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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
bf5438fc JB |
2 | #ifndef _LINUX_JUMP_LABEL_H |
3 | #define _LINUX_JUMP_LABEL_H | |
4 | ||
efb3040d PZ |
5 | /* |
6 | * Jump label support | |
7 | * | |
8 | * Copyright (C) 2009-2012 Jason Baron <jbaron@redhat.com> | |
90eec103 | 9 | * Copyright (C) 2011-2012 Red Hat, Inc., Peter Zijlstra |
efb3040d | 10 | * |
412758cb JB |
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); | |
ef0da55a CM |
25 | * DEFINE_STATIC_KEY_ARRAY_TRUE(keys, count); |
26 | * DEFINE_STATIC_KEY_ARRAY_FALSE(keys, count); | |
1975dbc2 JC |
27 | * static_branch_likely() |
28 | * static_branch_unlikely() | |
412758cb | 29 | * |
efb3040d | 30 | * Jump labels provide an interface to generate dynamic branches using |
412758cb JB |
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. | |
efb3040d | 41 | * |
412758cb JB |
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. | |
efb3040d | 50 | * |
1975dbc2 | 51 | * In addition to static_branch_{enable,disable}, we can also reference count |
412758cb JB |
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 | |
1975dbc2 | 54 | * static_branch_dec() as a 'make more false'. |
412758cb JB |
55 | * |
56 | * Since this relies on modifying code, the branch modifying functions | |
efb3040d | 57 | * must be considered absolute slow paths (machine wide synchronization etc.). |
fd3cbdc0 | 58 | * OTOH, since the affected branches are unconditional, their runtime overhead |
efb3040d PZ |
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 | * | |
fd3cbdc0 | 63 | * When the control is directly exposed to userspace, it is prudent to delay the |
efb3040d | 64 | * decrement to avoid high frequency code modifications which can (and do) |
c5905afb IM |
65 | * cause significant performance degradation. Struct static_key_deferred and |
66 | * static_key_slow_dec_deferred() provide for this. | |
efb3040d | 67 | * |
412758cb JB |
68 | * Lacking toolchain and or architecture support, static keys fall back to a |
69 | * simple conditional branch. | |
c5905afb | 70 | * |
8e2a46a4 | 71 | * Additional babbling in: Documentation/staging/static-keys.rst |
fd3cbdc0 | 72 | */ |
efb3040d | 73 | |
c0ccf6f9 AB |
74 | #ifndef __ASSEMBLY__ |
75 | ||
d430d3d7 JB |
76 | #include <linux/types.h> |
77 | #include <linux/compiler.h> | |
c4b2c0c5 HFS |
78 | |
79 | extern bool static_key_initialized; | |
80 | ||
5cdda511 BP |
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)) | |
d430d3d7 | 84 | |
e9666d10 | 85 | #ifdef CONFIG_JUMP_LABEL |
d430d3d7 | 86 | |
c5905afb | 87 | struct static_key { |
d430d3d7 | 88 | atomic_t enabled; |
3821fd35 | 89 | /* |
b17ef2ed SRV |
90 | * Note: |
91 | * To make anonymous unions work with old compilers, the static | |
92 | * initialization of them requires brackets. This creates a dependency | |
93 | * on the order of the struct with the initializers. If any fields | |
94 | * are added, STATIC_KEY_INIT_TRUE and STATIC_KEY_INIT_FALSE may need | |
95 | * to be modified. | |
96 | * | |
3821fd35 JB |
97 | * bit 0 => 1 if key is initially true |
98 | * 0 if initially false | |
99 | * bit 1 => 1 if points to struct static_key_mod | |
100 | * 0 if points to struct jump_entry | |
101 | */ | |
102 | union { | |
103 | unsigned long type; | |
104 | struct jump_entry *entries; | |
105 | struct static_key_mod *next; | |
