// SPDX-License-Identifier: GPL-2.0
/*
 * manager.c - Resource Management, Conflict Resolution, Activation and Disabling of Devices
 *
 * based on isapnp.c resource management (c) Jaroslav Kysela <perex@perex.cz>
 * Copyright 2003 Adam Belay <ambx1@neo.rr.com>
 * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
 *      Bjorn Helgaas <bjorn.helgaas@hp.com>
 */

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/pnp.h>
#include <linux/bitmap.h>
#include <linux/mutex.h>
#include "base.h"

DEFINE_MUTEX(pnp_res_mutex);

static struct resource *pnp_find_resource(struct pnp_dev *dev,
                                          unsigned char rule,
                                          unsigned long type,
                                          unsigned int bar)
{
        struct resource *res = pnp_get_resource(dev, type, bar);

        /* when the resource already exists, set its resource bits from rule */
        if (res) {
                res->flags &= ~IORESOURCE_BITS;
                res->flags |= rule & IORESOURCE_BITS;
        }

        return res;
}

static int pnp_assign_port(struct pnp_dev *dev, struct pnp_port *rule, int idx)
{
        struct resource *res, local_res;

        res = pnp_find_resource(dev, rule->flags, IORESOURCE_IO, idx);
        if (res) {
                pnp_dbg(&dev->dev, "  io %d already set to %#llx-%#llx "
                        "flags %#lx\n", idx, (unsigned long long) res->start,
                        (unsigned long long) res->end, res->flags);
                return 0;
        }

        res = &local_res;
        res->flags = rule->flags | IORESOURCE_AUTO;
        res->start = 0;
        res->end = 0;

        if (!rule->size) {
                res->flags |= IORESOURCE_DISABLED;
                pnp_dbg(&dev->dev, "  io %d disabled\n", idx);
                goto __add;
        }

        res->start = rule->min;
        res->end = res->start + rule->size - 1;

        while (!pnp_check_port(dev, res)) {
                res->start += rule->align;
                res->end = res->start + rule->size - 1;
                if (res->start > rule->max || !rule->align) {
                        pnp_dbg(&dev->dev, "  couldn't assign io %d "
                                "(min %#llx max %#llx)\n", idx,
                                (unsigned long long) rule->min,
                                (unsigned long long) rule->max);
                        return -EBUSY;
                }
        }

__add:
        pnp_add_io_resource(dev, res->start, res->end, res->flags);
        return 0;
}

static int pnp_assign_mem(struct pnp_dev *dev, struct pnp_mem *rule, int idx)
{
        struct resource *res, local_res;

        res = pnp_find_resource(dev, rule->flags, IORESOURCE_MEM, idx);
        if (res) {
                pnp_dbg(&dev->dev, "  mem %d already set to %#llx-%#llx "
                        "flags %#lx\n", idx, (unsigned long long) res->start,
                        (unsigned long long) res->end, res->flags);
                return 0;
        }

        res = &local_res;
        res->flags = rule->flags | IORESOURCE_AUTO;
        res->start = 0;
        res->end = 0;

        /* ??? rule->flags restricted to 8 bits, all tests bogus ??? */
        if (!(rule->flags & IORESOURCE_MEM_WRITEABLE))
                res->flags |= IORESOURCE_READONLY;
        if (rule->flags & IORESOURCE_MEM_RANGELENGTH)
                res->flags |= IORESOURCE_RANGELENGTH;
        if (rule->flags & IORESOURCE_MEM_SHADOWABLE)
                res->flags |= IORESOURCE_SHADOWABLE;

        if (!rule->size) {
                res->flags |= IORESOURCE_DISABLED;
                pnp_dbg(&dev->dev, "  mem %d disabled\n", idx);
                goto __add;
        }

        res->start = rule->min;
        res->end = res->start + rule->size - 1;

        while (!pnp_check_mem(dev, res)) {
                res->start += rule->align;
                res->end = res->start + rule->size - 1;
                if (res->start > rule->max || !rule->align) {
                        pnp_dbg(&dev->dev, "  couldn't assign mem %d "
                                "(min %#llx max %#llx)\n", idx,
                                (unsigned long long) rule->min,
                                (unsigned long long) rule->max);
                        return -EBUSY;
                }
        }

__add:
        pnp_add_mem_resource(dev, res->start, res->end, res->flags);
        return 0;
}

static int pnp_assign_irq(struct pnp_dev *dev, struct pnp_irq *rule, int idx)
{
        struct resource *res, local_res;
        int i;

