[PATCH] sky2: use netif_tx_lock instead of LLTX

Use the netdevice transmit lock via netif_tx_lock rather than putting
lock in device specific code and using lockless transmit.  The code is
cleaner using netif_tx_lock, and the performance is same.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 17 insertions, 41 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 64af764d0087..c83d7262a5a8 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -942,13 +942,13 @@ static void sky2_vlan_rx_register(struct net_device *dev, struct vlan_group *grp
         struct sky2_hw *hw = sky2->hw;
         u16 port = sky2->port;
 
-        spin_lock_bh(&sky2->tx_lock);
+        netif_tx_lock_bh(dev);
 
         sky2_write32(hw, SK_REG(port, RX_GMF_CTRL_T), RX_VLAN_STRIP_ON);
         sky2_write32(hw, SK_REG(port, TX_GMF_CTRL_T), TX_VLAN_TAG_ON);
         sky2->vlgrp = grp;
 
-        spin_unlock_bh(&sky2->tx_lock);
+        netif_tx_unlock_bh(dev);
 }
 
 static void sky2_vlan_rx_kill_vid(struct net_device *dev, unsigned short vid)
@@ -957,14 +957,14 @@ static void sky2_vlan_rx_kill_vid(struct net_device *dev, unsigned short vid)
         struct sky2_hw *hw = sky2->hw;
         u16 port = sky2->port;
 
-        spin_lock_bh(&sky2->tx_lock);
+        netif_tx_lock_bh(dev);
 
         sky2_write32(hw, SK_REG(port, RX_GMF_CTRL_T), RX_VLAN_STRIP_OFF);
         sky2_write32(hw, SK_REG(port, TX_GMF_CTRL_T), TX_VLAN_TAG_OFF);
         if (sky2->vlgrp)
                 sky2->vlgrp->vlan_devices[vid] = NULL;
 
-        spin_unlock_bh(&sky2->tx_lock);
+        netif_tx_unlock_bh(dev);
 }
 #endif
 
@@ -1202,8 +1202,6 @@ static unsigned tx_le_req(const struct sk_buff *skb)
  * A single packet can generate multiple list elements, and
  * the number of ring elements will probably be less than the number
  * of list elements used.
- *
- * No BH disabling for tx_lock here (like tg3)
  */
 static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
 {
@@ -1217,27 +1215,8 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
         u16 mss;
         u8 ctrl;
 
-        /* No BH disabling for tx_lock here.  We are running in BH disabled
-         * context and TX reclaim runs via poll inside of a software
-         * interrupt, and no related locks in IRQ processing.
-         */
-        if (!spin_trylock(&sky2->tx_lock))
-                return NETDEV_TX_LOCKED;
-
-        if (unlikely(tx_avail(sky2) < tx_le_req(skb))) {
-                /* There is a known but harmless race with lockless tx
-                 * and netif_stop_queue.
-                 */
-                if (!netif_queue_stopped(dev)) {
-                        netif_stop_queue(dev);
-                        if (net_ratelimit())
-                                printk(KERN_WARNING PFX "%s: ring full when queue awake!\n",
-                                       dev->name);
-                }
-                spin_unlock(&sky2->tx_lock);
-
-                return NETDEV_TX_BUSY;
-        }
+        if (unlikely(tx_avail(sky2) < tx_le_req(skb)))
+                return NETDEV_TX_BUSY;
 
         if (unlikely(netif_msg_tx_queued(sky2)))
                 printk(KERN_DEBUG "%s: tx queued, slot %u, len %d\n",
@@ -1352,8 +1331,6 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
 
         sky2_put_idx(hw, txqaddr[sky2->port], sky2->tx_prod);
 
-        spin_unlock(&sky2->tx_lock);
-
         dev->trans_start = jiffies;
         return NETDEV_TX_OK;
 }
@@ -1408,11 +1385,13 @@ static void sky2_tx_complete(struct sky2_port *sky2, u16 done)
 }
 
