/**
* gelic_descr_prepare_rx - reinitializes a rx descriptor
* @card: card structure
* @descr: descriptor to re-init
*
* return 0 on success, <0 on failure
*
* allocates a new rx skb, iommu-maps it and attaches it to the descriptor.
* Activate the descriptor state-wise
*/
static int gelic_descr_prepare_rx(struct gelic_card *card,
struct gelic_descr *descr)
{
int offset;
unsigned int bufsize;
if (gelic_descr_get_status(descr) != GELIC_DESCR_DMA_NOT_IN_USE)
dev_info(ctodev(card), "%s: ERROR status\n", __func__);
/* we need to round up the buffer size to a multiple of 128 */
bufsize = ALIGN(GELIC_NET_MAX_MTU, GELIC_NET_RXBUF_ALIGN);
/* and we need to have it 128 byte aligned, therefore we allocate a
* bit more */
descr->skb = dev_alloc_skb(bufsize + GELIC_NET_RXBUF_ALIGN - 1);
if (!descr->skb) {
descr->buf_addr = 0; /* tell DMAC don't touch memory */
dev_info(ctodev(card),
"%s:allocate skb failed !!\n", __func__);
return -ENOMEM;
}
descr->buf_size = cpu_to_be32(bufsize);
descr->dmac_cmd_status = 0;
descr->result_size = 0;
descr->valid_size = 0;
descr->data_error = 0;
offset = ((unsigned long)descr->skb->data) &
(GELIC_NET_RXBUF_ALIGN - 1);
if (offset)
skb_reserve(descr->skb, GELIC_NET_RXBUF_ALIGN - offset);
/* io-mmu-map the skb */
descr->buf_addr = cpu_to_be32(dma_map_single(ctodev(card),
descr->skb->data,
GELIC_NET_MAX_MTU,
DMA_FROM_DEVICE));
if (!descr->buf_addr) {
dev_kfree_skb_any(descr->skb);
descr->skb = NULL;
dev_info(ctodev(card),
"%s:Could not iommu-map rx buffer\n", __func__);
gelic_descr_set_status(descr, GELIC_DESCR_DMA_NOT_IN_USE);
return -ENOMEM;
} else {
gelic_descr_set_status(descr, GELIC_DESCR_DMA_CARDOWNED);
return 0;
}
}
/**
* gelic_card_init_chain - links descriptor chain
* @card: card structure
* @chain: address of chain
* @start_descr: address of descriptor array
* @no: number of descriptors
*
* we manage a circular list that mirrors the hardware structure,
* except that the hardware uses bus addresses.
*
* returns 0 on success, <0 on failure
*/
static int __devinit gelic_card_init_chain(struct gelic_card *card,
struct gelic_descr_chain *chain,
struct gelic_descr *start_descr,
int no)
{
int i;
struct gelic_descr *descr;
descr = start_descr;
memset(descr, 0, sizeof(*descr) * no);
/* set up the hardware pointers in each descriptor */
for (i = 0; i < no; i++, descr++) {
gelic_descr_set_status(descr, GELIC_DESCR_DMA_NOT_IN_USE);
descr->bus_addr =
dma_map_single(ctodev(card), descr,
GELIC_DESCR_SIZE,
DMA_BIDIRECTIONAL);
if (!descr->bus_addr)
goto iommu_error;
descr->next = descr + 1;
descr->prev = descr - 1;
}
/* make them as ring */
(descr - 1)->next = start_descr;
start_descr->prev = (descr - 1);
/* chain bus addr of hw descriptor */
descr = start_descr;
for (i = 0; i < no; i++, descr++) {
descr->next_descr_addr = cpu_to_be32(descr->next->bus_addr);
}
chain->head = start_descr;
chain->tail = start_descr;
/* do not chain last hw descriptor */
(descr - 1)->next_descr_addr = 0;
return 0;
iommu_error:
for (i--, descr--; 0 <= i; i--, descr--)
if (descr->bus_addr)
dma_unmap_single(ctodev(card), descr->bus_addr,
GELIC_DESCR_SIZE,
DMA_BIDIRECTIONAL);
return -ENOMEM;
}
/**
* gelic_card_reset_chain - reset status of a descriptor chain
* @card: card structure
* @chain: address of chain
* @start_descr: address of descriptor array
*
* Reset the status of dma descriptors to ready state
* and re-initialize the hardware chain for later use
*/
static void gelic_card_reset_chain(struct gelic_card *card,
struct gelic_descr_chain *chain,
struct gelic_descr *start_descr)
{
struct gelic_descr *descr;
for (descr = start_descr; start_descr != descr->next; descr++) {
gelic_descr_set_status(descr, GELIC_DESCR_DMA_CARDOWNED);
descr->next_descr_addr = cpu_to_be32(descr->next->bus_addr);
}
chain->head = start_descr;
chain->tail = (descr - 1);
(descr - 1)->next_descr_addr = 0;
}
/**
* gelic_card_release_rx_chain - free all skb of rx descr
* @card: card structure
*
*/
static void gelic_card_release_rx_chain(struct gelic_card *card)
{
struct gelic_descr *descr = card->rx_chain.head;
do {
if (descr->skb) {
dma_unmap_single(ctodev(card),
be32_to_cpu(descr->buf_addr),
descr->skb->len,
DMA_FROM_DEVICE);
descr->buf_addr = 0;
dev_kfree_skb_any(descr->skb);
descr->skb = NULL;
gelic_descr_set_status(descr,
GELIC_DESCR_DMA_NOT_IN_USE);
}
descr = descr->next;
} while (descr != card->rx_chain.head);
}
/**
* gelic_descr_release_tx - processes a used tx descriptor
* @card: card structure
* @descr: descriptor to release
*
* releases a used tx descriptor (unmapping, freeing of skb)
*/
static void gelic_descr_release_tx(struct gelic_card *card,
struct gelic_descr *descr)
{
struct sk_buff *skb = descr->skb;
BUG_ON(!(be32_to_cpu(descr->data_status) & GELIC_DESCR_TX_TAIL));
dma_unmap_single(ctodev(card), be32_to_cpu(descr->buf_addr), skb->len,
DMA_TO_DEVICE);
dev_kfree_skb_any(skb);
descr->buf_addr = 0;
descr->buf_size = 0;
descr->next_descr_addr = 0;
descr->result_size = 0;
descr->valid_size = 0;
descr->data_status = 0;
descr->data_error = 0;
descr->skb = NULL;
/* set descr status */
gelic_descr_set_status(descr, GELIC_DESCR_DMA_NOT_IN_USE);
}
/**
* 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;
}
