- Sync File API Guide
- ~~~~~~~~~~~~~~~~~~~
+===================
+Sync File API Guide
+===================
- Gustavo Padovan
- <gustavo at padovan dot org>
+:Author: Gustavo Padovan <gustavo at padovan dot org>
This document serves as a guide for device drivers writers on what the
sync_file API is, and how drivers can support it. Sync file is the carrier of
When a driver needs to send an out-fence userspace it creates a sync_file.
-Interface:
+Interface::
+
struct sync_file *sync_file_create(struct dma_fence *fence);
The caller pass the out-fence and gets back the sync_file. That is just the
first step, next it needs to install an fd on sync_file->file. So it gets an
-fd:
+fd::
fd = get_unused_fd_flags(O_CLOEXEC);
-and installs it on sync_file->file:
+and installs it on sync_file->file::
fd_install(fd, sync_file->file);
of the Sync File to the kernel. The kernel can then retrieve the fences
from it.
-Interface:
+Interface::
+
struct dma_fence *sync_file_get_fence(int fd);
afterwards using dma_fence_put(). In case of error, a NULL is returned instead.
References:
-[1] struct sync_file in include/linux/sync_file.h
-[2] All interfaces mentioned above defined in include/linux/sync_file.h
+
+1. struct sync_file in include/linux/sync_file.h
+2. All interfaces mentioned above defined in include/linux/sync_file.h