// SPDX-License-Identifier: GPL-2.0+
/*
 * PCI Hot Plug Controller Driver for RPA-compliant PPC64 platform.
 * Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
 *
 * All rights reserved.
 *
 * Send feedback to <lxie@us.ibm.com>
 *
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <asm/firmware.h>
#include <asm/eeh.h>       /* for eeh_add_device() */
#include <asm/rtas.h>           /* rtas_call */
#include <asm/pci-bridge.h>     /* for pci_controller */
#include "../pci.h"             /* for pci_add_new_bus */
                                /* and pci_do_scan_bus */
#include "rpaphp.h"

bool rpaphp_debug;
LIST_HEAD(rpaphp_slot_head);
EXPORT_SYMBOL_GPL(rpaphp_slot_head);

#define DRIVER_VERSION  "0.1"
#define DRIVER_AUTHOR   "Linda Xie <lxie@us.ibm.com>"
#define DRIVER_DESC     "RPA HOT Plug PCI Controller Driver"

#define MAX_LOC_CODE 128

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

module_param_named(debug, rpaphp_debug, bool, 0644);

/**
 * set_attention_status - set attention LED
 * @hotplug_slot: target &hotplug_slot
 * @value: LED control value
 *
 * echo 0 > attention -- set LED OFF
 * echo 1 > attention -- set LED ON
 * echo 2 > attention -- set LED ID(identify, light is blinking)
 */
static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 value)
{
        int rc;
        struct slot *slot = (struct slot *)hotplug_slot->private;

        switch (value) {
        case 0:
        case 1:
        case 2:
                break;
        default:
                value = 1;
                break;
        }

        rc = rtas_set_indicator(DR_INDICATOR, slot->index, value);
        if (!rc)
                hotplug_slot->info->attention_status = value;

        return rc;
}

/**
 * get_power_status - get power status of a slot
 * @hotplug_slot: slot to get status
 * @value: pointer to store status
 */
static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
        int retval, level;
        struct slot *slot = (struct slot *)hotplug_slot->private;

        retval = rtas_get_power_level(slot->power_domain, &level);
        if (!retval)
                *value = level;
        return retval;
}

/**
 * get_attention_status - get attention LED status
 * @hotplug_slot: slot to get status
 * @value: pointer to store status
 */
static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
        struct slot *slot = (struct slot *)hotplug_slot->private;
        *value = slot->hotplug_slot->info->attention_status;
        return 0;
}

static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
        struct slot *slot = (struct slot *)hotplug_slot->private;
        int rc, state;

        rc = rpaphp_get_sensor_state(slot, &state);

        *value = NOT_VALID;
        if (rc)
                return rc;

        if (state == EMPTY)
                *value = EMPTY;
        else if (state == PRESENT)
                *value = slot->state;

        return 0;
}

static enum pci_bus_speed get_max_bus_speed(struct slot *slot)
{
        enum pci_bus_speed speed;
        switch (slot->type) {
        case 1:
        case 2:
        case 3:
        case 4:
        case 5:
        case 6:
                speed = PCI_SPEED_33MHz;        /* speed for case 1-6 */
                break;
        case 7:
        case 8:
                speed = PCI_SPEED_66MHz;
                break;
        case 11:
        case 14:
                speed = PCI_SPEED_66MHz_PCIX;
                break;
        case 12:
        case 15:
                speed = PCI_SPEED_100MHz_PCIX;
                break;
        case 13:
        case 16:
                speed = PCI_SPEED_133MHz_PCIX;
                break;
        default:
                speed = PCI_SPEED_UNKNOWN;
                break;
        }

        return speed;
}

static int get_children_props(struct device_node *dn, const int **drc_indexes,
                const int **drc_names, const int **drc_types,
                const int **drc_power_domains)
{
        const int *indexes, *names, *types, *domains;

        indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
        names = of_get_property(dn, "ibm,drc-names", NULL);
        types = of_get_property(dn, "ibm,drc-types", NULL);
        domains = of_get_property(dn, "ibm,drc-power-domains", NULL);

        if (!indexes || !names || !types || !domains) {
                /* Slot does not have dynamically-removable children */
                return -EINVAL;
        }
        if (drc_indexes)
                *drc_indexes = indexes;
        if (drc_names)
                /* &drc_names[1] contains NULL terminated slot names */
                *drc_names = names;
        if (drc_types)
                /* &drc_types[1] contains NULL terminated slot types */
                *drc_types = types;
        if (drc_power_domains)
                *drc_power_domains = domains;

