1 files changed, 85 insertions, 365 deletions

diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
index da8175d9c6ff..e19525af0cce 100644
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -56,47 +56,16 @@
 #include "drm_internal.h"
 #include <drm/drm_syncobj.h>
 
-/* merge normal syncobj to timeline syncobj, the point interval is 1 */
-#define DRM_SYNCOBJ_BINARY_POINT 1
-
-struct drm_syncobj_stub_fence {
-	struct dma_fence base;
-	spinlock_t lock;
-};
-
-static const char *drm_syncobj_stub_fence_get_name(struct dma_fence *fence)
-{
-        return "syncobjstub";
-}
-
-static const struct dma_fence_ops drm_syncobj_stub_fence_ops = {
-	.get_driver_name = drm_syncobj_stub_fence_get_name,
-	.get_timeline_name = drm_syncobj_stub_fence_get_name,
-};
-
-struct drm_syncobj_signal_pt {
-	struct dma_fence_array *fence_array;
-	u64    value;
-	struct list_head list;
+struct syncobj_wait_entry {
+	struct list_head node;
+	struct task_struct *task;
+	struct dma_fence *fence;
+	struct dma_fence_cb fence_cb;
 };
 
-static DEFINE_SPINLOCK(signaled_fence_lock);
-static struct dma_fence signaled_fence;
-
-static struct dma_fence *drm_syncobj_get_stub_fence(void)
-{
-	spin_lock(&signaled_fence_lock);
-	if (!signaled_fence.ops) {
-		dma_fence_init(&signaled_fence,
-			       &drm_syncobj_stub_fence_ops,
-			       &signaled_fence_lock,
-			       0, 0);
-		dma_fence_signal_locked(&signaled_fence);
-	}
-	spin_unlock(&signaled_fence_lock);
+static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
+				      struct syncobj_wait_entry *wait);
 
-	return dma_fence_get(&signaled_fence);
-}
 /**
  * drm_syncobj_find - lookup and reference a sync object.
  * @file_private: drm file private pointer
@@ -123,302 +92,84 @@ struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
 }
 EXPORT_SYMBOL(drm_syncobj_find);
 
-static struct dma_fence *
-drm_syncobj_find_signal_pt_for_point(struct drm_syncobj *syncobj,
-				     uint64_t point)
+static void drm_syncobj_fence_add_wait(struct drm_syncobj *syncobj,
+				       struct syncobj_wait_entry *wait)
 {
-	struct drm_syncobj_signal_pt *signal_pt;
-
-	if ((syncobj->type == DRM_SYNCOBJ_TYPE_TIMELINE) &&
-	    (point <= syncobj->timeline))
-		return drm_syncobj_get_stub_fence();
-
-	list_for_each_entry(signal_pt, &syncobj->signal_pt_list, list) {
-		if (point > signal_pt->value)
-			continue;
-		if ((syncobj->type == DRM_SYNCOBJ_TYPE_BINARY) &&
-		    (point != signal_pt->value))
-			continue;
-		return dma_fence_get(&signal_pt->fence_array->base);
-	}
-	return NULL;
-}
-
-static void drm_syncobj_add_callback_locked(struct drm_syncobj *syncobj,
-					    struct drm_syncobj_cb *cb,
-					    drm_syncobj_func_t func)
-{
-	cb->func = func;
-	list_add_tail(&cb->node, &syncobj->cb_list);
-}
-
-static void drm_syncobj_fence_get_or_add_callback(struct drm_syncobj *syncobj,
-						  struct dma_fence **fence,
-						  struct drm_syncobj_cb *cb,
-						  drm_syncobj_func_t func)
-{
-	u64 pt_value = 0;
-
-	WARN_ON(*fence);
-
-	if (syncobj->type == DRM_SYNCOBJ_TYPE_BINARY) {
-		/*BINARY syncobj always wait on last pt */
-		pt_value = syncobj->signal_point;
-
-		if (pt_value == 0)
-			pt_value += DRM_SYNCOBJ_BINARY_POINT;
-	}
-
-	mutex_lock(&syncobj->cb_mutex);
-	spin_lock(&syncobj->pt_lock);
-	*fence = drm_syncobj_find_signal_pt_for_point(syncobj, pt_value);
-	spin_unlock(&syncobj->pt_lock);
-	if (!*fence)
-		drm_syncobj_add_callback_locked(syncobj, cb, func);
-	mutex_unlock(&syncobj->cb_mutex);
-}
-
-static void drm_syncobj_remove_callback(struct drm_syncobj *syncobj,
-					struct drm_syncobj_cb *cb)
-{
-	mutex_lock(&syncobj->cb_mutex);
-	list_del_init(&cb->node);
-	mutex_unlock(&syncobj->cb_mutex);
-}
+	if (wait->fence)
+		return;
 
