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/bug.h>
14
15/* Don't assign or return these: may not be this big! */
16typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
17
18/**
19 * cpumask_bits - get the bits in a cpumask
20 * @maskp: the struct cpumask *
21 *
22 * You should only assume nr_cpu_ids bits of this mask are valid. This is
23 * a macro so it's const-correct.
24 */
25#define cpumask_bits(maskp) ((maskp)->bits)
26
27/**
28 * cpumask_pr_args - printf args to output a cpumask
29 * @maskp: cpumask to be printed
30 *
31 * Can be used to provide arguments for '%*pb[l]' when printing a cpumask.
32 */
33#define cpumask_pr_args(maskp) nr_cpu_ids, cpumask_bits(maskp)
34
35#if NR_CPUS == 1
36#define nr_cpu_ids 1U
37#else
38extern unsigned int nr_cpu_ids;
39#endif
40
41#ifdef CONFIG_CPUMASK_OFFSTACK
42/* Assuming NR_CPUS is huge, a runtime limit is more efficient. Also,
43 * not all bits may be allocated. */
44#define nr_cpumask_bits nr_cpu_ids
45#else
46#define nr_cpumask_bits ((unsigned int)NR_CPUS)
47#endif
48
49/*
50 * The following particular system cpumasks and operations manage
51 * possible, present, active and online cpus.
52 *
53 * cpu_possible_mask- has bit 'cpu' set iff cpu is populatable
54 * cpu_present_mask - has bit 'cpu' set iff cpu is populated
55 * cpu_online_mask - has bit 'cpu' set iff cpu available to scheduler
56 * cpu_active_mask - has bit 'cpu' set iff cpu available to migration
57 *
58 * If !CONFIG_HOTPLUG_CPU, present == possible, and active == online.
59 *
60 * The cpu_possible_mask is fixed at boot time, as the set of CPU id's
61 * that it is possible might ever be plugged in at anytime during the
62 * life of that system boot. The cpu_present_mask is dynamic(*),
63 * representing which CPUs are currently plugged in. And
64 * cpu_online_mask is the dynamic subset of cpu_present_mask,
65 * indicating those CPUs available for scheduling.
66 *
67 * If HOTPLUG is enabled, then cpu_possible_mask is forced to have
68 * all NR_CPUS bits set, otherwise it is just the set of CPUs that
69 * ACPI reports present at boot.
70 *
71 * If HOTPLUG is enabled, then cpu_present_mask varies dynamically,
72 * depending on what ACPI reports as currently plugged in, otherwise
73 * cpu_present_mask is just a copy of cpu_possible_mask.
74 *
75 * (*) Well, cpu_present_mask is dynamic in the hotplug case. If not
76 * hotplug, it's a copy of cpu_possible_mask, hence fixed at boot.
77 *
78 * Subtleties:
79 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
80 * assumption that their single CPU is online. The UP
81 * cpu_{online,possible,present}_masks are placebos. Changing them
82 * will have no useful affect on the following num_*_cpus()
83 * and cpu_*() macros in the UP case. This ugliness is a UP
84 * optimization - don't waste any instructions or memory references
85 * asking if you're online or how many CPUs there are if there is
86 * only one CPU.
