ixgbevf: make the first tx_buffer a repository for most of the skb info
authorEmil Tantilov <emil.s.tantilov@intel.com>
Sat, 18 Jan 2014 02:30:03 +0000 (18:30 -0800)
committerDavid S. Miller <davem@davemloft.net>
Sat, 18 Jan 2014 03:15:10 +0000 (19:15 -0800)
This change makes it so that the first tx_buffer structure acts as a
central storage location for most of the info about the skb we are about
to transmit.

In addition this patch makes tx_flags part of the ixgbevf_tx_buffer struct.
This allows us to use the flags directly from the stucture and as result
removes the tx_flags parameter from some functions. Also as a cleanup
mapped_as_page is folded into tx_flags and some unused flags were removed.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c

index 00684281364089d56631d5a7d4e67a4b54535e7f..bad3219e440f46d6e47cc3e08a6e4180164ac494 100644 (file)
 /* wrapper around a pointer to a socket buffer,
  * so a DMA handle can be stored along with the buffer */
 struct ixgbevf_tx_buffer {
+       union ixgbe_adv_tx_desc *next_to_watch;
+       unsigned long time_stamp;
        struct sk_buff *skb;
+       unsigned int bytecount;
+       unsigned short gso_segs;
+       __be16 protocol;
        dma_addr_t dma;
-       unsigned long time_stamp;
-       union ixgbe_adv_tx_desc *next_to_watch;
+       u32 tx_flags;
        u16 length;
-       u16 mapped_as_page;
 };
 
 struct ixgbevf_rx_buffer {
@@ -144,8 +147,7 @@ struct ixgbevf_ring {
 #define IXGBE_TX_FLAGS_VLAN            (u32)(1 << 1)
 #define IXGBE_TX_FLAGS_TSO             (u32)(1 << 2)
 #define IXGBE_TX_FLAGS_IPV4            (u32)(1 << 3)
-#define IXGBE_TX_FLAGS_FCOE            (u32)(1 << 4)
-#define IXGBE_TX_FLAGS_FSO             (u32)(1 << 5)
+#define IXGBE_TX_FLAGS_MAPPED_AS_PAGE  (u32)(1 << 4)
 #define IXGBE_TX_FLAGS_VLAN_MASK       0xffff0000
 #define IXGBE_TX_FLAGS_VLAN_PRIO_MASK  0x0000e000
 #define IXGBE_TX_FLAGS_VLAN_SHIFT      16
index c2e1ef648137f7ca95fe9cdb3e7ec3262867601d..07a501638bdeccf26662b3b6a5aaaff610f17aa8 100644 (file)
@@ -149,7 +149,7 @@ static void ixgbevf_unmap_and_free_tx_resource(struct ixgbevf_ring *tx_ring,
                                               *tx_buffer_info)
 {
        if (tx_buffer_info->dma) {
-               if (tx_buffer_info->mapped_as_page)
+               if (tx_buffer_info->tx_flags & IXGBE_TX_FLAGS_MAPPED_AS_PAGE)
                        dma_unmap_page(tx_ring->dev,
                                       tx_buffer_info->dma,
                                       tx_buffer_info->length,
@@ -187,20 +187,21 @@ static bool ixgbevf_clean_tx_irq(struct ixgbevf_q_vector *q_vector,
                                 struct ixgbevf_ring *tx_ring)
 {
        struct ixgbevf_adapter *adapter = q_vector->adapter;
-       union ixgbe_adv_tx_desc *tx_desc, *eop_desc;
-       struct ixgbevf_tx_buffer *tx_buffer_info;
-       unsigned int i, count = 0;
+       struct ixgbevf_tx_buffer *tx_buffer;
+       union ixgbe_adv_tx_desc *tx_desc;
        unsigned int total_bytes = 0, total_packets = 0;
+       unsigned int budget = tx_ring->count / 2;
+       unsigned int i = tx_ring->next_to_clean;
 
        if (test_bit(__IXGBEVF_DOWN, &adapter->state))
                return true;
 
-       i = tx_ring->next_to_clean;
-       tx_buffer_info = &tx_ring->tx_buffer_info[i];
-       eop_desc = tx_buffer_info->next_to_watch;
+       tx_buffer = &tx_ring->tx_buffer_info[i];
+       tx_desc = IXGBEVF_TX_DESC(tx_ring, i);
+       i -= tx_ring->count;
 
        do {
-               bool cleaned = false;
+               union ixgbe_adv_tx_desc *eop_desc = tx_buffer->next_to_watch;
 
