| 1 | /* $NetBSD: subr_kcpuset.c,v 1.11 2014/05/19 20:39:23 rmind Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2011 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by Mindaugas Rasiukevicius. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in the |
| 17 | * documentation and/or other materials provided with the distribution. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 29 | * POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | /* |
| 33 | * Kernel CPU set implementation. |
| 34 | * |
| 35 | * Interface can be used by kernel subsystems as a unified dynamic CPU |
| 36 | * bitset implementation handling many CPUs. Facility also supports early |
| 37 | * use by MD code on boot, as it fixups bitsets on further boot. |
| 38 | * |
| 39 | * TODO: |
| 40 | * - Handle "reverse" bitset on fixup/grow. |
| 41 | */ |
| 42 | |
| 43 | #include <sys/cdefs.h> |
| 44 | __KERNEL_RCSID(0, "$NetBSD: subr_kcpuset.c,v 1.11 2014/05/19 20:39:23 rmind Exp $" ); |
| 45 | |
| 46 | #include <sys/param.h> |
| 47 | #include <sys/types.h> |
| 48 | |
| 49 | #include <sys/atomic.h> |
| 50 | #include <sys/sched.h> |
| 51 | #include <sys/kcpuset.h> |
| 52 | #include <sys/pool.h> |
| 53 | |
| 54 | /* Number of CPUs to support. */ |
| 55 | #define KC_MAXCPUS roundup2(MAXCPUS, 32) |
| 56 | |
| 57 | /* |
| 58 | * Structure of dynamic CPU set in the kernel. |
| 59 | */ |
| 60 | struct kcpuset { |
| 61 | uint32_t bits[0]; |
| 62 | }; |
| 63 | |
| 64 | typedef struct kcpuset_impl { |
| 65 | /* Reference count. */ |
| 66 | u_int kc_refcnt; |
| 67 | /* Next to free, if non-NULL (used when multiple references). */ |
| 68 | struct kcpuset * kc_next; |
| 69 | /* Actual variable-sized field of bits. */ |
| 70 | struct kcpuset kc_field; |
| 71 | } kcpuset_impl_t; |
| 72 | |
| 73 | #define KC_BITS_OFF (offsetof(struct kcpuset_impl, kc_field)) |
| 74 | #define KC_GETSTRUCT(b) ((kcpuset_impl_t *)((char *)(b) - KC_BITS_OFF)) |
| 75 | #define KC_GETCSTRUCT(b) ((const kcpuset_impl_t *)((const char *)(b) - KC_BITS_OFF)) |
| 76 | |
| 77 | /* Sizes of a single bitset. */ |
| 78 | #define KC_SHIFT 5 |
| 79 | #define KC_MASK 31 |
| 80 | |
| 81 | /* An array of noted early kcpuset creations and data. */ |
| 82 | #define KC_SAVE_NITEMS 8 |
| 83 | |
| 84 | /* Structures for early boot mechanism (must be statically initialised). */ |
| 85 | static kcpuset_t ** kc_noted_early[KC_SAVE_NITEMS]; |
| 86 | static uint32_t kc_bits_early[KC_SAVE_NITEMS]; |
| 87 | static int kc_last_idx = 0; |
| 88 | static bool kc_initialised = false; |
| 89 | |
| 90 | #define KC_BITSIZE_EARLY sizeof(kc_bits_early[0]) |
| 91 | #define KC_NFIELDS_EARLY 1 |
| 92 | |
| 93 | /* |