87 */
88
89extern struct cpumask __cpu_possible_mask;
90extern struct cpumask __cpu_online_mask;
91extern struct cpumask __cpu_present_mask;
92extern struct cpumask __cpu_active_mask;
93#define cpu_possible_mask ((const struct cpumask *)&__cpu_possible_mask)
94#define cpu_online_mask ((const struct cpumask *)&__cpu_online_mask)
95#define cpu_present_mask ((const struct cpumask *)&__cpu_present_mask)
96#define cpu_active_mask ((const struct cpumask *)&__cpu_active_mask)
97
98#if NR_CPUS > 1
99#define num_online_cpus() cpumask_weight(cpu_online_mask)
100#define num_possible_cpus() cpumask_weight(cpu_possible_mask)
101#define num_present_cpus() cpumask_weight(cpu_present_mask)
102#define num_active_cpus() cpumask_weight(cpu_active_mask)
103#define cpu_online(cpu) cpumask_test_cpu((cpu), cpu_online_mask)
104#define cpu_possible(cpu) cpumask_test_cpu((cpu), cpu_possible_mask)
105#define cpu_present(cpu) cpumask_test_cpu((cpu), cpu_present_mask)
106#define cpu_active(cpu) cpumask_test_cpu((cpu), cpu_active_mask)
107#else
108#define num_online_cpus() 1U
109#define num_possible_cpus() 1U
110#define num_present_cpus() 1U
111#define num_active_cpus() 1U
112#define cpu_online(cpu) ((cpu) == 0)
113#define cpu_possible(cpu) ((cpu) == 0)
114#define cpu_present(cpu) ((cpu) == 0)
115#define cpu_active(cpu) ((cpu) == 0)
116#endif
117
118static inline void cpu_max_bits_warn(unsigned int cpu, unsigned int bits)
119{
120#ifdef CONFIG_DEBUG_PER_CPU_MAPS
121 WARN_ON_ONCE(cpu >= bits);
122#endif /* CONFIG_DEBUG_PER_CPU_MAPS */
123}
124
125/* verify cpu argument to cpumask_* operators */
126static inline unsigned int cpumask_check(unsigned int cpu)
127{
128 cpu_max_bits_warn(cpu, nr_cpumask_bits);
129 return cpu;
130}
131
132#if NR_CPUS == 1
133/* Uniprocessor. Assume all masks are "1". */
134static inline unsigned int cpumask_first(const struct cpumask *srcp)
135{
136 return 0;
137}
138
139static inline unsigned int cpumask_last(const struct cpumask *srcp)
140{
141 return 0;
142}
143
144/* Valid inputs for n are -1 and 0. */
145static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
146{
147 return n+1;
148}
149
150static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
151{
152 return n+1;
153}
154
155static inline unsigned int cpumask_next_and(int n,
156 const struct cpumask *srcp,
157 const struct cpumask *andp)
158{
159 return n+1;
160}
161
162static inline unsigned int cpumask_next_wrap(int n, const struct cpumask *mask,
163 int start, bool wrap)
164{
165 /* cpu0 unless stop condition, wrap and at cpu0, then nr_cpumask_bits */
166 return (wrap && n == 0);
167}
168
169/* cpu must be a valid cpu, ie 0, so there's no other choice. */
170static inline unsigned int cpumask_any_but(const struct cpumask *mask,
171 unsigned int cpu)
172{
173 return 1;
174}
175
176static inline unsigned int cpumask_local_spread(unsigned int i, int node)
177{
178 return 0;
179}
180
181#define for_each_cpu(cpu, mask) \
182 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
183#define for_each_cpu_not(cpu, mask) \
184 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
185#define for_each_cpu_wrap(cpu, mask, start) \
186 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)(start))
187#define for_each_cpu_and(cpu, mask, and) \
188 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and)
189#else
190/**
191 * cpumask_first - get the first cpu in a cpumask
192 * @srcp: the cpumask pointer
193 *
194 * Returns >= nr_cpu_ids if no cpus set.
195 */
196static inline unsigned int cpumask_first(const struct cpumask *srcp)
197{
198 return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits);
199}
200
201/**
202 * cpumask_last - get the last CPU in a cpumask
203 * @srcp: - the cpumask pointer
204 *
205 * Returns >= nr_cpumask_bits if no CPUs set.
206 */
207static inline unsigned int cpumask_last(const struct cpumask *srcp)
208{
209 return find_last_bit(cpumask_bits(srcp), nr_cpumask_bits);
210}
211
212unsigned int cpumask_next(int n, const struct cpumask *srcp);
213
214/**
215 * cpumask_next_zero - get the next unset cpu in a cpumask
216 * @n: the cpu prior to the place to search (ie. return will be > @n)
217 * @srcp: the cpumask pointer
218 *
219 * Returns >= nr_cpu_ids if no further cpus unset.
