| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef _LINUX_JUMP_LABEL_H |
| 3 | #define _LINUX_JUMP_LABEL_H |
| 4 | |
| 5 | /* |
| 6 | * Jump label support |
| 7 | * |
| 8 | * Copyright (C) 2009-2012 Jason Baron <jbaron@redhat.com> |
| 9 | * Copyright (C) 2011-2012 Red Hat, Inc., Peter Zijlstra |
| 10 | * |
| 11 | * DEPRECATED API: |
| 12 | * |
| 13 | * The use of 'struct static_key' directly, is now DEPRECATED. In addition |
| 14 | * static_key_{true,false}() is also DEPRECATED. IE DO NOT use the following: |
| 15 | * |
| 16 | * struct static_key false = STATIC_KEY_INIT_FALSE; |
| 17 | * struct static_key true = STATIC_KEY_INIT_TRUE; |
| 18 | * static_key_true() |
| 19 | * static_key_false() |
| 20 | * |
| 21 | * The updated API replacements are: |
| 22 | * |
| 23 | * DEFINE_STATIC_KEY_TRUE(key); |
| 24 | * DEFINE_STATIC_KEY_FALSE(key); |
| 25 | * DEFINE_STATIC_KEY_ARRAY_TRUE(keys, count); |
| 26 | * DEFINE_STATIC_KEY_ARRAY_FALSE(keys, count); |
| 27 | * static_branch_likely() |
| 28 | * static_branch_unlikely() |
| 29 | * |
| 30 | * Jump labels provide an interface to generate dynamic branches using |
| 31 | * self-modifying code. Assuming toolchain and architecture support, if we |
| 32 | * define a "key" that is initially false via "DEFINE_STATIC_KEY_FALSE(key)", |
| 33 | * an "if (static_branch_unlikely(&key))" statement is an unconditional branch |
| 34 | * (which defaults to false - and the true block is placed out of line). |
| 35 | * Similarly, we can define an initially true key via |
| 36 | * "DEFINE_STATIC_KEY_TRUE(key)", and use it in the same |
| 37 | * "if (static_branch_unlikely(&key))", in which case we will generate an |
| 38 | * unconditional branch to the out-of-line true branch. Keys that are |
| 39 | * initially true or false can be using in both static_branch_unlikely() |
| 40 | * and static_branch_likely() statements. |
| 41 | * |
| 42 | * At runtime we can change the branch target by setting the key |
| 43 | * to true via a call to static_branch_enable(), or false using |
| 44 | * static_branch_disable(). If the direction of the branch is switched by |
| 45 | * these calls then we run-time modify the branch target via a |
| 46 | * no-op -> jump or jump -> no-op conversion. For example, for an |
| 47 | * initially false key that is used in an "if (static_branch_unlikely(&key))" |
| 48 | * statement, setting the key to true requires us to patch in a jump |
| 49 | * to the out-of-line of true branch. |
| 50 | * |
| 51 | * In addition to static_branch_{enable,disable}, we can also reference count |
| 52 | * the key or branch direction via static_branch_{inc,dec}. Thus, |
| 53 | * static_branch_inc() can be thought of as a 'make more true' and |
| 54 | * static_branch_dec() as a 'make more false'. |
| 55 | * |
| 56 | * Since this relies on modifying code, the branch modifying functions |
| 57 | * must be considered absolute slow paths (machine wide synchronization etc.). |
| 58 | * OTOH, since the affected branches are unconditional, their runtime overhead |
| 59 | * will be absolutely minimal, esp. in the default (off) case where the total |
| 60 | * effect is a single NOP of appropriate size. The on case will patch in a jump |
| 61 | * to the out-of-line block. |
| 62 | * |
| 63 | * When the control is directly exposed to userspace, it is prudent to delay the |
| 64 | * decrement to avoid high frequency code modifications which can (and do) |
| 65 | * cause significant performance degradation. Struct static_key_deferred and |
