[PATCH] skge: use prefetch on receive

Use prefetch() in the interrupt path to try and look ahead
at the next place will be looking at in the ring.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

diff --git a/drivers/net/skge.c b/drivers/net/skge.c
index ea68d4d3d57c3d9909766f93800907aaa02ac8c2..389d0be3586510495eda46db6e2b75ae02ce1a83 100644 (file)
--- a/drivers/net/skge.c
+++ b/drivers/net/skge.c
@@ -2627,7 +2627,7 @@ static int skge_poll(struct net_device *dev, int *budget)
        unsigned int to_do = min(dev->quota, *budget);
        unsigned int work_done = 0;
 
-       for (e = ring->to_clean; work_done < to_do; e = e->next) {
+       for (e = ring->to_clean; prefetch(e->next), work_done < to_do; e = e->next) {
                struct skge_rx_desc *rd = e->desc;
                struct sk_buff *skb;
                u32 control;
@@ -2660,11 +2660,11 @@ static int skge_poll(struct net_device *dev, int *budget)
        if (work_done >=  to_do)
                return 1; /* not done */
 
-       local_irq_disable();
-       __netif_rx_complete(dev);
+       netif_rx_complete(dev);
        hw->intr_mask |= portirqmask[skge->port];
        skge_write32(hw, B0_IMSK, hw->intr_mask);
-       local_irq_enable();
+       skge_read32(hw, B0_IMSK);
+
        return 0;
 }
 
@@ -2676,7 +2676,7 @@ static inline void skge_tx_intr(struct net_device *dev)
        struct skge_element *e;
 
        spin_lock(&skge->tx_lock);
-       for (e = ring->to_clean; e != ring->to_use; e = e->next) {
+       for (e = ring->to_clean; prefetch(e->next), e != ring->to_use; e = e->next) {
                struct skge_tx_desc *td = e->desc;
                u32 control;
 
@@ -2829,6 +2829,14 @@ static void skge_extirq(unsigned long data)
        local_irq_enable();
 }
 
+static inline void skge_wakeup(struct net_device *dev)
+{
+       struct skge_port *skge = netdev_priv(dev);
+
+       prefetch(skge->rx_ring.to_clean);
+       netif_rx_schedule(dev);
+}
+
 static irqreturn_t skge_intr(int irq, void *dev_id, struct pt_regs *regs)
 {
        struct skge_hw *hw = dev_id;
@@ -2840,12 +2848,12 @@ static irqreturn_t skge_intr(int irq, void *dev_id, struct pt_regs *regs)
        status &= hw->intr_mask;
        if (status & IS_R1_F) {
                hw->intr_mask &= ~IS_R1_F;
-               netif_rx_schedule(hw->dev[0]);
+               skge_wakeup(hw->dev[0]);
        }
 
        if (status & IS_R2_F) {
                hw->intr_mask &= ~IS_R2_F;
-               netif_rx_schedule(hw->dev[1]);
+               skge_wakeup(hw->dev[1]);
        }
 
        if (status & IS_XA1_F)