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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef __LINUX_CPUMASK_H
2#define __LINUX_CPUMASK_H
3
4/*
5 * Cpumasks provide a bitmap suitable for representing the
6 * set of CPU's in a system, one bit position per CPU number.
7 *
8 * See detailed comments in the file linux/bitmap.h describing the
9 * data type on which these cpumasks are based.
10 *
11 * For details of cpumask_scnprintf() and cpumask_parse(),
12 * see bitmap_scnprintf() and bitmap_parse() in lib/bitmap.c.
13 * For details of cpulist_scnprintf() and cpulist_parse(), see
14 * bitmap_scnlistprintf() and bitmap_parselist(), also in bitmap.c.
15 *
16 * The available cpumask operations are:
17 *
18 * void cpu_set(cpu, mask) turn on bit 'cpu' in mask
19 * void cpu_clear(cpu, mask) turn off bit 'cpu' in mask
20 * void cpus_setall(mask) set all bits
21 * void cpus_clear(mask) clear all bits
22 * int cpu_isset(cpu, mask) true iff bit 'cpu' set in mask
23 * int cpu_test_and_set(cpu, mask) test and set bit 'cpu' in mask
24 *
25 * void cpus_and(dst, src1, src2) dst = src1 & src2 [intersection]
26 * void cpus_or(dst, src1, src2) dst = src1 | src2 [union]
27 * void cpus_xor(dst, src1, src2) dst = src1 ^ src2
28 * void cpus_andnot(dst, src1, src2) dst = src1 & ~src2
29 * void cpus_complement(dst, src) dst = ~src
30 *
31 * int cpus_equal(mask1, mask2) Does mask1 == mask2?
32 * int cpus_intersects(mask1, mask2) Do mask1 and mask2 intersect?
33 * int cpus_subset(mask1, mask2) Is mask1 a subset of mask2?
34 * int cpus_empty(mask) Is mask empty (no bits sets)?
35 * int cpus_full(mask) Is mask full (all bits sets)?
36 * int cpus_weight(mask) Hamming weigh - number of set bits
37 *
38 * void cpus_shift_right(dst, src, n) Shift right
39 * void cpus_shift_left(dst, src, n) Shift left
40 *
41 * int first_cpu(mask) Number lowest set bit, or NR_CPUS
42 * int next_cpu(cpu, mask) Next cpu past 'cpu', or NR_CPUS
43 *
44 * cpumask_t cpumask_of_cpu(cpu) Return cpumask with bit 'cpu' set
45 * CPU_MASK_ALL Initializer - all bits set
46 * CPU_MASK_NONE Initializer - no bits set
47 * unsigned long *cpus_addr(mask) Array of unsigned long's in mask
48 *
49 * int cpumask_scnprintf(buf, len, mask) Format cpumask for printing
50 * int cpumask_parse(ubuf, ulen, mask) Parse ascii string as cpumask
51 * int cpulist_scnprintf(buf, len, mask) Format cpumask as list for printing
52 * int cpulist_parse(buf, map) Parse ascii string as cpulist
53 *
54 * for_each_cpu_mask(cpu, mask) for-loop cpu over mask
55 *
56 * int num_online_cpus() Number of online CPUs
57 * int num_possible_cpus() Number of all possible CPUs
58 * int num_present_cpus() Number of present CPUs
59 *
60 * int cpu_online(cpu) Is some cpu online?
61 * int cpu_possible(cpu) Is some cpu possible?
62 * int cpu_present(cpu) Is some cpu present (can schedule)?
63 *
64 * int any_online_cpu(mask) First online cpu in mask
65 *
66 * for_each_cpu(cpu) for-loop cpu over cpu_possible_map
67 * for_each_online_cpu(cpu) for-loop cpu over cpu_online_map
68 * for_each_present_cpu(cpu) for-loop cpu over cpu_present_map
69 *
70 * Subtlety:
71 * 1) The 'type-checked' form of cpu_isset() causes gcc (3.3.2, anyway)
72 * to generate slightly worse code. Note for example the additional
73 * 40 lines of assembly code compiling the "for each possible cpu"
74 * loops buried in the disk_stat_read() macros calls when compiling
75 * drivers/block/genhd.c (arch i386, CONFIG_SMP=y). So use a simple
76 * one-line #define for cpu_isset(), instead of wrapping an inline
77 * inside a macro, the way we do the other calls.
