// SPDX-License-Identifier: GPL-2.0-only
/****************************************************************************
 * Driver for Solarflare network controllers and boards
 * Copyright 2018 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 "net_driver.h"
#include <linux/module.h>
#include <linux/netdevice.h>
#include "efx_common.h"
#include "efx_channels.h"
#include "efx.h"
#include "mcdi.h"
#include "selftest.h"
#include "rx_common.h"
#include "tx_common.h"
#include "nic.h"
#include "io.h"
#include "mcdi_pcol.h"

static unsigned int debug = (NETIF_MSG_DRV | NETIF_MSG_PROBE |
                             NETIF_MSG_LINK | NETIF_MSG_IFDOWN |
                             NETIF_MSG_IFUP | NETIF_MSG_RX_ERR |
                             NETIF_MSG_TX_ERR | NETIF_MSG_HW);
module_param(debug, uint, 0);
MODULE_PARM_DESC(debug, "Bitmapped debugging message enable value");

/* This is the time (in jiffies) between invocations of the hardware
 * monitor.
 * On Falcon-based NICs, this will:
 * - Check the on-board hardware monitor;
 * - Poll the link state and reconfigure the hardware as necessary.
 * On Siena-based NICs for power systems with EEH support, this will give EEH a
 * chance to start.
 */
static unsigned int efx_monitor_interval = 1 * HZ;

/* How often and how many times to poll for a reset while waiting for a
 * BIST that another function started to complete.
 */
#define BIST_WAIT_DELAY_MS      100
#define BIST_WAIT_DELAY_COUNT   100

/* Default stats update time */
#define STATS_PERIOD_MS_DEFAULT 1000

const unsigned int efx_reset_type_max = RESET_TYPE_MAX;
const char *const efx_reset_type_names[] = {
        [RESET_TYPE_INVISIBLE]          = "INVISIBLE",
        [RESET_TYPE_ALL]                = "ALL",
        [RESET_TYPE_RECOVER_OR_ALL]     = "RECOVER_OR_ALL",
        [RESET_TYPE_WORLD]              = "WORLD",
        [RESET_TYPE_RECOVER_OR_DISABLE] = "RECOVER_OR_DISABLE",
        [RESET_TYPE_DATAPATH]           = "DATAPATH",
        [RESET_TYPE_MC_BIST]            = "MC_BIST",
        [RESET_TYPE_DISABLE]            = "DISABLE",
        [RESET_TYPE_TX_WATCHDOG]        = "TX_WATCHDOG",
        [RESET_TYPE_INT_ERROR]          = "INT_ERROR",
        [RESET_TYPE_DMA_ERROR]          = "DMA_ERROR",
        [RESET_TYPE_TX_SKIP]            = "TX_SKIP",
        [RESET_TYPE_MC_FAILURE]         = "MC_FAILURE",
        [RESET_TYPE_MCDI_TIMEOUT]       = "MCDI_TIMEOUT (FLR)",
};

#define RESET_TYPE(type) \
        STRING_TABLE_LOOKUP(type, efx_reset_type)

/* Loopback mode names (see LOOPBACK_MODE()) */
const unsigned int efx_loopback_mode_max = LOOPBACK_MAX;
const char *const efx_loopback_mode_names[] = {
        [LOOPBACK_NONE]         = "NONE",
        [LOOPBACK_DATA]         = "DATAPATH",
        [LOOPBACK_GMAC]         = "GMAC",
        [LOOPBACK_XGMII]        = "XGMII",
        [LOOPBACK_XGXS]         = "XGXS",
        [LOOPBACK_XAUI]         = "XAUI",
        [LOOPBACK_GMII]         = "GMII",
        [LOOPBACK_SGMII]        = "SGMII",
        [LOOPBACK_XGBR]         = "XGBR",
        [LOOPBACK_XFI]          = "XFI",
        [LOOPBACK_XAUI_FAR]     = "XAUI_FAR",
        [LOOPBACK_GMII_FAR]     = "GMII_FAR",
        [LOOPBACK_SGMII_FAR]    = "SGMII_FAR",
        [LOOPBACK_XFI_FAR]      = "XFI_FAR",
        [LOOPBACK_GPHY]         = "GPHY",
        [LOOPBACK_PHYXS]        = "PHYXS",
        [LOOPBACK_PCS]          = "PCS",
        [LOOPBACK_PMAPMD]       = "PMA/PMD",
        [LOOPBACK_XPORT]        = "XPORT",
        [LOOPBACK_XGMII_WS]     = "XGMII_WS",
        [LOOPBACK_XAUI_WS]      = "XAUI_WS",
        [LOOPBACK_XAUI_WS_FAR]  = "XAUI_WS_FAR",
        [LOOPBACK_XAUI_WS_NEAR] = "XAUI_WS_NEAR",
        [LOOPBACK_GMII_WS]      = "GMII_WS",
        [LOOPBACK_XFI_WS]       = "XFI_WS",
        [LOOPBACK_XFI_WS_FAR]   = "XFI_WS_FAR",
        [LOOPBACK_PHYXS_WS]     = "PHYXS_WS",
};