106 | }; | |
d430d3d7 JB |
107 | }; |
108 | ||
ea5e9539 MG |
109 | #else |
110 | struct static_key { | |
111 | atomic_t enabled; | |
112 | }; | |
e9666d10 | 113 | #endif /* CONFIG_JUMP_LABEL */ |
c0ccf6f9 AB |
114 | #endif /* __ASSEMBLY__ */ |
115 | ||
e9666d10 | 116 | #ifdef CONFIG_JUMP_LABEL |
c0ccf6f9 | 117 | #include <asm/jump_label.h> |
9ae033ac AB |
118 | |
119 | #ifndef __ASSEMBLY__ | |
50ff18ab AB |
120 | #ifdef CONFIG_HAVE_ARCH_JUMP_LABEL_RELATIVE |
121 | ||
122 | struct jump_entry { | |
123 | s32 code; | |
124 | s32 target; | |
125 | long key; // key may be far away from the core kernel under KASLR | |
126 | }; | |
127 | ||
128 | static inline unsigned long jump_entry_code(const struct jump_entry *entry) | |
129 | { | |
130 | return (unsigned long)&entry->code + entry->code; | |
131 | } | |
132 | ||
133 | static inline unsigned long jump_entry_target(const struct jump_entry *entry) | |
134 | { | |
135 | return (unsigned long)&entry->target + entry->target; | |
136 | } | |
137 | ||
138 | static inline struct static_key *jump_entry_key(const struct jump_entry *entry) | |
139 | { | |
19483677 | 140 | long offset = entry->key & ~3L; |
50ff18ab AB |
141 | |
142 | return (struct static_key *)((unsigned long)&entry->key + offset); | |
143 | } | |
144 | ||
145 | #else | |
9ae033ac AB |
146 | |
147 | static inline unsigned long jump_entry_code(const struct jump_entry *entry) | |
148 | { | |
149 | return entry->code; | |
150 | } | |
151 | ||
152 | static inline unsigned long jump_entry_target(const struct jump_entry *entry) | |
153 | { | |
154 | return entry->target; | |
155 | } | |
156 | ||
157 | static inline struct static_key *jump_entry_key(const struct jump_entry *entry) | |
158 | { | |
19483677 | 159 | return (struct static_key *)((unsigned long)entry->key & ~3UL); |
9ae033ac AB |
160 | } |
161 | ||
50ff18ab AB |
162 | #endif |
163 | ||
9ae033ac AB |
164 | static inline bool jump_entry_is_branch(const struct jump_entry *entry) |
165 | { | |
166 | return (unsigned long)entry->key & 1UL; | |
167 | } | |
168 | ||
169 | static inline bool jump_entry_is_init(const struct jump_entry *entry) | |
170 | { | |
19483677 | 171 | return (unsigned long)entry->key & 2UL; |
9ae033ac AB |
172 | } |
173 | ||
5af0ea29 | 174 | static inline void jump_entry_set_init(struct jump_entry *entry, bool set) |
9ae033ac | 175 | { |
5af0ea29 PZ |
176 | if (set) |
177 | entry->key |= 2; | |
178 | else | |
179 | entry->key &= ~2; | |
9ae033ac AB |
180 | } |
181 | ||
fa5e5dc3 PZ |
182 | static inline int jump_entry_size(struct jump_entry *entry) |
183 | { | |
184 | #ifdef JUMP_LABEL_NOP_SIZE | |
185 | return JUMP_LABEL_NOP_SIZE; | |
186 | #else | |
187 | return arch_jump_entry_size(entry); | |
188 | #endif | |
189 | } | |
190 | ||
9ae033ac | 191 | #endif |
c0ccf6f9 AB |
192 | #endif |
193 | ||
194 | #ifndef __ASSEMBLY__ | |
bf5438fc JB |
195 | |
196 | enum jump_label_type { | |
76b235c6 PZ |
197 | JUMP_LABEL_NOP = 0, |
198 | JUMP_LABEL_JMP, | |
bf5438fc JB |
199 | }; |
200 | ||
201 | struct module; | |
202 | ||
e9666d10 | 203 | #ifdef CONFIG_JUMP_LABEL |
4c5ea0a9 | 204 | |
3821fd35 JB |
205 | #define JUMP_TYPE_FALSE 0UL |
206 | #define JUMP_TYPE_TRUE 1UL | |
207 | #define JUMP_TYPE_LINKED 2UL | |
208 | #define JUMP_TYPE_MASK 3UL | |
c5905afb IM |
209 | |
210 | static __always_inline bool static_key_false(struct static_key *key) | |
211 | { | |
