X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Flinux%2Fspinlock.h;h=94b767d6427561297772ad556d9466333f424732;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=de381ec1ea1376fd7a7b30a6f4939c19457884b0;hpb=9213980e6a70d8473e0ffd4b39ab5b6caaba9ff5;p=linux-2.6.git diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index de381ec1e..94b767d64 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -2,469 +2,289 @@ #define __LINUX_SPINLOCK_H /* - * include/linux/spinlock.h - generic locking declarations + * 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 #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_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_START(extra) \ - ".subsection 1\n\t" \ - extra \ - ".ifndef " LOCK_SECTION_NAME "\n\t" \ - LOCK_SECTION_NAME ":\n\t" \ - ".endif\n\t" +#define LOCK_SECTION_END \ + ".previous\n\t" -#define LOCK_SECTION_END \ - ".previous\n\t" +#define __lockfunc fastcall __attribute__((section(".spinlock.text"))) /* - * If CONFIG_SMP is set, pull in the _raw_* definitions + * Pull the raw_spinlock_t and raw_rwlock_t definitions: */ -#ifdef CONFIG_SMP -#include +#include + +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 #else +# include +#endif -#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) +#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) -#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 +#else +# define spin_lock_init(lock) \ + do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0) #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; \ - }) - -/* 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) { } + 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 - typedef struct { int gcc_is_buggy; } spinlock_t; - #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } +# 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) + /* - * If CONFIG_SMP is unset, declare the _raw_* definitions as nops + * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: */ -#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 _raw_spin_trylock(lock) ((void)(lock), 1) -#define spin_unlock_wait(lock) do { (void)(lock); } while(0) -#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) { } +#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) +# include #else - typedef struct { int gcc_is_buggy; } rwlock_t; - #define RW_LOCK_UNLOCKED (rwlock_t) { 0 } +# include #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 _raw_write_trylock(lock) ({ (void)(lock); (1); }) +#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 -#endif /* !SMP */ +#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) ({preempt_disable(); _raw_spin_trylock(lock) ? \ - 1 : ({preempt_enable(); 0;});}) - -#define write_trylock(lock) ({preempt_disable();_raw_write_trylock(lock) ? \ - 1 : ({preempt_enable(); 0;});}) +#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)) -/* Where's read_trylock? */ - -#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT) -void __preempt_spin_lock(spinlock_t *lock); -void __preempt_write_lock(rwlock_t *lock); - -#define spin_lock(lock) \ -do { \ - preempt_disable(); \ - if (unlikely(!_raw_spin_trylock(lock))) \ - __preempt_spin_lock(lock); \ -} while (0) - -#define write_lock(lock) \ -do { \ - preempt_disable(); \ - if (unlikely(!_raw_write_trylock(lock))) \ - __preempt_write_lock(lock); \ -} while (0) +#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(lock) \ -do { \ - preempt_disable(); \ - _raw_spin_lock(lock); \ -} while(0) - -#define write_lock(lock) \ -do { \ - preempt_disable(); \ - _raw_write_lock(lock); \ -} while(0) +# define spin_lock_nested(lock, subclass) _spin_lock(lock) #endif -#define read_lock(lock) \ -do { \ - preempt_disable(); \ - _raw_read_lock(lock); \ -} while(0) - -#define spin_unlock(lock) \ -do { \ - _raw_spin_unlock(lock); \ - preempt_enable(); \ -} while (0) +#define write_lock(lock) _write_lock(lock) +#define read_lock(lock) _read_lock(lock) -#define write_unlock(lock) \ -do { \ - _raw_write_unlock(lock); \ - preempt_enable(); \ -} while(0) +#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) -#define read_unlock(lock) \ -do { \ - _raw_read_unlock(lock); \ - preempt_enable(); \ -} while(0) +#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) -#define spin_lock_irqsave(lock, flags) \ -do { \ - local_irq_save(flags); \ - preempt_disable(); \ - _raw_spin_lock_flags(lock, flags); \ -} while (0) - -#define spin_lock_irq(lock) \ -do { \ - local_irq_disable(); \ - preempt_disable(); \ - _raw_spin_lock(lock); \ -} while (0) +#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 -#define spin_lock_bh(lock) \ -do { \ - local_bh_disable(); \ - preempt_disable(); \ - _raw_spin_lock(lock); \ -} while (0) +#else -#define read_lock_irqsave(lock, flags) \ -do { \ - local_irq_save(flags); \ - preempt_disable(); \ - _raw_read_lock(lock); \ -} while (0) +#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) -#define read_lock_irq(lock) \ -do { \ - local_irq_disable(); \ - preempt_disable(); \ - _raw_read_lock(lock); \ -} while (0) +#endif -#define read_lock_bh(lock) \ -do { \ - local_bh_disable(); \ - preempt_disable(); \ - _raw_read_lock(lock); \ -} while (0) +#define spin_lock_irq(lock) _spin_lock_irq(lock) +#define spin_lock_bh(lock) _spin_lock_bh(lock) -#define write_lock_irqsave(lock, flags) \ -do { \ - local_irq_save(flags); \ - preempt_disable(); \ - _raw_write_lock(lock); \ -} while (0) +#define read_lock_irq(lock) _read_lock_irq(lock) +#define read_lock_bh(lock) _read_lock_bh(lock) -#define write_lock_irq(lock) \ -do { \ - local_irq_disable(); \ - preempt_disable(); \ - _raw_write_lock(lock); \ -} while (0) +#define write_lock_irq(lock) _write_lock_irq(lock) +#define write_lock_bh(lock) _write_lock_bh(lock) -#define write_lock_bh(lock) \ -do { \ - local_bh_disable(); \ - preempt_disable(); \ - _raw_write_lock(lock); \ -} while (0) +/* + * 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) __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) +# 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) \ -do { \ - _raw_spin_unlock(lock); \ - local_irq_restore(flags); \ - preempt_enable(); \ -} while (0) - -#define _raw_spin_unlock_irqrestore(lock, flags) \ -do { \ - _raw_spin_unlock(lock); \ - local_irq_restore(flags); \ -} while (0) - -#define spin_unlock_irq(lock) \ -do { \ - _raw_spin_unlock(lock); \ - local_irq_enable(); \ - preempt_enable(); \ -} while (0) - -#define spin_unlock_bh(lock) \ -do { \ - _raw_spin_unlock(lock); \ - preempt_enable(); \ - local_bh_enable(); \ -} while (0) + _spin_unlock_irqrestore(lock, flags) +#define spin_unlock_bh(lock) _spin_unlock_bh(lock) #define read_unlock_irqrestore(lock, flags) \ -do { \ - _raw_read_unlock(lock); \ - local_irq_restore(flags); \ - preempt_enable(); \ -} while (0) - -#define read_unlock_irq(lock) \ -do { \ - _raw_read_unlock(lock); \ - local_irq_enable(); \ - preempt_enable(); \ -} while (0) - -#define read_unlock_bh(lock) \ -do { \ - _raw_read_unlock(lock); \ - preempt_enable(); \ - local_bh_enable(); \ -} while (0) + _read_unlock_irqrestore(lock, flags) +#define read_unlock_bh(lock) _read_unlock_bh(lock) #define write_unlock_irqrestore(lock, flags) \ -do { \ - _raw_write_unlock(lock); \ - local_irq_restore(flags); \ - preempt_enable(); \ -} while (0) - -#define write_unlock_irq(lock) \ -do { \ - _raw_write_unlock(lock); \ - local_irq_enable(); \ - preempt_enable(); \ -} while (0) + _write_unlock_irqrestore(lock, flags) +#define write_unlock_bh(lock) _write_unlock_bh(lock) -#define write_unlock_bh(lock) \ -do { \ - _raw_write_unlock(lock); \ - preempt_enable(); \ - local_bh_enable(); \ -} while (0) +#define spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock)) -#define spin_trylock_bh(lock) ({ local_bh_disable(); preempt_disable(); \ - _raw_spin_trylock(lock) ? 1 : \ - ({preempt_enable(); local_bh_enable(); 0;});}) - -/* "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 spin_trylock_irq(lock) \ +({ \ + local_irq_disable(); \ + spin_trylock(lock) ? \ + 1 : ({ local_irq_enable(); 0; }); \ +}) -/* - * 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)) - cpu_relax(); - } -#endif -} +#define spin_trylock_irqsave(lock, flags) \ +({ \ + local_irq_save(flags); \ + spin_trylock(lock) ? \ + 1 : ({ local_irq_restore(flags); 0; }); \ +}) /* - * Return true if it was acquired + * Pull the atomic_t declaration: + * (asm-mips/atomic.h needs above definitions) */ -static inline int bit_spin_trylock(int bitnum, unsigned long *addr) -{ -#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) - int ret; - - preempt_disable(); - ret = !test_and_set_bit(bitnum, addr); - if (!ret) - preempt_enable(); - return ret; -#else - preempt_disable(); - return 1; -#endif -} - -/* - * bit-based spin_unlock() +#include +/** + * atomic_dec_and_lock - lock on reaching reference count zero + * @atomic: the atomic counter + * @lock: the spinlock in question */ -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(); -} +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)) -/* - * Return true if the lock is held. +/** + * spin_can_lock - would spin_trylock() succeed? + * @lock: the spinlock in question. */ -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 spin_can_lock(lock) (!spin_is_locked(lock)) #endif /* __LINUX_SPINLOCK_H */