intelxl.c

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/*
 * Copyright (C) 2018 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * You can also choose to distribute this program under the terms of
 * the Unmodified Binary Distribution Licence (as given in the file
 * COPYING.UBDL), provided that you have satisfied its requirements.
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <stdint.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <byteswap.h>
#include <ipxe/netdevice.h>
#include <ipxe/ethernet.h>
#include <ipxe/if_ether.h>
#include <ipxe/vlan.h>
#include <ipxe/iobuf.h>
#include <ipxe/pci.h>
#include <ipxe/version.h>
#include "intelxl.h"

/** @file
 *
 * Intel 40 Gigabit Ethernet network card driver
 *
 */

/******************************************************************************
 *
 * MSI-X interrupts
 *
 ******************************************************************************
 */

/**
 * Enable MSI-X dummy interrupt
 *
 * @v intelxl           Intel device
 * @v pci               PCI device
 * @v vector            MSI-X vector
 * @ret rc              Return status code
 */
int intelxl_msix_enable ( struct intelxl_nic *intelxl,
                          struct pci_device *pci, unsigned int vector ) {
        int rc;

        /* Enable MSI-X capability */
        if ( ( rc = pci_msix_enable ( pci, &intelxl->msix ) ) != 0 ) {
                DBGC ( intelxl, "INTELXL %p could not enable MSI-X: %s\n",
                       intelxl, strerror ( rc ) );
                goto err_enable;
        }

        /* Enable dummy interrupt */
        pci_msix_unmask ( &intelxl->msix, vector );

        return 0;

        pci_msix_disable ( pci, &intelxl->msix );
 err_enable:
        return rc;
}

/**
 * Disable MSI-X dummy interrupt
 *
 * @v intelxl           Intel device
 * @v pci               PCI device
 * @v vector            MSI-X vector
 */
void intelxl_msix_disable ( struct intelxl_nic *intelxl,
                            struct pci_device *pci, unsigned int vector ) {

        /* Disable dummy interrupts */
        pci_msix_mask ( &intelxl->msix, vector );

        /* Disable MSI-X capability */
        pci_msix_disable ( pci, &intelxl->msix );
}

/******************************************************************************
 *
 * Admin queue
 *
 ******************************************************************************
 */

/** Admin queue register offsets */
const struct intelxl_admin_offsets intelxl_admin_offsets = {
        .bal = INTELXL_ADMIN_BAL,
        .bah = INTELXL_ADMIN_BAH,
        .len = INTELXL_ADMIN_LEN,
        .head = INTELXL_ADMIN_HEAD,
        .tail = INTELXL_ADMIN_TAIL,
};

/**
 * Allocate admin queue
 *
 * @v intelxl           Intel device
 * @v admin             Admin queue
 * @ret rc              Return status code
 */
static int intelxl_alloc_admin ( struct intelxl_nic *intelxl,
                                 struct intelxl_admin *admin ) {
        size_t buf_len = ( sizeof ( admin->buf[0] ) * INTELXL_ADMIN_NUM_DESC );
        size_t len = ( sizeof ( admin->desc[0] ) * INTELXL_ADMIN_NUM_DESC );

        /* Allocate admin queue */
        admin->buf = dma_alloc ( intelxl->dma, &admin->map, ( buf_len + len ),
                                 INTELXL_ALIGN );
        if ( ! admin->buf )
                return -ENOMEM;
        admin->desc = ( ( ( void * ) admin->buf ) + buf_len );

        DBGC ( intelxl, "INTELXL %p A%cQ is at [%08lx,%08lx) buf "
               "[%08lx,%08lx)\n", intelxl,
               ( ( admin == &intelxl->command ) ? 'T' : 'R' ),
               virt_to_phys ( admin->desc ),
               ( virt_to_phys ( admin->desc ) + len ),
               virt_to_phys ( admin->buf ),
               ( virt_to_phys ( admin->buf ) + buf_len ) );
        return 0;
}

/**
 * Enable admin queue
 *
 * @v intelxl           Intel device
 * @v admin             Admin queue
 */
static void intelxl_enable_admin ( struct intelxl_nic *intelxl,
                                   struct intelxl_admin *admin ) {
        size_t len = ( sizeof ( admin->desc[0] ) * INTELXL_ADMIN_NUM_DESC );
        const struct intelxl_admin_offsets *regs = admin->regs;
        void *admin_regs = ( intelxl->regs + admin->base );
        physaddr_t address;

        /* Initialise admin queue */
        memset ( admin->desc, 0, len );

        /* Reset head and tail registers */
        writel ( 0, admin_regs + regs->head );
        writel ( 0, admin_regs + regs->tail );

        /* Reset queue index */
        admin->index = 0;

        /* Program queue address */
        address = dma ( &admin->map, admin->desc );
        writel ( ( address & 0xffffffffUL ), admin_regs + regs->bal );
        if ( sizeof ( physaddr_t ) > sizeof ( uint32_t ) ) {
                writel ( ( ( ( uint64_t ) address ) >> 32 ),
                         admin_regs + regs->bah );
        } else {
                writel ( 0, admin_regs + regs->bah );
        }

        /* Program queue length and enable queue */
        writel ( ( INTELXL_ADMIN_LEN_LEN ( INTELXL_ADMIN_NUM_DESC ) |
                   INTELXL_ADMIN_LEN_ENABLE ),
                 admin_regs + regs->len );
}

/**
 * Disable admin queue
 *
 * @v intelxl           Intel device
 * @v admin             Admin queue
 */
static void intelxl_disable_admin ( struct intelxl_nic *intelxl,
                                    struct intelxl_admin *admin ) {
        const struct intelxl_admin_offsets *regs = admin->regs;
        void *admin_regs = ( intelxl->regs + admin->base );

        /* Disable queue */
        writel ( 0, admin_regs + regs->len );
}

/**
 * Free admin queue
 *
 * @v intelxl           Intel device
 * @v admin             Admin queue
 */
static void intelxl_free_admin ( struct intelxl_nic *intelxl __unused,
                                 struct intelxl_admin *admin ) {
        size_t buf_len = ( sizeof ( admin->buf[0] ) * INTELXL_ADMIN_NUM_DESC );
        size_t len = ( sizeof ( admin->desc[0] ) * INTELXL_ADMIN_NUM_DESC );

        /* Free queue */
        dma_free ( &admin->map, admin->buf, ( buf_len + len ) );
}

/**
 * Get next admin command queue descriptor
 *
 * @v intelxl           Intel device
 * @ret cmd             Command descriptor
 */
struct intelxl_admin_descriptor *
intelxl_admin_command_descriptor ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin *admin = &intelxl->command;
        struct intelxl_admin_descriptor *cmd;

        /* Get and initialise next descriptor */
        cmd = &admin->desc[ admin->index % INTELXL_ADMIN_NUM_DESC ];
        memset ( cmd, 0, sizeof ( *cmd ) );
        return cmd;
}

/**
 * Get next admin command queue data buffer
 *
 * @v intelxl           Intel device
 * @ret buf             Data buffer
 */
union intelxl_admin_buffer *
intelxl_admin_command_buffer ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin *admin = &intelxl->command;
        union intelxl_admin_buffer *buf;

        /* Get next data buffer */
        buf = &admin->buf[ admin->index % INTELXL_ADMIN_NUM_DESC ];
        memset ( buf, 0, sizeof ( *buf ) );
        return buf;
}

/**
 * Initialise admin event queue descriptor
 *
 * @v intelxl           Intel device
 * @v index             Event queue index
 */
static void intelxl_admin_event_init ( struct intelxl_nic *intelxl,
                                       unsigned int index ) {
        struct intelxl_admin *admin = &intelxl->event;
        struct intelxl_admin_descriptor *evt;
        union intelxl_admin_buffer *buf;
        uint64_t address;

        /* Initialise descriptor */
        evt = &admin->desc[ index % INTELXL_ADMIN_NUM_DESC ];
        buf = &admin->buf[ index % INTELXL_ADMIN_NUM_DESC ];
        address = dma ( &admin->map, buf );
        evt->flags = cpu_to_le16 ( INTELXL_ADMIN_FL_BUF );
        evt->len = cpu_to_le16 ( sizeof ( *buf ) );
        evt->params.buffer.high = cpu_to_le32 ( address >> 32 );
        evt->params.buffer.low = cpu_to_le32 ( address & 0xffffffffUL );
}

/**
 * Issue admin queue command
 *
 * @v intelxl           Intel device
 * @ret rc              Return status code
 */
int intelxl_admin_command ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin *admin = &intelxl->command;
        const struct intelxl_admin_offsets *regs = admin->regs;
        void *admin_regs = ( intelxl->regs + admin->base );
        struct intelxl_admin_descriptor *cmd;
        union intelxl_admin_buffer *buf;
        uint64_t address;
        uint32_t cookie;
        uint16_t silence;
        unsigned int index;
        unsigned int tail;
        unsigned int i;
        int rc;