78 */
79
80#include <linux/kernel.h>
81#include <linux/threads.h>
82#include <linux/bitmap.h>
83#include <asm/bug.h>
84
85typedef struct { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
86extern cpumask_t _unused_cpumask_arg_;
87
88#define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
89static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
90{
91 set_bit(cpu, dstp->bits);
92}
93
94#define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
95static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
96{
97 clear_bit(cpu, dstp->bits);
98}
99
100#define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
101static inline void __cpus_setall(cpumask_t *dstp, int nbits)
102{
103 bitmap_fill(dstp->bits, nbits);
104}
105
106#define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
107static inline void __cpus_clear(cpumask_t *dstp, int nbits)
108{
109 bitmap_zero(dstp->bits, nbits);
110}
111
112/* No static inline type checking - see Subtlety (1) above. */
113#define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)
114
115#define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
116static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
117{
118 return test_and_set_bit(cpu, addr->bits);
119}
120
121#define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
122static inline void __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
123 const cpumask_t *src2p, int nbits)
124{
125 bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
126}
127
128#define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
129static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
130 const cpumask_t *src2p, int nbits)
131{
132 bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
133}
134
135#define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
136static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
137 const cpumask_t *src2p, int nbits)
138{
139 bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
140}
141
142#define cpus_andnot(dst, src1, src2) \
143 __cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
144static inline void __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
145 const cpumask_t *src2p, int nbits)
146{
147 bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
148}
149
150#define cpus_complement(dst, src) __cpus_complement(&(dst), &(src), NR_CPUS)
151static inline void __cpus_complement(cpumask_t *dstp,
152 const cpumask_t *srcp, int nbits)
153{
154 bitmap_complement(dstp->bits, srcp->bits, nbits);
155}
156
157#define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
158static inline int __cpus_equal(const cpumask_t *src1p,
159 const cpumask_t *src2p, int nbits)
160{
161 return bitmap_equal(src1p->bits, src2p->bits, nbits);
162}
163
164#define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
165static inline int __cpus_intersects(const cpumask_t *src1p,
166 const cpumask_t *src2p, int nbits)
167{
168 return bitmap_intersects(src1p->bits, src2p->bits, nbits);
169}
170
171#define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
172static inline int __cpus_subset(const cpumask_t *src1p,
173 const cpumask_t *src2p, int nbits)
174{
175 return bitmap_subset(src1p->bits, src2p->bits, nbits);
176}
177
178#define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
179static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
180{
181 return bitmap_empty(srcp->bits, nbits);
182}
183
184#define cpus_full(cpumask) __cpus_full(&(cpumask), NR_CPUS)
185static inline int __cpus_full(const cpumask_t *srcp, int nbits)
186{
187 return bitmap_full(srcp->bits, nbits);
188}
189
190#define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
191static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
192{
193 return bitmap_weight(srcp->bits, nbits);
194}
195
196#define cpus_shift_right(dst, src, n) \
197 __cpus_shift_right(&(dst), &(src), (n), NR_CPUS)
198static inline void __cpus_shift_right(cpumask_t *dstp,
199 const cpumask_t *srcp, int n, int nbits)
200{
201 bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
202}
203
204#define cpus_shift_left(dst, src, n) \
205 __cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
206static inline void __cpus_shift_left(cpumask_t *dstp,
207 const cpumask_t *srcp, int n, int nbits)
208{
209 bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
210}
211
212#define first_cpu(src) __first_cpu(&(src), NR_CPUS)
213static inline int __first_cpu(const cpumask_t *srcp, int nbits)
214{
215 return min_t(int, nbits, find_first_bit(srcp->bits, nbits));
216}
217
218#define next_cpu(n, src) __next_cpu((n), &(src), NR_CPUS)
219static inline int __next_cpu(int n, const cpumask_t *srcp, int nbits)
220{
221 return min_t(int, nbits, find_next_bit(srcp->bits, nbits, n+1));
222}
223
224#define cpumask_of_cpu(cpu) \
225({ \
226 typeof(_unused_cpumask_arg_) m; \
227 if (sizeof(m) == sizeof(unsigned long)) { \
228 m.bits[0] = 1UL<<(cpu); \
229 } else { \
230 cpus_clear(m); \
231 cpu_set((cpu), m); \
232 } \
233 m; \
234})
235
236#define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
237
238#if NR_CPUS <= BITS_PER_LONG
239
240#define CPU_MASK_ALL \
241(cpumask_t) { { \
242 [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \
243} }
244
245#else
246
247#define CPU_MASK_ALL \
248(cpumask_t) { { \
249 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \
250 [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \
251} }
252
253#endif
254
255#define CPU_MASK_NONE \
256(cpumask_t) { { \
257 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \
258} }
259
260#define CPU_MASK_CPU0 \
261(cpumask_t) { { \
262 [0] = 1UL \
263} }
264
265#define cpus_addr(src) ((src).bits)
266
267#define cpumask_scnprintf(buf, len, src) \
268 __cpumask_scnprintf((buf), (len), &(src), NR_CPUS)
269static inline int __cpumask_scnprintf(char *buf, int len,
270 const cpumask_t *srcp, int nbits)
271{
272 return bitmap_scnprintf(buf, len, srcp->bits, nbits);
273}
274
275#define cpumask_parse(ubuf, ulen, dst) \
276 __cpumask_parse((ubuf), (ulen), &(dst), NR_CPUS)
277static inline int __cpumask_parse(const char __user *buf, int len,
278 cpumask_t *dstp, int nbits)
279{
280 return bitmap_parse(buf, len, dstp->bits, nbits);
281}
282
283#define cpulist_scnprintf(buf, len, src) \
284 __cpulist_scnprintf((buf), (len), &(src), NR_CPUS)
285static inline int __cpulist_scnprintf(char *buf, int len,
286 const cpumask_t *srcp, int nbits)
287{
288 return bitmap_scnlistprintf(buf, len, srcp->bits, nbits);
289}
290
291#define cpulist_parse(buf, dst) __cpulist_parse((buf), &(dst), NR_CPUS)
292static inline int __cpulist_parse(const char *buf, cpumask_t *dstp, int nbits)
293{
294 return bitmap_parselist(buf, dstp->bits, nbits);
295}
296
297#if NR_CPUS > 1
298#define for_each_cpu_mask(cpu, mask) \
299 for ((cpu) = first_cpu(mask); \
300 (cpu) < NR_CPUS; \
301 (cpu) = next_cpu((cpu), (mask)))
302#else /* NR_CPUS == 1 */
303#define for_each_cpu_mask(cpu, mask) for ((cpu) = 0; (cpu) < 1; (cpu)++)
304#endif /* NR_CPUS */
305
306/*
307 * The following particular system cpumasks and operations manage
308 * possible, present and online cpus. Each of them is a fixed size
309 * bitmap of size NR_CPUS.
