linux/include/linux/cpumask.h
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   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
  14typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
  15
  16/**
  17 * cpumask_bits - get the bits in a cpumask
  18 * @maskp: the struct cpumask *
  19 *
  20 * You should only assume nr_cpu_ids bits of this mask are valid.  This is
  21 * a macro so it's const-correct.
  22 */
  23#define cpumask_bits(maskp) ((maskp)->bits)
  24
  25#if NR_CPUS == 1
  26#define nr_cpu_ids              1
  27#else
  28extern int nr_cpu_ids;
  29#endif
  30
  31#ifdef CONFIG_CPUMASK_OFFSTACK
  32/* Assuming NR_CPUS is huge, a runtime limit is more efficient.  Also,
  33 * not all bits may be allocated. */
  34#define nr_cpumask_bits nr_cpu_ids
  35#else
  36#define nr_cpumask_bits NR_CPUS
  37#endif
  38
  39/*
  40 * The following particular system cpumasks and operations manage
  41 * possible, present, active and online cpus.
  42 *
  43 *     cpu_possible_mask- has bit 'cpu' set iff cpu is populatable
  44 *     cpu_present_mask - has bit 'cpu' set iff cpu is populated
  45 *     cpu_online_mask  - has bit 'cpu' set iff cpu available to scheduler
  46 *     cpu_active_mask  - has bit 'cpu' set iff cpu available to migration
  47 *
  48 *  If !CONFIG_HOTPLUG_CPU, present == possible, and active == online.
  49 *
  50 *  The cpu_possible_mask is fixed at boot time, as the set of CPU id's
  51 *  that it is possible might ever be plugged in at anytime during the
  52 *  life of that system boot.  The cpu_present_mask is dynamic(*),
  53 *  representing which CPUs are currently plugged in.  And
  54 *  cpu_online_mask is the dynamic subset of cpu_present_mask,
  55 *  indicating those CPUs available for scheduling.
  56 *
  57 *  If HOTPLUG is enabled, then cpu_possible_mask is forced to have
  58 *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
  59 *  ACPI reports present at boot.
  60 *
  61 *  If HOTPLUG is enabled, then cpu_present_mask varies dynamically,
  62 *  depending on what ACPI reports as currently plugged in, otherwise
  63 *  cpu_present_mask is just a copy of cpu_possible_mask.
  64 *
  65 *  (*) Well, cpu_present_mask is dynamic in the hotplug case.  If not
  66 *      hotplug, it's a copy of cpu_possible_mask, hence fixed at boot.
  67 *
  68 * Subtleties:
  69 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
  70 *    assumption that their single CPU is online.  The UP
  71 *    cpu_{online,possible,present}_masks are placebos.  Changing them
  72 *    will have no useful affect on the following num_*_cpus()
  73 *    and cpu_*() macros in the UP case.  This ugliness is a UP
  74 *    optimization - don't waste any instructions or memory references
  75 *    asking if you're online or how many CPUs there are if there is
  76 *    only one CPU.
