From: Gustavo Padovan gustavo.padovan@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
Signed-off-by: Gustavo Padovan gustavo.padovan@collabora.co.uk --- drivers/dma-buf/sync_file.c | 60 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/sync_file.h | 3 +++ 2 files changed, 63 insertions(+)
diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c index 40ee098..5dd76c0 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-collection.h> #include <linux/sync_file.h> #include <uapi/linux/sync_file.h>
@@ -147,6 +148,62 @@ void sync_file_install(struct sync_file *sync_file, int fd) } EXPORT_SYMBOL(sync_file_install);
+/** + * sync_file_fences_get - get the fence(s) related to the sync_file fd + * @fd: sync_file fd to get the fence(s) 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_collection 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_fences_get(int fd) +{ + struct sync_file *sync_file; + struct fence_collection *collection; + struct fence_collection_cb *cb; + 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); + sync_file_put(sync_file); + return fence; + } + + cb = kcalloc(sync_file->num_fences, sizeof(*cb), GFP_KERNEL); + if (!cb) { + sync_file_put(sync_file); + return NULL; + } + + for (i = 0 ; i < sync_file->num_fences ; i++) + cb[i].fence = sync_file->cbs[i].fence; + + collection = fence_collection_create(sync_file->num_fences, cb); + if (!collection) { + kfree(cb); + sync_file_put(sync_file); + return NULL; + } + + sync_file->collection = collection; + fence_get(&collection->base); + sync_file_put(sync_file); + + return &collection->base; +} +EXPORT_SYMBOL(sync_file_fences_get); + static void sync_file_add_pt(struct sync_file *sync_file, int *i, struct fence *fence) { @@ -234,6 +291,9 @@ static void sync_file_free(struct kref *kref) kref); int i;
+ if (sync_file->collection) + fence_put(&sync_file->collection->base); + for (i = 0; i < sync_file->num_fences; ++i) { fence_remove_callback(sync_file->cbs[i].fence, &sync_file->cbs[i].cb); diff --git a/include/linux/sync_file.h b/include/linux/sync_file.h index 900fa0c..3eb3aad 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 + * @collection: collection with the fences in the sync_file * @cbs: sync_pts callback information */ struct sync_file { @@ -49,6 +50,7 @@ struct sync_file { wait_queue_head_t wq; atomic_t status;
+ struct fence_collection *collection; struct sync_file_cb cbs[]; };
@@ -59,4 +61,5 @@ void sync_file_install(struct sync_file *sync_file, int fd); struct sync_file *sync_file_merge(const char *name, struct sync_file *a, struct sync_file *b);
+struct fence *sync_file_fences_get(int fd); #endif /* _LINUX_SYNC_H */