[mirror_ubuntu-bionic-kernel.git] / include / linux / spinlock.h

#ifndef __LINUX_SPINLOCK_H
#define __LINUX_SPINLOCK_H

/*
 * include/linux/spinlock.h - generic spinlock/rwlock declarations
 *
 * here's the role of the various spinlock/rwlock related include files:
 *
 * on SMP builds:
 *
 *  asm/spinlock_types.h: contains the arch_spinlock_t/arch_rwlock_t and the
 *                        initializers
 *
 *  linux/spinlock_types.h:
 *                        defines the generic type and initializers
 *
 *  asm/spinlock.h:       contains the arch_spin_*()/etc. lowlevel
 *                        implementations, mostly inline assembly code
 *
 *   (also included on UP-debug builds:)
 *
 *  linux/spinlock_api_smp.h:
 *                        contains the prototypes for the _spin_*() APIs.
 *
 *  linux/spinlock.h:     builds the final spin_*() APIs.
 *
 * on UP builds:
 *
 *  linux/spinlock_type_up.h:
 *                        contains the generic, simplified UP spinlock type.
 *                        (which is an empty structure on non-debug builds)
 *
 *  linux/spinlock_types.h:
 *                        defines the generic type and initializers
 *
 *  linux/spinlock_up.h:
 *                        contains the arch_spin_*()/etc. version of UP
 *                        builds. (which are NOPs on non-debug, non-preempt
 *                        builds)
 *
 *   (included on UP-non-debug builds:)
 *
 *  linux/spinlock_api_up.h:
 *                        builds the _spin_*() APIs.
 *
 *  linux/spinlock.h:     builds the final spin_*() APIs.
 */

#include <linux/typecheck.h>
#include <linux/preempt.h>
#include <linux/linkage.h>
#include <linux/compiler.h>
#include <linux/irqflags.h>
#include <linux/thread_info.h>
#include <linux/kernel.h>
#include <linux/stringify.h>
#include <linux/bottom_half.h>
#include <asm/barrier.h>


/*
 * Must define these before including other files, inline functions need them
 */
#define LOCK_SECTION_NAME ".text..lock."KBUILD_BASENAME

#define LOCK_SECTION_START(extra)               \
        ".subsection 1\n\t"                     \
        extra                                   \
        ".ifndef " LOCK_SECTION_NAME "\n\t"     \
        LOCK_SECTION_NAME ":\n\t"               \
        ".endif\n"

#define LOCK_SECTION_END                        \
        ".previous\n\t"

#define __lockfunc __attribute__((section(".spinlock.text")))

/*
 * Pull the arch_spinlock_t and arch_rwlock_t definitions:
 */
#include <linux/spinlock_types.h>

/*
 * Pull the arch_spin*() functions/declarations (UP-nondebug doesn't need them):
 */
#ifdef CONFIG_SMP
# include <asm/spinlock.h>
#else
# include <linux/spinlock_up.h>
#endif

#ifdef CONFIG_DEBUG_SPINLOCK
  extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
				   struct lock_class_key *key);
# define raw_spin_lock_init(lock)				\
do {								\
	static struct lock_class_key __key;			\
								\
	__raw_spin_lock_init((lock), #lock, &__key);		\
} while (0)

#else
# define raw_spin_lock_init(lock)				\
	do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0)
#endif

#define raw_spin_is_locked(lock)	arch_spin_is_locked(&(lock)->raw_lock)

#ifdef CONFIG_GENERIC_LOCKBREAK
#define raw_spin_is_contended(lock) ((lock)->break_lock)
#else

#ifdef arch_spin_is_contended
#define raw_spin_is_contended(lock)	arch_spin_is_contended(&(lock)->raw_lock)
#else
#define raw_spin_is_contended(lock)	(((void)(lock), 0))
#endif /*arch_spin_is_contended*/
#endif

