sfc: Implement TSO for TCP/IPv6

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 39 insertions, 13 deletions

diff --git a/drivers/net/sfc/tx.c b/drivers/net/sfc/tx.c
index 389ede43e34a..582fc752da90 100644
--- a/drivers/net/sfc/tx.c
+++ b/drivers/net/sfc/tx.c
@@ -12,6 +12,8 @@
 #include <linux/tcp.h>
 #include <linux/ip.h>
 #include <linux/in.h>
+#include <linux/ipv6.h>
+#include <net/ipv6.h>
 #include <linux/if_ether.h>
 #include <linux/highmem.h>
 #include "net_driver.h"
@@ -531,6 +533,7 @@ void efx_remove_tx_queue(struct efx_tx_queue *tx_queue)
 #define ETH_HDR_LEN(skb)  (skb_network_header(skb) - (skb)->data)
 #define SKB_TCP_OFF(skb)  PTR_DIFF(tcp_hdr(skb), (skb)->data)
 #define SKB_IPV4_OFF(skb) PTR_DIFF(ip_hdr(skb), (skb)->data)
+#define SKB_IPV6_OFF(skb) PTR_DIFF(ipv6_hdr(skb), (skb)->data)
 
 /**
  * struct tso_state - TSO state for an SKB
@@ -543,6 +546,7 @@ void efx_remove_tx_queue(struct efx_tx_queue *tx_queue)
  * @unmap_len: Length of SKB fragment
  * @unmap_addr: DMA address of SKB fragment
  * @unmap_single: DMA single vs page mapping flag
+ * @protocol: Network protocol (after any VLAN header)
  * @header_len: Number of bytes of header
  * @full_packet_size: Number of bytes to put in each outgoing segment
  *
@@ -563,6 +567,7 @@ struct tso_state {
         dma_addr_t unmap_addr;
         bool unmap_single;
 
+        __be16 protocol;
         unsigned header_len;
         int full_packet_size;
 };
@@ -570,9 +575,9 @@ struct tso_state {
 
 /*
  * Verify that our various assumptions about sk_buffs and the conditions
- * under which TSO will be attempted hold true.
+ * under which TSO will be attempted hold true.  Return the protocol number.
  */
-static void efx_tso_check_safe(struct sk_buff *skb)
+static __be16 efx_tso_check_protocol(struct sk_buff *skb)
 {
         __be16 protocol = skb->protocol;
 
@@ -587,13 +592,22 @@ static void efx_tso_check_safe(struct sk_buff *skb)
                 if (protocol == htons(ETH_P_IP))
                         skb_set_transport_header(skb, sizeof(*veh) +
                                                  4 * ip_hdr(skb)->ihl);
+                else if (protocol == htons(ETH_P_IPV6))
+                        skb_set_transport_header(skb, sizeof(*veh) +
+                                                 sizeof(struct ipv6hdr));
         }
 
-        EFX_BUG_ON_PARANOID(protocol != htons(ETH_P_IP));
-        EFX_BUG_ON_PARANOID(ip_hdr(skb)->protocol != IPPROTO_TCP);
+        if (protocol == htons(ETH_P_IP)) {
+                EFX_BUG_ON_PARANOID(ip_hdr(skb)->protocol != IPPROTO_TCP);
+        } else {
+                EFX_BUG_ON_PARANOID(protocol != htons(ETH_P_IPV6));
+                EFX_BUG_ON_PARANOID(ipv6_hdr(skb)->nexthdr != NEXTHDR_TCP);
+        }
         EFX_BUG_ON_PARANOID((PTR_DIFF(tcp_hdr(skb), skb->data)
                              + (tcp_hdr(skb)->doff << 2u)) >
                             skb_headlen(skb));
+
+        return protocol;
 }
 
 
@@ -836,7 +850,10 @@ static void tso_start(struct tso_state *st, const struct sk_buff *skb)
                           + PTR_DIFF(tcp_hdr(skb), skb->data));
         st->full_packet_size = st->header_len + skb_shinfo(skb)->gso_size;
 
-        st->ipv4_id = ntohs(ip_hdr(skb)->id);
+        if (st->protocol == htons(ETH_P_IP))
+                st->ipv4_id = ntohs(ip_hdr(skb)->id);
+        else
+                st->ipv4_id = 0;
         st->seqnum = ntohl(tcp_hdr(skb)->seq);
 
         EFX_BUG_ON_PARANOID(tcp_hdr(skb)->urg);
@@ -951,7 +968,6 @@ static int tso_start_new_packet(struct efx_tx_queue *tx_queue,
                                 struct tso_state *st)
 {
         struct efx_tso_header *tsoh;
-        struct iphdr *tsoh_iph;
         struct tcphdr *tsoh_th;
         unsigned ip_length;
         u8 *header;
@@ -975,7 +991,6 @@ static int tso_start_new_packet(struct efx_tx_queue *tx_queue,
 
         header = TSOH_BUFFER(tsoh);
         tsoh_th = (struct tcphdr *)(header + SKB_TCP_OFF(skb));
-        tsoh_iph = (struct iphdr *)(header + SKB_IPV4_OFF(skb));
 
         /* Copy and update the headers. */
         memcpy(header, skb->data, st->header_len);
@@ -993,11 +1008,22 @@ static int tso_start_new_packet(struct efx_tx_queue *tx_queue,
                 tsoh_th->fin = tcp_hdr(skb)->fin;
                 tsoh_th->psh = tcp_hdr(skb)->psh;
         }
-        tsoh_iph->tot_len = htons(ip_length);
 
-        /* Linux leaves suitable gaps in the IP ID space for us to fill. */
-        tsoh_iph->id = htons(st->ipv4_id);
-        st->ipv4_id++;
+        if (st->protocol == htons(ETH_P_IP)) {
+                struct iphdr *tsoh_iph =
+                        (struct iphdr *)(header + SKB_IPV4_OFF(skb));
+
+                tsoh_iph->tot_len = htons(ip_length);
+
+                /* Linux leaves suitable gaps in the IP ID space for us to fill. */
+                tsoh_iph->id = htons(st->ipv4_id);
+                st->ipv4_id++;
+        } else {
+                struct ipv6hdr *tsoh_iph =
+                        (struct ipv6hdr *)(header + SKB_IPV6_OFF(skb));
+
+                tsoh_iph->payload_len = htons(ip_length - sizeof(*tsoh_iph));
+        }
 
         st->packet_space = skb_shinfo(skb)->gso_size;
         ++tx_queue->tso_packets;
@@ -1027,8 +1053,8 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
         int frag_i, rc, rc2 = NETDEV_TX_OK;
         struct tso_state state;
 
-        /* Verify TSO is safe - these checks should never fail. */
-        efx_tso_check_safe(skb);
+        /* Find the packet protocol and sanity-check it */
+        state.protocol = efx_tso_check_protocol(skb);
 
         EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count);