From: Lijun Pan ljp@linux.ibm.com
[ Upstream commit 42557dab78edc8235aba5b441f2eb35f725a0ede ]
dma_rmb() barrier is added to load the long term buffer before copying it to socket buffer; and dma_wmb() barrier is added to update the long term buffer before it being accessed by VIOS (virtual i/o server).
Fixes: 032c5e82847a ("Driver for IBM System i/p VNIC protocol") Signed-off-by: Lijun Pan ljp@linux.ibm.com Acked-by: Thomas Falcon tlfalcon@linux.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/ibm/ibmvnic.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 5518b56c2a967..788d944b3b51b 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -1521,6 +1521,9 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) skb_copy_from_linear_data(skb, dst, skb->len); }
+ /* post changes to long_term_buff *dst before VIOS accessing it */ + dma_wmb(); + tx_pool->consumer_index = (tx_pool->consumer_index + 1) % tx_pool->num_buffers;
@@ -2186,6 +2189,8 @@ static int ibmvnic_poll(struct napi_struct *napi, int budget) offset = be16_to_cpu(next->rx_comp.off_frame_data); flags = next->rx_comp.flags; skb = rx_buff->skb; + /* load long_term_buff before copying to skb */ + dma_rmb(); skb_copy_to_linear_data(skb, rx_buff->data + offset, length);