linux-kernel - [PATCH v4 15/15] drm/msm/gem: Convert to lockdep assert

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Date:   Tue,  2 Aug 2022 08:51:48 -0700
From:   Rob Clark <robdclark@...il.com>
To:     dri-devel@...ts.freedesktop.org
Cc:     freedreno@...ts.freedesktop.org, linux-arm-msm@...r.kernel.org,
        Rob Clark <robdclark@...omium.org>,
        Rob Clark <robdclark@...il.com>,
        Abhinav Kumar <quic_abhinavk@...cinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        Sean Paul <sean@...rly.run>, David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        linux-kernel@...r.kernel.org (open list)
Subject: [PATCH v4 15/15] drm/msm/gem: Convert to lockdep assert

From: Rob Clark <robdclark@...omium.org>

Signed-off-by: Rob Clark <robdclark@...omium.org>
---
 drivers/gpu/drm/msm/msm_gem.h | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h
index 3c6add51d13b..c4844cf3a585 100644
--- 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: */
-- 
2.36.1