aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/cpumask.h
blob: 23f55140ccd570fd45c321b8275ce04edc451288 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
#ifndef __LINUX_CPUMASK_H
#define __LINUX_CPUMASK_H

/*
 * Cpumasks provide a bitmap suitable for representing the
 * set of CPU's in a system, one bit position per CPU number.
 *
 * See detailed comments in the file linux/bitmap.h describing the
 * data type on which these cpumasks are based.
 *
 * For details of cpumask_scnprintf() and cpumask_parse_user(),
 * see bitmap_scnprintf() and bitmap_parse_user() in lib/bitmap.c.
 * For details of cpulist_scnprintf() and cpulist_parse(), see
 * bitmap_scnlistprintf() and bitmap_parselist(), also in bitmap.c.
 * For details of cpu_remap(), see bitmap_bitremap in lib/bitmap.c
 * For details of cpus_remap(), see bitmap_remap in lib/bitmap.c.
 *
 * The available cpumask operations are:
 *
 * void cpu_set(cpu, mask)		turn on bit 'cpu' in mask
 * void cpu_clear(cpu, mask)		turn off bit 'cpu' in mask
 * void cpus_setall(mask)		set all bits
 * void cpus_clear(mask)		clear all bits
 * int cpu_isset(cpu, mask)		true iff bit 'cpu' set in mask
 * int cpu_test_and_set(cpu, mask)	test and set bit 'cpu' in mask
 *
 * void cpus_and(dst, src1, src2)	dst = src1 & src2  [intersection]
 * void cpus_or(dst, src1, src2)	dst = src1 | src2  [union]
 * void cpus_xor(dst, src1, src2)	dst = src1 ^ src2
 * void cpus_andnot(dst, src1, src2)	dst = src1 & ~src2
 * void cpus_complement(dst, src)	dst = ~src
 *
 * int cpus_equal(mask1, mask2)		Does mask1 == mask2?
 * int cpus_intersects(mask1, mask2)	Do mask1 and mask2 intersect?
 * int cpus_subset(mask1, mask2)	Is mask1 a subset of mask2?
 * int cpus_empty(mask)			Is mask empty (no bits sets)?
 * int cpus_full(mask)			Is mask full (all bits sets)?
 * int cpus_weight(mask)		Hamming weigh - number of set bits
 *
 * void cpus_shift_right(dst, src, n)	Shift right
 * void cpus_shift_left(dst, src, n)	Shift left
 *
 * int first_cpu(mask)			Number lowest set bit, or NR_CPUS
 * int next_cpu(cpu, mask)		Next cpu past 'cpu', or NR_CPUS
 *
 * cpumask_t cpumask_of_cpu(cpu)	Return cpumask with bit 'cpu' set
 * CPU_MASK_ALL				Initializer - all bits set
 * CPU_MASK_NONE			Initializer - no bits set
 * unsigned long *cpus_addr(mask)	Array of unsigned long's in mask
 *
 * int cpumask_scnprintf(buf, len, mask) Format cpumask for printing
 * int cpumask_parse_user(ubuf, ulen, mask)	Parse ascii string as cpumask
 * int cpulist_scnprintf(buf, len, mask) Format cpumask as list for printing
 * int cpulist_parse(buf, map)		Parse ascii string as cpulist
 * int cpu_remap(oldbit, old, new)	newbit = map(old, new)(oldbit)
 * int cpus_remap(dst, src, old, new)	*dst = map(old, new)(src)
 *
 * for_each_cpu_mask(cpu, mask)		for-loop cpu over mask
 *
 * int num_online_cpus()		Number of online CPUs
 * int num_possible_cpus()		Number of all possible CPUs
 * int num_present_cpus()		Number of present CPUs
 *
 * int cpu_online(cpu)			Is some cpu online?
 * int cpu_possible(cpu)		Is some cpu possible?
 * int cpu_present(cpu)			Is some cpu present (can schedule)?
 *
 * int any_online_cpu(mask)		First online cpu in mask
 *
 * for_each_possible_cpu(cpu)		for-loop cpu over cpu_possible_map
 * for_each_online_cpu(cpu)		for-loop cpu over cpu_online_map
 * for_each_present_cpu(cpu)		for-loop cpu over cpu_present_map
 *
 * Subtlety:
 * 1) The 'type-checked' form of cpu_isset() causes gcc (3.3.2, anyway)
 *    to generate slightly worse code.  Note for example the additional
 *    40 lines of assembly code compiling the "for each possible cpu"
 *    loops buried in the disk_stat_read() macros calls when compiling
 *    drivers/block/genhd.c (arch i386, CONFIG_SMP=y).  So use a simple
 *    one-line #define for cpu_isset(), instead of wrapping an inline
 *    inside a macro, the way we do the other calls.
 */

