root/drivers/net/fjes/fjes_main.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  FUJITSU Extended Socket Network Device driver
 *  Copyright (c) 2015 FUJITSU LIMITED
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/nls.h>
#include <linux/platform_device.h>
#include <linux/netdevice.h>
#include <linux/interrupt.h>

#include "fjes.h"
#include "fjes_trace.h"

#define DRV_VERSION "1.2"
#define DRV_NAME        "fjes"
char fjes_driver_name[] = DRV_NAME;
char fjes_driver_version[] = DRV_VERSION;
static const char fjes_driver_string[] =
                "FUJITSU Extended Socket Network Device Driver";
static const char fjes_copyright[] =
                "Copyright (c) 2015 FUJITSU LIMITED";

MODULE_AUTHOR("Taku Izumi <izumi.taku@jp.fujitsu.com>");
MODULE_DESCRIPTION("FUJITSU Extended Socket Network Device Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);

#define ACPI_MOTHERBOARD_RESOURCE_HID "PNP0C02"

static const struct acpi_device_id fjes_acpi_ids[] = {
        {ACPI_MOTHERBOARD_RESOURCE_HID, 0},
        {"", 0},
};
MODULE_DEVICE_TABLE(acpi, fjes_acpi_ids);

static bool is_extended_socket_device(struct acpi_device *device)
{
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};
        char str_buf[sizeof(FJES_ACPI_SYMBOL) + 1];
        union acpi_object *str;
        acpi_status status;
        int result;

        status = acpi_evaluate_object(device->handle, "_STR", NULL, &buffer);
        if (ACPI_FAILURE(status))
                return false;

        str = buffer.pointer;
        result = utf16s_to_utf8s((wchar_t *)str->string.pointer,
                                 str->string.length, UTF16_LITTLE_ENDIAN,
                                 str_buf, sizeof(str_buf) - 1);
        str_buf[result] = 0;

        if (strncmp(FJES_ACPI_SYMBOL, str_buf, strlen(FJES_ACPI_SYMBOL)) != 0) {
                kfree(buffer.pointer);
                return false;
        }
        kfree(buffer.pointer);

        return true;
}

static int acpi_check_extended_socket_status(struct acpi_device *device)
{
        unsigned long long sta;
        acpi_status status;

        status = acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
        if (ACPI_FAILURE(status))
                return -ENODEV;

        if (!((sta & ACPI_STA_DEVICE_PRESENT) &&
              (sta & ACPI_STA_DEVICE_ENABLED) &&
              (sta & ACPI_STA_DEVICE_UI) &&
              (sta & ACPI_STA_DEVICE_FUNCTIONING)))
                return -ENODEV;

        return 0;
}

static acpi_status
fjes_get_acpi_resource(struct acpi_resource *acpi_res, void *data)
{
        struct acpi_resource_address32 *addr;
        struct acpi_resource_irq *irq;
        struct resource *res = data;

        switch (acpi_res->type) {
        case ACPI_RESOURCE_TYPE_ADDRESS32:
                addr = &acpi_res->data.address32;
                res[0].start = addr->address.minimum;
                res[0].end = addr->address.minimum +
                        addr->address.address_length - 1;
                break;

        case ACPI_RESOURCE_TYPE_IRQ:
                irq = &acpi_res->data.irq;
                if (irq->interrupt_count != 1)
                        return AE_ERROR;
                res[1].start = irq->interrupts[0];
                res[1].end = irq->interrupts[0];
                break;

        default:
                break;
        }

        return AE_OK;
}

static struct resource fjes_resource[] = {
        DEFINE_RES_MEM(0, 1),
        DEFINE_RES_IRQ(0)
};

static int fjes_acpi_add(struct acpi_device *device)
{
        struct platform_device *plat_dev;
        acpi_status status;

        if (!is_extended_socket_device(device))
                return -ENODEV;

        if (acpi_check_extended_socket_status(device))
                return -ENODEV;

        status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
                                     fjes_get_acpi_resource, fjes_resource);
        if (ACPI_FAILURE(status))
                return -ENODEV;

        /* create platform_device */
        plat_dev = platform_device_register_simple(DRV_NAME, 0, fjes_resource,
                                                   ARRAY_SIZE(fjes_resource));
        if (IS_ERR(plat_dev))
                return PTR_ERR(plat_dev);

        device->driver_data = plat_dev;

        return 0;
}

static void fjes_acpi_remove(struct acpi_device *device)
{
        struct platform_device *plat_dev;

        plat_dev = (struct platform_device *)acpi_driver_data(device);
        platform_device_unregister(plat_dev);
}

static struct acpi_driver fjes_acpi_driver = {
        .name = DRV_NAME,
        .class = DRV_NAME,
        .ids = fjes_acpi_ids,
        .ops = {
                .add = fjes_acpi_add,
                .remove = fjes_acpi_remove,
        },
};

static int fjes_setup_resources(struct fjes_adapter *adapter)
{
        struct net_device *netdev = adapter->netdev;
        struct ep_share_mem_info *buf_pair;
        struct fjes_hw *hw = &adapter->hw;
        unsigned long flags;
        int result;
        int epidx;

        mutex_lock(&hw->hw_info.lock);
        result = fjes_hw_request_info(hw);
        switch (result) {
        case 0:
                for (epidx = 0; epidx < hw->max_epid; epidx++) {
                        hw->ep_shm_info[epidx].es_status =
                            hw->hw_info.res_buf->info.info[epidx].es_status;
                        hw->ep_shm_info[epidx].zone =
                            hw->hw_info.res_buf->info.info[epidx].zone;
                }
                break;
        default:
        case -ENOMSG:
        case -EBUSY:
                adapter->force_reset = true;

                mutex_unlock(&hw->hw_info.lock);
                return result;
        }
        mutex_unlock(&hw->hw_info.lock);

        for (epidx = 0; epidx < (hw->max_epid); epidx++) {
                if ((epidx != hw->my_epid) &&
                    (hw->ep_shm_info[epidx].es_status ==
                     FJES_ZONING_STATUS_ENABLE)) {
                        fjes_hw_raise_interrupt(hw, epidx,
                                                REG_ICTL_MASK_INFO_UPDATE);
                        hw->ep_shm_info[epidx].ep_stats
                                .send_intr_zoneupdate += 1;
                }
        }

        msleep(FJES_OPEN_ZONE_UPDATE_WAIT * hw->max_epid);

        for (epidx = 0; epidx < (hw->max_epid); epidx++) {
                if (epidx == hw->my_epid)
                        continue;

                buf_pair = &hw->ep_shm_info[epidx];

                spin_lock_irqsave(&hw->rx_status_lock, flags);
                fjes_hw_setup_epbuf(&buf_pair->tx, netdev->dev_addr,
                                    netdev->mtu);
                spin_unlock_irqrestore(&hw->rx_status_lock, flags);

                if (fjes_hw_epid_is_same_zone(hw, epidx)) {
                        mutex_lock(&hw->hw_info.lock);
                        result =
                        fjes_hw_register_buff_addr(hw, epidx, buf_pair);
                        mutex_unlock(&hw->hw_info.lock);

