// SPDX-License-Identifier: GPL-2.0+
/*
 * Standard Hot Plug Controller Driver
 *
 * Copyright (C) 1995,2001 Compaq Computer Corporation
 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
 * Copyright (C) 2001 IBM Corp.
 * Copyright (C) 2003-2004 Intel Corporation
 *
 * All rights reserved.
 *
 * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include "../pci.h"
#include "shpchp.h"

static void interrupt_event_handler(struct work_struct *work);
static int shpchp_enable_slot(struct slot *p_slot);
static int shpchp_disable_slot(struct slot *p_slot);

static int queue_interrupt_event(struct slot *p_slot, u32 event_type)
{
        struct event_info *info;

        info = kmalloc_obj(*info, GFP_ATOMIC);
        if (!info)
                return -ENOMEM;

        info->event_type = event_type;
        info->p_slot = p_slot;
        INIT_WORK(&info->work, interrupt_event_handler);

        queue_work(p_slot->wq, &info->work);

        return 0;
}

u8 shpchp_handle_attention_button(u8 hp_slot, struct controller *ctrl)
{
        struct slot *p_slot;
        u32 event_type;

        /* Attention Button Change */
        ctrl_dbg(ctrl, "Attention button interrupt received\n");

        p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
        shpchp_get_adapter_status(p_slot, &p_slot->presence_save);

        /*
         *  Button pressed - See if need to TAKE ACTION!!!
         */
        ctrl_info(ctrl, "Button pressed on Slot(%s)\n", slot_name(p_slot));
        event_type = INT_BUTTON_PRESS;

        queue_interrupt_event(p_slot, event_type);

        return 0;

}

u8 shpchp_handle_switch_change(u8 hp_slot, struct controller *ctrl)
{
        struct slot *p_slot;
        u8 getstatus;
        u32 event_type;

        /* Switch Change */
        ctrl_dbg(ctrl, "Switch interrupt received\n");

        p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
        shpchp_get_adapter_status(p_slot, &p_slot->presence_save);
        shpchp_get_latch_status(p_slot, &getstatus);
        ctrl_dbg(ctrl, "Card present %x Power status %x\n",
                 p_slot->presence_save, p_slot->pwr_save);

        if (getstatus) {
                /*
                 * Switch opened
                 */
                ctrl_info(ctrl, "Latch open on Slot(%s)\n", slot_name(p_slot));
                event_type = INT_SWITCH_OPEN;
                if (p_slot->pwr_save && p_slot->presence_save) {
                        event_type = INT_POWER_FAULT;
                        ctrl_err(ctrl, "Surprise Removal of card\n");
                }
        } else {
                /*
                 *  Switch closed
                 */
                ctrl_info(ctrl, "Latch close on Slot(%s)\n", slot_name(p_slot));
                event_type = INT_SWITCH_CLOSE;
        }

        queue_interrupt_event(p_slot, event_type);

        return 1;
}

u8 shpchp_handle_presence_change(u8 hp_slot, struct controller *ctrl)
{
        struct slot *p_slot;
        u32 event_type;

        /* Presence Change */
        ctrl_dbg(ctrl, "Presence/Notify input change\n");

        p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);

        /*
         * Save the presence state
         */
        shpchp_get_adapter_status(p_slot, &p_slot->presence_save);
        if (p_slot->presence_save) {
                /*
                 * Card Present
                 */
                ctrl_info(ctrl, "Card present on Slot(%s)\n",
                          slot_name(p_slot));
                event_type = INT_PRESENCE_ON;
        } else {
                /*
                 * Not Present
                 */
                ctrl_info(ctrl, "Card not present on Slot(%s)\n",
                          slot_name(p_slot));
                event_type = INT_PRESENCE_OFF;
        }

        queue_interrupt_event(p_slot, event_type);

        return 1;
}

u8 shpchp_handle_power_fault(u8 hp_slot, struct controller *ctrl)
{
        struct slot *p_slot;
        u32 event_type;

