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

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