drivers/rtc/rtc-tps65910.c: enable/disable wake in suspend/resume

Making the rtc driver as wakeup capabale and leaving the wake
enable/disable decision to user space through a sysfs attribute.

In suspend, enable wake if device wakeup enabled.  In resume disable wake
again.

This change is inline with the Documentation/power/devices.txt#
/sys/devices/.../power/wakeup files

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

rtc-add-rtc-driver-for-tps80031-tps80032-v2-fix

remove obsolete __devinit/__devexit

Cc: Devendra Naga <devendra.aaru@gmail.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

rtc-add-rtc-driver-for-tps80031-tps80032-v2

Changes from V1:
- remvoe the checks for alarm time whether this is past or not in set_alarm.
- add error prints if rtc registration failed.
- add include of pm.h

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

rtc: add RTC driver for TPS80031/TPS80032

Add an RTC driver for TPS80031/TPS80032 chips by TI.
This driver supports:
- Setting and getting time and date.
- Setting and reading alarm time.
- Alarm and interrupt functionlity.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

rtc: add new lp8788 rtc driver

TI LP8788 PMU supports regulators, battery charger, RTC, ADC, backlight
driver and current sinks.  This patch enables LP8788 rtc module.

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Cc: "devendra.aaru" <devendra.aaru@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/rtc/rtc-ds2404.c: use module_platform_driver macro

Remove removes some code duplication by using module_platform_driver().

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/rtc: remove unnecessary semicolons

Found by Coccinelle: http://coccinelle.lip6.fr/

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/rtc/rtc-pxa.c: avoid cpuid checking

pxa-rtc is widely used in pxa27x/pxa3xx/pxa93x/pxa95x. Checking cpuid in
pxa-rtc driver is unnecessary since we assign on-chip device in soc files.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/rtc/rtc-twl: use of_match_ptr() macro

Used of_match_ptr() macro with CONFIG_OF defined.
This maintains code consistency with the rest of the drivers.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/rtc: use of_match_ptr() macro

This eliminates having an #ifdef returning NULL for the case when OF is
disabled.  Maintains consistency in cases where OF is always selected.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

rtc-pcf8523-add-low-battery-voltage-support-fix

omit pcf8563_rtc_ioctl() if CONFIG_RTC_INTF_DEV=n

Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

rtc-pcf8523: add low battery voltage support

Implement reading of the battery voltage low signal for rtc-pcf8523.

The bit is read-only and cannot be cleared by software, so no
clear function is implemented.

Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

rtc-max77686-add-maxim-77686-driver-fix

remove inline, __devinit annotations

Cc: Chiwoong Byun <woong.byun@samsung.com>
Cc: Jonghwa Lee <jonghwa3.lee@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Myugnjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

rtc: max77686: add Maxim 77686 driver

Add a driver to support max77686 rtc.  MAX77686 rtc support smpl and wtsr
mode.  It has two alarm register which can be used for alarming to wake
system up.  This drvier uses regmap to access its register.

Signed-off-by: Chiwoong Byun <woong.byun@samsung.com>
Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Signed-off-by: Myugnjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

rtc-ds1307-long-block-operations-bugfix-fix

rework code to avoid 80-column overflows

Cc: Bertrand Achard <ba@cykian.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/rtc/rtc-ds1307.c: long block operations bugfix

The rtc-ds1307 driver does not properly handle block operations bigger
than 32 bytes in either of the two modes supported (SMbus native, or
emulated if not supported by the SMbus platform driver).

It also does not properly handle userland-supplied input (block operation
length) through sysfs and may suffer a type of buffer overrun.

The driver has been modified with proper input validation, buffer sizes,
and now splits block transfers bigger than 32 bytes into separate
transfers.

Explanation : Buffer size allocated is I2C_SMBUS_BLOCK_MAX which equals to
32 as per the SMbus spec.  Reads and write may be up to 56 bytes (to the
NVRAM).  This patch allocated a 255 byte buffer, the maximum allowable
(address is an u8).  It's not only a buffer problem, SMbus only supports
up to 32 bytes transfer at once, so it's needed to split bigger transfers.

Patch successfully tested on 3.2.27; cleanly applies on 3.7-rc4.

