include/linux/cpumask.h

   1 #ifndef __LINUX_CPUMASK_H
   2 #define __LINUX_CPUMASK_H
   3
   4 /*
   5  * Cpumasks provide a bitmap suitable for representing the
   6  * set of CPU's in a system, one bit position per CPU number.
   7  *
   8  * See detailed comments in the file linux/bitmap.h describing the
   9  * data type on which these cpumasks are based.
  10  *
  11  * For details of cpumask_scnprintf() and cpumask_parse_user(),
  12  * see bitmap_scnprintf() and bitmap_parse_user() in lib/bitmap.c.
  13  * For details of cpulist_scnprintf() and cpulist_parse(), see
  14  * bitmap_scnlistprintf() and bitmap_parselist(), also in bitmap.c.
  15  * For details of cpu_remap(), see bitmap_bitremap in lib/bitmap.c
  16  * For details of cpus_remap(), see bitmap_remap in lib/bitmap.c.
  17  * For details of cpus_onto(), see bitmap_onto in lib/bitmap.c.
  18  * For details of cpus_fold(), see bitmap_fold in lib/bitmap.c.
  19  *
  20  * The available cpumask operations are:
  21  *
  22  * void cpu_set(cpu, mask)              turn on bit 'cpu' in mask
  23  * void cpu_clear(cpu, mask)            turn off bit 'cpu' in mask
  24  * void cpus_setall(mask)               set all bits
  25  * void cpus_clear(mask)                clear all bits
  26  * int cpu_isset(cpu, mask)             true iff bit 'cpu' set in mask
  27  * int cpu_test_and_set(cpu, mask)      test and set bit 'cpu' in mask
  28  *
  29  * void cpus_and(dst, src1, src2)       dst = src1 & src2  [intersection]
  30  * void cpus_or(dst, src1, src2)        dst = src1 | src2  [union]
  31  * void cpus_xor(dst, src1, src2)       dst = src1 ^ src2
  32  * void cpus_andnot(dst, src1, src2)    dst = src1 & ~src2
  33  * void cpus_complement(dst, src)       dst = ~src
  34  *
  35  * int cpus_equal(mask1, mask2)         Does mask1 == mask2?
  36  * int cpus_intersects(mask1, mask2)    Do mask1 and mask2 intersect?
  37  * int cpus_subset(mask1, mask2)        Is mask1 a subset of mask2?
  38  * int cpus_empty(mask)                 Is mask empty (no bits sets)?
  39  * int cpus_full(mask)                  Is mask full (all bits sets)?
  40  * int cpus_weight(mask)                Hamming weigh - number of set bits
  41  *
  42  * void cpus_shift_right(dst, src, n)   Shift right
  43  * void cpus_shift_left(dst, src, n)    Shift left
  44  *
  45  * int first_cpu(mask)                  Number lowest set bit, or NR_CPUS
  46  * int next_cpu(cpu, mask)              Next cpu past 'cpu', or NR_CPUS
  47  *
  48  * cpumask_t cpumask_of_cpu(cpu)        Return cpumask with bit 'cpu' set
  49  * CPU_MASK_ALL                         Initializer - all bits set
  50  * CPU_MASK_NONE                        Initializer - no bits set
  51  * unsigned long *cpus_addr(mask)       Array of unsigned long's in mask
  52  *
  53  * int cpumask_scnprintf(buf, len, mask) Format cpumask for printing
  54  * int cpumask_parse_user(ubuf, ulen, mask)     Parse ascii string as cpumask
  55  * int cpulist_scnprintf(buf, len, mask) Format cpumask as list for printing
  56  * int cpulist_parse(buf, map)          Parse ascii string as cpulist
  57  * int cpu_remap(oldbit, old, new)      newbit = map(old, new)(oldbit)
  58  * void cpus_remap(dst, src, old, new)  *dst = map(old, new)(src)
  59  * void cpus_onto(dst, orig, relmap)    *dst = orig relative to relmap
  60  * void cpus_fold(dst, orig, sz)        dst bits = orig bits mod sz
  61  *
  62  * for_each_cpu_mask(cpu, mask)         for-loop cpu over mask
  63  *
  64  * int num_online_cpus()                Number of online CPUs
  65  * int num_possible_cpus()              Number of all possible CPUs
  66  * int num_present_cpus()               Number of present CPUs
  67  *
  68  * int cpu_online(cpu)                  Is some cpu online?
