[deliverable/linux.git] / drivers / gpu / drm / ttm / ttm_execbuf_util.c

/**************************************************************************
 *
 * 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 <drm/ttm/ttm_execbuf_util.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_placement.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/module.h>

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;

		if (entry->removed) {
			ttm_bo_add_to_lru(bo);
			entry->removed = false;

		}
		entry->reserved = false;
		atomic_set(&bo->reserved, 0);
		wake_up_all(&bo->event_queue);
	}
}

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 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);
	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 list_head *list)
{
	struct ttm_bo_global *glob;
	struct ttm_validate_buffer *entry;
	int ret;
	uint32_t val_seq;

	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;

	spin_lock(&glob->lru_lock);
	val_seq = entry->bo->bdev->val_seq++;

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_nolru(bo, true, true, true, val_seq);
		switch (ret) {
		case 0:
			break;
		case -EBUSY:
			ttm_eu_del_from_lru_locked(list);
			spin_unlock(&glob->lru_lock);
			ret = ttm_bo_reserve_nolru(bo, true, false,
						   true, val_seq);
			spin_lock(&glob->lru_lock);
			if (!ret)
				break;

			if (unlikely(ret != -EAGAIN))
				goto err;

			/* fallthrough */
		case -EAGAIN:
			ttm_eu_backoff_reservation_locked(list);

			/*
			 * temporarily increase sequence number every retry,
			 * to prevent us from seeing our old reservation
			 * sequence when someone else reserved the buffer,
			 * but hasn't updated the seq_valid/seqno members yet.
			 */
			val_seq = entry->bo->bdev->val_seq++;

			spin_unlock(&glob->lru_lock);
			ttm_eu_list_ref_sub(list);
			ret = ttm_bo_reserve_slowpath_nolru(bo, true, val_seq);
			if (unlikely(ret != 0))
				return ret;
			spin_lock(&glob->lru_lock);
			entry->reserved = true;
			if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
				ret = -EBUSY;
				goto err;
			}
			goto retry;
		default:
			goto err;
		}

		entry->reserved = true;
		if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
			ret = -EBUSY;
			goto err;
		}
	}

	ttm_eu_del_from_lru_locked(list);
	spin_unlock(&glob->lru_lock);
	ttm_eu_list_ref_sub(list);

	return 0;

err:
	ttm_eu_backoff_reservation_locked(list);
	spin_unlock(&glob->lru_lock);
	ttm_eu_list_ref_sub(list);
	return ret;
}
EXPORT_SYMBOL(ttm_eu_reserve_buffers);

void ttm_eu_fence_buffer_objects(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_unreserve_locked(bo);
		entry->reserved = false;
	}
	spin_unlock(&bdev->fence_lock);
	spin_unlock(&glob->lru_lock);

