[deliverable/linux.git] / include / linux / jump_label.h

#ifndef _LINUX_JUMP_LABEL_H
#define _LINUX_JUMP_LABEL_H

/*
 * Jump label support
 *
 * Copyright (C) 2009-2012 Jason Baron <jbaron@redhat.com>
 * Copyright (C) 2011-2012 Red Hat, Inc., Peter Zijlstra
 *
 * DEPRECATED API:
 *
 * The use of 'struct static_key' directly, is now DEPRECATED. In addition
 * static_key_{true,false}() is also DEPRECATED. IE DO NOT use the following:
 *
 * struct static_key false = STATIC_KEY_INIT_FALSE;
 * struct static_key true = STATIC_KEY_INIT_TRUE;
 * static_key_true()
 * static_key_false()
 *
 * The updated API replacements are:
 *
 * DEFINE_STATIC_KEY_TRUE(key);
 * DEFINE_STATIC_KEY_FALSE(key);
 * static_branch_likely()
 * static_branch_unlikely()
 *
 * Jump labels provide an interface to generate dynamic branches using
 * self-modifying code. Assuming toolchain and architecture support, if we
 * define a "key" that is initially false via "DEFINE_STATIC_KEY_FALSE(key)",
 * an "if (static_branch_unlikely(&key))" statement is an unconditional branch
 * (which defaults to false - and the true block is placed out of line).
 * Similarly, we can define an initially true key via
 * "DEFINE_STATIC_KEY_TRUE(key)", and use it in the same
 * "if (static_branch_unlikely(&key))", in which case we will generate an
 * unconditional branch to the out-of-line true branch. Keys that are
 * initially true or false can be using in both static_branch_unlikely()
 * and static_branch_likely() statements.
 *
 * At runtime we can change the branch target by setting the key
 * to true via a call to static_branch_enable(), or false using
 * static_branch_disable(). If the direction of the branch is switched by
 * these calls then we run-time modify the branch target via a
 * no-op -> jump or jump -> no-op conversion. For example, for an
 * initially false key that is used in an "if (static_branch_unlikely(&key))"
 * statement, setting the key to true requires us to patch in a jump
 * to the out-of-line of true branch.
 *
 * In addition to static_branch_{enable,disable}, we can also reference count
 * the key or branch direction via static_branch_{inc,dec}. Thus,
 * static_branch_inc() can be thought of as a 'make more true' and
 * static_branch_dec() as a 'make more false'.
 *
 * Since this relies on modifying code, the branch modifying functions
 * must be considered absolute slow paths (machine wide synchronization etc.).
 * OTOH, since the affected branches are unconditional, their runtime overhead
 * will be absolutely minimal, esp. in the default (off) case where the total
 * effect is a single NOP of appropriate size. The on case will patch in a jump
 * to the out-of-line block.
 *
 * When the control is directly exposed to userspace, it is prudent to delay the
 * decrement to avoid high frequency code modifications which can (and do)
 * cause significant performance degradation. Struct static_key_deferred and
 * static_key_slow_dec_deferred() provide for this.
 *
 * Lacking toolchain and or architecture support, static keys fall back to a
 * simple conditional branch.
 *
 * Additional babbling in: Documentation/static-keys.txt
 */

#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
# define HAVE_JUMP_LABEL
#endif

#ifndef __ASSEMBLY__

#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/bug.h>

extern bool static_key_initialized;

#define STATIC_KEY_CHECK_USE() WARN(!static_key_initialized,		      \
				    "%s used before call to jump_label_init", \
				    __func__)

#ifdef HAVE_JUMP_LABEL

struct static_key {
	atomic_t enabled;
/* Set lsb bit to 1 if branch is default true, 0 ot */
	struct jump_entry *entries;
#ifdef CONFIG_MODULES
	struct static_key_mod *next;
#endif
};

#else
struct static_key {
	atomic_t enabled;
};
#endif	/* HAVE_JUMP_LABEL */
#endif /* __ASSEMBLY__ */

#ifdef HAVE_JUMP_LABEL
#include <asm/jump_label.h>
#endif

#ifndef __ASSEMBLY__

enum jump_label_type {
	JUMP_LABEL_NOP = 0,
	JUMP_LABEL_JMP,
};

struct module;

#include <linux/atomic.h>

static inline int static_key_count(struct static_key *key)
{
	return atomic_read(&key->enabled);
}

