[PATCH 1/3] nodemask: Introduce for_each_node_mask_wrap/for_each_node_state_wrap()

[Andrea Righi]

Introduce NUMA node iterators to support circular iteration, starting
from a specified node.

Signed-off-by: Andrea Righi <arighi@xxxxxxxxxx>
---
 include/linux/nodemask.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index b61438313a73..7ba35c65ab99 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -392,6 +392,16 @@ static inline void __nodes_fold(nodemask_t *dstp, const nodemask_t *origp,
 	for ((node) = 0; (node) < 1 && !nodes_empty(mask); (node)++)
 #endif /* MAX_NUMNODES */
 
+#if MAX_NUMNODES > 1
+#define for_each_node_mask_wrap(node, mask, start)			\
+	for_each_set_bit_wrap((node), (mask).bits, MAX_NUMNODES, (start))
+#else /* MAX_NUMNODES == 1 */
+#define for_each_node_mask_wrap(node, mask, start)			\
+	for ((node) = 0;						\
+	     (node) < 1 && !nodes_empty(mask);				\
+	     (node)++, (void)(start))
+#endif /* MAX_NUMNODES */
+
 /*
  * Bitmasks that are kept for all the nodes.
  */
@@ -441,6 +451,9 @@ static inline int num_node_state(enum node_states state)
 #define for_each_node_state(__node, __state) \
 	for_each_node_mask((__node), node_states[__state])
 
+#define for_each_node_state_wrap(__node, __state, __start) \
+	for_each_node_mask_wrap((__node), node_states[__state], __start)
+
 #define first_online_node	first_node(node_states[N_ONLINE])
 #define first_memory_node	first_node(node_states[N_MEMORY])
 static inline unsigned int next_online_node(int nid)
@@ -535,6 +548,7 @@ static inline int node_random(const nodemask_t *maskp)
 
 #define for_each_node(node)	   for_each_node_state(node, N_POSSIBLE)
 #define for_each_online_node(node) for_each_node_state(node, N_ONLINE)
+#define for_each_online_node_wrap(node, start) for_each_node_state(node, N_ONLINE, start)
 
 /*
  * For nodemask scratch area.
-- 
2.47.1