| 66 | * static_key_slow_dec_deferred() provide for this. |
| 67 | * |
| 68 | * Lacking toolchain and or architecture support, static keys fall back to a |
| 69 | * simple conditional branch. |
| 70 | * |
| 71 | * Additional babbling in: Documentation/staging/static-keys.rst |
| 72 | */ |
| 73 | |
| 74 | #ifndef __ASSEMBLY__ |
| 75 | |
| 76 | #include <linux/types.h> |
| 77 | #include <linux/compiler.h> |
| 78 | |
| 79 | extern bool static_key_initialized; |
| 80 | |
| 81 | #define STATIC_KEY_CHECK_USE(key) WARN(!static_key_initialized, \ |
| 82 | "%s(): static key '%pS' used before call to jump_label_init()", \ |
| 83 | __func__, (key)) |
| 84 | |
| 85 | struct static_key { |
| 86 | atomic_t enabled; |
| 87 | #ifdef CONFIG_JUMP_LABEL |
| 88 | /* |
| 89 | * Note: |
| 90 | * To make anonymous unions work with old compilers, the static |
| 91 | * initialization of them requires brackets. This creates a dependency |
| 92 | * on the order of the struct with the initializers. If any fields |
| 93 | * are added, STATIC_KEY_INIT_TRUE and STATIC_KEY_INIT_FALSE may need |
| 94 | * to be modified. |
| 95 | * |
| 96 | * bit 0 => 1 if key is initially true |
| 97 | * 0 if initially false |
| 98 | * bit 1 => 1 if points to struct static_key_mod |
| 99 | * 0 if points to struct jump_entry |
| 100 | */ |
| 101 | union { |
| 102 | unsigned long type; |
| 103 | struct jump_entry *entries; |
| 104 | struct static_key_mod *next; |
| 105 | }; |
| 106 | #endif /* CONFIG_JUMP_LABEL */ |
| 107 | }; |
| 108 | |
| 109 | #endif /* __ASSEMBLY__ */ |
| 110 | |
| 111 | #ifdef CONFIG_JUMP_LABEL |
| 112 | #include <asm/jump_label.h> |
| 113 | |
| 114 | #ifndef __ASSEMBLY__ |
| 115 | #ifdef CONFIG_HAVE_ARCH_JUMP_LABEL_RELATIVE |
| 116 | |
| 117 | struct jump_entry { |
| 118 | s32 code; |
| 119 | s32 target; |
| 120 | long key; // key may be far away from the core kernel under KASLR |
| 121 | }; |
| 122 | |
| 123 | static inline unsigned long jump_entry_code(const struct jump_entry *entry) |
| 124 | { |
| 125 | return (unsigned long)&entry->code + entry->code; |
| 126 | } |
| 127 | |
| 128 | static inline unsigned long jump_entry_target(const struct jump_entry *entry) |
| 129 | { |
| 130 | return (unsigned long)&entry->target + entry->target; |
| 131 | } |
| 132 | |
| 133 | static inline struct static_key *jump_entry_key(const struct jump_entry *entry) |
| 134 | { |
| 135 | long offset = entry->key & ~3L; |
| 136 | |
| 137 | return (struct static_key *)((unsigned long)&entry->key + offset); |
| 138 | } |
| 139 | |
| 140 | #else |
| 141 | |
| 142 | static inline unsigned long jump_entry_code(const struct jump_entry *entry) |
| 143 | { |
| 144 | return entry->code; |
| 145 | } |
| 146 | |
| 147 | static inline unsigned long jump_entry_target(const struct jump_entry *entry) |
| 148 | { |
| 149 | return entry->target; |
| 150 | } |
| 151 | |
| 152 | static inline struct static_key *jump_entry_key(const struct jump_entry *entry) |
| 153 | { |
| 154 | return (struct static_key *)((unsigned long)entry->key & ~3UL); |
| 155 | } |
| 156 | |
| 157 | #endif |
| 158 | |
| 159 | static inline bool jump_entry_is_branch(const struct jump_entry *entry) |
| 160 | { |
| 161 | return (unsigned long)entry->key & 1UL; |
| 162 | } |
| 163 | |
| 164 | static inline bool jump_entry_is_init(const struct jump_entry *entry) |
| 165 | { |
| 166 | return (unsigned long)entry->key & 2UL; |
| 167 | } |
| 168 | |
