skge: use per-port phy locking

Rather than a workqueue and a per-board mutex to control PHY,
use a tasklet and spinlock. Tasklet is lower overhead and works
just as well for this.

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

2 files changed, 47 insertions, 41 deletions

diff --git a/drivers/net/skge.c b/drivers/net/skge.c
index 6e1eb23d93c4..39c6677dff5e 100644
--- a/drivers/net/skge.c
+++ b/drivers/net/skge.c
@@ -672,7 +672,7 @@ static void skge_led(struct skge_port *skge, enum led_mode mode)
         struct skge_hw *hw = skge->hw;
         int port = skge->port;
 
-        mutex_lock(&hw->phy_mutex);
+        spin_lock_bh(&hw->phy_lock);
         if (hw->chip_id == CHIP_ID_GENESIS) {
                 switch (mode) {
                 case LED_MODE_OFF:
@@ -743,7 +743,7 @@ static void skge_led(struct skge_port *skge, enum led_mode mode)
                                      PHY_M_LED_MO_RX(MO_LED_ON));
                 }
         }
-        mutex_unlock(&hw->phy_mutex);
+        spin_unlock_bh(&hw->phy_lock);
 }
 
 /* blink LED's for finding board */
@@ -1317,7 +1317,7 @@ static void xm_phy_init(struct skge_port *skge)
         xm_phy_write(hw, port, PHY_XMAC_CTRL, ctrl);
 
         /* Poll PHY for status changes */
-        schedule_delayed_work(&skge->link_thread, LINK_HZ);
+        mod_timer(&skge->link_timer, jiffies + LINK_HZ);
 }
 
 static void xm_check_link(struct net_device *dev)
@@ -1392,10 +1392,9 @@ static void xm_check_link(struct net_device *dev)
  * Since internal PHY is wired to a level triggered pin, can't
  * get an interrupt when carrier is detected.
  */
-static void xm_link_timer(struct work_struct *work)
+static void xm_link_timer(unsigned long arg)
 {
-        struct skge_port *skge =
-                container_of(work, struct skge_port, link_thread.work);
+        struct skge_port *skge = (struct skge_port *) arg;
         struct net_device *dev = skge->netdev;
         struct skge_hw *hw = skge->hw;
         int port = skge->port;
@@ -1415,13 +1414,13 @@ static void xm_link_timer(struct work_struct *work)
                         goto nochange;
         }
 
-        mutex_lock(&hw->phy_mutex);
+        spin_lock(&hw->phy_lock);
         xm_check_link(dev);
-        mutex_unlock(&hw->phy_mutex);
+        spin_unlock(&hw->phy_lock);
 
 nochange:
         if (netif_running(dev))
-                schedule_delayed_work(&skge->link_thread, LINK_HZ);
+                mod_timer(&skge->link_timer, jiffies + LINK_HZ);
 }
 
 static void genesis_mac_init(struct skge_hw *hw, int port)
@@ -2324,7 +2323,7 @@ static void skge_phy_reset(struct skge_port *skge)
         netif_stop_queue(skge->netdev);
         netif_carrier_off(skge->netdev);
 
-        mutex_lock(&hw->phy_mutex);
+        spin_lock_bh(&hw->phy_lock);
         if (hw->chip_id == CHIP_ID_GENESIS) {
                 genesis_reset(hw, port);
                 genesis_mac_init(hw, port);
@@ -2332,7 +2331,7 @@ static void skge_phy_reset(struct skge_port *skge)
                 yukon_reset(hw, port);
                 yukon_init(hw, port);
         }
-        mutex_unlock(&hw->phy_mutex);
+        spin_unlock_bh(&hw->phy_lock);
 
         dev->set_multicast_list(dev);
 }
@@ -2355,12 +2354,12 @@ static int skge_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
                 /* fallthru */
         case SIOCGMIIREG: {
                 u16 val = 0;
-                mutex_lock(&hw->phy_mutex);
+                spin_lock_bh(&hw->phy_lock);
                 if (hw->chip_id == CHIP_ID_GENESIS)
                         err = __xm_phy_read(hw, skge->port, data->reg_num & 0x1f, &val);
                 else
                         err = __gm_phy_read(hw, skge->port, data->reg_num & 0x1f, &val);
-                mutex_unlock(&hw->phy_mutex);
+                spin_unlock_bh(&hw->phy_lock);
                 data->val_out = val;
                 break;
         }
@@ -2369,14 +2368,14 @@ static int skge_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
                 if (!capable(CAP_NET_ADMIN))
                         return -EPERM;
 
