e1000_main.c

intel E1000类型网卡驱动源代码,目前在2.4的内核下支持82573的芯片不是很好,其他都不错

		txd_lower |= E1000_TXD_CMD_VLE;
		txd_upper |= (tx_flags & E1000_TX_FLAGS_VLAN_MASK);
	}

	i = tx_ring->next_to_use;

	while(count--) {
		buffer_info = &tx_ring->buffer_info[i];
		tx_desc = E1000_TX_DESC(*tx_ring, i);
		tx_desc->buffer_addr = cpu_to_le64(buffer_info->dma);
		tx_desc->lower.data =
			cpu_to_le32(txd_lower | buffer_info->length);
		tx_desc->upper.data = cpu_to_le32(txd_upper);
		if(unlikely(++i == tx_ring->count)) i = 0;
	}

	tx_desc->lower.data |= cpu_to_le32(adapter->txd_cmd);

	/* Force memory writes to complete before letting h/w
	 * know there are new descriptors to fetch.  (Only
	 * applicable for weak-ordered memory model archs,
	 * such as IA-64). */
	wmb();

	tx_ring->next_to_use = i;
	E1000_WRITE_REG(&adapter->hw, TDT, i);
}

/**
 * 82547 workaround to avoid controller hang in half-duplex environment.
 * The workaround is to avoid queuing a large packet that would span
 * the internal Tx FIFO ring boundary by notifying the stack to resend
 * the packet at a later time.  This gives the Tx FIFO an opportunity to
 * flush all packets.  When that occurs, we reset the Tx FIFO pointers
 * to the beginning of the Tx FIFO.
 **/

#define E1000_FIFO_HDR			0x10
#define E1000_82547_PAD_LEN		0x3E0

static inline int
e1000_82547_fifo_workaround(struct e1000_adapter *adapter, struct sk_buff *skb)
{
	uint32_t fifo_space = adapter->tx_fifo_size - adapter->tx_fifo_head;
	uint32_t skb_fifo_len = skb->len + E1000_FIFO_HDR;

	E1000_ROUNDUP(skb_fifo_len, E1000_FIFO_HDR);

	if(adapter->link_duplex != HALF_DUPLEX)
		goto no_fifo_stall_required;

	if(atomic_read(&adapter->tx_fifo_stall))
		return 1;

	if(skb_fifo_len >= (E1000_82547_PAD_LEN + fifo_space)) {
		atomic_set(&adapter->tx_fifo_stall, 1);
		return 1;
	}

no_fifo_stall_required:
	adapter->tx_fifo_head += skb_fifo_len;
	if(adapter->tx_fifo_head >= adapter->tx_fifo_size)
		adapter->tx_fifo_head -= adapter->tx_fifo_size;
	return 0;
}

#define TXD_USE_COUNT(S, X) (((S) >> (X)) + 1 )
static int
e1000_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
{
	struct e1000_adapter *adapter = netdev->priv;
	unsigned int first, max_per_txd = E1000_MAX_DATA_PER_TXD;
	unsigned int max_txd_pwr = E1000_MAX_TXD_PWR;
	unsigned int tx_flags = 0;
	unsigned int len = skb->len;
	unsigned long flags;
	unsigned int nr_frags = 0;
	unsigned int mss = 0;
	int count = 0;
	unsigned int f;
	len -= skb->data_len;

	if(unlikely(skb->len <= 0)) {
		dev_kfree_skb_any(skb);
		return 0;
	}

#ifdef NETIF_F_TSO
	mss = skb_shinfo(skb)->tso_size;
	/* The controller does a simple calculation to
	 * make sure there is enough room in the FIFO before
	 * initiating the DMA for each buffer.  The calc is:
	 * 4 = ceil(buffer len/mss).  To make sure we don't
	 * overrun the FIFO, adjust the max buffer len if mss
	 * drops. */
	if(mss) {
		max_per_txd = min(mss << 2, max_per_txd);
		max_txd_pwr = fls(max_per_txd) - 1;
	}

	if((mss) || (skb->ip_summed == CHECKSUM_HW))
		count++;
	count++;	/* for sentinel desc */
#else
	if(skb->ip_summed == CHECKSUM_HW)
		count++;
#endif
	count += TXD_USE_COUNT(len, max_txd_pwr);

	if(adapter->pcix_82544)
		count++;

	nr_frags = skb_shinfo(skb)->nr_frags;
	for(f = 0; f < nr_frags; f++)
		count += TXD_USE_COUNT(skb_shinfo(skb)->frags[f].size,
				       max_txd_pwr);
	if(adapter->pcix_82544)
		count += nr_frags;

	spin_lock_irqsave(&adapter->tx_lock, flags);

