static netdev_tx_t
greth_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct greth_private *greth = netdev_priv(dev);
struct greth_bd *bdp;
int err = NETDEV_TX_OK;
u32 status, dma_addr, ctrl;
unsigned long flags;
/* Clean TX Ring */
greth_clean_tx(greth->netdev);
if (unlikely(greth->tx_free <= 0)) {
spin_lock_irqsave(&greth->devlock, flags);/*save from poll/irq*/
ctrl = GRETH_REGLOAD(greth->regs->control);
/* Enable TX IRQ only if not already in poll() routine */
if (ctrl & GRETH_RXI)
GRETH_REGSAVE(greth->regs->control, ctrl | GRETH_TXI);
netif_stop_queue(dev);
spin_unlock_irqrestore(&greth->devlock, flags);
return NETDEV_TX_BUSY;
}
if (netif_msg_pktdata(greth))
greth_print_tx_packet(skb);
if (unlikely(skb->len > MAX_FRAME_SIZE)) {
dev->stats.tx_errors++;
goto out;
}
bdp = greth->tx_bd_base + greth->tx_next;
dma_addr = greth_read_bd(&bdp->addr);
memcpy((unsigned char *) phys_to_virt(dma_addr), skb->data, skb->len);
dma_sync_single_for_device(greth->dev, dma_addr, skb->len, DMA_TO_DEVICE);
status = GRETH_BD_EN | GRETH_BD_IE | (skb->len & GRETH_BD_LEN);
greth->tx_bufs_length[greth->tx_next] = skb->len & GRETH_BD_LEN;
/* Wrap around descriptor ring */
if (greth->tx_next == GRETH_TXBD_NUM_MASK) {
status |= GRETH_BD_WR;
}
greth->tx_next = NEXT_TX(greth->tx_next);
greth->tx_free--;
/* Write descriptor control word and enable transmission */
greth_write_bd(&bdp->stat, status);
spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/
greth_enable_tx(greth);
spin_unlock_irqrestore(&greth->devlock, flags);
out:
dev_kfree_skb(skb);
return err;
}
static int greth_rx_gbit(struct net_device *dev, int limit)
{
struct greth_private *greth;
struct greth_bd *bdp;
struct sk_buff *skb, *newskb;
int pkt_len;
int bad, count = 0;
u32 status, dma_addr;
unsigned long flags;
greth = netdev_priv(dev);
for (count = 0; count < limit; ++count) {
bdp = greth->rx_bd_base + greth->rx_cur;
skb = greth->rx_skbuff[greth->rx_cur];
GRETH_REGSAVE(greth->regs->status, GRETH_INT_RE | GRETH_INT_RX);
mb();
status = greth_read_bd(&bdp->stat);
bad = 0;
if (status & GRETH_BD_EN)
break;
/* Check status for errors. */
if (unlikely(status & GRETH_RXBD_STATUS)) {
if (status & GRETH_RXBD_ERR_FT) {
dev->stats.rx_length_errors++;
bad = 1;
} else if (status &
(GRETH_RXBD_ERR_AE | GRETH_RXBD_ERR_OE | GRETH_RXBD_ERR_LE)) {
dev->stats.rx_frame_errors++;
bad = 1;
} else if (status & GRETH_RXBD_ERR_CRC) {
dev->stats.rx_crc_errors++;
bad = 1;
}
}
/* Allocate new skb to replace current, not needed if the
* current skb can be reused */
if (!bad && (newskb=netdev_alloc_skb(dev, MAX_FRAME_SIZE + NET_IP_ALIGN))) {
skb_reserve(newskb, NET_IP_ALIGN);
dma_addr = dma_map_single(greth->dev,
newskb->data,
MAX_FRAME_SIZE + NET_IP_ALIGN,
DMA_FROM_DEVICE);
if (!dma_mapping_error(greth->dev, dma_addr)) {
/* Process the incoming frame. */
pkt_len = status & GRETH_BD_LEN;
dma_unmap_single(greth->dev,
greth_read_bd(&bdp->addr),
MAX_FRAME_SIZE + NET_IP_ALIGN,
DMA_FROM_DEVICE);
if (netif_msg_pktdata(greth))