                        switch (result) {
                        case 0:
                                break;
                        case -ENOMSG:
                        case -EBUSY:
                        default:
                                adapter->force_reset = true;
                                return result;
                        }

                        hw->ep_shm_info[epidx].ep_stats
                                .com_regist_buf_exec += 1;
                }
        }

        return 0;
}

static void fjes_rx_irq(struct fjes_adapter *adapter, int src_epid)
{
        struct fjes_hw *hw = &adapter->hw;

        fjes_hw_set_irqmask(hw, REG_ICTL_MASK_RX_DATA, true);

        adapter->unset_rx_last = true;
        napi_schedule(&adapter->napi);
}

static void fjes_stop_req_irq(struct fjes_adapter *adapter, int src_epid)
{
        struct fjes_hw *hw = &adapter->hw;
        enum ep_partner_status status;
        unsigned long flags;

        set_bit(src_epid, &hw->hw_info.buffer_unshare_reserve_bit);

        status = fjes_hw_get_partner_ep_status(hw, src_epid);
        trace_fjes_stop_req_irq_pre(hw, src_epid, status);
        switch (status) {
        case EP_PARTNER_WAITING:
                spin_lock_irqsave(&hw->rx_status_lock, flags);
                hw->ep_shm_info[src_epid].tx.info->v1i.rx_status |=
                                FJES_RX_STOP_REQ_DONE;
                spin_unlock_irqrestore(&hw->rx_status_lock, flags);
                clear_bit(src_epid, &hw->txrx_stop_req_bit);
                fallthrough;
        case EP_PARTNER_UNSHARE:
        case EP_PARTNER_COMPLETE:
        default:
                set_bit(src_epid, &adapter->unshare_watch_bitmask);
                if (!work_pending(&adapter->unshare_watch_task))
                        queue_work(adapter->control_wq,
                                   &adapter->unshare_watch_task);
                break;
        case EP_PARTNER_SHARED:
                set_bit(src_epid, &hw->epstop_req_bit);

                if (!work_pending(&hw->epstop_task))
                        queue_work(adapter->control_wq, &hw->epstop_task);
                break;
        }
        trace_fjes_stop_req_irq_post(hw, src_epid);
}

static void fjes_txrx_stop_req_irq(struct fjes_adapter *adapter,
                                   int src_epid)
{
        struct fjes_hw *hw = &adapter->hw;
        enum ep_partner_status status;
        unsigned long flags;

        status = fjes_hw_get_partner_ep_status(hw, src_epid);
        trace_fjes_txrx_stop_req_irq_pre(hw, src_epid, status);
        switch (status) {
        case EP_PARTNER_UNSHARE:
        case EP_PARTNER_COMPLETE:
        default:
                break;
        case EP_PARTNER_WAITING:
                if (src_epid < hw->my_epid) {
                        spin_lock_irqsave(&hw->rx_status_lock, flags);
                        hw->ep_shm_info[src_epid].tx.info->v1i.rx_status |=
                                FJES_RX_STOP_REQ_DONE;
                        spin_unlock_irqrestore(&hw->rx_status_lock, flags);

                        clear_bit(src_epid, &hw->txrx_stop_req_bit);
                        set_bit(src_epid, &adapter->unshare_watch_bitmask);

                        if (!work_pending(&adapter->unshare_watch_task))
                                queue_work(adapter->control_wq,
                                           &adapter->unshare_watch_task);
                }
                break;
        case EP_PARTNER_SHARED:
                if (hw->ep_shm_info[src_epid].rx.info->v1i.rx_status &
                    FJES_RX_STOP_REQ_REQUEST) {
                        set_bit(src_epid, &hw->epstop_req_bit);
                        if (!work_pending(&hw->epstop_task))
                                queue_work(adapter->control_wq,
                                           &hw->epstop_task);
                }
                break;
        }
        trace_fjes_txrx_stop_req_irq_post(hw, src_epid);
}

static void fjes_update_zone_irq(struct fjes_adapter *adapter,
                                 int src_epid)
{
        struct fjes_hw *hw = &adapter->hw;

        if (!work_pending(&hw->update_zone_task))
                queue_work(adapter->control_wq, &hw->update_zone_task);
}

static irqreturn_t fjes_intr(int irq, void *data)
{
        struct fjes_adapter *adapter = data;
        struct fjes_hw *hw = &adapter->hw;
        irqreturn_t ret;
        u32 icr;

        icr = fjes_hw_capture_interrupt_status(hw);

        if (icr & REG_IS_MASK_IS_ASSERT) {
                if (icr & REG_ICTL_MASK_RX_DATA) {
                        fjes_rx_irq(adapter, icr & REG_IS_MASK_EPID);
                        hw->ep_shm_info[icr & REG_IS_MASK_EPID].ep_stats
                                .recv_intr_rx += 1;
                }

                if (icr & REG_ICTL_MASK_DEV_STOP_REQ) {
                        fjes_stop_req_irq(adapter, icr & REG_IS_MASK_EPID);
                        hw->ep_shm_info[icr & REG_IS_MASK_EPID].ep_stats
                                .recv_intr_stop += 1;
                }

                if (icr & REG_ICTL_MASK_TXRX_STOP_REQ) {
                        fjes_txrx_stop_req_irq(adapter, icr & REG_IS_MASK_EPID);
                        hw->ep_shm_info[icr & REG_IS_MASK_EPID].ep_stats
                                .recv_intr_unshare += 1;
                }

                if (icr & REG_ICTL_MASK_TXRX_STOP_DONE)
                        fjes_hw_set_irqmask(hw,
                                            REG_ICTL_MASK_TXRX_STOP_DONE, true);

                if (icr & REG_ICTL_MASK_INFO_UPDATE) {
                        fjes_update_zone_irq(adapter, icr & REG_IS_MASK_EPID);
                        hw->ep_shm_info[icr & REG_IS_MASK_EPID].ep_stats
                                .recv_intr_zoneupdate += 1;
                }