#ifdef HAVE_JUMP_LABEL

#define JUMP_TYPE_FALSE	0UL
#define JUMP_TYPE_TRUE	1UL
#define JUMP_TYPE_MASK	1UL

static __always_inline bool static_key_false(struct static_key *key)
{
	return arch_static_branch(key, false);
}

static __always_inline bool static_key_true(struct static_key *key)
{
	return !arch_static_branch(key, true);
}

extern struct jump_entry __start___jump_table[];
extern struct jump_entry __stop___jump_table[];

extern void jump_label_init(void);
extern void jump_label_lock(void);
extern void jump_label_unlock(void);
extern void arch_jump_label_transform(struct jump_entry *entry,
				      enum jump_label_type type);
extern void arch_jump_label_transform_static(struct jump_entry *entry,
					     enum jump_label_type type);
extern int jump_label_text_reserved(void *start, void *end);
extern void static_key_slow_inc(struct static_key *key);
extern void static_key_slow_dec(struct static_key *key);
extern void jump_label_apply_nops(struct module *mod);

#define STATIC_KEY_INIT_TRUE					\
	{ .enabled = ATOMIC_INIT(1),				\
	  .entries = (void *)JUMP_TYPE_TRUE }
#define STATIC_KEY_INIT_FALSE					\
	{ .enabled = ATOMIC_INIT(0),				\
	  .entries = (void *)JUMP_TYPE_FALSE }

#else  /* !HAVE_JUMP_LABEL */

static __always_inline void jump_label_init(void)
{
	static_key_initialized = true;
}

static __always_inline bool static_key_false(struct static_key *key)
{
	if (unlikely(static_key_count(key) > 0))
		return true;
	return false;
}

static __always_inline bool static_key_true(struct static_key *key)
{
	if (likely(static_key_count(key) > 0))
		return true;
	return false;
}

static inline void static_key_slow_inc(struct static_key *key)
{
	STATIC_KEY_CHECK_USE();
	atomic_inc(&key->enabled);
}

static inline void static_key_slow_dec(struct static_key *key)
{
	STATIC_KEY_CHECK_USE();
	atomic_dec(&key->enabled);
}

static inline int jump_label_text_reserved(void *start, void *end)
{
	return 0;
}

static inline void jump_label_lock(void) {}
static inline void jump_label_unlock(void) {}

static inline int jump_label_apply_nops(struct module *mod)
{
	return 0;
}

#define STATIC_KEY_INIT_TRUE	{ .enabled = ATOMIC_INIT(1) }
#define STATIC_KEY_INIT_FALSE	{ .enabled = ATOMIC_INIT(0) }

#endif	/* HAVE_JUMP_LABEL */

#define STATIC_KEY_INIT STATIC_KEY_INIT_FALSE
#define jump_label_enabled static_key_enabled

static inline void static_key_enable(struct static_key *key)
{
	int count = static_key_count(key);

	WARN_ON_ONCE(count < 0 || count > 1);

	if (!count)
		static_key_slow_inc(key);
}

static inline void static_key_disable(struct static_key *key)
{
	int count = static_key_count(key);

	WARN_ON_ONCE(count < 0 || count > 1);

	if (count)
		static_key_slow_dec(key);
}

/* -------------------------------------------------------------------------- */

/*
 * Two type wrappers around static_key, such that we can use compile time
 * type differentiation to emit the right code.
 *
 * All the below code is macros in order to play type games.
 */

struct static_key_true {
	struct static_key key;
};

struct static_key_false {
	struct static_key key;
};

#define STATIC_KEY_TRUE_INIT  (struct static_key_true) { .key = STATIC_KEY_INIT_TRUE,  }
#define STATIC_KEY_FALSE_INIT (struct static_key_false){ .key = STATIC_KEY_INIT_FALSE, }

#define DEFINE_STATIC_KEY_TRUE(name)	\
	struct static_key_true name = STATIC_KEY_TRUE_INIT

#define DEFINE_STATIC_KEY_FALSE(name)	\
	struct static_key_false name = STATIC_KEY_FALSE_INIT

extern bool ____wrong_branch_error(void);

#define static_key_enabled(x)							\
({										\
	if (!__builtin_types_compatible_p(typeof(*x), struct static_key) &&	\
	    !__builtin_types_compatible_p(typeof(*x), struct static_key_true) &&\
	    !__builtin_types_compatible_p(typeof(*x), struct static_key_false))	\
		____wrong_branch_error();					\
	static_key_count((struct static_key *)x) > 0;				\
})

