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/**************************************************************************

 *

 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., 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 above copyright notice and this permission notice (including the

 * next paragraph) shall be included in all copies or substantial portions

 * of the Software.

 *

 * 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.

 *

 **************************************************************************/

#include 

#include 

#include 

#include 

#include 

#include 

DEFINE_WW_CLASS(reservation_ww_class);

static void ttm_eu_backoff_reservation_reverse(struct list_head *list,

					      struct ttm_validate_buffer *entry)

{

	list_for_each_entry_continue_reverse(entry, list, head) {

		struct ttm_buffer_object *bo = entry->bo;

		__ttm_bo_unreserve(bo);

	}

}

static void ttm_eu_del_from_lru_locked(struct list_head *list)

{

	struct ttm_validate_buffer *entry;

	list_for_each_entry(entry, list, head) {

		struct ttm_buffer_object *bo = entry->bo;

		unsigned put_count = ttm_bo_del_from_lru(bo);

		ttm_bo_list_ref_sub(bo, put_count, true);

	}

}

void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,

				struct list_head *list)

{

	struct ttm_validate_buffer *entry;

	struct ttm_bo_global *glob;

	if (list_empty(list))

		return;

	entry = list_first_entry(list, struct ttm_validate_buffer, head);

	glob = entry->bo->glob;

	spin_lock(&glob->lru_lock);

	list_for_each_entry(entry, list, head) {

		struct ttm_buffer_object *bo = entry->bo;

		ttm_bo_add_to_lru(bo);

		__ttm_bo_unreserve(bo);

	}

	spin_unlock(&glob->lru_lock);

	if (ticket)

		ww_acquire_fini(ticket);

}

EXPORT_SYMBOL(ttm_eu_backoff_reservation);

/*

 * Reserve buffers for validation.

 *

 * If a buffer in the list is marked for CPU access, we back off and

 * wait for that buffer to become free for GPU access.

 *

 * If a buffer is reserved for another validation, the validator with

 * the highest validation sequence backs off and waits for that buffer

 * to become unreserved. This prevents deadlocks when validating multiple

 * buffers in different orders.

 */

int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,

			   struct list_head *list, bool intr,

			   struct list_head *dups)

{

	struct ttm_bo_global *glob;

	struct ttm_validate_buffer *entry;

	int ret;

	if (list_empty(list))

		return 0;

	entry = list_first_entry(list, struct ttm_validate_buffer, head);

	glob = entry->bo->glob;

	if (ticket)

		ww_acquire_init(ticket, &reservation_ww_class);

	list_for_each_entry(entry, list, head) {

		struct ttm_buffer_object *bo = entry->bo;

		ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), true,

				       ticket);

		if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) {

			__ttm_bo_unreserve(bo);

			ret = -EBUSY;

		} else if (ret == -EALREADY && dups) {

			struct ttm_validate_buffer *safe = entry;

			entry = list_prev_entry(entry, head);

			list_del(&safe->head);

			list_add(&safe->head, dups);

			continue;

		}

		if (!ret) {

			if (!entry->shared)

			continue;

			ret = reservation_object_reserve_shared(bo->resv);

			if (!ret)

				continue;

		}

			/* uh oh, we lost out, drop every reservation and try

			 * to only reserve this buffer, then start over if

			 * this succeeds.

			 */

		ttm_eu_backoff_reservation_reverse(list, entry);

		if (ret == -EDEADLK && intr) {

			ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,

							       ticket);

		} else if (ret == -EDEADLK) {

			ww_mutex_lock_slow(&bo->resv->lock, ticket);

			ret = 0;

		}

		if (!ret && entry->shared)

			ret = reservation_object_reserve_shared(bo->resv);

			if (unlikely(ret != 0)) {

				if (ret == -EINTR)

					ret = -ERESTARTSYS;

			if (ticket) {

				ww_acquire_done(ticket);

				ww_acquire_fini(ticket);

			}

			return ret;

			}

		/* move this item to the front of the list,

		 * forces correct iteration of the loop without keeping track

		 */

		list_del(&entry->head);

		list_add(&entry->head, list);

	}

	if (ticket)

		ww_acquire_done(ticket);

	spin_lock(&glob->lru_lock);

	ttm_eu_del_from_lru_locked(list);

	spin_unlock(&glob->lru_lock);

	return 0;

}

EXPORT_SYMBOL(ttm_eu_reserve_buffers);

void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,

				 struct list_head *list, struct fence *fence)

{

	struct ttm_validate_buffer *entry;

	struct ttm_buffer_object *bo;

	struct ttm_bo_global *glob;

	struct ttm_bo_device *bdev;

	struct ttm_bo_driver *driver;

	if (list_empty(list))

		return;

	bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;

	bdev = bo->bdev;

	driver = bdev->driver;

	glob = bo->glob;

	spin_lock(&glob->lru_lock);

	list_for_each_entry(entry, list, head) {

		bo = entry->bo;

		if (entry->shared)

			reservation_object_add_shared_fence(bo->resv, fence);

		else

			reservation_object_add_excl_fence(bo->resv, fence);

		ttm_bo_add_to_lru(bo);

		__ttm_bo_unreserve(bo);

	}

	spin_unlock(&glob->lru_lock);

	if (ticket)

		ww_acquire_fini(ticket);

}

EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);