[PATCH] sky2: improve receive performance

Changes to receive side processing:
	* bigger receive ring
	* clean up polling loop

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

1 files changed, 34 insertions, 32 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 83361aed49f6..e6f71c1232bc 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -72,10 +72,10 @@
         unlikely((hw)->chip_id == CHIP_ID_YUKON_EC && \
                  (hw)->chip_rev == CHIP_REV_YU_EC_A1)
 
-#define RX_LE_SIZE              256
+#define RX_LE_SIZE              512
 #define RX_LE_BYTES             (RX_LE_SIZE*sizeof(struct sky2_rx_le))
 #define RX_MAX_PENDING          (RX_LE_SIZE/2 - 2)
-#define RX_DEF_PENDING          128
+#define RX_DEF_PENDING          RX_MAX_PENDING
 #define RX_COPY_THRESHOLD       256
 
 #define TX_RING_SIZE            512
@@ -1596,7 +1596,6 @@ static struct sk_buff *sky2_receive(struct sky2_port *sky2,
 {
         struct ring_info *re = sky2->rx_ring + sky2->rx_next;
         struct sk_buff *skb = NULL;
-        struct net_device *dev;
         const unsigned int bufsize = rx_size(sky2);
 
         if (unlikely(netif_msg_rx_status(sky2)))
@@ -1643,11 +1642,6 @@ static struct sk_buff *sky2_receive(struct sky2_port *sky2,
         }
 
         skb_put(skb, length);
-        dev = sky2->netdev;
-        skb->dev = dev;
-        skb->protocol = eth_type_trans(skb, dev);
-        dev->last_rx = jiffies;
-
 resubmit:
         re->skb->ip_summed = CHECKSUM_NONE;
         sky2_rx_add(sky2, re);
@@ -1702,35 +1696,42 @@ static int sky2_poll(struct net_device *dev0, int *budget)
         BUG_ON(hwidx >= STATUS_RING_SIZE);
         rmb();
 
-        do {
-                struct sky2_status_le *le = hw->st_le + hw->st_idx;
+        while (hwidx != hw->st_idx) {
+                struct sky2_status_le *le  = hw->st_le + hw->st_idx;
+                struct net_device *dev;
                 struct sky2_port *sky2;
                 struct sk_buff *skb;
                 u32 status;
                 u16 length;
+                u8 op;
 
-                /* Are we done yet? */
-                if (hw->st_idx == hwidx) {
-                        sky2_write32(hw, STAT_CTRL, SC_STAT_CLR_IRQ);
-                        hwidx = sky2_read16(hw, STAT_PUT_IDX);
-                        if (hwidx == hw->st_idx)
-                                break;
-                }
-
+                le = hw->st_le + hw->st_idx;
                 hw->st_idx = (hw->st_idx + 1) % STATUS_RING_SIZE;
-                prefetch(&hw->st_le[hw->st_idx]);
+                prefetch(hw->st_le + hw->st_idx);
 
                 BUG_ON(le->link >= hw->ports || !hw->dev[le->link]);
 
-                sky2 = netdev_priv(hw->dev[le->link]);
+                BUG_ON(le->link >= 2);
+                dev = hw->dev[le->link];
+                if (dev == NULL || !netif_running(dev))
+                        continue;
+
+                sky2 = netdev_priv(dev);
                 status = le32_to_cpu(le->status);
                 length = le16_to_cpu(le->length);
+                op = le->opcode & ~HW_OWNER;
+                le->opcode = 0;
 
-                switch (le->opcode & ~HW_OWNER) {
+                switch (op) {
                 case OP_RXSTAT:
                         skb = sky2_receive(sky2, length, status);
                         if (!skb)
                                 break;
+
+                        skb->dev = dev;
+                        skb->protocol = eth_type_trans(skb, dev);
+                        dev->last_rx = jiffies;
+
 #ifdef SKY2_VLAN_TAG_USED
                         if (sky2->vlgrp && (status & GMR_FS_VLAN)) {
                                 vlan_hwaccel_receive_skb(skb,
@@ -1739,7 +1740,9 @@ static int sky2_poll(struct net_device *dev0, int *budget)
                         } else
 #endif
                                 netif_receive_skb(skb);
-                        ++work_done;
+
+                        if (++work_done >= to_do)
+                                goto exit_loop;
                         break;
 
 #ifdef SKY2_VLAN_TAG_USED
@@ -1765,18 +1768,15 @@ static int sky2_poll(struct net_device *dev0, int *budget)
                 default:
                         if (net_ratelimit())
                                 printk(KERN_WARNING PFX
-                                       "unknown status opcode 0x%x\n",
-                                       le->opcode);
+                                       "unknown status opcode 0x%x\n", op);
                         break;
                 }
+        }
 
-                le->opcode = 0; /* paranoia */
-        } while (work_done < to_do);
+exit_loop:
 
         mmiowb();
 
-        *budget -= work_done;
-        dev0->quota -= work_done;
         if (work_done < to_do) {
                 /*
                  * Another chip workaround, need to restart TX timer if status
@@ -1790,11 +1790,13 @@ static int sky2_poll(struct net_device *dev0, int *budget)
                 netif_rx_complete(dev0);
                 hw->intr_mask |= Y2_IS_STAT_BMU;
                 sky2_write32(hw, B0_IMSK, hw->intr_mask);
-                sky2_read32(hw, B0_IMSK);
+                mmiowb();
+                return 0;
+        } else {
+                *budget -= work_done;
+                dev0->quota -= work_done;
+                return 1;
         }
-
-        return work_done >= to_do;
-
 }
 
 static void sky2_hw_error(struct sky2_hw *hw, unsigned port, u32 status)