#include <linux/kernel.h>
#include <linux/threads.h>
#include <linux/bitmap.h>

typedef struct { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
extern cpumask_t _unused_cpumask_arg_;

#define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
{
	set_bit(cpu, dstp->bits);
}

#define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
{
	clear_bit(cpu, dstp->bits);
}

#define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
static inline void __cpus_setall(cpumask_t *dstp, int nbits)
{
	bitmap_fill(dstp->bits, nbits);
}

#define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
static inline void __cpus_clear(cpumask_t *dstp, int nbits)
{
	bitmap_zero(dstp->bits, nbits);
}

/* No static inline type checking - see Subtlety (1) above. */
#define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)

#define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
{
	return test_and_set_bit(cpu, addr->bits);
}

#define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
static inline void __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
					const cpumask_t *src2p, int nbits)
{
	bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
}

#define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
					const cpumask_t *src2p, int nbits)
{
	bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
}

#define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
					const cpumask_t *src2p, int nbits)
{
	bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
}

#define cpus_andnot(dst, src1, src2) \
				__cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
static inline void __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
					const cpumask_t *src2p, int nbits)
{
	bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
}

#define cpus_complement(dst, src) __cpus_complement(&(dst), &(src), NR_CPUS)
static inline void __cpus_complement(cpumask_t *dstp,
					const cpumask_t *srcp, int nbits)
{
	bitmap_complement(dstp->bits, srcp->bits, nbits);
}

#define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
static inline int __cpus_equal(const cpumask_t *src1p,
					const cpumask_t *src2p, int nbits)
{
	return bitmap_equal(src1p->bits, src2p->bits, nbits);
}

#define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
static inline int __cpus_intersects(const cpumask_t *src1p,
					const cpumask_t *src2p, int nbits)
{
	return bitmap_intersects(src1p->bits, src2p->bits, nbits);
}

#define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
static inline int __cpus_subset(const cpumask_t *src1p,
					const cpumask_t *src2p, int nbits)
{
	return bitmap_subset(src1p->bits, src2p->bits, nbits);
}

#define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
{
	return bitmap_empty(srcp->bits, nbits);
}

#define cpus_full(cpumask) __cpus_full(&(cpumask), NR_CPUS)
static inline int __cpus_full(const cpumask_t *srcp, int nbits)
{
	return bitmap_full(srcp->bits, nbits);
}

#define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
{
	return bitmap_weight(srcp->bits, nbits);
}

#define cpus_shift_right(dst, src, n) \
			__cpus_shift_right(&(dst), &(src), (n), NR_CPUS)
static inline void __cpus_shift_right(cpumask_t *dstp,
					const cpumask_t *srcp, int n, int nbits)
{
	bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
}

#define cpus_shift_left(dst, src, n) \
			__cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
static inline void __cpus_shift_left(cpumask_t *dstp,
					const cpumask_t *srcp, int n, int nbits)
{
	bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
}