| 94 | * The size of whole bitset fields and amount of fields. |
| 95 | * The whole size must statically initialise for early case. |
| 96 | */ |
| 97 | static size_t kc_bitsize __read_mostly = KC_BITSIZE_EARLY; |
| 98 | static size_t kc_nfields __read_mostly = KC_NFIELDS_EARLY; |
| 99 | |
| 100 | static pool_cache_t kc_cache __read_mostly; |
| 101 | |
| 102 | static kcpuset_t * kcpuset_create_raw(bool); |
| 103 | |
| 104 | /* |
| 105 | * kcpuset_sysinit: initialize the subsystem, transfer early boot cases |
| 106 | * to dynamically allocated sets. |
| 107 | */ |
| 108 | void |
| 109 | kcpuset_sysinit(void) |
| 110 | { |
| 111 | kcpuset_t *kc_dynamic[KC_SAVE_NITEMS], *kcp; |
| 112 | int i, s; |
| 113 | |
| 114 | /* Set a kcpuset_t sizes. */ |
| 115 | kc_nfields = (KC_MAXCPUS >> KC_SHIFT); |
| 116 | kc_bitsize = sizeof(uint32_t) * kc_nfields; |
| 117 | KASSERT(kc_nfields != 0 && kc_bitsize != 0); |
| 118 | |
| 119 | kc_cache = pool_cache_init(sizeof(kcpuset_impl_t) + kc_bitsize, |
| 120 | coherency_unit, 0, 0, "kcpuset" , NULL, IPL_NONE, NULL, NULL, NULL); |
| 121 | |
| 122 | /* First, pre-allocate kcpuset entries. */ |
| 123 | for (i = 0; i < kc_last_idx; i++) { |
| 124 | kcp = kcpuset_create_raw(true); |
| 125 | kc_dynamic[i] = kcp; |
| 126 | } |
| 127 | |
| 128 | /* |
| 129 | * Prepare to convert all early noted kcpuset uses to dynamic sets. |
| 130 | * All processors, except the one we are currently running (primary), |
| 131 | * must not be spinned yet. Since MD facilities can use kcpuset, |
| 132 | * raise the IPL to high. |
| 133 | */ |
| 134 | KASSERT(mp_online == false); |
| 135 | |
| 136 | s = splhigh(); |
| 137 | for (i = 0; i < kc_last_idx; i++) { |
| 138 | /* |
| 139 | * Transfer the bits from early static storage to the kcpuset. |
| 140 | */ |
| 141 | KASSERT(kc_bitsize >= KC_BITSIZE_EARLY); |
| 142 | memcpy(kc_dynamic[i], &kc_bits_early[i], KC_BITSIZE_EARLY); |
| 143 | |
| 144 | /* |
| 145 | * Store the new pointer, pointing to the allocated kcpuset. |
| 146 | * Note: we are not in an interrupt context and it is the only |
| 147 | * CPU running - thus store is safe (e.g. no need for pointer |
| 148 | * variable to be volatile). |
| 149 | */ |
| 150 | *kc_noted_early[i] = kc_dynamic[i]; |
| 151 | } |
| 152 | kc_initialised = true; |
| 153 | kc_last_idx = 0; |
| 154 | splx(s); |
| 155 | } |
| 156 | |
| 157 | /* |
| 158 | * kcpuset_early_ptr: note an early boot use by saving the pointer and |
| 159 | * returning a pointer to a static, temporary bit field. |
| 160 | */ |
| 161 | static kcpuset_t * |
| 162 | kcpuset_early_ptr(kcpuset_t **kcptr) |
| 163 | { |
| 164 | kcpuset_t *kcp; |
| 165 | int s; |
| 166 | |