                /* if next_to_watch is not set then there is no work pending */
                if (!eop_desc)
@@ -214,67 +215,77 @@ static bool ixgbevf_clean_tx_irq(struct ixgbevf_q_vector *q_vector,
                        break;
 
                /* clear next_to_watch to prevent false hangs */
-               tx_buffer_info->next_to_watch = NULL;
+               tx_buffer->next_to_watch = NULL;
 
-               for ( ; !cleaned; count++) {
-                       struct sk_buff *skb;
-                       tx_desc = IXGBEVF_TX_DESC(tx_ring, i);
-                       cleaned = (tx_desc == eop_desc);
-                       skb = tx_buffer_info->skb;
-
-                       if (cleaned && skb) {
-                               unsigned int segs, bytecount;
-
-                               /* gso_segs is currently only valid for tcp */
-                               segs = skb_shinfo(skb)->gso_segs ?: 1;
-                               /* multiply data chunks by size of headers */
-                               bytecount = ((segs - 1) * skb_headlen(skb)) +
-                                           skb->len;
-                               total_packets += segs;
-                               total_bytes += bytecount;
-                       }
+               /* update the statistics for this packet */
+               total_bytes += tx_buffer->bytecount;
+               total_packets += tx_buffer->gso_segs;
 
-                       ixgbevf_unmap_and_free_tx_resource(tx_ring,
-                                                          tx_buffer_info);
+               /* clear tx_buffer data */
+               ixgbevf_unmap_and_free_tx_resource(tx_ring, tx_buffer);
 
+               /* unmap remaining buffers */
+               while (tx_desc != eop_desc) {
                        tx_desc->wb.status = 0;
 
+                       tx_buffer++;
+                       tx_desc++;
                        i++;
-                       if (i == tx_ring->count)
-                               i = 0;
+                       if (unlikely(!i)) {
+                               i -= tx_ring->count;
+                               tx_buffer = tx_ring->tx_buffer_info;
+                               tx_desc = IXGBEVF_TX_DESC(tx_ring, 0);
+                       }
 
-                       tx_buffer_info = &tx_ring->tx_buffer_info[i];
+                       ixgbevf_unmap_and_free_tx_resource(tx_ring, tx_buffer);
                }
 
-               eop_desc = tx_buffer_info->next_to_watch;
-       } while (count < tx_ring->count);
+               tx_desc->wb.status = 0;
 
+               /* move us one more past the eop_desc for start of next pkt */
+               tx_buffer++;
+               tx_desc++;
+               i++;
+               if (unlikely(!i)) {
+                       i -= tx_ring->count;
+                       tx_buffer = tx_ring->tx_buffer_info;
+                       tx_desc = IXGBEVF_TX_DESC(tx_ring, 0);
+               }
+
+               /* issue prefetch for next Tx descriptor */
+               prefetch(tx_desc);
+
+               /* update budget accounting */
+               budget--;
+       } while (likely(budget));
+
+       i += tx_ring->count;
        tx_ring->next_to_clean = i;
+       u64_stats_update_begin(&tx_ring->syncp);
+       tx_ring->stats.bytes += total_bytes;
+       tx_ring->stats.packets += total_packets;
+       u64_stats_update_end(&tx_ring->syncp);
+       q_vector->tx.total_bytes += total_bytes;
+       q_vector->tx.total_packets += total_packets;
 
 #define TX_WAKE_THRESHOLD (DESC_NEEDED * 2)
-       if (unlikely(count && netif_carrier_ok(tx_ring->netdev) &&
+       if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) &&
                     (ixgbevf_desc_unused(tx_ring) >= TX_WAKE_THRESHOLD))) {
                /* Make sure that anybody stopping the queue after this
                 * sees the new next_to_clean.
                 */
                smp_mb();
+
                if (__netif_subqueue_stopped(tx_ring->netdev,
                                             tx_ring->queue_index) &&
                    !test_bit(__IXGBEVF_DOWN, &adapter->state)) {
                        netif_wake_subqueue(tx_ring->netdev,
                                            tx_ring->queue_index);
-                       ++adapter->restart_queue;
+                       ++tx_ring->tx_stats.restart_queue;
                }
        }
 
