3c505.c

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

 * to respond to the initial interrupt.
 *
 * We run initially with interrupts turned on, but with a semaphore set
 * so that nobody tries to re-enter this code.  Once the first byte has
 * gone through, we turn interrupts off and then send the others (the
 * timeout is reduced to 500us).
 */

static int send_pcb(struct device *dev, pcb_struct * pcb)
{
	int i;
	int timeout;
	elp_device *adapter = dev->priv;

	check_dma(dev);

	if (adapter->dmaing && adapter->current_dma.direction == 0)
		return FALSE;

	/* Avoid contention */
	if (set_bit(1, &adapter->send_pcb_semaphore)) {
		if (elp_debug >= 3) {
			printk("%s: send_pcb entered while threaded\n", dev->name);
		}
		return FALSE;
	}
	/*
	 * load each byte into the command register and
	 * wait for the HCRE bit to indicate the adapter
	 * had read the byte
	 */
	set_hsf(dev->base_addr, 0);

	if (send_pcb_slow(dev->base_addr, pcb->command))
		goto abort;

	cli();

	if (send_pcb_fast(dev->base_addr, pcb->length))
		goto sti_abort;

	for (i = 0; i < pcb->length; i++) {
		if (send_pcb_fast(dev->base_addr, pcb->data.raw[i]))
			goto sti_abort;
	}

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

	/* now wait for the acknowledgement */
	sti();

	for (timeout = jiffies + 5; jiffies < timeout;) {
		switch (GET_ASF(dev->base_addr)) {
		case ASF_PCB_ACK:
			adapter->send_pcb_semaphore = 0;
			return TRUE;
			break;
		case ASF_PCB_NAK:
			printk("%s: send_pcb got NAK\n", dev->name);
			goto abort;
			break;
		}
	}

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

      sti_abort:
	sti();
      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 device *dev, pcb_struct * pcb)
{
	int i, j;
	int total_length;
	int stat;
	int timeout;

	elp_device *adapter = dev->priv;

	set_hsf(dev->base_addr, 0);

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

	/* read the data length */
	timeout = jiffies + 3;
	while (((stat = get_status(dev->base_addr)) & ACRF) == 0 && jiffies < timeout);
	if (jiffies >= timeout) {
		TIMEOUT_MSG(__LINE__);
		printk("%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 */
	cli();
	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);
	sti();
	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("%s: mangled PCB received\n", dev->name);
		set_hsf(dev->base_addr, HSF_PCB_NAK);
		return FALSE;
	}

	if (pcb->command == CMD_RECEIVE_PACKET_COMPLETE) {
		if (set_bit(0, (void *) &adapter->busy)) {
			if (backlog_next(adapter->rx_backlog.in) == adapter->rx_backlog.out) {
				set_hsf(dev->base_addr, HSF_PCB_NAK);
				printk("%s: PCB rejected, transfer in progress and backlog full\n", dev->name);
				pcb->command = 0;
				return TRUE;
			} else {
				pcb->command = 0xff;
			}
		}
	}
	set_hsf(dev->base_addr, 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 device *dev, pcb_struct * tx_pcb)
{
	int status;
	elp_device *adapter = dev->priv;

	if (elp_debug >= 3)
		printk("%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 device *dev, int len)
{
	int rlen;
	elp_device *adapter = dev->priv;
	unsigned long target;
	struct sk_buff *skb;

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

	adapter->current_dma.copy_flag = 0;

	if (!skb) {
	  printk("%s: memory squeeze, dropping packet\n", dev->name);
	  target = virt_to_bus(adapter->dma_buffer);
	} else {
	  skb_reserve(skb, 2);
	  target = virt_to_bus(skb_put(skb, rlen));
	  if ((target + rlen) >= MAX_DMA_ADDRESS) {
	    target = virt_to_bus(adapter->dma_buffer);
	    adapter->current_dma.copy_flag = 1;
	  }
	}
	/* if this happens, we die */
	if (set_bit(0, (void *) &adapter->dmaing))
		printk("%s: rx blocked, DMA in progress, dir %d\n", dev->name, adapter->current_dma.direction);

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

	outb_control(inb_control(dev->base_addr) | DIR | TCEN | DMAE, dev->base_addr);

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

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

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

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

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

	if (irq < 0 || irq > 15) {
		printk("elp_interrupt(): illegal IRQ number found in interrupt routine (%i)\n", irq);
		return;
	}
	dev = irq2dev_map[irq];

	if (dev == NULL) {
		printk("elp_interrupt(): irq %d for unknown device.\n", irq);
		return;
	}
	adapter = (elp_device *) dev->priv;

	if (dev->interrupt) {
		printk("%s: re-entering the interrupt handler!\n", dev->name);
		return;
	}
	dev->interrupt = 1;

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

			outb_control(inb_control(dev->base_addr) & ~(DMAE | TCEN | DIR), dev->base_addr);
			if (adapter->current_dma.direction) {
				dev_kfree_skb(adapter->current_dma.skb, FREE_WRITE);
			} else {
				struct sk_buff *skb = adapter->current_dma.skb;
				if (skb) {
				  skb->dev = dev;
				  if (adapter->current_dma.copy_flag) {
				    memcpy(skb_put(skb, adapter->current_dma.length), adapter->dma_buffer, adapter->current_dma.length);
				  }
				  skb->protocol = eth_type_trans(skb,dev);
				  netif_rx(skb);
				}
			}
			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("%s: receiving backlogged packet (%d)\n", dev->name, t);
				receive_packet(dev, t);
			} else {
				adapter->busy = 0;
			}
		} else {
			/* has one timed out? */
			check_dma(dev);
		}

		sti();

		/*
		 * receive a PCB from the adapter
		 */
		timeout = jiffies + 3;
		while ((inb_status(dev->base_addr) & ACRF) != 0 && 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 (dev->start == 0)
						break;
					cli();
					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("%s: interrupt - packet not received correctly\n", dev->name);
						sti();
					} else {
						if (elp_debug >= 3) {
							sti();
							printk("%s: interrupt - packet received of length %i (%i)\n", dev->name, len, dlen);
							cli();
						}
						if (adapter->irx_pcb.command == 0xff) {
							if (elp_debug >= 2)
								printk("%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);
						}
						sti();
						if (elp_debug >= 3)
							printk("%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("%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("%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("%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("%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("%s: interrupt - statistics response received\n", dev->name);
					break;

					/*
					 * sent a packet
					 */
				case CMD_TRANSMIT_PACKET_COMPLETE:
					if (elp_debug >= 3)
						printk("%s: interrupt - packet sent\n", dev->name);
					if (dev->start == 0)
						break;