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.
   7 *
   8 * The new cpumask_ ops take a "struct cpumask *"; the old ones
   9 * use cpumask_t.
  10 *
  11 * See detailed comments in the file linux/bitmap.h describing the
  12 * data type on which these cpumasks are based.
  13 *
  14 * For details of cpumask_scnprintf() and cpumask_parse_user(),
  15 * see bitmap_scnprintf() and bitmap_parse_user() in lib/bitmap.c.
  16 * For details of cpulist_scnprintf() and cpulist_parse(), see
  17 * bitmap_scnlistprintf() and bitmap_parselist(), also in bitmap.c.
  18 * For details of cpu_remap(), see bitmap_bitremap in lib/bitmap.c
  19 * For details of cpus_remap(), see bitmap_remap in lib/bitmap.c.
  20 * For details of cpus_onto(), see bitmap_onto in lib/bitmap.c.
  21 * For details of cpus_fold(), see bitmap_fold in lib/bitmap.c.
  22 *
  23 * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
  24 * Note: The alternate operations with the suffix "_nr" are used
  25 *       to limit the range of the loop to nr_cpu_ids instead of
  26 *       NR_CPUS when NR_CPUS > 64 for performance reasons.
  27 *       If NR_CPUS is <= 64 then most assembler bitmask
  28 *       operators execute faster with a constant range, so
  29 *       the operator will continue to use NR_CPUS.
  30 *
  31 *       Another consideration is that nr_cpu_ids is initialized
  32 *       to NR_CPUS and isn't lowered until the possible cpus are
  33 *       discovered (including any disabled cpus).  So early uses
  34 *       will span the entire range of NR_CPUS.
  35 * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
  36 *
  37 * The obsolescent cpumask operations are:
  38 *
  39 * void cpu_set(cpu, mask)              turn on bit 'cpu' in mask
  40 * void cpu_clear(cpu, mask)            turn off bit 'cpu' in mask
  41 * void cpus_setall(mask)               set all bits
  42 * void cpus_clear(mask)                clear all bits
  43 * int cpu_isset(cpu, mask)             true iff bit 'cpu' set in mask
  44 * int cpu_test_and_set(cpu, mask)      test and set bit 'cpu' in mask
  45 *
  46 * void cpus_and(dst, src1, src2)       dst = src1 & src2  [intersection]
  47 * void cpus_or(dst, src1, src2)        dst = src1 | src2  [union]
  48 * void cpus_xor(dst, src1, src2)       dst = src1 ^ src2
  49 * void cpus_andnot(dst, src1, src2)    dst = src1 & ~src2
  50 * void cpus_complement(dst, src)       dst = ~src
  51 *
  52 * int cpus_equal(mask1, mask2)         Does mask1 == mask2?
  53 * int cpus_intersects(mask1, mask2)    Do mask1 and mask2 intersect?
  54 * int cpus_subset(mask1, mask2)        Is mask1 a subset of mask2?
  55 * int cpus_empty(mask)                 Is mask empty (no bits sets)?
  56 * int cpus_full(mask)                  Is mask full (all bits sets)?
  57 * int cpus_weight(mask)                Hamming weigh - number of set bits
  58 * int cpus_weight_nr(mask)             Same using nr_cpu_ids instead of NR_CPUS
  59 *
  60 * void cpus_shift_right(dst, src, n)   Shift right
  61 * void cpus_shift_left(dst, src, n)    Shift left
  62 *
  63 * int first_cpu(mask)                  Number lowest set bit, or NR_CPUS
  64 * int next_cpu(cpu, mask)              Next cpu past 'cpu', or NR_CPUS
  65 * int next_cpu_nr(cpu, mask)           Next cpu past 'cpu', or nr_cpu_ids
  66 *
  67 * cpumask_t cpumask_of_cpu(cpu)        Return cpumask with bit 'cpu' set
  68 *                                      (can be used as an lvalue)
  69 * CPU_MASK_ALL                         Initializer - all bits set
  70 * CPU_MASK_NONE                        Initializer - no bits set
  71 * unsigned long *cpus_addr(mask)       Array of unsigned long's in mask
  72 *
  73 * CPUMASK_ALLOC kmalloc's a structure that is a composite of many cpumask_t
  74 * variables, and CPUMASK_PTR provides pointers to each field.
  75 *
  76 * The structure should be defined something like this:
  77 * struct my_cpumasks {
  78 *      cpumask_t mask1;
  79 *      cpumask_t mask2;
  80 * };
  81 *
  82 * Usage is then:
  83 *      CPUMASK_ALLOC(my_cpumasks);
  84 *      CPUMASK_PTR(mask1, my_cpumasks);
  85 *      CPUMASK_PTR(mask2, my_cpumasks);
  86 *
  87 *      --- DO NOT reference cpumask_t pointers until this check ---
  88 *      if (my_cpumasks == NULL)
  89 *              "kmalloc failed"...
  90 *
  91 * References are now pointers to the cpumask_t variables (*mask1, ...)