        /* IRQ priority: this table is good for i386 */
        static unsigned short xtab[16] = {
                5, 10, 11, 12, 9, 14, 15, 7, 3, 4, 13, 0, 1, 6, 8, 2
        };

        res = pnp_find_resource(dev, rule->flags, IORESOURCE_IRQ, idx);
        if (res) {
                pnp_dbg(&dev->dev, "  irq %d already set to %d flags %#lx\n",
                        idx, (int) res->start, res->flags);
                return 0;
        }

        res = &local_res;
        res->flags = rule->flags | IORESOURCE_AUTO;
        res->start = -1;
        res->end = -1;

        if (bitmap_empty(rule->map.bits, PNP_IRQ_NR)) {
                res->flags |= IORESOURCE_DISABLED;
                pnp_dbg(&dev->dev, "  irq %d disabled\n", idx);
                goto __add;
        }

        /* TBD: need check for >16 IRQ */
        res->start = find_next_bit(rule->map.bits, PNP_IRQ_NR, 16);
        if (res->start < PNP_IRQ_NR) {
                res->end = res->start;
                goto __add;
        }
        for (i = 0; i < 16; i++) {
                if (test_bit(xtab[i], rule->map.bits)) {
                        res->start = res->end = xtab[i];
                        if (pnp_check_irq(dev, res))
                                goto __add;
                }
        }

        if (rule->flags & IORESOURCE_IRQ_OPTIONAL) {
                res->start = -1;
                res->end = -1;
                res->flags |= IORESOURCE_DISABLED;
                pnp_dbg(&dev->dev, "  irq %d disabled (optional)\n", idx);
                goto __add;
        }

        pnp_dbg(&dev->dev, "  couldn't assign irq %d\n", idx);
        return -EBUSY;

__add:
        pnp_add_irq_resource(dev, res->start, res->flags);
        return 0;
}

#ifdef CONFIG_ISA_DMA_API
static int pnp_assign_dma(struct pnp_dev *dev, struct pnp_dma *rule, int idx)
{
        struct resource *res, local_res;
        int i;

        /* DMA priority: this table is good for i386 */
        static unsigned short xtab[8] = {
                1, 3, 5, 6, 7, 0, 2, 4
        };

        res = pnp_find_resource(dev, rule->flags, IORESOURCE_DMA, idx);
        if (res) {
                pnp_dbg(&dev->dev, "  dma %d already set to %d flags %#lx\n",
                        idx, (int) res->start, res->flags);
                return 0;
        }

        res = &local_res;
        res->flags = rule->flags | IORESOURCE_AUTO;
        res->start = -1;
        res->end = -1;

        if (!rule->map) {
                res->flags |= IORESOURCE_DISABLED;
                pnp_dbg(&dev->dev, "  dma %d disabled\n", idx);
                goto __add;
        }

        for (i = 0; i < 8; i++) {
                if (rule->map & (1 << xtab[i])) {
                        res->start = res->end = xtab[i];
                        if (pnp_check_dma(dev, res))
                                goto __add;
                }
        }

        pnp_dbg(&dev->dev, "  couldn't assign dma %d\n", idx);
        return -EBUSY;

__add:
        pnp_add_dma_resource(dev, res->start, res->flags);
        return 0;
}
#endif /* CONFIG_ISA_DMA_API */

void pnp_init_resources(struct pnp_dev *dev)
{
        pnp_free_resources(dev);
}

static void pnp_clean_resource_table(struct pnp_dev *dev)
{
        struct pnp_resource *pnp_res, *tmp;

        list_for_each_entry_safe(pnp_res, tmp, &dev->resources, list) {
                if (pnp_res->res.flags & IORESOURCE_AUTO)
                        pnp_free_resource(pnp_res);
        }
}