        /* Get next queue entry */
        index = admin->index++;
        tail = ( admin->index % INTELXL_ADMIN_NUM_DESC );
        cmd = &admin->desc[ index % INTELXL_ADMIN_NUM_DESC ];
        buf = &admin->buf[ index % INTELXL_ADMIN_NUM_DESC ];
        DBGC2 ( intelxl, "INTELXL %p admin command %#x opcode %#04x",
                intelxl, index, le16_to_cpu ( cmd->opcode ) );
        if ( cmd->cookie )
                DBGC2 ( intelxl, "/%#08x", le32_to_cpu ( cmd->cookie ) );
        DBGC2 ( intelxl, ":\n" );

        /* Allow expected errors to be silenced */
        silence = cmd->ret;
        cmd->ret = 0;

        /* Sanity checks */
        assert ( ! ( cmd->flags & cpu_to_le16 ( INTELXL_ADMIN_FL_DD ) ) );
        assert ( ! ( cmd->flags & cpu_to_le16 ( INTELXL_ADMIN_FL_CMP ) ) );
        assert ( ! ( cmd->flags & cpu_to_le16 ( INTELXL_ADMIN_FL_ERR ) ) );

        /* Populate data buffer address if applicable */
        if ( cmd->flags & cpu_to_le16 ( INTELXL_ADMIN_FL_BUF ) ) {
                address = dma ( &admin->map, buf );
                cmd->params.buffer.high = cpu_to_le32 ( address >> 32 );
                cmd->params.buffer.low = cpu_to_le32 ( address & 0xffffffffUL );
        }

        /* Populate cookie, if not being (ab)used for VF opcode */
        if ( ! cmd->cookie )
                cmd->cookie = cpu_to_le32 ( index );

        /* Record cookie */
        cookie = cmd->cookie;

        /* Post command descriptor */
        DBGC2_HDA ( intelxl, virt_to_phys ( cmd ), cmd, sizeof ( *cmd ) );
        if ( cmd->flags & cpu_to_le16 ( INTELXL_ADMIN_FL_RD ) ) {
                DBGC2_HDA ( intelxl, virt_to_phys ( buf ), buf,
                            le16_to_cpu ( cmd->len ) );
        }
        wmb();
        writel ( tail, admin_regs + regs->tail );

        /* Wait for completion */
        for ( i = 0 ; i < INTELXL_ADMIN_MAX_WAIT_MS ; i++ ) {

                /* If response is not complete, delay 1ms and retry */
                if ( ! ( cmd->flags & INTELXL_ADMIN_FL_DD ) ) {
                        mdelay ( 1 );
                        continue;
                }
                DBGC2 ( intelxl, "INTELXL %p admin command %#x response:\n",
                        intelxl, index );
                DBGC2_HDA ( intelxl, virt_to_phys ( cmd ), cmd,
                            sizeof ( *cmd ) );
                if ( cmd->flags & cpu_to_le16 ( INTELXL_ADMIN_FL_BUF ) ) {
                        DBGC2_HDA ( intelxl, virt_to_phys ( buf ), buf,
                                    le16_to_cpu ( cmd->len ) );
                }

                /* Check for cookie mismatch */
                if ( cmd->cookie != cookie ) {
                        DBGC ( intelxl, "INTELXL %p admin command %#x bad "
                               "cookie %#x\n", intelxl, index,
                               le32_to_cpu ( cmd->cookie ) );
                        rc = -EPROTO;
                        goto err;
                }

                /* Check for unexpected errors */
                if ( ( cmd->ret != 0 ) && ( cmd->ret != silence ) ) {
                        DBGC ( intelxl, "INTELXL %p admin command %#x error "
                               "%d\n", intelxl, index,
                               le16_to_cpu ( cmd->ret ) );
                        rc = -EIO;
                        goto err;
                }

                /* Success */
                return 0;
        }

        rc = -ETIMEDOUT;
        DBGC ( intelxl, "INTELXL %p timed out waiting for admin command %#x:\n",
               intelxl, index );
 err:
        DBGC_HDA ( intelxl, virt_to_phys ( cmd ), cmd, sizeof ( *cmd ) );
        return rc;
}

/**
 * Get firmware version
 *
 * @v intelxl           Intel device
 * @ret rc              Return status code
 */
static int intelxl_admin_version ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin_descriptor *cmd;
        struct intelxl_admin_version_params *version;
        unsigned int api;
        int rc;

        /* Populate descriptor */
        cmd = intelxl_admin_command_descriptor ( intelxl );
        cmd->opcode = cpu_to_le16 ( INTELXL_ADMIN_VERSION );
        version = &cmd->params.version;

        /* Issue command */
        if ( ( rc = intelxl_admin_command ( intelxl ) ) != 0 )
                return rc;
        api = le16_to_cpu ( version->api.major );
        DBGC ( intelxl, "INTELXL %p firmware v%d.%d API v%d.%d\n",
               intelxl, le16_to_cpu ( version->firmware.major ),
               le16_to_cpu ( version->firmware.minor ),
               api, le16_to_cpu ( version->api.minor ) );

        /* Check for API compatibility */
        if ( api > INTELXL_ADMIN_API_MAJOR ) {
                DBGC ( intelxl, "INTELXL %p unsupported API v%d\n",
                       intelxl, api );
                return -ENOTSUP;
        }

        return 0;
}

/**
 * Report driver version
 *
 * @v intelxl           Intel device
 * @ret rc              Return status code
 */
static int intelxl_admin_driver ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin_descriptor *cmd;
        struct intelxl_admin_driver_params *driver;
        union intelxl_admin_buffer *buf;
        int rc;

        /* Populate descriptor */
        cmd = intelxl_admin_command_descriptor ( intelxl );
        cmd->opcode = cpu_to_le16 ( INTELXL_ADMIN_DRIVER );
        cmd->flags = cpu_to_le16 ( INTELXL_ADMIN_FL_RD | INTELXL_ADMIN_FL_BUF );
        cmd->len = cpu_to_le16 ( sizeof ( buf->driver ) );
        driver = &cmd->params.driver;
        driver->major = product_major_version;
        driver->minor = product_minor_version;
        buf = intelxl_admin_command_buffer ( intelxl );
        snprintf ( buf->driver.name, sizeof ( buf->driver.name ), "%s",
                   ( product_name[0] ? product_name : product_short_name ) );

        /* Issue command */
        if ( ( rc = intelxl_admin_command ( intelxl ) ) != 0 )
                return rc;

        return 0;
}

/**
 * Shutdown admin queues
 *
 * @v intelxl           Intel device
 * @ret rc              Return status code
 */
static int intelxl_admin_shutdown ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin_descriptor *cmd;
        struct intelxl_admin_shutdown_params *shutdown;
        int rc;

        /* Populate descriptor */
        cmd = intelxl_admin_command_descriptor ( intelxl );
        cmd->opcode = cpu_to_le16 ( INTELXL_ADMIN_SHUTDOWN );
        shutdown = &cmd->params.shutdown;
        shutdown->unloading = INTELXL_ADMIN_SHUTDOWN_UNLOADING;

        /* Issue command */
        if ( ( rc = intelxl_admin_command ( intelxl ) ) != 0 )
                return rc;

        return 0;
}

/**
 * Get MAC address
 *
 * @v netdev            Network device
 * @ret rc              Return status code
 */
static int intelxl_admin_mac_read ( struct net_device *netdev ) {
        struct intelxl_nic *intelxl = netdev->priv;
        struct intelxl_admin_descriptor *cmd;
        struct intelxl_admin_mac_read_params *read;
        union intelxl_admin_buffer *buf;
        uint8_t *mac;
        int rc;

        /* Populate descriptor */
        cmd = intelxl_admin_command_descriptor ( intelxl );
        cmd->opcode = cpu_to_le16 ( INTELXL_ADMIN_MAC_READ );
        cmd->flags = cpu_to_le16 ( INTELXL_ADMIN_FL_BUF );
        cmd->len = cpu_to_le16 ( sizeof ( buf->mac_read ) );
        read = &cmd->params.mac_read;
        buf = intelxl_admin_command_buffer ( intelxl );
        mac = buf->mac_read.pf;

        /* Issue command */
        if ( ( rc = intelxl_admin_command ( intelxl ) ) != 0 )
                return rc;

        /* Check that MAC address is present in response */
        if ( ! ( read->valid & INTELXL_ADMIN_MAC_READ_VALID_LAN ) ) {
                DBGC ( intelxl, "INTELXL %p has no MAC address\n", intelxl );
                return -ENOENT;
        }

        /* Check that address is valid */
        if ( ! is_valid_ether_addr ( mac ) ) {
                DBGC ( intelxl, "INTELXL %p has invalid MAC address (%s)\n",
                       intelxl, eth_ntoa ( mac ) );
                return -ENOENT;
        }

