The spinning mutex implementation uses cpu_relax() in busy loops as a
compiler barrier. Depending on the architecture, cpu_relax() may do more
than needed in this specific mutex spin loops. On System z we also give
up the time slice of the virtual cpu in cpu_relax(), which prevents
effective spinning on the mutex.

This patch replaces cpu_relax() in the spinning mutex code with
arch_mutex_cpu_relax(), which can be defined by each architecture that
selects HAVE_ARCH_MUTEX_CPU_RELAX. The default is still cpu_relax(), so
this patch should not affect other architectures than System z for now.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290437256.7455.4.camel@thinkpad>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Merge reason: Pick up latest fixes.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Add more clock information to /proc/sched_debug, Thomas wanted to see
the sched_clock_stable state.
Requested-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Oleg mentioned that there is no actual guarantee the dying cpu's
migration thread is actually finished running when we get there, so
replace the BUG_ON() with a spinloop waiting for it.
Reported-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

GCC warns us about:

 kernel/cpu.c: In function ‘take_cpu_down’:
 kernel/cpu.c:200:15: warning: unused variable ‘cpu’

This variable is unused since param->hcpu is directly
used later on in cpu_notify.
Signed-off-by: NDhaval Giani <dhaval_giani@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290091494.1145.5.camel@gondor.retis>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The recent cgroup-scheduling rework caused a UP build problem.

Cc: Paul Turner <pjt@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NErik Gilling <konkers@android.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290218934-8544-3-git-send-email-john.stultz@linaro.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: Add EXT4_IOC_TRIM ioctl to handle batched discard
  fs: Do not dispatch FITRIM through separate super_operation
  ext4: ext4_fill_super shouldn't return 0 on corruption
  jbd2: fix /proc/fs/jbd2/<dev> when using an external journal
  ext4: missing unlock in ext4_clear_request_list()
  ext4: fix setting random pages PageUptodate

Filesystem independent ioctl was rejected as not common enough to be in
core vfs ioctl. Since we still need to access to this functionality this
commit adds ext4 specific ioctl EXT4_IOC_TRIM to dispatch
ext4_trim_fs().

It takes fstrim_range structure as an argument. fstrim_range is definec in
the include/linux/fs.h and its definition is as follows.

struct fstrim_range {
	__u64 start;
	__u64 len;
	__u64 minlen;
}

start	- first Byte to trim
len	- number of Bytes to trim from start
minlen	- minimum extent length to trim, free extents shorter than this
  number of Bytes will be ignored. This will be rounded up to fs
  block size.

After the FITRIM is done, the number of actually discarded Bytes is stored
in fstrim_range.len to give the user better insight on how much storage
space has been really released for wear-leveling.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

There was concern that FITRIM ioctl is not common enough to be included
in core vfs ioctl, as Christoph Hellwig pointed out there's no real point
in dispatching this out to a separate vector instead of just through
->ioctl.

So this commit removes ioctl_fstrim() from vfs ioctl and trim_fs
from super_operation structure.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: fix readdir EOVERFLOW on 32-bit archs
  ceph: fix frag offset for non-leftmost frags
  ceph: fix dangling pointer
  ceph: explicitly specify page alignment in network messages
  ceph: make page alignment explicit in osd interface
  ceph: fix comment, remove extraneous args
  ceph: fix update of ctime from MDS
  ceph: fix version check on racing inode updates
  ceph: fix uid/gid on resent mds requests
  ceph: fix rdcache_gen usage and invalidate
  ceph: re-request max_size if cap auth changes
  ceph: only let auth caps update max_size
  ceph: fix open for write on clustered mds
  ceph: fix bad pointer dereference in ceph_fill_trace
  ceph: fix small seq message skipping
  Revert "ceph: update issue_seq on cap grant"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (31 commits)
  net: fix kernel-doc for sk_filter_rcu_release
  be2net: Fix to avoid firmware update when interface is not open.
  netfilter: fix IP_VS dependencies
  net: irda: irttp: sync error paths of data- and udata-requests
  ipv6: Expose reachable and retrans timer values as msecs
  ipv6: Expose IFLA_PROTINFO timer values in msecs instead of jiffies
  3c59x: fix build failure on !CONFIG_PCI
  ipg.c: remove id [SUNDANCE, 0x1021]
  net: caif: spi: fix potential NULL dereference
  ath9k_htc: Avoid setting QoS control for non-QoS frames
  net: zero kobject in rx_queue_release
  net: Fix duplicate volatile warning.
  MAINTAINERS: Add stmmac maintainer
  bonding: fix a race in IGMP handling
  cfg80211: fix can_beacon_sec_chan, reenable HT40
  gianfar: fix signedness issue
  net: bnx2x: fix error value sign
  8139cp: fix checksum broken
  r8169: fix checksum broken
  rds: Integer overflow in RDS cmsg handling
  ...