Signed-off-by: Bertrand Achard <ba@cykian.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers-rtc-rtc-pxac-fix-set-time-sync-time-issue-fix

The "fix set time sync time issue" adds calls to udelay(), but
doesn't add the include file. End result is build breakage:

drivers/rtc/rtc-pxa.c: In function 'pxa_rtc_set_time':
drivers/rtc/rtc-pxa.c:267:2: error: implicit declaration of function 'udelay' [-Werror=implicit-function-declaration]

Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: Leo Song <liangs@marvell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/rtc/rtc-pxa.c: fix set time sync time issue

Fix set time and sync time issue, add some delay when set pxa rtc timer
according to spec

Signed-off-by: Leo Song <liangs@marvell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/rtc/rtc-pxa.c: fix alarm can't wake up system issue

Fix alarm can't wake up system issue

Signed-off-by: Leo Song <liangs@marvell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/rtc/rtc-pxa.c: fix alarm not match issue

Fix pxa rtc alarm issue by setting week of month and day of week in
rdar/rdcr or it would not match.

Signed-off-by: Leo Song <liangs@marvell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/rtc: dump small buffers via %*ph

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kernel/nsproxy.c: remove duplicate task_cred_xxx for user_ns

We can use user_ns, which is also assigned from task_cred_xxx(tsk,
user_ns), at the beginning of copy_namespaces().

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

binfmt_elf.c: use get_random_int() to fix entropy depleting

Entropy is quickly depleted under normal operations like ls(1), cat(1),
etc...  between 2.6.30 to current mainline, for instance:

$ cat /proc/sys/kernel/random/entropy_avail
3428
$ cat /proc/sys/kernel/random/entropy_avail
2911
$cat /proc/sys/kernel/random/entropy_avail
2620

We observed this problem has been occurring since 2.6.30 with
fs/binfmt_elf.c: create_elf_tables()->get_random_bytes(), introduced by
f06295b44c296c8f ("ELF: implement AT_RANDOM for glibc PRNG seeding").

/*
 * Generate 16 random bytes for userspace PRNG seeding.
 */
get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));

The patch introduces a wrapper around get_random_int() which has lower
overhead than calling get_random_bytes() directly.

With this patch applied:
$ cat /proc/sys/kernel/random/entropy_avail
2731
$ cat /proc/sys/kernel/random/entropy_avail
2802
$ cat /proc/sys/kernel/random/entropy_avail
2878

Analyzed by John Sobecki.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <aedilger@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnn@arndb.de>
Cc: John Sobecki <john.sobecki@oracle.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

binfmt_elf: remove unused argument in fill_elf_header

In fill_elf_header(), elf->e_ident[EI_OSABI] is always set to ELF_OSABI,
so remove the unused argument 'osabi'.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

epoll: stop comparing pointers with 0 in self-test app

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Reviewed-by: Daniel Hazelton <dshadowwolf@gmail.com>
Cc: "Paton J. Lewis" <palewis@adobe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

epoll: support for disabling items, and a self-test app

It is not currently possible to reliably delete epoll items when using the
same epoll set from multiple threads.  After calling epoll_ctl with
EPOLL_CTL_DEL, another thread might still be executing code related to an
event for that epoll item (in response to epoll_wait).  Therefore the
deleting thread does not know when it is safe to delete resources
pertaining to the associated epoll item because another thread might be
using those resources.

The deleting thread could wait an arbitrary amount of time after calling
epoll_ctl with EPOLL_CTL_DEL and before deleting the item, but this is
inefficient and could result in the destruction of resources before
another thread is done handling an event returned by epoll_wait.

This patch enhances epoll_ctl to support EPOLL_CTL_DISABLE, which disables
an epoll item.  If epoll_ctl returns -EBUSY in this case, then another
thread may handling a return from epoll_wait for this item.  Otherwise if
epoll_ctl returns 0, then it is safe to delete the epoll item.  This
allows multiple threads to use a mutex to determine when it is safe to
delete an epoll item and its associated resources, which allows epoll
items to be deleted both efficiently and without error in a multi-threaded
environment.  Note that EPOLL_CTL_DISABLE is only useful in conjunction
with EPOLLONESHOT, and using EPOLL_CTL_DISABLE on an epoll item without
EPOLLONESHOT returns -EINVAL.

