1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_CPUMASK_H
3#define __LINUX_CPUMASK_H
4
5/*
6 * Cpumasks provide a bitmap suitable for representing the
7 * set of CPU's in a system, one bit position per CPU number. In general,
8 * only nr_cpu_ids (<= NR_CPUS) bits are valid.
9 */
10#include <linux/kernel.h>
11#include <linux/threads.h>
12#include <linux/bitmap.h>
13#include <linux/atomic.h>
14#include <linux/bug.h>
15#include <linux/gfp_types.h>
16#include <linux/numa.h>
17
18/* Don't assign or return these: may not be this big! */
19typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
20
21/**
22 * cpumask_bits - get the bits in a cpumask
23 * @maskp: the struct cpumask *
24 *
25 * You should only assume nr_cpu_ids bits of this mask are valid. This is
26 * a macro so it's const-correct.
27 */
28#define cpumask_bits(maskp) ((maskp)->bits)
29
30/**
31 * cpumask_pr_args - printf args to output a cpumask
32 * @maskp: cpumask to be printed
33 *
34 * Can be used to provide arguments for '%*pb[l]' when printing a cpumask.
35 */
36#define cpumask_pr_args(maskp) nr_cpu_ids, cpumask_bits(maskp)
37
38#if (NR_CPUS == 1) || defined(CONFIG_FORCE_NR_CPUS)
39#define nr_cpu_ids ((unsigned int)NR_CPUS)
40#else
41extern unsigned int nr_cpu_ids;
42#endif
43
44static inline void set_nr_cpu_ids(unsigned int nr)
45{
46#if (NR_CPUS == 1) || defined(CONFIG_FORCE_NR_CPUS)
47 WARN_ON(nr != nr_cpu_ids);
48#else
49 nr_cpu_ids = nr;
50#endif
51}
52
53/*
54 * We have several different "preferred sizes" for the cpumask
55 * operations, depending on operation.
56 *
57 * For example, the bitmap scanning and operating operations have
58 * optimized routines that work for the single-word case, but only when
59 * the size is constant. So if NR_CPUS fits in one single word, we are
60 * better off using that small constant, in order to trigger the
61 * optimized bit finding. That is 'small_cpumask_size'.
62 *
63 * The clearing and copying operations will similarly perform better
64 * with a constant size, but we limit that size arbitrarily to four
65 * words. We call this 'large_cpumask_size'.
66 *
67 * Finally, some operations just want the exact limit, either because
68 * they set bits or just don't have any faster fixed-sized versions. We
69 * call this just 'nr_cpumask_bits'.
70 *
71 * Note that these optional constants are always guaranteed to be at
72 * least as big as 'nr_cpu_ids' itself is, and all our cpumask
73 * allocations are at least that size (see cpumask_size()). The
74 * optimization comes from being able to potentially use a compile-time
75 * constant instead of a run-time generated exact number of CPUs.
76 */
77#if NR_CPUS <= BITS_PER_LONG
78 #define small_cpumask_bits ((unsigned int)NR_CPUS)
79 #define large_cpumask_bits ((unsigned int)NR_CPUS)
80#elif NR_CPUS <= 4*BITS_PER_LONG
81 #define small_cpumask_bits nr_cpu_ids
82 #define large_cpumask_bits ((unsigned int)NR_CPUS)
83#else
84 #define small_cpumask_bits nr_cpu_ids
85 #define large_cpumask_bits nr_cpu_ids
86#endif
87#define nr_cpumask_bits nr_cpu_ids
88
89/*
90 * The following particular system cpumasks and operations manage
91 * possible, present, active and online cpus.
92 *
93 * cpu_possible_mask- has bit 'cpu' set iff cpu is populatable
94 * cpu_present_mask - has bit 'cpu' set iff cpu is populated
95 * cpu_online_mask - has bit 'cpu' set iff cpu available to scheduler
96 * cpu_active_mask - has bit 'cpu' set iff cpu available to migration
97 *
98 * If !CONFIG_HOTPLUG_CPU, present == possible, and active == online.
99 *
100 * The cpu_possible_mask is fixed at boot time, as the set of CPU id's
101 * that it is possible might ever be plugged in at anytime during the
102 * life of that system boot. The cpu_present_mask is dynamic(*),
103 * representing which CPUs are currently plugged in. And
104 * cpu_online_mask is the dynamic subset of cpu_present_mask,
105 * indicating those CPUs available for scheduling.
106 *
107 * If HOTPLUG is enabled, then cpu_present_mask varies dynamically,
108 * depending on what ACPI reports as currently plugged in, otherwise
109 * cpu_present_mask is just a copy of cpu_possible_mask.
110 *
111 * (*) Well, cpu_present_mask is dynamic in the hotplug case. If not
112 * hotplug, it's a copy of cpu_possible_mask, hence fixed at boot.
113 *
114 * Subtleties:
115 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
116 * assumption that their single CPU is online. The UP
117 * cpu_{online,possible,present}_masks are placebos. Changing them
118 * will have no useful affect on the following num_*_cpus()
119 * and cpu_*() macros in the UP case. This ugliness is a UP
120 * optimization - don't waste any instructions or memory references
121 * asking if you're online or how many CPUs there are if there is
122 * only one CPU.