        /* Power fault */
        ctrl_dbg(ctrl, "Power fault interrupt received\n");

        p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);

        if (!(shpchp_query_power_fault(p_slot))) {
                /*
                 * Power fault Cleared
                 */
                ctrl_info(ctrl, "Power fault cleared on Slot(%s)\n",
                          slot_name(p_slot));
                p_slot->status = 0x00;
                event_type = INT_POWER_FAULT_CLEAR;
        } else {
                /*
                 *   Power fault
                 */
                ctrl_info(ctrl, "Power fault on Slot(%s)\n", slot_name(p_slot));
                event_type = INT_POWER_FAULT;
                /* set power fault status for this board */
                p_slot->status = 0xFF;
                ctrl_info(ctrl, "Power fault bit %x set\n", hp_slot);
        }

        queue_interrupt_event(p_slot, event_type);

        return 1;
}

/* The following routines constitute the bulk of the
   hotplug controller logic
 */
static int change_bus_speed(struct controller *ctrl, struct slot *p_slot,
                enum pci_bus_speed speed)
{
        int rc = 0;

        ctrl_dbg(ctrl, "Change speed to %d\n", speed);
        rc = shpchp_set_bus_speed_mode(p_slot, speed);
        if (rc) {
                ctrl_err(ctrl, "%s: Issue of set bus speed mode command failed\n",
                         __func__);
                return WRONG_BUS_FREQUENCY;
        }
        return rc;
}

static int fix_bus_speed(struct controller *ctrl, struct slot *pslot,
                u8 flag, enum pci_bus_speed asp, enum pci_bus_speed bsp,
                enum pci_bus_speed msp)
{
        int rc = 0;

        /*
         * If other slots on the same bus are occupied, we cannot
         * change the bus speed.
         */
        if (flag) {
                if (asp < bsp) {
                        ctrl_err(ctrl, "Speed of bus %x and adapter %x mismatch\n",
                                 bsp, asp);
                        rc = WRONG_BUS_FREQUENCY;
                }
                return rc;
        }

        if (asp < msp) {
                if (bsp != asp)
                        rc = change_bus_speed(ctrl, pslot, asp);
        } else {
                if (bsp != msp)
                        rc = change_bus_speed(ctrl, pslot, msp);
        }
        return rc;
}

/**
 * board_added - Called after a board has been added to the system.
 * @p_slot: target &slot
 *
 * Turns power on for the board.
 * Configures board.
 */
static int board_added(struct slot *p_slot)
{
        u8 hp_slot;
        u8 slots_not_empty = 0;
        int rc = 0;
        enum pci_bus_speed asp, bsp, msp;
        struct controller *ctrl = p_slot->ctrl;
        struct pci_bus *parent = ctrl->pci_dev->subordinate;

        hp_slot = p_slot->device - ctrl->slot_device_offset;

        ctrl_dbg(ctrl, "%s: p_slot->device, slot_offset, hp_slot = %d, %d ,%d\n",
                 __func__, p_slot->device, ctrl->slot_device_offset, hp_slot);

        /* Power on slot without connecting to bus */
        rc = shpchp_power_on_slot(p_slot);
        if (rc) {
                ctrl_err(ctrl, "Failed to power on slot\n");
                return -1;
        }

        if ((ctrl->pci_dev->vendor == 0x8086) && (ctrl->pci_dev->device == 0x0332)) {
                rc = shpchp_set_bus_speed_mode(p_slot, PCI_SPEED_33MHz);
                if (rc) {
                        ctrl_err(ctrl, "%s: Issue of set bus speed mode command failed\n",
                                 __func__);
                        return WRONG_BUS_FREQUENCY;
                }

                /* turn on board, blink green LED, turn off Amber LED */
                rc = shpchp_slot_enable(p_slot);
                if (rc) {
                        ctrl_err(ctrl, "Issue of Slot Enable command failed\n");
                        return rc;
                }
        }

        rc = shpchp_get_adapter_speed(p_slot, &asp);
        if (rc) {
                ctrl_err(ctrl, "Can't get adapter speed or bus mode mismatch\n");
                return WRONG_BUS_FREQUENCY;
        }

        bsp = ctrl->pci_dev->subordinate->cur_bus_speed;
        msp = ctrl->pci_dev->subordinate->max_bus_speed;

        /* Check if there are other slots or devices on the same bus */
        if (!list_empty(&ctrl->pci_dev->subordinate->devices))
                slots_not_empty = 1;

        ctrl_dbg(ctrl, "%s: slots_not_empty %d, adapter_speed %d, bus_speed %d, max_bus_speed %d\n",
                 __func__, slots_not_empty, asp,
                 bsp, msp);

        rc = fix_bus_speed(ctrl, p_slot, slots_not_empty, asp, bsp, msp);
        if (rc)
                return rc;

        /* turn on board, blink green LED, turn off Amber LED */
        rc = shpchp_slot_enable(p_slot);
        if (rc) {
                ctrl_err(ctrl, "Issue of Slot Enable command failed\n");
                return rc;
        }