This patch also adds a new test_epoll self-test program to both
demonstrate the need for this feature and test it.

Signed-off-by: Paton J. Lewis <palewis@adobe.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Paul Holland <pholland@adobe.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

checkpatch: fix USLEEP_RANGE test

Do not test udelay() for a value less than 10usec when passed a variable
instead of a hard-coded number; there is no way for checkpatch to know the
value of the variable.  As it is today, it will complain about variables
with alphanumeric characters plus '_', e.g.  foo_bar, but not variables
with other characters, eg.  foo->bar.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

checkpatch: Add check for kcalloc argument order

kcalloc is sometimes misused with the first and second arguments switched.

Same issue with kmalloc_array too.

Bleat if sizeof is the first argument

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

checkpatch: don't emit the CamelCase warning for PageFoo

I'm getting a ton of these:

WARNING: Avoid CamelCase: <PageTransHuge>
#140: FILE: mm/migrate.c:1576:
+       if (PageTransHuge(page) && page_count(page) != 3) {

So exclude anything which starts with "Page".

Tested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

checkpatch: add Joe to MAINTAINERS

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

checkpatch: warn on unnecessary __dev<foo> section markings

Get people to stop adding __devinit and __devexit section markings.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Andy Whitcroft <apw@canonical.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

checkpatch: prefer dev_<level>( to dev_printk(KERN_<LEVEL>

Add YA check to printk style.

dev_<level> uses are functions and generate smaller
object code than dev_printk(KERN_<LEVEL>.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

decompressors: make the default XZ_DEC_* config match the selected architecture

Change the defautl XZ_DEC_* config symbol to match the configured
architecture.  It is perfectly legitimate to support multiple XZ BCJ
filters for different architectures (e.g.: to mount foreign squashfs/xz
compressed filesystems), it is however more natural not to select them all
by default, but only the one matching the configured architecture.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

decompressors: drop dependency on CONFIG_EXPERT

Remove the XZ_DEC_* depedencey on CONFIG_EXPERT as recommended by Lasse
Colin.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

decompressors: group XZ_DEC_* symbols under an if XZ_BCJ / endif

Group all architecture-specific BCJ filter configuration symbols under an
if XZ_BCJ / endif statement.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/parser.c: fix up comments for valid return values from match_number

match_number() has return values of -ENOMEM, -EINVAL and -ERANGE.  So, for
all the functions calling match_number, the return value should include
these values.  Fix up the comments to reflect the correct values.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/leds/leds-ot200.c: fix error caused by shifted mask

During the development of this driver an in-house register documentation
was used.  The last week some integration tests were done and this problem
was found.  It turned out that the released register documentation is
wrong.

The fix is very simple: shift all masks by one.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Bryan Wu <cooloney@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/video/backlight/lm3630_bl.c: remove ret = -EIO of lm3630_backlight_register()

There is no need to return -EIO, because backlight_device_register()
already returns correct error values.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/video/backlight/s6e63m0.c: report ->gamma_table_count correctly

gamma_table has 3 arrays which each hold MAX_GAMMA_LEVEL pointers to int.

The current code sets ->gamma_table_count to 6 on 64bit arches and to 3 on
32 bit arches.  It should be 3 on everything.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/video/backlight/88pm860x_bl.c: add missing of_node_put()

of_find_node_by_name() returns a node pointer with refcount incremented,
use of_node_put() on it when done.

of_find_node_by_name() will call of_node_put() against the node pass to
from parameter, thus we also need to call of_node_get(from) before calling
of_find_node_by_name().

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: as3711: fix compilation breakage

Include the missing platform_device.h header to fix errors like

error: implicit declaration of function 'platform_set_drvdata'

and similar.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: add an AS3711 PMIC backlight driver

This is an initial commit of a backlight driver, using step-up DCDC power
supplies on AS3711 PMIC. Only one mode has actually been tested, several
further modes have been implemented "dry," but disabled to avoid accidental
hardware damage. Anyone wishing to use any of those modes will have to
modify the driver.

Tested on sh73a0-based kzm9g board.  Only one mode has been tested and is
enabled.  That mode copies the sample code from the manufacturer.
Deviations from that code proved to be fatal for the hardware...

