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. In general, 7 * only nr_cpu_ids (<= NR_CPUS) bits are valid. 8 */ 9 #include <linux/kernel.h> 10 #include <linux/threads.h> 11 #include <linux/bitmap.h> 12 #include <linux/bug.h> 13 14 /* Don't assign or return these: may not be this big! */ 15 typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t; 16 17 /** 18 * cpumask_bits - get the bits in a cpumask 19 * @maskp: the struct cpumask * 20 * 21 * You should only assume nr_cpu_ids bits of this mask are valid. This is 22 * a macro so it's const-correct. 23 */ 24 #define cpumask_bits(maskp) ((maskp)->bits) 25 26 /** 27 * cpumask_pr_args - printf args to output a cpumask 28 * @maskp: cpumask to be printed 29 * 30 * Can be used to provide arguments for '%*pb[l]' when printing a cpumask. 31 */ 32 #define cpumask_pr_args(maskp) nr_cpu_ids, cpumask_bits(maskp) 33 34 #if NR_CPUS == 1 35 #define nr_cpu_ids 1 36 #else 37 extern int nr_cpu_ids; 38 #endif 39 40 #ifdef CONFIG_CPUMASK_OFFSTACK 41 /* Assuming NR_CPUS is huge, a runtime limit is more efficient. Also, 42 * not all bits may be allocated. */ 43 #define nr_cpumask_bits ((unsigned int)nr_cpu_ids) 44 #else 45 #define nr_cpumask_bits ((unsigned int)NR_CPUS) 46 #endif 47 48 /* 49 * The following particular system cpumasks and operations manage 50 * possible, present, active and online cpus. 51 * 52 * cpu_possible_mask- has bit 'cpu' set iff cpu is populatable 53 * cpu_present_mask - has bit 'cpu' set iff cpu is populated 54 * cpu_online_mask - has bit 'cpu' set iff cpu available to scheduler 55 * cpu_active_mask - has bit 'cpu' set iff cpu available to migration 56 * 57 * If !CONFIG_HOTPLUG_CPU, present == possible, and active == online. 58 * 59 * The cpu_possible_mask is fixed at boot time, as the set of CPU id's 60 * that it is possible might ever be plugged in at anytime during the 61 * life of that system boot. The cpu_present_mask is dynamic(*), 62 * representing which CPUs are currently plugged in. And 63 * cpu_online_mask is the dynamic subset of cpu_present_mask, 64 * indicating those CPUs available for scheduling. 65 * 66 * If HOTPLUG is enabled, then cpu_possible_mask is forced to have 67 * all NR_CPUS bits set, otherwise it is just the set of CPUs that 68 * ACPI reports present at boot. 69 * 70 * If HOTPLUG is enabled, then cpu_present_mask varies dynamically, 71 * depending on what ACPI reports as currently plugged in, otherwise 72 * cpu_present_mask is just a copy of cpu_possible_mask. 73 * 74 * (*) Well, cpu_present_mask is dynamic in the hotplug case. If not 75 * hotplug, it's a copy of cpu_possible_mask, hence fixed at boot. 76 * 77 * Subtleties: 78 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode 79 * assumption that their single CPU is online. The UP 80 * cpu_{online,possible,present}_masks are placebos. Changing them 81 * will have no useful affect on the following num_*_cpus() 82 * and cpu_*() macros in the UP case. This ugliness is a UP 83 * optimization - don't waste any instructions or memory references 84 * asking if you're online or how many CPUs there are if there is 85 * only one CPU. 86 */ 87 88 extern struct cpumask __cpu_possible_mask; 89 extern struct cpumask __cpu_online_mask; 90 extern struct cpumask __cpu_present_mask; 91 extern struct cpumask __cpu_active_mask; 92 #define cpu_possible_mask ((const struct cpumask *)&__cpu_possible_mask) 93 #define cpu_online_mask ((const struct cpumask *)&__cpu_online_mask) 94 #define cpu_present_mask ((const struct cpumask *)&__cpu_present_mask) 95 #define cpu_active_mask ((const struct cpumask *)&__cpu_active_mask) 96 97 #if NR_CPUS > 1 98 #define num_online_cpus() cpumask_weight(cpu_online_mask) 99 #define num_possible_cpus() cpumask_weight(cpu_possible_mask) 100 #define num_present_cpus() cpumask_weight(cpu_present_mask) 101 #define num_active_cpus() cpumask_weight(cpu_active_mask) 102 #define cpu_online(cpu) cpumask_test_cpu((cpu), cpu_online_mask) 103 #define