123 */
124
125extern struct cpumask __cpu_possible_mask;
126extern struct cpumask __cpu_online_mask;
127extern struct cpumask __cpu_present_mask;
128extern struct cpumask __cpu_active_mask;
129extern struct cpumask __cpu_dying_mask;
130#define cpu_possible_mask ((const struct cpumask *)&__cpu_possible_mask)
131#define cpu_online_mask ((const struct cpumask *)&__cpu_online_mask)
132#define cpu_present_mask ((const struct cpumask *)&__cpu_present_mask)
133#define cpu_active_mask ((const struct cpumask *)&__cpu_active_mask)
134#define cpu_dying_mask ((const struct cpumask *)&__cpu_dying_mask)
135
136extern atomic_t __num_online_cpus;
137
138extern cpumask_t cpus_booted_once_mask;
139
140static __always_inline void cpu_max_bits_warn(unsigned int cpu, unsigned int bits)
141{
142#ifdef CONFIG_DEBUG_PER_CPU_MAPS
143 WARN_ON_ONCE(cpu >= bits);
144#endif /* CONFIG_DEBUG_PER_CPU_MAPS */
145}
146
147/* verify cpu argument to cpumask_* operators */
148static __always_inline unsigned int cpumask_check(unsigned int cpu)
149{
150 cpu_max_bits_warn(cpu, small_cpumask_bits);
151 return cpu;
152}
153
154/**
155 * cpumask_first - get the first cpu in a cpumask
156 * @srcp: the cpumask pointer
157 *
158 * Returns >= nr_cpu_ids if no cpus set.
159 */
160static inline unsigned int cpumask_first(const struct cpumask *srcp)
161{
162 return find_first_bit(cpumask_bits(srcp), small_cpumask_bits);
163}
164
165/**
166 * cpumask_first_zero - get the first unset cpu in a cpumask
167 * @srcp: the cpumask pointer
168 *
169 * Returns >= nr_cpu_ids if all cpus are set.
170 */
171static inline unsigned int cpumask_first_zero(const struct cpumask *srcp)
172{
173 return find_first_zero_bit(cpumask_bits(srcp), small_cpumask_bits);
174}
175
176/**
177 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2
178 * @src1p: the first input
179 * @src2p: the second input
180 *
181 * Returns >= nr_cpu_ids if no cpus set in both. See also cpumask_next_and().
182 */
183static inline
184unsigned int cpumask_first_and(const struct cpumask *srcp1, const struct cpumask *srcp2)
185{
186 return find_first_and_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), small_cpumask_bits);
187}
188
189/**
190 * cpumask_last - get the last CPU in a cpumask
191 * @srcp: - the cpumask pointer
192 *
193 * Returns >= nr_cpumask_bits if no CPUs set.
194 */
195static inline unsigned int cpumask_last(const struct cpumask *srcp)
196{
197 return find_last_bit(cpumask_bits(srcp), small_cpumask_bits);
198}
199
200/**
201 * cpumask_next - get the next cpu in a cpumask
202 * @n: the cpu prior to the place to search (ie. return will be > @n)
203 * @srcp: the cpumask pointer
204 *
205 * Returns >= nr_cpu_ids if no further cpus set.
206 */
207static inline
208unsigned int cpumask_next(int n, const struct cpumask *srcp)
209{
210 /* -1 is a legal arg here. */
211 if (n != -1)
212 cpumask_check(cpu: n);
213 return find_next_bit(cpumask_bits(srcp), small_cpumask_bits, offset: n + 1);
214}
215
216/**
217 * cpumask_next_zero - get the next unset cpu in a cpumask
218 * @n: the cpu prior to the place to search (ie. return will be > @n)
219 * @srcp: the cpumask pointer
220 *
221 * Returns >= nr_cpu_ids if no further cpus unset.
222 */
223static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
224{
225 /* -1 is a legal arg here. */
226 if (n != -1)
227 cpumask_check(cpu: n);
228 return find_next_zero_bit(cpumask_bits(srcp), small_cpumask_bits, offset: n+1);
229}
230
231#if NR_CPUS == 1
232/* Uniprocessor: there is only one valid CPU */
233static inline unsigned int cpumask_local_spread(unsigned int i, int node)
234{
235 return 0;
236}
237
238static inline unsigned int cpumask_any_and_distribute(const struct cpumask *src1p,
239 const struct cpumask *src2p)
240{
241 return cpumask_first_and(srcp1: src1p, srcp2: src2p);
242}
243
244static inline unsigned int cpumask_any_distribute(const struct cpumask *srcp)
245{
246 return cpumask_first(srcp);
247}
248#else
249unsigned int cpumask_local_spread(unsigned int i, int node);
250unsigned int cpumask_any_and_distribute(const struct cpumask *src1p,
251 const struct cpumask *src2p);
252unsigned int cpumask_any_distribute(const struct cpumask *srcp);
253#endif /* NR_CPUS */
254
255/**
256 * cpumask_next_and - get the next cpu in *src1p & *src2p
257 * @n: the cpu prior to the place to search (ie. return will be > @n)
258 * @src1p: the first cpumask pointer
259 * @src2p: the second cpumask pointer
260 *
261 * Returns >= nr_cpu_ids if no further cpus set in both.
