// SPDX-License-Identifier: GPL-2.0+
// Copyright (c) 2024 Hisilicon Limited.

#include <linux/etherdevice.h>
#include <linux/netdevice.h>
#include <linux/phy.h>
#include <linux/rtnetlink.h>
#include "hbg_common.h"
#include "hbg_err.h"
#include "hbg_hw.h"

static void hbg_restore_mac_table(struct hbg_priv *priv)
{
        struct hbg_mac_filter *filter = &priv->filter;
        u64 addr;
        u32 i;

        for (i = 0; i < filter->table_max_len; i++)
                if (!is_zero_ether_addr(filter->mac_table[i].addr)) {
                        addr = ether_addr_to_u64(filter->mac_table[i].addr);
                        hbg_hw_set_uc_addr(priv, addr, i);
                }

        hbg_hw_set_mac_filter_enable(priv, priv->filter.enabled);
}

static void hbg_restore_user_def_settings(struct hbg_priv *priv)
{
        /* The index of host mac is always 0. */
        u64 rx_pause_addr = ether_addr_to_u64(priv->filter.mac_table[0].addr);
        struct ethtool_pauseparam *pause_param = &priv->user_def.pause_param;

        hbg_restore_mac_table(priv);
        hbg_hw_set_mtu(priv, priv->netdev->mtu);
        hbg_hw_set_pause_enable(priv, pause_param->tx_pause,
                                pause_param->rx_pause);
        hbg_hw_set_rx_pause_mac_addr(priv, rx_pause_addr);
}

int hbg_rebuild(struct hbg_priv *priv)
{
        int ret;

        ret = hbg_hw_init(priv);
        if (ret)
                return ret;

        hbg_restore_user_def_settings(priv);
        return 0;
}

static int hbg_reset_prepare(struct hbg_priv *priv, enum hbg_reset_type type)
{
        int ret;

        if (test_and_set_bit(HBG_NIC_STATE_RESETTING, &priv->state))
                return -EBUSY;

        if (netif_running(priv->netdev)) {
                clear_bit(HBG_NIC_STATE_RESETTING, &priv->state);
                dev_warn(&priv->pdev->dev,
                         "failed to reset because port is up\n");
                return -EBUSY;
        }

        netif_device_detach(priv->netdev);

        priv->reset_type = type;
        clear_bit(HBG_NIC_STATE_RESET_FAIL, &priv->state);
        ret = hbg_hw_event_notify(priv, HBG_HW_EVENT_RESET);
        if (ret) {
                priv->stats.reset_fail_cnt++;
                set_bit(HBG_NIC_STATE_RESET_FAIL, &priv->state);
                clear_bit(HBG_NIC_STATE_RESETTING, &priv->state);
        }

        return ret;
}

static int hbg_reset_done(struct hbg_priv *priv, enum hbg_reset_type type)
{
        int ret;

        if (!test_bit(HBG_NIC_STATE_RESETTING, &priv->state) ||
            type != priv->reset_type)
                return 0;

        ret = hbg_rebuild(priv);
        if (ret) {
                priv->stats.reset_fail_cnt++;
                set_bit(HBG_NIC_STATE_RESET_FAIL, &priv->state);
                clear_bit(HBG_NIC_STATE_RESETTING, &priv->state);
                dev_err(&priv->pdev->dev, "failed to rebuild after reset\n");
                return ret;
        }

        netif_device_attach(priv->netdev);
        clear_bit(HBG_NIC_STATE_RESETTING, &priv->state);

        dev_info(&priv->pdev->dev, "reset done\n");
        return ret;
}

int hbg_reset(struct hbg_priv *priv)
{
        int ret;

        ret = hbg_reset_prepare(priv, HBG_RESET_TYPE_FUNCTION);
        if (ret)
                return ret;

        return hbg_reset_done(priv, HBG_RESET_TYPE_FUNCTION);
}

void hbg_err_reset(struct hbg_priv *priv)
{
        bool running;

        rtnl_lock();
        running = netif_running(priv->netdev);
        if (running)
                dev_close(priv->netdev);

        if (hbg_reset(priv))
                goto err_unlock;

        if (running)
                dev_open(priv->netdev, NULL);

err_unlock:
        rtnl_unlock();
}

static pci_ers_result_t hbg_pci_err_detected(struct pci_dev *pdev,
                                             pci_channel_state_t state)
{
        struct net_device *netdev = pci_get_drvdata(pdev);

        if (state == pci_channel_io_perm_failure) {
                netif_device_detach(netdev);
                return PCI_ERS_RESULT_DISCONNECT;
        }

        return PCI_ERS_RESULT_NEED_RESET;
}

static pci_ers_result_t hbg_pci_err_slot_reset(struct pci_dev *pdev)
{
        struct net_device *netdev = pci_get_drvdata(pdev);
        struct hbg_priv *priv = netdev_priv(netdev);

        netif_device_detach(netdev);
        pci_disable_device(pdev);

        if (pci_enable_device(pdev)) {
                dev_err(&pdev->dev,
                        "failed to re-enable PCI device after reset\n");
                return PCI_ERS_RESULT_DISCONNECT;
        }

        pci_set_master(pdev);
        pci_restore_state(pdev);

        hbg_err_reset(priv);
        return PCI_ERS_RESULT_RECOVERED;
}

static void hbg_pci_err_reset_prepare(struct pci_dev *pdev)
{
        struct net_device *netdev = pci_get_drvdata(pdev);
        struct hbg_priv *priv = netdev_priv(netdev);

        hbg_reset_prepare(priv, HBG_RESET_TYPE_FLR);
}

static void hbg_pci_err_reset_done(struct pci_dev *pdev)
{
        struct net_device *netdev = pci_get_drvdata(pdev);
        struct hbg_priv *priv = netdev_priv(netdev);

        hbg_reset_done(priv, HBG_RESET_TYPE_FLR);
}

static const struct pci_error_handlers hbg_pci_err_handler = {
        .error_detected = hbg_pci_err_detected,
        .slot_reset = hbg_pci_err_slot_reset,
        .reset_prepare = hbg_pci_err_reset_prepare,
        .reset_done = hbg_pci_err_reset_done,
};

void hbg_set_pci_err_handler(struct pci_driver *pdrv)
{
        pdrv->err_handler = &hbg_pci_err_handler;
}