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/video/backlight/Makefile: cleanup

Fix up indenting.  Also alphasort all entries, which reduces patch
collisions.

Cc: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fb: backlight: add the Himax HX-8357B LCD controller

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Brian Lilly <brian@crystalfontz.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/video/backlight/ld9040.c: use devm_regulator_bulk_get() API

devm_regulator_bulk_get is device managed and saves some cleanup
and exit code.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Donghwa Lee <dh09.lee@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/video/backlight/l4f00242t03.c: convert to devm_regulator_get()

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Cc: Alberto Panizzo <maramaopercheseimorto@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/video/backlight/lm3639_bl.c: remove ret = -EIO at error paths of probe

The APIs are returning correctly the err codes, no need to assign -EIO
to the ret again.

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Acked-by: Daniel Jeong <daniel.jeong@ti.com>
Cc: G.Shark Jeong <gshark.jeong@gmail.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: corgi_lcd: use lcd_get_data instead of dev_get_drvdata

Use the wrapper function for getting the driver data using lcd_device
instead of using dev_get_drvdata with &ld->dev, so we can directly pass a
struct lcd_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: omap1: use bl_get_data instead of dev_get_drvdata

Use the wrapper function for getting the driver data using
backlight_device instead of using dev_get_drvdata with &bd->dev, so we can
directly pass a struct backlight_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: tosa: use bl_get_data instead of dev_get_drvdata

Use the wrapper function for getting the driver data using
backlight_device instead of using dev_get_drvdata with &bd->dev, so we can
directly pass a struct backlight_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: corgi_lcd: use bl_get_data instead of dev_get_drvdata

Use the wrapper function for getting the driver data using
backlight_device instead of using dev_get_drvdata with &bd->dev, so we can
directly pass a struct backlight_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ams369fg06: use bl_get_data instead of dev_get_drvdata

Use the wrapper function for getting the driver data using
backlight_device instead of using dev_get_drvdata with &bd->dev, so we can
directly pass a struct backlight_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

pwm_backlight: use bl_get_data instead of dev_get_drvdata

Use the wrapper function for getting the driver data using
backlight_device instead of using dev_get_drvdata with &bd->dev, so we can
directly pass a struct backlight_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: aat2870: use bl_get_data instead of dev_get_drvdata

Use the wrapper function for getting the driver data using
backlight_device instead of using dev_get_drvdata with &bd->dev, so we can
directly pass a struct backlight_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: lms501kf03: use spi_get_drvdata and spi_set_drvdata

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: corgi_lcd: use spi_get_drvdata and spi_set_drvdata

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: tosa: use spi_get_drvdata and spi_set_drvdata

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: vgg2432a4: use spi_get_drvdata and spi_set_drvdata

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ams369fg06: use spi_get_drvdata and spi_set_drvdata

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: lms283gf05: use spi_get_drvdata and spi_set_drvdata

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: tdo24m: use spi_get_drvdata and spi_set_drvdata

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ltv350qv: use spi_get_drvdata and spi_set_drvdata

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: s6e63m0: use spi_get_drvdata and spi_set_drvdata

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ld9040: use spi_get_drvdata and spi_set_drvdata

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: l4f00242t03: use spi_get_drvdata and spi_set_drvdata

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight-add-new-lp8788-backlight-driver-checkpatch-fixes

WARNING: please write a paragraph that describes the config symbol fully
#45: FILE: drivers/video/backlight/Kconfig:380:
+config BACKLIGHT_LP8788

ERROR: code indent should use tabs where possible
#446: FILE: include/linux/mfd/lp8788.h:242:
+^I^I            Only valid when bl_mode is LP8788_BL_COMB_PWM_BASED$

total: 1 errors, 1 warnings, 403 lines checked

NOTE: whitespace errors detected, you may wish to use scripts/cleanpatch or
      scripts/cleanfile

./patches/backlight-add-new-lp8788-backlight-driver.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: "Kim, Milo" <Milo.Kim@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: add new lp8788 backlight driver

TI LP8788 PMU supports regulators, battery charger, RTC, ADC, backlight
dri= ver and current sinks.  This patch enables LP8788 backlight module.

(Brightness mode)
The brightness is controlled by PWM input or I2C register.
All modes are supported in the driver.