  92 *
  93 *if NR_CPUS > BITS_PER_LONG
  94 *   CPUMASK_ALLOC(m)                   Declares and allocates struct m *m =
  95 *                                              kmalloc(sizeof(*m), GFP_KERNEL)
  96 *   CPUMASK_FREE(m)                    Macro for kfree(m)
  97 *else
  98 *   CPUMASK_ALLOC(m)                   Declares struct m _m, *m = &_m
  99 *   CPUMASK_FREE(m)                    Nop
 100 *endif
 101 *   CPUMASK_PTR(v, m)                  Declares cpumask_t *v = &(m->v)
 102 * ------------------------------------------------------------------------
 103 *
 104 * int cpumask_scnprintf(buf, len, mask) Format cpumask for printing
 105 * int cpumask_parse_user(ubuf, ulen, mask)     Parse ascii string as cpumask
 106 * int cpulist_scnprintf(buf, len, mask) Format cpumask as list for printing
 107 * int cpulist_parse(buf, map)          Parse ascii string as cpulist
 108 * int cpu_remap(oldbit, old, new)      newbit = map(old, new)(oldbit)
 109 * void cpus_remap(dst, src, old, new)  *dst = map(old, new)(src)
 110 * void cpus_onto(dst, orig, relmap)    *dst = orig relative to relmap
 111 * void cpus_fold(dst, orig, sz)        dst bits = orig bits mod sz
 112 *
 113 * for_each_cpu_mask(cpu, mask)         for-loop cpu over mask using NR_CPUS
 114 * for_each_cpu_mask_nr(cpu, mask)      for-loop cpu over mask using nr_cpu_ids
 115 *
 116 * int num_online_cpus()                Number of online CPUs
 117 * int num_possible_cpus()              Number of all possible CPUs
 118 * int num_present_cpus()               Number of present CPUs
 119 *
 120 * int cpu_online(cpu)                  Is some cpu online?
 121 * int cpu_possible(cpu)                Is some cpu possible?
 122 * int cpu_present(cpu)                 Is some cpu present (can schedule)?
 123 *
 124 * int any_online_cpu(mask)             First online cpu in mask
 125 *
 126 * for_each_possible_cpu(cpu)           for-loop cpu over cpu_possible_map
 127 * for_each_online_cpu(cpu)             for-loop cpu over cpu_online_map
 128 * for_each_present_cpu(cpu)            for-loop cpu over cpu_present_map
 129 *
 130 * Subtlety:
 131 * 1) The 'type-checked' form of cpu_isset() causes gcc (3.3.2, anyway)
 132 *    to generate slightly worse code.  Note for example the additional
 133 *    40 lines of assembly code compiling the "for each possible cpu"
 134 *    loops buried in the disk_stat_read() macros calls when compiling
 135 *    drivers/block/genhd.c (arch i386, CONFIG_SMP=y).  So use a simple
 136 *    one-line #define for cpu_isset(), instead of wrapping an inline
 137 *    inside a macro, the way we do the other calls.
 138 */
 139
 140#include <linux/kernel.h>
 141#include <linux/threads.h>
 142#include <linux/bitmap.h>
 143
 144typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
 145extern cpumask_t _unused_cpumask_arg_;
 146
 147#ifndef CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
 148#define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
 149static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
 150{
 151        set_bit(cpu, dstp->bits);
 152}
 153
 154#define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
 155static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
 156{
 157        clear_bit(cpu, dstp->bits);
 158}
 159
 160#define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
 161static inline void __cpus_setall(cpumask_t *dstp, int nbits)
 162{
 163        bitmap_fill(dstp->bits, nbits);
 164}
 165
 166#define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
 167static inline void __cpus_clear(cpumask_t *dstp, int nbits)
 168{
 169        bitmap_zero(dstp->bits, nbits);
 170}
 171
 172/* No static inline type checking - see Subtlety (1) above. */
 173#define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)
 174
 175#define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
 176static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
 177{
 178        return test_and_set_bit(cpu, addr->bits);
 179}
 180
 181#define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
 182static inline void __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
 183                                        const cpumask_t *src2p, int nbits)
 184{
 185        bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
 186}
 187
 188#define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
 189static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
 190                                        const cpumask_t *src2p, int nbits)
 191{
 192        bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
 193}
 194
 195#define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
 196static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
 197                                        const cpumask_t *src2p, int nbits)
 198{
 199        bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
 200}
 201
 202#define cpus_andnot(dst, src1, src2) \
 203                                __cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
 204static inline void __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
 205                                        const cpumask_t *src2p, int nbits)
 206{
 207        bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
 208}
 209
 210#define cpus_complement(dst, src) __cpus_complement(&(dst), &(src), NR_CPUS)
 211static inline void __cpus_complement(cpumask_t *dstp,