220 */
221static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
222{
223 /* -1 is a legal arg here. */
224 if (n != -1)
225 cpumask_check(n);
226 return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
227}
228
229int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *);
230int cpumask_any_but(const struct cpumask *mask, unsigned int cpu);
231unsigned int cpumask_local_spread(unsigned int i, int node);
232
233/**
234 * for_each_cpu - iterate over every cpu in a mask
235 * @cpu: the (optionally unsigned) integer iterator
236 * @mask: the cpumask pointer
237 *
238 * After the loop, cpu is >= nr_cpu_ids.
239 */
240#define for_each_cpu(cpu, mask) \
241 for ((cpu) = -1; \
242 (cpu) = cpumask_next((cpu), (mask)), \
243 (cpu) < nr_cpu_ids;)
244
245/**
246 * for_each_cpu_not - iterate over every cpu in a complemented mask
247 * @cpu: the (optionally unsigned) integer iterator
248 * @mask: the cpumask pointer
249 *
250 * After the loop, cpu is >= nr_cpu_ids.
251 */
252#define for_each_cpu_not(cpu, mask) \
253 for ((cpu) = -1; \
254 (cpu) = cpumask_next_zero((cpu), (mask)), \
255 (cpu) < nr_cpu_ids;)
256
257extern int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap);
258
259/**
260 * for_each_cpu_wrap - iterate over every cpu in a mask, starting at a specified location
261 * @cpu: the (optionally unsigned) integer iterator
262 * @mask: the cpumask poiter
263 * @start: the start location
264 *
265 * The implementation does not assume any bit in @mask is set (including @start).
266 *
267 * After the loop, cpu is >= nr_cpu_ids.
268 */
269#define for_each_cpu_wrap(cpu, mask, start) \
270 for ((cpu) = cpumask_next_wrap((start)-1, (mask), (start), false); \
271 (cpu) < nr_cpumask_bits; \
272 (cpu) = cpumask_next_wrap((cpu), (mask), (start), true))
273
274/**
275 * for_each_cpu_and - iterate over every cpu in both masks
276 * @cpu: the (optionally unsigned) integer iterator
277 * @mask: the first cpumask pointer
278 * @and: the second cpumask pointer
279 *
280 * This saves a temporary CPU mask in many places. It is equivalent to:
281 * struct cpumask tmp;
282 * cpumask_and(&tmp, &mask, &and);
283 * for_each_cpu(cpu, &tmp)
284 * ...
285 *
286 * After the loop, cpu is >= nr_cpu_ids.
287 */
288#define for_each_cpu_and(cpu, mask, and) \
289 for ((cpu) = -1; \
290 (cpu) = cpumask_next_and((cpu), (mask), (and)), \
291 (cpu) < nr_cpu_ids;)
292#endif /* SMP */
293
294#define CPU_BITS_NONE \
295{ \
296 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \
297}
298
299#define CPU_BITS_CPU0 \
300{ \
301 [0] = 1UL \
302}
303
304/**
305 * cpumask_set_cpu - set a cpu in a cpumask
306 * @cpu: cpu number (< nr_cpu_ids)
307 * @dstp: the cpumask pointer
308 */
309static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
310{
311 set_bit(cpumask_check(cpu), cpumask_bits(dstp));
312}
313
314static inline void __cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
315{
316 __set_bit(cpumask_check(cpu), cpumask_bits(dstp));
317}
318
319
320/**
321 * cpumask_clear_cpu - clear a cpu in a cpumask
322 * @cpu: cpu number (< nr_cpu_ids)
323 * @dstp: the cpumask pointer
324 */
325static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
326{
327 clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
328}
329
330static inline void __cpumask_clear_cpu(int cpu, struct cpumask *dstp)
331{
332 __clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
333}
334
335/**
336 * cpumask_test_cpu - test for a cpu in a cpumask
337 * @cpu: cpu number (< nr_cpu_ids)
338 * @cpumask: the cpumask pointer
339 *
340 * Returns 1 if @cpu is set in @cpumask, else returns 0
341 */
342static inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask)
343{
344 return test_bit(cpumask_check(cpu), cpumask_bits((cpumask)));
345}
346
347/**
348 * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
349 * @cpu: cpu number (< nr_cpu_ids)
350 * @cpumask: the cpumask pointer
351 *
352 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
353 *
354 * test_and_set_bit wrapper for cpumasks.