        return 0;
}


/* Verify the existence of 'drc_name' and/or 'drc_type' within the
 * current node.  First obtain it's my-drc-index property.  Next,
 * obtain the DRC info from it's parent.  Use the my-drc-index for
 * correlation, and obtain/validate the requested properties.
 */

static int rpaphp_check_drc_props_v1(struct device_node *dn, char *drc_name,
                                char *drc_type, unsigned int my_index)
{
        char *name_tmp, *type_tmp;
        const int *indexes, *names;
        const int *types, *domains;
        int i, rc;

        rc = get_children_props(dn->parent, &indexes, &names, &types, &domains);
        if (rc < 0) {
                return -EINVAL;
        }

        name_tmp = (char *) &names[1];
        type_tmp = (char *) &types[1];

        /* Iterate through parent properties, looking for my-drc-index */
        for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
                if ((unsigned int) indexes[i + 1] == my_index)
                        break;

                name_tmp += (strlen(name_tmp) + 1);
                type_tmp += (strlen(type_tmp) + 1);
        }

        if (((drc_name == NULL) || (drc_name && !strcmp(drc_name, name_tmp))) &&
            ((drc_type == NULL) || (drc_type && !strcmp(drc_type, type_tmp))))
                return 0;

        return -EINVAL;
}

static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
                                char *drc_type, unsigned int my_index)
{
        struct property *info;
        unsigned int entries;
        struct of_drc_info drc;
        const __be32 *value;
        char cell_drc_name[MAX_DRC_NAME_LEN];
        int j, fndit;

        info = of_find_property(dn->parent, "ibm,drc-info", NULL);
        if (info == NULL)
                return -EINVAL;

        value = of_prop_next_u32(info, NULL, &entries);
        if (!value)
                return -EINVAL;

        for (j = 0; j < entries; j++) {
                of_read_drc_info_cell(&info, &value, &drc);

                /* Should now know end of current entry */

                if (my_index > drc.last_drc_index)
                        continue;

                fndit = 1;
                break;
        }
        /* Found it */

        if (fndit)
                sprintf(cell_drc_name, "%s%d", drc.drc_name_prefix, 
                        my_index);

        if (((drc_name == NULL) ||
             (drc_name && !strcmp(drc_name, cell_drc_name))) &&
            ((drc_type == NULL) ||
             (drc_type && !strcmp(drc_type, drc.drc_type))))
                return 0;

        return -EINVAL;
}

int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
                        char *drc_type)
{
        const unsigned int *my_index;

        my_index = of_get_property(dn, "ibm,my-drc-index", NULL);
        if (!my_index) {
                /* Node isn't DLPAR/hotplug capable */
                return -EINVAL;
        }

        if (firmware_has_feature(FW_FEATURE_DRC_INFO))
                return rpaphp_check_drc_props_v2(dn, drc_name, drc_type,
                                                *my_index);
        else
                return rpaphp_check_drc_props_v1(dn, drc_name, drc_type,
                                                *my_index);
}
EXPORT_SYMBOL_GPL(rpaphp_check_drc_props);


static int is_php_type(char *drc_type)
{
        unsigned long value;
        char *endptr;

        /* PCI Hotplug nodes have an integer for drc_type */
        value = simple_strtoul(drc_type, &endptr, 10);
        if (endptr == drc_type)
                return 0;

        return 1;
}

/**
 * is_php_dn() - return 1 if this is a hotpluggable pci slot, else 0
 * @dn: target &device_node
 * @indexes: passed to get_children_props()
 * @names: passed to get_children_props()
 * @types: returned from get_children_props()
 * @power_domains:
 *
 * This routine will return true only if the device node is
 * a hotpluggable slot. This routine will return false
 * for built-in pci slots (even when the built-in slots are
 * dlparable.)
 */
static int is_php_dn(struct device_node *dn, const int **indexes,
                const int **names, const int **types, const int **power_domains)
{
        const int *drc_types;
        int rc;

        rc = get_children_props(dn, indexes, names, &drc_types, power_domains);
        if (rc < 0)
                return 0;

        if (!is_php_type((char *) &drc_types[1]))
                return 0;

