lib82596.c

linux 内核源代码

		if (skb == NULL)
			return -1;
		skb_reserve(skb, 2);
		dma_addr = dma_map_single(dev->dev.parent, skb->data,
					  PKT_BUF_SZ, DMA_FROM_DEVICE);
		rbd->v_next = rbd+1;
		rbd->b_next = SWAP32(virt_to_dma(lp, rbd+1));
		rbd->b_addr = SWAP32(virt_to_dma(lp, rbd));
		rbd->skb = skb;
		rbd->v_data = skb->data;
		rbd->b_data = SWAP32(dma_addr);
		rbd->size = SWAP16(PKT_BUF_SZ);
	}
	lp->rbd_head = dma->rbds;
	rbd = dma->rbds + rx_ring_size - 1;
	rbd->v_next = dma->rbds;
	rbd->b_next = SWAP32(virt_to_dma(lp, dma->rbds));

	/* Now build the Receive Frame Descriptor List */

	for (i = 0, rfd = dma->rfds; i < rx_ring_size; i++, rfd++) {
		rfd->rbd = I596_NULL;
		rfd->v_next = rfd+1;
		rfd->v_prev = rfd-1;
		rfd->b_next = SWAP32(virt_to_dma(lp, rfd+1));
		rfd->cmd = SWAP16(CMD_FLEX);
	}
	lp->rfd_head = dma->rfds;
	dma->scb.rfd = SWAP32(virt_to_dma(lp, dma->rfds));
	rfd = dma->rfds;
	rfd->rbd = SWAP32(virt_to_dma(lp, lp->rbd_head));
	rfd->v_prev = dma->rfds + rx_ring_size - 1;
	rfd = dma->rfds + rx_ring_size - 1;
	rfd->v_next = dma->rfds;
	rfd->b_next = SWAP32(virt_to_dma(lp, dma->rfds));
	rfd->cmd = SWAP16(CMD_EOL|CMD_FLEX);

	DMA_WBACK_INV(dev, dma, sizeof(struct i596_dma));
	return 0;
}

static inline void remove_rx_bufs(struct net_device *dev)
{
	struct i596_private *lp = netdev_priv(dev);
	struct i596_rbd *rbd;
	int i;

	for (i = 0, rbd = lp->dma->rbds; i < rx_ring_size; i++, rbd++) {
		if (rbd->skb == NULL)
			break;
		dma_unmap_single(dev->dev.parent,
				 (dma_addr_t)SWAP32(rbd->b_data),
				 PKT_BUF_SZ, DMA_FROM_DEVICE);
		dev_kfree_skb(rbd->skb);
	}
}


static void rebuild_rx_bufs(struct net_device *dev)
{
	struct i596_private *lp = netdev_priv(dev);
	struct i596_dma *dma = lp->dma;
	int i;

	/* Ensure rx frame/buffer descriptors are tidy */

	for (i = 0; i < rx_ring_size; i++) {
		dma->rfds[i].rbd = I596_NULL;
		dma->rfds[i].cmd = SWAP16(CMD_FLEX);
	}
	dma->rfds[rx_ring_size-1].cmd = SWAP16(CMD_EOL|CMD_FLEX);
	lp->rfd_head = dma->rfds;
	dma->scb.rfd = SWAP32(virt_to_dma(lp, dma->rfds));
	lp->rbd_head = dma->rbds;
	dma->rfds[0].rbd = SWAP32(virt_to_dma(lp, dma->rbds));

	DMA_WBACK_INV(dev, dma, sizeof(struct i596_dma));
}


static int init_i596_mem(struct net_device *dev)
{
	struct i596_private *lp = netdev_priv(dev);
	struct i596_dma *dma = lp->dma;
	unsigned long flags;

	mpu_port(dev, PORT_RESET, 0);
	udelay(100);			/* Wait 100us - seems to help */

	/* change the scp address */

	lp->last_cmd = jiffies;

	dma->scp.sysbus = SYSBUS;
	dma->scp.iscp = SWAP32(virt_to_dma(lp, &(dma->iscp)));
	dma->iscp.scb = SWAP32(virt_to_dma(lp, &(dma->scb)));
	dma->iscp.stat = SWAP32(ISCP_BUSY);
	lp->cmd_backlog = 0;

	lp->cmd_head = NULL;
	dma->scb.cmd = I596_NULL;

	DEB(DEB_INIT, printk(KERN_DEBUG "%s: starting i82596.\n", dev->name));