 212                                        const cpumask_t *srcp, int nbits)
 213{
 214        bitmap_complement(dstp->bits, srcp->bits, nbits);
 215}
 216
 217#define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
 218static inline int __cpus_equal(const cpumask_t *src1p,
 219                                        const cpumask_t *src2p, int nbits)
 220{
 221        return bitmap_equal(src1p->bits, src2p->bits, nbits);
 222}
 223
 224#define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
 225static inline int __cpus_intersects(const cpumask_t *src1p,
 226                                        const cpumask_t *src2p, int nbits)
 227{
 228        return bitmap_intersects(src1p->bits, src2p->bits, nbits);
 229}
 230
 231#define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
 232static inline int __cpus_subset(const cpumask_t *src1p,
 233                                        const cpumask_t *src2p, int nbits)
 234{
 235        return bitmap_subset(src1p->bits, src2p->bits, nbits);
 236}
 237
 238#define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
 239static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
 240{
 241        return bitmap_empty(srcp->bits, nbits);
 242}
 243
 244#define cpus_full(cpumask) __cpus_full(&(cpumask), NR_CPUS)
 245static inline int __cpus_full(const cpumask_t *srcp, int nbits)
 246{
 247        return bitmap_full(srcp->bits, nbits);
 248}
 249
 250#define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
 251static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
 252{
 253        return bitmap_weight(srcp->bits, nbits);
 254}
 255
 256#define cpus_shift_right(dst, src, n) \
 257                        __cpus_shift_right(&(dst), &(src), (n), NR_CPUS)
 258static inline void __cpus_shift_right(cpumask_t *dstp,
 259                                        const cpumask_t *srcp, int n, int nbits)
 260{
 261        bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
 262}
 263
 264#define cpus_shift_left(dst, src, n) \
 265                        __cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
 266static inline void __cpus_shift_left(cpumask_t *dstp,
 267                                        const cpumask_t *srcp, int n, int nbits)
 268{
 269        bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
 270}
 271#endif /* !CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS */
 272
 273/**
 274 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *
 275 * @bitmap: the bitmap
 276 *
 277 * There are a few places where cpumask_var_t isn't appropriate and
 278 * static cpumasks must be used (eg. very early boot), yet we don't
 279 * expose the definition of 'struct cpumask'.
 280 *
 281 * This does the conversion, and can be used as a constant initializer.
 282 */
 283#define to_cpumask(bitmap)                                              \
 284        ((struct cpumask *)(1 ? (bitmap)                                \
 285                            : (void *)sizeof(__check_is_bitmap(bitmap))))
 286
 287static inline int __check_is_bitmap(const unsigned long *bitmap)
 288{
 289        return 1;
 290}
 291
 292/*
 293 * Special-case data structure for "single bit set only" constant CPU masks.
 294 *
 295 * We pre-generate all the 64 (or 32) possible bit positions, with enough
 296 * padding to the left and the right, and return the constant pointer
 297 * appropriately offset.
 298 */
 299extern const unsigned long
 300        cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
 301
 302static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
 303{
 304        const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
 305        p -= cpu / BITS_PER_LONG;
 306        return to_cpumask(p);
 307}
 308
 309#ifndef CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
 310/*
 311 * In cases where we take the address of the cpumask immediately,
 312 * gcc optimizes it out (it's a constant) and there's no huge stack
 313 * variable created:
 314 */
 315#define cpumask_of_cpu(cpu) (*get_cpu_mask(cpu))
 316
 317
 318#define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
 319
 320#if NR_CPUS <= BITS_PER_LONG
 321
 322#define CPU_MASK_ALL                                                    \
 323(cpumask_t) { {                                                         \
 324        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 325} }
 326
 327#define CPU_MASK_ALL_PTR        (&CPU_MASK_ALL)
 328
 329#else
 330
 331#define CPU_MASK_ALL                                                    \
 332(cpumask_t) { {                                                         \
 333        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                        \
 334        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 335} }
 336
 337/* cpu_mask_all is in init/main.c */
 338extern cpumask_t cpu_mask_all;
 339#define CPU_MASK_ALL_PTR        (&cpu_mask_all)
 340
 341#endif
 342
 343#define CPU_MASK_NONE                                                   \
 344(cpumask_t) { {                                                         \
 345        [0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL                         \
 346} }
 347
 348#define CPU_MASK_CPU0                                                   \
 349(cpumask_t) { {                                                         \
