3c507.c

LINUX1.0内核源代码,学习LINUX编程的一定要看。

el16_send_packet(struct sk_buff *skb, struct device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;
	int ioaddr = dev->base_addr;
	short *shmem = (short*)dev->mem_start;

	if (dev->tbusy) {
		/* If we get here, some higher level has decided we are broken.
		   There should really be a "kick me" function call instead. */
		int tickssofar = jiffies - dev->trans_start;
		if (tickssofar < 5)
			return 1;
		if (net_debug > 1)
			printk("%s: transmit timed out, %s?  ", dev->name,
				   shmem[iSCB_STATUS>>1] & 0x8000 ? "IRQ conflict" :
				   "network cable problem");
		/* Try to restart the adaptor. */
		if (lp->last_restart == lp->stats.tx_packets) {
			if (net_debug > 1) printk("Resetting board.\n");
			/* Completely reset the adaptor. */
			init_82586_mem(dev);
		} else {
			/* Issue the channel attention signal and hope it "gets better". */
			if (net_debug > 1) printk("Kicking board.\n");
			shmem[iSCB_CMD>>1] = 0xf000|CUC_START|RX_START;
			outb(0, ioaddr + SIGNAL_CA);			/* Issue channel-attn. */
			lp->last_restart = lp->stats.tx_packets;
		}
		dev->tbusy=0;
		dev->trans_start = jiffies;
	}

	/* If some higher layer thinks we've missed an tx-done interrupt
	   we are passed NULL. Caution: dev_tint() handles the cli()/sti()
	   itself. */
	if (skb == NULL) {
		dev_tint(dev);
		return 0;
	}

	/* For ethernet, fill in the header.  This should really be done by a
	   higher level, rather than duplicated for each ethernet adaptor. */
	if (!skb->arp  &&  dev->rebuild_header(skb->data, dev)) {
		skb->dev = dev;
		arp_queue (skb);
		return 0;
	}
	skb->arp=1;

	/* Block a timer-based transmit from overlapping. */
	if (set_bit(0, (void*)&dev->tbusy) != 0)
		printk("%s: Transmitter access conflict.\n", dev->name);
	else {
		short length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
		unsigned char *buf = skb->data;

		/* Disable the 82586's input to the interrupt line. */
		outb(0x80, ioaddr + MISC_CTRL);
		hardware_send_packet(dev, buf, length);
		dev->trans_start = jiffies;
		/* Enable the 82586 interrupt input. */
		outb(0x84, ioaddr + MISC_CTRL);
	}

	if (skb->free)
		kfree_skb (skb, FREE_WRITE);

	/* You might need to clean up and record Tx statistics here. */

	return 0;
}

/*	The typical workload of the driver:
	Handle the network interface interrupts. */
static void
el16_interrupt(int reg_ptr)
{
	int irq = -(((struct pt_regs *)reg_ptr)->orig_eax+2);
	struct device *dev = (struct device *)(irq2dev_map[irq]);
	struct net_local *lp;
	int ioaddr, status, boguscount = 0;
	ushort ack_cmd = 0;
	ushort *shmem;
	
	if (dev == NULL) {
		printk ("net_interrupt(): irq %d for unknown device.\n", irq);
		return;
	}
	dev->interrupt = 1;
	
	ioaddr = dev->base_addr;
	lp = (struct net_local *)dev->priv;
	shmem = ((ushort*)dev->mem_start);
	
	status = shmem[iSCB_STATUS>>1];
	
	if (net_debug > 4) {
		printk("%s: 3c507 interrupt, status %4.4x.\n", dev->name, status);
	}

	/* Disable the 82586's input to the interrupt line. */
	outb(0x80, ioaddr + MISC_CTRL);

	/* Reap the Tx packet buffers. */
	while (lp->tx_reap != lp->tx_head) {
	  unsigned short tx_status = shmem[lp->tx_reap>>1];