-static void drm_syncobj_init(struct drm_syncobj *syncobj)
-{
-	spin_lock(&syncobj->pt_lock);
-	syncobj->timeline_context = dma_fence_context_alloc(1);
-	syncobj->timeline = 0;
-	syncobj->signal_point = 0;
-	init_waitqueue_head(&syncobj->wq);
-
-	INIT_LIST_HEAD(&syncobj->signal_pt_list);
-	spin_unlock(&syncobj->pt_lock);
-}
-
-static void drm_syncobj_fini(struct drm_syncobj *syncobj)
-{
-	struct drm_syncobj_signal_pt *signal_pt = NULL, *tmp;
-
-	spin_lock(&syncobj->pt_lock);
-	list_for_each_entry_safe(signal_pt, tmp,
-				 &syncobj->signal_pt_list, list) {
-		list_del(&signal_pt->list);
-		dma_fence_put(&signal_pt->fence_array->base);
-		kfree(signal_pt);
-	}
-	spin_unlock(&syncobj->pt_lock);
+	spin_lock(&syncobj->lock);
+	/* We've already tried once to get a fence and failed.  Now that we
+	 * have the lock, try one more time just to be sure we don't add a
+	 * callback when a fence has already been set.
+	 */
+	if (syncobj->fence)
+		wait->fence = dma_fence_get(
+			rcu_dereference_protected(syncobj->fence, 1));
+	else
+		list_add_tail(&wait->node, &syncobj->cb_list);
+	spin_unlock(&syncobj->lock);
 }
 
-static int drm_syncobj_create_signal_pt(struct drm_syncobj *syncobj,
-					struct dma_fence *fence,
-					u64 point)
+static void drm_syncobj_remove_wait(struct drm_syncobj *syncobj,
+				    struct syncobj_wait_entry *wait)
 {
-	struct drm_syncobj_signal_pt *signal_pt =
-		kzalloc(sizeof(struct drm_syncobj_signal_pt), GFP_KERNEL);
-	struct drm_syncobj_signal_pt *tail_pt;
-	struct dma_fence **fences;
-	int num_fences = 0;
-	int ret = 0, i;
-
-	if (!signal_pt)
-		return -ENOMEM;
-	if (!fence)
-		goto out;
-
-	fences = kmalloc_array(sizeof(void *), 2, GFP_KERNEL);
-	if (!fences) {
-		ret = -ENOMEM;
-		goto out;
-	}
-	fences[num_fences++] = dma_fence_get(fence);
-	/* timeline syncobj must take this dependency */
-	if (syncobj->type == DRM_SYNCOBJ_TYPE_TIMELINE) {
-		spin_lock(&syncobj->pt_lock);
-		if (!list_empty(&syncobj->signal_pt_list)) {
-			tail_pt = list_last_entry(&syncobj->signal_pt_list,
-						  struct drm_syncobj_signal_pt, list);
-			fences[num_fences++] =
-				dma_fence_get(&tail_pt->fence_array->base);
-		}
-		spin_unlock(&syncobj->pt_lock);
-	}
-	signal_pt->fence_array = dma_fence_array_create(num_fences, fences,
-							syncobj->timeline_context,
-							point, false);
-	if (!signal_pt->fence_array) {
-		ret = -ENOMEM;
-		goto fail;
-	}
+	if (!wait->node.next)
+		return;
 
-	spin_lock(&syncobj->pt_lock);
-	if (syncobj->signal_point >= point) {
-		DRM_WARN("A later signal is ready!");
-		spin_unlock(&syncobj->pt_lock);
-		goto exist;
-	}
-	signal_pt->value = point;
-	list_add_tail(&signal_pt->list, &syncobj->signal_pt_list);
-	syncobj->signal_point = point;
-	spin_unlock(&syncobj->pt_lock);
-	wake_up_all(&syncobj->wq);
-
-	return 0;
-exist:
-	dma_fence_put(&signal_pt->fence_array->base);
-fail:
-	for (i = 0; i < num_fences; i++)
-		dma_fence_put(fences[i]);
-	kfree(fences);
-out:
-	kfree(signal_pt);
-	return ret;
+	spin_lock(&syncobj->lock);
+	list_del_init(&wait->node);
+	spin_unlock(&syncobj->lock);
 }
 