 350        [0] =  1UL                                                      \
 351} }
 352
 353#define cpus_addr(src) ((src).bits)
 354
 355#if NR_CPUS > BITS_PER_LONG
 356#define CPUMASK_ALLOC(m)        struct m *m = kmalloc(sizeof(*m), GFP_KERNEL)
 357#define CPUMASK_FREE(m)         kfree(m)
 358#else
 359#define CPUMASK_ALLOC(m)        struct m _m, *m = &_m
 360#define CPUMASK_FREE(m)
 361#endif
 362#define CPUMASK_PTR(v, m)       cpumask_t *v = &(m->v)
 363
 364#define cpu_remap(oldbit, old, new) \
 365                __cpu_remap((oldbit), &(old), &(new), NR_CPUS)
 366static inline int __cpu_remap(int oldbit,
 367                const cpumask_t *oldp, const cpumask_t *newp, int nbits)
 368{
 369        return bitmap_bitremap(oldbit, oldp->bits, newp->bits, nbits);
 370}
 371
 372#define cpus_remap(dst, src, old, new) \
 373                __cpus_remap(&(dst), &(src), &(old), &(new), NR_CPUS)
 374static inline void __cpus_remap(cpumask_t *dstp, const cpumask_t *srcp,
 375                const cpumask_t *oldp, const cpumask_t *newp, int nbits)
 376{
 377        bitmap_remap(dstp->bits, srcp->bits, oldp->bits, newp->bits, nbits);
 378}
 379
 380#define cpus_onto(dst, orig, relmap) \
 381                __cpus_onto(&(dst), &(orig), &(relmap), NR_CPUS)
 382static inline void __cpus_onto(cpumask_t *dstp, const cpumask_t *origp,
 383                const cpumask_t *relmapp, int nbits)
 384{
 385        bitmap_onto(dstp->bits, origp->bits, relmapp->bits, nbits);
 386}
 387
 388#define cpus_fold(dst, orig, sz) \
 389                __cpus_fold(&(dst), &(orig), sz, NR_CPUS)
 390static inline void __cpus_fold(cpumask_t *dstp, const cpumask_t *origp,
 391                int sz, int nbits)
 392{
 393        bitmap_fold(dstp->bits, origp->bits, sz, nbits);
 394}
 395#endif /* !CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS */
 396
 397#if NR_CPUS == 1
 398
 399#define nr_cpu_ids              1
 400#ifndef CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
 401#define first_cpu(src)          ({ (void)(src); 0; })
 402#define next_cpu(n, src)        ({ (void)(src); 1; })
 403#define any_online_cpu(mask)    0
 404#define for_each_cpu_mask(cpu, mask)    \
 405        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 406#endif /* !CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS */
 407#else /* NR_CPUS > 1 */
 408
 409extern int nr_cpu_ids;
 410#ifndef CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
 411int __first_cpu(const cpumask_t *srcp);
 412int __next_cpu(int n, const cpumask_t *srcp);
 413int __any_online_cpu(const cpumask_t *mask);
 414
 415#define first_cpu(src)          __first_cpu(&(src))
 416#define next_cpu(n, src)        __next_cpu((n), &(src))
 417#define any_online_cpu(mask) __any_online_cpu(&(mask))
 418#define for_each_cpu_mask(cpu, mask)                    \
 419        for ((cpu) = -1;                                \
 420                (cpu) = next_cpu((cpu), (mask)),        \
 421                (cpu) < NR_CPUS; )
 422#endif /* !CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS */
 423#endif
 424
 425#ifndef CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
 426#if NR_CPUS <= 64
 427
 428#define next_cpu_nr(n, src)             next_cpu(n, src)
 429#define cpus_weight_nr(cpumask)         cpus_weight(cpumask)
 430#define for_each_cpu_mask_nr(cpu, mask) for_each_cpu_mask(cpu, mask)
 431
 432#else /* NR_CPUS > 64 */
 433
 434int __next_cpu_nr(int n, const cpumask_t *srcp);
 435#define next_cpu_nr(n, src)     __next_cpu_nr((n), &(src))
 436#define cpus_weight_nr(cpumask) __cpus_weight(&(cpumask), nr_cpu_ids)
 437#define for_each_cpu_mask_nr(cpu, mask)                 \
 438        for ((cpu) = -1;                                \
 439                (cpu) = next_cpu_nr((cpu), (mask)),     \
 440                (cpu) < nr_cpu_ids; )
 441
 442#endif /* NR_CPUS > 64 */
 443#endif /* !CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS */
 444
 445/*
 446 * The following particular system cpumasks and operations manage
 447 * possible, present, active and online cpus.
 448 *
 449 *     cpu_possible_mask- has bit 'cpu' set iff cpu is populatable
 450 *     cpu_present_mask - has bit 'cpu' set iff cpu is populated
 451 *     cpu_online_mask  - has bit 'cpu' set iff cpu available to scheduler
 452 *     cpu_active_mask  - has bit 'cpu' set iff cpu available to migration
 453 *
 454 *  If !CONFIG_HOTPLUG_CPU, present == possible, and active == online.
 455 *
 456 *  The cpu_possible_mask is fixed at boot time, as the set of CPU id's
 457 *  that it is possible might ever be plugged in at anytime during the
 458 *  life of that system boot.  The cpu_present_mask is dynamic(*),
 459 *  representing which CPUs are currently plugged in.  And
 460 *  cpu_online_mask is the dynamic subset of cpu_present_mask,
 461 *  indicating those CPUs available for scheduling.
 462 *
 463 *  If HOTPLUG is enabled, then cpu_possible_mask is forced to have
 464 *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
 465 *  ACPI reports present at boot.
 466 *
 467 *  If HOTPLUG is enabled, then cpu_present_mask varies dynamically,
 468 *  depending on what ACPI reports as currently plugged in, otherwise
 469 *  cpu_present_mask is just a copy of cpu_possible_mask.
 470 *
 471 *  (*) Well, cpu_present_mask is dynamic in the hotplug case.  If not
 472 *      hotplug, it's a copy of cpu_possible_mask, hence fixed at boot.