        /* Wait for ~1 second */
        msleep(1000);

        ctrl_dbg(ctrl, "%s: slot status = %x\n", __func__, p_slot->status);
        /* Check for a power fault */
        if (p_slot->status == 0xFF) {
                /* power fault occurred, but it was benign */
                ctrl_dbg(ctrl, "%s: Power fault\n", __func__);
                p_slot->status = 0;
                goto err_exit;
        }

        if (shpchp_configure_device(p_slot)) {
                ctrl_err(ctrl, "Cannot add device at %04x:%02x:%02x\n",
                         pci_domain_nr(parent), p_slot->bus, p_slot->device);
                goto err_exit;
        }

        p_slot->status = 0;
        p_slot->is_a_board = 0x01;
        p_slot->pwr_save = 1;

        shpchp_green_led_on(p_slot);

        return 0;

err_exit:
        /* turn off slot, turn on Amber LED, turn off Green LED */
        rc = shpchp_slot_disable(p_slot);
        if (rc) {
                ctrl_err(ctrl, "%s: Issue of Slot Disable command failed\n",
                         __func__);
                return rc;
        }

        return(rc);
}


/**
 * remove_board - Turns off slot and LEDs
 * @p_slot: target &slot
 */
static int remove_board(struct slot *p_slot)
{
        struct controller *ctrl = p_slot->ctrl;
        u8 hp_slot;
        int rc;

        shpchp_unconfigure_device(p_slot);

        hp_slot = p_slot->device - ctrl->slot_device_offset;
        p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);

        ctrl_dbg(ctrl, "%s: hp_slot = %d\n", __func__, hp_slot);

        /* Change status to shutdown */
        if (p_slot->is_a_board)
                p_slot->status = 0x01;

        /* turn off slot, turn on Amber LED, turn off Green LED */
        rc = shpchp_slot_disable(p_slot);
        if (rc) {
                ctrl_err(ctrl, "%s: Issue of Slot Disable command failed\n",
                         __func__);
                return rc;
        }

        rc = shpchp_set_attention_status(p_slot, 0);
        if (rc) {
                ctrl_err(ctrl, "Issue of Set Attention command failed\n");
                return rc;
        }

        p_slot->pwr_save = 0;
        p_slot->is_a_board = 0;

        return 0;
}


struct pushbutton_work_info {
        struct slot *p_slot;
        struct work_struct work;
};

/**
 * shpchp_pushbutton_thread - handle pushbutton events
 * @work: &struct work_struct to be handled
 *
 * Scheduled procedure to handle blocking stuff for the pushbuttons.
 * Handles all pending events and exits.
 */
static void shpchp_pushbutton_thread(struct work_struct *work)
{
        struct pushbutton_work_info *info =
                container_of(work, struct pushbutton_work_info, work);
        struct slot *p_slot = info->p_slot;

        mutex_lock(&p_slot->lock);
        switch (p_slot->state) {
        case POWEROFF_STATE:
                mutex_unlock(&p_slot->lock);
                shpchp_disable_slot(p_slot);
                mutex_lock(&p_slot->lock);
                p_slot->state = STATIC_STATE;
                break;
        case POWERON_STATE:
                mutex_unlock(&p_slot->lock);
                if (shpchp_enable_slot(p_slot))
                        shpchp_green_led_off(p_slot);
                mutex_lock(&p_slot->lock);
                p_slot->state = STATIC_STATE;
                break;
        default:
                break;
        }
        mutex_unlock(&p_slot->lock);

        kfree(info);
}

void shpchp_queue_pushbutton_work(struct work_struct *work)
{
        struct slot *p_slot = container_of(work, struct slot, work.work);
        struct pushbutton_work_info *info;

        info = kmalloc_obj(*info);
        if (!info) {
                ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
                         __func__);
                return;
        }
        info->p_slot = p_slot;
        INIT_WORK(&info->work, shpchp_pushbutton_thread);

        mutex_lock(&p_slot->lock);
        switch (p_slot->state) {
        case BLINKINGOFF_STATE:
                p_slot->state = POWEROFF_STATE;
                break;
        case BLINKINGON_STATE:
                p_slot->state = POWERON_STATE;
                break;
        default:
                kfree(info);
                goto out;
        }
        queue_work(p_slot->wq, &info->work);
 out:
        mutex_unlock(&p_slot->lock);
}

static void update_slot_info(struct slot *slot)
{
        shpchp_get_power_status(slot, &slot->pwr_save);
        shpchp_get_attention_status(slot, &slot->attention_save);
        shpchp_get_latch_status(slot, &slot->latch_save);
        shpchp_get_adapter_status(slot, &slot->presence_save);
}