-       u64_stats_update_begin(&tx_ring->syncp);
-       tx_ring->stats.bytes += total_bytes;
-       tx_ring->stats.packets += total_packets;
-       u64_stats_update_end(&tx_ring->syncp);
-       q_vector->tx.total_bytes += total_bytes;
-       q_vector->tx.total_packets += total_packets;
-
-       return count < tx_ring->count;
+       return !!budget;
 }
 
 /**
@@ -2759,8 +2770,10 @@ static void ixgbevf_tx_ctxtdesc(struct ixgbevf_ring *tx_ring,
 }
 
 static int ixgbevf_tso(struct ixgbevf_ring *tx_ring,
-                      struct sk_buff *skb, u32 tx_flags, u8 *hdr_len)
+                      struct ixgbevf_tx_buffer *first,
+                      u8 *hdr_len)
 {
+       struct sk_buff *skb = first->skb;
        u32 vlan_macip_lens, type_tucmd;
        u32 mss_l4len_idx, l4len;
 
@@ -2785,12 +2798,17 @@ static int ixgbevf_tso(struct ixgbevf_ring *tx_ring,
                                                         IPPROTO_TCP,
                                                         0);
                type_tucmd |= IXGBE_ADVTXD_TUCMD_IPV4;
+               first->tx_flags |= IXGBE_TX_FLAGS_TSO |
+                                  IXGBE_TX_FLAGS_CSUM |
+                                  IXGBE_TX_FLAGS_IPV4;
        } else if (skb_is_gso_v6(skb)) {
                ipv6_hdr(skb)->payload_len = 0;
                tcp_hdr(skb)->check =
                    ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
                                     &ipv6_hdr(skb)->daddr,
                                     0, IPPROTO_TCP, 0);
+               first->tx_flags |= IXGBE_TX_FLAGS_TSO |
+                                  IXGBE_TX_FLAGS_CSUM;
        }
 
        /* compute header lengths */
@@ -2798,6 +2816,10 @@ static int ixgbevf_tso(struct ixgbevf_ring *tx_ring,
        *hdr_len += l4len;
        *hdr_len = skb_transport_offset(skb) + l4len;
 
+       /* update gso size and bytecount with header size */
+       first->gso_segs = skb_shinfo(skb)->gso_segs;
+       first->bytecount += (first->gso_segs - 1) * *hdr_len;
+
        /* mss_l4len_id: use 1 as index for TSO */
        mss_l4len_idx = l4len << IXGBE_ADVTXD_L4LEN_SHIFT;
        mss_l4len_idx |= skb_shinfo(skb)->gso_size << IXGBE_ADVTXD_MSS_SHIFT;
@@ -2806,7 +2828,7 @@ static int ixgbevf_tso(struct ixgbevf_ring *tx_ring,
        /* vlan_macip_lens: HEADLEN, MACLEN, VLAN tag */
        vlan_macip_lens = skb_network_header_len(skb);
        vlan_macip_lens |= skb_network_offset(skb) << IXGBE_ADVTXD_MACLEN_SHIFT;
-       vlan_macip_lens |= tx_flags & IXGBE_TX_FLAGS_VLAN_MASK;
+       vlan_macip_lens |= first->tx_flags & IXGBE_TX_FLAGS_VLAN_MASK;
 
        ixgbevf_tx_ctxtdesc(tx_ring, vlan_macip_lens,
                            type_tucmd, mss_l4len_idx);
@@ -2814,9 +2836,10 @@ static int ixgbevf_tso(struct ixgbevf_ring *tx_ring,
        return 1;
 }
 
-static bool ixgbevf_tx_csum(struct ixgbevf_ring *tx_ring,
-                           struct sk_buff *skb, u32 tx_flags)
+static void ixgbevf_tx_csum(struct ixgbevf_ring *tx_ring,
+                           struct ixgbevf_tx_buffer *first)
 {
+       struct sk_buff *skb = first->skb;
        u32 vlan_macip_lens = 0;
        u32 mss_l4len_idx = 0;
        u32 type_tucmd = 0;
@@ -2837,7 +2860,7 @@ static bool ixgbevf_tx_csum(struct ixgbevf_ring *tx_ring,
                        if (unlikely(net_ratelimit())) {
                                dev_warn(tx_ring->dev,
                                 "partial checksum but proto=%x!\n",
-                                skb->protocol);
+                                first->protocol);
                        }
                        break;
                }
@@ -2865,21 +2888,23 @@ static bool ixgbevf_tx_csum(struct ixgbevf_ring *tx_ring,
                        }
                        break;
                }
+
+               /* update TX checksum flag */
+               first->tx_flags |= IXGBE_TX_FLAGS_CSUM;
        }
 