(Platform data)
Configurable data can be defined in the platform side.
 name                  : backlight driver name. (default: "lcd-backlight")
 initial_brightness    : initial value of backlight brightness
 bl_mode               : brightness control by PWM or lp8788 register
 dim_mode              : dimming mode selection
 full_scale            : full scale current setting
 rise_time             : brightness ramp up step time
 fall_time             : brightness ramp down step time
 pwm_pol               : PWM polarity setting when bl_mode is PWM based
 period_ns             : platform specific PWM period value. unit is nano.

The default values are set in case no platform data is defined.

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Thierry Reding <thierry.reding@avionic-design.de>
Cc: "devendra.aaru" <devendra.aaru@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ams369fg06: reorder inclusions of <linux/xxx.h>

Reorder inclusions of <linux/xxx.h> for redability, according to
alphabetical ordering.  Also, unnecessary header comments are removed.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ams369fg06: remove redundant variable 'before_power'

'before_power' was used to check the previous status when resume() is
called.  However, FB_BLANK_POWERDOWN was used in suspend() all the time,
so there is no need to check the previous status.  Also, redundant return
variables are removed to reduce the code.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ams369fg06: replace EFAULT with EINVAL

Replace EFAULT with EINVAL, because EFAULT tends to be for the invalid
memory addresses.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ams369fg06: remove unnecessary NULL deference check

Remove unnecessary NULL deference check, because it was already checked in
ams369fg06_probe().  Also, unnecessary parentheses are removed in
ams369fg06_power_is_on().

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ams369fg06: use sleep instead of delay

Replace mdelay with msleep to remove the busy loop waiting.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: s6e63m0: reorder inclusions of <linux/xxx.h>

Reorder inclusions of <linux/xxx.h> for redability, according to
alphabetical ordering.  Also, unnecessary header comments are removed.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: s6e63m0: remove redundant variable 'before_power'

'before_power' was used to check the previous status when resume() is
called.  However, FB_BLANK_POWERDOWN was used in suspend() all the time,
so there is no need to check the previous status.  Also, redundant return
variables are removed to reduce the code.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: s6e63m0: replace EFAULT with EINVAL

Replace EFAULT with EINVAL, because EFAULT tends to be for the invalid
memory addresses.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: s6e63m0: remove unnecessary NULL deference check

Remove unnecessary NULL deference check, because it was already checked in
s6e63m0_probe().  Also, POWER_IS_ON is replaced with
s6e63m0_power_is_on().

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: s6e63m0: use sleep instead of delay

Replace mdelay with msleep to remove the busy loop waiting.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: s6e63m0: use lowercase names of structs

Lowercase names of structs should be used, because they are
not preprocessor macros.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ld9040: reorder inclusions of <linux/xxx.h>

Reorder inclusions of <linux/xxx.h> for redability, according to
alphabetical ordering.  Also, unnecessary header comments are removed.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ld9040: remove redundant return variables

Redundant return variables are removed to reduce the code.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ld9040: replace EFAULT with EINVAL

Replace EFAULT with EINVAL, because EFAULT tends to be for the invalid
memory addresses.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ld9040: remove unnecessary NULL deference check

Removee unnecessary NULL deference check, because it was already checked
in ld9040_probe().  Also, power_is_on is replaced with
ld9040_power_is_on().

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: ld9040: use sleep instead of delay

Replace mdelay with msleep to remove the busy loop waiting.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight-add-lms501kf03-lcd-driver-fix-fix

make lms501kf03_shutdown() static, per Fengguang

Cc: "devendra.aaru" <devendra.aaru@gmail.com>
Cc: Ilho Lee <Ilho215.lee@samsung.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight-add-lms501kf03-lcd-driver-fix

remove unused variable `before_power'

Cc: "devendra.aaru" <devendra.aaru@gmail.com>
Cc: Ilho Lee <Ilho215.lee@samsung.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

backlight: add lms501kf03 LCD driver

Add the lms501kf03 LCD panel driver.  The lms501kf03 LCD panel (800 x 480)
driver uses 3-wired SPI inteface.