355 */
356static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
357{
358 return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask));
359}
360
361/**
362 * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask
363 * @cpu: cpu number (< nr_cpu_ids)
364 * @cpumask: the cpumask pointer
365 *
366 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
367 *
368 * test_and_clear_bit wrapper for cpumasks.
369 */
370static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
371{
372 return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask));
373}
374
375/**
376 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask
377 * @dstp: the cpumask pointer
378 */
379static inline void cpumask_setall(struct cpumask *dstp)
380{
381 bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits);
382}
383
384/**
385 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask
386 * @dstp: the cpumask pointer
387 */
388static inline void cpumask_clear(struct cpumask *dstp)
389{
390 bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits);
391}
392
393/**
394 * cpumask_and - *dstp = *src1p & *src2p
395 * @dstp: the cpumask result
396 * @src1p: the first input
397 * @src2p: the second input
398 *
399 * If *@dstp is empty, returns 0, else returns 1
400 */
401static inline int cpumask_and(struct cpumask *dstp,
402 const struct cpumask *src1p,
403 const struct cpumask *src2p)
404{
405 return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
406 cpumask_bits(src2p), nr_cpumask_bits);
407}
408
409/**
410 * cpumask_or - *dstp = *src1p | *src2p
411 * @dstp: the cpumask result
412 * @src1p: the first input
413 * @src2p: the second input
414 */
415static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
416 const struct cpumask *src2p)
417{
418 bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
419 cpumask_bits(src2p), nr_cpumask_bits);
420}
421
422/**
423 * cpumask_xor - *dstp = *src1p ^ *src2p
424 * @dstp: the cpumask result
425 * @src1p: the first input
426 * @src2p: the second input
427 */
428static inline void cpumask_xor(struct cpumask *dstp,
429 const struct cpumask *src1p,
430 const struct cpumask *src2p)
431{
432 bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
433 cpumask_bits(src2p), nr_cpumask_bits);
434}
435
436/**
437 * cpumask_andnot - *dstp = *src1p & ~*src2p
438 * @dstp: the cpumask result
439 * @src1p: the first input
440 * @src2p: the second input
441 *
442 * If *@dstp is empty, returns 0, else returns 1
443 */
444static inline int cpumask_andnot(struct cpumask *dstp,
445 const struct cpumask *src1p,
446 const struct cpumask *src2p)
447{
448 return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
449 cpumask_bits(src2p), nr_cpumask_bits);
450}
451
452/**
453 * cpumask_complement - *dstp = ~*srcp
454 * @dstp: the cpumask result
455 * @srcp: the input to invert
456 */
457static inline void cpumask_complement(struct cpumask *dstp,
458 const struct cpumask *srcp)
459{
460 bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp),
461 nr_cpumask_bits);
462}
463
464/**
465 * cpumask_equal - *src1p == *src2p
466 * @src1p: the first input
467 * @src2p: the second input
468 */
469static inline bool cpumask_equal(const struct cpumask *src1p,
470 const struct cpumask *src2p)
471{
472 return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
473 nr_cpumask_bits);
474}
475
476/**
477 * cpumask_intersects - (*src1p & *src2p) != 0
478 * @src1p: the first input
479 * @src2p: the second input
480 */
481static inline bool cpumask_intersects(const struct cpumask *src1p,
482 const struct cpumask *src2p)
483{
484 return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
485 nr_cpumask_bits);
486}
487
488/**
489 * cpumask_subset - (*src1p & ~*src2p) == 0
490 * @src1p: the first input
491 * @src2p: the second input
492 *
493 * Returns 1 if *@src1p is a subset of *@src2p, else returns 0
494 */
495static inline int cpumask_subset(const struct cpumask *src1p,
496 const struct cpumask *src2p)
497{
498 return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
499 nr_cpumask_bits);
500}
501
502/**
503 * cpumask_empty - *srcp == 0
504 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear.