        /* vlan_macip_lens: MACLEN, VLAN tag */
        vlan_macip_lens |= skb_network_offset(skb) << IXGBE_ADVTXD_MACLEN_SHIFT;
-       vlan_macip_lens |= tx_flags & IXGBE_TX_FLAGS_VLAN_MASK;
+       vlan_macip_lens |= first->tx_flags & IXGBE_TX_FLAGS_VLAN_MASK;
 
        ixgbevf_tx_ctxtdesc(tx_ring, vlan_macip_lens,
                            type_tucmd, mss_l4len_idx);
-
-       return (skb->ip_summed == CHECKSUM_PARTIAL);
 }
 
 static int ixgbevf_tx_map(struct ixgbevf_ring *tx_ring,
-                         struct sk_buff *skb, u32 tx_flags)
+                         struct ixgbevf_tx_buffer *first)
 {
+       struct sk_buff *skb = first->skb;
        struct ixgbevf_tx_buffer *tx_buffer_info;
        unsigned int len;
        unsigned int total = skb->len;
@@ -2897,7 +2922,7 @@ static int ixgbevf_tx_map(struct ixgbevf_ring *tx_ring,
                size = min(len, (unsigned int)IXGBE_MAX_DATA_PER_TXD);
 
                tx_buffer_info->length = size;
-               tx_buffer_info->mapped_as_page = false;
+               tx_buffer_info->tx_flags = first->tx_flags;
                tx_buffer_info->dma = dma_map_single(tx_ring->dev,
                                                     skb->data + offset,
                                                     size, DMA_TO_DEVICE);
@@ -2928,10 +2953,11 @@ static int ixgbevf_tx_map(struct ixgbevf_ring *tx_ring,
                        tx_buffer_info->dma =
                                skb_frag_dma_map(tx_ring->dev, frag,
                                                 offset, size, DMA_TO_DEVICE);
+                       tx_buffer_info->tx_flags |=
+                                               IXGBE_TX_FLAGS_MAPPED_AS_PAGE;
                        if (dma_mapping_error(tx_ring->dev,
                                              tx_buffer_info->dma))
                                goto dma_error;
-                       tx_buffer_info->mapped_as_page = true;
 
                        len -= size;
                        total -= size;
@@ -2949,7 +2975,9 @@ static int ixgbevf_tx_map(struct ixgbevf_ring *tx_ring,
                i = tx_ring->count - 1;
        else
                i = i - 1;
-       tx_ring->tx_buffer_info[i].skb = skb;
+
+       first->next_to_watch = IXGBEVF_TX_DESC(tx_ring, i);
+       first->time_stamp = jiffies;
 
        return count;
 
@@ -2973,13 +3001,15 @@ dma_error:
        return count;
 }
 
-static void ixgbevf_tx_queue(struct ixgbevf_ring *tx_ring, int tx_flags,
-                            int count, unsigned int first, u32 paylen,
-                            u8 hdr_len)
+static void ixgbevf_tx_queue(struct ixgbevf_ring *tx_ring,
+                            struct ixgbevf_tx_buffer *first,
+                            int count, u8 hdr_len)
 {
        union ixgbe_adv_tx_desc *tx_desc = NULL;
+       struct sk_buff *skb = first->skb;
        struct ixgbevf_tx_buffer *tx_buffer_info;
        u32 olinfo_status = 0, cmd_type_len = 0;
+       u32 tx_flags = first->tx_flags;
        unsigned int i;
 
        u32 txd_cmd = IXGBE_TXD_CMD_EOP | IXGBE_TXD_CMD_RS | IXGBE_TXD_CMD_IFCS;
@@ -3009,7 +3039,7 @@ static void ixgbevf_tx_queue(struct ixgbevf_ring *tx_ring, int tx_flags,
         */
        olinfo_status |= IXGBE_ADVTXD_CC;
 
-       olinfo_status |= ((paylen - hdr_len) << IXGBE_ADVTXD_PAYLEN_SHIFT);
+       olinfo_status |= ((skb->len - hdr_len) << IXGBE_ADVTXD_PAYLEN_SHIFT);
 
        i = tx_ring->next_to_use;
        while (count--) {
@@ -3026,16 +3056,6 @@ static void ixgbevf_tx_queue(struct ixgbevf_ring *tx_ring, int tx_flags,
 
        tx_desc->read.cmd_type_len |= cpu_to_le32(txd_cmd);
 
