sfc: Add support for sub-10G speeds

[linux-2.6] / drivers / net / sfc / efx.c

/****************************************************************************
 * Driver for Solarflare Solarstorm network controllers and boards
 * Copyright 2005-2006 Fen Systems Ltd.
 * Copyright 2005-2008 Solarflare Communications Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation, incorporated herein by reference.
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/delay.h>
#include <linux/notifier.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/in.h>
#include <linux/crc32.h>
#include <linux/ethtool.h>
#include <linux/topology.h>
#include "net_driver.h"
#include "ethtool.h"
#include "tx.h"
#include "rx.h"
#include "efx.h"
#include "mdio_10g.h"
#include "falcon.h"

#define EFX_MAX_MTU (9 * 1024)

/* RX slow fill workqueue. If memory allocation fails in the fast path,
 * a work item is pushed onto this work queue to retry the allocation later,
 * to avoid the NIC being starved of RX buffers. Since this is a per cpu
 * workqueue, there is nothing to be gained in making it per NIC
 */
static struct workqueue_struct *refill_workqueue;

/* Reset workqueue. If any NIC has a hardware failure then a reset will be
 * queued onto this work queue. This is not a per-nic work queue, because
 * efx_reset_work() acquires the rtnl lock, so resets are naturally serialised.
 */
static struct workqueue_struct *reset_workqueue;

/**************************************************************************
 *
 * Configurable values
 *
 *************************************************************************/

/*
 * Enable large receive offload (LRO) aka soft segment reassembly (SSR)
 *
 * This sets the default for new devices.  It can be controlled later
 * using ethtool.
 */
static int lro = true;
module_param(lro, int, 0644);
MODULE_PARM_DESC(lro, "Large receive offload acceleration");

/*
 * Use separate channels for TX and RX events
 *
 * Set this to 1 to use separate channels for TX and RX. It allows us
 * to control interrupt affinity separately for TX and RX.
 *
 * This is only used in MSI-X interrupt mode
 */
static unsigned int separate_tx_channels;
module_param(separate_tx_channels, uint, 0644);
MODULE_PARM_DESC(separate_tx_channels,
                 "Use separate channels for TX and RX");

/* This is the weight assigned to each of the (per-channel) virtual
 * NAPI devices.
 */
static int napi_weight = 64;

/* This is the time (in jiffies) between invocations of the hardware
 * monitor, which checks for known hardware bugs and resets the
 * hardware and driver as necessary.
 */
unsigned int efx_monitor_interval = 1 * HZ;

/* This controls whether or not the driver will initialise devices
 * with invalid MAC addresses stored in the EEPROM or flash.  If true,
 * such devices will be initialised with a random locally-generated
 * MAC address.  This allows for loading the sfc_mtd driver to
 * reprogram the flash, even if the flash contents (including the MAC
 * address) have previously been erased.
 */
static unsigned int allow_bad_hwaddr;

/* Initial interrupt moderation settings.  They can be modified after
 * module load with ethtool.
 *
 * The default for RX should strike a balance between increasing the
 * round-trip latency and reducing overhead.
 */
static unsigned int rx_irq_mod_usec = 60;

/* Initial interrupt moderation settings.  They can be modified after
 * module load with ethtool.
 *
 * This default is chosen to ensure that a 10G link does not go idle
 * while a TX queue is stopped after it has become full.  A queue is
 * restarted when it drops below half full.  The time this takes (assuming
 * worst case 3 descriptors per packet and 1024 descriptors) is
 *   512 / 3 * 1.2 = 205 usec.
 */
static unsigned int tx_irq_mod_usec = 150;

/* This is the first interrupt mode to try out of:
 * 0 => MSI-X
 * 1 => MSI
 * 2 => legacy
 */
static unsigned int interrupt_mode;

/* This is the requested number of CPUs to use for Receive-Side Scaling (RSS),
 * i.e. the number of CPUs among which we may distribute simultaneous
 * interrupt handling.
 *
 * Cards without MSI-X will only target one CPU via legacy or MSI interrupt.
 * The default (0) means to assign an interrupt to each package (level II cache)
 */
static unsigned int rss_cpus;
module_param(rss_cpus, uint, 0444);
MODULE_PARM_DESC(rss_cpus, "Number of CPUs to use for Receive-Side Scaling");

static int phy_flash_cfg;
module_param(phy_flash_cfg, int, 0644);
MODULE_PARM_DESC(phy_flash_cfg, "Set PHYs into reflash mode initially");

/**************************************************************************
 *
 * Utility functions and prototypes
 *
 *************************************************************************/
static void efx_remove_channel(struct efx_channel *channel);
static void efx_remove_port(struct efx_nic *efx);
static void efx_fini_napi(struct efx_nic *efx);
static void efx_fini_channels(struct efx_nic *efx);

#define EFX_ASSERT_RESET_SERIALISED(efx)                \
        do {                                            \
                if (efx->state == STATE_RUNNING)        \
                        ASSERT_RTNL();                  \
        } while (0)

/**************************************************************************
 *
 * Event queue processing
 *
 *************************************************************************/

/* Process channel's event queue
 *
 * This function is responsible for processing the event queue of a
 * single channel.  The caller must guarantee that this function will
 * never be concurrently called more than once on the same channel,
 * though different channels may be being processed concurrently.
 */
static int efx_process_channel(struct efx_channel *channel, int rx_quota)
{
        struct efx_nic *efx = channel->efx;
        int rx_packets;

        if (unlikely(efx->reset_pending != RESET_TYPE_NONE ||
                     !channel->enabled))
                return 0;

        rx_packets = falcon_process_eventq(channel, rx_quota);
        if (rx_packets == 0)
                return 0;

        /* Deliver last RX packet. */
        if (channel->rx_pkt) {
                __efx_rx_packet(channel, channel->rx_pkt,
                                channel->rx_pkt_csummed);
                channel->rx_pkt = NULL;
        }

        efx_flush_lro(channel);
        efx_rx_strategy(channel);

        efx_fast_push_rx_descriptors(&efx->rx_queue[channel->channel]);

        return rx_packets;
}

/* Mark channel as finished processing
 *
 * Note that since we will not receive further interrupts for this
 * channel before we finish processing and call the eventq_read_ack()
 * method, there is no need to use the interrupt hold-off timers.
 */
static inline void efx_channel_processed(struct efx_channel *channel)
{
        /* The interrupt handler for this channel may set work_pending
         * as soon as we acknowledge the events we've seen.  Make sure
         * it's cleared before then. */
        channel->work_pending = false;
        smp_wmb();

        falcon_eventq_read_ack(channel);
}

/* NAPI poll handler
 *
 * NAPI guarantees serialisation of polls of the same device, which
 * provides the guarantee required by efx_process_channel().
 */
static int efx_poll(struct napi_struct *napi, int budget)
{
        struct efx_channel *channel =
                container_of(napi, struct efx_channel, napi_str);
        struct net_device *napi_dev = channel->napi_dev;
        int rx_packets;

        EFX_TRACE(channel->efx, "channel %d NAPI poll executing on CPU %d\n",
                  channel->channel, raw_smp_processor_id());

        rx_packets = efx_process_channel(channel, budget);

        if (rx_packets < budget) {
                /* There is no race here; although napi_disable() will
                 * only wait for netif_rx_complete(), this isn't a problem
                 * since efx_channel_processed() will have no effect if
                 * interrupts have already been disabled.
                 */
                netif_rx_complete(napi_dev, napi);
                efx_channel_processed(channel);
        }

        return rx_packets;
}

/* Process the eventq of the specified channel immediately on this CPU
 *
 * Disable hardware generated interrupts, wait for any existing
 * processing to finish, then directly poll (and ack ) the eventq.
 * Finally reenable NAPI and interrupts.
 *
 * Since we are touching interrupts the caller should hold the suspend lock
 */
void efx_process_channel_now(struct efx_channel *channel)
{
        struct efx_nic *efx = channel->efx;

        BUG_ON(!channel->used_flags);
        BUG_ON(!channel->enabled);

        /* Disable interrupts and wait for ISRs to complete */
        falcon_disable_interrupts(efx);
        if (efx->legacy_irq)
                synchronize_irq(efx->legacy_irq);
        if (channel->irq)
                synchronize_irq(channel->irq);

        /* Wait for any NAPI processing to complete */
        napi_disable(&channel->napi_str);

        /* Poll the channel */
        efx_process_channel(channel, efx->type->evq_size);