  69  * int cpu_possible(cpu)                Is some cpu possible?
  70  * int cpu_present(cpu)                 Is some cpu present (can schedule)?
  71  *
  72  * int any_online_cpu(mask)             First online cpu in mask
  73  *
  74  * for_each_possible_cpu(cpu)           for-loop cpu over cpu_possible_map
  75  * for_each_online_cpu(cpu)             for-loop cpu over cpu_online_map
  76  * for_each_present_cpu(cpu)            for-loop cpu over cpu_present_map
  77  *
  78  * Subtlety:
  79  * 1) The 'type-checked' form of cpu_isset() causes gcc (3.3.2, anyway)
  80  *    to generate slightly worse code.  Note for example the additional
  81  *    40 lines of assembly code compiling the "for each possible cpu"
  82  *    loops buried in the disk_stat_read() macros calls when compiling
  83  *    drivers/block/genhd.c (arch i386, CONFIG_SMP=y).  So use a simple
  84  *    one-line #define for cpu_isset(), instead of wrapping an inline
  85  *    inside a macro, the way we do the other calls.
  86  */
  87
  88 #include <linux/kernel.h>
  89 #include <linux/threads.h>
  90 #include <linux/bitmap.h>
  91
  92 typedef struct { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
  93 extern cpumask_t _unused_cpumask_arg_;
  94
  95 #define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
  96 static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
  97 {
  98         set_bit(cpu, dstp->bits);
  99 }
 100
 101 #define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
 102 static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
 103 {
 104         clear_bit(cpu, dstp->bits);
 105 }
 106
 107 #define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
 108 static inline void __cpus_setall(cpumask_t *dstp, int nbits)
 109 {
 110         bitmap_fill(dstp->bits, nbits);
 111 }
 112
 113 #define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
 114 static inline void __cpus_clear(cpumask_t *dstp, int nbits)
 115 {
 116         bitmap_zero(dstp->bits, nbits);
 117 }
 118
 119 /* No static inline type checking - see Subtlety (1) above. */
 120 #define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)
 121
 122 #define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
 123 static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
 124 {
 125         return test_and_set_bit(cpu, addr->bits);
 126 }
 127
 128 #define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
 129 static inline void __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
 130                                         const cpumask_t *src2p, int nbits)
 131 {
 132         bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
 133 }
 134
 135 #define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
 136 static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
 137                                         const cpumask_t *src2p, int nbits)
 138 {
 139         bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
 140 }
 141
 142 #define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
 143 static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
 144                                         const cpumask_t *src2p, int nbits)
 145 {
 146         bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
 147 }
 148
 149 #define cpus_andnot(dst, src1, src2) \
 150                                 __cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
 151 static inline void __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
 152                                         const cpumask_t *src2p, int nbits)
 153 {
 154         bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
 155 }
 156
 157 #define cpus_complement(dst, src) __cpus_complement(&(dst), &(src), NR_CPUS)
 158 static inline void __cpus_complement(cpumask_t *dstp,
 159                                         const cpumask_t *srcp, int nbits)
 160 {
 161         bitmap_complement(dstp->bits, srcp->bits, nbits);
 162 }
 163
 164 #define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
 165 static inline int __cpus_equal(const cpumask_t *src1p,
 166                                         const cpumask_t *src2p, int nbits)
 167 {
 168         return bitmap_equal(src1p->bits, src2p->bits, nbits);
 169 }
 170
 171 #define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
 172 static inline int __cpus_intersects(const cpumask_t *src1p,
