sync: add reference counting to timelines
If a timeline is destroyed while fences still hold pts on it, the reworked
fence release handler can cause the timeline to be freed before all it's points
are freed.
This change was squashed with the following change to resolve a
compilation failure.
Author: Erik Gilling <konkers@android.com>
Date: Fri Aug 24 13:48:34 2012 -0700
sync: clean up compiler warnings
Signed-off-by: Erik Gilling <konkers@android.com>
Change-Id: I1cd8ddb638eded7db9db446ff6b37f3dd165d6c4
Signed-off-by: Erik Gilling <konkers@android.com>
[mbohan@codeaurora.org: Fix compilation errors]
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
diff --git a/drivers/base/sync.c b/drivers/base/sync.c
index 5eb5d33..65b2a5a 100644
--- a/drivers/base/sync.c
+++ b/drivers/base/sync.c
@@ -51,6 +51,7 @@
if (obj == NULL)
return NULL;
+ kref_init(&obj->kref);
obj->ops = ops;
strlcpy(obj->name, name, sizeof(obj->name));
@@ -68,8 +69,10 @@
}
EXPORT_SYMBOL(sync_timeline_create);
-static void sync_timeline_free(struct sync_timeline *obj)
+static void sync_timeline_free(struct kref *kref)
{
+ struct sync_timeline *obj =
+ container_of(kref, struct sync_timeline, kref);
unsigned long flags;
if (obj->ops->release_obj)
@@ -84,17 +87,14 @@
void sync_timeline_destroy(struct sync_timeline *obj)
{
- unsigned long flags;
- bool needs_freeing;
-
- spin_lock_irqsave(&obj->child_list_lock, flags);
obj->destroyed = true;
- needs_freeing = list_empty(&obj->child_list_head);
- spin_unlock_irqrestore(&obj->child_list_lock, flags);
- if (needs_freeing)
- sync_timeline_free(obj);
- else
+ /*
+ * If this is not the last reference, signal any children
+ * that their parent is going away.
+ */
+
+ if (!kref_put(&obj->kref, sync_timeline_free))
sync_timeline_signal(obj);
}
EXPORT_SYMBOL(sync_timeline_destroy);
@@ -114,7 +114,6 @@
{
struct sync_timeline *obj = pt->parent;
unsigned long flags;
- bool needs_freeing = false;
spin_lock_irqsave(&obj->active_list_lock, flags);
if (!list_empty(&pt->active_list))
@@ -124,13 +123,8 @@
spin_lock_irqsave(&obj->child_list_lock, flags);
if (!list_empty(&pt->child_list)) {
list_del_init(&pt->child_list);
- needs_freeing = obj->destroyed &&
- list_empty(&obj->child_list_head);
}
spin_unlock_irqrestore(&obj->child_list_lock, flags);
-
- if (needs_freeing)
- sync_timeline_free(obj);
}
void sync_timeline_signal(struct sync_timeline *obj)
@@ -177,6 +171,7 @@
return NULL;
INIT_LIST_HEAD(&pt->active_list);
+ kref_get(&parent->kref);
sync_timeline_add_pt(parent, pt);
return pt;
@@ -190,6 +185,8 @@
sync_timeline_remove_pt(pt);
+ kref_put(&pt->parent->kref, sync_timeline_free);
+
kfree(pt);
}
EXPORT_SYMBOL(sync_pt_free);