#ifndef __LINUX_SPINLOCK_H #define __LINUX_SPINLOCK_H /* * include/linux/spinlock.h - generic locking declarations */ #include #include #include #include #include #include #include #include /* for cpu relax */ #include /* * Must define these before including other files, inline functions need them */ #define LOCK_SECTION_NAME \ ".text.lock." __stringify(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"))) /* * If CONFIG_SMP is set, pull in the _raw_* definitions */ #ifdef CONFIG_SMP #define assert_spin_locked(x) BUG_ON(!spin_is_locked(x)) #include int __lockfunc _spin_trylock(spinlock_t *lock); int __lockfunc _read_trylock(rwlock_t *lock); int __lockfunc _write_trylock(rwlock_t *lock); void __lockfunc _spin_lock(spinlock_t *lock) __acquires(spinlock_t); void __lockfunc _read_lock(rwlock_t *lock) __acquires(rwlock_t); void __lockfunc _write_lock(rwlock_t *lock) __acquires(rwlock_t); void __lockfunc _spin_unlock(spinlock_t *lock) __releases(spinlock_t); void __lockfunc _read_unlock(rwlock_t *lock) __releases(rwlock_t); void __lockfunc _write_unlock(rwlock_t *lock) __releases(rwlock_t); unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock) __acquires(spinlock_t); unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock) __acquires(rwlock_t); unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock) __acquires(rwlock_t); void __lockfunc _spin_lock_irq(spinlock_t *lock) __acquires(spinlock_t); void __lockfunc _spin_lock_bh(spinlock_t *lock) __acquires(spinlock_t); void __lockfunc _read_lock_irq(rwlock_t *lock) __acquires(rwlock_t); void __lockfunc _read_lock_bh(rwlock_t *lock) __acquires(rwlock_t); void __lockfunc _write_lock_irq(rwlock_t *lock) __acquires(rwlock_t); void __lockfunc _write_lock_bh(rwlock_t *lock) __acquires(rwlock_t); void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags) __releases(spinlock_t); void __lockfunc _spin_unlock_irq(spinlock_t *lock) __releases(spinlock_t); void __lockfunc _spin_unlock_bh(spinlock_t *lock) __releases(spinlock_t); void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags) __releases(rwlock_t); void __lockfunc _read_unlock_irq(rwlock_t *lock) __releases(rwlock_t); void __lockfunc _read_unlock_bh(rwlock_t *lock) __releases(rwlock_t); void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags) __releases(rwlock_t); void __lockfunc _write_unlock_irq(rwlock_t *lock) __releases(rwlock_t); void __lockfunc _write_unlock_bh(rwlock_t *lock) __releases(rwlock_t); int __lockfunc _spin_trylock_bh(spinlock_t *lock); int __lockfunc generic_raw_read_trylock(rwlock_t *lock); int in_lock_functions(unsigned long addr); #else #define in_lock_functions(ADDR) 0 #if !defined(CONFIG_PREEMPT) && !defined(CONFIG_DEBUG_SPINLOCK) # define _atomic_dec_and_lock(atomic,lock) atomic_dec_and_test(atomic) # define ATOMIC_DEC_AND_LOCK #endif #ifdef CONFIG_DEBUG_SPINLOCK #define SPINLOCK_MAGIC 0x1D244B3C typedef struct { unsigned long magic; volatile unsigned long lock; volatile unsigned int babble; const char *module; char *owner; int oline; } spinlock_t; #define SPIN_LOCK_UNLOCKED (spinlock_t) { SPINLOCK_MAGIC, 0, 10, __FILE__ , NULL, 0} #define spin_lock_init(x) \ do { \ (x)->magic = SPINLOCK_MAGIC; \ (x)->lock = 0; \ (x)->babble = 5; \ (x)->module = __FILE__; \ (x)->owner = NULL; \ (x)->oline = 0; \ } while (0) #define CHECK_LOCK(x) \ do { \ if ((x)->magic != SPINLOCK_MAGIC) { \ printk(KERN_ERR "%s:%d: spin_is_locked on uninitialized spinlock %p.