  77 */
  78
  79extern const struct cpumask *const cpu_possible_mask;
  80extern const struct cpumask *const cpu_online_mask;
  81extern const struct cpumask *const cpu_present_mask;
  82extern const struct cpumask *const cpu_active_mask;
  83
  84#if NR_CPUS > 1
  85#define num_online_cpus()       cpumask_weight(cpu_online_mask)
  86#define num_possible_cpus()     cpumask_weight(cpu_possible_mask)
  87#define num_present_cpus()      cpumask_weight(cpu_present_mask)
  88#define num_active_cpus()       cpumask_weight(cpu_active_mask)
  89#define cpu_online(cpu)         cpumask_test_cpu((cpu), cpu_online_mask)
  90#define cpu_possible(cpu)       cpumask_test_cpu((cpu), cpu_possible_mask)
  91#define cpu_present(cpu)        cpumask_test_cpu((cpu), cpu_present_mask)
  92#define cpu_active(cpu)         cpumask_test_cpu((cpu), cpu_active_mask)
  93#else
  94#define num_online_cpus()       1U
  95#define num_possible_cpus()     1U
  96#define num_present_cpus()      1U
  97#define num_active_cpus()       1U
  98#define cpu_online(cpu)         ((cpu) == 0)
  99#define cpu_possible(cpu)       ((cpu) == 0)
 100#define cpu_present(cpu)        ((cpu) == 0)
 101#define cpu_active(cpu)         ((cpu) == 0)
 102#endif
 103
 104/* verify cpu argument to cpumask_* operators */
 105static inline unsigned int cpumask_check(unsigned int cpu)
 106{
 107#ifdef CONFIG_DEBUG_PER_CPU_MAPS
 108        WARN_ON_ONCE(cpu >= nr_cpumask_bits);
 109#endif /* CONFIG_DEBUG_PER_CPU_MAPS */
 110        return cpu;
 111}
 112
 113#if NR_CPUS == 1
 114/* Uniprocessor.  Assume all masks are "1". */
 115static inline unsigned int cpumask_first(const struct cpumask *srcp)
 116{
 117        return 0;
 118}
 119
 120/* Valid inputs for n are -1 and 0. */
 121static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 122{
 123        return n+1;
 124}
 125
 126static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 127{
 128        return n+1;
 129}
 130
 131static inline unsigned int cpumask_next_and(int n,
 132                                            const struct cpumask *srcp,
 133                                            const struct cpumask *andp)
 134{
 135        return n+1;
 136}
 137
 138/* cpu must be a valid cpu, ie 0, so there's no other choice. */
 139static inline unsigned int cpumask_any_but(const struct cpumask *mask,
 140                                           unsigned int cpu)
 141{
 142        return 1;
 143}
 144
 145static inline int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp)
 146{
 147        set_bit(0, cpumask_bits(dstp));
 148
 149        return 0;
 150}
 151
 152#define for_each_cpu(cpu, mask)                 \
 153        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 154#define for_each_cpu_not(cpu, mask)             \
 155        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 156#define for_each_cpu_and(cpu, mask, and)        \
 157        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and)
 158#else
 159/**
 160 * cpumask_first - get the first cpu in a cpumask
 161 * @srcp: the cpumask pointer
 162 *
 163 * Returns >= nr_cpu_ids if no cpus set.
 164 */
 165static inline unsigned int cpumask_first(const struct cpumask *srcp)
 166{
 167        return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits);
 168}
 169
 170/**
 171 * cpumask_next - get the next cpu in a cpumask
 172 * @n: the cpu prior to the place to search (ie. return will be > @n)
 173 * @srcp: the cpumask pointer
 174 *
 175 * Returns >= nr_cpu_ids if no further cpus set.
 176 */
 177static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 178{
 179        /* -1 is a legal arg here. */
 180        if (n != -1)
 181                cpumask_check(n);
 182        return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 183}
 184
 185/**
 186 * cpumask_next_zero - get the next unset cpu in a cpumask
 187 * @n: the cpu prior to the place to search (ie. return will be > @n)
 188 * @srcp: the cpumask pointer
 189 *
 190 * Returns >= nr_cpu_ids if no further cpus unset.
 191 */
 192static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 193{
 194        /* -1 is a legal arg here. */
 195        if (n != -1)
 196                cpumask_check(n);
 197        return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 198}
 199
 200int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *);
 201int cpumask_any_but(const struct cpumask *mask, unsigned int cpu);
 202int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp);
 203
 204/**
 205 * for_each_cpu - iterate over every cpu in a mask
 206 * @cpu: the (optionally unsigned) integer iterator
 207 * @mask: the cpumask pointer
 208 *
 209 * After the loop, cpu is >= nr_cpu_ids.
 210 */
 211#define for_each_cpu(cpu, mask)                         \
 212        for ((cpu) = -1;                                \
 213                (cpu) = cpumask_next((cpu), (mask)),    \
 214                (cpu) < nr_cpu_ids;)
 215
 216/**
 217 * for_each_cpu_not - iterate over every cpu in a complemented mask
 218 * @cpu: the (optionally unsigned) integer iterator
 219 * @mask: the cpumask pointer
 220 *
 221 * After the loop, cpu is >= nr_cpu_ids.
