[PATCH 2.6.7-rc3-mm2 3/5] via-velocity: velocity_receive_frame diets

[Francois Romieu <romieu@xxxxxxxxxxxxx>]

Weight loss in velocity_receive_frame():
- isolate the ip header alignment tsk from velocity_receive_frame();
- following p.30 of the datasheet, rdesc0.len includes the CRC length:
  the amount of data copied during the ip alignment can be shortened.

diff -puN drivers/net/via-velocity.c~via-velocity-40 drivers/net/via-velocity.c
--- linux-2.6.7-rc3/drivers/net/via-velocity.c~via-velocity-40  2004-06-18 
21:38:59.000000000 +0200
+++ linux-2.6.7-rc3-fr/drivers/net/via-velocity.c       2004-06-18 
21:58:58.000000000 +0200
@@ -1255,6 +1255,28 @@ static inline void velocity_rx_csum(stru
 }
 
 /**
+ *     velocity_iph_realign    -       IP header alignment
+ *     @vptr: velocity we are handling
+ *     @skb: network layer packet buffer
+ *     @pkt_size: received data size
+ *
+ *     Align IP header on a 2 bytes boundary. This behavior can be
+ *     configured by the user.
+ */
+static inline void velocity_iph_realign(struct velocity_info *vptr,
+                                       struct sk_buff *skb, int pkt_size)
+{
+       /* FIXME - memmove ? */
+       if (vptr->flags & VELOCITY_FLAGS_IP_ALIGN) {
+               int i;
+
+               for (i = pkt_size; i >= 0; i--)
+                       *(skb->data + i + 2) = *(skb->data + i);
+               skb_reserve(skb, 2);
+       }
+}
+
+/**
  *     velocity_receive_frame  -       received packet processor
  *     @vptr: velocity we are handling
  *     @idx: ring index
@@ -1268,6 +1290,7 @@ static int velocity_receive_frame(struct
        struct net_device_stats *stats = &vptr->stats;
        struct velocity_rd_info *rd_info = &(vptr->rd_info[idx]);
        struct rx_desc *rd = &(vptr->rd_ring[idx]);
+       int pkt_len = rd->rdesc0.len;
        struct sk_buff *skb;
 
        if (rd->rdesc0.RSR & (RSR_STP | RSR_EDP)) {
@@ -1287,16 +1310,9 @@ static int velocity_receive_frame(struct
        rd_info->skb_dma = (dma_addr_t) NULL;
        rd_info->skb = NULL;
 
-       /* FIXME - memmove ? */
-       if (vptr->flags & VELOCITY_FLAGS_IP_ALIGN) {
-               int i;
-               for (i = rd->rdesc0.len + 4; i >= 0; i--)
-                       *(skb->data + i + 2) = *(skb->data + i);
-               skb->data += 2;
-               skb->tail += 2;
-       }
+       velocity_iph_realign(vptr, skb, pkt_len);
 
-       skb_put(skb, (rd->rdesc0.len - 4));
+       skb_put(skb, pkt_len - 4);
        skb->protocol = eth_type_trans(skb, skb->dev);
 
        /*
@@ -1316,7 +1332,7 @@ static int velocity_receive_frame(struct
         *      FIXME: need rx_copybreak handling
         */
 
-       stats->rx_bytes += skb->len;
+       stats->rx_bytes += pkt_len;
        netif_rx(skb);
 
        return 0;

_