Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent

Merge RCU fixes from Paul E. McKenney:

 " This series has four patches, the major point of which is to eliminate
   some slowdowns (including boot-time slowdowns) resulting from some
   RCU_FAST_NO_HZ changes.  The issue with the changes is that posting timers
   from the idle loop has no effect if the CPU has entered dyntick-idle
   mode because the CPU has already computed its wakeup time, and posting
   a timer does not cause it to be recomputed.  The short-term fix is for
   RCU to precompute the timeout value so that the CPU's calculation is
   correct. "
Signed-off-by: Ingo Molnar <mingo@kernel.org>

At first glance one would think that memblock_is_region_memory()
and memblock_is_region_reserved() would be implemented in the
same way. Unfortunately they aren't and the former returns
whether the region specified is a subset of a memory bank while
the latter returns whether the region specified intersects with
reserved memory.

Document the two functions so that users aren't tempted to
make the implementation the same between them and to clarify the
purpose of the functions.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1337845521-32755-1-git-send-email-sboyd@codeaurora.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

When a CPU is entering dyntick-idle mode, tick_nohz_stop_sched_tick()
calls rcu_needs_cpu() see if RCU needs that CPU, and, if not, computes the
next wakeup time based on the timer wheels.  Only later, when actually
entering the idle loop, rcu_prepare_for_idle() will be invoked.  In some
cases, rcu_prepare_for_idle() will post timers to wake the CPU back up.
But all for naught: The next wakeup time for the CPU has already been
computed, and posting a timer afterwards does not force that wakeup
time to be recomputed.  This means that rcu_prepare_for_idle()'s have
no effect.

This is not a problem on a busy system because something else will wake
up the CPU soon enough.  However, on lightly loaded systems, the CPU
might stay asleep for a considerable length of time.  If that CPU has
a callback that the rest of the system is waiting on, the system might
run very slowly or (in theory) even hang.

This commit avoids this problem by having rcu_needs_cpu() give
tick_nohz_stop_sched_tick() an estimate of when RCU will need the CPU
to wake back up, which tick_nohz_stop_sched_tick() takes into account
when programming the CPU's wakeup time.  An alternative approach is
for rcu_prepare_for_idle() to use hrtimers instead of normal timers,
but timers are much more efficient than are hrtimers for frequently
and repeatedly posting and cancelling a given timer, which is exactly
what RCU_FAST_NO_HZ does.
Reported-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>

The RCU_FAST_NO_HZ code relies on a number of per-CPU variables.
This works, but is hidden from someone scanning the data structures
in rcutree.h.  This commit therefore converts these per-CPU variables
to fields in the per-CPU rcu_dynticks structures.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>

In the current code, a short dyntick-idle interval (where there is
at least one non-lazy callback on the CPU) and a long dyntick-idle
interval (where there are only lazy callbacks on the CPU) are traced
identically, which can be less than helpful.  This commit therefore
emits different event traces in these two cases.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>

In the present implementations of CPU hotplug, the outgoing CPU is
guaranteed to run its stop-machine process on the way out, which
will guarantee that RCU_FAST_NO_HZ forces the CPU out of dyntick-idle
mode.

However, new versions of CPU hotplug might not work this way.  This
commit therefore removes this design constraint by explicitly notifying
CPUs when they adopt non-lazy RCU callbacks.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>

On an over-committed KVM system we got a:

  "BUG: spinlock lockup on CPU#2, swapper/2/0"

message on the heavily contended virtio blk spinlock.

While we might want to reconsider the locking of virtio-blk
(lock is held while switching to the host) this patch tries to
make the message clearer: the lockup is only suspected.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1338283124-7063-1-git-send-email-borntraeger@de.ibm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Merge two debugging patchlets that were waiting for
preparatory commits to hit upstream.
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull MCE regression fix from Tony Luck:
 "Typo/thinko in a cleanup caused a semantic change. Fix it."

* tag 'please-pull-mce' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  x86/mce: Fix the MCE poll timer logic

Pull arm CMA fix from Marek Szyprowski:
 "This removes the ARMv6+ CMA dependency and lets one use old, well-
  tested dma-mapping implementation also on ARMv6+ systems without the
  need to use EXPERIMENTAL stuff."

Russell King complained (rightly) about the experimental feature being
forced on by the ARM config.

Here CMA is "continuous memory allocator", not "cross-memory attach".
We really neet to stop using insane TLA's for things that aren't big
industry standards.

* 'fixes-for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
  ARM: dma-mapping: remove unconditional dependency on CMA

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Karel Zak <kzak@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull two scsi target fixes from Nicholas Bellinger:
 "The first is a small name-space collision fix from Stefan for the new
  sbp-target / ieee-1394 code, and second is the FILEIO backend
  conversion patch to always use O_DSYNC by default instead of O_SYNC as
  recommended by hch.  Note the latter is CC'ed stable."