        /* Ack the eventq. This may cause an interrupt to be generated
         * when they are reenabled */
        efx_channel_processed(channel);

        napi_enable(&channel->napi_str);
        falcon_enable_interrupts(efx);
}

/* Create event queue
 * Event queue memory allocations are done only once.  If the channel
 * is reset, the memory buffer will be reused; this guards against
 * errors during channel reset and also simplifies interrupt handling.
 */
static int efx_probe_eventq(struct efx_channel *channel)
{
        EFX_LOG(channel->efx, "chan %d create event queue\n", channel->channel);

        return falcon_probe_eventq(channel);
}

/* Prepare channel's event queue */
static void efx_init_eventq(struct efx_channel *channel)
{
        EFX_LOG(channel->efx, "chan %d init event queue\n", channel->channel);

        channel->eventq_read_ptr = 0;

        falcon_init_eventq(channel);
}

static void efx_fini_eventq(struct efx_channel *channel)
{
        EFX_LOG(channel->efx, "chan %d fini event queue\n", channel->channel);

        falcon_fini_eventq(channel);
}

static void efx_remove_eventq(struct efx_channel *channel)
{
        EFX_LOG(channel->efx, "chan %d remove event queue\n", channel->channel);

        falcon_remove_eventq(channel);
}

/**************************************************************************
 *
 * Channel handling
 *
 *************************************************************************/

static int efx_probe_channel(struct efx_channel *channel)
{
        struct efx_tx_queue *tx_queue;
        struct efx_rx_queue *rx_queue;
        int rc;

        EFX_LOG(channel->efx, "creating channel %d\n", channel->channel);

        rc = efx_probe_eventq(channel);
        if (rc)
                goto fail1;

        efx_for_each_channel_tx_queue(tx_queue, channel) {
                rc = efx_probe_tx_queue(tx_queue);
                if (rc)
                        goto fail2;
        }

        efx_for_each_channel_rx_queue(rx_queue, channel) {
                rc = efx_probe_rx_queue(rx_queue);
                if (rc)
                        goto fail3;
        }

        channel->n_rx_frm_trunc = 0;

        return 0;

 fail3:
        efx_for_each_channel_rx_queue(rx_queue, channel)
                efx_remove_rx_queue(rx_queue);
 fail2:
        efx_for_each_channel_tx_queue(tx_queue, channel)
                efx_remove_tx_queue(tx_queue);
 fail1:
        return rc;
}


static void efx_set_channel_names(struct efx_nic *efx)
{
        struct efx_channel *channel;
        const char *type = "";
        int number;

        efx_for_each_channel(channel, efx) {
                number = channel->channel;
                if (efx->n_channels > efx->n_rx_queues) {
                        if (channel->channel < efx->n_rx_queues) {
                                type = "-rx";
                        } else {
                                type = "-tx";
                                number -= efx->n_rx_queues;
                        }
                }
                snprintf(channel->name, sizeof(channel->name),
                         "%s%s-%d", efx->name, type, number);
        }
}

/* Channels are shutdown and reinitialised whilst the NIC is running
 * to propagate configuration changes (mtu, checksum offload), or
 * to clear hardware error conditions
 */
static void efx_init_channels(struct efx_nic *efx)
{
        struct efx_tx_queue *tx_queue;
        struct efx_rx_queue *rx_queue;
        struct efx_channel *channel;

        /* Calculate the rx buffer allocation parameters required to
         * support the current MTU, including padding for header
         * alignment and overruns.
         */
        efx->rx_buffer_len = (max(EFX_PAGE_IP_ALIGN, NET_IP_ALIGN) +
                              EFX_MAX_FRAME_LEN(efx->net_dev->mtu) +
                              efx->type->rx_buffer_padding);
        efx->rx_buffer_order = get_order(efx->rx_buffer_len);

        /* Initialise the channels */
        efx_for_each_channel(channel, efx) {
                EFX_LOG(channel->efx, "init chan %d\n", channel->channel);

                efx_init_eventq(channel);

                efx_for_each_channel_tx_queue(tx_queue, channel)
                        efx_init_tx_queue(tx_queue);

                /* The rx buffer allocation strategy is MTU dependent */
                efx_rx_strategy(channel);

                efx_for_each_channel_rx_queue(rx_queue, channel)
                        efx_init_rx_queue(rx_queue);

                WARN_ON(channel->rx_pkt != NULL);
                efx_rx_strategy(channel);
        }
}

/* This enables event queue processing and packet transmission.
 *
 * Note that this function is not allowed to fail, since that would
 * introduce too much complexity into the suspend/resume path.
 */
static void efx_start_channel(struct efx_channel *channel)
{
        struct efx_rx_queue *rx_queue;

        EFX_LOG(channel->efx, "starting chan %d\n", channel->channel);

        if (!(channel->efx->net_dev->flags & IFF_UP))
                netif_napi_add(channel->napi_dev, &channel->napi_str,
                               efx_poll, napi_weight);

        /* The interrupt handler for this channel may set work_pending
         * as soon as we enable it.  Make sure it's cleared before
         * then.  Similarly, make sure it sees the enabled flag set. */
        channel->work_pending = false;
        channel->enabled = true;
        smp_wmb();

        napi_enable(&channel->napi_str);

        /* Load up RX descriptors */
        efx_for_each_channel_rx_queue(rx_queue, channel)
                efx_fast_push_rx_descriptors(rx_queue);
}

/* This disables event queue processing and packet transmission.
 * This function does not guarantee that all queue processing
 * (e.g. RX refill) is complete.
 */
static void efx_stop_channel(struct efx_channel *channel)
{
        struct efx_rx_queue *rx_queue;

        if (!channel->enabled)
                return;

        EFX_LOG(channel->efx, "stop chan %d\n", channel->channel);

        channel->enabled = false;
        napi_disable(&channel->napi_str);

        /* Ensure that any worker threads have exited or will be no-ops */
        efx_for_each_channel_rx_queue(rx_queue, channel) {
                spin_lock_bh(&rx_queue->add_lock);
                spin_unlock_bh(&rx_queue->add_lock);
        }
}

static void efx_fini_channels(struct efx_nic *efx)
{
        struct efx_channel *channel;
        struct efx_tx_queue *tx_queue;
        struct efx_rx_queue *rx_queue;
        int rc;

        EFX_ASSERT_RESET_SERIALISED(efx);
        BUG_ON(efx->port_enabled);

        rc = falcon_flush_queues(efx);
        if (rc)
                EFX_ERR(efx, "failed to flush queues\n");
        else
                EFX_LOG(efx, "successfully flushed all queues\n");

        efx_for_each_channel(channel, efx) {
                EFX_LOG(channel->efx, "shut down chan %d\n", channel->channel);

                efx_for_each_channel_rx_queue(rx_queue, channel)
                        efx_fini_rx_queue(rx_queue);
                efx_for_each_channel_tx_queue(tx_queue, channel)
                        efx_fini_tx_queue(tx_queue);
                efx_fini_eventq(channel);
        }
}

static void efx_remove_channel(struct efx_channel *channel)
{
        struct efx_tx_queue *tx_queue;
        struct efx_rx_queue *rx_queue;

        EFX_LOG(channel->efx, "destroy chan %d\n", channel->channel);

        efx_for_each_channel_rx_queue(rx_queue, channel)
                efx_remove_rx_queue(rx_queue);
        efx_for_each_channel_tx_queue(tx_queue, channel)
                efx_remove_tx_queue(tx_queue);
        efx_remove_eventq(channel);

        channel->used_flags = 0;
}

void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue, int delay)
{
        queue_delayed_work(refill_workqueue, &rx_queue->work, delay);
}

/**************************************************************************
 *
 * Port handling
 *
 **************************************************************************/

/* This ensures that the kernel is kept informed (via
 * netif_carrier_on/off) of the link status, and also maintains the
 * link status's stop on the port's TX queue.
 */
static void efx_link_status_changed(struct efx_nic *efx)
{
        /* SFC Bug 5356: A net_dev notifier is registered, so we must ensure
         * that no events are triggered between unregister_netdev() and the
         * driver unloading. A more general condition is that NETDEV_CHANGE
         * can only be generated between NETDEV_UP and NETDEV_DOWN */
        if (!netif_running(efx->net_dev))
                return;

        if (efx->port_inhibited) {
                netif_carrier_off(efx->net_dev);
                return;
        }

        if (efx->link_up != netif_carrier_ok(efx->net_dev)) {
                efx->n_link_state_changes++;

                if (efx->link_up)
                        netif_carrier_on(efx->net_dev);
                else
                        netif_carrier_off(efx->net_dev);
        }

        /* Status message for kernel log */
        if (efx->link_up) {
                EFX_INFO(efx, "link up at %uMbps %s-duplex (MTU %d)%s\n",
                         efx->link_speed, efx->link_fd ? "full" : "half",
                         efx->net_dev->mtu,
                         (efx->promiscuous ? " [PROMISC]" : ""));
        } else {
                EFX_INFO(efx, "link down\n");
        }

