netxen_nic_main.c

/*
 * Copyright (C) 2003 - 2006 NetXen, Inc.
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA  02111-1307, USA.
 *
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.
 *
 * Contact Information:
 *    info@netxen.com
 * NetXen,
 * 3965 Freedom Circle, Fourth floor,
 * Santa Clara, CA 95054
 *
 *
 *  Main source file for NetXen NIC Driver on Linux
 *
 */

#include <linux/vmalloc.h>
#include <linux/highmem.h>
#include "netxen_nic_hw.h"

#include "netxen_nic.h"
#include "netxen_nic_phan_reg.h"

#include <linux/dma-mapping.h>
#include <net/ip.h>

MODULE_DESCRIPTION("NetXen Multi port (1/10) Gigabit Network Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(NETXEN_NIC_LINUX_VERSIONID);

char netxen_nic_driver_name[] = "netxen_nic";
static char netxen_nic_driver_string[] = "NetXen Network Driver version "
    NETXEN_NIC_LINUX_VERSIONID;

static int port_mode = NETXEN_PORT_MODE_AUTO_NEG;

/* Default to restricted 1G auto-neg mode */
static int wol_port_mode = 5;

static int use_msi = 1;

static int use_msi_x = 1;

#define NETXEN_NETDEV_WEIGHT 120
#define NETXEN_ADAPTER_UP_MAGIC 777
#define NETXEN_NIC_PEG_TUNE 0

/* Local functions to NetXen NIC driver */
static int __devinit netxen_nic_probe(struct pci_dev *pdev,
		const struct pci_device_id *ent);
static void __devexit netxen_nic_remove(struct pci_dev *pdev);
static int netxen_nic_open(struct net_device *netdev);
static int netxen_nic_close(struct net_device *netdev);
static int netxen_nic_xmit_frame(struct sk_buff *, struct net_device *);
static void netxen_tx_timeout(struct net_device *netdev);
static void netxen_tx_timeout_task(struct work_struct *work);
static void netxen_watchdog(unsigned long);
static int netxen_nic_poll(struct napi_struct *napi, int budget);
#ifdef CONFIG_NET_POLL_CONTROLLER
static void netxen_nic_poll_controller(struct net_device *netdev);
#endif
static irqreturn_t netxen_intr(int irq, void *data);
static irqreturn_t netxen_msi_intr(int irq, void *data);

/*  PCI Device ID Table  */
#define ENTRY(device) \
	{PCI_DEVICE(0x4040, (device)), \
	.class = PCI_CLASS_NETWORK_ETHERNET << 8, .class_mask = ~0}

static struct pci_device_id netxen_pci_tbl[] __devinitdata = {
	ENTRY(0x0001),
	ENTRY(0x0002),
	ENTRY(0x0003),
	ENTRY(0x0004),
	ENTRY(0x0005),
	ENTRY(0x0024),
	ENTRY(0x0025),
	ENTRY(0x0100),
	{0,}
};

MODULE_DEVICE_TABLE(pci, netxen_pci_tbl);

/*
 * In netxen_nic_down(), we must wait for any pending callback requests into
 * netxen_watchdog_task() to complete; eg otherwise the watchdog_timer could be
 * reenabled right after it is deleted in netxen_nic_down().
 * FLUSH_SCHEDULED_WORK()  does this synchronization.
 *
 * Normally, schedule_work()/flush_scheduled_work() could have worked, but
 * netxen_nic_close() is invoked with kernel rtnl lock held. netif_carrier_off()
 * call in netxen_nic_close() triggers a schedule_work(&linkwatch_work), and a
 * subsequent call to flush_scheduled_work() in netxen_nic_down() would cause
 * linkwatch_event() to be executed which also attempts to acquire the rtnl
 * lock thus causing a deadlock.
 */

static struct workqueue_struct *netxen_workq;
#define SCHEDULE_WORK(tp)	queue_work(netxen_workq, tp)
#define FLUSH_SCHEDULED_WORK()	flush_workqueue(netxen_workq)

static void netxen_watchdog(unsigned long);

static uint32_t crb_cmd_producer[4] = {
	CRB_CMD_PRODUCER_OFFSET, CRB_CMD_PRODUCER_OFFSET_1,
	CRB_CMD_PRODUCER_OFFSET_2, CRB_CMD_PRODUCER_OFFSET_3
};

static inline void
netxen_nic_update_cmd_producer(struct netxen_adapter *adapter,
		uint32_t crb_producer)
{
	adapter->pci_write_normalize(adapter,
			adapter->crb_addr_cmd_producer, crb_producer);
}

static uint32_t crb_cmd_consumer[4] = {
	CRB_CMD_CONSUMER_OFFSET, CRB_CMD_CONSUMER_OFFSET_1,
	CRB_CMD_CONSUMER_OFFSET_2, CRB_CMD_CONSUMER_OFFSET_3
};

static inline void
netxen_nic_update_cmd_consumer(struct netxen_adapter *adapter,
		u32 crb_consumer)
{
	adapter->pci_write_normalize(adapter,
			adapter->crb_addr_cmd_consumer, crb_consumer);
}

static uint32_t msi_tgt_status[8] = {
	ISR_INT_TARGET_STATUS, ISR_INT_TARGET_STATUS_F1,
	ISR_INT_TARGET_STATUS_F2, ISR_INT_TARGET_STATUS_F3,
	ISR_INT_TARGET_STATUS_F4, ISR_INT_TARGET_STATUS_F5,
	ISR_INT_TARGET_STATUS_F6, ISR_INT_TARGET_STATUS_F7
};

static uint32_t sw_int_mask[4] = {
	CRB_SW_INT_MASK_0, CRB_SW_INT_MASK_1,
	CRB_SW_INT_MASK_2, CRB_SW_INT_MASK_3
};

static struct netxen_legacy_intr_set legacy_intr[] = NX_LEGACY_INTR_CONFIG;

static void netxen_nic_disable_int(struct netxen_adapter *adapter)
{
	u32 mask = 0x7ff;
	int retries = 32;
	int port = adapter->portnum;
	int pci_fn = adapter->ahw.pci_func;

	if (adapter->msi_mode != MSI_MODE_MULTIFUNC)
		adapter->pci_write_normalize(adapter, sw_int_mask[port], 0);

	if (adapter->intr_scheme != -1 &&
	    adapter->intr_scheme != INTR_SCHEME_PERPORT)
		adapter->pci_write_immediate(adapter, ISR_INT_MASK, mask);

	if (!NETXEN_IS_MSI_FAMILY(adapter)) {
		do {
			adapter->pci_write_immediate(adapter,
					ISR_INT_TARGET_STATUS, 0xffffffff);
			mask = adapter->pci_read_immediate(adapter,
					ISR_INT_VECTOR);
			if (!(mask & 0x80))
				break;
			udelay(10);
		} while (--retries);

		if (!retries) {
			printk(KERN_NOTICE "%s: Failed to disable interrupt completely\n",
					netxen_nic_driver_name);
		}
	} else {
		if (adapter->msi_mode == MSI_MODE_MULTIFUNC) {
			adapter->pci_write_immediate(adapter,
					msi_tgt_status[pci_fn], 0xffffffff);
		}
	}
}

static void netxen_nic_enable_int(struct netxen_adapter *adapter)
{
	u32 mask;
	int port = adapter->portnum;

