3c505.c

linux设备驱动开发详解（书代码）

		if (send_pcb_fast(dev->base_addr, pcb->data.raw[i]))
			goto sti_abort;
	}

	outb_control(adapter->hcr_val | 3, dev);	/* signal end of PCB */
	outb_command(2 + pcb->length, dev->base_addr);

	/* now wait for the acknowledgement */
	spin_unlock_irqrestore(&adapter->lock, flags);

	for (timeout = jiffies + 5*HZ/100; time_before(jiffies, timeout);) {
		switch (GET_ASF(dev->base_addr)) {
		case ASF_PCB_ACK:
			adapter->send_pcb_semaphore = 0;
			return TRUE;

		case ASF_PCB_NAK:
#ifdef ELP_DEBUG
			printk(KERN_DEBUG "%s: send_pcb got NAK\n", dev->name);
#endif
			goto abort;
		}
	}

	if (elp_debug >= 1)
		printk(KERN_DEBUG "%s: timeout waiting for PCB acknowledge (status %02x)\n", dev->name, inb_status(dev->base_addr));
	goto abort;

      sti_abort:
	spin_unlock_irqrestore(&adapter->lock, flags);
      abort:
	adapter->send_pcb_semaphore = 0;
	return FALSE;
}


/*****************************************************************
 *
 * receive_pcb
 *   Read a PCB from the adapter
 *
 *	wait for ACRF to be non-zero        ---<---+
 *	input a byte                               |
 *	if ASF1 and ASF2 were not both one         |
 *		before byte was read, loop      --->---+
 *	set HSF1 and HSF2 for ack
 *
 *****************************************************************/

static int receive_pcb(struct net_device *dev, pcb_struct * pcb)
{
	int i, j;
	int total_length;
	int stat;
	unsigned long timeout;
	unsigned long flags;

	elp_device *adapter = dev->priv;

	set_hsf(dev, 0);

	/* get the command code */
	timeout = jiffies + 2*HZ/100;
	while (((stat = get_status(dev->base_addr)) & ACRF) == 0 && time_before(jiffies, timeout));
	if (time_after_eq(jiffies, timeout)) {
		TIMEOUT_MSG(__LINE__);
		return FALSE;
	}
	pcb->command = inb_command(dev->base_addr);

	/* read the data length */
	timeout = jiffies + 3*HZ/100;
	while (((stat = get_status(dev->base_addr)) & ACRF) == 0 && time_before(jiffies, timeout));
	if (time_after_eq(jiffies, timeout)) {
		TIMEOUT_MSG(__LINE__);
		printk(KERN_INFO "%s: status %02x\n", dev->name, stat);
		return FALSE;
	}
	pcb->length = inb_command(dev->base_addr);

	if (pcb->length > MAX_PCB_DATA) {
		INVALID_PCB_MSG(pcb->length);
		adapter_reset(dev);
		return FALSE;
	}
	/* read the data */
	spin_lock_irqsave(&adapter->lock, flags);
	i = 0;
	do {
		j = 0;
		while (((stat = get_status(dev->base_addr)) & ACRF) == 0 && j++ < 20000);
		pcb->data.raw[i++] = inb_command(dev->base_addr);
		if (i > MAX_PCB_DATA)
			INVALID_PCB_MSG(i);
	} while ((stat & ASF_PCB_MASK) != ASF_PCB_END && j < 20000);
	spin_unlock_irqrestore(&adapter->lock, flags);
	if (j >= 20000) {
		TIMEOUT_MSG(__LINE__);
		return FALSE;
	}
	/* woops, the last "data" byte was really the length! */
	total_length = pcb->data.raw[--i];

	/* safety check total length vs data length */
	if (total_length != (pcb->length + 2)) {
		if (elp_debug >= 2)
			printk(KERN_WARNING "%s: mangled PCB received\n", dev->name);
		set_hsf(dev, HSF_PCB_NAK);
		return FALSE;
	}

	if (pcb->command == CMD_RECEIVE_PACKET_COMPLETE) {
		if (test_and_set_bit(0, (void *) &adapter->busy)) {
			if (backlog_next(adapter->rx_backlog.in) == adapter->rx_backlog.out) {
				set_hsf(dev, HSF_PCB_NAK);
				printk(KERN_WARNING "%s: PCB rejected, transfer in progress and backlog full\n", dev->name);
				pcb->command = 0;
				return TRUE;
			} else {
				pcb->command = 0xff;
			}
		}
	}
	set_hsf(dev, HSF_PCB_ACK);
	return TRUE;
}

/******************************************************
 *
 *  queue a receive command on the adapter so we will get an
 *  interrupt when a packet is received.
 *
 ******************************************************/

static int start_receive(struct net_device *dev, pcb_struct * tx_pcb)
{
	int status;
	elp_device *adapter = dev->priv;

	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: restarting receiver\n", dev->name);
	tx_pcb->command = CMD_RECEIVE_PACKET;
	tx_pcb->length = sizeof(struct Rcv_pkt);
	tx_pcb->data.rcv_pkt.buf_seg
	    = tx_pcb->data.rcv_pkt.buf_ofs = 0;		/* Unused */
	tx_pcb->data.rcv_pkt.buf_len = 1600;
	tx_pcb->data.rcv_pkt.timeout = 0;	/* set timeout to zero */
	status = send_pcb(dev, tx_pcb);
	if (status)
		adapter->rx_active++;
	return status;
}

