netdev.c

DELL755 Intel 网卡驱动

	rx_ring->next_to_clean = 0;
	rx_ring->next_to_use = 0;

	writel(0, adapter->hw.hw_addr + rx_ring->head);
	writel(0, adapter->hw.hw_addr + rx_ring->tail);
}

/**
 * e1000_free_rx_resources - Free Rx Resources
 * @adapter: board private structure
 *
 * Free all receive software resources
 **/

void e1000_free_rx_resources(struct e1000_adapter *adapter)
{
	struct pci_dev *pdev = adapter->pdev;
	struct e1000_ring *rx_ring = adapter->rx_ring;
	int i;

	e1000_clean_rx_ring(adapter);

	for (i = 0; i < rx_ring->count; i++) {
		kfree(rx_ring->buffer_info[i].ps_pages);
	}

	vfree(rx_ring->buffer_info);
	rx_ring->buffer_info = NULL;

	dma_free_coherent(&pdev->dev, rx_ring->size, rx_ring->desc,
			  rx_ring->dma);
	rx_ring->desc = NULL;
}

/**
 * e1000_update_itr - update the dynamic ITR value based on statistics
 * @adapter: pointer to adapter
 * @itr_setting: current adapter->itr
 * @packets: the number of packets during this measurement interval
 * @bytes: the number of bytes during this measurement interval
 *
 *      Stores a new ITR value based on packets and byte
 *      counts during the last interrupt.  The advantage of per interrupt
 *      computation is faster updates and more accurate ITR for the current
 *      traffic pattern.  Constants in this function were computed
 *      based on theoretical maximum wire speed and thresholds were set based
 *      on testing data as well as attempting to minimize response time
 *      while increasing bulk throughput.  This functionality is controlled
 *      by the InterruptThrottleRate module parameter.
 **/
static unsigned int e1000_update_itr(struct e1000_adapter *adapter,
				     u16 itr_setting, int packets,
				     int bytes)
{
	unsigned int retval = itr_setting;

	if (packets == 0)
		goto update_itr_done;

	switch (itr_setting) {
	case lowest_latency:
		/* handle TSO and jumbo frames */
		if (bytes/packets > 8000)
			retval = bulk_latency;
		else if ((packets < 5) && (bytes > 512)) {
			retval = low_latency;
		}
		break;
	case low_latency:  /* 50 usec aka 20000 ints/s */
		if (bytes > 10000) {
			/* this if handles the TSO accounting */
			if (bytes/packets > 8000) {
				retval = bulk_latency;
			} else if ((packets < 10) || ((bytes/packets) > 1200)) {
				retval = bulk_latency;
			} else if ((packets > 35)) {
				retval = lowest_latency;
			}
		} else if (bytes/packets > 2000) {
			retval = bulk_latency;
		} else if (packets <= 2 && bytes < 512) {
			retval = lowest_latency;
		}
		break;
	case bulk_latency: /* 250 usec aka 4000 ints/s */
		if (bytes > 25000) {
			if (packets > 35) {
				retval = low_latency;
			}
		} else if (bytes < 6000) {
			retval = low_latency;
		}
		break;
	}

update_itr_done:
	return retval;
}

static void e1000_set_itr(struct e1000_adapter *adapter)
{
	struct e1000_hw *hw = &adapter->hw;
	u16 current_itr;
	u32 new_itr = adapter->itr;

	/* for non-gigabit speeds, just fix the interrupt rate at 4000 */
	if (adapter->link_speed != SPEED_1000) {
		current_itr = 0;
		new_itr = 4000;
		goto set_itr_now;
	}

	adapter->tx_itr = e1000_update_itr(adapter,
				    adapter->tx_itr,
				    adapter->total_tx_packets,
				    adapter->total_tx_bytes);
	/* conservative mode (itr 3) eliminates the lowest_latency setting */
	if (adapter->itr_setting == 3 && adapter->tx_itr == lowest_latency)
		adapter->tx_itr = low_latency;

	adapter->rx_itr = e1000_update_itr(adapter,
				    adapter->rx_itr,
				    adapter->total_rx_packets,
				    adapter->total_rx_bytes);
	/* conservative mode (itr 3) eliminates the lowest_latency setting */
	if (adapter->itr_setting == 3 && adapter->rx_itr == lowest_latency)
		adapter->rx_itr = low_latency;