-static void drm_syncobj_garbage_collection(struct drm_syncobj *syncobj)
-{
-	struct drm_syncobj_signal_pt *signal_pt, *tmp, *tail_pt;
-
-	spin_lock(&syncobj->pt_lock);
-	tail_pt = list_last_entry(&syncobj->signal_pt_list,
-				  struct drm_syncobj_signal_pt,
-				  list);
-	list_for_each_entry_safe(signal_pt, tmp,
-				 &syncobj->signal_pt_list, list) {
-		if (syncobj->type == DRM_SYNCOBJ_TYPE_BINARY &&
-		    signal_pt == tail_pt)
-			continue;
-		if (dma_fence_is_signaled(&signal_pt->fence_array->base)) {
-			syncobj->timeline = signal_pt->value;
-			list_del(&signal_pt->list);
-			dma_fence_put(&signal_pt->fence_array->base);
-			kfree(signal_pt);
-		} else {
-			/*signal_pt is in order in list, from small to big, so
-			 * the later must not be signal either */
-			break;
-		}
-	}
-
-	spin_unlock(&syncobj->pt_lock);
-}
 /**
  * drm_syncobj_replace_fence - replace fence in a sync object.
  * @syncobj: Sync object to replace fence in
- * @point: timeline point
  * @fence: fence to install in sync file.
  *
- * This replaces the fence on a sync object, or a timeline point fence.
+ * This replaces the fence on a sync object.
  */
 void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
-			       u64 point,
 			       struct dma_fence *fence)
 {
-	u64 pt_value = point;
-
-	drm_syncobj_garbage_collection(syncobj);
-	if (syncobj->type == DRM_SYNCOBJ_TYPE_BINARY) {
-		if (!fence) {
-			drm_syncobj_fini(syncobj);
-			drm_syncobj_init(syncobj);
-			return;
-		}
-		pt_value = syncobj->signal_point +
-			DRM_SYNCOBJ_BINARY_POINT;
-	}
-	drm_syncobj_create_signal_pt(syncobj, fence, pt_value);
-	if (fence) {
-		struct drm_syncobj_cb *cur, *tmp;
-		LIST_HEAD(cb_list);
+	struct dma_fence *old_fence;
+	struct syncobj_wait_entry *cur, *tmp;
+
+	if (fence)
+		dma_fence_get(fence);
+
+	spin_lock(&syncobj->lock);
+
+	old_fence = rcu_dereference_protected(syncobj->fence,
+					      lockdep_is_held(&syncobj->lock));
+	rcu_assign_pointer(syncobj->fence, fence);
 
-		mutex_lock(&syncobj->cb_mutex);
+	if (fence != old_fence) {
 		list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node) {
 			list_del_init(&cur->node);
-			cur->func(syncobj, cur);
+			syncobj_wait_syncobj_func(syncobj, cur);
 		}
-		mutex_unlock(&syncobj->cb_mutex);
 	}
-}
-EXPORT_SYMBOL(drm_syncobj_replace_fence);
-
-static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
-{
-	struct drm_syncobj_stub_fence *fence;
-	fence = kzalloc(sizeof(*fence), GFP_KERNEL);
-	if (fence == NULL)
-		return -ENOMEM;
 
-	spin_lock_init(&fence->lock);
-	dma_fence_init(&fence->base, &drm_syncobj_stub_fence_ops,
-		       &fence->lock, 0, 0);
-	dma_fence_signal(&fence->base);
+	spin_unlock(&syncobj->lock);
 
-	drm_syncobj_replace_fence(syncobj, 0, &fence->base);
-
-	dma_fence_put(&fence->base);
-
-	return 0;
-}
-
-static int
-drm_syncobj_point_get(struct drm_syncobj *syncobj, u64 point, u64 flags,
-		      struct dma_fence **fence)
-{
-	int ret = 0;
-
-	if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
-		ret = wait_event_interruptible(syncobj->wq,
-					       point <= syncobj->signal_point);
-		if (ret < 0)
-			return ret;
-	}
-	spin_lock(&syncobj->pt_lock);
-	*fence = drm_syncobj_find_signal_pt_for_point(syncobj, point);
-	if (!*fence)
-		ret = -EINVAL;
-	spin_unlock(&syncobj->pt_lock);
-	return ret;
+	dma_fence_put(old_fence);
 }
+EXPORT_SYMBOL(drm_syncobj_replace_fence);
 