	  if (tx_status == 0) {
		if (net_debug > 5)  printk("Couldn't reap %#x.\n", lp->tx_reap);
		break;
	  }
	  if (tx_status & 0x2000) {
		lp->stats.tx_packets++;
		lp->stats.collisions += tx_status & 0xf;
		dev->tbusy = 0;
		mark_bh(INET_BH);		/* Inform upper layers. */
	  } else {
		lp->stats.tx_errors++;
		if (tx_status & 0x0600)  lp->stats.tx_carrier_errors++;
		if (tx_status & 0x0100)  lp->stats.tx_fifo_errors++;
		if (!(tx_status & 0x0040))  lp->stats.tx_heartbeat_errors++;
		if (tx_status & 0x0020)  lp->stats.tx_aborted_errors++;
	  }
	  if (net_debug > 5)
		  printk("Reaped %x, Tx status %04x.\n" , lp->tx_reap, tx_status);
	  lp->tx_reap += TX_BUF_SIZE;
	  if (lp->tx_reap > RX_BUF_START - TX_BUF_SIZE)
		lp->tx_reap = TX_BUF_START;
	  if (++boguscount > 4)
		break;
	}

	if (status & 0x4000) { /* Packet received. */
		if (net_debug > 5)
			printk("Received packet, rx_head %04x.\n", lp->rx_head);
		el16_rx(dev);
	}

	/* Acknowledge the interrupt sources. */
	ack_cmd = status & 0xf000;

	if ((status & 0x0700) != 0x0200 && dev->start) {
		if (net_debug)
			printk("%s: Command unit stopped, status %04x, restarting.\n",
				   dev->name, status);
		/* If this ever occurs we should really re-write the idle loop, reset
		   the Tx list, and do a complete restart of the command unit.
		   For now we rely on the Tx timeout if the resume doesn't work. */
		ack_cmd |= CUC_RESUME;
	}

	if ((status & 0x0070) != 0x0040  &&  dev->start) {
	  static void init_rx_bufs(struct device *);
		/* The Rx unit is not ready, it must be hung.  Restart the receiver by
		   initializing the rx buffers, and issuing an Rx start command. */
		if (net_debug)
			printk("%s: Rx unit stopped, status %04x, restarting.\n",
				   dev->name, status);
		init_rx_bufs(dev);
		shmem[iSCB_RFA >> 1] = RX_BUF_START;
		ack_cmd |= RX_START;
	}

	shmem[iSCB_CMD>>1] = ack_cmd;
	outb(0, ioaddr + SIGNAL_CA);			/* Issue channel-attn. */

	/* Clear the latched interrupt. */
	outb(0, ioaddr + RESET_IRQ);

	/* Enable the 82586's interrupt input. */
	outb(0x84, ioaddr + MISC_CTRL);

	return;
}

static int
el16_close(struct device *dev)
{
	int ioaddr = dev->base_addr;
	ushort *shmem = (short*)dev->mem_start;

	dev->tbusy = 1;
	dev->start = 0;

	/* Flush the Tx and disable Rx. */
	shmem[iSCB_CMD >> 1] = RX_SUSPEND | CUC_SUSPEND;
	outb(0, ioaddr + SIGNAL_CA);

	/* Disable the 82586's input to the interrupt line. */
	outb(0x80, ioaddr + MISC_CTRL);

	/* We always physically use the IRQ line, so we don't do free_irq().
	   We do remove ourselves from the map. */

	irq2dev_map[dev->irq] = 0;

	/* Update the statistics here. */

	return 0;
}

/* Get the current statistics.	This may be called with the card open or
   closed. */
static struct enet_statistics *
el16_get_stats(struct device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;

	/* ToDo: decide if there are any useful statistics from the SCB. */

	return &lp->stats;
}

/* Initialize the Rx-block list. */
static void
init_rx_bufs(struct device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;
	unsigned short *write_ptr;
	unsigned short SCB_base = SCB_BASE;

	int cur_rxbuf = lp->rx_head = RX_BUF_START;
	
	/* Initialize each Rx frame + data buffer. */
	do {	/* While there is room for one more. */

	  write_ptr = (unsigned short *)(dev->mem_start + cur_rxbuf);

		*write_ptr++ = 0x0000; 				/* Status */
		*write_ptr++ = 0x0000;				/* Command */
		*write_ptr++ = cur_rxbuf + RX_BUF_SIZE; /* Link */
		*write_ptr++ = cur_rxbuf + 22;		/* Buffer offset */
		*write_ptr++ = 0x0000; 				/* Pad for dest addr. */
		*write_ptr++ = 0x0000;
		*write_ptr++ = 0x0000;
		*write_ptr++ = 0x0000; 				/* Pad for source addr. */
		*write_ptr++ = 0x0000;
		*write_ptr++ = 0x0000;
		*write_ptr++ = 0x0000;				/* Pad for protocol. */
		
