82596.c

讲述linux的初始化过程

	struct i596_tbd *tbd;
	short length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
	dev->trans_start = jiffies;

	DEB(DEB_STARTTX,printk("%s: i596_start_xmit(%x,%x) called\n", dev->name,
				skb->len, (unsigned int)skb->data));

	netif_stop_queue(dev);

	tx_cmd = lp->tx_cmds + lp->next_tx_cmd;
	tbd = lp->tbds + lp->next_tx_cmd;

	if (tx_cmd->cmd.command) {
		DEB(DEB_ERRORS,printk ("%s: xmit ring full, dropping packet.\n",
				dev->name));
		lp->stats.tx_dropped++;

		dev_kfree_skb(skb);
	} else {
		if (++lp->next_tx_cmd == TX_RING_SIZE)
			lp->next_tx_cmd = 0;
		tx_cmd->tbd = WSWAPtbd(virt_to_bus(tbd));
		tbd->next = I596_NULL;

		tx_cmd->cmd.command = CMD_FLEX | CmdTx;
		tx_cmd->skb = skb;

		tx_cmd->pad = 0;
		tx_cmd->size = 0;
		tbd->pad = 0;
		tbd->size = EOF | length;

		tbd->data = WSWAPchar(virt_to_bus(skb->data));

#ifdef __mc68000__
		cache_push(virt_to_phys(skb->data), length);
#endif
		DEB(DEB_TXADDR,print_eth(skb->data, "tx-queued"));
		i596_add_cmd(dev, &tx_cmd->cmd);

		lp->stats.tx_packets++;
		lp->stats.tx_bytes += length;
	}

	netif_start_queue(dev);

	return 0;
}

static void print_eth(unsigned char *add, char *str)
{
	int i;

	printk("i596 0x%p, ", add);
	for (i = 0; i < 6; i++)
		printk(" %02X", add[i + 6]);
	printk(" -->");
	for (i = 0; i < 6; i++)
		printk(" %02X", add[i]);
	printk(" %02X%02X, %s\n", add[12], add[13], str);
}

int __init i82596_probe(struct net_device *dev)
{
	int i;
	struct i596_private *lp;
	char eth_addr[8];
	static int probed = 0;

	if (probed)
		return -ENODEV;
	probed++;
#ifdef ENABLE_MVME16x_NET
	if (MACH_IS_MVME16x) {
		if (mvme16x_config & MVME16x_CONFIG_NO_ETHERNET) {
			printk("Ethernet probe disabled - chip not present\n");
			return -ENODEV;
		}
		memcpy(eth_addr, (void *) 0xfffc1f2c, 6);	/* YUCK! Get addr from NOVRAM */
		dev->base_addr = MVME_I596_BASE;
		dev->irq = (unsigned) MVME16x_IRQ_I596;
	}
#endif
#ifdef ENABLE_BVME6000_NET
	if (MACH_IS_BVME6000) {
		volatile unsigned char *rtc = (unsigned char *) BVME_RTC_BASE;
		unsigned char msr = rtc[3];
		int i;

		rtc[3] |= 0x80;
		for (i = 0; i < 6; i++)
			eth_addr[i] = rtc[i * 4 + 7];	/* Stored in RTC RAM at offset 1 */
		rtc[3] = msr;
		dev->base_addr = BVME_I596_BASE;
		dev->irq = (unsigned) BVME_IRQ_I596;
	}
#endif
#ifdef ENABLE_APRICOT
	{
		int checksum = 0;
		int ioaddr = 0x300;

		/* this is easy the ethernet interface can only be at 0x300 */
		/* first check nothing is already registered here */

		if (check_region(ioaddr, I596_TOTAL_SIZE)) {
			printk("82596: IO address 0x%04x in use\n", ioaddr);
			return -ENODEV;
		}

		for (i = 0; i < 8; i++) {
			eth_addr[i] = inb(ioaddr + 8 + i);
			checksum += eth_addr[i];
		}

		/* checksum is a multiple of 0x100, got this wrong first time
		   some machines have 0x100, some 0x200. The DOS driver doesn't
		   even bother with the checksum */

		if (checksum % 0x100)
			return -ENODEV;

