1 #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_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. 19 * 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. 27 * 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 * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 * 34 * The available cpumask operations are: 35 * 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 42 * 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 48 * 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 56 * 57 * void cpus_shift_right(dst, src, n) Shift right 58 * void cpus_shift_left(dst, src, n) Shift left 59 * 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 63 * 64 * cpumask_t cpumask_of_cpu(cpu) Return cpumask with bit 'cpu' set 65 *ifdef CONFIG_HAS_CPUMASK_OF_CPU 66 * cpumask_of_cpu_ptr_declare(v) Declares cpumask_t *v 67 * cpumask_of_cpu_ptr_next(v, cpu) Sets v = &cpumask_of_cpu_map[cpu] 68 * cpumask_of_cpu_ptr(v, cpu) Combines above two operations 69 *else 70 * cpumask_of_cpu_ptr_declare(v) Declares cpumask_t _v and *v = &_v 71 * cpumask_of_cpu_ptr_next(v, cpu) Sets _v = cpumask_of_cpu(cpu) 72 * cpumask_of_cpu_ptr(v, cpu) Combines above two operations 73 *endif 74 * CPU_MASK_ALL Initializer - all bits set 75 * CPU_MASK_NONE Initializer - no bits set 76 * unsigned long *cpus_addr(mask) Array of unsigned long's in mask 77 * 78 * CPUMASK_ALLOC kmalloc's a structure that is a composite of many cpumask_t 79 * variables, and CPUMASK_PTR provides pointers to each field. 80 * 81 * The structure should be defined something like this: 82 * struct my_cpumasks { 83 * cpumask_t mask1; 84 * cpumask_t mask2; 85 * }; 86 * 87 * Usage is then: 88 * CPUMASK_ALLOC(my_cpumasks); 89 * CPUMASK_PTR(mask1, my_cpumasks); 90 * CPUMASK_PTR(mask2, my_cpumasks); 91 * 92 * --- DO NOT reference cpumask_t pointers until this check --- 93 * if (my_cpumasks == NULL) 94 * "kmalloc failed"... 95 * 96 * References are now pointers to the cpumask_t variables (*mask1, ...) 97 * 98 *if NR_CPUS > BITS_PER_LONG 99 * CPUMASK_ALLOC(m) Declares and allocates struct m *m = 100 * kmalloc(sizeof(*m), GFP_KERNEL) 101 * CPUMASK_FREE(m) Macro for kfree(m) 102 *else 103 * CPUMASK_ALLOC(m) Declares struct m _m, *m = &_m 104 * CPUMASK_FREE(m) Nop 105 *endif 106 * CPUMASK_PTR(v, m) Declares cpumask_t *v = &(m->v) 107 * ------------------------------------------------------------------------ 108 * 109 * int cpumask_scnprintf(buf, len, mask) Format cpumask for printing 110 * int cpumask_parse_user(ubuf, ulen, mask) Parse ascii string as cpumask 111 * int cpulist_scnprintf(buf, len, mask) Format cpumask as list for printing 112 * int cpulist_parse(buf, map) Parse ascii string as cpulist 113 * int cpu_remap(oldbit, old, new) newbit = map(old, new)(oldbit) 114 * void cpus_remap(dst, src, old, new) *dst = map(old, new)(src) 115 * void cpus_onto(dst, orig, relmap) *dst = orig relative to relmap 116 * void cpus_fold(dst, orig, sz) dst bits = orig bits mod sz 117 * 118 * for_each_cpu_mask(cpu, mask) for-loop cpu over mask using NR_CPUS 119 * for_each_cpu_mask_nr(cpu, mask) for-loop cpu over mask using nr_cpu_ids 120 * 121 * int num_online_cpus() Number of online CPUs 122 * int num_possible_cpus() Number of all possible CPUs 123 * int num_present_cpus() Number of present CPUs 124 * 125 * int cpu_online(cpu) Is some cpu online? 126 * int cpu_possible(cpu) Is some cpu possible? 127 * int cpu_present(cpu) Is some cpu present (can schedule)? 