	DMA_WBACK(dev, &(dma->scp), sizeof(struct i596_scp));
	DMA_WBACK(dev, &(dma->iscp), sizeof(struct i596_iscp));
	DMA_WBACK(dev, &(dma->scb), sizeof(struct i596_scb));

	mpu_port(dev, PORT_ALTSCP, virt_to_dma(lp, &dma->scp));
	ca(dev);
	if (wait_istat(dev, dma, 1000, "initialization timed out"))
		goto failed;
	DEB(DEB_INIT, printk(KERN_DEBUG
			     "%s: i82596 initialization successful\n",
			     dev->name));

	if (request_irq(dev->irq, &i596_interrupt, 0, "i82596", dev)) {
		printk(KERN_ERR "%s: IRQ %d not free\n", dev->name, dev->irq);
		goto failed;
	}

	/* Ensure rx frame/buffer descriptors are tidy */
	rebuild_rx_bufs(dev);

	dma->scb.command = 0;
	DMA_WBACK(dev, &(dma->scb), sizeof(struct i596_scb));

	DEB(DEB_INIT, printk(KERN_DEBUG
			     "%s: queuing CmdConfigure\n", dev->name));
	memcpy(dma->cf_cmd.i596_config, init_setup, 14);
	dma->cf_cmd.cmd.command = SWAP16(CmdConfigure);
	DMA_WBACK(dev, &(dma->cf_cmd), sizeof(struct cf_cmd));
	i596_add_cmd(dev, &dma->cf_cmd.cmd);

	DEB(DEB_INIT, printk(KERN_DEBUG "%s: queuing CmdSASetup\n", dev->name));
	memcpy(dma->sa_cmd.eth_addr, dev->dev_addr, 6);
	dma->sa_cmd.cmd.command = SWAP16(CmdSASetup);
	DMA_WBACK(dev, &(dma->sa_cmd), sizeof(struct sa_cmd));
	i596_add_cmd(dev, &dma->sa_cmd.cmd);

	DEB(DEB_INIT, printk(KERN_DEBUG "%s: queuing CmdTDR\n", dev->name));
	dma->tdr_cmd.cmd.command = SWAP16(CmdTDR);
	DMA_WBACK(dev, &(dma->tdr_cmd), sizeof(struct tdr_cmd));
	i596_add_cmd(dev, &dma->tdr_cmd.cmd);

	spin_lock_irqsave (&lp->lock, flags);

	if (wait_cmd(dev, dma, 1000, "timed out waiting to issue RX_START")) {
		spin_unlock_irqrestore (&lp->lock, flags);
		goto failed_free_irq;
	}
	DEB(DEB_INIT, printk(KERN_DEBUG "%s: Issuing RX_START\n", dev->name));
	dma->scb.command = SWAP16(RX_START);
	dma->scb.rfd = SWAP32(virt_to_dma(lp, dma->rfds));
	DMA_WBACK(dev, &(dma->scb), sizeof(struct i596_scb));

	ca(dev);

	spin_unlock_irqrestore (&lp->lock, flags);
	if (wait_cmd(dev, dma, 1000, "RX_START not processed"))
		goto failed_free_irq;
	DEB(DEB_INIT, printk(KERN_DEBUG
			     "%s: Receive unit started OK\n", dev->name));
	return 0;

failed_free_irq:
	free_irq(dev->irq, dev);
failed:
	printk(KERN_ERR "%s: Failed to initialise 82596\n", dev->name);
	mpu_port(dev, PORT_RESET, 0);
	return -1;
}


static inline int i596_rx(struct net_device *dev)
{
	struct i596_private *lp = netdev_priv(dev);
	struct i596_rfd *rfd;
	struct i596_rbd *rbd;
	int frames = 0;

	DEB(DEB_RXFRAME, printk(KERN_DEBUG
				"i596_rx(), rfd_head %p, rbd_head %p\n",
				lp->rfd_head, lp->rbd_head));


	rfd = lp->rfd_head;		/* Ref next frame to check */

	DMA_INV(dev, rfd, sizeof(struct i596_rfd));
	while (rfd->stat & SWAP16(STAT_C)) {	/* Loop while complete frames */
		if (rfd->rbd == I596_NULL)
			rbd = NULL;
		else if (rfd->rbd == lp->rbd_head->b_addr) {
			rbd = lp->rbd_head;
			DMA_INV(dev, rbd, sizeof(struct i596_rbd));
		} else {
			printk(KERN_ERR "%s: rbd chain broken!\n", dev->name);
			/* XXX Now what? */
			rbd = NULL;
		}
		DEB(DEB_RXFRAME, printk(KERN_DEBUG
				      "  rfd %p, rfd.rbd %08x, rfd.stat %04x\n",
				      rfd, rfd->rbd, rfd->stat));

		if (rbd != NULL && (rfd->stat & SWAP16(STAT_OK))) {
			/* a good frame */
			int pkt_len = SWAP16(rbd->count) & 0x3fff;
			struct sk_buff *skb = rbd->skb;
			int rx_in_place = 0;

			DEB(DEB_RXADDR, print_eth(rbd->v_data, "received"));
			frames++;