-                mutex_lock(&hw->phy_mutex);
+                spin_lock_bh(&hw->phy_lock);
                 if (hw->chip_id == CHIP_ID_GENESIS)
                         err = xm_phy_write(hw, skge->port, data->reg_num & 0x1f,
                                    data->val_in);
                 else
                         err = gm_phy_write(hw, skge->port, data->reg_num & 0x1f,
                                    data->val_in);
-                mutex_unlock(&hw->phy_mutex);
+                spin_unlock_bh(&hw->phy_lock);
                 break;
         }
         return err;
@@ -2482,12 +2481,12 @@ static int skge_up(struct net_device *dev)
                 goto free_rx_ring;
 
         /* Initialize MAC */
-        mutex_lock(&hw->phy_mutex);
+        spin_lock_bh(&hw->phy_lock);
         if (hw->chip_id == CHIP_ID_GENESIS)
                 genesis_mac_init(hw, port);
         else
                 yukon_mac_init(hw, port);
-        mutex_unlock(&hw->phy_mutex);
+        spin_unlock_bh(&hw->phy_lock);
 
         /* Configure RAMbuffers */
         chunk = hw->ram_size / ((hw->ports + 1)*2);
@@ -2537,7 +2536,7 @@ static int skge_down(struct net_device *dev)
 
         netif_stop_queue(dev);
         if (hw->chip_id == CHIP_ID_GENESIS && hw->phy_type == SK_PHY_XMAC)
-                cancel_delayed_work(&skge->link_thread);
+                del_timer_sync(&skge->link_timer);
 
         netif_poll_disable(dev);
 
@@ -3173,28 +3172,29 @@ static void skge_error_irq(struct skge_hw *hw)
 }
 
 /*
- * Interrupt from PHY are handled in work queue
+ * Interrupt from PHY are handled in tasklet (softirq)
  * because accessing phy registers requires spin wait which might
  * cause excess interrupt latency.
  */
-static void skge_extirq(struct work_struct *work)
+static void skge_extirq(unsigned long arg)
 {
-        struct skge_hw *hw = container_of(work, struct skge_hw, phy_work);
+        struct skge_hw *hw = (struct skge_hw *) arg;
         int port;
 
-        mutex_lock(&hw->phy_mutex);
         for (port = 0; port < hw->ports; port++) {
                 struct net_device *dev = hw->dev[port];
-                struct skge_port *skge = netdev_priv(dev);
 
                 if (netif_running(dev)) {
+                        struct skge_port *skge = netdev_priv(dev);
+
+                        spin_lock(&hw->phy_lock);
                         if (hw->chip_id != CHIP_ID_GENESIS)
                                 yukon_phy_intr(skge);
                         else if (hw->phy_type == SK_PHY_BCOM)
                                 bcom_phy_intr(skge);
+                        spin_unlock(&hw->phy_lock);
                 }
         }
-        mutex_unlock(&hw->phy_mutex);
 
         spin_lock_irq(&hw->hw_lock);
         hw->intr_mask |= IS_EXT_REG;
@@ -3219,7 +3219,7 @@ static irqreturn_t skge_intr(int irq, void *dev_id)
         status &= hw->intr_mask;
         if (status & IS_EXT_REG) {
                 hw->intr_mask &= ~IS_EXT_REG;
-                schedule_work(&hw->phy_work);
+                tasklet_schedule(&hw->phy_task);
         }
 
         if (status & (IS_XA1_F|IS_R1_F)) {
@@ -3295,23 +3295,28 @@ static int skge_set_mac_address(struct net_device *dev, void *p)
 
         memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 
-        /* disable Rx */
-        ctrl = gma_read16(hw, port, GM_GP_CTRL);
-        gma_write16(hw, port, GM_GP_CTRL, ctrl & ~GM_GPCR_RX_ENA);
+        if (!netif_running(dev)) {
+                memcpy_toio(hw->regs + B2_MAC_1 + port*8, dev->dev_addr, ETH_ALEN);
+                memcpy_toio(hw->regs + B2_MAC_2 + port*8, dev->dev_addr, ETH_ALEN);
+        } else {
+                /* disable Rx */
+                spin_lock_bh(&hw->phy_lock);
+                ctrl = gma_read16(hw, port, GM_GP_CTRL);
+                gma_write16(hw, port, GM_GP_CTRL, ctrl & ~GM_GPCR_RX_ENA);
 
