hugetlb: factor init_nodemask_of_node()

Factor init_nodemask_of_node() out of the nodemask_of_node() macro.

This will be used to populate the huge pages "nodes_allowed" nodemask for
a single node when basing nodes_allowed on a preferred/local mempolicy or
when a persistent huge page pool page count is modified via a per node
sysfs attribute.

Signed-off-by: Lee Schermerhorn <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Reviewed-by: Andi Kleen <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Nishanth Aravamudan <[email protected]>
Acked-by: David Rientjes <[email protected]>
Cc: Adam Litke <[email protected]>
Cc: Andy Whitcroft <[email protected]>
Cc: Eric Whitney <[email protected]>
Cc: Christoph Lameter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Lee Schermerhorn

include/linux/nodemask.h

@@ -245,14 +245,19 @@ static inline int __next_node(int n, const nodemask_t *srcp)
 	return min_t(int,MAX_NUMNODES,find_next_bit(srcp->bits, MAX_NUMNODES, n+1));
 }
 
+static inline void init_nodemask_of_node(nodemask_t *mask, int node)
+{
+	nodes_clear(*mask);
+	node_set(node, *mask);
+}
+
 #define nodemask_of_node(node)						\
 ({									\
 	typeof(_unused_nodemask_arg_) m;				\
 	if (sizeof(m) == sizeof(unsigned long)) {			\
-		m.bits[0] = 1UL<<(node);				\
+		m.bits[0] = 1UL << (node);				\
 	} else {							\
-		nodes_clear(m);						\
-		node_set((node), m);					\
+		init_nodemask_of_node(&m, (node));			\
 	}								\
 	m;								\
 })