 /**
- * drm_syncobj_search_fence - lookup and reference the fence in a sync object or
- * in a timeline point
- * @syncobj: sync object pointer
- * @point: timeline point
- * @flags: DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT or not
- * @fence: out parameter for the fence
- *
- * if flags is DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT, the function will block
- * here until specific timeline points is reached.
- * if not, you need a submit thread and block in userspace until all future
- * timeline points have materialized, only then you can submit to the kernel,
- * otherwise, function will fail to return fence.
+ * drm_syncobj_assign_null_handle - assign a stub fence to the sync object
+ * @syncobj: sync object to assign the fence on
  *
- * Returns 0 on success or a negative error value on failure. On success @fence
- * contains a reference to the fence, which must be released by calling
- * dma_fence_put().
+ * Assign a already signaled stub fence to the sync object.
  */
-int drm_syncobj_search_fence(struct drm_syncobj *syncobj, u64 point,
-			     u64 flags, struct dma_fence **fence)
+static void drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
 {
-	u64 pt_value = point;
-
-	if (!syncobj)
-		return -ENOENT;
+	struct dma_fence *fence = dma_fence_get_stub();
 
-	drm_syncobj_garbage_collection(syncobj);
-	if (syncobj->type == DRM_SYNCOBJ_TYPE_BINARY) {
-		/*BINARY syncobj always wait on last pt */
-		pt_value = syncobj->signal_point;
-
-		if (pt_value == 0)
-			pt_value += DRM_SYNCOBJ_BINARY_POINT;
-	}
-	return drm_syncobj_point_get(syncobj, pt_value, flags, fence);
+	drm_syncobj_replace_fence(syncobj, fence);
+	dma_fence_put(fence);
 }
-EXPORT_SYMBOL(drm_syncobj_search_fence);
 
 /**
  * drm_syncobj_find_fence - lookup and reference the fence in a sync object
@@ -429,7 +180,7 @@ EXPORT_SYMBOL(drm_syncobj_search_fence);
  * @fence: out parameter for the fence
  *
  * This is just a convenience function that combines drm_syncobj_find() and
- * drm_syncobj_lookup_fence().
+ * drm_syncobj_fence_get().
  *
  * Returns 0 on success or a negative error value on failure. On success @fence
  * contains a reference to the fence, which must be released by calling
@@ -440,11 +191,16 @@ int drm_syncobj_find_fence(struct drm_file *file_private,
 			   struct dma_fence **fence)
 {
 	struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
-	int ret;
+	int ret = 0;
 
-	ret = drm_syncobj_search_fence(syncobj, point, flags, fence);
-	if (syncobj)
-		drm_syncobj_put(syncobj);
+	if (!syncobj)
+		return -ENOENT;
+
+	*fence = drm_syncobj_fence_get(syncobj);
+	if (!*fence) {
+		ret = -EINVAL;
+	}
+	drm_syncobj_put(syncobj);
 	return ret;
 }
 EXPORT_SYMBOL(drm_syncobj_find_fence);
@@ -460,7 +216,7 @@ void drm_syncobj_free(struct kref *kref)
 	struct drm_syncobj *syncobj = container_of(kref,
 						   struct drm_syncobj,
 						   refcount);
-	drm_syncobj_fini(syncobj);
+	drm_syncobj_replace_fence(syncobj, NULL);
 	kfree(syncobj);
 }
 EXPORT_SYMBOL(drm_syncobj_free);
@@ -480,7 +236,6 @@ EXPORT_SYMBOL(drm_syncobj_free);
 int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
 		       struct dma_fence *fence)
 {
-	int ret;
 	struct drm_syncobj *syncobj;
 
 	syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
@@ -489,24 +244,13 @@ int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
 
 	kref_init(&syncobj->refcount);
 	INIT_LIST_HEAD(&syncobj->cb_list);
-	spin_lock_init(&syncobj->pt_lock);
-	mutex_init(&syncobj->cb_mutex);
-	if (flags & DRM_SYNCOBJ_CREATE_TYPE_TIMELINE)
-		syncobj->type = DRM_SYNCOBJ_TYPE_TIMELINE;
-	else
-		syncobj->type = DRM_SYNCOBJ_TYPE_BINARY;
-	drm_syncobj_init(syncobj);
-
-	if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
-		ret = drm_syncobj_assign_null_handle(syncobj);
-		if (ret < 0) {
-			drm_syncobj_put(syncobj);
-			return ret;
-		}
-	}
+	spin_lock_init(&syncobj->lock);
+
+	if (flags & DRM_SYNCOBJ_CREATE_SIGNALED)
+		drm_syncobj_assign_null_handle(syncobj);
 
 	if (fence)
-		drm_syncobj_replace_fence(syncobj, 0, fence);
+		drm_syncobj_replace_fence(syncobj, fence);
 