}

/* This call reinitialises the MAC to pick up new PHY settings. The
 * caller must hold the mac_lock */
void __efx_reconfigure_port(struct efx_nic *efx)
{
        WARN_ON(!mutex_is_locked(&efx->mac_lock));

        EFX_LOG(efx, "reconfiguring MAC from PHY settings on CPU %d\n",
                raw_smp_processor_id());

        /* Serialise the promiscuous flag with efx_set_multicast_list. */
        if (efx_dev_registered(efx)) {
                netif_addr_lock_bh(efx->net_dev);
                netif_addr_unlock_bh(efx->net_dev);
        }

        falcon_deconfigure_mac_wrapper(efx);

        /* Reconfigure the PHY, disabling transmit in mac level loopback. */
        if (LOOPBACK_INTERNAL(efx))
                efx->phy_mode |= PHY_MODE_TX_DISABLED;
        else
                efx->phy_mode &= ~PHY_MODE_TX_DISABLED;
        efx->phy_op->reconfigure(efx);

        if (falcon_switch_mac(efx))
                goto fail;

        efx->mac_op->reconfigure(efx);

        /* Inform kernel of loss/gain of carrier */
        efx_link_status_changed(efx);
        return;

fail:
        EFX_ERR(efx, "failed to reconfigure MAC\n");
        efx->phy_op->fini(efx);
        efx->port_initialized = false;
}

/* Reinitialise the MAC to pick up new PHY settings, even if the port is
 * disabled. */
void efx_reconfigure_port(struct efx_nic *efx)
{
        EFX_ASSERT_RESET_SERIALISED(efx);

        mutex_lock(&efx->mac_lock);
        __efx_reconfigure_port(efx);
        mutex_unlock(&efx->mac_lock);
}

/* Asynchronous efx_reconfigure_port work item. To speed up efx_flush_all()
 * we don't efx_reconfigure_port() if the port is disabled. Care is taken
 * in efx_stop_all() and efx_start_port() to prevent PHY events being lost */
static void efx_reconfigure_work(struct work_struct *data)
{
        struct efx_nic *efx = container_of(data, struct efx_nic,
                                           reconfigure_work);

        mutex_lock(&efx->mac_lock);
        if (efx->port_enabled)
                __efx_reconfigure_port(efx);
        mutex_unlock(&efx->mac_lock);
}

static int efx_probe_port(struct efx_nic *efx)
{
        int rc;

        EFX_LOG(efx, "create port\n");

        /* Connect up MAC/PHY operations table and read MAC address */
        rc = falcon_probe_port(efx);
        if (rc)
                goto err;

        if (phy_flash_cfg)
                efx->phy_mode = PHY_MODE_SPECIAL;

        /* Sanity check MAC address */
        if (is_valid_ether_addr(efx->mac_address)) {
                memcpy(efx->net_dev->dev_addr, efx->mac_address, ETH_ALEN);
        } else {
                EFX_ERR(efx, "invalid MAC address %pM\n",
                        efx->mac_address);
                if (!allow_bad_hwaddr) {
                        rc = -EINVAL;
                        goto err;
                }
                random_ether_addr(efx->net_dev->dev_addr);
                EFX_INFO(efx, "using locally-generated MAC %pM\n",
                         efx->net_dev->dev_addr);
        }

        return 0;

 err:
        efx_remove_port(efx);
        return rc;
}

static int efx_init_port(struct efx_nic *efx)
{
        int rc;

        EFX_LOG(efx, "init port\n");

        rc = efx->phy_op->init(efx);
        if (rc)
                return rc;
        efx->phy_op->reconfigure(efx);

        mutex_lock(&efx->mac_lock);
        rc = falcon_switch_mac(efx);
        mutex_unlock(&efx->mac_lock);
        if (rc)
                goto fail;
        efx->mac_op->reconfigure(efx);

        efx->port_initialized = true;
        efx->stats_enabled = true;
        return 0;

fail:
        efx->phy_op->fini(efx);
        return rc;
}

/* Allow efx_reconfigure_port() to be scheduled, and close the window
 * between efx_stop_port and efx_flush_all whereby a previously scheduled
 * efx_reconfigure_port() may have been cancelled */
static void efx_start_port(struct efx_nic *efx)
{
        EFX_LOG(efx, "start port\n");
        BUG_ON(efx->port_enabled);

        mutex_lock(&efx->mac_lock);
        efx->port_enabled = true;
        __efx_reconfigure_port(efx);
        mutex_unlock(&efx->mac_lock);
}

/* Prevent efx_reconfigure_work and efx_monitor() from executing, and
 * efx_set_multicast_list() from scheduling efx_reconfigure_work.
 * efx_reconfigure_work can still be scheduled via NAPI processing
 * until efx_flush_all() is called */
static void efx_stop_port(struct efx_nic *efx)
{
        EFX_LOG(efx, "stop port\n");

        mutex_lock(&efx->mac_lock);
        efx->port_enabled = false;
        mutex_unlock(&efx->mac_lock);

        /* Serialise against efx_set_multicast_list() */
        if (efx_dev_registered(efx)) {
                netif_addr_lock_bh(efx->net_dev);
                netif_addr_unlock_bh(efx->net_dev);
        }
}

static void efx_fini_port(struct efx_nic *efx)
{
        EFX_LOG(efx, "shut down port\n");

        if (!efx->port_initialized)
                return;

        efx->phy_op->fini(efx);
        efx->port_initialized = false;

        efx->link_up = false;
        efx_link_status_changed(efx);
}

static void efx_remove_port(struct efx_nic *efx)
{
        EFX_LOG(efx, "destroying port\n");

        falcon_remove_port(efx);
}

/**************************************************************************
 *
 * NIC handling
 *
 **************************************************************************/

/* This configures the PCI device to enable I/O and DMA. */
static int efx_init_io(struct efx_nic *efx)
{
        struct pci_dev *pci_dev = efx->pci_dev;
        dma_addr_t dma_mask = efx->type->max_dma_mask;
        int rc;

        EFX_LOG(efx, "initialising I/O\n");

        rc = pci_enable_device(pci_dev);
        if (rc) {
                EFX_ERR(efx, "failed to enable PCI device\n");
                goto fail1;
        }

        pci_set_master(pci_dev);

        /* Set the PCI DMA mask.  Try all possibilities from our
         * genuine mask down to 32 bits, because some architectures
         * (e.g. x86_64 with iommu_sac_force set) will allow 40 bit
         * masks event though they reject 46 bit masks.
         */
        while (dma_mask > 0x7fffffffUL) {
                if (pci_dma_supported(pci_dev, dma_mask) &&
                    ((rc = pci_set_dma_mask(pci_dev, dma_mask)) == 0))
                        break;
                dma_mask >>= 1;
        }
        if (rc) {
                EFX_ERR(efx, "could not find a suitable DMA mask\n");
                goto fail2;
        }
        EFX_LOG(efx, "using DMA mask %llx\n", (unsigned long long) dma_mask);
        rc = pci_set_consistent_dma_mask(pci_dev, dma_mask);
        if (rc) {
                /* pci_set_consistent_dma_mask() is not *allowed* to
                 * fail with a mask that pci_set_dma_mask() accepted,
                 * but just in case...
                 */
                EFX_ERR(efx, "failed to set consistent DMA mask\n");
                goto fail2;
        }

        efx->membase_phys = pci_resource_start(efx->pci_dev,
                                               efx->type->mem_bar);
        rc = pci_request_region(pci_dev, efx->type->mem_bar, "sfc");
        if (rc) {
                EFX_ERR(efx, "request for memory BAR failed\n");
                rc = -EIO;
                goto fail3;
        }
        efx->membase = ioremap_nocache(efx->membase_phys,
                                       efx->type->mem_map_size);
        if (!efx->membase) {
                EFX_ERR(efx, "could not map memory BAR %d at %llx+%x\n",
                        efx->type->mem_bar,
                        (unsigned long long)efx->membase_phys,
                        efx->type->mem_map_size);
                rc = -ENOMEM;
                goto fail4;
        }
        EFX_LOG(efx, "memory BAR %u at %llx+%x (virtual %p)\n",
                efx->type->mem_bar, (unsigned long long)efx->membase_phys,
                efx->type->mem_map_size, efx->membase);

        return 0;

 fail4:
        pci_release_region(efx->pci_dev, efx->type->mem_bar);
 fail3:
        efx->membase_phys = 0;
 fail2:
        pci_disable_device(efx->pci_dev);
 fail1:
        return rc;
}

static void efx_fini_io(struct efx_nic *efx)
{
        EFX_LOG(efx, "shutting down I/O\n");