 222 */
 223#define for_each_cpu_not(cpu, mask)                             \
 224        for ((cpu) = -1;                                        \
 225                (cpu) = cpumask_next_zero((cpu), (mask)),       \
 226                (cpu) < nr_cpu_ids;)
 227
 228/**
 229 * for_each_cpu_and - iterate over every cpu in both masks
 230 * @cpu: the (optionally unsigned) integer iterator
 231 * @mask: the first cpumask pointer
 232 * @and: the second cpumask pointer
 233 *
 234 * This saves a temporary CPU mask in many places.  It is equivalent to:
 235 *      struct cpumask tmp;
 236 *      cpumask_and(&tmp, &mask, &and);
 237 *      for_each_cpu(cpu, &tmp)
 238 *              ...
 239 *
 240 * After the loop, cpu is >= nr_cpu_ids.
 241 */
 242#define for_each_cpu_and(cpu, mask, and)                                \
 243        for ((cpu) = -1;                                                \
 244                (cpu) = cpumask_next_and((cpu), (mask), (and)),         \
 245                (cpu) < nr_cpu_ids;)
 246#endif /* SMP */
 247
 248#define CPU_BITS_NONE                                           \
 249{                                                               \
 250        [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL                  \
 251}
 252
 253#define CPU_BITS_CPU0                                           \
 254{                                                               \
 255        [0] =  1UL                                              \
 256}
 257
 258/**
 259 * cpumask_set_cpu - set a cpu in a cpumask
 260 * @cpu: cpu number (< nr_cpu_ids)
 261 * @dstp: the cpumask pointer
 262 */
 263static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
 264{
 265        set_bit(cpumask_check(cpu), cpumask_bits(dstp));
 266}
 267
 268/**
 269 * cpumask_clear_cpu - clear a cpu in a cpumask
 270 * @cpu: cpu number (< nr_cpu_ids)
 271 * @dstp: the cpumask pointer
 272 */
 273static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
 274{
 275        clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
 276}
 277
 278/**
 279 * cpumask_test_cpu - test for a cpu in a cpumask
 280 * @cpu: cpu number (< nr_cpu_ids)
 281 * @cpumask: the cpumask pointer
 282 *
 283 * Returns 1 if @cpu is set in @cpumask, else returns 0
 284 *
 285 * No static inline type checking - see Subtlety (1) above.
 286 */
 287#define cpumask_test_cpu(cpu, cpumask) \
 288        test_bit(cpumask_check(cpu), cpumask_bits((cpumask)))
 289
 290/**
 291 * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
 292 * @cpu: cpu number (< nr_cpu_ids)
 293 * @cpumask: the cpumask pointer
 294 *
 295 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
 296 *
 297 * test_and_set_bit wrapper for cpumasks.
 298 */
 299static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
 300{
 301        return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 302}
 303
 304/**
 305 * cpumask_test_and_clear_cpu - atomically test and clear 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 old bitmap of @cpumask, else returns 0
 310 *
 311 * test_and_clear_bit wrapper for cpumasks.