	/* need: count + 2 desc gap to keep tail from touching
	 * head, otherwise try next time */
	if(unlikely(E1000_DESC_UNUSED(&adapter->tx_ring) < count + 2)) {
		netif_stop_queue(netdev);
		spin_unlock_irqrestore(&adapter->tx_lock, flags);
		return 1;
	}

	if(unlikely(adapter->hw.mac_type == e1000_82547)) {
		if(unlikely(e1000_82547_fifo_workaround(adapter, skb))) {
			netif_stop_queue(netdev);
			mod_timer(&adapter->tx_fifo_stall_timer, jiffies);
			return 1;
			spin_unlock_irqrestore(&adapter->tx_lock, flags);
		}
	}

	spin_unlock_irqrestore(&adapter->tx_lock, flags);
	if(unlikely(adapter->vlgrp && vlan_tx_tag_present(skb))) {
		tx_flags |= E1000_TX_FLAGS_VLAN;
		tx_flags |= (vlan_tx_tag_get(skb) << E1000_TX_FLAGS_VLAN_SHIFT);
	}

	first = adapter->tx_ring.next_to_use;
	
	if(likely(e1000_tso(adapter, skb)))
		tx_flags |= E1000_TX_FLAGS_TSO;
	else if(likely(e1000_tx_csum(adapter, skb)))
		tx_flags |= E1000_TX_FLAGS_CSUM;

	e1000_tx_queue(adapter,
		e1000_tx_map(adapter, skb, first, max_per_txd, nr_frags, mss),
		tx_flags);

	netdev->trans_start = jiffies;

	return 0;
}

/**
 * e1000_tx_timeout - Respond to a Tx Hang
 * @netdev: network interface device structure
 **/

static void
e1000_tx_timeout(struct net_device *netdev)
{
	struct e1000_adapter *adapter = netdev->priv;

	/* Do the reset outside of interrupt context */
	schedule_task(&adapter->tx_timeout_task);
}

static void
e1000_tx_timeout_task(struct net_device *netdev)
{
	struct e1000_adapter *adapter = netdev->priv;

	e1000_down(adapter);
	e1000_up(adapter);
}

/**
 * e1000_get_stats - Get System Network Statistics
 * @netdev: network interface device structure
 *
 * Returns the address of the device statistics structure.
 * The statistics are actually updated from the timer callback.
 **/

static struct net_device_stats *
e1000_get_stats(struct net_device *netdev)
{
	struct e1000_adapter *adapter = netdev->priv;

	e1000_update_stats(adapter);
	return &adapter->net_stats;
}

/**
 * e1000_change_mtu - Change the Maximum Transfer Unit
 * @netdev: network interface device structure
 * @new_mtu: new value for maximum frame size
 *
 * Returns 0 on success, negative on failure
 **/

static int
e1000_change_mtu(struct net_device *netdev, int new_mtu)
{
	struct e1000_adapter *adapter = netdev->priv;
	int old_mtu = adapter->rx_buffer_len;
	int max_frame = new_mtu + ENET_HEADER_SIZE + ETHERNET_FCS_SIZE;

	if((max_frame < MINIMUM_ETHERNET_FRAME_SIZE) ||
		(max_frame > MAX_JUMBO_FRAME_SIZE)) {
			DPRINTK(PROBE, ERR, "Invalid MTU setting\n");
			return -EINVAL;
	}

	if(max_frame <= MAXIMUM_ETHERNET_FRAME_SIZE) {
		adapter->rx_buffer_len = E1000_RXBUFFER_2048;

	} else if(adapter->hw.mac_type < e1000_82543) {
		DPRINTK(PROBE, ERR, "Jumbo Frames not supported on 82542\n");
		return -EINVAL;

	} else if(max_frame <= E1000_RXBUFFER_4096) {
		adapter->rx_buffer_len = E1000_RXBUFFER_4096;

	} else if(max_frame <= E1000_RXBUFFER_8192) {
		adapter->rx_buffer_len = E1000_RXBUFFER_8192;

	} else {
		adapter->rx_buffer_len = E1000_RXBUFFER_16384;
	}

	if(old_mtu != adapter->rx_buffer_len && netif_running(netdev)) {
		e1000_down(adapter);
		e1000_up(adapter);
	}

	netdev->mtu = new_mtu;
	adapter->hw.max_frame_size = max_frame;

	return 0;
}

/**
 * e1000_update_stats - Update the board statistics counters
 * @adapter: board private structure
 **/

void
e1000_update_stats(struct e1000_adapter *adapter)
{
	struct e1000_hw *hw = &adapter->hw;
	unsigned long flags;
	uint16_t phy_tmp;

#define PHY_IDLE_ERROR_COUNT_MASK 0x00FF

	spin_lock_irqsave(&adapter->stats_lock, flags);

