1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_CPUMASK_H
3 #define __LINUX_CPUMASK_H
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.
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>
18 /* Don't assign or return these: may not be this big! */
19 typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
22 * cpumask_bits - get the bits in a cpumask
23 * @maskp: the struct cpumask *
25 * You should only assume nr_cpu_ids bits of this mask are valid. This is
26 * a macro so it's const-correct.
28 #define cpumask_bits(maskp) ((maskp)->bits)
31 * cpumask_pr_args - printf args to output a cpumask
32 * @maskp: cpumask to be printed
34 * Can be used to provide arguments for '%*pb[l]' when printing a cpumask.
36 #define cpumask_pr_args(maskp) nr_cpu_ids, cpumask_bits(maskp)
38 #if (NR_CPUS == 1) || defined(CONFIG_FORCE_NR_CPUS)
39 #define nr_cpu_ids ((unsigned int)NR_CPUS)
41 extern unsigned int nr_cpu_ids;
44 static inline void set_nr_cpu_ids(unsigned int nr)
46 #if (NR_CPUS == 1) || defined(CONFIG_FORCE_NR_CPUS)
47 WARN_ON(nr != nr_cpu_ids);
53 /* Deprecated. Always use nr_cpu_ids. */
54 #define nr_cpumask_bits nr_cpu_ids
57 * The following particular system cpumasks and operations manage
58 * possible, present, active and online cpus.
60 * cpu_possible_mask- has bit 'cpu' set iff cpu is populatable
61 * cpu_present_mask - has bit 'cpu' set iff cpu is populated
62 * cpu_online_mask - has bit 'cpu' set iff cpu available to scheduler
63 * cpu_active_mask - has bit 'cpu' set iff cpu available to migration
65 * If !CONFIG_HOTPLUG_CPU, present == possible, and active == online.
67 * The cpu_possible_mask is fixed at boot time, as the set of CPU id's
68 * that it is possible might ever be plugged in at anytime during the
69 * life of that system boot. The cpu_present_mask is dynamic(*),
70 * representing which CPUs are currently plugged in. And
71 * cpu_online_mask is the dynamic subset of cpu_present_mask,
72 * indicating those CPUs available for scheduling.
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.
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.
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
92 extern struct cpumask __cpu_possible_mask;
93 extern struct cpumask __cpu_online_mask;
94 extern struct cpumask __cpu_present_mask;
95 extern struct cpumask __cpu_active_mask;
96 extern 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)
103 extern atomic_t __num_online_cpus;
105 extern cpumask_t cpus_booted_once_mask;
107 static __always_inline void cpu_max_bits_warn(unsigned int cpu, unsigned int bits)
109 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
110 WARN_ON_ONCE(cpu >= bits);
111 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */
114 /* verify cpu argument to cpumask_* operators */
115 static __always_inline unsigned int cpumask_check(unsigned int cpu)
117 cpu_max_bits_warn(cpu, nr_cpumask_bits);
122 * cpumask_first - get the first cpu in a cpumask
123 * @srcp: the cpumask pointer
125 * Returns >= nr_cpu_ids if no cpus set.
127 static inline unsigned int cpumask_first(const struct cpumask *srcp)
129 return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits);
133 * cpumask_first_zero - get the first unset cpu in a cpumask
134 * @srcp: the cpumask pointer
136 * Returns >= nr_cpu_ids if all cpus are set.
138 static inline unsigned int cpumask_first_zero(const struct cpumask *srcp)
140 return find_first_zero_bit(cpumask_bits(srcp), nr_cpumask_bits);
144 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2
145 * @src1p: the first input
146 * @src2p: the second input
148 * Returns >= nr_cpu_ids if no cpus set in both. See also cpumask_next_and().
151 unsigned int cpumask_first_and(const struct cpumask *srcp1, const struct cpumask *srcp2)
153 return find_first_and_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_cpumask_bits);
157 * cpumask_last - get the last CPU in a cpumask
158 * @srcp: - the cpumask pointer
160 * Returns >= nr_cpumask_bits if no CPUs set.