/* 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;

int efx_create_reset_workqueue(void)
{
        reset_workqueue = create_singlethread_workqueue("sfc_reset");
        if (!reset_workqueue) {
                printk(KERN_ERR "Failed to create reset workqueue\n");
                return -ENOMEM;
        }

        return 0;
}

void efx_queue_reset_work(struct efx_nic *efx)
{
        queue_work(reset_workqueue, &efx->reset_work);
}

void efx_flush_reset_workqueue(struct efx_nic *efx)
{
        cancel_work_sync(&efx->reset_work);
}

void efx_destroy_reset_workqueue(void)
{
        if (reset_workqueue) {
                destroy_workqueue(reset_workqueue);
                reset_workqueue = NULL;
        }
}

/* We assume that efx->type->reconfigure_mac will always try to sync RX
 * filters and therefore needs to read-lock the filter table against freeing
 */
void efx_mac_reconfigure(struct efx_nic *efx)
{
        if (efx->type->reconfigure_mac) {
                down_read(&efx->filter_sem);
                efx->type->reconfigure_mac(efx);
                up_read(&efx->filter_sem);
        }
}

/* Asynchronous work item for changing MAC promiscuity and multicast
 * hash.  Avoid a drain/rx_ingress enable by reconfiguring the current
 * MAC directly.
 */
static void efx_mac_work(struct work_struct *data)
{
        struct efx_nic *efx = container_of(data, struct efx_nic, mac_work);

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

/* 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.
 */
void efx_link_status_changed(struct efx_nic *efx)
{
        struct efx_link_state *link_state = &efx->link_state;

        /* 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 (link_state->up != netif_carrier_ok(efx->net_dev)) {
                efx->n_link_state_changes++;

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

        /* Status message for kernel log */
        if (link_state->up)
                netif_info(efx, link, efx->net_dev,
                           "link up at %uMbps %s-duplex (MTU %d)\n",
                           link_state->speed, link_state->fd ? "full" : "half",
                           efx->net_dev->mtu);
        else
                netif_info(efx, link, efx->net_dev, "link down\n");
}

unsigned int efx_xdp_max_mtu(struct efx_nic *efx)
{
        /* The maximum MTU that we can fit in a single page, allowing for
         * framing, overhead and XDP headroom + tailroom.
         */
        int overhead = EFX_MAX_FRAME_LEN(0) + sizeof(struct efx_rx_page_state) +
                       efx->rx_prefix_size + efx->type->rx_buffer_padding +
                       efx->rx_ip_align + EFX_XDP_HEADROOM + EFX_XDP_TAILROOM;

        return PAGE_SIZE - overhead;
}

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

        rc = efx_check_disabled(efx);
        if (rc)
                return rc;

        if (rtnl_dereference(efx->xdp_prog) &&
            new_mtu > efx_xdp_max_mtu(efx)) {
                netif_err(efx, drv, efx->net_dev,
                          "Requested MTU of %d too big for XDP (max: %d)\n",
                          new_mtu, efx_xdp_max_mtu(efx));
                return -EINVAL;
        }

        netif_dbg(efx, drv, efx->net_dev, "changing MTU to %d\n", new_mtu);

        efx_device_detach_sync(efx);
        efx_stop_all(efx);

        mutex_lock(&efx->mac_lock);
        net_dev->mtu = new_mtu;
        efx_mac_reconfigure(efx);
        mutex_unlock(&efx->mac_lock);

        efx_start_all(efx);
        efx_device_attach_if_not_resetting(efx);
        return 0;
}

