/*
 * Copyright 2015 Advanced Micro Devices, Inc.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 */
/*
 * Authors:
 *    Christian König <deathsimple@vodafone.de>
 */

#include <linux/uaccess.h>

#include "amdgpu.h"
#include "amdgpu_trace.h"

#define AMDGPU_BO_LIST_MAX_PRIORITY     32u
#define AMDGPU_BO_LIST_NUM_BUCKETS      (AMDGPU_BO_LIST_MAX_PRIORITY + 1)

static void amdgpu_bo_list_free_rcu(struct rcu_head *rcu)
{
        struct amdgpu_bo_list *list = container_of(rcu, struct amdgpu_bo_list,
                                                   rhead);

        kvfree(list);
}

static void amdgpu_bo_list_free(struct kref *ref)
{
        struct amdgpu_bo_list *list = container_of(ref, struct amdgpu_bo_list,
                                                   refcount);
        struct amdgpu_bo_list_entry *e;

        amdgpu_bo_list_for_each_entry(e, list) {
                struct amdgpu_bo *bo = ttm_to_amdgpu_bo(e->tv.bo);

                amdgpu_bo_unref(&bo);
        }

        call_rcu(&list->rhead, amdgpu_bo_list_free_rcu);
}

int amdgpu_bo_list_create(struct amdgpu_device *adev, struct drm_file *filp,
                          struct drm_amdgpu_bo_list_entry *info,
                          unsigned num_entries, struct amdgpu_bo_list **result)
{
        unsigned last_entry = 0, first_userptr = num_entries;
        struct amdgpu_bo_list_entry *array;
        struct amdgpu_bo_list *list;
        uint64_t total_size = 0;
        size_t size;
        unsigned i;
        int r;

        if (num_entries > (SIZE_MAX - sizeof(struct amdgpu_bo_list))
                                / sizeof(struct amdgpu_bo_list_entry))
                return -EINVAL;

        size = sizeof(struct amdgpu_bo_list);
        size += num_entries * sizeof(struct amdgpu_bo_list_entry);
        list = kvmalloc(size, GFP_KERNEL);
        if (!list)
                return -ENOMEM;

        kref_init(&list->refcount);
        list->gds_obj = NULL;
        list->gws_obj = NULL;
        list->oa_obj = NULL;

        array = amdgpu_bo_list_array_entry(list, 0);
        memset(array, 0, num_entries * sizeof(struct amdgpu_bo_list_entry));

        for (i = 0; i < num_entries; ++i) {
                struct amdgpu_bo_list_entry *entry;
                struct drm_gem_object *gobj;
                struct amdgpu_bo *bo;
                struct mm_struct *usermm;

                gobj = drm_gem_object_lookup(filp, info[i].bo_handle);
                if (!gobj) {
                        r = -ENOENT;
                        goto error_free;
                }

                bo = amdgpu_bo_ref(gem_to_amdgpu_bo(gobj));
                drm_gem_object_put(gobj);

                usermm = amdgpu_ttm_tt_get_usermm(bo->tbo.ttm);
                if (usermm) {
                        if (usermm != current->mm) {
                                amdgpu_bo_unref(&bo);
                                r = -EPERM;
                                goto error_free;
                        }
                        entry = &array[--first_userptr];
                } else {
                        entry = &array[last_entry++];
                }

                entry->priority = min(info[i].bo_priority,
                                      AMDGPU_BO_LIST_MAX_PRIORITY);
                entry->tv.bo = &bo->tbo;

                if (bo->preferred_domains == AMDGPU_GEM_DOMAIN_GDS)
                        list->gds_obj = bo;
                if (bo->preferred_domains == AMDGPU_GEM_DOMAIN_GWS)
                        list->gws_obj = bo;
                if (bo->preferred_domains == AMDGPU_GEM_DOMAIN_OA)
                        list->oa_obj = bo;

                total_size += amdgpu_bo_size(bo);
                trace_amdgpu_bo_list_set(list, bo);
        }

        list->first_userptr = first_userptr;
        list->num_entries = num_entries;

        trace_amdgpu_cs_bo_status(list->num_entries, total_size);

        *result = list;
        return 0;

error_free:
        for (i = 0; i < last_entry; ++i) {
                struct amdgpu_bo *bo = ttm_to_amdgpu_bo(array[i].tv.bo);

                amdgpu_bo_unref(&bo);
        }
        for (i = first_userptr; i < num_entries; ++i) {
                struct amdgpu_bo *bo = ttm_to_amdgpu_bo(array[i].tv.bo);

                amdgpu_bo_unref(&bo);
        }
        kvfree(list);
        return r;