		/* Some other boards trip the checksum.. but then appear as
		 * ether address 0. Trap these - AC */

		if (memcmp(eth_addr, "\x00\x00\x49", 3) != 0)
			return -ENODEV;

		if (!request_region(ioaddr, I596_TOTAL_SIZE, "i596"))
			return -ENODEV;

		dev->base_addr = ioaddr;
		dev->irq = 10;
	}
#endif
	dev->mem_start = (int)__get_free_pages(GFP_ATOMIC, 0);
	if (!dev->mem_start) {
#ifdef ENABLE_APRICOT
		release_region(dev->base_addr, I596_TOTAL_SIZE);
#endif
		return -ENOMEM;
	}

	ether_setup(dev);
	DEB(DEB_PROBE,printk("%s: 82596 at %#3lx,", dev->name, dev->base_addr));

	for (i = 0; i < 6; i++)
		DEB(DEB_PROBE,printk(" %2.2X", dev->dev_addr[i] = eth_addr[i]));

	DEB(DEB_PROBE,printk(" IRQ %d.\n", dev->irq));

	DEB(DEB_PROBE,printk(version));

	/* The 82596-specific entries in the device structure. */
	dev->open = i596_open;
	dev->stop = i596_close;
	dev->hard_start_xmit = i596_start_xmit;
	dev->get_stats = i596_get_stats;
	dev->set_multicast_list = set_multicast_list;
	dev->tx_timeout = i596_tx_timeout;
	dev->watchdog_timeo = TX_TIMEOUT;

	dev->priv = (void *)(dev->mem_start);

	lp = (struct i596_private *) dev->priv;
	DEB(DEB_INIT,printk ("%s: lp at 0x%08lx (%d bytes), lp->scb at 0x%08lx\n",
			dev->name, (unsigned long)lp,
			sizeof(struct i596_private), (unsigned long)&lp->scb));
	memset((void *) lp, 0, sizeof(struct i596_private));

#ifdef __mc68000__
	cache_push(virt_to_phys((void *)(dev->mem_start)), 4096);
	cache_clear(virt_to_phys((void *)(dev->mem_start)), 4096);
	kernel_set_cachemode((void *)(dev->mem_start), 4096, IOMAP_NOCACHE_SER);
#endif
	lp->scb.command = 0;
	lp->scb.cmd = I596_NULL;
	lp->scb.rfd = I596_NULL;
	lp->lock = SPIN_LOCK_UNLOCKED;

	return 0;
}

static void i596_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *dev = dev_id;
	struct i596_private *lp;
	short ioaddr;
	unsigned short status, ack_cmd = 0;

#ifdef ENABLE_BVME6000_NET
	if (MACH_IS_BVME6000) {
		if (*(char *) BVME_LOCAL_IRQ_STAT & BVME_ETHERR) {
			i596_error(BVME_IRQ_I596, NULL, NULL);
			return;
		}
	}
#endif
	if (dev == NULL) {
		printk("i596_interrupt(): irq %d for unknown device.\n", irq);
		return;
	}

	ioaddr = dev->base_addr;
	lp = (struct i596_private *) dev->priv;

	spin_lock (&lp->lock);

	wait_cmd(dev,lp,100,"i596 interrupt, timeout");
	status = lp->scb.status;

	DEB(DEB_INTS,printk("%s: i596 interrupt, IRQ %d, status %4.4x.\n",
			dev->name, irq, status));

	ack_cmd = status & 0xf000;

	if ((status & 0x8000) || (status & 0x2000)) {
		struct i596_cmd *ptr;

		if ((status & 0x8000))
			DEB(DEB_INTS,printk("%s: i596 interrupt completed command.\n", dev->name));
		if ((status & 0x2000))
			DEB(DEB_INTS,printk("%s: i596 interrupt command unit inactive %x.\n", dev->name, status & 0x0700));

		while ((lp->cmd_head != I596_NULL) && (lp->cmd_head->status & STAT_C)) {
			ptr = lp->cmd_head;

			DEB(DEB_STATUS,printk("cmd_head->status = %04x, ->command = %04x\n",
				       lp->cmd_head->status, lp->cmd_head->command));
			lp->cmd_head = ptr->v_next;
			lp->cmd_backlog--;

			switch ((ptr->command) & 0x7) {
			case CmdTx:
			    {
				struct tx_cmd *tx_cmd = (struct tx_cmd *) ptr;
				struct sk_buff *skb = tx_cmd->skb;

				if ((ptr->status) & STAT_OK) {
					DEB(DEB_TXADDR,print_eth(skb->data, "tx-done"));
				} else {
					lp->stats.tx_errors++;
					if ((ptr->status) & 0x0020)
						lp->stats.collisions++;
					if (!((ptr->status) & 0x0040))
						lp->stats.tx_heartbeat_errors++;
					if ((ptr->status) & 0x0400)
						lp->stats.tx_carrier_errors++;
					if ((ptr->status) & 0x0800)
						lp->stats.collisions++;
					if ((ptr->status) & 0x1000)
						lp->stats.tx_aborted_errors++;
				}

