qlcnic: Code optimization patch

Optimized code resulted in achieving lower CPU utilization on transmit path
and higher throughput for small packet sizes (64 bytes).

Signed-off-by: Anirban Chakraborty <anirban.chakraborty@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/qlcnic/qlcnic.h b/drivers/net/qlcnic/qlcnic.h
index 15d950a..a5b28d1 100644 (file)
--- a/drivers/net/qlcnic/qlcnic.h
+++ b/drivers/net/qlcnic/qlcnic.h
@@ -434,50 +434,49 @@ struct qlcnic_adapter_stats {
  * be one Rcv Descriptor for normal packets, one for jumbo and may be others.
  */
 struct qlcnic_host_rds_ring {
-       u32 producer;
+       void __iomem *crb_rcv_producer;
+       struct rcv_desc *desc_head;
+       struct qlcnic_rx_buffer *rx_buf_arr;
        u32 num_desc;
+       u32 producer;
        u32 dma_size;
        u32 skb_size;
        u32 flags;
-       void __iomem *crb_rcv_producer;
-       struct rcv_desc *desc_head;
-       struct qlcnic_rx_buffer *rx_buf_arr;
        struct list_head free_list;
        spinlock_t lock;
        dma_addr_t phys_addr;
-};
+} ____cacheline_internodealigned_in_smp;
 
 struct qlcnic_host_sds_ring {
        u32 consumer;
        u32 num_desc;
        void __iomem *crb_sts_consumer;
-       void __iomem *crb_intr_mask;
 
        struct status_desc *desc_head;
        struct qlcnic_adapter *adapter;
        struct napi_struct napi;
        struct list_head free_list[NUM_RCV_DESC_RINGS];
 
+       void __iomem *crb_intr_mask;
        int irq;
 
        dma_addr_t phys_addr;
        char name[IFNAMSIZ+4];
-};
+} ____cacheline_internodealigned_in_smp;
 
 struct qlcnic_host_tx_ring {
        u32 producer;
-       __le32 *hw_consumer;
        u32 sw_consumer;
-       void __iomem *crb_cmd_producer;
        u32 num_desc;
-
-       struct netdev_queue *txq;
-
-       struct qlcnic_cmd_buffer *cmd_buf_arr;
+       void __iomem *crb_cmd_producer;
        struct cmd_desc_type0 *desc_head;
+       struct qlcnic_cmd_buffer *cmd_buf_arr;
+       __le32 *hw_consumer;
+
        dma_addr_t phys_addr;
        dma_addr_t hw_cons_phys_addr;
-};
+       struct netdev_queue *txq;
+} ____cacheline_internodealigned_in_smp;
 
 /*
  * Receive context. There is one such structure per instance of the
@@ -1328,8 +1327,7 @@ static const struct qlcnic_brdinfo qlcnic_boards[] = {
 
 static inline u32 qlcnic_tx_avail(struct qlcnic_host_tx_ring *tx_ring)
 {
-       smp_mb();
-       if (tx_ring->producer < tx_ring->sw_consumer)
+       if (likely(tx_ring->producer < tx_ring->sw_consumer))
                return tx_ring->sw_consumer - tx_ring->producer;
        else
                return tx_ring->sw_consumer + tx_ring->num_desc -

diff --git a/drivers/net/qlcnic/qlcnic_main.c b/drivers/net/qlcnic/qlcnic_main.c
index dde7e44..3b740f5 100644 (file)
--- a/drivers/net/qlcnic/qlcnic_main.c
+++ b/drivers/net/qlcnic/qlcnic_main.c
@@ -1861,6 +1861,7 @@ static void qlcnic_change_filter(struct qlcnic_adapter *adapter,
        vlan_req->vlan_id = vlan_id;
 
        tx_ring->producer = get_next_index(producer, tx_ring->num_desc);
+       smp_mb();
 }
 
 #define QLCNIC_MAC_HASH(MAC)\
@@ -1921,58 +1922,122 @@ qlcnic_send_filter(struct qlcnic_adapter *adapter,
        spin_unlock(&adapter->mac_learn_lock);
 }
 
