// SPDX-License-Identifier: GPL-2.0
/*
 * fsl-mc object allocator driver
 *
 * Copyright (C) 2013-2016 Freescale Semiconductor, Inc.
 *
 */

#include <linux/module.h>
#include <linux/msi.h>
#include <linux/fsl/mc.h>

#include "fsl-mc-private.h"

static bool __must_check fsl_mc_is_allocatable(struct fsl_mc_device *mc_dev)
{
        return is_fsl_mc_bus_dpbp(mc_dev) ||
               is_fsl_mc_bus_dpmcp(mc_dev) ||
               is_fsl_mc_bus_dpcon(mc_dev);
}

/**
 * fsl_mc_resource_pool_add_device - add allocatable object to a resource
 * pool of a given fsl-mc bus
 *
 * @mc_bus: pointer to the fsl-mc bus
 * @pool_type: pool type
 * @mc_dev: pointer to allocatable fsl-mc device
 */
static int __must_check fsl_mc_resource_pool_add_device(struct fsl_mc_bus
                                                                *mc_bus,
                                                        enum fsl_mc_pool_type
                                                                pool_type,
                                                        struct fsl_mc_device
                                                                *mc_dev)
{
        struct fsl_mc_resource_pool *res_pool;
        struct fsl_mc_resource *resource;
        struct fsl_mc_device *mc_bus_dev = &mc_bus->mc_dev;
        int error = -EINVAL;

        if (pool_type < 0 || pool_type >= FSL_MC_NUM_POOL_TYPES)
                goto out;
        if (!fsl_mc_is_allocatable(mc_dev))
                goto out;
        if (mc_dev->resource)
                goto out;

        res_pool = &mc_bus->resource_pools[pool_type];
        if (res_pool->type != pool_type)
                goto out;
        if (res_pool->mc_bus != mc_bus)
                goto out;

        mutex_lock(&res_pool->mutex);

        if (res_pool->max_count < 0)
                goto out_unlock;
        if (res_pool->free_count < 0 ||
            res_pool->free_count > res_pool->max_count)
                goto out_unlock;

        resource = devm_kzalloc(&mc_bus_dev->dev, sizeof(*resource),
                                GFP_KERNEL);
        if (!resource) {
                error = -ENOMEM;
                dev_err(&mc_bus_dev->dev,
                        "Failed to allocate memory for fsl_mc_resource\n");
                goto out_unlock;
        }

        resource->type = pool_type;
        resource->id = mc_dev->obj_desc.id;
        resource->data = mc_dev;
        resource->parent_pool = res_pool;
        INIT_LIST_HEAD(&resource->node);
        list_add_tail(&resource->node, &res_pool->free_list);
        mc_dev->resource = resource;
        res_pool->free_count++;
        res_pool->max_count++;
        error = 0;
out_unlock:
        mutex_unlock(&res_pool->mutex);
out:
        return error;
}

/**
 * fsl_mc_resource_pool_remove_device - remove an allocatable device from a
 * resource pool
 *
 * @mc_dev: pointer to allocatable fsl-mc device
 *
 * It permanently removes an allocatable fsl-mc device from the resource
 * pool. It's an error if the device is in use.
 */
static int __must_check fsl_mc_resource_pool_remove_device(struct fsl_mc_device
                                                                   *mc_dev)
{
        struct fsl_mc_device *mc_bus_dev;
        struct fsl_mc_bus *mc_bus;
        struct fsl_mc_resource_pool *res_pool;
        struct fsl_mc_resource *resource;
        int error = -EINVAL;

        if (!fsl_mc_is_allocatable(mc_dev))
                goto out;

        resource = mc_dev->resource;
        if (!resource || resource->data != mc_dev)
                goto out;

        mc_bus_dev = to_fsl_mc_device(mc_dev->dev.parent);
        mc_bus = to_fsl_mc_bus(mc_bus_dev);
        res_pool = resource->parent_pool;
        if (res_pool != &mc_bus->resource_pools[resource->type])
                goto out;

        mutex_lock(&res_pool->mutex);

        if (res_pool->max_count <= 0)
                goto out_unlock;
        if (res_pool->free_count <= 0 ||
            res_pool->free_count > res_pool->max_count)
                goto out_unlock;

