/**
* gelic_card_fill_rx_chain - fills descriptors/skbs in the rx chains
* @card: card structure
*
* fills all descriptors in the rx chain: allocates skbs
* and iommu-maps them.
* returns 0 on success, < 0 on failure
*/
static int gelic_card_fill_rx_chain(struct gelic_card *card)
{
struct gelic_descr *descr = card->rx_chain.head;
int ret;
do {
if (!descr->skb) {
ret = gelic_descr_prepare_rx(card, descr);
if (ret)
goto rewind;
}
descr = descr->next;
} while (descr != card->rx_chain.head);
return 0;
rewind:
gelic_card_release_rx_chain(card);
return ret;
}
/**
* gelic_card_decode_one_descr - processes an rx descriptor
* @card: card structure
*
* returns 1 if a packet has been sent to the stack, otherwise 0
*
* processes an rx descriptor by iommu-unmapping the data buffer and passing
* the packet up to the stack
*/
static int gelic_card_decode_one_descr(struct gelic_card *card)
{
enum gelic_descr_dma_status status;
struct gelic_descr_chain *chain = &card->rx_chain;
struct gelic_descr *descr = chain->head;
struct net_device *netdev = NULL;
int dmac_chain_ended;
status = gelic_descr_get_status(descr);
/* is this descriptor terminated with next_descr == NULL? */
dmac_chain_ended =
be32_to_cpu(descr->dmac_cmd_status) &
GELIC_DESCR_RX_DMA_CHAIN_END;
if (status == GELIC_DESCR_DMA_CARDOWNED)
return 0;
if (status == GELIC_DESCR_DMA_NOT_IN_USE) {
dev_dbg(ctodev(card), "dormant descr? %p\n", descr);
return 0;
}
/* netdevice select */
if (card->vlan_required) {
unsigned int i;
u16 vid;
vid = *(u16 *)(descr->skb->data) & VLAN_VID_MASK;
for (i = 0; i < GELIC_PORT_MAX; i++) {
if (card->vlan[i].rx == vid) {
netdev = card->netdev[i];
break;
}
};
if (GELIC_PORT_MAX <= i) {
pr_info("%s: unknown packet vid=%x\n", __func__, vid);
goto refill;
}
} else
netdev = card->netdev[GELIC_PORT_ETHERNET];
if ((status == GELIC_DESCR_DMA_RESPONSE_ERROR) ||
(status == GELIC_DESCR_DMA_PROTECTION_ERROR) ||
(status == GELIC_DESCR_DMA_FORCE_END)) {
dev_info(ctodev(card), "dropping RX descriptor with state %x\n",
status);
netdev->stats.rx_dropped++;
goto refill;
}
if (status == GELIC_DESCR_DMA_BUFFER_FULL) {
/*
* Buffer full would occur if and only if
* the frame length was longer than the size of this
* descriptor's buffer. If the frame length was equal
* to or shorter than buffer'size, FRAME_END condition
* would occur.
* Anyway this frame was longer than the MTU,
* just drop it.
*/
dev_info(ctodev(card), "overlength frame\n");
goto refill;
}
/*
* descriptoers any other than FRAME_END here should
* be treated as error.
*/
if (status != GELIC_DESCR_DMA_FRAME_END) {
dev_dbg(ctodev(card), "RX descriptor with state %x\n",
status);
goto refill;
}
/* ok, we've got a packet in descr */
gelic_net_pass_skb_up(descr, card, netdev);
refill:
/*
* So that always DMAC can see the end
* of the descriptor chain to avoid
* from unwanted DMAC overrun.
*/
descr->next_descr_addr = 0;
/* change the descriptor state: */
gelic_descr_set_status(descr, GELIC_DESCR_DMA_NOT_IN_USE);
/*
* this call can fail, but for now, just leave this
* decriptor without skb
*/
gelic_descr_prepare_rx(card, descr);
chain->tail = descr;
chain->head = descr->next;
/*
* Set this descriptor the end of the chain.
*/
descr->prev->next_descr_addr = cpu_to_be32(descr->bus_addr);
/*
* If dmac chain was met, DMAC stopped.
* thus re-enable it
*/
if (dmac_chain_ended) {
card->rx_dma_restart_required = 1;
dev_dbg(ctodev(card), "reenable rx dma scheduled\n");
}
return 1;
}