	DPRINTK(1, INFO, "Entered ISR Enable \n");

	if (adapter->intr_scheme != -1 &&
		adapter->intr_scheme != INTR_SCHEME_PERPORT) {
		switch (adapter->ahw.board_type) {
		case NETXEN_NIC_GBE:
			mask  =  0x77b;
			break;
		case NETXEN_NIC_XGBE:
			mask  =  0x77f;
			break;
		default:
			mask  =  0x7ff;
			break;
		}

		adapter->pci_write_immediate(adapter, ISR_INT_MASK, mask);
	}

	adapter->pci_write_normalize(adapter, sw_int_mask[port], 0x1);

	if (!NETXEN_IS_MSI_FAMILY(adapter)) {
		mask = 0xbff;
		if (adapter->intr_scheme != -1 &&
			adapter->intr_scheme != INTR_SCHEME_PERPORT) {
			adapter->pci_write_normalize(adapter,
					CRB_INT_VECTOR, 0);
		}
		adapter->pci_write_immediate(adapter,
				ISR_INT_TARGET_MASK, mask);
	}

	DPRINTK(1, INFO, "Done with enable Int\n");
}

static int nx_set_dma_mask(struct netxen_adapter *adapter, uint8_t revision_id)
{
	struct pci_dev *pdev = adapter->pdev;
	int err;
	uint64_t mask;

#ifdef CONFIG_IA64
	adapter->dma_mask = DMA_32BIT_MASK;
#else
	if (revision_id >= NX_P3_B0) {
		/* should go to DMA_64BIT_MASK */
		adapter->dma_mask = DMA_39BIT_MASK;
		mask = DMA_39BIT_MASK;
	} else if (revision_id == NX_P3_A2) {
		adapter->dma_mask = DMA_39BIT_MASK;
		mask = DMA_39BIT_MASK;
	} else if (revision_id == NX_P2_C1) {
		adapter->dma_mask = DMA_35BIT_MASK;
		mask = DMA_35BIT_MASK;
	} else {
		adapter->dma_mask = DMA_32BIT_MASK;
		mask = DMA_32BIT_MASK;
		goto set_32_bit_mask;
	}

	/*
	 * Consistent DMA mask is set to 32 bit because it cannot be set to
	 * 35 bits. For P3 also leave it at 32 bits for now. Only the rings
	 * come off this pool.
	 */
	if (pci_set_dma_mask(pdev, mask) == 0 &&
		pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK) == 0) {
		adapter->pci_using_dac = 1;
		return 0;
	}
#endif /* CONFIG_IA64 */

set_32_bit_mask:
	err = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
	if (!err)
		err = pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK);
	if (err) {
		DPRINTK(ERR, "No usable DMA configuration, aborting:%d\n", err);
		return err;
	}

	adapter->pci_using_dac = 0;
	return 0;
}

static void netxen_check_options(struct netxen_adapter *adapter)
{
	switch (adapter->ahw.boardcfg.board_type) {
	case NETXEN_BRDTYPE_P3_HMEZ:
	case NETXEN_BRDTYPE_P3_XG_LOM:
	case NETXEN_BRDTYPE_P3_10G_CX4:
	case NETXEN_BRDTYPE_P3_10G_CX4_LP:
	case NETXEN_BRDTYPE_P3_IMEZ:
	case NETXEN_BRDTYPE_P3_10G_SFP_PLUS:
	case NETXEN_BRDTYPE_P3_10G_XFP:
	case NETXEN_BRDTYPE_P3_10000_BASE_T:
		adapter->msix_supported = !!use_msi_x;
		adapter->max_rx_desc_count = MAX_RCV_DESCRIPTORS_10G;
		break;

	case NETXEN_BRDTYPE_P2_SB31_10G:
	case NETXEN_BRDTYPE_P2_SB31_10G_CX4:
	case NETXEN_BRDTYPE_P2_SB31_10G_IMEZ:
	case NETXEN_BRDTYPE_P2_SB31_10G_HMEZ:
		adapter->msix_supported = 0;
		adapter->max_rx_desc_count = MAX_RCV_DESCRIPTORS_10G;
		break;

	case NETXEN_BRDTYPE_P3_REF_QG:
	case NETXEN_BRDTYPE_P3_4_GB:
	case NETXEN_BRDTYPE_P3_4_GB_MM:
	case NETXEN_BRDTYPE_P2_SB35_4G:
	case NETXEN_BRDTYPE_P2_SB31_2G:
		adapter->msix_supported = 0;
		adapter->max_rx_desc_count = MAX_RCV_DESCRIPTORS_1G;
		break;

	default:
		adapter->msix_supported = 0;
		adapter->max_rx_desc_count = MAX_RCV_DESCRIPTORS_1G;

		printk(KERN_WARNING "Unknown board type(0x%x)\n",
				adapter->ahw.boardcfg.board_type);
		break;
	}

	adapter->max_tx_desc_count = MAX_CMD_DESCRIPTORS_HOST;
	adapter->max_jumbo_rx_desc_count = MAX_JUMBO_RCV_DESCRIPTORS;
	adapter->max_lro_rx_desc_count = MAX_LRO_RCV_DESCRIPTORS;

	adapter->max_possible_rss_rings = 1;
	return;
}

static int
netxen_check_hw_init(struct netxen_adapter *adapter, int first_boot)
{
	int ret = 0;

	if (first_boot == 0x55555555) {
		/* This is the first boot after power up */

		/* PCI bus master workaround */
		adapter->hw_read_wx(adapter,
			NETXEN_PCIE_REG(0x4), &first_boot, 4);
		if (!(first_boot & 0x4)) {
			first_boot |= 0x4;
			adapter->hw_write_wx(adapter,
				NETXEN_PCIE_REG(0x4), &first_boot, 4);
			adapter->hw_read_wx(adapter,
				NETXEN_PCIE_REG(0x4), &first_boot, 4);
		}

