e4:       e1a03000        mov     r3, r0
800554e8:       e583000c        str     r0, [r3, #12]
800554ec:       e5830000        str     r0, [r3]
800554f0:       e5830004        str     r0, [r3, #4]
800554f4:       e8bd8008        pop     {r3, pc}

GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
register/memory corruptions.

This patch fixes the return value of the assembly version of memset.
It adds a 'mov' instruction and merges an additional load+store into
existing load/store instructions.
For ease of review, here is a breakdown of the patch into 4 simple steps:

Step 1
======
Perform the following substitutions:
ip -> r8, then
r0 -> ip,
and insert 'mov ip, r0' as the first statement of the function.
At this point, we have a memset() implementation returning the proper result,
but corrupting r8 on some paths (the ones that were using ip).

Step 2
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:

save r8:
-       str     lr, [sp, #-4]!
+       stmfd   sp!, {r8, lr}

and restore r8 on both exit paths:
-       ldmeqfd sp!, {pc}               @ Now <64 bytes to go.
+       ldmeqfd sp!, {r8, pc}           @ Now <64 bytes to go.
(...)
        tst     r2, #16
        stmneia ip!, {r1, r3, r8, lr}
-       ldr     lr, [sp], #4
+       ldmfd   sp!, {r8, lr}

Step 3
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 0:

save r8:
-       stmfd   sp!, {r4-r7, lr}
+       stmfd   sp!, {r4-r8, lr}

and restore r8 on both exit paths:
        bgt     3b
-       ldmeqfd sp!, {r4-r7, pc}
+       ldmeqfd sp!, {r4-r8, pc}
(...)
        tst     r2, #16
        stmneia ip!, {r4-r7}
-       ldmfd   sp!, {r4-r7, lr}
+       ldmfd   sp!, {r4-r8, lr}

Step 4
======
Rewrite register list "r4-r7, r8" as "r4-r8".

Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7670/1: fix the memset fix

Commit 455bd4c430b0 ("ARM: 7668/1: fix memset-related crashes caused by
recent GCC (4.7.2) optimizations") attempted to fix a compliance issue
with the memset return value.  However the memset itself became broken
by that patch for misaligned pointers.

This fixes the above by branching over the entry code from the
misaligned fixup code to avoid reloading the original pointer.

Also, because the function entry alignment is wrong in the Thumb mode
compilation, that fixup code is moved to the end.

While at it, the entry instructions are slightly reworked to help dual
issue pipelines.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: compressed/head.S: work around new binutils warning

In August 2012, Matthew Gretton-Dann checked a change
into binutils labelled "Error on obsolete & warn on
deprecated registers", apparently as part of ARMv8
support. Apparently, this was supposed to emit
the message "Warning: This coprocessor register access
is deprecated in ARMv8" when using certain mcr/mrc
instructions and building for ARMv8. Unfortunately,
the message that is actually emitted appears to be
'(null)', which is less helpful in comparison.

Even more unfortunately, this is biting us on
every single kernel build with a new gas, because
arch/arm/boot/compressed/head.S and some other files
in that directory are built with -march=all since
kernel commit 80cec14a8 "[ARM] Add -march=all to
assembly file build in arch/arm/boot/compressed"
back in v2.6.28.

This patch reverts Russell's nice solution and
replaces it with a more complex one that sprinkles
.arch statements inside of the head.S file in
functions that are executed in different architecture
levels, which seems to solve the original problem
just as well, and gets rid of the new one, too.

Without this patch, building anything results in:

arch/arm/boot/compressed/head.S: Assembler messages:
arch/arm/boot/compressed/head.S:565: Warning: (null)
arch/arm/boot/compressed/head.S:676: Warning: (null)
arch/arm/boot/compressed/head.S:698: Warning: (null)
arch/arm/boot/compressed/head.S:722: Warning: (null)
arch/arm/boot/compressed/head.S:726: Warning: (null)
arch/arm/boot/compressed/head.S:957: Warning: (null)
arch/arm/boot/compressed/head.S:996: Warning: (null)
arch/arm/boot/compressed/head.S:997: Warning: (null)
arch/arm/boot/compressed/head.S:1027: Warning: (null)
arch/arm/boot/compressed/head.S:1035: Warning: (null)
arch/arm/boot/compressed/head.S:1046: Warning: (null)
arch/arm/boot/compressed/head.S:1060: Warning: (null)
arch/arm/boot/compressed/head.S:1092: Warning: (null)
arch/arm/boot/compressed/head.S:1094: Warning: (null)
arch/arm/boot/compressed/head.S:1095: Warning: (null)
arch/arm/boot/compressed/head.S:1102: Warning: (null)
arch/arm/boot/compressed/head.S:1134: Warning: (null)

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Gretton-Dann <matthew.gretton-dann@arm.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Paul Beeler <sparksco@gmail.com>
vfp: hardfloat

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>
Signed-off-by: bart452 <bart_96@live.nl>

Conflicts:
	arch/arm/vfp/Makefile

Conflicts:
	arch/arm/vfp/Makefile
make default readahead size a kernel parameter
From: Nikanth Karthikesan <knikanth@suse.de>

Add new kernel parameter "readahead", which would be used instead of the
value of VM_MAX_READAHEAD. If the parameter is not specified, the default
of 128kb would be used.

CC: Ankit Jain <radical@gmail.com>
CC: Dave Chinner <david@fromorbit.com>
CC: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Dan Trifan <jimsth@gmail.com>

Conflicts:
	include/linux/mm.h
mm: finetune the filesystem dynamic read-ahead

Signed-off-by: Dan Trifan <jimsth@gmail.com>
Signed-off-by: bart452 <bart_96@live.nl>

Conflicts:
	include/linux/mm.h

Conflicts:
	include/linux/mm.h

Conflicts:
	include/linux/mm.h