		*write_ptr++ = 0x0000;				/* Buffer: Actual count */
		*write_ptr++ = -1;					/* Buffer: Next (none). */
		*write_ptr++ = cur_rxbuf + 0x20 + SCB_base;	/* Buffer: Address low */
		*write_ptr++ = 0x0000;
		/* Finally, the number of bytes in the buffer. */
		*write_ptr++ = 0x8000 + RX_BUF_SIZE-0x20;
		
		lp->rx_tail = cur_rxbuf;
		cur_rxbuf += RX_BUF_SIZE;
	} while (cur_rxbuf <= RX_BUF_END - RX_BUF_SIZE);
	
	/* Terminate the list by setting the EOL bit, and wrap the pointer to make
	   the list a ring. */
	write_ptr = (unsigned short *)
	  (dev->mem_start + lp->rx_tail + 2);
	*write_ptr++ = 0xC000;					/* Command, mark as last. */
	*write_ptr++ = lp->rx_head;				/* Link */

}

void
init_82586_mem(struct device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;
	short ioaddr = dev->base_addr;
	ushort *shmem = (short*)dev->mem_start;

	/* Enable loopback to protect the wire while starting up,
	   and hold the 586 in reset during the memory initialization. */
	outb(0x20, ioaddr + MISC_CTRL);

	/* Fix the ISCP address and base. */
	init_words[3] = SCB_BASE;
	init_words[7] = SCB_BASE;

	/* Write the words at 0xfff6 (address-aliased to 0xfffff6). */
	memcpy((void*)dev->mem_end-10, init_words, 10);

	/* Write the words at 0x0000. */
	memcpy((char*)dev->mem_start, init_words + 5, sizeof(init_words) - 10);

	/* Fill in the station address. */
	memcpy((char*)dev->mem_start+SA_OFFSET, dev->dev_addr,
		   sizeof(dev->dev_addr));

	/* The Tx-block list is written as needed.  We just set up the values. */
	lp->tx_cmd_link = IDLELOOP + 4;
	lp->tx_head = lp->tx_reap = TX_BUF_START;

	init_rx_bufs(dev);

	/* Start the 586 by releasing the reset line, but leave loopback. */
	outb(0xA0, ioaddr + MISC_CTRL);

	/* This was time consuming to track down: you need to give two channel
	   attention signals to reliably start up the i82586. */
	outb(0, ioaddr + SIGNAL_CA);

	{
		int boguscnt = 50;
		while (shmem[iSCB_STATUS>>1] == 0)
			if (--boguscnt == 0) {
				printk("%s: i82586 initialization timed out with status %04x,"
					   "cmd %04x.\n", dev->name,
					   shmem[iSCB_STATUS>>1], shmem[iSCB_CMD>>1]);
				break;
			}
		/* Issue channel-attn -- the 82586 won't start. */
		outb(0, ioaddr + SIGNAL_CA);
	}

	/* Disable loopback and enable interrupts. */
	outb(0x84, ioaddr + MISC_CTRL);
	if (net_debug > 4)
		printk("%s: Initialized 82586, status %04x.\n", dev->name,
			   shmem[iSCB_STATUS>>1]);
	return;
}

static void
hardware_send_packet(struct device *dev, void *buf, short length)
{
	struct net_local *lp = (struct net_local *)dev->priv;
	short ioaddr = dev->base_addr;
	ushort tx_block = lp->tx_head;
	ushort *write_ptr =	  (ushort *)(dev->mem_start + tx_block);

	/* Set the write pointer to the Tx block, and put out the header. */
	*write_ptr++ = 0x0000;				/* Tx status */
	*write_ptr++ = CMD_INTR|CmdTx;		/* Tx command */
	*write_ptr++ = tx_block+16;			/* Next command is a NoOp. */
	*write_ptr++ = tx_block+8;			/* Data Buffer offset. */

	/* Output the data buffer descriptor. */
	*write_ptr++ = length | 0x8000;		/* Byte count parameter. */
	*write_ptr++ = -1;					/* No next data buffer. */
	*write_ptr++ = tx_block+22+SCB_BASE;/* Buffer follows the NoOp command. */
	*write_ptr++ = 0x0000;				/* Buffer address high bits (always zero). */

	/* Output the Loop-back NoOp command. */
	*write_ptr++ = 0x0000;				/* Tx status */
	*write_ptr++ = CmdNOp;				/* Tx command */
	*write_ptr++ = tx_block+16;			/* Next is myself. */