 312 */
 313static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
 314{
 315        return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 316}
 317
 318/**
 319 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask
 320 * @dstp: the cpumask pointer
 321 */
 322static inline void cpumask_setall(struct cpumask *dstp)
 323{
 324        bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits);
 325}
 326
 327/**
 328 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask
 329 * @dstp: the cpumask pointer
 330 */
 331static inline void cpumask_clear(struct cpumask *dstp)
 332{
 333        bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits);
 334}
 335
 336/**
 337 * cpumask_and - *dstp = *src1p & *src2p
 338 * @dstp: the cpumask result
 339 * @src1p: the first input
 340 * @src2p: the second input
 341 *
 342 * If *@dstp is empty, returns 0, else returns 1
 343 */
 344static inline int cpumask_and(struct cpumask *dstp,
 345                               const struct cpumask *src1p,
 346                               const struct cpumask *src2p)
 347{
 348        return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
 349                                       cpumask_bits(src2p), nr_cpumask_bits);
 350}
 351
 352/**
 353 * cpumask_or - *dstp = *src1p | *src2p
 354 * @dstp: the cpumask result
 355 * @src1p: the first input
 356 * @src2p: the second input
 357 */
 358static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
 359                              const struct cpumask *src2p)
 360{
 361        bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
 362                                      cpumask_bits(src2p), nr_cpumask_bits);
 363}
 364
 365/**
 366 * cpumask_xor - *dstp = *src1p ^ *src2p
 367 * @dstp: the cpumask result
 368 * @src1p: the first input
 369 * @src2p: the second input
 370 */
 371static inline void cpumask_xor(struct cpumask *dstp,
 372                               const struct cpumask *src1p,
 373                               const struct cpumask *src2p)
 374{
 375        bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
 376                                       cpumask_bits(src2p), nr_cpumask_bits);
 377}
 378
 379/**
 380 * cpumask_andnot - *dstp = *src1p & ~*src2p
 381 * @dstp: the cpumask result
 382 * @src1p: the first input
 383 * @src2p: the second input
 384 *
 385 * If *@dstp is empty, returns 0, else returns 1
 386 */
 387static inline int cpumask_andnot(struct cpumask *dstp,
 388                                  const struct cpumask *src1p,
 389                                  const struct cpumask *src2p)
 390{
 391        return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
 392                                          cpumask_bits(src2p), nr_cpumask_bits);
 393}
 394
 395/**
 396 * cpumask_complement - *dstp = ~*srcp
 397 * @dstp: the cpumask result
 398 * @srcp: the input to invert
 399 */
 400static inline void cpumask_complement(struct cpumask *dstp,
 401                                      const struct cpumask *srcp)
 402{
 403        bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp),
 404                                              nr_cpumask_bits);
 405}
 406
 407/**
 408 * cpumask_equal - *src1p == *src2p
 409 * @src1p: the first input
 410 * @src2p: the second input
 411 */
 412static inline bool cpumask_equal(const struct cpumask *src1p,
 413                                const struct cpumask *src2p)
 414{
 415        return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
 416                                                 nr_cpumask_bits);
 417}
 418
 419/**
 420 * cpumask_intersects - (*src1p & *src2p) != 0
 421 * @src1p: the first input
 422 * @src2p: the second input
 423 */
 424static inline bool cpumask_intersects(const struct cpumask *src1p,
 425                                     const struct cpumask *src2p)
 426{
 427        return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
 428                                                      nr_cpumask_bits);
 429}
 430
 431/**
 432 * cpumask_subset - (*src1p & ~*src2p) == 0
 433 * @src1p: the first input
 434 * @src2p: the second input
 435 *
 436 * Returns 1 if *@src1p is a subset of *@src2p, else returns 0
 437 */
 438static inline int cpumask_subset(const struct cpumask *src1p,
 439                                 const struct cpumask *src2p)
 440{
 441        return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
 442                                                  nr_cpumask_bits);
 443}
 444
 445/**
 446 * cpumask_empty - *srcp == 0
 447 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear.
 448 */
 449static inline bool cpumask_empty(const struct cpumask *srcp)
 450{
 451        return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits);
 452}
 453
 454/**
 455 * cpumask_full - *srcp == 0xFFFFFFFF...
 456 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set.
 457 */
 458static inline bool cpumask_full(const struct cpumask *srcp)
 459{
 460        return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
 461}
 462
 463/**
 464 * cpumask_weight - Count of bits in *srcp
 465 * @srcp: the cpumask to count bits (< nr_cpu_ids) in.