/*
 * This barrier must provide two things:
 *
 *   - it must guarantee a STORE before the spin_lock() is ordered against a
 *     LOAD after it, see the comments at its two usage sites.
 *
 *   - it must ensure the critical section is RCsc.
 *
 * The latter is important for cases where we observe values written by other
 * CPUs in spin-loops, without barriers, while being subject to scheduling.
 *
 * CPU0			CPU1			CPU2
 *
 *			for (;;) {
 *			  if (READ_ONCE(X))
 *			    break;
 *			}
 * X=1
 *			<sched-out>
 *						<sched-in>
 *						r = X;
 *
 * without transitivity it could be that CPU1 observes X!=0 breaks the loop,
 * we get migrated and CPU2 sees X==0.
 *
 * Since most load-store architectures implement ACQUIRE with an smp_mb() after
 * the LL/SC loop, they need no further barriers. Similarly all our TSO
 * architectures imply an smp_mb() for each atomic instruction and equally don't
 * need more.
 *
 * Architectures that can implement ACQUIRE better need to take care.
 */
#ifndef smp_mb__after_spinlock
#define smp_mb__after_spinlock()	do { } while (0)
#endif

#ifdef CONFIG_DEBUG_SPINLOCK
 extern void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock);
#define do_raw_spin_lock_flags(lock, flags) do_raw_spin_lock(lock)
 extern int do_raw_spin_trylock(raw_spinlock_t *lock);
 extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock);
#else
static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock)
{
	__acquire(lock);
	arch_spin_lock(&lock->raw_lock);
}

static inline void
do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lock)
{
	__acquire(lock);
	arch_spin_lock_flags(&lock->raw_lock, *flags);
}

static inline int do_raw_spin_trylock(raw_spinlock_t *lock)
{
	return arch_spin_trylock(&(lock)->raw_lock);
}

static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock)
{
	arch_spin_unlock(&lock->raw_lock);
	__release(lock);
}
#endif

/*
 * Define the various spin_lock methods.  Note we define these
 * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The
 * various methods are defined as nops in the case they are not
 * required.
 */
#define raw_spin_trylock(lock)	__cond_lock(lock, _raw_spin_trylock(lock))

#define raw_spin_lock(lock)	_raw_spin_lock(lock)

#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define raw_spin_lock_nested(lock, subclass) \
	_raw_spin_lock_nested(lock, subclass)

# define raw_spin_lock_nest_lock(lock, nest_lock)			\
	 do {								\
		 typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
		 _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map);	\
	 } while (0)
#else
/*
 * Always evaluate the 'subclass' argument to avoid that the compiler
 * warns about set-but-not-used variables when building with
 * CONFIG_DEBUG_LOCK_ALLOC=n and with W=1.
 */
# define raw_spin_lock_nested(lock, subclass)		\
	_raw_spin_lock(((void)(subclass), (lock)))
# define raw_spin_lock_nest_lock(lock, nest_lock)	_raw_spin_lock(lock)
#endif

#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)

#define raw_spin_lock_irqsave(lock, flags)			\
	do {						\
		typecheck(unsigned long, flags);	\
		flags = _raw_spin_lock_irqsave(lock);	\
	} while (0)

#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define raw_spin_lock_irqsave_nested(lock, flags, subclass)		\
	do {								\
		typecheck(unsigned long, flags);			\
		flags = _raw_spin_lock_irqsave_nested(lock, subclass);	\
	} while (0)
#else
#define raw_spin_lock_irqsave_nested(lock, flags, subclass)		\
	do {								\
		typecheck(unsigned long, flags);			\
		flags = _raw_spin_lock_irqsave(lock);			\
	} while (0)
#endif

#else

#define raw_spin_lock_irqsave(lock, flags)		\
	do {						\
		typecheck(unsigned long, flags);	\
		_raw_spin_lock_irqsave(lock, flags);	\
	} while (0)

#define raw_spin_lock_irqsave_nested(lock, flags, subclass)	\
	raw_spin_lock_irqsave(lock, flags)