 173                                         const cpumask_t *src2p, int nbits)
 174 {
 175         return bitmap_intersects(src1p->bits, src2p->bits, nbits);
 176 }
 177
 178 #define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
 179 static inline int __cpus_subset(const cpumask_t *src1p,
 180                                         const cpumask_t *src2p, int nbits)
 181 {
 182         return bitmap_subset(src1p->bits, src2p->bits, nbits);
 183 }
 184
 185 #define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
 186 static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
 187 {
 188         return bitmap_empty(srcp->bits, nbits);
 189 }
 190
 191 #define cpus_full(cpumask) __cpus_full(&(cpumask), NR_CPUS)
 192 static inline int __cpus_full(const cpumask_t *srcp, int nbits)
 193 {
 194         return bitmap_full(srcp->bits, nbits);
 195 }
 196
 197 #define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
 198 static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
 199 {
 200         return bitmap_weight(srcp->bits, nbits);
 201 }
 202
 203 #define cpus_shift_right(dst, src, n) \
 204                         __cpus_shift_right(&(dst), &(src), (n), NR_CPUS)
 205 static inline void __cpus_shift_right(cpumask_t *dstp,
 206                                         const cpumask_t *srcp, int n, int nbits)
 207 {
 208         bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
 209 }
 210
 211 #define cpus_shift_left(dst, src, n) \
 212                         __cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
 213 static inline void __cpus_shift_left(cpumask_t *dstp,
 214                                         const cpumask_t *srcp, int n, int nbits)
 215 {
 216         bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
 217 }
 218
 219 #ifdef CONFIG_SMP
 220 int __first_cpu(const cpumask_t *srcp);
 221 #define first_cpu(src) __first_cpu(&(src))
 222 int __next_cpu(int n, const cpumask_t *srcp);
 223 #define next_cpu(n, src) __next_cpu((n), &(src))
 224 #else
 225 #define first_cpu(src)          ({ (void)(src); 0; })
 226 #define next_cpu(n, src)        ({ (void)(src); 1; })
 227 #endif
 228
 229 #ifdef CONFIG_HAVE_CPUMASK_OF_CPU_MAP
 230 extern cpumask_t *cpumask_of_cpu_map;
 231 #define cpumask_of_cpu(cpu)    (cpumask_of_cpu_map[cpu])
 232
 233 #else
 234 #define cpumask_of_cpu(cpu)                                             \
 235 (*({                                                                    \
 236         typeof(_unused_cpumask_arg_) m;                                 \
 237         if (sizeof(m) == sizeof(unsigned long)) {                       \
 238                 m.bits[0] = 1UL<<(cpu);                                 \
 239         } else {                                                        \
 240                 cpus_clear(m);                                          \
 241                 cpu_set((cpu), m);                                      \
 242         }                                                               \
 243         &m;                                                             \
 244 }))
 245 #endif
 246
 247 #define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
 248
 249 #if NR_CPUS <= BITS_PER_LONG
 250
 251 #define CPU_MASK_ALL                                                    \
 252 (cpumask_t) { {                                                         \
 253         [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 254 } }
 255
 256 #define CPU_MASK_ALL_PTR        (&CPU_MASK_ALL)
 257
 258 #else
 259
 260 #define CPU_MASK_ALL                                                    \
 261 (cpumask_t) { {                                                         \
 262         [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                        \
 263         [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 264 } }
 265
 266 /* cpu_mask_all is in init/main.c */
 267 extern cpumask_t cpu_mask_all;
 268 #define CPU_MASK_ALL_PTR        (&cpu_mask_all)
 269
 270 #endif
 271
 272 #define CPU_MASK_NONE                                                   \
 273 (cpumask_t) { {                                                         \
 274         [0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL                         \
 275 } }
 276