162 static inline unsigned int cpumask_last(const struct cpumask *srcp)
164 return find_last_bit(cpumask_bits(srcp), nr_cpumask_bits);
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
172 * Returns >= nr_cpu_ids if no further cpus set.
175 unsigned int cpumask_next(int n, const struct cpumask *srcp)
177 /* -1 is a legal arg here. */
180 return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1);
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
188 * Returns >= nr_cpu_ids if no further cpus unset.
190 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
192 /* -1 is a legal arg here. */
195 return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
199 /* Uniprocessor: there is only one valid CPU */
200 static inline unsigned int cpumask_local_spread(unsigned int i, int node)
205 static inline unsigned int cpumask_any_and_distribute(const struct cpumask *src1p,
206 const struct cpumask *src2p)
208 return cpumask_first_and(src1p, src2p);
211 static inline unsigned int cpumask_any_distribute(const struct cpumask *srcp)
213 return cpumask_first(srcp);
216 unsigned int cpumask_local_spread(unsigned int i, int node);
217 unsigned int cpumask_any_and_distribute(const struct cpumask *src1p,
218 const struct cpumask *src2p);
219 unsigned int cpumask_any_distribute(const struct cpumask *srcp);
223 * cpumask_next_and - get the next cpu in *src1p & *src2p
224 * @n: the cpu prior to the place to search (ie. return will be > @n)
225 * @src1p: the first cpumask pointer
226 * @src2p: the second cpumask pointer
228 * Returns >= nr_cpu_ids if no further cpus set in both.
231 unsigned int cpumask_next_and(int n, const struct cpumask *src1p,
232 const struct cpumask *src2p)
234 /* -1 is a legal arg here. */
237 return find_next_and_bit(cpumask_bits(src1p), cpumask_bits(src2p),
238 nr_cpumask_bits, n + 1);
242 * for_each_cpu - iterate over every cpu in a mask
243 * @cpu: the (optionally unsigned) integer iterator
244 * @mask: the cpumask pointer
246 * After the loop, cpu is >= nr_cpu_ids.
248 #define for_each_cpu(cpu, mask) \
249 for_each_set_bit(cpu, cpumask_bits(mask), nr_cpumask_bits)
252 * for_each_cpu_not - iterate over every cpu in a complemented mask
253 * @cpu: the (optionally unsigned) integer iterator
254 * @mask: the cpumask pointer
256 * After the loop, cpu is >= nr_cpu_ids.
258 #define for_each_cpu_not(cpu, mask) \
259 for_each_clear_bit(cpu, cpumask_bits(mask), nr_cpumask_bits)
263 unsigned int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap)
265 cpumask_check(start);
270 * Return the first available CPU when wrapping, or when starting before cpu0,
271 * since there is only one valid option.
274 return nr_cpumask_bits;
276 return cpumask_first(mask);
279 unsigned int __pure cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap);
283 * for_each_cpu_wrap - iterate over every cpu in a mask, starting at a specified location
284 * @cpu: the (optionally unsigned) integer iterator
285 * @mask: the cpumask pointer
286 * @start: the start location
288 * The implementation does not assume any bit in @mask is set (including @start).
290 * After the loop, cpu is >= nr_cpu_ids.
292 #define for_each_cpu_wrap(cpu, mask, start) \
293 for_each_set_bit_wrap(cpu, cpumask_bits(mask), nr_cpumask_bits, start)
296 * for_each_cpu_and - iterate over every cpu in both masks
297 * @cpu: the (optionally unsigned) integer iterator
298 * @mask1: the first cpumask pointer
299 * @mask2: the second cpumask pointer
301 * This saves a temporary CPU mask in many places. It is equivalent to:
302 * struct cpumask tmp;
303 * cpumask_and(&tmp, &mask1, &mask2);
304 * for_each_cpu(cpu, &tmp)
307 * After the loop, cpu is >= nr_cpu_ids.
