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#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\t"
#define LOCK_SECTION_END \
".previous\n\t"
/*
* If CONFIG_SMP is set, pull in the _raw_* definitions
*/
#ifdef CONFIG_SMP
#include <asm/spinlock.h>
#else
#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; \
})
/* 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 _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) { }
#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 _raw_write_trylock(lock) ({ (void)(lock); (1); })
#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) ({preempt_disable(); _raw_spin_trylock(lock) ? \
1 : ({preempt_enable(); 0;});})
#define write_trylock(lock) ({preempt_disable();_raw_write_trylock(lock) ? \
1 : ({preempt_enable(); 0;});})
/* 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)
#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)
#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_unlock(lock) \
do { \
_raw_write_unlock(lock); \
preempt_enable(); \
} while(0)
#define read_unlock(lock) \
do { \
_raw_read_unlock(lock); \
preempt_enable(); \
} while(0)
#define spin_lock_irqsave(lock, flags) \
do { \
local_irq_save(flags); \
preempt_disable(); \
_raw_spin_lock(lock); \
} while (0)
#define spin_lock_irq(lock) \
do { \
local_irq_disable(); \
preempt_disable(); \
_raw_spin_lock(lock); \
} while (0)
#define spin_lock_bh(lock) \
do { \
local_bh_disable(); \
preempt_disable(); \
_raw_spin_lock(lock); \
} while (0)
#define read_lock_irqsave(lock, flags) \
do { \
local_irq_save(flags); \
preempt_disable(); \
_raw_read_lock(lock); \
} while (0)
#define read_lock_irq(lock) \
do { \
local_irq_disable(); \
preempt_disable(); \
_raw_read_lock(lock); \
} while (0)
#define read_lock_bh(lock) \
do { \
local_bh_disable(); \
preempt_disable(); \
_raw_read_lock(lock); \
} while (0)
#define write_lock_irqsave(lock, flags) \
do { \
local_irq_save(flags); \
preempt_disable(); \
_raw_write_lock(lock); \
} while (0)
#define write_lock_irq(lock) \
do { \
local_irq_disable(); \
preempt_disable(); \
_raw_write_lock(lock); \
} while (0)
#define write_lock_bh(lock) \
do { \
local_bh_disable(); \
preempt_disable(); \
_raw_write_lock(lock); \
} while (0)
#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)
#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)
#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)
#define write_unlock_bh(lock) \
do { \
_raw_write_unlock(lock); \
preempt_enable(); \
local_bh_enable(); \
} while (0)
#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 <asm/atomic.h>
extern int atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
#endif
/*
* 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
}
/*
* Return true if it was acquired
*/
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()
*/
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();
}
/*
* 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
}
#endif /* __LINUX_SPINLOCK_H */