static inline void complete_tx_only(struct xdpsock *xsk)
{
u64 descs[BATCH_SIZE];
unsigned int rcvd;
if (!xsk->outstanding_tx)
return;
kick_tx(xsk->sfd);
rcvd = umem_complete_from_kernel(&xsk->umem->cq, descs, BATCH_SIZE);
if (rcvd > 0) {
xsk->outstanding_tx -= rcvd;
xsk->tx_npkts += rcvd;
}
}
static inline void complete_tx_l2fwd(struct xdpsock *xsk)
{
u64 descs[BATCH_SIZE];
unsigned int rcvd;
size_t ndescs;
if (!xsk->outstanding_tx)
return;
kick_tx(xsk->sfd);
ndescs = (xsk->outstanding_tx > BATCH_SIZE) ? BATCH_SIZE :
xsk->outstanding_tx;
/* re-add completed Tx buffers */
rcvd = umem_complete_from_kernel(&xsk->umem->cq, descs, ndescs);
if (rcvd > 0) {
umem_fill_to_kernel(&xsk->umem->fq, descs, rcvd);
xsk->outstanding_tx -= rcvd;
xsk->tx_npkts += rcvd;
}
}
static int sgiseeq_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct sgiseeq_private *sp = netdev_priv(dev);
struct hpc3_ethregs *hregs = sp->hregs;
unsigned long flags;
struct sgiseeq_tx_desc *td;
int len, entry;
spin_lock_irqsave(&sp->tx_lock, flags);
/* Setup... */
len = skb->len;
if (len < ETH_ZLEN) {
if (skb_padto(skb, ETH_ZLEN)) {
spin_unlock_irqrestore(&sp->tx_lock, flags);
return NETDEV_TX_OK;
}
len = ETH_ZLEN;
}
dev->stats.tx_bytes += len;
entry = sp->tx_new;
td = &sp->tx_desc[entry];
dma_sync_desc_cpu(dev, td);
/* Create entry. There are so many races with adding a new
* descriptor to the chain:
* 1) Assume that the HPC is off processing a DMA chain while
* we are changing all of the following.
* 2) Do no allow the HPC to look at a new descriptor until
* we have completely set up it's state. This means, do
* not clear HPCDMA_EOX in the current last descritptor
* until the one we are adding looks consistent and could
* be processes right now.
* 3) The tx interrupt code must notice when we've added a new
* entry and the HPC got to the end of the chain before we
* added this new entry and restarted it.
*/
td->skb = skb;
td->tdma.pbuf = dma_map_single(dev->dev.parent, skb->data,
len, DMA_TO_DEVICE);
td->tdma.cntinfo = (len & HPCDMA_BCNT) |
HPCDMA_XIU | HPCDMA_EOXP | HPCDMA_XIE | HPCDMA_EOX;
dma_sync_desc_dev(dev, td);
if (sp->tx_old != sp->tx_new) {
struct sgiseeq_tx_desc *backend;
backend = &sp->tx_desc[PREV_TX(sp->tx_new)];
dma_sync_desc_cpu(dev, backend);
backend->tdma.cntinfo &= ~HPCDMA_EOX;
dma_sync_desc_dev(dev, backend);
}
sp->tx_new = NEXT_TX(sp->tx_new); /* Advance. */
/* Maybe kick the HPC back into motion. */
if (!(hregs->tx_ctrl & HPC3_ETXCTRL_ACTIVE))
kick_tx(dev, sp, hregs);
dev->trans_start = jiffies;
if (!TX_BUFFS_AVAIL(sp))
netif_stop_queue(dev);
spin_unlock_irqrestore(&sp->tx_lock, flags);
return NETDEV_TX_OK;
}