cpu_possible(cpu) cpumask_test_cpu((cpu), cpu_possible_mask) 104 #define cpu_present(cpu) cpumask_test_cpu((cpu), cpu_present_mask) 105 #define cpu_active(cpu) cpumask_test_cpu((cpu), cpu_active_mask) 106 #else 107 #define num_online_cpus() 1U 108 #define num_possible_cpus() 1U 109 #define num_present_cpus() 1U 110 #define num_active_cpus() 1U 111 #define cpu_online(cpu) ((cpu) == 0) 112 #define cpu_possible(cpu) ((cpu) == 0) 113 #define cpu_present(cpu) ((cpu) == 0) 114 #define cpu_active(cpu) ((cpu) == 0) 115 #endif 116 117 /* verify cpu argument to cpumask_* operators */ 118 static inline unsigned int cpumask_check(unsigned int cpu) 119 { 120 #ifdef CONFIG_DEBUG_PER_CPU_MAPS 121 WARN_ON_ONCE(cpu >= nr_cpumask_bits); 122 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */ 123 return cpu; 124 } 125 126 #if NR_CPUS == 1 127 /* Uniprocessor. Assume all masks are "1". */ 128 static inline unsigned int cpumask_first(const struct cpumask *srcp) 129 { 130 return 0; 131 } 132 133 /* Valid inputs for n are -1 and 0. */ 134 static inline unsigned int cpumask_next(int n, const struct cpumask *srcp) 135 { 136 return n+1; 137 } 138 139 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp) 140 { 141 return n+1; 142 } 143 144 static inline unsigned int cpumask_next_and(int n, 145 const struct cpumask *srcp, 146 const struct cpumask *andp) 147 { 148 return n+1; 149 } 150 151 /* cpu must be a valid cpu, ie 0, so there's no other choice. */ 152 static inline unsigned int cpumask_any_but(const struct cpumask *mask, 153 unsigned int cpu) 154 { 155 return 1; 156 } 157 158 static inline unsigned int cpumask_local_spread(unsigned int i, int node) 159 { 160 return 0; 161 } 162 163 #define for_each_cpu(cpu, mask) \ 164 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask) 165 #define for_each_cpu_not(cpu, mask) \ 166 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask) 167 #define for_each_cpu_and(cpu, mask, and) \ 168 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and) 169 #else 170 /** 171 * cpumask_first - get the first cpu in a cpumask 172 * @srcp: the cpumask pointer 173 * 174 * Returns >= nr_cpu_ids if no cpus set. 175 */ 176 static inline unsigned int cpumask_first(const struct cpumask *srcp) 177 { 178 return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits); 179 } 180 181 /** 182 * cpumask_next - get the next cpu in a cpumask 183 * @n: the cpu prior to the place to search (ie. return will be > @n) 184 * @srcp: the cpumask pointer 185 * 186 * Returns >= nr_cpu_ids if no further cpus set. 187 */ 188 static inline unsigned int cpumask_next(int n, const struct cpumask *srcp) 189 { 190 /* -1 is a legal arg here. */ 191 if (n != -1) 192 cpumask_check(n); 193 return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1); 194 } 195 196 /** 197 * cpumask_next_zero - get the next unset cpu in a cpumask 198 * @n: the cpu prior to the place to search (ie. return will be > @n) 199 * @srcp: the cpumask pointer 200 * 201 * Returns >= nr_cpu_ids if no further cpus unset. 202 */ 203 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp) 204 { 205 /* -1 is a legal arg here. */ 206 if (n != -1) 207 cpumask_check(n); 208 return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1); 209 } 210 211 int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *); 212 int cpumask_any_but(const struct cpumask *mask, unsigned int cpu); 213 unsigned int cpumask_local_spread(unsigned int i, int node); 214 215 /** 216 * for_each_cpu - iterate over every cpu in a mask 217 * @cpu: the (optionally unsigned) integer iterator 218 * @mask: the cpumask pointer 219 * 220 * After the loop, cpu is >= nr_cpu_ids. 221 */ 222 #define for_each_cpu(cpu, mask) \ 223 for ((cpu) = -1; \ 224 (cpu) = cpumask_next((cpu), (mask)), \ 225 (cpu) < nr_cpu_ids;) 226 227 /** 228 * for_each_cpu_not - iterate over every cpu in a complemented mask 229 * @cpu: the (optionally unsigned) integer iterator 230 * @mask: the cpumask pointer 231 * 232 * After the loop, cpu is >= nr_cpu_ids. 233 */ 234 #define for_each_cpu_not(cpu, mask) \ 235 for ((cpu) = -1; \ 236 (cpu) = cpumask_next_zero((cpu), (mask)), \ 237 (cpu) < nr_cpu_ids;) 238 239 extern int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap); 240 241 /** 242 * for_each_cpu_wrap - iterate over every cpu in a mask, starting at a specified location 243 * @cpu: the (optionally unsigned) integer iterator 244 * @mask: the cpumask poiter 245 * @start: the start location 246 * 247 * The implementation does not assume any bit in @mask is set (including @start). 