greth_print_rx_packet(phys_to_virt(greth_read_bd(&bdp->addr)), pkt_len);
skb_put(skb, pkt_len);
if (dev->features & NETIF_F_RXCSUM && hw_checksummed(status))
skb->ip_summed = CHECKSUM_UNNECESSARY;
else
skb_checksum_none_assert(skb);
skb->protocol = eth_type_trans(skb, dev);
dev->stats.rx_packets++;
dev->stats.rx_bytes += pkt_len;
netif_receive_skb(skb);
greth->rx_skbuff[greth->rx_cur] = newskb;
greth_write_bd(&bdp->addr, dma_addr);
} else {
if (net_ratelimit())
dev_warn(greth->dev, "Could not create DMA mapping, dropping packet\n");
dev_kfree_skb(newskb);
/* reusing current skb, so it is a drop */
dev->stats.rx_dropped++;
}
} else if (bad) {
/* Bad Frame transfer, the skb is reused */
dev->stats.rx_dropped++;
} else {
/* Failed Allocating a new skb. This is rather stupid
* but the current "filled" skb is reused, as if
* transfer failure. One could argue that RX descriptor
* table handling should be divided into cleaning and
* filling as the TX part of the driver
*/
if (net_ratelimit())
dev_warn(greth->dev, "Could not allocate SKB, dropping packet\n");
/* reusing current skb, so it is a drop */
dev->stats.rx_dropped++;
}
status = GRETH_BD_EN | GRETH_BD_IE;
if (greth->rx_cur == GRETH_RXBD_NUM_MASK) {
status |= GRETH_BD_WR;
}
wmb();
greth_write_bd(&bdp->stat, status);
spin_lock_irqsave(&greth->devlock, flags);
greth_enable_rx(greth);
spin_unlock_irqrestore(&greth->devlock, flags);
greth->rx_cur = NEXT_RX(greth->rx_cur);
}
return count;
}
static int greth_rx(struct net_device *dev, int limit)
{
struct greth_private *greth;
struct greth_bd *bdp;
struct sk_buff *skb;
int pkt_len;
int bad, count;
u32 status, dma_addr;
unsigned long flags;
greth = netdev_priv(dev);
for (count = 0; count < limit; ++count) {
bdp = greth->rx_bd_base + greth->rx_cur;
GRETH_REGSAVE(greth->regs->status, GRETH_INT_RE | GRETH_INT_RX);
mb();
status = greth_read_bd(&bdp->stat);
if (unlikely(status & GRETH_BD_EN)) {
break;
}
dma_addr = greth_read_bd(&bdp->addr);
bad = 0;
/* Check status for errors. */
if (unlikely(status & GRETH_RXBD_STATUS)) {
if (status & GRETH_RXBD_ERR_FT) {
dev->stats.rx_length_errors++;
bad = 1;
}
if (status & (GRETH_RXBD_ERR_AE | GRETH_RXBD_ERR_OE)) {
dev->stats.rx_frame_errors++;
bad = 1;
}
if (status & GRETH_RXBD_ERR_CRC) {
dev->stats.rx_crc_errors++;
bad = 1;
}
}
if (unlikely(bad)) {
dev->stats.rx_errors++;
} else {
pkt_len = status & GRETH_BD_LEN;
skb = netdev_alloc_skb(dev, pkt_len + NET_IP_ALIGN);
if (unlikely(skb == NULL)) {
if (net_ratelimit())
dev_warn(&dev->dev, "low on memory - " "packet dropped\n");
dev->stats.rx_dropped++;
} else {
skb_reserve(skb, NET_IP_ALIGN);
dma_sync_single_for_cpu(greth->dev,
dma_addr,
pkt_len,
DMA_FROM_DEVICE);
if (netif_msg_pktdata(greth))
greth_print_rx_packet(phys_to_virt(dma_addr), pkt_len);
memcpy(skb_put(skb, pkt_len), phys_to_virt(dma_addr), pkt_len);
skb->protocol = eth_type_trans(skb, dev);
dev->stats.rx_bytes += pkt_len;
dev->stats.rx_packets++;
netif_receive_skb(skb);
}
}
status = GRETH_BD_EN | GRETH_BD_IE;
