From: Benjamin Herrenschmidt benh@kernel.crashing.org
[ Upstream commit 88824e3bf29a2fcacfd9ebbfe03063649f0f3254 ]
We are calling the checksum helper after the dma_map_single() call to map the packet. This is incorrect as the checksumming code will touch the packet from the CPU. This means the cache won't be properly flushes (or the bounce buffering will leave us with the unmodified packet to DMA).
This moves the calculation of the checksum & vlan tags to before the DMA mapping.
This also has the side effect of fixing another bug: If the checksum helper fails, we goto "drop" to drop the packet, which will not unmap the DMA mapping.
Signed-off-by: Benjamin Herrenschmidt benh@kernel.crashing.org Fixes: 05690d633f30 ("ftgmac100: Upgrade to NETIF_F_HW_CSUM") Reviewed-by: Vijay Khemka vijaykhemka@fb.com Tested-by: Vijay Khemka vijaykhemka@fb.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/faraday/ftgmac100.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-)
--- a/drivers/net/ethernet/faraday/ftgmac100.c +++ b/drivers/net/ethernet/faraday/ftgmac100.c @@ -726,6 +726,18 @@ static netdev_tx_t ftgmac100_hard_start_ */ nfrags = skb_shinfo(skb)->nr_frags;
+ /* Setup HW checksumming */ + csum_vlan = 0; + if (skb->ip_summed == CHECKSUM_PARTIAL && + !ftgmac100_prep_tx_csum(skb, &csum_vlan)) + goto drop; + + /* Add VLAN tag */ + if (skb_vlan_tag_present(skb)) { + csum_vlan |= FTGMAC100_TXDES1_INS_VLANTAG; + csum_vlan |= skb_vlan_tag_get(skb) & 0xffff; + } + /* Get header len */ len = skb_headlen(skb);
@@ -752,19 +764,6 @@ static netdev_tx_t ftgmac100_hard_start_ if (nfrags == 0) f_ctl_stat |= FTGMAC100_TXDES0_LTS; txdes->txdes3 = cpu_to_le32(map); - - /* Setup HW checksumming */ - csum_vlan = 0; - if (skb->ip_summed == CHECKSUM_PARTIAL && - !ftgmac100_prep_tx_csum(skb, &csum_vlan)) - goto drop; - - /* Add VLAN tag */ - if (skb_vlan_tag_present(skb)) { - csum_vlan |= FTGMAC100_TXDES1_INS_VLANTAG; - csum_vlan |= skb_vlan_tag_get(skb) & 0xffff; - } - txdes->txdes1 = cpu_to_le32(csum_vlan);
/* Next descriptor */