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

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

        netif_vdbg(efx, timer, efx->net_dev,
                   "hardware monitor executing on CPU %d\n",
                   raw_smp_processor_id());
        BUG_ON(efx->type->monitor == NULL);

        /* 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 monitor() anyway.
         */
        if (mutex_trylock(&efx->mac_lock)) {
                if (efx->port_enabled && efx->type->monitor)
                        efx->type->monitor(efx);
                mutex_unlock(&efx->mac_lock);
        }

        efx_start_monitor(efx);
}

void efx_start_monitor(struct efx_nic *efx)
{
        if (efx->type->monitor)
                queue_delayed_work(efx->workqueue, &efx->monitor_work,
                                   efx_monitor_interval);
}

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

/* 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_start_datapath(struct efx_nic *efx)
{
        netdev_features_t old_features = efx->net_dev->features;
        bool old_rx_scatter = efx->rx_scatter;
        size_t rx_buf_len;

        /* Calculate the rx buffer allocation parameters required to
         * support the current MTU, including padding for header
         * alignment and overruns.
         */
        efx->rx_dma_len = (efx->rx_prefix_size +
                           EFX_MAX_FRAME_LEN(efx->net_dev->mtu) +
                           efx->type->rx_buffer_padding);
        rx_buf_len = (sizeof(struct efx_rx_page_state)   + EFX_XDP_HEADROOM +
                      efx->rx_ip_align + efx->rx_dma_len + EFX_XDP_TAILROOM);

        if (rx_buf_len <= PAGE_SIZE) {
                efx->rx_scatter = efx->type->always_rx_scatter;
                efx->rx_buffer_order = 0;
        } else if (efx->type->can_rx_scatter) {
                BUILD_BUG_ON(EFX_RX_USR_BUF_SIZE % L1_CACHE_BYTES);
                BUILD_BUG_ON(sizeof(struct efx_rx_page_state) +
                             2 * ALIGN(NET_IP_ALIGN + EFX_RX_USR_BUF_SIZE,
                                       EFX_RX_BUF_ALIGNMENT) >
                             PAGE_SIZE);
                efx->rx_scatter = true;
                efx->rx_dma_len = EFX_RX_USR_BUF_SIZE;
                efx->rx_buffer_order = 0;
        } else {
                efx->rx_scatter = false;
                efx->rx_buffer_order = get_order(rx_buf_len);
        }

        efx_rx_config_page_split(efx);
        if (efx->rx_buffer_order)
                netif_dbg(efx, drv, efx->net_dev,
                          "RX buf len=%u; page order=%u batch=%u\n",
                          efx->rx_dma_len, efx->rx_buffer_order,
                          efx->rx_pages_per_batch);
        else
                netif_dbg(efx, drv, efx->net_dev,
                          "RX buf len=%u step=%u bpp=%u; page batch=%u\n",
                          efx->rx_dma_len, efx->rx_page_buf_step,
                          efx->rx_bufs_per_page, efx->rx_pages_per_batch);

        /* Restore previously fixed features in hw_features and remove
         * features which are fixed now
         */
        efx->net_dev->hw_features |= efx->net_dev->features;
        efx->net_dev->hw_features &= ~efx->fixed_features;
        efx->net_dev->features |= efx->fixed_features;
        if (efx->net_dev->features != old_features)
                netdev_features_change(efx->net_dev);

        /* RX filters may also have scatter-enabled flags */
        if ((efx->rx_scatter != old_rx_scatter) &&
            efx->type->filter_update_rx_scatter)
                efx->type->filter_update_rx_scatter(efx);

        /* We must keep at least one descriptor in a TX ring empty.
         * We could avoid this when the queue size does not exactly
         * match the hardware ring size, but it's not that important.
         * Therefore we stop the queue when one more skb might fill
         * the ring completely.  We wake it when half way back to
         * empty.
         */
        efx->txq_stop_thresh = efx->txq_entries - efx_tx_max_skb_descs(efx);
        efx->txq_wake_thresh = efx->txq_stop_thresh / 2;

