drm/msm/gem: Convert to lockdep assert

Utilize the power of lockdep for our GEM locking related sanity
checking.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/496139/
Link: https://lore.kernel.org/r/20220802155152.1727594-16-robdclark@gmail.com

diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h
index 3c6add5..c4844cf 100644 (file)
--- a/drivers/gpu/drm/msm/msm_gem.h
+++ b/drivers/gpu/drm/msm/msm_gem.h
@@ -197,8 +197,8 @@ msm_gem_unlock(struct drm_gem_object *obj)
        dma_resv_unlock(obj->resv);
 }
 
-static inline bool
-msm_gem_is_locked(struct drm_gem_object *obj)
+static inline void
+msm_gem_assert_locked(struct drm_gem_object *obj)
 {
        /*
         * Destroying the object is a special case.. msm_gem_free_object()
@@ -212,13 +212,10 @@ msm_gem_is_locked(struct drm_gem_object *obj)
         * Unfortunately lockdep is not aware of this detail.  So when the
         * refcount drops to zero, we pretend it is already locked.
         */
-       return dma_resv_is_locked(obj->resv) || (kref_read(&obj->refcount) == 0);
-}
-
-static inline void
-msm_gem_assert_locked(struct drm_gem_object *obj)
-{
-       GEM_WARN_ON(!msm_gem_is_locked(obj));
+       lockdep_assert_once(
+               (kref_read(&obj->refcount) == 0) ||
+               (lockdep_is_held(&obj->resv->lock.base) != LOCK_STATE_NOT_HELD)
+       );
 }
 
 /* imported/exported objects are not purgeable: */