if (greth->rx_cur == GRETH_RXBD_NUM_MASK) {
status |= GRETH_BD_WR;
}
wmb();
greth_write_bd(&bdp->stat, status);
dma_sync_single_for_device(greth->dev, dma_addr, MAX_FRAME_SIZE, DMA_FROM_DEVICE);
spin_lock_irqsave(&greth->devlock, flags); /* save from XMIT */
greth_enable_rx(greth);
spin_unlock_irqrestore(&greth->devlock, flags);
greth->rx_cur = NEXT_RX(greth->rx_cur);
}
return count;
}
static netdev_tx_t
greth_start_xmit_gbit(struct sk_buff *skb, struct net_device *dev)
{
struct greth_private *greth = netdev_priv(dev);
struct greth_bd *bdp;
u32 status, dma_addr;
int curr_tx, nr_frags, i, err = NETDEV_TX_OK;
unsigned long flags;
u16 tx_last;
nr_frags = skb_shinfo(skb)->nr_frags;
tx_last = greth->tx_last;
rmb(); /* tx_last is updated by the poll task */
if (greth_num_free_bds(tx_last, greth->tx_next) < nr_frags + 1) {
netif_stop_queue(dev);
err = NETDEV_TX_BUSY;
goto out;
}
if (netif_msg_pktdata(greth))
greth_print_tx_packet(skb);
if (unlikely(skb->len > MAX_FRAME_SIZE)) {
dev->stats.tx_errors++;
goto out;
}
/* Save skb pointer. */
greth->tx_skbuff[greth->tx_next] = skb;
/* Linear buf */
if (nr_frags != 0)
status = GRETH_TXBD_MORE;
else
status = GRETH_BD_IE;
if (skb->ip_summed == CHECKSUM_PARTIAL)
status |= GRETH_TXBD_CSALL;
status |= skb_headlen(skb) & GRETH_BD_LEN;
if (greth->tx_next == GRETH_TXBD_NUM_MASK)
status |= GRETH_BD_WR;
bdp = greth->tx_bd_base + greth->tx_next;
greth_write_bd(&bdp->stat, status);
dma_addr = dma_map_single(greth->dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
if (unlikely(dma_mapping_error(greth->dev, dma_addr)))
goto map_error;
greth_write_bd(&bdp->addr, dma_addr);
curr_tx = NEXT_TX(greth->tx_next);
/* Frags */
for (i = 0; i < nr_frags; i++) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
greth->tx_skbuff[curr_tx] = NULL;
bdp = greth->tx_bd_base + curr_tx;
status = GRETH_BD_EN;
if (skb->ip_summed == CHECKSUM_PARTIAL)
status |= GRETH_TXBD_CSALL;
status |= skb_frag_size(frag) & GRETH_BD_LEN;
/* Wrap around descriptor ring */
if (curr_tx == GRETH_TXBD_NUM_MASK)
status |= GRETH_BD_WR;
/* More fragments left */
if (i < nr_frags - 1)
status |= GRETH_TXBD_MORE;
else
status |= GRETH_BD_IE; /* enable IRQ on last fragment */
greth_write_bd(&bdp->stat, status);
dma_addr = skb_frag_dma_map(greth->dev, frag, 0, skb_frag_size(frag),
DMA_TO_DEVICE);
if (unlikely(dma_mapping_error(greth->dev, dma_addr)))
goto frag_map_error;
greth_write_bd(&bdp->addr, dma_addr);
curr_tx = NEXT_TX(curr_tx);
}
wmb();
/* Enable the descriptor chain by enabling the first descriptor */
bdp = greth->tx_bd_base + greth->tx_next;
greth_write_bd(&bdp->stat,
greth_read_bd(&bdp->stat) | GRETH_BD_EN);
spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/
greth->tx_next = curr_tx;
greth_enable_tx_and_irq(greth);
spin_unlock_irqrestore(&greth->devlock, flags);
return NETDEV_TX_OK;
frag_map_error:
/* Unmap SKB mappings that succeeded and disable descriptor */
for (i = 0; greth->tx_next + i != curr_tx; i++) {
bdp = greth->tx_bd_base + greth->tx_next + i;