309 #define for_each_cpu_and(cpu, mask1, mask2) \
310 for_each_and_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), nr_cpumask_bits)
313 * for_each_cpu_andnot - iterate over every cpu present in one mask, excluding
314 * those present in another.
315 * @cpu: the (optionally unsigned) integer iterator
316 * @mask1: the first cpumask pointer
317 * @mask2: the second cpumask pointer
319 * This saves a temporary CPU mask in many places. It is equivalent to:
320 * struct cpumask tmp;
321 * cpumask_andnot(&tmp, &mask1, &mask2);
322 * for_each_cpu(cpu, &tmp)
325 * After the loop, cpu is >= nr_cpu_ids.
327 #define for_each_cpu_andnot(cpu, mask1, mask2) \
328 for_each_andnot_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), nr_cpumask_bits)
331 * cpumask_any_but - return a "random" in a cpumask, but not this one.
332 * @mask: the cpumask to search
333 * @cpu: the cpu to ignore.
335 * Often used to find any cpu but smp_processor_id() in a mask.
336 * Returns >= nr_cpu_ids if no cpus set.
339 unsigned int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
344 for_each_cpu(i, mask)
351 * cpumask_nth - get the first cpu in a cpumask
352 * @srcp: the cpumask pointer
353 * @cpu: the N'th cpu to find, starting from 0
355 * Returns >= nr_cpu_ids if such cpu doesn't exist.
357 static inline unsigned int cpumask_nth(unsigned int cpu, const struct cpumask *srcp)
359 return find_nth_bit(cpumask_bits(srcp), nr_cpumask_bits, cpumask_check(cpu));
363 * cpumask_nth_and - get the first cpu in 2 cpumasks
364 * @srcp1: the cpumask pointer
365 * @srcp2: the cpumask pointer
366 * @cpu: the N'th cpu to find, starting from 0
368 * Returns >= nr_cpu_ids if such cpu doesn't exist.
371 unsigned int cpumask_nth_and(unsigned int cpu, const struct cpumask *srcp1,
372 const struct cpumask *srcp2)
374 return find_nth_and_bit(cpumask_bits(srcp1), cpumask_bits(srcp2),
375 nr_cpumask_bits, cpumask_check(cpu));
379 * cpumask_nth_andnot - get the first cpu set in 1st cpumask, and clear in 2nd.
380 * @srcp1: the cpumask pointer
381 * @srcp2: the cpumask pointer
382 * @cpu: the N'th cpu to find, starting from 0
384 * Returns >= nr_cpu_ids if such cpu doesn't exist.
387 unsigned int cpumask_nth_andnot(unsigned int cpu, const struct cpumask *srcp1,
388 const struct cpumask *srcp2)
390 return find_nth_andnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2),
391 nr_cpumask_bits, cpumask_check(cpu));
394 #define CPU_BITS_NONE \
396 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \
399 #define CPU_BITS_CPU0 \
405 * cpumask_set_cpu - set a cpu in a cpumask
406 * @cpu: cpu number (< nr_cpu_ids)
407 * @dstp: the cpumask pointer
409 static __always_inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
411 set_bit(cpumask_check(cpu), cpumask_bits(dstp));
414 static __always_inline void __cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
416 __set_bit(cpumask_check(cpu), cpumask_bits(dstp));
421 * cpumask_clear_cpu - clear a cpu in a cpumask
422 * @cpu: cpu number (< nr_cpu_ids)
423 * @dstp: the cpumask pointer
425 static __always_inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
427 clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
430 static __always_inline void __cpumask_clear_cpu(int cpu, struct cpumask *dstp)
432 __clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
436 * cpumask_test_cpu - test for a cpu in a cpumask
437 * @cpu: cpu number (< nr_cpu_ids)
438 * @cpumask: the cpumask pointer
440 * Returns true if @cpu is set in @cpumask, else returns false
442 static __always_inline bool cpumask_test_cpu(int cpu, const struct cpumask *cpumask)
444 return test_bit(cpumask_check(cpu), cpumask_bits((cpumask)));
448 * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
449 * @cpu: cpu number (< nr_cpu_ids)
450 * @cpumask: the cpumask pointer
452 * Returns true if @cpu is set in old bitmap of @cpumask, else returns false
454 * test_and_set_bit wrapper for cpumasks.