}

static void amdgpu_bo_list_destroy(struct amdgpu_fpriv *fpriv, int id)
{
        struct amdgpu_bo_list *list;

        mutex_lock(&fpriv->bo_list_lock);
        list = idr_remove(&fpriv->bo_list_handles, id);
        mutex_unlock(&fpriv->bo_list_lock);
        if (list)
                kref_put(&list->refcount, amdgpu_bo_list_free);
}

int amdgpu_bo_list_get(struct amdgpu_fpriv *fpriv, int id,
                       struct amdgpu_bo_list **result)
{
        rcu_read_lock();
        *result = idr_find(&fpriv->bo_list_handles, id);

        if (*result && kref_get_unless_zero(&(*result)->refcount)) {
                rcu_read_unlock();
                return 0;
        }

        rcu_read_unlock();
        return -ENOENT;
}

void amdgpu_bo_list_get_list(struct amdgpu_bo_list *list,
                             struct list_head *validated)
{
        /* This is based on the bucket sort with O(n) time complexity.
         * An item with priority "i" is added to bucket[i]. The lists are then
         * concatenated in descending order.
         */
        struct list_head bucket[AMDGPU_BO_LIST_NUM_BUCKETS];
        struct amdgpu_bo_list_entry *e;
        unsigned i;

        for (i = 0; i < AMDGPU_BO_LIST_NUM_BUCKETS; i++)
                INIT_LIST_HEAD(&bucket[i]);

        /* Since buffers which appear sooner in the relocation list are
         * likely to be used more often than buffers which appear later
         * in the list, the sort mustn't change the ordering of buffers
         * with the same priority, i.e. it must be stable.
         */
        amdgpu_bo_list_for_each_entry(e, list) {
                struct amdgpu_bo *bo = ttm_to_amdgpu_bo(e->tv.bo);
                unsigned priority = e->priority;

                if (!bo->parent)
                        list_add_tail(&e->tv.head, &bucket[priority]);

                e->user_pages = NULL;
        }

        /* Connect the sorted buckets in the output list. */
        for (i = 0; i < AMDGPU_BO_LIST_NUM_BUCKETS; i++)
                list_splice(&bucket[i], validated);
}

void amdgpu_bo_list_put(struct amdgpu_bo_list *list)
{
        kref_put(&list->refcount, amdgpu_bo_list_free);
}

int amdgpu_bo_create_list_entry_array(struct drm_amdgpu_bo_list_in *in,
                                      struct drm_amdgpu_bo_list_entry **info_param)
{
        const void __user *uptr = u64_to_user_ptr(in->bo_info_ptr);
        const uint32_t info_size = sizeof(struct drm_amdgpu_bo_list_entry);
        struct drm_amdgpu_bo_list_entry *info;
        int r;

        info = kvmalloc_array(in->bo_number, info_size, GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        /* copy the handle array from userspace to a kernel buffer */
        r = -EFAULT;
        if (likely(info_size == in->bo_info_size)) {
                unsigned long bytes = in->bo_number *
                        in->bo_info_size;

                if (copy_from_user(info, uptr, bytes))
                        goto error_free;

        } else {
                unsigned long bytes = min(in->bo_info_size, info_size);
                unsigned i;

                memset(info, 0, in->bo_number * info_size);
                for (i = 0; i < in->bo_number; ++i) {
                        if (copy_from_user(&info[i], uptr, bytes))
                                goto error_free;

                        uptr += in->bo_info_size;
                }
        }

        *info_param = info;
        return 0;

error_free:
        kvfree(info);
        return r;
}

int amdgpu_bo_list_ioctl(struct drm_device *dev, void *data,
                                struct drm_file *filp)
{
        struct amdgpu_device *adev = drm_to_adev(dev);
        struct amdgpu_fpriv *fpriv = filp->driver_priv;
        union drm_amdgpu_bo_list *args = data;
        uint32_t handle = args->in.list_handle;
        struct drm_amdgpu_bo_list_entry *info = NULL;
        struct amdgpu_bo_list *list, *old;
        int r;

        r = amdgpu_bo_create_list_entry_array(&args->in, &info);
        if (r)
                return r;

        switch (args->in.operation) {
        case AMDGPU_BO_LIST_OP_CREATE:
                r = amdgpu_bo_list_create(adev, filp, info, args->in.bo_number,
                                          &list);
                if (r)
                        goto error_free;

                mutex_lock(&fpriv->bo_list_lock);
                r = idr_alloc(&fpriv->bo_list_handles, list, 1, 0, GFP_KERNEL);
                mutex_unlock(&fpriv->bo_list_lock);
                if (r < 0) {
                        goto error_put_list;
                }

                handle = r;
                break;

        case AMDGPU_BO_LIST_OP_DESTROY:
                amdgpu_bo_list_destroy(fpriv, handle);
                handle = 0;
                break;

        case AMDGPU_BO_LIST_OP_UPDATE:
                r = amdgpu_bo_list_create(adev, filp, info, args->in.bo_number,
                                          &list);
                if (r)
                        goto error_free;

                mutex_lock(&fpriv->bo_list_lock);
                old = idr_replace(&fpriv->bo_list_handles, list, handle);
                mutex_unlock(&fpriv->bo_list_lock);

                if (IS_ERR(old)) {
                        r = PTR_ERR(old);
                        goto error_put_list;
                }

                amdgpu_bo_list_put(old);
                break;

        default:
                r = -EINVAL;
                goto error_free;
        }

        memset(args, 0, sizeof(*args));
        args->out.list_handle = handle;
        kvfree(info);

        return 0;

error_put_list:
        amdgpu_bo_list_put(list);

error_free:
        kvfree(info);
        return r;
}