| 169 | static inline void jump_entry_set_init(struct jump_entry *entry, bool set) |
| 170 | { |
| 171 | if (set) |
| 172 | entry->key |= 2; |
| 173 | else |
| 174 | entry->key &= ~2; |
| 175 | } |
| 176 | |
| 177 | static inline int jump_entry_size(struct jump_entry *entry) |
| 178 | { |
| 179 | #ifdef JUMP_LABEL_NOP_SIZE |
| 180 | return JUMP_LABEL_NOP_SIZE; |
| 181 | #else |
| 182 | return arch_jump_entry_size(entry); |
| 183 | #endif |
| 184 | } |
| 185 | |
| 186 | #endif |
| 187 | #endif |
| 188 | |
| 189 | #ifndef __ASSEMBLY__ |
| 190 | |
| 191 | enum jump_label_type { |
| 192 | JUMP_LABEL_NOP = 0, |
| 193 | JUMP_LABEL_JMP, |
| 194 | }; |
| 195 | |
| 196 | struct module; |
| 197 | |
| 198 | #ifdef CONFIG_JUMP_LABEL |
| 199 | |
| 200 | #define JUMP_TYPE_FALSE 0UL |
| 201 | #define JUMP_TYPE_TRUE 1UL |
| 202 | #define JUMP_TYPE_LINKED 2UL |
| 203 | #define JUMP_TYPE_MASK 3UL |
| 204 | |
| 205 | static __always_inline bool static_key_false(struct static_key *key) |
| 206 | { |
| 207 | return arch_static_branch(key, false); |
| 208 | } |
| 209 | |
| 210 | static __always_inline bool static_key_true(struct static_key *key) |
| 211 | { |
| 212 | return !arch_static_branch(key, true); |
| 213 | } |
| 214 | |
| 215 | extern struct jump_entry __start___jump_table[]; |
| 216 | extern struct jump_entry __stop___jump_table[]; |
| 217 | |
| 218 | extern void jump_label_init(void); |
| 219 | extern void jump_label_lock(void); |
| 220 | extern void jump_label_unlock(void); |
| 221 | extern void arch_jump_label_transform(struct jump_entry *entry, |
| 222 | enum jump_label_type type); |
| 223 | extern bool arch_jump_label_transform_queue(struct jump_entry *entry, |
| 224 | enum jump_label_type type); |
| 225 | extern void arch_jump_label_transform_apply(void); |
| 226 | extern int jump_label_text_reserved(void *start, void *end); |
| 227 | extern bool static_key_slow_inc(struct static_key *key); |
| 228 | extern bool static_key_fast_inc_not_disabled(struct static_key *key); |
| 229 | extern void static_key_slow_dec(struct static_key *key); |
| 230 | extern bool static_key_slow_inc_cpuslocked(struct static_key *key); |
| 231 | extern void static_key_slow_dec_cpuslocked(struct static_key *key); |
| 232 | extern int static_key_count(struct static_key *key); |
| 233 | extern void static_key_enable(struct static_key *key); |
| 234 | extern void static_key_disable(struct static_key *key); |
| 235 | extern void static_key_enable_cpuslocked(struct static_key *key); |
| 236 | extern void static_key_disable_cpuslocked(struct static_key *key); |
| 237 | extern enum jump_label_type jump_label_init_type(struct jump_entry *entry); |
| 238 | |
| 239 | /* |
| 240 | * We should be using ATOMIC_INIT() for initializing .enabled, but |
| 241 | * the inclusion of atomic.h is problematic for inclusion of jump_label.h |
| 242 | * in 'low-level' headers. Thus, we are initializing .enabled with a |
| 243 | * raw value, but have added a BUILD_BUG_ON() to catch any issues in |
| 244 | * jump_label_init() see: kernel/jump_label.c. |
| 245 | */ |
| 246 | #define STATIC_KEY_INIT_TRUE \ |
| 247 | { .enabled = { 1 }, \ |
| 248 | { .type = JUMP_TYPE_TRUE } } |
| 249 | #define STATIC_KEY_INIT_FALSE \ |
| 250 | { .enabled = { 0 }, \ |
| 251 | { .type = JUMP_TYPE_FALSE } } |
| 252 | |
| 253 | #else /* !CONFIG_JUMP_LABEL */ |
| 254 | |
| 255 | #include <linux/atomic.h> |
| 256 | #include <linux/bug.h> |
| 257 | |
| 258 | static __always_inline int static_key_count(struct static_key *key) |