11276d53 | 212 | return arch_static_branch(key, false); |
c5905afb | 213 | } |
d430d3d7 | 214 | |
c5905afb IM |
215 | static __always_inline bool static_key_true(struct static_key *key) |
216 | { | |
11276d53 | 217 | return !arch_static_branch(key, true); |
c5905afb IM |
218 | } |
219 | ||
bf5438fc JB |
220 | extern struct jump_entry __start___jump_table[]; |
221 | extern struct jump_entry __stop___jump_table[]; | |
222 | ||
97ce2c88 | 223 | extern void jump_label_init(void); |
91bad2f8 JB |
224 | extern void jump_label_lock(void); |
225 | extern void jump_label_unlock(void); | |
bf5438fc | 226 | extern void arch_jump_label_transform(struct jump_entry *entry, |
37348804 | 227 | enum jump_label_type type); |
20284aa7 JF |
228 | extern void arch_jump_label_transform_static(struct jump_entry *entry, |
229 | enum jump_label_type type); | |
c2ba8a15 DBO |
230 | extern bool arch_jump_label_transform_queue(struct jump_entry *entry, |
231 | enum jump_label_type type); | |
232 | extern void arch_jump_label_transform_apply(void); | |
4c3ef6d7 | 233 | extern int jump_label_text_reserved(void *start, void *end); |
c5905afb IM |
234 | extern void static_key_slow_inc(struct static_key *key); |
235 | extern void static_key_slow_dec(struct static_key *key); | |
ce48c146 PZ |
236 | extern void static_key_slow_inc_cpuslocked(struct static_key *key); |
237 | extern void static_key_slow_dec_cpuslocked(struct static_key *key); | |
d430d3d7 | 238 | extern void jump_label_apply_nops(struct module *mod); |
1f69bf9c JB |
239 | extern int static_key_count(struct static_key *key); |
240 | extern void static_key_enable(struct static_key *key); | |
241 | extern void static_key_disable(struct static_key *key); | |
5a40527f MZ |
242 | extern void static_key_enable_cpuslocked(struct static_key *key); |
243 | extern void static_key_disable_cpuslocked(struct static_key *key); | |
c5905afb | 244 | |
1f69bf9c JB |
245 | /* |
246 | * We should be using ATOMIC_INIT() for initializing .enabled, but | |
247 | * the inclusion of atomic.h is problematic for inclusion of jump_label.h | |
248 | * in 'low-level' headers. Thus, we are initializing .enabled with a | |
249 | * raw value, but have added a BUILD_BUG_ON() to catch any issues in | |
250 | * jump_label_init() see: kernel/jump_label.c. | |
251 | */ | |
11276d53 | 252 | #define STATIC_KEY_INIT_TRUE \ |
1f69bf9c | 253 | { .enabled = { 1 }, \ |
cd8d860d | 254 | { .entries = (void *)JUMP_TYPE_TRUE } } |
11276d53 | 255 | #define STATIC_KEY_INIT_FALSE \ |
1f69bf9c | 256 | { .enabled = { 0 }, \ |
cd8d860d | 257 | { .entries = (void *)JUMP_TYPE_FALSE } } |
bf5438fc | 258 | |
e9666d10 | 259 | #else /* !CONFIG_JUMP_LABEL */ |
bf5438fc | 260 | |
1f69bf9c JB |
261 | #include <linux/atomic.h> |
262 | #include <linux/bug.h> | |
263 | ||
4c5ea0a9 PB |
264 | static inline int static_key_count(struct static_key *key) |
265 | { | |
266 | return atomic_read(&key->enabled); | |
267 | } | |
268 | ||
97ce2c88 JF |
269 | static __always_inline void jump_label_init(void) |
270 | { | |
c4b2c0c5 | 271 | static_key_initialized = true; |
97ce2c88 JF |
272 | } |
273 | ||
c5905afb IM |
274 | static __always_inline bool static_key_false(struct static_key *key) |
275 | { | |
2f0df49c | 276 | if (unlikely_notrace(static_key_count(key) > 0)) |
c5905afb IM |
277 | return true; |
278 | return false; | |
279 | } | |
280 | ||
281 | static __always_inline bool static_key_true(struct static_key *key) | |