        if (efx->membase) {
                iounmap(efx->membase);
                efx->membase = NULL;
        }

        if (efx->membase_phys) {
                pci_release_region(efx->pci_dev, efx->type->mem_bar);
                efx->membase_phys = 0;
        }

        pci_disable_device(efx->pci_dev);
}

/* Get number of RX queues wanted.  Return number of online CPU
 * packages in the expectation that an IRQ balancer will spread
 * interrupts across them. */
static int efx_wanted_rx_queues(void)
{
        cpumask_t core_mask;
        int count;
        int cpu;

        cpus_clear(core_mask);
        count = 0;
        for_each_online_cpu(cpu) {
                if (!cpu_isset(cpu, core_mask)) {
                        ++count;
                        cpus_or(core_mask, core_mask,
                                topology_core_siblings(cpu));
                }
        }

        return count;
}

/* Probe the number and type of interrupts we are able to obtain, and
 * the resulting numbers of channels and RX queues.
 */
static void efx_probe_interrupts(struct efx_nic *efx)
{
        int max_channels =
                min_t(int, efx->type->phys_addr_channels, EFX_MAX_CHANNELS);
        int rc, i;

        if (efx->interrupt_mode == EFX_INT_MODE_MSIX) {
                struct msix_entry xentries[EFX_MAX_CHANNELS];
                int wanted_ints;
                int rx_queues;

                /* We want one RX queue and interrupt per CPU package
                 * (or as specified by the rss_cpus module parameter).
                 * We will need one channel per interrupt.
                 */
                rx_queues = rss_cpus ? rss_cpus : efx_wanted_rx_queues();
                wanted_ints = rx_queues + (separate_tx_channels ? 1 : 0);
                wanted_ints = min(wanted_ints, max_channels);

                for (i = 0; i < wanted_ints; i++)
                        xentries[i].entry = i;
                rc = pci_enable_msix(efx->pci_dev, xentries, wanted_ints);
                if (rc > 0) {
                        EFX_ERR(efx, "WARNING: Insufficient MSI-X vectors"
                                " available (%d < %d).\n", rc, wanted_ints);
                        EFX_ERR(efx, "WARNING: Performance may be reduced.\n");
                        EFX_BUG_ON_PARANOID(rc >= wanted_ints);
                        wanted_ints = rc;
                        rc = pci_enable_msix(efx->pci_dev, xentries,
                                             wanted_ints);
                }

                if (rc == 0) {
                        efx->n_rx_queues = min(rx_queues, wanted_ints);
                        efx->n_channels = wanted_ints;
                        for (i = 0; i < wanted_ints; i++)
                                efx->channel[i].irq = xentries[i].vector;
                } else {
                        /* Fall back to single channel MSI */
                        efx->interrupt_mode = EFX_INT_MODE_MSI;
                        EFX_ERR(efx, "could not enable MSI-X\n");
                }
        }

        /* Try single interrupt MSI */
        if (efx->interrupt_mode == EFX_INT_MODE_MSI) {
                efx->n_rx_queues = 1;
                efx->n_channels = 1;
                rc = pci_enable_msi(efx->pci_dev);
                if (rc == 0) {
                        efx->channel[0].irq = efx->pci_dev->irq;
                } else {
                        EFX_ERR(efx, "could not enable MSI\n");
                        efx->interrupt_mode = EFX_INT_MODE_LEGACY;
                }
        }

        /* Assume legacy interrupts */
        if (efx->interrupt_mode == EFX_INT_MODE_LEGACY) {
                efx->n_rx_queues = 1;
                efx->n_channels = 1 + (separate_tx_channels ? 1 : 0);
                efx->legacy_irq = efx->pci_dev->irq;
        }
}

static void efx_remove_interrupts(struct efx_nic *efx)
{
        struct efx_channel *channel;

        /* Remove MSI/MSI-X interrupts */
        efx_for_each_channel(channel, efx)
                channel->irq = 0;
        pci_disable_msi(efx->pci_dev);
        pci_disable_msix(efx->pci_dev);

        /* Remove legacy interrupt */
        efx->legacy_irq = 0;
}

static void efx_set_channels(struct efx_nic *efx)
{
        struct efx_tx_queue *tx_queue;
        struct efx_rx_queue *rx_queue;

        efx_for_each_tx_queue(tx_queue, efx) {
                if (separate_tx_channels)
                        tx_queue->channel = &efx->channel[efx->n_channels-1];
                else
                        tx_queue->channel = &efx->channel[0];
                tx_queue->channel->used_flags |= EFX_USED_BY_TX;
        }

        efx_for_each_rx_queue(rx_queue, efx) {
                rx_queue->channel = &efx->channel[rx_queue->queue];
                rx_queue->channel->used_flags |= EFX_USED_BY_RX;
        }
}

static int efx_probe_nic(struct efx_nic *efx)
{
        int rc;

        EFX_LOG(efx, "creating NIC\n");

        /* Carry out hardware-type specific initialisation */
        rc = falcon_probe_nic(efx);
        if (rc)
                return rc;

        /* Determine the number of channels and RX queues by trying to hook
         * in MSI-X interrupts. */
        efx_probe_interrupts(efx);

        efx_set_channels(efx);

        /* Initialise the interrupt moderation settings */
        efx_init_irq_moderation(efx, tx_irq_mod_usec, rx_irq_mod_usec);

        return 0;
}

static void efx_remove_nic(struct efx_nic *efx)
{
        EFX_LOG(efx, "destroying NIC\n");

        efx_remove_interrupts(efx);
        falcon_remove_nic(efx);
}

/**************************************************************************
 *
 * NIC startup/shutdown
 *
 *************************************************************************/

static int efx_probe_all(struct efx_nic *efx)
{
        struct efx_channel *channel;
        int rc;

        /* Create NIC */
        rc = efx_probe_nic(efx);
        if (rc) {
                EFX_ERR(efx, "failed to create NIC\n");
                goto fail1;
        }

        /* Create port */
        rc = efx_probe_port(efx);
        if (rc) {
                EFX_ERR(efx, "failed to create port\n");
                goto fail2;
        }

        /* Create channels */
        efx_for_each_channel(channel, efx) {
                rc = efx_probe_channel(channel);
                if (rc) {
                        EFX_ERR(efx, "failed to create channel %d\n",
                                channel->channel);
                        goto fail3;
                }
        }
        efx_set_channel_names(efx);

        return 0;

 fail3:
        efx_for_each_channel(channel, efx)
                efx_remove_channel(channel);
        efx_remove_port(efx);
 fail2:
        efx_remove_nic(efx);
 fail1:
        return rc;
}

/* Called after previous invocation(s) of efx_stop_all, restarts the
 * port, kernel transmit queue, NAPI processing and hardware interrupts,
 * and ensures that the port is scheduled to be reconfigured.
 * This function is safe to call multiple times when the NIC is in any
 * state. */
static void efx_start_all(struct efx_nic *efx)
{
        struct efx_channel *channel;

        EFX_ASSERT_RESET_SERIALISED(efx);

        /* Check that it is appropriate to restart the interface. All
         * of these flags are safe to read under just the rtnl lock */
        if (efx->port_enabled)
                return;
        if ((efx->state != STATE_RUNNING) && (efx->state != STATE_INIT))
                return;
        if (efx_dev_registered(efx) && !netif_running(efx->net_dev))
                return;

        /* Mark the port as enabled so port reconfigurations can start, then
         * restart the transmit interface early so the watchdog timer stops */
        efx_start_port(efx);
        if (efx_dev_registered(efx))
                efx_wake_queue(efx);

        efx_for_each_channel(channel, efx)
                efx_start_channel(channel);

        falcon_enable_interrupts(efx);

        /* Start hardware monitor if we're in RUNNING */
        if (efx->state == STATE_RUNNING)
                queue_delayed_work(efx->workqueue, &efx->monitor_work,
                                   efx_monitor_interval);
}

/* Flush all delayed work. Should only be called when no more delayed work
 * will be scheduled. This doesn't flush pending online resets (efx_reset),
 * since we're holding the rtnl_lock at this point. */
static void efx_flush_all(struct efx_nic *efx)
{
        struct efx_rx_queue *rx_queue;

        /* Make sure the hardware monitor is stopped */
        cancel_delayed_work_sync(&efx->monitor_work);

        /* Ensure that all RX slow refills are complete. */
        efx_for_each_rx_queue(rx_queue, efx)
                cancel_delayed_work_sync(&rx_queue->work);

        /* Stop scheduled port reconfigurations */
        cancel_work_sync(&efx->reconfigure_work);