        /* Copy MAC address */
        DBGC ( intelxl, "INTELXL %p has MAC address %s\n",
               intelxl, eth_ntoa ( mac ) );
        memcpy ( netdev->hw_addr, mac, ETH_ALEN );

        return 0;
}

/**
 * Set MAC address
 *
 * @v netdev            Network device
 * @ret rc              Return status code
 */
static int intelxl_admin_mac_write ( struct net_device *netdev ) {
        struct intelxl_nic *intelxl = netdev->priv;
        struct intelxl_admin_descriptor *cmd;
        struct intelxl_admin_mac_write_params *write;
        union {
                uint8_t raw[ETH_ALEN];
                struct {
                        uint16_t high;
                        uint32_t low;
                } __attribute__ (( packed ));
        } mac;
        int rc;

        /* Populate descriptor */
        cmd = intelxl_admin_command_descriptor ( intelxl );
        cmd->opcode = cpu_to_le16 ( INTELXL_ADMIN_MAC_WRITE );
        write = &cmd->params.mac_write;
        memcpy ( mac.raw, netdev->ll_addr, ETH_ALEN );
        write->high = bswap_16 ( mac.high );
        write->low = bswap_32 ( mac.low );

        /* Issue command */
        if ( ( rc = intelxl_admin_command ( intelxl ) ) != 0 )
                return rc;

        return 0;
}

/**
 * Clear PXE mode
 *
 * @v intelxl           Intel device
 * @ret rc              Return status code
 */
int intelxl_admin_clear_pxe ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin_descriptor *cmd;
        struct intelxl_admin_clear_pxe_params *pxe;
        int rc;

        /* Populate descriptor */
        cmd = intelxl_admin_command_descriptor ( intelxl );
        cmd->opcode = cpu_to_le16 ( INTELXL_ADMIN_CLEAR_PXE );
        cmd->ret = cpu_to_le16 ( INTELXL_ADMIN_EEXIST );
        pxe = &cmd->params.pxe;
        pxe->magic = INTELXL_ADMIN_CLEAR_PXE_MAGIC;

        /* Issue command */
        if ( ( rc = intelxl_admin_command ( intelxl ) ) != 0 )
                return rc;

        /* Check for expected errors */
        if ( cmd->ret == cpu_to_le16 ( INTELXL_ADMIN_EEXIST ) ) {
                DBGC ( intelxl, "INTELXL %p already in non-PXE mode\n",
                       intelxl );
                return 0;
        }

        return 0;
}

/**
 * Get switch configuration
 *
 * @v intelxl           Intel device
 * @ret rc              Return status code
 */
static int intelxl_admin_switch ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin_descriptor *cmd;
        struct intelxl_admin_switch_params *sw;
        union intelxl_admin_buffer *buf;
        uint16_t next = 0;
        int rc;

        /* Get each configuration in turn */
        do {
                /* Populate descriptor */
                cmd = intelxl_admin_command_descriptor ( intelxl );
                cmd->opcode = cpu_to_le16 ( INTELXL_ADMIN_SWITCH );
                cmd->flags = cpu_to_le16 ( INTELXL_ADMIN_FL_BUF );
                cmd->len = cpu_to_le16 ( sizeof ( buf->sw ) );
                sw = &cmd->params.sw;
                sw->next = next;
                buf = intelxl_admin_command_buffer ( intelxl );

                /* Issue command */
                if ( ( rc = intelxl_admin_command ( intelxl ) ) != 0 )
                        return rc;

                /* Dump raw configuration */
                DBGC2 ( intelxl, "INTELXL %p SEID %#04x:\n",
                        intelxl, le16_to_cpu ( buf->sw.cfg.seid ) );
                DBGC2_HDA ( intelxl, 0, &buf->sw.cfg, sizeof ( buf->sw.cfg ) );

                /* Parse response */
                if ( buf->sw.cfg.type == INTELXL_ADMIN_SWITCH_TYPE_VSI ) {
                        intelxl->vsi = le16_to_cpu ( buf->sw.cfg.seid );
                        DBGC ( intelxl, "INTELXL %p VSI %#04x uplink %#04x "
                               "downlink %#04x conn %#02x\n", intelxl,
                               intelxl->vsi, le16_to_cpu ( buf->sw.cfg.uplink ),
                               le16_to_cpu ( buf->sw.cfg.downlink ),
                               buf->sw.cfg.connection );
                }

        } while ( ( next = sw->next ) );

        /* Check that we found a VSI */
        if ( ! intelxl->vsi ) {
                DBGC ( intelxl, "INTELXL %p has no VSI\n", intelxl );
                return -ENOENT;
        }

        return 0;
}

/**
 * Get VSI parameters
 *
 * @v intelxl           Intel device
 * @ret rc              Return status code
 */
static int intelxl_admin_vsi ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin_descriptor *cmd;
        struct intelxl_admin_vsi_params *vsi;
        union intelxl_admin_buffer *buf;
        int rc;

        /* Populate descriptor */
        cmd = intelxl_admin_command_descriptor ( intelxl );
        cmd->opcode = cpu_to_le16 ( INTELXL_ADMIN_VSI );
        cmd->flags = cpu_to_le16 ( INTELXL_ADMIN_FL_BUF );
        cmd->len = cpu_to_le16 ( sizeof ( buf->vsi ) );
        vsi = &cmd->params.vsi;
        vsi->vsi = cpu_to_le16 ( intelxl->vsi );
        buf = intelxl_admin_command_buffer ( intelxl );

        /* Issue command */
        if ( ( rc = intelxl_admin_command ( intelxl ) ) != 0 )
                return rc;

        /* Parse response */
        intelxl->queue = le16_to_cpu ( buf->vsi.queue[0] );
        intelxl->qset = le16_to_cpu ( buf->vsi.qset[0] );
        DBGC ( intelxl, "INTELXL %p VSI %#04x queue %#04x qset %#04x\n",
               intelxl, intelxl->vsi, intelxl->queue, intelxl->qset );

        return 0;
}

/**
 * Set VSI promiscuous modes
 *
 * @v intelxl           Intel device
 * @ret rc              Return status code
 */
static int intelxl_admin_promisc ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin_descriptor *cmd;
        struct intelxl_admin_promisc_params *promisc;
        uint16_t flags;
        int rc;

        /* Populate descriptor */
        cmd = intelxl_admin_command_descriptor ( intelxl );
        cmd->opcode = cpu_to_le16 ( INTELXL_ADMIN_PROMISC );
        flags = ( INTELXL_ADMIN_PROMISC_FL_UNICAST |
                  INTELXL_ADMIN_PROMISC_FL_MULTICAST |
                  INTELXL_ADMIN_PROMISC_FL_BROADCAST |
                  INTELXL_ADMIN_PROMISC_FL_VLAN );
        promisc = &cmd->params.promisc;
        promisc->flags = cpu_to_le16 ( flags );
        promisc->valid = cpu_to_le16 ( flags );
        promisc->vsi = cpu_to_le16 ( intelxl->vsi );

        /* Issue command */
        if ( ( rc = intelxl_admin_command ( intelxl ) ) != 0 )
                return rc;

        return 0;
}

/**
 * Set MAC configuration
 *
 * @v intelxl           Intel device
 * @ret rc              Return status code
 */
int intelxl_admin_mac_config ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin_descriptor *cmd;
        struct intelxl_admin_mac_config_params *config;
        int rc;

        /* Populate descriptor */
        cmd = intelxl_admin_command_descriptor ( intelxl );
        cmd->opcode = cpu_to_le16 ( INTELXL_ADMIN_MAC_CONFIG );
        config = &cmd->params.mac_config;
        config->mfs = cpu_to_le16 ( intelxl->mfs );
        config->flags = INTELXL_ADMIN_MAC_CONFIG_FL_CRC;

        /* Issue command */
        if ( ( rc = intelxl_admin_command ( intelxl ) ) != 0 )
                return rc;

        return 0;
}

/**
 * Restart autonegotiation
 *
 * @v intelxl           Intel device
 * @ret rc              Return status code
 */
static int intelxl_admin_autoneg ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin_descriptor *cmd;
        struct intelxl_admin_autoneg_params *autoneg;
        int rc;

        /* Populate descriptor */
        cmd = intelxl_admin_command_descriptor ( intelxl );
        cmd->opcode = cpu_to_le16 ( INTELXL_ADMIN_AUTONEG );
        autoneg = &cmd->params.autoneg;
        autoneg->flags = ( INTELXL_ADMIN_AUTONEG_FL_RESTART |
                           INTELXL_ADMIN_AUTONEG_FL_ENABLE );

