@@ -2403,6 +2403,12 @@ static int ibmvnic_poll(struct napi_struct *napi, int budget)
if (!pending_scrq(adapter, adapter->rx_scrq[scrq_num]))
break;
+ /* The queue entry at the current index is peeked at above
+ * to determine that there is a valid descriptor awaiting
+ * processing. We want to be sure that the current slot
+ * holds a valid descriptor before reading its contents.
+ */
+ dma_rmb();
next = ibmvnic_next_scrq(adapter, adapter->rx_scrq[scrq_num]);
rx_buff =
(struct ibmvnic_rx_buff *)be64_to_cpu(next->
@@ -3098,6 +3104,13 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter,
unsigned int pool = scrq->pool_index;
int num_entries = 0;
+ /* The queue entry at the current index is peeked at above
+ * to determine that there is a valid descriptor awaiting
+ * processing. We want to be sure that the current slot
+ * holds a valid descriptor before reading its contents.
+ */
+ dma_rmb();
+
next = ibmvnic_next_scrq(adapter, scrq);
for (i = 0; i < next->tx_comp.num_comps; i++) {
if (next->tx_comp.rcs[i]) {
@@ -3498,6 +3511,11 @@ static union sub_crq *ibmvnic_next_scrq(struct ibmvnic_adapter *adapter,
}
spin_unlock_irqrestore(&scrq->lock, flags);
+ /* Ensure that the entire buffer descriptor has been
+ * loaded before reading its contents
+ */
+ dma_rmb();
+
return entry;
}
Ensure that received Subordinate Command-Response Queue (SCRQ) entries are properly read in order by the driver. These queues are used in the ibmvnic device to process RX buffer and TX completion descriptors. dma_rmb barriers have been added after checking for a pending descriptor to ensure the correct descriptor entry is checked and after reading the SCRQ descriptor to ensure the entire descriptor is read before processing. Fixes: 032c5e828 ("Driver for IBM System i/p VNIC protocol") Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com> --- drivers/net/ethernet/ibm/ibmvnic.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)