	current_itr = max(adapter->rx_itr, adapter->tx_itr);

	switch (current_itr) {
	/* counts and packets in update_itr are dependent on these numbers */
	case lowest_latency:
		new_itr = 70000;
		break;
	case low_latency:
		new_itr = 20000; /* aka hwitr = ~200 */
		break;
	case bulk_latency:
		new_itr = 4000;
		break;
	default:
		break;
	}

set_itr_now:
	if (new_itr != adapter->itr) {
		/*
		 * this attempts to bias the interrupt rate towards Bulk
		 * by adding intermediate steps when interrupt rate is
		 * increasing
		 */
		new_itr = new_itr > adapter->itr ?
			     min(adapter->itr + (new_itr >> 2), new_itr) :
			     new_itr;
		adapter->itr = new_itr;
#ifdef CONFIG_E1000E_MSIX
		adapter->rx_ring->itr_val = new_itr;
		if (adapter->msix_entries)
			adapter->rx_ring->set_itr = 1;
		else
#endif
			ew32(ITR, 1000000000 / (new_itr * 256));
	}
}

/**
 * e1000_clean_tx_irq - Reclaim resources after transmit completes
 * @adapter: board private structure
 *
 * the return value indicates if there is more work to do (later)
 **/
static bool e1000_clean_tx_irq(struct e1000_adapter *adapter)
{
	struct net_device *netdev = adapter->netdev;
	struct e1000_hw *hw = &adapter->hw;
	struct e1000_ring *tx_ring = adapter->tx_ring;
	struct e1000_tx_desc *tx_desc, *eop_desc;
	struct e1000_buffer *buffer_info;
	unsigned int i, eop;
	bool cleaned = 0, retval = 1;
	unsigned int total_tx_bytes = 0, total_tx_packets = 0;

	i = tx_ring->next_to_clean;
	eop = tx_ring->buffer_info[i].next_to_watch;
	eop_desc = E1000_TX_DESC(*tx_ring, eop);

	while (eop_desc->upper.data & cpu_to_le32(E1000_TXD_STAT_DD)) {
		for (cleaned = 0; !cleaned; ) {
			tx_desc = E1000_TX_DESC(*tx_ring, i);
			buffer_info = &tx_ring->buffer_info[i];
			cleaned = (i == eop);

			if (cleaned) {
				struct sk_buff *skb = buffer_info->skb;
#ifdef NETIF_F_TSO
				unsigned int segs, bytecount;
				segs = skb_shinfo(skb)->gso_segs ?: 1;
				/* multiply data chunks by size of headers */
				bytecount = ((segs - 1) * skb_headlen(skb)) +
					    skb->len;
				total_tx_packets += segs;
				total_tx_bytes += bytecount;
#else
				total_tx_packets++;
				total_tx_bytes += skb->len;
#endif
			}

			e1000_put_txbuf(adapter, buffer_info);
			tx_desc->upper.data = 0;

			i++;
			if (i == tx_ring->count)
				i = 0;
#ifdef CONFIG_E1000E_NAPI
			if (total_tx_packets >= tx_ring->count) {
				retval = 0;
				goto done_cleaning;
			}
#endif
		}

		eop = tx_ring->buffer_info[i].next_to_watch;
		eop_desc = E1000_TX_DESC(*tx_ring, eop);
	}

#ifdef CONFIG_E1000E_NAPI
done_cleaning:
#endif
	tx_ring->next_to_clean = i;

#define TX_WAKE_THRESHOLD 32
	if (cleaned && netif_carrier_ok(netdev) &&
	    e1000_desc_unused(tx_ring) >= TX_WAKE_THRESHOLD) {
		/*
		 * Make sure that anybody stopping the queue after this
		 * sees the new next_to_clean.
		 */
		smp_mb();

		if (netif_queue_stopped(netdev) &&
		    !(test_bit(__E1000_DOWN, &adapter->state))) {
			netif_wake_queue(netdev);
			++adapter->restart_queue;
		}
	}

	if (adapter->detect_tx_hung) {
		/*
		 * Detect a transmit hang in hardware, this serializes the
		 * check with the clearing of time_stamp and movement of i
		 */
		adapter->detect_tx_hung = 0;
		if (tx_ring->buffer_info[eop].dma &&
		    time_after(jiffies, tx_ring->buffer_info[eop].time_stamp
			       + (adapter->tx_timeout_factor * HZ))
		    && !(er32(STATUS) & E1000_STATUS_TXOFF)) {
			e1000_print_tx_hang(adapter);
			netif_stop_queue(netdev);
		}
	}
	adapter->total_tx_bytes += total_tx_bytes;
	adapter->total_tx_packets += total_tx_packets;
	adapter->net_stats.tx_bytes += total_tx_bytes;
	adapter->net_stats.tx_packets += total_tx_packets;
	return retval;
}