505 */
506static inline bool cpumask_empty(const struct cpumask *srcp)
507{
508 return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits);
509}
510
511/**
512 * cpumask_full - *srcp == 0xFFFFFFFF...
513 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set.
514 */
515static inline bool cpumask_full(const struct cpumask *srcp)
516{
517 return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
518}
519
520/**
521 * cpumask_weight - Count of bits in *srcp
522 * @srcp: the cpumask to count bits (< nr_cpu_ids) in.
523 */
524static inline unsigned int cpumask_weight(const struct cpumask *srcp)
525{
526 return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits);
527}
528
529/**
530 * cpumask_shift_right - *dstp = *srcp >> n
531 * @dstp: the cpumask result
532 * @srcp: the input to shift
533 * @n: the number of bits to shift by
534 */
535static inline void cpumask_shift_right(struct cpumask *dstp,
536 const struct cpumask *srcp, int n)
537{
538 bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n,
539 nr_cpumask_bits);
540}
541
542/**
543 * cpumask_shift_left - *dstp = *srcp << n
544 * @dstp: the cpumask result
545 * @srcp: the input to shift
546 * @n: the number of bits to shift by
547 */
548static inline void cpumask_shift_left(struct cpumask *dstp,
549 const struct cpumask *srcp, int n)
550{
551 bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n,
552 nr_cpumask_bits);
553}
554
555/**
556 * cpumask_copy - *dstp = *srcp
557 * @dstp: the result
558 * @srcp: the input cpumask
559 */
560static inline void cpumask_copy(struct cpumask *dstp,
561 const struct cpumask *srcp)
562{
563 bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits);
564}
565
566/**
567 * cpumask_any - pick a "random" cpu from *srcp
568 * @srcp: the input cpumask
569 *
570 * Returns >= nr_cpu_ids if no cpus set.
571 */
572#define cpumask_any(srcp) cpumask_first(srcp)
573
574/**
575 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2
576 * @src1p: the first input
577 * @src2p: the second input
578 *
579 * Returns >= nr_cpu_ids if no cpus set in both. See also cpumask_next_and().
580 */
581#define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
582
583/**
584 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2
585 * @mask1: the first input cpumask
586 * @mask2: the second input cpumask
587 *
588 * Returns >= nr_cpu_ids if no cpus set.
589 */
590#define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2))
591
592/**
593 * cpumask_of - the cpumask containing just a given cpu
594 * @cpu: the cpu (<= nr_cpu_ids)
595 */
596#define cpumask_of(cpu) (get_cpu_mask(cpu))
597
598/**
599 * cpumask_parse_user - extract a cpumask from a user string
600 * @buf: the buffer to extract from
601 * @len: the length of the buffer
602 * @dstp: the cpumask to set.
603 *
604 * Returns -errno, or 0 for success.
605 */
606static inline int cpumask_parse_user(const char __user *buf, int len,
607 struct cpumask *dstp)
608{
609 return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
610}
611
612/**
613 * cpumask_parselist_user - extract a cpumask from a user string
614 * @buf: the buffer to extract from
615 * @len: the length of the buffer
616 * @dstp: the cpumask to set.
617 *
618 * Returns -errno, or 0 for success.
619 */
620static inline int cpumask_parselist_user(const char __user *buf, int len,
621 struct cpumask *dstp)
622{
623 return bitmap_parselist_user(buf, len, cpumask_bits(dstp),
624 nr_cpumask_bits);
625}
626
627/**
628 * cpumask_parse - extract a cpumask from a string
629 * @buf: the buffer to extract from
630 * @dstp: the cpumask to set.
631 *
632 * Returns -errno, or 0 for success.