}

/* Quiesce hardware and software without bringing the link down.
 * Safe to call multiple times, when the nic and interface is in any
 * state. The caller is guaranteed to subsequently be in a position
 * to modify any hardware and software state they see fit without
 * taking locks. */
static void efx_stop_all(struct efx_nic *efx)
{
        struct efx_channel *channel;

        EFX_ASSERT_RESET_SERIALISED(efx);

        /* port_enabled can be read safely under the rtnl lock */
        if (!efx->port_enabled)
                return;

        /* Disable interrupts and wait for ISR to complete */
        falcon_disable_interrupts(efx);
        if (efx->legacy_irq)
                synchronize_irq(efx->legacy_irq);
        efx_for_each_channel(channel, efx) {
                if (channel->irq)
                        synchronize_irq(channel->irq);
        }

        /* Stop all NAPI processing and synchronous rx refills */
        efx_for_each_channel(channel, efx)
                efx_stop_channel(channel);

        /* Stop all asynchronous port reconfigurations. Since all
         * event processing has already been stopped, there is no
         * window to loose phy events */
        efx_stop_port(efx);

        /* Flush reconfigure_work, refill_workqueue, monitor_work */
        efx_flush_all(efx);

        /* Isolate the MAC from the TX and RX engines, so that queue
         * flushes will complete in a timely fashion. */
        falcon_drain_tx_fifo(efx);

        /* Stop the kernel transmit interface late, so the watchdog
         * timer isn't ticking over the flush */
        if (efx_dev_registered(efx)) {
                efx_stop_queue(efx);
                netif_tx_lock_bh(efx->net_dev);
                netif_tx_unlock_bh(efx->net_dev);
        }
}

static void efx_remove_all(struct efx_nic *efx)
{
        struct efx_channel *channel;

        efx_for_each_channel(channel, efx)
                efx_remove_channel(channel);
        efx_remove_port(efx);
        efx_remove_nic(efx);
}

/* A convinience function to safely flush all the queues */
void efx_flush_queues(struct efx_nic *efx)
{
        EFX_ASSERT_RESET_SERIALISED(efx);

        efx_stop_all(efx);

        efx_fini_channels(efx);
        efx_init_channels(efx);

        efx_start_all(efx);
}

/**************************************************************************
 *
 * Interrupt moderation
 *
 **************************************************************************/

/* Set interrupt moderation parameters */
void efx_init_irq_moderation(struct efx_nic *efx, int tx_usecs, int rx_usecs)
{
        struct efx_tx_queue *tx_queue;
        struct efx_rx_queue *rx_queue;

        EFX_ASSERT_RESET_SERIALISED(efx);

        efx_for_each_tx_queue(tx_queue, efx)
                tx_queue->channel->irq_moderation = tx_usecs;

        efx_for_each_rx_queue(rx_queue, efx)
                rx_queue->channel->irq_moderation = rx_usecs;
}

/**************************************************************************
 *
 * Hardware monitor
 *
 **************************************************************************/

/* Run periodically off the general workqueue. Serialised against
 * efx_reconfigure_port via the mac_lock */
static void efx_monitor(struct work_struct *data)
{
        struct efx_nic *efx = container_of(data, struct efx_nic,
                                           monitor_work.work);

        EFX_TRACE(efx, "hardware monitor executing on CPU %d\n",
                  raw_smp_processor_id());


        /* If the mac_lock is already held then it is likely a port
         * reconfiguration is already in place, which will likely do
         * most of the work of check_hw() anyway. */
        if (!mutex_trylock(&efx->mac_lock)) {
                queue_delayed_work(efx->workqueue, &efx->monitor_work,
                                   efx_monitor_interval);
                return;
        }

        if (efx->port_enabled)
                efx->mac_op->check_hw(efx);
        mutex_unlock(&efx->mac_lock);

        queue_delayed_work(efx->workqueue, &efx->monitor_work,
                           efx_monitor_interval);
}

/**************************************************************************
 *
 * ioctls
 *
 *************************************************************************/

/* Net device ioctl
 * Context: process, rtnl_lock() held.
 */
static int efx_ioctl(struct net_device *net_dev, struct ifreq *ifr, int cmd)
{
        struct efx_nic *efx = netdev_priv(net_dev);

        EFX_ASSERT_RESET_SERIALISED(efx);

        return generic_mii_ioctl(&efx->mii, if_mii(ifr), cmd, NULL);
}

/**************************************************************************
 *
 * NAPI interface
 *
 **************************************************************************/

static int efx_init_napi(struct efx_nic *efx)
{
        struct efx_channel *channel;
        int rc;

        efx_for_each_channel(channel, efx) {
                channel->napi_dev = efx->net_dev;
                rc = efx_lro_init(&channel->lro_mgr, efx);
                if (rc)
                        goto err;
        }
        return 0;
 err:
        efx_fini_napi(efx);
        return rc;
}

static void efx_fini_napi(struct efx_nic *efx)
{
        struct efx_channel *channel;

        efx_for_each_channel(channel, efx) {
                efx_lro_fini(&channel->lro_mgr);
                channel->napi_dev = NULL;
        }
}

/**************************************************************************
 *
 * Kernel netpoll interface
 *
 *************************************************************************/

#ifdef CONFIG_NET_POLL_CONTROLLER

/* Although in the common case interrupts will be disabled, this is not
 * guaranteed. However, all our work happens inside the NAPI callback,
 * so no locking is required.
 */
static void efx_netpoll(struct net_device *net_dev)
{
        struct efx_nic *efx = netdev_priv(net_dev);
        struct efx_channel *channel;

        efx_for_each_channel(channel, efx)
                efx_schedule_channel(channel);
}

#endif

/**************************************************************************
 *
 * Kernel net device interface
 *
 *************************************************************************/

/* Context: process, rtnl_lock() held. */
static int efx_net_open(struct net_device *net_dev)
{
        struct efx_nic *efx = netdev_priv(net_dev);
        EFX_ASSERT_RESET_SERIALISED(efx);

        EFX_LOG(efx, "opening device %s on CPU %d\n", net_dev->name,
                raw_smp_processor_id());

        if (efx->phy_mode & PHY_MODE_SPECIAL)
                return -EBUSY;

        efx_start_all(efx);
        return 0;
}

/* Context: process, rtnl_lock() held.
 * Note that the kernel will ignore our return code; this method
 * should really be a void.
 */
static int efx_net_stop(struct net_device *net_dev)
{
        struct efx_nic *efx = netdev_priv(net_dev);

        EFX_LOG(efx, "closing %s on CPU %d\n", net_dev->name,
                raw_smp_processor_id());

        /* Stop the device and flush all the channels */
        efx_stop_all(efx);
        efx_fini_channels(efx);
        efx_init_channels(efx);

        return 0;
}

/* Context: process, dev_base_lock or RTNL held, non-blocking. */
static struct net_device_stats *efx_net_stats(struct net_device *net_dev)
{
        struct efx_nic *efx = netdev_priv(net_dev);
        struct efx_mac_stats *mac_stats = &efx->mac_stats;
        struct net_device_stats *stats = &net_dev->stats;

        /* Update stats if possible, but do not wait if another thread
         * is updating them (or resetting the NIC); slightly stale
         * stats are acceptable.
         */
        if (!spin_trylock(&efx->stats_lock))
                return stats;
        if (efx->stats_enabled) {
                efx->mac_op->update_stats(efx);
                falcon_update_nic_stats(efx);
        }
        spin_unlock(&efx->stats_lock);

        stats->rx_packets = mac_stats->rx_packets;
        stats->tx_packets = mac_stats->tx_packets;
        stats->rx_bytes = mac_stats->rx_bytes;
        stats->tx_bytes = mac_stats->tx_bytes;
        stats->multicast = mac_stats->rx_multicast;
        stats->collisions = mac_stats->tx_collision;
        stats->rx_length_errors = (mac_stats->rx_gtjumbo +
                                   mac_stats->rx_length_error);
        stats->rx_over_errors = efx->n_rx_nodesc_drop_cnt;
        stats->rx_crc_errors = mac_stats->rx_bad;
        stats->rx_frame_errors = mac_stats->rx_align_error;
        stats->rx_fifo_errors = mac_stats->rx_overflow;
        stats->rx_missed_errors = mac_stats->rx_missed;
        stats->tx_window_errors = mac_stats->tx_late_collision;

        stats->rx_errors = (stats->rx_length_errors +
                            stats->rx_over_errors +
                            stats->rx_crc_errors +
                            stats->rx_frame_errors +
                            stats->rx_fifo_errors +
                            stats->rx_missed_errors +
                            mac_stats->rx_symbol_error);
        stats->tx_errors = (stats->tx_window_errors +
                            mac_stats->tx_bad);

        return stats;
}

/* Context: netif_tx_lock held, BHs disabled. */
static void efx_watchdog(struct net_device *net_dev)
{
        struct efx_nic *efx = netdev_priv(net_dev);