			/* Check if the packet is long enough to just accept
			 * without copying to a properly sized skbuff.
			 */

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

				dma_unmap_single(dev->dev.parent,
						 (dma_addr_t)SWAP32(rbd->b_data),
						 PKT_BUF_SZ, DMA_FROM_DEVICE);
				/* Get fresh skbuff to replace filled one. */
				newskb = netdev_alloc_skb(dev, PKT_BUF_SZ + 4);
				if (newskb == NULL) {
					skb = NULL;	/* drop pkt */
					goto memory_squeeze;
				}
				skb_reserve(newskb, 2);

				/* Pass up the skb already on the Rx ring. */
				skb_put(skb, pkt_len);
				rx_in_place = 1;
				rbd->skb = newskb;
				dma_addr = dma_map_single(dev->dev.parent,
							  newskb->data,
							  PKT_BUF_SZ,
							  DMA_FROM_DEVICE);
				rbd->v_data = newskb->data;
				rbd->b_data = SWAP32(dma_addr);
				DMA_WBACK_INV(dev, rbd, sizeof(struct i596_rbd));
			} else
				skb = netdev_alloc_skb(dev, pkt_len + 2);
memory_squeeze:
			if (skb == NULL) {
				/* XXX tulip.c can defer packets here!! */
				printk(KERN_ERR
				       "%s: i596_rx Memory squeeze, dropping packet.\n",
				       dev->name);
				dev->stats.rx_dropped++;
			} else {
				if (!rx_in_place) {
					/* 16 byte align the data fields */
					dma_sync_single_for_cpu(dev->dev.parent,
								(dma_addr_t)SWAP32(rbd->b_data),
								PKT_BUF_SZ, DMA_FROM_DEVICE);
					skb_reserve(skb, 2);
					memcpy(skb_put(skb, pkt_len), rbd->v_data, pkt_len);
					dma_sync_single_for_device(dev->dev.parent,
								   (dma_addr_t)SWAP32(rbd->b_data),
								   PKT_BUF_SZ, DMA_FROM_DEVICE);
				}
				skb->len = pkt_len;
				skb->protocol = eth_type_trans(skb, dev);
				netif_rx(skb);
				dev->last_rx = jiffies;
				dev->stats.rx_packets++;
				dev->stats.rx_bytes += pkt_len;
			}
		} else {
			DEB(DEB_ERRORS, printk(KERN_DEBUG
					       "%s: Error, rfd.stat = 0x%04x\n",
					       dev->name, rfd->stat));
			dev->stats.rx_errors++;
			if (rfd->stat & SWAP16(0x0100))
				dev->stats.collisions++;
			if (rfd->stat & SWAP16(0x8000))
				dev->stats.rx_length_errors++;
			if (rfd->stat & SWAP16(0x0001))
				dev->stats.rx_over_errors++;
			if (rfd->stat & SWAP16(0x0002))
				dev->stats.rx_fifo_errors++;
			if (rfd->stat & SWAP16(0x0004))
				dev->stats.rx_frame_errors++;
			if (rfd->stat & SWAP16(0x0008))
				dev->stats.rx_crc_errors++;
			if (rfd->stat & SWAP16(0x0010))
				dev->stats.rx_length_errors++;
		}

		/* Clear the buffer descriptor count and EOF + F flags */

		if (rbd != NULL && (rbd->count & SWAP16(0x4000))) {
			rbd->count = 0;
			lp->rbd_head = rbd->v_next;
			DMA_WBACK_INV(dev, rbd, sizeof(struct i596_rbd));
		}

		/* Tidy the frame descriptor, marking it as end of list */

		rfd->rbd = I596_NULL;
		rfd->stat = 0;
		rfd->cmd = SWAP16(CMD_EOL|CMD_FLEX);
		rfd->count = 0;

		/* Update record of next frame descriptor to process */

		lp->dma->scb.rfd = rfd->b_next;
		lp->rfd_head = rfd->v_next;
		DMA_WBACK_INV(dev, rfd, sizeof(struct i596_rfd));

		/* Remove end-of-list from old end descriptor */

		rfd->v_prev->cmd = SWAP16(CMD_FLEX);
		DMA_WBACK_INV(dev, rfd->v_prev, sizeof(struct i596_rfd));
		rfd = lp->rfd_head;
		DMA_INV(dev, rfd, sizeof(struct i596_rfd));
	}