 473 *
 474 * Subtleties:
 475 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
 476 *    assumption that their single CPU is online.  The UP
 477 *    cpu_{online,possible,present}_masks are placebos.  Changing them
 478 *    will have no useful affect on the following num_*_cpus()
 479 *    and cpu_*() macros in the UP case.  This ugliness is a UP
 480 *    optimization - don't waste any instructions or memory references
 481 *    asking if you're online or how many CPUs there are if there is
 482 *    only one CPU.
 483 */
 484
 485extern const struct cpumask *const cpu_possible_mask;
 486extern const struct cpumask *const cpu_online_mask;
 487extern const struct cpumask *const cpu_present_mask;
 488extern const struct cpumask *const cpu_active_mask;
 489
 490/* These strip const, as traditionally they weren't const. */
 491#define cpu_possible_map        (*(cpumask_t *)cpu_possible_mask)
 492#define cpu_online_map          (*(cpumask_t *)cpu_online_mask)
 493#define cpu_present_map         (*(cpumask_t *)cpu_present_mask)
 494#define cpu_active_map          (*(cpumask_t *)cpu_active_mask)
 495
 496#if NR_CPUS > 1
 497#define num_online_cpus()       cpumask_weight(cpu_online_mask)
 498#define num_possible_cpus()     cpumask_weight(cpu_possible_mask)
 499#define num_present_cpus()      cpumask_weight(cpu_present_mask)
 500#define cpu_online(cpu)         cpumask_test_cpu((cpu), cpu_online_mask)
 501#define cpu_possible(cpu)       cpumask_test_cpu((cpu), cpu_possible_mask)
 502#define cpu_present(cpu)        cpumask_test_cpu((cpu), cpu_present_mask)
 503#define cpu_active(cpu)         cpumask_test_cpu((cpu), cpu_active_mask)
 504#else
 505#define num_online_cpus()       1
 506#define num_possible_cpus()     1
 507#define num_present_cpus()      1
 508#define cpu_online(cpu)         ((cpu) == 0)
 509#define cpu_possible(cpu)       ((cpu) == 0)
 510#define cpu_present(cpu)        ((cpu) == 0)
 511#define cpu_active(cpu)         ((cpu) == 0)
 512#endif
 513
 514#define cpu_is_offline(cpu)     unlikely(!cpu_online(cpu))
 515
 516/* These are the new versions of the cpumask operators: passed by pointer.
 517 * The older versions will be implemented in terms of these, then deleted. */
 518#define cpumask_bits(maskp) ((maskp)->bits)
 519
 520#if NR_CPUS <= BITS_PER_LONG
 521#define CPU_BITS_ALL                                            \
 522{                                                               \
 523        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \
 524}
 525
 526#else /* NR_CPUS > BITS_PER_LONG */
 527
 528#define CPU_BITS_ALL                                            \
 529{                                                               \
 530        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                \
 531        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD         \
 532}
 533#endif /* NR_CPUS > BITS_PER_LONG */
 534
 535#ifdef CONFIG_CPUMASK_OFFSTACK
 536/* Assuming NR_CPUS is huge, a runtime limit is more efficient.  Also,
 537 * not all bits may be allocated. */
 538#define nr_cpumask_bits nr_cpu_ids
 539#else
 540#define nr_cpumask_bits NR_CPUS
 541#endif
 542
 543/* verify cpu argument to cpumask_* operators */
 544static inline unsigned int cpumask_check(unsigned int cpu)
 545{
 546#ifdef CONFIG_DEBUG_PER_CPU_MAPS
 547        WARN_ON_ONCE(cpu >= nr_cpumask_bits);
 548#endif /* CONFIG_DEBUG_PER_CPU_MAPS */
 549        return cpu;
 550}
 551
 552#if NR_CPUS == 1
 553/* Uniprocessor.  Assume all masks are "1". */
 554static inline unsigned int cpumask_first(const struct cpumask *srcp)
 555{
 556        return 0;
 557}
 558
 559/* Valid inputs for n are -1 and 0. */
 560static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 561{
 562        return n+1;
 563}
 564
 565static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 566{
 567        return n+1;
 568}
 569
 570static inline unsigned int cpumask_next_and(int n,
 571                                            const struct cpumask *srcp,
 572                                            const struct cpumask *andp)
 573{
 574        return n+1;
 575}
 576
 577/* cpu must be a valid cpu, ie 0, so there's no other choice. */
 578static inline unsigned int cpumask_any_but(const struct cpumask *mask,
 579                                           unsigned int cpu)
 580{
 581        return 1;
 582}
 583
 584#define for_each_cpu(cpu, mask)                 \
 585        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 586#define for_each_cpu_and(cpu, mask, and)        \
 587        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and)
 588#else
 589/**
 590 * cpumask_first - get the first cpu in a cpumask
 591 * @srcp: the cpumask pointer
 592 *
 593 * Returns >= nr_cpu_ids if no cpus set.
 594 */
 595static inline unsigned int cpumask_first(const struct cpumask *srcp)
 596{
 597        return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits);
 598}
 599
 600/**
 601 * cpumask_next - get the next cpu in a cpumask
 602 * @n: the cpu prior to the place to search (ie. return will be > @n)
 603 * @srcp: the cpumask pointer
 604 *
 605 * Returns >= nr_cpu_ids if no further cpus set.