                ret = IRQ_HANDLED;
        } else {
                ret = IRQ_NONE;
        }

        return ret;
}

static int fjes_request_irq(struct fjes_adapter *adapter)
{
        struct net_device *netdev = adapter->netdev;
        int result = -1;

        adapter->interrupt_watch_enable = true;
        if (!delayed_work_pending(&adapter->interrupt_watch_task)) {
                queue_delayed_work(adapter->control_wq,
                                   &adapter->interrupt_watch_task,
                                   FJES_IRQ_WATCH_DELAY);
        }

        if (!adapter->irq_registered) {
                result = request_irq(adapter->hw.hw_res.irq, fjes_intr,
                                     IRQF_SHARED, netdev->name, adapter);
                if (result)
                        adapter->irq_registered = false;
                else
                        adapter->irq_registered = true;
        }

        return result;
}

static void fjes_free_irq(struct fjes_adapter *adapter)
{
        struct fjes_hw *hw = &adapter->hw;

        adapter->interrupt_watch_enable = false;
        cancel_delayed_work_sync(&adapter->interrupt_watch_task);

        fjes_hw_set_irqmask(hw, REG_ICTL_MASK_ALL, true);

        if (adapter->irq_registered) {
                free_irq(adapter->hw.hw_res.irq, adapter);
                adapter->irq_registered = false;
        }
}

static void fjes_free_resources(struct fjes_adapter *adapter)
{
        struct net_device *netdev = adapter->netdev;
        struct fjes_device_command_param param;
        struct ep_share_mem_info *buf_pair;
        struct fjes_hw *hw = &adapter->hw;
        bool reset_flag = false;
        unsigned long flags;
        int result;
        int epidx;

        for (epidx = 0; epidx < hw->max_epid; epidx++) {
                if (epidx == hw->my_epid)
                        continue;

                mutex_lock(&hw->hw_info.lock);
                result = fjes_hw_unregister_buff_addr(hw, epidx);
                mutex_unlock(&hw->hw_info.lock);

                hw->ep_shm_info[epidx].ep_stats.com_unregist_buf_exec += 1;

                if (result)
                        reset_flag = true;

                buf_pair = &hw->ep_shm_info[epidx];

                spin_lock_irqsave(&hw->rx_status_lock, flags);
                fjes_hw_setup_epbuf(&buf_pair->tx,
                                    netdev->dev_addr, netdev->mtu);
                spin_unlock_irqrestore(&hw->rx_status_lock, flags);

                clear_bit(epidx, &hw->txrx_stop_req_bit);
        }

        if (reset_flag || adapter->force_reset) {
                result = fjes_hw_reset(hw);

                adapter->force_reset = false;

                if (result)
                        adapter->open_guard = true;

                hw->hw_info.buffer_share_bit = 0;

                memset((void *)&param, 0, sizeof(param));

                param.req_len = hw->hw_info.req_buf_size;
                param.req_start = __pa(hw->hw_info.req_buf);
                param.res_len = hw->hw_info.res_buf_size;
                param.res_start = __pa(hw->hw_info.res_buf);
                param.share_start = __pa(hw->hw_info.share->ep_status);

                fjes_hw_init_command_registers(hw, &param);
        }
}

/* fjes_open - Called when a network interface is made active */
static int fjes_open(struct net_device *netdev)
{
        struct fjes_adapter *adapter = netdev_priv(netdev);
        struct fjes_hw *hw = &adapter->hw;
        int result;

        if (adapter->open_guard)
                return -ENXIO;

        result = fjes_setup_resources(adapter);
        if (result)
                goto err_setup_res;

        hw->txrx_stop_req_bit = 0;
        hw->epstop_req_bit = 0;

        napi_enable(&adapter->napi);

        fjes_hw_capture_interrupt_status(hw);

        result = fjes_request_irq(adapter);
        if (result)
                goto err_req_irq;

        fjes_hw_set_irqmask(hw, REG_ICTL_MASK_ALL, false);

        netif_tx_start_all_queues(netdev);
        netif_carrier_on(netdev);

        return 0;

err_req_irq:
        fjes_free_irq(adapter);
        napi_disable(&adapter->napi);

err_setup_res:
        fjes_free_resources(adapter);
        return result;
}

/* fjes_close - Disables a network interface */
static int fjes_close(struct net_device *netdev)
{
        struct fjes_adapter *adapter = netdev_priv(netdev);
        struct fjes_hw *hw = &adapter->hw;
        unsigned long flags;
        int epidx;

        netif_tx_stop_all_queues(netdev);
        netif_carrier_off(netdev);

        fjes_hw_raise_epstop(hw);

        napi_disable(&adapter->napi);

        spin_lock_irqsave(&hw->rx_status_lock, flags);
        for (epidx = 0; epidx < hw->max_epid; epidx++) {
                if (epidx == hw->my_epid)
                        continue;

                if (fjes_hw_get_partner_ep_status(hw, epidx) ==
                    EP_PARTNER_SHARED)
                        adapter->hw.ep_shm_info[epidx]
                                   .tx.info->v1i.rx_status &=
                                ~FJES_RX_POLL_WORK;
        }
        spin_unlock_irqrestore(&hw->rx_status_lock, flags);

        fjes_free_irq(adapter);

        cancel_delayed_work_sync(&adapter->interrupt_watch_task);
        cancel_work_sync(&adapter->unshare_watch_task);
        adapter->unshare_watch_bitmask = 0;
        cancel_work_sync(&adapter->raise_intr_rxdata_task);
        cancel_work_sync(&adapter->tx_stall_task);

        cancel_work_sync(&hw->update_zone_task);
        cancel_work_sync(&hw->epstop_task);

        fjes_hw_wait_epstop(hw);

        fjes_free_resources(adapter);

        return 0;
}

static int fjes_tx_send(struct fjes_adapter *adapter, int dest,
                        void *data, size_t len)
{
        int retval;

        retval = fjes_hw_epbuf_tx_pkt_send(&adapter->hw.ep_shm_info[dest].tx,
                                           data, len);
        if (retval)
                return retval;

        adapter->hw.ep_shm_info[dest].tx.info->v1i.tx_status =
                FJES_TX_DELAY_SEND_PENDING;
        if (!work_pending(&adapter->raise_intr_rxdata_task))
                queue_work(adapter->txrx_wq,
                           &adapter->raise_intr_rxdata_task);

        retval = 0;
        return retval;
}

static netdev_tx_t
fjes_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
{
        struct fjes_adapter *adapter = netdev_priv(netdev);
        struct fjes_hw *hw = &adapter->hw;