* '3.5-merge-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  target/file: Use O_DSYNC by default for FILEIO backends
  sbp-target: rename a variable to avoid name clash

Pull cgroup fix from Tejun Heo:
 "This fixes the possible premature superblock release on umount bug
  mentioned during v3.5-rc1 pull request.

  Originally, cgroup dentry destruction path assumed that cgroup dentry
  didn't have any reference left after cgroup removal thus put super
  during dentry removal.  Now that there can be lingering dentry
  references, this led to super being put with live dentries.  This
  patch fixes the problem by putting super ref on dentry release instead
  of removal."

* 'for-3.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: superblock can't be released with active dentries

Pull embedded i2c update from Wolfram Sang:
 "This only contains one new driver which had multiple dependencies
  (pinctrl, i2c-mux-rework, new devm_* functions), so I decided to wait
  for rc1.  Plus, it had to wait a little for the ack of a devicetree
  maintainer since the bindings were not trivial enough for me to pass
  through.

  So, given that, I hope there is still something like the "new driver
  rule", so we could have the driver in 3.5 and people can start using
  it.  That would make merging support for some boards easier for 3.6
  since the dependency on this driver is gone then."

* 'i2c-embedded/for-current' of git://git.pengutronix.de/git/wsa/linux:
  i2c: Add generic I2C multiplexer using pinctrl API

Pull kvm fix from Avi Kivity:
 "A one-liner fix for a buffer overflow"

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Fix buffer overflow in kvm_set_irq()

Pull drm radeon fixes from Dave Airlie:
 "This is just radeon fixes and a bunch of new PCI ids.  The fixes are
  for a deadlock, an audio regression, and a couple of audio fixes."

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon/kms: add new SI PCI ids
  drm/radeon/kms: add new BTC PCI ids
  drm/radeon/kms: add new Palm, Sumo PCI ids
  drm/radeon/kms: add new Trinity PCI ids
  drm/radeon: fix vm deadlocks on cayman
  drm/radeon: fix gpu_init on si
  drm/radeon/hdmi: don't set SEND_MAX_PACKETS bit
  drm/radeon/audio: don't hardcode CRTC id
  drm/radeon: make audio_init consistent across asics

This patch fixes bug in macro radix_tree_for_each_contig().

If radix_tree_next_slot() sees NULL in next slot it returns NULL, but following
radix_tree_next_chunk() switches iterating into next chunk. As result iterating
becomes non-contiguous and breaks vfs "splice" and all its users.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Reported-and-bisected-by: Hans de Bruin <jmdebruin@xmsnet.nl>
Reported-and-bisected-by: Ondrej Zary <linux@rainbow-software.org>
Reported-bisected-and-tested-by: Toralf Förster <toralf.foerster@gmx.de>
Link: https://lkml.org/lkml/2012/6/5/64
Cc: stable <stable@vger.kernel.org> # 3.4.x
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In commit 82f7af09 (x86/mce: Cleanup timer mess), Thomas just forgot
the "/ 2" there while cleaning up.
Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Pull fuse updates from Miklos Szeredi.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: fix blksize calculation
  fuse: fix stat call on 32 bit platforms
  fuse: optimize fallocate on permanent failure
  fuse: add FALLOCATE operation
  fuse: Convert to kstrtoul_from_user

Pull scheduler fixes from Ingo Molnar.

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Remove NULL assignment of dattr_cur
  sched: Remove the last NULL entry from sched_feat_names
  sched: Make sched_feat_names const
  sched/rt: Fix SCHED_RR across cgroups
  sched: Move nr_cpus_allowed out of 'struct sched_rt_entity'
  sched: Make sure to not re-read variables after validation
  sched: Fix SD_OVERLAP
  sched: Don't try allocating memory from offline nodes
  sched/nohz: Fix rq->cpu_load calculations some more
  sched/x86: Use cpu_llc_shared_mask(cpu) for coregroup_mask

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

kvm_set_irq() has an internal buffer of three irq routing entries, allowing
connecting a GSI to three IRQ chips or on MSI.  However setup_routing_entry()
does not properly enforce this, allowing three irqchip routes followed by
an MSI route to overflow the buffer.

Fix by ensuring that an MSI entry is added to an empty list.
Signed-off-by: Avi Kivity <avi@redhat.com>

Locking mutex in different orders just screams for
deadlocks, and some testing showed that it is actually
quite easy to trigger them.
Signed-off-by: Christian König <deathsimple@vodafone.de>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

- Properly set up the RBs
- Properly set up the SPI
- Properly set up gb_addr_config

This should fix rendering issues on certain cards.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Many TVs and A/V receivers don't work with this bit set. Problem was
confirmed using: Onkyo TX-SR605, Sony BRAVIA KDL-52X3500, Sony BRAVIA
KDL-40S40xx. In theory this bit shouldn't affect audio engine when
feeding it with data, however it seems it does. Driver fglrx doesn't set
that bit in any of the above cases.
This fixes a regression introduced by 3.5-rc1.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

This is based on info released by AMD, should allow using audio in much
more cases.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Call it in the asic startup callback on all asics.
Previously r600 and rv770 called it in the startup
and resume callbacks while all the other asics called
it in the startup callback.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Pull signal and vfs compile breakage fixes from Al Viro.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
  fixups for signal breakage

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  nommu: fix compilation of nommu.c

Pull cifs fixes from Steve French.

