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[PATCH] i386: 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 8b059d2373
commit fb2e284856
2 changed files with 68 additions and 77 deletions
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14
include/asm-i386/rwlock.h
View file

@ -20,18 +20,6 @@
#define RW_LOCK_BIAS 0x01000000
#define RW_LOCK_BIAS_STR "0x01000000"
#define __build_read_lock(rw, helper) \
asm volatile(LOCK_PREFIX " subl $1,(%0)\n\t" \
"jns 1f\n" \
"call " helper "\n\t" \
"1:\n" \
::"a" (rw) : "memory")
#define __build_write_lock(rw, helper) \
asm volatile(LOCK_PREFIX " subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
"jz 1f\n" \
"call " helper "\n\t" \
"1:\n" \
::"a" (rw) : "memory")
/* Code is in asm-i386/spinlock.h */
#endif

131
include/asm-i386/spinlock.h
View file

@ -4,6 +4,7 @@
#include <asm/atomic.h>
#include <asm/rwlock.h>
#include <asm/page.h>
#include <asm/processor.h>
#include <linux/compiler.h>
/*
@ -17,67 +18,64 @@
* (the type definitions are in asm/spinlock_types.h)
*/
#define __raw_spin_is_locked(x) \
(*(volatile signed char *)(&(x)->slock) <= 0)
#define __raw_spin_lock_string \
"\n1:\t" \
LOCK_PREFIX " ; decb %0\n\t" \
"jns 3f\n" \
"2:\t" \
"rep;nop\n\t" \
"cmpb $0,%0\n\t" \
"jle 2b\n\t" \
"jmp 1b\n" \
"3:\n\t"
/*
* NOTE: there's an irqs-on section here, which normally would have to be
* irq-traced, but on CONFIG_TRACE_IRQFLAGS we never use
* __raw_spin_lock_string_flags().
*/
#define __raw_spin_lock_string_flags \
"\n1:\t" \
LOCK_PREFIX " ; decb %0\n\t" \
"jns 5f\n" \
"2:\t" \
"testl $0x200, %1\n\t" \
"jz 4f\n\t" \
"sti\n" \
"3:\t" \
"rep;nop\n\t" \
"cmpb $0, %0\n\t" \
"jle 3b\n\t" \
"cli\n\t" \
"jmp 1b\n" \
"4:\t" \
"rep;nop\n\t" \
"cmpb $0, %0\n\t" \
"jg 1b\n\t" \
"jmp 4b\n" \
"5:\n\t"
static inline int __raw_spin_is_locked(raw_spinlock_t *x)
{
return *(volatile signed char *)(&(x)->slock) <= 0;
}
static inline void __raw_spin_lock(raw_spinlock_t *lock)
{
asm(__raw_spin_lock_string : "+m" (lock->slock) : : "memory");
asm volatile("\n1:\t"
LOCK_PREFIX " ; decb %0\n\t"
"jns 3f\n"
"2:\t"
"rep;nop\n\t"
"cmpb $0,%0\n\t"
"jle 2b\n\t"
"jmp 1b\n"
"3:\n\t"
: "+m" (lock->slock) : : "memory");
}
/*
* It is easier for the lock validator if interrupts are not re-enabled
* in the middle of a lock-acquire. This is a performance feature anyway
* so we turn it off:
*
* NOTE: there's an irqs-on section here, which normally would have to be
* irq-traced, but on CONFIG_TRACE_IRQFLAGS we never use this variant.
*/
#ifndef CONFIG_PROVE_LOCKING
static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
{
asm(__raw_spin_lock_string_flags : "+m" (lock->slock) : "r" (flags) : "memory");
asm volatile(
"\n1:\t"
LOCK_PREFIX " ; decb %0\n\t"
"jns 5f\n"
"2:\t"
"testl $0x200, %1\n\t"
"jz 4f\n\t"
"sti\n"
"3:\t"
"rep;nop\n\t"
"cmpb $0, %0\n\t"
"jle 3b\n\t"
"cli\n\t"
"jmp 1b\n"
"4:\t"
"rep;nop\n\t"
"cmpb $0, %0\n\t"
"jg 1b\n\t"
"jmp 4b\n"
"5:\n\t"
: "+m" (lock->slock) : "r" (flags) : "memory");
}
#endif
static inline int __raw_spin_trylock(raw_spinlock_t *lock)
{
char oldval;
__asm__ __volatile__(
asm volatile(
"xchgb %b0,%1"
:"=q" (oldval), "+m" (lock->slock)
:"0" (0) : "memory");
@ -93,38 +91,29 @@ static inline int __raw_spin_trylock(raw_spinlock_t *lock)
#if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE)
#define __raw_spin_unlock_string \
"movb $1,%0" \
:"+m" (lock->slock) : : "memory"
static inline void __raw_spin_unlock(raw_spinlock_t *lock)
{
__asm__ __volatile__(
__raw_spin_unlock_string
);
asm volatile("movb $1,%0" : "+m" (lock->slock) :: "memory");
}
#else
#define __raw_spin_unlock_string \
"xchgb %b0, %1" \
:"=q" (oldval), "+m" (lock->slock) \
:"0" (oldval) : "memory"
static inline void __raw_spin_unlock(raw_spinlock_t *lock)
{
char oldval = 1;
__asm__ __volatile__(
__raw_spin_unlock_string
);
asm volatile("xchgb %b0, %1"
: "=q" (oldval), "+m" (lock->slock)
: "0" (oldval) : "memory");
}
#endif
#define __raw_spin_unlock_wait(lock) \
do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0)
static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)
{
while (__raw_spin_is_locked(lock))
cpu_relax();
}
/*
* Read-write spinlocks, allowing multiple readers
@ -151,22 +140,36 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lock)
* read_can_lock - would read_trylock() succeed?
* @lock: the rwlock in question.
*/
#define __raw_read_can_lock(x) ((int)(x)->lock > 0)
static inline int __raw_read_can_lock(raw_rwlock_t *x)
{
return (int)(x)->lock > 0;
}
/**
* write_can_lock - would write_trylock() succeed?
* @lock: the rwlock in question.
*/
#define __raw_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS)
static inline int __raw_write_can_lock(raw_rwlock_t *x)
{
return (x)->lock == RW_LOCK_BIAS;
}
static inline void __raw_read_lock(raw_rwlock_t *rw)
{
__build_read_lock(rw, "__read_lock_failed");
asm volatile(LOCK_PREFIX " subl $1,(%0)\n\t"
"jns 1f\n"
"call __read_lock_failed\n\t"
"1:\n"
::"a" (rw) : "memory");
}
static inline void __raw_write_lock(raw_rwlock_t *rw)
{
__build_write_lock(rw, "__write_lock_failed");
asm volatile(LOCK_PREFIX " subl $" RW_LOCK_BIAS_STR ",(%0)\n\t"
"jz 1f\n"
"call __write_lock_failed\n\t"
"1:\n"
::"a" (rw) : "memory");
}
static inline int __raw_read_trylock(raw_rwlock_t *lock)