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[PATCH] Clean up spin/rwlocks

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- Inline spinlock strings into their inline functions
- Convert macros to typesafe inlines
- Replace some leftover __asm__ __volatile__s with asm volatile

Signed-off-by: Andi Kleen <ak@suse.de>
This commit is contained in:
Andi Kleen 2006-09-26 10:52:32 +02:00 committed by Andi Kleen
parent a752d7194c
commit 8b059d2373
2 changed files with 41 additions and 44 deletions
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14
include/asm-x86_64/rwlock.h
View file

@ -21,18 +21,6 @@
#define RW_LOCK_BIAS 0x01000000 #define RW_LOCK_BIAS 0x01000000
#define RW_LOCK_BIAS_STR "0x01000000" #define RW_LOCK_BIAS_STR "0x01000000"
#define __build_read_lock(rw) \ /* Actual code is in asm/spinlock.h or in arch/x86_64/lib/rwlock.S */
asm volatile(LOCK_PREFIX "subl $1,(%0)\n\t" \
"jns 1f\n" \
"call __read_lock_failed\n" \
"1:\n" \
::"D" (rw), "i" (RW_LOCK_BIAS) : "memory")
#define __build_write_lock(rw) \
asm volatile(LOCK_PREFIX "subl %1,(%0)\n\t" \
"jz 1f\n" \
"\tcall __write_lock_failed\n\t" \
"1:\n" \
::"D" (rw), "i" (RW_LOCK_BIAS) : "memory")
#endif #endif

71
include/asm-x86_64/spinlock.h
View file

@ -16,30 +16,23 @@
* (the type definitions are in asm/spinlock_types.h) * (the type definitions are in asm/spinlock_types.h)
*/ */
#define __raw_spin_is_locked(x) \ static inline int __raw_spin_is_locked(raw_spinlock_t *lock)
(*(volatile signed int *)(&(x)->slock) <= 0) {
return *(volatile signed int *)(&(lock)->slock) <= 0;
#define __raw_spin_lock_string \ }
"\n1:\t" \
LOCK_PREFIX " ; decl %0\n\t" \
"jns 2f\n" \
"3:\n" \
"rep;nop\n\t" \
"cmpl $0,%0\n\t" \
"jle 3b\n\t" \
"jmp 1b\n" \
"2:\t" \
#define __raw_spin_lock_string_up \
"\n\tdecl %0"
#define __raw_spin_unlock_string \
"movl $1,%0" \
:"=m" (lock->slock) : : "memory"
static inline void __raw_spin_lock(raw_spinlock_t *lock) static inline void __raw_spin_lock(raw_spinlock_t *lock)
{ {
asm volatile(__raw_spin_lock_string : "=m" (lock->slock) : : "memory"); asm volatile(
"\n1:\t"
LOCK_PREFIX " ; decl %0\n\t"
"jns 2f\n"
"3:\n"
"rep;nop\n\t"
"cmpl $0,%0\n\t"
"jle 3b\n\t"
"jmp 1b\n"
"2:\t" : "=m" (lock->slock) : : "memory");
} }
#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) #define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
@ -48,7 +41,7 @@ static inline int __raw_spin_trylock(raw_spinlock_t *lock)
{ {
int oldval; int oldval;
__asm__ __volatile__( asm volatile(
"xchgl %0,%1" "xchgl %0,%1"
:"=q" (oldval), "=m" (lock->slock) :"=q" (oldval), "=m" (lock->slock)
:"0" (0) : "memory"); :"0" (0) : "memory");
@ -58,13 +51,14 @@ static inline int __raw_spin_trylock(raw_spinlock_t *lock)
static inline void __raw_spin_unlock(raw_spinlock_t *lock) static inline void __raw_spin_unlock(raw_spinlock_t *lock)
{ {
__asm__ __volatile__( asm volatile("movl $1,%0" :"=m" (lock->slock) :: "memory");
__raw_spin_unlock_string
);
} }
#define __raw_spin_unlock_wait(lock) \ static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)
do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0) {
while (__raw_spin_is_locked(lock))
cpu_relax();
}
/* /*
* Read-write spinlocks, allowing multiple readers * Read-write spinlocks, allowing multiple readers
@ -80,17 +74,32 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lock)
* with the high bit (sign) being the "contended" bit. * with the high bit (sign) being the "contended" bit.
*/ */
#define __raw_read_can_lock(x) ((int)(x)->lock > 0) static inline int __raw_read_can_lock(raw_rwlock_t *lock)
#define __raw_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) {
return (int)(lock)->lock > 0;
}
static inline int __raw_write_can_lock(raw_rwlock_t *lock)
{
return (lock)->lock == RW_LOCK_BIAS;
}
static inline void __raw_read_lock(raw_rwlock_t *rw) static inline void __raw_read_lock(raw_rwlock_t *rw)
{ {
__build_read_lock(rw); asm volatile(LOCK_PREFIX "subl $1,(%0)\n\t"
"jns 1f\n"
"call __read_lock_failed\n"
"1:\n"
::"D" (rw), "i" (RW_LOCK_BIAS) : "memory");
} }
static inline void __raw_write_lock(raw_rwlock_t *rw) static inline void __raw_write_lock(raw_rwlock_t *rw)
{ {
__build_write_lock(rw); asm volatile(LOCK_PREFIX "subl %1,(%0)\n\t"
"jz 1f\n"
"\tcall __write_lock_failed\n\t"
"1:\n"
::"D" (rw), "i" (RW_LOCK_BIAS) : "memory");
} }
static inline int __raw_read_trylock(raw_rwlock_t *lock) static inline int __raw_read_trylock(raw_rwlock_t *lock)