		/* This is the first boot after power up */
		adapter->hw_read_wx(adapter,
			NETXEN_ROMUSB_GLB_SW_RESET, &first_boot, 4);
		if (first_boot != 0x80000f) {
			/* clear the register for future unloads/loads */
			adapter->pci_write_normalize(adapter,
					NETXEN_CAM_RAM(0x1fc), 0);
			ret = -1;
		}

		if (NX_IS_REVISION_P2(adapter->ahw.revision_id)) {
			/* Start P2 boot loader */
			adapter->pci_write_normalize(adapter,
				NETXEN_CAM_RAM(0x1fc), NETXEN_BDINFO_MAGIC);
			adapter->pci_write_normalize(adapter,
					NETXEN_ROMUSB_GLB_PEGTUNE_DONE, 1);
		}
	}
	return ret;
}

static void netxen_set_port_mode(struct netxen_adapter *adapter)
{
	u32 val, data;

	val = adapter->ahw.boardcfg.board_type;
	if ((val == NETXEN_BRDTYPE_P3_HMEZ) ||
		(val == NETXEN_BRDTYPE_P3_XG_LOM)) {
		if (port_mode == NETXEN_PORT_MODE_802_3_AP) {
			data = NETXEN_PORT_MODE_802_3_AP;
			adapter->hw_write_wx(adapter,
				NETXEN_PORT_MODE_ADDR, &data, 4);
		} else if (port_mode == NETXEN_PORT_MODE_XG) {
			data = NETXEN_PORT_MODE_XG;
			adapter->hw_write_wx(adapter,
				NETXEN_PORT_MODE_ADDR, &data, 4);
		} else if (port_mode == NETXEN_PORT_MODE_AUTO_NEG_1G) {
			data = NETXEN_PORT_MODE_AUTO_NEG_1G;
			adapter->hw_write_wx(adapter,
				NETXEN_PORT_MODE_ADDR, &data, 4);
		} else if (port_mode == NETXEN_PORT_MODE_AUTO_NEG_XG) {
			data = NETXEN_PORT_MODE_AUTO_NEG_XG;
			adapter->hw_write_wx(adapter,
				NETXEN_PORT_MODE_ADDR, &data, 4);
		} else {
			data = NETXEN_PORT_MODE_AUTO_NEG;
			adapter->hw_write_wx(adapter,
				NETXEN_PORT_MODE_ADDR, &data, 4);
		}

		if ((wol_port_mode != NETXEN_PORT_MODE_802_3_AP) &&
			(wol_port_mode != NETXEN_PORT_MODE_XG) &&
			(wol_port_mode != NETXEN_PORT_MODE_AUTO_NEG_1G) &&
			(wol_port_mode != NETXEN_PORT_MODE_AUTO_NEG_XG)) {
			wol_port_mode = NETXEN_PORT_MODE_AUTO_NEG;
		}
		adapter->hw_write_wx(adapter, NETXEN_WOL_PORT_MODE,
			&wol_port_mode, 4);
	}
}

#define PCI_CAP_ID_GEN  0x10

static void netxen_pcie_strap_init(struct netxen_adapter *adapter)
{
	u32 pdevfuncsave;
	u32 c8c9value = 0;
	u32 chicken = 0;
	u32 control = 0;
	int i, pos;
	struct pci_dev *pdev;

	pdev = pci_get_device(0x1166, 0x0140, NULL);
	if (pdev) {
		pci_dev_put(pdev);
		adapter->hw_read_wx(adapter,
			NETXEN_PCIE_REG(PCIE_TGT_SPLIT_CHICKEN), &chicken, 4);
		chicken |= 0x4000;
		adapter->hw_write_wx(adapter,
			NETXEN_PCIE_REG(PCIE_TGT_SPLIT_CHICKEN), &chicken, 4);
	}

	pdev = adapter->pdev;

	adapter->hw_read_wx(adapter,
		NETXEN_PCIE_REG(PCIE_CHICKEN3), &chicken, 4);
	/* clear chicken3.25:24 */
	chicken &= 0xFCFFFFFF;
	/*
	 * if gen1 and B0, set F1020 - if gen 2, do nothing
	 * if gen2 set to F1000
	 */
	pos = pci_find_capability(pdev, PCI_CAP_ID_GEN);
	if (pos == 0xC0) {
		pci_read_config_dword(pdev, pos + 0x10, &control);
		if ((control & 0x000F0000) != 0x00020000) {
			/*  set chicken3.24 if gen1 */
			chicken |= 0x01000000;
		}
		printk(KERN_INFO "%s Gen2 strapping detected\n",
				netxen_nic_driver_name);
		c8c9value = 0xF1000;
	} else {
		/* set chicken3.24 if gen1 */
		chicken |= 0x01000000;
		printk(KERN_INFO "%s Gen1 strapping detected\n",
				netxen_nic_driver_name);
		if (adapter->ahw.revision_id == NX_P3_B0)
			c8c9value = 0xF1020;
		else
			c8c9value = 0;

	}
	adapter->hw_write_wx(adapter,
		NETXEN_PCIE_REG(PCIE_CHICKEN3), &chicken, 4);

	if (!c8c9value)
		return;

	pdevfuncsave = pdev->devfn;
	if (pdevfuncsave & 0x07)
		return;

	for (i = 0; i < 8; i++) {
		pci_read_config_dword(pdev, pos + 8, &control);
		pci_read_config_dword(pdev, pos + 8, &control);
		pci_write_config_dword(pdev, pos + 8, c8c9value);
		pdev->devfn++;
	}
	pdev->devfn = pdevfuncsave;
}

static void netxen_set_msix_bit(struct pci_dev *pdev, int enable)
{
	u32 control;
	int pos;

	pos = pci_find_capability(pdev, PCI_CAP_ID_MSIX);
	if (pos) {
		pci_read_config_dword(pdev, pos, &control);
		if (enable)
			control |= PCI_MSIX_FLAGS_ENABLE;
		else
			control = 0;
		pci_write_config_dword(pdev, pos, control);
	}
}

static void netxen_init_msix_entries(struct netxen_adapter *adapter)
{
	int i;

	for (i = 0; i < MSIX_ENTRIES_PER_ADAPTER; i++)
		adapter->msix_entries[i].entry = i;
}

/*
 * netxen_nic_probe()
 *
 * The Linux system will invoke this after identifying the vendor ID and
 * device Id in the pci_tbl supported by this module.
 *
 * A quad port card has one operational PCI config space, (function 0),
 * which is used to access all four ports.
 *
 * This routine will initialize the adapter, and setup the global parameters
 * along with the port's specific structure.
 */
static int __devinit
netxen_nic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
	struct net_device *netdev = NULL;
	struct netxen_adapter *adapter = NULL;
	void __iomem *mem_ptr0 = NULL;
	void __iomem *mem_ptr1 = NULL;
	void __iomem *mem_ptr2 = NULL;
	unsigned long first_page_group_end;
	unsigned long first_page_group_start;


	u8 __iomem *db_ptr = NULL;
	unsigned long mem_base, mem_len, db_base, db_len, pci_len0 = 0;
	int i = 0, err;
	int first_driver, first_boot;
	__le64 mac_addr[FLASH_NUM_PORTS + 1];
	u32 val;
	int pci_func_id = PCI_FUNC(pdev->devfn);
	DECLARE_MAC_BUF(mac);
	struct netxen_legacy_intr_set *legacy_intrp;
	uint8_t revision_id;

