myri10ge: add IPv6 TSO support

Add support for IPv6 TSO to the myri10ge driver.

Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 79 insertions, 8 deletions

diff --git a/drivers/net/myri10ge/myri10ge.c b/drivers/net/myri10ge/myri10ge.c
index 5c103128e248..6d5af080d7d5 100644
--- a/drivers/net/myri10ge/myri10ge.c
+++ b/drivers/net/myri10ge/myri10ge.c
@@ -214,6 +214,8 @@ struct myri10ge_priv {
         unsigned long serial_number;
         int vendor_specific_offset;
         int fw_multicast_support;
+        unsigned long features;
+        u32 max_tso6;
         u32 read_dma;
         u32 write_dma;
         u32 read_write_dma;
@@ -311,6 +313,7 @@ MODULE_PARM_DESC(myri10ge_wcfifo, "Enable WC Fifo when WC is enabled\n");
 #define myri10ge_pio_copy(to,from,size) __iowrite64_copy(to,from,size/8)
 
 static void myri10ge_set_multicast_list(struct net_device *dev);
+static int myri10ge_sw_tso(struct sk_buff *skb, struct net_device *dev);
 
 static inline void put_be32(__be32 val, __be32 __iomem * p)
 {
@@ -612,6 +615,7 @@ static int myri10ge_load_firmware(struct myri10ge_priv *mgp)
         __be32 buf[16];
         u32 dma_low, dma_high, size;
         int status, i;
+        struct myri10ge_cmd cmd;
 
         size = 0;
         status = myri10ge_load_hotplug_firmware(mgp, &size);
@@ -688,6 +692,14 @@ static int myri10ge_load_firmware(struct myri10ge_priv *mgp)
         dev_info(&mgp->pdev->dev, "handoff confirmed\n");
         myri10ge_dummy_rdma(mgp, 1);
 
+        /* probe for IPv6 TSO support */
+        mgp->features = NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_TSO;
+        status = myri10ge_send_cmd(mgp, MXGEFW_CMD_GET_MAX_TSO6_HDR_SIZE,
+                                   &cmd, 0);
+        if (status == 0) {
+                mgp->max_tso6 = cmd.data0;
+                mgp->features |= NETIF_F_TSO6;
+        }
         return 0;
 }
 
@@ -1384,6 +1396,18 @@ static int myri10ge_set_rx_csum(struct net_device *netdev, u32 csum_enabled)
         return 0;
 }
 
+static int myri10ge_set_tso(struct net_device *netdev, u32 tso_enabled)
+{
+        struct myri10ge_priv *mgp = netdev_priv(netdev);
+        unsigned long flags = mgp->features & (NETIF_F_TSO6 | NETIF_F_TSO);
+
+        if (tso_enabled)
+                netdev->features |= flags;
+        else
+                netdev->features &= ~flags;
+        return 0;
+}
+
 static const char myri10ge_gstrings_stats[][ETH_GSTRING_LEN] = {
         "rx_packets", "tx_packets", "rx_bytes", "tx_bytes", "rx_errors",
         "tx_errors", "rx_dropped", "tx_dropped", "multicast", "collisions",
@@ -1508,7 +1532,7 @@ static const struct ethtool_ops myri10ge_ethtool_ops = {
         .set_rx_csum = myri10ge_set_rx_csum,
         .set_tx_csum = ethtool_op_set_tx_hw_csum,
         .set_sg = ethtool_op_set_sg,
-        .set_tso = ethtool_op_set_tso,
+        .set_tso = myri10ge_set_tso,
         .get_link = ethtool_op_get_link,
         .get_strings = myri10ge_get_strings,
         .get_sset_count = myri10ge_get_sset_count,
@@ -2166,7 +2190,8 @@ again:
                 pseudo_hdr_offset = cksum_offset + skb->csum_offset;
                 /* If the headers are excessively large, then we must
                  * fall back to a software checksum */
-                if (unlikely(cksum_offset > 255 || pseudo_hdr_offset > 127)) {
+                if (unlikely(!mss && (cksum_offset > 255 ||
+                                      pseudo_hdr_offset > 127))) {
                         if (skb_checksum_help(skb))
                                 goto drop;
                         cksum_offset = 0;
@@ -2186,9 +2211,18 @@ again:
                 /* negative cum_len signifies to the
                  * send loop that we are still in the
                  * header portion of the TSO packet.
-                 * TSO header must be at most 134 bytes long */
+                 * TSO header can be at most 1KB long */
                 cum_len = -(skb_transport_offset(skb) + tcp_hdrlen(skb));
 
+                /* for IPv6 TSO, the checksum offset stores the
+                 * TCP header length, to save the firmware from
+                 * the need to parse the headers */
+                if (skb_is_gso_v6(skb)) {
+                        cksum_offset = tcp_hdrlen(skb);
+                        /* Can only handle headers <= max_tso6 long */
+                        if (unlikely(-cum_len > mgp->max_tso6))
+                                return myri10ge_sw_tso(skb, dev);
+                }
                 /* for TSO, pseudo_hdr_offset holds mss.
                  * The firmware figures out where to put
                  * the checksum by parsing the header. */
@@ -2303,10 +2337,12 @@ again:
                         req++;
                         count++;
                         rdma_count++;
-                        if (unlikely(cksum_offset > seglen))
-                                cksum_offset -= seglen;
-                        else
-                                cksum_offset = 0;
+                        if (cksum_offset != 0 && !(mss && skb_is_gso_v6(skb))) {
+                                if (unlikely(cksum_offset > seglen))
+                                        cksum_offset -= seglen;
+                                else
+                                        cksum_offset = 0;
+                        }
                 }
                 if (frag_idx == frag_cnt)
                         break;
@@ -2389,6 +2425,41 @@ drop:
 
 }
 
+static int myri10ge_sw_tso(struct sk_buff *skb, struct net_device *dev)
+{
+        struct sk_buff *segs, *curr;
+        struct myri10ge_priv *mgp = dev->priv;
+        int status;
+
+        segs = skb_gso_segment(skb, dev->features & ~NETIF_F_TSO6);
+        if (unlikely(IS_ERR(segs)))
+                goto drop;
+
+        while (segs) {
+                curr = segs;
+                segs = segs->next;
+                curr->next = NULL;
+                status = myri10ge_xmit(curr, dev);
+                if (status != 0) {
+                        dev_kfree_skb_any(curr);
+                        if (segs != NULL) {
+                                curr = segs;
+                                segs = segs->next;
+                                curr->next = NULL;
+                                dev_kfree_skb_any(segs);
+                        }
+                        goto drop;
+                }
+        }
+        dev_kfree_skb_any(skb);
+        return 0;
+
+drop:
+        dev_kfree_skb_any(skb);
+        mgp->stats.tx_dropped += 1;
+        return 0;
+}
+
 static struct net_device_stats *myri10ge_get_stats(struct net_device *dev)
 {
         struct myri10ge_priv *mgp = netdev_priv(dev);
@@ -3076,7 +3147,7 @@ static int myri10ge_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
         netdev->change_mtu = myri10ge_change_mtu;
         netdev->set_multicast_list = myri10ge_set_multicast_list;
         netdev->set_mac_address = myri10ge_set_mac_address;
-        netdev->features = NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_TSO;
+        netdev->features = mgp->features;
         if (dac_enabled)
                 netdev->features |= NETIF_F_HIGHDMA;