/*
 * Note: This function must be called with slot->lock held
 */
static void handle_button_press_event(struct slot *p_slot)
{
        u8 getstatus;
        struct controller *ctrl = p_slot->ctrl;

        switch (p_slot->state) {
        case STATIC_STATE:
                shpchp_get_power_status(p_slot, &getstatus);
                if (getstatus) {
                        p_slot->state = BLINKINGOFF_STATE;
                        ctrl_info(ctrl, "PCI slot #%s - powering off due to button press\n",
                                  slot_name(p_slot));
                } else {
                        p_slot->state = BLINKINGON_STATE;
                        ctrl_info(ctrl, "PCI slot #%s - powering on due to button press\n",
                                  slot_name(p_slot));
                }
                /* blink green LED and turn off amber */
                shpchp_green_led_blink(p_slot);
                shpchp_set_attention_status(p_slot, 0);

                queue_delayed_work(p_slot->wq, &p_slot->work, 5*HZ);
                break;
        case BLINKINGOFF_STATE:
        case BLINKINGON_STATE:
                /*
                 * Cancel if we are still blinking; this means that we
                 * press the attention again before the 5 sec. limit
                 * expires to cancel hot-add or hot-remove
                 */
                ctrl_info(ctrl, "Button cancel on Slot(%s)\n",
                          slot_name(p_slot));
                cancel_delayed_work(&p_slot->work);
                if (p_slot->state == BLINKINGOFF_STATE)
                        shpchp_green_led_on(p_slot);
                else
                        shpchp_green_led_off(p_slot);
                shpchp_set_attention_status(p_slot, 0);
                ctrl_info(ctrl, "PCI slot #%s - action canceled due to button press\n",
                          slot_name(p_slot));
                p_slot->state = STATIC_STATE;
                break;
        case POWEROFF_STATE:
        case POWERON_STATE:
                /*
                 * Ignore if the slot is on power-on or power-off state;
                 * this means that the previous attention button action
                 * to hot-add or hot-remove is undergoing
                 */
                ctrl_info(ctrl, "Button ignore on Slot(%s)\n",
                          slot_name(p_slot));
                update_slot_info(p_slot);
                break;
        default:
                ctrl_warn(ctrl, "Not a valid state\n");
                break;
        }
}

static void interrupt_event_handler(struct work_struct *work)
{
        struct event_info *info = container_of(work, struct event_info, work);
        struct slot *p_slot = info->p_slot;

        mutex_lock(&p_slot->lock);
        switch (info->event_type) {
        case INT_BUTTON_PRESS:
                handle_button_press_event(p_slot);
                break;
        case INT_POWER_FAULT:
                ctrl_dbg(p_slot->ctrl, "%s: Power fault\n", __func__);
                shpchp_set_attention_status(p_slot, 1);
                shpchp_green_led_off(p_slot);
                break;
        default:
                update_slot_info(p_slot);
                break;
        }
        mutex_unlock(&p_slot->lock);

        kfree(info);
}


static int shpchp_enable_slot (struct slot *p_slot)
{
        u8 getstatus = 0;
        int rc, retval = -ENODEV;
        struct controller *ctrl = p_slot->ctrl;

        /* Check to see if (latch closed, card present, power off) */
        mutex_lock(&p_slot->ctrl->crit_sect);
        rc = shpchp_get_adapter_status(p_slot, &getstatus);
        if (rc || !getstatus) {
                ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
                goto out;
        }
        rc = shpchp_get_latch_status(p_slot, &getstatus);
        if (rc || getstatus) {
                ctrl_info(ctrl, "Latch open on slot(%s)\n", slot_name(p_slot));
                goto out;
        }
        rc = shpchp_get_power_status(p_slot, &getstatus);
        if (rc || getstatus) {
                ctrl_info(ctrl, "Already enabled on slot(%s)\n",
                          slot_name(p_slot));
                goto out;
        }

        p_slot->is_a_board = 1;