-        memcpy_toio(hw->regs + B2_MAC_1 + port*8, dev->dev_addr, ETH_ALEN);
-        memcpy_toio(hw->regs + B2_MAC_2 + port*8, dev->dev_addr, ETH_ALEN);
+                memcpy_toio(hw->regs + B2_MAC_1 + port*8, dev->dev_addr, ETH_ALEN);
+                memcpy_toio(hw->regs + B2_MAC_2 + port*8, dev->dev_addr, ETH_ALEN);
 
-        if (netif_running(dev)) {
                 if (hw->chip_id == CHIP_ID_GENESIS)
                         xm_outaddr(hw, port, XM_SA, dev->dev_addr);
                 else {
                         gma_set_addr(hw, port, GM_SRC_ADDR_1L, dev->dev_addr);
                         gma_set_addr(hw, port, GM_SRC_ADDR_2L, dev->dev_addr);
                 }
-        }
 
-        gma_write16(hw, port, GM_GP_CTRL, ctrl);
+                gma_write16(hw, port, GM_GP_CTRL, ctrl);
+                spin_unlock_bh(&hw->phy_lock);
+        }
 
         return 0;
 }
@@ -3496,14 +3501,12 @@ static int skge_reset(struct skge_hw *hw)
 
         skge_write32(hw, B0_IMSK, hw->intr_mask);
 
-        mutex_lock(&hw->phy_mutex);
         for (i = 0; i < hw->ports; i++) {
                 if (hw->chip_id == CHIP_ID_GENESIS)
                         genesis_reset(hw, i);
                 else
                         yukon_reset(hw, i);
         }
-        mutex_unlock(&hw->phy_mutex);
 
         return 0;
 }
@@ -3551,6 +3554,7 @@ static struct net_device *skge_devinit(struct skge_hw *hw, int port,
         skge->netdev = dev;
         skge->hw = hw;
         skge->msg_enable = netif_msg_init(debug, default_msg);
+
         skge->tx_ring.count = DEFAULT_TX_RING_SIZE;
         skge->rx_ring.count = DEFAULT_RX_RING_SIZE;
 
@@ -3567,7 +3571,7 @@ static struct net_device *skge_devinit(struct skge_hw *hw, int port,
         skge->port = port;
 
         /* Only used for Genesis XMAC */
-        INIT_DELAYED_WORK(&skge->link_thread, xm_link_timer);
+        setup_timer(&skge->link_timer, xm_link_timer, (unsigned long) skge);
 
         if (hw->chip_id != CHIP_ID_GENESIS) {
                 dev->features |= NETIF_F_IP_CSUM | NETIF_F_SG;
@@ -3649,9 +3653,9 @@ static int __devinit skge_probe(struct pci_dev *pdev,
         }
 
         hw->pdev = pdev;
-        mutex_init(&hw->phy_mutex);
-        INIT_WORK(&hw->phy_work, skge_extirq);
         spin_lock_init(&hw->hw_lock);
+        spin_lock_init(&hw->phy_lock);
+        tasklet_init(&hw->phy_task, &skge_extirq, (unsigned long) hw);
 
         hw->regs = ioremap_nocache(pci_resource_start(pdev, 0), 0x4000);
         if (!hw->regs) {
@@ -3737,6 +3741,8 @@ static void __devexit skge_remove(struct pci_dev *pdev)
         dev0 = hw->dev[0];
         unregister_netdev(dev0);
 
+        tasklet_disable(&hw->phy_task);
+
         spin_lock_irq(&hw->hw_lock);
         hw->intr_mask = 0;
         skge_write32(hw, B0_IMSK, 0);
diff --git a/drivers/net/skge.h b/drivers/net/skge.h
index e9354dfa7e9a..86467ae74d45 100644
--- a/drivers/net/skge.h
+++ b/drivers/net/skge.h
@@ -2424,8 +2424,8 @@ struct skge_hw {
         u32                  ram_size;
         u32                  ram_offset;
         u16                  phy_addr;
-        struct work_struct   phy_work;
-        struct mutex         phy_mutex;
+        spinlock_t           phy_lock;
+        struct tasklet_struct phy_task;
 };
 
 enum pause_control {
@@ -2457,7 +2457,7 @@ struct skge_port {
 
         struct net_device_stats net_stats;
 
-        struct delayed_work  link_thread;
+        struct timer_list    link_timer;
         enum pause_control   flow_control;
         enum pause_status    flow_status;
         u8                   rx_csum;