[JFFS2] Correct parameter names of jffs2_compress() in comments
[linux-2.6/mini2440.git] / include / linux / cpumask.h
blobd3219d73f8e655f8d33f1b7e3af1a64ccfc2b3df
1 #ifndef __LINUX_CPUMASK_H
2 #define __LINUX_CPUMASK_H
4 /*
5 * Cpumasks provide a bitmap suitable for representing the
6 * set of CPU's in a system, one bit position per CPU number.
8 * See detailed comments in the file linux/bitmap.h describing the
9 * data type on which these cpumasks are based.
11 * For details of cpumask_scnprintf() and cpumask_parse_user(),
12 * see bitmap_scnprintf() and bitmap_parse_user() 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 * For details of cpu_remap(), see bitmap_bitremap in lib/bitmap.c
16 * For details of cpus_remap(), see bitmap_remap in lib/bitmap.c.
17 * For details of cpus_onto(), see bitmap_onto in lib/bitmap.c.
18 * For details of cpus_fold(), see bitmap_fold in lib/bitmap.c.
20 * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21 * Note: The alternate operations with the suffix "_nr" are used
22 * to limit the range of the loop to nr_cpu_ids instead of
23 * NR_CPUS when NR_CPUS > 64 for performance reasons.
24 * If NR_CPUS is <= 64 then most assembler bitmask
25 * operators execute faster with a constant range, so
26 * the operator will continue to use NR_CPUS.
28 * Another consideration is that nr_cpu_ids is initialized
29 * to NR_CPUS and isn't lowered until the possible cpus are
30 * discovered (including any disabled cpus). So early uses
31 * will span the entire range of NR_CPUS.
32 * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34 * The available cpumask operations are:
36 * void cpu_set(cpu, mask) turn on bit 'cpu' in mask
37 * void cpu_clear(cpu, mask) turn off bit 'cpu' in mask
38 * void cpus_setall(mask) set all bits
39 * void cpus_clear(mask) clear all bits
40 * int cpu_isset(cpu, mask) true iff bit 'cpu' set in mask
41 * int cpu_test_and_set(cpu, mask) test and set bit 'cpu' in mask
43 * void cpus_and(dst, src1, src2) dst = src1 & src2 [intersection]
44 * void cpus_or(dst, src1, src2) dst = src1 | src2 [union]
45 * void cpus_xor(dst, src1, src2) dst = src1 ^ src2
46 * void cpus_andnot(dst, src1, src2) dst = src1 & ~src2
47 * void cpus_complement(dst, src) dst = ~src
49 * int cpus_equal(mask1, mask2) Does mask1 == mask2?
50 * int cpus_intersects(mask1, mask2) Do mask1 and mask2 intersect?
51 * int cpus_subset(mask1, mask2) Is mask1 a subset of mask2?
52 * int cpus_empty(mask) Is mask empty (no bits sets)?
53 * int cpus_full(mask) Is mask full (all bits sets)?
54 * int cpus_weight(mask) Hamming weigh - number of set bits
55 * int cpus_weight_nr(mask) Same using nr_cpu_ids instead of NR_CPUS
57 * void cpus_shift_right(dst, src, n) Shift right
58 * void cpus_shift_left(dst, src, n) Shift left
60 * int first_cpu(mask) Number lowest set bit, or NR_CPUS
61 * int next_cpu(cpu, mask) Next cpu past 'cpu', or NR_CPUS
62 * int next_cpu_nr(cpu, mask) Next cpu past 'cpu', or nr_cpu_ids
64 * cpumask_t cpumask_of_cpu(cpu) Return cpumask with bit 'cpu' set
65 * (can be used as an lvalue)
66 * CPU_MASK_ALL Initializer - all bits set
67 * CPU_MASK_NONE Initializer - no bits set
68 * unsigned long *cpus_addr(mask) Array of unsigned long's in mask
70 * CPUMASK_ALLOC kmalloc's a structure that is a composite of many cpumask_t
71 * variables, and CPUMASK_PTR provides pointers to each field.
73 * The structure should be defined something like this:
74 * struct my_cpumasks {
75 * cpumask_t mask1;
76 * cpumask_t mask2;
77 * };
79 * Usage is then:
80 * CPUMASK_ALLOC(my_cpumasks);
81 * CPUMASK_PTR(mask1, my_cpumasks);
82 * CPUMASK_PTR(mask2, my_cpumasks);
84 * --- DO NOT reference cpumask_t pointers until this check ---
85 * if (my_cpumasks == NULL)
86 * "kmalloc failed"...
