From 42557dab78edc8235aba5b441f2eb35f725a0ede Mon Sep 17 00:00:00 2001 From: Lijun Pan Date: Fri, 12 Feb 2021 20:48:40 -0600 Subject: ibmvnic: add memory barrier to protect long term buffer 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 Acked-by: Thomas Falcon Signed-off-by: David S. Miller --- drivers/net/ethernet/ibm/ibmvnic.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/net/ethernet/ibm') diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 621be6d2da97..f6402a20ba32 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -1700,6 +1700,9 @@ 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; @@ -2539,6 +2542,8 @@ restart_poll: 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); -- cgit v1.2.3