X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fgpu%2Fdrm%2Fdrm_vma_manager.c;fp=kernel%2Fdrivers%2Fgpu%2Fdrm%2Fdrm_vma_manager.c;h=2f2ecde8285bda5fdaa77aaf47fdb112fbed6db8;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=68c1f32fb086babba23c883cb6ec5b2f431dd3d6;hpb=f93b97fd65072de626c074dbe099a1fff05ce060;p=kvmfornfv.git

diff --git a/kernel/drivers/gpu/drm/drm_vma_manager.c b/kernel/drivers/gpu/drm/drm_vma_manager.c
index 68c1f32fb..2f2ecde82 100644
--- a/kernel/drivers/gpu/drm/drm_vma_manager.c
+++ b/kernel/drivers/gpu/drm/drm_vma_manager.c
@@ -112,7 +112,7 @@ void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr)
 EXPORT_SYMBOL(drm_vma_offset_manager_destroy);
 
 /**
- * drm_vma_offset_lookup() - Find node in offset space
+ * drm_vma_offset_lookup_locked() - Find node in offset space
  * @mgr: Manager object
  * @start: Start address for object (page-based)
  * @pages: Size of object (page-based)
@@ -122,37 +122,21 @@ EXPORT_SYMBOL(drm_vma_offset_manager_destroy);
  * region and the given node will be returned, as long as the node spans the
  * whole requested area (given the size in number of pages as @pages).
  *
- * RETURNS:
- * Returns NULL if no suitable node can be found. Otherwise, the best match
- * is returned. It's the caller's responsibility to make sure the node doesn't
- * get destroyed before the caller can access it.
- */
-struct drm_vma_offset_node *drm_vma_offset_lookup(struct drm_vma_offset_manager *mgr,
-						  unsigned long start,
-						  unsigned long pages)
-{
-	struct drm_vma_offset_node *node;
-
-	read_lock(&mgr->vm_lock);
-	node = drm_vma_offset_lookup_locked(mgr, start, pages);
-	read_unlock(&mgr->vm_lock);
-
-	return node;
-}
-EXPORT_SYMBOL(drm_vma_offset_lookup);
-
-/**
- * drm_vma_offset_lookup_locked() - Find node in offset space
- * @mgr: Manager object
- * @start: Start address for object (page-based)
- * @pages: Size of object (page-based)
+ * Note that before lookup the vma offset manager lookup lock must be acquired
+ * with drm_vma_offset_lock_lookup(). See there for an example. This can then be
+ * used to implement weakly referenced lookups using kref_get_unless_zero().
  *
- * Same as drm_vma_offset_lookup() but requires the caller to lock offset lookup
- * manually. See drm_vma_offset_lock_lookup() for an example.
+ * Example:
+ *     drm_vma_offset_lock_lookup(mgr);
+ *     node = drm_vma_offset_lookup_locked(mgr);
+ *     if (node)
+ *         kref_get_unless_zero(container_of(node, sth, entr));
+ *     drm_vma_offset_unlock_lookup(mgr);
  *
  * RETURNS:
  * Returns NULL if no suitable node can be found. Otherwise, the best match
- * is returned.
+ * is returned. It's the caller's responsibility to make sure the node doesn't
+ * get destroyed before the caller can access it.
  */
 struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr,
 							 unsigned long start,