633 */
634static inline int cpumask_parse(const char *buf, struct cpumask *dstp)
635{
636 char *nl = strchr(buf, '\n');
637 unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf);
638
639 return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
640}
641
642/**
643 * cpulist_parse - extract a cpumask from a user string of ranges
644 * @buf: the buffer to extract from
645 * @dstp: the cpumask to set.
646 *
647 * Returns -errno, or 0 for success.
648 */
649static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
650{
651 return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits);
652}
653
654/**
655 * cpumask_size - size to allocate for a 'struct cpumask' in bytes
656 */
657static inline unsigned int cpumask_size(void)
658{
659 return BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long);
660}
661
662/*
663 * cpumask_var_t: struct cpumask for stack usage.
664 *
665 * Oh, the wicked games we play! In order to make kernel coding a
666 * little more difficult, we typedef cpumask_var_t to an array or a
667 * pointer: doing &mask on an array is a noop, so it still works.
668 *
669 * ie.
670 * cpumask_var_t tmpmask;
671 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
672 * return -ENOMEM;
673 *
674 * ... use 'tmpmask' like a normal struct cpumask * ...
675 *
676 * free_cpumask_var(tmpmask);
677 *
678 *
679 * However, one notable exception is there. alloc_cpumask_var() allocates
680 * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has
681 * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t.
682 *
683 * cpumask_var_t tmpmask;
684 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
685 * return -ENOMEM;
686 *
687 * var = *tmpmask;
688 *
689 * This code makes NR_CPUS length memcopy and brings to a memory corruption.
690 * cpumask_copy() provide safe copy functionality.
691 *
692 * Note that there is another evil here: If you define a cpumask_var_t
693 * as a percpu variable then the way to obtain the address of the cpumask
694 * structure differently influences what this_cpu_* operation needs to be
695 * used. Please use this_cpu_cpumask_var_t in those cases. The direct use
696 * of this_cpu_ptr() or this_cpu_read() will lead to failures when the
697 * other type of cpumask_var_t implementation is configured.
698 *
699 * Please also note that __cpumask_var_read_mostly can be used to declare
700 * a cpumask_var_t variable itself (not its content) as read mostly.
701 */
702#ifdef CONFIG_CPUMASK_OFFSTACK
703typedef struct cpumask *cpumask_var_t;
704
705#define this_cpu_cpumask_var_ptr(x) this_cpu_read(x)
706#define __cpumask_var_read_mostly __read_mostly
707
708bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
709bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
710bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
711bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
712void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
713void free_cpumask_var(cpumask_var_t mask);
714void free_bootmem_cpumask_var(cpumask_var_t mask);
715
716static inline bool cpumask_available(cpumask_var_t mask)
717{
718 return mask != NULL;
719}
720
721#else
722typedef struct cpumask cpumask_var_t[1];
723
724#define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x)
725#define __cpumask_var_read_mostly
726
727static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
728{
729 return true;
730}
731
732static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
733 int node)
734{
735 return true;
736}
737
738static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
739{
740 cpumask_clear(*mask);
741 return true;
742}
743
744static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
745 int node)
746{
747 cpumask_clear(*mask);
748 return true;
749}
750
751static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask)
752{
753}
754
755static inline void free_cpumask_var(cpumask_var_t mask)
756{
757}
758
759static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
760{
761}
762
763static inline bool cpumask_available(cpumask_var_t mask)
764{
765 return true;
766}
767#endif /* CONFIG_CPUMASK_OFFSTACK */
768
769/* It's common to want to use cpu_all_mask in struct member initializers,
770 * so it has to refer to an address rather than a pointer. */
771extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
772#define cpu_all_mask to_cpumask(cpu_all_bits)
