e100.c

网卡的驱动程序源代码

		cb->prev = (i == 0) ? nic->cbs + count - 1 : cb - 1;

		cb->dma_addr = nic->cbs_dma_addr + i * sizeof(struct cb);
		cb->link = cpu_to_le32(nic->cbs_dma_addr +
			((i+1) % count) * sizeof(struct cb));
		cb->skb = NULL;
	}

	nic->cb_to_use = nic->cb_to_send = nic->cb_to_clean = nic->cbs;
	nic->cbs_avail = count;

	return 0;
}

static inline void e100_start_receiver(struct nic *nic, struct rx *rx)
{
	if(!nic->rxs) return;
	if(RU_SUSPENDED != nic->ru_running) return;

	/* handle init time starts */
	if(!rx) rx = nic->rxs;

	/* (Re)start RU if suspended or idle and RFA is non-NULL */
	if(rx->skb) {
		e100_exec_cmd(nic, ruc_start, rx->dma_addr);
		nic->ru_running = RU_RUNNING;
	}
}

#define RFD_BUF_LEN (sizeof(struct rfd) + VLAN_ETH_FRAME_LEN)
static int e100_rx_alloc_skb(struct nic *nic, struct rx *rx)
{
	if(!(rx->skb = dev_alloc_skb(RFD_BUF_LEN + NET_IP_ALIGN)))
		return -ENOMEM;

	/* Align, init, and map the RFD. */
	rx->skb->dev = nic->netdev;
	skb_reserve(rx->skb, NET_IP_ALIGN);
	memcpy(rx->skb->data, &nic->blank_rfd, sizeof(struct rfd));
	rx->dma_addr = pci_map_single(nic->pdev, rx->skb->data,
		RFD_BUF_LEN, PCI_DMA_BIDIRECTIONAL);

	if(pci_dma_mapping_error(rx->dma_addr)) {
		dev_kfree_skb_any(rx->skb);
		rx->skb = NULL;
		rx->dma_addr = 0;
		return -ENOMEM;
	}

	/* Link the RFD to end of RFA by linking previous RFD to
	 * this one, and clearing EL bit of previous.  */
	if(rx->prev->skb) {
		struct rfd *prev_rfd = (struct rfd *)rx->prev->skb->data;
		put_unaligned(cpu_to_le32(rx->dma_addr),
			(u32 *)&prev_rfd->link);
		wmb();
		prev_rfd->command &= ~cpu_to_le16(cb_el);
		pci_dma_sync_single_for_device(nic->pdev, rx->prev->dma_addr,
			sizeof(struct rfd), PCI_DMA_TODEVICE);
	}

	return 0;
}

static int e100_rx_indicate(struct nic *nic, struct rx *rx,
	unsigned int *work_done, unsigned int work_to_do)
{
	struct sk_buff *skb = rx->skb;
	struct rfd *rfd = (struct rfd *)skb->data;
	u16 rfd_status, actual_size;

	if(unlikely(work_done && *work_done >= work_to_do))
		return -EAGAIN;

	/* Need to sync before taking a peek at cb_complete bit */
	pci_dma_sync_single_for_cpu(nic->pdev, rx->dma_addr,
		sizeof(struct rfd), PCI_DMA_FROMDEVICE);
	rfd_status = le16_to_cpu(rfd->status);

	DPRINTK(RX_STATUS, DEBUG, "status=0x%04X\n", rfd_status);

	/* If data isn't ready, nothing to indicate */
	if(unlikely(!(rfd_status & cb_complete)))
		return -ENODATA;

	/* Get actual data size */
	actual_size = le16_to_cpu(rfd->actual_size) & 0x3FFF;
	if(unlikely(actual_size > RFD_BUF_LEN - sizeof(struct rfd)))
		actual_size = RFD_BUF_LEN - sizeof(struct rfd);

	/* Get data */
	pci_unmap_single(nic->pdev, rx->dma_addr,
		RFD_BUF_LEN, PCI_DMA_FROMDEVICE);

	/* this allows for a fast restart without re-enabling interrupts */
	if(le16_to_cpu(rfd->command) & cb_el)
		nic->ru_running = RU_SUSPENDED;

	/* Pull off the RFD and put the actual data (minus eth hdr) */
	skb_reserve(skb, sizeof(struct rfd));
	skb_put(skb, actual_size);
	skb->protocol = eth_type_trans(skb, nic->netdev);

	if(unlikely(!(rfd_status & cb_ok))) {
		/* Don't indicate if hardware indicates errors */
		dev_kfree_skb_any(skb);
	} else if(actual_size > ETH_DATA_LEN + VLAN_ETH_HLEN) {
		/* Don't indicate oversized frames */
		nic->rx_over_length_errors++;
		dev_kfree_skb_any(skb);
	} else {
		nic->net_stats.rx_packets++;
		nic->net_stats.rx_bytes += actual_size;
		nic->netdev->last_rx = jiffies;
#ifdef CONFIG_E100_NAPI
		netif_receive_skb(skb);
#else
		netif_rx(skb);
#endif
		if(work_done)
			(*work_done)++;
	}

	rx->skb = NULL;

	return 0;
}

static void e100_rx_clean(struct nic *nic, unsigned int *work_done,
	unsigned int work_to_do)
{
	struct rx *rx;
	int restart_required = 0;
	struct rx *rx_to_start = NULL;