 466 */
 467static inline unsigned int cpumask_weight(const struct cpumask *srcp)
 468{
 469        return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits);
 470}
 471
 472/**
 473 * cpumask_shift_right - *dstp = *srcp >> n
 474 * @dstp: the cpumask result
 475 * @srcp: the input to shift
 476 * @n: the number of bits to shift by
 477 */
 478static inline void cpumask_shift_right(struct cpumask *dstp,
 479                                       const struct cpumask *srcp, int n)
 480{
 481        bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n,
 482                                               nr_cpumask_bits);
 483}
 484
 485/**
 486 * cpumask_shift_left - *dstp = *srcp << n
 487 * @dstp: the cpumask result
 488 * @srcp: the input to shift
 489 * @n: the number of bits to shift by
 490 */
 491static inline void cpumask_shift_left(struct cpumask *dstp,
 492                                      const struct cpumask *srcp, int n)
 493{
 494        bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n,
 495                                              nr_cpumask_bits);
 496}
 497
 498/**
 499 * cpumask_copy - *dstp = *srcp
 500 * @dstp: the result
 501 * @srcp: the input cpumask
 502 */
 503static inline void cpumask_copy(struct cpumask *dstp,
 504                                const struct cpumask *srcp)
 505{
 506        bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits);
 507}
 508
 509/**
 510 * cpumask_any - pick a "random" cpu from *srcp
 511 * @srcp: the input cpumask
 512 *
 513 * Returns >= nr_cpu_ids if no cpus set.
 514 */
 515#define cpumask_any(srcp) cpumask_first(srcp)
 516
 517/**
 518 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2
 519 * @src1p: the first input
 520 * @src2p: the second input
 521 *
 522 * Returns >= nr_cpu_ids if no cpus set in both.  See also cpumask_next_and().
 523 */
 524#define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
 525
 526/**
 527 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2
 528 * @mask1: the first input cpumask
 529 * @mask2: the second input cpumask
 530 *
 531 * Returns >= nr_cpu_ids if no cpus set.
 532 */
 533#define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2))
 534
 535/**
 536 * cpumask_of - the cpumask containing just a given cpu
 537 * @cpu: the cpu (<= nr_cpu_ids)
 538 */
 539#define cpumask_of(cpu) (get_cpu_mask(cpu))
 540
 541/**
 542 * cpumask_scnprintf - print a cpumask into a string as comma-separated hex
 543 * @buf: the buffer to sprintf into
 544 * @len: the length of the buffer
 545 * @srcp: the cpumask to print
 546 *
 547 * If len is zero, returns zero.  Otherwise returns the length of the
 548 * (nul-terminated) @buf string.
 549 */
 550static inline int cpumask_scnprintf(char *buf, int len,
 551                                    const struct cpumask *srcp)
 552{
 553        return bitmap_scnprintf(buf, len, cpumask_bits(srcp), nr_cpumask_bits);
 554}
 555
 556/**
 557 * cpumask_parse_user - extract a cpumask from a user string
 558 * @buf: the buffer to extract from
 559 * @len: the length of the buffer
 560 * @dstp: the cpumask to set.
 561 *
 562 * Returns -errno, or 0 for success.
 563 */
 564static inline int cpumask_parse_user(const char __user *buf, int len,
 565                                     struct cpumask *dstp)
 566{
 567        return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
 568}
 569
 570/**
 571 * cpumask_parselist_user - extract a cpumask from a user string
 572 * @buf: the buffer to extract from
 573 * @len: the length of the buffer
 574 * @dstp: the cpumask to set.
 575 *
 576 * Returns -errno, or 0 for success.
 577 */
 578static inline int cpumask_parselist_user(const char __user *buf, int len,
 579                                     struct cpumask *dstp)
 580{
 581        return bitmap_parselist_user(buf, len, cpumask_bits(dstp),
 582                                                        nr_cpumask_bits);
 583}
 584
 585/**
 586 * cpulist_scnprintf - print a cpumask into a string as comma-separated list
 587 * @buf: the buffer to sprintf into
 588 * @len: the length of the buffer
 589 * @srcp: the cpumask to print
 590 *
 591 * If len is zero, returns zero.  Otherwise returns the length of the
 592 * (nul-terminated) @buf string.
 593 */
 594static inline int cpulist_scnprintf(char *buf, int len,
 595                                    const struct cpumask *srcp)
 596{
 597        return bitmap_scnlistprintf(buf, len, cpumask_bits(srcp),
 598                                    nr_cpumask_bits);
 599}
 600
 601/**
 602 * cpumask_parse - extract a cpumask from from a string
 603 * @buf: the buffer to extract from
 604 * @dstp: the cpumask to set.
