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1 #ifndef __LINUX_NODEMASK_H
2 #define __LINUX_NODEMASK_H
3 
4 /*
5  * Nodemasks provide a bitmap suitable for representing the
6  * set of Node's in a system, one bit position per Node number.
7  *
8  * See detailed comments in the file linux/bitmap.h describing the
9  * data type on which these nodemasks are based.
10  *
11  * For details of nodemask_scnprintf() and nodemask_parse_user(),
12  * see bitmap_scnprintf() and bitmap_parse_user() in lib/bitmap.c.
13  * For details of nodelist_scnprintf() and nodelist_parse(), see
14  * bitmap_scnlistprintf() and bitmap_parselist(), also in bitmap.c.
15  * For details of node_remap(), see bitmap_bitremap in lib/bitmap.c.
16  * For details of nodes_remap(), see bitmap_remap in lib/bitmap.c.
17  * For details of nodes_onto(), see bitmap_onto in lib/bitmap.c.
18  * For details of nodes_fold(), see bitmap_fold in lib/bitmap.c.
19  *
20  * The available nodemask operations are:
21  *
22  * void node_set(node, mask)		turn on bit 'node' in mask
23  * void node_clear(node, mask)		turn off bit 'node' in mask
24  * void nodes_setall(mask)		set all bits
25  * void nodes_clear(mask)		clear all bits
26  * int node_isset(node, mask)		true iff bit 'node' set in mask
27  * int node_test_and_set(node, mask)	test and set bit 'node' in mask
28  *
29  * void nodes_and(dst, src1, src2)	dst = src1 & src2  [intersection]
30  * void nodes_or(dst, src1, src2)	dst = src1 | src2  [union]
31  * void nodes_xor(dst, src1, src2)	dst = src1 ^ src2
32  * void nodes_andnot(dst, src1, src2)	dst = src1 & ~src2
33  * void nodes_complement(dst, src)	dst = ~src
34  *
35  * int nodes_equal(mask1, mask2)	Does mask1 == mask2?
36  * int nodes_intersects(mask1, mask2)	Do mask1 and mask2 intersect?
37  * int nodes_subset(mask1, mask2)	Is mask1 a subset of mask2?
38  * int nodes_empty(mask)		Is mask empty (no bits sets)?
39  * int nodes_full(mask)			Is mask full (all bits sets)?
40  * int nodes_weight(mask)		Hamming weight - number of set bits
41  *
42  * void nodes_shift_right(dst, src, n)	Shift right
43  * void nodes_shift_left(dst, src, n)	Shift left
44  *
45  * int first_node(mask)			Number lowest set bit, or MAX_NUMNODES
46  * int next_node(node, mask)		Next node past 'node', or MAX_NUMNODES
47  * int first_unset_node(mask)		First node not set in mask, or
48  *					MAX_NUMNODES.
49  *
50  * nodemask_t nodemask_of_node(node)	Return nodemask with bit 'node' set
51  * NODE_MASK_ALL			Initializer - all bits set
52  * NODE_MASK_NONE			Initializer - no bits set
53  * unsigned long *nodes_addr(mask)	Array of unsigned long's in mask
54  *
55  * int nodemask_scnprintf(buf, len, mask) Format nodemask for printing
56  * int nodemask_parse_user(ubuf, ulen, mask)	Parse ascii string as nodemask
57  * int nodelist_scnprintf(buf, len, mask) Format nodemask as list for printing
58  * int nodelist_parse(buf, map)		Parse ascii string as nodelist
59  * int node_remap(oldbit, old, new)	newbit = map(old, new)(oldbit)
60  * void nodes_remap(dst, src, old, new)	*dst = map(old, new)(src)
61  * void nodes_onto(dst, orig, relmap)	*dst = orig relative to relmap
62  * void nodes_fold(dst, orig, sz)	dst bits = orig bits mod sz
63  *
64  * for_each_node_mask(node, mask)	for-loop node over mask
65  *
66  * int num_online_nodes()		Number of online Nodes
67  * int num_possible_nodes()		Number of all possible Nodes
68  *
69  * int node_random(mask)		Random node with set bit in mask
70  *
71  * int node_online(node)		Is some node online?
72  * int node_possible(node)		Is some node possible?