-       tx_ring->tx_buffer_info[first].time_stamp = jiffies;
-
-       /* Force memory writes to complete before letting h/w
-        * know there are new descriptors to fetch.  (Only
-        * applicable for weak-ordered memory model archs,
-        * such as IA-64).
-        */
-       wmb();
-
-       tx_ring->tx_buffer_info[first].next_to_watch = tx_desc;
        tx_ring->next_to_use = i;
 }
 
@@ -3069,22 +3089,23 @@ static int ixgbevf_maybe_stop_tx(struct ixgbevf_ring *tx_ring, int size)
 static int ixgbevf_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 {
        struct ixgbevf_adapter *adapter = netdev_priv(netdev);
+       struct ixgbevf_tx_buffer *first;
        struct ixgbevf_ring *tx_ring;
-       unsigned int first;
-       unsigned int tx_flags = 0;
-       u8 hdr_len = 0;
-       int r_idx = 0, tso;
+       int tso;
+       u32 tx_flags = 0;
        u16 count = TXD_USE_COUNT(skb_headlen(skb));
 #if PAGE_SIZE > IXGBE_MAX_DATA_PER_TXD
        unsigned short f;
 #endif
+       u8 hdr_len = 0;
        u8 *dst_mac = skb_header_pointer(skb, 0, 0, NULL);
+
        if (!dst_mac || is_link_local_ether_addr(dst_mac)) {
                dev_kfree_skb(skb);
                return NETDEV_TX_OK;
        }
 
-       tx_ring = adapter->tx_ring[r_idx];
+       tx_ring = adapter->tx_ring[skb->queue_mapping];
 
        /*
         * need: 1 descriptor per page * PAGE_SIZE/IXGBE_MAX_DATA_PER_TXD,
@@ -3104,35 +3125,47 @@ static int ixgbevf_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
                return NETDEV_TX_BUSY;
        }
 
+       /* record the location of the first descriptor for this packet */
+       first = &tx_ring->tx_buffer_info[tx_ring->next_to_use];
+       first->skb = skb;
+       first->bytecount = skb->len;
+       first->gso_segs = 1;
+
        if (vlan_tx_tag_present(skb)) {
                tx_flags |= vlan_tx_tag_get(skb);
                tx_flags <<= IXGBE_TX_FLAGS_VLAN_SHIFT;
                tx_flags |= IXGBE_TX_FLAGS_VLAN;
        }
 
-       first = tx_ring->next_to_use;
+       /* record initial flags and protocol */
+       first->tx_flags = tx_flags;
+       first->protocol = vlan_get_protocol(skb);
 
-       if (skb->protocol == htons(ETH_P_IP))
-               tx_flags |= IXGBE_TX_FLAGS_IPV4;
-       tso = ixgbevf_tso(tx_ring, skb, tx_flags, &hdr_len);
-       if (tso < 0) {
-               dev_kfree_skb_any(skb);
-               return NETDEV_TX_OK;
-       }
+       tso = ixgbevf_tso(tx_ring, first, &hdr_len);
+       if (tso < 0)
+               goto out_drop;
+       else
+               ixgbevf_tx_csum(tx_ring, first);
 
-       if (tso)
-               tx_flags |= IXGBE_TX_FLAGS_TSO | IXGBE_TX_FLAGS_CSUM;
-       else if (ixgbevf_tx_csum(tx_ring, skb, tx_flags))
-               tx_flags |= IXGBE_TX_FLAGS_CSUM;
+       ixgbevf_tx_queue(tx_ring, first,
+                        ixgbevf_tx_map(tx_ring, first), hdr_len);
 
-       ixgbevf_tx_queue(tx_ring, tx_flags,
-                        ixgbevf_tx_map(tx_ring, skb, tx_flags),
-                        first, skb->len, hdr_len);
+       /* Force memory writes to complete before letting h/w
+        * know there are new descriptors to fetch.  (Only
+        * applicable for weak-ordered memory model archs,
+        * such as IA-64).
+        */
+       wmb();
 
        writel(tx_ring->next_to_use, tx_ring->tail);
-
        ixgbevf_maybe_stop_tx(tx_ring, DESC_NEEDED);
 
+       return NETDEV_TX_OK;
+
+out_drop:
+       dev_kfree_skb_any(first->skb);
+       first->skb = NULL;
+
        return NETDEV_TX_OK;
 }
 
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