 605 *
 606 * Returns -errno, or 0 for success.
 607 */
 608static inline int cpumask_parse(const char *buf, struct cpumask *dstp)
 609{
 610        char *nl = strchr(buf, '\n');
 611        unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf);
 612
 613        return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
 614}
 615
 616/**
 617 * cpulist_parse - extract a cpumask from a user string of ranges
 618 * @buf: the buffer to extract from
 619 * @dstp: the cpumask to set.
 620 *
 621 * Returns -errno, or 0 for success.
 622 */
 623static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
 624{
 625        return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits);
 626}
 627
 628/**
 629 * cpumask_size - size to allocate for a 'struct cpumask' in bytes
 630 *
 631 * This will eventually be a runtime variable, depending on nr_cpu_ids.
 632 */
 633static inline size_t cpumask_size(void)
 634{
 635        /* FIXME: Once all cpumask assignments are eliminated, this
 636         * can be nr_cpumask_bits */
 637        return BITS_TO_LONGS(NR_CPUS) * sizeof(long);
 638}
 639
 640/*
 641 * cpumask_var_t: struct cpumask for stack usage.
 642 *
 643 * Oh, the wicked games we play!  In order to make kernel coding a
 644 * little more difficult, we typedef cpumask_var_t to an array or a
 645 * pointer: doing &mask on an array is a noop, so it still works.
 646 *
 647 * ie.
 648 *      cpumask_var_t tmpmask;
 649 *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
 650 *              return -ENOMEM;
 651 *
 652 *        ... use 'tmpmask' like a normal struct cpumask * ...
 653 *
 654 *      free_cpumask_var(tmpmask);
 655 *
 656 *
 657 * However, one notable exception is there. alloc_cpumask_var() allocates
 658 * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has
 659 * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t.
 660 *
 661 *      cpumask_var_t tmpmask;
 662 *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
 663 *              return -ENOMEM;
 664 *
 665 *      var = *tmpmask;
 666 *
 667 * This code makes NR_CPUS length memcopy and brings to a memory corruption.
 668 * cpumask_copy() provide safe copy functionality.
 669 *
 670 * Note that there is another evil here: If you define a cpumask_var_t
 671 * as a percpu variable then the way to obtain the address of the cpumask
 672 * structure differently influences what this_cpu_* operation needs to be
 673 * used. Please use this_cpu_cpumask_var_t in those cases. The direct use
 674 * of this_cpu_ptr() or this_cpu_read() will lead to failures when the
 675 * other type of cpumask_var_t implementation is configured.
 676 */
 677#ifdef CONFIG_CPUMASK_OFFSTACK
 678typedef struct cpumask *cpumask_var_t;
 679
 680#define this_cpu_cpumask_var_ptr(x) this_cpu_read(x)
 681
 682bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
 683bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
 684bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
 685bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
 686void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
 687void free_cpumask_var(cpumask_var_t mask);
 688void free_bootmem_cpumask_var(cpumask_var_t mask);
 689
 690#else
 691typedef struct cpumask cpumask_var_t[1];
 692
 693#define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x)
 694
 695static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
 696{
 697        return true;
 698}
 699
 700static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
 701                                          int node)
 702{
 703        return true;
 704}
 705
 706static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
 707{
 708        cpumask_clear(*mask);
 709        return true;
 710}
 711
 712static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
 713                                          int node)
 714{
 715        cpumask_clear(*mask);
 716        return true;
 717}
 718
 719static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask)
 720{
 721}
 722
 723static inline void free_cpumask_var(cpumask_var_t mask)
 724{
 725}
 726
 727static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
 728{
 729}
 730#endif /* CONFIG_CPUMASK_OFFSTACK */
 731
 732/* It's common to want to use cpu_all_mask in struct member initializers,
 733 * so it has to refer to an address rather than a pointer. */
 734extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
 735#define cpu_all_mask to_cpumask(cpu_all_bits)
 736
 737/* First bits of cpu_bit_bitmap are in fact unset. */
 738#define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
 739
 740#define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask)
 741#define for_each_online_cpu(cpu)   for_each_cpu((cpu), cpu_online_mask)
 742#define for_each_present_cpu(cpu)  for_each_cpu((cpu), cpu_present_mask)
 743
 744/* Wrappers for arch boot code to manipulate normally-constant masks */
 745void set_cpu_possible(unsigned int cpu, bool possible);
 746void set_cpu_present(unsigned int cpu, bool present);
 747void set_cpu_online(unsigned int cpu, bool online);
 748void set_cpu_active(unsigned int cpu, bool active);
 749void init_cpu_present(const struct cpumask *src);
 750void init_cpu_possible(const struct cpumask *src);
 751void init_cpu_online(const struct cpumask *src);
 752
 753/**
 754 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *
 755 * @bitmap: the bitmap
 756 *
 757 * There are a few places where cpumask_var_t isn't appropriate and
 758 * static cpumasks must be used (eg. very early boot), yet we don't
 759 * expose the definition of 'struct cpumask'.
