drm/nouveau/nvkm: add locking to subdev/engine init paths

This wasn't really needed before; the main place this could race is with
channel recovery, but (through potentially fragile means) shouldn't have
been possible.

However, a number of upcoming patches benefit from having better control
over subdev init, necessitating some improvements here.

- allows subdev/engine oneinit() without init() (host/fifo patches)
- merges engine use locking/tracking into subdev, and extends it to fix
  some issues that will arise with future usage patterns (acr patches)

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

1 files changed, 0 insertions, 6 deletions

diff --git a/drivers/gpu/drm/nouveau/include/nvkm/core/engine.h b/drivers/gpu/drm/nouveau/include/nvkm/core/engine.h
index e58923b67d74..6d15c13509bf 100644
--- a/drivers/gpu/drm/nouveau/include/nvkm/core/engine.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/core/engine.h
@@ -12,12 +12,6 @@ struct nvkm_engine {
 	const struct nvkm_engine_func *func;
 	struct nvkm_subdev subdev;
 	spinlock_t lock;
-
-	struct {
-		refcount_t refcount;
-		struct mutex mutex;
-		bool enabled;
-	} use;
 };
 
 struct nvkm_engine_func {