 277 #define CPU_MASK_CPU0                                                   \
 278 (cpumask_t) { {                                                         \
 279         [0] =  1UL                                                      \
 280 } }
 281
 282 #define cpus_addr(src) ((src).bits)
 283
 284 #define cpumask_scnprintf(buf, len, src) \
 285                         __cpumask_scnprintf((buf), (len), &(src), NR_CPUS)
 286 static inline int __cpumask_scnprintf(char *buf, int len,
 287                                         const cpumask_t *srcp, int nbits)
 288 {
 289         return bitmap_scnprintf(buf, len, srcp->bits, nbits);
 290 }
 291
 292 #define cpumask_parse_user(ubuf, ulen, dst) \
 293                         __cpumask_parse_user((ubuf), (ulen), &(dst), NR_CPUS)
 294 static inline int __cpumask_parse_user(const char __user *buf, int len,
 295                                         cpumask_t *dstp, int nbits)
 296 {
 297         return bitmap_parse_user(buf, len, dstp->bits, nbits);
 298 }
 299
 300 #define cpulist_scnprintf(buf, len, src) \
 301                         __cpulist_scnprintf((buf), (len), &(src), NR_CPUS)
 302 static inline int __cpulist_scnprintf(char *buf, int len,
 303                                         const cpumask_t *srcp, int nbits)
 304 {
 305         return bitmap_scnlistprintf(buf, len, srcp->bits, nbits);
 306 }
 307
 308 #define cpulist_parse(buf, dst) __cpulist_parse((buf), &(dst), NR_CPUS)
 309 static inline int __cpulist_parse(const char *buf, cpumask_t *dstp, int nbits)
 310 {
 311         return bitmap_parselist(buf, dstp->bits, nbits);
 312 }
 313
 314 #define cpu_remap(oldbit, old, new) \
 315                 __cpu_remap((oldbit), &(old), &(new), NR_CPUS)
 316 static inline int __cpu_remap(int oldbit,
 317                 const cpumask_t *oldp, const cpumask_t *newp, int nbits)
 318 {
 319         return bitmap_bitremap(oldbit, oldp->bits, newp->bits, nbits);
 320 }
 321
 322 #define cpus_remap(dst, src, old, new) \
 323                 __cpus_remap(&(dst), &(src), &(old), &(new), NR_CPUS)
 324 static inline void __cpus_remap(cpumask_t *dstp, const cpumask_t *srcp,
 325                 const cpumask_t *oldp, const cpumask_t *newp, int nbits)
 326 {
 327         bitmap_remap(dstp->bits, srcp->bits, oldp->bits, newp->bits, nbits);
 328 }
 329
 330 #define cpus_onto(dst, orig, relmap) \
 331                 __cpus_onto(&(dst), &(orig), &(relmap), NR_CPUS)
 332 static inline void __cpus_onto(cpumask_t *dstp, const cpumask_t *origp,
 333                 const cpumask_t *relmapp, int nbits)
 334 {
 335         bitmap_onto(dstp->bits, origp->bits, relmapp->bits, nbits);
 336 }
 337
 338 #define cpus_fold(dst, orig, sz) \
 339                 __cpus_fold(&(dst), &(orig), sz, NR_CPUS)
 340 static inline void __cpus_fold(cpumask_t *dstp, const cpumask_t *origp,
 341                 int sz, int nbits)
 342 {
 343         bitmap_fold(dstp->bits, origp->bits, sz, nbits);
 344 }
 345
 346 #if NR_CPUS > 1
 347 #define for_each_cpu_mask(cpu, mask)            \
 348         for ((cpu) = first_cpu(mask);           \
 349                 (cpu) < NR_CPUS;                \
 350                 (cpu) = next_cpu((cpu), (mask)))
 351 #else /* NR_CPUS == 1 */
 352 #define for_each_cpu_mask(cpu, mask)            \
 353         for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 354 #endif /* NR_CPUS */
 355
 356 /*
 357  * The following particular system cpumasks and operations manage
 358  * possible, present and online cpus.  Each of them is a fixed size
 359  * bitmap of size NR_CPUS.
 360  *
 361  *  #ifdef CONFIG_HOTPLUG_CPU
 362  *     cpu_possible_map - has bit 'cpu' set iff cpu is populatable
 363  *     cpu_present_map  - has bit 'cpu' set iff cpu is populated
 364  *     cpu_online_map   - has bit 'cpu' set iff cpu available to scheduler
 365  *  #else
 366  *     cpu_possible_map - has bit 'cpu' set iff cpu is populated
 367  *     cpu_present_map  - copy of cpu_possible_map
 368  *     cpu_online_map   - has bit 'cpu' set iff cpu available to scheduler
 369  *  #endif
 370  *
 371  *  In either case, NR_CPUS is fixed at compile time, as the static
 372  *  size of these bitmaps.  The cpu_possible_map is fixed at boot
 373  *  time, as the set of CPU id's that it is possible might ever
 374  *  be plugged in at anytime during the life of that system boot.
