drm: introduce sync objects (v4)

Sync objects are new toplevel drm object, that contain a
pointer to a fence. This fence can be updated via command
submission ioctls via drivers.

There is also a generic wait obj API modelled on the vulkan
wait API (with code modelled on some amdgpu code).

These objects can be converted to an opaque fd that can be
passes between processes.

v2: rename reference/unreference to put/get (Chris)
fix leaked reference (David Zhou)
drop mutex in favour of cmpxchg (Chris)
v3: cleanups from danvet, rebase on drm_fops rename
check fd_flags is 0 in ioctls.
v4: export find/free, change replace fence to take a
syncobj. In order to support lookup first, replace
later semantics which seem in the end to be cleaner.

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index d66f7ee07fb5..0e0c868451a5 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -232,6 +232,11 @@ struct drm_file {
 	/** @table_lock: Protects @object_idr. */
 	spinlock_t table_lock;
 
+	/** @syncobj_idr: Mapping of sync object handles to object pointers. */
+	struct idr syncobj_idr;
+	/** @syncobj_table_lock: Protects @syncobj_idr. */
+	spinlock_t syncobj_table_lock;
+
 	/** @filp: Pointer to the core file structure. */
 	struct file *filp;