diff options
Diffstat (limited to 'include/linux/spinlock.h')
| -rw-r--r-- | include/linux/spinlock.h | 606 |
1 files changed, 606 insertions, 0 deletions
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h new file mode 100644 index 00000000000..e895f3eaf53 --- /dev/null +++ b/include/linux/spinlock.h @@ -0,0 +1,606 @@ +#ifndef __LINUX_SPINLOCK_H +#define __LINUX_SPINLOCK_H + +/* + * include/linux/spinlock.h - generic locking declarations + */ + +#include <linux/config.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 <asm/processor.h> /* for cpu relax */ +#include <asm/system.h> + +/* + * 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 <asm/spinlock.h> + +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(); 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(); \ + local_bh_enable(); \ + __release(lock); \ +} while (0) + +#define _write_unlock_bh(lock) \ +do { \ + _raw_write_unlock(lock); \ + preempt_enable(); \ + 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); \ + local_bh_enable(); \ + preempt_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 <asm/atomic.h> +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 */ |