From: Gustavo Padovan <gustavo.pado...@collabora.co.uk>
Creates a function that given an sync file descriptor returns a
fence_collection containing all fences in the sync_file.
If there is only one fence in the sync_file this fence itself is returned,
however if there is more than one, a fence_collection fence is returned.
v2: Comments by Daniel Vetter
- Adapt to new version of fence_collection_init()
- Hold a reference for the fence we return
v3: - Adapt to use fput() directly
- rename to sync_file_get_fence() as we always return one fence
v4: Adapt to use fence_array
Signed-off-by: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
---
drivers/dma-buf/sync_file.c | 61 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/sync_file.h | 4 ++-
2 files changed, 64 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c
index 59f3445..daaf411 100644
--- a/drivers/dma-buf/sync_file.c
+++ b/drivers/dma-buf/sync_file.c
@@ -23,6 +23,7 @@
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/anon_inodes.h>
+#include <linux/fence-array.h>
#include <linux/sync_file.h>
#include <uapi/linux/sync_file.h>
@@ -122,6 +123,63 @@ err:
return NULL;
}
+/**
+ * sync_file_get_fence - get the fence related to the sync_file fd
+ * @fd: sync_file fd to get the fence from
+ *
+ * Ensures @fd references a valid sync_file and returns a fence that
+ * represents all fence in the sync_file.
+ *
+ * If there is only one fence in the sync_file, this fence is returned.
+ * If there is more than one, a fence_array containing all fences
+ * is created and its base fence object is returned.
+ * On both cases a reference to the returned fence is held. On error
+ * NULL is returned.
+ */
+struct fence *sync_file_get_fence(int fd)
+{
+ struct sync_file *sync_file;
+ struct fence_array *fence_array;
+ struct fence **fences;
+ int i;
+
+ sync_file = sync_file_fdget(fd);
+ if (!sync_file)
+ return NULL;
+
+ if (sync_file->num_fences == 1) {
+ struct fence *fence = sync_file->cbs[0].fence;
+
+ fence_get(fence);
+ fput(sync_file->file);
+ return fence;
+ }
+
+ fences = kcalloc(sync_file->num_fences, sizeof(**fences), GFP_KERNEL);
+ if (!fences) {
+ fput(sync_file->file);
+ return NULL;
+ }
+
+ for (i = 0 ; i < sync_file->num_fences ; i++)
+ fences[i] = sync_file->cbs[i].fence;
+
+ fence_array = fence_array_create(sync_file->num_fences, fences,
+ fence_context_alloc(1), 1, false);
+ if (!fence_array) {
+ kfree(fences);
+ fput(sync_file->file);
+ return NULL;
+ }
+
+ sync_file->fence_array = fence_array;
+ fence_get(&fence_array->base);
+ fput(sync_file->file);
+
+ return &fence_array->base;
+}
+EXPORT_SYMBOL(sync_file_get_fence);
+
static void sync_file_add_pt(struct sync_file *sync_file, int *i,
struct fence *fence)
{
@@ -209,6 +267,9 @@ static void sync_file_free(struct kref *kref)
kref);
int i;
+ if (sync_file->fence_array)
+ fence_put(&sync_file->fence_array->base);
+
for (i = 0; i < sync_file->num_fences; ++i)
fence_put(sync_file->cbs[i].fence);
diff --git a/include/linux/sync_file.h b/include/linux/sync_file.h
index c6ffe8b..33cb3d6 100644
--- a/include/linux/sync_file.h
+++ b/include/linux/sync_file.h
@@ -35,6 +35,7 @@ struct sync_file_cb {
* @num_fences: number of sync_pts in the fence
* @wq: wait queue for fence signaling
* @status: 0: signaled, >0:active, <0: error
+ * @fence_array: array with the fences in the sync_file
* @cbs: sync_pts callback information
*/
struct sync_file {
@@ -49,9 +50,10 @@ struct sync_file {
wait_queue_head_t wq;
atomic_t status;
+ struct fence_array *fence_array;
struct sync_file_cb cbs[];
};
struct sync_file *sync_file_create(struct fence *fence);
-
+struct fence *sync_file_get_fence(int fd);
#endif /* _LINUX_SYNC_H */
--
2.5.5
