ext4: honor O_(D)SYNC semantic in ext4_fallocate()

Ext4 must make sure the transaction to be commited to the disk when
user opens a file with O_(D)SYNC flag and do a fallocate(2) call.

This problem had been reported by Christoph Hellwig in this thread:
http://www.spinics.net/lists/linux-btrfs/msg13621.html

Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: pass a char * to ext4_count_free() instead of a buffer_head ptr

Make it possible for ext4_count_free to operate on buffers and not
just data in buffer_heads.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

Conflicts:
	fs/ext4/ext4.h

Conflicts:
	fs/ext4/ext4.h
ext4: fix out-of-date comments in extents.c

In this patch, ext4_ext_try_to_merge has been change to merge
an extent both left and right.  So we need to update the comment
in here.

Signed-off-by: HaiboLiu <HaiboLiu6@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: remove an unused statement in ext4_mb_get_buddy_page_lock()

In this patch, the statement "poff = block % blocks_per_page"
in ext4_mb_get_buddy_page_lock has no effect.

It will be optimized out by the compiler, but it's better to remove it.

Signed-off-by: Haibo Liu <HaiboLiu6@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: get rid of open-coded d_find_any_alias()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
ext4: speed up truncate/unlink by not using bforget() unless needed

Do not iterate over data blocks scanning for bh's to forget as they're
never exist. This improves time taken by unlink / truncate syscall.
Tested by continuously truncating file that is being written by dd.
Another test is rm -rf of linux tree while tar unpacks it. With
ordered data mode condition unlikely(!tbh) was always met in
ext4_free_blocks. With journal data mode tbh was found only few times,
so optimisation is also possible.

Unlinking fallocated 60G file after doing sync && echo 3 >
/proc/sys/vm/drop_caches && time rm --help

X86 before (linux 3.6-rc4):
# time rm -f test1
real    0m2.710s
user    0m0.000s
sys     0m1.530s

X86 after:
# time rm -f test1
real    0m0.644s
user    0m0.003s
sys     0m0.060s

MIPS before (linux 2.6.37):
# time rm -f test1
real    0m 4.93s
user    0m 0.00s
sys     0m 4.61s

MIPS after:
# time rm -f test1
real    0m 0.16s
user    0m 0.00s
sys     0m 0.06s

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrey Sidorov <qrxd43@motorola.com>
ext4: use kmem_cache_zalloc instead of kmem_cache_alloc/memset

Using kmem_cache_zalloc() instead of kmem_cache_alloc() and memset().

spatch with a semantic match is used to found this problem.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: optimize test_root()

The test_root() function could potentially loop forever due to
overflow issues.  So rewrite test_root() to avoid this issue; as a
bonus, it is 38% faster when benchmarked via a test loop:

int main(int argc, char **argv)
{
	int  i;

	for (i = 0; i < 1 << 24; i++) {
		if (test_root(i, 7))
			printf("%d\n", i);
	}
}

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
msm: pm: Add support for retention on each core

Allow each core on 8974 to enter retention and retain
the state of the CPU. On 8960 as hardware restriction does
not permit all cores to enter retention at the same time,
allow only core 0 to enter retention when all other cores
are offline to maintain backward compatibility.

CRs-fixed: 437281
Change-Id: I6690e901afc9fa3a27010c264fa3acc9a0722c1a
Signed-off-by: Priyanka Mathur <pmathur@codeaurora.org>
Signed-off-by: Venkat Devarasetty <vdevaras@codeaurora.org>
msm: pm-data: Enable powercollapse/suspend_enabled for non-boot cpus

Allow non-boot cpus to be hotplugged and power collapsed by default.
This facilitates the cores to be offlined by kernel drivers during the
boot process.

CRs-Fixed: 460083
Change-Id: If44b6b594504dab61dff662c581b60e6fb664936
Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org>
msm: pm: Update spm retention sequence to support per core retention

On krait revision < 3, power driver is not using full spm sequence and
calling into trustzone as a part of executing krait retention.
Also krait retention is not supported on secondary cores.

krait pass3 is upgraded to use full spm sequence, hence add support
for per core retention and avoid calling into trustzone
while executing retention.

CRs-fixed: 437281
Change-Id: I6a2b3d7c4d0fd5b9a340957b16b940b7a09bbd91
Signed-off-by: Anji Jonnala <anjir@codeaurora.org>
Signed-off-by: Venkat Devarasetty <vdevaras@codeaurora.org>
mako: Update spm retention sequence to support per core retention

Change-Id: I77c49ef2fbc539d6f46ede1a60d49fd0e1a8e0cd
Implement kexec-hardboot

"Allows hard booting (i.e., with a full hardware reboot) to a kernel
previously loaded in memory by kexec.  This works around the problem of
soft-booted kernel hangs due to improper device shutdown and/or
reinitialization."
More info in /arch/arm/Kconfig.