	if (pci_func_id == 0)
		printk(KERN_INFO "%s\n", netxen_nic_driver_string);

	if (pdev->class != 0x020000) {
		printk(KERN_DEBUG "NetXen function %d, class %x will not "
				"be enabled.\n",pci_func_id, pdev->class);
		return -ENODEV;
	}

	if ((err = pci_enable_device(pdev)))
		return err;

	if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
		err = -ENODEV;
		goto err_out_disable_pdev;
	}

	if ((err = pci_request_regions(pdev, netxen_nic_driver_name)))
		goto err_out_disable_pdev;

	pci_set_master(pdev);

	netdev = alloc_etherdev(sizeof(struct netxen_adapter));
	if(!netdev) {
		printk(KERN_ERR"%s: Failed to allocate memory for the "
				"device block.Check system memory resource"
				" usage.\n", netxen_nic_driver_name);
		goto err_out_free_res;
	}

	SET_NETDEV_DEV(netdev, &pdev->dev);

	adapter = netdev->priv;
	adapter->netdev  = netdev;
	adapter->pdev    = pdev;
	adapter->ahw.pci_func  = pci_func_id;

	revision_id = pdev->revision;
	adapter->ahw.revision_id = revision_id;

	err = nx_set_dma_mask(adapter, revision_id);
	if (err)
		goto err_out_free_netdev;

	rwlock_init(&adapter->adapter_lock);
	adapter->ahw.qdr_sn_window = -1;
	adapter->ahw.ddr_mn_window = -1;

	/* remap phys address */
	mem_base = pci_resource_start(pdev, 0);	/* 0 is for BAR 0 */
	mem_len = pci_resource_len(pdev, 0);
	pci_len0 = 0;

	adapter->hw_write_wx = netxen_nic_hw_write_wx_128M;
	adapter->hw_read_wx = netxen_nic_hw_read_wx_128M;
	adapter->pci_read_immediate = netxen_nic_pci_read_immediate_128M;
	adapter->pci_write_immediate = netxen_nic_pci_write_immediate_128M;
	adapter->pci_read_normalize = netxen_nic_pci_read_normalize_128M;
	adapter->pci_write_normalize = netxen_nic_pci_write_normalize_128M;
	adapter->pci_set_window = netxen_nic_pci_set_window_128M;
	adapter->pci_mem_read = netxen_nic_pci_mem_read_128M;
	adapter->pci_mem_write = netxen_nic_pci_mem_write_128M;

	/* 128 Meg of memory */
	if (mem_len == NETXEN_PCI_128MB_SIZE) {
		mem_ptr0 = ioremap(mem_base, FIRST_PAGE_GROUP_SIZE);
		mem_ptr1 = ioremap(mem_base + SECOND_PAGE_GROUP_START,
				SECOND_PAGE_GROUP_SIZE);
		mem_ptr2 = ioremap(mem_base + THIRD_PAGE_GROUP_START,
				THIRD_PAGE_GROUP_SIZE);
		first_page_group_start = FIRST_PAGE_GROUP_START;
		first_page_group_end   = FIRST_PAGE_GROUP_END;
	} else if (mem_len == NETXEN_PCI_32MB_SIZE) {
		mem_ptr1 = ioremap(mem_base, SECOND_PAGE_GROUP_SIZE);
		mem_ptr2 = ioremap(mem_base + THIRD_PAGE_GROUP_START -
			SECOND_PAGE_GROUP_START, THIRD_PAGE_GROUP_SIZE);
		first_page_group_start = 0;
		first_page_group_end   = 0;
	} else if (mem_len == NETXEN_PCI_2MB_SIZE) {
		adapter->hw_write_wx = netxen_nic_hw_write_wx_2M;
		adapter->hw_read_wx = netxen_nic_hw_read_wx_2M;
		adapter->pci_read_immediate = netxen_nic_pci_read_immediate_2M;
		adapter->pci_write_immediate =
			netxen_nic_pci_write_immediate_2M;
		adapter->pci_read_normalize = netxen_nic_pci_read_normalize_2M;
		adapter->pci_write_normalize =
			netxen_nic_pci_write_normalize_2M;
		adapter->pci_set_window = netxen_nic_pci_set_window_2M;
		adapter->pci_mem_read = netxen_nic_pci_mem_read_2M;
		adapter->pci_mem_write = netxen_nic_pci_mem_write_2M;

		mem_ptr0 = ioremap(mem_base, mem_len);
		pci_len0 = mem_len;
		first_page_group_start = 0;
		first_page_group_end   = 0;

		adapter->ahw.ddr_mn_window = 0;
		adapter->ahw.qdr_sn_window = 0;

		adapter->ahw.mn_win_crb = 0x100000 + PCIX_MN_WINDOW +
			(pci_func_id * 0x20);
		adapter->ahw.ms_win_crb = 0x100000 + PCIX_SN_WINDOW;
		if (pci_func_id < 4)
			adapter->ahw.ms_win_crb += (pci_func_id * 0x20);
		else
			adapter->ahw.ms_win_crb +=
					0xA0 + ((pci_func_id - 4) * 0x10);
	} else {
		err = -EIO;
		goto err_out_free_netdev;
	}

	dev_info(&pdev->dev, "%dMB memory map\n", (int)(mem_len>>20));

	db_base = pci_resource_start(pdev, 4);	/* doorbell is on bar 4 */
	db_len = pci_resource_len(pdev, 4);

	if (db_len == 0) {
		printk(KERN_ERR "%s: doorbell is disabled\n",
				netxen_nic_driver_name);
		err = -EIO;
		goto err_out_iounmap;
	}
	DPRINTK(INFO, "doorbell ioremap from %lx a size of %lx\n", db_base,
		db_len);

	db_ptr = ioremap(db_base, NETXEN_DB_MAPSIZE_BYTES);
	if (!db_ptr) {
		printk(KERN_ERR "%s: Failed to allocate doorbell map.",
				netxen_nic_driver_name);
		err = -EIO;
		goto err_out_iounmap;
	}
	DPRINTK(INFO, "doorbell ioremaped at %p\n", db_ptr);

	adapter->ahw.pci_base0 = mem_ptr0;
	adapter->ahw.pci_len0 = pci_len0;
	adapter->ahw.first_page_group_start = first_page_group_start;
	adapter->ahw.first_page_group_end   = first_page_group_end;
	adapter->ahw.pci_base1 = mem_ptr1;
	adapter->ahw.pci_base2 = mem_ptr2;
	adapter->ahw.db_base = db_ptr;
	adapter->ahw.db_len = db_len;

	netif_napi_add(netdev, &adapter->napi,
			netxen_nic_poll, NETXEN_NETDEV_WEIGHT);

	if (revision_id >= NX_P3_B0)
		legacy_intrp = &legacy_intr[pci_func_id];
	else
		legacy_intrp = &legacy_intr[0];

	adapter->legacy_intr.int_vec_bit = legacy_intrp->int_vec_bit;
	adapter->legacy_intr.tgt_status_reg = legacy_intrp->tgt_status_reg;
	adapter->legacy_intr.tgt_mask_reg = legacy_intrp->tgt_mask_reg;
	adapter->legacy_intr.pci_int_reg = legacy_intrp->pci_int_reg;