	DEB(DEB_RXFRAME, printk(KERN_DEBUG "frames %d\n", frames));

	return 0;
}


static inline void i596_cleanup_cmd(struct net_device *dev, struct i596_private *lp)
{
	struct i596_cmd *ptr;

	while (lp->cmd_head != NULL) {
		ptr = lp->cmd_head;
		lp->cmd_head = ptr->v_next;
		lp->cmd_backlog--;

		switch (SWAP16(ptr->command) & 0x7) {
		case CmdTx:
			{
				struct tx_cmd *tx_cmd = (struct tx_cmd *) ptr;
				struct sk_buff *skb = tx_cmd->skb;
				dma_unmap_single(dev->dev.parent,
						 tx_cmd->dma_addr,
						 skb->len, DMA_TO_DEVICE);

				dev_kfree_skb(skb);

				dev->stats.tx_errors++;
				dev->stats.tx_aborted_errors++;

				ptr->v_next = NULL;
				ptr->b_next = I596_NULL;
				tx_cmd->cmd.command = 0;  /* Mark as free */
				break;
			}
		default:
			ptr->v_next = NULL;
			ptr->b_next = I596_NULL;
		}
		DMA_WBACK_INV(dev, ptr, sizeof(struct i596_cmd));
	}

	wait_cmd(dev, lp->dma, 100, "i596_cleanup_cmd timed out");
	lp->dma->scb.cmd = I596_NULL;
	DMA_WBACK(dev, &(lp->dma->scb), sizeof(struct i596_scb));
}


static inline void i596_reset(struct net_device *dev, struct i596_private *lp)
{
	unsigned long flags;

	DEB(DEB_RESET, printk(KERN_DEBUG "i596_reset\n"));

	spin_lock_irqsave (&lp->lock, flags);

	wait_cmd(dev, lp->dma, 100, "i596_reset timed out");

	netif_stop_queue(dev);

	/* FIXME: this command might cause an lpmc */
	lp->dma->scb.command = SWAP16(CUC_ABORT | RX_ABORT);
	DMA_WBACK(dev, &(lp->dma->scb), sizeof(struct i596_scb));
	ca(dev);

	/* wait for shutdown */
	wait_cmd(dev, lp->dma, 1000, "i596_reset 2 timed out");
	spin_unlock_irqrestore (&lp->lock, flags);

	i596_cleanup_cmd(dev, lp);
	i596_rx(dev);

	netif_start_queue(dev);
	init_i596_mem(dev);
}


static void i596_add_cmd(struct net_device *dev, struct i596_cmd *cmd)
{
	struct i596_private *lp = netdev_priv(dev);
	struct i596_dma *dma = lp->dma;
	unsigned long flags;

	DEB(DEB_ADDCMD, printk(KERN_DEBUG "i596_add_cmd cmd_head %p\n",
			       lp->cmd_head));

	cmd->status = 0;
	cmd->command |= SWAP16(CMD_EOL | CMD_INTR);
	cmd->v_next = NULL;
	cmd->b_next = I596_NULL;
	DMA_WBACK(dev, cmd, sizeof(struct i596_cmd));

	spin_lock_irqsave (&lp->lock, flags);

	if (lp->cmd_head != NULL) {
		lp->cmd_tail->v_next = cmd;
		lp->cmd_tail->b_next = SWAP32(virt_to_dma(lp, &cmd->status));
		DMA_WBACK(dev, lp->cmd_tail, sizeof(struct i596_cmd));
	} else {
		lp->cmd_head = cmd;
		wait_cmd(dev, dma, 100, "i596_add_cmd timed out");
		dma->scb.cmd = SWAP32(virt_to_dma(lp, &cmd->status));
		dma->scb.command = SWAP16(CUC_START);
		DMA_WBACK(dev, &(dma->scb), sizeof(struct i596_scb));
		ca(dev);
	}
	lp->cmd_tail = cmd;
	lp->cmd_backlog++;

	spin_unlock_irqrestore (&lp->lock, flags);

	if (lp->cmd_backlog > max_cmd_backlog) {
		unsigned long tickssofar = jiffies - lp->last_cmd;

		if (tickssofar < ticks_limit)
			return;

		printk(KERN_ERR
		       "%s: command unit timed out, status resetting.\n",
		       dev->name);
#if 1
		i596_reset(dev, lp);
#endif
	}
}

static int i596_open(struct net_device *dev)
{
	DEB(DEB_OPEN, printk(KERN_DEBUG
			     "%s: i596_open() irq %d.\n", dev->name, dev->irq));

	if (init_rx_bufs(dev)) {
		printk(KERN_ERR "%s: Failed to init rx bufs\n", dev->name);
		return -EAGAIN;
	}
	if (init_i596_mem(dev)) {
		printk(KERN_ERR "%s: Failed to init memory\n", dev->name);
		goto out_remove_rx_bufs;
	}
	netif_start_queue(dev);

	return 0;

out_remove_rx_bufs:
	remove_rx_bufs(dev);
	return -EAGAIN;
}

static void i596_tx_timeout (struct net_device *dev)
{
	struct i596_private *lp = netdev_priv(dev);