| 167 | s = splhigh(); |
| 168 | if (kc_last_idx < KC_SAVE_NITEMS) { |
| 169 | /* |
| 170 | * Save the pointer, return pointer to static early field. |
| 171 | * Need to zero it out. |
| 172 | */ |
| 173 | kc_noted_early[kc_last_idx] = kcptr; |
| 174 | kcp = (kcpuset_t *)&kc_bits_early[kc_last_idx]; |
| 175 | kc_last_idx++; |
| 176 | memset(kcp, 0, KC_BITSIZE_EARLY); |
| 177 | KASSERT(kc_bitsize == KC_BITSIZE_EARLY); |
| 178 | } else { |
| 179 | panic("kcpuset(9): all early-use entries exhausted; " |
| 180 | "increase KC_SAVE_NITEMS\n" ); |
| 181 | } |
| 182 | splx(s); |
| 183 | |
| 184 | return kcp; |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * Routines to create or destroy the CPU set. |
| 189 | * Early boot case is handled. |
| 190 | */ |
| 191 | |
| 192 | static kcpuset_t * |
| 193 | kcpuset_create_raw(bool zero) |
| 194 | { |
| 195 | kcpuset_impl_t *kc; |
| 196 | |
| 197 | kc = pool_cache_get(kc_cache, PR_WAITOK); |
| 198 | kc->kc_refcnt = 1; |
| 199 | kc->kc_next = NULL; |
| 200 | |
| 201 | if (zero) { |
| 202 | memset(&kc->kc_field, 0, kc_bitsize); |
| 203 | } |
| 204 | |
| 205 | /* Note: return pointer to the actual field of bits. */ |
| 206 | KASSERT((uint8_t *)kc + KC_BITS_OFF == (uint8_t *)&kc->kc_field); |
| 207 | return &kc->kc_field; |
| 208 | } |
| 209 | |
| 210 | void |
| 211 | kcpuset_create(kcpuset_t **retkcp, bool zero) |
| 212 | { |
| 213 | if (__predict_false(!kc_initialised)) { |
| 214 | /* Early boot use - special case. */ |
| 215 | *retkcp = kcpuset_early_ptr(retkcp); |
| 216 | return; |
| 217 | } |
| 218 | *retkcp = kcpuset_create_raw(zero); |
| 219 | } |
| 220 | |
| 221 | void |
| 222 | kcpuset_clone(kcpuset_t **retkcp, const kcpuset_t *kcp) |
| 223 | { |
| 224 | kcpuset_create(retkcp, false); |
| 225 | memcpy(*retkcp, kcp, kc_bitsize); |
| 226 | } |
| 227 | |
| 228 | void |
| 229 | kcpuset_destroy(kcpuset_t *kcp) |
| 230 | { |
| 231 | kcpuset_impl_t *kc; |
| 232 | |
| 233 | KASSERT(kc_initialised); |
| 234 | KASSERT(kcp != NULL); |
| 235 | |
| 236 | do { |
| 237 | kc = KC_GETSTRUCT(kcp); |
| 238 | kcp = kc->kc_next; |
| 239 | pool_cache_put(kc_cache, kc); |
| 240 | } while (kcp); |
| 241 | } |
| 242 | |
| 243 | /* |
| 244 | * Routines to reference/unreference the CPU set. |
| 245 | * Note: early boot case is not supported by these routines. |
| 246 | */ |
| 247 | |
| 248 | void |
| 249 | kcpuset_use(kcpuset_t *kcp) |
| 250 | { |
| 251 | kcpuset_impl_t *kc = KC_GETSTRUCT(kcp); |
| 252 | |
| 253 | KASSERT(kc_initialised); |
| 254 | atomic_inc_uint(&kc->kc_refcnt); |
| 255 | } |
| 256 | |
| 257 | void |
| 258 | kcpuset_unuse(kcpuset_t *kcp, kcpuset_t **lst) |
| 259 | { |