#ifdef CONFIG_SMP
int __first_cpu(const cpumask_t *srcp);
#define first_cpu(src) __first_cpu(&(src))
int __next_cpu(int n, const cpumask_t *srcp);
#define next_cpu(n, src) __next_cpu((n), &(src))
#else
#define first_cpu(src)		0
#define next_cpu(n, src)	1
#endif

#define cpumask_of_cpu(cpu)						\
({									\
	typeof(_unused_cpumask_arg_) m;					\
	if (sizeof(m) == sizeof(unsigned long)) {			\
		m.bits[0] = 1UL<<(cpu);					\
	} else {							\
		cpus_clear(m);						\
		cpu_set((cpu), m);					\
	}								\
	m;								\
})

#define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)

#if NR_CPUS <= BITS_PER_LONG

#define CPU_MASK_ALL							\
(cpumask_t) { {								\
	[BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD			\
} }

#else

#define CPU_MASK_ALL							\
(cpumask_t) { {								\
	[0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,			\
	[BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD			\
} }

#endif

#define CPU_MASK_NONE							\
(cpumask_t) { {								\
	[0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL				\
} }

#define CPU_MASK_CPU0							\
(cpumask_t) { {								\
	[0] =  1UL							\
} }

#define cpus_addr(src) ((src).bits)

#define cpumask_scnprintf(buf, len, src) \
			__cpumask_scnprintf((buf), (len), &(src), NR_CPUS)
static inline int __cpumask_scnprintf(char *buf, int len,
					const cpumask_t *srcp, int nbits)
{
	return bitmap_scnprintf(buf, len, srcp->bits, nbits);
}

#define cpumask_parse_user(ubuf, ulen, dst) \
			__cpumask_parse_user((ubuf), (ulen), &(dst), NR_CPUS)
static inline int __cpumask_parse_user(const char __user *buf, int len,
					cpumask_t *dstp, int nbits)
{
	return bitmap_parse_user(buf, len, dstp->bits, nbits);
}

#define cpulist_scnprintf(buf, len, src) \
			__cpulist_scnprintf((buf), (len), &(src), NR_CPUS)
static inline int __cpulist_scnprintf(char *buf, int len,
					const cpumask_t *srcp, int nbits)
{
	return bitmap_scnlistprintf(buf, len, srcp->bits, nbits);
}

#define cpulist_parse(buf, dst) __cpulist_parse((buf), &(dst), NR_CPUS)
static inline int __cpulist_parse(const char *buf, cpumask_t *dstp, int nbits)
{
	return bitmap_parselist(buf, dstp->bits, nbits);
}

#define cpu_remap(oldbit, old, new) \
		__cpu_remap((oldbit), &(old), &(new), NR_CPUS)
static inline int __cpu_remap(int oldbit,
		const cpumask_t *oldp, const cpumask_t *newp, int nbits)
{
	return bitmap_bitremap(oldbit, oldp->bits, newp->bits, nbits);
}

#define cpus_remap(dst, src, old, new) \
		__cpus_remap(&(dst), &(src), &(old), &(new), NR_CPUS)
static inline void __cpus_remap(cpumask_t *dstp, const cpumask_t *srcp,
		const cpumask_t *oldp, const cpumask_t *newp, int nbits)
{
	bitmap_remap(dstp->bits, srcp->bits, oldp->bits, newp->bits, nbits);
}

#if NR_CPUS > 1
#define for_each_cpu_mask(cpu, mask)		\
	for ((cpu) = first_cpu(mask);		\
		(cpu) < NR_CPUS;		\
		(cpu) = next_cpu((cpu), (mask)))
#else /* NR_CPUS == 1 */
#define for_each_cpu_mask(cpu, mask)		\
	for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
#endif /* NR_CPUS */