        /* Issue command */
        if ( ( rc = intelxl_admin_command ( intelxl ) ) != 0 )
                return rc;

        return 0;
}

/**
 * Get link status
 *
 * @v netdev            Network device
 * @ret rc              Return status code
 */
static int intelxl_admin_link ( struct net_device *netdev ) {
        struct intelxl_nic *intelxl = netdev->priv;
        struct intelxl_admin_descriptor *cmd;
        struct intelxl_admin_link_params *link;
        int rc;

        /* Populate descriptor */
        cmd = intelxl_admin_command_descriptor ( intelxl );
        cmd->opcode = cpu_to_le16 ( INTELXL_ADMIN_LINK );
        link = &cmd->params.link;
        link->notify = INTELXL_ADMIN_LINK_NOTIFY;

        /* Issue command */
        if ( ( rc = intelxl_admin_command ( intelxl ) ) != 0 )
                return rc;
        DBGC ( intelxl, "INTELXL %p PHY %#02x speed %#02x status %#02x\n",
               intelxl, link->phy, link->speed, link->status );

        /* Update network device */
        if ( link->status & INTELXL_ADMIN_LINK_UP ) {
                netdev_link_up ( netdev );
        } else {
                netdev_link_down ( netdev );
        }

        return 0;
}

/**
 * Handle admin event
 *
 * @v netdev            Network device
 * @v evt               Event descriptor
 * @v buf               Data buffer
 */
static void intelxl_admin_event ( struct net_device *netdev,
                                  struct intelxl_admin_descriptor *evt,
                                  union intelxl_admin_buffer *buf __unused ) {
        struct intelxl_nic *intelxl = netdev->priv;

        /* Ignore unrecognised events */
        if ( evt->opcode != cpu_to_le16 ( INTELXL_ADMIN_LINK ) ) {
                DBGC ( intelxl, "INTELXL %p unrecognised event opcode "
                       "%#04x\n", intelxl, le16_to_cpu ( evt->opcode ) );
                return;
        }

        /* Update link status */
        intelxl_admin_link ( netdev );
}

/**
 * Refill admin event queue
 *
 * @v intelxl           Intel device
 */
static void intelxl_refill_admin ( struct intelxl_nic *intelxl ) {
        struct intelxl_admin *admin = &intelxl->event;
        const struct intelxl_admin_offsets *regs = admin->regs;
        void *admin_regs = ( intelxl->regs + admin->base );
        unsigned int tail;

        /* Update tail pointer */
        tail = ( ( admin->index + INTELXL_ADMIN_NUM_DESC - 1 ) %
                 INTELXL_ADMIN_NUM_DESC );
        wmb();
        writel ( tail, admin_regs + regs->tail );
}

/**
 * Poll admin event queue
 *
 * @v netdev            Network device
 */
void intelxl_poll_admin ( struct net_device *netdev ) {
        struct intelxl_nic *intelxl = netdev->priv;
        struct intelxl_admin *admin = &intelxl->event;
        struct intelxl_admin_descriptor *evt;
        union intelxl_admin_buffer *buf;

        /* Check for events */
        while ( 1 ) {

                /* Get next event descriptor and data buffer */
                evt = &admin->desc[ admin->index % INTELXL_ADMIN_NUM_DESC ];
                buf = &admin->buf[ admin->index % INTELXL_ADMIN_NUM_DESC ];

                /* Stop if descriptor is not yet completed */
                if ( ! ( evt->flags & INTELXL_ADMIN_FL_DD ) )
                        return;
                DBGC2 ( intelxl, "INTELXL %p admin event %#x:\n",
                        intelxl, admin->index );
                DBGC2_HDA ( intelxl, virt_to_phys ( evt ), evt,
                            sizeof ( *evt ) );
                if ( evt->flags & cpu_to_le16 ( INTELXL_ADMIN_FL_BUF ) ) {
                        DBGC2_HDA ( intelxl, virt_to_phys ( buf ), buf,
                                    le16_to_cpu ( evt->len ) );
                }

                /* Handle event */
                intelxl->handle ( netdev, evt, buf );

                /* Reset descriptor and refill queue */
                intelxl_admin_event_init ( intelxl, admin->index );
                admin->index++;
                intelxl_refill_admin ( intelxl );
        }
}

/**
 * Open admin queues
 *
 * @v intelxl           Intel device
 * @ret rc              Return status code
 */
int intelxl_open_admin ( struct intelxl_nic *intelxl ) {
        int rc;

        /* Allocate admin event queue */
        if ( ( rc = intelxl_alloc_admin ( intelxl, &intelxl->event ) ) != 0 )
                goto err_alloc_event;

        /* Allocate admin command queue */
        if ( ( rc = intelxl_alloc_admin ( intelxl, &intelxl->command ) ) != 0 )
                goto err_alloc_command;

        /* (Re)open admin queues */
        intelxl_reopen_admin ( intelxl );

        return 0;

        intelxl_disable_admin ( intelxl, &intelxl->command );
        intelxl_disable_admin ( intelxl, &intelxl->event );
        intelxl_free_admin ( intelxl, &intelxl->command );
 err_alloc_command:
        intelxl_free_admin ( intelxl, &intelxl->event );
 err_alloc_event:
        return rc;
}

/**
 * Reopen admin queues (after virtual function reset)
 *
 * @v intelxl           Intel device
 */
void intelxl_reopen_admin ( struct intelxl_nic *intelxl ) {
        unsigned int i;

        /* Enable admin event queue */
        intelxl_enable_admin ( intelxl, &intelxl->event );

        /* Enable admin command queue */
        intelxl_enable_admin ( intelxl, &intelxl->command );

        /* Initialise all admin event queue descriptors */
        for ( i = 0 ; i < INTELXL_ADMIN_NUM_DESC ; i++ )
                intelxl_admin_event_init ( intelxl, i );

        /* Post all descriptors to event queue */
        intelxl_refill_admin ( intelxl );
}

/**
 * Close admin queues
 *
 * @v intelxl           Intel device
 */
void intelxl_close_admin ( struct intelxl_nic *intelxl ) {

        /* Shut down admin queues */
        intelxl_admin_shutdown ( intelxl );

        /* Disable admin queues */
        intelxl_disable_admin ( intelxl, &intelxl->command );
        intelxl_disable_admin ( intelxl, &intelxl->event );

        /* Free admin queues */
        intelxl_free_admin ( intelxl, &intelxl->command );
        intelxl_free_admin ( intelxl, &intelxl->event );
}

/******************************************************************************
 *
 * Descriptor rings
 *
 ******************************************************************************
 */

/**
 * Allocate descriptor ring
 *
 * @v intelxl           Intel device
 * @v ring              Descriptor ring
 * @ret rc              Return status code
 */
int intelxl_alloc_ring ( struct intelxl_nic *intelxl,
                         struct intelxl_ring *ring ) {
        int rc;

        /* Allocate descriptor ring */
        ring->desc.raw = dma_alloc ( intelxl->dma, &ring->map, ring->len,
                                     INTELXL_ALIGN );
        if ( ! ring->desc.raw ) {
                rc = -ENOMEM;
                goto err_alloc;
        }

        /* Initialise descriptor ring */
        memset ( ring->desc.raw, 0, ring->len );

        /* Reset tail pointer */
        writel ( 0, ( intelxl->regs + ring->tail ) );

        /* Reset counters */
        ring->prod = 0;
        ring->cons = 0;

        DBGC ( intelxl, "INTELXL %p ring %06x is at [%08lx,%08lx)\n",
               intelxl, ring->tail, virt_to_phys ( ring->desc.raw ),
               ( virt_to_phys ( ring->desc.raw ) + ring->len ) );

        return 0;

        dma_free ( &ring->map, ring->desc.raw, ring->len );
 err_alloc:
        return rc;
}

/**
 * Free descriptor ring
 *
 * @v intelxl           Intel device
 * @v ring              Descriptor ring
 */
void intelxl_free_ring ( struct intelxl_nic *intelxl __unused,
                         struct intelxl_ring *ring ) {

        /* Free descriptor ring */
        dma_free ( &ring->map, ring->desc.raw, ring->len );
        ring->desc.raw = NULL;
}

/**
 * Dump queue context (for debugging)
 *
 * @v intelxl           Intel device
 * @v op                Context operation
 * @v len               Size of context
 */
static __attribute__ (( unused )) void
intelxl_context_dump ( struct intelxl_nic *intelxl, uint32_t op, size_t len ) {
        struct intelxl_context_line line;
        uint32_t pfcm_lanctxctl;
        uint32_t pfcm_lanctxstat;
        unsigned int queue;
        unsigned int index;
        unsigned int i;

        /* Do nothing unless debug output is enabled */
        if ( ! DBG_EXTRA )
                return;

        /* Dump context */
        DBGC2 ( intelxl, "INTELXL %p context %#08x:\n", intelxl, op );
        for ( index = 0 ; ( sizeof ( line ) * index ) < len ; index++ ) {