dma_unmap_single(greth->dev,
greth_read_bd(&bdp->addr),
greth_read_bd(&bdp->stat) & GRETH_BD_LEN,
DMA_TO_DEVICE);
greth_write_bd(&bdp->stat, 0);
}
map_error:
if (net_ratelimit())
dev_warn(greth->dev, "Could not create TX DMA mapping\n");
dev_kfree_skb(skb);
out:
return err;
}
static int greth_init_rings(struct greth_private *greth)
{
struct sk_buff *skb;
struct greth_bd *rx_bd, *tx_bd;
u32 dma_addr;
int i;
rx_bd = greth->rx_bd_base;
tx_bd = greth->tx_bd_base;
/* Initialize descriptor rings and buffers */
if (greth->gbit_mac) {
for (i = 0; i < GRETH_RXBD_NUM; i++) {
skb = netdev_alloc_skb(greth->netdev, MAX_FRAME_SIZE+NET_IP_ALIGN);
if (skb == NULL) {
if (netif_msg_ifup(greth))
dev_err(greth->dev, "Error allocating DMA ring.\n");
goto cleanup;
}
skb_reserve(skb, NET_IP_ALIGN);
dma_addr = dma_map_single(greth->dev,
skb->data,
MAX_FRAME_SIZE+NET_IP_ALIGN,
DMA_FROM_DEVICE);
if (dma_mapping_error(greth->dev, dma_addr)) {
if (netif_msg_ifup(greth))
dev_err(greth->dev, "Could not create initial DMA mapping\n");
goto cleanup;
}
greth->rx_skbuff[i] = skb;
greth_write_bd(&rx_bd[i].addr, dma_addr);
greth_write_bd(&rx_bd[i].stat, GRETH_BD_EN | GRETH_BD_IE);
}
} else {
/* 10/100 MAC uses a fixed set of buffers and copy to/from SKBs */
for (i = 0; i < GRETH_RXBD_NUM; i++) {
greth->rx_bufs[i] = kmalloc(MAX_FRAME_SIZE, GFP_KERNEL);
if (greth->rx_bufs[i] == NULL) {
if (netif_msg_ifup(greth))
dev_err(greth->dev, "Error allocating DMA ring.\n");
goto cleanup;
}
dma_addr = dma_map_single(greth->dev,
greth->rx_bufs[i],
MAX_FRAME_SIZE,
DMA_FROM_DEVICE);
if (dma_mapping_error(greth->dev, dma_addr)) {
if (netif_msg_ifup(greth))
dev_err(greth->dev, "Could not create initial DMA mapping\n");
goto cleanup;
}
greth_write_bd(&rx_bd[i].addr, dma_addr);
greth_write_bd(&rx_bd[i].stat, GRETH_BD_EN | GRETH_BD_IE);
}
for (i = 0; i < GRETH_TXBD_NUM; i++) {
greth->tx_bufs[i] = kmalloc(MAX_FRAME_SIZE, GFP_KERNEL);
if (greth->tx_bufs[i] == NULL) {
if (netif_msg_ifup(greth))
dev_err(greth->dev, "Error allocating DMA ring.\n");
goto cleanup;
}
dma_addr = dma_map_single(greth->dev,
greth->tx_bufs[i],
MAX_FRAME_SIZE,
DMA_TO_DEVICE);
if (dma_mapping_error(greth->dev, dma_addr)) {
if (netif_msg_ifup(greth))
dev_err(greth->dev, "Could not create initial DMA mapping\n");
goto cleanup;
}
greth_write_bd(&tx_bd[i].addr, dma_addr);
greth_write_bd(&tx_bd[i].stat, 0);
}
}
greth_write_bd(&rx_bd[GRETH_RXBD_NUM - 1].stat,
greth_read_bd(&rx_bd[GRETH_RXBD_NUM - 1].stat) | GRETH_BD_WR);
/* Initialize pointers. */
greth->rx_cur = 0;
greth->tx_next = 0;
greth->tx_last = 0;
greth->tx_free = GRETH_TXBD_NUM;
/* Initialize descriptor base address */
GRETH_REGSAVE(greth->regs->tx_desc_p, greth->tx_bd_base_phys);
GRETH_REGSAVE(greth->regs->rx_desc_p, greth->rx_bd_base_phys);
return 0;
cleanup:
greth_clean_rings(greth);
return -ENOMEM;
}
static netdev_tx_t
greth_start_xmit_gbit(struct sk_buff *skb, struct net_device *dev)
{
struct greth_private *greth = netdev_priv(dev);
struct greth_bd *bdp;
u32 status = 0, dma_addr, ctrl;