#ifdef HAVE_JUMP_LABEL

/*
 * Combine the right initial value (type) with the right branch order
 * to generate the desired result.
 *
 *
 * type\branch|	likely (1)	      |	unlikely (0)
 * -----------+-----------------------+------------------
 *            |                       |
 *  true (1)  |	   ...		      |	   ...
 *            |    NOP		      |	   JMP L
 *            |    <br-stmts>	      |	1: ...
 *            |	L: ...		      |
 *            |			      |
 *            |			      |	L: <br-stmts>
 *            |			      |	   jmp 1b
 *            |                       |
 * -----------+-----------------------+------------------
 *            |                       |
 *  false (0) |	   ...		      |	   ...
 *            |    JMP L	      |	   NOP
 *            |    <br-stmts>	      |	1: ...
 *            |	L: ...		      |
 *            |			      |
 *            |			      |	L: <br-stmts>
 *            |			      |	   jmp 1b
 *            |                       |
 * -----------+-----------------------+------------------
 *
 * The initial value is encoded in the LSB of static_key::entries,
 * type: 0 = false, 1 = true.
 *
 * The branch type is encoded in the LSB of jump_entry::key,
 * branch: 0 = unlikely, 1 = likely.
 *
 * This gives the following logic table:
 *
 *	enabled	type	branch	  instuction
 * -----------------------------+-----------
 *	0	0	0	| NOP
 *	0	0	1	| JMP
 *	0	1	0	| NOP
 *	0	1	1	| JMP
 *
 *	1	0	0	| JMP
 *	1	0	1	| NOP
 *	1	1	0	| JMP
 *	1	1	1	| NOP
 *
 * Which gives the following functions:
 *
 *   dynamic: instruction = enabled ^ branch
 *   static:  instruction = type ^ branch
 *
 * See jump_label_type() / jump_label_init_type().
 */

#define static_branch_likely(x)							\
({										\
	bool branch;								\
	if (__builtin_types_compatible_p(typeof(*x), struct static_key_true))	\
		branch = !arch_static_branch(&(x)->key, true);			\
	else if (__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \
		branch = !arch_static_branch_jump(&(x)->key, true);		\
	else									\
		branch = ____wrong_branch_error();				\
	branch;									\
})

#define static_branch_unlikely(x)						\
({										\
	bool branch;								\
	if (__builtin_types_compatible_p(typeof(*x), struct static_key_true))	\
		branch = arch_static_branch_jump(&(x)->key, false);		\
	else if (__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \
		branch = arch_static_branch(&(x)->key, false);			\
	else									\
		branch = ____wrong_branch_error();				\
	branch;									\
})

#else /* !HAVE_JUMP_LABEL */

#define static_branch_likely(x)		likely(static_key_enabled(&(x)->key))
#define static_branch_unlikely(x)	unlikely(static_key_enabled(&(x)->key))

#endif /* HAVE_JUMP_LABEL */

/*
 * Advanced usage; refcount, branch is enabled when: count != 0
 */

#define static_branch_inc(x)		static_key_slow_inc(&(x)->key)
#define static_branch_dec(x)		static_key_slow_dec(&(x)->key)

/*
 * Normal usage; boolean enable/disable.
 */

#define static_branch_enable(x)		static_key_enable(&(x)->key)
#define static_branch_disable(x)	static_key_disable(&(x)->key)

