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| author | Jason Wang <jasowang@redhat.com> | 2013-06-18 13:04:23 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-07 16:02:10 -0700 |
| commit | 4f9e14fad5e381e075f942677e9c1ae70e0f186e (patch) | |
| tree | b76fa9d320acce2a9213ca33f3f1fa45194a9ae6 /drivers/hv | |
| parent | f40ed19c957e23cee2a178a688c45197aa1bc30c (diff) | |
| download | lwn-4f9e14fad5e381e075f942677e9c1ae70e0f186e.tar.gz lwn-4f9e14fad5e381e075f942677e9c1ae70e0f186e.zip | |
drivers: hv: switch to use mb() instead of smp_mb()
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>
[bwh: Backported to 3.2:
- Drop changes to functions that don't exist here
- hv_ringbuffer_write() has only a write memory barrier]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[hq: Backported to 3.4:
- Add the change in hv_ringbuffer_read]
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv')
| -rw-r--r-- | drivers/hv/ring_buffer.c | 4 | ||||
| -rw-r--r-- | drivers/hv/vmbus_drv.c | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 8af25a097d75..d01edf3c7b28 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -383,7 +383,7 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info, sizeof(u64)); /* Make sure we flush all writes before updating the writeIndex */ - smp_wmb(); + wmb(); /* Now, update the write location */ hv_set_next_write_location(outring_info, next_write_location); @@ -485,7 +485,7 @@ 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 a220e5746d67..10619b34bd31 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -466,7 +466,7 @@ 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) { /* |