Signed-off-by: Ilho Lee <Ilho215.lee@samsung.com>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: "devendra.aaru" <devendra.aaru@gmail.com>
Cc: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

MAINTAINERS: mm: add additional include files to listing

Add gfp.h, mmzone.h, memory_hotplug.h & vmalloc.h to the "MEMORY
MANAGMENT" section so scripts/get_maintainer.pl can do a better job of
making recommendations.

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

get_maintainer.pl: find maintainers for removed files

For removed files, get_maintainer.pl doesn't find any maintainers (besides
the default linux-kernel@vger.kernel.org), as it only looks at the "+++"
lines, which are "/dev/null" for removals.  Fix this by extending the
parsing to the "---" lines.

E.g. for the two line test patch below the real score maintainers will now
be found:

    --- a/arch/score/include/asm/dma-mapping.h
    +++ /dev/null

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/vsprintf.c: add %pa format specifier for phys_addr_t types

Add the %pa format specifier for printing a phys_addr_t type and its
derivative types (such as resource_size_t), since the physical address
size on some platforms can vary based on build options, regardless of the
native integer type.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Cc: Rob Landley <rob@landley.net>
Cc: George Spelvin <linux@horizon.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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>

include/linux/fs.h: disable preempt when acquire i_size_seqcount write lock

Two rt tasks bind to one CPU core.

The higher priority rt task A preempts a lower priority rt task B which
has already taken the write seq lock, and then the higher priority rt task
A try to acquire read seq lock, it's doomed to lockup.

rt task A with lower priority: call write
i_size_write                                        rt task B with higher priority: call sync, and preempt task A
  write_seqcount_begin(&inode->i_size_seqcount);    i_size_read
  inode->i_size = i_size;                             read_seqcount_begin <-- lockup here...

So disable preempt when acquiring every i_size_seqcount *write* lock will
cure the problem.

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/Kconfig.debug: unhide CONFIG_PANIC_ON_OOPS

CONFIG_EXPERT doesn't really make sense, and hides it unintentionally.
Remove superfluous "default n" pointed out by Ingo as well.

Signed-off-by: Kyle McMartin <kyle@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

smp: make smp_call_function_many() use logic similar to smp_call_function_single()

I'm testing swapout workload in a two-socket Xeon machine.  The workload
has 10 threads, each thread sequentially accesses separate memory region.
TLB flush overhead is very big in the workload.  For each page, page
reclaim need move it from active lru list and then unmap it.  Both need a
TLB flush.  And this is a multthread workload, TLB flush happens in 10
CPUs.  In X86, TLB flush uses generic smp_call)function.  So this workload
stress smp_call_function_many heavily.

Without patch, perf shows:
+  24.49%  [k] generic_smp_call_function_interrupt
-  21.72%  [k] _raw_spin_lock
   - _raw_spin_lock
      + 79.80% __page_check_address
      + 6.42% generic_smp_call_function_interrupt
      + 3.31% get_swap_page
      + 2.37% free_pcppages_bulk
      + 1.75% handle_pte_fault
      + 1.54% put_super
      + 1.41% grab_super_passive
      + 1.36% __swap_duplicate
      + 0.68% blk_flush_plug_list
      + 0.62% swap_info_get
+   6.55%  [k] flush_tlb_func
+   6.46%  [k] smp_call_function_many
+   5.09%  [k] call_function_interrupt
+   4.75%  [k] default_send_IPI_mask_sequence_phys
+   2.18%  [k] find_next_bit

swapout throughput is around 1300M/s.

With the patch, perf shows:
-  27.23%  [k] _raw_spin_lock
   - _raw_spin_lock
      + 80.53% __page_check_address
      + 8.39% generic_smp_call_function_single_interrupt
      + 2.44% get_swap_page
      + 1.76% free_pcppages_bulk
      + 1.40% handle_pte_fault
      + 1.15% __swap_duplicate
      + 1.05% put_super
      + 0.98% grab_super_passive
      + 0.86% blk_flush_plug_list
      + 0.57% swap_info_get
+   8.25%  [k] default_send_IPI_mask_sequence_phys
+   7.55%  [k] call_function_interrupt
+   7.47%  [k] smp_call_function_many
+   7.25%  [k] flush_tlb_func
+   3.81%  [k] _raw_spin_lock_irqsave
+   3.78%  [k] generic_smp_call_function_single_interrupt

swapout throughput is around 1400M/s.  So there is around a 7%
improvement, and total cpu utilization doesn't change.