128 * 129 * int any_online_cpu(mask) First online cpu in mask 130 * 131 * for_each_possible_cpu(cpu) for-loop cpu over cpu_possible_map 132 * for_each_online_cpu(cpu) for-loop cpu over cpu_online_map 133 * for_each_present_cpu(cpu) for-loop cpu over cpu_present_map 134 * 135 * Subtlety: 136 * 1) The 'type-checked' form of cpu_isset() causes gcc (3.3.2, anyway) 137 * to generate slightly worse code. Note for example the additional 138 * 40 lines of assembly code compiling the "for each possible cpu" 139 * loops buried in the disk_stat_read() macros calls when compiling 140 * drivers/block/genhd.c (arch i386, CONFIG_SMP=y). So use a simple 141 * one-line #define for cpu_isset(), instead of wrapping an inline 142 * inside a macro, the way we do the other calls. 143 */ 144 145 #include <linux/kernel.h> 146 #include <linux/threads.h> 147 #include <linux/bitmap.h> 148 149 typedef struct { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t; 150 extern cpumask_t _unused_cpumask_arg_; 151 152 #define cpu_set(cpu, dst) __cpu_set((cpu), &(dst)) 153 static inline void __cpu_set(int cpu, volatile cpumask_t *dstp) 154 { 155 set_bit(cpu, dstp->bits); 156 } 157 158 #define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst)) 159 static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp) 160 { 161 clear_bit(cpu, dstp->bits); 162 } 163 164 #define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS) 165 static inline void __cpus_setall(cpumask_t *dstp, int nbits) 166 { 167 bitmap_fill(dstp->bits, nbits); 168 } 169 170 #define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS) 171 static inline void __cpus_clear(cpumask_t *dstp, int nbits) 172 { 173 bitmap_zero(dstp->bits, nbits); 174 } 175 176 /* No static inline type checking - see Subtlety (1) above. */ 177 #define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits) 178 179 #define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask)) 180 static inline int __cpu_test_and_set(int cpu, cpumask_t *addr) 181 { 182 return test_and_set_bit(cpu, addr->bits); 183 } 184 185 #define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS) 186 static inline void __cpus_and(cpumask_t *dstp, const cpumask_t *src1p, 187 const cpumask_t *src2p, int nbits) 188 { 189 bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits); 190 } 191 192 #define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS) 193 static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p, 194 const cpumask_t *src2p, int nbits) 195 { 196 bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits); 197 } 198 199 #define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS) 200 static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p, 201 const cpumask_t *src2p, int nbits) 202 { 203 bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits); 204 } 205 206 #define cpus_andnot(dst, src1, src2) \ 207 __cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS) 208 static inline void __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p, 209 const cpumask_t *src2p, int nbits) 210 { 211 bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits); 212 } 213 214 #define cpus_complement(dst, src) __cpus_complement(&(dst), &(src), NR_CPUS) 215 static inline void __cpus_complement(cpumask_t *dstp, 216 const cpumask_t *srcp, int nbits) 217 { 218 bitmap_complement(dstp->bits, srcp->bits, nbits); 219 } 220 221 #define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS) 222 static inline int __cpus_equal(const cpumask_t *src1p, 223 const cpumask_t *src2p, int nbits) 224 { 225 return bitmap_equal(src1p->bits, src2p->bits, nbits); 226 } 227 228 #define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS) 229 static inline int __cpus_intersects(const cpumask_t *src1p, 230 const cpumask_t *src2p, int nbits) 231 { 232 return bitmap_intersects(src1p->bits, src2p->bits, nbits); 233 } 234 235 #define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS) 