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- #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 <linux/bottom_half.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):
- */
- #ifdef CONFIG_SMP
- # include <asm/spinlock.h>
- #else
- # include <linux/spinlock_up.h>
- #endif
- #ifdef CONFIG_DEBUG_SPINLOCK
- extern void __spin_lock_init(spinlock_t *lock, const char *name,
- struct lock_class_key *key);
- # define spin_lock_init(lock) \
- do { \
- static struct lock_class_key __key; \
- \
- __spin_lock_init((lock), #lock, &__key); \
- } while (0)
- #else
- # define spin_lock_init(lock) \
- do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
- #endif
- #ifdef CONFIG_DEBUG_SPINLOCK
- extern void __rwlock_init(rwlock_t *lock, const char *name,
- struct lock_class_key *key);
- # define rwlock_init(lock) \
- do { \
- static struct lock_class_key __key; \
- \
- __rwlock_init((lock), #lock, &__key); \
- } while (0)
- #else
- # define rwlock_init(lock) \
- do { *(lock) = RW_LOCK_UNLOCKED; } while (0)
- #endif
- #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_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_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
- # define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
- # define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
- # define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
- # define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
- # define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
- # define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
- # define _raw_write_unlock(rwlock) __raw_write_unlock(&(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(lock, _spin_trylock(lock))
- #define read_trylock(lock) __cond_lock(lock, _read_trylock(lock))
- #define write_trylock(lock) __cond_lock(lock, _write_trylock(lock))
- #define spin_lock(lock) _spin_lock(lock)
- #ifdef CONFIG_DEBUG_LOCK_ALLOC
- # define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
- #else
- # define spin_lock_nested(lock, subclass) _spin_lock(lock)
- #endif
- #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)
- #ifdef CONFIG_DEBUG_LOCK_ALLOC
- #define spin_lock_irqsave_nested(lock, flags, subclass) \
- flags = _spin_lock_irqsave_nested(lock, subclass)
- #else
- #define spin_lock_irqsave_nested(lock, flags, subclass) \
- flags = _spin_lock_irqsave(lock)
- #endif
- #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)
- #define spin_lock_irqsave_nested(lock, flags, subclass) \
- spin_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)
- # 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(lock) \
- do {__raw_spin_unlock(&(lock)->raw_lock); __release(lock); } while (0)
- # define read_unlock(lock) \
- do {__raw_read_unlock(&(lock)->raw_lock); __release(lock); } while (0)
- # define write_unlock(lock) \
- do {__raw_write_unlock(&(lock)->raw_lock); __release(lock); } while (0)
- # define spin_unlock_irq(lock) \
- do { \
- __raw_spin_unlock(&(lock)->raw_lock); \
- __release(lock); \
- local_irq_enable(); \
- } while (0)
- # define read_unlock_irq(lock) \
- do { \
- __raw_read_unlock(&(lock)->raw_lock); \
- __release(lock); \
- local_irq_enable(); \
- } while (0)
- # define write_unlock_irq(lock) \
- do { \
- __raw_write_unlock(&(lock)->raw_lock); \
- __release(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(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; }); \
- })
- /*
- * Locks two spinlocks l1 and l2.
- * l1_first indicates if spinlock l1 should be taken first.
- */
- static inline void double_spin_lock(spinlock_t *l1, spinlock_t *l2,
- bool l1_first)
- __acquires(l1)
- __acquires(l2)
- {
- if (l1_first) {
- spin_lock(l1);
- spin_lock(l2);
- } else {
- spin_lock(l2);
- spin_lock(l1);
- }
- }
- /*
- * Unlocks two spinlocks l1 and l2.
- * l1_taken_first indicates if spinlock l1 was taken first and therefore
- * should be released after spinlock l2.
- */
- static inline void double_spin_unlock(spinlock_t *l1, spinlock_t *l2,
- bool l1_taken_first)
- __releases(l1)
- __releases(l2)
- {
- if (l1_taken_first) {
- spin_unlock(l2);
- spin_unlock(l1);
- } else {
- spin_unlock(l1);
- spin_unlock(l2);
- }
- }
- /*
- * 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(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 */
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