kernel-ark/include/asm-alpha/spinlock.h
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

213 lines
4.1 KiB
C

#ifndef _ALPHA_SPINLOCK_H
#define _ALPHA_SPINLOCK_H
#include <linux/config.h>
#include <asm/system.h>
#include <linux/kernel.h>
#include <asm/current.h>
/*
* 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 int lock;
#ifdef CONFIG_DEBUG_SPINLOCK
int on_cpu;
int line_no;
void *previous;
struct task_struct * task;
const char *base_file;
#endif
} spinlock_t;
#ifdef CONFIG_DEBUG_SPINLOCK
#define SPIN_LOCK_UNLOCKED (spinlock_t){ 0, -1, 0, NULL, NULL, NULL }
#else
#define SPIN_LOCK_UNLOCKED (spinlock_t){ 0 }
#endif
#define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
#define spin_is_locked(x) ((x)->lock != 0)
#define spin_unlock_wait(x) do { barrier(); } while ((x)->lock)
#ifdef CONFIG_DEBUG_SPINLOCK
extern void _raw_spin_unlock(spinlock_t * lock);
extern void debug_spin_lock(spinlock_t * lock, const char *, int);
extern int debug_spin_trylock(spinlock_t * lock, const char *, int);
#define _raw_spin_lock(LOCK) \
debug_spin_lock(LOCK, __BASE_FILE__, __LINE__)
#define _raw_spin_trylock(LOCK) \
debug_spin_trylock(LOCK, __BASE_FILE__, __LINE__)
#else
static inline void _raw_spin_unlock(spinlock_t * lock)
{
mb();
lock->lock = 0;
}
static inline void _raw_spin_lock(spinlock_t * lock)
{
long tmp;
__asm__ __volatile__(
"1: ldl_l %0,%1\n"
" bne %0,2f\n"
" lda %0,1\n"
" stl_c %0,%1\n"
" beq %0,2f\n"
" mb\n"
".subsection 2\n"
"2: ldl %0,%1\n"
" bne %0,2b\n"
" br 1b\n"
".previous"
: "=&r" (tmp), "=m" (lock->lock)
: "m"(lock->lock) : "memory");
}
static inline int _raw_spin_trylock(spinlock_t *lock)
{
return !test_and_set_bit(0, &lock->lock);
}
#endif /* CONFIG_DEBUG_SPINLOCK */
#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
/***********************************************************/
typedef struct {
volatile unsigned int lock;
} rwlock_t;
#define RW_LOCK_UNLOCKED (rwlock_t){ 0 }
#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0)
static inline int read_can_lock(rwlock_t *lock)
{
return (lock->lock & 1) == 0;
}
static inline int write_can_lock(rwlock_t *lock)
{
return lock->lock == 0;
}
#ifdef CONFIG_DEBUG_RWLOCK
extern void _raw_write_lock(rwlock_t * lock);
extern void _raw_read_lock(rwlock_t * lock);
#else
static inline void _raw_write_lock(rwlock_t * lock)
{
long regx;
__asm__ __volatile__(
"1: ldl_l %1,%0\n"
" bne %1,6f\n"
" lda %1,1\n"
" stl_c %1,%0\n"
" beq %1,6f\n"
" mb\n"
".subsection 2\n"
"6: ldl %1,%0\n"
" bne %1,6b\n"
" br 1b\n"
".previous"
: "=m" (*lock), "=&r" (regx)
: "m" (*lock) : "memory");
}
static inline void _raw_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"
" mb\n"
".subsection 2\n"
"6: ldl %1,%0\n"
" blbs %1,6b\n"
" br 1b\n"
".previous"
: "=m" (*lock), "=&r" (regx)
: "m" (*lock) : "memory");
}
#endif /* CONFIG_DEBUG_RWLOCK */
static inline int _raw_read_trylock(rwlock_t * lock)
{
long regx;
int success;
__asm__ __volatile__(
"1: ldl_l %1,%0\n"
" lda %2,0\n"
" blbs %1,2f\n"
" subl %1,2,%2\n"
" stl_c %2,%0\n"
" beq %2,6f\n"
"2: mb\n"
".subsection 2\n"
"6: br 1b\n"
".previous"
: "=m" (*lock), "=&r" (regx), "=&r" (success)
: "m" (*lock) : "memory");
return success;
}
static inline int _raw_write_trylock(rwlock_t * lock)
{
long regx;
int success;
__asm__ __volatile__(
"1: ldl_l %1,%0\n"
" lda %2,0\n"
" bne %1,2f\n"
" lda %2,1\n"
" stl_c %2,%0\n"
" beq %2,6f\n"
"2: mb\n"
".subsection 2\n"
"6: br 1b\n"
".previous"
: "=m" (*lock), "=&r" (regx), "=&r" (success)
: "m" (*lock) : "memory");
return success;
}
static inline void _raw_write_unlock(rwlock_t * lock)
{
mb();
lock->lock = 0;
}
static inline void _raw_read_unlock(rwlock_t * lock)
{
long regx;
__asm__ __volatile__(
" mb\n"
"1: ldl_l %1,%0\n"
" addl %1,2,%1\n"
" stl_c %1,%0\n"
" beq %1,6f\n"
".subsection 2\n"
"6: br 1b\n"
".previous"
: "=m" (*lock), "=&r" (regx)
: "m" (*lock) : "memory");
}
#endif /* _ALPHA_SPINLOCK_H */