/*
 * 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 <drm/drmP.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 int amdgpu_bo_list_set(struct amdgpu_device *adev,
                                     struct drm_file *filp,
                                     struct amdgpu_bo_list *list,
                                     struct drm_amdgpu_bo_list_entry *info,
                                     unsigned num_entries);

static void amdgpu_bo_list_release_rcu(struct kref *ref)
{
        unsigned i;
        struct amdgpu_bo_list *list = container_of(ref, struct amdgpu_bo_list,
                                                   refcount);

        for (i = 0; i < list->num_entries; ++i)
                amdgpu_bo_unref(&list->array[i].robj);

        mutex_destroy(&list->lock);
        kvfree(list->array);
        kfree_rcu(list, rhead);
}

static int amdgpu_bo_list_create(struct amdgpu_device *adev,
                                 struct drm_file *filp,
                                 struct drm_amdgpu_bo_list_entry *info,
                                 unsigned num_entries,
                                 int *id)
{
        int r;
        struct amdgpu_fpriv *fpriv = filp->driver_priv;
        struct amdgpu_bo_list *list;

        list = kzalloc(sizeof(struct amdgpu_bo_list), GFP_KERNEL);
        if (!list)
                return -ENOMEM;

        /* initialize bo list*/
        mutex_init(&list->lock);
        kref_init(&list->refcount);
        r = amdgpu_bo_list_set(adev, filp, list, info, num_entries);
        if (r) {
                kfree(list);
                return r;
        }

        /* idr alloc should be called only after initialization of bo list. */
        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) {
                amdgpu_bo_list_free(list);
                return r;
        }
        *id = r;

        return 0;
}

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_find(&fpriv->bo_list_handles, id);
        if (list) {
                mutex_lock(&list->lock);
                idr_remove(&fpriv->bo_list_handles, id);
                mutex_unlock(&list->lock);
                amdgpu_bo_list_free(list);
        }
        mutex_unlock(&fpriv->bo_list_lock);
}

static int amdgpu_bo_list_set(struct amdgpu_device *adev,
                                     struct drm_file *filp,
                                     struct amdgpu_bo_list *list,
                                     struct drm_amdgpu_bo_list_entry *info,
                                     unsigned num_entries)
{
        struct amdgpu_bo_list_entry *array;
        struct amdgpu_bo *gds_obj = adev->gds.gds_gfx_bo;
        struct amdgpu_bo *gws_obj = adev->gds.gws_gfx_bo;
        struct amdgpu_bo *oa_obj = adev->gds.oa_gfx_bo;

        unsigned last_entry = 0, first_userptr = num_entries;
        unsigned i;
        int r;
        unsigned long total_size = 0;

        array = kvmalloc_array(num_entries, sizeof(struct amdgpu_bo_list_entry), GFP_KERNEL);
        if (!array)
                return -ENOMEM;
        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_unlocked(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->robj = bo;
                entry->priority = min(info[i].bo_priority,
                                      AMDGPU_BO_LIST_MAX_PRIORITY);
                entry->tv.bo = &entry->robj->tbo;
                entry->tv.shared = !entry->robj->prime_shared_count;

                if (entry->robj->preferred_domains == AMDGPU_GEM_DOMAIN_GDS)
                        gds_obj = entry->robj;
                if (entry->robj->preferred_domains == AMDGPU_GEM_DOMAIN_GWS)
                        gws_obj = entry->robj;
                if (entry->robj->preferred_domains == AMDGPU_GEM_DOMAIN_OA)
                        oa_obj = entry->robj;

                total_size += amdgpu_bo_size(entry->robj);
                trace_amdgpu_bo_list_set(list, entry->robj);
        }

        for (i = 0; i < list->num_entries; ++i)
                amdgpu_bo_unref(&list->array[i].robj);

        kvfree(list->array);

        list->gds_obj = gds_obj;
        list->gws_obj = gws_obj;
        list->oa_obj = oa_obj;
        list->first_userptr = first_userptr;
        list->array = array;
        list->num_entries = num_entries;

        trace_amdgpu_cs_bo_status(list->num_entries, total_size);
        return 0;

error_free:
        while (i--)
                amdgpu_bo_unref(&array[i].robj);
        kvfree(array);
        return r;
}

struct amdgpu_bo_list *
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) {
                if (kref_get_unless_zero(&result->refcount)) {
                        rcu_read_unlock();
                        mutex_lock(&result->lock);
                } else {
                        rcu_read_unlock();
                        result = NULL;
                }
        } else {
                rcu_read_unlock();
        }

        return result;
}

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];
        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.
         */
        for (i = 0; i < list->num_entries; i++) {
                unsigned priority = list->array[i].priority;

                if (!list->array[i].robj->parent)
                        list_add_tail(&list->array[i].tv.head,
                                      &bucket[priority]);

                list->array[i].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)
{
        mutex_unlock(&list->lock);
        kref_put(&list->refcount, amdgpu_bo_list_release_rcu);
}

void amdgpu_bo_list_free(struct amdgpu_bo_list *list)
{
        unsigned i;

        for (i = 0; i < list->num_entries; ++i)
                amdgpu_bo_unref(&list->array[i].robj);

        mutex_destroy(&list->lock);
        kvfree(list->array);
        kfree(list);
}

int amdgpu_bo_list_ioctl(struct drm_device *dev, void *data,
                                struct drm_file *filp)
{
        const uint32_t info_size = sizeof(struct drm_amdgpu_bo_list_entry);

        struct amdgpu_device *adev = dev->dev_private;
        struct amdgpu_fpriv *fpriv = filp->driver_priv;
        union drm_amdgpu_bo_list *args = data;
        uint32_t handle = args->in.list_handle;
        const void __user *uptr = u64_to_user_ptr(args->in.bo_info_ptr);

        struct drm_amdgpu_bo_list_entry *info;
        struct amdgpu_bo_list *list;

        int r;

        info = kvmalloc_array(args->in.bo_number,
                             sizeof(struct drm_amdgpu_bo_list_entry), GFP_KERNEL);
        if (!info)
                return -ENOMEM;

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

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

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

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

                        uptr += args->in.bo_info_size;
                }
        }

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

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

        case AMDGPU_BO_LIST_OP_UPDATE:
                r = -ENOENT;
                list = amdgpu_bo_list_get(fpriv, handle);
                if (!list)
                        goto error_free;

                r = amdgpu_bo_list_set(adev, filp, list, info,
                                              args->in.bo_number);
                amdgpu_bo_list_put(list);
                if (r)
                        goto error_free;

                break;

        default:
                r = -EINVAL;
                goto error_free;
        }

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

        return 0;

error_free:
        kvfree(info);
        return r;
}