88 * References are now pointers to the cpumask_t variables (*mask1, ...)
90 *if NR_CPUS > BITS_PER_LONG
91 * CPUMASK_ALLOC(m) Declares and allocates struct m *m =
92 * kmalloc(sizeof(*m), GFP_KERNEL)
93 * CPUMASK_FREE(m) Macro for kfree(m)
94 *else
95 * CPUMASK_ALLOC(m) Declares struct m _m, *m = &_m
96 * CPUMASK_FREE(m) Nop
97 *endif
98 * CPUMASK_PTR(v, m) Declares cpumask_t *v = &(m->v)
99 * ------------------------------------------------------------------------
101 * int cpumask_scnprintf(buf, len, mask) Format cpumask for printing
102 * int cpumask_parse_user(ubuf, ulen, mask) Parse ascii string as cpumask
103 * int cpulist_scnprintf(buf, len, mask) Format cpumask as list for printing
104 * int cpulist_parse(buf, map) Parse ascii string as cpulist
105 * int cpu_remap(oldbit, old, new) newbit = map(old, new)(oldbit)
106 * void cpus_remap(dst, src, old, new) *dst = map(old, new)(src)
107 * void cpus_onto(dst, orig, relmap) *dst = orig relative to relmap
108 * void cpus_fold(dst, orig, sz) dst bits = orig bits mod sz
110 * for_each_cpu_mask(cpu, mask) for-loop cpu over mask using NR_CPUS
111 * for_each_cpu_mask_nr(cpu, mask) for-loop cpu over mask using nr_cpu_ids
113 * int num_online_cpus() Number of online CPUs
114 * int num_possible_cpus() Number of all possible CPUs
115 * int num_present_cpus() Number of present CPUs
117 * int cpu_online(cpu) Is some cpu online?
118 * int cpu_possible(cpu) Is some cpu possible?
119 * int cpu_present(cpu) Is some cpu present (can schedule)?
121 * int any_online_cpu(mask) First online cpu in mask
123 * for_each_possible_cpu(cpu) for-loop cpu over cpu_possible_map
124 * for_each_online_cpu(cpu) for-loop cpu over cpu_online_map
125 * for_each_present_cpu(cpu) for-loop cpu over cpu_present_map
127 * Subtlety:
128 * 1) The 'type-checked' form of cpu_isset() causes gcc (3.3.2, anyway)
129 * to generate slightly worse code. Note for example the additional
130 * 40 lines of assembly code compiling the "for each possible cpu"
131 * loops buried in the disk_stat_read() macros calls when compiling
132 * drivers/block/genhd.c (arch i386, CONFIG_SMP=y). So use a simple
133 * one-line #define for cpu_isset(), instead of wrapping an inline
134 * inside a macro, the way we do the other calls.
137 #include <linux/kernel.h>
138 #include <linux/threads.h>
139 #include <linux/bitmap.h>
141 typedef struct { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
142 extern cpumask_t _unused_cpumask_arg_;
144 #define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
145 static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
147 set_bit(cpu, dstp->bits);
150 #define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
151 static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
153 clear_bit(cpu, dstp->bits);
156 #define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
157 static inline void __cpus_setall(cpumask_t *dstp, int nbits)
159 bitmap_fill(dstp->bits, nbits);
162 #define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
163 static inline void __cpus_clear(cpumask_t *dstp, int nbits)
165 bitmap_zero(dstp->bits, nbits);
168 /* No static inline type checking - see Subtlety (1) above. */
169 #define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)
171 #define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
172 static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
174 return test_and_set_bit(cpu, addr->bits);
177 #define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
178 static inline void __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
179 const cpumask_t *src2p, int nbits)
181 bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
184 #define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
185 static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
186 const cpumask_t *src2p, int nbits)
188 bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
191 #define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