73  *
74  * node_set_online(node)		set bit 'node' in node_online_map
75  * node_set_offline(node)		clear bit 'node' in node_online_map
76  *
77  * for_each_node(node)			for-loop node over node_possible_map
78  * for_each_online_node(node)		for-loop node over node_online_map
79  *
80  * Subtlety:
81  * 1) The 'type-checked' form of node_isset() causes gcc (3.3.2, anyway)
82  *    to generate slightly worse code.  So use a simple one-line #define
83  *    for node_isset(), instead of wrapping an inline inside a macro, the
84  *    way we do the other calls.
85  *
86  * NODEMASK_SCRATCH
87  * When doing above logical AND, OR, XOR, Remap operations the callers tend to
88  * need temporary nodemask_t's on the stack. But if NODES_SHIFT is large,
89  * nodemask_t's consume too much stack space.  NODEMASK_SCRATCH is a helper
90  * for such situations. See below and CPUMASK_ALLOC also.
91  */
92 
93 #include <linux/kernel.h>
94 #include <linux/threads.h>
95 #include <linux/bitmap.h>
96 #include <linux/numa.h>
97 
98 typedef struct { DECLARE_BITMAP(bits, MAX_NUMNODES); } nodemask_t;
99 extern nodemask_t _unused_nodemask_arg_;
100 
101 /**
102  * nodemask_pr_args - printf args to output a nodemask
103  * @maskp: nodemask to be printed
104  *
105  * Can be used to provide arguments for '%*pb[l]' when printing a nodemask.
106  */
107 #define nodemask_pr_args(maskp)		MAX_NUMNODES, (maskp)->bits
108 
109 /*
110  * The inline keyword gives the compiler room to decide to inline, or
111  * not inline a function as it sees best.  However, as these functions
112  * are called in both __init and non-__init functions, if they are not
113  * inlined we will end up with a section mis-match error (of the type of
114  * freeable items not being freed).  So we must use __always_inline here
115  * to fix the problem.  If other functions in the future also end up in
116  * this situation they will also need to be annotated as __always_inline
117  */
118 #define node_set(node, dst) __node_set((node), &(dst))
__node_set(int node,volatile nodemask_t * dstp)119 static __always_inline void __node_set(int node, volatile nodemask_t *dstp)
120 {
121 	set_bit(node, dstp->bits);
122 }
123 
124 #define node_clear(node, dst) __node_clear((node), &(dst))
__node_clear(int node,volatile nodemask_t * dstp)125 static inline void __node_clear(int node, volatile nodemask_t *dstp)
126 {
127 	clear_bit(node, dstp->bits);
128 }
129 
130 #define nodes_setall(dst) __nodes_setall(&(dst), MAX_NUMNODES)
__nodes_setall(nodemask_t * dstp,int nbits)131 static inline void __nodes_setall(nodemask_t *dstp, int nbits)
132 {
133 	bitmap_fill(dstp->bits, nbits);
134 }
135 
136 #define nodes_clear(dst) __nodes_clear(&(dst), MAX_NUMNODES)
__nodes_clear(nodemask_t * dstp,int nbits)137 static inline void __nodes_clear(nodemask_t *dstp, int nbits)
138 {
139 	bitmap_zero(dstp->bits, nbits);
140 }
141 
142 /* No static inline type checking - see Subtlety (1) above. */
143 #define node_isset(node, nodemask) test_bit((node), (nodemask).bits)
144 
145 #define node_test_and_set(node, nodemask) \
146 			__node_test_and_set((node), &(nodemask))
__node_test_and_set(int node,nodemask_t * addr)147 static inline int __node_test_and_set(int node, nodemask_t *addr)
148 {
149 	return test_and_set_bit(node, addr->bits);
150 }
151 
152 #define nodes_and(dst, src1, src2) \
153 			__nodes_and(&(dst), &(src1), &(src2), MAX_NUMNODES)
__nodes_and(nodemask_t * dstp,const nodemask_t * src1p,const nodemask_t * src2p,int nbits)154 static inline void __nodes_and(nodemask_t *dstp, const nodemask_t *src1p,
155 					const nodemask_t *src2p, int nbits)
