ar71xx: ethernet: cache skb->len in the tx function to avoid accessing it again in...

Improves ethernet performance, especially during bridging

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@37761 3c298f89-4303-0410-b956-a3cf2f4a3e73

diff --git a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h
index b9d95ad..6d51e72 100644 (file)
--- a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h
+++ b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h
@@ -91,8 +91,11 @@ struct ag71xx_buf {
                void            *rx_buf;
        };
        struct ag71xx_desc      *desc;
-       dma_addr_t              dma_addr;
-       unsigned long           timestamp;
+       union {
+               dma_addr_t      dma_addr;
+               unsigned long   timestamp;
+       };
+       unsigned int            len;
 };
 
 struct ag71xx_ring {

diff --git a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
index 9307169..fc6be0e 100644 (file)
--- a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
+++ b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
@@ -145,7 +145,7 @@ static void ag71xx_ring_tx_clean(struct ag71xx *ag)
                }
 
                if (ring->buf[i].skb) {
-                       bytes_compl += ring->buf[i].skb->len;
+                       bytes_compl += ring->buf[i].len;
                        pkts_compl++;
                        dev_kfree_skb_any(ring->buf[i].skb);
                }
@@ -684,6 +684,7 @@ static netdev_tx_t ag71xx_hard_start_xmit(struct sk_buff *skb,
                                  DMA_TO_DEVICE);
 
        netdev_sent_queue(dev, skb->len);
+       ring->buf[i].len = skb->len;
        ring->buf[i].skb = skb;
        ring->buf[i].timestamp = jiffies;
 
@@ -824,6 +825,7 @@ static int ag71xx_tx_packets(struct ag71xx *ag)
                unsigned int i = ring->dirty % ring->size;
                struct ag71xx_desc *desc = ring->buf[i].desc;
                struct sk_buff *skb = ring->buf[i].skb;
+               int len = ring->buf[i].len;
 
                if (!ag71xx_desc_empty(desc)) {
                        if (pdata->is_ar7240 &&
@@ -834,8 +836,8 @@ static int ag71xx_tx_packets(struct ag71xx *ag)
 
                ag71xx_wr(ag, AG71XX_REG_TX_STATUS, TX_STATUS_PS);
 
-               bytes_compl += skb->len;
-               ag->dev->stats.tx_bytes += skb->len;
+               bytes_compl += len;
+               ag->dev->stats.tx_bytes += len;
                ag->dev->stats.tx_packets++;
 
                dev_kfree_skb_any(skb);