                /* Start context operation */
                queue = ( intelxl->base + intelxl->queue );
                pfcm_lanctxctl =
                        ( INTELXL_PFCM_LANCTXCTL_QUEUE_NUM ( queue ) |
                          INTELXL_PFCM_LANCTXCTL_SUB_LINE ( index ) |
                          INTELXL_PFCM_LANCTXCTL_OP_CODE_READ | op );
                writel ( pfcm_lanctxctl,
                         intelxl->regs + INTELXL_PFCM_LANCTXCTL );

                /* Wait for operation to complete */
                for ( i = 0 ; i < INTELXL_CTX_MAX_WAIT_MS ; i++ ) {

                        /* Check if operation is complete */
                        pfcm_lanctxstat = readl ( intelxl->regs +
                                                  INTELXL_PFCM_LANCTXSTAT );
                        if ( pfcm_lanctxstat & INTELXL_PFCM_LANCTXSTAT_DONE )
                                break;

                        /* Delay */
                        mdelay ( 1 );
                }

                /* Read context data */
                for ( i = 0 ; i < ( sizeof ( line ) /
                                    sizeof ( line.raw[0] ) ) ; i++ ) {
                        line.raw[i] = readl ( intelxl->regs +
                                              INTELXL_PFCM_LANCTXDATA ( i ) );
                }
                DBGC2_HDA ( intelxl, ( sizeof ( line ) * index ),
                            &line, sizeof ( line ) );
        }
}

/**
 * Program queue context line
 *
 * @v intelxl           Intel device
 * @v line              Queue context line
 * @v index             Line number
 * @v op                Context operation
 * @ret rc              Return status code
 */
static int intelxl_context_line ( struct intelxl_nic *intelxl,
                                  struct intelxl_context_line *line,
                                  unsigned int index, uint32_t op ) {
        uint32_t pfcm_lanctxctl;
        uint32_t pfcm_lanctxstat;
        unsigned int queue;
        unsigned int i;

        /* Write context data */
        for ( i = 0; i < ( sizeof ( *line ) / sizeof ( line->raw[0] ) ); i++ ) {
                writel ( le32_to_cpu ( line->raw[i] ),
                         intelxl->regs + INTELXL_PFCM_LANCTXDATA ( i ) );
        }

        /* Start context operation */
        queue = ( intelxl->base + intelxl->queue );
        pfcm_lanctxctl = ( INTELXL_PFCM_LANCTXCTL_QUEUE_NUM ( queue ) |
                           INTELXL_PFCM_LANCTXCTL_SUB_LINE ( index ) |
                           INTELXL_PFCM_LANCTXCTL_OP_CODE_WRITE | op );
        writel ( pfcm_lanctxctl, intelxl->regs + INTELXL_PFCM_LANCTXCTL );

        /* Wait for operation to complete */
        for ( i = 0 ; i < INTELXL_CTX_MAX_WAIT_MS ; i++ ) {

                /* Check if operation is complete */
                pfcm_lanctxstat = readl ( intelxl->regs +
                                          INTELXL_PFCM_LANCTXSTAT );
                if ( pfcm_lanctxstat & INTELXL_PFCM_LANCTXSTAT_DONE )
                        return 0;

                /* Delay */
                mdelay ( 1 );
        }

        DBGC ( intelxl, "INTELXL %p timed out waiting for context: %#08x\n",
               intelxl, pfcm_lanctxctl );
        return -ETIMEDOUT;
}

/**
 * Program queue context
 *
 * @v intelxl           Intel device
 * @v line              Queue context lines
 * @v len               Size of context
 * @v op                Context operation
 * @ret rc              Return status code
 */
static int intelxl_context ( struct intelxl_nic *intelxl,
                             struct intelxl_context_line *line,
                             size_t len, uint32_t op ) {
        unsigned int index;
        int rc;

        DBGC2 ( intelxl, "INTELXL %p context %#08x len %#zx:\n",
                intelxl, op, len );
        DBGC2_HDA ( intelxl, 0, line, len );

        /* Program one line at a time */
        for ( index = 0 ; ( sizeof ( *line ) * index ) < len ; index++ ) {
                if ( ( rc = intelxl_context_line ( intelxl, line++, index,
                                                   op ) ) != 0 )
                        return rc;
        }

        return 0;
}

/**
 * Program transmit queue context
 *
 * @v intelxl           Intel device
 * @v address           Descriptor ring base address
 * @ret rc              Return status code
 */
static int intelxl_context_tx ( struct intelxl_nic *intelxl,
                                physaddr_t address ) {
        union {
                struct intelxl_context_tx tx;
                struct intelxl_context_line line;
        } ctx;
        int rc;

        /* Initialise context */
        memset ( &ctx, 0, sizeof ( ctx ) );
        ctx.tx.flags = cpu_to_le16 ( INTELXL_CTX_TX_FL_NEW );
        ctx.tx.base = cpu_to_le64 ( INTELXL_CTX_TX_BASE ( address ) );
        ctx.tx.count =
                cpu_to_le16 ( INTELXL_CTX_TX_COUNT ( INTELXL_TX_NUM_DESC ) );
        ctx.tx.qset = INTELXL_CTX_TX_QSET ( intelxl->qset );

        /* Program context */
        if ( ( rc = intelxl_context ( intelxl, &ctx.line, sizeof ( ctx ),
                                      INTELXL_PFCM_LANCTXCTL_TYPE_TX ) ) != 0 )
                return rc;

        return 0;
}

/**
 * Program receive queue context
 *
 * @v intelxl           Intel device
 * @v address           Descriptor ring base address
 * @ret rc              Return status code
 */
static int intelxl_context_rx ( struct intelxl_nic *intelxl,
                                physaddr_t address ) {
        union {
                struct intelxl_context_rx rx;
                struct intelxl_context_line line;
        } ctx;
        uint64_t base_count;
        int rc;

        /* Initialise context */
        memset ( &ctx, 0, sizeof ( ctx ) );
        base_count = INTELXL_CTX_RX_BASE_COUNT ( address, INTELXL_RX_NUM_DESC );
        ctx.rx.base_count = cpu_to_le64 ( base_count );
        ctx.rx.len = cpu_to_le16 ( INTELXL_CTX_RX_LEN ( intelxl->mfs ) );
        ctx.rx.flags = ( INTELXL_CTX_RX_FL_DSIZE | INTELXL_CTX_RX_FL_CRCSTRIP );
        ctx.rx.mfs = cpu_to_le16 ( INTELXL_CTX_RX_MFS ( intelxl->mfs ) );

        /* Program context */
        if ( ( rc = intelxl_context ( intelxl, &ctx.line, sizeof ( ctx ),
                                      INTELXL_PFCM_LANCTXCTL_TYPE_RX ) ) != 0 )
                return rc;

        return 0;
}

/**
 * Enable descriptor ring
 *
 * @v intelxl           Intel device
 * @v ring              Descriptor ring
 * @ret rc              Return status code
 */
static int intelxl_enable_ring ( struct intelxl_nic *intelxl,
                                 struct intelxl_ring *ring ) {
        void *ring_regs = ( intelxl->regs + ring->reg );
        uint32_t qxx_ena;

        /* Enable ring */
        writel ( INTELXL_QXX_ENA_REQ, ( ring_regs + INTELXL_QXX_ENA ) );
        udelay ( INTELXL_QUEUE_ENABLE_DELAY_US );
        qxx_ena = readl ( ring_regs + INTELXL_QXX_ENA );
        if ( ! ( qxx_ena & INTELXL_QXX_ENA_STAT ) ) {
                DBGC ( intelxl, "INTELXL %p ring %06x failed to enable: "
                       "%#08x\n", intelxl, ring->tail, qxx_ena );
                return -EIO;
        }

        return 0;
}

/**
 * Disable descriptor ring
 *
 * @v intelxl           Intel device
 * @v ring              Descriptor ring
 * @ret rc              Return status code
 */
static int intelxl_disable_ring ( struct intelxl_nic *intelxl,
                                  struct intelxl_ring *ring ) {
        void *ring_regs = ( intelxl->regs + ring->reg );
        uint32_t qxx_ena;
        unsigned int i;

        /* Disable ring */
        writel ( 0, ( ring_regs + INTELXL_QXX_ENA ) );

        /* Wait for ring to be disabled */
        for ( i = 0 ; i < INTELXL_QUEUE_DISABLE_MAX_WAIT_MS ; i++ ) {

                /* Check if ring is disabled */
                qxx_ena = readl ( ring_regs + INTELXL_QXX_ENA );
                if ( ! ( qxx_ena & INTELXL_QXX_ENA_STAT ) )
                        return 0;

                /* Delay */
                mdelay ( 1 );
        }

        DBGC ( intelxl, "INTELXL %p ring %06x timed out waiting for disable: "
               "%#08x\n", intelxl, ring->tail, qxx_ena );
        return -ETIMEDOUT;
}