156 {
157 	bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
158 }
159 
160 #define nodes_or(dst, src1, src2) \
161 			__nodes_or(&(dst), &(src1), &(src2), MAX_NUMNODES)
__nodes_or(nodemask_t * dstp,const nodemask_t * src1p,const nodemask_t * src2p,int nbits)162 static inline void __nodes_or(nodemask_t *dstp, const nodemask_t *src1p,
163 					const nodemask_t *src2p, int nbits)
164 {
165 	bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
166 }
167 
168 #define nodes_xor(dst, src1, src2) \
169 			__nodes_xor(&(dst), &(src1), &(src2), MAX_NUMNODES)
__nodes_xor(nodemask_t * dstp,const nodemask_t * src1p,const nodemask_t * src2p,int nbits)170 static inline void __nodes_xor(nodemask_t *dstp, const nodemask_t *src1p,
171 					const nodemask_t *src2p, int nbits)
172 {
173 	bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
174 }
175 
176 #define nodes_andnot(dst, src1, src2) \
177 			__nodes_andnot(&(dst), &(src1), &(src2), MAX_NUMNODES)
__nodes_andnot(nodemask_t * dstp,const nodemask_t * src1p,const nodemask_t * src2p,int nbits)178 static inline void __nodes_andnot(nodemask_t *dstp, const nodemask_t *src1p,
179 					const nodemask_t *src2p, int nbits)
180 {
181 	bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
182 }
183 
184 #define nodes_complement(dst, src) \
185 			__nodes_complement(&(dst), &(src), MAX_NUMNODES)
__nodes_complement(nodemask_t * dstp,const nodemask_t * srcp,int nbits)186 static inline void __nodes_complement(nodemask_t *dstp,
187 					const nodemask_t *srcp, int nbits)
188 {
189 	bitmap_complement(dstp->bits, srcp->bits, nbits);
190 }
191 
192 #define nodes_equal(src1, src2) \
193 			__nodes_equal(&(src1), &(src2), MAX_NUMNODES)
__nodes_equal(const nodemask_t * src1p,const nodemask_t * src2p,int nbits)194 static inline int __nodes_equal(const nodemask_t *src1p,
195 					const nodemask_t *src2p, int nbits)
196 {
197 	return bitmap_equal(src1p->bits, src2p->bits, nbits);
198 }
199 
200 #define nodes_intersects(src1, src2) \
201 			__nodes_intersects(&(src1), &(src2), MAX_NUMNODES)
__nodes_intersects(const nodemask_t * src1p,const nodemask_t * src2p,int nbits)202 static inline int __nodes_intersects(const nodemask_t *src1p,
203 					const nodemask_t *src2p, int nbits)
204 {
205 	return bitmap_intersects(src1p->bits, src2p->bits, nbits);
206 }
207 
208 #define nodes_subset(src1, src2) \
209 			__nodes_subset(&(src1), &(src2), MAX_NUMNODES)
__nodes_subset(const nodemask_t * src1p,const nodemask_t * src2p,int nbits)210 static inline int __nodes_subset(const nodemask_t *src1p,
211 					const nodemask_t *src2p, int nbits)
212 {
213 	return bitmap_subset(src1p->bits, src2p->bits, nbits);
214 }
215 
216 #define nodes_empty(src) __nodes_empty(&(src), MAX_NUMNODES)
__nodes_empty(const nodemask_t * srcp,int nbits)217 static inline int __nodes_empty(const nodemask_t *srcp, int nbits)
218 {
219 	return bitmap_empty(srcp->bits, nbits);
220 }
221 
222 #define nodes_full(nodemask) __nodes_full(&(nodemask), MAX_NUMNODES)
__nodes_full(const nodemask_t * srcp,int nbits)223 static inline int __nodes_full(const nodemask_t *srcp, int nbits)
224 {
225 	return bitmap_full(srcp->bits, nbits);
226 }
227 
228 #define nodes_weight(nodemask) __nodes_weight(&(nodemask), MAX_NUMNODES)
__nodes_weight(const nodemask_t * srcp,int nbits)229 static inline int __nodes_weight(const nodemask_t *srcp, int nbits)
230 {
231 	return bitmap_weight(srcp->bits, nbits);