#endif

#define raw_spin_lock_irq(lock)		_raw_spin_lock_irq(lock)
#define raw_spin_lock_bh(lock)		_raw_spin_lock_bh(lock)
#define raw_spin_unlock(lock)		_raw_spin_unlock(lock)
#define raw_spin_unlock_irq(lock)	_raw_spin_unlock_irq(lock)

#define raw_spin_unlock_irqrestore(lock, flags)		\
	do {							\
		typecheck(unsigned long, flags);		\
		_raw_spin_unlock_irqrestore(lock, flags);	\
	} while (0)
#define raw_spin_unlock_bh(lock)	_raw_spin_unlock_bh(lock)

#define raw_spin_trylock_bh(lock) \
	__cond_lock(lock, _raw_spin_trylock_bh(lock))

#define raw_spin_trylock_irq(lock) \
({ \
	local_irq_disable(); \
	raw_spin_trylock(lock) ? \
	1 : ({ local_irq_enable(); 0;  }); \
})

#define raw_spin_trylock_irqsave(lock, flags) \
({ \
	local_irq_save(flags); \
	raw_spin_trylock(lock) ? \
	1 : ({ local_irq_restore(flags); 0; }); \
})

/**
 * raw_spin_can_lock - would raw_spin_trylock() succeed?
 * @lock: the spinlock in question.
 */
#define raw_spin_can_lock(lock)	(!raw_spin_is_locked(lock))

/* Include rwlock functions */
#include <linux/rwlock.h>

/*
 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
 */
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
# include <linux/spinlock_api_smp.h>
#else
# include <linux/spinlock_api_up.h>
#endif

/*
 * Map the spin_lock functions to the raw variants for PREEMPT_RT=n
 */

static __always_inline raw_spinlock_t *spinlock_check(spinlock_t *lock)
{
	return &lock->rlock;
}

#define spin_lock_init(_lock)				\
do {							\
	spinlock_check(_lock);				\
	raw_spin_lock_init(&(_lock)->rlock);		\
} while (0)

static __always_inline void spin_lock(spinlock_t *lock)
{
	raw_spin_lock(&lock->rlock);
}

static __always_inline void spin_lock_bh(spinlock_t *lock)
{
	raw_spin_lock_bh(&lock->rlock);
}

static __always_inline int spin_trylock(spinlock_t *lock)
{
	return raw_spin_trylock(&lock->rlock);
}

#define spin_lock_nested(lock, subclass)			\
do {								\
	raw_spin_lock_nested(spinlock_check(lock), subclass);	\
} while (0)

#define spin_lock_nest_lock(lock, nest_lock)				\
do {									\
	raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock);	\
} while (0)

static __always_inline void spin_lock_irq(spinlock_t *lock)
{
	raw_spin_lock_irq(&lock->rlock);
}

#define spin_lock_irqsave(lock, flags)				\
do {								\
	raw_spin_lock_irqsave(spinlock_check(lock), flags);	\
} while (0)

#define spin_lock_irqsave_nested(lock, flags, subclass)			\
do {									\
	raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \
} while (0)

static __always_inline void spin_unlock(spinlock_t *lock)
{
	raw_spin_unlock(&lock->rlock);
}

static __always_inline void spin_unlock_bh(spinlock_t *lock)
{
	raw_spin_unlock_bh(&lock->rlock);
}

static __always_inline void spin_unlock_irq(spinlock_t *lock)
{
	raw_spin_unlock_irq(&lock->rlock);
}

static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
{
	raw_spin_unlock_irqrestore(&lock->rlock, flags);
}

static __always_inline int spin_trylock_bh(spinlock_t *lock)
{
	return raw_spin_trylock_bh(&lock->rlock);
}

static __always_inline int spin_trylock_irq(spinlock_t *lock)
{
	return raw_spin_trylock_irq(&lock->rlock);
}

#define spin_trylock_irqsave(lock, flags)			\
({								\
	raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
})

static __always_inline int spin_is_locked(spinlock_t *lock)
{
	return raw_spin_is_locked(&lock->rlock);
}

static __always_inline int spin_is_contended(spinlock_t *lock)
{
	return raw_spin_is_contended(&lock->rlock);
}

static __always_inline int spin_can_lock(spinlock_t *lock)
{
	return raw_spin_can_lock(&lock->rlock);
}

