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ibmvnic: add memory barrier to protect long term buffer

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[ 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>
This commit is contained in:
Lijun Pan 2021-02-12 20:48:40 -06:00 committed by Greg Kroah-Hartman
parent 8022d52a10
commit 64a87b0b65
1 changed files with 5 additions and 0 deletions
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5
drivers/net/ethernet/ibm/ibmvnic.c
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@ -1518,6 +1518,9 @@ 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;
@ -2340,6 +2343,8 @@ 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);