[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 raw_spinlock_t/raw_rwlock_t and the
 *                        initializers
 *
 *  linux/spinlock_types.h:
 *                        defines the generic type and initializers
 *
 *  asm/spinlock.h:       contains the __raw_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 __raw_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/preempt.h>
#include <linux/linkage.h>
#include <linux/compiler.h>
#include <linux/thread_info.h>
#include <linux/kernel.h>
#include <linux/stringify.h>

#include <asm/system.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 fastcall __attribute__((section(".spinlock.text")))

/*
 * Pull the raw_spinlock_t and raw_rwlock_t definitions:
 */
#include <linux/spinlock_types.h>

extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);

/*
 * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
 */
#if defined(CONFIG_SMP)
# include <asm/spinlock.h>
#else
# include <linux/spinlock_up.h>
#endif

#define spin_lock_init(lock)	do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
#define rwlock_init(lock)	do { *(lock) = RW_LOCK_UNLOCKED; } while (0)

#define spin_is_locked(lock)	__raw_spin_is_locked(&(lock)->raw_lock)

/**
 * spin_unlock_wait - wait until the spinlock gets unlocked
 * @lock: the spinlock in question.
 */
#define spin_unlock_wait(lock)	__raw_spin_unlock_wait(&(lock)->raw_lock)

/*
 * 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

#ifdef CONFIG_DEBUG_SPINLOCK
 extern void _raw_spin_lock(spinlock_t *lock);
#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
 extern int _raw_spin_trylock(spinlock_t *lock);
 extern void _raw_spin_unlock(spinlock_t *lock);

 extern void _raw_read_lock(rwlock_t *lock);
 extern int _raw_read_trylock(rwlock_t *lock);
 extern void _raw_read_unlock(rwlock_t *lock);
 extern void _raw_write_lock(rwlock_t *lock);
 extern int _raw_write_trylock(rwlock_t *lock);
 extern void _raw_write_unlock(rwlock_t *lock);
#else
# define _raw_spin_unlock(lock)		__raw_spin_unlock(&(lock)->raw_lock)
# define _raw_spin_trylock(lock)	__raw_spin_trylock(&(lock)->raw_lock)
# define _raw_spin_lock(lock)		__raw_spin_lock(&(lock)->raw_lock)
# define _raw_spin_lock_flags(lock, flags) \
		__raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
# define _raw_read_lock(rwlock)		__raw_read_lock(&(rwlock)->raw_lock)
# define _raw_write_lock(rwlock)	__raw_write_lock(&(rwlock)->raw_lock)
# define _raw_read_unlock(rwlock)	__raw_read_unlock(&(rwlock)->raw_lock)
# define _raw_write_unlock(rwlock)	__raw_write_unlock(&(rwlock)->raw_lock)
# define _raw_read_trylock(rwlock)	__raw_read_trylock(&(rwlock)->raw_lock)
# define _raw_write_trylock(rwlock)	__raw_write_trylock(&(rwlock)->raw_lock)
#endif

#define read_can_lock(rwlock)		__raw_read_can_lock(&(rwlock)->raw_lock)
#define write_can_lock(rwlock)		__raw_write_can_lock(&(rwlock)->raw_lock)

/*
 * Define the various spin_lock and rw_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 spin_trylock(lock)		__cond_lock(_spin_trylock(lock))
#define read_trylock(lock)		__cond_lock(_read_trylock(lock))
#define write_trylock(lock)		__cond_lock(_write_trylock(lock))

#define spin_lock(lock)			_spin_lock(lock)
#define write_lock(lock)		_write_lock(lock)
#define read_lock(lock)			_read_lock(lock)

#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
#define spin_lock_irqsave(lock, flags)	flags = _spin_lock_irqsave(lock)
#define read_lock_irqsave(lock, flags)	flags = _read_lock_irqsave(lock)
#define write_lock_irqsave(lock, flags)	flags = _write_lock_irqsave(lock)
#else
#define spin_lock_irqsave(lock, flags)	_spin_lock_irqsave(lock, flags)
#define read_lock_irqsave(lock, flags)	_read_lock_irqsave(lock, flags)
#define write_lock_irqsave(lock, flags)	_write_lock_irqsave(lock, flags)
#endif