        /* Initialise the channels */
        efx_start_channels(efx);

        efx_ptp_start_datapath(efx);

        if (netif_device_present(efx->net_dev))
                netif_tx_wake_all_queues(efx->net_dev);
}

static void efx_stop_datapath(struct efx_nic *efx)
{
        EFX_ASSERT_RESET_SERIALISED(efx);
        BUG_ON(efx->port_enabled);

        efx_ptp_stop_datapath(efx);

        efx_stop_channels(efx);
}

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

static void efx_start_port(struct efx_nic *efx)
{
        netif_dbg(efx, ifup, efx->net_dev, "start port\n");
        BUG_ON(efx->port_enabled);

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

        /* Ensure MAC ingress/egress is enabled */
        efx_mac_reconfigure(efx);

        mutex_unlock(&efx->mac_lock);
}

/* Cancel work for MAC reconfiguration, periodic hardware monitoring
 * and the async self-test, wait for them to finish and prevent them
 * being scheduled again.  This doesn't cover online resets, which
 * should only be cancelled when removing the device.
 */
static void efx_stop_port(struct efx_nic *efx)
{
        netif_dbg(efx, ifdown, efx->net_dev, "stop port\n");

        EFX_ASSERT_RESET_SERIALISED(efx);

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

        /* Serialise against efx_set_multicast_list() */
        netif_addr_lock_bh(efx->net_dev);
        netif_addr_unlock_bh(efx->net_dev);

        cancel_delayed_work_sync(&efx->monitor_work);
        efx_selftest_async_cancel(efx);
        cancel_work_sync(&efx->mac_work);
}

/* If the interface is supposed to be running but is not, start
 * the hardware and software data path, regular activity for the port
 * (MAC statistics, link polling, etc.) and schedule the port to be
 * reconfigured.  Interrupts must already be enabled.  This function
 * is safe to call multiple times, so long as the NIC is not disabled.
 * Requires the RTNL lock.
 */
void efx_start_all(struct efx_nic *efx)
{
        EFX_ASSERT_RESET_SERIALISED(efx);
        BUG_ON(efx->state == STATE_DISABLED);

        /* 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 || !netif_running(efx->net_dev) ||
            efx->reset_pending)
                return;

        efx_start_port(efx);
        efx_start_datapath(efx);

        /* Start the hardware monitor if there is one */
        efx_start_monitor(efx);

        /* Link state detection is normally event-driven; we have
         * to poll now because we could have missed a change
         */
        mutex_lock(&efx->mac_lock);
        if (efx->phy_op->poll(efx))
                efx_link_status_changed(efx);
        mutex_unlock(&efx->mac_lock);

        if (efx->type->start_stats) {
                efx->type->start_stats(efx);
                efx->type->pull_stats(efx);
                spin_lock_bh(&efx->stats_lock);
                efx->type->update_stats(efx, NULL, NULL);
                spin_unlock_bh(&efx->stats_lock);
        }
}

/* Quiesce the hardware and software data path, and regular activity
 * for the port without bringing the link down.  Safe to call multiple
 * times with the NIC in almost any state, but interrupts should be
 * enabled.  Requires the RTNL lock.
 */
void efx_stop_all(struct efx_nic *efx)
{
        EFX_ASSERT_RESET_SERIALISED(efx);

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

        if (efx->type->update_stats) {
                /* update stats before we go down so we can accurately count
                 * rx_nodesc_drops
                 */
                efx->type->pull_stats(efx);
                spin_lock_bh(&efx->stats_lock);
                efx->type->update_stats(efx, NULL, NULL);
                spin_unlock_bh(&efx->stats_lock);
                efx->type->stop_stats(efx);
        }

        efx_stop_port(efx);

        /* Stop the kernel transmit interface.  This is only valid if
         * the device is stopped or detached; otherwise the watchdog
         * may fire immediately.
         */
        WARN_ON(netif_running(efx->net_dev) &&
                netif_device_present(efx->net_dev));
        netif_tx_disable(efx->net_dev);

        efx_stop_datapath(efx);
}

/* Context: process, dev_base_lock or RTNL held, non-blocking. */
void efx_net_stats(struct net_device *net_dev, struct rtnl_link_stats64 *stats)
{
        struct efx_nic *efx = netdev_priv(net_dev);

        spin_lock_bh(&efx->stats_lock);
        efx->type->update_stats(efx, NULL, stats);
        spin_unlock_bh(&efx->stats_lock);
}

