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[PATCH] pcnet32: break receive routine into two pieces.
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Breaking the receive frame processing into two routines for greater clarity.

Tested ia32 and ppc64.

Signed-off-by:  Don Fry <brazilnut@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
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Don Fry authored and Jeff Garzik committed Sep 13, 2006
1 parent 9691edd commit 3904c32
Showing 1 changed file with 141 additions and 161 deletions.
302 changes: 141 additions & 161 deletions drivers/net/pcnet32.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1124,161 +1124,140 @@ static int pcnet32_suspend(struct net_device *dev, unsigned long *flags,
return 1;
}

/*
* process one receive descriptor entry
*/

static void pcnet32_rx_entry(struct net_device *dev,
struct pcnet32_private *lp,
struct pcnet32_rx_head *rxp,
int entry)
{
int status = (short)le16_to_cpu(rxp->status) >> 8;
int rx_in_place = 0;
struct sk_buff *skb;
short pkt_len;

if (status != 0x03) { /* There was an error. */
/*
* There is a tricky error noted by John Murphy,
* <murf@perftech.com> to Russ Nelson: Even with full-sized
* buffers it's possible for a jabber packet to use two
* buffers, with only the last correctly noting the error.
*/
if (status & 0x01) /* Only count a general error at the */
lp->stats.rx_errors++; /* end of a packet. */
if (status & 0x20)
lp->stats.rx_frame_errors++;
if (status & 0x10)
lp->stats.rx_over_errors++;
if (status & 0x08)
lp->stats.rx_crc_errors++;
if (status & 0x04)
lp->stats.rx_fifo_errors++;
return;
}

pkt_len = (le32_to_cpu(rxp->msg_length) & 0xfff) - 4;

/* Discard oversize frames. */
if (unlikely(pkt_len > PKT_BUF_SZ - 2)) {
if (netif_msg_drv(lp))
printk(KERN_ERR "%s: Impossible packet size %d!\n",
dev->name, pkt_len);
lp->stats.rx_errors++;
return;
}
if (pkt_len < 60) {
if (netif_msg_rx_err(lp))
printk(KERN_ERR "%s: Runt packet!\n", dev->name);
lp->stats.rx_errors++;
return;
}

if (pkt_len > rx_copybreak) {
struct sk_buff *newskb;

if ((newskb = dev_alloc_skb(PKT_BUF_SZ))) {
skb_reserve(newskb, 2);
skb = lp->rx_skbuff[entry];
pci_unmap_single(lp->pci_dev,
lp->rx_dma_addr[entry],
PKT_BUF_SZ - 2,
PCI_DMA_FROMDEVICE);
skb_put(skb, pkt_len);
lp->rx_skbuff[entry] = newskb;
newskb->dev = dev;
lp->rx_dma_addr[entry] =
pci_map_single(lp->pci_dev,
newskb->data,
PKT_BUF_SZ - 2,
PCI_DMA_FROMDEVICE);
rxp->base = le32_to_cpu(lp->rx_dma_addr[entry]);
rx_in_place = 1;
} else
skb = NULL;
} else {
skb = dev_alloc_skb(pkt_len + 2);
}

if (skb == NULL) {
if (netif_msg_drv(lp))
printk(KERN_ERR
"%s: Memory squeeze, dropping packet.\n",
dev->name);
lp->stats.rx_dropped++;
return;
}
skb->dev = dev;
if (!rx_in_place) {
skb_reserve(skb, 2); /* 16 byte align */
skb_put(skb, pkt_len); /* Make room */
pci_dma_sync_single_for_cpu(lp->pci_dev,
lp->rx_dma_addr[entry],
PKT_BUF_SZ - 2,
PCI_DMA_FROMDEVICE);
eth_copy_and_sum(skb,
(unsigned char *)(lp->rx_skbuff[entry]->data),
pkt_len, 0);
pci_dma_sync_single_for_device(lp->pci_dev,
lp->rx_dma_addr[entry],
PKT_BUF_SZ - 2,
PCI_DMA_FROMDEVICE);
}
lp->stats.rx_bytes += skb->len;
skb->protocol = eth_type_trans(skb, dev);
netif_rx(skb);
dev->last_rx = jiffies;
lp->stats.rx_packets++;
return;
}


static int pcnet32_rx(struct net_device *dev)
static void pcnet32_rx(struct net_device *dev)
{
struct pcnet32_private *lp = dev->priv;
int entry = lp->cur_rx & lp->rx_mod_mask;
struct pcnet32_rx_head *rxp = &lp->rx_ring[entry];
int npackets = 0;
int boguscnt = lp->rx_ring_size / 2;

