This helper tests whether a given node is currently linked into a drm_mm manager. We use the node->mm pointer for that as it is set for all linked objects.
We also reset node->mm whenever a node is removed. All such access is currently safe as everyone calls kfree() on the object directly after removing it. Furthermore, no-one is supposed to access node->mm from outside drm_mm.c, anyway.
Signed-off-by: David Herrmann dh.herrmann@gmail.com --- drivers/gpu/drm/drm_mm.c | 1 + include/drm/drm_mm.h | 5 +++++ 2 files changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c index 7917729..3bd43ce 100644 --- a/drivers/gpu/drm/drm_mm.c +++ b/drivers/gpu/drm/drm_mm.c @@ -374,6 +374,7 @@ void drm_mm_remove_node(struct drm_mm_node *node)
list_del(&node->node_list); node->allocated = 0; + node->mm = NULL; } EXPORT_SYMBOL(drm_mm_remove_node);
diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h index de92425..d83b966 100644 --- a/include/drm/drm_mm.h +++ b/include/drm/drm_mm.h @@ -85,6 +85,11 @@ static inline bool drm_mm_node_allocated(struct drm_mm_node *node) return node->allocated; }
+static inline bool drm_mm_node_linked(struct drm_mm_node *node) +{ + return node->mm; +} + static inline bool drm_mm_initialized(struct drm_mm *mm) { return mm->hole_stack.next;