d430d3d7 | 282 | { |
2f0df49c | 283 | if (likely_notrace(static_key_count(key) > 0)) |
d430d3d7 JB |
284 | return true; |
285 | return false; | |
286 | } | |
bf5438fc | 287 | |
c5905afb | 288 | static inline void static_key_slow_inc(struct static_key *key) |
d430d3d7 | 289 | { |
5cdda511 | 290 | STATIC_KEY_CHECK_USE(key); |
d430d3d7 JB |
291 | atomic_inc(&key->enabled); |
292 | } | |
bf5438fc | 293 | |
c5905afb | 294 | static inline void static_key_slow_dec(struct static_key *key) |
bf5438fc | 295 | { |
5cdda511 | 296 | STATIC_KEY_CHECK_USE(key); |
d430d3d7 | 297 | atomic_dec(&key->enabled); |
bf5438fc JB |
298 | } |
299 | ||
ce48c146 PZ |
300 | #define static_key_slow_inc_cpuslocked(key) static_key_slow_inc(key) |
301 | #define static_key_slow_dec_cpuslocked(key) static_key_slow_dec(key) | |
302 | ||
4c3ef6d7 JB |
303 | static inline int jump_label_text_reserved(void *start, void *end) |
304 | { | |
305 | return 0; | |
306 | } | |
307 | ||
91bad2f8 JB |
308 | static inline void jump_label_lock(void) {} |
309 | static inline void jump_label_unlock(void) {} | |
310 | ||
d430d3d7 JB |
311 | static inline int jump_label_apply_nops(struct module *mod) |
312 | { | |
313 | return 0; | |
314 | } | |
b2029520 | 315 | |
e33886b3 PZ |
316 | static inline void static_key_enable(struct static_key *key) |
317 | { | |
5cdda511 | 318 | STATIC_KEY_CHECK_USE(key); |
e33886b3 | 319 | |
1dbb6704 PB |
320 | if (atomic_read(&key->enabled) != 0) { |
321 | WARN_ON_ONCE(atomic_read(&key->enabled) != 1); | |
322 | return; | |
323 | } | |
324 | atomic_set(&key->enabled, 1); | |
e33886b3 PZ |
325 | } |
326 | ||
327 | static inline void static_key_disable(struct static_key *key) | |
328 | { | |
5cdda511 | 329 | STATIC_KEY_CHECK_USE(key); |
e33886b3 | 330 | |
1dbb6704 PB |
331 | if (atomic_read(&key->enabled) != 1) { |
332 | WARN_ON_ONCE(atomic_read(&key->enabled) != 0); | |
333 | return; | |
334 | } | |
335 | atomic_set(&key->enabled, 0); | |
e33886b3 PZ |
336 | } |
337 | ||
5a40527f MZ |
338 | #define static_key_enable_cpuslocked(k) static_key_enable((k)) |
339 | #define static_key_disable_cpuslocked(k) static_key_disable((k)) | |
340 | ||
1f69bf9c JB |
341 | #define STATIC_KEY_INIT_TRUE { .enabled = ATOMIC_INIT(1) } |
342 | #define STATIC_KEY_INIT_FALSE { .enabled = ATOMIC_INIT(0) } | |
343 | ||
e9666d10 | 344 | #endif /* CONFIG_JUMP_LABEL */ |
1f69bf9c JB |
345 | |
346 | #define STATIC_KEY_INIT STATIC_KEY_INIT_FALSE | |
347 | #define jump_label_enabled static_key_enabled | |
348 | ||
11276d53 PZ |
349 | /* -------------------------------------------------------------------------- */ |
350 | ||
351 | /* | |
352 | * Two type wrappers around static_key, such that we can use compile time | |
353 | * type differentiation to emit the right code. | |
354 | * | |
355 | * All the below code is macros in order to play type games. | |
356 | */ | |
357 | ||
358 | struct static_key_true { | |
359 | struct static_key key; | |
360 | }; | |
361 | ||
362 | struct static_key_false { | |
363 | struct static_key key; | |
364 | }; | |
365 | ||
366 | #define STATIC_KEY_TRUE_INIT (struct static_key_true) { .key = STATIC_KEY_INIT_TRUE, } | |
367 | #define STATIC_KEY_FALSE_INIT (struct static_key_false){ .key = STATIC_KEY_INIT_FALSE, } | |
368 | ||
369 | #define DEFINE_STATIC_KEY_TRUE(name) \ | |
370 | struct static_key_true name = STATIC_KEY_TRUE_INIT | |
371 | ||