/* If we own the next entry, it's a new packet. Send it up. */
while ((short)le16_to_cpu(lp->rx_ring[entry].status) >= 0) {
int status = (short)le16_to_cpu(lp->rx_ring[entry].status) >> 8;

if (status != 0x03) { /* There was an error. */
/*
* There is a tricky error noted by John Murphy,
* <murf@perftech.com> to Russ Nelson: Even with full-sized
* buffers it's possible for a jabber packet to use two
* buffers, with only the last correctly noting the error.
*/
if (status & 0x01) /* Only count a general error at the */
lp->stats.rx_errors++; /* end of a packet. */
if (status & 0x20)
lp->stats.rx_frame_errors++;
if (status & 0x10)
lp->stats.rx_over_errors++;
if (status & 0x08)
lp->stats.rx_crc_errors++;
if (status & 0x04)
lp->stats.rx_fifo_errors++;
lp->rx_ring[entry].status &= le16_to_cpu(0x03ff);
} else {
/* Malloc up new buffer, compatible with net-2e. */
short pkt_len =
(le32_to_cpu(lp->rx_ring[entry].msg_length) & 0xfff)
- 4;
struct sk_buff *skb;

/* Discard oversize frames. */
if (unlikely(pkt_len > PKT_BUF_SZ - 2)) {
if (netif_msg_drv(lp))
printk(KERN_ERR
"%s: Impossible packet size %d!\n",
dev->name, pkt_len);
lp->stats.rx_errors++;
} else if (pkt_len < 60) {
if (netif_msg_rx_err(lp))
printk(KERN_ERR "%s: Runt packet!\n",
dev->name);
lp->stats.rx_errors++;
} else {
int rx_in_place = 0;

if (pkt_len > rx_copybreak) {
struct sk_buff *newskb;

if ((newskb =
dev_alloc_skb(PKT_BUF_SZ))) {
skb_reserve(newskb, 2);
skb = lp->rx_skbuff[entry];
pci_unmap_single(lp->pci_dev,
lp->
rx_dma_addr
[entry],
PKT_BUF_SZ - 2,
PCI_DMA_FROMDEVICE);
skb_put(skb, pkt_len);
lp->rx_skbuff[entry] = newskb;
newskb->dev = dev;
lp->rx_dma_addr[entry] =
pci_map_single(lp->pci_dev,
newskb->data,
PKT_BUF_SZ -
2,
PCI_DMA_FROMDEVICE);
lp->rx_ring[entry].base =
le32_to_cpu(lp->
rx_dma_addr
[entry]);
rx_in_place = 1;
} else
skb = NULL;
} else {
skb = dev_alloc_skb(pkt_len + 2);
}

if (skb == NULL) {
int i;
if (netif_msg_drv(lp))
printk(KERN_ERR
"%s: Memory squeeze, deferring packet.\n",
dev->name);
for (i = 0; i < lp->rx_ring_size; i++)
if ((short)
le16_to_cpu(lp->
rx_ring[(entry +
i)
& lp->
rx_mod_mask].
status) < 0)
break;

if (i > lp->rx_ring_size - 2) {
lp->stats.rx_dropped++;
lp->rx_ring[entry].status |=
le16_to_cpu(0x8000);
wmb(); /* Make sure adapter sees owner change */
lp->cur_rx++;
}
break;
}
skb->dev = dev;
if (!rx_in_place) {
skb_reserve(skb, 2); /* 16 byte align */
skb_put(skb, pkt_len); /* Make room */
pci_dma_sync_single_for_cpu(lp->pci_dev,
lp->
rx_dma_addr
[entry],
PKT_BUF_SZ -
2,
PCI_DMA_FROMDEVICE);
eth_copy_and_sum(skb,
(unsigned char *)(lp->
rx_skbuff
[entry]->
data),
pkt_len, 0);
pci_dma_sync_single_for_device(lp->
pci_dev,
lp->
rx_dma_addr
[entry],
PKT_BUF_SZ
- 2,
PCI_DMA_FROMDEVICE);
}
lp->stats.rx_bytes += skb->len;
skb->protocol = eth_type_trans(skb, dev);
netif_rx(skb);
dev->last_rx = jiffies;
lp->stats.rx_packets++;
}
}
while (boguscnt > npackets && (short)le16_to_cpu(rxp->status) >= 0) {
pcnet32_rx_entry(dev, lp, rxp, entry);
npackets += 1;
/*
* The docs say that the buffer length isn't touched, but Andrew Boyd
* of QNX reports that some revs of the 79C965 clear it.
* The docs say that the buffer length isn't touched, but Andrew
* Boyd of QNX reports that some revs of the 79C965 clear it.
*/
lp->rx_ring[entry].buf_length = le16_to_cpu(2 - PKT_BUF_SZ);
wmb(); /* Make sure owner changes after all others are visible */
lp->rx_ring[entry].status |= le16_to_cpu(0x8000);
rxp->buf_length = le16_to_cpu(2 - PKT_BUF_SZ);
wmb(); /* Make sure owner changes after others are visible */
rxp->status = le16_to_cpu(0x8000);
entry = (++lp->cur_rx) & lp->rx_mod_mask;
if (--boguscnt <= 0)
break; /* don't stay in loop forever */
rxp = &lp->rx_ring[entry];
}

