static void myri_tx(struct myri_eth *mp, struct net_device *dev)
{
struct sendq *sq = mp->sq;
int entry = mp->tx_old;
int limit = sbus_readl(&sq->head);
DTX(("entry[%d] limit[%d] ", entry, limit));
if (entry == limit)
return;
while (entry != limit) {
struct sk_buff *skb = mp->tx_skbs[entry];
u32 dma_addr;
DTX(("SKB[%d] ", entry));
dma_addr = sbus_readl(&sq->myri_txd[entry].myri_gathers[0].addr);
sbus_unmap_single(mp->myri_sdev, dma_addr, skb->len, SBUS_DMA_TODEVICE);
dev_kfree_skb(skb);
mp->tx_skbs[entry] = NULL;
mp->enet_stats.tx_packets++;
entry = NEXT_TX(entry);
}
mp->tx_old = entry;
}
static int myri_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct myri_eth *mp = netdev_priv(dev);
struct sendq __iomem *sq = mp->sq;
struct myri_txd __iomem *txd;
unsigned long flags;
unsigned int head, tail;
int len, entry;
u32 dma_addr;
DTX(("myri_start_xmit: "));
myri_tx(mp, dev);
netif_stop_queue(dev);
/* This is just to prevent multiple PIO reads for TX_BUFFS_AVAIL. */
head = sbus_readl(&sq->head);
tail = sbus_readl(&sq->tail);
if (!TX_BUFFS_AVAIL(head, tail)) {
DTX(("no buffs available, returning 1\n"));
return NETDEV_TX_BUSY;
}
spin_lock_irqsave(&mp->irq_lock, flags);
DHDR(("xmit[skbdata(%p)]\n", skb->data));
#ifdef DEBUG_HEADER
dump_ehdr_and_myripad(((unsigned char *) skb->data));
#endif
/* XXX Maybe this can go as well. */
len = skb->len;
if (len & 3) {
DTX(("len&3 "));
len = (len + 4) & (~3);
}
entry = sbus_readl(&sq->tail);
txd = &sq->myri_txd[entry];
mp->tx_skbs[entry] = skb;
/* Must do this before we sbus map it. */
if (skb->data[MYRI_PAD_LEN] & 0x1) {
sbus_writew(0xffff, &txd->addr[0]);
sbus_writew(0xffff, &txd->addr[1]);
sbus_writew(0xffff, &txd->addr[2]);
sbus_writew(0xffff, &txd->addr[3]);
} else {
sbus_writew(0xffff, &txd->addr[0]);
sbus_writew((skb->data[0] << 8) | skb->data[1], &txd->addr[1]);
sbus_writew((skb->data[2] << 8) | skb->data[3], &txd->addr[2]);
sbus_writew((skb->data[4] << 8) | skb->data[5], &txd->addr[3]);
}
dma_addr = dma_map_single(&mp->myri_op->dev, skb->data,
len, DMA_TO_DEVICE);
sbus_writel(dma_addr, &txd->myri_gathers[0].addr);
sbus_writel(len, &txd->myri_gathers[0].len);
sbus_writel(1, &txd->num_sg);
sbus_writel(KERNEL_CHANNEL, &txd->chan);
sbus_writel(len, &txd->len);
sbus_writel((u32)-1, &txd->csum_off);
sbus_writel(0, &txd->csum_field);
sbus_writel(NEXT_TX(entry), &sq->tail);
DTX(("BangTheChip "));
bang_the_chip(mp);
DTX(("tbusy=0, returning 0\n"));
netif_start_queue(dev);
spin_unlock_irqrestore(&mp->irq_lock, flags);
return NETDEV_TX_OK;
}