| 259 | { |
| 260 | return arch_atomic_read(&key->enabled); |
| 261 | } |
| 262 | |
| 263 | static __always_inline void jump_label_init(void) |
| 264 | { |
| 265 | static_key_initialized = true; |
| 266 | } |
| 267 | |
| 268 | static __always_inline bool static_key_false(struct static_key *key) |
| 269 | { |
| 270 | if (unlikely_notrace(static_key_count(key) > 0)) |
| 271 | return true; |
| 272 | return false; |
| 273 | } |
| 274 | |
| 275 | static __always_inline bool static_key_true(struct static_key *key) |
| 276 | { |
| 277 | if (likely_notrace(static_key_count(key) > 0)) |
| 278 | return true; |
| 279 | return false; |
| 280 | } |
| 281 | |
| 282 | static inline bool static_key_fast_inc_not_disabled(struct static_key *key) |
| 283 | { |
| 284 | int v; |
| 285 | |
| 286 | STATIC_KEY_CHECK_USE(key); |
| 287 | /* |
| 288 | * Prevent key->enabled getting negative to follow the same semantics |
| 289 | * as for CONFIG_JUMP_LABEL=y, see kernel/jump_label.c comment. |
| 290 | */ |
| 291 | v = atomic_read(&key->enabled); |
| 292 | do { |
| 293 | if (v < 0 || (v + 1) < 0) |
| 294 | return false; |
| 295 | } while (!likely(atomic_try_cmpxchg(&key->enabled, &v, v + 1))); |
| 296 | return true; |
| 297 | } |
| 298 | #define static_key_slow_inc(key) static_key_fast_inc_not_disabled(key) |
| 299 | |
| 300 | static inline void static_key_slow_dec(struct static_key *key) |
| 301 | { |
| 302 | STATIC_KEY_CHECK_USE(key); |
| 303 | atomic_dec(&key->enabled); |
| 304 | } |
| 305 | |
| 306 | #define static_key_slow_inc_cpuslocked(key) static_key_slow_inc(key) |
| 307 | #define static_key_slow_dec_cpuslocked(key) static_key_slow_dec(key) |
| 308 | |
| 309 | static inline int jump_label_text_reserved(void *start, void *end) |
| 310 | { |
| 311 | return 0; |
| 312 | } |
| 313 | |
| 314 | static inline void jump_label_lock(void) {} |
| 315 | static inline void jump_label_unlock(void) {} |
| 316 | |
| 317 | static inline void static_key_enable(struct static_key *key) |
| 318 | { |
| 319 | STATIC_KEY_CHECK_USE(key); |
| 320 | |
| 321 | if (atomic_read(&key->enabled) != 0) { |
| 322 | WARN_ON_ONCE(atomic_read(&key->enabled) != 1); |
| 323 | return; |
| 324 | } |
| 325 | atomic_set(&key->enabled, 1); |
| 326 | } |
| 327 | |
| 328 | static inline void static_key_disable(struct static_key *key) |
| 329 | { |
| 330 | STATIC_KEY_CHECK_USE(key); |
| 331 | |
| 332 | if (atomic_read(&key->enabled) != 1) { |
| 333 | WARN_ON_ONCE(atomic_read(&key->enabled) != 0); |
| 334 | return; |
| 335 | } |
| 336 | atomic_set(&key->enabled, 0); |
| 337 | } |
| 338 | |
| 339 | #define static_key_enable_cpuslocked(k) static_key_enable((k)) |
| 340 | #define static_key_disable_cpuslocked(k) static_key_disable((k)) |
| 341 | |
| 342 | #define STATIC_KEY_INIT_TRUE { .enabled = ATOMIC_INIT(1) } |
| 343 | #define STATIC_KEY_INIT_FALSE { .enabled = ATOMIC_INIT(0) } |
| 344 | |
| 345 | #endif /* CONFIG_JUMP_LABEL */ |
| 346 | |
| 347 | #define STATIC_KEY_INIT STATIC_KEY_INIT_FALSE |
| 348 | #define jump_label_enabled static_key_enabled |
| 349 | |
| 350 | /* -------------------------------------------------------------------------- */ |
| 351 | |
| 352 | /* |
| 353 | * Two type wrappers around static_key, such that we can use compile time |
| 354 | * type differentiation to emit the right code. |
| 355 | * |
| 356 | * All the below code is macros in order to play type games. |
| 357 | */ |
| 358 | |
| 359 | struct static_key_true { |
| 360 | struct static_key key; |