Original author: Mike Kasick <mike@kasick.org>

Vojtech Bocek <vbocek@gmail.com>:
  I've ported it to mako and flo, it is based of my grouper port, which is
  based of Asus TF201 patche ported by Jens Andersen <jens.andersen@gmail.com>

  I've moved atags copying from guest to the host kernel, which means there
  is no need to patch the guest kernel, assuming the --mem-min in kexec call
  is within the first 256MB of System RAM, otherwise it will take a long time
  to load. I've also fixed /proc/atags entry, which would give the kexec-tools
  userspace binary only the first 1024 bytes of atags,
  see arch/arm/kernel/atags.c for more details.

  Other than that, memory-reservation code for the hardboot page and
  some assembler to do the watchdog reset on MSM chip are new for this device.

ayysir <dresadd09691@gmail.com>:
  kexec: use mem_text_write_kernel_word to set reboot_code_buffer args
  in order to avoid protection faults (writes to read-only
  kernel memory) when CONFIG_STRICT_MEMORY_RWX is enabled.

Signed-off-by: Vojtech Bocek <vbocek@gmail.com>

Conflicts:
	arch/arm/configs/mako_defconfig
core.c: Disable Software CRC check
msm: mdp: Adjust bandwidth parameters
720p video on 1080p panel have upscaling, mdp clk should not be
increased for this case. Also slightly increase mdp ib to make
sure there is no bw access bottleneck.
arm/Makefile: Optimize and add New arm flags

Conflicts:
	arch/arm/Makefile
mmc: core: Allow changing bus frequency for SD/eMMC cards in runtime

Currently, bus frequency is set during the card initialization and
never changed until a new card is inserted. In some low power use
cases, scaling the clock frequencies while the card is in transfer
state would allow power savings. This change allows bus frequency
to be changed after the card initialization.

Change-Id: Iac064221199f69d162d91f5311becd735c15700a
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
mmc: core: Fix some driver hangs when dealing with broken devices

There are infinite loops in the mmc code that can be caused by bad
hardware.  The code will loop forever if the device never comes back
from program mode, R1_STATE_PRG, and it is not ready for data,
R1_READY_FOR_DATA.

A long timeout is added to prevent the code from looping forever.
The timeout will occur if the device never comes back from program
state or the device never becomes ready for data.

It's not clear whether the timeout will do more than log a pr_err()
and then start a fresh hang all over again.  We may need to extend
this patch later to perform some kind of reset of the device (is
that possible?) or rejection of new I/O to the device.

Change-Id: I1f3e5fddffb5134743fbfbcdef5e97803fd25fc6
Signed-off-by: Trey Ramsay <tramsay@linux.vnet.ibm.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>

Conflicts:
	drivers/mmc/card/block.c
mmc: core: Add load based clock scaling support

The SD3.0/eMMC4.5/SDIO3.0 cards can support clock rates upto
200MHz (SDR104 or HS200 bus speed modes). For some workloads
like video playback it isn't necessary for these cards to run
at such high speed. Running at lower frequency, say 50MHz, in
such cases can still meet the deadlines for data transfers.
Scaling down the clock frequency dynamically has huge power
savings not only because the bus is running at lower frequency
but also has an advantage of scaling down the system core
voltage, if supported.

Provide an ondemand clock scaling support similar to cpufreq
ondemand governor having two thresholds, up_threshold and
down_threshold to decide whether to increase the frequency or
scale it down respectively. The sampling interval is in the
order of milliseconds and should be chosen by host drivers that
enable MMC_CAP2_CLK_SCALE capability to take advantage of clock
scaling. The sampling interval mainly depends on the the clock
switching delays and hence a host driver decision. If sampling
interval is too low frequent switching of frequencies can lead
to high power consumption and if sampling interval is too high,
the clock scaling logic would take long time to realize that the
underlying hardware (controller and card) is busy and scale up
the clocks.

Change-Id: I22a5054beec41b0b66b3bf030ddfcf284de448b3
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
mmc: core: Add sysfs entries for dynamic control of clock scaling

Add sysfs attributes to allow dynamic control of clock scaling
parameters. These attributes are used to enable/disable clock
scaling at runtime and change the up_threshold, down_threshold,
and polling_interval values. Complete documentation for these
sysfs entries are provided at "Documentation/mmc/mmc-dev-attrs.txt".

Change-Id: I4753c75c3b3eeea91e93bceba7af2535b793612e
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>