[RFC PATCH 1/7] android: Support creating sync fence from drm fences

Lauri Peltonen lpeltonen at nvidia.com
Fri Sep 26 03:00:06 PDT 2014


Modify sync_fence_create to accept an array of 'struct fence' objects.
This will allow drm drivers to create sync_fence objects and pass sync
fd's between user space with minimal modifications, without ever creating
sync_timeline or sync_pt objects, and without implementing the
sync_timeline_ops interface.

Modify the sync driver debug code to not assume that every 'struct fence'
(that is associated with a 'struct sync_fence') is embedded within a
'struct sync_pt'.

Signed-off-by: Lauri Peltonen <lpeltonen at nvidia.com>
---
 drivers/staging/android/sw_sync.c    |  3 ++-
 drivers/staging/android/sync.c       | 34 ++++++++++++++++++---------------
 drivers/staging/android/sync.h       | 11 ++++++-----
 drivers/staging/android/sync_debug.c | 37 +++++++++++++++++-------------------
 4 files changed, 44 insertions(+), 41 deletions(-)

diff --git a/drivers/staging/android/sw_sync.c b/drivers/staging/android/sw_sync.c
index a76db3f..6949812 100644
--- a/drivers/staging/android/sw_sync.c
+++ b/drivers/staging/android/sw_sync.c
@@ -184,7 +184,8 @@ static long sw_sync_ioctl_create_fence(struct sw_sync_timeline *obj,
 	}
 
 	data.name[sizeof(data.name) - 1] = '\0';
-	fence = sync_fence_create(data.name, pt);
+	fence = sync_fence_create(data.name,
+				  (struct fence *[]){ &pt->base }, 1);
 	if (fence == NULL) {
 		sync_pt_free(pt);
 		err = -ENOMEM;
diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c
index e7b2e02..1d0d968 100644
--- a/drivers/staging/android/sync.c
+++ b/drivers/staging/android/sync.c
@@ -187,28 +187,32 @@ static void fence_check_cb_func(struct fence *f, struct fence_cb *cb)
 		wake_up_all(&fence->wq);
 }
 
-/* TODO: implement a create which takes more that one sync_pt */
-struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt)
+struct sync_fence *sync_fence_create(const char *name,
+				     struct fence **fences, int num_fences)
 {
-	struct sync_fence *fence;
+	struct sync_fence *sync_fence;
+	int size = offsetof(struct sync_fence, cbs[num_fences]);
+	int i;
 
-	fence = sync_fence_alloc(offsetof(struct sync_fence, cbs[1]), name);
-	if (fence == NULL)
+	sync_fence = sync_fence_alloc(size, name);
+	if (sync_fence == NULL)
 		return NULL;
 
-	fence->num_fences = 1;
-	atomic_set(&fence->status, 1);
+	sync_fence->num_fences = num_fences;
+	atomic_set(&sync_fence->status, 0);
 
-	fence_get(&pt->base);
-	fence->cbs[0].sync_pt = &pt->base;
-	fence->cbs[0].fence = fence;
-	if (fence_add_callback(&pt->base, &fence->cbs[0].cb,
-			       fence_check_cb_func))
-		atomic_dec(&fence->status);
+	for (i = 0; i < num_fences; i++) {
+		struct fence *f = fences[i];
+		struct sync_fence_cb *cb = &sync_fence->cbs[i];
 
-	sync_fence_debug_add(fence);
+		cb->sync_pt = fence_get(f);
+		cb->fence = sync_fence;
+		if (!fence_add_callback(f, &cb->cb, fence_check_cb_func))
+			atomic_inc(&sync_fence->status);
+	}
+	sync_fence_debug_add(sync_fence);
 
-	return fence;
+	return sync_fence;
 }
 EXPORT_SYMBOL(sync_fence_create);
 
diff --git a/drivers/staging/android/sync.h b/drivers/staging/android/sync.h
index 66b0f43..b8ad72c 100644
--- a/drivers/staging/android/sync.h
+++ b/drivers/staging/android/sync.h
@@ -246,13 +246,14 @@ void sync_pt_free(struct sync_pt *pt);
 