	/* these counters are modified from e1000_adjust_tbi_stats,
	 * called from the interrupt context, so they must only
	 * be written while holding adapter->stats_lock
	 */

	adapter->stats.crcerrs += E1000_READ_REG(hw, CRCERRS);
	adapter->stats.gprc += E1000_READ_REG(hw, GPRC);
	adapter->stats.gorcl += E1000_READ_REG(hw, GORCL);
	adapter->stats.gorch += E1000_READ_REG(hw, GORCH);
	adapter->stats.bprc += E1000_READ_REG(hw, BPRC);
	adapter->stats.mprc += E1000_READ_REG(hw, MPRC);
	adapter->stats.roc += E1000_READ_REG(hw, ROC);
	adapter->stats.prc64 += E1000_READ_REG(hw, PRC64);
	adapter->stats.prc127 += E1000_READ_REG(hw, PRC127);
	adapter->stats.prc255 += E1000_READ_REG(hw, PRC255);
	adapter->stats.prc511 += E1000_READ_REG(hw, PRC511);
	adapter->stats.prc1023 += E1000_READ_REG(hw, PRC1023);
	adapter->stats.prc1522 += E1000_READ_REG(hw, PRC1522);

	adapter->stats.symerrs += E1000_READ_REG(hw, SYMERRS);
	adapter->stats.mpc += E1000_READ_REG(hw, MPC);
	adapter->stats.scc += E1000_READ_REG(hw, SCC);
	adapter->stats.ecol += E1000_READ_REG(hw, ECOL);
	adapter->stats.mcc += E1000_READ_REG(hw, MCC);
	adapter->stats.latecol += E1000_READ_REG(hw, LATECOL);
	adapter->stats.dc += E1000_READ_REG(hw, DC);
	adapter->stats.sec += E1000_READ_REG(hw, SEC);
	adapter->stats.rlec += E1000_READ_REG(hw, RLEC);
	adapter->stats.xonrxc += E1000_READ_REG(hw, XONRXC);
	adapter->stats.xontxc += E1000_READ_REG(hw, XONTXC);
	adapter->stats.xoffrxc += E1000_READ_REG(hw, XOFFRXC);
	adapter->stats.xofftxc += E1000_READ_REG(hw, XOFFTXC);
	adapter->stats.fcruc += E1000_READ_REG(hw, FCRUC);
	adapter->stats.gptc += E1000_READ_REG(hw, GPTC);
	adapter->stats.gotcl += E1000_READ_REG(hw, GOTCL);
	adapter->stats.gotch += E1000_READ_REG(hw, GOTCH);
	adapter->stats.rnbc += E1000_READ_REG(hw, RNBC);
	adapter->stats.ruc += E1000_READ_REG(hw, RUC);
	adapter->stats.rfc += E1000_READ_REG(hw, RFC);
	adapter->stats.rjc += E1000_READ_REG(hw, RJC);
	adapter->stats.torl += E1000_READ_REG(hw, TORL);
	adapter->stats.torh += E1000_READ_REG(hw, TORH);
	adapter->stats.totl += E1000_READ_REG(hw, TOTL);
	adapter->stats.toth += E1000_READ_REG(hw, TOTH);
	adapter->stats.tpr += E1000_READ_REG(hw, TPR);
	adapter->stats.ptc64 += E1000_READ_REG(hw, PTC64);
	adapter->stats.ptc127 += E1000_READ_REG(hw, PTC127);
	adapter->stats.ptc255 += E1000_READ_REG(hw, PTC255);
	adapter->stats.ptc511 += E1000_READ_REG(hw, PTC511);
	adapter->stats.ptc1023 += E1000_READ_REG(hw, PTC1023);
	adapter->stats.ptc1522 += E1000_READ_REG(hw, PTC1522);
	adapter->stats.mptc += E1000_READ_REG(hw, MPTC);
	adapter->stats.bptc += E1000_READ_REG(hw, BPTC);

	/* used for adaptive IFS */

	hw->tx_packet_delta = E1000_READ_REG(hw, TPT);
	adapter->stats.tpt += hw->tx_packet_delta;
	hw->collision_delta = E1000_READ_REG(hw, COLC);
	adapter->stats.colc += hw->collision_delta;

	if(hw->mac_type >= e1000_82543) {
		adapter->stats.algnerrc += E1000_READ_REG(hw, ALGNERRC);
		adapter->stats.rxerrc += E1000_READ_REG(hw, RXERRC);
		adapter->stats.tncrs += E1000_READ_REG(hw, TNCRS);
		adapter->stats.cexterr += E1000_READ_REG(hw, CEXTERR);
		adapter->stats.tsctc += E1000_READ_REG(hw, TSCTC);
		adapter->stats.tsctfc += E1000_READ_REG(hw, TSCTFC);
	}