262 */
263static inline
264unsigned int cpumask_next_and(int n, const struct cpumask *src1p,
265 const struct cpumask *src2p)
266{
267 /* -1 is a legal arg here. */
268 if (n != -1)
269 cpumask_check(cpu: n);
270 return find_next_and_bit(cpumask_bits(src1p), cpumask_bits(src2p),
271 small_cpumask_bits, offset: n + 1);
272}
273
274/**
275 * for_each_cpu - iterate over every cpu in a mask
276 * @cpu: the (optionally unsigned) integer iterator
277 * @mask: the cpumask pointer
278 *
279 * After the loop, cpu is >= nr_cpu_ids.
280 */
281#define for_each_cpu(cpu, mask) \
282 for_each_set_bit(cpu, cpumask_bits(mask), small_cpumask_bits)
283
284#if NR_CPUS == 1
285static inline
286unsigned int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap)
287{
288 cpumask_check(cpu: start);
289 if (n != -1)
290 cpumask_check(cpu: n);
291
292 /*
293 * Return the first available CPU when wrapping, or when starting before cpu0,
294 * since there is only one valid option.
295 */
296 if (wrap && n >= 0)
297 return nr_cpumask_bits;
298
299 return cpumask_first(srcp: mask);
300}
301#else
302unsigned int __pure cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap);
303#endif
304
305/**
306 * for_each_cpu_wrap - iterate over every cpu in a mask, starting at a specified location
307 * @cpu: the (optionally unsigned) integer iterator
308 * @mask: the cpumask pointer
309 * @start: the start location
310 *
311 * The implementation does not assume any bit in @mask is set (including @start).
312 *
313 * After the loop, cpu is >= nr_cpu_ids.
314 */
315#define for_each_cpu_wrap(cpu, mask, start) \
316 for_each_set_bit_wrap(cpu, cpumask_bits(mask), small_cpumask_bits, start)
317
318/**
319 * for_each_cpu_and - iterate over every cpu in both masks
320 * @cpu: the (optionally unsigned) integer iterator
321 * @mask1: the first cpumask pointer
322 * @mask2: the second cpumask pointer
323 *
324 * This saves a temporary CPU mask in many places. It is equivalent to:
325 * struct cpumask tmp;
326 * cpumask_and(&tmp, &mask1, &mask2);
327 * for_each_cpu(cpu, &tmp)
328 * ...
329 *
330 * After the loop, cpu is >= nr_cpu_ids.
331 */
332#define for_each_cpu_and(cpu, mask1, mask2) \
333 for_each_and_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), small_cpumask_bits)
334
335/**
336 * for_each_cpu_andnot - iterate over every cpu present in one mask, excluding
337 * those present in another.
338 * @cpu: the (optionally unsigned) integer iterator
339 * @mask1: the first cpumask pointer
340 * @mask2: the second cpumask pointer
341 *
342 * This saves a temporary CPU mask in many places. It is equivalent to:
343 * struct cpumask tmp;
344 * cpumask_andnot(&tmp, &mask1, &mask2);
345 * for_each_cpu(cpu, &tmp)
346 * ...
347 *
348 * After the loop, cpu is >= nr_cpu_ids.
349 */
350#define for_each_cpu_andnot(cpu, mask1, mask2) \
351 for_each_andnot_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), small_cpumask_bits)
352
353/**
354 * for_each_cpu_or - iterate over every cpu present in either mask
355 * @cpu: the (optionally unsigned) integer iterator
356 * @mask1: the first cpumask pointer
357 * @mask2: the second cpumask pointer
358 *
359 * This saves a temporary CPU mask in many places. It is equivalent to:
360 * struct cpumask tmp;
361 * cpumask_or(&tmp, &mask1, &mask2);
362 * for_each_cpu(cpu, &tmp)
363 * ...
364 *
365 * After the loop, cpu is >= nr_cpu_ids.
366 */
367#define for_each_cpu_or(cpu, mask1, mask2) \
368 for_each_or_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), small_cpumask_bits)
369
370/**
371 * cpumask_any_but - return a "random" in a cpumask, but not this one.
372 * @mask: the cpumask to search
373 * @cpu: the cpu to ignore.
374 *
375 * Often used to find any cpu but smp_processor_id() in a mask.
376 * Returns >= nr_cpu_ids if no cpus set.
377 */
378static inline
379unsigned int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
380{
381 unsigned int i;
382
383 cpumask_check(cpu);
384 for_each_cpu(i, mask)
385 if (i != cpu)
386 break;
387 return i;
388}
389
390/**
391 * cpumask_nth - get the first cpu in a cpumask
392 * @srcp: the cpumask pointer
393 * @cpu: the N'th cpu to find, starting from 0
394 *
395 * Returns >= nr_cpu_ids if such cpu doesn't exist.
396 */
397static inline unsigned int cpumask_nth(unsigned int cpu, const struct cpumask *srcp)
398{
399 return find_nth_bit(cpumask_bits(srcp), small_cpumask_bits, n: cpumask_check(cpu));
400}
401
402/**
403 * cpumask_nth_and - get the first cpu in 2 cpumasks
404 * @srcp1: the cpumask pointer
405 * @srcp2: the cpumask pointer
406 * @cpu: the N'th cpu to find, starting from 0
407 *
408 * Returns >= nr_cpu_ids if such cpu doesn't exist.
409 */
410static inline
411unsigned int cpumask_nth_and(unsigned int cpu, const struct cpumask *srcp1,
412 const struct cpumask *srcp2)
413{
414 return find_nth_and_bit(cpumask_bits(srcp1), cpumask_bits(srcp2),
415 small_cpumask_bits, n: cpumask_check(cpu));
416}
417
418/**
419 * cpumask_nth_andnot - get the first cpu set in 1st cpumask, and clear in 2nd.