| 260 | kcpuset_impl_t *kc = KC_GETSTRUCT(kcp); |
| 261 | |
| 262 | KASSERT(kc_initialised); |
| 263 | KASSERT(kc->kc_refcnt > 0); |
| 264 | |
| 265 | if (atomic_dec_uint_nv(&kc->kc_refcnt) != 0) { |
| 266 | return; |
| 267 | } |
| 268 | KASSERT(kc->kc_next == NULL); |
| 269 | if (lst == NULL) { |
| 270 | kcpuset_destroy(kcp); |
| 271 | return; |
| 272 | } |
| 273 | kc->kc_next = *lst; |
| 274 | *lst = kcp; |
| 275 | } |
| 276 | |
| 277 | /* |
| 278 | * Routines to transfer the CPU set from / to userspace. |
| 279 | * Note: early boot case is not supported by these routines. |
| 280 | */ |
| 281 | |
| 282 | int |
| 283 | kcpuset_copyin(const cpuset_t *ucp, kcpuset_t *kcp, size_t len) |
| 284 | { |
| 285 | kcpuset_impl_t *kc __diagused = KC_GETSTRUCT(kcp); |
| 286 | |
| 287 | KASSERT(kc_initialised); |
| 288 | KASSERT(kc->kc_refcnt > 0); |
| 289 | KASSERT(kc->kc_next == NULL); |
| 290 | |
| 291 | if (len > kc_bitsize) { /* XXX */ |
| 292 | return EINVAL; |
| 293 | } |
| 294 | return copyin(ucp, kcp, len); |
| 295 | } |
| 296 | |
| 297 | int |
| 298 | kcpuset_copyout(kcpuset_t *kcp, cpuset_t *ucp, size_t len) |
| 299 | { |
| 300 | kcpuset_impl_t *kc __diagused = KC_GETSTRUCT(kcp); |
| 301 | |
| 302 | KASSERT(kc_initialised); |
| 303 | KASSERT(kc->kc_refcnt > 0); |
| 304 | KASSERT(kc->kc_next == NULL); |
| 305 | |
| 306 | if (len > kc_bitsize) { /* XXX */ |
| 307 | return EINVAL; |
| 308 | } |
| 309 | return copyout(kcp, ucp, len); |
| 310 | } |
| 311 | |
| 312 | void |
| 313 | kcpuset_export_u32(const kcpuset_t *kcp, uint32_t *bitfield, size_t len) |
| 314 | { |
| 315 | size_t rlen = MIN(kc_bitsize, len); |
| 316 | |
| 317 | KASSERT(kcp != NULL); |
| 318 | memcpy(bitfield, kcp->bits, rlen); |
| 319 | } |
| 320 | |
| 321 | /* |
| 322 | * Routines to change bit field - zero, fill, copy, set, unset, etc. |
| 323 | */ |
| 324 | |
| 325 | void |
| 326 | kcpuset_zero(kcpuset_t *kcp) |
| 327 | { |
| 328 | |
| 329 | KASSERT(!kc_initialised || KC_GETSTRUCT(kcp)->kc_refcnt > 0); |
| 330 | KASSERT(!kc_initialised || KC_GETSTRUCT(kcp)->kc_next == NULL); |
| 331 | memset(kcp, 0, kc_bitsize); |
| 332 | } |
| 333 | |
| 334 | void |
| 335 | kcpuset_fill(kcpuset_t *kcp) |
| 336 | { |
| 337 | |
| 338 | KASSERT(!kc_initialised || KC_GETSTRUCT(kcp)->kc_refcnt > 0); |
| 339 | KASSERT(!kc_initialised || KC_GETSTRUCT(kcp)->kc_next == NULL); |
| 340 | memset(kcp, ~0, kc_bitsize); |
| 341 | } |
| 342 | |
| 343 | void |
| 344 | kcpuset_copy(kcpuset_t *dkcp, const kcpuset_t *skcp) |
| 345 | { |
| 346 | |
| 347 | KASSERT(!kc_initialised || KC_GETSTRUCT(dkcp)->kc_refcnt > 0); |
| 348 | KASSERT(!kc_initialised || KC_GETSTRUCT(dkcp)->kc_next == NULL); |