        int max_epid, my_epid, dest_epid;
        enum ep_partner_status pstatus;
        struct netdev_queue *cur_queue;
        char shortpkt[VLAN_ETH_HLEN];
        bool is_multi, vlan;
        struct ethhdr *eth;
        u16 queue_no = 0;
        u16 vlan_id = 0;
        netdev_tx_t ret;
        char *data;
        int len;

        ret = NETDEV_TX_OK;
        is_multi = false;
        cur_queue = netdev_get_tx_queue(netdev, queue_no);

        eth = (struct ethhdr *)skb->data;
        my_epid = hw->my_epid;

        vlan = (vlan_get_tag(skb, &vlan_id) == 0) ? true : false;

        data = skb->data;
        len = skb->len;

        if (is_multicast_ether_addr(eth->h_dest)) {
                dest_epid = 0;
                max_epid = hw->max_epid;
                is_multi = true;
        } else if (is_local_ether_addr(eth->h_dest)) {
                dest_epid = eth->h_dest[ETH_ALEN - 1];
                max_epid = dest_epid + 1;

                if ((eth->h_dest[0] == 0x02) &&
                    (0x00 == (eth->h_dest[1] | eth->h_dest[2] |
                              eth->h_dest[3] | eth->h_dest[4])) &&
                    (dest_epid < hw->max_epid)) {
                        ;
                } else {
                        dest_epid = 0;
                        max_epid = 0;
                        ret = NETDEV_TX_OK;

                        adapter->stats64.tx_packets += 1;
                        hw->ep_shm_info[my_epid].net_stats.tx_packets += 1;
                        adapter->stats64.tx_bytes += len;
                        hw->ep_shm_info[my_epid].net_stats.tx_bytes += len;
                }
        } else {
                dest_epid = 0;
                max_epid = 0;
                ret = NETDEV_TX_OK;

                adapter->stats64.tx_packets += 1;
                hw->ep_shm_info[my_epid].net_stats.tx_packets += 1;
                adapter->stats64.tx_bytes += len;
                hw->ep_shm_info[my_epid].net_stats.tx_bytes += len;
        }

        for (; dest_epid < max_epid; dest_epid++) {
                if (my_epid == dest_epid)
                        continue;

                pstatus = fjes_hw_get_partner_ep_status(hw, dest_epid);
                if (pstatus != EP_PARTNER_SHARED) {
                        if (!is_multi)
                                hw->ep_shm_info[dest_epid].ep_stats
                                        .tx_dropped_not_shared += 1;
                        ret = NETDEV_TX_OK;
                } else if (!fjes_hw_check_epbuf_version(
                                &adapter->hw.ep_shm_info[dest_epid].rx, 0)) {
                        /* version is NOT 0 */
                        adapter->stats64.tx_carrier_errors += 1;
                        hw->ep_shm_info[dest_epid].net_stats
                                                .tx_carrier_errors += 1;
                        hw->ep_shm_info[dest_epid].ep_stats
                                        .tx_dropped_ver_mismatch += 1;

                        ret = NETDEV_TX_OK;
                } else if (!fjes_hw_check_mtu(
                                &adapter->hw.ep_shm_info[dest_epid].rx,
                                netdev->mtu)) {
                        adapter->stats64.tx_dropped += 1;
                        hw->ep_shm_info[dest_epid].net_stats.tx_dropped += 1;
                        adapter->stats64.tx_errors += 1;
                        hw->ep_shm_info[dest_epid].net_stats.tx_errors += 1;
                        hw->ep_shm_info[dest_epid].ep_stats
                                        .tx_dropped_buf_size_mismatch += 1;

                        ret = NETDEV_TX_OK;
                } else if (vlan &&
                           !fjes_hw_check_vlan_id(
                                &adapter->hw.ep_shm_info[dest_epid].rx,
                                vlan_id)) {
                        hw->ep_shm_info[dest_epid].ep_stats
                                .tx_dropped_vlanid_mismatch += 1;
                        ret = NETDEV_TX_OK;
                } else {
                        if (len < VLAN_ETH_HLEN) {
                                memset(shortpkt, 0, VLAN_ETH_HLEN);
                                memcpy(shortpkt, skb->data, skb->len);
                                len = VLAN_ETH_HLEN;
                                data = shortpkt;
                        }

                        if (adapter->tx_retry_count == 0) {
                                adapter->tx_start_jiffies = jiffies;
                                adapter->tx_retry_count = 1;
                        } else {
                                adapter->tx_retry_count++;
                        }

                        if (fjes_tx_send(adapter, dest_epid, data, len)) {
                                if (is_multi) {
                                        ret = NETDEV_TX_OK;
                                } else if (
                                           ((long)jiffies -
                                            (long)adapter->tx_start_jiffies) >=
                                            FJES_TX_RETRY_TIMEOUT) {
                                        adapter->stats64.tx_fifo_errors += 1;
                                        hw->ep_shm_info[dest_epid].net_stats
                                                                .tx_fifo_errors += 1;
                                        adapter->stats64.tx_errors += 1;
                                        hw->ep_shm_info[dest_epid].net_stats
                                                                .tx_errors += 1;

                                        ret = NETDEV_TX_OK;
                                } else {
                                        netif_trans_update(netdev);
                                        hw->ep_shm_info[dest_epid].ep_stats
                                                .tx_buffer_full += 1;
                                        netif_tx_stop_queue(cur_queue);

                                        if (!work_pending(&adapter->tx_stall_task))
                                                queue_work(adapter->txrx_wq,
                                                           &adapter->tx_stall_task);

                                        ret = NETDEV_TX_BUSY;
                                }
                        } else {
                                if (!is_multi) {
                                        adapter->stats64.tx_packets += 1;
                                        hw->ep_shm_info[dest_epid].net_stats
                                                                .tx_packets += 1;
                                        adapter->stats64.tx_bytes += len;
                                        hw->ep_shm_info[dest_epid].net_stats
                                                                .tx_bytes += len;
                                }

