linux.git/drivers/hv, branch v4.6-rc2

Merge tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2016-03-17T20:47:50+00:00

Pull char/misc updates from Greg KH:
 "Here is the big char/misc driver update for 4.6-rc1.

  The majority of the patches here is hwtracing and some new mic
  drivers, but there's a lot of other driver updates as well.  Full
  details in the shortlog.

  All have been in linux-next for a while with no reported issues"

* tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (238 commits)
  goldfish: Fix build error of missing ioremap on UM
  nvmem: mediatek: Fix later provider initialization
  nvmem: imx-ocotp: Fix return value of imx_ocotp_read
  nvmem: Fix dependencies for !HAS_IOMEM archs
  char: genrtc: replace blacklist with whitelist
  drivers/hwtracing: make coresight-etm-perf.c explicitly non-modular
  drivers: char: mem: fix IS_ERROR_VALUE usage
  char: xillybus: Fix internal data structure initialization
  pch_phub: return -ENODATA if ROM can't be mapped
  Drivers: hv: vmbus: Support kexec on ws2012 r2 and above
  Drivers: hv: vmbus: Support handling messages on multiple CPUs
  Drivers: hv: utils: Remove util transport handler from list if registration fails
  Drivers: hv: util: Pass the channel information during the init call
  Drivers: hv: vmbus: avoid unneeded compiler optimizations in vmbus_wait_for_unload()
  Drivers: hv: vmbus: remove code duplication in message handling
  Drivers: hv: vmbus: avoid wait_for_completion() on crash
  Drivers: hv: vmbus: don't loose HVMSG_TIMER_EXPIRED messages
  misc: at24: replace memory_accessor with nvmem_device_read
  eeprom: 93xx46: extend driver to plug into the NVMEM framework
  eeprom: at25: extend driver to plug into the NVMEM framework
  ...

Drivers: hv: vmbus: Support kexec on ws2012 r2 and above

2016-03-02T00:57:20+00:00

WS2012 R2 and above hosts can support kexec in that thay can support
reconnecting to the host (as would be needed in the kexec path)
on any CPU. Enable this. Pre ws2012 r2 hosts don't have this ability
and consequently cannot support kexec.

Signed-off-by: Alex Ng 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Support handling messages on multiple CPUs

2016-03-02T00:57:20+00:00

Starting with Windows 2012 R2, message inteerupts can be delivered
on any VCPU in the guest. Support this functionality.

Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: utils: Remove util transport handler from list if registration fails

2016-03-02T00:57:20+00:00

If util transport fails to initialize for any reason, the list of transport
handlers may become corrupted due to freeing the transport handler without
removing it from the list. Fix this by cleaning it up from the list.

Signed-off-by: Alex Ng 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: util: Pass the channel information during the init call

2016-03-02T00:57:20+00:00

Pass the channel information to the util drivers that need to defer
reading the channel while they are processing a request. This would address
the following issue reported by Vitaly:

Commit 3cace4a61610 ("Drivers: hv: utils: run polling callback always in
interrupt context") removed direct *_transaction.state = HVUTIL_READY
assignments from *_handle_handshake() functions introducing the following
race: if a userspace daemon connects before we get first non-negotiation
request from the server hv_poll_channel() won't set transaction state to
HVUTIL_READY as (!channel) condition will fail, we set it to non-NULL on
the first real request from the server.

Signed-off-by: K. Y. Srinivasan 
Reported-by: Vitaly Kuznetsov 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: avoid unneeded compiler optimizations in vmbus_wait_for_unload()

2016-03-02T00:57:20+00:00

Message header is modified by the hypervisor and we read it in a loop,
we need to prevent compilers from optimizing accesses. There are no such
optimizations at this moment, this is just a future proof.

Suggested-by: Radim Krcmar 
Signed-off-by: Vitaly Kuznetsov 
Reviewed-by: Radim Kr.má
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: remove code duplication in message handling

2016-03-02T00:57:20+00:00

We have 3 functions dealing with messages and they all implement
the same logic to finalize reads, move it to vmbus_signal_eom().

Suggested-by: Radim Krcmar 
Signed-off-by: Vitaly Kuznetsov 
Reviewed-by: Radim Kr.má
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: avoid wait_for_completion() on crash

2016-03-02T00:57:20+00:00

wait_for_completion() may sleep, it enables interrupts and this
is something we really want to avoid on crashes because interrupt
handlers can cause other crashes. Switch to the recently introduced
vmbus_wait_for_unload() doing busy wait instead.

Reported-by: Radim Krcmar 
Signed-off-by: Vitaly Kuznetsov 
Reviewed-by: Radim Kr.má
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: don't loose HVMSG_TIMER_EXPIRED messages

2016-03-02T00:57:20+00:00

We must handle HVMSG_TIMER_EXPIRED messages in the interrupt context
and we offload all the rest to vmbus_on_msg_dpc() tasklet. This functions
loops to see if there are new messages pending. In case we'll ever see
HVMSG_TIMER_EXPIRED message there we're going to lose it as we can't
handle it from there. Avoid looping in vmbus_on_msg_dpc(), we're OK
with handling one message per interrupt.

Signed-off-by: Vitaly Kuznetsov 
Reviewed-by: Radim Kr.má
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

drivers/hv: Move VMBus hypercall codes into Hyper-V UAPI header

2016-02-16T17:48:40+00:00

VMBus hypercall codes inside Hyper-V UAPI header will
be used by QEMU to implement VMBus host devices support.

Signed-off-by: Andrey Smetanin 
Acked-by: K. Y. Srinivasan 
Reviewed-by: Roman Kagan 
CC: Gleb Natapov 
CC: Paolo Bonzini 
CC: Joerg Roedel 
CC: "K. Y. Srinivasan" 
CC: Haiyang Zhang 
CC: Roman Kagan 
CC: Denis V. Lunev 
CC: qemu-devel@nongnu.org
[Do not rename the constant at the same time as moving it, as that
 would cause semantic conflicts with the Hyper-V tree. - Paolo]
Signed-off-by: Paolo Bonzini