drivers: hv: switch to use mb() instead of smp_mb()

Even if guest were compiled without SMP support, it could not assume that host
wasn't. So switch to use mb() instead of smp_mb() to force memory barriers for
UP guest.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jason Wang 2013-06-18 13:04:23 +08:00 committed by Greg Kroah-Hartman
parent 36dd68319c
commit 35848f68b0
2 changed files with 6 additions and 6 deletions

View File

@ -32,7 +32,7 @@
void hv_begin_read(struct hv_ring_buffer_info *rbi)
{
rbi->ring_buffer->interrupt_mask = 1;
smp_mb();
mb();
}
u32 hv_end_read(struct hv_ring_buffer_info *rbi)
@ -41,7 +41,7 @@ u32 hv_end_read(struct hv_ring_buffer_info *rbi)
u32 write;
rbi->ring_buffer->interrupt_mask = 0;
smp_mb();
mb();
/*
* Now check to see if the ring buffer is still empty.
@ -71,7 +71,7 @@ u32 hv_end_read(struct hv_ring_buffer_info *rbi)
static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi)
{
smp_mb();
mb();
if (rbi->ring_buffer->interrupt_mask)
return false;
@ -442,7 +442,7 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
sizeof(u64));
/* Issue a full memory barrier before updating the write index */
smp_mb();
mb();
/* Now, update the write location */
hv_set_next_write_location(outring_info, next_write_location);
@ -549,7 +549,7 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer,
/* Make sure all reads are done before we update the read index since */
/* the writer may start writing to the read area once the read index */
/*is updated */
smp_mb();
mb();
/* Update the read index */
hv_set_next_read_location(inring_info, next_read_location);

View File

@ -434,7 +434,7 @@ static void vmbus_on_msg_dpc(unsigned long data)
* will not deliver any more messages since there is
* no empty slot
*/
smp_mb();
mb();
if (msg->header.message_flags.msg_pending) {
/*