	/* are we already rnr? then pay attention!!! this ensures that
	 * the state machine progression never allows a start with a
	 * partially cleaned list, avoiding a race between hardware
	 * and rx_to_clean when in NAPI mode */
	if(RU_SUSPENDED == nic->ru_running)
		restart_required = 1;

	/* Indicate newly arrived packets */
	for(rx = nic->rx_to_clean; rx->skb; rx = nic->rx_to_clean = rx->next) {
		int err = e100_rx_indicate(nic, rx, work_done, work_to_do);
		if(-EAGAIN == err) {
			/* hit quota so have more work to do, restart once
			 * cleanup is complete */
			restart_required = 0;
			break;
		} else if(-ENODATA == err)
			break; /* No more to clean */
	}

	/* save our starting point as the place we'll restart the receiver */
	if(restart_required)
		rx_to_start = nic->rx_to_clean;

	/* Alloc new skbs to refill list */
	for(rx = nic->rx_to_use; !rx->skb; rx = nic->rx_to_use = rx->next) {
		if(unlikely(e100_rx_alloc_skb(nic, rx)))
			break; /* Better luck next time (see watchdog) */
	}

	if(restart_required) {
		// ack the rnr?
		writeb(stat_ack_rnr, &nic->csr->scb.stat_ack);
		e100_start_receiver(nic, rx_to_start);
		if(work_done)
			(*work_done)++;
	}
}

static void e100_rx_clean_list(struct nic *nic)
{
	struct rx *rx;
	unsigned int i, count = nic->params.rfds.count;

	nic->ru_running = RU_UNINITIALIZED;

	if(nic->rxs) {
		for(rx = nic->rxs, i = 0; i < count; rx++, i++) {
			if(rx->skb) {
				pci_unmap_single(nic->pdev, rx->dma_addr,
					RFD_BUF_LEN, PCI_DMA_FROMDEVICE);
				dev_kfree_skb(rx->skb);
			}
		}
		kfree(nic->rxs);
		nic->rxs = NULL;
	}

	nic->rx_to_use = nic->rx_to_clean = NULL;
}

static int e100_rx_alloc_list(struct nic *nic)
{
	struct rx *rx;
	unsigned int i, count = nic->params.rfds.count;

	nic->rx_to_use = nic->rx_to_clean = NULL;
	nic->ru_running = RU_UNINITIALIZED;

	if(!(nic->rxs = kmalloc(sizeof(struct rx) * count, GFP_ATOMIC)))
		return -ENOMEM;
	memset(nic->rxs, 0, sizeof(struct rx) * count);

	for(rx = nic->rxs, i = 0; i < count; rx++, i++) {
		rx->next = (i + 1 < count) ? rx + 1 : nic->rxs;
		rx->prev = (i == 0) ? nic->rxs + count - 1 : rx - 1;
		if(e100_rx_alloc_skb(nic, rx)) {
			e100_rx_clean_list(nic);
			return -ENOMEM;
		}
	}

	nic->rx_to_use = nic->rx_to_clean = nic->rxs;
	nic->ru_running = RU_SUSPENDED;

	return 0;
}

static irqreturn_t e100_intr(int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *netdev = dev_id;
	struct nic *nic = netdev_priv(netdev);
	u8 stat_ack = readb(&nic->csr->scb.stat_ack);

	DPRINTK(INTR, DEBUG, "stat_ack = 0x%02X\n", stat_ack);

	if(stat_ack == stat_ack_not_ours ||	/* Not our interrupt */
	   stat_ack == stat_ack_not_present)	/* Hardware is ejected */
		return IRQ_NONE;

	/* Ack interrupt(s) */
	writeb(stat_ack, &nic->csr->scb.stat_ack);

	/* We hit Receive No Resource (RNR); restart RU after cleaning */
	if(stat_ack & stat_ack_rnr)
		nic->ru_running = RU_SUSPENDED;

#ifdef CONFIG_E100_NAPI
	if(likely(netif_rx_schedule_prep(netdev))) {
		e100_disable_irq(nic);
		__netif_rx_schedule(netdev);
	}
#else
	e100_rx_clean(nic, NULL, 0);
	e100_tx_clean(nic);
#endif

	return IRQ_HANDLED;
}

#ifdef CONFIG_E100_NAPI
static int e100_poll(struct net_device *netdev, int *budget)
{
	struct nic *nic = netdev_priv(netdev);
	unsigned int work_to_do = min(netdev->quota, *budget);
	unsigned int work_done = 0;
	int tx_cleaned;

	e100_rx_clean(nic, &work_done, work_to_do);
	tx_cleaned = e100_tx_clean(nic);

	/* If no Rx and Tx cleanup work was done, exit polling mode. */
	if((!tx_cleaned && (work_done == 0)) || !netif_running(netdev)) {
		netif_rx_complete(netdev);
		e100_enable_irq(nic);
		return 0;
	}