232 }
233 
234 #define nodes_shift_right(dst, src, n) \
235 			__nodes_shift_right(&(dst), &(src), (n), MAX_NUMNODES)
__nodes_shift_right(nodemask_t * dstp,const nodemask_t * srcp,int n,int nbits)236 static inline void __nodes_shift_right(nodemask_t *dstp,
237 					const nodemask_t *srcp, int n, int nbits)
238 {
239 	bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
240 }
241 
242 #define nodes_shift_left(dst, src, n) \
243 			__nodes_shift_left(&(dst), &(src), (n), MAX_NUMNODES)
__nodes_shift_left(nodemask_t * dstp,const nodemask_t * srcp,int n,int nbits)244 static inline void __nodes_shift_left(nodemask_t *dstp,
245 					const nodemask_t *srcp, int n, int nbits)
246 {
247 	bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
248 }
249 
250 /* FIXME: better would be to fix all architectures to never return
251           > MAX_NUMNODES, then the silly min_ts could be dropped. */
252 
253 #define first_node(src) __first_node(&(src))
__first_node(const nodemask_t * srcp)254 static inline int __first_node(const nodemask_t *srcp)
255 {
256 	return min_t(int, MAX_NUMNODES, find_first_bit(srcp->bits, MAX_NUMNODES));
257 }
258 
259 #define next_node(n, src) __next_node((n), &(src))
__next_node(int n,const nodemask_t * srcp)260 static inline int __next_node(int n, const nodemask_t *srcp)
261 {
262 	return min_t(int,MAX_NUMNODES,find_next_bit(srcp->bits, MAX_NUMNODES, n+1));
263 }
264 
init_nodemask_of_node(nodemask_t * mask,int node)265 static inline void init_nodemask_of_node(nodemask_t *mask, int node)
266 {
267 	nodes_clear(*mask);
268 	node_set(node, *mask);
269 }
270 
271 #define nodemask_of_node(node)						\
272 ({									\
273 	typeof(_unused_nodemask_arg_) m;				\
274 	if (sizeof(m) == sizeof(unsigned long)) {			\
275 		m.bits[0] = 1UL << (node);				\
276 	} else {							\
277 		init_nodemask_of_node(&m, (node));			\
278 	}								\
279 	m;								\
280 })
281 
282 #define first_unset_node(mask) __first_unset_node(&(mask))
__first_unset_node(const nodemask_t * maskp)283 static inline int __first_unset_node(const nodemask_t *maskp)
284 {
285 	return min_t(int,MAX_NUMNODES,
286 			find_first_zero_bit(maskp->bits, MAX_NUMNODES));
287 }
288 
289 #define NODE_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(MAX_NUMNODES)
290 
291 #if MAX_NUMNODES <= BITS_PER_LONG
292 
293 #define NODE_MASK_ALL							\
294 ((nodemask_t) { {							\
295 	[BITS_TO_LONGS(MAX_NUMNODES)-1] = NODE_MASK_LAST_WORD		\
296 } })
297 
298 #else
299 
300 #define NODE_MASK_ALL							\
301 ((nodemask_t) { {							\
302 	[0 ... BITS_TO_LONGS(MAX_NUMNODES)-2] = ~0UL,			\
303 	[BITS_TO_LONGS(MAX_NUMNODES)-1] = NODE_MASK_LAST_WORD		\
304 } })
305 
306 #endif
307 
308 #define NODE_MASK_NONE							\
309 ((nodemask_t) { {							\
310 	[0 ... BITS_TO_LONGS(MAX_NUMNODES)-1] =  0UL			\
311 } })
312 
313 #define nodes_addr(src) ((src).bits)
314 
315 #define nodemask_scnprintf(buf, len, src) \
316 			__nodemask_scnprintf((buf), (len), &(src), MAX_NUMNODES)
__nodemask_scnprintf(char * buf,int len,const nodemask_t * srcp,int nbits)317 static inline int __nodemask_scnprintf(char *buf, int len,
318 					const nodemask_t *srcp, int nbits)
319 {
320 	return bitmap_scnprintf(buf, len, srcp->bits, nbits);
321 }
322 
323 #define nodemask_parse_user(ubuf, ulen, dst) \
324 		__nodemask_parse_user((ubuf), (ulen), &(dst), MAX_NUMNODES)
__nodemask_parse_user(const char __user * buf,int len,nodemask_t * dstp,int nbits)325 static inline int __nodemask_parse_user(const char __user *buf, int len,
326 					nodemask_t *dstp, int nbits)