-static void
-qlcnic_tso_check(struct net_device *netdev,
-               struct qlcnic_host_tx_ring *tx_ring,
+static int
+qlcnic_tx_pkt(struct qlcnic_adapter *adapter,
                struct cmd_desc_type0 *first_desc,
                struct sk_buff *skb)
 {
-       u8 opcode = TX_ETHER_PKT;
-       __be16 protocol = skb->protocol;
-       u16 flags = 0;
-       int copied, offset, copy_len, hdr_len = 0, tso = 0;
+       u8 opcode = 0, hdr_len = 0;
+       u16 flags = 0, vlan_tci = 0;
+       int copied, offset, copy_len;
        struct cmd_desc_type0 *hwdesc;
        struct vlan_ethhdr *vh;
-       struct qlcnic_adapter *adapter = netdev_priv(netdev);
+       struct qlcnic_host_tx_ring *tx_ring = adapter->tx_ring;
+       u16 protocol = ntohs(skb->protocol);
        u32 producer = tx_ring->producer;
-       __le16 vlan_oob = first_desc->flags_opcode &
-                               cpu_to_le16(FLAGS_VLAN_OOB);
+
+       if (protocol == ETH_P_8021Q) {
+               vh = (struct vlan_ethhdr *)skb->data;
+               flags = FLAGS_VLAN_TAGGED;
+               vlan_tci = vh->h_vlan_TCI;
+       } else if (vlan_tx_tag_present(skb)) {
+               flags = FLAGS_VLAN_OOB;
+               vlan_tci = vlan_tx_tag_get(skb);
+       }
+       if (unlikely(adapter->pvid)) {
+               if (vlan_tci && !(adapter->flags & QLCNIC_TAGGING_ENABLED))
+                       return -EIO;
+               if (vlan_tci && (adapter->flags & QLCNIC_TAGGING_ENABLED))
+                       goto set_flags;
+
+               flags = FLAGS_VLAN_OOB;
+               vlan_tci = adapter->pvid;
+       }
+set_flags:
+       qlcnic_set_tx_vlan_tci(first_desc, vlan_tci);
+       qlcnic_set_tx_flags_opcode(first_desc, flags, opcode);
 
        if (*(skb->data) & BIT_0) {
                flags |= BIT_0;
                memcpy(&first_desc->eth_addr, skb->data, ETH_ALEN);
        }
-
-       if ((netdev->features & (NETIF_F_TSO | NETIF_F_TSO6)) &&
+       opcode = TX_ETHER_PKT;
+       if ((adapter->netdev->features & (NETIF_F_TSO | NETIF_F_TSO6)) &&
                        skb_shinfo(skb)->gso_size > 0) {
 
                hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
 
                first_desc->mss = cpu_to_le16(skb_shinfo(skb)->gso_size);
                first_desc->total_hdr_length = hdr_len;
-               if (vlan_oob) {
+
+               opcode = (protocol == ETH_P_IPV6) ? TX_TCP_LSO6 : TX_TCP_LSO;
+
+               /* For LSO, we need to copy the MAC/IP/TCP headers into
+               * the descriptor ring */
+               copied = 0;
+               offset = 2;
+
+               if (flags & FLAGS_VLAN_OOB) {
                        first_desc->total_hdr_length += VLAN_HLEN;
                        first_desc->tcp_hdr_offset = VLAN_HLEN;
                        first_desc->ip_hdr_offset = VLAN_HLEN;
                        /* Only in case of TSO on vlan device */
                        flags |= FLAGS_VLAN_TAGGED;
+
+                       /* Create a TSO vlan header template for firmware */
+
+                       hwdesc = &tx_ring->desc_head[producer];
+                       tx_ring->cmd_buf_arr[producer].skb = NULL;
+
+                       copy_len = min((int)sizeof(struct cmd_desc_type0) -
+                               offset, hdr_len + VLAN_HLEN);
+
+                       vh = (struct vlan_ethhdr *)((char *) hwdesc + 2);
+                       skb_copy_from_linear_data(skb, vh, 12);
+                       vh->h_vlan_proto = htons(ETH_P_8021Q);
+                       vh->h_vlan_TCI = htons(vlan_tci);
+
+                       skb_copy_from_linear_data_offset(skb, 12,
+                               (char *)vh + 16, copy_len - 16);
+
+                       copied = copy_len - VLAN_HLEN;
+                       offset = 0;
+
+                       producer = get_next_index(producer, tx_ring->num_desc);
                }
 
