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 1U 36 #else 37 extern unsigned 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 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 unsigned int cpumask_next(int n, const struct cpumask *srcp); 182 183 /** 184 * cpumask_next_zero - get the next unset cpu in a cpumask 185 * @n: the cpu prior to the place to search (ie. return will be > @n) 186 * @srcp: the cpumask pointer 187 * 188 * Returns >= nr_cpu_ids if no further cpus unset. 189 */ 190 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp) 191 { 192 /* -1 is a legal arg here. */ 193 if (n != -1) 194 cpumask_check(n); 195 return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1); 196 } 197 198 int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *); 199 int cpumask_any_but(const struct cpumask *mask, unsigned int cpu); 200 unsigned int cpumask_local_spread(unsigned int i, int node); 201 202 /** 203 * for_each_cpu - iterate over every cpu in a mask 204 * @cpu: the (optionally unsigned) integer iterator 205 * @mask: the cpumask pointer 206 * 207 * After the loop, cpu is >= nr_cpu_ids. 208 */ 209 #define for_each_cpu(cpu, mask) \ 210 for ((cpu) = -1; \ 211 (cpu) = cpumask_next((cpu), (mask)), \ 212 (cpu) < nr_cpu_ids;) 213 214 /** 215 * for_each_cpu_not - iterate over every cpu in a complemented mask 216 * @cpu: the (optionally unsigned) integer iterator 217 * @mask: the cpumask pointer 218 * 219 * After the loop, cpu is >= nr_cpu_ids. 220 */ 221 #define for_each_cpu_not(cpu, mask) \ 222 for ((cpu) = -1; \ 223 (cpu) = cpumask_next_zero((cpu), (mask)), \ 224 (cpu) < nr_cpu_ids;) 225 226 extern int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap); 227 228 /** 229 * for_each_cpu_wrap - iterate over every cpu in a mask, starting at a specified location 230 * @cpu: the (optionally unsigned) integer iterator 231 * @mask: the cpumask poiter 232 * @start: the start location 233 * 234 * The implementation does not assume any bit in @mask is set (including @start). 235 * 236 * After the loop, cpu is >= nr_cpu_ids. 237 */ 238 #define for_each_cpu_wrap(cpu, mask, start) \ 239 for ((cpu) = cpumask_next_wrap((start)-1, (mask), (start), false); \ 240 (cpu) < nr_cpumask_bits; \ 241 (cpu) = cpumask_next_wrap((cpu), (mask), (start), true)) 242 243 /** 244 * for_each_cpu_and - iterate over every cpu in both masks 245 * @cpu: the (optionally unsigned) integer iterator 246 * @mask: the first cpumask pointer 247 * @and: the second cpumask pointer 248 * 249 * This saves a temporary CPU mask in many places. It is equivalent to: 250 * struct cpumask tmp; 251 * cpumask_and(&tmp, &mask, &and); 252 * for_each_cpu(cpu, &tmp) 253 * ... 254 * 255 * After the loop, cpu is >= nr_cpu_ids. 256 */ 257 #define for_each_cpu_and(cpu, mask, and) \ 258 for ((cpu) = -1; \ 259 (cpu) = cpumask_next_and((cpu), (mask), (and)), \ 260 (cpu) < nr_cpu_ids;) 261 #endif /* SMP */ 262 263 #define CPU_BITS_NONE \ 264 { \ 265 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 266 } 267 268 #define CPU_BITS_CPU0 \ 269 { \ 270 [0] = 1UL \ 271 } 272 273 /** 274 * cpumask_set_cpu - set a cpu in a cpumask 275 * @cpu: cpu number (< nr_cpu_ids) 276 * @dstp: the cpumask pointer 277 */ 278 static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp) 279 { 280 set_bit(cpumask_check(cpu), cpumask_bits(dstp)); 281 } 282 283 static inline void __cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp) 284 { 285 __set_bit(cpumask_check(cpu), cpumask_bits(dstp)); 286 } 287 288 289 /** 290 * cpumask_clear_cpu - clear a cpu in a cpumask 291 * @cpu: cpu number (< nr_cpu_ids) 292 * @dstp: the cpumask pointer 293 */ 294 static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp) 295 { 296 clear_bit(cpumask_check(cpu), cpumask_bits(dstp)); 297 } 298 299 static inline void __cpumask_clear_cpu(int cpu, struct cpumask *dstp) 300 { 301 __clear_bit(cpumask_check(cpu), cpumask_bits(dstp)); 302 } 303 304 /** 305 * cpumask_test_cpu - test for a cpu in a cpumask 306 * @cpu: cpu number (< nr_cpu_ids) 307 * @cpumask: the cpumask pointer 308 * 309 * Returns 1 if @cpu is set in @cpumask, else returns 0 310 */ 311 static inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask) 312 { 313 return test_bit(cpumask_check(cpu), cpumask_bits((cpumask))); 314 } 315 316 /** 317 * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask 318 * @cpu: cpu number (< nr_cpu_ids) 319 * @cpumask: the cpumask pointer 320 * 321 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0 322 * 323 * test_and_set_bit wrapper for cpumasks. 