/**
 * Create descriptor ring
 *
 * @v intelxl           Intel device
 * @v ring              Descriptor ring
 * @ret rc              Return status code
 */
int intelxl_create_ring ( struct intelxl_nic *intelxl,
                          struct intelxl_ring *ring ) {
        physaddr_t address;
        int rc;

        /* Allocate descriptor ring */
        if ( ( rc = intelxl_alloc_ring ( intelxl, ring ) ) != 0 )
                goto err_alloc;

        /* Program queue context */
        address = dma ( &ring->map, ring->desc.raw );
        if ( ( rc = ring->context ( intelxl, address ) ) != 0 )
                goto err_context;

        /* Enable ring */
        if ( ( rc = intelxl_enable_ring ( intelxl, ring ) ) != 0 )
                goto err_enable;

        return 0;

        intelxl_disable_ring ( intelxl, ring );
 err_enable:
 err_context:
        intelxl_free_ring ( intelxl, ring );
 err_alloc:
        return rc;
}

/**
 * Destroy descriptor ring
 *
 * @v intelxl           Intel device
 * @v ring              Descriptor ring
 */
void intelxl_destroy_ring ( struct intelxl_nic *intelxl,
                            struct intelxl_ring *ring ) {
        int rc;

        /* Disable ring */
        if ( ( rc = intelxl_disable_ring ( intelxl, ring ) ) != 0 ) {
                /* Leak memory; there's nothing else we can do */
                return;
        }

        /* Free descriptor ring */
        intelxl_free_ring ( intelxl, ring );
}

/**
 * Refill receive descriptor ring
 *
 * @v intelxl           Intel device
 */
static void intelxl_refill_rx ( struct intelxl_nic *intelxl ) {
        struct intelxl_rx_data_descriptor *rx;
        struct io_buffer *iobuf;
        unsigned int rx_idx;
        unsigned int rx_tail;
        unsigned int refilled = 0;

        /* Refill ring */
        while ( ( intelxl->rx.prod - intelxl->rx.cons ) < INTELXL_RX_FILL ) {

                /* Allocate I/O buffer */
                iobuf = alloc_rx_iob ( intelxl->mfs, intelxl->dma );
                if ( ! iobuf ) {
                        /* Wait for next refill */
                        break;
                }

                /* Get next receive descriptor */
                rx_idx = ( intelxl->rx.prod++ % INTELXL_RX_NUM_DESC );
                rx = &intelxl->rx.desc.rx[rx_idx].data;

                /* Populate receive descriptor */
                rx->address = cpu_to_le64 ( iob_dma ( iobuf ) );
                rx->flags = 0;

                /* Record I/O buffer */
                assert ( intelxl->rx_iobuf[rx_idx] == NULL );
                intelxl->rx_iobuf[rx_idx] = iobuf;

                DBGC2 ( intelxl, "INTELXL %p RX %d is [%08lx,%08lx)\n",
                        intelxl, rx_idx, virt_to_phys ( iobuf->data ),
                        ( virt_to_phys ( iobuf->data ) +  intelxl->mfs ) );
                refilled++;
        }

        /* Push descriptors to card, if applicable */
        if ( refilled ) {
                wmb();
                rx_tail = ( intelxl->rx.prod % INTELXL_RX_NUM_DESC );
                writel ( rx_tail, ( intelxl->regs + intelxl->rx.tail ) );
        }
}

/**
 * Discard unused receive I/O buffers
 *
 * @v intelxl           Intel device
 */
void intelxl_empty_rx ( struct intelxl_nic *intelxl ) {
        unsigned int i;

        /* Discard any unused receive buffers */
        for ( i = 0 ; i < INTELXL_RX_NUM_DESC ; i++ ) {
                if ( intelxl->rx_iobuf[i] )
                        free_rx_iob ( intelxl->rx_iobuf[i] );
                intelxl->rx_iobuf[i] = NULL;
        }
}

/******************************************************************************
 *
 * Network device interface
 *
 ******************************************************************************
 */

/**
 * Open network device
 *
 * @v netdev            Network device
 * @ret rc              Return status code
 */
static int intelxl_open ( struct net_device *netdev ) {
        struct intelxl_nic *intelxl = netdev->priv;
        unsigned int queue;
        int rc;

        /* Calculate maximum frame size */
        intelxl->mfs = ( ( ETH_HLEN + netdev->mtu + 4 /* CRC */ +
                           INTELXL_ALIGN - 1 ) & ~( INTELXL_ALIGN - 1 ) );

        /* Set MAC address */
        if ( ( rc = intelxl_admin_mac_write ( netdev ) ) != 0 )
                goto err_mac_write;

        /* Set maximum frame size */
        if ( ( rc = intelxl_admin_mac_config ( intelxl ) ) != 0 )
                goto err_mac_config;

        /* Associate transmit queue to PF */
        writel ( ( INTELXL_QXX_CTL_PFVF_Q_PF |
                   INTELXL_QXX_CTL_PFVF_PF_INDX ( intelxl->pf ) ),
                 ( intelxl->regs + intelxl->tx.reg + INTELXL_QXX_CTL ) );

        /* Clear transmit pre queue disable */
        queue = ( intelxl->base + intelxl->queue );
        writel ( ( INTELXL_GLLAN_TXPRE_QDIS_CLEAR_QDIS |
                   INTELXL_GLLAN_TXPRE_QDIS_QINDX ( queue ) ),
                 ( intelxl->regs + INTELXL_GLLAN_TXPRE_QDIS ( queue ) ) );

        /* Reset transmit queue head */
        writel ( 0, ( intelxl->regs + INTELXL_QTX_HEAD ( intelxl->queue ) ) );

        /* Create receive descriptor ring */
        if ( ( rc = intelxl_create_ring ( intelxl, &intelxl->rx ) ) != 0 )
                goto err_create_rx;

        /* Create transmit descriptor ring */
        if ( ( rc = intelxl_create_ring ( intelxl, &intelxl->tx ) ) != 0 )
                goto err_create_tx;

        /* Fill receive ring */
        intelxl_refill_rx ( intelxl );

        /* Restart autonegotiation */
        intelxl_admin_autoneg ( intelxl );

        /* Update link state */
        intelxl_admin_link ( netdev );

        return 0;

        writel ( ( INTELXL_GLLAN_TXPRE_QDIS_SET_QDIS |
                   INTELXL_GLLAN_TXPRE_QDIS_QINDX ( queue ) ),
                 ( intelxl->regs + INTELXL_GLLAN_TXPRE_QDIS ( queue ) ) );
        udelay ( INTELXL_QUEUE_PRE_DISABLE_DELAY_US );
        intelxl_destroy_ring ( intelxl, &intelxl->tx );
 err_create_tx:
        intelxl_destroy_ring ( intelxl, &intelxl->rx );
 err_create_rx:
 err_mac_config:
 err_mac_write:
        return rc;
}

/**
 * Close network device
 *
 * @v netdev            Network device
 */
static void intelxl_close ( struct net_device *netdev ) {
        struct intelxl_nic *intelxl = netdev->priv;
        unsigned int queue;

        /* Dump contexts (for debugging) */
        intelxl_context_dump ( intelxl, INTELXL_PFCM_LANCTXCTL_TYPE_TX,
                               sizeof ( struct intelxl_context_tx ) );
        intelxl_context_dump ( intelxl, INTELXL_PFCM_LANCTXCTL_TYPE_RX,
                               sizeof ( struct intelxl_context_rx ) );

        /* Pre-disable transmit queue */
        queue = ( intelxl->base + intelxl->queue );
        writel ( ( INTELXL_GLLAN_TXPRE_QDIS_SET_QDIS |
                   INTELXL_GLLAN_TXPRE_QDIS_QINDX ( queue ) ),
                 ( intelxl->regs + INTELXL_GLLAN_TXPRE_QDIS ( queue ) ) );
        udelay ( INTELXL_QUEUE_PRE_DISABLE_DELAY_US );

        /* Destroy transmit descriptor ring */
        intelxl_destroy_ring ( intelxl, &intelxl->tx );

        /* Destroy receive descriptor ring */
        intelxl_destroy_ring ( intelxl, &intelxl->rx );

        /* Discard any unused receive buffers */
        intelxl_empty_rx ( intelxl );
}

/**
 * Transmit packet
 *
 * @v netdev            Network device
 * @v iobuf             I/O buffer
 * @ret rc              Return status code
 */
int intelxl_transmit ( struct net_device *netdev, struct io_buffer *iobuf ) {
        struct intelxl_nic *intelxl = netdev->priv;
        struct intelxl_tx_data_descriptor *tx;
        unsigned int tx_idx;
        unsigned int tx_tail;
        size_t len;