-               opcode = (protocol == cpu_to_be16(ETH_P_IPV6)) ?
-                               TX_TCP_LSO6 : TX_TCP_LSO;
-               tso = 1;
+               while (copied < hdr_len) {
+
+                       copy_len = min((int)sizeof(struct cmd_desc_type0) -
+                               offset, (hdr_len - copied));
+
+                       hwdesc = &tx_ring->desc_head[producer];
+                       tx_ring->cmd_buf_arr[producer].skb = NULL;
+
+                       skb_copy_from_linear_data_offset(skb, copied,
+                                (char *) hwdesc + offset, copy_len);
+
+                       copied += copy_len;
+                       offset = 0;
+
+                       producer = get_next_index(producer, tx_ring->num_desc);
+               }
+
+               tx_ring->producer = producer;
+               smp_mb();
+               adapter->stats.lso_frames++;
 
        } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
                u8 l4proto;
 
-               if (protocol == cpu_to_be16(ETH_P_IP)) {
+               if (protocol == ETH_P_IP) {
                        l4proto = ip_hdr(skb)->protocol;
 
                        if (l4proto == IPPROTO_TCP)
                                opcode = TX_TCP_PKT;
                        else if (l4proto == IPPROTO_UDP)
                                opcode = TX_UDP_PKT;
-               } else if (protocol == cpu_to_be16(ETH_P_IPV6)) {
+               } else if (protocol == ETH_P_IPV6) {
                        l4proto = ipv6_hdr(skb)->nexthdr;
 
                        if (l4proto == IPPROTO_TCP)
@@ -1981,63 +2046,11 @@ qlcnic_tso_check(struct net_device *netdev,
                                opcode = TX_UDPV6_PKT;
                }
        }
-
        first_desc->tcp_hdr_offset += skb_transport_offset(skb);
        first_desc->ip_hdr_offset += skb_network_offset(skb);
        qlcnic_set_tx_flags_opcode(first_desc, flags, opcode);
 
-       if (!tso)
-               return;
-
-       /* For LSO, we need to copy the MAC/IP/TCP headers into
-        * the descriptor ring
-        */
-       copied = 0;
-       offset = 2;
-
-       if (vlan_oob) {
-               /* Create a TSO vlan header template for firmware */
-
-               hwdesc = &tx_ring->desc_head[producer];
-               tx_ring->cmd_buf_arr[producer].skb = NULL;
-
-               copy_len = min((int)sizeof(struct cmd_desc_type0) - offset,
-                               hdr_len + VLAN_HLEN);
-
-               vh = (struct vlan_ethhdr *)((char *)hwdesc + 2);
-               skb_copy_from_linear_data(skb, vh, 12);
-               vh->h_vlan_proto = htons(ETH_P_8021Q);
-               vh->h_vlan_TCI = (__be16)swab16((u16)first_desc->vlan_TCI);
-
-               skb_copy_from_linear_data_offset(skb, 12,
-                               (char *)vh + 16, copy_len - 16);
-
-               copied = copy_len - VLAN_HLEN;
-               offset = 0;
-
-               producer = get_next_index(producer, tx_ring->num_desc);
-       }
-
-       while (copied < hdr_len) {
-
-               copy_len = min((int)sizeof(struct cmd_desc_type0) - offset,
-                               (hdr_len - copied));
-
-               hwdesc = &tx_ring->desc_head[producer];
-               tx_ring->cmd_buf_arr[producer].skb = NULL;
-
-               skb_copy_from_linear_data_offset(skb, copied,
-                                (char *)hwdesc + offset, copy_len);
-
-               copied += copy_len;
-               offset = 0;
-
-               producer = get_next_index(producer, tx_ring->num_desc);
-       }
-
-       tx_ring->producer = producer;
-       barrier();
-       adapter->stats.lso_frames++;
+       return 0;
 }
 
 static int
@@ -2088,39 +2101,21 @@ out_err:
        return -ENOMEM;
 }
 
-static int
-qlcnic_check_tx_tagging(struct qlcnic_adapter *adapter,
-                       struct sk_buff *skb,
-                       struct cmd_desc_type0 *first_desc)
+static void
+qlcnic_unmap_buffers(struct pci_dev *pdev, struct sk_buff *skb,
+                       struct qlcnic_cmd_buffer *pbuf)
 {
-       u8 opcode = 0;
-       u16 flags = 0;
-       __be16 protocol = skb->protocol;
-       struct vlan_ethhdr *vh;
+       struct qlcnic_skb_frag *nf = &pbuf->frag_array[0];
+       int nr_frags = skb_shinfo(skb)->nr_frags;
+       int i;
 