        /*
         * If the device is currently allocated, its resource is not
         * in the free list and thus, the device cannot be removed.
         */
        if (list_empty(&resource->node)) {
                error = -EBUSY;
                dev_err(&mc_bus_dev->dev,
                        "Device %s cannot be removed from resource pool\n",
                        dev_name(&mc_dev->dev));
                goto out_unlock;
        }

        list_del_init(&resource->node);
        res_pool->free_count--;
        res_pool->max_count--;

        devm_kfree(&mc_bus_dev->dev, resource);
        mc_dev->resource = NULL;
        error = 0;
out_unlock:
        mutex_unlock(&res_pool->mutex);
out:
        return error;
}

static const char *const fsl_mc_pool_type_strings[] = {
        [FSL_MC_POOL_DPMCP] = "dpmcp",
        [FSL_MC_POOL_DPBP] = "dpbp",
        [FSL_MC_POOL_DPCON] = "dpcon",
        [FSL_MC_POOL_IRQ] = "irq",
};

static int __must_check object_type_to_pool_type(const char *object_type,
                                                 enum fsl_mc_pool_type
                                                                *pool_type)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(fsl_mc_pool_type_strings); i++) {
                if (strcmp(object_type, fsl_mc_pool_type_strings[i]) == 0) {
                        *pool_type = i;
                        return 0;
                }
        }

        return -EINVAL;
}

int __must_check fsl_mc_resource_allocate(struct fsl_mc_bus *mc_bus,
                                          enum fsl_mc_pool_type pool_type,
                                          struct fsl_mc_resource **new_resource)
{
        struct fsl_mc_resource_pool *res_pool;
        struct fsl_mc_resource *resource;
        struct fsl_mc_device *mc_bus_dev = &mc_bus->mc_dev;
        int error = -EINVAL;

        BUILD_BUG_ON(ARRAY_SIZE(fsl_mc_pool_type_strings) !=
                     FSL_MC_NUM_POOL_TYPES);

        *new_resource = NULL;
        if (pool_type < 0 || pool_type >= FSL_MC_NUM_POOL_TYPES)
                goto out;

        res_pool = &mc_bus->resource_pools[pool_type];
        if (res_pool->mc_bus != mc_bus)
                goto out;

        mutex_lock(&res_pool->mutex);
        resource = list_first_entry_or_null(&res_pool->free_list,
                                            struct fsl_mc_resource, node);

        if (!resource) {
                error = -ENXIO;
                dev_err(&mc_bus_dev->dev,
                        "No more resources of type %s left\n",
                        fsl_mc_pool_type_strings[pool_type]);
                goto out_unlock;
        }

        if (resource->type != pool_type)
                goto out_unlock;
        if (resource->parent_pool != res_pool)
                goto out_unlock;
        if (res_pool->free_count <= 0 ||
            res_pool->free_count > res_pool->max_count)
                goto out_unlock;

        list_del_init(&resource->node);

        res_pool->free_count--;
        error = 0;
out_unlock:
        mutex_unlock(&res_pool->mutex);
        *new_resource = resource;
out:
        return error;
}
EXPORT_SYMBOL_GPL(fsl_mc_resource_allocate);

void fsl_mc_resource_free(struct fsl_mc_resource *resource)
{
        struct fsl_mc_resource_pool *res_pool;

        res_pool = resource->parent_pool;
        if (resource->type != res_pool->type)
                return;

        mutex_lock(&res_pool->mutex);
        if (res_pool->free_count < 0 ||
            res_pool->free_count >= res_pool->max_count)
                goto out_unlock;

        if (!list_empty(&resource->node))
                goto out_unlock;

        list_add_tail(&resource->node, &res_pool->free_list);
        res_pool->free_count++;
out_unlock:
        mutex_unlock(&res_pool->mutex);
}
EXPORT_SYMBOL_GPL(fsl_mc_resource_free);

/**
 * fsl_mc_object_allocate - Allocates an fsl-mc object of the given
 * pool type from a given fsl-mc bus instance
 *
 * @mc_dev: fsl-mc device which is used in conjunction with the
 * allocated object
 * @pool_type: pool type
 * @new_mc_dev: pointer to area where the pointer to the allocated device
 * is to be returned
 *
 * Allocatable objects are always used in conjunction with some functional
 * device.  This function allocates an object of the specified type from
 * the DPRC containing the functional device.
 *
 * NOTE: pool_type must be different from FSL_MC_POOL_MCP, since MC
 * portals are allocated using fsl_mc_portal_allocate(), instead of
 * this function.
 */
int __must_check fsl_mc_object_allocate(struct fsl_mc_device *mc_dev,
                                        enum fsl_mc_pool_type pool_type,
                                        struct fsl_mc_device **new_mc_adev)
{
        struct fsl_mc_device *mc_bus_dev;
        struct fsl_mc_bus *mc_bus;
        struct fsl_mc_device *mc_adev;
        int error = -EINVAL;
        struct fsl_mc_resource *resource = NULL;