b5cb15d9 CR |
372 | #define DEFINE_STATIC_KEY_TRUE_RO(name) \ |
373 | struct static_key_true name __ro_after_init = STATIC_KEY_TRUE_INIT | |
374 | ||
b8fb0378 TL |
375 | #define DECLARE_STATIC_KEY_TRUE(name) \ |
376 | extern struct static_key_true name | |
377 | ||
11276d53 PZ |
378 | #define DEFINE_STATIC_KEY_FALSE(name) \ |
379 | struct static_key_false name = STATIC_KEY_FALSE_INIT | |
380 | ||
b5cb15d9 CR |
381 | #define DEFINE_STATIC_KEY_FALSE_RO(name) \ |
382 | struct static_key_false name __ro_after_init = STATIC_KEY_FALSE_INIT | |
383 | ||
b8fb0378 TL |
384 | #define DECLARE_STATIC_KEY_FALSE(name) \ |
385 | extern struct static_key_false name | |
386 | ||
ef0da55a CM |
387 | #define DEFINE_STATIC_KEY_ARRAY_TRUE(name, count) \ |
388 | struct static_key_true name[count] = { \ | |
389 | [0 ... (count) - 1] = STATIC_KEY_TRUE_INIT, \ | |
390 | } | |
391 | ||
392 | #define DEFINE_STATIC_KEY_ARRAY_FALSE(name, count) \ | |
393 | struct static_key_false name[count] = { \ | |
394 | [0 ... (count) - 1] = STATIC_KEY_FALSE_INIT, \ | |
395 | } | |
396 | ||
0d66ccc1 KC |
397 | #define _DEFINE_STATIC_KEY_1(name) DEFINE_STATIC_KEY_TRUE(name) |
398 | #define _DEFINE_STATIC_KEY_0(name) DEFINE_STATIC_KEY_FALSE(name) | |
399 | #define DEFINE_STATIC_KEY_MAYBE(cfg, name) \ | |
400 | __PASTE(_DEFINE_STATIC_KEY_, IS_ENABLED(cfg))(name) | |
401 | ||
402 | #define _DEFINE_STATIC_KEY_RO_1(name) DEFINE_STATIC_KEY_TRUE_RO(name) | |
403 | #define _DEFINE_STATIC_KEY_RO_0(name) DEFINE_STATIC_KEY_FALSE_RO(name) | |
404 | #define DEFINE_STATIC_KEY_MAYBE_RO(cfg, name) \ | |
405 | __PASTE(_DEFINE_STATIC_KEY_RO_, IS_ENABLED(cfg))(name) | |
406 | ||
407 | #define _DECLARE_STATIC_KEY_1(name) DECLARE_STATIC_KEY_TRUE(name) | |
408 | #define _DECLARE_STATIC_KEY_0(name) DECLARE_STATIC_KEY_FALSE(name) | |
409 | #define DECLARE_STATIC_KEY_MAYBE(cfg, name) \ | |
410 | __PASTE(_DECLARE_STATIC_KEY_, IS_ENABLED(cfg))(name) | |
411 | ||
fa128fd7 TH |
412 | extern bool ____wrong_branch_error(void); |
413 | ||
414 | #define static_key_enabled(x) \ | |
415 | ({ \ | |
416 | if (!__builtin_types_compatible_p(typeof(*x), struct static_key) && \ | |
417 | !__builtin_types_compatible_p(typeof(*x), struct static_key_true) &&\ | |
418 | !__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \ | |
419 | ____wrong_branch_error(); \ | |
420 | static_key_count((struct static_key *)x) > 0; \ | |
421 | }) | |
422 | ||
e9666d10 | 423 | #ifdef CONFIG_JUMP_LABEL |
11276d53 PZ |
424 | |
425 | /* | |
426 | * Combine the right initial value (type) with the right branch order | |
427 | * to generate the desired result. | |
428 | * | |
429 | * | |
430 | * type\branch| likely (1) | unlikely (0) | |
431 | * -----------+-----------------------+------------------ | |
432 | * | | | |
433 | * true (1) | ... | ... | |
434 | * | NOP | JMP L | |
435 | * | <br-stmts> | 1: ... | |
436 | * | L: ... | | |
437 | * | | | |
438 | * | | L: <br-stmts> | |
439 | * | | jmp 1b | |
440 | * | | | |
441 | * -----------+-----------------------+------------------ | |
442 | * | | | |
443 | * false (0) | ... | ... | |
444 | * | JMP L | NOP | |
445 | * | <br-stmts> | 1: ... | |
446 | * | L: ... | | |
447 | * | | | |
448 | * | | L: <br-stmts> | |
449 | * | | jmp 1b | |
450 | * | | | |
451 | * -----------+-----------------------+------------------ | |
452 | * | |
453 | * The initial value is encoded in the LSB of static_key::entries, | |