327 {
328 	return bitmap_parse_user(buf, len, dstp->bits, nbits);
329 }
330 
331 #define nodelist_scnprintf(buf, len, src) \
332 			__nodelist_scnprintf((buf), (len), &(src), MAX_NUMNODES)
__nodelist_scnprintf(char * buf,int len,const nodemask_t * srcp,int nbits)333 static inline int __nodelist_scnprintf(char *buf, int len,
334 					const nodemask_t *srcp, int nbits)
335 {
336 	return bitmap_scnlistprintf(buf, len, srcp->bits, nbits);
337 }
338 
339 #define nodelist_parse(buf, dst) __nodelist_parse((buf), &(dst), MAX_NUMNODES)
__nodelist_parse(const char * buf,nodemask_t * dstp,int nbits)340 static inline int __nodelist_parse(const char *buf, nodemask_t *dstp, int nbits)
341 {
342 	return bitmap_parselist(buf, dstp->bits, nbits);
343 }
344 
345 #define node_remap(oldbit, old, new) \
346 		__node_remap((oldbit), &(old), &(new), MAX_NUMNODES)
__node_remap(int oldbit,const nodemask_t * oldp,const nodemask_t * newp,int nbits)347 static inline int __node_remap(int oldbit,
348 		const nodemask_t *oldp, const nodemask_t *newp, int nbits)
349 {
350 	return bitmap_bitremap(oldbit, oldp->bits, newp->bits, nbits);
351 }
352 
353 #define nodes_remap(dst, src, old, new) \
354 		__nodes_remap(&(dst), &(src), &(old), &(new), MAX_NUMNODES)
__nodes_remap(nodemask_t * dstp,const nodemask_t * srcp,const nodemask_t * oldp,const nodemask_t * newp,int nbits)355 static inline void __nodes_remap(nodemask_t *dstp, const nodemask_t *srcp,
356 		const nodemask_t *oldp, const nodemask_t *newp, int nbits)
357 {
358 	bitmap_remap(dstp->bits, srcp->bits, oldp->bits, newp->bits, nbits);
359 }
360 
361 #define nodes_onto(dst, orig, relmap) \
362 		__nodes_onto(&(dst), &(orig), &(relmap), MAX_NUMNODES)
__nodes_onto(nodemask_t * dstp,const nodemask_t * origp,const nodemask_t * relmapp,int nbits)363 static inline void __nodes_onto(nodemask_t *dstp, const nodemask_t *origp,
364 		const nodemask_t *relmapp, int nbits)
365 {
366 	bitmap_onto(dstp->bits, origp->bits, relmapp->bits, nbits);
367 }
368 
369 #define nodes_fold(dst, orig, sz) \
370 		__nodes_fold(&(dst), &(orig), sz, MAX_NUMNODES)
__nodes_fold(nodemask_t * dstp,const nodemask_t * origp,int sz,int nbits)371 static inline void __nodes_fold(nodemask_t *dstp, const nodemask_t *origp,
372 		int sz, int nbits)
373 {
374 	bitmap_fold(dstp->bits, origp->bits, sz, nbits);
375 }
376 
377 #if MAX_NUMNODES > 1
378 #define for_each_node_mask(node, mask)			\
379 	for ((node) = first_node(mask);			\
380 		(node) < MAX_NUMNODES;			\
381 		(node) = next_node((node), (mask)))
382 #else /* MAX_NUMNODES == 1 */
383 #define for_each_node_mask(node, mask)			\
384 	if (!nodes_empty(mask))				\
385 		for ((node) = 0; (node) < 1; (node)++)
386 #endif /* MAX_NUMNODES */
387 
388 /*
389  * Bitmasks that are kept for all the nodes.
390  */
391 enum node_states {
392 	N_POSSIBLE,		/* The node could become online at some point */
393 	N_ONLINE,		/* The node is online */
394 	N_NORMAL_MEMORY,	/* The node has regular memory */
395 #ifdef CONFIG_HIGHMEM
396 	N_HIGH_MEMORY,		/* The node has regular or high memory */
397 #else
398 	N_HIGH_MEMORY = N_NORMAL_MEMORY,
399 #endif
400 #ifdef CONFIG_MOVABLE_NODE
401 	N_MEMORY,		/* The node has memory(regular, high, movable) */
402 #else
403 	N_MEMORY = N_HIGH_MEMORY,
404 #endif
405 	N_CPU,		/* The node has one or more cpus */
406 	NR_NODE_STATES
407 };
408 
409 /*
410  * The following particular system nodemasks and operations
411  * on them manage all possible and online nodes.