 606 */
 607static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 608{
 609        /* -1 is a legal arg here. */
 610        if (n != -1)
 611                cpumask_check(n);
 612        return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 613}
 614
 615/**
 616 * cpumask_next_zero - get the next unset cpu in a cpumask
 617 * @n: the cpu prior to the place to search (ie. return will be > @n)
 618 * @srcp: the cpumask pointer
 619 *
 620 * Returns >= nr_cpu_ids if no further cpus unset.
 621 */
 622static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 623{
 624        /* -1 is a legal arg here. */
 625        if (n != -1)
 626                cpumask_check(n);
 627        return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 628}
 629
 630int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *);
 631int cpumask_any_but(const struct cpumask *mask, unsigned int cpu);
 632
 633/**
 634 * for_each_cpu - iterate over every cpu in a mask
 635 * @cpu: the (optionally unsigned) integer iterator
 636 * @mask: the cpumask pointer
 637 *
 638 * After the loop, cpu is >= nr_cpu_ids.
 639 */
 640#define for_each_cpu(cpu, mask)                         \
 641        for ((cpu) = -1;                                \
 642                (cpu) = cpumask_next((cpu), (mask)),    \
 643                (cpu) < nr_cpu_ids;)
 644
 645/**
 646 * for_each_cpu_and - iterate over every cpu in both masks
 647 * @cpu: the (optionally unsigned) integer iterator
 648 * @mask: the first cpumask pointer
 649 * @and: the second cpumask pointer
 650 *
 651 * This saves a temporary CPU mask in many places.  It is equivalent to:
 652 *      struct cpumask tmp;
 653 *      cpumask_and(&tmp, &mask, &and);
 654 *      for_each_cpu(cpu, &tmp)
 655 *              ...
 656 *
 657 * After the loop, cpu is >= nr_cpu_ids.
 658 */
 659#define for_each_cpu_and(cpu, mask, and)                                \
 660        for ((cpu) = -1;                                                \
 661                (cpu) = cpumask_next_and((cpu), (mask), (and)),         \
 662                (cpu) < nr_cpu_ids;)
 663#endif /* SMP */
 664
 665#define CPU_BITS_NONE                                           \
 666{                                                               \
 667        [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL                  \
 668}
 669
 670#define CPU_BITS_CPU0                                           \
 671{                                                               \
 672        [0] =  1UL                                              \
 673}
 674
 675/**
 676 * cpumask_set_cpu - set a cpu in a cpumask
 677 * @cpu: cpu number (< nr_cpu_ids)
 678 * @dstp: the cpumask pointer
 679 */
 680static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
 681{
 682        set_bit(cpumask_check(cpu), cpumask_bits(dstp));
 683}
 684
 685/**
 686 * cpumask_clear_cpu - clear a cpu in a cpumask
 687 * @cpu: cpu number (< nr_cpu_ids)
 688 * @dstp: the cpumask pointer
 689 */
 690static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
 691{
 692        clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
 693}
 694
 695/**
 696 * cpumask_test_cpu - test for a cpu in a cpumask
 697 * @cpu: cpu number (< nr_cpu_ids)
 698 * @cpumask: the cpumask pointer
 699 *
 700 * No static inline type checking - see Subtlety (1) above.
 701 */
 702#define cpumask_test_cpu(cpu, cpumask) \
 703        test_bit(cpumask_check(cpu), cpumask_bits((cpumask)))
 704
 705/**
 706 * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
 707 * @cpu: cpu number (< nr_cpu_ids)
 708 * @cpumask: the cpumask pointer
 709 *
 710 * test_and_set_bit wrapper for cpumasks.
