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Make <asm-x86/spinlock.h> use ACCESS_ONCE()
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..instead of cooking up its own uglier local version of it.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds committed May 11, 2008
1 parent 9c3cdc1 commit 39f004b
Showing 1 changed file with 4 additions and 14 deletions.
18 changes: 4 additions & 14 deletions include/asm-x86/spinlock.h
Original file line number Diff line number Diff line change
Expand Up @@ -20,18 +20,8 @@
*/

#ifdef CONFIG_X86_32
typedef char _slock_t;
# define LOCK_INS_DEC "decb"
# define LOCK_INS_XCH "xchgb"
# define LOCK_INS_MOV "movb"
# define LOCK_INS_CMP "cmpb"
# define LOCK_PTR_REG "a"
#else
typedef int _slock_t;
# define LOCK_INS_DEC "decl"
# define LOCK_INS_XCH "xchgl"
# define LOCK_INS_MOV "movl"
# define LOCK_INS_CMP "cmpl"
# define LOCK_PTR_REG "D"
#endif

Expand Down Expand Up @@ -66,14 +56,14 @@ typedef int _slock_t;
#if (NR_CPUS < 256)
static inline int __raw_spin_is_locked(raw_spinlock_t *lock)
{
int tmp = *(volatile signed int *)(&(lock)->slock);
int tmp = ACCESS_ONCE(lock->slock);

return (((tmp >> 8) & 0xff) != (tmp & 0xff));
}

static inline int __raw_spin_is_contended(raw_spinlock_t *lock)
{
int tmp = *(volatile signed int *)(&(lock)->slock);
int tmp = ACCESS_ONCE(lock->slock);

return (((tmp >> 8) & 0xff) - (tmp & 0xff)) > 1;
}
Expand Down Expand Up @@ -130,14 +120,14 @@ static __always_inline void __raw_spin_unlock(raw_spinlock_t *lock)
#else
static inline int __raw_spin_is_locked(raw_spinlock_t *lock)
{
int tmp = *(volatile signed int *)(&(lock)->slock);
int tmp = ACCESS_ONCE(lock->slock);

return (((tmp >> 16) & 0xffff) != (tmp & 0xffff));
}

static inline int __raw_spin_is_contended(raw_spinlock_t *lock)
{
int tmp = *(volatile signed int *)(&(lock)->slock);
int tmp = ACCESS_ONCE(lock->slock);

return (((tmp >> 16) & 0xffff) - (tmp & 0xffff)) > 1;
}
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