/* Push loopback/power/transmit disable settings to the PHY, and reconfigure
 * the MAC appropriately. All other PHY configuration changes are pushed
 * through phy_op->set_settings(), and pushed asynchronously to the MAC
 * through efx_monitor().
 *
 * Callers must hold the mac_lock
 */
int __efx_reconfigure_port(struct efx_nic *efx)
{
        enum efx_phy_mode phy_mode;
        int rc = 0;

        WARN_ON(!mutex_is_locked(&efx->mac_lock));

        /* Disable PHY transmit in mac level loopbacks */
        phy_mode = efx->phy_mode;
        if (LOOPBACK_INTERNAL(efx))
                efx->phy_mode |= PHY_MODE_TX_DISABLED;
        else
                efx->phy_mode &= ~PHY_MODE_TX_DISABLED;

        if (efx->type->reconfigure_port)
                rc = efx->type->reconfigure_port(efx);

        if (rc)
                efx->phy_mode = phy_mode;

        return rc;
}

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

        EFX_ASSERT_RESET_SERIALISED(efx);

        mutex_lock(&efx->mac_lock);
        rc = __efx_reconfigure_port(efx);
        mutex_unlock(&efx->mac_lock);

        return rc;
}

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

static void efx_wait_for_bist_end(struct efx_nic *efx)
{
        int i;

        for (i = 0; i < BIST_WAIT_DELAY_COUNT; ++i) {
                if (efx_mcdi_poll_reboot(efx))
                        goto out;
                msleep(BIST_WAIT_DELAY_MS);
        }

        netif_err(efx, drv, efx->net_dev, "Warning: No MC reboot after BIST mode\n");
out:
        /* Either way unset the BIST flag. If we found no reboot we probably
         * won't recover, but we should try.
         */
        efx->mc_bist_for_other_fn = false;
}

/* Try recovery mechanisms.
 * For now only EEH is supported.
 * Returns 0 if the recovery mechanisms are unsuccessful.
 * Returns a non-zero value otherwise.
 */
int efx_try_recovery(struct efx_nic *efx)
{
#ifdef CONFIG_EEH
        /* A PCI error can occur and not be seen by EEH because nothing
         * happens on the PCI bus. In this case the driver may fail and
         * schedule a 'recover or reset', leading to this recovery handler.
         * Manually call the eeh failure check function.
         */
        struct eeh_dev *eehdev = pci_dev_to_eeh_dev(efx->pci_dev);
        if (eeh_dev_check_failure(eehdev)) {
                /* The EEH mechanisms will handle the error and reset the
                 * device if necessary.
                 */
                return 1;
        }
#endif
        return 0;
}

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

        if (method == RESET_TYPE_MCDI_TIMEOUT)
                efx->type->prepare_flr(efx);

        efx_stop_all(efx);
        efx_disable_interrupts(efx);

        mutex_lock(&efx->mac_lock);
        down_write(&efx->filter_sem);
        mutex_lock(&efx->rss_lock);
        if (efx->port_initialized && method != RESET_TYPE_INVISIBLE &&
            method != RESET_TYPE_DATAPATH)
                efx->phy_op->fini(efx);
        efx->type->fini(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, enum reset_type method, bool ok)
{
        int rc;

        EFX_ASSERT_RESET_SERIALISED(efx);

        if (method == RESET_TYPE_MCDI_TIMEOUT)
                efx->type->finish_flr(efx);

        /* Ensure that SRAM is initialised even if we're disabling the device */
        rc = efx->type->init(efx);
        if (rc) {
                netif_err(efx, drv, efx->net_dev, "failed to initialise NIC\n");
                goto fail;
        }

        if (!ok)
                goto fail;

        if (efx->port_initialized && method != RESET_TYPE_INVISIBLE &&
            method != RESET_TYPE_DATAPATH) {
                rc = efx->phy_op->init(efx);
                if (rc)
                        goto fail;
                rc = efx->phy_op->reconfigure(efx);
                if (rc && rc != -EPERM)
                        netif_err(efx, drv, efx->net_dev,
                                  "could not restore PHY settings\n");
        }

        rc = efx_enable_interrupts(efx);
        if (rc)
                goto fail;