236 static inline int __cpus_subset(const cpumask_t *src1p, 237 const cpumask_t *src2p, int nbits) 238 { 239 return bitmap_subset(src1p->bits, src2p->bits, nbits); 240 } 241 242 #define cpus_empty(src) __cpus_empty(&(src), NR_CPUS) 243 static inline int __cpus_empty(const cpumask_t *srcp, int nbits) 244 { 245 return bitmap_empty(srcp->bits, nbits); 246 } 247 248 #define cpus_full(cpumask) __cpus_full(&(cpumask), NR_CPUS) 249 static inline int __cpus_full(const cpumask_t *srcp, int nbits) 250 { 251 return bitmap_full(srcp->bits, nbits); 252 } 253 254 #define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS) 255 static inline int __cpus_weight(const cpumask_t *srcp, int nbits) 256 { 257 return bitmap_weight(srcp->bits, nbits); 258 } 259 260 #define cpus_shift_right(dst, src, n) \ 261 __cpus_shift_right(&(dst), &(src), (n), NR_CPUS) 262 static inline void __cpus_shift_right(cpumask_t *dstp, 263 const cpumask_t *srcp, int n, int nbits) 264 { 265 bitmap_shift_right(dstp->bits, srcp->bits, n, nbits); 266 } 267 268 #define cpus_shift_left(dst, src, n) \ 269 __cpus_shift_left(&(dst), &(src), (n), NR_CPUS) 270 static inline void __cpus_shift_left(cpumask_t *dstp, 271 const cpumask_t *srcp, int n, int nbits) 272 { 273 bitmap_shift_left(dstp->bits, srcp->bits, n, nbits); 274 } 275 276 277 #ifdef CONFIG_HAVE_CPUMASK_OF_CPU_MAP 278 extern cpumask_t *cpumask_of_cpu_map; 279 #define cpumask_of_cpu(cpu) (cpumask_of_cpu_map[cpu]) 280 #define cpumask_of_cpu_ptr(v, cpu) \ 281 const cpumask_t *v = &cpumask_of_cpu(cpu) 282 #define cpumask_of_cpu_ptr_declare(v) \ 283 const cpumask_t *v 284 #define cpumask_of_cpu_ptr_next(v, cpu) \ 285 v = &cpumask_of_cpu(cpu) 286 #else 287 #define cpumask_of_cpu(cpu) \ 288 ({ \ 289 typeof(_unused_cpumask_arg_) m; \ 290 if (sizeof(m) == sizeof(unsigned long)) { \ 291 m.bits[0] = 1UL<<(cpu); \ 292 } else { \ 293 cpus_clear(m); \ 294 cpu_set((cpu), m); \ 295 } \ 296 m; \ 297 }) 298 #define cpumask_of_cpu_ptr(v, cpu) \ 299 cpumask_t _##v = cpumask_of_cpu(cpu); \ 300 const cpumask_t *v = &_##v 301 #define cpumask_of_cpu_ptr_declare(v) \ 302 cpumask_t _##v; \ 303 const cpumask_t *v = &_##v 304 #define cpumask_of_cpu_ptr_next(v, cpu) \ 305 _##v = cpumask_of_cpu(cpu) 306 #endif 307 308 #define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS) 309 310 #if NR_CPUS <= BITS_PER_LONG 311 312 #define CPU_MASK_ALL \ 313 (cpumask_t) { { \ 314 [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \ 315 } } 316 317 #define CPU_MASK_ALL_PTR (&CPU_MASK_ALL) 318 319 #else 320 321 #define CPU_MASK_ALL \ 322 (cpumask_t) { { \ 323 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 324 [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \ 325 } } 326 327 /* cpu_mask_all is in init/main.c */ 328 extern cpumask_t cpu_mask_all; 329 #define CPU_MASK_ALL_PTR (&cpu_mask_all) 330 331 #endif 332 333 #define CPU_MASK_NONE \ 334 (cpumask_t) { { \ 335 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 336 } } 337 338 #define CPU_MASK_CPU0 \ 339 (cpumask_t) { { \ 340 [0] = 1UL \ 341 } } 342 343 #define cpus_addr(src) ((src).bits) 344 345 #if NR_CPUS > BITS_PER_LONG 346 #define CPUMASK_ALLOC(m) struct m *m = kmalloc(sizeof(*m), GFP_KERNEL) 347 #define CPUMASK_FREE(m) kfree(m) 348 #else 349 #define CPUMASK_ALLOC(m) struct m _m, *m = &_m 350 #define CPUMASK_FREE(m) 351 #endif 352 #define CPUMASK_PTR(v, m) cpumask_t *v = &(m->v) 353 354 #define cpumask_scnprintf(buf, len, src) \ 355 __cpumask_scnprintf((buf), (len), &(src), NR_CPUS) 356 static inline int __cpumask_scnprintf(char *buf, int len, 357 const cpumask_t *srcp, int nbits) 358 { 359 return bitmap_scnprintf(buf, len, srcp->bits, nbits); 