return 0;
return;
}

static int pcnet32_tx(struct net_device *dev, u16 csr0)
Expand All @@ -1298,7 +1277,7 @@ static int pcnet32_tx(struct net_device *dev, u16 csr0)
lp->tx_ring[entry].base = 0;

if (status & 0x4000) {
/* There was an major error, log it. */
/* There was a major error, log it. */
int err_status = le32_to_cpu(lp->tx_ring[entry].misc);
lp->stats.tx_errors++;
if (netif_msg_tx_err(lp))
Expand Down Expand Up @@ -1329,8 +1308,7 @@ static int pcnet32_tx(struct net_device *dev, u16 csr0)
if (!lp->dxsuflo) { /* If controller doesn't recover ... */
/* Ackk! On FIFO errors the Tx unit is turned off! */
/* Remove this verbosity later! */
if (netif_msg_tx_err
(lp))
if (netif_msg_tx_err(lp))
printk(KERN_ERR
"%s: Tx FIFO error! CSR0=%4.4x\n",
dev->name, csr0);
Expand All @@ -1350,16 +1328,14 @@ static int pcnet32_tx(struct net_device *dev, u16 csr0)
lp->tx_dma_addr[entry],
lp->tx_skbuff[entry]->
len, PCI_DMA_TODEVICE);
dev_kfree_skb_irq(lp->tx_skbuff[entry]);
dev_kfree_skb_any(lp->tx_skbuff[entry]);
lp->tx_skbuff[entry] = NULL;
lp->tx_dma_addr[entry] = 0;
}
dirty_tx++;
}

delta =
(lp->cur_tx - dirty_tx) & (lp->tx_mod_mask +
lp->tx_ring_size);
delta = (lp->cur_tx - dirty_tx) & (lp->tx_mod_mask + lp->tx_ring_size);
if (delta > lp->tx_ring_size) {
if (netif_msg_drv(lp))
printk(KERN_ERR
Expand Down Expand Up @@ -2535,19 +2511,20 @@ pcnet32_interrupt(int irq, void *dev_id, struct pt_regs *regs)

spin_lock(&lp->lock);

while ((csr0 = lp->a.read_csr(ioaddr, 0)) & 0x8f00 && --boguscnt >= 0) {
csr0 = lp->a.read_csr(ioaddr, CSR0);
while ((csr0 & 0x8f00) && --boguscnt >= 0) {
if (csr0 == 0xffff) {
break; /* PCMCIA remove happened */
}
/* Acknowledge all of the current interrupt sources ASAP. */
lp->a.write_csr(ioaddr, 0, csr0 & ~0x004f);
lp->a.write_csr(ioaddr, CSR0, csr0 & ~0x004f);

must_restart = 0;

if (netif_msg_intr(lp))
printk(KERN_DEBUG
"%s: interrupt csr0=%#2.2x new csr=%#2.2x.\n",
dev->name, csr0, lp->a.read_csr(ioaddr, 0));
dev->name, csr0, lp->a.read_csr(ioaddr, CSR0));

if (csr0 & 0x0400) /* Rx interrupt */
pcnet32_rx(dev);
Expand All @@ -2561,14 +2538,16 @@ pcnet32_interrupt(int irq, void *dev_id, struct pt_regs *regs)
lp->stats.tx_errors++; /* Tx babble. */
if (csr0 & 0x1000) {
/*
* this happens when our receive ring is full. This shouldn't
* be a problem as we will see normal rx interrupts for the frames
* in the receive ring. But there are some PCI chipsets (I can
* reproduce this on SP3G with Intel saturn chipset) which have
* sometimes problems and will fill up the receive ring with
* error descriptors. In this situation we don't get a rx
* interrupt, but a missed frame interrupt sooner or later.
* So we try to clean up our receive ring here.
* This happens when our receive ring is full. This
* shouldn't be a problem as we will see normal rx
* interrupts for the frames in the receive ring. But
* there are some PCI chipsets (I can reproduce this
* on SP3G with Intel saturn chipset) which have
* sometimes problems and will fill up the receive
* ring with error descriptors. In this situation we
* don't get a rx interrupt, but a missed frame
* interrupt sooner or later. So we try to clean up
* our receive ring here.
*/
pcnet32_rx(dev);
lp->stats.rx_errors++; /* Missed a Rx frame. */
Expand All @@ -2588,6 +2567,7 @@ pcnet32_interrupt(int irq, void *dev_id, struct pt_regs *regs)
pcnet32_restart(dev, CSR0_START);
netif_wake_queue(dev);
}
csr0 = lp->a.read_csr(ioaddr, CSR0);
}

/* Set interrupt enable. */
Expand Down

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