#endif	/* _LINUX_JUMP_LABEL_H */

#endif /* __ASSEMBLY__ */
Commit	Line	Data
	1	#ifndef _LINUX_JUMP_LABEL_H
	2	#define _LINUX_JUMP_LABEL_H
	3
	4	/*
	5	* Jump label support
	6	*
	7	* Copyright (C) 2009-2012 Jason Baron <jbaron@redhat.com>
	8	* Copyright (C) 2011-2012 Red Hat, Inc., Peter Zijlstra
	9	*
	10	* DEPRECATED API:
	11	*
	12	* The use of 'struct static_key' directly, is now DEPRECATED. In addition
	13	* static_key_{true,false}() is also DEPRECATED. IE DO NOT use the following:
	14	*
	15	* struct static_key false = STATIC_KEY_INIT_FALSE;
	16	* struct static_key true = STATIC_KEY_INIT_TRUE;
	17	* static_key_true()
	18	* static_key_false()
	19	*
	20	* The updated API replacements are:
	21	*
	22	* DEFINE_STATIC_KEY_TRUE(key);
	23	* DEFINE_STATIC_KEY_FALSE(key);
	24	* static_branch_likely()
	25	* static_branch_unlikely()
	26	*
	27	* Jump labels provide an interface to generate dynamic branches using
	28	* self-modifying code. Assuming toolchain and architecture support, if we
	29	* define a "key" that is initially false via "DEFINE_STATIC_KEY_FALSE(key)",
	30	* an "if (static_branch_unlikely(&key))" statement is an unconditional branch
	31	* (which defaults to false - and the true block is placed out of line).
	32	* Similarly, we can define an initially true key via
	33	* "DEFINE_STATIC_KEY_TRUE(key)", and use it in the same
	34	* "if (static_branch_unlikely(&key))", in which case we will generate an
	35	* unconditional branch to the out-of-line true branch. Keys that are
	36	* initially true or false can be using in both static_branch_unlikely()
	37	* and static_branch_likely() statements.
	38	*
	39	* At runtime we can change the branch target by setting the key
	40	* to true via a call to static_branch_enable(), or false using
	41	* static_branch_disable(). If the direction of the branch is switched by
	42	* these calls then we run-time modify the branch target via a
	43	* no-op -> jump or jump -> no-op conversion. For example, for an
	44	* initially false key that is used in an "if (static_branch_unlikely(&key))"
	45	* statement, setting the key to true requires us to patch in a jump
	46	* to the out-of-line of true branch.
	47	*
	48	* In addition to static_branch_{enable,disable}, we can also reference count
	49	* the key or branch direction via static_branch_{inc,dec}. Thus,
	50	* static_branch_inc() can be thought of as a 'make more true' and
	51	* static_branch_dec() as a 'make more false'.
	52	*
	53	* Since this relies on modifying code, the branch modifying functions
	54	* must be considered absolute slow paths (machine wide synchronization etc.).
	55	* OTOH, since the affected branches are unconditional, their runtime overhead
	56	* will be absolutely minimal, esp. in the default (off) case where the total
	57	* effect is a single NOP of appropriate size. The on case will patch in a jump
	58	* to the out-of-line block.
	59	*
	60	* When the control is directly exposed to userspace, it is prudent to delay the
	61	* decrement to avoid high frequency code modifications which can (and do)
	62	* cause significant performance degradation. Struct static_key_deferred and
	63	* static_key_slow_dec_deferred() provide for this.
	64	*
	65	* Lacking toolchain and or architecture support, static keys fall back to a
	66	* simple conditional branch.
	67	*
	68	* Additional babbling in: Documentation/static-keys.txt
	69	*/
	70
	71	#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
	72	# define HAVE_JUMP_LABEL
	73	#endif
	74
	75	#ifndef __ASSEMBLY__
	76
	77	#include <linux/types.h>
	78	#include <linux/compiler.h>
	79	#include <linux/bug.h>
	80
	81	extern bool static_key_initialized;
	82
	83	#define STATIC_KEY_CHECK_USE() WARN(!static_key_initialized, \
	84	"%s used before call to jump_label_init", \
	85	__func__)
	86
	87	#ifdef HAVE_JUMP_LABEL
	88
	89	struct static_key {
	90	atomic_t enabled;
	91	/* Set lsb bit to 1 if branch is default true, 0 ot */
	92	struct jump_entry *entries;
	93	#ifdef CONFIG_MODULES
	94	struct static_key_mod *next;
	95	#endif
	96	};
	97