#define assert_spin_locked(lock)	assert_raw_spin_locked(&(lock)->rlock)

/*
 * Pull the atomic_t declaration:
 * (asm-mips/atomic.h needs above definitions)
 */
#include <linux/atomic.h>
/**
 * atomic_dec_and_lock - lock on reaching reference count zero
 * @atomic: the atomic counter
 * @lock: the spinlock in question
 *
 * Decrements @atomic by 1.  If the result is 0, returns true and locks
 * @lock.  Returns false for all other cases.
 */
extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
#define atomic_dec_and_lock(atomic, lock) \
		__cond_lock(lock, _atomic_dec_and_lock(atomic, lock))

#endif /* __LINUX_SPINLOCK_H */
Commit	Line	Data
	1	#ifndef __LINUX_SPINLOCK_H
	2	#define __LINUX_SPINLOCK_H
	3
	4	/*
	5	* include/linux/spinlock.h - generic spinlock/rwlock declarations
	6	*
	7	* here's the role of the various spinlock/rwlock related include files:
	8	*
	9	* on SMP builds:
	10	*
	11	* asm/spinlock_types.h: contains the arch_spinlock_t/arch_rwlock_t and the
	12	* initializers
	13	*
	14	* linux/spinlock_types.h:
	15	* defines the generic type and initializers
	16	*
	17	* asm/spinlock.h: contains the arch_spin_*()/etc. lowlevel
	18	* implementations, mostly inline assembly code
	19	*
	20	* (also included on UP-debug builds:)
	21	*
	22	* linux/spinlock_api_smp.h:
	23	* contains the prototypes for the _spin_*() APIs.
	24	*
	25	* linux/spinlock.h: builds the final spin_*() APIs.
	26	*
	27	* on UP builds:
	28	*
	29	* linux/spinlock_type_up.h:
	30	* contains the generic, simplified UP spinlock type.
	31	* (which is an empty structure on non-debug builds)
	32	*
	33	* linux/spinlock_types.h:
	34	* defines the generic type and initializers
	35	*
	36	* linux/spinlock_up.h:
	37	* contains the arch_spin_*()/etc. version of UP
	38	* builds. (which are NOPs on non-debug, non-preempt
	39	* builds)
	40	*
	41	* (included on UP-non-debug builds:)
	42	*
	43	* linux/spinlock_api_up.h:
	44	* builds the _spin_*() APIs.
	45	*
	46	* linux/spinlock.h: builds the final spin_*() APIs.
	47	*/
	48
	49	#include <linux/typecheck.h>
	50	#include <linux/preempt.h>
	51	#include <linux/linkage.h>
	52	#include <linux/compiler.h>
	53	#include <linux/irqflags.h>
	54	#include <linux/thread_info.h>
	55	#include <linux/kernel.h>
	56	#include <linux/stringify.h>
	57	#include <linux/bottom_half.h>
	58	#include <asm/barrier.h>
	59
	60
	61	/*
	62	* Must define these before including other files, inline functions need them
	63	*/
	64	#define LOCK_SECTION_NAME ".text..lock."KBUILD_BASENAME
	65
	66	#define LOCK_SECTION_START(extra) \
	67	".subsection 1\n\t" \
	68	extra \
	69	".ifndef " LOCK_SECTION_NAME "\n\t" \
	70	LOCK_SECTION_NAME ":\n\t" \
	71	".endif\n"
	72
	73	#define LOCK_SECTION_END \
	74	".previous\n\t"
	75
	76	#define __lockfunc __attribute__((section(".spinlock.text")))
	77
	78	/*
	79	* Pull the arch_spinlock_t and arch_rwlock_t definitions:
	80	*/
	81	#include <linux/spinlock_types.h>
	82
	83	/*
	84	* Pull the arch_spin*() functions/declarations (UP-nondebug doesn't need them):
	85	*/
	86	#ifdef CONFIG_SMP
	87	# include <asm/spinlock.h>
	88	#else
	89	# include <linux/spinlock_up.h>
	90	#endif
	91
	92	#ifdef CONFIG_DEBUG_SPINLOCK
	93	extern void __raw_spin_lock_init(raw_spinlock_t lock, const char name,
	94	struct lock_class_key *key);
	95	# define raw_spin_lock_init(lock) \