/**
 * e1000_intr_msi - Interrupt Handler
 * @irq: interrupt number
 * @data: pointer to a network interface device structure
 **/
static irqreturn_t e1000_intr_msi(int irq, void *data)
{
	struct net_device *netdev = data;
	struct e1000_adapter *adapter = netdev_priv(netdev);
	struct e1000_hw *hw = &adapter->hw;
#ifndef CONFIG_E1000E_NAPI
	int i;
#endif
	/* read ICR disables interrupts using IAM */
	u32 icr = er32(ICR);

	if (icr & (E1000_ICR_RXSEQ | E1000_ICR_LSC)) {
		hw->mac.get_link_status = 1;
		/*
		 * ICH8 workaround-- Call gig speed drop workaround on cable
		 * disconnect (LSC) before accessing any PHY registers
		 */
		if ((adapter->flags & FLAG_LSC_GIG_SPEED_DROP) &&
		    (!(er32(STATUS) & E1000_STATUS_LU)))
			e1000_gig_downshift_workaround_ich8lan(hw);

		/*
		 * 80003ES2LAN workaround-- For packet buffer work-around on
		 * link down event; disable receives here in the ISR and reset
		 * adapter in watchdog
		 */
		if (netif_carrier_ok(netdev) &&
		    adapter->flags & FLAG_RX_NEEDS_RESTART) {
			/* disable receives */
			u32 rctl = er32(RCTL);
			ew32(RCTL, rctl & ~E1000_RCTL_EN);
			adapter->flags |= FLAG_RX_RESTART_NOW;
		}
		/* guard against interrupt when we're going down */
		if (!test_bit(__E1000_DOWN, &adapter->state))
			mod_timer(&adapter->watchdog_timer, jiffies + 1);
	}

#ifdef CONFIG_E1000E_NAPI
	if (netif_rx_schedule_prep(netdev, &adapter->napi)) {
		adapter->total_tx_bytes = 0;
		adapter->total_tx_packets = 0;
		adapter->total_rx_bytes = 0;
		adapter->total_rx_packets = 0;
		__netif_rx_schedule(netdev, &adapter->napi);
	}
#else
	adapter->total_tx_bytes = 0;
	adapter->total_rx_bytes = 0;
	adapter->total_tx_packets = 0;
	adapter->total_rx_packets = 0;

	for (i = 0; i < E1000_MAX_INTR; i++) {
		int rx_cleaned = adapter->clean_rx(adapter);
		int tx_cleaned_complete = e1000_clean_tx_irq(adapter);
		if (!rx_cleaned && tx_cleaned_complete)
			break;
	}

	if (likely(adapter->itr_setting & 3))
		e1000_set_itr(adapter);
#endif /* CONFIG_E1000E_NAPI */

	return IRQ_HANDLED;
}

/**
 * e1000_intr - Interrupt Handler
 * @irq: interrupt number
 * @data: pointer to a network interface device structure
 **/
static irqreturn_t e1000_intr(int irq, void *data)
{
	struct net_device *netdev = data;
	struct e1000_adapter *adapter = netdev_priv(netdev);
	struct e1000_hw *hw = &adapter->hw;
#ifndef CONFIG_E1000E_NAPI
	int i;
	int rx_cleaned, tx_cleaned_complete;
#endif
	u32 rctl, icr = er32(ICR);

	if (!icr)
		return IRQ_NONE;  /* Not our interrupt */

#ifdef CONFIG_E1000E_NAPI
	/*
	 * IMS will not auto-mask if INT_ASSERTED is not set, and if it is
	 * not set, then the adapter didn't send an interrupt
	 */
	if (!(icr & E1000_ICR_INT_ASSERTED))
		return IRQ_NONE;