/*
 * The following particular system cpumasks and operations manage
 * possible, present and online cpus.  Each of them is a fixed size
 * bitmap of size NR_CPUS.
 *
 *  #ifdef CONFIG_HOTPLUG_CPU
 *     cpu_possible_map - has bit 'cpu' set iff cpu is populatable
 *     cpu_present_map  - has bit 'cpu' set iff cpu is populated
 *     cpu_online_map   - has bit 'cpu' set iff cpu available to scheduler
 *  #else
 *     cpu_possible_map - has bit 'cpu' set iff cpu is populated
 *     cpu_present_map  - copy of cpu_possible_map
 *     cpu_online_map   - has bit 'cpu' set iff cpu available to scheduler
 *  #endif
 *
 *  In either case, NR_CPUS is fixed at compile time, as the static
 *  size of these bitmaps.  The cpu_possible_map is fixed at boot
 *  time, as the set of CPU id's that it is possible might ever
 *  be plugged in at anytime during the life of that system boot.
 *  The cpu_present_map is dynamic(*), representing which CPUs
 *  are currently plugged in.  And cpu_online_map is the dynamic
 *  subset of cpu_present_map, indicating those CPUs available
 *  for scheduling.
 *
 *  If HOTPLUG is enabled, then cpu_possible_map is forced to have
 *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
 *  ACPI reports present at boot.
 *
 *  If HOTPLUG is enabled, then cpu_present_map varies dynamically,
 *  depending on what ACPI reports as currently plugged in, otherwise
 *  cpu_present_map is just a copy of cpu_possible_map.
 *
 *  (*) Well, cpu_present_map is dynamic in the hotplug case.  If not
 *      hotplug, it's a copy of cpu_possible_map, hence fixed at boot.
 *
 * Subtleties:
 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
 *    assumption that their single CPU is online.  The UP
 *    cpu_{online,possible,present}_maps are placebos.  Changing them
 *    will have no useful affect on the following num_*_cpus()
 *    and cpu_*() macros in the UP case.  This ugliness is a UP
 *    optimization - don't waste any instructions or memory references
 *    asking if you're online or how many CPUs there are if there is
 *    only one CPU.
 * 2) Most SMP arch's #define some of these maps to be some
 *    other map specific to that arch.  Therefore, the following
 *    must be #define macros, not inlines.  To see why, examine
 *    the assembly code produced by the following.  Note that
 *    set1() writes phys_x_map, but set2() writes x_map:
 *        int x_map, phys_x_map;
 *        #define set1(a) x_map = a
 *        inline void set2(int a) { x_map = a; }
 *        #define x_map phys_x_map
 *        main(){ set1(3); set2(5); }
 */

extern cpumask_t cpu_possible_map;
extern cpumask_t cpu_online_map;
extern cpumask_t cpu_present_map;

#if NR_CPUS > 1
#define num_online_cpus()	cpus_weight(cpu_online_map)
#define num_possible_cpus()	cpus_weight(cpu_possible_map)
#define num_present_cpus()	cpus_weight(cpu_present_map)
#define cpu_online(cpu)		cpu_isset((cpu), cpu_online_map)
#define cpu_possible(cpu)	cpu_isset((cpu), cpu_possible_map)
#define cpu_present(cpu)	cpu_isset((cpu), cpu_present_map)
#else
#define num_online_cpus()	1
#define num_possible_cpus()	1
#define num_present_cpus()	1
#define cpu_online(cpu)		((cpu) == 0)
#define cpu_possible(cpu)	((cpu) == 0)
#define cpu_present(cpu)	((cpu) == 0)
#endif

#ifdef CONFIG_SMP
extern int nr_cpu_ids;
#define any_online_cpu(mask) __any_online_cpu(&(mask))
int __any_online_cpu(const cpumask_t *mask);
#else
#define nr_cpu_ids			1
#define any_online_cpu(mask)		0
#endif

#define for_each_possible_cpu(cpu)  for_each_cpu_mask((cpu), cpu_possible_map)
#define for_each_online_cpu(cpu)  for_each_cpu_mask((cpu), cpu_online_map)
#define for_each_present_cpu(cpu) for_each_cpu_mask((cpu), cpu_present_map)

#endif /* __LINUX_CPUMASK_H */

Privacy Policy