/******************************************************
 *
 * extract a packet from the adapter
 * this routine is only called from within the interrupt
 * service routine, so no cli/sti calls are needed
 * note that the length is always assumed to be even
 *
 ******************************************************/

static void receive_packet(struct net_device *dev, int len)
{
	int rlen;
	elp_device *adapter = dev->priv;
	void *target;
	struct sk_buff *skb;
	unsigned long flags;

	rlen = (len + 1) & ~1;
	skb = dev_alloc_skb(rlen + 2);

	if (!skb) {
		printk(KERN_WARNING "%s: memory squeeze, dropping packet\n", dev->name);
		target = adapter->dma_buffer;
		adapter->current_dma.target = NULL;
		/* FIXME: stats */
		return;
	}

	skb_reserve(skb, 2);
	target = skb_put(skb, rlen);
	if ((unsigned long)(target + rlen) >= MAX_DMA_ADDRESS) {
		adapter->current_dma.target = target;
		target = adapter->dma_buffer;
	} else {
		adapter->current_dma.target = NULL;
	}

	/* if this happens, we die */
	if (test_and_set_bit(0, (void *) &adapter->dmaing))
		printk(KERN_ERR "%s: rx blocked, DMA in progress, dir %d\n", dev->name, adapter->current_dma.direction);

	skb->dev = dev;
	adapter->current_dma.direction = 0;
	adapter->current_dma.length = rlen;
	adapter->current_dma.skb = skb;
	adapter->current_dma.start_time = jiffies;

	outb_control(adapter->hcr_val | DIR | TCEN | DMAE, dev);

	flags=claim_dma_lock();
	disable_dma(dev->dma);
	clear_dma_ff(dev->dma);
	set_dma_mode(dev->dma, 0x04);	/* dma read */
	set_dma_addr(dev->dma, isa_virt_to_bus(target));
	set_dma_count(dev->dma, rlen);
	enable_dma(dev->dma);
	release_dma_lock(flags);

	if (elp_debug >= 3) {
		printk(KERN_DEBUG "%s: rx DMA transfer started\n", dev->name);
	}

	if (adapter->rx_active)
		adapter->rx_active--;

	if (!adapter->busy)
		printk(KERN_WARNING "%s: receive_packet called, busy not set.\n", dev->name);
}

/******************************************************
 *
 * interrupt handler
 *
 ******************************************************/

static irqreturn_t elp_interrupt(int irq, void *dev_id, struct pt_regs *reg_ptr)
{
	int len;
	int dlen;
	int icount = 0;
	struct net_device *dev;
	elp_device *adapter;
	unsigned long timeout;

	dev = dev_id;
	adapter = (elp_device *) dev->priv;
	
	spin_lock(&adapter->lock);

	do {
		/*
		 * has a DMA transfer finished?
		 */
		if (inb_status(dev->base_addr) & DONE) {
			if (!adapter->dmaing) {
				printk(KERN_WARNING "%s: phantom DMA completed\n", dev->name);
			}
			if (elp_debug >= 3) {
				printk(KERN_DEBUG "%s: %s DMA complete, status %02x\n", dev->name, adapter->current_dma.direction ? "tx" : "rx", inb_status(dev->base_addr));
			}

			outb_control(adapter->hcr_val & ~(DMAE | TCEN | DIR), dev);
			if (adapter->current_dma.direction) {
				dev_kfree_skb_irq(adapter->current_dma.skb);
			} else {
				struct sk_buff *skb = adapter->current_dma.skb;
				if (skb) {
					if (adapter->current_dma.target) {
				  	/* have already done the skb_put() */
				  	memcpy(adapter->current_dma.target, adapter->dma_buffer, adapter->current_dma.length);
					}
					skb->protocol = eth_type_trans(skb,dev);
					adapter->stats.rx_bytes += skb->len;
					netif_rx(skb);
					dev->last_rx = jiffies;
				}
			}
			adapter->dmaing = 0;
			if (adapter->rx_backlog.in != adapter->rx_backlog.out) {
				int t = adapter->rx_backlog.length[adapter->rx_backlog.out];
				adapter->rx_backlog.out = backlog_next(adapter->rx_backlog.out);
				if (elp_debug >= 2)
					printk(KERN_DEBUG "%s: receiving backlogged packet (%d)\n", dev->name, t);
				receive_packet(dev, t);
			} else {
				adapter->busy = 0;
			}
		} else {
			/* has one timed out? */
			check_3c505_dma(dev);
		}

