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: 032c5e82847a ("Driver for IBM System i/p VNIC protocol")
Signed-off-by: Lijun Pan <l...@linux.ibm.com>
---
v2: drop dma_wmb according to Jakub's opinion
drivers/net/ethernet/ibm/ibmvnic.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c
b/drivers/net/ethernet/ibm/ibmvnic.c
index 9778c83150f1..d84369bd5fc9 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -5084,6 +5084,14 @@ 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) {
+ /* Ensure that the entire CRQ descriptor queue->msgs
+ * has been loaded before reading its contents.
+ * 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;
}
--
2.23.0