420 * @srcp1: the cpumask pointer
421 * @srcp2: the cpumask pointer
422 * @cpu: the N'th cpu to find, starting from 0
423 *
424 * Returns >= nr_cpu_ids if such cpu doesn't exist.
425 */
426static inline
427unsigned int cpumask_nth_andnot(unsigned int cpu, const struct cpumask *srcp1,
428 const struct cpumask *srcp2)
429{
430 return find_nth_andnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2),
431 small_cpumask_bits, n: cpumask_check(cpu));
432}
433
434/**
435 * cpumask_nth_and_andnot - get the Nth cpu set in 1st and 2nd cpumask, and clear in 3rd.
436 * @srcp1: the cpumask pointer
437 * @srcp2: the cpumask pointer
438 * @srcp3: the cpumask pointer
439 * @cpu: the N'th cpu to find, starting from 0
440 *
441 * Returns >= nr_cpu_ids if such cpu doesn't exist.
442 */
443static __always_inline
444unsigned int cpumask_nth_and_andnot(unsigned int cpu, const struct cpumask *srcp1,
445 const struct cpumask *srcp2,
446 const struct cpumask *srcp3)
447{
448 return find_nth_and_andnot_bit(cpumask_bits(srcp1),
449 cpumask_bits(srcp2),
450 cpumask_bits(srcp3),
451 small_cpumask_bits, n: cpumask_check(cpu));
452}
453
454#define CPU_BITS_NONE \
455{ \
456 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \
457}
458
459#define CPU_BITS_CPU0 \
460{ \
461 [0] = 1UL \
462}
463
464/**
465 * cpumask_set_cpu - set a cpu in a cpumask
466 * @cpu: cpu number (< nr_cpu_ids)
467 * @dstp: the cpumask pointer
468 */
469static __always_inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
470{
471 set_bit(nr: cpumask_check(cpu), cpumask_bits(dstp));
472}
473
474static __always_inline void __cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
475{
476 __set_bit(cpumask_check(cpu), cpumask_bits(dstp));
477}
478
479
480/**
481 * cpumask_clear_cpu - clear a cpu in a cpumask
482 * @cpu: cpu number (< nr_cpu_ids)
483 * @dstp: the cpumask pointer
484 */
485static __always_inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
486{
487 clear_bit(nr: cpumask_check(cpu), cpumask_bits(dstp));
488}
489
490static __always_inline void __cpumask_clear_cpu(int cpu, struct cpumask *dstp)
491{
492 __clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
493}
494
495/**
496 * cpumask_test_cpu - test for a cpu in a cpumask
497 * @cpu: cpu number (< nr_cpu_ids)
498 * @cpumask: the cpumask pointer
499 *
500 * Returns true if @cpu is set in @cpumask, else returns false
501 */
502static __always_inline bool cpumask_test_cpu(int cpu, const struct cpumask *cpumask)
503{
504 return test_bit(cpumask_check(cpu), cpumask_bits((cpumask)));
505}
506
507/**
508 * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
509 * @cpu: cpu number (< nr_cpu_ids)
510 * @cpumask: the cpumask pointer
511 *
512 * Returns true if @cpu is set in old bitmap of @cpumask, else returns false
513 *
514 * test_and_set_bit wrapper for cpumasks.
515 */
516static __always_inline bool cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
517{
518 return test_and_set_bit(nr: cpumask_check(cpu), cpumask_bits(cpumask));
519}
520
521/**
522 * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask
523 * @cpu: cpu number (< nr_cpu_ids)
524 * @cpumask: the cpumask pointer
525 *
526 * Returns true if @cpu is set in old bitmap of @cpumask, else returns false
527 *
528 * test_and_clear_bit wrapper for cpumasks.