324 */ 325 static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask) 326 { 327 return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask)); 328 } 329 330 /** 331 * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask 332 * @cpu: cpu number (< nr_cpu_ids) 333 * @cpumask: the cpumask pointer 334 * 335 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0 336 * 337 * test_and_clear_bit wrapper for cpumasks. 338 */ 339 static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask) 340 { 341 return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask)); 342 } 343 344 /** 345 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask 346 * @dstp: the cpumask pointer 347 */ 348 static inline void cpumask_setall(struct cpumask *dstp) 349 { 350 bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits); 351 } 352 353 /** 354 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask 355 * @dstp: the cpumask pointer 356 */ 357 static inline void cpumask_clear(struct cpumask *dstp) 358 { 359 bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits); 360 } 361 362 /** 363 * cpumask_and - *dstp = *src1p & *src2p 364 * @dstp: the cpumask result 365 * @src1p: the first input 366 * @src2p: the second input 367 * 368 * If *@dstp is empty, returns 0, else returns 1 369 */ 370 static inline int cpumask_and(struct cpumask *dstp, 371 const struct cpumask *src1p, 372 const struct cpumask *src2p) 373 { 374 return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p), 375 cpumask_bits(src2p), nr_cpumask_bits); 376 } 377 378 /** 379 * cpumask_or - *dstp = *src1p | *src2p 380 * @dstp: the cpumask result 381 * @src1p: the first input 382 * @src2p: the second input 383 */ 384 static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p, 385 const struct cpumask *src2p) 386 { 387 bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p), 388 cpumask_bits(src2p), nr_cpumask_bits); 389 } 390 391 /** 392 * cpumask_xor - *dstp = *src1p ^ *src2p 393 * @dstp: the cpumask result 394 * @src1p: the first input 395 * @src2p: the second input 396 */ 397 static inline void cpumask_xor(struct cpumask *dstp, 398 const struct cpumask *src1p, 399 const struct cpumask *src2p) 400 { 401 bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p), 402 cpumask_bits(src2p), nr_cpumask_bits); 403 } 404 405 /** 406 * cpumask_andnot - *dstp = *src1p & ~*src2p 407 * @dstp: the cpumask result 408 * @src1p: the first input 409 * @src2p: the second input 410 * 411 * If *@dstp is empty, returns 0, else returns 1 412 */ 413 static inline int cpumask_andnot(struct cpumask *dstp, 414 const struct cpumask *src1p, 415 const struct cpumask *src2p) 416 { 417 return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p), 418 cpumask_bits(src2p), nr_cpumask_bits); 419 } 420 421 /** 422 * cpumask_complement - *dstp = ~*srcp 423 * @dstp: the cpumask result 424 * @srcp: the input to invert 425 */ 426 static inline void cpumask_complement(struct cpumask *dstp, 427 const struct cpumask *srcp) 428 { 429 bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp), 430 nr_cpumask_bits); 431 } 432 433 /** 434 * cpumask_equal - *src1p == *src2p 435 * @src1p: the first input 436 * @src2p: the second input 437 */ 438 static inline bool cpumask_equal(const struct cpumask *src1p, 439 const struct cpumask *src2p) 440 { 441 return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p), 442 nr_cpumask_bits); 443 } 444 445 /** 446 * cpumask_intersects - (*src1p & *src2p) != 0 447 * @src1p: the first input 448 * @src2p: the second input 449 */ 450 static inline bool cpumask_intersects(const struct cpumask *src1p, 451 const struct cpumask *src2p) 452 { 453 return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p), 454 nr_cpumask_bits); 455 } 456 457 /** 458 * cpumask_subset - (*src1p & ~*src2p) == 0 459 * @src1p: the first input 460 * @src2p: the second input 461 * 462 * Returns 1 if *@src1p is a subset of *@src2p, else returns 0 463 */ 464 static inline int cpumask_subset(const struct cpumask *src1p, 465 const struct cpumask *src2p) 466 { 467 return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p), 468 nr_cpumask_bits); 469 } 470 471 /** 472 * cpumask_empty - *srcp == 0 473 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear. 474 */ 475 static inline bool cpumask_empty(const struct cpumask *srcp) 476 { 477 return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits); 478 } 479 480 /** 481 * cpumask_full - *srcp == 0xFFFFFFFF... 