                                adapter->tx_retry_count = 0;
                                ret = NETDEV_TX_OK;
                        }
                }
        }

        if (ret == NETDEV_TX_OK) {
                dev_kfree_skb(skb);
                if (is_multi) {
                        adapter->stats64.tx_packets += 1;
                        hw->ep_shm_info[my_epid].net_stats.tx_packets += 1;
                        adapter->stats64.tx_bytes += 1;
                        hw->ep_shm_info[my_epid].net_stats.tx_bytes += len;
                }
        }

        return ret;
}

static void
fjes_get_stats64(struct net_device *netdev, struct rtnl_link_stats64 *stats)
{
        struct fjes_adapter *adapter = netdev_priv(netdev);

        memcpy(stats, &adapter->stats64, sizeof(struct rtnl_link_stats64));
}

static int fjes_change_mtu(struct net_device *netdev, int new_mtu)
{
        struct fjes_adapter *adapter = netdev_priv(netdev);
        bool running = netif_running(netdev);
        struct fjes_hw *hw = &adapter->hw;
        unsigned long flags;
        int ret = -EINVAL;
        int idx, epidx;

        for (idx = 0; fjes_support_mtu[idx] != 0; idx++) {
                if (new_mtu <= fjes_support_mtu[idx]) {
                        new_mtu = fjes_support_mtu[idx];
                        if (new_mtu == netdev->mtu)
                                return 0;

                        ret = 0;
                        break;
                }
        }

        if (ret)
                return ret;

        if (running) {
                spin_lock_irqsave(&hw->rx_status_lock, flags);
                for (epidx = 0; epidx < hw->max_epid; epidx++) {
                        if (epidx == hw->my_epid)
                                continue;
                        hw->ep_shm_info[epidx].tx.info->v1i.rx_status &=
                                ~FJES_RX_MTU_CHANGING_DONE;
                }
                spin_unlock_irqrestore(&hw->rx_status_lock, flags);

                netif_tx_stop_all_queues(netdev);
                netif_carrier_off(netdev);
                cancel_work_sync(&adapter->tx_stall_task);
                napi_disable(&adapter->napi);

                msleep(1000);

                netif_tx_stop_all_queues(netdev);
        }

        WRITE_ONCE(netdev->mtu, new_mtu);

        if (running) {
                for (epidx = 0; epidx < hw->max_epid; epidx++) {
                        if (epidx == hw->my_epid)
                                continue;

                        spin_lock_irqsave(&hw->rx_status_lock, flags);
                        fjes_hw_setup_epbuf(&hw->ep_shm_info[epidx].tx,
                                            netdev->dev_addr,
                                            netdev->mtu);

                        hw->ep_shm_info[epidx].tx.info->v1i.rx_status |=
                                FJES_RX_MTU_CHANGING_DONE;
                        spin_unlock_irqrestore(&hw->rx_status_lock, flags);
                }

                netif_tx_wake_all_queues(netdev);
                netif_carrier_on(netdev);
                napi_enable(&adapter->napi);
                napi_schedule(&adapter->napi);
        }

        return ret;
}

static void fjes_tx_retry(struct net_device *netdev, unsigned int txqueue)
{
        struct netdev_queue *queue = netdev_get_tx_queue(netdev, 0);

        netif_tx_wake_queue(queue);
}

static int fjes_vlan_rx_add_vid(struct net_device *netdev,
                                __be16 proto, u16 vid)
{
        struct fjes_adapter *adapter = netdev_priv(netdev);
        bool ret = true;
        int epid;

        for (epid = 0; epid < adapter->hw.max_epid; epid++) {
                if (epid == adapter->hw.my_epid)
                        continue;

                if (!fjes_hw_check_vlan_id(
                        &adapter->hw.ep_shm_info[epid].tx, vid))
                        ret = fjes_hw_set_vlan_id(
                                &adapter->hw.ep_shm_info[epid].tx, vid);
        }

        return ret ? 0 : -ENOSPC;
}

static int fjes_vlan_rx_kill_vid(struct net_device *netdev,
                                 __be16 proto, u16 vid)
{
        struct fjes_adapter *adapter = netdev_priv(netdev);
        int epid;

        for (epid = 0; epid < adapter->hw.max_epid; epid++) {
                if (epid == adapter->hw.my_epid)
                        continue;

                fjes_hw_del_vlan_id(&adapter->hw.ep_shm_info[epid].tx, vid);
        }

        return 0;
}

static const struct net_device_ops fjes_netdev_ops = {
        .ndo_open               = fjes_open,
        .ndo_stop               = fjes_close,
        .ndo_start_xmit         = fjes_xmit_frame,
        .ndo_get_stats64        = fjes_get_stats64,
        .ndo_change_mtu         = fjes_change_mtu,
        .ndo_tx_timeout         = fjes_tx_retry,
        .ndo_vlan_rx_add_vid    = fjes_vlan_rx_add_vid,
        .ndo_vlan_rx_kill_vid = fjes_vlan_rx_kill_vid,
};

/* fjes_netdev_setup - netdevice initialization routine */
static void fjes_netdev_setup(struct net_device *netdev)
{
        ether_setup(netdev);

        netdev->watchdog_timeo = FJES_TX_RETRY_INTERVAL;
        netdev->netdev_ops = &fjes_netdev_ops;
        fjes_set_ethtool_ops(netdev);
        netdev->mtu = fjes_support_mtu[3];
        netdev->min_mtu = fjes_support_mtu[0];
        netdev->max_mtu = fjes_support_mtu[3];
        netdev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
}

static int fjes_rxframe_search_exist(struct fjes_adapter *adapter,
                                     int start_epid)
{
        struct fjes_hw *hw = &adapter->hw;
        enum ep_partner_status pstatus;
        int max_epid, cur_epid;
        int i;

        max_epid = hw->max_epid;
        start_epid = (start_epid + 1 + max_epid) % max_epid;

        for (i = 0; i < max_epid; i++) {
                cur_epid = (start_epid + i) % max_epid;
                if (cur_epid == hw->my_epid)
                        continue;

                pstatus = fjes_hw_get_partner_ep_status(hw, cur_epid);
                if (pstatus == EP_PARTNER_SHARED) {
                        if (!fjes_hw_epbuf_rx_is_empty(
                                &hw->ep_shm_info[cur_epid].rx))
                                return cur_epid;
                }
        }
        return -1;
}

static void *fjes_rxframe_get(struct fjes_adapter *adapter, size_t *psize,
                              int *cur_epid)
{
        void *frame;

