/*
 * Freescale MC object device allocator driver
 *
 * Copyright (C) 2013 Freescale Semiconductor, Inc.
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include "../include/mc-private.h"
#include "../include/mc-sys.h"
#include <linux/module.h>
#include "../include/dpbp-cmd.h"
#include "../include/dpcon-cmd.h"
#include "dpmcp-cmd.h"
#include "dpmcp.h"

/**
 * fsl_mc_resource_pool_add_device - add allocatable device to a resource
 * pool of a given MC bus
 *
 * @mc_bus: pointer to the MC bus
 * @pool_type: MC bus pool type
 * @mc_dev: Pointer to allocatable MC object device
 *
 * It adds an allocatable MC object device to a container's resource pool of
 * the given resource type
 */
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;
        bool mutex_locked = false;

        if (WARN_ON(pool_type < 0 || pool_type >= FSL_MC_NUM_POOL_TYPES))
                goto out;
        if (WARN_ON(!FSL_MC_IS_ALLOCATABLE(mc_dev->obj_desc.type)))
                goto out;
        if (WARN_ON(mc_dev->resource))
                goto out;

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

        mutex_lock(&res_pool->mutex);
        mutex_locked = true;

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

        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;
        }

        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:
        if (mutex_locked)
                mutex_unlock(&res_pool->mutex);

        return error;
}

/**
 * fsl_mc_resource_pool_remove_device - remove an allocatable device from a
 * resource pool
 *
 * @mc_dev: Pointer to allocatable MC object device
 *
 * It permanently removes an allocatable MC object device from the resource
 * pool, the device is currently in, as long as it is in the pool's free list.
 */
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;
        bool mutex_locked = false;

        if (WARN_ON(!FSL_MC_IS_ALLOCATABLE(mc_dev->obj_desc.type)))
                goto out;

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

        mutex_lock(&res_pool->mutex);
        mutex_locked = true;

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

        /*
         * 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;
        }

        list_del(&resource->node);
        INIT_LIST_HEAD(&resource->node);
        res_pool->free_count--;
        res_pool->max_count--;

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

        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",
};

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;
        bool mutex_locked = false;

        BUILD_BUG_ON(ARRAY_SIZE(fsl_mc_pool_type_strings) !=
                     FSL_MC_NUM_POOL_TYPES);

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

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

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

        if (!resource) {
                WARN_ON(res_pool->free_count != 0);
                error = -ENXIO;
                dev_err(&mc_bus_dev->dev,
                        "No more resources of type %s left\n",
                        fsl_mc_pool_type_strings[pool_type]);
                goto error;
        }

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

        list_del(&resource->node);
        INIT_LIST_HEAD(&resource->node);

        res_pool->free_count--;
        mutex_unlock(&res_pool->mutex);
        *new_resource = resource;
        return 0;
error:
        if (mutex_locked)
                mutex_unlock(&res_pool->mutex);

        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;
        bool mutex_locked = false;

        res_pool = resource->parent_pool;
        if (WARN_ON(resource->type != res_pool->type))
                goto out;

        mutex_lock(&res_pool->mutex);
        mutex_locked = true;
        if (WARN_ON(res_pool->free_count < 0 ||
                    res_pool->free_count >= res_pool->max_count))
                goto out;

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

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

/**
 * fsl_mc_portal_allocate - Allocates an MC portal
 *
 * @mc_dev: MC device for which the MC portal is to be allocated
 * @mc_io_flags: Flags for the fsl_mc_io object that wraps the allocated
 * MC portal.
 * @new_mc_io: Pointer to area where the pointer to the fsl_mc_io object
 * that wraps the allocated MC portal is to be returned
 *
 * This function allocates an MC portal from the device's parent DPRC,
 * from the corresponding MC bus' pool of MC portals and wraps
 * it in a new fsl_mc_io object. If 'mc_dev' is a DPRC itself, the
 * portal is allocated from its own MC bus.
 */
int __must_check fsl_mc_portal_allocate(struct fsl_mc_device *mc_dev,
                                        uint16_t mc_io_flags,
                                        struct fsl_mc_io **new_mc_io)
{
        struct fsl_mc_device *mc_bus_dev;
        struct fsl_mc_bus *mc_bus;
        phys_addr_t mc_portal_phys_addr;
        size_t mc_portal_size;
        struct fsl_mc_device *mc_adev;
        int error = -EINVAL;
        struct fsl_mc_resource *resource = NULL;
        struct fsl_mc_io *mc_io = NULL;

        if (mc_dev->flags & FSL_MC_IS_DPRC) {
                mc_bus_dev = mc_dev;
        } else {
                if (WARN_ON(mc_dev->dev.parent->bus != &fsl_mc_bus_type))
                        return error;

                mc_bus_dev = to_fsl_mc_device(mc_dev->dev.parent);
        }

        mc_bus = to_fsl_mc_bus(mc_bus_dev);
        *new_mc_io = NULL;
        error = fsl_mc_resource_allocate(mc_bus, FSL_MC_POOL_DPMCP, &resource);
        if (error < 0)
                return error;

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

        if (WARN_ON(mc_adev->obj_desc.region_count == 0))
                goto error_cleanup_resource;

        mc_portal_phys_addr = mc_adev->regions[0].start;
        mc_portal_size = mc_adev->regions[0].end -
                         mc_adev->regions[0].start + 1;

        if (WARN_ON(mc_portal_size != mc_bus_dev->mc_io->portal_size))
                goto error_cleanup_resource;

        error = fsl_create_mc_io(&mc_bus_dev->dev,
                                 mc_portal_phys_addr,
                                 mc_portal_size, resource,
                                 mc_io_flags, &mc_io);
        if (error < 0)
                goto error_cleanup_resource;