248 * 249 * After the loop, cpu is >= nr_cpu_ids. 250 */ 251 #define for_each_cpu_wrap(cpu, mask, start) \ 252 for ((cpu) = cpumask_next_wrap((start)-1, (mask), (start), false); \ 253 (cpu) < nr_cpumask_bits; \ 254 (cpu) = cpumask_next_wrap((cpu), (mask), (start), true)) 255 256 /** 257 * for_each_cpu_and - iterate over every cpu in both masks 258 * @cpu: the (optionally unsigned) integer iterator 259 * @mask: the first cpumask pointer 260 * @and: the second cpumask pointer 261 * 262 * This saves a temporary CPU mask in many places. It is equivalent to: 263 * struct cpumask tmp; 264 * cpumask_and(&tmp, &mask, &and); 265 * for_each_cpu(cpu, &tmp) 266 * ... 267 * 268 * After the loop, cpu is >= nr_cpu_ids. 269 */ 270 #define for_each_cpu_and(cpu, mask, and) \ 271 for ((cpu) = -1; \ 272 (cpu) = cpumask_next_and((cpu), (mask), (and)), \ 273 (cpu) < nr_cpu_ids;) 274 #endif /* SMP */ 275 276 #define CPU_BITS_NONE \ 277 { \ 278 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 279 } 280 281 #define CPU_BITS_CPU0 \ 282 { \ 283 [0] = 1UL \ 284 } 285 286 /** 287 * cpumask_set_cpu - set a cpu in a cpumask 288 * @cpu: cpu number (< nr_cpu_ids) 289 * @dstp: the cpumask pointer 290 */ 291 static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp) 292 { 293 set_bit(cpumask_check(cpu), cpumask_bits(dstp)); 294 } 295 296 static inline void __cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp) 297 { 298 __set_bit(cpumask_check(cpu), cpumask_bits(dstp)); 299 } 300 301 302 /** 303 * cpumask_clear_cpu - clear a cpu in a cpumask 304 * @cpu: cpu number (< nr_cpu_ids) 305 * @dstp: the cpumask pointer 306 */ 307 static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp) 308 { 309 clear_bit(cpumask_check(cpu), cpumask_bits(dstp)); 310 } 311 312 static inline void __cpumask_clear_cpu(int cpu, struct cpumask *dstp) 313 { 314 __clear_bit(cpumask_check(cpu), cpumask_bits(dstp)); 315 } 316 317 /** 318 * cpumask_test_cpu - test for a cpu in a cpumask 319 * @cpu: cpu number (< nr_cpu_ids) 320 * @cpumask: the cpumask pointer 321 * 322 * Returns 1 if @cpu is set in @cpumask, else returns 0 323 */ 324 static inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask) 325 { 326 return test_bit(cpumask_check(cpu), cpumask_bits((cpumask))); 327 } 328 329 /** 330 * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask 331 * @cpu: cpu number (< nr_cpu_ids) 332 * @cpumask: the cpumask pointer 333 * 334 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0 335 * 336 * test_and_set_bit wrapper for cpumasks. 337 */ 338 static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask) 339 { 340 return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask)); 341 } 342 343 /** 344 * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask 345 * @cpu: cpu number (< nr_cpu_ids) 346 * @cpumask: the cpumask pointer 347 * 348 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0 349 * 350 * test_and_clear_bit wrapper for cpumasks. 