	96	do { \
	97	static struct lock_class_key __key; \
	98	\
	99	__raw_spin_lock_init((lock), #lock, &__key); \
	100	} while (0)
	101
	102	#else
	103	# define raw_spin_lock_init(lock) \
	104	do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0)
	105	#endif
	106
	107	#define raw_spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock)
	108
	109	#ifdef CONFIG_GENERIC_LOCKBREAK
	110	#define raw_spin_is_contended(lock) ((lock)->break_lock)
	111	#else
	112
	113	#ifdef arch_spin_is_contended
	114	#define raw_spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock)
	115	#else
	116	#define raw_spin_is_contended(lock) (((void)(lock), 0))
	117	#endif /arch_spin_is_contended/
	118	#endif
	119
	120	/*
	121	* This barrier must provide two things:
	122	*
	123	* - it must guarantee a STORE before the spin_lock() is ordered against a
	124	* LOAD after it, see the comments at its two usage sites.
	125	*
	126	* - it must ensure the critical section is RCsc.
	127	*
	128	* The latter is important for cases where we observe values written by other
	129	* CPUs in spin-loops, without barriers, while being subject to scheduling.
	130	*
	131	* CPU0 CPU1 CPU2
	132	*
	133	* for (;;) {
	134	* if (READ_ONCE(X))
	135	* break;
	136	* }
	137	* X=1
	138	* <sched-out>
	139	* <sched-in>
	140	* r = X;
	141	*
	142	* without transitivity it could be that CPU1 observes X!=0 breaks the loop,
	143	* we get migrated and CPU2 sees X==0.
	144	*
	145	* Since most load-store architectures implement ACQUIRE with an smp_mb() after
	146	* the LL/SC loop, they need no further barriers. Similarly all our TSO
	147	* architectures imply an smp_mb() for each atomic instruction and equally don't
	148	* need more.
	149	*
	150	* Architectures that can implement ACQUIRE better need to take care.
	151	*/
	152	#ifndef smp_mb__after_spinlock
	153	#define smp_mb__after_spinlock() do { } while (0)
	154	#endif
	155
	156	#ifdef CONFIG_DEBUG_SPINLOCK
	157	extern void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock);
	158	#define do_raw_spin_lock_flags(lock, flags) do_raw_spin_lock(lock)
	159	extern int do_raw_spin_trylock(raw_spinlock_t *lock);
	160	extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock);
	161	#else
	162	static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock)
	163	{
	164	__acquire(lock);
	165	arch_spin_lock(&lock->raw_lock);
	166	}
	167
	168	static inline void
	169	do_raw_spin_lock_flags(raw_spinlock_t lock, unsigned long flags) __acquires(lock)
	170	{
	171	__acquire(lock);
	172	arch_spin_lock_flags(&lock->raw_lock, *flags);
	173	}
	174
	175	static inline int do_raw_spin_trylock(raw_spinlock_t *lock)
	176	{
	177	return arch_spin_trylock(&(lock)->raw_lock);
	178	}
	179
	180	static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock)
	181	{
	182	arch_spin_unlock(&lock->raw_lock);
	183	__release(lock);
	184	}
	185	#endif
	186
	187	/*
	188	* Define the various spin_lock methods. Note we define these
	189	* regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The
	190	* various methods are defined as nops in the case they are not
	191	* required.
	192	*/
	193	#define raw_spin_trylock(lock) __cond_lock(lock, _raw_spin_trylock(lock))
	194
	195	#define raw_spin_lock(lock) _raw_spin_lock(lock)
	196
	197	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	198	# define raw_spin_lock_nested(lock, subclass) \
