[RFC 2/5] dma-buf/fence-array: add fence_array_teardown()

[Gustavo Padovan <gustavo@padovan.org>]

From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

When using fences in sync files we need to clean up everything when
the sync file needs to be freed, thus we need to teardown fence_array,
by removing the callback of its fences and putting extra references to the
fence_array base fence.

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
---
 drivers/dma-buf/fence-array.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/dma-buf/fence-array.c b/drivers/dma-buf/fence-array.c
index a8731c8..601448a 100644
--- a/drivers/dma-buf/fence-array.c
+++ b/drivers/dma-buf/fence-array.c
@@ -79,6 +79,21 @@ static bool fence_array_signaled(struct fence *fence)
 	return atomic_read(&array->num_pending) <= 0;
 }
 
+static void fence_array_teardown(struct fence *fence)
+{
+	struct fence_array *array = to_fence_array(fence);
+	struct fence_array_cb *cb = (void *)(&array[1]);
+	int i;
+
+	for (i = 0; i < array->num_fences; i++) {
+		if (fence_is_signaled(array->fences[i]))
+		    continue;
+
+		fence_remove_callback(array->fences[i], &cb[i].cb);
+		fence_put(&array->base);
+	}
+}
+
 static void fence_array_release(struct fence *fence)
 {
 	struct fence_array *array = to_fence_array(fence);
@@ -97,6 +112,7 @@ const struct fence_ops fence_array_ops = {
 	.enable_signaling = fence_array_enable_signaling,
 	.signaled = fence_array_signaled,
 	.wait = fence_default_wait,
+	.teardown = fence_array_teardown,
 	.release = fence_array_release,
 };
 
-- 
2.5.5