529 */
530static __always_inline bool cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
531{
532 return test_and_clear_bit(nr: cpumask_check(cpu), cpumask_bits(cpumask));
533}
534
535/**
536 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask
537 * @dstp: the cpumask pointer
538 */
539static inline void cpumask_setall(struct cpumask *dstp)
540{
541 if (small_const_nbits(small_cpumask_bits)) {
542 cpumask_bits(dstp)[0] = BITMAP_LAST_WORD_MASK(nr_cpumask_bits);
543 return;
544 }
545 bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits);
546}
547
548/**
549 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask
550 * @dstp: the cpumask pointer
551 */
552static inline void cpumask_clear(struct cpumask *dstp)
553{
554 bitmap_zero(cpumask_bits(dstp), large_cpumask_bits);
555}
556
557/**
558 * cpumask_and - *dstp = *src1p & *src2p
559 * @dstp: the cpumask result
560 * @src1p: the first input
561 * @src2p: the second input
562 *
563 * If *@dstp is empty, returns false, else returns true
564 */
565static inline bool cpumask_and(struct cpumask *dstp,
566 const struct cpumask *src1p,
567 const struct cpumask *src2p)
568{
569 return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
570 cpumask_bits(src2p), small_cpumask_bits);
571}
572
573/**
574 * cpumask_or - *dstp = *src1p | *src2p
575 * @dstp: the cpumask result
576 * @src1p: the first input
577 * @src2p: the second input
578 */
579static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
580 const struct cpumask *src2p)
581{
582 bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
583 cpumask_bits(src2p), small_cpumask_bits);
584}
585
586/**
587 * cpumask_xor - *dstp = *src1p ^ *src2p
588 * @dstp: the cpumask result
589 * @src1p: the first input
590 * @src2p: the second input
591 */
592static inline void cpumask_xor(struct cpumask *dstp,
593 const struct cpumask *src1p,
594 const struct cpumask *src2p)
595{
596 bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
597 cpumask_bits(src2p), small_cpumask_bits);
598}
599
600/**
601 * cpumask_andnot - *dstp = *src1p & ~*src2p
602 * @dstp: the cpumask result
603 * @src1p: the first input
604 * @src2p: the second input
605 *
606 * If *@dstp is empty, returns false, else returns true
607 */
608static inline bool cpumask_andnot(struct cpumask *dstp,
609 const struct cpumask *src1p,
610 const struct cpumask *src2p)
611{
612 return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
613 cpumask_bits(src2p), small_cpumask_bits);
614}
615
616/**
617 * cpumask_equal - *src1p == *src2p
618 * @src1p: the first input
619 * @src2p: the second input
620 */
621static inline bool cpumask_equal(const struct cpumask *src1p,
622 const struct cpumask *src2p)
623{
624 return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
625 small_cpumask_bits);
626}
627
628/**
629 * cpumask_or_equal - *src1p | *src2p == *src3p
630 * @src1p: the first input
631 * @src2p: the second input
632 * @src3p: the third input
633 */
634static inline bool cpumask_or_equal(const struct cpumask *src1p,
635 const struct cpumask *src2p,
636 const struct cpumask *src3p)
637{
638 return bitmap_or_equal(cpumask_bits(src1p), cpumask_bits(src2p),
639 cpumask_bits(src3p), small_cpumask_bits);
640}
641
642/**
643 * cpumask_intersects - (*src1p & *src2p) != 0
644 * @src1p: the first input
645 * @src2p: the second input
646 */
647static inline bool cpumask_intersects(const struct cpumask *src1p,
648 const struct cpumask *src2p)
649{
650 return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
651 small_cpumask_bits);
652}
653
654/**
655 * cpumask_subset - (*src1p & ~*src2p) == 0
656 * @src1p: the first input
657 * @src2p: the second input
658 *
659 * Returns true if *@src1p is a subset of *@src2p, else returns false
660 */
661static inline bool cpumask_subset(const struct cpumask *src1p,
662 const struct cpumask *src2p)
663{
664 return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
665 small_cpumask_bits);
666}
667
668/**
669 * cpumask_empty - *srcp == 0
670 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear.
671 */
672static inline bool cpumask_empty(const struct cpumask *srcp)
673{
674 return bitmap_empty(cpumask_bits(srcp), small_cpumask_bits);
675}
676
677/**
678 * cpumask_full - *srcp == 0xFFFFFFFF...
679 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set.
680 */
681static inline bool cpumask_full(const struct cpumask *srcp)
682{
683 return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
684}
685
686/**
687 * cpumask_weight - Count of bits in *srcp
688 * @srcp: the cpumask to count bits (< nr_cpu_ids) in.
689 */
690static inline unsigned int cpumask_weight(const struct cpumask *srcp)
691{
692 return bitmap_weight(cpumask_bits(srcp), small_cpumask_bits);
693}
694
695/**
696 * cpumask_weight_and - Count of bits in (*srcp1 & *srcp2)
697 * @srcp1: the cpumask to count bits (< nr_cpu_ids) in.
698 * @srcp2: the cpumask to count bits (< nr_cpu_ids) in.
699 */
700static inline unsigned int cpumask_weight_and(const struct cpumask *srcp1,
701 const struct cpumask *srcp2)
702{
703 return bitmap_weight_and(cpumask_bits(srcp1), cpumask_bits(srcp2), small_cpumask_bits);
704}
705
706/**
707 * cpumask_shift_right - *dstp = *srcp >> n
708 * @dstp: the cpumask result
709 * @srcp: the input to shift
710 * @n: the number of bits to shift by
711 */
712static inline void cpumask_shift_right(struct cpumask *dstp,
713 const struct cpumask *srcp, int n)
714{
715 bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), shift: n,
716 small_cpumask_bits);
717}
718
719/**
720 * cpumask_shift_left - *dstp = *srcp << n
721 * @dstp: the cpumask result
722 * @srcp: the input to shift
723 * @n: the number of bits to shift by
724 */
725static inline void cpumask_shift_left(struct cpumask *dstp,
726 const struct cpumask *srcp, int n)
727{
728 bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), shift: n,
729 nr_cpumask_bits);
730}
731
732/**
733 * cpumask_copy - *dstp = *srcp
734 * @dstp: the result
735 * @srcp: the input cpumask
736 */
737static inline void cpumask_copy(struct cpumask *dstp,
738 const struct cpumask *srcp)
739{
740 bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), large_cpumask_bits);
741}
742
743/**
744 * cpumask_any - pick a "random" cpu from *srcp
745 * @srcp: the input cpumask
746 *
747 * Returns >= nr_cpu_ids if no cpus set.
748 */
749#define cpumask_any(srcp) cpumask_first(srcp)
750
751/**
752 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2
753 * @mask1: the first input cpumask
754 * @mask2: the second input cpumask
755 *
756 * Returns >= nr_cpu_ids if no cpus set.
