#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/typecheck.h> #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 __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) #ifdef CONFIG_GENERIC_LOCKBREAK #define spin_is_contended(lock) ((lock)->break_lock) #else #ifdef __raw_spin_is_contended #define spin_is_contended(lock) __raw_spin_is_contended(&(lock)->raw_lock) #else #define spin_is_contended(lock) (((void)(lock), 0)) #endif /*__raw_spin_is_contended*/ #endif /* The lock does not imply full memory barrier. */ #ifndef ARCH_HAS_SMP_MB_AFTER_LOCK static inline void smp_mb__after_lock(void) { smp_mb(); } #endif /** * 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) #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); #define _raw_read_lock_flags(lock, flags) _raw_read_lock(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); #define _raw_write_lock_flags(lock, flags) _raw_write_lock(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_lock_flags(lock, flags) \ __raw_read_lock_flags(&(lock)->raw_lock, *(flags)) # 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_lock_flags(lock, flags) \ __raw_write_lock_flags(&(lock)->raw_lock, *(flags)) # 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) # define spin_lock_nest_lock(lock, nest_lock) \ do { \ typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\ _spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \ } while (0) #else # define spin_lock_nested(lock, subclass) _spin_lock(lock) # define spin_lock_nest_lock(lock, nest_lock) _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) \ do { \ typecheck(unsigned long, flags); \ flags = _spin_lock_irqsave(lock); \ } while (0) #define read_lock_irqsave(lock, flags) \ do { \ typecheck(unsigned long, flags); \ flags = _read_lock_irqsave(lock); \ } while (0) #define write_lock_irqsave(lock, flags) \ do { \ typecheck(unsigned long, flags); \ flags = _write_lock_irqsave(lock); \ } while (0) #ifdef CONFIG_DEBUG_LOCK_ALLOC #define spin_lock_irqsave_nested(lock, flags, subclass) \ do { \ typecheck(unsigned long, flags); \ flags = _spin_lock_irqsave_nested(lock, subclass); \ } while (0) #else #define spin_lock_irqsave_nested(lock, flags, subclass) \ do { \ typecheck(unsigned long, flags); \ flags = _spin_lock_irqsave(lock); \ } while (0) #endif #else #define spin_lock_irqsave(lock, flags) \ do { \ typecheck(unsigned long, flags); \ _spin_lock_irqsave(lock, flags); \ } while (0) #define read_lock_irqsave(lock, flags) \ do { \ typecheck(unsigned long, flags); \ _read_lock_irqsave(lock, flags); \ } while (0) #define write_lock_irqsave(lock, flags) \ do { \ typecheck(unsigned long, flags); \ _write_lock_irqsave(lock, flags); \ } while (0) #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) #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) #define spin_unlock_irqrestore(lock, flags) \ do { \ typecheck(unsigned long, flags); \ _spin_unlock_irqrestore(lock, flags); \ } while (0) #define spin_unlock_bh(lock) _spin_unlock_bh(lock) #define read_unlock_irqrestore(lock, flags) \ do { \ typecheck(unsigned long, flags); \ _read_unlock_irqrestore(lock, flags); \ } while (0) #define read_unlock_bh(lock) _read_unlock_bh(lock) #define write_unlock_irqrestore(lock, flags) \ do { \ typecheck(unsigned long, flags); \ _write_unlock_irqrestore(lock, flags); \ } while (0) #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; }); \ }) #define write_trylock_irqsave(lock, flags) \ ({ \ local_irq_save(flags); \ write_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 * * 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)) /** * spin_can_lock - would spin_trylock() succeed? * @lock: the spinlock in question. */ #define spin_can_lock(lock) (!spin_is_locked(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 #endif /* __LINUX_SPINLOCK_H */