 760 *
 761 * This does the conversion, and can be used as a constant initializer.
 762 */
 763#define to_cpumask(bitmap)                                              \
 764        ((struct cpumask *)(1 ? (bitmap)                                \
 765                            : (void *)sizeof(__check_is_bitmap(bitmap))))
 766
 767static inline int __check_is_bitmap(const unsigned long *bitmap)
 768{
 769        return 1;
 770}
 771
 772/*
 773 * Special-case data structure for "single bit set only" constant CPU masks.
 774 *
 775 * We pre-generate all the 64 (or 32) possible bit positions, with enough
 776 * padding to the left and the right, and return the constant pointer
 777 * appropriately offset.
 778 */
 779extern const unsigned long
 780        cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
 781
 782static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
 783{
 784        const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
 785        p -= cpu / BITS_PER_LONG;
 786        return to_cpumask(p);
 787}
 788
 789#define cpu_is_offline(cpu)     unlikely(!cpu_online(cpu))
 790
 791#if NR_CPUS <= BITS_PER_LONG
 792#define CPU_BITS_ALL                                            \
 793{                                                               \
 794        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \
 795}
 796
 797#else /* NR_CPUS > BITS_PER_LONG */
 798
 799#define CPU_BITS_ALL                                            \
 800{                                                               \
 801        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                \
 802        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD         \
 803}
 804#endif /* NR_CPUS > BITS_PER_LONG */
 805
 806/**
 807 * cpumap_print_to_pagebuf  - copies the cpumask into the buffer either
 808 *      as comma-separated list of cpus or hex values of cpumask
 809 * @list: indicates whether the cpumap must be list
 810 * @mask: the cpumask to copy
 811 * @buf: the buffer to copy into
 812 *
 813 * Returns the length of the (null-terminated) @buf string, zero if
 814 * nothing is copied.
 815 */
 816static inline ssize_t
 817cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
 818{
 819        return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask),
 820                                      nr_cpumask_bits);
 821}
 822
 823/*
 824 *
 825 * From here down, all obsolete.  Use cpumask_ variants!