        *types = drc_types;
        return 1;
}

/**
 * rpaphp_add_slot -- declare a hotplug slot to the hotplug subsystem.
 * @dn: device node of slot
 *
 * This subroutine will register a hotpluggable slot with the
 * PCI hotplug infrastructure. This routine is typically called
 * during boot time, if the hotplug slots are present at boot time,
 * or is called later, by the dlpar add code, if the slot is
 * being dynamically added during runtime.
 *
 * If the device node points at an embedded (built-in) slot, this
 * routine will just return without doing anything, since embedded
 * slots cannot be hotplugged.
 *
 * To remove a slot, it suffices to call rpaphp_deregister_slot().
 */
int rpaphp_add_slot(struct device_node *dn)
{
        struct slot *slot;
        int retval = 0;
        int i;
        const int *indexes, *names, *types, *power_domains;
        char *name, *type;

        if (!dn->name || strcmp(dn->name, "pci"))
                return 0;

        /* If this is not a hotplug slot, return without doing anything. */
        if (!is_php_dn(dn, &indexes, &names, &types, &power_domains))
                return 0;

        dbg("Entry %s: dn=%pOF\n", __func__, dn);

        /* register PCI devices */
        name = (char *) &names[1];
        type = (char *) &types[1];
        for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
                int index;

                index = be32_to_cpu(indexes[i + 1]);
                slot = alloc_slot_struct(dn, index, name,
                                         be32_to_cpu(power_domains[i + 1]));
                if (!slot)
                        return -ENOMEM;

                slot->type = simple_strtoul(type, NULL, 10);

                dbg("Found drc-index:0x%x drc-name:%s drc-type:%s\n",
                                index, name, type);

                retval = rpaphp_enable_slot(slot);
                if (!retval)
                        retval = rpaphp_register_slot(slot);

                if (retval)
                        dealloc_slot_struct(slot);

                name += strlen(name) + 1;
                type += strlen(type) + 1;
        }
        dbg("%s - Exit: rc[%d]\n", __func__, retval);

        /* XXX FIXME: reports a failure only if last entry in loop failed */
        return retval;
}
EXPORT_SYMBOL_GPL(rpaphp_add_slot);

static void __exit cleanup_slots(void)
{
        struct slot *slot, *next;

        /*
         * Unregister all of our slots with the pci_hotplug subsystem,
         * and free up all memory that we had allocated.
         * memory will be freed in release_slot callback.
         */

        list_for_each_entry_safe(slot, next, &rpaphp_slot_head,
                                 rpaphp_slot_list) {
                list_del(&slot->rpaphp_slot_list);
                pci_hp_deregister(slot->hotplug_slot);
        }
        return;
}

static int __init rpaphp_init(void)
{
        struct device_node *dn;

        info(DRIVER_DESC " version: " DRIVER_VERSION "\n");

        for_each_node_by_name(dn, "pci")
                rpaphp_add_slot(dn);

        return 0;
}

static void __exit rpaphp_exit(void)
{
        cleanup_slots();
}

static int enable_slot(struct hotplug_slot *hotplug_slot)
{
        struct slot *slot = (struct slot *)hotplug_slot->private;
        int state;
        int retval;

        if (slot->state == CONFIGURED)
                return 0;

        retval = rpaphp_get_sensor_state(slot, &state);
        if (retval)
                return retval;

        if (state == PRESENT) {
                pci_lock_rescan_remove();
                pci_hp_add_devices(slot->bus);
                pci_unlock_rescan_remove();
                slot->state = CONFIGURED;
        } else if (state == EMPTY) {
                slot->state = EMPTY;
        } else {
                err("%s: slot[%s] is in invalid state\n", __func__, slot->name);
                slot->state = NOT_VALID;
                return -EINVAL;
        }

        slot->bus->max_bus_speed = get_max_bus_speed(slot);
        return 0;
}

static int disable_slot(struct hotplug_slot *hotplug_slot)
{
        struct slot *slot = (struct slot *)hotplug_slot->private;
        if (slot->state == NOT_CONFIGURED)
                return -EINVAL;

        pci_lock_rescan_remove();
        pci_hp_remove_devices(slot->bus);
        pci_unlock_rescan_remove();
        vm_unmap_aliases();

        slot->state = NOT_CONFIGURED;
        return 0;
}

struct hotplug_slot_ops rpaphp_hotplug_slot_ops = {
        .enable_slot = enable_slot,
        .disable_slot = disable_slot,
        .set_attention_status = set_attention_status,
        .get_power_status = get_power_status,
        .get_attention_status = get_attention_status,
        .get_adapter_status = get_adapter_status,
};

module_init(rpaphp_init);
module_exit(rpaphp_exit);