From 563eaf53317f2511f78217a1f8d785b8c8ed1cad Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Thu, 2 Nov 2017 22:03:35 +0200 Subject: [PATCH] drm/syncobj: Use proper methods for accessing rcu protected pointers MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Use rcu_dereference_protected() and rcu_assign_pointer() for accessing the rcu protected syncobj->fence pointer. This eliminates several sparse warnings. Cc: Dave Airlie Cc: Jason Ekstrand Cc: linaro-mm-sig@lists.linaro.org Cc: linux-media@vger.kernel.org Cc: Alex Deucher Cc: Christian König Cc: Sumit Semwal Cc: Chris Wilson Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20171102200336.23347-4-ville.syrjala@linux.intel.com Reviewed-by: Daniel Vetter Acked-by: Christian König --- drivers/gpu/drm/drm_syncobj.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index 7081ae601d6f..7943c215a03c 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -106,7 +106,8 @@ static int drm_syncobj_fence_get_or_add_callback(struct drm_syncobj *syncobj, * callback when a fence has already been set. */ if (syncobj->fence) { - *fence = dma_fence_get(syncobj->fence); + *fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, + lockdep_is_held(&syncobj->lock))); ret = 1; } else { *fence = NULL; @@ -168,8 +169,9 @@ void drm_syncobj_replace_fence(struct drm_syncobj *syncobj, spin_lock(&syncobj->lock); - old_fence = syncobj->fence; - syncobj->fence = fence; + old_fence = rcu_dereference_protected(syncobj->fence, + lockdep_is_held(&syncobj->lock)); + rcu_assign_pointer(syncobj->fence, fence); if (fence != old_fence) { list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node) { @@ -613,7 +615,8 @@ static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj, container_of(cb, struct syncobj_wait_entry, syncobj_cb); /* This happens inside the syncobj lock */ - wait->fence = dma_fence_get(syncobj->fence); + wait->fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, + lockdep_is_held(&syncobj->lock))); wake_up_process(wait->task); } -- 2.30.2