#ifdef CONFIG_SFC_SRIOV
        rc = efx->type->vswitching_restore(efx);
        if (rc) /* not fatal; the PF will still work fine */
                netif_warn(efx, probe, efx->net_dev,
                           "failed to restore vswitching rc=%d;"
                           " VFs may not function\n", rc);
#endif

        if (efx->type->rx_restore_rss_contexts)
                efx->type->rx_restore_rss_contexts(efx);
        mutex_unlock(&efx->rss_lock);
        efx->type->filter_table_restore(efx);
        up_write(&efx->filter_sem);
        if (efx->type->sriov_reset)
                efx->type->sriov_reset(efx);

        mutex_unlock(&efx->mac_lock);

        efx_start_all(efx);

        if (efx->type->udp_tnl_push_ports)
                efx->type->udp_tnl_push_ports(efx);

        return 0;

fail:
        efx->port_initialized = false;

        mutex_unlock(&efx->rss_lock);
        up_write(&efx->filter_sem);
        mutex_unlock(&efx->mac_lock);

        return rc;
}

/* Reset the NIC using the specified method.  Note that the reset may
 * fail, in which case the card will be left in an unusable state.
 *
 * Caller must hold the rtnl_lock.
 */
int efx_reset(struct efx_nic *efx, enum reset_type method)
{
        bool disabled;
        int rc, rc2;

        netif_info(efx, drv, efx->net_dev, "resetting (%s)\n",
                   RESET_TYPE(method));

        efx_device_detach_sync(efx);
        efx_reset_down(efx, method);

        rc = efx->type->reset(efx, method);
        if (rc) {
                netif_err(efx, drv, efx->net_dev, "failed to reset hardware\n");
                goto out;
        }

        /* Clear flags for the scopes we covered.  We assume the NIC and
         * driver are now quiescent so that there is no race here.
         */
        if (method < RESET_TYPE_MAX_METHOD)
                efx->reset_pending &= -(1 << (method + 1));
        else /* it doesn't fit into the well-ordered scope hierarchy */
                __clear_bit(method, &efx->reset_pending);

        /* 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);

out:
        /* Leave device stopped if necessary */
        disabled = rc ||
                method == RESET_TYPE_DISABLE ||
                method == RESET_TYPE_RECOVER_OR_DISABLE;
        rc2 = efx_reset_up(efx, method, !disabled);
        if (rc2) {
                disabled = true;
                if (!rc)
                        rc = rc2;
        }

        if (disabled) {
                dev_close(efx->net_dev);
                netif_err(efx, drv, efx->net_dev, "has been disabled\n");
                efx->state = STATE_DISABLED;
        } else {
                netif_dbg(efx, drv, efx->net_dev, "reset complete\n");
                efx_device_attach_if_not_resetting(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 *efx = container_of(data, struct efx_nic, reset_work);
        unsigned long pending;
        enum reset_type method;

        pending = READ_ONCE(efx->reset_pending);
        method = fls(pending) - 1;

        if (method == RESET_TYPE_MC_BIST)
                efx_wait_for_bist_end(efx);

        if ((method == RESET_TYPE_RECOVER_OR_DISABLE ||
             method == RESET_TYPE_RECOVER_OR_ALL) &&
            efx_try_recovery(efx))
                return;

        if (!pending)
                return;

        rtnl_lock();

        /* We checked the state in efx_schedule_reset() but it may
         * have changed by now.  Now that we have the RTNL lock,
         * it cannot change again.
         */
        if (efx->state == STATE_READY)
                (void)efx_reset(efx, method);

        rtnl_unlock();
}

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

        if (efx->state == STATE_RECOVERY) {
                netif_dbg(efx, drv, efx->net_dev,
                          "recovering: skip scheduling %s reset\n",
                          RESET_TYPE(type));
                return;
        }