        *cur_epid = fjes_rxframe_search_exist(adapter, *cur_epid);
        if (*cur_epid < 0)
                return NULL;

        frame =
        fjes_hw_epbuf_rx_curpkt_get_addr(
                &adapter->hw.ep_shm_info[*cur_epid].rx, psize);

        return frame;
}

static void fjes_rxframe_release(struct fjes_adapter *adapter, int cur_epid)
{
        fjes_hw_epbuf_rx_curpkt_drop(&adapter->hw.ep_shm_info[cur_epid].rx);
}

static int fjes_poll(struct napi_struct *napi, int budget)
{
        struct fjes_adapter *adapter =
                        container_of(napi, struct fjes_adapter, napi);
        struct net_device *netdev = napi->dev;
        struct fjes_hw *hw = &adapter->hw;
        struct sk_buff *skb;
        int work_done = 0;
        int cur_epid = 0;
        int epidx;
        size_t frame_len;
        void *frame;

        spin_lock(&hw->rx_status_lock);
        for (epidx = 0; epidx < hw->max_epid; epidx++) {
                if (epidx == hw->my_epid)
                        continue;

                if (fjes_hw_get_partner_ep_status(hw, epidx) ==
                    EP_PARTNER_SHARED)
                        adapter->hw.ep_shm_info[epidx]
                                   .tx.info->v1i.rx_status |= FJES_RX_POLL_WORK;
        }
        spin_unlock(&hw->rx_status_lock);

        while (work_done < budget) {
                prefetch(&adapter->hw);
                frame = fjes_rxframe_get(adapter, &frame_len, &cur_epid);

                if (frame) {
                        skb = napi_alloc_skb(napi, frame_len);
                        if (!skb) {
                                adapter->stats64.rx_dropped += 1;
                                hw->ep_shm_info[cur_epid].net_stats
                                                         .rx_dropped += 1;
                                adapter->stats64.rx_errors += 1;
                                hw->ep_shm_info[cur_epid].net_stats
                                                         .rx_errors += 1;
                        } else {
                                skb_put_data(skb, frame, frame_len);
                                skb->protocol = eth_type_trans(skb, netdev);
                                skb->ip_summed = CHECKSUM_UNNECESSARY;

                                netif_receive_skb(skb);

                                work_done++;

                                adapter->stats64.rx_packets += 1;
                                hw->ep_shm_info[cur_epid].net_stats
                                                         .rx_packets += 1;
                                adapter->stats64.rx_bytes += frame_len;
                                hw->ep_shm_info[cur_epid].net_stats
                                                         .rx_bytes += frame_len;

                                if (is_multicast_ether_addr(
                                        ((struct ethhdr *)frame)->h_dest)) {
                                        adapter->stats64.multicast += 1;
                                        hw->ep_shm_info[cur_epid].net_stats
                                                                 .multicast += 1;
                                }
                        }

                        fjes_rxframe_release(adapter, cur_epid);
                        adapter->unset_rx_last = true;
                } else {
                        break;
                }
        }

        if (work_done < budget) {
                napi_complete_done(napi, work_done);

                if (adapter->unset_rx_last) {
                        adapter->rx_last_jiffies = jiffies;
                        adapter->unset_rx_last = false;
                }

                if (((long)jiffies - (long)adapter->rx_last_jiffies) < 3) {
                        napi_schedule(napi);
                } else {
                        spin_lock(&hw->rx_status_lock);
                        for (epidx = 0; epidx < hw->max_epid; epidx++) {
                                if (epidx == hw->my_epid)
                                        continue;
                                if (fjes_hw_get_partner_ep_status(hw, epidx) ==
                                    EP_PARTNER_SHARED)
                                        adapter->hw.ep_shm_info[epidx].tx
                                                   .info->v1i.rx_status &=
                                                ~FJES_RX_POLL_WORK;
                        }
                        spin_unlock(&hw->rx_status_lock);

                        fjes_hw_set_irqmask(hw, REG_ICTL_MASK_RX_DATA, false);
                }
        }

        return work_done;
}

static int fjes_sw_init(struct fjes_adapter *adapter)
{
        struct net_device *netdev = adapter->netdev;

        netif_napi_add(netdev, &adapter->napi, fjes_poll);

        return 0;
}

static void fjes_force_close_task(struct work_struct *work)
{
        struct fjes_adapter *adapter = container_of(work,
                        struct fjes_adapter, force_close_task);
        struct net_device *netdev = adapter->netdev;

        rtnl_lock();
        dev_close(netdev);
        rtnl_unlock();
}

static void fjes_tx_stall_task(struct work_struct *work)
{
        struct fjes_adapter *adapter = container_of(work,
                        struct fjes_adapter, tx_stall_task);
        struct net_device *netdev = adapter->netdev;
        struct fjes_hw *hw = &adapter->hw;
        int all_queue_available, sendable;
        enum ep_partner_status pstatus;
        int max_epid, my_epid, epid;
        union ep_buffer_info *info;
        int i;

        if (((long)jiffies -
                dev_trans_start(netdev)) > FJES_TX_TX_STALL_TIMEOUT) {
                netif_wake_queue(netdev);
                return;
        }

        my_epid = hw->my_epid;
        max_epid = hw->max_epid;

        for (i = 0; i < 5; i++) {
                all_queue_available = 1;

                for (epid = 0; epid < max_epid; epid++) {
                        if (my_epid == epid)
                                continue;

                        pstatus = fjes_hw_get_partner_ep_status(hw, epid);
                        sendable = (pstatus == EP_PARTNER_SHARED);
                        if (!sendable)
                                continue;

                        info = adapter->hw.ep_shm_info[epid].tx.info;

                        if (!(info->v1i.rx_status & FJES_RX_MTU_CHANGING_DONE))
                                return;

                        if (EP_RING_FULL(info->v1i.head, info->v1i.tail,
                                         info->v1i.count_max)) {
                                all_queue_available = 0;
                                break;
                        }
                }

                if (all_queue_available) {
                        netif_wake_queue(netdev);
                        return;
                }
        }

        usleep_range(50, 100);

        queue_work(adapter->txrx_wq, &adapter->tx_stall_task);
}

static void fjes_raise_intr_rxdata_task(struct work_struct *work)
{
        struct fjes_adapter *adapter = container_of(work,
                        struct fjes_adapter, raise_intr_rxdata_task);
        struct fjes_hw *hw = &adapter->hw;
        enum ep_partner_status pstatus;
        int max_epid, my_epid, epid;

        my_epid = hw->my_epid;
        max_epid = hw->max_epid;

        for (epid = 0; epid < max_epid; epid++)
                hw->ep_shm_info[epid].tx_status_work = 0;

        for (epid = 0; epid < max_epid; epid++) {
                if (epid == my_epid)
                        continue;

                pstatus = fjes_hw_get_partner_ep_status(hw, epid);
                if (pstatus == EP_PARTNER_SHARED) {
                        hw->ep_shm_info[epid].tx_status_work =
                                hw->ep_shm_info[epid].tx.info->v1i.tx_status;