Without the patch, cfd_data is shared by all CPUs.
generic_smp_call_function_interrupt does read/write cfd_data several times
which will create a lot of cache ping-pong.  With the patch, the data
becomes per-cpu.  The ping-pong is avoided.  And from the perf data, this
doesn't make call_single_queue lock contend.

Next step is to remove generic_smp_call_function_interrupt() from arch
code.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

scripts-pnmtologo-fix-for-plain-pbm-checkpatch-fixes

ERROR: do not initialise statics to 0 or NULL
#24: FILE: scripts/pnmtologo.c:77:
+static int is_plain_pbm = 0;

WARNING: line over 80 characters
#33: FILE: scripts/pnmtologo.c:108:
+  * between the digits. This is Ok cause we know a PBM can only have a '1'

total: 1 errors, 1 warnings, 25 lines checked

./patches/scripts-pnmtologo-fix-for-plain-pbm.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Andreas Bießmann <andreas@biessmann.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: use vm_unmapped_area() on alpha architecture

Update the alpha arch_get_unmapped_area function to make use of
vm_unmapped_area() instead of implementing a brute force search.

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

ubifs: wait for page writeback to provide stable pages

When stable pages are required, we have to wait if the page is just going
to disk and we want to modify it.  Add proper callback to
ubifs_vm_page_mkwrite().

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

ocfs2: wait for page writeback to provide stable pages

When stable pages are required, we have to wait if the page is just going
to disk and we want to modify it.  Add proper callback to
ocfs2_grab_pages_for_write().

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

block: optionally snapshot page contents to provide stable pages during write

This provides a band-aid to provide stable page writes on jbd without
needing to backport the fixed locking and page writeback bit handling
schemes of jbd2.  The band-aid works by using bounce buffers to snapshot
page contents instead of waiting.

For those wondering about the ext3 bandage -- fixing the jbd locking
(which was done as part of ext4dev years ago) is a lot of surgery, and
setting PG_writeback on data pages when we actually hold the page lock
dropped ext3 performance by nearly an order of magnitude.  If we're going
to migrate iscsi and raid to use stable page writes, the complaints about
high latency will likely return.  We might as well centralize their page
snapshotting thing to one place.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

9pfs: fix filesystem to wait for stable page writeback

Fix up the ->page_mkwrite handler to provide stable page writes if necessary.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: only enforce stable page writes if the backing device requires it

Create a helper function to check if a backing device requires stable page
writes and, if so, performs the necessary wait.  Then, make it so that all
points in the memory manager that handle making pages writable use the
helper function.  This should provide stable page write support to most
filesystems, while eliminating unnecessary waiting for devices that don't
require the feature.

Before this patchset, all filesystems would block, regardless of whether
or not it was necessary.  ext3 would wait, but still generate occasional
checksum errors.  The network filesystems were left to do their own thing,
so they'd wait too.

After this patchset, all the disk filesystems except ext3 and btrfs will
wait only if the hardware requires it.  ext3 (if necessary) snapshots
pages instead of blocking, and btrfs provides its own bdi so the mm will
never wait.  Network filesystems haven't been touched, so either they
provide their own stable page guarantees or they don't block at all.  The
blocking behavior is back to what it was before 3.0 if you don't have a
disk requiring stable page writes.

Here's the result of using dbench to test latency on ext2:

3.8.0-rc3:
 Operation      Count    AvgLat    MaxLat
 ----------------------------------------
 WriteX        109347     0.028    59.817
 ReadX         347180     0.004     3.391
 Flush          15514    29.828   287.283

Throughput 57.429 MB/sec  4 clients  4 procs  max_latency=287.290 ms

3.8.0-rc3 + patches:
 WriteX        105556     0.029     4.273
 ReadX         335004     0.005     4.112
 Flush          14982    30.540   298.634

Throughput 55.4496 MB/sec  4 clients  4 procs  max_latency=298.650 ms

As you can see, the maximum write latency drops considerably with this
patch enabled.  The other filesystems (ext3/ext4/xfs/btrfs) behave
similarly, but see the cover letter for those results.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>