ibmvnic: Ensure that CRQ entry read are correctly ordered

Ensure that received Command-Response Queue (CRQ) entries are
properly read in order by the driver. dma_rmb barrier has
been added before accessing the CRQ descriptor to ensure
the entire descriptor is read before processing.

Fixes: 032c5e8284 ("Driver for IBM System i/p VNIC protocol")
Signed-off-by: Lijun Pan <ljp@linux.ibm.com>
Link: https://lore.kernel.org/r/20210128013442.88319-1-ljp@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Lijun Pan 2021-01-27 19:34:42 -06:00 committed by Jakub Kicinski
parent 0f764eec3e
commit e41aec79e6
1 changed files with 6 additions and 0 deletions

View File

@ -5084,6 +5084,12 @@ static void ibmvnic_tasklet(struct tasklet_struct *t)
while (!done) {
/* Pull all the valid messages off the CRQ */
while ((crq = ibmvnic_next_crq(adapter)) != NULL) {
/* This barrier makes sure ibmvnic_next_crq()'s
* crq->generic.first & IBMVNIC_CRQ_CMD_RSP is loaded
* before ibmvnic_handle_crq()'s
* switch(gen_crq->first) and switch(gen_crq->cmd).
*/
dma_rmb();
ibmvnic_handle_crq(crq, adapter);
crq->generic.first = 0;
}