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  sata_via: apply magic FIFO fix to vt6420 too

This reverts commit 59365d13.

It turns out that this can break certain existing user land setups.
Quoth Sarah Sharp:

 "On Wednesday, I updated my branch to commit 460781b5 from linus' tree,
  and my box would not boot.  klogd segfaulted, which stalled the whole
  system.

  At first I thought it actually hung the box, but it continued booting
  after 5 minutes, and I was able to log in.  It dropped back to the
  text console instead of the graphical bootup display for that period
  of time.  dmesg surprisingly still works.  I've bisected the problem
  down to this commit (commit 59365d13)

  The box is running klogd 1.5.5ubuntu3 (from Jaunty).  Yes, I know
  that's old.  I read the bit in the commit about changing the
  permissions of kallsyms after boot, but if I can't boot that doesn't
  help."

So let's just keep the old default, and encourage distributions to do
the "chmod -r /proc/kallsyms" in their bootup scripts.  This is not
worth a kernel option to change default behavior, since it's so easily
done in user space.
Reported-and-bisected-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Marcus Meissner <meissner@suse.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Eugene Teo <eugeneteo@kernel.org>
Cc: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: fix typo in keycode validation supporting large scancodes
  Input: aiptek - tighten up permissions on sysfs attributes
  Input: sysrq - pass along lone Alt + SysRq

* 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ickle/drm-intel:
  drm/i915: Disable FBC on Ironlake to save 1W
  drm/i915: Take advantage of auto-polling CRT hotplug detection on PCH hardware
  drm/i915/crt: Introduce struct intel_crt
  drm/i915: Do not hold mutex when faulting in user addresses
  drm: radeon: fix error value sign
  drm/radeon/kms: fix and unify tiled buffer alignment checking for r6xx/7xx
  drm/i915: Retire any pending operations on the old scanout when switching
  drm/i915: Fix I2C adapter registration

* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (40 commits)
  drm/radeon/kms: i2c s/sprintf/snprintf/g for safety
  drm/radeon/kms: fix i2c pad masks on rs4xx
  drm/ttm: Fix up a theoretical deadlock
  drm/radeon/kms: fix tiling info on evergreen
  drm/radeon/kms: fix alignment when allocating buffers
  drm/vmwgfx: Fix up an error path during bo creation
  drm/radeon/kms: register an i2c adapter name for the dp aux bus
  drm/radeon/kms/atom: add proper external encoders support
  drm/radeon/kms/atom: cleanup and unify DVO handling
  drm/radeon/kms: properly power up/down the eDP panel as needed (v4)
  drm/radeon/kms/atom: set sane defaults in atombios_get_encoder_mode()
  drm/radeon/kms: turn the backlight off explicitly for dpms
  drm/radeon/kms: fix typo in r600 cs checker
  drm: radeon: fix error value sign
  drm/radeon/kms: fix and unify tiled buffer alignment checking for r6xx/7xx
  nouveau: Acknowledge HPD irq in handler, not bottom half
  drm/nouveau: Fix a few confusions between "chipset" and "card_type".
  drm/nouveau: don't expose backlight control when available through ACPI
  drm/nouveau/pm: improve memtiming mappings
  drm/nouveau: Make PCIE GART size depend on the available RAMIN space.
  ...

vt6420 has the same FIFO overflow problem as vt6421 when combined with
certain devices.  This patch applies the magic fix to vt6420 too.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NMartin Qvist <q@maq.dk>
Reported-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Joseph Chan <JosephChan@via.com.tw>
Cc: stable@kernel.org
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Fix kernel-doc warning for sk_filter_rcu_release():

Warning(net/core/filter.c:586): missing initial short description on line:
 * 	sk_filter_rcu_release: Release a socket filter by rcu_head
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc:	"David S. Miller" <davem@davemloft.net>
Cc:	netdev@vger.kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since interrupts are enabled only when open is called on the interface,
Attempting a firmware update operation when interface is down could lead to
partial success or failure of operation. This fix fails the request if
netif_running is false.
Signed-off-by: NSarveshwar Bandi <Sarveshwar.Bandi@emulex.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

At the start of ext4_fill_super, ret is set to -EINVAL, and any failure path
out of that function returns ret.  However, the generic_check_addressable
clause sets ret = 0 (if it passes), which means that a subsequent failure (e.g.
a group checksum error) returns 0 even though the mount should fail.  This
causes vfs_kern_mount in turn to think that the mount succeeded, leading to an
oops.