351 */ 352 static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask) 353 { 354 return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask)); 355 } 356 357 /** 358 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask 359 * @dstp: the cpumask pointer 360 */ 361 static inline void cpumask_setall(struct cpumask *dstp) 362 { 363 bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits); 364 } 365 366 /** 367 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask 368 * @dstp: the cpumask pointer 369 */ 370 static inline void cpumask_clear(struct cpumask *dstp) 371 { 372 bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits); 373 } 374 375 /** 376 * cpumask_and - *dstp = *src1p & *src2p 377 * @dstp: the cpumask result 378 * @src1p: the first input 379 * @src2p: the second input 380 * 381 * If *@dstp is empty, returns 0, else returns 1 382 */ 383 static inline int cpumask_and(struct cpumask *dstp, 384 const struct cpumask *src1p, 385 const struct cpumask *src2p) 386 { 387 return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p), 388 cpumask_bits(src2p), nr_cpumask_bits); 389 } 390 391 /** 392 * cpumask_or - *dstp = *src1p | *src2p 393 * @dstp: the cpumask result 394 * @src1p: the first input 395 * @src2p: the second input 396 */ 397 static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p, 398 const struct cpumask *src2p) 399 { 400 bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p), 401 cpumask_bits(src2p), nr_cpumask_bits); 402 } 403 404 /** 405 * cpumask_xor - *dstp = *src1p ^ *src2p 406 * @dstp: the cpumask result 407 * @src1p: the first input 408 * @src2p: the second input 409 */ 410 static inline void cpumask_xor(struct cpumask *dstp, 411 const struct cpumask *src1p, 412 const struct cpumask *src2p) 413 { 414 bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p), 415 cpumask_bits(src2p), nr_cpumask_bits); 416 } 417 418 /** 419 * cpumask_andnot - *dstp = *src1p & ~*src2p 420 * @dstp: the cpumask result 421 * @src1p: the first input 422 * @src2p: the second input 423 * 424 * If *@dstp is empty, returns 0, else returns 1 425 */ 426 static inline int cpumask_andnot(struct cpumask *dstp, 427 const struct cpumask *src1p, 428 const struct cpumask *src2p) 429 { 430 return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p), 431 cpumask_bits(src2p), nr_cpumask_bits); 432 } 433 434 /** 435 * cpumask_complement - *dstp = ~*srcp 436 * @dstp: the cpumask result 437 * @srcp: the input to invert 438 */ 439 static inline void cpumask_complement(struct cpumask *dstp, 440 const struct cpumask *srcp) 441 { 442 bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp), 443 nr_cpumask_bits); 444 } 445 446 /** 447 * cpumask_equal - *src1p == *src2p 448 * @src1p: the first input 449 * @src2p: the second input 450 */ 451 static inline bool cpumask_equal(const struct cpumask *src1p, 452 const struct cpumask *src2p) 453 { 454 return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p), 455 nr_cpumask_bits); 456 } 457 458 /** 459 * cpumask_intersects - (*src1p & *src2p) != 0 460 * @src1p: the first input 461 * @src2p: the second input 462 */ 463 static inline bool cpumask_intersects(const struct cpumask *src1p, 464 const struct cpumask *src2p) 465 { 466 return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p), 467 nr_cpumask_bits); 468 } 469 470 /** 471 * cpumask_subset - (*src1p & ~*src2p) == 0 472 * @src1p: the first input 473 * @src2p: the second input 474 * 475 * Returns 1 if *@src1p is a subset of *@src2p, else returns 0 476 */ 477 static inline int cpumask_subset(const struct cpumask *src1p, 478 const struct cpumask *src2p) 479 { 480 return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p), 481 nr_cpumask_bits); 482 } 483 484 /** 485 * cpumask_empty - *srcp == 0 486 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear. 487 */ 488 static inline bool cpumask_empty(const struct cpumask *srcp) 489 { 490 return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits); 491 } 492 493 /** 494 * cpumask_full - *srcp == 0xFFFFFFFF... 