                        if (hw->ep_shm_info[epid].tx_status_work ==
                                FJES_TX_DELAY_SEND_PENDING) {
                                hw->ep_shm_info[epid].tx.info->v1i.tx_status =
                                        FJES_TX_DELAY_SEND_NONE;
                        }
                }
        }

        for (epid = 0; epid < max_epid; epid++) {
                if (epid == my_epid)
                        continue;

                pstatus = fjes_hw_get_partner_ep_status(hw, epid);
                if ((hw->ep_shm_info[epid].tx_status_work ==
                     FJES_TX_DELAY_SEND_PENDING) &&
                    (pstatus == EP_PARTNER_SHARED) &&
                    !(hw->ep_shm_info[epid].rx.info->v1i.rx_status &
                      FJES_RX_POLL_WORK)) {
                        fjes_hw_raise_interrupt(hw, epid,
                                                REG_ICTL_MASK_RX_DATA);
                        hw->ep_shm_info[epid].ep_stats.send_intr_rx += 1;
                }
        }

        usleep_range(500, 1000);
}

static void fjes_watch_unshare_task(struct work_struct *work)
{
        struct fjes_adapter *adapter =
        container_of(work, struct fjes_adapter, unshare_watch_task);

        struct net_device *netdev = adapter->netdev;
        struct fjes_hw *hw = &adapter->hw;

        int unshare_watch, unshare_reserve;
        int max_epid, my_epid, epidx;
        int stop_req, stop_req_done;
        ulong unshare_watch_bitmask;
        unsigned long flags;
        int wait_time = 0;
        int is_shared;
        int ret;

        my_epid = hw->my_epid;
        max_epid = hw->max_epid;

        unshare_watch_bitmask = adapter->unshare_watch_bitmask;
        adapter->unshare_watch_bitmask = 0;

        while ((unshare_watch_bitmask || hw->txrx_stop_req_bit) &&
               (wait_time < 3000)) {
                for (epidx = 0; epidx < max_epid; epidx++) {
                        if (epidx == my_epid)
                                continue;

                        is_shared = fjes_hw_epid_is_shared(hw->hw_info.share,
                                                           epidx);

                        stop_req = test_bit(epidx, &hw->txrx_stop_req_bit);

                        stop_req_done = hw->ep_shm_info[epidx].rx.info->v1i.rx_status &
                                        FJES_RX_STOP_REQ_DONE;

                        unshare_watch = test_bit(epidx, &unshare_watch_bitmask);

                        unshare_reserve = test_bit(epidx,
                                                   &hw->hw_info.buffer_unshare_reserve_bit);

                        if ((!stop_req ||
                             (is_shared && (!is_shared || !stop_req_done))) &&
                            (is_shared || !unshare_watch || !unshare_reserve))
                                continue;

                        mutex_lock(&hw->hw_info.lock);
                        ret = fjes_hw_unregister_buff_addr(hw, epidx);
                        switch (ret) {
                        case 0:
                                break;
                        case -ENOMSG:
                        case -EBUSY:
                        default:
                                if (!work_pending(
                                        &adapter->force_close_task)) {
                                        adapter->force_reset = true;
                                        schedule_work(
                                                &adapter->force_close_task);
                                }
                                break;
                        }
                        mutex_unlock(&hw->hw_info.lock);
                        hw->ep_shm_info[epidx].ep_stats
                                        .com_unregist_buf_exec += 1;

                        spin_lock_irqsave(&hw->rx_status_lock, flags);
                        fjes_hw_setup_epbuf(&hw->ep_shm_info[epidx].tx,
                                            netdev->dev_addr, netdev->mtu);
                        spin_unlock_irqrestore(&hw->rx_status_lock, flags);

                        clear_bit(epidx, &hw->txrx_stop_req_bit);
                        clear_bit(epidx, &unshare_watch_bitmask);
                        clear_bit(epidx,
                                  &hw->hw_info.buffer_unshare_reserve_bit);
                }

                msleep(100);
                wait_time += 100;
        }

        if (hw->hw_info.buffer_unshare_reserve_bit) {
                for (epidx = 0; epidx < max_epid; epidx++) {
                        if (epidx == my_epid)
                                continue;

                        if (test_bit(epidx,
                                     &hw->hw_info.buffer_unshare_reserve_bit)) {
                                mutex_lock(&hw->hw_info.lock);

                                ret = fjes_hw_unregister_buff_addr(hw, epidx);
                                switch (ret) {
                                case 0:
                                        break;
                                case -ENOMSG:
                                case -EBUSY:
                                default:
                                        if (!work_pending(
                                                &adapter->force_close_task)) {
                                                adapter->force_reset = true;
                                                schedule_work(
                                                        &adapter->force_close_task);
                                        }
                                        break;
                                }
                                mutex_unlock(&hw->hw_info.lock);

                                hw->ep_shm_info[epidx].ep_stats
                                        .com_unregist_buf_exec += 1;

                                spin_lock_irqsave(&hw->rx_status_lock, flags);
                                fjes_hw_setup_epbuf(
                                        &hw->ep_shm_info[epidx].tx,
                                        netdev->dev_addr, netdev->mtu);
                                spin_unlock_irqrestore(&hw->rx_status_lock,
                                                       flags);

                                clear_bit(epidx, &hw->txrx_stop_req_bit);
                                clear_bit(epidx, &unshare_watch_bitmask);
                                clear_bit(epidx, &hw->hw_info.buffer_unshare_reserve_bit);
                        }

                        if (test_bit(epidx, &unshare_watch_bitmask)) {
                                spin_lock_irqsave(&hw->rx_status_lock, flags);
                                hw->ep_shm_info[epidx].tx.info->v1i.rx_status &=
                                                ~FJES_RX_STOP_REQ_DONE;
                                spin_unlock_irqrestore(&hw->rx_status_lock,
                                                       flags);
                        }
                }
        }
}

static void fjes_irq_watch_task(struct work_struct *work)
{
        struct fjes_adapter *adapter = container_of(to_delayed_work(work),
                        struct fjes_adapter, interrupt_watch_task);

        local_irq_disable();
        fjes_intr(adapter->hw.hw_res.irq, adapter);
        local_irq_enable();

        if (fjes_rxframe_search_exist(adapter, 0) >= 0)
                napi_schedule(&adapter->napi);

        if (adapter->interrupt_watch_enable) {
                if (!delayed_work_pending(&adapter->interrupt_watch_task))
                        queue_delayed_work(adapter->control_wq,
                                           &adapter->interrupt_watch_task,
                                           FJES_IRQ_WATCH_DELAY);
        }
}