 826 *
 827 */
 828#ifndef CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
 829#define cpumask_of_cpu(cpu) (*get_cpu_mask(cpu))
 830
 831#define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
 832
 833#if NR_CPUS <= BITS_PER_LONG
 834
 835#define CPU_MASK_ALL                                                    \
 836(cpumask_t) { {                                                         \
 837        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 838} }
 839
 840#else
 841
 842#define CPU_MASK_ALL                                                    \
 843(cpumask_t) { {                                                         \
 844        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                        \
 845        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 846} }
 847
 848#endif
 849
 850#define CPU_MASK_NONE                                                   \
 851(cpumask_t) { {                                                         \
 852        [0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL                         \
 853} }
 854
 855#define CPU_MASK_CPU0                                                   \
 856(cpumask_t) { {                                                         \
 857        [0] =  1UL                                                      \
 858} }
 859
 860#if NR_CPUS == 1
 861#define first_cpu(src)          ({ (void)(src); 0; })
 862#define next_cpu(n, src)        ({ (void)(src); 1; })
 863#define any_online_cpu(mask)    0
 864#define for_each_cpu_mask(cpu, mask)    \
 865        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 866#else /* NR_CPUS > 1 */
 867int __first_cpu(const cpumask_t *srcp);
 868int __next_cpu(int n, const cpumask_t *srcp);
 869
 870#define first_cpu(src)          __first_cpu(&(src))
 871#define next_cpu(n, src)        __next_cpu((n), &(src))
 872#define any_online_cpu(mask) cpumask_any_and(&mask, cpu_online_mask)
 873#define for_each_cpu_mask(cpu, mask)                    \
 874        for ((cpu) = -1;                                \
 875                (cpu) = next_cpu((cpu), (mask)),        \
 876                (cpu) < NR_CPUS; )
 877#endif /* SMP */
 878
 879#if NR_CPUS <= 64
 880
 881#define for_each_cpu_mask_nr(cpu, mask) for_each_cpu_mask(cpu, mask)
 882
 883#else /* NR_CPUS > 64 */
 884
 885int __next_cpu_nr(int n, const cpumask_t *srcp);
 886#define for_each_cpu_mask_nr(cpu, mask)                 \
 887        for ((cpu) = -1;                                \
 888                (cpu) = __next_cpu_nr((cpu), &(mask)),  \
 889                (cpu) < nr_cpu_ids; )
 890
 891#endif /* NR_CPUS > 64 */
 892
 893#define cpus_addr(src) ((src).bits)
 894
 895#define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
 896static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
 897{
 898        set_bit(cpu, dstp->bits);
 899}
 900
 901#define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
 902static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
 903{
 904        clear_bit(cpu, dstp->bits);
 905}
 906
 907#define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
 908static inline void __cpus_setall(cpumask_t *dstp, int nbits)
 909{
 910        bitmap_fill(dstp->bits, nbits);
 911}
 912
 913#define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
 914static inline void __cpus_clear(cpumask_t *dstp, int nbits)
 915{
 916        bitmap_zero(dstp->bits, nbits);
 917}
 918
 919/* No static inline type checking - see Subtlety (1) above. */
 920#define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)
 921
 922#define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
 923static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
 924{
 925        return test_and_set_bit(cpu, addr->bits);
 926}
 927
 928#define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
 929static inline int __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
 930                                        const cpumask_t *src2p, int nbits)
 931{
 932        return bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
 933}
 934
 935#define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
 936static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
 937                                        const cpumask_t *src2p, int nbits)
 938{
 939        bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
 940}
 941
 942#define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
 943static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
 944                                        const cpumask_t *src2p, int nbits)
 945{
 946        bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
 947}
 948
 949#define cpus_andnot(dst, src1, src2) \
 950                                __cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
 951static inline int __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
 952                                        const cpumask_t *src2p, int nbits)
 953{
 954        return bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
 955}
 956
 957#define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
 958static inline int __cpus_equal(const cpumask_t *src1p,
 959                                        const cpumask_t *src2p, int nbits)
 960{
 961        return bitmap_equal(src1p->bits, src2p->bits, nbits);
 962}
 963
 964#define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
 965static inline int __cpus_intersects(const cpumask_t *src1p,
 966                                        const cpumask_t *src2p, int nbits)
 967{
 968        return bitmap_intersects(src1p->bits, src2p->bits, nbits);
 969}
 970
 971#define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
 972static inline int __cpus_subset(const cpumask_t *src1p,
 973                                        const cpumask_t *src2p, int nbits)
 974{
 975        return bitmap_subset(src1p->bits, src2p->bits, nbits);
 976}
 977
 978#define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
 979static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
 980{
 981        return bitmap_empty(srcp->bits, nbits);
 982}
 983
 984#define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
 985static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
 986{
 987        return bitmap_weight(srcp->bits, nbits);
 988}
 989
 990#define cpus_shift_left(dst, src, n) \
 991                        __cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
 992static inline void __cpus_shift_left(cpumask_t *dstp,
 993                                        const cpumask_t *srcp, int n, int nbits)
 994{
 995        bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
 996}
 997#endif /* !CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS */
 998
 999#endif /* __LINUX_CPUMASK_H */
1000
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