192 static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
193 const cpumask_t *src2p, int nbits)
195 bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
198 #define cpus_andnot(dst, src1, src2) \
199 __cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
200 static inline void __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
201 const cpumask_t *src2p, int nbits)
203 bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
206 #define cpus_complement(dst, src) __cpus_complement(&(dst), &(src), NR_CPUS)
207 static inline void __cpus_complement(cpumask_t *dstp,
208 const cpumask_t *srcp, int nbits)
210 bitmap_complement(dstp->bits, srcp->bits, nbits);
213 #define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
214 static inline int __cpus_equal(const cpumask_t *src1p,
215 const cpumask_t *src2p, int nbits)
217 return bitmap_equal(src1p->bits, src2p->bits, nbits);
220 #define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
221 static inline int __cpus_intersects(const cpumask_t *src1p,
222 const cpumask_t *src2p, int nbits)
224 return bitmap_intersects(src1p->bits, src2p->bits, nbits);
227 #define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
228 static inline int __cpus_subset(const cpumask_t *src1p,
229 const cpumask_t *src2p, int nbits)
231 return bitmap_subset(src1p->bits, src2p->bits, nbits);
234 #define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
235 static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
237 return bitmap_empty(srcp->bits, nbits);
240 #define cpus_full(cpumask) __cpus_full(&(cpumask), NR_CPUS)
241 static inline int __cpus_full(const cpumask_t *srcp, int nbits)
243 return bitmap_full(srcp->bits, nbits);
246 #define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
247 static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
249 return bitmap_weight(srcp->bits, nbits);
252 #define cpus_shift_right(dst, src, n) \
253 __cpus_shift_right(&(dst), &(src), (n), NR_CPUS)
254 static inline void __cpus_shift_right(cpumask_t *dstp,
255 const cpumask_t *srcp, int n, int nbits)
257 bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
260 #define cpus_shift_left(dst, src, n) \
261 __cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
262 static inline void __cpus_shift_left(cpumask_t *dstp,
263 const cpumask_t *srcp, int n, int nbits)
265 bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
269 * Special-case data structure for "single bit set only" constant CPU masks.
271 * We pre-generate all the 64 (or 32) possible bit positions, with enough
272 * padding to the left and the right, and return the constant pointer
273 * appropriately offset.
275 extern const unsigned long
276 cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
278 static inline const cpumask_t *get_cpu_mask(unsigned int cpu)
280 const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
281 p -= cpu / BITS_PER_LONG;
282 return (const cpumask_t *)p;
286 * In cases where we take the address of the cpumask immediately,
287 * gcc optimizes it out (it's a constant) and there's no huge stack
288 * variable created:
290 #define cpumask_of_cpu(cpu) (*get_cpu_mask(cpu))
293 #define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
295 #if NR_CPUS <= BITS_PER_LONG
297 #define CPU_MASK_ALL \
298 (cpumask_t) { { \
299 [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \
302 #define CPU_MASK_ALL_PTR (&CPU_MASK_ALL)
304 #else
306 #define CPU_MASK_ALL \
307 (cpumask_t) { { \
308 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \
309 [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \
312 /* cpu_mask_all is in init/main.c */
313 extern cpumask_t cpu_mask_all;
314 #define CPU_MASK_ALL_PTR (&cpu_mask_all)
316 #endif
318 #define CPU_MASK_NONE \
319 (cpumask_t) { { \
320 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \
323 #define CPU_MASK_CPU0 \
324 (cpumask_t) { { \
325 [0] = 1UL \
328 #define cpus_addr(src) ((src).bits)