#define spin_lock_irq(lock)		_spin_lock_irq(lock)
#define spin_lock_bh(lock)		_spin_lock_bh(lock)

#define read_lock_irq(lock)		_read_lock_irq(lock)
#define read_lock_bh(lock)		_read_lock_bh(lock)

#define write_lock_irq(lock)		_write_lock_irq(lock)
#define write_lock_bh(lock)		_write_lock_bh(lock)

/*
 * We inline the unlock functions in the nondebug case:
 */
#if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP)
# define spin_unlock(lock)		_spin_unlock(lock)
# define read_unlock(lock)		_read_unlock(lock)
# define write_unlock(lock)		_write_unlock(lock)
#else
# define spin_unlock(lock)		__raw_spin_unlock(&(lock)->raw_lock)
# define read_unlock(lock)		__raw_read_unlock(&(lock)->raw_lock)
# define write_unlock(lock)		__raw_write_unlock(&(lock)->raw_lock)
#endif

#if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP)
# define spin_unlock_irq(lock)		_spin_unlock_irq(lock)
# define read_unlock_irq(lock)		_read_unlock_irq(lock)
# define write_unlock_irq(lock)		_write_unlock_irq(lock)
#else
# define spin_unlock_irq(lock) \
    do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
# define read_unlock_irq(lock) \
    do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
# define write_unlock_irq(lock) \
    do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
#endif

#define spin_unlock_irqrestore(lock, flags) \
					_spin_unlock_irqrestore(lock, flags)
#define spin_unlock_bh(lock)		_spin_unlock_bh(lock)

#define read_unlock_irqrestore(lock, flags) \
					_read_unlock_irqrestore(lock, flags)
#define read_unlock_bh(lock)		_read_unlock_bh(lock)

#define write_unlock_irqrestore(lock, flags) \
					_write_unlock_irqrestore(lock, flags)
#define write_unlock_bh(lock)		_write_unlock_bh(lock)

#define spin_trylock_bh(lock)		__cond_lock(_spin_trylock_bh(lock))

#define spin_trylock_irq(lock) \
({ \
	local_irq_disable(); \
	_spin_trylock(lock) ? \
	1 : ({ local_irq_enable(); 0;  }); \
})

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

/*
 * Pull the atomic_t declaration:
 * (asm-mips/atomic.h needs above definitions)
 */
#include <asm/atomic.h>
/**
 * atomic_dec_and_lock - lock on reaching reference count zero
 * @atomic: the atomic counter
 * @lock: the spinlock in question
 */
extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
#define atomic_dec_and_lock(atomic, lock) \
		__cond_lock(_atomic_dec_and_lock(atomic, lock))

/**
 * spin_can_lock - would spin_trylock() succeed?
 * @lock: the spinlock in question.
 */
#define spin_can_lock(lock)	(!spin_is_locked(lock))