| 349 | memcpy(dkcp, skcp, kc_bitsize); |
| 350 | } |
| 351 | |
| 352 | void |
| 353 | kcpuset_set(kcpuset_t *kcp, cpuid_t i) |
| 354 | { |
| 355 | const size_t j = i >> KC_SHIFT; |
| 356 | |
| 357 | KASSERT(!kc_initialised || KC_GETSTRUCT(kcp)->kc_next == NULL); |
| 358 | KASSERT(j < kc_nfields); |
| 359 | |
| 360 | kcp->bits[j] |= 1 << (i & KC_MASK); |
| 361 | } |
| 362 | |
| 363 | void |
| 364 | kcpuset_clear(kcpuset_t *kcp, cpuid_t i) |
| 365 | { |
| 366 | const size_t j = i >> KC_SHIFT; |
| 367 | |
| 368 | KASSERT(!kc_initialised || KC_GETCSTRUCT(kcp)->kc_next == NULL); |
| 369 | KASSERT(j < kc_nfields); |
| 370 | |
| 371 | kcp->bits[j] &= ~(1 << (i & KC_MASK)); |
| 372 | } |
| 373 | |
| 374 | bool |
| 375 | kcpuset_isset(const kcpuset_t *kcp, cpuid_t i) |
| 376 | { |
| 377 | const size_t j = i >> KC_SHIFT; |
| 378 | |
| 379 | KASSERT(kcp != NULL); |
| 380 | KASSERT(!kc_initialised || KC_GETCSTRUCT(kcp)->kc_refcnt > 0); |
| 381 | KASSERT(!kc_initialised || KC_GETCSTRUCT(kcp)->kc_next == NULL); |
| 382 | KASSERT(j < kc_nfields); |
| 383 | |
| 384 | return ((1 << (i & KC_MASK)) & kcp->bits[j]) != 0; |
| 385 | } |
| 386 | |
| 387 | bool |
| 388 | kcpuset_isotherset(const kcpuset_t *kcp, cpuid_t i) |
| 389 | { |
| 390 | const size_t j2 = i >> KC_SHIFT; |
| 391 | const uint32_t mask = ~(1 << (i & KC_MASK)); |
| 392 | |
| 393 | for (size_t j = 0; j < kc_nfields; j++) { |
| 394 | const uint32_t bits = kcp->bits[j]; |
| 395 | if (bits && (j != j2 || (bits & mask) != 0)) { |
| 396 | return true; |
| 397 | } |
| 398 | } |
| 399 | return false; |
| 400 | } |
| 401 | |
| 402 | bool |
| 403 | kcpuset_iszero(const kcpuset_t *kcp) |
| 404 | { |
| 405 | |
| 406 | for (size_t j = 0; j < kc_nfields; j++) { |
| 407 | if (kcp->bits[j] != 0) { |
| 408 | return false; |
| 409 | } |
| 410 | } |
| 411 | return true; |
| 412 | } |
| 413 | |
| 414 | bool |
| 415 | kcpuset_match(const kcpuset_t *kcp1, const kcpuset_t *kcp2) |
| 416 | { |
| 417 | |
| 418 | return memcmp(kcp1, kcp2, kc_bitsize) == 0; |
| 419 | } |
| 420 | |
| 421 | bool |
| 422 | kcpuset_intersecting_p(const kcpuset_t *kcp1, const kcpuset_t *kcp2) |
| 423 | { |
| 424 | |
| 425 | for (size_t j = 0; j < kc_nfields; j++) { |
| 426 | if (kcp1->bits[j] & kcp2->bits[j]) |
| 427 | return true; |
| 428 | } |
| 429 | return false; |
| 430 | } |
| 431 | |
| 432 | cpuid_t |
| 433 | kcpuset_ffs(const kcpuset_t *kcp) |
| 434 | { |
| 435 | |
| 436 | for (size_t j = 0; j < kc_nfields; j++) { |
| 437 | if (kcp->bits[j]) |
| 438 | return 32 * j + ffs(kcp->bits[j]); |
| 439 | } |
| 440 | return 0; |
| 441 | } |
| 442 | |
| 443 | cpuid_t |
| 444 | kcpuset_ffs_intersecting(const kcpuset_t *kcp1, const kcpuset_t *kcp2) |
