1 // SPDX-License-Identifier: MIT
3  * Copyright (C) 2012-2014 Canonical Ltd (Maarten Lankhorst)
8  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
12  * copy of this software and associated documentation files (the
13  * "Software"), to deal in the Software without restriction, including
15  * distribute, sub license, and/or sell copies of the Software, and to
16  * permit persons to whom the Software is furnished to do so, subject to
21  * of the Software.
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
25  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
28  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
29  * USE OR OTHER DEALINGS IN THE SOFTWARE.
33  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
36 #include <linux/dma-resv.h>
37 #include <linux/dma-fence-array.h>
52  * locked write-side updates.
76 	tmp = (long)rcu_dereference_check(list->table[index],  in dma_resv_list_entry()
91 	RCU_INIT_POINTER(list->table[index], (struct dma_fence *)tmp);  in dma_resv_list_set()
111 	list->max_fences = (size - offsetof(typeof(*list), table)) /  in dma_resv_list_alloc()
112 		sizeof(*list->table);  in dma_resv_list_alloc()
125 	for (i = 0; i < list->num_fences; ++i) {  in dma_resv_list_free()
135  * dma_resv_init - initialize a reservation object
140 	ww_mutex_init(&obj->lock, &reservation_ww_class);  in dma_resv_init()
142 	RCU_INIT_POINTER(obj->fences, NULL);  in dma_resv_init()
147  * dma_resv_fini - destroys a reservation object
156 	dma_resv_list_free(rcu_dereference_protected(obj->fences, true));  in dma_resv_fini()
157 	ww_mutex_destroy(&obj->lock);  in dma_resv_fini()
164 	return rcu_dereference_check(obj->fences, dma_resv_held(obj));  in dma_resv_fences_list()
168  * dma_resv_reserve_fences - Reserve space to add fences to a dma_resv object.
173  * locked through dma_resv_lock().
175  * Note that the preallocated slots need to be re-reserved if @obj is unlocked
180  * Zero for success, or -errno
194 		return -EINVAL;  in dma_resv_reserve_fences()
197 	if (old && old->max_fences) {  in dma_resv_reserve_fences()
198 		if ((old->num_fences + num_fences) <= old->max_fences)  in dma_resv_reserve_fences()
200 		max = max(old->num_fences + num_fences, old->max_fences * 2);  in dma_resv_reserve_fences()
207 		return -ENOMEM;  in dma_resv_reserve_fences()
215 	for (i = 0, j = 0, k = max; i < (old ? old->num_fences : 0); ++i) {  in dma_resv_reserve_fences()
221 			RCU_INIT_POINTER(new->table[--k], fence);  in dma_resv_reserve_fences()
225 	new->num_fences = j;  in dma_resv_reserve_fences()
235 	rcu_assign_pointer(obj->fences, new);  in dma_resv_reserve_fences()
244 		fence = rcu_dereference_protected(new->table[i],  in dma_resv_reserve_fences()
256  * dma_resv_reset_max_fences - reset fences for debugging
259  * Reset the number of pre-reserved fence slots to test that drivers do
271 		fences->max_fences = fences->num_fences;  in dma_resv_reset_max_fences()
277  * dma_resv_add_fence - Add a fence to the dma_resv obj
282  * Add a fence to a slot, @obj must be locked with dma_resv_lock(), and
304 	count = fobj->num_fences;  in dma_resv_add_fence()
310 		if ((old->context == fence->context && old_usage >= usage &&  in dma_resv_add_fence()
319 	BUG_ON(fobj->num_fences >= fobj->max_fences);  in dma_resv_add_fence()
324 	smp_store_mb(fobj->num_fences, count);  in dma_resv_add_fence()
329  * dma_resv_replace_fences - replace fences in the dma_resv obj
352 	for (i = 0; list && i < list->num_fences; ++i) {  in dma_resv_replace_fences()
356 		if (old->context != context)  in dma_resv_replace_fences()
368 	cursor->index = 0;  in dma_resv_iter_restart_unlocked()
369 	cursor->num_fences = 0;  in dma_resv_iter_restart_unlocked()
370 	cursor->fences = dma_resv_fences_list(cursor->obj);  in dma_resv_iter_restart_unlocked()
371 	if (cursor->fences)  in dma_resv_iter_restart_unlocked()
372 		cursor->num_fences = cursor->fences->num_fences;  in dma_resv_iter_restart_unlocked()
373 	cursor->is_restarted = true;  in dma_resv_iter_restart_unlocked()
379 	if (!cursor->fences)  in dma_resv_iter_walk_unlocked()
384 		dma_fence_put(cursor->fence);  in dma_resv_iter_walk_unlocked()
386 		if (cursor->index >= cursor->num_fences) {  in dma_resv_iter_walk_unlocked()
387 			cursor->fence = NULL;  in dma_resv_iter_walk_unlocked()
392 		dma_resv_list_entry(cursor->fences, cursor->index++,  in dma_resv_iter_walk_unlocked()
393 				    cursor->obj, &cursor->fence,  in dma_resv_iter_walk_unlocked()
394 				    &cursor->fence_usage);  in dma_resv_iter_walk_unlocked()
395 		cursor->fence = dma_fence_get_rcu(cursor->fence);  in dma_resv_iter_walk_unlocked()
396 		if (!cursor->fence) {  in dma_resv_iter_walk_unlocked()
401 		if (!dma_fence_is_signaled(cursor->fence) &&  in dma_resv_iter_walk_unlocked()
402 		    cursor->usage >= cursor->fence_usage)  in dma_resv_iter_walk_unlocked()
408  * dma_resv_iter_first_unlocked - first fence in an unlocked dma_resv obj.