 /**
  * sync_fence_create() - creates a sync fence
- * @name:	name of fence to create
- * @pt:		sync_pt to add to the fence
+ * @name:	name of the sync fence to create
+ * @fences:	fences to add to the sync fence
+ * @num_fences:	the number of fences in the @fences array
  *
- * Creates a fence containg @pt.  Once this is called, the fence takes
- * ownership of @pt.
+ * Creates a sync fence from an array of drm fences. Takes refs to @fences.
  */
-struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt);
+struct sync_fence *sync_fence_create(const char *name,
+				     struct fence **fences, int num_fences);
 
 /*
  * API for sync_fence consumers
diff --git a/drivers/staging/android/sync_debug.c b/drivers/staging/android/sync_debug.c
index 257fc91..2d8873e 100644
--- a/drivers/staging/android/sync_debug.c
+++ b/drivers/staging/android/sync_debug.c
@@ -81,33 +81,33 @@ static const char *sync_status_str(int status)
 	return "error";
 }
 
-static void sync_print_pt(struct seq_file *s, struct sync_pt *pt, bool fence)
+static void sync_print_pt(struct seq_file *s, struct fence *pt, bool fence)
 {
 	int status = 1;
-	struct sync_timeline *parent = sync_pt_parent(pt);
 
-	if (fence_is_signaled_locked(&pt->base))
-		status = pt->base.status;
+	if (fence_is_signaled_locked(pt))
+		status = pt->status;
 
-	seq_printf(s, "  %s%spt %s",
-		   fence ? parent->name : "",
-		   fence ? "_" : "",
-		   sync_status_str(status));
+	if (fence)
+		seq_printf(s, "  %d_pt %s", pt->context,
+			   sync_status_str(status));
+	else
+		seq_printf(s, "  pt %s", sync_status_str(status));
 
 	if (status <= 0) {
-		struct timeval tv = ktime_to_timeval(pt->base.timestamp);
+		struct timeval tv = ktime_to_timeval(pt->timestamp);
 
 		seq_printf(s, "@%ld.%06ld", tv.tv_sec, tv.tv_usec);
 	}
 
-	if (parent->ops->timeline_value_str &&
-	    parent->ops->pt_value_str) {
+	if (pt->ops->timeline_value_str &&
+	    pt->ops->fence_value_str) {
 		char value[64];
 
-		parent->ops->pt_value_str(pt, value, sizeof(value));
+		pt->ops->fence_value_str(pt, value, sizeof(value));
 		seq_printf(s, ": %s", value);
 		if (fence) {
-			parent->ops->timeline_value_str(parent, value,
+			pt->ops->timeline_value_str(pt, value,
 						    sizeof(value));
 			seq_printf(s, " / %s", value);
 		}
@@ -121,7 +121,8 @@ static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
 	struct list_head *pos;
 	unsigned long flags;
 
-	seq_printf(s, "%s %s", obj->name, obj->ops->driver_name);
+	seq_printf(s, "%d %s %s", obj->context, obj->name,
+		   obj->ops->driver_name);
 
 	if (obj->ops->timeline_value_str) {
 		char value[64];
@@ -136,7 +137,7 @@ static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
 	list_for_each(pos, &obj->child_list_head) {
 		struct sync_pt *pt =
 			container_of(pos, struct sync_pt, child_list);
-		sync_print_pt(s, pt, false);
+		sync_print_pt(s, &pt->base, false);
 	}
 	spin_unlock_irqrestore(&obj->child_list_lock, flags);
 }
@@ -151,11 +152,7 @@ static void sync_print_fence(struct seq_file *s, struct sync_fence *fence)
 		   sync_status_str(atomic_read(&fence->status)));
 
 	for (i = 0; i < fence->num_fences; ++i) {
-		struct sync_pt *pt =
-			container_of(fence->cbs[i].sync_pt,
-				     struct sync_pt, base);
-
-		sync_print_pt(s, pt, true);
+		sync_print_pt(s, fence->cbs[i].sync_pt, true);
 	}
 
 	spin_lock_irqsave(&fence->wq.lock, flags);
-- 
1.8.1.5



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