diff options
Diffstat (limited to 'drivers/net/ethernet/cortina/gemini.c')
| -rw-r--r-- | drivers/net/ethernet/cortina/gemini.c | 37 |
1 files changed, 29 insertions, 8 deletions
diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c index 517a15904fb0..6a2004bbe87f 100644 --- a/drivers/net/ethernet/cortina/gemini.c +++ b/drivers/net/ethernet/cortina/gemini.c @@ -1144,6 +1144,7 @@ static int gmac_map_tx_bufs(struct net_device *netdev, struct sk_buff *skb, struct gmac_txdesc *txd; skb_frag_t *skb_frag; dma_addr_t mapping; + bool tcp = false; void *buffer; u16 mss; int ret; @@ -1151,6 +1152,13 @@ static int gmac_map_tx_bufs(struct net_device *netdev, struct sk_buff *skb, word1 = skb->len; word3 = SOF_BIT; + /* Determine if we are doing TCP */ + if (skb->protocol == htons(ETH_P_IP)) + tcp = (ip_hdr(skb)->protocol == IPPROTO_TCP); + else + /* IPv6 */ + tcp = (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP); + mss = skb_shinfo(skb)->gso_size; if (mss) { /* This means we are dealing with TCP and skb->len is the @@ -1163,8 +1171,26 @@ static int gmac_map_tx_bufs(struct net_device *netdev, struct sk_buff *skb, mss, skb->len); word1 |= TSS_MTU_ENABLE_BIT; word3 |= mss; + } else if (tcp) { + /* Even if we are not using TSO, use the hardware offloader + * for transferring the TCP frame: this hardware has partial + * TCP awareness (called TOE - TCP Offload Engine) and will + * according to the datasheet put packets belonging to the + * same TCP connection in the same queue for the TOE/TSO + * engine to process. The engine will deal with chopping + * up frames that exceed ETH_DATA_LEN which the + * checksumming engine cannot handle (see below) into + * manageable chunks. It flawlessly deals with quite big + * frames and frames containing custom DSA EtherTypes. + */ + mss = netdev->mtu + skb_tcp_all_headers(skb); + mss = min(mss, skb->len); + netdev_dbg(netdev, "TOE/TSO len %04x mtu %04x mss %04x\n", + skb->len, netdev->mtu, mss); + word1 |= TSS_MTU_ENABLE_BIT; + word3 |= mss; } else if (skb->len >= ETH_FRAME_LEN) { - /* Hardware offloaded checksumming isn't working on frames + /* Hardware offloaded checksumming isn't working on non-TCP frames * bigger than 1514 bytes. A hypothesis about this is that the * checksum buffer is only 1518 bytes, so when the frames get * bigger they get truncated, or the last few bytes get @@ -1181,21 +1207,16 @@ static int gmac_map_tx_bufs(struct net_device *netdev, struct sk_buff *skb, } if (skb->ip_summed == CHECKSUM_PARTIAL) { - int tcp = 0; - /* We do not switch off the checksumming on non TCP/UDP * frames: as is shown from tests, the checksumming engine * is smart enough to see that a frame is not actually TCP * or UDP and then just pass it through without any changes * to the frame. */ - if (skb->protocol == htons(ETH_P_IP)) { + if (skb->protocol == htons(ETH_P_IP)) word1 |= TSS_IP_CHKSUM_BIT; - tcp = ip_hdr(skb)->protocol == IPPROTO_TCP; - } else { /* IPv6 */ + else word1 |= TSS_IPV6_ENABLE_BIT; - tcp = ipv6_hdr(skb)->nexthdr == IPPROTO_TCP; - } word1 |= tcp ? TSS_TCP_CHKSUM_BIT : TSS_UDP_CHKSUM_BIT; } |