456 static __always_inline bool cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
458 return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask));
462 * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask
463 * @cpu: cpu number (< nr_cpu_ids)
464 * @cpumask: the cpumask pointer
466 * Returns true if @cpu is set in old bitmap of @cpumask, else returns false
468 * test_and_clear_bit wrapper for cpumasks.
470 static __always_inline bool cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
472 return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask));
476 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask
477 * @dstp: the cpumask pointer
479 static inline void cpumask_setall(struct cpumask *dstp)
481 bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits);
485 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask
486 * @dstp: the cpumask pointer
488 static inline void cpumask_clear(struct cpumask *dstp)
490 bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits);
494 * cpumask_and - *dstp = *src1p & *src2p
495 * @dstp: the cpumask result
496 * @src1p: the first input
497 * @src2p: the second input
499 * If *@dstp is empty, returns false, else returns true
501 static inline bool cpumask_and(struct cpumask *dstp,
502 const struct cpumask *src1p,
503 const struct cpumask *src2p)
505 return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
506 cpumask_bits(src2p), nr_cpumask_bits);
510 * cpumask_or - *dstp = *src1p | *src2p
511 * @dstp: the cpumask result
512 * @src1p: the first input
513 * @src2p: the second input
515 static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
516 const struct cpumask *src2p)
518 bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
519 cpumask_bits(src2p), nr_cpumask_bits);
523 * cpumask_xor - *dstp = *src1p ^ *src2p
524 * @dstp: the cpumask result
525 * @src1p: the first input
526 * @src2p: the second input
528 static inline void cpumask_xor(struct cpumask *dstp,
529 const struct cpumask *src1p,
530 const struct cpumask *src2p)
532 bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
533 cpumask_bits(src2p), nr_cpumask_bits);
537 * cpumask_andnot - *dstp = *src1p & ~*src2p
538 * @dstp: the cpumask result
539 * @src1p: the first input
540 * @src2p: the second input
542 * If *@dstp is empty, returns false, else returns true
544 static inline bool cpumask_andnot(struct cpumask *dstp,
545 const struct cpumask *src1p,
546 const struct cpumask *src2p)
548 return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
549 cpumask_bits(src2p), nr_cpumask_bits);
553 * cpumask_complement - *dstp = ~*srcp
554 * @dstp: the cpumask result
555 * @srcp: the input to invert
557 static inline void cpumask_complement(struct cpumask *dstp,
558 const struct cpumask *srcp)
560 bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp),
565 * cpumask_equal - *src1p == *src2p
566 * @src1p: the first input
567 * @src2p: the second input
569 static inline bool cpumask_equal(const struct cpumask *src1p,
570 const struct cpumask *src2p)
572 return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
577 * cpumask_or_equal - *src1p | *src2p == *src3p
578 * @src1p: the first input
579 * @src2p: the second input
580 * @src3p: the third input
582 static inline bool cpumask_or_equal(const struct cpumask *src1p,
583 const struct cpumask *src2p,
584 const struct cpumask *src3p)
586 return bitmap_or_equal(cpumask_bits(src1p), cpumask_bits(src2p),
587 cpumask_bits(src3p), nr_cpumask_bits);
591 * cpumask_intersects - (*src1p & *src2p) != 0
592 * @src1p: the first input
593 * @src2p: the second input
595 static inline bool cpumask_intersects(const struct cpumask *src1p,
596 const struct cpumask *src2p)
598 return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
603 * cpumask_subset - (*src1p & ~*src2p) == 0
604 * @src1p: the first input
605 * @src2p: the second input
607 * Returns true if *@src1p is a subset of *@src2p, else returns false
609 static inline bool cpumask_subset(const struct cpumask *src1p,
610 const struct cpumask *src2p)
612 return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
617 * cpumask_empty - *srcp == 0
618 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear.