 	*out_syncobj = syncobj;
 	return 0;
@@ -691,7 +435,7 @@ static int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
 		return -ENOENT;
 	}
 
-	drm_syncobj_replace_fence(syncobj, 0, fence);
+	drm_syncobj_replace_fence(syncobj, fence);
 	dma_fence_put(fence);
 	drm_syncobj_put(syncobj);
 	return 0;
@@ -778,8 +522,7 @@ drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
 		return -EOPNOTSUPP;
 
 	/* no valid flags yet */
-	if (args->flags & ~(DRM_SYNCOBJ_CREATE_SIGNALED |
-			    DRM_SYNCOBJ_CREATE_TYPE_TIMELINE))
+	if (args->flags & ~DRM_SYNCOBJ_CREATE_SIGNALED)
 		return -EINVAL;
 
 	return drm_syncobj_create_as_handle(file_private,
@@ -850,13 +593,6 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
 					&args->handle);
 }
 
-struct syncobj_wait_entry {
-	struct task_struct *task;
-	struct dma_fence *fence;
-	struct dma_fence_cb fence_cb;
-	struct drm_syncobj_cb syncobj_cb;
-};
-
 static void syncobj_wait_fence_func(struct dma_fence *fence,
 				    struct dma_fence_cb *cb)
 {
@@ -867,13 +603,11 @@ static void syncobj_wait_fence_func(struct dma_fence *fence,
 }
 
 static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
-				      struct drm_syncobj_cb *cb)
+				      struct syncobj_wait_entry *wait)
 {
-	struct syncobj_wait_entry *wait =
-		container_of(cb, struct syncobj_wait_entry, syncobj_cb);
-
-	drm_syncobj_search_fence(syncobj, 0, 0, &wait->fence);
-
+	/* This happens inside the syncobj lock */
+	wait->fence = dma_fence_get(rcu_dereference_protected(syncobj->fence,
+							      lockdep_is_held(&syncobj->lock)));
 	wake_up_process(wait->task);
 }
 
@@ -899,8 +633,7 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
 	signaled_count = 0;
 	for (i = 0; i < count; ++i) {
 		entries[i].task = current;
-		drm_syncobj_search_fence(syncobjs[i], 0, 0,
-					 &entries[i].fence);
+		entries[i].fence = drm_syncobj_fence_get(syncobjs[i]);
 		if (!entries[i].fence) {
 			if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
 				continue;
@@ -930,15 +663,8 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
 	 */
 
 	if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
-		for (i = 0; i < count; ++i) {
-			if (entries[i].fence)
-				continue;
-
-			drm_syncobj_fence_get_or_add_callback(syncobjs[i],
-							      &entries[i].fence,
-							      &entries[i].syncobj_cb,
-							      syncobj_wait_syncobj_func);
-		}
+		for (i = 0; i < count; ++i)
+			drm_syncobj_fence_add_wait(syncobjs[i], &entries[i]);
 	}
 
 	do {
@@ -987,9 +713,7 @@ done_waiting:
 
 cleanup_entries:
 	for (i = 0; i < count; ++i) {
-		if (entries[i].syncobj_cb.func)
-			drm_syncobj_remove_callback(syncobjs[i],
-						    &entries[i].syncobj_cb);
+		drm_syncobj_remove_wait(syncobjs[i], &entries[i]);
 		if (entries[i].fence_cb.func)
 			dma_fence_remove_callback(entries[i].fence,
 						  &entries[i].fence_cb);
@@ -1165,13 +889,12 @@ drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
 	if (ret < 0)
 		return ret;
 
-	for (i = 0; i < args->count_handles; i++) {
-		drm_syncobj_fini(syncobjs[i]);
-		drm_syncobj_init(syncobjs[i]);
-	}
+	for (i = 0; i < args->count_handles; i++)
+		drm_syncobj_replace_fence(syncobjs[i], NULL);
+
 	drm_syncobj_array_free(syncobjs, args->count_handles);
 
-	return ret;
+	return 0;
 }
 
 int
@@ -1199,11 +922,8 @@ drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
 	if (ret < 0)
 		return ret;
 
-	for (i = 0; i < args->count_handles; i++) {
-		ret = drm_syncobj_assign_null_handle(syncobjs[i]);
-		if (ret < 0)
-			break;
-	}
+	for (i = 0; i < args->count_handles; i++)
+		drm_syncobj_assign_null_handle(syncobjs[i]);
 
 	drm_syncobj_array_free(syncobjs, args->count_handles);