        EFX_ERR(efx, "TX stuck with stop_count=%d port_enabled=%d:"
                " resetting channels\n",
                atomic_read(&efx->netif_stop_count), efx->port_enabled);

        efx_schedule_reset(efx, RESET_TYPE_TX_WATCHDOG);
}


/* Context: process, rtnl_lock() held. */
static int efx_change_mtu(struct net_device *net_dev, int new_mtu)
{
        struct efx_nic *efx = netdev_priv(net_dev);
        int rc = 0;

        EFX_ASSERT_RESET_SERIALISED(efx);

        if (new_mtu > EFX_MAX_MTU)
                return -EINVAL;

        efx_stop_all(efx);

        EFX_LOG(efx, "changing MTU to %d\n", new_mtu);

        efx_fini_channels(efx);
        net_dev->mtu = new_mtu;
        efx_init_channels(efx);

        efx_start_all(efx);
        return rc;
}

static int efx_set_mac_address(struct net_device *net_dev, void *data)
{
        struct efx_nic *efx = netdev_priv(net_dev);
        struct sockaddr *addr = data;
        char *new_addr = addr->sa_data;

        EFX_ASSERT_RESET_SERIALISED(efx);

        if (!is_valid_ether_addr(new_addr)) {
                EFX_ERR(efx, "invalid ethernet MAC address requested: %pM\n",
                        new_addr);
                return -EINVAL;
        }

        memcpy(net_dev->dev_addr, new_addr, net_dev->addr_len);

        /* Reconfigure the MAC */
        efx_reconfigure_port(efx);

        return 0;
}

/* Context: netif_addr_lock held, BHs disabled. */
static void efx_set_multicast_list(struct net_device *net_dev)
{
        struct efx_nic *efx = netdev_priv(net_dev);
        struct dev_mc_list *mc_list = net_dev->mc_list;
        union efx_multicast_hash *mc_hash = &efx->multicast_hash;
        bool promiscuous = !!(net_dev->flags & IFF_PROMISC);
        bool changed = (efx->promiscuous != promiscuous);
        u32 crc;
        int bit;
        int i;

        efx->promiscuous = promiscuous;

        /* Build multicast hash table */
        if (promiscuous || (net_dev->flags & IFF_ALLMULTI)) {
                memset(mc_hash, 0xff, sizeof(*mc_hash));
        } else {
                memset(mc_hash, 0x00, sizeof(*mc_hash));
                for (i = 0; i < net_dev->mc_count; i++) {
                        crc = ether_crc_le(ETH_ALEN, mc_list->dmi_addr);
                        bit = crc & (EFX_MCAST_HASH_ENTRIES - 1);
                        set_bit_le(bit, mc_hash->byte);
                        mc_list = mc_list->next;
                }
        }

        if (!efx->port_enabled)
                /* Delay pushing settings until efx_start_port() */
                return;

        if (changed)
                queue_work(efx->workqueue, &efx->reconfigure_work);

        /* Create and activate new global multicast hash table */
        falcon_set_multicast_hash(efx);
}

static const struct net_device_ops efx_netdev_ops = {
        .ndo_open               = efx_net_open,
        .ndo_stop               = efx_net_stop,
        .ndo_get_stats          = efx_net_stats,
        .ndo_tx_timeout         = efx_watchdog,
        .ndo_start_xmit         = efx_hard_start_xmit,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_do_ioctl           = efx_ioctl,
        .ndo_change_mtu         = efx_change_mtu,
        .ndo_set_mac_address    = efx_set_mac_address,
        .ndo_set_multicast_list = efx_set_multicast_list,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller = efx_netpoll,
#endif
};

static int efx_netdev_event(struct notifier_block *this,
                            unsigned long event, void *ptr)
{
        struct net_device *net_dev = ptr;

        if (net_dev->netdev_ops == &efx_netdev_ops && event == NETDEV_CHANGENAME) {
                struct efx_nic *efx = netdev_priv(net_dev);

                strcpy(efx->name, net_dev->name);
                efx_mtd_rename(efx);
                efx_set_channel_names(efx);
        }

        return NOTIFY_DONE;
}

static struct notifier_block efx_netdev_notifier = {
        .notifier_call = efx_netdev_event,
};

static ssize_t
show_phy_type(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct efx_nic *efx = pci_get_drvdata(to_pci_dev(dev));
        return sprintf(buf, "%d\n", efx->phy_type);
}
static DEVICE_ATTR(phy_type, 0644, show_phy_type, NULL);

static int efx_register_netdev(struct efx_nic *efx)
{
        struct net_device *net_dev = efx->net_dev;
        int rc;

        net_dev->watchdog_timeo = 5 * HZ;
        net_dev->irq = efx->pci_dev->irq;
        net_dev->netdev_ops = &efx_netdev_ops;
        SET_NETDEV_DEV(net_dev, &efx->pci_dev->dev);
        SET_ETHTOOL_OPS(net_dev, &efx_ethtool_ops);

        /* Always start with carrier off; PHY events will detect the link */
        netif_carrier_off(efx->net_dev);

        /* Clear MAC statistics */
        efx->mac_op->update_stats(efx);
        memset(&efx->mac_stats, 0, sizeof(efx->mac_stats));

        rc = register_netdev(net_dev);
        if (rc) {
                EFX_ERR(efx, "could not register net dev\n");
                return rc;
        }
        strcpy(efx->name, net_dev->name);
        efx_set_channel_names(efx);

        rc = device_create_file(&efx->pci_dev->dev, &dev_attr_phy_type);
        if (rc) {
                EFX_ERR(efx, "failed to init net dev attributes\n");
                goto fail_registered;
        }

        return 0;

fail_registered:
        unregister_netdev(net_dev);
        return rc;
}

static void efx_unregister_netdev(struct efx_nic *efx)
{
        struct efx_tx_queue *tx_queue;

        if (!efx->net_dev)
                return;

        BUG_ON(netdev_priv(efx->net_dev) != efx);

        /* Free up any skbs still remaining. This has to happen before
         * we try to unregister the netdev as running their destructors
         * may be needed to get the device ref. count to 0. */
        efx_for_each_tx_queue(tx_queue, efx)
                efx_release_tx_buffers(tx_queue);

        if (efx_dev_registered(efx)) {
                strlcpy(efx->name, pci_name(efx->pci_dev), sizeof(efx->name));
                device_remove_file(&efx->pci_dev->dev, &dev_attr_phy_type);
                unregister_netdev(efx->net_dev);
        }
}

/**************************************************************************
 *
 * Device reset and suspend
 *
 **************************************************************************/

/* Tears down the entire software state and most of the hardware state
 * before reset.  */
void efx_reset_down(struct efx_nic *efx, struct ethtool_cmd *ecmd)
{
        EFX_ASSERT_RESET_SERIALISED(efx);

        /* The net_dev->get_stats handler is quite slow, and will fail
         * if a fetch is pending over reset. Serialise against it. */
        spin_lock(&efx->stats_lock);
        efx->stats_enabled = false;
        spin_unlock(&efx->stats_lock);

        efx_stop_all(efx);
        mutex_lock(&efx->mac_lock);
        mutex_lock(&efx->spi_lock);

        efx->phy_op->get_settings(efx, ecmd);

        efx_fini_channels(efx);
}

/* This function will always ensure that the locks acquired in
 * efx_reset_down() are released. A failure return code indicates
 * that we were unable to reinitialise the hardware, and the
 * driver should be disabled. If ok is false, then the rx and tx
 * engines are not restarted, pending a RESET_DISABLE. */
int efx_reset_up(struct efx_nic *efx, struct ethtool_cmd *ecmd, bool ok)
{
        int rc;

        EFX_ASSERT_RESET_SERIALISED(efx);

        rc = falcon_init_nic(efx);
        if (rc) {
                EFX_ERR(efx, "failed to initialise NIC\n");
                ok = false;
        }

        if (ok) {
                efx_init_channels(efx);

                if (efx->phy_op->set_settings(efx, ecmd))
                        EFX_ERR(efx, "could not restore PHY settings\n");
        }

        mutex_unlock(&efx->spi_lock);
        mutex_unlock(&efx->mac_lock);

        if (ok) {
                efx_start_all(efx);
                efx->stats_enabled = true;
        }
        return rc;
}

/* Reset the NIC as transparently as possible. Do not reset the PHY
 * Note that the reset may fail, in which case the card will be left
 * in a most-probably-unusable state.
 *
 * This function will sleep.  You cannot reset from within an atomic
 * state; use efx_schedule_reset() instead.
 *
 * Grabs the rtnl_lock.
 */
static int efx_reset(struct efx_nic *efx)
{
        struct ethtool_cmd ecmd;
        enum reset_type method = efx->reset_pending;
        int rc;