	*budget -= work_done;
	netdev->quota -= work_done;

	return 1;
}
#endif

#ifdef CONFIG_NET_POLL_CONTROLLER
static void e100_netpoll(struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);

	e100_disable_irq(nic);
	e100_intr(nic->pdev->irq, netdev, NULL);
	e100_tx_clean(nic);
	e100_enable_irq(nic);
}
#endif

static struct net_device_stats *e100_get_stats(struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);
	return &nic->net_stats;
}

static int e100_set_mac_address(struct net_device *netdev, void *p)
{
	struct nic *nic = netdev_priv(netdev);
	struct sockaddr *addr = p;

	if (!is_valid_ether_addr(addr->sa_data))
		return -EADDRNOTAVAIL;

	memcpy(netdev->dev_addr, addr->sa_data, netdev->addr_len);
	e100_exec_cb(nic, NULL, e100_setup_iaaddr);

	return 0;
}

static int e100_change_mtu(struct net_device *netdev, int new_mtu)
{
	if(new_mtu < ETH_ZLEN || new_mtu > ETH_DATA_LEN)
		return -EINVAL;
	netdev->mtu = new_mtu;
	return 0;
}

#ifdef CONFIG_PM
static int e100_asf(struct nic *nic)
{
	/* ASF can be enabled from eeprom */
	return((nic->pdev->device >= 0x1050) && (nic->pdev->device <= 0x1057) &&
	   (nic->eeprom[eeprom_config_asf] & eeprom_asf) &&
	   !(nic->eeprom[eeprom_config_asf] & eeprom_gcl) &&
	   ((nic->eeprom[eeprom_smbus_addr] & 0xFF) != 0xFE));
}
#endif

static int e100_up(struct nic *nic)
{
	int err;

	if((err = e100_rx_alloc_list(nic)))
		return err;
	if((err = e100_alloc_cbs(nic)))
		goto err_rx_clean_list;
	if((err = e100_hw_init(nic)))
		goto err_clean_cbs;
	e100_set_multicast_list(nic->netdev);
	e100_start_receiver(nic, NULL);
	mod_timer(&nic->watchdog, jiffies);
	if((err = request_irq(nic->pdev->irq, e100_intr, SA_SHIRQ,
		nic->netdev->name, nic->netdev)))
		goto err_no_irq;
	netif_wake_queue(nic->netdev);
#ifdef CONFIG_E100_NAPI
	netif_poll_enable(nic->netdev);
	/* enable ints _after_ enabling poll, preventing a race between
	 * disable ints+schedule */
#endif
	e100_enable_irq(nic);
	return 0;

err_no_irq:
	del_timer_sync(&nic->watchdog);
err_clean_cbs:
	e100_clean_cbs(nic);
err_rx_clean_list:
	e100_rx_clean_list(nic);
	return err;
}

static void e100_down(struct nic *nic)
{
#ifdef CONFIG_E100_NAPI
	/* wait here for poll to complete */
	netif_poll_disable(nic->netdev);
#endif
	netif_stop_queue(nic->netdev);
	e100_hw_reset(nic);
	free_irq(nic->pdev->irq, nic->netdev);
	del_timer_sync(&nic->watchdog);
	netif_carrier_off(nic->netdev);
	e100_clean_cbs(nic);
	e100_rx_clean_list(nic);
}

static void e100_tx_timeout(struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);

	/* Reset outside of interrupt context, to avoid request_irq
	 * in interrupt context */
	schedule_work(&nic->tx_timeout_task);
}

static void e100_tx_timeout_task(struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);

	DPRINTK(TX_ERR, DEBUG, "scb.status=0x%02X\n",
		readb(&nic->csr->scb.status));
	e100_down(netdev_priv(netdev));
	e100_up(netdev_priv(netdev));
}

static int e100_loopback_test(struct nic *nic, enum loopback loopback_mode)
{
	int err;
	struct sk_buff *skb;

	/* Use driver resources to perform internal MAC or PHY
	 * loopback test.  A single packet is prepared and transmitted
	 * in loopback mode, and the test passes if the received
	 * packet compares byte-for-byte to the transmitted packet. */

	if((err = e100_rx_alloc_list(nic)))
		return err;
	if((err = e100_alloc_cbs(nic)))
		goto err_clean_rx;

	/* ICH PHY loopback is broken so do MAC loopback instead */
	if(nic->flags & ich && loopback_mode == lb_phy)
		loopback_mode = lb_mac;

	nic->loopback = loopback_mode;
	if((err = e100_hw_init(nic)))
		goto err_loopback_none;

	if(loopback_mode == lb_phy)
		mdio_write(nic->netdev, nic->mii.phy_id, MII_BMCR,
			BMCR_LOOPBACK);

	e100_start_receiver(nic, NULL);

	if(!(skb = dev_alloc_skb(ETH_DATA_LEN))) {
		err = -ENOMEM;
		goto err_loopback_none;
	}
	skb_put(skb, ETH_DATA_LEN);
	memset(skb->data, 0xFF, ETH_DATA_LEN);
	e100_xmit_frame(skb, nic->netdev);

	msleep(10)