#endif /* __LINUX_SPINLOCK_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef __LINUX_SPINLOCK_H
	2	#define __LINUX_SPINLOCK_H
	3
	4	/*
fb1c8f93 IM	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 raw_spinlock_t/raw_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 __raw_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 __raw_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.
1da177e4 LT	47	*/
1da177e4 LT	48
1da177e4 LT	49	#include <linux/preempt.h>
	50	#include <linux/linkage.h>
	51	#include <linux/compiler.h>
	52	#include <linux/thread_info.h>
	53	#include <linux/kernel.h>
	54	#include <linux/stringify.h>
	55
1da177e4 LT	56	#include <asm/system.h>
	57
	58	/*
	59	* Must define these before including other files, inline functions need them
	60	*/
f83b5e32	61	#define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
1da177e4 LT	62
	63	#define LOCK_SECTION_START(extra) \
	64	".subsection 1\n\t" \
	65	extra \
	66	".ifndef " LOCK_SECTION_NAME "\n\t" \
	67	LOCK_SECTION_NAME ":\n\t" \
	68	".endif\n"
	69
	70	#define LOCK_SECTION_END \
	71	".previous\n\t"
	72
	73	#define __lockfunc fastcall __attribute__((section(".spinlock.text")))
	74
	75	/*
fb1c8f93	76	* Pull the raw_spinlock_t and raw_rwlock_t definitions:
1da177e4	77	*/
fb1c8f93	78	#include <linux/spinlock_types.h>
1da177e4	79
fb1c8f93	80	extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
1da177e4	81
1da177e4	82	/*
fb1c8f93	83	* Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
1da177e4	84	*/
fb1c8f93 IM	85	#if defined(CONFIG_SMP)
fb1c8f93 IM	86	# include <asm/spinlock.h>
1da177e4	87	#else
fb1c8f93	88	# include <linux/spinlock_up.h>
1da177e4 LT	89	#endif
1da177e4 LT	90
fb1c8f93 IM	91	#define spin_lock_init(lock) do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
	92	#define rwlock_init(lock) do { *(lock) = RW_LOCK_UNLOCKED; } while (0)
	93
	94	#define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
	95
	96	/**
	97	* spin_unlock_wait - wait until the spinlock gets unlocked
	98	* @lock: the spinlock in question.
	99	*/
	100	#define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock)
	101
1da177e4	102	/*
fb1c8f93	103	* Pull the _spin_()/_read_()/_write_*() functions/declarations:
1da177e4	104	*/
fb1c8f93 IM	105	#if defined(CONFIG_SMP) \|\| defined(CONFIG_DEBUG_SPINLOCK)
fb1c8f93 IM	106	# include <linux/spinlock_api_smp.h>
1da177e4	107	#else
fb1c8f93	108	# include <linux/spinlock_api_up.h>
1da177e4 LT	109	#endif
1da177e4 LT	110
fb1c8f93 IM	111	#ifdef CONFIG_DEBUG_SPINLOCK
	112	extern void _raw_spin_lock(spinlock_t *lock);
	113	#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
	114	extern int _raw_spin_trylock(spinlock_t *lock);
	115	extern void _raw_spin_unlock(spinlock_t *lock);
	116
	117	extern void _raw_read_lock(rwlock_t *lock);
	118	extern int _raw_read_trylock(rwlock_t *lock);
	119	extern void _raw_read_unlock(rwlock_t *lock);
	120	extern void _raw_write_lock(rwlock_t *lock);
	121	extern int _raw_write_trylock(rwlock_t *lock);
	122	extern void _raw_write_unlock(rwlock_t *lock);
	123	#else
	124	# define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
	125	# define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
	126	# define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock)
	127	# define _raw_spin_lock_flags(lock, flags) \
	128	__raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
	129	# define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
	130	# define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
	131	# define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
	132	# define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock)
	133	# define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
	134	# define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
	135	#endif
1da177e4	136
fb1c8f93 IM	137	#define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock)
fb1c8f93 IM	138	#define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock)
1da177e4 LT	139
	140	/*
	141	* Define the various spin_lock and rw_lock methods. Note we define these
	142	* regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
	143	* methods are defined as nops in the case they are not required.
	144	*/
fb1c8f93 IM	145	#define spin_trylock(lock) __cond_lock(_spin_trylock(lock))