	98	#else
	99	struct static_key {
	100	atomic_t enabled;
	101	};
	102	#endif /* HAVE_JUMP_LABEL */
	103	#endif /* __ASSEMBLY__ */
	104
	105	#ifdef HAVE_JUMP_LABEL
	106	#include <asm/jump_label.h>
	107	#endif
	108
	109	#ifndef __ASSEMBLY__
	110
	111	enum jump_label_type {
	112	JUMP_LABEL_NOP = 0,
	113	JUMP_LABEL_JMP,
	114	};
	115
	116	struct module;
	117
	118	#include <linux/atomic.h>
	119
	120	static inline int static_key_count(struct static_key *key)
	121	{
	122	return atomic_read(&key->enabled);
	123	}
	124
	125	#ifdef HAVE_JUMP_LABEL
	126
	127	#define JUMP_TYPE_FALSE 0UL
	128	#define JUMP_TYPE_TRUE 1UL
	129	#define JUMP_TYPE_MASK 1UL
	130
	131	static __always_inline bool static_key_false(struct static_key *key)
	132	{
	133	return arch_static_branch(key, false);
	134	}
	135
	136	static __always_inline bool static_key_true(struct static_key *key)
	137	{
	138	return !arch_static_branch(key, true);
	139	}
	140
	141	extern struct jump_entry __start___jump_table[];
	142	extern struct jump_entry __stop___jump_table[];
	143
	144	extern void jump_label_init(void);
	145	extern void jump_label_lock(void);
	146	extern void jump_label_unlock(void);
	147	extern void arch_jump_label_transform(struct jump_entry *entry,
	148	enum jump_label_type type);
	149	extern void arch_jump_label_transform_static(struct jump_entry *entry,
	150	enum jump_label_type type);
	151	extern int jump_label_text_reserved(void start, void end);
	152	extern void static_key_slow_inc(struct static_key *key);
	153	extern void static_key_slow_dec(struct static_key *key);
	154	extern void jump_label_apply_nops(struct module *mod);
	155
	156	#define STATIC_KEY_INIT_TRUE \
	157	{ .enabled = ATOMIC_INIT(1), \
	158	.entries = (void *)JUMP_TYPE_TRUE }
	159	#define STATIC_KEY_INIT_FALSE \
	160	{ .enabled = ATOMIC_INIT(0), \
	161	.entries = (void *)JUMP_TYPE_FALSE }
	162
	163	#else /* !HAVE_JUMP_LABEL */
	164
	165	static __always_inline void jump_label_init(void)
	166	{
	167	static_key_initialized = true;
	168	}
	169
	170	static __always_inline bool static_key_false(struct static_key *key)
	171	{
	172	if (unlikely(static_key_count(key) > 0))
	173	return true;
	174	return false;
	175	}
	176
	177	static __always_inline bool static_key_true(struct static_key *key)
	178	{
	179	if (likely(static_key_count(key) > 0))
	180	return true;
	181	return false;
	182	}
	183
	184	static inline void static_key_slow_inc(struct static_key *key)
	185	{
	186	STATIC_KEY_CHECK_USE();
	187	atomic_inc(&key->enabled);
	188	}
	189
	190	static inline void static_key_slow_dec(struct static_key *key)
	191	{
	192	STATIC_KEY_CHECK_USE();
	193	atomic_dec(&key->enabled);
	194	}
	195
	196	static inline int jump_label_text_reserved(void start, void end)
	197	{
	198	return 0;
	199	}
	200
	201	static inline void jump_label_lock(void) {}
	202	static inline void jump_label_unlock(void) {}
	203
	204	static inline int jump_label_apply_nops(struct module *mod)
	205	{
	206	return 0;
	207	}
	208
	209	#define STATIC_KEY_INIT_TRUE { .enabled = ATOMIC_INIT(1) }
	210	#define STATIC_KEY_INIT_FALSE { .enabled = ATOMIC_INIT(0) }
	211
	212	#endif /* HAVE_JUMP_LABEL */
	213
	214	#define STATIC_KEY_INIT STATIC_KEY_INIT_FALSE
	215	#define jump_label_enabled static_key_enabled
	216
	217	static inline void static_key_enable(struct static_key *key)
	218	{
	219	int count = static_key_count(key);
	220
	221	WARN_ON_ONCE(count < 0 \|\| count > 1);
	222
	223	if (!count)
	224	static_key_slow_inc(key);
	225	}
	226
	227	static inline void static_key_disable(struct static_key *key)
	228	{
	229	int count = static_key_count(key);
	230
	231	WARN_ON_ONCE(count < 0 \|\| count > 1);
	232
	233	if (count)
	234	static_key_slow_dec(key);
	235	}
	236
	237	/* -------------------------------------------------------------------------- */
	238
	239	/*
	240	* Two type wrappers around static_key, such that we can use compile time
	241	* type differentiation to emit the right code.
	242	*
	243	* All the below code is macros in order to play type games.
	244	*/
	245
	246	struct static_key_true {