        /* Serialise with kernel interfaces */
        rtnl_lock();

        /* If we're not RUNNING then don't reset. Leave the reset_pending
         * flag set so that efx_pci_probe_main will be retried */
        if (efx->state != STATE_RUNNING) {
                EFX_INFO(efx, "scheduled reset quenched. NIC not RUNNING\n");
                goto unlock_rtnl;
        }

        EFX_INFO(efx, "resetting (%d)\n", method);

        efx_reset_down(efx, &ecmd);

        rc = falcon_reset_hw(efx, method);
        if (rc) {
                EFX_ERR(efx, "failed to reset hardware\n");
                goto fail;
        }

        /* Allow resets to be rescheduled. */
        efx->reset_pending = RESET_TYPE_NONE;

        /* Reinitialise bus-mastering, which may have been turned off before
         * the reset was scheduled. This is still appropriate, even in the
         * RESET_TYPE_DISABLE since this driver generally assumes the hardware
         * can respond to requests. */
        pci_set_master(efx->pci_dev);

        /* Leave device stopped if necessary */
        if (method == RESET_TYPE_DISABLE) {
                rc = -EIO;
                goto fail;
        }

        rc = efx_reset_up(efx, &ecmd, true);
        if (rc)
                goto disable;

        EFX_LOG(efx, "reset complete\n");
 unlock_rtnl:
        rtnl_unlock();
        return 0;

 fail:
        efx_reset_up(efx, &ecmd, false);
 disable:
        EFX_ERR(efx, "has been disabled\n");
        efx->state = STATE_DISABLED;

        rtnl_unlock();
        efx_unregister_netdev(efx);
        efx_fini_port(efx);
        return rc;
}

/* The worker thread exists so that code that cannot sleep can
 * schedule a reset for later.
 */
static void efx_reset_work(struct work_struct *data)
{
        struct efx_nic *nic = container_of(data, struct efx_nic, reset_work);

        efx_reset(nic);
}

void efx_schedule_reset(struct efx_nic *efx, enum reset_type type)
{
        enum reset_type method;

        if (efx->reset_pending != RESET_TYPE_NONE) {
                EFX_INFO(efx, "quenching already scheduled reset\n");
                return;
        }

        switch (type) {
        case RESET_TYPE_INVISIBLE:
        case RESET_TYPE_ALL:
        case RESET_TYPE_WORLD:
        case RESET_TYPE_DISABLE:
                method = type;
                break;
        case RESET_TYPE_RX_RECOVERY:
        case RESET_TYPE_RX_DESC_FETCH:
        case RESET_TYPE_TX_DESC_FETCH:
        case RESET_TYPE_TX_SKIP:
                method = RESET_TYPE_INVISIBLE;
                break;
        default:
                method = RESET_TYPE_ALL;
                break;
        }

        if (method != type)
                EFX_LOG(efx, "scheduling reset (%d:%d)\n", type, method);
        else
                EFX_LOG(efx, "scheduling reset (%d)\n", method);

        efx->reset_pending = method;

        queue_work(reset_workqueue, &efx->reset_work);
}

/**************************************************************************
 *
 * List of NICs we support
 *
 **************************************************************************/

/* PCI device ID table */
static struct pci_device_id efx_pci_table[] __devinitdata = {
        {PCI_DEVICE(EFX_VENDID_SFC, FALCON_A_P_DEVID),
         .driver_data = (unsigned long) &falcon_a_nic_type},
        {PCI_DEVICE(EFX_VENDID_SFC, FALCON_B_P_DEVID),
         .driver_data = (unsigned long) &falcon_b_nic_type},
        {0}                     /* end of list */
};

/**************************************************************************
 *
 * Dummy PHY/MAC/Board operations
 *
 * Can be used for some unimplemented operations
 * Needed so all function pointers are valid and do not have to be tested
 * before use
 *
 **************************************************************************/
int efx_port_dummy_op_int(struct efx_nic *efx)
{
        return 0;
}
void efx_port_dummy_op_void(struct efx_nic *efx) {}
void efx_port_dummy_op_blink(struct efx_nic *efx, bool blink) {}

static struct efx_mac_operations efx_dummy_mac_operations = {
        .reconfigure    = efx_port_dummy_op_void,
};

static struct efx_phy_operations efx_dummy_phy_operations = {
        .init            = efx_port_dummy_op_int,
        .reconfigure     = efx_port_dummy_op_void,
        .check_hw        = efx_port_dummy_op_int,
        .fini            = efx_port_dummy_op_void,
        .clear_interrupt = efx_port_dummy_op_void,
};

static struct efx_board efx_dummy_board_info = {
        .init           = efx_port_dummy_op_int,
        .init_leds      = efx_port_dummy_op_int,
        .set_fault_led  = efx_port_dummy_op_blink,
        .monitor        = efx_port_dummy_op_int,
        .blink          = efx_port_dummy_op_blink,
        .fini           = efx_port_dummy_op_void,
};

/**************************************************************************
 *
 * Data housekeeping
 *
 **************************************************************************/

/* This zeroes out and then fills in the invariants in a struct
 * efx_nic (including all sub-structures).
 */
static int efx_init_struct(struct efx_nic *efx, struct efx_nic_type *type,
                           struct pci_dev *pci_dev, struct net_device *net_dev)
{
        struct efx_channel *channel;
        struct efx_tx_queue *tx_queue;
        struct efx_rx_queue *rx_queue;
        int i;

        /* Initialise common structures */
        memset(efx, 0, sizeof(*efx));
        spin_lock_init(&efx->biu_lock);
        spin_lock_init(&efx->phy_lock);
        mutex_init(&efx->spi_lock);
        INIT_WORK(&efx->reset_work, efx_reset_work);
        INIT_DELAYED_WORK(&efx->monitor_work, efx_monitor);
        efx->pci_dev = pci_dev;
        efx->state = STATE_INIT;
        efx->reset_pending = RESET_TYPE_NONE;
        strlcpy(efx->name, pci_name(pci_dev), sizeof(efx->name));
        efx->board_info = efx_dummy_board_info;

        efx->net_dev = net_dev;
        efx->rx_checksum_enabled = true;
        spin_lock_init(&efx->netif_stop_lock);
        spin_lock_init(&efx->stats_lock);
        mutex_init(&efx->mac_lock);
        efx->mac_op = &efx_dummy_mac_operations;
        efx->phy_op = &efx_dummy_phy_operations;
        efx->mii.dev = net_dev;
        INIT_WORK(&efx->reconfigure_work, efx_reconfigure_work);
        atomic_set(&efx->netif_stop_count, 1);

        for (i = 0; i < EFX_MAX_CHANNELS; i++) {
                channel = &efx->channel[i];
                channel->efx = efx;
                channel->channel = i;
                channel->work_pending = false;
        }
        for (i = 0; i < EFX_TX_QUEUE_COUNT; i++) {
                tx_queue = &efx->tx_queue[i];
                tx_queue->efx = efx;
                tx_queue->queue = i;
                tx_queue->buffer = NULL;
                tx_queue->channel = &efx->channel[0]; /* for safety */
                tx_queue->tso_headers_free = NULL;
        }
        for (i = 0; i < EFX_MAX_RX_QUEUES; i++) {
                rx_queue = &efx->rx_queue[i];
                rx_queue->efx = efx;
                rx_queue->queue = i;
                rx_queue->channel = &efx->channel[0]; /* for safety */
                rx_queue->buffer = NULL;
                spin_lock_init(&rx_queue->add_lock);
                INIT_DELAYED_WORK(&rx_queue->work, efx_rx_work);
        }

        efx->type = type;

        /* Sanity-check NIC type */
        EFX_BUG_ON_PARANOID(efx->type->txd_ring_mask &
                            (efx->type->txd_ring_mask + 1));
        EFX_BUG_ON_PARANOID(efx->type->rxd_ring_mask &
                            (efx->type->rxd_ring_mask + 1));
        EFX_BUG_ON_PARANOID(efx->type->evq_size &
                            (efx->type->evq_size - 1));
        /* As close as we can get to guaranteeing that we don't overflow */
        EFX_BUG_ON_PARANOID(efx->type->evq_size <
                            (efx->type->txd_ring_mask + 1 +
                             efx->type->rxd_ring_mask + 1));
        EFX_BUG_ON_PARANOID(efx->type->phys_addr_channels > EFX_MAX_CHANNELS);