482 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set. 483 */ 484 static inline bool cpumask_full(const struct cpumask *srcp) 485 { 486 return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits); 487 } 488 489 /** 490 * cpumask_weight - Count of bits in *srcp 491 * @srcp: the cpumask to count bits (< nr_cpu_ids) in. 492 */ 493 static inline unsigned int cpumask_weight(const struct cpumask *srcp) 494 { 495 return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits); 496 } 497 498 /** 499 * cpumask_shift_right - *dstp = *srcp >> n 500 * @dstp: the cpumask result 501 * @srcp: the input to shift 502 * @n: the number of bits to shift by 503 */ 504 static inline void cpumask_shift_right(struct cpumask *dstp, 505 const struct cpumask *srcp, int n) 506 { 507 bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n, 508 nr_cpumask_bits); 509 } 510 511 /** 512 * cpumask_shift_left - *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_left(struct cpumask *dstp, 518 const struct cpumask *srcp, int n) 519 { 520 bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n, 521 nr_cpumask_bits); 522 } 523 524 /** 525 * cpumask_copy - *dstp = *srcp 526 * @dstp: the result 527 * @srcp: the input cpumask 528 */ 529 static inline void cpumask_copy(struct cpumask *dstp, 530 const struct cpumask *srcp) 531 { 532 bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits); 533 } 534 535 /** 536 * cpumask_any - pick a "random" cpu from *srcp 537 * @srcp: the input cpumask 538 * 539 * Returns >= nr_cpu_ids if no cpus set. 540 */ 541 #define cpumask_any(srcp) cpumask_first(srcp) 542 543 /** 544 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2 545 * @src1p: the first input 546 * @src2p: the second input 547 * 548 * Returns >= nr_cpu_ids if no cpus set in both. See also cpumask_next_and(). 549 */ 550 #define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p)) 551 552 /** 553 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2 554 * @mask1: the first input cpumask 555 * @mask2: the second input cpumask 556 * 557 * Returns >= nr_cpu_ids if no cpus set. 558 */ 559 #define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2)) 560 561 /** 562 * cpumask_of - the cpumask containing just a given cpu 563 * @cpu: the cpu (<= nr_cpu_ids) 564 */ 565 #define cpumask_of(cpu) (get_cpu_mask(cpu)) 566 567 /** 568 * cpumask_parse_user - extract a cpumask from a user string 569 * @buf: the buffer to extract from 570 * @len: the length of the buffer 571 * @dstp: the cpumask to set. 572 * 573 * Returns -errno, or 0 for success. 574 */ 575 static inline int cpumask_parse_user(const char __user *buf, int len, 576 struct cpumask *dstp) 577 { 578 return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits); 579 } 580 581 /** 582 * cpumask_parselist_user - extract a cpumask from a user string 583 * @buf: the buffer to extract from 584 * @len: the length of the buffer 585 * @dstp: the cpumask to set. 586 * 587 * Returns -errno, or 0 for success. 588 */ 589 static inline int cpumask_parselist_user(const char __user *buf, int len, 590 struct cpumask *dstp) 591 { 592 return bitmap_parselist_user(buf, len, cpumask_bits(dstp), 593 nr_cpumask_bits); 594 } 595 596 /** 597 * cpumask_parse - extract a cpumask from a string 598 * @buf: the buffer to extract from 599 * @dstp: the cpumask to set. 600 * 601 * Returns -errno, or 0 for success. 602 */ 603 static inline int cpumask_parse(const char *buf, struct cpumask *dstp) 604 { 605 char *nl = strchr(buf, '\n'); 606 unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf); 607 608 return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits); 609 } 610 611 /** 612 * cpulist_parse - extract a cpumask from a user string of ranges 613 * @buf: the buffer to extract from 614 * @dstp: the cpumask to set. 615 * 616 * Returns -errno, or 0 for success. 