-       if (protocol == cpu_to_be16(ETH_P_8021Q)) {
-               vh = (struct vlan_ethhdr *)skb->data;
-               protocol = vh->h_vlan_encapsulated_proto;
-               flags = FLAGS_VLAN_TAGGED;
-               qlcnic_set_tx_vlan_tci(first_desc, ntohs(vh->h_vlan_TCI));
-       } else if (vlan_tx_tag_present(skb)) {
-               flags = FLAGS_VLAN_OOB;
-               qlcnic_set_tx_vlan_tci(first_desc, vlan_tx_tag_get(skb));
+       for (i = 0; i < nr_frags; i++) {
+               nf = &pbuf->frag_array[i+1];
+               pci_unmap_page(pdev, nf->dma, nf->length, PCI_DMA_TODEVICE);
        }
-       if (unlikely(adapter->pvid)) {
-               if (first_desc->vlan_TCI &&
-                               !(adapter->flags & QLCNIC_TAGGING_ENABLED))
-                       return -EIO;
-               if (first_desc->vlan_TCI &&
-                               (adapter->flags & QLCNIC_TAGGING_ENABLED))
-                       goto set_flags;
 
-               flags = FLAGS_VLAN_OOB;
-               qlcnic_set_tx_vlan_tci(first_desc, adapter->pvid);
-       }
-set_flags:
-       qlcnic_set_tx_flags_opcode(first_desc, flags, opcode);
-       return 0;
+       nf = &pbuf->frag_array[0];
+       pci_unmap_single(pdev, nf->dma, skb_headlen(skb), PCI_DMA_TODEVICE);
 }
 
 static inline void
@@ -2144,7 +2139,7 @@ qlcnic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
        int i, k;
 
        u32 producer;
-       int frag_count, no_of_desc;
+       int frag_count;
        u32 num_txd = tx_ring->num_desc;
 
        if (!test_bit(__QLCNIC_DEV_UP, &adapter->state)) {
@@ -2161,12 +2156,8 @@ qlcnic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 
        frag_count = skb_shinfo(skb)->nr_frags + 1;
 
-       /* 4 fragments per cmd des */
-       no_of_desc = (frag_count + 3) >> 2;
-
        if (unlikely(qlcnic_tx_avail(tx_ring) <= TX_STOP_THRESH)) {
                netif_stop_queue(netdev);
-               smp_mb();
                if (qlcnic_tx_avail(tx_ring) > TX_STOP_THRESH)
                        netif_start_queue(netdev);
                else {
@@ -2183,9 +2174,6 @@ qlcnic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
        first_desc = hwdesc = &tx_ring->desc_head[producer];
        qlcnic_clear_cmddesc((u64 *)hwdesc);
 
-       if (qlcnic_check_tx_tagging(adapter, skb, first_desc))
-               goto drop_packet;
-
        if (qlcnic_map_tx_skb(pdev, skb, pbuf)) {
                adapter->stats.tx_dma_map_error++;
                goto drop_packet;
@@ -2229,8 +2217,10 @@ qlcnic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
        }
 
        tx_ring->producer = get_next_index(producer, num_txd);
+       smp_mb();
 
-       qlcnic_tso_check(netdev, tx_ring, first_desc, skb);
+       if (unlikely(qlcnic_tx_pkt(adapter, first_desc, skb)))
+               goto unwind_buff;
 
        if (qlcnic_mac_learn)
                qlcnic_send_filter(adapter, tx_ring, first_desc, skb);
@@ -2242,6 +2232,8 @@ qlcnic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 
        return NETDEV_TX_OK;
 
+unwind_buff:
+       qlcnic_unmap_buffers(pdev, skb, pbuf);
 drop_packet:
        adapter->stats.txdropped++;
        dev_kfree_skb_any(skb);