        *new_mc_adev = NULL;
        if (mc_dev->flags & FSL_MC_IS_DPRC)
                goto error;

        if (!dev_is_fsl_mc(mc_dev->dev.parent))
                goto error;

        if (pool_type == FSL_MC_POOL_DPMCP)
                goto error;

        mc_bus_dev = to_fsl_mc_device(mc_dev->dev.parent);
        mc_bus = to_fsl_mc_bus(mc_bus_dev);
        error = fsl_mc_resource_allocate(mc_bus, pool_type, &resource);
        if (error < 0)
                goto error;

        mc_adev = resource->data;
        if (!mc_adev)
                goto error;

        mc_adev->consumer_link = device_link_add(&mc_dev->dev,
                                                 &mc_adev->dev,
                                                 DL_FLAG_AUTOREMOVE_CONSUMER);
        if (!mc_adev->consumer_link) {
                error = -EINVAL;
                goto error;
        }

        *new_mc_adev = mc_adev;
        return 0;
error:
        if (resource)
                fsl_mc_resource_free(resource);

        return error;
}
EXPORT_SYMBOL_GPL(fsl_mc_object_allocate);

/**
 * fsl_mc_object_free - Returns an fsl-mc object to the resource
 * pool where it came from.
 * @mc_adev: Pointer to the fsl-mc device
 */
void fsl_mc_object_free(struct fsl_mc_device *mc_adev)
{
        struct fsl_mc_resource *resource;

        resource = mc_adev->resource;
        if (resource->type == FSL_MC_POOL_DPMCP)
                return;
        if (resource->data != mc_adev)
                return;

        fsl_mc_resource_free(resource);

        device_link_del(mc_adev->consumer_link);
        mc_adev->consumer_link = NULL;
}
EXPORT_SYMBOL_GPL(fsl_mc_object_free);

/*
 * A DPRC and the devices in the DPRC all share the same GIC-ITS device
 * ID.  A block of IRQs is pre-allocated and maintained in a pool
 * from which devices can allocate them when needed.
 */

/*
 * Initialize the interrupt pool associated with an fsl-mc bus.
 * It allocates a block of IRQs from the GIC-ITS.
 */
int fsl_mc_populate_irq_pool(struct fsl_mc_bus *mc_bus,
                             unsigned int irq_count)
{
        unsigned int i;
        struct msi_desc *msi_desc;
        struct fsl_mc_device_irq *irq_resources;
        struct fsl_mc_device_irq *mc_dev_irq;
        int error;
        struct fsl_mc_device *mc_bus_dev = &mc_bus->mc_dev;
        struct fsl_mc_resource_pool *res_pool =
                        &mc_bus->resource_pools[FSL_MC_POOL_IRQ];

        if (irq_count == 0 ||
            irq_count > FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS)
                return -EINVAL;

        error = fsl_mc_msi_domain_alloc_irqs(&mc_bus_dev->dev, irq_count);
        if (error < 0)
                return error;

        irq_resources = devm_kcalloc(&mc_bus_dev->dev,
                                     irq_count, sizeof(*irq_resources),
                                     GFP_KERNEL);
        if (!irq_resources) {
                error = -ENOMEM;
                goto cleanup_msi_irqs;
        }

        for (i = 0; i < irq_count; i++) {
                mc_dev_irq = &irq_resources[i];

                /*
                 * NOTE: This mc_dev_irq's MSI addr/value pair will be set
                 * by the fsl_mc_msi_write_msg() callback
                 */
                mc_dev_irq->resource.type = res_pool->type;
                mc_dev_irq->resource.data = mc_dev_irq;
                mc_dev_irq->resource.parent_pool = res_pool;
                INIT_LIST_HEAD(&mc_dev_irq->resource.node);
                list_add_tail(&mc_dev_irq->resource.node, &res_pool->free_list);
        }

        for_each_msi_entry(msi_desc, &mc_bus_dev->dev) {
                mc_dev_irq = &irq_resources[msi_desc->fsl_mc.msi_index];
                mc_dev_irq->msi_desc = msi_desc;
                mc_dev_irq->resource.id = msi_desc->irq;
        }

        res_pool->max_count = irq_count;
        res_pool->free_count = irq_count;
        mc_bus->irq_resources = irq_resources;
        return 0;

cleanup_msi_irqs:
        fsl_mc_msi_domain_free_irqs(&mc_bus_dev->dev);
        return error;
}
EXPORT_SYMBOL_GPL(fsl_mc_populate_irq_pool);

