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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_locked(struct list_head *list)

{

	struct ttm_validate_buffer *entry;

	list_for_each_entry(entry, list, head) {

		struct ttm_buffer_object *bo = entry->bo;

		if (!entry->reserved)

			continue;

		entry->reserved = false;

		if (entry->removed) {

			ttm_bo_add_to_lru(bo);

			entry->removed = false;

		}

		__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;

		if (!entry->reserved)

			continue;

		if (!entry->removed) {

			entry->put_count = ttm_bo_del_from_lru(bo);

			entry->removed = true;

		}

	}

}

static void ttm_eu_list_ref_sub(struct list_head *list)

{

	struct ttm_validate_buffer *entry;

	list_for_each_entry(entry, list, head) {

		struct ttm_buffer_object *bo = entry->bo;

		if (entry->put_count) {

			ttm_bo_list_ref_sub(bo, entry->put_count, true);

			entry->put_count = 0;

		}

	}

}

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);

	ttm_eu_backoff_reservation_locked(list);

	if (ticket)

		ww_acquire_fini(ticket);

	spin_unlock(&glob->lru_lock);

}

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)

{

	struct ttm_bo_global *glob;

	struct ttm_validate_buffer *entry;

	int ret;

	if (list_empty(list))

		return 0;

	list_for_each_entry(entry, list, head) {

		entry->reserved = false;

		entry->put_count = 0;

		entry->removed = false;

	}

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

	glob = entry->bo->glob;

	if (ticket)

		ww_acquire_init(ticket, &reservation_ww_class);

retry:

	list_for_each_entry(entry, list, head) {

		struct ttm_buffer_object *bo = entry->bo;

		/* already slowpath reserved? */

		if (entry->reserved)

			continue;

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

				       ticket);

		if (ret == -EDEADLK) {

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

			 * to only reserve this buffer, then start over if

			 * this succeeds.

			 */

			BUG_ON(ticket == NULL);

			spin_lock(&glob->lru_lock);

			ttm_eu_backoff_reservation_locked(list);

			spin_unlock(&glob->lru_lock);

			ttm_eu_list_ref_sub(list);

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

							       ticket);

			if (unlikely(ret != 0)) {

				if (ret == -EINTR)

					ret = -ERESTARTSYS;

				goto err_fini;

			}

			entry->reserved = true;

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

				ret = -EBUSY;

				goto err;

			}

			goto retry;

		} else if (ret)

			goto err;

		entry->reserved = true;

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

			ret = -EBUSY;

			goto err;

		}

	}

	if (ticket)

		ww_acquire_done(ticket);

	spin_lock(&glob->lru_lock);

	ttm_eu_del_from_lru_locked(list);

	spin_unlock(&glob->lru_lock);

	ttm_eu_list_ref_sub(list);

	return 0;

err:

	spin_lock(&glob->lru_lock);

	ttm_eu_backoff_reservation_locked(list);

	spin_unlock(&glob->lru_lock);

	ttm_eu_list_ref_sub(list);

err_fini:

	if (ticket) {

		ww_acquire_done(ticket);

		ww_acquire_fini(ticket);

	}

	return ret;

}

EXPORT_SYMBOL(ttm_eu_reserve_buffers);

void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,

				 struct list_head *list, void *sync_obj)

{

	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);

	spin_lock(&bdev->fence_lock);

	list_for_each_entry(entry, list, head) {

		bo = entry->bo;

		entry->old_sync_obj = bo->sync_obj;

		bo->sync_obj = driver->sync_obj_ref(sync_obj);

		ttm_bo_add_to_lru(bo);

		__ttm_bo_unreserve(bo);

		entry->reserved = false;

	}

	spin_unlock(&bdev->fence_lock);

	spin_unlock(&glob->lru_lock);

	if (ticket)

		ww_acquire_fini(ticket);

	list_for_each_entry(entry, list, head) {

		if (entry->old_sync_obj)

			driver->sync_obj_unref(&entry->old_sync_obj);

	}

}

EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);