#endif /* CONFIG_E1000E_NAPI */
	if (icr & (E1000_ICR_RXSEQ | E1000_ICR_LSC)) {
		hw->mac.get_link_status = 1;
		/*
		 * ICH8 workaround-- Call gig speed drop workaround on cable
		 * disconnect (LSC) before accessing any PHY registers
		 */
		if ((adapter->flags & FLAG_LSC_GIG_SPEED_DROP) &&
		    (!(er32(STATUS) & E1000_STATUS_LU)))
			e1000_gig_downshift_workaround_ich8lan(hw);

		/*
		 * 80003ES2LAN workaround--
		 * For packet buffer work-around on link down event;
		 * disable receives here in the ISR and
		 * reset adapter in watchdog
		 */
		if (netif_carrier_ok(netdev) &&
		    (adapter->flags & FLAG_RX_NEEDS_RESTART)) {
			/* disable receives */
			rctl = er32(RCTL);
			ew32(RCTL, rctl & ~E1000_RCTL_EN);
			adapter->flags |= FLAG_RX_RESTART_NOW;
		}
		/* guard against interrupt when we're going down */
		if (!test_bit(__E1000_DOWN, &adapter->state))
			mod_timer(&adapter->watchdog_timer, jiffies + 1);
	}

#ifdef CONFIG_E1000E_NAPI
	if (netif_rx_schedule_prep(netdev, &adapter->napi)) {
		adapter->total_tx_bytes = 0;
		adapter->total_tx_packets = 0;
		adapter->total_rx_bytes = 0;
		adapter->total_rx_packets = 0;
		__netif_rx_schedule(netdev, &adapter->napi);
	}
#else
	adapter->total_tx_bytes = 0;
	adapter->total_rx_bytes = 0;
	adapter->total_tx_packets = 0;
	adapter->total_rx_packets = 0;

	for (i = 0; i < E1000_MAX_INTR; i++) {
		rx_cleaned = adapter->clean_rx(adapter);
		tx_cleaned_complete = e1000_clean_tx_irq(adapter);
		if (!rx_cleaned && tx_cleaned_complete)
			break;
	}

	if (likely(adapter->itr_setting & 3))
		e1000_set_itr(adapter);
#endif /* CONFIG_E1000E_NAPI */

	return IRQ_HANDLED;
}

#ifdef CONFIG_E1000E_MSIX
static irqreturn_t e1000_msix_other(int irq, void *data)
{
	struct net_device *netdev = data;
	struct e1000_adapter *adapter = netdev_priv(netdev);
	struct e1000_hw *hw = &adapter->hw;
	u32 icr = er32(ICR);

	if (!(icr & E1000_ICR_INT_ASSERTED))
	{
		ew32(IMS, E1000_IMS_OTHER);
		return IRQ_NONE;
	}

	if (icr & adapter->eiac_mask)
		ew32(ICS, (icr & adapter->eiac_mask));

	if (icr & E1000_ICR_OTHER) {
		if (!(icr & E1000_ICR_LSC))
			goto no_link_interrupt;
		hw->mac.get_link_status = 1;
		/* guard against interrupt when we're going down */
		if (!test_bit(__E1000_DOWN, &adapter->state))
			mod_timer(&adapter->watchdog_timer, jiffies + 1);
	}

no_link_interrupt:
	ew32(IMS, E1000_IMS_LSC | E1000_IMS_OTHER);

	return IRQ_HANDLED;
}


#ifdef CONFIG_E1000E_SEPARATE_TX_HANDLER
static irqreturn_t e1000_intr_msix_tx(int irq, void *data)
{
	struct net_device *netdev = data;
	struct e1000_adapter *adapter = netdev_priv(netdev);
	struct e1000_hw *hw = &adapter->hw;
	struct e1000_ring *tx_ring = adapter->tx_ring;


	adapter->total_tx_bytes = 0;
	adapter->total_tx_packets = 0;

	if (!e1000_clean_tx_irq(adapter))
		/* Ring was not completely cleaned, so fire another interrupt */
		ew32(ICS, tx_ring->ims_val);

	return IRQ_HANDLED;
}

#endif  /* CONFIG_E1000E_SEPARATE_TX_HANDLER */
static irqreturn_t e1000_intr_msix_rx(int irq, void *data)
{
	struct net_device *netdev = data;
	struct e1000_adapter *adapter = netdev_priv(netdev);
#ifndef CONFIG_E1000E_NAPI
	int i;