| From 35848f68b07df3f917cb13fc3c134718669f569b Mon Sep 17 00:00:00 2001 |
| From: Jason Wang <jasowang@redhat.com> |
| Date: Tue, 18 Jun 2013 13:04:23 +0800 |
| Subject: drivers: hv: switch to use mb() instead of smp_mb() |
| |
| From: Jason Wang <jasowang@redhat.com> |
| |
| commit 35848f68b07df3f917cb13fc3c134718669f569b upstream. |
| |
| 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> |
| Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/hv/ring_buffer.c | 10 +++++----- |
| drivers/hv/vmbus_drv.c | 2 +- |
| 2 files changed, 6 insertions(+), 6 deletions(-) |
| |
| --- a/drivers/hv/ring_buffer.c |
| +++ b/drivers/hv/ring_buffer.c |
| @@ -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_in |
| 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_in |
| |
| 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_b |
| 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_bu |
| /* 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); |
| --- a/drivers/hv/vmbus_drv.c |
| +++ b/drivers/hv/vmbus_drv.c |
| @@ -434,7 +434,7 @@ static void vmbus_on_msg_dpc(unsigned lo |
| * will not deliver any more messages since there is |
| * no empty slot |
| */ |
| - smp_mb(); |
| + mb(); |
| |
| if (msg->header.message_flags.msg_pending) { |
| /* |