757 */
758#define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2))
759
760/**
761 * cpumask_of - the cpumask containing just a given cpu
762 * @cpu: the cpu (<= nr_cpu_ids)
763 */
764#define cpumask_of(cpu) (get_cpu_mask(cpu))
765
766/**
767 * cpumask_parse_user - extract a cpumask from a user string
768 * @buf: the buffer to extract from
769 * @len: the length of the buffer
770 * @dstp: the cpumask to set.
771 *
772 * Returns -errno, or 0 for success.
773 */
774static inline int cpumask_parse_user(const char __user *buf, int len,
775 struct cpumask *dstp)
776{
777 return bitmap_parse_user(ubuf: buf, ulen: len, cpumask_bits(dstp), nr_cpumask_bits);
778}
779
780/**
781 * cpumask_parselist_user - extract a cpumask from a user string
782 * @buf: the buffer to extract from
783 * @len: the length of the buffer
784 * @dstp: the cpumask to set.
785 *
786 * Returns -errno, or 0 for success.
787 */
788static inline int cpumask_parselist_user(const char __user *buf, int len,
789 struct cpumask *dstp)
790{
791 return bitmap_parselist_user(ubuf: buf, ulen: len, cpumask_bits(dstp),
792 nr_cpumask_bits);
793}
794
795/**
796 * cpumask_parse - extract a cpumask from a string
797 * @buf: the buffer to extract from
798 * @dstp: the cpumask to set.
799 *
800 * Returns -errno, or 0 for success.
801 */
802static inline int cpumask_parse(const char *buf, struct cpumask *dstp)
803{
804 return bitmap_parse(buf, UINT_MAX, cpumask_bits(dstp), nr_cpumask_bits);
805}
806
807/**
808 * cpulist_parse - extract a cpumask from a user string of ranges
809 * @buf: the buffer to extract from
810 * @dstp: the cpumask to set.
811 *
812 * Returns -errno, or 0 for success.
813 */
814static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
815{
816 return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits);
817}
818
819/**
820 * cpumask_size - size to allocate for a 'struct cpumask' in bytes
821 */
822static inline unsigned int cpumask_size(void)
823{
824 return BITS_TO_LONGS(large_cpumask_bits) * sizeof(long);
825}
826
827/*
828 * cpumask_var_t: struct cpumask for stack usage.
829 *
830 * Oh, the wicked games we play! In order to make kernel coding a
831 * little more difficult, we typedef cpumask_var_t to an array or a
832 * pointer: doing &mask on an array is a noop, so it still works.
833 *
834 * ie.
835 * cpumask_var_t tmpmask;
836 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
837 * return -ENOMEM;
838 *
839 * ... use 'tmpmask' like a normal struct cpumask * ...
840 *
841 * free_cpumask_var(tmpmask);
842 *
843 *
844 * However, one notable exception is there. alloc_cpumask_var() allocates
845 * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has
846 * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t.
847 *
848 * cpumask_var_t tmpmask;
849 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
850 * return -ENOMEM;
851 *
852 * var = *tmpmask;
853 *
854 * This code makes NR_CPUS length memcopy and brings to a memory corruption.
855 * cpumask_copy() provide safe copy functionality.
856 *
857 * Note that there is another evil here: If you define a cpumask_var_t
858 * as a percpu variable then the way to obtain the address of the cpumask
859 * structure differently influences what this_cpu_* operation needs to be
860 * used. Please use this_cpu_cpumask_var_t in those cases. The direct use
861 * of this_cpu_ptr() or this_cpu_read() will lead to failures when the
862 * other type of cpumask_var_t implementation is configured.
863 *
864 * Please also note that __cpumask_var_read_mostly can be used to declare
865 * a cpumask_var_t variable itself (not its content) as read mostly.
866 */
867#ifdef CONFIG_CPUMASK_OFFSTACK
868typedef struct cpumask *cpumask_var_t;
869
870#define this_cpu_cpumask_var_ptr(x) this_cpu_read(x)
871#define __cpumask_var_read_mostly __read_mostly
872
873bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
874
875static inline
876bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
877{
878 return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
879}
880
881/**
882 * alloc_cpumask_var - allocate a struct cpumask
883 * @mask: pointer to cpumask_var_t where the cpumask is returned
884 * @flags: GFP_ flags
885 *
886 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
887 * a nop returning a constant 1 (in <linux/cpumask.h>).
888 *
889 * See alloc_cpumask_var_node.