int curr_tx, nr_frags, i, err = NETDEV_TX_OK;
unsigned long flags;
nr_frags = skb_shinfo(skb)->nr_frags;
/* Clean TX Ring */
greth_clean_tx_gbit(dev);
if (greth->tx_free < nr_frags + 1) {
spin_lock_irqsave(&greth->devlock, flags);/*save from poll/irq*/
ctrl = GRETH_REGLOAD(greth->regs->control);
/* Enable TX IRQ only if not already in poll() routine */
if (ctrl & GRETH_RXI)
GRETH_REGSAVE(greth->regs->control, ctrl | GRETH_TXI);
netif_stop_queue(dev);
spin_unlock_irqrestore(&greth->devlock, flags);
err = NETDEV_TX_BUSY;
goto out;
}
if (netif_msg_pktdata(greth))
greth_print_tx_packet(skb);
if (unlikely(skb->len > MAX_FRAME_SIZE)) {
dev->stats.tx_errors++;
goto out;
}
/* Save skb pointer. */
greth->tx_skbuff[greth->tx_next] = skb;
/* Linear buf */
if (nr_frags != 0)
status = GRETH_TXBD_MORE;
status |= GRETH_TXBD_CSALL;
status |= skb_headlen(skb) & GRETH_BD_LEN;
if (greth->tx_next == GRETH_TXBD_NUM_MASK)
status |= GRETH_BD_WR;
bdp = greth->tx_bd_base + greth->tx_next;
greth_write_bd(&bdp->stat, status);
dma_addr = dma_map_single(greth->dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
if (unlikely(dma_mapping_error(greth->dev, dma_addr)))
goto map_error;
greth_write_bd(&bdp->addr, dma_addr);
curr_tx = NEXT_TX(greth->tx_next);
/* Frags */
for (i = 0; i < nr_frags; i++) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
greth->tx_skbuff[curr_tx] = NULL;
bdp = greth->tx_bd_base + curr_tx;
status = GRETH_TXBD_CSALL | GRETH_BD_EN;
status |= frag->size & GRETH_BD_LEN;
/* Wrap around descriptor ring */
if (curr_tx == GRETH_TXBD_NUM_MASK)
status |= GRETH_BD_WR;
/* More fragments left */
if (i < nr_frags - 1)
status |= GRETH_TXBD_MORE;
else
status |= GRETH_BD_IE; /* enable IRQ on last fragment */
greth_write_bd(&bdp->stat, status);
dma_addr = dma_map_page(greth->dev,
frag->page,
frag->page_offset,
frag->size,
DMA_TO_DEVICE);
if (unlikely(dma_mapping_error(greth->dev, dma_addr)))
goto frag_map_error;
greth_write_bd(&bdp->addr, dma_addr);
curr_tx = NEXT_TX(curr_tx);
}
wmb();
/* Enable the descriptor chain by enabling the first descriptor */
bdp = greth->tx_bd_base + greth->tx_next;
greth_write_bd(&bdp->stat, greth_read_bd(&bdp->stat) | GRETH_BD_EN);
greth->tx_next = curr_tx;
greth->tx_free -= nr_frags + 1;
wmb();
spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/
greth_enable_tx(greth);
spin_unlock_irqrestore(&greth->devlock, flags);
return NETDEV_TX_OK;
frag_map_error:
/* Unmap SKB mappings that succeeded and disable descriptor */
for (i = 0; greth->tx_next + i != curr_tx; i++) {
bdp = greth->tx_bd_base + greth->tx_next + i;
dma_unmap_single(greth->dev,
greth_read_bd(&bdp->addr),
greth_read_bd(&bdp->stat) & GRETH_BD_LEN,
DMA_TO_DEVICE);
greth_write_bd(&bdp->stat, 0);
}
map_error:
if (net_ratelimit())
dev_warn(greth->dev, "Could not create TX DMA mapping\n");
dev_kfree_skb(skb);
out:
return err;
}
static int greth_rx_gbit(struct net_device *dev, int limit)
{
struct greth_private *greth;
struct greth_bd *bdp;
struct sk_buff *skb, *newskb;
