e1000_main.c

一个2.4.21版本的嵌入式linux内核

e1000_tx_csum(struct e1000_adapter *adapter, struct sk_buff *skb)
{
	struct e1000_context_desc *context_desc;
	int i;
	uint8_t css, cso;

	if(skb->ip_summed == CHECKSUM_HW) {
		css = skb->h.raw - skb->data;
		cso = (skb->h.raw + skb->csum) - skb->data;

		i = adapter->tx_ring.next_to_use;
		context_desc = E1000_CONTEXT_DESC(adapter->tx_ring, i);

		context_desc->upper_setup.tcp_fields.tucss = css;
		context_desc->upper_setup.tcp_fields.tucso = cso;
		context_desc->upper_setup.tcp_fields.tucse = 0;
		context_desc->tcp_seg_setup.data = 0;
		context_desc->cmd_and_length =
			cpu_to_le32(adapter->txd_cmd | E1000_TXD_CMD_DEXT);

		if(++i == adapter->tx_ring.count) i = 0;
		adapter->tx_ring.next_to_use = i;

		return TRUE;
	}

	return FALSE;
}

#define E1000_MAX_TXD_PWR	12
#define E1000_MAX_DATA_PER_TXD	(1<<E1000_MAX_TXD_PWR)

static inline int
e1000_tx_map(struct e1000_adapter *adapter, struct sk_buff *skb)
{
	struct e1000_desc_ring *tx_ring = &adapter->tx_ring;
	int len = skb->len, offset = 0, size, count = 0, i;

	int f;
	len -= skb->data_len;

	i = tx_ring->next_to_use;

	while(len) {
		size = min(len, E1000_MAX_DATA_PER_TXD);
		tx_ring->buffer_info[i].length = size;
		tx_ring->buffer_info[i].dma =
			pci_map_single(adapter->pdev,
				skb->data + offset,
				size,
				PCI_DMA_TODEVICE);
		tx_ring->buffer_info[i].time_stamp = jiffies;

		len -= size;
		offset += size;
		count++;
		if(++i == tx_ring->count) i = 0;
	}

	for(f = 0; f < skb_shinfo(skb)->nr_frags; f++) {
		struct skb_frag_struct *frag;

		frag = &skb_shinfo(skb)->frags[f];
		len = frag->size;
		offset = 0;

		while(len) {
			size = min(len, E1000_MAX_DATA_PER_TXD);
			tx_ring->buffer_info[i].length = size;
			tx_ring->buffer_info[i].dma =
				pci_map_page(adapter->pdev,
					frag->page,
					frag->page_offset + offset,
					size,
					PCI_DMA_TODEVICE);
			tx_ring->buffer_info[i].time_stamp = jiffies;

			len -= size;
			offset += size;
			count++;
			if(++i == tx_ring->count) i = 0;
		}
	}
	if(--i < 0) i = tx_ring->count - 1;
	tx_ring->buffer_info[i].skb = skb;

	return count;
}

static inline void
e1000_tx_queue(struct e1000_adapter *adapter, int count, int tx_flags)
{
	struct e1000_desc_ring *tx_ring = &adapter->tx_ring;
	struct e1000_tx_desc *tx_desc = NULL;
	uint32_t txd_upper, txd_lower;
	int i;

	txd_upper = 0;
	txd_lower = adapter->txd_cmd;

	if(tx_flags & E1000_TX_FLAGS_CSUM) {
		txd_lower |= E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D;
		txd_upper |= E1000_TXD_POPTS_TXSM << 8;
	}

	if(tx_flags & E1000_TX_FLAGS_VLAN) {
		txd_lower |= E1000_TXD_CMD_VLE;
		txd_upper |= (tx_flags & E1000_TX_FLAGS_VLAN_MASK);
	}

	i = tx_ring->next_to_use;

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

	tx_desc->lower.data |= cpu_to_le32(E1000_TXD_CMD_EOP);

	/* 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;
}

/* Tx Descriptors needed, worst case */
#define TXD_USE_COUNT(S) (((S) >> E1000_MAX_TXD_PWR) + \
			 (((S) & (E1000_MAX_DATA_PER_TXD - 1)) ? 1 : 0))
#define DESC_NEEDED TXD_USE_COUNT(MAX_JUMBO_FRAME_SIZE) + \
	MAX_SKB_FRAGS * TXD_USE_COUNT(PAGE_SIZE) + 1

static int
e1000_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
{
	struct e1000_adapter *adapter = netdev->priv;
	int tx_flags = 0;

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

	if(E1000_DESC_UNUSED(&adapter->tx_ring) < DESC_NEEDED) {
		netif_stop_queue(netdev);
		return 1;
	}

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

	if(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);
	}

	if(e1000_tx_csum(adapter, skb))
		tx_flags |= E1000_TX_FLAGS_CSUM;

	e1000_tx_queue(adapter, e1000_tx_map(adapter, skb), 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;

	netif_device_detach(netdev);
	e1000_down(adapter);
	e1000_up(adapter);
	netif_device_attach(netdev);
}

/**
 * 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;

	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)) {
		E1000_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) {
		E1000_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
 **/

static 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->gorcl = E1000_READ_REG(hw, GORCL);
	adapter->stats.gorcl += adapter->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);

	spin_unlock_irqrestore(&adapter->stats_lock, flags);

	/* the rest of the counters are only modified here */

	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->gotcl = E1000_READ_REG(hw, GOTCL);
	adapter->stats.gotcl += adapter->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) &&
		   !e1000_read_phy_reg(hw, M88E1000_RX_ERR_CNTR, &phy_tmp))
			adapter->phy_stats.receive_errors += phy_tmp;
	}
}

/**
 * e1000_irq_disable - Mask off interrupt generation on the NIC
 * @adapter: board private structure
 **/

static inline void
e1000_irq_disable(struct e1000_adapter *adapter)
{
	atomic_inc(&adapter->irq_sem);
	E1000_WRITE_REG(&adapter->hw, IMC, ~0);
	E1000_WRITE_FLUSH(&adapter->hw);
	synchronize_irq();
}

/**
 * e1000_irq_enable - Enable default interrupt generation settings
 * @adapter: board private structure
 **/

static inline void
e1000_irq_enable(struct e1000_adapter *adapter)
{
	if(atomic_dec_and_test(&adapter->irq_sem)) {
		E1000_WRITE_REG(&adapter->hw, IMS, IMS_ENABLE_MASK);
		E1000_WRITE_FLUSH(&adapter->hw);
	}
}