495 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set. 496 */ 497 static inline bool cpumask_full(const struct cpumask *srcp) 498 { 499 return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits); 500 } 501 502 /** 503 * cpumask_weight - Count of bits in *srcp 504 * @srcp: the cpumask to count bits (< nr_cpu_ids) in. 505 */ 506 static inline unsigned int cpumask_weight(const struct cpumask *srcp) 507 { 508 return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits); 509 } 510 511 /** 512 * cpumask_shift_right - *dstp = *srcp >> n 513 * @dstp: the cpumask result 514 * @srcp: the input to shift 515 * @n: the number of bits to shift by 516 */ 517 static inline void cpumask_shift_right(struct cpumask *dstp, 518 const struct cpumask *srcp, int n) 519 { 520 bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n, 521 nr_cpumask_bits); 522 } 523 524 /** 525 * cpumask_shift_left - *dstp = *srcp << n 526 * @dstp: the cpumask result 527 * @srcp: the input to shift 528 * @n: the number of bits to shift by 529 */ 530 static inline void cpumask_shift_left(struct cpumask *dstp, 531 const struct cpumask *srcp, int n) 532 { 533 bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n, 534 nr_cpumask_bits); 535 } 536 537 /** 538 * cpumask_copy - *dstp = *srcp 539 * @dstp: the result 540 * @srcp: the input cpumask 541 */ 542 static inline void cpumask_copy(struct cpumask *dstp, 543 const struct cpumask *srcp) 544 { 545 bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits); 546 } 547 548 /** 549 * cpumask_any - pick a "random" cpu from *srcp 550 * @srcp: the input cpumask 551 * 552 * Returns >= nr_cpu_ids if no cpus set. 553 */ 554 #define cpumask_any(srcp) cpumask_first(srcp) 555 556 /** 557 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2 558 * @src1p: the first input 559 * @src2p: the second input 560 * 561 * Returns >= nr_cpu_ids if no cpus set in both. See also cpumask_next_and(). 562 */ 563 #define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p)) 564 565 /** 566 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2 567 * @mask1: the first input cpumask 568 * @mask2: the second input cpumask 569 * 570 * Returns >= nr_cpu_ids if no cpus set. 571 */ 572 #define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2)) 573 574 /** 575 * cpumask_of - the cpumask containing just a given cpu 576 * @cpu: the cpu (<= nr_cpu_ids) 577 */ 578 #define cpumask_of(cpu) (get_cpu_mask(cpu)) 579 580 /** 581 * cpumask_parse_user - extract a cpumask from a user string 582 * @buf: the buffer to extract from 583 * @len: the length of the buffer 584 * @dstp: the cpumask to set. 585 * 586 * Returns -errno, or 0 for success. 587 */ 588 static inline int cpumask_parse_user(const char __user *buf, int len, 589 struct cpumask *dstp) 590 { 591 return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits); 592 } 593 594 /** 595 * cpumask_parselist_user - extract a cpumask from a user string 596 * @buf: the buffer to extract from 597 * @len: the length of the buffer 598 * @dstp: the cpumask to set. 599 * 600 * Returns -errno, or 0 for success. 601 */ 602 static inline int cpumask_parselist_user(const char __user *buf, int len, 603 struct cpumask *dstp) 604 { 605 return bitmap_parselist_user(buf, len, cpumask_bits(dstp), 606 nr_cpumask_bits); 607 } 608 609 /** 610 * cpumask_parse - extract a cpumask from a string 611 * @buf: the buffer to extract from 612 * @dstp: the cpumask to set. 613 * 614 * Returns -errno, or 0 for success. 615 */ 616 static inline int cpumask_parse(const char *buf, struct cpumask *dstp) 617 { 618 char *nl = strchr(buf, '\n'); 619 unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf); 620 621 return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits); 622 } 623 624 /** 625 * cpulist_parse - extract a cpumask from a user string of ranges 626 * @buf: the buffer to extract from 627 * @dstp: the cpumask to set. 628 * 629 * Returns -errno, or 0 for success. 630 */ 631 static inline int cpulist_parse(const char *buf, struct cpumask *dstp) 632 { 633 return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits); 634 } 635 636 /** 637 * cpumask_size - size to allocate for a 'struct cpumask' in bytes 638 */ 639 static inline size_t cpumask_size(void) 640 { 641 return BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long); 642 } 643 644 /* 645 * cpumask_var_t: struct cpumask for stack usage. 