        switch (type) {
        case RESET_TYPE_INVISIBLE:
        case RESET_TYPE_ALL:
        case RESET_TYPE_RECOVER_OR_ALL:
        case RESET_TYPE_WORLD:
        case RESET_TYPE_DISABLE:
        case RESET_TYPE_RECOVER_OR_DISABLE:
        case RESET_TYPE_DATAPATH:
        case RESET_TYPE_MC_BIST:
        case RESET_TYPE_MCDI_TIMEOUT:
                method = type;
                netif_dbg(efx, drv, efx->net_dev, "scheduling %s reset\n",
                          RESET_TYPE(method));
                break;
        default:
                method = efx->type->map_reset_reason(type);
                netif_dbg(efx, drv, efx->net_dev,
                          "scheduling %s reset for %s\n",
                          RESET_TYPE(method), RESET_TYPE(type));
                break;
        }

        set_bit(method, &efx->reset_pending);
        smp_mb(); /* ensure we change reset_pending before checking state */

        /* If we're not READY then just leave the flags set as the cue
         * to abort probing or reschedule the reset later.
         */
        if (READ_ONCE(efx->state) != STATE_READY)
                return;

        /* efx_process_channel() will no longer read events once a
         * reset is scheduled. So switch back to poll'd MCDI completions.
         */
        efx_mcdi_mode_poll(efx);

        efx_queue_reset_work(efx);
}

/**************************************************************************
 *
 * Dummy PHY/MAC 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) {}

static bool efx_port_dummy_op_poll(struct efx_nic *efx)
{
        return false;
}

static const struct efx_phy_operations efx_dummy_phy_operations = {
        .init            = efx_port_dummy_op_int,
        .reconfigure     = efx_port_dummy_op_int,
        .poll            = efx_port_dummy_op_poll,
        .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).
 */
int efx_init_struct(struct efx_nic *efx,
                    struct pci_dev *pci_dev, struct net_device *net_dev)
{
        int rc = -ENOMEM;

        /* Initialise common structures */
        INIT_LIST_HEAD(&efx->node);
        INIT_LIST_HEAD(&efx->secondary_list);
        spin_lock_init(&efx->biu_lock);
#ifdef CONFIG_SFC_MTD
        INIT_LIST_HEAD(&efx->mtd_list);
#endif
        INIT_WORK(&efx->reset_work, efx_reset_work);
        INIT_DELAYED_WORK(&efx->monitor_work, efx_monitor);
        efx_selftest_async_init(efx);
        efx->pci_dev = pci_dev;
        efx->msg_enable = debug;
        efx->state = STATE_UNINIT;
        strlcpy(efx->name, pci_name(pci_dev), sizeof(efx->name));

        efx->net_dev = net_dev;
        efx->rx_prefix_size = efx->type->rx_prefix_size;
        efx->rx_ip_align =
                NET_IP_ALIGN ? (efx->rx_prefix_size + NET_IP_ALIGN) % 4 : 0;
        efx->rx_packet_hash_offset =
                efx->type->rx_hash_offset - efx->type->rx_prefix_size;
        efx->rx_packet_ts_offset =
                efx->type->rx_ts_offset - efx->type->rx_prefix_size;
        INIT_LIST_HEAD(&efx->rss_context.list);
        mutex_init(&efx->rss_lock);
        spin_lock_init(&efx->stats_lock);
        efx->vi_stride = EFX_DEFAULT_VI_STRIDE;
        efx->num_mac_stats = MC_CMD_MAC_NSTATS;
        BUILD_BUG_ON(MC_CMD_MAC_NSTATS - 1 != MC_CMD_MAC_GENERATION_END);
        mutex_init(&efx->mac_lock);
#ifdef CONFIG_RFS_ACCEL
        mutex_init(&efx->rps_mutex);
        spin_lock_init(&efx->rps_hash_lock);
        /* Failure to allocate is not fatal, but may degrade ARFS performance */
        efx->rps_hash_table = kcalloc(EFX_ARFS_HASH_TABLE_SIZE,
                                      sizeof(*efx->rps_hash_table), GFP_KERNEL);
#endif
        efx->phy_op = &efx_dummy_phy_operations;
        efx->mdio.dev = net_dev;
        INIT_WORK(&efx->mac_work, efx_mac_work);
        init_waitqueue_head(&efx->flush_wq);

        rc = efx_init_channels(efx);
        if (rc)
                goto fail;