620 static inline bool cpumask_empty(const struct cpumask *srcp)
622 return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits);
626 * cpumask_full - *srcp == 0xFFFFFFFF...
627 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set.
629 static inline bool cpumask_full(const struct cpumask *srcp)
631 return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
635 * cpumask_weight - Count of bits in *srcp
636 * @srcp: the cpumask to count bits (< nr_cpu_ids) in.
638 static inline unsigned int cpumask_weight(const struct cpumask *srcp)
640 return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits);
644 * cpumask_weight_and - Count of bits in (*srcp1 & *srcp2)
645 * @srcp1: the cpumask to count bits (< nr_cpu_ids) in.
646 * @srcp2: the cpumask to count bits (< nr_cpu_ids) in.
648 static inline unsigned int cpumask_weight_and(const struct cpumask *srcp1,
649 const struct cpumask *srcp2)
651 return bitmap_weight_and(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_cpumask_bits);
655 * cpumask_shift_right - *dstp = *srcp >> n
656 * @dstp: the cpumask result
657 * @srcp: the input to shift
658 * @n: the number of bits to shift by
660 static inline void cpumask_shift_right(struct cpumask *dstp,
661 const struct cpumask *srcp, int n)
663 bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n,
668 * cpumask_shift_left - *dstp = *srcp << n
669 * @dstp: the cpumask result
670 * @srcp: the input to shift
671 * @n: the number of bits to shift by
673 static inline void cpumask_shift_left(struct cpumask *dstp,
674 const struct cpumask *srcp, int n)
676 bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n,
681 * cpumask_copy - *dstp = *srcp
683 * @srcp: the input cpumask
685 static inline void cpumask_copy(struct cpumask *dstp,
686 const struct cpumask *srcp)
688 bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits);
692 * cpumask_any - pick a "random" cpu from *srcp
693 * @srcp: the input cpumask
695 * Returns >= nr_cpu_ids if no cpus set.
697 #define cpumask_any(srcp) cpumask_first(srcp)
700 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2
701 * @mask1: the first input cpumask
702 * @mask2: the second input cpumask
704 * Returns >= nr_cpu_ids if no cpus set.
706 #define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2))
709 * cpumask_of - the cpumask containing just a given cpu
710 * @cpu: the cpu (<= nr_cpu_ids)
712 #define cpumask_of(cpu) (get_cpu_mask(cpu))
715 * cpumask_parse_user - extract a cpumask from a user string
716 * @buf: the buffer to extract from
717 * @len: the length of the buffer
718 * @dstp: the cpumask to set.
720 * Returns -errno, or 0 for success.
722 static inline int cpumask_parse_user(const char __user *buf, int len,
723 struct cpumask *dstp)
725 return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
729 * cpumask_parselist_user - extract a cpumask from a user string
730 * @buf: the buffer to extract from
731 * @len: the length of the buffer
732 * @dstp: the cpumask to set.
734 * Returns -errno, or 0 for success.
736 static inline int cpumask_parselist_user(const char __user *buf, int len,
737 struct cpumask *dstp)
739 return bitmap_parselist_user(buf, len, cpumask_bits(dstp),
744 * cpumask_parse - extract a cpumask from a string
745 * @buf: the buffer to extract from
746 * @dstp: the cpumask to set.
748 * Returns -errno, or 0 for success.
750 static inline int cpumask_parse(const char *buf, struct cpumask *dstp)
752 return bitmap_parse(buf, UINT_MAX, cpumask_bits(dstp), nr_cpumask_bits);
756 * cpulist_parse - extract a cpumask from a user string of ranges
757 * @buf: the buffer to extract from
758 * @dstp: the cpumask to set.