330 #if NR_CPUS > BITS_PER_LONG
331 #define CPUMASK_ALLOC(m) struct m *m = kmalloc(sizeof(*m), GFP_KERNEL)
332 #define CPUMASK_FREE(m) kfree(m)
333 #else
334 #define CPUMASK_ALLOC(m) struct m _m, *m = &_m
335 #define CPUMASK_FREE(m)
336 #endif
337 #define CPUMASK_PTR(v, m) cpumask_t *v = &(m->v)
339 #define cpumask_scnprintf(buf, len, src) \
340 __cpumask_scnprintf((buf), (len), &(src), NR_CPUS)
341 static inline int __cpumask_scnprintf(char *buf, int len,
342 const cpumask_t *srcp, int nbits)
344 return bitmap_scnprintf(buf, len, srcp->bits, nbits);
347 #define cpumask_parse_user(ubuf, ulen, dst) \
348 __cpumask_parse_user((ubuf), (ulen), &(dst), NR_CPUS)
349 static inline int __cpumask_parse_user(const char __user *buf, int len,
350 cpumask_t *dstp, int nbits)
352 return bitmap_parse_user(buf, len, dstp->bits, nbits);
355 #define cpulist_scnprintf(buf, len, src) \
356 __cpulist_scnprintf((buf), (len), &(src), NR_CPUS)
357 static inline int __cpulist_scnprintf(char *buf, int len,
358 const cpumask_t *srcp, int nbits)
360 return bitmap_scnlistprintf(buf, len, srcp->bits, nbits);
363 #define cpulist_parse(buf, dst) __cpulist_parse((buf), &(dst), NR_CPUS)
364 static inline int __cpulist_parse(const char *buf, cpumask_t *dstp, int nbits)
366 return bitmap_parselist(buf, dstp->bits, nbits);
369 #define cpu_remap(oldbit, old, new) \
370 __cpu_remap((oldbit), &(old), &(new), NR_CPUS)
371 static inline int __cpu_remap(int oldbit,
372 const cpumask_t *oldp, const cpumask_t *newp, int nbits)
374 return bitmap_bitremap(oldbit, oldp->bits, newp->bits, nbits);
377 #define cpus_remap(dst, src, old, new) \
378 __cpus_remap(&(dst), &(src), &(old), &(new), NR_CPUS)
379 static inline void __cpus_remap(cpumask_t *dstp, const cpumask_t *srcp,
380 const cpumask_t *oldp, const cpumask_t *newp, int nbits)
382 bitmap_remap(dstp->bits, srcp->bits, oldp->bits, newp->bits, nbits);
385 #define cpus_onto(dst, orig, relmap) \
386 __cpus_onto(&(dst), &(orig), &(relmap), NR_CPUS)
387 static inline void __cpus_onto(cpumask_t *dstp, const cpumask_t *origp,
388 const cpumask_t *relmapp, int nbits)
390 bitmap_onto(dstp->bits, origp->bits, relmapp->bits, nbits);
393 #define cpus_fold(dst, orig, sz) \
394 __cpus_fold(&(dst), &(orig), sz, NR_CPUS)
395 static inline void __cpus_fold(cpumask_t *dstp, const cpumask_t *origp,
396 int sz, int nbits)
398 bitmap_fold(dstp->bits, origp->bits, sz, nbits);
401 #if NR_CPUS == 1
403 #define nr_cpu_ids 1
404 #define first_cpu(src) ({ (void)(src); 0; })
405 #define next_cpu(n, src) ({ (void)(src); 1; })
406 #define any_online_cpu(mask) 0
407 #define for_each_cpu_mask(cpu, mask) \
408 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
410 #else /* NR_CPUS > 1 */
412 extern int nr_cpu_ids;
413 int __first_cpu(const cpumask_t *srcp);
414 int __next_cpu(int n, const cpumask_t *srcp);
415 int __any_online_cpu(const cpumask_t *mask);
417 #define first_cpu(src) __first_cpu(&(src))
418 #define next_cpu(n, src) __next_cpu((n), &(src))
419 #define any_online_cpu(mask) __any_online_cpu(&(mask))
420 #define for_each_cpu_mask(cpu, mask) \
421 for ((cpu) = -1; \
422 (cpu) = next_cpu((cpu), (mask)), \
423 (cpu) < NR_CPUS; )
424 #endif
426 #if NR_CPUS <= 64
428 #define next_cpu_nr(n, src) next_cpu(n, src)
429 #define cpus_weight_nr(cpumask) cpus_weight(cpumask)
430 #define for_each_cpu_mask_nr(cpu, mask) for_each_cpu_mask(cpu, mask)
432 #else /* NR_CPUS > 64 */
434 int __next_cpu_nr(int n, const cpumask_t *srcp);
435 #define next_cpu_nr(n, src) __next_cpu_nr((n), &(src))
436 #define cpus_weight_nr(cpumask) __cpus_weight(&(cpumask), nr_cpu_ids)
437 #define for_each_cpu_mask_nr(cpu, mask) \
438 for ((cpu) = -1; \
439 (cpu) = next_cpu_nr((cpu), (mask)), \
440 (cpu) < nr_cpu_ids; )
442 #endif /* NR_CPUS > 64 */
445 * The following particular system cpumasks and operations manage
446 * possible, present, active and online cpus. Each of them is a fixed size
447 * bitmap of size NR_CPUS.