\n", \ __FILE__, __LINE__, (x)); \ } \ } while(0) #define _raw_spin_lock(x) \ do { \ CHECK_LOCK(x); \ if ((x)->lock&&(x)->babble) { \ (x)->babble--; \ printk("%s:%d: spin_lock(%s:%p) already locked by %s/%d\n", \ __FILE__,__LINE__, (x)->module, \ (x), (x)->owner, (x)->oline); \ } \ (x)->lock = 1; \ (x)->owner = __FILE__; \ (x)->oline = __LINE__; \ } while (0) /* without debugging, spin_is_locked on UP always says * FALSE. --> printk if already locked. */ #define spin_is_locked(x) \ ({ \ CHECK_LOCK(x); \ if ((x)->lock&&(x)->babble) { \ (x)->babble--; \ printk("%s:%d: spin_is_locked(%s:%p) already locked by %s/%d\n", \ __FILE__,__LINE__, (x)->module, \ (x), (x)->owner, (x)->oline); \ } \ 0; \ }) /* with debugging, assert_spin_locked() on UP does check * the lock value properly */ #define assert_spin_locked(x) \ ({ \ CHECK_LOCK(x); \ BUG_ON(!(x)->lock); \ }) /* without debugging, spin_trylock on UP always says * TRUE. --> printk if already locked. */ #define _raw_spin_trylock(x) \ ({ \ CHECK_LOCK(x); \ if ((x)->lock&&(x)->babble) { \ (x)->babble--; \ printk("%s:%d: spin_trylock(%s:%p) already locked by %s/%d\n", \ __FILE__,__LINE__, (x)->module, \ (x), (x)->owner, (x)->oline); \ } \ (x)->lock = 1; \ (x)->owner = __FILE__; \ (x)->oline = __LINE__; \ 1; \ }) #define spin_unlock_wait(x) \ do { \ CHECK_LOCK(x); \ if ((x)->lock&&(x)->babble) { \ (x)->babble--; \ printk("%s:%d: spin_unlock_wait(%s:%p) owned by %s/%d\n", \ __FILE__,__LINE__, (x)->module, (x), \ (x)->owner, (x)->oline); \ }\ } while (0) #define _raw_spin_unlock(x) \ do { \ CHECK_LOCK(x); \ if (!(x)->lock&&(x)->babble) { \ (x)->babble--; \ printk("%s:%d: spin_unlock(%s:%p) not locked\n", \ __FILE__,__LINE__, (x)->module, (x));\ } \ (x)->lock = 0; \ } while (0) #else /* * gcc versions before ~2.95 have a nasty bug with empty initializers. */ #if (__GNUC__ > 2) typedef struct { } spinlock_t; #define SPIN_LOCK_UNLOCKED (spinlock_t) { } #else typedef struct { int gcc_is_buggy; } spinlock_t; #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } #endif /* * If CONFIG_SMP is unset, declare the _raw_* definitions as nops */ #define spin_lock_init(lock) do { (void)(lock); } while(0) #define _raw_spin_lock(lock) do { (void)(lock); } while(0) #define spin_is_locked(lock) ((void)(lock), 0) #define assert_spin_locked(lock) do { (void)(lock); } while(0) #define _raw_spin_trylock(lock) (((void)(lock), 1)) #define spin_unlock_wait(lock) (void)(lock) #define _raw_spin_unlock(lock) do { (void)(lock); } while(0) #endif /* CONFIG_DEBUG_SPINLOCK */ /* RW spinlocks: No debug version */ #if (__GNUC__ > 2) typedef struct { } rwlock_t; #define RW_LOCK_UNLOCKED (rwlock_t) { } #else typedef struct { int gcc_is_buggy; } rwlock_t; #define RW_LOCK_UNLOCKED (rwlock_t) { 0 } #endif #define rwlock_init(lock) do { (void)(lock); } while(0) #define _raw_read_lock(lock) do { (void)(lock); } while(0) #define _raw_read_unlock(lock) do { (void)(lock); } while(0) #define _raw_write_lock(lock) do { (void)(lock); } while(0) #define _raw_write_unlock(lock) do { (void)(lock); } while(0) #define read_can_lock(lock) (((void)(lock), 1)) #define write_can_lock(lock) (((void)(lock), 1)) #define _raw_read_trylock(lock) ({ (void)(lock); (1); }) #define _raw_write_trylock(lock) ({ (void)(lock); (1); }) #define _spin_trylock(lock) ({preempt_disable(); _raw_spin_trylock(lock) ? \ 1 : ({preempt_enable(); 0;});}) #define _read_trylock(lock) ({preempt_disable();_raw_read_trylock(lock) ? \ 1 : ({preempt_enable(); 0;});}) #define _write_trylock(lock) ({preempt_disable(); _raw_write_trylock(lock) ? \ 1 : ({preempt_enable(); 0;});}) #define _spin_trylock_bh(lock) ({preempt_disable(); local_bh_disable(); \ _raw_spin_trylock(lock) ? \ 1 : ({preempt_enable_no_resched(); local_bh_enable(); 0;});}) #define _spin_lock(lock) \ do { \ preempt_disable(); \ _raw_spin_lock(lock); \ __acquire(lock); \ } while(0) #define _write_lock(lock) \ do { \ preempt_disable(); \ _raw_write_lock(lock); \ __acquire(lock); \ } while(0) #define _read_lock(lock) \ do { \ preempt_disable(); \ _raw_read_lock(lock); \ __acquire(lock); \ } while(0) #define _spin_unlock(lock) \ do { \ _raw_spin_unlock(lock); \ preempt_enable(); \ __release(lock); \ } while (0) #define _write_unlock(lock) \ do { \ _raw_write_unlock(lock); \ preempt_enable(); \ __release(lock); \ } while(0) #define _read_unlock(lock) \ do { \ _raw_read_unlock(lock); \ preempt_enable(); \ __release(lock); \ } while(0) #define _spin_lock_irqsave(lock, flags) \ do { \ local_irq_save(flags); \ preempt_disable(); \ _raw_spin_lock(lock); \ __acquire(lock); \ } while (0) #define _spin_lock_irq(lock) \ do { \ local_irq_disable(); \ preempt_disable(); \ _raw_spin_lock(lock); \ __acquire(lock); \ } while (0) #define _spin_lock_bh(lock) \ do { \ local_bh_disable(); \ preempt_disable(); \ _raw_spin_lock(lock); \ __acquire(lock); \ } while (0) #define _read_lock_irqsave(lock, flags) \ do { \ local_irq_save(flags); \ preempt_disable(); \ _raw_read_lock(lock); \ __acquire(lock); \ } while (0) #define _read_lock_irq(lock) \ do { \ local_irq_disable(); \ preempt_disable(); \ _raw_read_lock(lock); \ __acquire(lock); \ } while (0) #define _read_lock_bh(lock) \ do { \ local_bh_disable(); \ preempt_disable(); \ _raw_read_lock(lock); \ __acquire(lock); \ } while (0) #define _write_lock_irqsave(lock, flags) \ do { \ local_irq_save(flags); \ preempt_disable(); \ _raw_write_lock(lock); \ __acquire(lock); \ } while (0) #define _write_lock_irq(lock) \ do { \ local_irq_disable(); \ preempt_disable(); \ _raw_write_lock(lock); \ __acquire(lock); \ } while (0) #define _write_lock_bh(lock) \ do { \ local_bh_disable(); \ preempt_disable(); \ _raw_write_lock(lock); \ __acquire(lock); \ } while (0) #define _spin_unlock_irqrestore(lock, flags) \ do { \ _raw_spin_unlock(lock); \ local_irq_restore(flags); \ preempt_enable(); \ __release(lock); \ } while (0) #define _spin_unlock_irq(lock) \ do { \ _raw_spin_unlock(lock); \ local_irq_enable(); \ preempt_enable(); \ __release(lock); \ } while (0) #define _spin_unlock_bh(lock) \ do { \ _raw_spin_unlock(lock); \ preempt_enable_no_resched(); \ local_bh_enable(); \ __release(lock); \ } while (0) #define _write_unlock_bh(lock) \ do { \ _raw_write_unlock(lock); \ preempt_enable_no_resched(); \ local_bh_enable(); \ __release(lock); \ } while (0) #define _read_unlock_irqrestore(lock, flags) \ do { \ _raw_read_unlock(lock); \ local_irq_restore(flags); \ preempt_enable(); \ __release(lock); \ } while (0) #define _write_unlock_irqrestore(lock, flags) \ do { \ _raw_write_unlock(lock); \ local_irq_restore(flags); \ preempt_enable(); \ __release(lock); \ } while (0) #define _read_unlock_irq(lock) \ do { \ _raw_read_unlock(lock); \ local_irq_enable(); \ preempt_enable(); \ __release(lock); \ } while (0) #define _read_unlock_bh(lock) \ do { \ _raw_read_unlock(lock); \ preempt_enable_no_resched(); \ local_bh_enable(); \ __release(lock); \ } while (0) #define _write_unlock_irq(lock) \ do { \ _raw_write_unlock(lock); \ local_irq_enable(); \ preempt_enable(); \ __release(lock); \ } while (0) #endif /* !SMP */ /* * 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) #ifdef CONFIG_SMP #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) #define spin_unlock(lock) _spin_unlock(lock) #define write_unlock(lock) _write_unlock(lock) #define read_unlock(lock) _read_unlock(lock) #define spin_unlock_irqrestore(lock, flags) _spin_unlock_irqrestore(lock, flags) #define spin_unlock_irq(lock) _spin_unlock_irq(lock) #define spin_unlock_bh(lock) _spin_unlock_bh(lock) #define read_unlock_irqrestore(lock, flags) _read_unlock_irqrestore(lock, flags) #define read_unlock_irq(lock) _read_unlock_irq(lock) #define read_unlock_bh(lock) _read_unlock_bh(lock) #define write_unlock_irqrestore(lock, flags) _write_unlock_irqrestore(lock, flags) #define write_unlock_irq(lock) _write_unlock_irq(lock) #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;}); \ }) #ifdef CONFIG_LOCKMETER extern void _metered_spin_lock (spinlock_t *lock); extern void _metered_spin_unlock (spinlock_t *lock); extern int _metered_spin_trylock(spinlock_t *lock); extern void _metered_read_lock (rwlock_t *lock); extern void _metered_read_unlock (rwlock_t *lock); extern void _metered_write_lock (rwlock_t *lock); extern void _metered_write_unlock (rwlock_t *lock); extern int _metered_read_trylock (rwlock_t *lock); extern int _metered_write_trylock(rwlock_t *lock); #endif /* "lock on reference count zero" */ #ifndef ATOMIC_DEC_AND_LOCK #include extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); #endif #define atomic_dec_and_lock(atomic,lock) __cond_lock(_atomic_dec_and_lock(atomic,lock)) /* * bit-based spin_lock() * * Don't use this unless you really need to: spin_lock() and spin_unlock() * are significantly faster. */ static inline void bit_spin_lock(int bitnum, unsigned long *addr) { /* * Assuming the lock is uncontended, this never enters * the body of the outer loop. If it is contended, then * within the inner loop a non-atomic test is used to * busywait with less bus contention for a good time to * attempt to acquire the lock bit. */ preempt_disable(); #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) while (test_and_set_bit(bitnum, addr)) { while (test_bit(bitnum, addr)) { preempt_enable(); cpu_relax(); preempt_disable(); } } #endif __acquire(bitlock); } /* * Return true if it was acquired */ static inline int bit_spin_trylock(int bitnum, unsigned long *addr) { preempt_disable(); #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) if (test_and_set_bit(bitnum, addr)) { preempt_enable(); return 0; } #endif __acquire(bitlock); return 1; } /* * bit-based spin_unlock() */ static inline void bit_spin_unlock(int bitnum, unsigned long *addr) { #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) BUG_ON(!test_bit(bitnum, addr)); smp_mb__before_clear_bit(); clear_bit(bitnum, addr); #endif preempt_enable(); __release(bitlock); } /* * Return true if the lock is held. */ static inline int bit_spin_is_locked(int bitnum, unsigned long *addr) { #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) return test_bit(bitnum, addr); #elif defined CONFIG_PREEMPT return preempt_count(); #else return 1; #endif } #define DEFINE_SPINLOCK(x) spinlock_t x = SPIN_LOCK_UNLOCKED #define DEFINE_RWLOCK(x) rwlock_t x = RW_LOCK_UNLOCKED /** * 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 */