760 * Returns -errno, or 0 for success.
762 static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
764 return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits);
768 * cpumask_size - size to allocate for a 'struct cpumask' in bytes
770 static inline unsigned int cpumask_size(void)
772 return BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long);
776 * cpumask_var_t: struct cpumask for stack usage.
778 * Oh, the wicked games we play! In order to make kernel coding a
779 * little more difficult, we typedef cpumask_var_t to an array or a
780 * pointer: doing &mask on an array is a noop, so it still works.
783 * cpumask_var_t tmpmask;
784 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
787 * ... use 'tmpmask' like a normal struct cpumask * ...
789 * free_cpumask_var(tmpmask);
792 * However, one notable exception is there. alloc_cpumask_var() allocates
793 * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has
794 * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t.
796 * cpumask_var_t tmpmask;
797 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
802 * This code makes NR_CPUS length memcopy and brings to a memory corruption.
803 * cpumask_copy() provide safe copy functionality.
805 * Note that there is another evil here: If you define a cpumask_var_t
806 * as a percpu variable then the way to obtain the address of the cpumask
807 * structure differently influences what this_cpu_* operation needs to be
808 * used. Please use this_cpu_cpumask_var_t in those cases. The direct use
809 * of this_cpu_ptr() or this_cpu_read() will lead to failures when the
810 * other type of cpumask_var_t implementation is configured.
812 * Please also note that __cpumask_var_read_mostly can be used to declare
813 * a cpumask_var_t variable itself (not its content) as read mostly.
815 #ifdef CONFIG_CPUMASK_OFFSTACK
816 typedef struct cpumask *cpumask_var_t;
818 #define this_cpu_cpumask_var_ptr(x) this_cpu_read(x)
819 #define __cpumask_var_read_mostly __read_mostly
821 bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
824 bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
826 return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
830 * alloc_cpumask_var - allocate a struct cpumask
831 * @mask: pointer to cpumask_var_t where the cpumask is returned
834 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
835 * a nop returning a constant 1 (in <linux/cpumask.h>).
837 * See alloc_cpumask_var_node.
840 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
842 return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE);
846 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
848 return alloc_cpumask_var(mask, flags | __GFP_ZERO);
851 void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
852 void free_cpumask_var(cpumask_var_t mask);
853 void free_bootmem_cpumask_var(cpumask_var_t mask);
855 static inline bool cpumask_available(cpumask_var_t mask)
861 typedef struct cpumask cpumask_var_t[1];
863 #define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x)
864 #define __cpumask_var_read_mostly
866 static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
871 static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
877 static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
879 cpumask_clear(*mask);
883 static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
886 cpumask_clear(*mask);
890 static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask)
894 static inline void free_cpumask_var(cpumask_var_t mask)
898 static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
902 static inline bool cpumask_available(cpumask_var_t mask)
906 #endif /* CONFIG_CPUMASK_OFFSTACK */
908 /* It's common to want to use cpu_all_mask in struct member initializers,
909 * so it has to refer to an address rather than a pointer. */
910 extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
911 #define cpu_all_mask to_cpumask(cpu_all_bits)
913 /* First bits of cpu_bit_bitmap are in fact unset. */
914 #define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
917 /* Uniprocessor: the possible/online/present masks are always "1" */
918 #define for_each_possible_cpu(cpu) for ((cpu) = 0; (cpu) < 1; (cpu)++)
919 #define for_each_online_cpu(cpu) for ((cpu) = 0; (cpu) < 1; (cpu)++)
920 #define for_each_present_cpu(cpu) for ((cpu) = 0; (cpu) < 1; (cpu)++)
922 #define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask)
923 #define for_each_online_cpu(cpu) for_each_cpu((cpu), cpu_online_mask)