		/*
		 * receive a PCB from the adapter
		 */
		timeout = jiffies + 3*HZ/100;
		while ((inb_status(dev->base_addr) & ACRF) != 0 && time_before(jiffies, timeout)) {
			if (receive_pcb(dev, &adapter->irx_pcb)) {
				switch (adapter->irx_pcb.command) 
				{
				case 0:
					break;
					/*
					 * received a packet - this must be handled fast
					 */
				case 0xff:
				case CMD_RECEIVE_PACKET_COMPLETE:
					/* if the device isn't open, don't pass packets up the stack */
					if (!netif_running(dev))
						break;
					len = adapter->irx_pcb.data.rcv_resp.pkt_len;
					dlen = adapter->irx_pcb.data.rcv_resp.buf_len;
					if (adapter->irx_pcb.data.rcv_resp.timeout != 0) {
						printk(KERN_ERR "%s: interrupt - packet not received correctly\n", dev->name);
					} else {
						if (elp_debug >= 3) {
							printk(KERN_DEBUG "%s: interrupt - packet received of length %i (%i)\n", dev->name, len, dlen);
						}
						if (adapter->irx_pcb.command == 0xff) {
							if (elp_debug >= 2)
								printk(KERN_DEBUG "%s: adding packet to backlog (len = %d)\n", dev->name, dlen);
							adapter->rx_backlog.length[adapter->rx_backlog.in] = dlen;
							adapter->rx_backlog.in = backlog_next(adapter->rx_backlog.in);
						} else {
							receive_packet(dev, dlen);
						}
						if (elp_debug >= 3)
							printk(KERN_DEBUG "%s: packet received\n", dev->name);
					}
					break;

					/*
					 * 82586 configured correctly
					 */
				case CMD_CONFIGURE_82586_RESPONSE:
					adapter->got[CMD_CONFIGURE_82586] = 1;
					if (elp_debug >= 3)
						printk(KERN_DEBUG "%s: interrupt - configure response received\n", dev->name);
					break;

					/*
					 * Adapter memory configuration
					 */
				case CMD_CONFIGURE_ADAPTER_RESPONSE:
					adapter->got[CMD_CONFIGURE_ADAPTER_MEMORY] = 1;
					if (elp_debug >= 3)
						printk(KERN_DEBUG "%s: Adapter memory configuration %s.\n", dev->name,
						       adapter->irx_pcb.data.failed ? "failed" : "succeeded");
					break;

					/*
					 * Multicast list loading
					 */
				case CMD_LOAD_MULTICAST_RESPONSE:
					adapter->got[CMD_LOAD_MULTICAST_LIST] = 1;
					if (elp_debug >= 3)
						printk(KERN_DEBUG "%s: Multicast address list loading %s.\n", dev->name,
						       adapter->irx_pcb.data.failed ? "failed" : "succeeded");
					break;

					/*
					 * Station address setting
					 */
				case CMD_SET_ADDRESS_RESPONSE:
					adapter->got[CMD_SET_STATION_ADDRESS] = 1;
					if (elp_debug >= 3)
						printk(KERN_DEBUG "%s: Ethernet address setting %s.\n", dev->name,
						       adapter->irx_pcb.data.failed ? "failed" : "succeeded");
					break;


					/*
					 * received board statistics
					 */
				case CMD_NETWORK_STATISTICS_RESPONSE:
					adapter->stats.rx_packets += adapter->irx_pcb.data.netstat.tot_recv;
					adapter->stats.tx_packets += adapter->irx_pcb.data.netstat.tot_xmit;
					adapter->stats.rx_crc_errors += adapter->irx_pcb.data.netstat.err_CRC;
					adapter->stats.rx_frame_errors += adapter->irx_pcb.data.netstat.err_align;
					adapter->stats.rx_fifo_errors += adapter->irx_pcb.data.netstat.err_ovrrun;
					adapter->stats.rx_over_errors += adapter->irx_pcb.data.netstat.err_res;
					adapter->got[CMD_NETWORK_STATISTICS] = 1;
					if (elp_debug >= 3)
						printk(KERN_DEBUG "%s: interrupt - statistics response received\n", dev->name);
					break;

					/*
					 * sent a packet
					 */
				case CMD_TRANSMIT_PACKET_COMPLETE:
					if (elp_debug >= 3)
						printk(KERN_DEBUG "%s: interrupt - packet sent\n", dev->name);
					if (!netif_running(dev))
						break;
					switch (adapter->irx_pcb.data.xmit_resp.c_stat) {
					case 0xffff:
						adapter->stats.tx_aborted_errors++;
						printk(KERN_INFO "%s: transmit timed out, network cable problem?\n", dev->name);
						break;
					case 0xfffe:
						adapter->stats.tx_fifo_errors++;
						printk(KERN_INFO "%s: transmit timed out, FIFO underrun\n", dev->name);
						break;
					}
					netif_wake_queue(dev);
					break;

					/*
					 * some unknown PCB
					 */
				default:
					printk(KERN_DEBUG "%s: unknown PCB received - %2.2x\n", dev->name, adapter->irx_pcb.command);
					break;
				}
			} else {
				printk(KERN_WARNING "%s: failed to read PCB on interrupt\n", dev->name);
				adapter_reset(dev);
			}
		}

	} while (icount++ < 5 && (inb_status(dev->base_addr) & (ACRF | DONE)));

	prime_rx(dev);

	/*
	 * indicate no longer in interrupt routine
	 */
	spin_unlock(&adapter->lock);
	return IRQ_HANDLED;
}