xen-blkback: implement safe iterator for the list of persistent grants

Change foreach_grant iterator to a safe version, that allows freeing
the element while iterating. Also move the free code in
free_persistent_gnts to prevent freeing the element before the rb_next
call.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: xen-devel@lists.xen.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
HID: remove x bit from sensor doc

Reported-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
llist/xen-blkfront: implement safe version of llist_for_each_entry

Implement a safe version of llist_for_each_entry, and use it in
blkif_free. Previously grants where freed while iterating the list,
which lead to dereferences when trying to fetch the next item.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by:  Andrew Morton <akpm@linux-foundation.org>
[v2: Move the llist_for_each_entry_safe in llist.h]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
xen-blkfront: handle bvecs with partial data

Currently blkfront fails to handle cases in blkif_completion like the
following:

1st loop in rq_for_each_segment
 * bv_offset: 3584
 * bv_len: 512
 * offset += bv_len
 * i: 0

2nd loop:
 * bv_offset: 0
 * bv_len: 512
 * i: 0

In the second loop i should be 1, since we assume we only wanted to
read a part of the previous page. This patches fixes this cases where
only a part of the shared page is read, and blkif_completion assumes
that if the bv_offset of a bvec is less than the previous bv_offset
plus the bv_size we have to switch to the next shared page.

Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: linux-kernel@vger.kernel.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
block: remove deadlock in disk_clear_events

In disk_clear_events, do not put work on system_nrt_freezable_wq.
Instead, put it on system_nrt_wq.

There is a race between probing a usb and suspending the device.  Since
probing a usb calls disk_clear_events, which puts work on a frozen
workqueue, probing cannot finish after the workqueue is frozen.  However,
suspending cannot finish until the usb probe is finished, so we get a
deadlock, causing the system to reboot.

The way to reproduce this bug is to wake up from suspend with a usb
storage device plugged in, or plugging in a usb storage device right
before suspend.  The window of time is on the order of time it takes to
probe the usb device.  As long as the workqueues are frozen before the
call to add_disk within sd_probe_async finishes, there will be a deadlock
(which calls blkdev_get, sd_open, check_disk_change, then
disk_clear_events).  This is not difficult to reproduce after figuring out
the timings.

[akpm@linux-foundation.org: fix up comment]
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Reviewed-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: prevent race/cleanup

Remove a race condition which causes a warning in disk_clear_events.  This
is a race between disk_clear_events() and disk_flush_events().
ev->clearing will be altered by disk_flush_events() even though we are
blocking event checking through disk_flush_events().  If this happens
after ev->clearing was cleared for disk_clear_events(), this can cause the
WARN_ON_ONCE() in that function to be triggered.

This change also has disk_clear_events() not go through a workqueue.
Since we have to wait for the work to complete, we should just call the
function directly.  Also, since this work cannot be put on a freezable
workqueue, it will have to contend with increased demand, so calling the
function directly avoids this.

[akpm@linux-foundation.org: fix spello in comment]
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge branch 'stable/for-jens-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus

Konrad writes:

Please git pull the following branch:

 git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/for-jens-3.8

which has a bug-fix to the xen-blkfront and xen-blkback driver
when using the persistent mode. An issue was discovered where LVM
disks could not be read correctly and this fixes it. There
is also a change in llist.h which has been blessed by akpm.
mtd: bcm47xxnflash: increase NFLASH_READY_RETRIES

Recently imlemented writing support has shown that current num of
retries is too low. Writing requires longer waiting than simple reading.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
ARM: dts: cfa10049: Add PCA9555 GPIO expander to the device tree

Add the GPIO expander found on the i2c1 bus, behind the muxer to the
device tree.

This gpio expander will be used to get tachymeters values and data ready
interruptions from the nuvoton NAU7802 ADCs.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
HID: usbhid: quirk for Formosa IR receiver

Patch to add the Formosa Industrial Computing, Inc. Infrared Receiver
[IR605A/Q] to hid-ids.h and hid-quirks.c.  This IR receiver causes about a 10
second timeout when the usbhid driver attempts to initialze the device.  Adding
this device to the quirks list with HID_QUIRK_NO_INIT_REPORTS removes the
delay.

Signed-off-by: Nicholas Santos <nicholas.santos@gmail.com>
[jkosina@suse.cz: fix ordering]
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
ARM: sunxi: Add device tree for Miniand Hackberry

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
rcu: Prevent soft-lockup complaints about no-CBs CPUs

The wait_event() at the head of the rcu_nocb_kthread() can result in
soft-lockup complaints if the CPU in question does not register RCU
callbacks for an extended period.  This commit therefore changes
the wait_event() to a wait_event_interruptible().

Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
rcu: Make rcu_nocb_poll an early_param instead of module_param

The as-documented rcu_nocb_poll will fail to enable this feature
for two reasons.  (1) there is an extra "s" in the documented
name which is not in the code, and (2) since it uses module_param,
it really is expecting a prefix, akin to "rcutree.fanout_leaf"
and the prefix isn't documented.

However, there are several reasons why we might not want to
simply fix the typo and add the prefix:

1) we'd end up with rcutree.rcu_nocb_poll, and rather probably make
a change to rcutree.nocb_poll

2) if we did #1, then the prefix wouldn't be consistent with the
rcu_nocbs=<cpumap> parameter (i.e. one with, one without prefix)

3) the use of module_param in a header file is less than desired,
since it isn't immediately obvious that it will get processed
via rcutree.c and get the prefix from that (although use of
module_param_named() could clarify that.)

4) the implied export of /sys/module/rcutree/parameters/rcu_nocb_poll
data to userspace via module_param() doesn't really buy us anything,
as it is read-only and we can tell if it is enabled already without
it, since there is a printk at early boot telling us so.

In light of all that, just change it from a module_param() to an
early_setup() call, and worry about adding it to /sys later on if
we decide to allow a dynamic setting of it.

Also change the variable to be tagged as read_mostly, since it
will only ever be fiddled with at most, once at boot.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
cpufreq: exynos: cleanup exynos-cpufreq header

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
ARM: S5P64X0: remove gpiolib.c file in mach-s5p64x0

Since S5P64X0 gpiolib is supported in drivers/gpio/gpio-samsung.c,
this can be removed. Probably, removing this file is missed when
S5P64X0 gpiolib was supported in drivers/gpio/.

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
ARM: S5P64X0: move i2c.h into local directory

The <mach/i2c.h> can be moved into mach-s5p64x0/.

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
ARM: S5P64X0: move s5p64x0-clock.h into local directory

The <mach/s5p64x0-clock.h> can be moved into mach-s5p64x0/.

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
ARM: S5PV210: move regs-sys.h into setup-usb-phy.c file

The <mach/regs-sys.h> can be moved into mach-s5pv210/setup-usb-phy.c
file.

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
ARM: EXYNOS: move mach/pmu.h file into common.h

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
ARM: SAMSUNG: cleanup mach/regs-audss.h file

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>