646 * 647 * Oh, the wicked games we play! In order to make kernel coding a 648 * little more difficult, we typedef cpumask_var_t to an array or a 649 * pointer: doing &mask on an array is a noop, so it still works. 650 * 651 * ie. 652 * cpumask_var_t tmpmask; 653 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) 654 * return -ENOMEM; 655 * 656 * ... use 'tmpmask' like a normal struct cpumask * ... 657 * 658 * free_cpumask_var(tmpmask); 659 * 660 * 661 * However, one notable exception is there. alloc_cpumask_var() allocates 662 * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has 663 * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t. 664 * 665 * cpumask_var_t tmpmask; 666 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) 667 * return -ENOMEM; 668 * 669 * var = *tmpmask; 670 * 671 * This code makes NR_CPUS length memcopy and brings to a memory corruption. 672 * cpumask_copy() provide safe copy functionality. 673 * 674 * Note that there is another evil here: If you define a cpumask_var_t 675 * as a percpu variable then the way to obtain the address of the cpumask 676 * structure differently influences what this_cpu_* operation needs to be 677 * used. Please use this_cpu_cpumask_var_t in those cases. The direct use 678 * of this_cpu_ptr() or this_cpu_read() will lead to failures when the 679 * other type of cpumask_var_t implementation is configured. 680 * 681 * Please also note that __cpumask_var_read_mostly can be used to declare 682 * a cpumask_var_t variable itself (not its content) as read mostly. 683 */ 684 #ifdef CONFIG_CPUMASK_OFFSTACK 685 typedef struct cpumask *cpumask_var_t; 686 687 #define this_cpu_cpumask_var_ptr(x) this_cpu_read(x) 688 #define __cpumask_var_read_mostly __read_mostly 689 690 bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node); 691 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags); 692 bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node); 693 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags); 694 void alloc_bootmem_cpumask_var(cpumask_var_t *mask); 695 void free_cpumask_var(cpumask_var_t mask); 696 void free_bootmem_cpumask_var(cpumask_var_t mask); 697 698 static inline bool cpumask_available(cpumask_var_t mask) 699 { 700 return mask != NULL; 701 } 702 703 #else 704 typedef struct cpumask cpumask_var_t[1]; 705 706 #define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x) 707 #define __cpumask_var_read_mostly 708 709 static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 710 { 711 return true; 712 } 713 714 static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, 715 int node) 716 { 717 return true; 718 } 719 720 static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 721 { 722 cpumask_clear(*mask); 723 return true; 724 } 725 726 static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, 727 int node) 728 { 729 cpumask_clear(*mask); 730 return true; 731 } 732 733 static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask) 734 { 735 } 736 737 static inline void free_cpumask_var(cpumask_var_t mask) 738 { 739 } 740 741 static inline void free_bootmem_cpumask_var(cpumask_var_t mask) 742 { 743 } 744 745 static inline bool cpumask_available(cpumask_var_t mask) 746 { 747 return true; 748 } 749 #endif /* CONFIG_CPUMASK_OFFSTACK */ 750 751 /* It's common to want to use cpu_all_mask in struct member initializers, 752 * so it has to refer to an address rather than a pointer. */ 753 extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS); 754 #define cpu_all_mask to_cpumask(cpu_all_bits) 755 756 /* First bits of cpu_bit_bitmap are in fact unset. */ 757 #define cpu_none_mask to_cpumask(cpu_bit_bitmap[0]) 758 759 #define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask) 760 #define for_each_online_cpu(cpu) for_each_cpu((cpu), cpu_online_mask) 761 #define for_each_present_cpu(cpu) for_each_cpu((cpu), cpu_present_mask) 762 763 /* Wrappers for arch boot code to manipulate normally-constant