924 #define for_each_present_cpu(cpu) for_each_cpu((cpu), cpu_present_mask)
927 /* Wrappers for arch boot code to manipulate normally-constant masks */
928 void init_cpu_present(const struct cpumask *src);
929 void init_cpu_possible(const struct cpumask *src);
930 void init_cpu_online(const struct cpumask *src);
932 static inline void reset_cpu_possible_mask(void)
934 bitmap_zero(cpumask_bits(&__cpu_possible_mask), NR_CPUS);
938 set_cpu_possible(unsigned int cpu, bool possible)
941 cpumask_set_cpu(cpu, &__cpu_possible_mask);
943 cpumask_clear_cpu(cpu, &__cpu_possible_mask);
947 set_cpu_present(unsigned int cpu, bool present)
950 cpumask_set_cpu(cpu, &__cpu_present_mask);
952 cpumask_clear_cpu(cpu, &__cpu_present_mask);
955 void set_cpu_online(unsigned int cpu, bool online);
958 set_cpu_active(unsigned int cpu, bool active)
961 cpumask_set_cpu(cpu, &__cpu_active_mask);
963 cpumask_clear_cpu(cpu, &__cpu_active_mask);
967 set_cpu_dying(unsigned int cpu, bool dying)
970 cpumask_set_cpu(cpu, &__cpu_dying_mask);
972 cpumask_clear_cpu(cpu, &__cpu_dying_mask);
976 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *
977 * @bitmap: the bitmap
979 * There are a few places where cpumask_var_t isn't appropriate and
980 * static cpumasks must be used (eg. very early boot), yet we don't
981 * expose the definition of 'struct cpumask'.
983 * This does the conversion, and can be used as a constant initializer.
985 #define to_cpumask(bitmap) \
986 ((struct cpumask *)(1 ? (bitmap) \
987 : (void *)sizeof(__check_is_bitmap(bitmap))))
989 static inline int __check_is_bitmap(const unsigned long *bitmap)
995 * Special-case data structure for "single bit set only" constant CPU masks.
997 * We pre-generate all the 64 (or 32) possible bit positions, with enough
998 * padding to the left and the right, and return the constant pointer
999 * appropriately offset.
1001 extern const unsigned long
1002 cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
1004 static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
1006 const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
1007 p -= cpu / BITS_PER_LONG;
1008 return to_cpumask(p);
1013 * num_online_cpus() - Read the number of online CPUs
1015 * Despite the fact that __num_online_cpus is of type atomic_t, this
1016 * interface gives only a momentary snapshot and is not protected against
1017 * concurrent CPU hotplug operations unless invoked from a cpuhp_lock held
1020 static inline unsigned int num_online_cpus(void)
1022 return atomic_read(&__num_online_cpus);
1024 #define num_possible_cpus() cpumask_weight(cpu_possible_mask)
1025 #define num_present_cpus() cpumask_weight(cpu_present_mask)
1026 #define num_active_cpus() cpumask_weight(cpu_active_mask)
1028 static inline bool cpu_online(unsigned int cpu)
1030 return cpumask_test_cpu(cpu, cpu_online_mask);
1033 static inline bool cpu_possible(unsigned int cpu)
1035 return cpumask_test_cpu(cpu, cpu_possible_mask);
1038 static inline bool cpu_present(unsigned int cpu)
1040 return cpumask_test_cpu(cpu, cpu_present_mask);
1043 static inline bool cpu_active(unsigned int cpu)
1045 return cpumask_test_cpu(cpu, cpu_active_mask);
1048 static inline bool cpu_dying(unsigned int cpu)
1050 return cpumask_test_cpu(cpu, cpu_dying_mask);
1055 #define num_online_cpus() 1U
1056 #define num_possible_cpus() 1U
1057 #define num_present_cpus() 1U
1058 #define num_active_cpus() 1U
1060 static inline bool cpu_online(unsigned int cpu)
1065 static inline bool cpu_possible(unsigned int cpu)
1070 static inline bool cpu_present(unsigned int cpu)
1075 static inline bool cpu_active(unsigned int cpu)
1080 static inline bool cpu_dying(unsigned int cpu)
1085 #endif /* NR_CPUS > 1 */
1087 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
1089 #if NR_CPUS <= BITS_PER_LONG
1090 #define CPU_BITS_ALL \
1092 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
1095 #else /* NR_CPUS > BITS_PER_LONG */
1097 #define CPU_BITS_ALL \
1099 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \
1100 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
1102 #endif /* NR_CPUS > BITS_PER_LONG */
1105 * cpumap_print_to_pagebuf - copies the cpumask into the buffer either
1106 * as comma-separated list of cpus or hex values of cpumask
1107 * @list: indicates whether the cpumap must be list
1108 * @mask: the cpumask to copy
1109 * @buf: the buffer to copy into
1111 * Returns the length of the (null-terminated) @buf string, zero if
1112 * nothing is copied.