 711 */
 712static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
 713{
 714        return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 715}
 716
 717/**
 718 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask
 719 * @dstp: the cpumask pointer
 720 */
 721static inline void cpumask_setall(struct cpumask *dstp)
 722{
 723        bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits);
 724}
 725
 726/**
 727 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask
 728 * @dstp: the cpumask pointer
 729 */
 730static inline void cpumask_clear(struct cpumask *dstp)
 731{
 732        bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits);
 733}
 734
 735/**
 736 * cpumask_and - *dstp = *src1p & *src2p
 737 * @dstp: the cpumask result
 738 * @src1p: the first input
 739 * @src2p: the second input
 740 */
 741static inline void cpumask_and(struct cpumask *dstp,
 742                               const struct cpumask *src1p,
 743                               const struct cpumask *src2p)
 744{
 745        bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
 746                                       cpumask_bits(src2p), nr_cpumask_bits);
 747}
 748
 749/**
 750 * cpumask_or - *dstp = *src1p | *src2p
 751 * @dstp: the cpumask result
 752 * @src1p: the first input
 753 * @src2p: the second input
 754 */
 755static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
 756                              const struct cpumask *src2p)
 757{
 758        bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
 759                                      cpumask_bits(src2p), nr_cpumask_bits);
 760}
 761
 762/**
 763 * cpumask_xor - *dstp = *src1p ^ *src2p
 764 * @dstp: the cpumask result
 765 * @src1p: the first input
 766 * @src2p: the second input
 767 */
 768static inline void cpumask_xor(struct cpumask *dstp,
 769                               const struct cpumask *src1p,
 770                               const struct cpumask *src2p)
 771{
 772        bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
 773                                       cpumask_bits(src2p), nr_cpumask_bits);
 774}
 775
 776/**
 777 * cpumask_andnot - *dstp = *src1p & ~*src2p
 778 * @dstp: the cpumask result
 779 * @src1p: the first input
 780 * @src2p: the second input
 781 */
 782static inline void cpumask_andnot(struct cpumask *dstp,
 783                                  const struct cpumask *src1p,
 784                                  const struct cpumask *src2p)
 785{
 786        bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
 787                                          cpumask_bits(src2p), nr_cpumask_bits);
 788}
 789
 790/**
 791 * cpumask_complement - *dstp = ~*srcp
 792 * @dstp: the cpumask result
 793 * @srcp: the input to invert
 794 */
 795static inline void cpumask_complement(struct cpumask *dstp,
 796                                      const struct cpumask *srcp)
 797{
 798        bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp),
 799                                              nr_cpumask_bits);
 800}
 801
 802/**
 803 * cpumask_equal - *src1p == *src2p
 804 * @src1p: the first input
 805 * @src2p: the second input
 806 */
 807static inline bool cpumask_equal(const struct cpumask *src1p,
 808                                const struct cpumask *src2p)
 809{
 810        return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
 811                                                 nr_cpumask_bits);
 812}
 813
 814/**
 815 * cpumask_intersects - (*src1p & *src2p) != 0
 816 * @src1p: the first input
 817 * @src2p: the second input
 818 */
 819static inline bool cpumask_intersects(const struct cpumask *src1p,
 820                                     const struct cpumask *src2p)
 821{
 822        return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
 823                                                      nr_cpumask_bits);
 824}
 825
 826/**
 827 * cpumask_subset - (*src1p & ~*src2p) == 0
 828 * @src1p: the first input
 829 * @src2p: the second input
 830 */
 831static inline int cpumask_subset(const struct cpumask *src1p,
 832                                 const struct cpumask *src2p)
 833{
 834        return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
 835                                                  nr_cpumask_bits);
 836}
 837
 838/**
 839 * cpumask_empty - *srcp == 0
 840 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear.
 841 */
 842static inline bool cpumask_empty(const struct cpumask *srcp)
 843{
 844        return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits);
 845}
 846
 847/**
 848 * cpumask_full - *srcp == 0xFFFFFFFF...
 849 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set.
 850 */
 851static inline bool cpumask_full(const struct cpumask *srcp)
 852{
 853        return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
 854}
 855
 856/**
 857 * cpumask_weight - Count of bits in *srcp
 858 * @srcp: the cpumask to count bits (< nr_cpu_ids) in.
 859 */
 860static inline unsigned int cpumask_weight(const struct cpumask *srcp)
 861{
 862        return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits);
 863}
 864
 865/**
 866 * cpumask_shift_right - *dstp = *srcp >> n
 867 * @dstp: the cpumask result
 868 * @srcp: the input to shift
 869 * @n: the number of bits to shift by
 870 */
 871static inline void cpumask_shift_right(struct cpumask *dstp,
 872                                       const struct cpumask *srcp, int n)
 873{
 874        bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n,
 875                                               nr_cpumask_bits);
 876}
 877
 878/**
 879 * cpumask_shift_left - *dstp = *srcp << n
 880 * @dstp: the cpumask result
 881 * @srcp: the input to shift
 882 * @n: the number of bits to shift by
 883 */
 884static inline void cpumask_shift_left(struct cpumask *dstp,
 885                                      const struct cpumask *srcp, int n)
 886{
 887        bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n,
 888                                              nr_cpumask_bits);
 889}
 890
 891/**
 892 * cpumask_copy - *dstp = *srcp
 893 * @dstp: the result
 894 * @srcp: the input cpumask
 895 */
 896static inline void cpumask_copy(struct cpumask *dstp,
 897                                const struct cpumask *srcp)
 898{
 899        bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits);
 900}
 901
 902/**
 903 * cpumask_any - pick a "random" cpu from *srcp
 904 * @srcp: the input cpumask
 905 *
 906 * Returns >= nr_cpu_ids if no cpus set.
 907 */
 908#define cpumask_any(srcp) cpumask_first(srcp)
 909
 910/**
 911 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2
 912 * @src1p: the first input
 913 * @src2p: the second input
 914 *
 915 * Returns >= nr_cpu_ids if no cpus set in both.  See also cpumask_next_and().
 916 */
 917#define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
 918
 919/**
 920 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2
 921 * @mask1: the first input cpumask
 922 * @mask2: the second input cpumask
 923 *
 924 * Returns >= nr_cpu_ids if no cpus set.