/**
 * Teardown the interrupt pool associated with an fsl-mc bus.
 * It frees the IRQs that were allocated to the pool, back to the GIC-ITS.
 */
void fsl_mc_cleanup_irq_pool(struct fsl_mc_bus *mc_bus)
{
        struct fsl_mc_device *mc_bus_dev = &mc_bus->mc_dev;
        struct fsl_mc_resource_pool *res_pool =
                        &mc_bus->resource_pools[FSL_MC_POOL_IRQ];

        if (!mc_bus->irq_resources)
                return;

        if (res_pool->max_count == 0)
                return;

        if (res_pool->free_count != res_pool->max_count)
                return;

        INIT_LIST_HEAD(&res_pool->free_list);
        res_pool->max_count = 0;
        res_pool->free_count = 0;
        mc_bus->irq_resources = NULL;
        fsl_mc_msi_domain_free_irqs(&mc_bus_dev->dev);
}
EXPORT_SYMBOL_GPL(fsl_mc_cleanup_irq_pool);

/**
 * Allocate the IRQs required by a given fsl-mc device.
 */
int __must_check fsl_mc_allocate_irqs(struct fsl_mc_device *mc_dev)
{
        int i;
        int irq_count;
        int res_allocated_count = 0;
        int error = -EINVAL;
        struct fsl_mc_device_irq **irqs = NULL;
        struct fsl_mc_bus *mc_bus;
        struct fsl_mc_resource_pool *res_pool;

        if (mc_dev->irqs)
                return -EINVAL;

        irq_count = mc_dev->obj_desc.irq_count;
        if (irq_count == 0)
                return -EINVAL;

        if (is_fsl_mc_bus_dprc(mc_dev))
                mc_bus = to_fsl_mc_bus(mc_dev);
        else
                mc_bus = to_fsl_mc_bus(to_fsl_mc_device(mc_dev->dev.parent));

        if (!mc_bus->irq_resources)
                return -EINVAL;

        res_pool = &mc_bus->resource_pools[FSL_MC_POOL_IRQ];
        if (res_pool->free_count < irq_count) {
                dev_err(&mc_dev->dev,
                        "Not able to allocate %u irqs for device\n", irq_count);
                return -ENOSPC;
        }

        irqs = devm_kcalloc(&mc_dev->dev, irq_count, sizeof(irqs[0]),
                            GFP_KERNEL);
        if (!irqs)
                return -ENOMEM;

        for (i = 0; i < irq_count; i++) {
                struct fsl_mc_resource *resource;

                error = fsl_mc_resource_allocate(mc_bus, FSL_MC_POOL_IRQ,
                                                 &resource);
                if (error < 0)
                        goto error_resource_alloc;

                irqs[i] = to_fsl_mc_irq(resource);
                res_allocated_count++;

                irqs[i]->mc_dev = mc_dev;
                irqs[i]->dev_irq_index = i;
        }

        mc_dev->irqs = irqs;
        return 0;

error_resource_alloc:
        for (i = 0; i < res_allocated_count; i++) {
                irqs[i]->mc_dev = NULL;
                fsl_mc_resource_free(&irqs[i]->resource);
        }

        return error;
}
EXPORT_SYMBOL_GPL(fsl_mc_allocate_irqs);

/*
 * Frees the IRQs that were allocated for an fsl-mc device.
 */
void fsl_mc_free_irqs(struct fsl_mc_device *mc_dev)
{
        int i;
        int irq_count;
        struct fsl_mc_bus *mc_bus;
        struct fsl_mc_device_irq **irqs = mc_dev->irqs;

        if (!irqs)
                return;

        irq_count = mc_dev->obj_desc.irq_count;

        if (is_fsl_mc_bus_dprc(mc_dev))
                mc_bus = to_fsl_mc_bus(mc_dev);
        else
                mc_bus = to_fsl_mc_bus(to_fsl_mc_device(mc_dev->dev.parent));

        if (!mc_bus->irq_resources)
                return;

        for (i = 0; i < irq_count; i++) {
                irqs[i]->mc_dev = NULL;
                fsl_mc_resource_free(&irqs[i]->resource);
        }

