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author | Tyrel Datwyler <tyreld@linux.vnet.ibm.com> | 2016-12-07 17:31:26 -0600 |
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committer | Martin K. Petersen <martin.petersen@oracle.com> | 2016-12-08 17:04:25 -0500 |
commit | b39205d248b9c3ce0548859ed786badb2e0db0bd (patch) | |
tree | c3b9fce151e5c5029497a7c5ff45144927e86390 | |
parent | 15c9274699e8b6dd4bfd7a205c0dc06653e6400d (diff) | |
download | linux-b39205d248b9c3ce0548859ed786badb2e0db0bd.tar.gz linux-b39205d248b9c3ce0548859ed786badb2e0db0bd.tar.bz2 linux-b39205d248b9c3ce0548859ed786badb2e0db0bd.zip |
scsi: ibmvscsi: add write memory barrier to CRQ processing
The first byte of each CRQ entry is used to indicate whether an entry is
a valid response or free for the VIOS to use. After processing a
response the driver sets the valid byte to zero to indicate the entry is
now free to be reused. Add a memory barrier after this write to ensure
no other stores are reordered when updating the valid byte.
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
-rw-r--r-- | drivers/scsi/ibmvscsi/ibmvscsi.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c index 7752656c3d21..50cd01165e35 100644 --- a/drivers/scsi/ibmvscsi/ibmvscsi.c +++ b/drivers/scsi/ibmvscsi/ibmvscsi.c @@ -233,6 +233,7 @@ static void ibmvscsi_task(void *data) while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) { ibmvscsi_handle_crq(crq, hostdata); crq->valid = VIOSRP_CRQ_FREE; + wmb(); } vio_enable_interrupts(vdev); @@ -241,6 +242,7 @@ static void ibmvscsi_task(void *data) vio_disable_interrupts(vdev); ibmvscsi_handle_crq(crq, hostdata); crq->valid = VIOSRP_CRQ_FREE; + wmb(); } else { done = 1; } |