xen-netfront: recreate queues correctly when reconnecting

When reconnecting to the backend (after a resume/migration, for example),
a different number of queues may be required (since the guest may have
moved to a different host with different capabilities).  During the
reconnection the old queues are torn down and new ones created.

Introduce xennet_create_queues() and xennet_destroy_queues() that fixes
three bugs during the reconnection.

- The old info->queues was leaked.
- The old queue's napi instances were not deleted.
- The new queue's napi instances were left disabled (which meant no
  packets could be received).

The xennet_destroy_queues() calls is deferred until the reconnection
instead of the disconnection (in xennet_disconnect_backend()) because
napi_disable() might sleep.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge branch 'xen-netfront'

David Vrabel says:

====================
xen-netfront: fix resume regressions in 3.16-rc1

The introduction of multi-queue support to xen-netfront in 3.16-rc1,
broke resume/migration.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
irqchip: spear_shirq: Fix interrupt offset

The ras3 block on spear320 claims to have 3 interrupts. In fact it has
one and 6 reserved interrupts. Account the 6 reserved to this block so
it has 7 interrupts total. That matches the datasheet and the device
tree entries.

Broken since commit 80515a5a(ARM: SPEAr3xx: shirq: simplify and move
the shared irq multiplexor to DT). Testing is overrated....

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20140619212712.872379208@linutronix.de
Fixes: 80515a5a2e3c ('ARM: SPEAr3xx: shirq: simplify and move the shared irq multiplexor to DT')
Cc: <stable@vger.kernel.org> # v3.8+
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
drivers: net: cpsw: fix dual EMAC stall when connected to same switch

In commit 629c9a8fd0bbdfc6d702526b327470166ec39c6b (drivers: net: cpsw: Add
default vlan for dual emac case also), api cpsw_add_default_vlan() also
changes the port vlan which is required to seperate the ports which results
in the following behavior

In Dual EMAC mode, when both the Etnernet connected is connected to same
switch, it creates a loop in the switch and when a broadcast packet is
received it is forwarded to the other port which stalls the whole switch
and needs a reset/power cycle to the switch to recover. So intead of using
the api, add only the default VLAN entry in dual EMAC case.

Cc: Yegor Yefremov <yegorslists@googlemail.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
Tested-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge branch 'for-3.16' of git://linux-nfs.org/~bfields/linux

Pull nfsd bugfixes from Bruce Fields:
 "Fixes for a new regression from the xdr encoding rewrite, and a
  delegation problem we've had for a while (made somewhat more annoying
  by the vfs delegation support added in 3.13)"

* 'for-3.16' of git://linux-nfs.org/~bfields/linux:
  NFSD: fix bug for readdir of pseudofs
  NFSD: Don't hand out delegations for 30 seconds after recalling them.
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs fixes from Chris Mason:
 "This fixes some lockups in btrfs reported with rc1.  It probably has
  some performance impact because it is backing off our spinning locks
  more often and switching to a blocking lock.  I'll be able to nail
  that down next week, but for now I want to get the lockups taken care
  of.

  Otherwise some more stack reduction and assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix wrong error handle when the device is missing or is not writeable
  Btrfs: fix deadlock when mounting a degraded fs
  Btrfs: use bio_endio_nodec instead of open code
  Btrfs: fix NULL pointer crash when running balance and scrub concurrently
  btrfs: Skip scrubbing removed chunks to avoid -ENOENT.
  Btrfs: fix broken free space cache after the system crashed
  Btrfs: make free space cache write out functions more readable
  Btrfs: remove unused wait queue in struct extent_buffer
  Btrfs: fix deadlocks with trylock on tree nodes
net: huawei_cdc_ncm: increase command buffer size

Messages from the modem exceeding 256 bytes cause communication
failure.

The WDM protocol is strictly "read on demand", meaning that we only
poll for unread data after receiving a notification from the modem.
Since we have no way to know how much data the modem has to send,
we must make sure that the buffer we provide is "big enough".
Message truncation does not work. Truncated messages are left unread
until the modem has another message to send.  Which often won't
happen until the userspace application has given up waiting for the
final part of the last message, and therefore sends another command.

With a proper CDC WDM function there is a descriptor telling us
which buffer size the modem uses. But with this vendor specific
implementation there is no known way to calculate the exact "big
enough" number.  It is an unknown property of the modem firmware.
Experience has shown that 256 is too small.  The discussion of
this failure ended up concluding that 512 might be too small as
well. So 1024 seems like a reasonable value for now.

Fixes: 41c47d8cfd68 ("net: huawei_cdc_ncm: Introduce the huawei_cdc_ncm driver")
Cc: Enrico Mioso <mrkiko.rs@gmail.com>
Reported-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Acked-By: Enrico Mioso <mrkiko.rs@gmail.com>
Tested-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge branch 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

Pull kbuild fixes from Michal Marek:
 "There are three fixes for regressions caused by the relative paths
  series: deb-pkg, tar-pkg and *docs did not work with O=.

