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#ifndef _ALPHA_SPINLOCK_H
#define _ALPHA_SPINLOCK_H
#include <asm/system.h>
#ifndef __SMP__
/* gcc 2.7.2 can crash initializing an empty structure. */
typedef struct { int dummy; } spinlock_t;
#define SPIN_LOCK_UNLOCKED { 0 }
#define spin_lock_init(lock) ((void) 0)
#define spin_lock(lock) ((void) 0)
#define spin_trylock(lock) ((void) 0)
#define spin_unlock_wait(lock) ((void) 0)
#define spin_unlock(lock) ((void) 0)
#define spin_lock_irq(lock) cli()
#define spin_unlock_irq(lock) sti()
#define spin_lock_irqsave(lock, flags) save_and_cli(flags)
#define spin_unlock_irqrestore(lock, flags) restore_flags(flags)
/*
* Read-write spinlocks, allowing multiple readers
* but only one writer.
*
* NOTE! it is quite common to have readers in interrupts
* but no interrupt writers. For those circumstances we
* can "mix" irq-safe locks - any writer needs to get a
* irq-safe write-lock, but readers can get non-irqsafe
* read-locks.
*/
typedef struct { int dummy; } rwlock_t;
#define RW_LOCK_UNLOCKED { 0 }
#define read_lock(lock) ((void) 0)
#define read_unlock(lock) ((void) 0)
#define write_lock(lock) ((void) 0)
#define write_unlock(lock) ((void) 0)
#define read_lock_irq(lock) cli()
#define read_unlock_irq(lock) sti()
#define write_lock_irq(lock) cli()
#define write_unlock_irq(lock) sti()
#define read_lock_irqsave(lock, flags) save_and_cli(flags)
#define read_unlock_irqrestore(lock, flags) restore_flags(flags)
#define write_lock_irqsave(lock, flags) save_and_cli(flags)
#define write_unlock_irqrestore(lock, flags) restore_flags(flags)
#else /* __SMP__ */
#include <linux/kernel.h>
#include <asm/current.h>
#define DEBUG_SPINLOCK 1
#define DEBUG_RWLOCK 1
/*
* Simple spin lock operations. There are two variants, one clears IRQ's
* on the local processor, one does not.
*
* We make no fairness assumptions. They have a cost.
*/
typedef struct {
volatile unsigned long lock;
void *previous;
struct task_struct * task;
} spinlock_t;
#define SPIN_LOCK_UNLOCKED { 0, 0, 0 }
#define spin_lock_init(x) \
((x)->lock = 0, (x)->previous = 0, (x)->task = 0)
#define spin_unlock_wait(x) \
({ do { barrier(); } while(((volatile spinlock_t *)x)->lock); })
typedef struct { unsigned long a[100]; } __dummy_lock_t;
#define __dummy_lock(lock) (*(__dummy_lock_t *)(lock))
#if DEBUG_SPINLOCK
extern void spin_lock(spinlock_t * lock);
#else
static inline void spin_lock(spinlock_t * lock)
{
long tmp;
/* Use sub-sections to put the actual loop at the end
of this object file's text section so as to perfect
branch prediction. */
__asm__ __volatile__(
"1: ldq_l %0,%1\n"
" blbs %0,2f\n"
" or %0,1,%0\n"
" stq_c %0,%1\n"
" beq %0,2f\n"
" mb\n"
".section .text2,\"ax\"\n"
"2: ldq %0,%1\n"
" blbs %0,2b\n"
" br 1b\n"
".previous"
: "=r" (tmp), "=m" (__dummy_lock(lock))
: "m"(__dummy_lock(lock)));
}
#endif /* DEBUG_SPINLOCK */
static inline void spin_unlock(spinlock_t * lock)
{
mb();
lock->lock = 0;
}
#define spin_trylock(lock) (!test_and_set_bit(0,(lock)))
#define spin_lock_irq(lock) \
(__cli(), spin_lock(lock))
#define spin_unlock_irq(lock) \
(spin_unlock(lock), __sti())
#define spin_lock_irqsave(lock, flags) \
(__save_and_cli(flags), spin_lock(lock))
#define spin_unlock_irqrestore(lock, flags) \
(spin_unlock(lock), __restore_flags(flags))
/***********************************************************/
typedef struct { volatile int write_lock:1, read_counter:31; } rwlock_t;
#define RW_LOCK_UNLOCKED { 0, 0 }
#if DEBUG_RWLOCK
extern void write_lock(rwlock_t * lock);
extern void read_lock(rwlock_t * lock);
#else
static inline void write_lock(rwlock_t * lock)
{
long regx;
__asm__ __volatile__(
"1: ldl_l %1,%0\n"
" bne %1,6f\n"
" or $31,1,%1\n"
" stl_c %1,%0\n"
" beq %1,6f\n"
" mb\n"
".section .text2,\"ax\"\n"
"6: ldl %1,%0\n"
" bne %1,6b\n"
" br 1b\n"
".previous"
: "=m" (__dummy_lock(lock)), "=&r" (regx)
: "0" (__dummy_lock(lock))
);
}
static inline void read_lock(rwlock_t * lock)
{
long regx;
__asm__ __volatile__(
"1: ldl_l %1,%0\n"
" blbs %1,6f\n"
" subl %1,2,%1\n"
" stl_c %1,%0\n"
" beq %1,6f\n"
"4: mb\n"
".section .text2,\"ax\"\n"
"6: ldl %1,%0\n"
" blbs %1,6b\n"
" br 1b\n"
".previous"
: "=m" (__dummy_lock(lock)), "=&r" (regx)
: "0" (__dummy_lock(lock))
);
}
#endif /* DEBUG_RWLOCK */
static inline void write_unlock(rwlock_t * lock)
{
mb();
*(volatile int *)lock = 0;
}
static inline void read_unlock(rwlock_t * lock)
{
long regx;
__asm__ __volatile__(
"1: ldl_l %1,%0\n"
" addl %1,2,%1\n"
" stl_c %1,%0\n"
" beq %1,6f\n"
".section .text2,\"ax\"\n"
"6: br 1b\n"
".previous"
: "=m" (__dummy_lock(lock)), "=&r" (regx)
: "0" (__dummy_lock(lock)));
}
#define read_lock_irq(lock) (__cli(), read_lock(lock))
#define read_unlock_irq(lock) (read_unlock(lock), __sti())
#define write_lock_irq(lock) (__cli(), write_lock(lock))
#define write_unlock_irq(lock) (write_unlock(lock), __sti())
#define read_lock_irqsave(lock, flags) \
(__save_and_cli(flags), read_lock(lock))
#define read_unlock_irqrestore(lock, flags) \
(read_unlock(lock), __restore_flags(flags))
#define write_lock_irqsave(lock, flags) \
(__save_and_cli(flags), write_lock(lock))
#define write_unlock_irqrestore(lock, flags) \
(write_unlock(lock), __restore_flags(flags))
#endif /* SMP */
#endif /* _ALPHA_SPINLOCK_H */
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