454 | * type: 0 = false, 1 = true. | |
455 | * | |
456 | * The branch type is encoded in the LSB of jump_entry::key, | |
457 | * branch: 0 = unlikely, 1 = likely. | |
458 | * | |
459 | * This gives the following logic table: | |
460 | * | |
461 | * enabled type branch instuction | |
462 | * -----------------------------+----------- | |
463 | * 0 0 0 | NOP | |
464 | * 0 0 1 | JMP | |
465 | * 0 1 0 | NOP | |
466 | * 0 1 1 | JMP | |
467 | * | |
468 | * 1 0 0 | JMP | |
469 | * 1 0 1 | NOP | |
470 | * 1 1 0 | JMP | |
471 | * 1 1 1 | NOP | |
472 | * | |
473 | * Which gives the following functions: | |
474 | * | |
475 | * dynamic: instruction = enabled ^ branch | |
476 | * static: instruction = type ^ branch | |
477 | * | |
478 | * See jump_label_type() / jump_label_init_type(). | |
479 | */ | |
480 | ||
11276d53 PZ |
481 | #define static_branch_likely(x) \ |
482 | ({ \ | |
483 | bool branch; \ | |
484 | if (__builtin_types_compatible_p(typeof(*x), struct static_key_true)) \ | |
485 | branch = !arch_static_branch(&(x)->key, true); \ | |
486 | else if (__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \ | |
487 | branch = !arch_static_branch_jump(&(x)->key, true); \ | |
488 | else \ | |
489 | branch = ____wrong_branch_error(); \ | |
2f0df49c | 490 | likely_notrace(branch); \ |
11276d53 PZ |
491 | }) |
492 | ||
493 | #define static_branch_unlikely(x) \ | |
494 | ({ \ | |
495 | bool branch; \ | |
496 | if (__builtin_types_compatible_p(typeof(*x), struct static_key_true)) \ | |
497 | branch = arch_static_branch_jump(&(x)->key, false); \ | |
498 | else if (__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \ | |
499 | branch = arch_static_branch(&(x)->key, false); \ | |
500 | else \ | |
501 | branch = ____wrong_branch_error(); \ | |
2f0df49c | 502 | unlikely_notrace(branch); \ |
11276d53 PZ |
503 | }) |
504 | ||
e9666d10 | 505 | #else /* !CONFIG_JUMP_LABEL */ |
11276d53 | 506 | |
2f0df49c SRV |
507 | #define static_branch_likely(x) likely_notrace(static_key_enabled(&(x)->key)) |
508 | #define static_branch_unlikely(x) unlikely_notrace(static_key_enabled(&(x)->key)) | |
11276d53 | 509 | |
e9666d10 | 510 | #endif /* CONFIG_JUMP_LABEL */ |
11276d53 | 511 | |
0d66ccc1 KC |
512 | #define static_branch_maybe(config, x) \ |
513 | (IS_ENABLED(config) ? static_branch_likely(x) \ | |
514 | : static_branch_unlikely(x)) | |
515 | ||
11276d53 PZ |
516 | /* |
517 | * Advanced usage; refcount, branch is enabled when: count != 0 | |
518 | */ | |
519 | ||
520 | #define static_branch_inc(x) static_key_slow_inc(&(x)->key) | |
521 | #define static_branch_dec(x) static_key_slow_dec(&(x)->key) | |
ce48c146 PZ |
522 | #define static_branch_inc_cpuslocked(x) static_key_slow_inc_cpuslocked(&(x)->key) |
523 | #define static_branch_dec_cpuslocked(x) static_key_slow_dec_cpuslocked(&(x)->key) | |
11276d53 PZ |
524 | |
525 | /* | |
526 | * Normal usage; boolean enable/disable. | |
527 | */ | |
528 | ||
5a40527f MZ |
529 | #define static_branch_enable(x) static_key_enable(&(x)->key) |
530 | #define static_branch_disable(x) static_key_disable(&(x)->key) | |
531 | #define static_branch_enable_cpuslocked(x) static_key_enable_cpuslocked(&(x)->key) | |
532 | #define static_branch_disable_cpuslocked(x) static_key_disable_cpuslocked(&(x)->key) | |
11276d53 | 533 | |
c0ccf6f9 | 534 | #endif /* __ASSEMBLY__ */ |
85b36c93 LR |
535 | |
536 | #endif /* _LINUX_JUMP_LABEL_H */ |