int pkt_len;
int bad, count = 0;
u32 status, dma_addr;
greth = netdev_priv(dev);
for (count = 0; count < limit; ++count) {
bdp = greth->rx_bd_base + greth->rx_cur;
skb = greth->rx_skbuff[greth->rx_cur];
status = greth_read_bd(&bdp->stat);
bad = 0;
if (status & GRETH_BD_EN)
break;
/* Check status for errors. */
if (unlikely(status & GRETH_RXBD_STATUS)) {
if (status & GRETH_RXBD_ERR_FT) {
dev->stats.rx_length_errors++;
bad = 1;
} else if (status &
(GRETH_RXBD_ERR_AE | GRETH_RXBD_ERR_OE | GRETH_RXBD_ERR_LE)) {
dev->stats.rx_frame_errors++;
bad = 1;
} else if (status & GRETH_RXBD_ERR_CRC) {
dev->stats.rx_crc_errors++;
bad = 1;
}
}
/* Allocate new skb to replace current */
newskb = netdev_alloc_skb(dev, MAX_FRAME_SIZE + NET_IP_ALIGN);
if (!bad && newskb) {
skb_reserve(newskb, NET_IP_ALIGN);
dma_addr = dma_map_single(greth->dev,
newskb->data,
MAX_FRAME_SIZE + NET_IP_ALIGN,
DMA_FROM_DEVICE);
if (!dma_mapping_error(greth->dev, dma_addr)) {
/* Process the incoming frame. */
pkt_len = status & GRETH_BD_LEN;
dma_unmap_single(greth->dev,
greth_read_bd(&bdp->addr),
MAX_FRAME_SIZE + NET_IP_ALIGN,
DMA_FROM_DEVICE);
if (netif_msg_pktdata(greth))
greth_print_rx_packet(phys_to_virt(greth_read_bd(&bdp->addr)), pkt_len);
skb_put(skb, pkt_len);
if (greth->flags & GRETH_FLAG_RX_CSUM && hw_checksummed(status))
skb->ip_summed = CHECKSUM_UNNECESSARY;
else
skb->ip_summed = CHECKSUM_NONE;
skb->protocol = eth_type_trans(skb, dev);
dev->stats.rx_packets++;
netif_receive_skb(skb);
greth->rx_skbuff[greth->rx_cur] = newskb;
greth_write_bd(&bdp->addr, dma_addr);
} else {
if (net_ratelimit())
dev_warn(greth->dev, "Could not create DMA mapping, dropping packet\n");
dev_kfree_skb(newskb);
dev->stats.rx_dropped++;
}
} else {
if (net_ratelimit())
dev_warn(greth->dev, "Could not allocate SKB, dropping packet\n");
dev->stats.rx_dropped++;
}
status = GRETH_BD_EN | GRETH_BD_IE;
if (greth->rx_cur == GRETH_RXBD_NUM_MASK) {
status |= GRETH_BD_WR;
}
wmb();
greth_write_bd(&bdp->stat, status);
greth_enable_rx(greth);
greth->rx_cur = NEXT_RX(greth->rx_cur);
}
return count;
}
static netdev_tx_t
greth_start_xmit_gbit(struct sk_buff *skb, struct net_device *dev)
{
struct greth_private *greth = netdev_priv(dev);
struct greth_bd *bdp;
u32 status = 0, dma_addr;
int curr_tx, nr_frags, i, err = NETDEV_TX_OK;
nr_frags = skb_shinfo(skb)->nr_frags;
if (greth->tx_free < nr_frags + 1) {
netif_stop_queue(dev);
err = NETDEV_TX_BUSY;
goto out;
}
if (netif_msg_pktdata(greth))
greth_print_tx_packet(skb);
if (unlikely(skb->len > MAX_FRAME_SIZE)) {
dev->stats.tx_errors++;
goto out;
}
/* Save skb pointer. */
greth->tx_skbuff[greth->tx_next] = skb;
/* Linear buf */
if (nr_frags != 0)
status = GRETH_TXBD_MORE;
status |= GRETH_TXBD_CSALL;
status |= skb_headlen(skb) & GRETH_BD_LEN;
if (greth->tx_next == GRETH_TXBD_NUM_MASK)
status |= GRETH_BD_WR;
bdp = greth->tx_bd_base + greth->tx_next;
greth_write_bd(&bdp->stat, status);
dma_addr = dma_map_single(greth->dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