| 361 | }; |
| 362 | |
| 363 | struct static_key_false { |
| 364 | struct static_key key; |
| 365 | }; |
| 366 | |
| 367 | #define STATIC_KEY_TRUE_INIT (struct static_key_true) { .key = STATIC_KEY_INIT_TRUE, } |
| 368 | #define STATIC_KEY_FALSE_INIT (struct static_key_false){ .key = STATIC_KEY_INIT_FALSE, } |
| 369 | |
| 370 | #define DEFINE_STATIC_KEY_TRUE(name) \ |
| 371 | struct static_key_true name = STATIC_KEY_TRUE_INIT |
| 372 | |
| 373 | #define DEFINE_STATIC_KEY_TRUE_RO(name) \ |
| 374 | struct static_key_true name __ro_after_init = STATIC_KEY_TRUE_INIT |
| 375 | |
| 376 | #define DECLARE_STATIC_KEY_TRUE(name) \ |
| 377 | extern struct static_key_true name |
| 378 | |
| 379 | #define DEFINE_STATIC_KEY_FALSE(name) \ |
| 380 | struct static_key_false name = STATIC_KEY_FALSE_INIT |
| 381 | |
| 382 | #define DEFINE_STATIC_KEY_FALSE_RO(name) \ |
| 383 | struct static_key_false name __ro_after_init = STATIC_KEY_FALSE_INIT |
| 384 | |
| 385 | #define DECLARE_STATIC_KEY_FALSE(name) \ |
| 386 | extern struct static_key_false name |
| 387 | |
| 388 | #define DEFINE_STATIC_KEY_ARRAY_TRUE(name, count) \ |
| 389 | struct static_key_true name[count] = { \ |
| 390 | [0 ... (count) - 1] = STATIC_KEY_TRUE_INIT, \ |
| 391 | } |
| 392 | |
| 393 | #define DEFINE_STATIC_KEY_ARRAY_FALSE(name, count) \ |
| 394 | struct static_key_false name[count] = { \ |
| 395 | [0 ... (count) - 1] = STATIC_KEY_FALSE_INIT, \ |
| 396 | } |
| 397 | |
| 398 | #define _DEFINE_STATIC_KEY_1(name) DEFINE_STATIC_KEY_TRUE(name) |
| 399 | #define _DEFINE_STATIC_KEY_0(name) DEFINE_STATIC_KEY_FALSE(name) |
| 400 | #define DEFINE_STATIC_KEY_MAYBE(cfg, name) \ |
| 401 | __PASTE(_DEFINE_STATIC_KEY_, IS_ENABLED(cfg))(name) |
| 402 | |
| 403 | #define _DEFINE_STATIC_KEY_RO_1(name) DEFINE_STATIC_KEY_TRUE_RO(name) |
| 404 | #define _DEFINE_STATIC_KEY_RO_0(name) DEFINE_STATIC_KEY_FALSE_RO(name) |
| 405 | #define DEFINE_STATIC_KEY_MAYBE_RO(cfg, name) \ |
| 406 | __PASTE(_DEFINE_STATIC_KEY_RO_, IS_ENABLED(cfg))(name) |
| 407 | |
| 408 | #define _DECLARE_STATIC_KEY_1(name) DECLARE_STATIC_KEY_TRUE(name) |
| 409 | #define _DECLARE_STATIC_KEY_0(name) DECLARE_STATIC_KEY_FALSE(name) |
| 410 | #define DECLARE_STATIC_KEY_MAYBE(cfg, name) \ |
| 411 | __PASTE(_DECLARE_STATIC_KEY_, IS_ENABLED(cfg))(name) |
| 412 | |
| 413 | extern bool ____wrong_branch_error(void); |
| 414 | |
| 415 | #define static_key_enabled(x) \ |
| 416 | ({ \ |
| 417 | if (!__builtin_types_compatible_p(typeof(*x), struct static_key) && \ |
| 418 | !__builtin_types_compatible_p(typeof(*x), struct static_key_true) &&\ |
| 419 | !__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \ |
| 420 | ____wrong_branch_error(); \ |
| 421 | static_key_count((struct static_key *)x) > 0; \ |
| 422 | }) |
| 423 | |
| 424 | #ifdef CONFIG_JUMP_LABEL |
| 425 | |
| 426 | /* |
| 427 | * Combine the right initial value (type) with the right branch order |
| 428 | * to generate the desired result. |
| 429 | * |
| 430 | * |
| 431 | * type\branch| likely (1) | unlikely (0) |
| 432 | * -----------+-----------------------+------------------ |
| 433 | * | | |
| 434 | * true (1) | ... | ... |
| 435 | * | NOP | JMP L |
| 436 | * | <br-stmts> | 1: ... |
| 437 | * | L: ... | |
| 438 | * | | |
| 439 | * | | L: <br-stmts> |
| 440 | * | | jmp 1b |
| 441 | * | | |
| 442 | * -----------+-----------------------+------------------ |
| 443 | * | | |
| 444 | * false (0) | ... | ... |
| 445 | * | JMP L | NOP |
| 446 | * | <br-stmts> | 1: ... |
