sfc: Fold tso_get_head_fragment() into tso_start()

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
index 2ac91c5b5eeae4e7a210e5b3693c9f01a04c9f9c..9025356969289508196a3af15f25555bf93ca7b0 100644 (file)
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -822,11 +822,17 @@ static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue)
 
 
 /* Parse the SKB header and initialise state. */
-static void tso_start(struct tso_state *st, const struct sk_buff *skb)
+static int tso_start(struct tso_state *st, struct efx_nic *efx,
+                    const struct sk_buff *skb)
 {
+       unsigned int header_len, in_len;
+
        st->ip_off = skb_network_header(skb) - skb->data;
        st->tcp_off = skb_transport_header(skb) - skb->data;
-       st->header_len = st->tcp_off + (tcp_hdr(skb)->doff << 2u);
+       header_len = st->tcp_off + (tcp_hdr(skb)->doff << 2u);
+       in_len = skb_headlen(skb) - header_len;
+       st->header_len = header_len;
+       st->in_len = in_len;
        if (st->protocol == htons(ETH_P_IP)) {
                st->ip_base_len = st->header_len - st->ip_off;
                st->ipv4_id = ntohs(ip_hdr(skb)->id);
@@ -840,9 +846,24 @@ static void tso_start(struct tso_state *st, const struct sk_buff *skb)
        EFX_BUG_ON_PARANOID(tcp_hdr(skb)->syn);
        EFX_BUG_ON_PARANOID(tcp_hdr(skb)->rst);
 
-       st->out_len = skb->len - st->header_len;
-       st->unmap_len = 0;
-       st->dma_flags = 0;
+       st->out_len = skb->len - header_len;
+
+       if (likely(in_len == 0)) {
+               st->unmap_len = 0;
+               st->dma_flags = 0;
+               return 0;
+       }
+
+       st->unmap_addr = dma_map_single(&efx->pci_dev->dev,
+                                       skb->data + header_len, in_len,
+                                       DMA_TO_DEVICE);
+       if (unlikely(dma_mapping_error(&efx->pci_dev->dev, st->unmap_addr)))
+               return -ENOMEM;
+
+       st->dma_flags = EFX_TX_BUF_MAP_SINGLE;
+       st->unmap_len = in_len;
+       st->dma_addr = st->unmap_addr;
+       return 0;
 }
 
 static int tso_get_fragment(struct tso_state *st, struct efx_nic *efx,
@@ -860,24 +881,6 @@ static int tso_get_fragment(struct tso_state *st, struct efx_nic *efx,
        return -ENOMEM;
 }
 
-static int tso_get_head_fragment(struct tso_state *st, struct efx_nic *efx,
-                                const struct sk_buff *skb)
-{
-       int hl = st->header_len;
-       int len = skb_headlen(skb) - hl;
-
-       st->unmap_addr = dma_map_single(&efx->pci_dev->dev, skb->data + hl,
-                                       len, DMA_TO_DEVICE);
-       if (likely(!dma_mapping_error(&efx->pci_dev->dev, st->unmap_addr))) {
-               st->dma_flags = EFX_TX_BUF_MAP_SINGLE;
-               st->unmap_len = len;
-               st->in_len = len;
-               st->dma_addr = st->unmap_addr;
-               return 0;
-       }
-       return -ENOMEM;
-}
-
 
 /**
  * tso_fill_packet_with_fragment - form descriptors for the current fragment
@@ -1023,12 +1026,11 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
 
        EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count);
 
-       tso_start(&state, skb);
+       rc = tso_start(&state, efx, skb);
+       if (rc)
+               goto mem_err;
 
-       /* Assume that skb header area contains exactly the headers, and
-        * all payload is in the frag list.
-        */
-       if (skb_headlen(skb) == state.header_len) {
+       if (likely(state.in_len == 0)) {
                /* Grab the first payload fragment. */
                EFX_BUG_ON_PARANOID(skb_shinfo(skb)->nr_frags < 1);
                frag_i = 0;
@@ -1037,9 +1039,7 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
                if (rc)
                        goto mem_err;
        } else {
-               rc = tso_get_head_fragment(&state, efx, skb);
-               if (rc)
-                       goto mem_err;
+               /* Payload starts in the header area. */
                frag_i = -1;
        }