	/* this will be read from FW later */
	adapter->intr_scheme = -1;
	adapter->msi_mode = -1;

	/* This will be reset for mezz cards  */
	adapter->portnum = pci_func_id;
	adapter->status   &= ~NETXEN_NETDEV_STATUS;
	adapter->rx_csum = 1;
	adapter->mc_enabled = 0;
	if (NX_IS_REVISION_P3(revision_id))
		adapter->max_mc_count = 38;
	else
		adapter->max_mc_count = 16;

	netdev->open		   = netxen_nic_open;
	netdev->stop		   = netxen_nic_close;
	netdev->hard_start_xmit    = netxen_nic_xmit_frame;
	netdev->get_stats	   = netxen_nic_get_stats;
	netdev->set_multicast_list = netxen_nic_set_multi;
	netdev->set_mac_address    = netxen_nic_set_mac;
	netdev->change_mtu	   = netxen_nic_change_mtu;
	netdev->tx_timeout	   = netxen_tx_timeout;
	netdev->watchdog_timeo     = 2*HZ;

	netxen_nic_change_mtu(netdev, netdev->mtu);

	SET_ETHTOOL_OPS(netdev, &netxen_nic_ethtool_ops);
#ifdef CONFIG_NET_POLL_CONTROLLER
	netdev->poll_controller = netxen_nic_poll_controller;
#endif
	/* ScatterGather support */
	netdev->features = NETIF_F_SG;
	netdev->features |= NETIF_F_IP_CSUM;
	netdev->features |= NETIF_F_TSO;
	if (NX_IS_REVISION_P3(revision_id))
		netdev->features |= NETIF_F_TSO6;

	if (adapter->pci_using_dac)
		netdev->features |= NETIF_F_HIGHDMA;

	/*
	 * Set the CRB window to invalid. If any register in window 0 is
	 * accessed it should set the window to 0 and then reset it to 1.
	 */
	adapter->curr_window = 255;

	if (netxen_nic_get_board_info(adapter) != 0) {
		printk("%s: Error getting board config info.\n",
				netxen_nic_driver_name);
		err = -EIO;
		goto err_out_iounmap;
	}

	netxen_initialize_adapter_ops(adapter);

	/* Mezz cards have PCI function 0,2,3 enabled */
	switch (adapter->ahw.boardcfg.board_type) {
	case NETXEN_BRDTYPE_P2_SB31_10G_IMEZ:
	case NETXEN_BRDTYPE_P2_SB31_10G_HMEZ:
		if (pci_func_id >= 2)
			adapter->portnum = pci_func_id - 2;
		break;
	default:
		break;
	}

	/*
	 * This call will setup various max rx/tx counts.
	 * It must be done before any buffer/ring allocations.
	 */
	netxen_check_options(adapter);

	first_driver = 0;
	if (NX_IS_REVISION_P3(revision_id)) {
		if (adapter->ahw.pci_func == 0)
			first_driver = 1;
	} else {
		if (adapter->portnum == 0)
			first_driver = 1;
	}
	adapter->crb_addr_cmd_producer = crb_cmd_producer[adapter->portnum];
	adapter->crb_addr_cmd_consumer = crb_cmd_consumer[adapter->portnum];
	netxen_nic_update_cmd_producer(adapter, 0);
	netxen_nic_update_cmd_consumer(adapter, 0);

	if (first_driver) {
		first_boot = adapter->pci_read_normalize(adapter,
				NETXEN_CAM_RAM(0x1fc));

		err = netxen_check_hw_init(adapter, first_boot);
		if (err) {
			printk(KERN_ERR "%s: error in init HW init sequence\n",
					netxen_nic_driver_name);
			goto err_out_iounmap;
		}

		if (NX_IS_REVISION_P3(revision_id))
			netxen_set_port_mode(adapter);

		if (first_boot != 0x55555555) {
			adapter->pci_write_normalize(adapter,
						CRB_CMDPEG_STATE, 0);
			netxen_pinit_from_rom(adapter, 0);
			msleep(1);
			netxen_load_firmware(adapter);
		}

		if (NX_IS_REVISION_P3(revision_id))
			netxen_pcie_strap_init(adapter);

		if (NX_IS_REVISION_P2(revision_id)) {

			/* Initialize multicast addr pool owners */
			val = 0x7654;
			if (adapter->ahw.board_type == NETXEN_NIC_XGBE)
				val |= 0x0f000000;
			netxen_crb_writelit_adapter(adapter,
					NETXEN_MAC_ADDR_CNTL_REG, val);

		}

		if ((first_boot == 0x55555555) &&
			(NX_IS_REVISION_P2(revision_id))) {
			/* Unlock the HW, prompting the boot sequence */
			adapter->pci_write_normalize(adapter,
					NETXEN_ROMUSB_GLB_PEGTUNE_DONE, 1);
		}

		err = netxen_initialize_adapter_offload(adapter);
		if (err)
			goto err_out_iounmap;

		/*
		 * Tell the hardware our version number.
		 */
		i = (_NETXEN_NIC_LINUX_MAJOR << 16)
			| ((_NETXEN_NIC_LINUX_MINOR << 8))
			| (_NETXEN_NIC_LINUX_SUBVERSION);
		adapter->pci_write_normalize(adapter, CRB_DRIVER_VERSION, i);

		/* Handshake with the card before we register the devices. */
		netxen_phantom_init(adapter, NETXEN_NIC_PEG_TUNE);

		if (NX_IS_REVISION_P3(revision_id)) {
			adapter->hw_read_wx(adapter,
					NETXEN_MIU_MN_CONTROL, &val, 4);
			adapter->ahw.cut_through = (val & 0x4) ? 1 : 0;
			dev_info(&pdev->dev, "firmware running in %s mode\n",
			adapter->ahw.cut_through ? "cut through" : "legacy");
		}
	}	/* first_driver */

	netxen_nic_flash_print(adapter);