  Plus, there is a fix for the linux-headers deb package and a fixed
  typo.  These are not regression fixes but are safe enough"

* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: fix a typo in a kbuild document
  builddeb: fix missing headers in linux-headers package
  Documentation: Fix DocBook build with relative $(srctree)
  kbuild: Fix tar-pkg with relative $(objtree)
  deb-pkg: Fix for relative paths
Merge tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux

Pull file locking fixes from Jeff Layton:
 "File locking related bugfixes

  Nothing too earth-shattering here.  A fix for a potential regression
  due to a patch in pile #1, and the addition of a memory barrier to
  prevent a race condition between break_deleg and generic_add_lease"

* tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux:
  locks: set fl_owner for leases back to current->files
  locks: add missing memory barrier in break_deleg
Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c new drivers from Wolfram Sang:
 "Here is a pull request from i2c hoping for the "new driver" rule.

  Originally, I wanted to send this request during the merge window, but
  code checkers with very recent additions complained, so a few fixups
  were needed.  So, some more time went by and I merged rc1 to get a
  stable base"

So the "new driver" rule is really about drivers that people absolutely
need for the kernel to work on new hardware, which is not so much the
case for i2c.  So I considered not pulling this, but eventually
relented.

Just for FYI: the whole (and only) point of "new drivers" is not that
new drivers cannot regress things (they can, and they have - by
triggering badly tested code on machines that never triggered that code
before), but because they can bring to life machines that otherwise
wouldn't be useful at all without the drivers.

So the new driver rule is for essential things that actual consumers
would care about, ie devices like networking or disk drivers that matter
to normal people (not server people - they run old kernels anyway, so
mainlining new drivers is irrelevant for them).

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: sun6-p2wi: fix call to snprintf
  i2c: rk3x: add NULL entry to the end of_device_id array
  i2c: sun6i-p2wi: use proper return value in probe
  i2c: sunxi: add P2WI (Push/Pull 2 Wire Interface) controller support
  i2c: sunxi: add P2WI DT bindings documentation
  i2c: rk3x: add driver for Rockchip RK3xxx SoC I2C adapter
Linux 3.16-rc2
spi: qup: Remove chip select function

This patch removes the chip select function.  Chip select should instead be
supported using GPIOs, defining the DT entry "cs-gpios", and letting the SPI
core assert/deassert the chip select as it sees fit.

The chip select control inside the controller is buggy.  It is supposed to
automatically assert the chip select based on the activity in the controller,
but it is buggy and doesn't work at all.  So instead we elect to use GPIOs.

Signed-off-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
regulator: bcm590xx: fix vbus name

The vbus regulator was not getting its name set. This results
in the sysfs entry being empty. The lack of a bcm590xx_regs[]
table entry also upsets Coverity runs. Add the table entry
so the name gets set properly.

Signed-off-by: Graham Williams <graham.williams@linaro.org>
Acked-by: Matt Porter <mporter@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
drm/msm: Replace type of paddr to uint32_t.

This patch helps to avoid the following build issue:

drivers/gpu/drm/msm/msm_fbdev.c:108:2: error: passing argument 3 of 'msm_gem_get_iova_locked' from incompatible pointer type [-Werror]
   msm_gem_get_iova_locked(fbdev->bo, 0, &paddr);
   ^
In file included from drivers/gpu/drm/msm/msm_fbdev.c:18:0:
drivers/gpu/drm/msm/msm_drv.h:153:5: note: expected 'uint32_t *' but argument is of type 'dma_addr_t *'
  int msm_gem_get_iova_locked(struct drm_gem_object *obj, int id,
      ^

Signed-off-by: Matwey V. Kornilov <matwey@sai.msu.ru>
Signed-off-by: Rob Clark <robdclark@gmail.com>
drm/msm: storage class should be before const qualifier

The C99 specification states in section 6.11.5:

The placement of a storage-class specifier other than at the beginning
of the declaration specifiers in a declaration is an obsolescent
feature.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Rob Clark <robdclark@gmail.com>
drm/msm/hdmi: set hdp clock rate before prepare_enable

The clock driver usually complains when a clock is being prepared
before setting its rate. It is the case here for "core_clk" which
needs to be set at 19.2 MHz before we attempt a prepare_enable().

Signed-off-by: Stephane Viau <sviau@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
drm/msm: use PAGE_ALIGNED instead of IS_ALIGNED(PAGE_SIZE)

use mm.h definition

Cc: David Airlie <airlied@linux.ie>
Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Rob Clark <robdclark@gmail.com>
drm/msm: fix IOMMU cleanup for -EPROBE_DEFER

If probe fails after IOMMU is attached, we need to detach in order to
clean up properly.  Before this change, IOMMU faults would occur if the
probe failed (-EPROBE_DEFER).

