/**************************************************************************
 *
 * Copyright 2006 Tungsten Graphics, Inc., Bismarck., ND., USA.
 * 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.
 *
 *
 **************************************************************************/
/*
 * Simple memory manager interface that keeps track on allocate regions on a
 * per "owner" basis. All regions associated with an "owner" can be released
 * with a simple call. Typically if the "owner" exists. The owner is any
 * "unsigned long" identifier. Can typically be a pointer to a file private
 * struct or a context identifier.
 *
 * Authors:
 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
 */

#include "drm_sman.h"

struct drm_owner_item {
        struct drm_hash_item owner_hash;
        struct list_head sman_list;
        struct list_head mem_blocks;
};

void drm_sman_takedown(struct drm_sman * sman)
{
        drm_ht_remove(&sman->user_hash_tab);
        drm_ht_remove(&sman->owner_hash_tab);
        kfree(sman->mm);
}

EXPORT_SYMBOL(drm_sman_takedown);

int
drm_sman_init(struct drm_sman * sman, unsigned int num_managers,
              unsigned int user_order, unsigned int owner_order)
{
        int ret = 0;

        sman->mm = (struct drm_sman_mm *) kcalloc(num_managers,
                                                  sizeof(*sman->mm),
                                                  GFP_KERNEL);
        if (!sman->mm) {
                ret = -ENOMEM;
                goto out;
        }
        sman->num_managers = num_managers;
        INIT_LIST_HEAD(&sman->owner_items);
        ret = drm_ht_create(&sman->owner_hash_tab, owner_order);
        if (ret)
                goto out1;
        ret = drm_ht_create(&sman->user_hash_tab, user_order);
        if (!ret)
                goto out;

        drm_ht_remove(&sman->owner_hash_tab);
out1:
        kfree(sman->mm);
out:
        return ret;
}

EXPORT_SYMBOL(drm_sman_init);

static void *drm_sman_mm_allocate(void *private, unsigned long size,
                                  unsigned alignment)
{
        struct drm_mm *mm = (struct drm_mm *) private;
        struct drm_mm_node *tmp;

        tmp = drm_mm_search_free(mm, size, alignment, 1);
        if (!tmp) {
                return NULL;
        }
        tmp = drm_mm_get_block(tmp, size, alignment);
        return tmp;
}

static void drm_sman_mm_free(void *private, void *ref)
{
        struct drm_mm_node *node = (struct drm_mm_node *) ref;

        drm_mm_put_block(node);
}

static void drm_sman_mm_destroy(void *private)
{
        struct drm_mm *mm = (struct drm_mm *) private;
        drm_mm_takedown(mm);
        kfree(mm);
}

static unsigned long drm_sman_mm_offset(void *private, void *ref)
{
        struct drm_mm_node *node = (struct drm_mm_node *) ref;
        return node->start;
}

int
drm_sman_set_range(struct drm_sman * sman, unsigned int manager,
                   unsigned long start, unsigned long size)
{
        struct drm_sman_mm *sman_mm;
        struct drm_mm *mm;
        int ret;

        BUG_ON(manager >= sman->num_managers);

        sman_mm = &sman->mm[manager];
        mm = kzalloc(sizeof(*mm), GFP_KERNEL);
        if (!mm) {
                return -ENOMEM;
        }
        sman_mm->private = mm;
        ret = drm_mm_init(mm, start, size);

        if (ret) {
                kfree(mm);
                return ret;
        }

        sman_mm->allocate = drm_sman_mm_allocate;
        sman_mm->free = drm_sman_mm_free;
        sman_mm->destroy = drm_sman_mm_destroy;
        sman_mm->offset = drm_sman_mm_offset;

        return 0;
}

EXPORT_SYMBOL(drm_sman_set_range);

int
drm_sman_set_manager(struct drm_sman * sman, unsigned int manager,
                     struct drm_sman_mm * allocator)
{
        BUG_ON(manager >= sman->num_managers);
        sman->mm[manager] = *allocator;

        return 0;
}
EXPORT_SYMBOL(drm_sman_set_manager);

static struct drm_owner_item *drm_sman_get_owner_item(struct drm_sman * sman,
                                                 unsigned long owner)
{
        int ret;
        struct drm_hash_item *owner_hash_item;
        struct drm_owner_item *owner_item;

        ret = drm_ht_find_item(&sman->owner_hash_tab, owner, &owner_hash_item);
        if (!ret) {
                return drm_hash_entry(owner_hash_item, struct drm_owner_item,
                                      owner_hash);
        }

        owner_item = kzalloc(sizeof(*owner_item), GFP_KERNEL);
        if (!owner_item)
                goto out;