360 } 361 362 #define cpumask_parse_user(ubuf, ulen, dst) \ 363 __cpumask_parse_user((ubuf), (ulen), &(dst), NR_CPUS) 364 static inline int __cpumask_parse_user(const char __user *buf, int len, 365 cpumask_t *dstp, int nbits) 366 { 367 return bitmap_parse_user(buf, len, dstp->bits, nbits); 368 } 369 370 #define cpulist_scnprintf(buf, len, src) \ 371 __cpulist_scnprintf((buf), (len), &(src), NR_CPUS) 372 static inline int __cpulist_scnprintf(char *buf, int len, 373 const cpumask_t *srcp, int nbits) 374 { 375 return bitmap_scnlistprintf(buf, len, srcp->bits, nbits); 376 } 377 378 #define cpulist_parse(buf, dst) __cpulist_parse((buf), &(dst), NR_CPUS) 379 static inline int __cpulist_parse(const char *buf, cpumask_t *dstp, int nbits) 380 { 381 return bitmap_parselist(buf, dstp->bits, nbits); 382 } 383 384 #define cpu_remap(oldbit, old, new) \ 385 __cpu_remap((oldbit), &(old), &(new), NR_CPUS) 386 static inline int __cpu_remap(int oldbit, 387 const cpumask_t *oldp, const cpumask_t *newp, int nbits) 388 { 389 return bitmap_bitremap(oldbit, oldp->bits, newp->bits, nbits); 390 } 391 392 #define cpus_remap(dst, src, old, new) \ 393 __cpus_remap(&(dst), &(src), &(old), &(new), NR_CPUS) 394 static inline void __cpus_remap(cpumask_t *dstp, const cpumask_t *srcp, 395 const cpumask_t *oldp, const cpumask_t *newp, int nbits) 396 { 397 bitmap_remap(dstp->bits, srcp->bits, oldp->bits, newp->bits, nbits); 398 } 399 400 #define cpus_onto(dst, orig, relmap) \ 401 __cpus_onto(&(dst), &(orig), &(relmap), NR_CPUS) 402 static inline void __cpus_onto(cpumask_t *dstp, const cpumask_t *origp, 403 const cpumask_t *relmapp, int nbits) 404 { 405 bitmap_onto(dstp->bits, origp->bits, relmapp->bits, nbits); 406 } 407 408 #define cpus_fold(dst, orig, sz) \ 409 __cpus_fold(&(dst), &(orig), sz, NR_CPUS) 410 static inline void __cpus_fold(cpumask_t *dstp, const cpumask_t *origp, 411 int sz, int nbits) 412 { 413 bitmap_fold(dstp->bits, origp->bits, sz, nbits); 414 } 415 416 #if NR_CPUS == 1 417 418 #define nr_cpu_ids 1 419 #define first_cpu(src) ({ (void)(src); 0; }) 420 #define next_cpu(n, src) ({ (void)(src); 1; }) 421 #define any_online_cpu(mask) 0 422 #define for_each_cpu_mask(cpu, mask) \ 423 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask) 424 425 #else /* NR_CPUS > 1 */ 426 427 extern int nr_cpu_ids; 428 int __first_cpu(const cpumask_t *srcp); 429 int __next_cpu(int n, const cpumask_t *srcp); 430 int __any_online_cpu(const cpumask_t *mask); 431 432 #define first_cpu(src) __first_cpu(&(src)) 433 #define next_cpu(n, src) __next_cpu((n), &(src)) 434 #define any_online_cpu(mask) __any_online_cpu(&(mask)) 435 #define for_each_cpu_mask(cpu, mask) \ 436 for ((cpu) = -1; \ 437 (cpu) = next_cpu((cpu), (mask)), \ 438 (cpu) < NR_CPUS; ) 439 #endif 440 441 #if NR_CPUS <= 64 442 443 #define next_cpu_nr(n, src) next_cpu(n, src) 444 #define cpus_weight_nr(cpumask) cpus_weight(cpumask) 445 #define for_each_cpu_mask_nr(cpu, mask) for_each_cpu_mask(cpu, mask) 446 447 #else /* NR_CPUS > 64 */ 448 449 int __next_cpu_nr(int n, const cpumask_t *srcp); 450 #define next_cpu_nr(n, src) __next_cpu_nr((n), &(src)) 451 #define cpus_weight_nr(cpumask) __cpus_weight(&(cpumask), nr_cpu_ids) 452 #define for_each_cpu_mask_nr(cpu, mask) \ 453 for ((cpu) = -1; \ 454 (cpu) = next_cpu_nr((cpu), (mask)), \ 455 (cpu) < nr_cpu_ids; ) 456 457 #endif /* NR_CPUS > 64 */ 458 459 /* 460 * The following particular system cpumasks and operations manage 461 * possible, present, active and online cpus. Each of them is a fixed size 462 * bitmap of size NR_CPUS. 463 * 464 * #ifdef CONFIG_HOTPLUG_CPU 465 * cpu_possible_map - has bit 'cpu' set iff cpu is populatable 466 * cpu_present_map - has bit 'cpu' set iff cpu is populated 467 * cpu_online_map - has bit 'cpu' set iff cpu available to scheduler 468 * cpu_active_map - has bit 'cpu' set iff cpu available to migration 469 * #else 470 * cpu_possible_map - has bit 'cpu' set iff cpu is populated 471 * cpu_present_map - copy of cpu_possible_map 472 * cpu_online_map - has bit 'cpu' set iff cpu available to scheduler 473 * #endif 474 * 475 * In either case, NR_CPUS is fixed at compile time, as the static 476 * size of these bitmaps. The cpu_possible_map is fixed at boot 477 * time, as the set of CPU id's that it is possible might ever 478 * be plugged in at anytime during the life of that system boot. 479 * The cpu_present_map is dynamic(*), representing which CPUs 480 * are currently plugged in. And cpu_online_map is the dynamic 481 * subset of cpu_present_map, indicating those CPUs available 482 * for scheduling. 483 * 484 * If HOTPLUG is enabled, then cpu_possible_map is forced to have 485 * all NR_CPUS bits set, otherwise it is just the set of CPUs that 486 * ACPI reports present at boot. 487 * 488 * If HOTPLUG is enabled, then cpu_present_map varies dynamically, 489 * depending on what ACPI reports as currently plugged in, otherwise 490 * cpu_present_map is just a copy of cpu_possible_map. 491 * 492 * (*) Well, cpu_present_map is dynamic in the hotplug case. If not 493 * hotplug, it's a copy of cpu_possible_map, hence fixed at boot. 494 * 495 * Subtleties: 496 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode 497 * assumption that their single CPU is online. The UP 498 * cpu_{online,possible,present}_maps are placebos. Changing them 499 * will have no useful affect on the following num_*_cpus() 500 * and cpu_*() macros in the UP case. This ugliness is a UP 501 * optimization - don't waste any instructions or memory references 502 * asking if you're online or how many CPUs there are if there is 503 * only one CPU. 504 * 2) Most SMP arch's #define some of these maps to be some 505 * other map specific to that arch. Therefore, the following 506 * must be #define macros, not inlines. To see why, examine 507 * the assembly code produced by the following. Note that 508 * set1() writes phys_x_map, but set2() writes x_map: 509 * int x_map, phys_x_map; 510 * #define set1(a) x_map = a 511 * inline void set2(int a) { x_map = a; } 512 * #define x_map phys_x_map 513 * main(){ set1(3); set2(5); } 514 */ 515 516 extern cpumask_t cpu_possible_map; 517 extern cpumask_t cpu_online_map; 518 extern cpumask_t cpu_present_map; 519 extern cpumask_t cpu_active_map; 520 521 #if NR_CPUS > 1 522 #define num_online_cpus() cpus_weight_nr(cpu_online_map) 523 #define num_possible_cpus() cpus_weight_nr(cpu_possible_map) 524 #define num_present_cpus() cpus_weight_nr(cpu_present_map) 525 #define cpu_online(cpu) cpu_isset((cpu), cpu_online_map) 526 #define cpu_possible(cpu) cpu_isset((cpu), cpu_possible_map) 527 #define cpu_present(cpu) cpu_isset((cpu), cpu_present_map) 528 #define cpu_active(cpu) cpu_isset((cpu), cpu_active_map) 529 #else 530 #define num_online_cpus() 1 531 #define num_possible_cpus() 1 532 #define num_present_cpus() 1 533 #define cpu_online(cpu) ((cpu) == 0) 534 #define cpu_possible(cpu) ((cpu) == 0) 535 #define cpu_present(cpu) ((cpu) == 0) 536 #define cpu_active(cpu) ((cpu) == 0) 537 #endif 538 539 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) 540 541 #define for_each_possible_cpu(cpu) for_each_cpu_mask_nr((cpu), cpu_possible_map) 542 #define for_each_online_cpu(cpu) for_each_cpu_mask_nr((cpu), cpu_online_map) 543 #define for_each_present_cpu(cpu) for_each_cpu_mask_nr((cpu), cpu_present_map) 544 545 #endif /* __LINUX_CPUMASK_H */ 546