	/* Output the packet at the write pointer. */
	memcpy(write_ptr, buf, length);

	/* Set the old command link pointing to this send packet. */
	*(ushort*)(dev->mem_start + lp->tx_cmd_link) = tx_block;
	lp->tx_cmd_link = tx_block + 20;

	/* Set the next free tx region. */
	lp->tx_head = tx_block + TX_BUF_SIZE;
	if (lp->tx_head > RX_BUF_START - TX_BUF_SIZE)
		lp->tx_head = TX_BUF_START;

	if (net_debug > 4) {
		printk("%s: 3c507 @%x send length = %d, tx_block %3x, next %3x.\n",
			   dev->name, ioaddr, length, tx_block, lp->tx_head);
	}

	if (lp->tx_head != lp->tx_reap)
		dev->tbusy = 0;
}

static void
el16_rx(struct device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;
	short *shmem = (short*)dev->mem_start;
	ushort rx_head = lp->rx_head;
	ushort rx_tail = lp->rx_tail;
	ushort boguscount = 10;
	short frame_status;

	while ((frame_status = shmem[rx_head>>1]) < 0) {   /* Command complete */
		ushort *read_frame =  (short *)(dev->mem_start + rx_head);
		ushort rfd_cmd = read_frame[1];
		ushort next_rx_frame = read_frame[2];
		ushort data_buffer_addr = read_frame[3];
		ushort *data_frame = (short *)(dev->mem_start + data_buffer_addr);
		ushort pkt_len = data_frame[0];

		if (rfd_cmd != 0 || data_buffer_addr != rx_head + 22
			|| pkt_len & 0xC000 != 0xC000) {
			printk("%s: Rx frame at %#x corrupted, status %04x cmd %04x"
				   "next %04x data-buf @%04x %04x.\n", dev->name, rx_head,
				   frame_status, rfd_cmd, next_rx_frame, data_buffer_addr,
				   pkt_len);
		} else if ((frame_status & 0x2000) == 0) {
			/* Frame Rxed, but with error. */
			lp->stats.rx_errors++;
			if (frame_status & 0x0800) lp->stats.rx_crc_errors++;
			if (frame_status & 0x0400) lp->stats.rx_frame_errors++;
			if (frame_status & 0x0200) lp->stats.rx_fifo_errors++;
			if (frame_status & 0x0100) lp->stats.rx_over_errors++;
			if (frame_status & 0x0080) lp->stats.rx_length_errors++;
		} else {
			/* Malloc up new buffer. */
			int sksize;
			struct sk_buff *skb;

			pkt_len &= 0x3fff;
			sksize = sizeof(struct sk_buff) + pkt_len;
			skb = alloc_skb(sksize, GFP_ATOMIC);
			if (skb == NULL) {
				printk("%s: Memory squeeze, dropping packet.\n", dev->name);
				lp->stats.rx_dropped++;
				break;
			}
			skb->mem_len = sksize;
			skb->mem_addr = skb;
			skb->len = pkt_len;
			skb->dev = dev;

			/* 'skb->data' points to the start of sk_buff data area. */
			memcpy(skb->data, data_frame + 5, pkt_len);
		
#ifdef HAVE_NETIF_RX
			netif_rx(skb);
#else
			skb->lock = 0;
			if (dev_rint((unsigned char*)skb, pkt_len, IN_SKBUFF, dev) != 0) {
				kfree_skbmem(skb, sksize);
				lp->stats.rx_dropped++;
				break;
			}
#endif
			lp->stats.rx_packets++;
		}

		/* Clear the status word and set End-of-List on the rx frame. */
		read_frame[0] = 0;
		read_frame[1] = 0xC000;
		/* Clear the end-of-list on the prev. RFD. */
		*(short*)(dev->mem_start + rx_tail + 2) = 0x0000;

		rx_tail = rx_head;
		rx_head = next_rx_frame;
		if (--boguscount == 0)
			break;
	}

	lp->rx_head = rx_head;
	lp->rx_tail = rx_tail;
}

/*
 * Local variables:
 *  compile-command: "gcc -D__KERNEL__ -I/usr/src/linux/net/inet -I/usr/src/linux/drivers/net -Wall -Wstrict-prototypes -O6 -m486 -c 3c507.c"
 *  version-control: t
 *  kept-new-versions: 5
 *  tab-width: 4
 *  c-indent-level: 4
 * End:
 */