| 445 | { |
| 446 | |
| 447 | for (size_t j = 0; j < kc_nfields; j++) { |
| 448 | uint32_t bits = kcp1->bits[j] & kcp2->bits[j]; |
| 449 | if (bits) |
| 450 | return 32 * j + ffs(bits); |
| 451 | } |
| 452 | return 0; |
| 453 | } |
| 454 | |
| 455 | void |
| 456 | kcpuset_merge(kcpuset_t *kcp1, const kcpuset_t *kcp2) |
| 457 | { |
| 458 | |
| 459 | for (size_t j = 0; j < kc_nfields; j++) { |
| 460 | kcp1->bits[j] |= kcp2->bits[j]; |
| 461 | } |
| 462 | } |
| 463 | |
| 464 | void |
| 465 | kcpuset_intersect(kcpuset_t *kcp1, const kcpuset_t *kcp2) |
| 466 | { |
| 467 | |
| 468 | for (size_t j = 0; j < kc_nfields; j++) { |
| 469 | kcp1->bits[j] &= kcp2->bits[j]; |
| 470 | } |
| 471 | } |
| 472 | |
| 473 | void |
| 474 | kcpuset_remove(kcpuset_t *kcp1, const kcpuset_t *kcp2) |
| 475 | { |
| 476 | |
| 477 | for (size_t j = 0; j < kc_nfields; j++) { |
| 478 | kcp1->bits[j] &= ~kcp2->bits[j]; |
| 479 | } |
| 480 | } |
| 481 | |
| 482 | int |
| 483 | kcpuset_countset(const kcpuset_t *kcp) |
| 484 | { |
| 485 | int count = 0; |
| 486 | |
| 487 | for (size_t j = 0; j < kc_nfields; j++) { |
| 488 | count += popcount32(kcp->bits[j]); |
| 489 | } |
| 490 | return count; |
| 491 | } |
| 492 | |
| 493 | /* |
| 494 | * Routines to set/clear the flags atomically. |
| 495 | */ |
| 496 | |
| 497 | void |
| 498 | kcpuset_atomic_set(kcpuset_t *kcp, cpuid_t i) |
| 499 | { |
| 500 | const size_t j = i >> KC_SHIFT; |
| 501 | |
| 502 | KASSERT(j < kc_nfields); |
| 503 | atomic_or_32(&kcp->bits[j], 1 << (i & KC_MASK)); |
| 504 | } |
| 505 | |
| 506 | void |
| 507 | kcpuset_atomic_clear(kcpuset_t *kcp, cpuid_t i) |
| 508 | { |
| 509 | const size_t j = i >> KC_SHIFT; |
| 510 | |
| 511 | KASSERT(j < kc_nfields); |
| 512 | atomic_and_32(&kcp->bits[j], ~(1 << (i & KC_MASK))); |
| 513 | } |
| 514 | |
| 515 | void |
| 516 | kcpuset_atomicly_intersect(kcpuset_t *kcp1, const kcpuset_t *kcp2) |
| 517 | { |
| 518 | |
| 519 | for (size_t j = 0; j < kc_nfields; j++) { |
| 520 | if (kcp2->bits[j]) |
| 521 | atomic_and_32(&kcp1->bits[j], kcp2->bits[j]); |
| 522 | } |
| 523 | } |
| 524 | |
| 525 | void |
| 526 | kcpuset_atomicly_merge(kcpuset_t *kcp1, const kcpuset_t *kcp2) |
| 527 | { |
| 528 | |
| 529 | for (size_t j = 0; j < kc_nfields; j++) { |
| 530 | if (kcp2->bits[j]) |
| 531 | atomic_or_32(&kcp1->bits[j], kcp2->bits[j]); |
| 532 | } |
| 533 | } |
| 534 | |
| 535 | void |
| 536 | kcpuset_atomicly_remove(kcpuset_t *kcp1, const kcpuset_t *kcp2) |
| 537 | { |
| 538 | |
| 539 | for (size_t j = 0; j < kc_nfields; j++) { |
| 540 | if (kcp2->bits[j]) |
| 541 | atomic_and_32(&kcp1->bits[j], ~kcp2->bits[j]); |
| 542 | } |
| 543 | } |
| 544 | |