	/*
	 * See if the firmware gave us a virtual-physical port mapping.
	 */
	adapter->physical_port = adapter->portnum;
	i = adapter->pci_read_normalize(adapter, CRB_V2P(adapter->portnum));
	if (i != 0x55555555)
		adapter->physical_port = i;

	adapter->flags &= ~(NETXEN_NIC_MSI_ENABLED | NETXEN_NIC_MSIX_ENABLED);

	netxen_set_msix_bit(pdev, 0);

	if (NX_IS_REVISION_P3(revision_id)) {
		if ((mem_len != NETXEN_PCI_128MB_SIZE) &&
			mem_len != NETXEN_PCI_2MB_SIZE)
			adapter->msix_supported = 0;
	}

	if (adapter->msix_supported) {

		netxen_init_msix_entries(adapter);

		if (pci_enable_msix(pdev, adapter->msix_entries,
					MSIX_ENTRIES_PER_ADAPTER))
			goto request_msi;

		adapter->flags |= NETXEN_NIC_MSIX_ENABLED;
		netxen_set_msix_bit(pdev, 1);
		dev_info(&pdev->dev, "using msi-x interrupts\n");

	} else {
request_msi:
		if (use_msi && !pci_enable_msi(pdev)) {
			adapter->flags |= NETXEN_NIC_MSI_ENABLED;
			dev_info(&pdev->dev, "using msi interrupts\n");
		} else
			dev_info(&pdev->dev, "using legacy interrupts\n");
	}

	if (adapter->flags & NETXEN_NIC_MSIX_ENABLED)
		netdev->irq = adapter->msix_entries[0].vector;
	else
		netdev->irq = pdev->irq;

	err = netxen_receive_peg_ready(adapter);
	if (err)
		goto err_out_disable_msi;

	init_timer(&adapter->watchdog_timer);
	adapter->ahw.xg_linkup = 0;
	adapter->watchdog_timer.function = &netxen_watchdog;
	adapter->watchdog_timer.data = (unsigned long)adapter;
	INIT_WORK(&adapter->watchdog_task, netxen_watchdog_task);
	INIT_WORK(&adapter->tx_timeout_task, netxen_tx_timeout_task);

	if (netxen_is_flash_supported(adapter) == 0 &&
			netxen_get_flash_mac_addr(adapter, mac_addr) == 0) {
		unsigned char *p;

		p = (unsigned char *)&mac_addr[adapter->portnum];
		netdev->dev_addr[0] = *(p + 5);
		netdev->dev_addr[1] = *(p + 4);
		netdev->dev_addr[2] = *(p + 3);
		netdev->dev_addr[3] = *(p + 2);
		netdev->dev_addr[4] = *(p + 1);
		netdev->dev_addr[5] = *(p + 0);

		memcpy(netdev->perm_addr, netdev->dev_addr,
			netdev->addr_len);
		if (!is_valid_ether_addr(netdev->perm_addr)) {
			printk(KERN_ERR "%s: Bad MAC address %s.\n",
					netxen_nic_driver_name,
					print_mac(mac, netdev->dev_addr));
		} else {
			adapter->macaddr_set(adapter, netdev->dev_addr);
		}
	}

	netif_carrier_off(netdev);
	netif_stop_queue(netdev);

	if ((err = register_netdev(netdev))) {
		printk(KERN_ERR "%s: register_netdev failed port #%d"
			       " aborting\n", netxen_nic_driver_name,
			       adapter->portnum);
		err = -EIO;
		goto err_out_disable_msi;
	}

	pci_set_drvdata(pdev, adapter);

	switch (adapter->ahw.board_type) {
	case NETXEN_NIC_GBE:
		dev_info(&adapter->pdev->dev, "%s: GbE port initialized\n",
				adapter->netdev->name);
		break;
	case NETXEN_NIC_XGBE:
		dev_info(&adapter->pdev->dev, "%s: XGbE port initialized\n",
				adapter->netdev->name);
		break;
	}

	return 0;

err_out_disable_msi:
	if (adapter->flags & NETXEN_NIC_MSIX_ENABLED)
		pci_disable_msix(pdev);
	if (adapter->flags & NETXEN_NIC_MSI_ENABLED)
		pci_disable_msi(pdev);

	if (first_driver)
		netxen_free_adapter_offload(adapter);

err_out_iounmap:
	if (db_ptr)
		iounmap(db_ptr);

	if (mem_ptr0)
		iounmap(mem_ptr0);
	if (mem_ptr1)
		iounmap(mem_ptr1);
	if (mem_ptr2)
		iounmap(mem_ptr2);

err_out_free_netdev:
	free_netdev(netdev);

err_out_free_res:
	pci_release_regions(pdev);

err_out_disable_pdev:
	pci_set_drvdata(pdev, NULL);
	pci_disable_device(pdev);
	return err;
}

static void __devexit netxen_nic_remove(struct pci_dev *pdev)
{
	struct netxen_adapter *adapter;
	struct net_device *netdev;

	adapter = pci_get_drvdata(pdev);
	if (adapter == NULL)
		return;

	netdev = adapter->netdev;

	unregister_netdev(netdev);

	if (adapter->is_up == NETXEN_ADAPTER_UP_MAGIC) {
		netxen_free_hw_resources(adapter);
		netxen_free_sw_resources(adapter);
	}

	if (adapter->portnum == 0)
		netxen_free_adapter_offload(adapter);

	if (adapter->irq)
		free_irq(adapter->irq, adapter);

	if (adapter->flags & NETXEN_NIC_MSIX_ENABLED)
		pci_disable_msix(pdev);
	if (adapter->flags & NETXEN_NIC_MSI_ENABLED)
		pci_disable_msi(pdev);

	iounmap(adapter->ahw.db_base);
	iounmap(adapter->ahw.pci_base0);
	iounmap(adapter->ahw.pci_base1);
	iounmap(adapter->ahw.pci_base2);

	pci_release_regions(pdev);
	pci_disable_device(pdev);
	pci_set_drvdata(pdev, NULL);

	free_netdev(netdev);
}

/*
 * Called when a network interface is made active
 * @returns 0 on success, negative value on failure
 */
static int netxen_nic_open(struct net_device *netdev)
{
	struct netxen_adapter *adapter = (struct netxen_adapter *)netdev->priv;
	int err = 0;
	int ctx, ring;
	irq_handler_t handler;
	unsigned long flags = IRQF_SAMPLE_RANDOM;

	if (adapter->driver_mismatch)
		return -EIO;

	if (adapter->is_up != NETXEN_ADAPTER_UP_MAGIC) {
		err = netxen_init_firmware(adapter);
		if (err != 0) {
			printk(KERN_ERR "Failed to init firmware\n");
			return -EIO;
		}

		err = netxen_alloc_sw_resources(adapter);
		if (err) {
			printk(KERN_ERR "%s: Error in setting sw resources\n",
					netdev->name);
			return err;
		}

		netxen_nic_clear_stats(adapter);

		err = netxen_alloc_hw_resources(adapter);
		if (err) {
			printk(KERN_ERR "%s: Error in setting hw resources\n",
					netdev->name);
			goto err_out_free_sw;
		}