449 * #ifdef CONFIG_HOTPLUG_CPU
450 * cpu_possible_map - has bit 'cpu' set iff cpu is populatable
451 * cpu_present_map - has bit 'cpu' set iff cpu is populated
452 * cpu_online_map - has bit 'cpu' set iff cpu available to scheduler
453 * cpu_active_map - has bit 'cpu' set iff cpu available to migration
454 * #else
455 * cpu_possible_map - has bit 'cpu' set iff cpu is populated
456 * cpu_present_map - copy of cpu_possible_map
457 * cpu_online_map - has bit 'cpu' set iff cpu available to scheduler
458 * #endif
460 * In either case, NR_CPUS is fixed at compile time, as the static
461 * size of these bitmaps. The cpu_possible_map is fixed at boot
462 * time, as the set of CPU id's that it is possible might ever
463 * be plugged in at anytime during the life of that system boot.
464 * The cpu_present_map is dynamic(*), representing which CPUs
465 * are currently plugged in. And cpu_online_map is the dynamic
466 * subset of cpu_present_map, indicating those CPUs available
467 * for scheduling.
469 * If HOTPLUG is enabled, then cpu_possible_map is forced to have
470 * all NR_CPUS bits set, otherwise it is just the set of CPUs that
471 * ACPI reports present at boot.
473 * If HOTPLUG is enabled, then cpu_present_map varies dynamically,
474 * depending on what ACPI reports as currently plugged in, otherwise
475 * cpu_present_map is just a copy of cpu_possible_map.
477 * (*) Well, cpu_present_map is dynamic in the hotplug case. If not
478 * hotplug, it's a copy of cpu_possible_map, hence fixed at boot.
480 * Subtleties:
481 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
482 * assumption that their single CPU is online. The UP
483 * cpu_{online,possible,present}_maps are placebos. Changing them
484 * will have no useful affect on the following num_*_cpus()
485 * and cpu_*() macros in the UP case. This ugliness is a UP
486 * optimization - don't waste any instructions or memory references
487 * asking if you're online or how many CPUs there are if there is
488 * only one CPU.
489 * 2) Most SMP arch's #define some of these maps to be some
490 * other map specific to that arch. Therefore, the following
491 * must be #define macros, not inlines. To see why, examine
492 * the assembly code produced by the following. Note that
493 * set1() writes phys_x_map, but set2() writes x_map:
494 * int x_map, phys_x_map;
495 * #define set1(a) x_map = a
496 * inline void set2(int a) { x_map = a; }
497 * #define x_map phys_x_map
498 * main(){ set1(3); set2(5); }
501 extern cpumask_t cpu_possible_map;
502 extern cpumask_t cpu_online_map;
503 extern cpumask_t cpu_present_map;
504 extern cpumask_t cpu_active_map;
506 #if NR_CPUS > 1
507 #define num_online_cpus() cpus_weight_nr(cpu_online_map)
508 #define num_possible_cpus() cpus_weight_nr(cpu_possible_map)
509 #define num_present_cpus() cpus_weight_nr(cpu_present_map)
510 #define cpu_online(cpu) cpu_isset((cpu), cpu_online_map)
511 #define cpu_possible(cpu) cpu_isset((cpu), cpu_possible_map)
512 #define cpu_present(cpu) cpu_isset((cpu), cpu_present_map)
513 #define cpu_active(cpu) cpu_isset((cpu), cpu_active_map)
514 #else
515 #define num_online_cpus() 1
516 #define num_possible_cpus() 1
517 #define num_present_cpus() 1
518 #define cpu_online(cpu) ((cpu) == 0)
519 #define cpu_possible(cpu) ((cpu) == 0)
520 #define cpu_present(cpu) ((cpu) == 0)
521 #define cpu_active(cpu) ((cpu) == 0)
522 #endif
524 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
526 #define for_each_possible_cpu(cpu) for_each_cpu_mask_nr((cpu), cpu_possible_map)
527 #define for_each_online_cpu(cpu) for_each_cpu_mask_nr((cpu), cpu_online_map)
528 #define for_each_present_cpu(cpu) for_each_cpu_mask_nr((cpu), cpu_present_map)
530 #endif /* __LINUX_CPUMASK_H */