415  * this reason prefer the locked dma_resv_iter_first() whenever possible.
425 	} while (dma_resv_fences_list(cursor->obj) != cursor->fences);  in dma_resv_iter_first_unlocked()
428 	return cursor->fence;  in dma_resv_iter_first_unlocked()
433  * dma_resv_iter_next_unlocked - next fence in an unlocked dma_resv obj.
438  * this reason prefer the locked dma_resv_iter_next() whenever possible.
447 	cursor->is_restarted = false;  in dma_resv_iter_next_unlocked()
448 	restart = dma_resv_fences_list(cursor->obj) != cursor->fences;  in dma_resv_iter_next_unlocked()
454 	} while (dma_resv_fences_list(cursor->obj) != cursor->fences);  in dma_resv_iter_next_unlocked()
457 	return cursor->fence;  in dma_resv_iter_next_unlocked()
462  * dma_resv_iter_first - first fence from a locked dma_resv object
474 	dma_resv_assert_held(cursor->obj);  in dma_resv_iter_first()
476 	cursor->index = 0;  in dma_resv_iter_first()
477 	cursor->fences = dma_resv_fences_list(cursor->obj);  in dma_resv_iter_first()
480 	cursor->is_restarted = true;  in dma_resv_iter_first()
486  * dma_resv_iter_next - next fence from a locked dma_resv object
496 	dma_resv_assert_held(cursor->obj);  in dma_resv_iter_next()
498 	cursor->is_restarted = false;  in dma_resv_iter_next()
501 		if (!cursor->fences ||  in dma_resv_iter_next()
502 		    cursor->index >= cursor->fences->num_fences)  in dma_resv_iter_next()
505 		dma_resv_list_entry(cursor->fences, cursor->index++,  in dma_resv_iter_next()
506 				    cursor->obj, &fence, &cursor->fence_usage);  in dma_resv_iter_next()
507 	} while (cursor->fence_usage > cursor->usage);  in dma_resv_iter_next()
514  * dma_resv_copy_fences - Copy all fences from src to dst.
518  * Copy all fences from src to dst. dst-lock must be held.
539 				return -ENOMEM;  in dma_resv_copy_fences()
541 			list->num_fences = 0;  in dma_resv_copy_fences()
545 		dma_resv_list_set(list, list->num_fences++, f,  in dma_resv_copy_fences()
550 	list = rcu_replace_pointer(dst->fences, list, dma_resv_held(dst));  in dma_resv_copy_fences()
557  * dma_resv_get_fences - Get an object's fences
566  * Returns either zero or -ENOMEM.
585 				dma_fence_put((*fences)[--(*num_fences)]);  in dma_resv_get_fences()
589 			/* Eventually re-allocate the array */  in dma_resv_get_fences()
598 				return -ENOMEM;  in dma_resv_get_fences()
612  * dma_resv_get_singleton - Get a single fence for all the fences
618  * Returns either 0 for success or -ENOMEM.
653 		while (count--)  in dma_resv_get_singleton()
656 		return -ENOMEM;  in dma_resv_get_singleton()
659 	*fence = &array->base;  in dma_resv_get_singleton()
665  * dma_resv_wait_timeout - Wait on reservation's objects fences
674  * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or
700  * dma_resv_set_deadline - Set a deadline on reservation's objects fences
723  * dma_resv_test_signaled - Test if a reservation object's fences have been
751  * dma_resv_describe - Dump description of the resv object into seq_file
782 		return -ENOMEM;  in dma_resv_lockdep()
790 	if (ret == -EDEADLK)  in dma_resv_lockdep()