masks */ 764 void init_cpu_present(const struct cpumask *src); 765 void init_cpu_possible(const struct cpumask *src); 766 void init_cpu_online(const struct cpumask *src); 767 768 static inline void reset_cpu_possible_mask(void) 769 { 770 bitmap_zero(cpumask_bits(&__cpu_possible_mask), NR_CPUS); 771 } 772 773 static inline void 774 set_cpu_possible(unsigned int cpu, bool possible) 775 { 776 if (possible) 777 cpumask_set_cpu(cpu, &__cpu_possible_mask); 778 else 779 cpumask_clear_cpu(cpu, &__cpu_possible_mask); 780 } 781 782 static inline void 783 set_cpu_present(unsigned int cpu, bool present) 784 { 785 if (present) 786 cpumask_set_cpu(cpu, &__cpu_present_mask); 787 else 788 cpumask_clear_cpu(cpu, &__cpu_present_mask); 789 } 790 791 static inline void 792 set_cpu_online(unsigned int cpu, bool online) 793 { 794 if (online) 795 cpumask_set_cpu(cpu, &__cpu_online_mask); 796 else 797 cpumask_clear_cpu(cpu, &__cpu_online_mask); 798 } 799 800 static inline void 801 set_cpu_active(unsigned int cpu, bool active) 802 { 803 if (active) 804 cpumask_set_cpu(cpu, &__cpu_active_mask); 805 else 806 cpumask_clear_cpu(cpu, &__cpu_active_mask); 807 } 808 809 810 /** 811 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask * 812 * @bitmap: the bitmap 813 * 814 * There are a few places where cpumask_var_t isn't appropriate and 815 * static cpumasks must be used (eg. very early boot), yet we don't 816 * expose the definition of 'struct cpumask'. 817 * 818 * This does the conversion, and can be used as a constant initializer. 819 */ 820 #define to_cpumask(bitmap) \ 821 ((struct cpumask *)(1 ? (bitmap) \ 822 : (void *)sizeof(__check_is_bitmap(bitmap)))) 823 824 static inline int __check_is_bitmap(const unsigned long *bitmap) 825 { 826 return 1; 827 } 828 829 /* 830 * Special-case data structure for "single bit set only" constant CPU masks. 831 * 832 * We pre-generate all the 64 (or 32) possible bit positions, with enough 833 * padding to the left and the right, and return the constant pointer 834 * appropriately offset. 835 */ 836 extern const unsigned long 837 cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)]; 838 839 static inline const struct cpumask *get_cpu_mask(unsigned int cpu) 840 { 841 const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG]; 842 p -= cpu / BITS_PER_LONG; 843 return to_cpumask(p); 844 } 845 846 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) 847 848 #if NR_CPUS <= BITS_PER_LONG 849 #define CPU_BITS_ALL \ 850 { \ 851 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 852 } 853 854 #else /* NR_CPUS > BITS_PER_LONG */ 855 856 #define CPU_BITS_ALL \ 857 { \ 858 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 859 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 860 } 861 #endif /* NR_CPUS > BITS_PER_LONG */ 862 863 /** 864 * cpumap_print_to_pagebuf - copies the cpumask into the buffer either 865 * as comma-separated list of cpus or hex values of cpumask 866 * @list: indicates whether the cpumap must be list 867 * @mask: the cpumask to copy 868 * @buf: the buffer to copy into 869 * 870 * Returns the length of the (null-terminated) @buf string, zero if 871 * nothing is copied. 872 */ 873 static inline ssize_t 874 cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask) 875 { 876 return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask), 877 nr_cpu_ids); 878 } 879 880 #if NR_CPUS <= BITS_PER_LONG 881 #define CPU_MASK_ALL \ 882 (cpumask_t) { { \ 883 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 884 } } 885 #else 886 #define CPU_MASK_ALL \ 887 (cpumask_t) { { \ 888 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 889 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 890 } } 891 #endif /* NR_CPUS > BITS_PER_LONG */ 892 893 #define CPU_MASK_NONE \ 894 (cpumask_t) { { \ 895 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 896 } } 897 898 #define CPU_MASK_CPU0 \ 899 (cpumask_t) { { \ 900 [0] = 1UL \ 901 } } 902 903 #endif /* __LINUX_CPUMASK_H */ 904