1114 static inline ssize_t
1115 cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
1117 return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask),
1122 * cpumap_print_bitmask_to_buf - copies the cpumask into the buffer as
1123 * hex values of cpumask
1125 * @buf: the buffer to copy into
1126 * @mask: the cpumask to copy
1127 * @off: in the string from which we are copying, we copy to @buf
1128 * @count: the maximum number of bytes to print
1130 * The function prints the cpumask into the buffer as hex values of
1131 * cpumask; Typically used by bin_attribute to export cpumask bitmask
1134 * Returns the length of how many bytes have been copied, excluding
1137 static inline ssize_t
1138 cpumap_print_bitmask_to_buf(char *buf, const struct cpumask *mask,
1139 loff_t off, size_t count)
1141 return bitmap_print_bitmask_to_buf(buf, cpumask_bits(mask),
1142 nr_cpu_ids, off, count) - 1;
1146 * cpumap_print_list_to_buf - copies the cpumask into the buffer as
1147 * comma-separated list of cpus
1149 * Everything is same with the above cpumap_print_bitmask_to_buf()
1150 * except the print format.
1152 static inline ssize_t
1153 cpumap_print_list_to_buf(char *buf, const struct cpumask *mask,
1154 loff_t off, size_t count)
1156 return bitmap_print_list_to_buf(buf, cpumask_bits(mask),
1157 nr_cpu_ids, off, count) - 1;
1160 #if NR_CPUS <= BITS_PER_LONG
1161 #define CPU_MASK_ALL \
1163 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
1166 #define CPU_MASK_ALL \
1168 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \
1169 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
1171 #endif /* NR_CPUS > BITS_PER_LONG */
1173 #define CPU_MASK_NONE \
1175 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \
1178 #define CPU_MASK_CPU0 \
1184 * Provide a valid theoretical max size for cpumap and cpulist sysfs files
1185 * to avoid breaking userspace which may allocate a buffer based on the size
1186 * reported by e.g. fstat.
1188 * for cpumap NR_CPUS * 9/32 - 1 should be an exact length.
1190 * For cpulist 7 is (ceil(log10(NR_CPUS)) + 1) allowing for NR_CPUS to be up
1191 * to 2 orders of magnitude larger than 8192. And then we divide by 2 to
1192 * cover a worst-case of every other cpu being on one of two nodes for a
1193 * very large NR_CPUS.
1195 * Use PAGE_SIZE as a minimum for smaller configurations while avoiding
1196 * unsigned comparison to -1.
1198 #define CPUMAP_FILE_MAX_BYTES (((NR_CPUS * 9)/32 > PAGE_SIZE) \
1199 ? (NR_CPUS * 9)/32 - 1 : PAGE_SIZE)
1200 #define CPULIST_FILE_MAX_BYTES (((NR_CPUS * 7)/2 > PAGE_SIZE) ? (NR_CPUS * 7)/2 : PAGE_SIZE)
1202 #endif /* __LINUX_CPUMASK_H */