617 */ 618 static inline int cpulist_parse(const char *buf, struct cpumask *dstp) 619 { 620 return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits); 621 } 622 623 /** 624 * cpumask_size - size to allocate for a 'struct cpumask' in bytes 625 */ 626 static inline size_t cpumask_size(void) 627 { 628 return BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long); 629 } 630 631 /* 632 * cpumask_var_t: struct cpumask for stack usage. 633 * 634 * Oh, the wicked games we play! In order to make kernel coding a 635 * little more difficult, we typedef cpumask_var_t to an array or a 636 * pointer: doing &mask on an array is a noop, so it still works. 637 * 638 * ie. 639 * cpumask_var_t tmpmask; 640 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) 641 * return -ENOMEM; 642 * 643 * ... use 'tmpmask' like a normal struct cpumask * ... 644 * 645 * free_cpumask_var(tmpmask); 646 * 647 * 648 * However, one notable exception is there. alloc_cpumask_var() allocates 649 * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has 650 * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t. 651 * 652 * cpumask_var_t tmpmask; 653 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) 654 * return -ENOMEM; 655 * 656 * var = *tmpmask; 657 * 658 * This code makes NR_CPUS length memcopy and brings to a memory corruption. 659 * cpumask_copy() provide safe copy functionality. 660 * 661 * Note that there is another evil here: If you define a cpumask_var_t 662 * as a percpu variable then the way to obtain the address of the cpumask 663 * structure differently influences what this_cpu_* operation needs to be 664 * used. Please use this_cpu_cpumask_var_t in those cases. The direct use 665 * of this_cpu_ptr() or this_cpu_read() will lead to failures when the 666 * other type of cpumask_var_t implementation is configured. 667 * 668 * Please also note that __cpumask_var_read_mostly can be used to declare 669 * a cpumask_var_t variable itself (not its content) as read mostly. 670 */ 671 #ifdef CONFIG_CPUMASK_OFFSTACK 672 typedef struct cpumask *cpumask_var_t; 673 674 #define this_cpu_cpumask_var_ptr(x) this_cpu_read(x) 675 #define __cpumask_var_read_mostly __read_mostly 676 677 bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node); 678 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags); 679 bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node); 680 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags); 681 void alloc_bootmem_cpumask_var(cpumask_var_t *mask); 682 void free_cpumask_var(cpumask_var_t mask); 683 void free_bootmem_cpumask_var(cpumask_var_t mask); 684 685 static inline bool cpumask_available(cpumask_var_t mask) 686 { 687 return mask != NULL; 688 } 689 690 #else 691 typedef struct cpumask cpumask_var_t[1]; 692 693 #define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x) 694 #define __cpumask_var_read_mostly 695 696 static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 697 { 698 return true; 699 } 700 701 static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, 702 int node) 703 { 704 return true; 705 } 706 707 static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 708 { 709 cpumask_clear(*mask); 710 return true; 711 } 712 713 static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, 714 int node) 715 { 716 cpumask_clear(*mask); 717 return true; 718 } 719 720 static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask) 721 { 722 } 723 724 static inline void free_cpumask_var(cpumask_var_t mask) 725 { 726 } 727 728 static inline void free_bootmem_cpumask_var(cpumask_var_t mask) 729 { 730 } 731 732 static inline bool cpumask_available(cpumask_var_t mask) 733 { 734 return true; 735 } 736 #endif /* CONFIG_CPUMASK_OFFSTACK */ 737 738 /* It's common to want to use cpu_all_mask in struct member initializers, 739 * so it has to refer to an address rather than a pointer. */ 740 extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS); 741 #define cpu_all_mask to_cpumask(cpu_all_bits) 742 743 /* First bits of cpu_bit_bitmap are in fact unset. */ 744 #define cpu_none_mask to_cpumask(cpu_bit_bitmap[0]) 745 746 #define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask) 747 #define for_each_online_cpu(cpu) for_each_cpu((cpu), cpu_online_mask) 748 #define for_each_present_cpu(cpu) for_each_cpu((cpu), cpu_present_mask) 749 750 /* Wrappers for arch boot code to manipulate normally-constant masks */ 751 void init_cpu_present(const struct cpumask *src); 752 void init_cpu_possible(const struct cpumask *src); 753 void init_cpu_online(const struct cpumask *src); 754 755 static inline void reset_cpu_possible_mask(void) 756 { 757 bitmap_zero(cpumask_bits(&__cpu_possible_mask), NR_CPUS); 758 } 759 760 static inline void 761 set_cpu_possible(unsigned int cpu, bool possible) 762 { 763 if (possible) 764 cpumask_set_cpu(cpu, &__cpu_possible_mask); 765 else 766 cpumask_clear_cpu(cpu, &__cpu_possible_mask); 767 } 768 769 static inline void 770 set_cpu_present(unsigned int cpu, bool present) 771 { 772 if (present) 773 cpumask_set_cpu(cpu, &__cpu_present_mask); 774 else 775 cpumask_clear_cpu(cpu, &__cpu_present_mask); 776 } 777 778 static inline void 779 set_cpu_online(unsigned int cpu, bool online) 780 { 781 if (online) 782 cpumask_set_cpu(cpu, &__cpu_online_mask); 783 else 784 cpumask_clear_cpu(cpu, &__cpu_online_mask); 785 } 786 787 static inline void 788 set_cpu_active(unsigned int cpu, bool active) 789 { 790 if (active) 791 cpumask_set_cpu(cpu, &__cpu_active_mask); 792 else 793 cpumask_clear_cpu(cpu, &__cpu_active_mask); 794 } 795 796 797 /** 798 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask * 799 * @bitmap: the bitmap 800 * 801 * There are a few places where cpumask_var_t isn't appropriate and 802 * static cpumasks must be used (eg. very early boot), yet we don't 803 * expose the definition of 'struct cpumask'. 804 * 805 * This does the conversion, and can be used as a constant initializer. 806 */ 807 #define to_cpumask(bitmap) \ 808 ((struct cpumask *)(1 ? (bitmap) \ 809 : (void *)sizeof(__check_is_bitmap(bitmap)))) 810 811 static inline int __check_is_bitmap(const unsigned long *bitmap) 812 { 813 return 1; 814 } 815 816 /* 817 * Special-case data structure for "single bit set only" constant CPU masks. 818 * 819 * We pre-generate all the 64 (or 32) possible bit positions, with enough 820 * padding to the left and the right, and return the constant pointer 821 * appropriately offset. 822 */ 823 extern const unsigned long 824 cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)]; 825 826 static inline const struct cpumask *get_cpu_mask(unsigned int cpu) 827 { 828 const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG]; 829 p -= cpu / BITS_PER_LONG; 830 return to_cpumask(p); 831 } 832 833 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) 834 835 #if NR_CPUS <= BITS_PER_LONG 836 #define CPU_BITS_ALL \ 837 { \ 838 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 839 } 840 841 #else /* NR_CPUS > BITS_PER_LONG */ 842 843 #define CPU_BITS_ALL \ 844 { \ 845 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 846 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 847 } 848 #endif /* NR_CPUS > BITS_PER_LONG */ 849 850 /** 851 * cpumap_print_to_pagebuf - copies the cpumask into the buffer either 852 * as comma-separated list of cpus or hex values of cpumask 853 * @list: indicates whether the cpumap must be list 854 * @mask: the cpumask to copy 855 * @buf: the buffer to copy into 856 * 857 * Returns the length of the (null-terminated) @buf string, zero if 858 * nothing is copied. 859 */ 860 static inline ssize_t 861 cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask) 862 { 863 return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask), 864 nr_cpu_ids); 865 } 866 867 #if NR_CPUS <= BITS_PER_LONG 868 #define CPU_MASK_ALL \ 869 (cpumask_t) { { \ 870 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 871 } } 872 #else 873 #define CPU_MASK_ALL \ 874 (cpumask_t) { { \ 875 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 876 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 877 } } 878 #endif /* NR_CPUS > BITS_PER_LONG */ 879 880 #define CPU_MASK_NONE \ 881 (cpumask_t) { { \ 882 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 883 } } 884 885 #define CPU_MASK_CPU0 \ 886 (cpumask_t) { { \ 887 [0] = 1UL \ 888 } } 889 890 #endif /* __LINUX_CPUMASK_H */ 891