				dev_kfree_skb_irq(skb);

				tx_cmd->cmd.command = 0; /* Mark free */
				break;
			    }
			case CmdTDR:
			    {
				unsigned short status = ((struct tdr_cmd *)ptr)->status;

				if (status & 0x8000) {
					DEB(DEB_ANY,printk("%s: link ok.\n", dev->name));
				} else {
					if (status & 0x4000)
						printk("%s: Transceiver problem.\n", dev->name);
					if (status & 0x2000)
						printk("%s: Termination problem.\n", dev->name);
					if (status & 0x1000)
						printk("%s: Short circuit.\n", dev->name);

					DEB(DEB_TDR,printk("%s: Time %d.\n", dev->name, status & 0x07ff));
				}
				break;
			    }
			case CmdConfigure:
				/* Zap command so set_multicast_list() knows it is free */
				ptr->command = 0;
				break;
			}
			ptr->v_next = ptr->b_next = I596_NULL;
			lp->last_cmd = jiffies;
		}

		ptr = lp->cmd_head;
		while ((ptr != I596_NULL) && (ptr != lp->cmd_tail)) {
			ptr->command &= 0x1fff;
			ptr = ptr->v_next;
		}

		if ((lp->cmd_head != I596_NULL))
			ack_cmd |= CUC_START;
		lp->scb.cmd = WSWAPcmd(virt_to_bus(&lp->cmd_head->status));
	}
	if ((status & 0x1000) || (status & 0x4000)) {
		if ((status & 0x4000))
			DEB(DEB_INTS,printk("%s: i596 interrupt received a frame.\n", dev->name));
		i596_rx(dev);
		/* Only RX_START if stopped - RGH 07-07-96 */
		if (status & 0x1000) {
			if (netif_running(dev)) {
				DEB(DEB_ERRORS,printk("%s: i596 interrupt receive unit inactive, status 0x%x\n", dev->name, status));
				ack_cmd |= RX_START;
				lp->stats.rx_errors++;
				lp->stats.rx_fifo_errors++;
				rebuild_rx_bufs(dev);
			}
		}
	}
	wait_cmd(dev,lp,100,"i596 interrupt, timeout");
	lp->scb.command = ack_cmd;

#ifdef ENABLE_MVME16x_NET
	if (MACH_IS_MVME16x) {
		/* Ack the interrupt */

		volatile unsigned char *pcc2 = (unsigned char *) 0xfff42000;

		pcc2[0x2a] |= 0x08;
	}
#endif
#ifdef ENABLE_BVME6000_NET
	if (MACH_IS_BVME6000) {
		volatile unsigned char *ethirq = (unsigned char *) BVME_ETHIRQ_REG;

		*ethirq = 1;
		*ethirq = 3;
	}
#endif
#ifdef ENABLE_APRICOT
	(void) inb(ioaddr + 0x10);
	outb(4, ioaddr + 0xf);
#endif
	CA(dev);

	DEB(DEB_INTS,printk("%s: exiting interrupt.\n", dev->name));

	spin_unlock (&lp->lock);
	return;
}

static int i596_close(struct net_device *dev)
{
	struct i596_private *lp = (struct i596_private *) dev->priv;
	unsigned long flags;

	netif_stop_queue(dev);

	DEB(DEB_INIT,printk("%s: Shutting down ethercard, status was %4.4x.\n",
		       dev->name, lp->scb.status));

	save_flags(flags);
	cli();

	wait_cmd(dev,lp,100,"close1 timed out");
	lp->scb.command = CUC_ABORT | RX_ABORT;
	CA(dev);

	wait_cmd(dev,lp,100,"close2 timed out");
	restore_flags(flags);
	DEB(DEB_STRUCT,i596_display_data(dev));
	i596_cleanup_cmd(dev,lp);

#ifdef ENABLE_MVME16x_NET
	if (MACH_IS_MVME16x) {
		volatile unsigned char *pcc2 = (unsigned char *) 0xfff42000;

		/* Disable all ints */
		pcc2[0x28] = 1;
		pcc2[0x2a] = 0x40;
		pcc2[0x2b] = 0x40;	/* Set snooping bits now! */
	}
#endif
#ifdef ENABLE_BVME6000_NET
	if (MACH_IS_BVME6000) {
		volatile unsigned char *ethirq = (unsigned char *) BVME_ETHIRQ_REG;

