redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

Make <asm-x86/spinlock.h> use ACCESS_ONCE()

Browse source 
..instead of cooking up its own uglier local version of it.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2008-05-10 19:52:43 -07:00
parent 9c3cdc1f83
commit 39f004ba27
1 changed files with 4 additions and 14 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

18
include/asm-x86/spinlock.h
View file

@ -20,18 +20,8 @@
*/ */
#ifdef CONFIG_X86_32 #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" # define LOCK_PTR_REG "a"
#else #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" # define LOCK_PTR_REG "D"
#endif #endif
@ -66,14 +56,14 @@ typedef int _slock_t;
#if (NR_CPUS < 256) #if (NR_CPUS < 256)
static inline int __raw_spin_is_locked(raw_spinlock_t *lock) 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)); return (((tmp >> 8) & 0xff) != (tmp & 0xff));
} }
static inline int __raw_spin_is_contended(raw_spinlock_t *lock) 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; return (((tmp >> 8) & 0xff) - (tmp & 0xff)) > 1;
} }
@ -130,14 +120,14 @@ static __always_inline void __raw_spin_unlock(raw_spinlock_t *lock)
#else #else
static inline int __raw_spin_is_locked(raw_spinlock_t *lock) 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)); return (((tmp >> 16) & 0xffff) != (tmp & 0xffff));
} }
static inline int __raw_spin_is_contended(raw_spinlock_t *lock) 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; return (((tmp >> 16) & 0xffff) - (tmp & 0xffff)) > 1;
} }