	/* Fill out the OS statistics structure */

	adapter->net_stats.rx_packets = adapter->stats.gprc;
	adapter->net_stats.tx_packets = adapter->stats.gptc;
	adapter->net_stats.rx_bytes = adapter->stats.gorcl;
	adapter->net_stats.tx_bytes = adapter->stats.gotcl;
	adapter->net_stats.multicast = adapter->stats.mprc;
	adapter->net_stats.collisions = adapter->stats.colc;

	/* Rx Errors */

	adapter->net_stats.rx_errors = adapter->stats.rxerrc +
		adapter->stats.crcerrs + adapter->stats.algnerrc +
		adapter->stats.rlec + adapter->stats.rnbc +
		adapter->stats.mpc + adapter->stats.cexterr;
	adapter->net_stats.rx_dropped = adapter->stats.rnbc;
	adapter->net_stats.rx_length_errors = adapter->stats.rlec;
	adapter->net_stats.rx_crc_errors = adapter->stats.crcerrs;
	adapter->net_stats.rx_frame_errors = adapter->stats.algnerrc;
	adapter->net_stats.rx_fifo_errors = adapter->stats.mpc;
	adapter->net_stats.rx_missed_errors = adapter->stats.mpc;

	/* Tx Errors */

	adapter->net_stats.tx_errors = adapter->stats.ecol +
	                               adapter->stats.latecol;
	adapter->net_stats.tx_aborted_errors = adapter->stats.ecol;
	adapter->net_stats.tx_window_errors = adapter->stats.latecol;
	adapter->net_stats.tx_carrier_errors = adapter->stats.tncrs;

	/* Tx Dropped needs to be maintained elsewhere */

	/* Phy Stats */

	if(hw->media_type == e1000_media_type_copper) {
		if((adapter->link_speed == SPEED_1000) &&
		   (!e1000_read_phy_reg(hw, PHY_1000T_STATUS, &phy_tmp))) {
			phy_tmp &= PHY_IDLE_ERROR_COUNT_MASK;
			adapter->phy_stats.idle_errors += phy_tmp;
		}

		if((hw->mac_type <= e1000_82546) &&
		   (hw->phy_type == e1000_phy_m88) &&
		   !e1000_read_phy_reg(hw, M88E1000_RX_ERR_CNTR, &phy_tmp))
			adapter->phy_stats.receive_errors += phy_tmp;
	}

	spin_unlock_irqrestore(&adapter->stats_lock, flags);
}

/**
 * e1000_intr - Interrupt Handler
 * @irq: interrupt number
 * @data: pointer to a network interface device structure
 * @pt_regs: CPU registers structure
 **/

static irqreturn_t
e1000_intr(int irq, void *data, struct pt_regs *regs)
{
	struct net_device *netdev = data;
	struct e1000_adapter *adapter = netdev->priv;
	struct e1000_hw *hw = &adapter->hw;
	uint32_t icr = E1000_READ_REG(hw, ICR);
#ifndef CONFIG_E1000_NAPI
	unsigned int i;
#endif

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

	if(unlikely(icr & (E1000_ICR_RXSEQ | E1000_ICR_LSC))) {
		hw->get_link_status = 1;
		mod_timer(&adapter->watchdog_timer, jiffies);
	}

#ifdef CONFIG_E1000_NAPI
	if(likely(netif_rx_schedule_prep(netdev))) {

		/* Disable interrupts and register for poll. The flush 
		  of the posted write is intentionally left out.
		*/

		atomic_inc(&adapter->irq_sem);
		E1000_WRITE_REG(hw, IMC, ~0);
		__netif_rx_schedule(netdev);
	}
#else
	/* Writing IMC and IMS is needed for 82547.
	   Due to Hub Link bus being occupied, an interrupt
	   de-assertion message is not able to be sent.
	   When an interrupt assertion message is generated later,
	   two messages are re-ordered and sent out.
	   That causes APIC to think 82547 is in de-assertion
	   state, while 82547 is in assertion state, resulting
	   in dead lock. Writing IMC forces 82547 into
	   de-assertion state.
	*/
	if(hw->mac_type == e1000_82547 || hw->mac_type == e1000_82547_rev_2){
		atomic_inc(&adapter->irq_sem);
		E1000_WRITE_REG(&adapter->hw, IMC, ~0);
	}

	for(i = 0; i < E1000_MAX_INTR; i++)
		if(unlikely(!e1000_clean_rx_irq(adapter) &
		   !e1000_clean_tx_irq(adapter)))
			break;

	if(hw->mac_type == e1000_82547 || hw->mac_type == e1000_82547_rev_2)
		e1000_irq_enable(adapter);
#endif

	return IRQ_HANDLED;
}

#ifdef CONFIG_E1000_NAPI
/**
 * e10