890 */
891static inline
892bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
893{
894 return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE);
895}
896
897static inline
898bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
899{
900 return alloc_cpumask_var(mask, flags | __GFP_ZERO);
901}
902
903void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
904void free_cpumask_var(cpumask_var_t mask);
905void free_bootmem_cpumask_var(cpumask_var_t mask);
906
907static inline bool cpumask_available(cpumask_var_t mask)
908{
909 return mask != NULL;
910}
911
912#else
913typedef struct cpumask cpumask_var_t[1];
914
915#define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x)
916#define __cpumask_var_read_mostly
917
918static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
919{
920 return true;
921}
922
923static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
924 int node)
925{
926 return true;
927}
928
929static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
930{
931 cpumask_clear(dstp: *mask);
932 return true;
933}
934
935static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
936 int node)
937{
938 cpumask_clear(dstp: *mask);
939 return true;
940}
941
942static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask)
943{
944}
945
946static inline void free_cpumask_var(cpumask_var_t mask)
947{
948}
949
950static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
951{
952}
953
954static inline bool cpumask_available(cpumask_var_t mask)
955{
956 return true;
957}
958#endif /* CONFIG_CPUMASK_OFFSTACK */
959
960/* It's common to want to use cpu_all_mask in struct member initializers,
961 * so it has to refer to an address rather than a pointer. */
962extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
963#define cpu_all_mask to_cpumask(cpu_all_bits)
964
965/* First bits of cpu_bit_bitmap are in fact unset. */
966#define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
967
968#if NR_CPUS == 1
969/* Uniprocessor: the possible/online/present masks are always "1" */
970#define for_each_possible_cpu(cpu) for ((cpu) = 0; (cpu) < 1; (cpu)++)
971#define for_each_online_cpu(cpu) for ((cpu) = 0; (cpu) < 1; (cpu)++)
972#define for_each_present_cpu(cpu) for ((cpu) = 0; (cpu) < 1; (cpu)++)
973#else
974#define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask)
975#define for_each_online_cpu(cpu) for_each_cpu((cpu), cpu_online_mask)
976#define for_each_present_cpu(cpu) for_each_cpu((cpu), cpu_present_mask)
977#endif
978
979/* Wrappers for arch boot code to manipulate normally-constant masks */
980void init_cpu_present(const struct cpumask *src);
981void init_cpu_possible(const struct cpumask *src);
982void init_cpu_online(const struct cpumask *src);
983
984static inline void reset_cpu_possible_mask(void)
985{
986 bitmap_zero(cpumask_bits(&__cpu_possible_mask), NR_CPUS);
987}
988
989static inline void
990set_cpu_possible(unsigned int cpu, bool possible)
991{
992 if (possible)
993 cpumask_set_cpu(cpu, dstp: &__cpu_possible_mask);
994 else
995 cpumask_clear_cpu(cpu, dstp: &__cpu_possible_mask);
996}
997
998static inline void
999set_cpu_present(unsigned int cpu, bool present)
1000{
1001 if (present)
1002 cpumask_set_cpu(cpu, dstp: &__cpu_present_mask);
1003 else
1004 cpumask_clear_cpu(cpu, dstp: &__cpu_present_mask);
1005}
1006
1007void set_cpu_online(unsigned int cpu, bool online);
1008
1009static inline void
1010set_cpu_active(unsigned int cpu, bool active)
1011{
1012 if (active)
1013 cpumask_set_cpu(cpu, dstp: &__cpu_active_mask);
1014 else
1015 cpumask_clear_cpu(cpu, dstp: &__cpu_active_mask);
1016}
1017
1018static inline void
1019set_cpu_dying(unsigned int cpu, bool dying)
1020{
1021 if (dying)
1022 cpumask_set_cpu(cpu, dstp: &__cpu_dying_mask);
1023 else
1024 cpumask_clear_cpu(cpu, dstp: &__cpu_dying_mask);
1025}
1026
1027/**
1028 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *
1029 * @bitmap: the bitmap
1030 *
1031 * There are a few places where cpumask_var_t isn't appropriate and
1032 * static cpumasks must be used (eg. very early boot), yet we don't
1033 * expose the definition of 'struct cpumask'.
1034 *
1035 * This does the conversion, and can be used as a constant initializer.
1036 */
1037#define to_cpumask(bitmap) \
1038 ((struct cpumask *)(1 ? (bitmap) \
1039 : (void *)sizeof(__check_is_bitmap(bitmap))))
1040
1041static inline int __check_is_bitmap(const unsigned long *bitmap)
1042{
1043 return 1;
1044}
1045
1046/*
1047 * Special-case data structure for "single bit set only" constant CPU masks.
1048 *
1049 * We pre-generate all the 64 (or 32) possible bit positions, with enough
1050 * padding to the left and the right, and return the constant pointer
1051 * appropriately offset.
1052 */
1053extern const unsigned long
1054 cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
1055
1056static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
1057{
1058 const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
1059 p -= cpu / BITS_PER_LONG;
1060 return to_cpumask(p);
1061}
1062
1063#if NR_CPUS > 1
1064/**
1065 * num_online_cpus() - Read the number of online CPUs
1066 *
1067 * Despite the fact that __num_online_cpus is of type atomic_t, this
1068 * interface gives only a momentary snapshot and is not protected against
1069 * concurrent CPU hotplug operations unless invoked from a cpuhp_lock held
1070 * region.
