[PATCH v3 1/3] drm/drm_mm: Safe macro for iterating through nodes in range

[Tomasz Lis <tomasz.lis@intel.com>]

Benefits of drm_mm_for_each_node_safe and drm_mm_for_each_node_in_range
squished together into one macro.

Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
---
 include/drm/drm_mm.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h
index f654874c4ce6..43e99441f6ba 100644
--- a/include/drm/drm_mm.h
+++ b/include/drm/drm_mm.h
@@ -504,6 +504,25 @@ __drm_mm_interval_first(const struct drm_mm *mm, u64 start, u64 last);
 	     node__->start < (end__);					\
 	     node__ = list_next_entry(node__, node_list))
 
+/**
+ * drm_mm_for_each_node_in_range_safe - iterator to walk over a range of
+ * allocated nodes
+ * @node__: drm_mm_node structure to assign to in each iteration step
+ * @next__: &struct drm_mm_node to store the next step
+ * @mm__: drm_mm allocator to walk
+ * @start__: starting offset, the first node will overlap this
+ * @end__: ending offset, the last node will start before this (but may overlap)
+ *
+ * This iterator walks over all nodes in the range allocator that lie
+ * between @start and @end. It is implemented similarly to list_for_each_safe(),
+ * so safe against removal of elements.
+ */
+#define drm_mm_for_each_node_in_range_safe(node__, next__, mm__, start__, end__)	\
+	for (node__ = __drm_mm_interval_first((mm__), (start__), (end__)-1), \
+		next__ = list_next_entry(node__, node_list); \
+	     node__->start < (end__);					\
+	     node__ = next__, next__ = list_next_entry(next__, node_list))
+
 void drm_mm_scan_init_with_range(struct drm_mm_scan *scan,
 				 struct drm_mm *mm,
 				 u64 size, u64 alignment, unsigned long color,
-- 
2.25.1