        /* Higher numbered interrupt modes are less capable! */
        efx->interrupt_mode = max(efx->type->max_interrupt_mode,
                                  interrupt_mode);

        efx->workqueue = create_singlethread_workqueue("sfc_work");
        if (!efx->workqueue)
                return -ENOMEM;

        return 0;
}

static void efx_fini_struct(struct efx_nic *efx)
{
        if (efx->workqueue) {
                destroy_workqueue(efx->workqueue);
                efx->workqueue = NULL;
        }
}

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

/* Main body of final NIC shutdown code
 * This is called only at module unload (or hotplug removal).
 */
static void efx_pci_remove_main(struct efx_nic *efx)
{
        EFX_ASSERT_RESET_SERIALISED(efx);

        /* Skip everything if we never obtained a valid membase */
        if (!efx->membase)
                return;

        efx_fini_channels(efx);
        efx_fini_port(efx);

        /* Shutdown the board, then the NIC and board state */
        efx->board_info.fini(efx);
        falcon_fini_interrupt(efx);

        efx_fini_napi(efx);
        efx_remove_all(efx);
}

/* Final NIC shutdown
 * This is called only at module unload (or hotplug removal).
 */
static void efx_pci_remove(struct pci_dev *pci_dev)
{
        struct efx_nic *efx;

        efx = pci_get_drvdata(pci_dev);
        if (!efx)
                return;

        efx_mtd_remove(efx);

        /* Mark the NIC as fini, then stop the interface */
        rtnl_lock();
        efx->state = STATE_FINI;
        dev_close(efx->net_dev);

        /* Allow any queued efx_resets() to complete */
        rtnl_unlock();

        if (efx->membase == NULL)
                goto out;

        efx_unregister_netdev(efx);

        /* Wait for any scheduled resets to complete. No more will be
         * scheduled from this point because efx_stop_all() has been
         * called, we are no longer registered with driverlink, and
         * the net_device's have been removed. */
        cancel_work_sync(&efx->reset_work);

        efx_pci_remove_main(efx);

out:
        efx_fini_io(efx);
        EFX_LOG(efx, "shutdown successful\n");

        pci_set_drvdata(pci_dev, NULL);
        efx_fini_struct(efx);
        free_netdev(efx->net_dev);
};

/* Main body of NIC initialisation
 * This is called at module load (or hotplug insertion, theoretically).
 */
static int efx_pci_probe_main(struct efx_nic *efx)
{
        int rc;

        /* Do start-of-day initialisation */
        rc = efx_probe_all(efx);
        if (rc)
                goto fail1;

        rc = efx_init_napi(efx);
        if (rc)
                goto fail2;

        /* Initialise the board */
        rc = efx->board_info.init(efx);
        if (rc) {
                EFX_ERR(efx, "failed to initialise board\n");
                goto fail3;
        }

        rc = falcon_init_nic(efx);
        if (rc) {
                EFX_ERR(efx, "failed to initialise NIC\n");
                goto fail4;
        }

        rc = efx_init_port(efx);
        if (rc) {
                EFX_ERR(efx, "failed to initialise port\n");
                goto fail5;
        }

        efx_init_channels(efx);

        rc = falcon_init_interrupt(efx);
        if (rc)
                goto fail6;

        return 0;

 fail6:
        efx_fini_channels(efx);
        efx_fini_port(efx);
 fail5:
 fail4:
        efx->board_info.fini(efx);
 fail3:
        efx_fini_napi(efx);
 fail2:
        efx_remove_all(efx);
 fail1:
        return rc;
}

/* NIC initialisation
 *
 * This is called at module load (or hotplug insertion,
 * theoretically).  It sets up PCI mappings, tests and resets the NIC,
 * sets up and registers the network devices with the kernel and hooks
 * the interrupt service routine.  It does not prepare the device for
 * transmission; this is left to the first time one of the network
 * interfaces is brought up (i.e. efx_net_open).
 */
static int __devinit efx_pci_probe(struct pci_dev *pci_dev,
                                   const struct pci_device_id *entry)
{
        struct efx_nic_type *type = (struct efx_nic_type *) entry->driver_data;
        struct net_device *net_dev;
        struct efx_nic *efx;
        int i, rc;

        /* Allocate and initialise a struct net_device and struct efx_nic */
        net_dev = alloc_etherdev(sizeof(*efx));
        if (!net_dev)
                return -ENOMEM;
        net_dev->features |= (NETIF_F_IP_CSUM | NETIF_F_SG |
                              NETIF_F_HIGHDMA | NETIF_F_TSO);
        if (lro)
                net_dev->features |= NETIF_F_LRO;
        /* Mask for features that also apply to VLAN devices */
        net_dev->vlan_features |= (NETIF_F_ALL_CSUM | NETIF_F_SG |
                                   NETIF_F_HIGHDMA | NETIF_F_TSO);
        efx = netdev_priv(net_dev);
        pci_set_drvdata(pci_dev, efx);
        rc = efx_init_struct(efx, type, pci_dev, net_dev);
        if (rc)
                goto fail1;

        EFX_INFO(efx, "Solarflare Communications NIC detected\n");

        /* Set up basic I/O (BAR mappings etc) */
        rc = efx_init_io(efx);
        if (rc)
                goto fail2;

        /* No serialisation is required with the reset path because
         * we're in STATE_INIT. */
        for (i = 0; i < 5; i++) {
                rc = efx_pci_probe_main(efx);
                if (rc == 0)
                        break;

                /* Serialise against efx_reset(). No more resets will be
                 * scheduled since efx_stop_all() has been called, and we
                 * have not and never have been registered with either
                 * the rtnetlink or driverlink layers. */
                cancel_work_sync(&efx->reset_work);

                /* Retry if a recoverably reset event has been scheduled */
                if ((efx->reset_pending != RESET_TYPE_INVISIBLE) &&
                    (efx->reset_pending != RESET_TYPE_ALL))
                        goto fail3;

                efx->reset_pending = RESET_TYPE_NONE;
        }

        if (rc) {
                EFX_ERR(efx, "Could not reset NIC\n");
                goto fail4;
        }

        /* Switch to the running state before we expose the device to
         * the OS.  This is to ensure that the initial gathering of
         * MAC stats succeeds. */
        rtnl_lock();
        efx->state = STATE_RUNNING;
        rtnl_unlock();

        rc = efx_register_netdev(efx);
        if (rc)
                goto fail5;

        EFX_LOG(efx, "initialisation successful\n");

        efx_mtd_probe(efx); /* allowed to fail */
        return 0;

 fail5:
        efx_pci_remove_main(efx);
 fail4:
 fail3:
        efx_fini_io(efx);
 fail2:
        efx_fini_struct(efx);
 fail1:
        EFX_LOG(efx, "initialisation failed. rc=%d\n", rc);
        free_netdev(net_dev);
        return rc;
}

static struct pci_driver efx_pci_driver = {
        .name           = EFX_DRIVER_NAME,
        .id_table       = efx_pci_table,
        .probe          = efx_pci_probe,
        .remove         = efx_pci_remove,
};

/**************************************************************************
 *
 * Kernel module interface
 *
 *************************************************************************/

module_param(interrupt_mode, uint, 0444);
MODULE_PARM_DESC(interrupt_mode,
                 "Interrupt mode (0=>MSIX 1=>MSI 2=>legacy)");

static int __init efx_init_module(void)
{
        int rc;

        printk(KERN_INFO "Solarflare NET driver v" EFX_DRIVER_VERSION "\n");

        rc = register_netdevice_notifier(&efx_netdev_notifier);
        if (rc)
                goto err_notifier;

        refill_workqueue = create_workqueue("sfc_refill");
        if (!refill_workqueue) {
                rc = -ENOMEM;
                goto err_refill;
        }
        reset_workqueue = create_singlethread_workqueue("sfc_reset");
        if (!reset_workqueue) {
                rc = -ENOMEM;
                goto err_reset;
        }

        rc = pci_register_driver(&efx_pci_driver);
        if (rc < 0)
                goto err_pci;

        return 0;

 err_pci:
        destroy_workqueue(reset_workqueue);
 err_reset:
        destroy_workqueue(refill_workqueue);
 err_refill:
        unregister_netdevice_notifier(&efx_netdev_notifier);
 err_notifier:
        return rc;
}

static void __exit efx_exit_module(void)
{
        printk(KERN_INFO "Solarflare NET driver unloading\n");

        pci_unregister_driver(&efx_pci_driver);
        destroy_workqueue(reset_workqueue);
        destroy_workqueue(refill_workqueue);
        unregister_netdevice_notifier(&efx_netdev_notifier);

}

module_init(efx_init_module);
module_exit(efx_exit_module);

MODULE_AUTHOR("Michael Brown <mbrown@fensystems.co.uk> and "
              "Solarflare Communications");
MODULE_DESCRIPTION("Solarflare Communications network driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, efx_pci_table);