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