/*
 * 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/sort.h>
#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)
#define AMDGPU_BO_LIST_MAX_ENTRIES      (128 * 1024)

static void amdgpu_bo_list_free_rcu(struct rcu_head *rcu)
{
        struct amdgpu_bo_list *list = container_of(rcu, struct amdgpu_bo_list,
                                                   rhead);
        mutex_destroy(&list->bo_list_mutex);
        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)
                amdgpu_bo_unref(&e->bo);
        call_rcu(&list->rhead, amdgpu_bo_list_free_rcu);
}

static int amdgpu_bo_list_entry_cmp(const void *_a, const void *_b)
{
        const struct amdgpu_bo_list_entry *a = _a, *b = _b;

        BUILD_BUG_ON(AMDGPU_BO_LIST_MAX_PRIORITY >= INT_MAX);

        return (int)a->priority - (int)b->priority;
}

int amdgpu_bo_list_create(struct amdgpu_device *adev, struct drm_file *filp,
                          struct drm_amdgpu_bo_list_entry *info,
                          size_t 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;
        unsigned i;
        int r;

        list = kvzalloc_flex(*list, entries, num_entries);
        if (!list)
                return -ENOMEM;

        kref_init(&list->refcount);

        list->num_entries = num_entries;
        array = list->entries;

        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->bo = bo;

                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;
        sort(array, last_entry, sizeof(struct amdgpu_bo_list_entry),
             amdgpu_bo_list_entry_cmp, NULL);

        trace_amdgpu_cs_bo_status(list->num_entries, total_size);

        mutex_init(&list->bo_list_mutex);
        *result = list;
        return 0;

error_free:
        for (i = 0; i < last_entry; ++i)
                amdgpu_bo_unref(&array[i].bo);
        for (i = first_userptr; i < num_entries; ++i)
                amdgpu_bo_unref(&array[i].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();
        *result = NULL;
        return -ENOENT;
}

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 uint32_t info_size = sizeof(struct drm_amdgpu_bo_list_entry);
        const void __user *uptr = u64_to_user_ptr(in->bo_info_ptr);
        const uint32_t bo_info_size = in->bo_info_size;
        const uint32_t bo_number = in->bo_number;
        struct drm_amdgpu_bo_list_entry *info;

        if (bo_number > AMDGPU_BO_LIST_MAX_ENTRIES)
                return -EINVAL;

        /* copy the handle array from userspace to a kernel buffer */
        if (likely(info_size == bo_info_size)) {
                info = vmemdup_array_user(uptr, bo_number, info_size);
                if (IS_ERR(info))
                        return PTR_ERR(info);
        } else {
                const uint32_t bytes = min(bo_info_size, info_size);
                unsigned i;

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

                memset(info, 0, bo_number * info_size);
                for (i = 0; i < bo_number; ++i, uptr += bo_info_size) {
                        if (copy_from_user(&info[i], uptr, bytes)) {
                                kvfree(info);
                                return -EFAULT;
                        }
                }
        }

        *info_param = info;
        return 0;
}

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;
}