	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);
Commit	Line	Data
	1	/**************************************************************************
	2	*
	3	* Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
	4	* All Rights Reserved.
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a
	7	* copy of this software and associated documentation files (the
	8	* "Software"), to deal in the Software without restriction, including
	9	* without limitation the rights to use, copy, modify, merge, publish,
	10	* distribute, sub license, and/or sell copies of the Software, and to
	11	* permit persons to whom the Software is furnished to do so, subject to
	12	* the following conditions:
	13	*
	14	* The above copyright notice and this permission notice (including the
	15	* next paragraph) shall be included in all copies or substantial portions
	16	* of the Software.
	17	*
	18	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	19	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	20	* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
	21	* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
	22	* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
	23	* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
	24	* USE OR OTHER DEALINGS IN THE SOFTWARE.
	25	*
	26	**************************************************************************/
	27
	28	#include <drm/ttm/ttm_execbuf_util.h>
	29	#include <drm/ttm/ttm_bo_driver.h>
	30	#include <drm/ttm/ttm_placement.h>
	31	#include <linux/wait.h>
	32	#include <linux/sched.h>
	33	#include <linux/module.h>
	34
	35	static void ttm_eu_backoff_reservation_locked(struct list_head *list)
	36	{
	37	struct ttm_validate_buffer *entry;
	38
	39	list_for_each_entry(entry, list, head) {
	40	struct ttm_buffer_object *bo = entry->bo;
	41	if (!entry->reserved)
	42	continue;
	43
	44	if (entry->removed) {
	45	ttm_bo_add_to_lru(bo);
	46	entry->removed = false;
	47
	48	}
	49	entry->reserved = false;
	50	atomic_set(&bo->reserved, 0);
	51	wake_up_all(&bo->event_queue);
	52	}
	53	}
	54
	55	static void ttm_eu_del_from_lru_locked(struct list_head *list)
	56	{
	57	struct ttm_validate_buffer *entry;
	58
	59	list_for_each_entry(entry, list, head) {
	60	struct ttm_buffer_object *bo = entry->bo;
	61	if (!entry->reserved)
	62	continue;
	63
	64	if (!entry->removed) {
	65	entry->put_count = ttm_bo_del_from_lru(bo);
	66	entry->removed = true;
	67	}
	68	}
	69	}
	70
	71	static void ttm_eu_list_ref_sub(struct list_head *list)
	72	{
	73	struct ttm_validate_buffer *entry;
	74
	75	list_for_each_entry(entry, list, head) {
	76	struct ttm_buffer_object *bo = entry->bo;
	77
	78	if (entry->put_count) {
	79	ttm_bo_list_ref_sub(bo, entry->put_count, true);
	80	entry->put_count = 0;
	81	}
	82	}
	83	}
	84
	85	void ttm_eu_backoff_reservation(struct list_head *list)
	86	{
	87	struct ttm_validate_buffer *entry;
	88	struct ttm_bo_global *glob;
	89
	90	if (list_empty(list))
	91	return;
	92
	93	entry = list_first_entry(list, struct ttm_validate_buffer, head);
	94	glob = entry->bo->glob;
	95	spin_lock(&glob->lru_lock);
	96	ttm_eu_backoff_reservation_locked(list);
	97	spin_unlock(&glob->lru_lock);
	98	}
	99	EXPORT_SYMBOL(ttm_eu_backoff_reservation);
	100
	101	/*
	102	* Reserve buffers for validation.
	103	*
	104	* If a buffer in the list is marked for CPU access, we back off and
	105	* wait for that buffer to become free for GPU access.
	106	*
	107	* If a buffer is reserved for another validation, the validator with
	108	* the highest validation sequence backs off and waits for that buffer
	109	* to become unreserved. This prevents deadlocks when validating multiple
	110	* buffers in different orders.
	111	*/
	112
	113	int ttm_eu_reserve_buffers(struct list_head *list)
	114	{
	115	struct ttm_bo_global *glob;
	116	struct ttm_validate_buffer *entry;
	117	int ret;
	118	uint32_t val_seq;
	119
	120	if (list_empty(list))
	121	return 0;
	122
	123	list_for_each_entry(entry, list, head) {
	124	entry->reserved = false;
	125	entry->put_count = 0;
	126	entry->removed = false;
	127	}
	128
	129	entry = list_first_entry(list, struct ttm_validate_buffer, head);
	130	glob = entry->bo->glob;
	131
	132	spin_lock(&glob->lru_lock);
	133	val_seq = entry->bo->bdev->val_seq++;
	134
	135	retry:
	136	list_for_each_entry(entry, list, head) {
	137	struct ttm_buffer_object *bo = entry->bo;
	138
	139	/* already slowpath reserved? */
	140	if (entry->reserved)
	141	continue;
	142
	143	ret = ttm_bo_reserve_nolru(bo, true, true, true, val_seq);
	144	switch (ret) {
	145	case 0:
	146	break;
	147	case -EBUSY:
	148	ttm_eu_del_from_lru_locked(list);
	149	spin_unlock(&glob->lru_lock);
	150	ret = ttm_bo_reserve_nolru(bo, true, false,
	151	true, val_seq);
	152	spin_lock(&glob->lru_lock);
	153	if (!ret)
	154	break;
	155
	156	if (unlikely(ret != -EAGAIN))
	157	goto err;
	158
	159	/* fallthrough */
	160	case -EAGAIN:
	161	ttm_eu_backoff_reservation_locked(list);
	162
	163	/*
	164	* temporarily increase sequence number every retry,
	165	* to prevent us from seeing our old reservation
	166	* sequence when someone else reserved the buffer,
	167	* but hasn't updated the seq_valid/seqno members yet.
	168	*/
	169	val_seq = entry->bo->bdev->val_seq++;
	170
	171	spin_unlock(&glob->lru_lock);
	172	ttm_eu_list_ref_sub(list);
	173	ret = ttm_bo_reserve_slowpath_nolru(bo, true, val_seq);
	174	if (unlikely(ret != 0))
	175	return ret;
	176	spin_lock(&glob->lru_lock);
	177	entry->reserved = true;
	178	if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
	179	ret = -EBUSY;
	180	goto err;
	181	}
	182	goto retry;
	183	default:
	184	goto err;
	185	}
	186
	187	entry->reserved = true;
	188	if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
	189	ret = -EBUSY;
	190	goto err;
	191	}
	192	}
	193
	194	ttm_eu_del_from_lru_locked(list);
	195	spin_unlock(&glob->lru_lock);
	196	ttm_eu_list_ref_sub(list);
	197
	198	return 0;
	199
	200	err:
	201	ttm_eu_backoff_reservation_locked(list);
	202	spin_unlock(&glob->lru_lock);
	203	ttm_eu_list_ref_sub(list);
	204	return ret;
	205	}
	206	EXPORT_SYMBOL(ttm_eu_reserve_buffers);
	207
	208	void ttm_eu_fence_buffer_objects(struct list_head list, void sync_obj)
	209	{
	210	struct ttm_validate_buffer *entry;
	211	struct ttm_buffer_object *bo;
	212	struct ttm_bo_global *glob;
	213	struct ttm_bo_device *bdev;
	214	struct ttm_bo_driver *driver;
	215
	216	if (list_empty(list))
	217	return;
	218
	219	bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
	220	bdev = bo->bdev;
	221	driver = bdev->driver;
	222	glob = bo->glob;
	223
	224	spin_lock(&glob->lru_lock);
	225	spin_lock(&bdev->fence_lock);
	226
	227	list_for_each_entry(entry, list, head) {
	228	bo = entry->bo;
	229	entry->old_sync_obj = bo->sync_obj;
	230	bo->sync_obj = driver->sync_obj_ref(sync_obj);
	231	ttm_bo_unreserve_locked(bo);
	232	entry->reserved = false;
	233	}
	234	spin_unlock(&bdev->fence_lock);
	235	spin_unlock(&glob->lru_lock);
	236
	237	list_for_each_entry(entry, list, head) {
	238	if (entry->old_sync_obj)
	239	driver->sync_obj_unref(&entry->old_sync_obj);
	240	}
	241	}
	242	EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);