 375  *  The cpu_present_map is dynamic(*), representing which CPUs
 376  *  are currently plugged in.  And cpu_online_map is the dynamic
 377  *  subset of cpu_present_map, indicating those CPUs available
 378  *  for scheduling.
 379  *
 380  *  If HOTPLUG is enabled, then cpu_possible_map is forced to have
 381  *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
 382  *  ACPI reports present at boot.
 383  *
 384  *  If HOTPLUG is enabled, then cpu_present_map varies dynamically,
 385  *  depending on what ACPI reports as currently plugged in, otherwise
 386  *  cpu_present_map is just a copy of cpu_possible_map.
 387  *
 388  *  (*) Well, cpu_present_map is dynamic in the hotplug case.  If not
 389  *      hotplug, it's a copy of cpu_possible_map, hence fixed at boot.
 390  *
 391  * Subtleties:
 392  * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
 393  *    assumption that their single CPU is online.  The UP
 394  *    cpu_{online,possible,present}_maps are placebos.  Changing them
 395  *    will have no useful affect on the following num_*_cpus()
 396  *    and cpu_*() macros in the UP case.  This ugliness is a UP
 397  *    optimization - don't waste any instructions or memory references
 398  *    asking if you're online or how many CPUs there are if there is
 399  *    only one CPU.
 400  * 2) Most SMP arch's #define some of these maps to be some
 401  *    other map specific to that arch.  Therefore, the following
 402  *    must be #define macros, not inlines.  To see why, examine
 403  *    the assembly code produced by the following.  Note that
 404  *    set1() writes phys_x_map, but set2() writes x_map:
 405  *        int x_map, phys_x_map;
 406  *        #define set1(a) x_map = a
 407  *        inline void set2(int a) { x_map = a; }
 408  *        #define x_map phys_x_map
 409  *        main(){ set1(3); set2(5); }
 410  */
 411
 412 extern cpumask_t cpu_possible_map;
 413 extern cpumask_t cpu_online_map;
 414 extern cpumask_t cpu_present_map;
 415
 416 #if NR_CPUS > 1
 417 #define num_online_cpus()       cpus_weight(cpu_online_map)
 418 #define num_possible_cpus()     cpus_weight(cpu_possible_map)
 419 #define num_present_cpus()      cpus_weight(cpu_present_map)
 420 #define cpu_online(cpu)         cpu_isset((cpu), cpu_online_map)
 421 #define cpu_possible(cpu)       cpu_isset((cpu), cpu_possible_map)
 422 #define cpu_present(cpu)        cpu_isset((cpu), cpu_present_map)
 423 #else
 424 #define num_online_cpus()       1
 425 #define num_possible_cpus()     1
 426 #define num_present_cpus()      1
 427 #define cpu_online(cpu)         ((cpu) == 0)
 428 #define cpu_possible(cpu)       ((cpu) == 0)
 429 #define cpu_present(cpu)        ((cpu) == 0)
 430 #endif
 431
 432 #define cpu_is_offline(cpu)     unlikely(!cpu_online(cpu))
 433
 434 #ifdef CONFIG_SMP
 435 extern int nr_cpu_ids;
 436 #define any_online_cpu(mask) __any_online_cpu(&(mask))
 437 int __any_online_cpu(const cpumask_t *mask);
 438 #else
 439 #define nr_cpu_ids                      1
 440 #define any_online_cpu(mask)            0
 441 #endif
 442
 443 #define for_each_possible_cpu(cpu)  for_each_cpu_mask((cpu), cpu_possible_map)
 444 #define for_each_online_cpu(cpu)  for_each_cpu_mask((cpu), cpu_online_map)
 445 #define for_each_present_cpu(cpu) for_each_cpu_mask((cpu), cpu_present_map)
 446
 447 #endif /* __LINUX_CPUMASK_H */