	199	_raw_spin_lock_nested(lock, subclass)
	200
	201	# define raw_spin_lock_nest_lock(lock, nest_lock) \
	202	do { \
	203	typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
	204	_raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \
	205	} while (0)
	206	#else
	207	/*
	208	* Always evaluate the 'subclass' argument to avoid that the compiler
	209	* warns about set-but-not-used variables when building with
	210	* CONFIG_DEBUG_LOCK_ALLOC=n and with W=1.
	211	*/
	212	# define raw_spin_lock_nested(lock, subclass) \
	213	_raw_spin_lock(((void)(subclass), (lock)))
	214	# define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock)
	215	#endif
	216
	217	#if defined(CONFIG_SMP) \|\| defined(CONFIG_DEBUG_SPINLOCK)
	218
	219	#define raw_spin_lock_irqsave(lock, flags) \
	220	do { \
	221	typecheck(unsigned long, flags); \
	222	flags = _raw_spin_lock_irqsave(lock); \
	223	} while (0)
	224
	225	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	226	#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
	227	do { \
	228	typecheck(unsigned long, flags); \
	229	flags = _raw_spin_lock_irqsave_nested(lock, subclass); \
	230	} while (0)
	231	#else
	232	#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
	233	do { \
	234	typecheck(unsigned long, flags); \
	235	flags = _raw_spin_lock_irqsave(lock); \
	236	} while (0)
	237	#endif
	238
	239	#else
	240
	241	#define raw_spin_lock_irqsave(lock, flags) \
	242	do { \
	243	typecheck(unsigned long, flags); \
	244	_raw_spin_lock_irqsave(lock, flags); \
	245	} while (0)
	246
	247	#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
	248	raw_spin_lock_irqsave(lock, flags)
	249
	250	#endif
	251
	252	#define raw_spin_lock_irq(lock) _raw_spin_lock_irq(lock)
	253	#define raw_spin_lock_bh(lock) _raw_spin_lock_bh(lock)
	254	#define raw_spin_unlock(lock) _raw_spin_unlock(lock)
	255	#define raw_spin_unlock_irq(lock) _raw_spin_unlock_irq(lock)
	256
	257	#define raw_spin_unlock_irqrestore(lock, flags) \
	258	do { \
	259	typecheck(unsigned long, flags); \
	260	_raw_spin_unlock_irqrestore(lock, flags); \
	261	} while (0)
	262	#define raw_spin_unlock_bh(lock) _raw_spin_unlock_bh(lock)
	263
	264	#define raw_spin_trylock_bh(lock) \
	265	__cond_lock(lock, _raw_spin_trylock_bh(lock))
	266
	267	#define raw_spin_trylock_irq(lock) \
	268	({ \
	269	local_irq_disable(); \
	270	raw_spin_trylock(lock) ? \
	271	1 : ({ local_irq_enable(); 0; }); \
	272	})
	273
	274	#define raw_spin_trylock_irqsave(lock, flags) \
	275	({ \
	276	local_irq_save(flags); \
	277	raw_spin_trylock(lock) ? \
	278	1 : ({ local_irq_restore(flags); 0; }); \
	279	})
	280
	281	/**
	282	* raw_spin_can_lock - would raw_spin_trylock() succeed?
	283	* @lock: the spinlock in question.
	284	*/
	285	#define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock))
	286
	287	/* Include rwlock functions */
	288	#include <linux/rwlock.h>
	289
	290	/*
	291	* Pull the _spin_()/_read_()/_write_*() functions/declarations:
	292	*/
	293	#if defined(CONFIG_SMP) \|\| defined(CONFIG_DEBUG_SPINLOCK)
	294	# include <linux/spinlock_api_smp.h>
	295	#else
	296	# include <linux/spinlock_api_up.h>
	297	#endif
	298
	299	/*
	300	* Map the spin_lock functions to the raw variants for PREEMPT_RT=n
	301	*/
	302
	303	static __always_inline raw_spinlock_t spinlock_check(spinlock_t lock)