310 *
311 * #ifdef CONFIG_HOTPLUG_CPU
312 * cpu_possible_map - all NR_CPUS bits set
313 * cpu_present_map - has bit 'cpu' set iff cpu is populated
314 * cpu_online_map - has bit 'cpu' set iff cpu available to scheduler
315 * #else
316 * cpu_possible_map - has bit 'cpu' set iff cpu is populated
317 * cpu_present_map - copy of cpu_possible_map
318 * cpu_online_map - has bit 'cpu' set iff cpu available to scheduler
319 * #endif
320 *
321 * In either case, NR_CPUS is fixed at compile time, as the static
322 * size of these bitmaps. The cpu_possible_map is fixed at boot
323 * time, as the set of CPU id's that it is possible might ever
324 * be plugged in at anytime during the life of that system boot.
325 * The cpu_present_map is dynamic(*), representing which CPUs
326 * are currently plugged in. And cpu_online_map is the dynamic
327 * subset of cpu_present_map, indicating those CPUs available
328 * for scheduling.
329 *
330 * If HOTPLUG is enabled, then cpu_possible_map is forced to have
331 * all NR_CPUS bits set, otherwise it is just the set of CPUs that
332 * ACPI reports present at boot.
333 *
334 * If HOTPLUG is enabled, then cpu_present_map varies dynamically,
335 * depending on what ACPI reports as currently plugged in, otherwise
336 * cpu_present_map is just a copy of cpu_possible_map.
337 *
338 * (*) Well, cpu_present_map is dynamic in the hotplug case. If not
339 * hotplug, it's a copy of cpu_possible_map, hence fixed at boot.
340 *
341 * Subtleties:
342 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
343 * assumption that their single CPU is online. The UP
344 * cpu_{online,possible,present}_maps are placebos. Changing them
345 * will have no useful affect on the following num_*_cpus()
346 * and cpu_*() macros in the UP case. This ugliness is a UP
347 * optimization - don't waste any instructions or memory references
348 * asking if you're online or how many CPUs there are if there is
349 * only one CPU.
350 * 2) Most SMP arch's #define some of these maps to be some
351 * other map specific to that arch. Therefore, the following
352 * must be #define macros, not inlines. To see why, examine
353 * the assembly code produced by the following. Note that
354 * set1() writes phys_x_map, but set2() writes x_map:
355 * int x_map, phys_x_map;
356 * #define set1(a) x_map = a
357 * inline void set2(int a) { x_map = a; }
358 * #define x_map phys_x_map
359 * main(){ set1(3); set2(5); }
360 */
361
362extern cpumask_t cpu_possible_map;
363extern cpumask_t cpu_online_map;
364extern cpumask_t cpu_present_map;
365
366#if NR_CPUS > 1
367#define num_online_cpus() cpus_weight(cpu_online_map)
368#define num_possible_cpus() cpus_weight(cpu_possible_map)
369#define num_present_cpus() cpus_weight(cpu_present_map)
370#define cpu_online(cpu) cpu_isset((cpu), cpu_online_map)
371#define cpu_possible(cpu) cpu_isset((cpu), cpu_possible_map)
372#define cpu_present(cpu) cpu_isset((cpu), cpu_present_map)
373#else
374#define num_online_cpus() 1
375#define num_possible_cpus() 1
376#define num_present_cpus() 1
377#define cpu_online(cpu) ((cpu) == 0)
378#define cpu_possible(cpu) ((cpu) == 0)
379#define cpu_present(cpu) ((cpu) == 0)
380#endif
381
382#define any_online_cpu(mask) \
383({ \
384 int cpu; \
385 for_each_cpu_mask(cpu, (mask)) \
386 if (cpu_online(cpu)) \
387 break; \
388 cpu; \
389})
390
391#define for_each_cpu(cpu) for_each_cpu_mask((cpu), cpu_possible_map)
392#define for_each_online_cpu(cpu) for_each_cpu_mask((cpu), cpu_online_map)
393#define for_each_present_cpu(cpu) for_each_cpu_mask((cpu), cpu_present_map)
394
395#endif /* __LINUX_CPUMASK_H */