        INIT_LIST_HEAD(&owner_item->mem_blocks);
        owner_item->owner_hash.key = owner;
        if (drm_ht_insert_item(&sman->owner_hash_tab, &owner_item->owner_hash))
                goto out1;

        list_add_tail(&owner_item->sman_list, &sman->owner_items);
        return owner_item;

out1:
        kfree(owner_item);
out:
        return NULL;
}

struct drm_memblock_item *drm_sman_alloc(struct drm_sman *sman, unsigned int manager,
                                    unsigned long size, unsigned alignment,
                                    unsigned long owner)
{
        void *tmp;
        struct drm_sman_mm *sman_mm;
        struct drm_owner_item *owner_item;
        struct drm_memblock_item *memblock;

        BUG_ON(manager >= sman->num_managers);

        sman_mm = &sman->mm[manager];
        tmp = sman_mm->allocate(sman_mm->private, size, alignment);

        if (!tmp) {
                return NULL;
        }

        memblock = kzalloc(sizeof(*memblock), GFP_KERNEL);

        if (!memblock)
                goto out;

        memblock->mm_info = tmp;
        memblock->mm = sman_mm;
        memblock->sman = sman;

        if (drm_ht_just_insert_please
            (&sman->user_hash_tab, &memblock->user_hash,
             (unsigned long)memblock, 32, 0, 0))
                goto out1;

        owner_item = drm_sman_get_owner_item(sman, owner);
        if (!owner_item)
                goto out2;

        list_add_tail(&memblock->owner_list, &owner_item->mem_blocks);

        return memblock;

out2:
        drm_ht_remove_item(&sman->user_hash_tab, &memblock->user_hash);
out1:
        kfree(memblock);
out:
        sman_mm->free(sman_mm->private, tmp);

        return NULL;
}

EXPORT_SYMBOL(drm_sman_alloc);

static void drm_sman_free(struct drm_memblock_item *item)
{
        struct drm_sman *sman = item->sman;

        list_del(&item->owner_list);
        drm_ht_remove_item(&sman->user_hash_tab, &item->user_hash);
        item->mm->free(item->mm->private, item->mm_info);
        kfree(item);
}

int drm_sman_free_key(struct drm_sman *sman, unsigned int key)
{
        struct drm_hash_item *hash_item;
        struct drm_memblock_item *memblock_item;

        if (drm_ht_find_item(&sman->user_hash_tab, key, &hash_item))
                return -EINVAL;

        memblock_item = drm_hash_entry(hash_item, struct drm_memblock_item,
                                       user_hash);
        drm_sman_free(memblock_item);
        return 0;
}

EXPORT_SYMBOL(drm_sman_free_key);

static void drm_sman_remove_owner(struct drm_sman *sman,
                                  struct drm_owner_item *owner_item)
{
        list_del(&owner_item->sman_list);
        drm_ht_remove_item(&sman->owner_hash_tab, &owner_item->owner_hash);
        kfree(owner_item);
}

int drm_sman_owner_clean(struct drm_sman *sman, unsigned long owner)
{

        struct drm_hash_item *hash_item;
        struct drm_owner_item *owner_item;

        if (drm_ht_find_item(&sman->owner_hash_tab, owner, &hash_item)) {
                return -1;
        }

        owner_item = drm_hash_entry(hash_item, struct drm_owner_item, owner_hash);
        if (owner_item->mem_blocks.next == &owner_item->mem_blocks) {
                drm_sman_remove_owner(sman, owner_item);
                return -1;
        }

        return 0;
}

EXPORT_SYMBOL(drm_sman_owner_clean);

static void drm_sman_do_owner_cleanup(struct drm_sman *sman,
                                      struct drm_owner_item *owner_item)
{
        struct drm_memblock_item *entry, *next;

        list_for_each_entry_safe(entry, next, &owner_item->mem_blocks,
                                 owner_list) {
                drm_sman_free(entry);
        }
        drm_sman_remove_owner(sman, owner_item);
}

void drm_sman_owner_cleanup(struct drm_sman *sman, unsigned long owner)
{

        struct drm_hash_item *hash_item;
        struct drm_owner_item *owner_item;

        if (drm_ht_find_item(&sman->owner_hash_tab, owner, &hash_item)) {

                return;
        }

        owner_item = drm_hash_entry(hash_item, struct drm_owner_item, owner_hash);
        drm_sman_do_owner_cleanup(sman, owner_item);
}

EXPORT_SYMBOL(drm_sman_owner_cleanup);

void drm_sman_cleanup(struct drm_sman *sman)
{
        struct drm_owner_item *entry, *next;
        unsigned int i;
        struct drm_sman_mm *sman_mm;

        list_for_each_entry_safe(entry, next, &sman->owner_items, sman_list) {
                drm_sman_do_owner_cleanup(sman, entry);
        }
        if (sman->mm) {
                for (i = 0; i < sman->num_managers; ++i) {
                        sman_mm = &sman->mm[i];
                        if (sman_mm->private) {
                                sman_mm->destroy(sman_mm->private);
                                sman_mm->private = NULL;
                        }
                }
        }
}

EXPORT_SYMBOL(drm_sman_cleanup);