 925 */
 926#define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2))
 927
 928/**
 929 * cpumask_of - the cpumask containing just a given cpu
 930 * @cpu: the cpu (<= nr_cpu_ids)
 931 */
 932#define cpumask_of(cpu) (get_cpu_mask(cpu))
 933
 934/**
 935 * cpumask_scnprintf - print a cpumask into a string as comma-separated hex
 936 * @buf: the buffer to sprintf into
 937 * @len: the length of the buffer
 938 * @srcp: the cpumask to print
 939 *
 940 * If len is zero, returns zero.  Otherwise returns the length of the
 941 * (nul-terminated) @buf string.
 942 */
 943static inline int cpumask_scnprintf(char *buf, int len,
 944                                    const struct cpumask *srcp)
 945{
 946        return bitmap_scnprintf(buf, len, cpumask_bits(srcp), nr_cpumask_bits);
 947}
 948
 949/**
 950 * cpumask_parse_user - extract a cpumask from a user string
 951 * @buf: the buffer to extract from
 952 * @len: the length of the buffer
 953 * @dstp: the cpumask to set.
 954 *
 955 * Returns -errno, or 0 for success.
 956 */
 957static inline int cpumask_parse_user(const char __user *buf, int len,
 958                                     struct cpumask *dstp)
 959{
 960        return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
 961}
 962
 963/**
 964 * cpulist_scnprintf - print a cpumask into a string as comma-separated list
 965 * @buf: the buffer to sprintf into
 966 * @len: the length of the buffer
 967 * @srcp: the cpumask to print
 968 *
 969 * If len is zero, returns zero.  Otherwise returns the length of the
 970 * (nul-terminated) @buf string.
 971 */
 972static inline int cpulist_scnprintf(char *buf, int len,
 973                                    const struct cpumask *srcp)
 974{
 975        return bitmap_scnlistprintf(buf, len, cpumask_bits(srcp),
 976                                    nr_cpumask_bits);
 977}
 978
 979/**
 980 * cpulist_parse_user - extract a cpumask from a user string of ranges
 981 * @buf: the buffer to extract from
 982 * @len: the length of the buffer
 983 * @dstp: the cpumask to set.
 984 *
 985 * Returns -errno, or 0 for success.
 986 */
 987static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
 988{
 989        return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits);
 990}
 991
 992/**
 993 * cpumask_size - size to allocate for a 'struct cpumask' in bytes
 994 *
 995 * This will eventually be a runtime variable, depending on nr_cpu_ids.
 996 */
 997static inline size_t cpumask_size(void)
 998{
 999        /* FIXME: Once all cpumask assignments are eliminated, this
1000         * can be nr_cpumask_bits */
1001        return BITS_TO_LONGS(NR_CPUS) * sizeof(long);
1002}
1003
1004/*
1005 * cpumask_var_t: struct cpumask for stack usage.
1006 *
1007 * Oh, the wicked games we play!  In order to make kernel coding a
1008 * little more difficult, we typedef cpumask_var_t to an array or a
1009 * pointer: doing &mask on an array is a noop, so it still works.
1010 *
1011 * ie.
1012 *      cpumask_var_t tmpmask;
1013 *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
1014 *              return -ENOMEM;
1015 *
1016 *        ... use 'tmpmask' like a normal struct cpumask * ...
1017 *
1018 *      free_cpumask_var(tmpmask);
1019 */
1020#ifdef CONFIG_CPUMASK_OFFSTACK
1021typedef struct cpumask *cpumask_var_t;
1022
1023bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
1024bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
1025void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
1026void free_cpumask_var(cpumask_var_t mask);
1027void free_bootmem_cpumask_var(cpumask_var_t mask);
1028
1029#else
1030typedef struct cpumask cpumask_var_t[1];
1031
1032static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
1033{
1034        return true;
1035}
1036
1037static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
1038                                          int node)
1039{
1040        return true;
1041}
1042
1043static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask)
1044{
1045}
1046
1047static inline void free_cpumask_var(cpumask_var_t mask)
1048{
1049}
1050
1051static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
1052{
1053}
1054#endif /* CONFIG_CPUMASK_OFFSTACK */
1055
1056/* It's common to want to use cpu_all_mask in struct member initializers,
1057 * so it has to refer to an address rather than a pointer. */
1058extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
1059#define cpu_all_mask to_cpumask(cpu_all_bits)
1060
1061/* First bits of cpu_bit_bitmap are in fact unset. */
1062#define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
1063
1064#define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask)
1065#define for_each_online_cpu(cpu)   for_each_cpu((cpu), cpu_online_mask)
1066#define for_each_present_cpu(cpu)  for_each_cpu((cpu), cpu_present_mask)
1067
1068/* Wrappers for arch boot code to manipulate normally-constant masks */
1069void set_cpu_possible(unsigned int cpu, bool possible);
1070void set_cpu_present(unsigned int cpu, bool present);
1071void set_cpu_online(unsigned int cpu, bool online);
1072void set_cpu_active(unsigned int cpu, bool active);
1073void init_cpu_present(const struct cpumask *src);
1074void init_cpu_possible(const struct cpumask *src);
1075void init_cpu_online(const struct cpumask *src);
1076#endif /* __LINUX_CPUMASK_H */
1077
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