	247	struct static_key key;
	248	};
	249
	250	struct static_key_false {
	251	struct static_key key;
	252	};
	253
	254	#define STATIC_KEY_TRUE_INIT (struct static_key_true) { .key = STATIC_KEY_INIT_TRUE, }
	255	#define STATIC_KEY_FALSE_INIT (struct static_key_false){ .key = STATIC_KEY_INIT_FALSE, }
	256
	257	#define DEFINE_STATIC_KEY_TRUE(name) \
	258	struct static_key_true name = STATIC_KEY_TRUE_INIT
	259
	260	#define DEFINE_STATIC_KEY_FALSE(name) \
	261	struct static_key_false name = STATIC_KEY_FALSE_INIT
	262
	263	extern bool ____wrong_branch_error(void);
	264
	265	#define static_key_enabled(x) \
	266	({ \
	267	if (!__builtin_types_compatible_p(typeof(*x), struct static_key) && \
	268	!__builtin_types_compatible_p(typeof(*x), struct static_key_true) &&\
	269	!__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \
	270	____wrong_branch_error(); \
	271	static_key_count((struct static_key *)x) > 0; \
	272	})
	273
	274	#ifdef HAVE_JUMP_LABEL
	275
	276	/*
	277	* Combine the right initial value (type) with the right branch order
	278	* to generate the desired result.
	279	*
	280	*
	281	* type\branch\| likely (1) \| unlikely (0)
	282	* -----------+-----------------------+------------------
	283	* \| \|
	284	* true (1) \| ... \| ...
	285	* \| NOP \| JMP L
	286	* \| <br-stmts> \| 1: ...
	287	* \| L: ... \|
	288	* \| \|
	289	* \| \| L: <br-stmts>
	290	* \| \| jmp 1b
	291	* \| \|
	292	* -----------+-----------------------+------------------
	293	* \| \|
	294	* false (0) \| ... \| ...
	295	* \| JMP L \| NOP
	296	* \| <br-stmts> \| 1: ...
	297	* \| L: ... \|
	298	* \| \|
	299	* \| \| L: <br-stmts>
	300	* \| \| jmp 1b
	301	* \| \|
	302	* -----------+-----------------------+------------------
	303	*
	304	* The initial value is encoded in the LSB of static_key::entries,
	305	* type: 0 = false, 1 = true.
	306	*
	307	* The branch type is encoded in the LSB of jump_entry::key,
	308	* branch: 0 = unlikely, 1 = likely.
	309	*
	310	* This gives the following logic table:
	311	*
	312	* enabled type branch instuction
	313	* -----------------------------+-----------
	314	* 0 0 0 \| NOP
	315	* 0 0 1 \| JMP
	316	* 0 1 0 \| NOP
	317	* 0 1 1 \| JMP
	318	*
	319	* 1 0 0 \| JMP
	320	* 1 0 1 \| NOP
	321	* 1 1 0 \| JMP
	322	* 1 1 1 \| NOP
	323	*
	324	* Which gives the following functions:
	325	*
	326	* dynamic: instruction = enabled ^ branch
	327	* static: instruction = type ^ branch
	328	*
	329	* See jump_label_type() / jump_label_init_type().
	330	*/
	331
	332	#define static_branch_likely(x) \
	333	({ \
	334	bool branch; \
	335	if (__builtin_types_compatible_p(typeof(*x), struct static_key_true)) \
	336	branch = !arch_static_branch(&(x)->key, true); \
	337	else if (__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \
	338	branch = !arch_static_branch_jump(&(x)->key, true); \
	339	else \
	340	branch = ____wrong_branch_error(); \
	341	branch; \
	342	})
	343
	344	#define static_branch_unlikely(x) \
	345	({ \
	346	bool branch; \
	347	if (__builtin_types_compatible_p(typeof(*x), struct static_key_true)) \
	348	branch = arch_static_branch_jump(&(x)->key, false); \
	349	else if (__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \
	350	branch = arch_static_branch(&(x)->key, false); \
	351	else \
	352	branch = ____wrong_branch_error(); \
	353	branch; \
	354	})
	355
	356	#else /* !HAVE_JUMP_LABEL */
	357
	358	#define static_branch_likely(x) likely(static_key_enabled(&(x)->key))
	359	#define static_branch_unlikely(x) unlikely(static_key_enabled(&(x)->key))
	360
	361	#endif /* HAVE_JUMP_LABEL */
	362
	363	/*
	364	* Advanced usage; refcount, branch is enabled when: count != 0
	365	*/
	366
	367	#define static_branch_inc(x) static_key_slow_inc(&(x)->key)
	368	#define static_branch_dec(x) static_key_slow_dec(&(x)->key)
	369
	370	/*
	371	* Normal usage; boolean enable/disable.
	372	*/
	373
	374	#define static_branch_enable(x) static_key_enable(&(x)->key)
	375	#define static_branch_disable(x) static_key_disable(&(x)->key)
	376
	377	#endif /* _LINUX_JUMP_LABEL_H */
	378
	379	#endif /* __ASSEMBLY__ */