        *new_mc_io = mc_io;
        return 0;

error_cleanup_resource:
        fsl_mc_resource_free(resource);
        return error;
}
EXPORT_SYMBOL_GPL(fsl_mc_portal_allocate);

/**
 * fsl_mc_portal_free - Returns an MC portal to the pool of free MC portals
 * of a given MC bus
 *
 * @mc_io: Pointer to the fsl_mc_io object that wraps the MC portal to free
 */
void fsl_mc_portal_free(struct fsl_mc_io *mc_io)
{
        struct fsl_mc_resource *resource;

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

        fsl_destroy_mc_io(mc_io);
        fsl_mc_resource_free(resource);
}
EXPORT_SYMBOL_GPL(fsl_mc_portal_free);

/**
 * fsl_mc_portal_reset - Resets the dpmcp object for a given fsl_mc_io object
 *
 * @mc_io: Pointer to the fsl_mc_io object that wraps the MC portal to free
 */
int fsl_mc_portal_reset(struct fsl_mc_io *mc_io)
{
        int error;
        uint16_t token;
        struct fsl_mc_resource *resource = mc_io->resource;
        struct fsl_mc_device *mc_dev = resource->data;

        if (WARN_ON(resource->type != FSL_MC_POOL_DPMCP))
                return -EINVAL;

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

        error = dpmcp_open(mc_io, mc_dev->obj_desc.id, &token);
        if (error < 0) {
                dev_err(&mc_dev->dev, "dpmcp_open() failed: %d\n", error);
                return error;
        }

        error = dpmcp_reset(mc_io, token);
        if (error < 0) {
                dev_err(&mc_dev->dev, "dpmcp_reset() failed: %d\n", error);
                return error;
        }

        error = dpmcp_close(mc_io, token);
        if (error < 0) {
                dev_err(&mc_dev->dev, "dpmcp_close() failed: %d\n", error);
                return error;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(fsl_mc_portal_reset);

/**
 * fsl_mc_object_allocate - Allocates a MC object device of the given
 * pool type from a given MC bus
 *
 * @mc_dev: MC device for which the MC object device is to be allocated
 * @pool_type: MC bus resource pool type
 * @new_mc_dev: Pointer to area where the pointer to the allocated
 * MC object device is to be returned
 *
 * This function allocates a MC object device from the device's parent DPRC,
 * from the corresponding MC bus' pool of allocatable MC object devices of
 * the given resource type. mc_dev cannot be a DPRC itself.
 *
 * 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 (WARN_ON(mc_dev->flags & FSL_MC_IS_DPRC))
                goto error;

        if (WARN_ON(mc_dev->dev.parent->bus != &fsl_mc_bus_type))
                goto error;

        if (WARN_ON(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 (WARN_ON(!mc_adev))
                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 allocatable MC object device to the
 * corresponding resource pool of a given MC bus.
 *
 * @mc_adev: Pointer to the MC object device
 */
void fsl_mc_object_free(struct fsl_mc_device *mc_adev)
{
        struct fsl_mc_resource *resource;

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

        fsl_mc_resource_free(resource);
}
EXPORT_SYMBOL_GPL(fsl_mc_object_free);

/**
 * 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 = -EINVAL;

        if (WARN_ON(!FSL_MC_IS_ALLOCATABLE(mc_dev->obj_desc.type)))
                goto error;

        mc_bus_dev = to_fsl_mc_device(mc_dev->dev.parent);
        if (WARN_ON(mc_bus_dev->dev.bus != &fsl_mc_bus_type))
                goto error;

        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)
                goto error;

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

        dev_info(&mc_dev->dev,
                 "Allocatable MC object device bound to fsl_mc_allocator driver");
        return 0;
error:

        return error;
}

/**
 * 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 = -EINVAL;

        if (WARN_ON(!FSL_MC_IS_ALLOCATABLE(mc_dev->obj_desc.type)))
                goto out;

        error = fsl_mc_resource_pool_remove_device(mc_dev);
        if (error < 0)
                goto out;

        dev_info(&mc_dev->dev,
                 "Allocatable MC object device unbound from fsl_mc_allocator driver");
        error = 0;
out:
        return error;
}

static const struct fsl_mc_device_match_id match_id_table[] = {
        {
         .vendor = FSL_MC_VENDOR_FREESCALE,
         .obj_type = "dpbp",
         .ver_major = DPBP_VER_MAJOR,
         .ver_minor = DPBP_VER_MINOR
        },
        {
         .vendor = FSL_MC_VENDOR_FREESCALE,
         .obj_type = "dpmcp",
         .ver_major = DPMCP_VER_MAJOR,
         .ver_minor = DPMCP_VER_MINOR
        },
        {
         .vendor = FSL_MC_VENDOR_FREESCALE,
         .obj_type = "dpcon",
         .ver_major = DPCON_VER_MAJOR,
         .ver_minor = DPCON_VER_MINOR
        },
        {.vendor = 0x0},
};

static struct fsl_mc_driver fsl_mc_allocator_driver = {
        .driver = {
                   .name = "fsl_mc_allocator",
                   .owner = THIS_MODULE,
                   .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 __exit fsl_mc_allocator_driver_exit(void)
{
        fsl_mc_driver_unregister(&fsl_mc_allocator_driver);
}