/**
 * pnp_assign_resources - assigns resources to the device based on the specified dependent number
 * @dev: pointer to the desired device
 * @set: the dependent function number
 */
static int pnp_assign_resources(struct pnp_dev *dev, int set)
{
        struct pnp_option *option;
        int nport = 0, nmem = 0, nirq = 0;
        int ndma __maybe_unused = 0;
        int ret = 0;

        pnp_dbg(&dev->dev, "pnp_assign_resources, try dependent set %d\n", set);
        mutex_lock(&pnp_res_mutex);
        pnp_clean_resource_table(dev);

        list_for_each_entry(option, &dev->options, list) {
                if (pnp_option_is_dependent(option) &&
                    pnp_option_set(option) != set)
                                continue;

                switch (option->type) {
                case IORESOURCE_IO:
                        ret = pnp_assign_port(dev, &option->u.port, nport++);
                        break;
                case IORESOURCE_MEM:
                        ret = pnp_assign_mem(dev, &option->u.mem, nmem++);
                        break;
                case IORESOURCE_IRQ:
                        ret = pnp_assign_irq(dev, &option->u.irq, nirq++);
                        break;
#ifdef CONFIG_ISA_DMA_API
                case IORESOURCE_DMA:
                        ret = pnp_assign_dma(dev, &option->u.dma, ndma++);
                        break;
#endif
                default:
                        ret = -EINVAL;
                        break;
                }
                if (ret < 0)
                        break;
        }

        mutex_unlock(&pnp_res_mutex);
        if (ret < 0) {
                pnp_dbg(&dev->dev, "pnp_assign_resources failed (%d)\n", ret);
                pnp_clean_resource_table(dev);
        } else
                dbg_pnp_show_resources(dev, "pnp_assign_resources succeeded");
        return ret;
}

/**
 * pnp_auto_config_dev - automatically assigns resources to a device
 * @dev: pointer to the desired device
 */
int pnp_auto_config_dev(struct pnp_dev *dev)
{
        int i, ret;

        if (!pnp_can_configure(dev)) {
                pnp_dbg(&dev->dev, "configuration not supported\n");
                return -ENODEV;
        }

        ret = pnp_assign_resources(dev, 0);
        if (ret == 0)
                return 0;

        for (i = 1; i < dev->num_dependent_sets; i++) {
                ret = pnp_assign_resources(dev, i);
                if (ret == 0)
                        return 0;
        }

        dev_err(&dev->dev, "unable to assign resources\n");
        return ret;
}

/**
 * pnp_start_dev - low-level start of the PnP device
 * @dev: pointer to the desired device
 *
 * assumes that resources have already been allocated
 */
int pnp_start_dev(struct pnp_dev *dev)
{
        if (!pnp_can_write(dev)) {
                pnp_dbg(&dev->dev, "activation not supported\n");
                return -EINVAL;
        }

        dbg_pnp_show_resources(dev, "pnp_start_dev");
        if (dev->protocol->set(dev) < 0) {
                dev_err(&dev->dev, "activation failed\n");
                return -EIO;
        }

        dev_info(&dev->dev, "activated\n");
        return 0;
}

/**
 * pnp_stop_dev - low-level disable of the PnP device
 * @dev: pointer to the desired device
 *
 * does not free resources
 */
int pnp_stop_dev(struct pnp_dev *dev)
{
        if (!pnp_can_disable(dev)) {
                pnp_dbg(&dev->dev, "disabling not supported\n");
                return -EINVAL;
        }
        if (dev->protocol->disable(dev) < 0) {
                dev_err(&dev->dev, "disable failed\n");
                return -EIO;
        }

        dev_info(&dev->dev, "disabled\n");
        return 0;
}

/**
 * pnp_activate_dev - activates a PnP device for use
 * @dev: pointer to the desired device
 *
 * does not validate or set resources so be careful.
 */
int pnp_activate_dev(struct pnp_dev *dev)
{
        int error;

        if (dev->active)
                return 0;

        /* ensure resources are allocated */
        if (pnp_auto_config_dev(dev))
                return -EBUSY;

        error = pnp_start_dev(dev);
        if (error)
                return error;

        dev->active = 1;
        return 0;
}

/**
 * pnp_disable_dev - disables device
 * @dev: pointer to the desired device
 *
 * inform the correct pnp protocol so that resources can be used by other devices
 */
int pnp_disable_dev(struct pnp_dev *dev)
{
        int error;

        if (!dev->active)
                return 0;

        error = pnp_stop_dev(dev);
        if (error)
                return error;

        dev->active = 0;

        /* release the resources so that other devices can use them */
        mutex_lock(&pnp_res_mutex);
        pnp_clean_resource_table(dev);
        mutex_unlock(&pnp_res_mutex);

        return 0;
}

EXPORT_SYMBOL(pnp_start_dev);
EXPORT_SYMBOL(pnp_stop_dev);
EXPORT_SYMBOL(pnp_activate_dev);
EXPORT_SYMBOL(pnp_disable_dev);