		*ethirq = 1;
	}
#endif

	free_irq(dev->irq, dev);
	remove_rx_bufs(dev);
	MOD_DEC_USE_COUNT;

	return 0;
}

static struct net_device_stats *
 i596_get_stats(struct net_device *dev)
{
	struct i596_private *lp = (struct i596_private *) dev->priv;

	return &lp->stats;
}

/*
 *    Set or clear the multicast filter for this adaptor.
 */

static void set_multicast_list(struct net_device *dev)
{
	struct i596_private *lp = (struct i596_private *) dev->priv;
	int config = 0, cnt;

	DEB(DEB_MULTI,printk("%s: set multicast list, %d entries, promisc %s, allmulti %s\n", dev->name, dev->mc_count, dev->flags & IFF_PROMISC ? "ON" : "OFF", dev->flags & IFF_ALLMULTI ? "ON" : "OFF"));

	if ((dev->flags & IFF_PROMISC) && !(lp->cf_cmd.i596_config[8] & 0x01)) {
		lp->cf_cmd.i596_config[8] |= 0x01;
		config = 1;
	}
	if (!(dev->flags & IFF_PROMISC) && (lp->cf_cmd.i596_config[8] & 0x01)) {
		lp->cf_cmd.i596_config[8] &= ~0x01;
		config = 1;
	}
	if ((dev->flags & IFF_ALLMULTI) && (lp->cf_cmd.i596_config[11] & 0x20)) {
		lp->cf_cmd.i596_config[11] &= ~0x20;
		config = 1;
	}
	if (!(dev->flags & IFF_ALLMULTI) && !(lp->cf_cmd.i596_config[11] & 0x20)) {
		lp->cf_cmd.i596_config[11] |= 0x20;
		config = 1;
	}
	if (config) {
		if (lp->cf_cmd.cmd.command)
			printk("%s: config change request already queued\n",
			       dev->name);
		else {
			lp->cf_cmd.cmd.command = CmdConfigure;
			i596_add_cmd(dev, &lp->cf_cmd.cmd);
		}
	}

	cnt = dev->mc_count;
	if (cnt > MAX_MC_CNT)
	{
		cnt = MAX_MC_CNT;
		printk("%s: Only %d multicast addresses supported",
			dev->name, cnt);
	}
	
	if (dev->mc_count > 0) {
		struct dev_mc_list *dmi;
		unsigned char *cp;
		struct mc_cmd *cmd;

		cmd = &lp->mc_cmd;
		cmd->cmd.command = CmdMulticastList;
		cmd->mc_cnt = dev->mc_count * 6;
		cp = cmd->mc_addrs;
		for (dmi = dev->mc_list; cnt && dmi != NULL; dmi = dmi->next, cnt--, cp += 6) {
			memcpy(cp, dmi->dmi_addr, 6);
			if (i596_debug > 1)
				DEB(DEB_MULTI,printk("%s: Adding address %02x:%02x:%02x:%02x:%02x:%02x\n",
						dev->name, cp[0],cp[1],cp[2],cp[3],cp[4],cp[5]));
		}
		i596_add_cmd(dev, &cmd->cmd);
	}
}

#ifdef MODULE
static struct net_device dev_82596 = { init: i82596_probe };

#ifdef ENABLE_APRICOT
static int io = 0x300;
static int irq = 10;
MODULE_PARM(irq, "i");
#endif

MODULE_PARM(debug, "i");
static int debug = -1;

int init_module(void)
{
#ifdef ENABLE_APRICOT
	dev_82596.base_addr = io;
	dev_82596.irq = irq;
#endif
	if (debug >= 0)
		i596_debug = debug;
	if (register_netdev(&dev_82596) != 0)
		return -EIO;
	return 0;
}

void cleanup_module(void)
{
	unregister_netdev(&dev_82596);
#ifdef __mc68000__
	/* XXX This assumes default cache mode to be IOMAP_FULL_CACHING,
	 * XXX which may be invalid (CONFIG_060_WRITETHROUGH)
	 */

	kernel_set_cachemode((void *)(dev_82596.mem_start), 4096,
			IOMAP_FULL_CACHING);
#endif
	free_page ((u32)(dev_82596.mem_start));
	dev_82596.priv = NULL;
#ifdef ENABLE_APRICOT
	/* If we don't do this, we can't re-insmod it later. */
	release_region(dev_82596.base_addr, I596_TOTAL_SIZE);
#endif
}

#endif				/* MODULE */

/*
 * Local variables:
 *  compile-command: "gcc -D__KERNEL__ -I/usr/src/linux/net/inet -Wall -Wstrict-prototypes -O6 -m486 -c 82596.c"
 * End:
 */