	304	{
	305	return &lock->rlock;
	306	}
	307
	308	#define spin_lock_init(_lock) \
	309	do { \
	310	spinlock_check(_lock); \
	311	raw_spin_lock_init(&(_lock)->rlock); \
	312	} while (0)
	313
	314	static __always_inline void spin_lock(spinlock_t *lock)
	315	{
	316	raw_spin_lock(&lock->rlock);
	317	}
	318
	319	static __always_inline void spin_lock_bh(spinlock_t *lock)
	320	{
	321	raw_spin_lock_bh(&lock->rlock);
	322	}
	323
	324	static __always_inline int spin_trylock(spinlock_t *lock)
	325	{
	326	return raw_spin_trylock(&lock->rlock);
	327	}
	328
	329	#define spin_lock_nested(lock, subclass) \
	330	do { \
	331	raw_spin_lock_nested(spinlock_check(lock), subclass); \
	332	} while (0)
	333
	334	#define spin_lock_nest_lock(lock, nest_lock) \
	335	do { \
	336	raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock); \
	337	} while (0)
	338
	339	static __always_inline void spin_lock_irq(spinlock_t *lock)
	340	{
	341	raw_spin_lock_irq(&lock->rlock);
	342	}
	343
	344	#define spin_lock_irqsave(lock, flags) \
	345	do { \
	346	raw_spin_lock_irqsave(spinlock_check(lock), flags); \
	347	} while (0)
	348
	349	#define spin_lock_irqsave_nested(lock, flags, subclass) \
	350	do { \
	351	raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \
	352	} while (0)
	353
	354	static __always_inline void spin_unlock(spinlock_t *lock)
	355	{
	356	raw_spin_unlock(&lock->rlock);
	357	}
	358
	359	static __always_inline void spin_unlock_bh(spinlock_t *lock)
	360	{
	361	raw_spin_unlock_bh(&lock->rlock);
	362	}
	363
	364	static __always_inline void spin_unlock_irq(spinlock_t *lock)
	365	{
	366	raw_spin_unlock_irq(&lock->rlock);
	367	}
	368
	369	static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
	370	{
	371	raw_spin_unlock_irqrestore(&lock->rlock, flags);
	372	}
	373
	374	static __always_inline int spin_trylock_bh(spinlock_t *lock)
	375	{
	376	return raw_spin_trylock_bh(&lock->rlock);
	377	}
	378
	379	static __always_inline int spin_trylock_irq(spinlock_t *lock)
	380	{
	381	return raw_spin_trylock_irq(&lock->rlock);
	382	}
	383
	384	#define spin_trylock_irqsave(lock, flags) \
	385	({ \
	386	raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
	387	})
	388
	389	static __always_inline int spin_is_locked(spinlock_t *lock)
	390	{
	391	return raw_spin_is_locked(&lock->rlock);
	392	}
	393
	394	static __always_inline int spin_is_contended(spinlock_t *lock)
	395	{
	396	return raw_spin_is_contended(&lock->rlock);
	397	}
	398
	399	static __always_inline int spin_can_lock(spinlock_t *lock)
	400	{
	401	return raw_spin_can_lock(&lock->rlock);
	402	}
	403
	404	#define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock)
	405
	406	/*
	407	* Pull the atomic_t declaration:
	408	* (asm-mips/atomic.h needs above definitions)
	409	*/
	410	#include <linux/atomic.h>
	411	/**
	412	* atomic_dec_and_lock - lock on reaching reference count zero
	413	* @atomic: the atomic counter
	414	* @lock: the spinlock in question
	415	*
	416	* Decrements @atomic by 1. If the result is 0, returns true and locks
	417	* @lock. Returns false for all other cases.
	418	*/
	419	extern int _atomic_dec_and_lock(atomic_t atomic, spinlock_t lock);
	420	#define atomic_dec_and_lock(atomic, lock) \
	421	__cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
	422
	423	#endif /* __LINUX_SPINLOCK_H */