412  */
413 
414 extern nodemask_t node_states[NR_NODE_STATES];
415 
416 #if MAX_NUMNODES > 1
node_state(int node,enum node_states state)417 static inline int node_state(int node, enum node_states state)
418 {
419 	return node_isset(node, node_states[state]);
420 }
421 
node_set_state(int node,enum node_states state)422 static inline void node_set_state(int node, enum node_states state)
423 {
424 	__node_set(node, &node_states[state]);
425 }
426 
node_clear_state(int node,enum node_states state)427 static inline void node_clear_state(int node, enum node_states state)
428 {
429 	__node_clear(node, &node_states[state]);
430 }
431 
num_node_state(enum node_states state)432 static inline int num_node_state(enum node_states state)
433 {
434 	return nodes_weight(node_states[state]);
435 }
436 
437 #define for_each_node_state(__node, __state) \
438 	for_each_node_mask((__node), node_states[__state])
439 
440 #define first_online_node	first_node(node_states[N_ONLINE])
441 #define first_memory_node	first_node(node_states[N_MEMORY])
next_online_node(int nid)442 static inline int next_online_node(int nid)
443 {
444 	return next_node(nid, node_states[N_ONLINE]);
445 }
next_memory_node(int nid)446 static inline int next_memory_node(int nid)
447 {
448 	return next_node(nid, node_states[N_MEMORY]);
449 }
450 
451 extern int nr_node_ids;
452 extern int nr_online_nodes;
453 
node_set_online(int nid)454 static inline void node_set_online(int nid)
455 {
456 	node_set_state(nid, N_ONLINE);
457 	nr_online_nodes = num_node_state(N_ONLINE);
458 }
459 
node_set_offline(int nid)460 static inline void node_set_offline(int nid)
461 {
462 	node_clear_state(nid, N_ONLINE);
463 	nr_online_nodes = num_node_state(N_ONLINE);
464 }
465 
466 #else
467 
node_state(int node,enum node_states state)468 static inline int node_state(int node, enum node_states state)
469 {
470 	return node == 0;
471 }
472 
node_set_state(int node,enum node_states state)473 static inline void node_set_state(int node, enum node_states state)
474 {
475 }
476 
node_clear_state(int node,enum node_states state)477 static inline void node_clear_state(int node, enum node_states state)
478 {
479 }
480 
num_node_state(enum node_states state)481 static inline int num_node_state(enum node_states state)
482 {
483 	return 1;
484 }
485 
486 #define for_each_node_state(node, __state) \
487 	for ( (node) = 0; (node) == 0; (node) = 1)
488 
489 #define first_online_node	0
490 #define first_memory_node	0
491 #define next_online_node(nid)	(MAX_NUMNODES)
492 #define nr_node_ids		1
493 #define nr_online_nodes		1
494 
495 #define node_set_online(node)	   node_set_state((node), N_ONLINE)
496 #define node_set_offline(node)	   node_clear_state((node), N_ONLINE)
497 
498 #endif
499 
500 #if defined(CONFIG_NUMA) && (MAX_NUMNODES > 1)
501 extern int node_random(const nodemask_t *maskp);
502 #else
node_random(const nodemask_t * mask)503 static inline int node_random(const nodemask_t *mask)
504 {
505 	return 0;
506 }
507 #endif
508 
509 #define node_online_map 	node_states[N_ONLINE]
510 #define node_possible_map 	node_states[N_POSSIBLE]
511 
512 #define num_online_nodes()	num_node_state(N_ONLINE)
513 #define num_possible_nodes()	num_node_state(N_POSSIBLE)
514 #define node_online(node)	node_state((node), N_ONLINE)
515 #define node_possible(node)	node_state((node), N_POSSIBLE)
516 
517 #define for_each_node(node)	   for_each_node_state(node, N_POSSIBLE)
518 #define for_each_online_node(node) for_each_node_state(node, N_ONLINE)
519 
520 /*
521  * For nodemask scrach area.
522  * NODEMASK_ALLOC(type, name) allocates an object with a specified type and
523  * name.
524  */
525 #if NODES_SHIFT > 8 /* nodemask_t > 256 bytes */
526 #define NODEMASK_ALLOC(type, name, gfp_flags)	\
527 			type *name = kmalloc(sizeof(*name), gfp_flags)
528 #define NODEMASK_FREE(m)			kfree(m)
529 #else
530 #define NODEMASK_ALLOC(type, name, gfp_flags)	type _##name, *name = &_##name
531 #define NODEMASK_FREE(m)			do {} while (0)
532 #endif
533 
534 /* A example struture for using NODEMASK_ALLOC, used in mempolicy. */
535 struct nodemask_scratch {
536 	nodemask_t	mask1;
537 	nodemask_t	mask2;
538 };
539 
540 #define NODEMASK_SCRATCH(x)						\
541 			NODEMASK_ALLOC(struct nodemask_scratch, x,	\
542 					GFP_KERNEL | __GFP_NORETRY)
543 #define NODEMASK_SCRATCH_FREE(x)	NODEMASK_FREE(x)
544 
545 
546 #endif /* __LINUX_NODEMASK_H */
547