diff options
| author | K. Y. Srinivasan <kys@microsoft.com> | 2016-04-03 02:59:47 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-04-30 23:00:19 +0200 |
| commit | d45faaeedb762a3965a0246cf831e55045dd6ef8 (patch) | |
| tree | d33ec75e96196b925c1ba72933f5e73016c73ddb /drivers/hv | |
| parent | Drivers: hv: vmbus: Introduce functions for estimating room in the ring buffer (diff) | |
| download | linux-d45faaeedb762a3965a0246cf831e55045dd6ef8.tar.xz linux-d45faaeedb762a3965a0246cf831e55045dd6ef8.zip | |
Drivers: hv: vmbus: Use READ_ONCE() to read variables that are volatile
Use the READ_ONCE macro to access variabes that can change asynchronously.
This is the recommended mechanism for dealing with "unsafe" compiler
optimizations.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv')
| -rw-r--r-- | drivers/hv/ring_buffer.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 544362c6a9ca..6ea1b552cc8a 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -69,7 +69,7 @@ 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) { mb(); - if (rbi->ring_buffer->interrupt_mask) + if (READ_ONCE(rbi->ring_buffer->interrupt_mask)) return false; /* check interrupt_mask before read_index */ @@ -78,7 +78,7 @@ static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi) * This is the only case we need to signal when the * ring transitions from being empty to non-empty. */ - if (old_write == rbi->ring_buffer->read_index) + if (old_write == READ_ONCE(rbi->ring_buffer->read_index)) return true; return false; @@ -117,7 +117,7 @@ static bool hv_need_to_signal_on_read(struct hv_ring_buffer_info *rbi) */ mb(); - pending_sz = rbi->ring_buffer->pending_send_sz; + pending_sz = READ_ONCE(rbi->ring_buffer->pending_send_sz); /* If the other end is not blocked on write don't bother. */ if (pending_sz == 0) return false; |