	146	#define read_trylock(lock) __cond_lock(_read_trylock(lock))
	147	#define write_trylock(lock) __cond_lock(_write_trylock(lock))
1da177e4	148
fb1c8f93 IM	149	#define spin_lock(lock) _spin_lock(lock)
	150	#define write_lock(lock) _write_lock(lock)
	151	#define read_lock(lock) _read_lock(lock)
1da177e4	152
fb1c8f93	153	#if defined(CONFIG_SMP) \|\| defined(CONFIG_DEBUG_SPINLOCK)
1da177e4 LT	154	#define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock)
	155	#define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock)
	156	#define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock)
	157	#else
	158	#define spin_lock_irqsave(lock, flags) _spin_lock_irqsave(lock, flags)
	159	#define read_lock_irqsave(lock, flags) _read_lock_irqsave(lock, flags)
	160	#define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags)
	161	#endif
	162
	163	#define spin_lock_irq(lock) _spin_lock_irq(lock)
	164	#define spin_lock_bh(lock) _spin_lock_bh(lock)
	165
	166	#define read_lock_irq(lock) _read_lock_irq(lock)
	167	#define read_lock_bh(lock) _read_lock_bh(lock)
	168
	169	#define write_lock_irq(lock) _write_lock_irq(lock)
	170	#define write_lock_bh(lock) _write_lock_bh(lock)
	171
bda98685 IM	172	/*
	173	* We inline the unlock functions in the nondebug case:
	174	*/
	175	#if defined(CONFIG_DEBUG_SPINLOCK) \|\| defined(CONFIG_PREEMPT) \|\| !defined(CONFIG_SMP)
	176	# define spin_unlock(lock) _spin_unlock(lock)
	177	# define read_unlock(lock) _read_unlock(lock)
	178	# define write_unlock(lock) _write_unlock(lock)
	179	#else
	180	# define spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
	181	# define read_unlock(lock) __raw_read_unlock(&(lock)->raw_lock)
	182	# define write_unlock(lock) __raw_write_unlock(&(lock)->raw_lock)
	183	#endif
	184
	185	#if defined(CONFIG_DEBUG_SPINLOCK) \|\| defined(CONFIG_PREEMPT) \|\| !defined(CONFIG_SMP)
	186	# define spin_unlock_irq(lock) _spin_unlock_irq(lock)
	187	# define read_unlock_irq(lock) _read_unlock_irq(lock)
	188	# define write_unlock_irq(lock) _write_unlock_irq(lock)
	189	#else
	190	# define spin_unlock_irq(lock) \
	191	do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
	192	# define read_unlock_irq(lock) \
	193	do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
	194	# define write_unlock_irq(lock) \
	195	do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
	196	#endif
1da177e4	197
fb1c8f93 IM	198	#define spin_unlock_irqrestore(lock, flags) \
fb1c8f93 IM	199	_spin_unlock_irqrestore(lock, flags)
1da177e4 LT	200	#define spin_unlock_bh(lock) _spin_unlock_bh(lock)
1da177e4 LT	201
fb1c8f93 IM	202	#define read_unlock_irqrestore(lock, flags) \
fb1c8f93 IM	203	_read_unlock_irqrestore(lock, flags)
fb1c8f93	204	#define read_unlock_bh(lock) _read_unlock_bh(lock)
1da177e4	205
fb1c8f93 IM	206	#define write_unlock_irqrestore(lock, flags) \
fb1c8f93 IM	207	_write_unlock_irqrestore(lock, flags)
fb1c8f93	208	#define write_unlock_bh(lock) _write_unlock_bh(lock)
1da177e4	209
fb1c8f93	210	#define spin_trylock_bh(lock) __cond_lock(_spin_trylock_bh(lock))
1da177e4 LT	211
	212	#define spin_trylock_irq(lock) \
	213	({ \
	214	local_irq_disable(); \
	215	_spin_trylock(lock) ? \
fb1c8f93	216	1 : ({ local_irq_enable(); 0; }); \
1da177e4 LT	217	})
	218
	219	#define spin_trylock_irqsave(lock, flags) \
	220	({ \
	221	local_irq_save(flags); \
	222	_spin_trylock(lock) ? \
fb1c8f93	223	1 : ({ local_irq_restore(flags); 0; }); \
1da177e4 LT	224	})
1da177e4 LT	225
1da177e4	226	/*
fb1c8f93 IM	227	* Pull the atomic_t declaration:
fb1c8f93 IM	228	* (asm-mips/atomic.h needs above definitions)
1da177e4	229	*/
fb1c8f93 IM	230	#include <asm/atomic.h>
	231	/**
	232	* atomic_dec_and_lock - lock on reaching reference count zero
	233	* @atomic: the atomic counter
	234	* @lock: the spinlock in question
1da177e4	235	*/
fb1c8f93 IM	236	extern int _atomic_dec_and_lock(atomic_t atomic, spinlock_t lock);
	237	#define atomic_dec_and_lock(atomic, lock) \
	238	__cond_lock(_atomic_dec_and_lock(atomic, lock))
1da177e4 LT	239
	240	/**
	241	* spin_can_lock - would spin_trylock() succeed?
	242	* @lock: the spinlock in question.
	243	*/
fb1c8f93	244	#define spin_can_lock(lock) (!spin_is_locked(lock))
1da177e4 LT	245
1da177e4 LT	246	#endif /* __LINUX_SPINLOCK_H */