From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: 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! --- include/asm-alpha/spinlock.h | 212 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 212 insertions(+) create mode 100644 include/asm-alpha/spinlock.h (limited to 'include/asm-alpha/spinlock.h') diff --git a/include/asm-alpha/spinlock.h b/include/asm-alpha/spinlock.h new file mode 100644 index 0000000..80780dba --- /dev/null +++ b/include/asm-alpha/spinlock.h @@ -0,0 +1,212 @@ +#ifndef _ALPHA_SPINLOCK_H +#define _ALPHA_SPINLOCK_H + +#include +#include +#include +#include + + +/* + * 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 */ -- cgit v1.1