| 447 | * | L: ... | |
| 448 | * | | |
| 449 | * | | L: <br-stmts> |
| 450 | * | | jmp 1b |
| 451 | * | | |
| 452 | * -----------+-----------------------+------------------ |
| 453 | * |
| 454 | * The initial value is encoded in the LSB of static_key::entries, |
| 455 | * type: 0 = false, 1 = true. |
| 456 | * |
| 457 | * The branch type is encoded in the LSB of jump_entry::key, |
| 458 | * branch: 0 = unlikely, 1 = likely. |
| 459 | * |
| 460 | * This gives the following logic table: |
| 461 | * |
| 462 | * enabled type branch instuction |
| 463 | * -----------------------------+----------- |
| 464 | * 0 0 0 | NOP |
| 465 | * 0 0 1 | JMP |
| 466 | * 0 1 0 | NOP |
| 467 | * 0 1 1 | JMP |
| 468 | * |
| 469 | * 1 0 0 | JMP |
| 470 | * 1 0 1 | NOP |
| 471 | * 1 1 0 | JMP |
| 472 | * 1 1 1 | NOP |
| 473 | * |
| 474 | * Which gives the following functions: |
| 475 | * |
| 476 | * dynamic: instruction = enabled ^ branch |
| 477 | * static: instruction = type ^ branch |
| 478 | * |
| 479 | * See jump_label_type() / jump_label_init_type(). |
| 480 | */ |
| 481 | |
| 482 | #define static_branch_likely(x) \ |
| 483 | ({ \ |
| 484 | bool branch; \ |
| 485 | if (__builtin_types_compatible_p(typeof(*x), struct static_key_true)) \ |
| 486 | branch = !arch_static_branch(&(x)->key, true); \ |
| 487 | else if (__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \ |
| 488 | branch = !arch_static_branch_jump(&(x)->key, true); \ |
| 489 | else \ |
| 490 | branch = ____wrong_branch_error(); \ |
| 491 | likely_notrace(branch); \ |
| 492 | }) |
| 493 | |
| 494 | #define static_branch_unlikely(x) \ |
| 495 | ({ \ |
| 496 | bool branch; \ |
| 497 | if (__builtin_types_compatible_p(typeof(*x), struct static_key_true)) \ |
| 498 | branch = arch_static_branch_jump(&(x)->key, false); \ |
| 499 | else if (__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \ |
| 500 | branch = arch_static_branch(&(x)->key, false); \ |
| 501 | else \ |
| 502 | branch = ____wrong_branch_error(); \ |
| 503 | unlikely_notrace(branch); \ |
| 504 | }) |
| 505 | |
| 506 | #else /* !CONFIG_JUMP_LABEL */ |
| 507 | |
| 508 | #define static_branch_likely(x) likely_notrace(static_key_enabled(&(x)->key)) |
| 509 | #define static_branch_unlikely(x) unlikely_notrace(static_key_enabled(&(x)->key)) |
| 510 | |
| 511 | #endif /* CONFIG_JUMP_LABEL */ |
| 512 | |
| 513 | #define static_branch_maybe(config, x) \ |
| 514 | (IS_ENABLED(config) ? static_branch_likely(x) \ |
| 515 | : static_branch_unlikely(x)) |
| 516 | |
| 517 | /* |
| 518 | * Advanced usage; refcount, branch is enabled when: count != 0 |
| 519 | */ |
| 520 | |
| 521 | #define static_branch_inc(x) static_key_slow_inc(&(x)->key) |
| 522 | #define static_branch_dec(x) static_key_slow_dec(&(x)->key) |
| 523 | #define static_branch_inc_cpuslocked(x) static_key_slow_inc_cpuslocked(&(x)->key) |
| 524 | #define static_branch_dec_cpuslocked(x) static_key_slow_dec_cpuslocked(&(x)->key) |
| 525 | |
| 526 | /* |
| 527 | * Normal usage; boolean enable/disable. |
| 528 | */ |
| 529 | |
| 530 | #define static_branch_enable(x) static_key_enable(&(x)->key) |
| 531 | #define static_branch_disable(x) static_key_disable(&(x)->key) |
| 532 | #define static_branch_enable_cpuslocked(x) static_key_enable_cpuslocked(&(x)->key) |
| 533 | #define static_branch_disable_cpuslocked(x) static_key_disable_cpuslocked(&(x)->key) |
| 534 | |
| 535 | #endif /* __ASSEMBLY__ */ |
| 536 | |
| 537 | #endif /* _LINUX_JUMP_LABEL_H */ |