        mc_dev->irqs = NULL;
}
EXPORT_SYMBOL_GPL(fsl_mc_free_irqs);

void fsl_mc_init_all_resource_pools(struct fsl_mc_device *mc_bus_dev)
{
        int pool_type;
        struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);

        for (pool_type = 0; pool_type < FSL_MC_NUM_POOL_TYPES; pool_type++) {
                struct fsl_mc_resource_pool *res_pool =
                    &mc_bus->resource_pools[pool_type];

                res_pool->type = pool_type;
                res_pool->max_count = 0;
                res_pool->free_count = 0;
                res_pool->mc_bus = mc_bus;
                INIT_LIST_HEAD(&res_pool->free_list);
                mutex_init(&res_pool->mutex);
        }
}

static void fsl_mc_cleanup_resource_pool(struct fsl_mc_device *mc_bus_dev,
                                         enum fsl_mc_pool_type pool_type)
{
        struct fsl_mc_resource *resource;
        struct fsl_mc_resource *next;
        struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
        struct fsl_mc_resource_pool *res_pool =
                                        &mc_bus->resource_pools[pool_type];
        int free_count = 0;

        list_for_each_entry_safe(resource, next, &res_pool->free_list, node) {
                free_count++;
                devm_kfree(&mc_bus_dev->dev, resource);
        }
}

void fsl_mc_cleanup_all_resource_pools(struct fsl_mc_device *mc_bus_dev)
{
        int pool_type;

        for (pool_type = 0; pool_type < FSL_MC_NUM_POOL_TYPES; pool_type++)
                fsl_mc_cleanup_resource_pool(mc_bus_dev, pool_type);
}

/**
 * fsl_mc_allocator_probe - callback invoked when an allocatable device is
 * being added to the system
 */
static int fsl_mc_allocator_probe(struct fsl_mc_device *mc_dev)
{
        enum fsl_mc_pool_type pool_type;
        struct fsl_mc_device *mc_bus_dev;
        struct fsl_mc_bus *mc_bus;
        int error;

        if (!fsl_mc_is_allocatable(mc_dev))
                return -EINVAL;

        mc_bus_dev = to_fsl_mc_device(mc_dev->dev.parent);
        if (!dev_is_fsl_mc(&mc_bus_dev->dev))
                return -EINVAL;

        mc_bus = to_fsl_mc_bus(mc_bus_dev);
        error = object_type_to_pool_type(mc_dev->obj_desc.type, &pool_type);
        if (error < 0)
                return error;

        error = fsl_mc_resource_pool_add_device(mc_bus, pool_type, mc_dev);
        if (error < 0)
                return error;

        dev_dbg(&mc_dev->dev,
                "Allocatable fsl-mc device bound to fsl_mc_allocator driver");
        return 0;
}

/**
 * fsl_mc_allocator_remove - callback invoked when an allocatable device is
 * being removed from the system
 */
static int fsl_mc_allocator_remove(struct fsl_mc_device *mc_dev)
{
        int error;

        if (!fsl_mc_is_allocatable(mc_dev))
                return -EINVAL;

        if (mc_dev->resource) {
                error = fsl_mc_resource_pool_remove_device(mc_dev);
                if (error < 0)
                        return error;
        }

        dev_dbg(&mc_dev->dev,
                "Allocatable fsl-mc device unbound from fsl_mc_allocator driver");
        return 0;
}

static const struct fsl_mc_device_id match_id_table[] = {
        {
         .vendor = FSL_MC_VENDOR_FREESCALE,
         .obj_type = "dpbp",
        },
        {
         .vendor = FSL_MC_VENDOR_FREESCALE,
         .obj_type = "dpmcp",
        },
        {
         .vendor = FSL_MC_VENDOR_FREESCALE,
         .obj_type = "dpcon",
        },
        {.vendor = 0x0},
};

static struct fsl_mc_driver fsl_mc_allocator_driver = {
        .driver = {
                   .name = "fsl_mc_allocator",
                   .pm = NULL,
                   },
        .match_id_table = match_id_table,
        .probe = fsl_mc_allocator_probe,
        .remove = fsl_mc_allocator_remove,
};

int __init fsl_mc_allocator_driver_init(void)
{
        return fsl_mc_driver_register(&fsl_mc_allocator_driver);
}

void fsl_mc_allocator_driver_exit(void)
{
        fsl_mc_driver_unregister(&fsl_mc_allocator_driver);
}