        /* Get next transmit descriptor */
        if ( ( intelxl->tx.prod - intelxl->tx.cons ) >= INTELXL_TX_FILL ) {
                DBGC ( intelxl, "INTELXL %p out of transmit descriptors\n",
                       intelxl );
                return -ENOBUFS;
        }
        tx_idx = ( intelxl->tx.prod++ % INTELXL_TX_NUM_DESC );
        tx_tail = ( intelxl->tx.prod % INTELXL_TX_NUM_DESC );
        tx = &intelxl->tx.desc.tx[tx_idx].data;

        /* Populate transmit descriptor */
        len = iob_len ( iobuf );
        tx->address = cpu_to_le64 ( iob_dma ( iobuf ) );
        tx->len = cpu_to_le32 ( INTELXL_TX_DATA_LEN ( len ) );
        tx->flags = cpu_to_le32 ( INTELXL_TX_DATA_DTYP | INTELXL_TX_DATA_EOP |
                                  INTELXL_TX_DATA_RS | INTELXL_TX_DATA_JFDI );
        wmb();

        /* Notify card that there are packets ready to transmit */
        writel ( tx_tail, ( intelxl->regs + intelxl->tx.tail ) );

        DBGC2 ( intelxl, "INTELXL %p TX %d is [%08lx,%08lx)\n",
                intelxl, tx_idx, virt_to_phys ( iobuf->data ),
                ( virt_to_phys ( iobuf->data ) + len ) );
        return 0;
}

/**
 * Poll for completed packets
 *
 * @v netdev            Network device
 */
static void intelxl_poll_tx ( struct net_device *netdev ) {
        struct intelxl_nic *intelxl = netdev->priv;
        struct intelxl_tx_writeback_descriptor *tx_wb;
        unsigned int tx_idx;

        /* Check for completed packets */
        while ( intelxl->tx.cons != intelxl->tx.prod ) {

                /* Get next transmit descriptor */
                tx_idx = ( intelxl->tx.cons % INTELXL_TX_NUM_DESC );
                tx_wb = &intelxl->tx.desc.tx[tx_idx].wb;

                /* Stop if descriptor is still in use */
                if ( ! ( tx_wb->flags & INTELXL_TX_WB_FL_DD ) )
                        return;
                DBGC2 ( intelxl, "INTELXL %p TX %d complete\n",
                        intelxl, tx_idx );

                /* Complete TX descriptor */
                netdev_tx_complete_next ( netdev );
                intelxl->tx.cons++;
        }
}

/**
 * Poll for received packets
 *
 * @v netdev            Network device
 */
static void intelxl_poll_rx ( struct net_device *netdev ) {
        struct intelxl_nic *intelxl = netdev->priv;
        struct intelxl_rx_writeback_descriptor *rx_wb;
        struct io_buffer *iobuf;
        unsigned int rx_idx;
        unsigned int tag;
        size_t len;

        /* Check for received packets */
        while ( intelxl->rx.cons != intelxl->rx.prod ) {

                /* Get next receive descriptor */
                rx_idx = ( intelxl->rx.cons % INTELXL_RX_NUM_DESC );
                rx_wb = &intelxl->rx.desc.rx[rx_idx].wb;

                /* Stop if descriptor is still in use */
                if ( ! ( rx_wb->flags & cpu_to_le32 ( INTELXL_RX_WB_FL_DD ) ) )
                        return;

                /* Populate I/O buffer */
                iobuf = intelxl->rx_iobuf[rx_idx];
                intelxl->rx_iobuf[rx_idx] = NULL;
                len = INTELXL_RX_WB_LEN ( le32_to_cpu ( rx_wb->len ) );
                iob_put ( iobuf, len );

                /* Find VLAN device, if applicable */
                if ( rx_wb->flags & cpu_to_le32 ( INTELXL_RX_WB_FL_VLAN ) ) {
                        tag = VLAN_TAG ( le16_to_cpu ( rx_wb->vlan ) );
                } else {
                        tag = 0;
                }

                /* Hand off to network stack */
                if ( rx_wb->flags & cpu_to_le32 ( INTELXL_RX_WB_FL_RXE ) ) {
                        DBGC ( intelxl, "INTELXL %p RX %d error (length %zd, "
                               "flags %08x)\n", intelxl, rx_idx, len,
                               le32_to_cpu ( rx_wb->flags ) );
                        vlan_netdev_rx_err ( netdev, tag, iobuf, -EIO );
                } else {
                        DBGC2 ( intelxl, "INTELXL %p RX %d complete (length "
                                "%zd)\n", intelxl, rx_idx, len );
                        vlan_netdev_rx ( netdev, tag, iobuf );
                }
                intelxl->rx.cons++;
        }
}

/**
 * Poll for completed and received packets
 *
 * @v netdev            Network device
 */
void intelxl_poll ( struct net_device *netdev ) {
        struct intelxl_nic *intelxl = netdev->priv;

        /* Poll for completed packets */
        intelxl_poll_tx ( netdev );

        /* Poll for received packets */
        intelxl_poll_rx ( netdev );

        /* Poll for admin events */
        intelxl_poll_admin ( netdev );

        /* Refill RX ring */
        intelxl_refill_rx ( intelxl );

        /* Rearm interrupt, since otherwise receive descriptors will
         * be written back only after a complete cacheline (four
         * packets) have been received.
         *
         * There is unfortunately no efficient way to determine
         * whether or not rearming the interrupt is necessary.  If we
         * are running inside a hypervisor (e.g. using a VF or PF as a
         * passed-through PCI device), then the MSI-X write is
         * redirected by the hypervisor to the real host APIC and the
         * host ISR then raises an interrupt within the guest.  We
         * therefore cannot poll the nominal MSI-X target location to
         * watch for the value being written.  We could read from the
         * INT_DYN_CTL register, but this is even less efficient than
         * just unconditionally rearming the interrupt.
         */
        writel ( INTELXL_INT_DYN_CTL_INTENA, intelxl->regs + intelxl->intr );
}

/** Network device operations */
static struct net_device_operations intelxl_operations = {
        .open           = intelxl_open,
        .close          = intelxl_close,
        .transmit       = intelxl_transmit,
        .poll           = intelxl_poll,
};

/******************************************************************************
 *
 * PCI interface
 *
 ******************************************************************************
 */

/**
 * Probe PCI device
 *
 * @v pci               PCI device
 * @ret rc              Return status code
 */
static int intelxl_probe ( struct pci_device *pci ) {
        struct net_device *netdev;
        struct intelxl_nic *intelxl;
        uint32_t pffunc_rid;
        uint32_t pfgen_portnum;
        uint32_t pflan_qalloc;
        int rc;

        /* Allocate and initialise net device */
        netdev = alloc_etherdev ( sizeof ( *intelxl ) );
        if ( ! netdev ) {
                rc = -ENOMEM;
                goto err_alloc;
        }
        netdev_init ( netdev, &intelxl_operations );
        netdev->max_pkt_len = INTELXL_MAX_PKT_LEN;
        intelxl = netdev->priv;
        pci_set_drvdata ( pci, netdev );
        netdev->dev = &pci->dev;
        memset ( intelxl, 0, sizeof ( *intelxl ) );
        intelxl->intr = INTELXL_PFINT_DYN_CTL0;
        intelxl->handle = intelxl_admin_event;
        intelxl_init_admin ( &intelxl->command, INTELXL_ADMIN_CMD,
                             &intelxl_admin_offsets );
        intelxl_init_admin ( &intelxl->event, INTELXL_ADMIN_EVT,
                             &intelxl_admin_offsets );
        intelxl_init_ring ( &intelxl->tx, INTELXL_TX_NUM_DESC,
                            sizeof ( intelxl->tx.desc.tx[0] ),
                            intelxl_context_tx );
        intelxl_init_ring ( &intelxl->rx, INTELXL_RX_NUM_DESC,
                            sizeof ( intelxl->rx.desc.rx[0] ),
                            intelxl_context_rx );

        /* Fix up PCI device */
        adjust_pci_device ( pci );

        /* Map registers */
        intelxl->regs = pci_ioremap ( pci, pci->membase, INTELXL_BAR_SIZE );
        if ( ! intelxl->regs ) {
                rc = -ENODEV;
                goto err_ioremap;
        }

        /* Configure DMA */
        intelxl->dma = &pci->dma;
        dma_set_mask_64bit ( intelxl->dma );
        netdev->dma = intelxl->dma;

        /* Locate PCI Express capability */
        intelxl->exp = pci_find_capability ( pci, PCI_CAP_ID_EXP );
        if ( ! intelxl->exp ) {
                DBGC ( intelxl, "INTELXL %p missing PCIe capability\n",
                       intelxl );
                rc = -ENXIO;
                goto err_exp;
        }

        /* Reset the function via PCIe FLR */
        pci_reset ( pci, intelxl->exp );