 /* Cleanup all untransmitted buffers, assume transmitter not running */
-static void sky2_tx_clean(struct sky2_port *sky2)
+static void sky2_tx_clean(struct net_device *dev)
 {
-        spin_lock_bh(&sky2->tx_lock);
+        struct sky2_port *sky2 = netdev_priv(dev);
+
+        netif_tx_lock_bh(dev);
         sky2_tx_complete(sky2, sky2->tx_prod);
-        spin_unlock_bh(&sky2->tx_lock);
+        netif_tx_unlock_bh(dev);
 }
 
 /* Network shutdown */
@@ -1496,7 +1475,7 @@ static int sky2_down(struct net_device *dev)
 
         synchronize_irq(hw->pdev->irq);
 
-        sky2_tx_clean(sky2);
+        sky2_tx_clean(dev);
         sky2_rx_clean(sky2);
 
         pci_free_consistent(hw->pdev, RX_LE_BYTES,
@@ -1748,16 +1727,16 @@ static void sky2_tx_timeout(struct net_device *dev)
         } else if (report != sky2->tx_cons) {
                 printk(KERN_INFO PFX "status report lost?\n");
 
-                spin_lock_bh(&sky2->tx_lock);
+                netif_tx_lock_bh(dev);
                 sky2_tx_complete(sky2, report);
-                spin_unlock_bh(&sky2->tx_lock);
+                netif_tx_unlock_bh(dev);
         } else {
                 printk(KERN_INFO PFX "hardware hung? flushing\n");
 
                 sky2_write32(hw, Q_ADDR(txq, Q_CSR), BMU_STOP);
                 sky2_write32(hw, Y2_QADDR(txq, PREF_UNIT_CTRL), PREF_UNIT_RST_SET);
 
-                sky2_tx_clean(sky2);
+                sky2_tx_clean(dev);
 
                 sky2_qset(hw, txq);
                 sky2_prefetch_init(hw, txq, sky2->tx_le_map, TX_RING_SIZE - 1);
@@ -1927,9 +1906,9 @@ static inline void sky2_tx_done(struct net_device *dev, u16 last)
         struct sky2_port *sky2 = netdev_priv(dev);
 
         if (netif_running(dev)) {
-                spin_lock(&sky2->tx_lock);
+                netif_tx_lock(dev);
                 sky2_tx_complete(sky2, last);
-                spin_unlock(&sky2->tx_lock);
+                netif_tx_unlock(dev);
         }
 }
 
@@ -3134,7 +3113,6 @@ static __devinit struct net_device *sky2_init_netdev(struct sky2_hw *hw,
         sky2->hw = hw;
         sky2->msg_enable = netif_msg_init(debug, default_msg);
 
-        spin_lock_init(&sky2->tx_lock);
         /* Auto speed and flow control */
         sky2->autoneg = AUTONEG_ENABLE;
         sky2->tx_pause = 1;
@@ -3153,7 +3131,6 @@ static __devinit struct net_device *sky2_init_netdev(struct sky2_hw *hw,
 
         sky2->port = port;
 
-        dev->features |= NETIF_F_LLTX;
         if (hw->chip_id != CHIP_ID_YUKON_EC_U)
                 dev->features |= NETIF_F_TSO;
         if (highmem)
diff --git a/drivers/net/sky2.h b/drivers/net/sky2.h
index c1e45123d44f..403486a3831d 100644
--- a/drivers/net/sky2.h
+++ b/drivers/net/sky2.h
@@ -1789,7 +1789,6 @@ struct sky2_port {
         u32                  msg_enable;
         spinlock_t           phy_lock;
 
-        spinlock_t           tx_lock  ____cacheline_aligned_in_smp;
         struct tx_ring_info  *tx_ring;
         struct sky2_tx_le    *tx_le;
         u16                  tx_cons;           /* next le to check */