if (unlikely(dma_mapping_error(greth->dev, dma_addr)))
goto map_error;
greth_write_bd(&bdp->addr, dma_addr);
curr_tx = NEXT_TX(greth->tx_next);
/* Frags */
for (i = 0; i < nr_frags; i++) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
greth->tx_skbuff[curr_tx] = NULL;
bdp = greth->tx_bd_base + curr_tx;
status = GRETH_TXBD_CSALL;
status |= frag->size & GRETH_BD_LEN;
/* Wrap around descriptor ring */
if (curr_tx == GRETH_TXBD_NUM_MASK)
status |= GRETH_BD_WR;
/* More fragments left */
if (i < nr_frags - 1)
status |= GRETH_TXBD_MORE;
/* ... last fragment, check if out of descriptors */
else if (greth->tx_free - nr_frags - 1 < (MAX_SKB_FRAGS + 1)) {
/* Enable interrupts and stop queue */
status |= GRETH_BD_IE;
netif_stop_queue(dev);
}
greth_write_bd(&bdp->stat, status);
dma_addr = dma_map_page(greth->dev,
frag->page,
frag->page_offset,
frag->size,
DMA_TO_DEVICE);
if (unlikely(dma_mapping_error(greth->dev, dma_addr)))
goto frag_map_error;
greth_write_bd(&bdp->addr, dma_addr);
curr_tx = NEXT_TX(curr_tx);
}
wmb();
/* Enable the descriptors that we configured ... */
for (i = 0; i < nr_frags + 1; i++) {
bdp = greth->tx_bd_base + greth->tx_next;
greth_write_bd(&bdp->stat, greth_read_bd(&bdp->stat) | GRETH_BD_EN);
greth->tx_next = NEXT_TX(greth->tx_next);
greth->tx_free--;
}
greth_enable_tx(greth);
return NETDEV_TX_OK;
frag_map_error:
/* Unmap SKB mappings that succeeded */
for (i = 0; greth->tx_next + i != curr_tx; i++) {
bdp = greth->tx_bd_base + greth->tx_next + i;
dma_unmap_single(greth->dev,
greth_read_bd(&bdp->addr),
greth_read_bd(&bdp->stat) & GRETH_BD_LEN,
DMA_TO_DEVICE);
}
map_error:
if (net_ratelimit())
dev_warn(greth->dev, "Could not create TX DMA mapping\n");
dev_kfree_skb(skb);
out:
return err;
}
static netdev_tx_t
greth_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct greth_private *greth = netdev_priv(dev);
struct greth_bd *bdp;
int err = NETDEV_TX_OK;
u32 status, dma_addr;
bdp = greth->tx_bd_base + greth->tx_next;
if (unlikely(greth->tx_free <= 0)) {
netif_stop_queue(dev);
return NETDEV_TX_BUSY;
}
if (netif_msg_pktdata(greth))
greth_print_tx_packet(skb);
if (unlikely(skb->len > MAX_FRAME_SIZE)) {
dev->stats.tx_errors++;
goto out;
}
dma_addr = greth_read_bd(&bdp->addr);
memcpy((unsigned char *) phys_to_virt(dma_addr), skb->data, skb->len);
dma_sync_single_for_device(greth->dev, dma_addr, skb->len, DMA_TO_DEVICE);
status = GRETH_BD_EN | (skb->len & GRETH_BD_LEN);
/* Wrap around descriptor ring */
if (greth->tx_next == GRETH_TXBD_NUM_MASK) {
status |= GRETH_BD_WR;
}
greth->tx_next = NEXT_TX(greth->tx_next);
greth->tx_free--;
/* No more descriptors */
if (unlikely(greth->tx_free == 0)) {
/* Free transmitted descriptors */
greth_clean_tx(dev);
/* If nothing was cleaned, stop queue & wait for irq */
if (unlikely(greth->tx_free == 0)) {
status |= GRETH_BD_IE;
netif_stop_queue(dev);
}
}
/* Write descriptor control word and enable transmission */
greth_write_bd(&bdp->stat, status);
greth_enable_tx(greth);
out:
dev_kfree_skb(skb);
return err;
}