773
774/* First bits of cpu_bit_bitmap are in fact unset. */
775#define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
776
777#define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask)
778#define for_each_online_cpu(cpu) for_each_cpu((cpu), cpu_online_mask)
779#define for_each_present_cpu(cpu) for_each_cpu((cpu), cpu_present_mask)
780
781/* Wrappers for arch boot code to manipulate normally-constant masks */
782void init_cpu_present(const struct cpumask *src);
783void init_cpu_possible(const struct cpumask *src);
784void init_cpu_online(const struct cpumask *src);
785
786static inline void reset_cpu_possible_mask(void)
787{
788 bitmap_zero(cpumask_bits(&__cpu_possible_mask), NR_CPUS);
789}
790
791static inline void
792set_cpu_possible(unsigned int cpu, bool possible)
793{
794 if (possible)
795 cpumask_set_cpu(cpu, &__cpu_possible_mask);
796 else
797 cpumask_clear_cpu(cpu, &__cpu_possible_mask);
798}
799
800static inline void
801set_cpu_present(unsigned int cpu, bool present)
802{
803 if (present)
804 cpumask_set_cpu(cpu, &__cpu_present_mask);
805 else
806 cpumask_clear_cpu(cpu, &__cpu_present_mask);
807}
808
809static inline void
810set_cpu_online(unsigned int cpu, bool online)
811{
812 if (online)
813 cpumask_set_cpu(cpu, &__cpu_online_mask);
814 else
815 cpumask_clear_cpu(cpu, &__cpu_online_mask);
816}
817
818static inline void
819set_cpu_active(unsigned int cpu, bool active)
820{
821 if (active)
822 cpumask_set_cpu(cpu, &__cpu_active_mask);
823 else
824 cpumask_clear_cpu(cpu, &__cpu_active_mask);
825}
826
827
828/**
829 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *
830 * @bitmap: the bitmap
831 *
832 * There are a few places where cpumask_var_t isn't appropriate and
833 * static cpumasks must be used (eg. very early boot), yet we don't
834 * expose the definition of 'struct cpumask'.
835 *
836 * This does the conversion, and can be used as a constant initializer.
837 */
838#define to_cpumask(bitmap) \
839 ((struct cpumask *)(1 ? (bitmap) \
840 : (void *)sizeof(__check_is_bitmap(bitmap))))
841
842static inline int __check_is_bitmap(const unsigned long *bitmap)
843{
844 return 1;
845}
846
847/*
848 * Special-case data structure for "single bit set only" constant CPU masks.
849 *
850 * We pre-generate all the 64 (or 32) possible bit positions, with enough
851 * padding to the left and the right, and return the constant pointer
852 * appropriately offset.
853 */
854extern const unsigned long
855 cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
856
857static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
858{
859 const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
860 p -= cpu / BITS_PER_LONG;
861 return to_cpumask(p);
862}
863
864#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
865
866#if NR_CPUS <= BITS_PER_LONG
867#define CPU_BITS_ALL \
868{ \
869 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
870}
871
872#else /* NR_CPUS > BITS_PER_LONG */
873
874#define CPU_BITS_ALL \
875{ \
876 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \
877 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
878}
879#endif /* NR_CPUS > BITS_PER_LONG */
880
881/**
882 * cpumap_print_to_pagebuf - copies the cpumask into the buffer either
883 * as comma-separated list of cpus or hex values of cpumask
884 * @list: indicates whether the cpumap must be list
885 * @mask: the cpumask to copy
886 * @buf: the buffer to copy into
887 *
888 * Returns the length of the (null-terminated) @buf string, zero if
889 * nothing is copied.
890 */
891static inline ssize_t
892cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
893{
894 return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask),
895 nr_cpu_ids);
896}
897
898#if NR_CPUS <= BITS_PER_LONG
899#define CPU_MASK_ALL \
900(cpumask_t) { { \
901 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
902} }
903#else
904#define CPU_MASK_ALL \
905(cpumask_t) { { \
906 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \
907 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
908} }
909#endif /* NR_CPUS > BITS_PER_LONG */
910
911#define CPU_MASK_NONE \
912(cpumask_t) { { \
913 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \
914} }
915
916#define CPU_MASK_CPU0 \
917(cpumask_t) { { \
918 [0] = 1UL \
919} }
920
921#endif /* __LINUX_CPUMASK_H */
922