		if (adapter->fw_major < 4) {
			adapter->crb_addr_cmd_producer =
				crb_cmd_producer[adapter->portnum];
			adapter->crb_addr_cmd_consumer =
				crb_cmd_consumer[adapter->portnum];
		}

		netxen_nic_update_cmd_producer(adapter, 0);
		netxen_nic_update_cmd_consumer(adapter, 0);

		for (ctx = 0; ctx < MAX_RCV_CTX; ++ctx) {
			for (ring = 0; ring < NUM_RCV_DESC_RINGS; ring++)
				netxen_post_rx_buffers(adapter, ctx, ring);
		}
		if (NETXEN_IS_MSI_FAMILY(adapter))
			handler = netxen_msi_intr;
		else {
			flags |= IRQF_SHARED;
			handler = netxen_intr;
		}
		adapter->irq = netdev->irq;
		err = request_irq(adapter->irq, handler,
				  flags, netdev->name, adapter);
		if (err) {
			printk(KERN_ERR "request_irq failed with: %d\n", err);
			goto err_out_free_hw;
		}

		adapter->is_up = NETXEN_ADAPTER_UP_MAGIC;
	}

	/* Done here again so that even if phantom sw overwrote it,
	 * we set it */
	err = adapter->init_port(adapter, adapter->portnum);
	if (err) {
		printk(KERN_ERR "%s: Failed to initialize port %d\n",
				netxen_nic_driver_name, adapter->portnum);
		goto err_out_free_irq;
	}
	adapter->macaddr_set(adapter, netdev->dev_addr);

	netxen_nic_set_link_parameters(adapter);

	netxen_nic_set_multi(netdev);
	adapter->set_mtu(adapter, netdev->mtu);

	mod_timer(&adapter->watchdog_timer, jiffies);

	napi_enable(&adapter->napi);
	netxen_nic_enable_int(adapter);

	netif_start_queue(netdev);

	return 0;

err_out_free_irq:
	free_irq(adapter->irq, adapter);
err_out_free_hw:
	netxen_free_hw_resources(adapter);
err_out_free_sw:
	netxen_free_sw_resources(adapter);
	return err;
}

/*
 * netxen_nic_close - Disables a network interface entry point
 */
static int netxen_nic_close(struct net_device *netdev)
{
	struct netxen_adapter *adapter = netdev_priv(netdev);

	netif_carrier_off(netdev);
	netif_stop_queue(netdev);
	napi_disable(&adapter->napi);

	if (adapter->stop_port)
		adapter->stop_port(adapter);

	netxen_nic_disable_int(adapter);

	netxen_release_tx_buffers(adapter);

	if (adapter->is_up == NETXEN_ADAPTER_UP_MAGIC) {
		FLUSH_SCHEDULED_WORK();
		del_timer_sync(&adapter->watchdog_timer);
	}

	return 0;
}

static int netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
{
	struct netxen_adapter *adapter = netdev_priv(netdev);
	struct netxen_hardware_context *hw = &adapter->ahw;
	unsigned int first_seg_len = skb->len - skb->data_len;
	struct netxen_skb_frag *buffrag;
	unsigned int i;

	u32 producer, consumer;
	u32 saved_producer = 0;
	struct cmd_desc_type0 *hwdesc;
	int k;
	struct netxen_cmd_buffer *pbuf = NULL;
	int frag_count;
	int no_of_desc;
	u32 num_txd = adapter->max_tx_desc_count;

	frag_count = skb_shinfo(skb)->nr_frags + 1;

	/* There 4 fragments per descriptor */
	no_of_desc = (frag_count + 3) >> 2;
	if (netdev->features & NETIF_F_TSO) {
		if (skb_shinfo(skb)->gso_size > 0) {

			no_of_desc++;
			if ((ip_hdrlen(skb) + tcp_hdrlen(skb) +
			     sizeof(struct ethhdr)) >
			    (sizeof(struct cmd_desc_type0) - 2)) {
				no_of_desc++;
			}
		}
	}

	producer = adapter->cmd_producer;
	smp_mb();
	consumer = adapter->last_cmd_consumer;
	if ((no_of_desc+2) > find_diff_among(producer, consumer, num_txd)) {
		netif_stop_queue(netdev);
		smp_mb();
		return NETDEV_TX_BUSY;
	}

	/* Copy the descriptors into the hardware    */
	saved_producer = producer;
	hwdesc = &hw->cmd_desc_head[producer];
	memset(hwdesc, 0, sizeof(struct cmd_desc_type0));
	/* Take skb->data itself */
	pbuf = &adapter->cmd_buf_arr[producer];
	if ((netdev->features & NETIF_F_TSO) && skb_shinfo(skb)->gso_size > 0) {
		pbuf->mss = skb_shinfo(skb)->gso_size;
		hwdesc->mss = cpu_to_le16(skb_shinfo(skb)->gso_size);
	} else {
		pbuf->mss = 0;
		hwdesc->mss = 0;
	}
	pbuf->total_length = skb->len;
	pbuf->skb = skb;
	pbuf->cmd = TX_ETHER_PKT;
	pbuf->frag_count = frag_count;
	pbuf->port = adapter->portnum;
	buffrag = &pbuf->frag_array[0];
	buffrag->dma = pci_map_single(adapter->pdev, skb->data, first_seg_len,
				      PCI_DMA_TODEVICE);
	buffrag->length = first_seg_len;
	netxen_set_cmd_desc_totallength(hwdesc, skb->len);
	netxen_set_cmd_desc_num_of_buff(hwdesc, frag_count);
	netxen_set_cmd_desc_opcode(hwdesc, TX_ETHER_PKT);

	netxen_set_cmd_desc_port(hwdesc, adapter->portnum);
	netxen_set_cmd_desc_ctxid(hwdesc, adapter->portnum);
	hwdesc->buffer1_length = cpu_to_le16(first_seg_len);
	hwdesc->addr_buffer1 = cpu_to_le64(buffrag->dma);

	for (i = 1, k = 1; i < frag_count; i++, k++) {
		struct skb_frag_struct *frag;
		int len, temp_len;
		unsigned long offset;
		dma_addr_t temp_dma;

		/* move to next desc. if there is a need */
		if ((i & 0x3) == 0) {
			k = 0;
			producer = get_next_index(producer, num_txd);
			hwdesc = &hw->cmd_desc_head[producer];
			memset(hwdesc, 0, sizeof(struct cmd_desc_type0));
			pbuf = &adapter->cmd_buf_arr[producer];
			pbuf->skb = NULL;
		}
		frag = &skb_shinfo(skb)->frags[i - 1];
		len = frag->size;
		offset = frag->page_offset;

		temp_len = len;
		temp_dma = pci_map_page(adapter->pdev, frag->page, offset,
					len, PCI_DMA_TODEVICE);

		buffrag++;
		buffrag->dma = temp_dma;
		buffrag->length = temp_len;

		switch (k) {
		case 0:
			hwdesc->buffer1_length = cpu_to_le16(temp_len);
			hwdesc->addr_buffer1 = cpu_to_le64(temp_dma);
			break;
		case 1:
			hwdesc->buffer2_length = cpu_to_le16(temp_len);
			hwdesc->addr_buffer2 = cpu_to_le64(temp_dma);
			break;
		case 2:
			hwdesc->buffer3_length = cpu_to_le16(temp_len);
			hwdesc->addr_buffer3 = cpu_to_le64(temp_dma);
			break;
		case 3:
			hwdesc->buffer4_length = cpu_to_le16(temp_len);
			hwdesc->addr_buffer4 = cpu_to_le64(temp_dma);
			break;
		}
		frag++;
	}
	producer = get_next_index(producer, num_txd);