/* fjes_probe - Device Initialization Routine */
static int fjes_probe(struct platform_device *plat_dev)
{
        struct fjes_adapter *adapter;
        struct net_device *netdev;
        struct resource *res;
        struct fjes_hw *hw;
        u8 addr[ETH_ALEN];
        int err;

        err = -ENOMEM;
        netdev = alloc_netdev_mq(sizeof(struct fjes_adapter), "es%d",
                                 NET_NAME_UNKNOWN, fjes_netdev_setup,
                                 FJES_MAX_QUEUES);

        if (!netdev)
                goto err_out;

        SET_NETDEV_DEV(netdev, &plat_dev->dev);

        dev_set_drvdata(&plat_dev->dev, netdev);
        adapter = netdev_priv(netdev);
        adapter->netdev = netdev;
        adapter->plat_dev = plat_dev;
        hw = &adapter->hw;
        hw->back = adapter;

        /* setup the private structure */
        err = fjes_sw_init(adapter);
        if (err)
                goto err_free_netdev;

        INIT_WORK(&adapter->force_close_task, fjes_force_close_task);
        adapter->force_reset = false;
        adapter->open_guard = false;

        adapter->txrx_wq = alloc_workqueue(DRV_NAME "/txrx",
                                           WQ_MEM_RECLAIM | WQ_PERCPU, 0);
        if (unlikely(!adapter->txrx_wq)) {
                err = -ENOMEM;
                goto err_free_netdev;
        }

        adapter->control_wq = alloc_workqueue(DRV_NAME "/control",
                                              WQ_MEM_RECLAIM | WQ_PERCPU, 0);
        if (unlikely(!adapter->control_wq)) {
                err = -ENOMEM;
                goto err_free_txrx_wq;
        }

        INIT_WORK(&adapter->tx_stall_task, fjes_tx_stall_task);
        INIT_WORK(&adapter->raise_intr_rxdata_task,
                  fjes_raise_intr_rxdata_task);
        INIT_WORK(&adapter->unshare_watch_task, fjes_watch_unshare_task);
        adapter->unshare_watch_bitmask = 0;

        INIT_DELAYED_WORK(&adapter->interrupt_watch_task, fjes_irq_watch_task);
        adapter->interrupt_watch_enable = false;

        res = platform_get_resource(plat_dev, IORESOURCE_MEM, 0);
        if (!res) {
                err = -EINVAL;
                goto err_free_control_wq;
        }
        hw->hw_res.start = res->start;
        hw->hw_res.size = resource_size(res);
        hw->hw_res.irq = platform_get_irq(plat_dev, 0);
        if (hw->hw_res.irq < 0) {
                err = hw->hw_res.irq;
                goto err_free_control_wq;
        }

        err = fjes_hw_init(&adapter->hw);
        if (err)
                goto err_free_control_wq;

        /* setup MAC address (02:00:00:00:00:[epid])*/
        addr[0] = 2;
        addr[1] = 0;
        addr[2] = 0;
        addr[3] = 0;
        addr[4] = 0;
        addr[5] = hw->my_epid; /* EPID */
        eth_hw_addr_set(netdev, addr);

        err = register_netdev(netdev);
        if (err)
                goto err_hw_exit;

        netif_carrier_off(netdev);

        fjes_dbg_adapter_init(adapter);

        return 0;

err_hw_exit:
        fjes_hw_exit(&adapter->hw);
err_free_control_wq:
        destroy_workqueue(adapter->control_wq);
err_free_txrx_wq:
        destroy_workqueue(adapter->txrx_wq);
err_free_netdev:
        free_netdev(netdev);
err_out:
        return err;
}

/* fjes_remove - Device Removal Routine */
static void fjes_remove(struct platform_device *plat_dev)
{
        struct net_device *netdev = dev_get_drvdata(&plat_dev->dev);
        struct fjes_adapter *adapter = netdev_priv(netdev);
        struct fjes_hw *hw = &adapter->hw;

        fjes_dbg_adapter_exit(adapter);

        cancel_delayed_work_sync(&adapter->interrupt_watch_task);
        cancel_work_sync(&adapter->unshare_watch_task);
        cancel_work_sync(&adapter->raise_intr_rxdata_task);
        cancel_work_sync(&adapter->tx_stall_task);
        if (adapter->control_wq)
                destroy_workqueue(adapter->control_wq);
        if (adapter->txrx_wq)
                destroy_workqueue(adapter->txrx_wq);

        unregister_netdev(netdev);

        fjes_hw_exit(hw);

        netif_napi_del(&adapter->napi);

        free_netdev(netdev);
}

static struct platform_driver fjes_driver = {
        .driver = {
                .name = DRV_NAME,
        },
        .probe = fjes_probe,
        .remove = fjes_remove,
};

static acpi_status
acpi_find_extended_socket_device(acpi_handle obj_handle, u32 level,
                                 void *context, void **return_value)
{
        struct acpi_device *device;
        bool *found = context;

        device = acpi_fetch_acpi_dev(obj_handle);
        if (!device)
                return AE_OK;

        if (strcmp(acpi_device_hid(device), ACPI_MOTHERBOARD_RESOURCE_HID))
                return AE_OK;

        if (!is_extended_socket_device(device))
                return AE_OK;

        if (acpi_check_extended_socket_status(device))
                return AE_OK;

        *found = true;
        return AE_CTRL_TERMINATE;
}

/* fjes_init_module - Driver Registration Routine */
static int __init fjes_init_module(void)
{
        bool found = false;
        int result;

        acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX,
                            acpi_find_extended_socket_device, NULL, &found,
                            NULL);

        if (!found)
                return -ENODEV;

        pr_info("%s - version %s - %s\n",
                fjes_driver_string, fjes_driver_version, fjes_copyright);

        fjes_dbg_init();

        result = platform_driver_register(&fjes_driver);
        if (result < 0) {
                fjes_dbg_exit();
                return result;
        }

        result = acpi_bus_register_driver(&fjes_acpi_driver);
        if (result < 0)
                goto fail_acpi_driver;

        return 0;

fail_acpi_driver:
        platform_driver_unregister(&fjes_driver);
        fjes_dbg_exit();
        return result;
}

module_init(fjes_init_module);

/* fjes_exit_module - Driver Exit Cleanup Routine */
static void __exit fjes_exit_module(void)
{
        acpi_bus_unregister_driver(&fjes_acpi_driver);
        platform_driver_unregister(&fjes_driver);
        fjes_dbg_exit();
}

module_exit(fjes_exit_module);