        /* We have to save the presence info for these slots */
        shpchp_get_adapter_status(p_slot, &p_slot->presence_save);
        shpchp_get_power_status(p_slot, &p_slot->pwr_save);
        ctrl_dbg(ctrl, "%s: p_slot->pwr_save %x\n", __func__, p_slot->pwr_save);
        shpchp_get_latch_status(p_slot, &getstatus);

        if ((p_slot->ctrl->pci_dev->vendor == PCI_VENDOR_ID_AMD &&
             p_slot->ctrl->pci_dev->device == PCI_DEVICE_ID_AMD_POGO_7458)
             && p_slot->ctrl->num_slots == 1) {
                /* handle AMD POGO errata; this must be done before enable  */
                amd_pogo_errata_save_misc_reg(p_slot);
                retval = board_added(p_slot);
                /* handle AMD POGO errata; this must be done after enable  */
                amd_pogo_errata_restore_misc_reg(p_slot);
        } else
                retval = board_added(p_slot);

        if (retval) {
                shpchp_get_adapter_status(p_slot, &p_slot->presence_save);
                shpchp_get_latch_status(p_slot, &getstatus);
        }

        update_slot_info(p_slot);
 out:
        mutex_unlock(&p_slot->ctrl->crit_sect);
        return retval;
}


static int shpchp_disable_slot (struct slot *p_slot)
{
        u8 getstatus = 0;
        int rc, retval = -ENODEV;
        struct controller *ctrl = p_slot->ctrl;

        if (!p_slot->ctrl)
                return -ENODEV;

        /* Check to see if (latch closed, card present, power on) */
        mutex_lock(&p_slot->ctrl->crit_sect);

        rc = shpchp_get_adapter_status(p_slot, &getstatus);
        if (rc || !getstatus) {
                ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
                goto out;
        }
        rc = shpchp_get_latch_status(p_slot, &getstatus);
        if (rc || getstatus) {
                ctrl_info(ctrl, "Latch open on slot(%s)\n", slot_name(p_slot));
                goto out;
        }
        rc = shpchp_get_power_status(p_slot, &getstatus);
        if (rc || !getstatus) {
                ctrl_info(ctrl, "Already disabled on slot(%s)\n",
                          slot_name(p_slot));
                goto out;
        }

        retval = remove_board(p_slot);
        update_slot_info(p_slot);
 out:
        mutex_unlock(&p_slot->ctrl->crit_sect);
        return retval;
}

int shpchp_sysfs_enable_slot(struct slot *p_slot)
{
        int retval = -ENODEV;
        struct controller *ctrl = p_slot->ctrl;

        mutex_lock(&p_slot->lock);
        switch (p_slot->state) {
        case BLINKINGON_STATE:
                cancel_delayed_work(&p_slot->work);
                fallthrough;
        case STATIC_STATE:
                p_slot->state = POWERON_STATE;
                mutex_unlock(&p_slot->lock);
                retval = shpchp_enable_slot(p_slot);
                mutex_lock(&p_slot->lock);
                p_slot->state = STATIC_STATE;
                break;
        case POWERON_STATE:
                ctrl_info(ctrl, "Slot %s is already in powering on state\n",
                          slot_name(p_slot));
                break;
        case BLINKINGOFF_STATE:
        case POWEROFF_STATE:
                ctrl_info(ctrl, "Already enabled on slot %s\n",
                          slot_name(p_slot));
                break;
        default:
                ctrl_err(ctrl, "Not a valid state on slot %s\n",
                         slot_name(p_slot));
                break;
        }
        mutex_unlock(&p_slot->lock);

        return retval;
}

int shpchp_sysfs_disable_slot(struct slot *p_slot)
{
        int retval = -ENODEV;
        struct controller *ctrl = p_slot->ctrl;

        mutex_lock(&p_slot->lock);
        switch (p_slot->state) {
        case BLINKINGOFF_STATE:
                cancel_delayed_work(&p_slot->work);
                fallthrough;
        case STATIC_STATE:
                p_slot->state = POWEROFF_STATE;
                mutex_unlock(&p_slot->lock);
                retval = shpchp_disable_slot(p_slot);
                mutex_lock(&p_slot->lock);
                p_slot->state = STATIC_STATE;
                break;
        case POWEROFF_STATE:
                ctrl_info(ctrl, "Slot %s is already in powering off state\n",
                          slot_name(p_slot));
                break;
        case BLINKINGON_STATE:
        case POWERON_STATE:
                ctrl_info(ctrl, "Already disabled on slot %s\n",
                          slot_name(p_slot));
                break;
        default:
                ctrl_err(ctrl, "Not a valid state on slot %s\n",
                         slot_name(p_slot));
                break;
        }
        mutex_unlock(&p_slot->lock);

        return retval;
}