	/* might change opcode to TX_TCP_LSO */
	netxen_tso_check(adapter, &hw->cmd_desc_head[saved_producer], skb);

	/* For LSO, we need to copy the MAC/IP/TCP headers into
	 * the descriptor ring
	 */
	if (netxen_get_cmd_desc_opcode(&hw->cmd_desc_head[saved_producer])
	    == TX_TCP_LSO) {
		int hdr_len, first_hdr_len, more_hdr;
		hdr_len = hw->cmd_desc_head[saved_producer].total_hdr_length;
		if (hdr_len > (sizeof(struct cmd_desc_type0) - 2)) {
			first_hdr_len = sizeof(struct cmd_desc_type0) - 2;
			more_hdr = 1;
		} else {
			first_hdr_len = hdr_len;
			more_hdr = 0;
		}
		/* copy the MAC/IP/TCP headers to the cmd descriptor list */
		hwdesc = &hw->cmd_desc_head[producer];
		pbuf = &adapter->cmd_buf_arr[producer];
		pbuf->skb = NULL;

		/* copy the first 64 bytes */
		memcpy(((void *)hwdesc) + 2,
		       (void *)(skb->data), first_hdr_len);
		producer = get_next_index(producer, num_txd);

		if (more_hdr) {
			hwdesc = &hw->cmd_desc_head[producer];
			pbuf = &adapter->cmd_buf_arr[producer];
			pbuf->skb = NULL;
			/* copy the next 64 bytes - should be enough except
			 * for pathological case
			 */
			skb_copy_from_linear_data_offset(skb, first_hdr_len,
							 hwdesc,
							 (hdr_len -
							  first_hdr_len));
			producer = get_next_index(producer, num_txd);
		}
	}

	adapter->cmd_producer = producer;
	adapter->stats.txbytes += skb->len;

	netxen_nic_update_cmd_producer(adapter, adapter->cmd_producer);

	adapter->stats.xmitcalled++;
	netdev->trans_start = jiffies;

	return NETDEV_TX_OK;
}

static void netxen_watchdog(unsigned long v)
{
	struct netxen_adapter *adapter = (struct netxen_adapter *)v;

	SCHEDULE_WORK(&adapter->watchdog_task);
}

static void netxen_tx_timeout(struct net_device *netdev)
{
	struct netxen_adapter *adapter = (struct netxen_adapter *)
						netdev_priv(netdev);
	SCHEDULE_WORK(&adapter->tx_timeout_task);
}

static void netxen_tx_timeout_task(struct work_struct *work)
{
	struct netxen_adapter *adapter =
		container_of(work, struct netxen_adapter, tx_timeout_task);

	printk(KERN_ERR "%s %s: transmit timeout, resetting.\n",
	       netxen_nic_driver_name, adapter->netdev->name);

	netxen_nic_disable_int(adapter);
	napi_disable(&adapter->napi);

	adapter->netdev->trans_start = jiffies;

	napi_enable(&adapter->napi);
	netxen_nic_enable_int(adapter);
	netif_wake_queue(adapter->netdev);
}

static inline void
netxen_handle_int(struct netxen_adapter *adapter)
{
	netxen_nic_disable_int(adapter);
	napi_schedule(&adapter->napi);
}

static irqreturn_t netxen_intr(int irq, void *data)
{
	struct netxen_adapter *adapter = data;
	u32 our_int = 0;

	our_int = adapter->pci_read_normalize(adapter, CRB_INT_VECTOR);
	/* not our interrupt */
	if ((our_int & (0x80 << adapter->portnum)) == 0)
		return IRQ_NONE;

	if (adapter->intr_scheme == INTR_SCHEME_PERPORT) {
		/* claim interrupt */
		adapter->pci_write_normalize(adapter, CRB_INT_VECTOR,
				our_int & ~((u32)(0x80 << adapter->portnum)));
	}

	netxen_handle_int(adapter);

	return IRQ_HANDLED;
}

static irqreturn_t netxen_msi_intr(int irq, void *data)
{
	struct netxen_adapter *adapter = data;

	netxen_handle_int(adapter);
	return IRQ_HANDLED;
}

static int netxen_nic_poll(struct napi_struct *napi, int budget)
{
	struct netxen_adapter *adapter = container_of(napi, struct netxen_adapter, napi);
	int tx_complete;
	int ctx;
	int work_done;

	tx_complete = netxen_process_cmd_ring(adapter);

	work_done = 0;
	for (ctx = 0; ctx < MAX_RCV_CTX; ++ctx) {
		/*
		 * Fairness issue. This will give undue weight to the
		 * receive context 0.
		 */

		/*
		 * To avoid starvation, we give each of our receivers,
		 * a fraction of the quota. Sometimes, it might happen that we
		 * have enough quota to process every packet, but since all the
		 * packets are on one context, it gets only half of the quota,
		 * and ends up not processing it.
		 */
		work_done += netxen_process_rcv_ring(adapter, ctx,
						     budget / MAX_RCV_CTX);
	}

	if ((work_done < budget) && tx_complete) {
		netif_rx_complete(adapter->netdev, &adapter->napi);
		netxen_nic_enable_int(adapter);
	}

	return work_done;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void netxen_nic_poll_controller(struct net_device *netdev)
{
	struct netxen_adapter *adapter = netdev_priv(netdev);
	disable_irq(adapter->irq);
	netxen_intr(adapter->irq, adapter);
	enable_irq(adapter->irq);
}
#endif

static struct pci_driver netxen_driver = {
	.name = netxen_nic_driver_name,
	.id_table = netxen_pci_tbl,
	.probe = netxen_nic_probe,
	.remove = __devexit_p(netxen_nic_remove)
};

/* Driver Registration on NetXen card    */

static int __init netxen_init_module(void)
{
	if ((netxen_workq = create_singlethread_workqueue("netxen")) == NULL)
		return -ENOMEM;

	return pci_register_driver(&netxen_driver);
}

module_init(netxen_init_module);

static void __exit netxen_exit_module(void)
{
	pci_unregister_driver(&netxen_driver);
	destroy_workqueue(netxen_workq);
}

module_exit(netxen_exit_module);