1071 */
1072static __always_inline unsigned int num_online_cpus(void)
1073{
1074 return arch_atomic_read(&__num_online_cpus);
1075}
1076#define num_possible_cpus() cpumask_weight(cpu_possible_mask)
1077#define num_present_cpus() cpumask_weight(cpu_present_mask)
1078#define num_active_cpus() cpumask_weight(cpu_active_mask)
1079
1080static inline bool cpu_online(unsigned int cpu)
1081{
1082 return cpumask_test_cpu(cpu, cpu_online_mask);
1083}
1084
1085static inline bool cpu_possible(unsigned int cpu)
1086{
1087 return cpumask_test_cpu(cpu, cpu_possible_mask);
1088}
1089
1090static inline bool cpu_present(unsigned int cpu)
1091{
1092 return cpumask_test_cpu(cpu, cpu_present_mask);
1093}
1094
1095static inline bool cpu_active(unsigned int cpu)
1096{
1097 return cpumask_test_cpu(cpu, cpu_active_mask);
1098}
1099
1100static inline bool cpu_dying(unsigned int cpu)
1101{
1102 return cpumask_test_cpu(cpu, cpu_dying_mask);
1103}
1104
1105#else
1106
1107#define num_online_cpus() 1U
1108#define num_possible_cpus() 1U
1109#define num_present_cpus() 1U
1110#define num_active_cpus() 1U
1111
1112static inline bool cpu_online(unsigned int cpu)
1113{
1114 return cpu == 0;
1115}
1116
1117static inline bool cpu_possible(unsigned int cpu)
1118{
1119 return cpu == 0;
1120}
1121
1122static inline bool cpu_present(unsigned int cpu)
1123{
1124 return cpu == 0;
1125}
1126
1127static inline bool cpu_active(unsigned int cpu)
1128{
1129 return cpu == 0;
1130}
1131
1132static inline bool cpu_dying(unsigned int cpu)
1133{
1134 return false;
1135}
1136
1137#endif /* NR_CPUS > 1 */
1138
1139#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
1140
1141#if NR_CPUS <= BITS_PER_LONG
1142#define CPU_BITS_ALL \
1143{ \
1144 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
1145}
1146
1147#else /* NR_CPUS > BITS_PER_LONG */
1148
1149#define CPU_BITS_ALL \
1150{ \
1151 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \
1152 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
1153}
1154#endif /* NR_CPUS > BITS_PER_LONG */
1155
1156/**
1157 * cpumap_print_to_pagebuf - copies the cpumask into the buffer either
1158 * as comma-separated list of cpus or hex values of cpumask
1159 * @list: indicates whether the cpumap must be list
1160 * @mask: the cpumask to copy
1161 * @buf: the buffer to copy into
1162 *
1163 * Returns the length of the (null-terminated) @buf string, zero if
1164 * nothing is copied.
1165 */
1166static inline ssize_t
1167cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
1168{
1169 return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask),
1170 nr_cpu_ids);
1171}
1172
1173/**
1174 * cpumap_print_bitmask_to_buf - copies the cpumask into the buffer as
1175 * hex values of cpumask
1176 *
1177 * @buf: the buffer to copy into
1178 * @mask: the cpumask to copy
1179 * @off: in the string from which we are copying, we copy to @buf
1180 * @count: the maximum number of bytes to print
1181 *
1182 * The function prints the cpumask into the buffer as hex values of
1183 * cpumask; Typically used by bin_attribute to export cpumask bitmask
1184 * ABI.
1185 *
1186 * Returns the length of how many bytes have been copied, excluding
1187 * terminating '\0'.
1188 */
1189static inline ssize_t
1190cpumap_print_bitmask_to_buf(char *buf, const struct cpumask *mask,
1191 loff_t off, size_t count)
1192{
1193 return bitmap_print_bitmask_to_buf(buf, cpumask_bits(mask),
1194 nr_cpu_ids, off, count) - 1;
1195}
1196
1197/**
1198 * cpumap_print_list_to_buf - copies the cpumask into the buffer as
1199 * comma-separated list of cpus
1200 *
1201 * Everything is same with the above cpumap_print_bitmask_to_buf()
1202 * except the print format.
1203 */
1204static inline ssize_t
1205cpumap_print_list_to_buf(char *buf, const struct cpumask *mask,
1206 loff_t off, size_t count)
1207{
1208 return bitmap_print_list_to_buf(buf, cpumask_bits(mask),
1209 nr_cpu_ids, off, count) - 1;
1210}
1211
1212#if NR_CPUS <= BITS_PER_LONG
1213#define CPU_MASK_ALL \
1214(cpumask_t) { { \
1215 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
1216} }
1217#else
1218#define CPU_MASK_ALL \
1219(cpumask_t) { { \
1220 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \
1221 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
1222} }
1223#endif /* NR_CPUS > BITS_PER_LONG */
1224
1225#define CPU_MASK_NONE \
1226(cpumask_t) { { \
1227 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \
1228} }
1229
1230#define CPU_MASK_CPU0 \
1231(cpumask_t) { { \
1232 [0] = 1UL \
1233} }
1234
1235/*
1236 * Provide a valid theoretical max size for cpumap and cpulist sysfs files
1237 * to avoid breaking userspace which may allocate a buffer based on the size
1238 * reported by e.g. fstat.
1239 *
1240 * for cpumap NR_CPUS * 9/32 - 1 should be an exact length.
1241 *
1242 * For cpulist 7 is (ceil(log10(NR_CPUS)) + 1) allowing for NR_CPUS to be up
1243 * to 2 orders of magnitude larger than 8192. And then we divide by 2 to
1244 * cover a worst-case of every other cpu being on one of two nodes for a
1245 * very large NR_CPUS.
1246 *
1247 * Use PAGE_SIZE as a minimum for smaller configurations while avoiding
1248 * unsigned comparison to -1.
1249 */
1250#define CPUMAP_FILE_MAX_BYTES (((NR_CPUS * 9)/32 > PAGE_SIZE) \
1251 ? (NR_CPUS * 9)/32 - 1 : PAGE_SIZE)
1252#define CPULIST_FILE_MAX_BYTES (((NR_CPUS * 7)/2 > PAGE_SIZE) ? (NR_CPUS * 7)/2 : PAGE_SIZE)
1253
1254#endif /* __LINUX_CPUMASK_H */
1255

source code of linux/include/linux/cpumask.h