        /* Get function number, port number and base queue number */
        pffunc_rid = readl ( intelxl->regs + INTELXL_PFFUNC_RID );
        intelxl->pf = INTELXL_PFFUNC_RID_FUNC_NUM ( pffunc_rid );
        pfgen_portnum = readl ( intelxl->regs + INTELXL_PFGEN_PORTNUM );
        intelxl->port = INTELXL_PFGEN_PORTNUM_PORT_NUM ( pfgen_portnum );
        pflan_qalloc = readl ( intelxl->regs + INTELXL_PFLAN_QALLOC );
        intelxl->base = INTELXL_PFLAN_QALLOC_FIRSTQ ( pflan_qalloc );
        DBGC ( intelxl, "INTELXL %p PF %d using port %d queues [%#04x-%#04x]\n",
               intelxl, intelxl->pf, intelxl->port, intelxl->base,
               INTELXL_PFLAN_QALLOC_LASTQ ( pflan_qalloc ) );

        /* Enable MSI-X dummy interrupt */
        if ( ( rc = intelxl_msix_enable ( intelxl, pci,
                                          INTELXL_MSIX_VECTOR ) ) != 0 )
                goto err_msix;

        /* Open admin queues */
        if ( ( rc = intelxl_open_admin ( intelxl ) ) != 0 )
                goto err_open_admin;

        /* Get firmware version */
        if ( ( rc = intelxl_admin_version ( intelxl ) ) != 0 )
                goto err_admin_version;

        /* Report driver version */
        if ( ( rc = intelxl_admin_driver ( intelxl ) ) != 0 )
                goto err_admin_driver;

        /* Clear PXE mode */
        if ( ( rc = intelxl_admin_clear_pxe ( intelxl ) ) != 0 )
                goto err_admin_clear_pxe;

        /* Get switch configuration */
        if ( ( rc = intelxl_admin_switch ( intelxl ) ) != 0 )
                goto err_admin_switch;

        /* Get VSI configuration */
        if ( ( rc = intelxl_admin_vsi ( intelxl ) ) != 0 )
                goto err_admin_vsi;

        /* Configure switch for promiscuous mode */
        if ( ( rc = intelxl_admin_promisc ( intelxl ) ) != 0 )
                goto err_admin_promisc;

        /* Get MAC address */
        if ( ( rc = intelxl_admin_mac_read ( netdev ) ) != 0 )
                goto err_admin_mac_read;

        /* Configure queue register addresses */
        intelxl->tx.reg = INTELXL_QTX ( intelxl->queue );
        intelxl->tx.tail = ( intelxl->tx.reg + INTELXL_QXX_TAIL );
        intelxl->rx.reg = INTELXL_QRX ( intelxl->queue );
        intelxl->rx.tail = ( intelxl->rx.reg + INTELXL_QXX_TAIL );

        /* Configure interrupt causes */
        writel ( ( INTELXL_QINT_TQCTL_NEXTQ_INDX_NONE |
                   INTELXL_QINT_TQCTL_CAUSE_ENA ),
                 intelxl->regs + INTELXL_QINT_TQCTL ( intelxl->queue ) );
        writel ( ( INTELXL_QINT_RQCTL_NEXTQ_INDX ( intelxl->queue ) |
                   INTELXL_QINT_RQCTL_NEXTQ_TYPE_TX |
                   INTELXL_QINT_RQCTL_CAUSE_ENA ),
                 intelxl->regs + INTELXL_QINT_RQCTL ( intelxl->queue ) );
        writel ( ( INTELXL_PFINT_LNKLST0_FIRSTQ_INDX ( intelxl->queue ) |
                   INTELXL_PFINT_LNKLST0_FIRSTQ_TYPE_RX ),
                 intelxl->regs + INTELXL_PFINT_LNKLST0 );
        writel ( INTELXL_PFINT_ICR0_ENA_ADMINQ,
                 intelxl->regs + INTELXL_PFINT_ICR0_ENA );

        /* Register network device */
        if ( ( rc = register_netdev ( netdev ) ) != 0 )
                goto err_register_netdev;

        /* Set initial link state */
        intelxl_admin_link ( netdev );

        return 0;

        unregister_netdev ( netdev );
 err_register_netdev:
 err_admin_mac_read:
 err_admin_promisc:
 err_admin_vsi:
 err_admin_switch:
 err_admin_clear_pxe:
 err_admin_driver:
 err_admin_version:
        intelxl_close_admin ( intelxl );
 err_open_admin:
        intelxl_msix_disable ( intelxl, pci, INTELXL_MSIX_VECTOR );
 err_msix:
        pci_reset ( pci, intelxl->exp );
 err_exp:
        iounmap ( intelxl->regs );
 err_ioremap:
        netdev_nullify ( netdev );
        netdev_put ( netdev );
 err_alloc:
        return rc;
}

/**
 * Remove PCI device
 *
 * @v pci               PCI device
 */
static void intelxl_remove ( struct pci_device *pci ) {
        struct net_device *netdev = pci_get_drvdata ( pci );
        struct intelxl_nic *intelxl = netdev->priv;

        /* Unregister network device */
        unregister_netdev ( netdev );

        /* Close admin queues */
        intelxl_close_admin ( intelxl );

        /* Disable MSI-X dummy interrupt */
        intelxl_msix_disable ( intelxl, pci, INTELXL_MSIX_VECTOR );

        /* Reset the NIC */
        pci_reset ( pci, intelxl->exp );

        /* Free network device */
        iounmap ( intelxl->regs );
        netdev_nullify ( netdev );
        netdev_put ( netdev );
}

/** PCI device IDs */
static struct pci_device_id intelxl_nics[] = {
        PCI_ROM ( 0x8086, 0x0cf8, "x710-n3000", "X710 FPGA N3000", 0 ),
        PCI_ROM ( 0x8086, 0x0d58, "xxv710-n3000", "XXV710 FPGA N3000", 0 ),
        PCI_ROM ( 0x8086, 0x104e, "x710-sfp-b", "X710 10GbE SFP+", 0 ),
        PCI_ROM ( 0x8086, 0x104f, "x710-kx-b", "X710 10GbE backplane", 0 ),
        PCI_ROM ( 0x8086, 0x1572, "x710-sfp", "X710 10GbE SFP+", 0 ),
        PCI_ROM ( 0x8086, 0x1574, "xl710-qemu", "Virtual XL710", 0 ),
        PCI_ROM ( 0x8086, 0x1580, "xl710-kx-b", "XL710 40GbE backplane", 0 ),
        PCI_ROM ( 0x8086, 0x1581, "xl710-kx-c", "XL710 10GbE backplane", 0 ),
        PCI_ROM ( 0x8086, 0x1583, "xl710-qda2", "XL710 40GbE QSFP+", 0 ),
        PCI_ROM ( 0x8086, 0x1584, "xl710-qda1", "XL710 40GbE QSFP+", 0 ),
        PCI_ROM ( 0x8086, 0x1585, "x710-qsfp", "X710 10GbE QSFP+", 0 ),
        PCI_ROM ( 0x8086, 0x1586, "x710-10gt", "X710 10GBASE-T", 0 ),
        PCI_ROM ( 0x8086, 0x1587, "x710-kr2", "XL710 20GbE backplane", 0 ),
        PCI_ROM ( 0x8086, 0x1588, "x710-kr2-a", "XL710 20GbE backplane", 0 ),
        PCI_ROM ( 0x8086, 0x1589, "x710-10gt4", "X710 10GBASE-T4", 0 ),
        PCI_ROM ( 0x8086, 0x158a, "xxv710", "XXV710 25GbE backplane", 0 ),
        PCI_ROM ( 0x8086, 0x158b, "xxv710-sfp28", "XXV710 25GbE SFP28", 0 ),
        PCI_ROM ( 0x8086, 0x15ff, "x710-10gt-b", "X710 10GBASE-T", 0 ),
        PCI_ROM ( 0x8086, 0x37ce, "x722-kx", "X722 10GbE backplane", 0 ),
        PCI_ROM ( 0x8086, 0x37cf, "x722-qsfp", "X722 10GbE QSFP+", 0 ),
        PCI_ROM ( 0x8086, 0x37d0, "x722-sfp", "X722 10GbE SFP+", 0 ),
        PCI_ROM ( 0x8086, 0x37d1, "x722-1gt", "X722 1GBASE-T", 0 ),
        PCI_ROM ( 0x8086, 0x37d2, "x722-10gt", "X722 10GBASE-T", 0 ),
        PCI_ROM ( 0x8086, 0x37d3, "x722-sfp-i", "X722 10GbE SFP+", 0 ),
};

/** PCI driver */
struct pci_driver intelxl_driver __pci_driver = {
        .ids = intelxl_nics,
        .id_count = ( sizeof ( intelxl_nics ) / sizeof ( intelxl_nics[0] ) ),
        .probe = intelxl_probe,
        .remove = intelxl_remove,
};