Signed-off-by: Stephane Viau <sviau@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Merge tag 'samsung-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into fixes

Merge Samsung fixes for 3.16 from Kukjin Kim:

- use WFI macro in platform_do_lowpower because exynos cpuhotplug
  includes a hardcoded WFI instruction and it causes compile error
  in Thumb-2 mode.
- fix GIC reg sizes for exynos4 SoCs
- remove reset timer counter value during boot and resume for mct
  to fix a big jump in printk timestamps
- fix pm code to check cortex-A9 for another exynos SoCs
- don't rely on firmware's secondary_cpu_start for mcpm

* tag 'samsung-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
  ARM: EXYNOS: Don't rely on firmware's secondary_cpu_start for mcpm
  ARM: EXYNOS: fix pm code to check for cortex A9 rather than the SoC
  clocksource: exynos_mct: Don't reset the counter during boot and resume
  ARM: dts: fix reg sizes of GIC for exynos4
  ARM: EXYNOS: Use wfi macro in platform_do_lowpower

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
blkcg: fix use-after-free in __blkg_release_rcu() by making blkcg_gq refcnt an atomic_t

Hello,

So, this patch should do.  Joe, Vivek, can one of you guys please
verify that the oops goes away with this patch?

Jens, the original thread can be read at

  http://thread.gmane.org/gmane.linux.kernel/1720729

The fix converts blkg->refcnt from int to atomic_t.  It does some
overhead but it should be minute compared to everything else which is
going on and the involved cacheline bouncing, so I think it's highly
unlikely to cause any noticeable difference.  Also, the refcnt in
question should be converted to a perpcu_ref for blk-mq anyway, so the
atomic_t is likely to go away pretty soon anyway.

Thanks.

------- 8< -------
__blkg_release_rcu() may be invoked after the associated request_queue
is released with a RCU grace period inbetween.  As such, the function
and callbacks invoked from it must not dereference the associated
request_queue.  This is clearly indicated in the comment above the
function.

Unfortunately, while trying to fix a different issue, 2a4fd070ee85
("blkcg: move bulk of blkcg_gq release operations to the RCU
callback") ignored this and added [un]locking of @blkg->q->queue_lock
to __blkg_release_rcu().  This of course can cause oops as the
request_queue may be long gone by the time this code gets executed.

  general protection fault: 0000 [#1] SMP
  CPU: 21 PID: 30 Comm: rcuos/21 Not tainted 3.15.0 #1
  Hardware name: Stratus ftServer 6400/G7LAZ, BIOS BIOS Version 6.3:57 12/25/2013
  task: ffff880854021de0 ti: ffff88085403c000 task.ti: ffff88085403c000
  RIP: 0010:[<ffffffff8162e9e5>]  [<ffffffff8162e9e5>] _raw_spin_lock_irq+0x15/0x60
  RSP: 0018:ffff88085403fdf0  EFLAGS: 00010086
  RAX: 0000000000020000 RBX: 0000000000000010 RCX: 0000000000000000
  RDX: 000060ef80008248 RSI: 0000000000000286 RDI: 6b6b6b6b6b6b6b6b
  RBP: ffff88085403fdf0 R08: 0000000000000286 R09: 0000000000009f39
  R10: 0000000000020001 R11: 0000000000020001 R12: ffff88103c17a130
  R13: ffff88103c17a080 R14: 0000000000000000 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff88107fca0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000006e5ab8 CR3: 000000000193d000 CR4: 00000000000407e0
  Stack:
   ffff88085403fe18 ffffffff812cbfc2 ffff88103c17a130 0000000000000000
   ffff88103c17a130 ffff88085403fec0 ffffffff810d1d28 ffff880854021de0
   ffff880854021de0 ffff88107fcaec58 ffff88085403fe80 ffff88107fcaec30
  Call Trace:
   [<ffffffff812cbfc2>] __blkg_release_rcu+0x72/0x150
   [<ffffffff810d1d28>] rcu_nocb_kthread+0x1e8/0x300
   [<ffffffff81091d81>] kthread+0xe1/0x100
   [<ffffffff8163813c>] ret_from_fork+0x7c/0xb0
  Code: ff 47 04 48 8b 7d 08 be 00 02 00 00 e8 55 48 a4 ff 5d c3 0f 1f 00 66 66 66 66 90 55 48 89 e5
  +fa 66 66 90 66 66 90 b8 00 00 02 00 <f0> 0f c1 07 89 c2 c1 ea 10 66 39 c2 75 02 5d c3 83 e2 fe 0f
  +b7
  RIP  [<ffffffff8162e9e5>] _raw_spin_lock_irq+0x15/0x60
   RSP <ffff88085403fdf0>

The request_queue locking was added because blkcg_gq->refcnt is an int
protected with the queue lock and __blkg_release_rcu() needs to put
the parent.  Let's fix it by making blkcg_gq->refcnt an atomic_t and
dropping queue locking in the function.

Given the general heavy weight of the current request_queue and blkcg
operations, this is unlikely to cause any noticeable overhead.
Moreover, blkcg_gq->refcnt is likely to be converted to percpu_ref in
the near future, so whatever (most likely negligible) overhead it may
add is temporary.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/g/alpine.DEB.2.02.1406081816540.17948@jlaw-desktop.mno.stratus.com
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>