From: Jason Wang <jasowang@redhat.com>
To: kys@microsoft.com, haiyangz@microsoft.com,
devel@linuxdriverproject.org, linux-kernel@vger.kernel.org
Cc: Jason Wang <jasowang@redhat.com>, stable@vger.kernel.org
Subject: [PATCH] drivers: hv: switch to use mb() instead of smp_mb()
Date: Tue, 18 Jun 2013 13:04:23 +0800 [thread overview]
Message-ID: <1371531863-12491-1-git-send-email-jasowang@redhat.com> (raw)
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.
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/hv/ring_buffer.c | 10 +++++-----
drivers/hv/vmbus_drv.c | 2 +-
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index d6fbb57..791f45d 100644
--- 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_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);
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index bf421e0..4004e54 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -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) {
/*
--
1.7.1
next reply other threads:[~2013-06-18 5:14 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-18 5:04 Jason Wang [this message]
2013-06-18 12:58 ` [PATCH] drivers: hv: switch to use mb() instead of smp_mb() KY Srinivasan
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