A simple fix is to avoid using ret for the generic_check_addressable check,
which was last changed in commit 30ca22c7.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Frame buffer compression is broken on Ironlake due to buggy hardware.
Currently it is disabled through chicken bits, but it still consumes
over 1W more than if we simply never attempt to enable the FBC code
paths.
Signed-off-by: NAlex Shi <alex.shi@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

Both IBX and CPT have an automatic hotplug detection mode which appears to work reliably enough
that we can dispense with the manual force hotplug trigger stuff. This means that
hotplug detection is as simple as reading the current hotplug register values.

The first time the hotplug detection is activated, the code synchronously waits for a hotplug
sequence in case the hardware hasn't bothered to do a detection cycle since being initialized.
Signed-off-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We will use this structure in future patches to store CRT specific
information on the encoder.

Split out and tweaked from a patch by Keith Packard.
Signed-off-by: NKeith Packard <keithp@kithp.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Linus Torvalds found that it was rather trivial to trigger a system
freeze:

  In fact, with lockdep, I don't even need to do the sysrq-d thing: it
  shows the bug as it happens. It's the X server taking the same lock
  recursively.

  Here's the problem:

    =============================================
    [ INFO: possible recursive locking detected ]
    2.6.37-rc2-00012-gbdbd01ac #7
    ---------------------------------------------
    Xorg/2816 is trying to acquire lock:
     (&dev->struct_mutex){+.+.+.}, at: [<ffffffff812c626c>] i915_gem_fault+0x50/0x17e

    but task is already holding lock:
     (&dev->struct_mutex){+.+.+.}, at: [<ffffffff812c403b>] i915_mutex_lock_interruptible+0x28/0x4a

    other info that might help us debug this:
    2 locks held by Xorg/2816:
     #0:  (&dev->struct_mutex){+.+.+.}, at: [<ffffffff812c403b>] i915_mutex_lock_interruptible+0x28/0x4a
     #1:  (&mm->mmap_sem){++++++}, at: [<ffffffff81022d4f>] page_fault+0x156/0x37b

This recursion was introduced by rearranging the locking to avoid the
double locking on the fast path (4f27b5d and fbd5a26d) and the
introduction of the prefault to encourage the fast paths (b5e4f2b). In
order to undo the problem, we rearrange the code to perform the access
validation upfront, attempt to prefault and then fight for control of the
mutex.  the best case scenario where the mutex is uncontended the
prefaulting is not wasted.
Reported-and-tested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

As per advice from Jean Delvare.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

These got lost in the last i2c cleanup.  Fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=23222Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  [libata] remove SCSI host lock and serial number usage from ata_scsi_queuecmd

Update kernel-doc and Documentation maintainers info.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Document things that I would've liked to have known when submitting a driver
to gregkh for staging.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is confusing, as we have "staging" trees for drivers/staging.  Call
them -next trees.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

My old mail address doesn't exist anymore. This changes all occurrences
to my new address.
Signed-off-by: NHans J. Koch <hjk@hansjkoch.de>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a bit more information how to use poll(2) on GPIO value files
correctly. For me it was not clear that I need to poll(2) for
POLLPRI|POLLERR or select(2) for exceptfds.
Signed-off-by: NBernhard Walle <walle@corscience.de>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If "p" is NULL then it will cause an oops when we pass it to
simple_strtoul().  In this case "p" can not be NULL so I removed the
check.  I also changed the check a little to make it more explicit that
we are testing whether p points to the NUL char.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Acked-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

scripts/kernel-doc was leaving unescaped '<', '>', and '&' in
generated xml output for structs.  This causes xml parser errors.
Convert these characters to "&lt;", "&gt;", and "&amp;" as needed
to prevent errors.

Most of the conversion was already done; complete it just before
output.

Documentation/DocBook/device-drivers.xml:41883: parser error : StartTag: invalid element name
#define INPUT_KEYMAP_BY_INDEX	(1 << 0)
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When NF_CONNTRACK is enabled, IP_VS uses conntrack symbols.
Therefore IP_VS can't be linked statically when conntrack
is built modular.
Reported-by: NJustin P. Mattock <justinmattock@gmail.com>
Tested-by: NJustin P. Mattock <justinmattock@gmail.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

irttp_data_request() returns meaningful errorcodes, while irttp_udata_request()
just returns -1 in similar situations. Sync the two and the loglevels of the
accompanying output.
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Expose reachable and retrans timer values in msecs instead of jiffies.
Both timer values are already exposed as msecs in the neighbour table
netlink interface.

The creation timestamp format with increased precision is kept but
cleaned up.
Signed-off-by: NThomas Graf <tgraf@infradead.org>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>