/* Initialize the Rx and Tx rings, along with various 'dev' bits. */
static void tulip_init_ring(/*RTnet*/struct rtnet_device *rtdev)
{
struct tulip_private *tp = (struct tulip_private *)rtdev->priv;
int i;
tp->susp_rx = 0;
tp->ttimer = 0;
tp->nir = 0;
for (i = 0; i < RX_RING_SIZE; i++) {
tp->rx_ring[i].status = 0x00000000;
tp->rx_ring[i].length = cpu_to_le32(PKT_BUF_SZ);
tp->rx_ring[i].buffer2 = cpu_to_le32(tp->rx_ring_dma + sizeof(struct tulip_rx_desc) * (i + 1));
tp->rx_buffers[i].skb = NULL;
tp->rx_buffers[i].mapping = 0;
}
/* Mark the last entry as wrapping the ring. */
tp->rx_ring[i-1].length = cpu_to_le32(PKT_BUF_SZ | DESC_RING_WRAP);
tp->rx_ring[i-1].buffer2 = cpu_to_le32(tp->rx_ring_dma);
for (i = 0; i < RX_RING_SIZE; i++) {
dma_addr_t mapping;
/* Note the receive buffer must be longword aligned.
dev_alloc_skb() provides 16 byte alignment. But do *not*
use skb_reserve() to align the IP header! */
struct /*RTnet*/rtskb *skb = /*RTnet*/rtnetdev_alloc_rtskb(rtdev, PKT_BUF_SZ);
tp->rx_buffers[i].skb = skb;
if (skb == NULL)
break;
mapping = pci_map_single(tp->pdev, skb->tail, PKT_BUF_SZ, PCI_DMA_FROMDEVICE);
tp->rx_buffers[i].mapping = mapping;
tp->rx_ring[i].status = cpu_to_le32(DescOwned); /* Owned by Tulip chip */
tp->rx_ring[i].buffer1 = cpu_to_le32(mapping);
}
tp->dirty_rx = (unsigned int)(i - RX_RING_SIZE);
/* The Tx buffer descriptor is filled in as needed, but we
do need to clear the ownership bit. */
for (i = 0; i < TX_RING_SIZE; i++) {
tp->tx_buffers[i].skb = NULL;
tp->tx_buffers[i].mapping = 0;
tp->tx_ring[i].status = 0x00000000;
tp->tx_ring[i].buffer2 = cpu_to_le32(tp->tx_ring_dma + sizeof(struct tulip_tx_desc) * (i + 1));
}
tp->tx_ring[i-1].buffer2 = cpu_to_le32(tp->tx_ring_dma);
}
/* During a receive, the cur_rx points to the current incoming buffer.
* When we update through the ring, if the next incoming buffer has
* not been given to the system, we just set the empty indicator,
* effectively tossing the packet.
*/
static int
scc_enet_rx(struct rtnet_device *rtdev, int* packets, nanosecs_abs_t *time_stamp)
{
struct scc_enet_private *cep;
volatile cbd_t *bdp;
ushort pkt_len;
struct rtskb *skb;
RT_DEBUG(__FUNCTION__": ...\n");
cep = (struct scc_enet_private *)rtdev->priv;
/* First, grab all of the stats for the incoming packet.
* These get messed up if we get called due to a busy condition.
*/
bdp = cep->cur_rx;
for (;;) {
if (bdp->cbd_sc & BD_ENET_RX_EMPTY)
break;
#ifndef final_version
/* Since we have allocated space to hold a complete frame, both
* the first and last indicators should be set.
*/
if ((bdp->cbd_sc & (BD_ENET_RX_FIRST | BD_ENET_RX_LAST)) !=
(BD_ENET_RX_FIRST | BD_ENET_RX_LAST))
rtdm_printk("CPM ENET: rcv is not first+last\n");
#endif
/* Frame too long or too short.
*/
if (bdp->cbd_sc & (BD_ENET_RX_LG | BD_ENET_RX_SH))
cep->stats.rx_length_errors++;
if (bdp->cbd_sc & BD_ENET_RX_NO) /* Frame alignment */
cep->stats.rx_frame_errors++;
if (bdp->cbd_sc & BD_ENET_RX_CR) /* CRC Error */
cep->stats.rx_crc_errors++;
if (bdp->cbd_sc & BD_ENET_RX_OV) /* FIFO overrun */
cep->stats.rx_crc_errors++;
/* Report late collisions as a frame error.
* On this error, the BD is closed, but we don't know what we
* have in the buffer. So, just drop this frame on the floor.
*/
if (bdp->cbd_sc & BD_ENET_RX_CL) {
cep->stats.rx_frame_errors++;
}
else {
/* Process the incoming frame.
*/
cep->stats.rx_packets++;
pkt_len = bdp->cbd_datlen;
cep->stats.rx_bytes += pkt_len;
/* This does 16 byte alignment, much more than we need.
* The packet length includes FCS, but we don't want to
* include that when passing upstream as it messes up
* bridging applications.
*/
skb = rtnetdev_alloc_rtskb(rtdev, pkt_len-4);
if (skb == NULL) {
rtdm_printk("%s: Memory squeeze, dropping packet.\n", rtdev->name);
cep->stats.rx_dropped++;
}
else {
rtskb_put(skb,pkt_len-4); /* Make room */
memcpy(skb->data,
cep->rx_vaddr[bdp - cep->rx_bd_base],
pkt_len-4);
skb->protocol=rt_eth_type_trans(skb,rtdev);
skb->time_stamp = *time_stamp;
rtnetif_rx(skb);
(*packets)++;
}
}
/* Clear the status flags for this buffer.
*/
bdp->cbd_sc &= ~BD_ENET_RX_STATS;
/* Mark the buffer empty.
*/
bdp->cbd_sc |= BD_ENET_RX_EMPTY;
/* Update BD pointer to next entry.
*/
if (bdp->cbd_sc & BD_ENET_RX_WRAP)
bdp = cep->rx_bd_base;
else
bdp++;
}
cep->cur_rx = (cbd_t *)bdp;
return 0;
}