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Move get_next_mid to ops struct
  CIFS: Make accessing is_valid_oplock/dump_detail ops struct field safe
  CIFS: Improve identation in cifs_unlock_range
  CIFS: Fix possible wrong memory allocation

Obvious brainos spotted by Geert.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Compiling 3.5-rc1 for nommu targets gives:

  CC      mm/nommu.o
mm/nommu.c: In function ‘sys_mmap_pgoff’:
mm/nommu.c:1489:2: error: ‘ret’ undeclared (first use in this function)
mm/nommu.c:1489:2: note: each undeclared identifier is reported only once for each function it appears in

It is trivially fixed by replacing 'ret' with the local variable that is
already defined for the return value 'retval'.
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull frontswap feature from Konrad Rzeszutek Wilk:
 "Frontswap provides a "transcendent memory" interface for swap pages.
  In some environments, dramatic performance savings may be obtained
  because swapped pages are saved in RAM (or a RAM-like device) instead
  of a swap disk.  This tag provides the basic infrastructure along with
  some changes to the existing backends."

Fix up trivial conflict in mm/Makefile due to removal of swap token code
changing a line next to the new frontswap entry.

This pull request came in before the merge window even opened, it got
delayed to after the merge window by me just wanting to make sure it had
actual users.  Apparently IBM is using this on their embedded side, and
Jan Beulich says that it's already made available for SLES and OpenSUSE
users.

Also acked by Rik van Riel, and Konrad points to other people liking it
too.  So in it goes.

By Dan Magenheimer (4) and Konrad Rzeszutek Wilk (2)
via Konrad Rzeszutek Wilk
* tag 'stable/frontswap.v16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm:
  frontswap: s/put_page/store/g s/get_page/load
  MAINTAINER: Add myself for the frontswap API
  mm: frontswap: config and doc files
  mm: frontswap: core frontswap functionality
  mm: frontswap: core swap subsystem hooks and headers
  mm: frontswap: add frontswap header file

Merge branches 'irq-urgent-for-linus' and 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq and smpboot updates from Thomas Gleixner:
 "Just cleanup patches with no functional change and a fix for suspend
  issues."

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Introduce irq_do_set_affinity() to reduce duplicated code
  genirq: Add IRQS_PENDING for nested and simple irq

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smpboot, idle: Fix comment mismatch over idle_threads_init()
  smpboot, idle: Optimize calls to smp_processor_id() in idle_threads_init()

Pull timer updates from Thomas Gleixner:
 "The clocksource driver is pure hardware enablement and the skew option
  is default off, well tested and non dangerous."

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick: Move skew_tick option into the HIGH_RES_TIMER section
  clocksource: em_sti: Add DT support
  clocksource: em_sti: Emma Mobile STI driver
  clockevents: Make clockevents_config() a global symbol
  tick: Add tick skew boot option

Cyrill Gorcunov reports that I broke the fdinfo files with commit
30a08bf2 ("proc: move fd symlink i_mode calculations into
tid_fd_revalidate()"), and he's quite right.

The tid_fd_revalidate() function is not just used for the <tid>/fd
symlinks, it's also used for the <tid>/fdinfo/<fd> files, and the
permission model for those are different.

So do the dynamic symlink permission handling just for symlinks, making
the fdinfo files once more appear as the proper regular files they are.

Of course, Al Viro argued (probably correctly) that we shouldn't do the
symlink permission games at all, and make the symlinks always just be
the normal 'lrwxrwxrwx'.  That would have avoided this issue too, but
since somebody noticed that the permissions had changed (which was the
reason for that original commit 30a08bf2 in the first place), people
do apparently use this feature.

[ Basically, you can use the symlink permission data as a cheap "fdinfo"
  replacement, since you see whether the file is open for reading and/or
  writing by just looking at st_mode of the symlink.  So the feature
  does make sense, even if the pain it has caused means we probably
  shouldn't have done it to begin with. ]
Reported-and-tested-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is useful for SoCs whose I2C module's signals can be routed to
different sets of pins at run-time, using the pinctrl API.

                                 +-----+  +-----+
                                 | dev |  | dev |
    +------------------------+   +-----+  +-----+
    | SoC                    |      |        |
    |                   /----|------+--------+
    |   +---+   +------+     | child bus A, on first set of pins
    |   |I2C|---|Pinmux|     |
    |   +---+   +------+     | child bus B, on second set of pins
    |                   \----|------+--------+--------+
    |                        |      |        |        |
    +------------------------+  +-----+  +-----+  +-----+
                                | dev |  | dev |  | dev |
                                +-----+  +-----+  +-----+
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>