        /* Would be good to use the net_dev name, but we're too early */
        snprintf(efx->workqueue_name, sizeof(efx->workqueue_name), "sfc%s",
                 pci_name(pci_dev));
        efx->workqueue = create_singlethread_workqueue(efx->workqueue_name);
        if (!efx->workqueue) {
                rc = -ENOMEM;
                goto fail;
        }

        return 0;

fail:
        efx_fini_struct(efx);
        return rc;
}

void efx_fini_struct(struct efx_nic *efx)
{
#ifdef CONFIG_RFS_ACCEL
        kfree(efx->rps_hash_table);
#endif

        efx_fini_channels(efx);

        kfree(efx->vpd_sn);

        if (efx->workqueue) {
                destroy_workqueue(efx->workqueue);
                efx->workqueue = NULL;
        }
}

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

        netif_dbg(efx, probe, efx->net_dev, "initialising I/O\n");

        rc = pci_enable_device(pci_dev);
        if (rc) {
                netif_err(efx, probe, efx->net_dev,
                          "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) {
                rc = dma_set_mask_and_coherent(&pci_dev->dev, dma_mask);
                if (rc == 0)
                        break;
                dma_mask >>= 1;
        }
        if (rc) {
                netif_err(efx, probe, efx->net_dev,
                          "could not find a suitable DMA mask\n");
                goto fail2;

        }
        netif_dbg(efx, probe, efx->net_dev,
                  "using DMA mask %llx\n", (unsigned long long)dma_mask);

        efx->membase_phys = pci_resource_start(efx->pci_dev, bar);
        if (!efx->membase_phys) {
                netif_err(efx, probe, efx->net_dev,
                          "ERROR: No BAR%d mapping from the BIOS. "
                          "Try pci=realloc on the kernel command line\n", bar);
                rc = -ENODEV;
                goto fail3;
        }

        rc = pci_request_region(pci_dev, bar, "sfc");
        if (rc) {
                netif_err(efx, probe, efx->net_dev,
                          "request for memory BAR failed\n");
                rc = -EIO;
                goto fail3;
        }

        efx->membase = ioremap(efx->membase_phys, mem_map_size);
        if (!efx->membase) {
                netif_err(efx, probe, efx->net_dev,
                          "could not map memory BAR at %llx+%x\n",
                          (unsigned long long)efx->membase_phys, mem_map_size);
                rc = -ENOMEM;
                goto fail4;
        }
        netif_dbg(efx, probe, efx->net_dev,
                  "memory BAR at %llx+%x (virtual %p)\n",
                  (unsigned long long)efx->membase_phys, mem_map_size,
                  efx->membase);

        return 0;

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

void efx_fini_io(struct efx_nic *efx, int bar)
{
        netif_dbg(efx, drv, efx->net_dev, "shutting down I/O\n");

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

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

        /* Don't disable bus-mastering if VFs are assigned */
        if (!pci_vfs_assigned(efx->pci_dev))
                pci_disable_device(efx->pci_dev);
}

#ifdef CONFIG_SFC_MCDI_LOGGING
static ssize_t show_mcdi_log(struct device *dev, struct device_attribute *attr,
                             char *buf)
{
        struct efx_nic *efx = dev_get_drvdata(dev);
        struct efx_mcdi_iface *mcdi = efx_mcdi(efx);

        return scnprintf(buf, PAGE_SIZE, "%d\n", mcdi->logging_enabled);
}

static ssize_t set_mcdi_log(struct device *dev, struct device_attribute *attr,
                            const char *buf, size_t count)
{
        struct efx_nic *efx = dev_get_drvdata(dev);
        struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
        bool enable = count > 0 && *buf != '0';

        mcdi->logging_enabled = enable;
        return count;
}

static DEVICE_ATTR(mcdi_logging, 0644, show_mcdi_log, set_mcdi_log);

void efx_init_mcdi_logging(struct efx_nic *efx)
{
        int rc = device_create_file(&efx->pci_dev->dev, &dev_attr_mcdi_logging);

        if (rc) {
                netif_warn(efx, drv, efx->net_dev,
                           "failed to init net dev attributes\n");
        }
}

void efx_fini_mcdi_logging(struct efx_nic *efx)
{
        device_remove_file(&efx->pci_dev->dev, &dev_attr_mcdi_logging);
}
#endif