ixgbe: Introduce Multiqueue TX

Now that the irq vector code is in place, we can add the conditional
multiqueue TX code in the driver. This requires the optional
CONFIG_NETDEVICES_MULTIQUEUE=y and will not be enabled without
it.

Signed-off-by: Ayyappan Veeraiyan <ayyappan.veeraiyan@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Acked-by: Waskiewicz Jr, Peter P <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 52 insertions, 4 deletions

diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index fecc8ea79e9d..fc1c226f5751 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -256,16 +256,28 @@ static bool ixgbe_clean_tx_irq(struct ixgbe_adapter *adapter,
                  * sees the new next_to_clean.
                  */
                 smp_mb();
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+                if (__netif_subqueue_stopped(netdev, tx_ring->queue_index) &&
+                    !test_bit(__IXGBE_DOWN, &adapter->state)) {
+                        netif_wake_subqueue(netdev, tx_ring->queue_index);
+                        adapter->restart_queue++;
+                }
+#else
                 if (netif_queue_stopped(netdev) &&
                     !test_bit(__IXGBE_DOWN, &adapter->state)) {
                         netif_wake_queue(netdev);
                         adapter->restart_queue++;
                 }
+#endif
         }
 
         if (adapter->detect_tx_hung)
                 if (ixgbe_check_tx_hang(adapter, tx_ring, eop, eop_desc))
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+                        netif_stop_subqueue(netdev, tx_ring->queue_index);
+#else
                         netif_stop_queue(netdev);
+#endif
 
         if (total_tx_packets >= tx_ring->work_limit)
                 IXGBE_WRITE_REG(&adapter->hw, IXGBE_EICS, tx_ring->eims_value);
@@ -1812,7 +1824,11 @@ static void __devinit ixgbe_set_num_queues(struct ixgbe_adapter *adapter)
                 case (IXGBE_FLAG_RSS_ENABLED):
                         rss_m = 0xF;
                         nrq = rss_i;
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+                        ntq = rss_i;
+#else
                         ntq = 1;
+#endif
                         break;
                 case 0:
                 default:
@@ -1986,6 +2002,10 @@ try_msi:
         }
 
 out:
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        /* Notify the stack of the (possibly) reduced Tx Queue count. */
+        adapter->netdev->egress_subqueue_count = adapter->num_tx_queues;
+#endif
 
         return err;
 }
@@ -2504,6 +2524,9 @@ static void ixgbe_watchdog(unsigned long data)
         struct net_device *netdev = adapter->netdev;
         bool link_up;
         u32 link_speed = 0;
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        int i;
+#endif
 
         adapter->hw.mac.ops.check_link(&adapter->hw, &(link_speed), &link_up);
 
@@ -2525,6 +2548,10 @@ static void ixgbe_watchdog(unsigned long data)
 
                         netif_carrier_on(netdev);
                         netif_wake_queue(netdev);
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+                        for (i = 0; i < adapter->num_tx_queues; i++)
+                                netif_wake_subqueue(netdev, i);
+#endif
                 } else {
                         /* Force detection of hung controller */
                         adapter->detect_tx_hung = true;
@@ -2568,7 +2595,6 @@ static int ixgbe_tso(struct ixgbe_adapter *adapter,
         struct ixgbe_tx_buffer *tx_buffer_info;
         u32 vlan_macip_lens = 0, type_tucmd_mlhl = 0;
         u32 mss_l4len_idx = 0, l4len;
-        *hdr_len = 0;
 
         if (skb_is_gso(skb)) {
                 if (skb_header_cloned(skb)) {
@@ -2852,7 +2878,11 @@ static int __ixgbe_maybe_stop_tx(struct net_device *netdev,
 {
         struct ixgbe_adapter *adapter = netdev_priv(netdev);
 
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        netif_stop_subqueue(netdev, tx_ring->queue_index);
+#else
         netif_stop_queue(netdev);
+#endif
         /* Herbert's original patch had:
          *  smp_mb__after_netif_stop_queue();
          * but since that doesn't exist yet, just open code it. */
@@ -2864,7 +2894,11 @@ static int __ixgbe_maybe_stop_tx(struct net_device *netdev,
                 return -EBUSY;
 
         /* A reprieve! - use start_queue because it doesn't call schedule */
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        netif_wake_subqueue(netdev, tx_ring->queue_index);
+#else
         netif_wake_queue(netdev);
+#endif
         ++adapter->restart_queue;
         return 0;
 }
@@ -2885,15 +2919,18 @@ static int ixgbe_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
         unsigned int len = skb->len;
         unsigned int first;
         unsigned int tx_flags = 0;
-        u8 hdr_len;
-        int tso;
+        u8 hdr_len = 0;
+        int r_idx = 0, tso;
         unsigned int mss = 0;
         int count = 0;
         unsigned int f;
         unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
         len -= skb->data_len;
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        r_idx = (adapter->num_tx_queues - 1) & skb->queue_mapping;
+#endif
+        tx_ring = &adapter->tx_ring[r_idx];
 
-        tx_ring = adapter->tx_ring;
 
         if (skb->len <= 0) {
                 dev_kfree_skb(skb);
@@ -3078,7 +3115,11 @@ static int __devinit ixgbe_probe(struct pci_dev *pdev,
 
         pci_set_master(pdev);
 
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        netdev = alloc_etherdev_mq(sizeof(struct ixgbe_adapter), MAX_TX_QUEUES);
+#else
         netdev = alloc_etherdev(sizeof(struct ixgbe_adapter));
+#endif
         if (!netdev) {
                 err = -ENOMEM;
                 goto err_alloc_etherdev;
@@ -3164,6 +3205,9 @@ static int __devinit ixgbe_probe(struct pci_dev *pdev,
         if (pci_using_dac)
                 netdev->features |= NETIF_F_HIGHDMA;
 
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        netdev->features |= NETIF_F_MULTI_QUEUE;
+#endif
 
         /* make sure the EEPROM is good */
         if (ixgbe_validate_eeprom_checksum(hw, NULL) < 0) {
@@ -3231,6 +3275,10 @@ static int __devinit ixgbe_probe(struct pci_dev *pdev,
 
         netif_carrier_off(netdev);
         netif_stop_queue(netdev);
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        for (i = 0; i < adapter->num_tx_queues; i++)
+                netif_stop_subqueue(netdev, i);
+#endif
 
         ixgbe_napi_add_all(adapter);