Add cmpxchg_local to sparc, move __cmpxchg to system.h

Move cmpxchg and add cmpxchg_local to system.h.
Use the new generic cmpxchg_local (disables interrupt).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mathieu Desnoyers 2008-02-07 00:16:24 -08:00 committed by Linus Torvalds
parent fe4130131e
commit 405321d3ab
2 changed files with 48 additions and 36 deletions

View file

@ -17,42 +17,6 @@ typedef struct { volatile int counter; } atomic_t;
#ifdef __KERNEL__
/* Emulate cmpxchg() the same way we emulate atomics,
* by hashing the object address and indexing into an array
* of spinlocks to get a bit of performance...
*
* See arch/sparc/lib/atomic32.c for implementation.
*
* Cribbed from <asm-parisc/atomic.h>
*/
#define __HAVE_ARCH_CMPXCHG 1
/* bug catcher for when unsupported size is used - won't link */
extern void __cmpxchg_called_with_bad_pointer(void);
/* we only need to support cmpxchg of a u32 on sparc */
extern unsigned long __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_);
/* don't worry...optimizer will get rid of most of this */
static inline unsigned long
__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
{
switch(size) {
case 4:
return __cmpxchg_u32((u32 *)ptr, (u32)old, (u32)new_);
default:
__cmpxchg_called_with_bad_pointer();
break;
}
return old;
}
#define cmpxchg(ptr,o,n) ({ \
__typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
(unsigned long)_n_, sizeof(*(ptr))); \
})
#define ATOMIC_INIT(i) { (i) }
extern int __atomic_add_return(int, atomic_t *);

View file

@ -225,6 +225,54 @@ static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr, int
return x;
}
/* Emulate cmpxchg() the same way we emulate atomics,
* by hashing the object address and indexing into an array
* of spinlocks to get a bit of performance...
*
* See arch/sparc/lib/atomic32.c for implementation.
*
* Cribbed from <asm-parisc/atomic.h>
*/
#define __HAVE_ARCH_CMPXCHG 1
/* bug catcher for when unsupported size is used - won't link */
extern void __cmpxchg_called_with_bad_pointer(void);
/* we only need to support cmpxchg of a u32 on sparc */
extern unsigned long __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_);
/* don't worry...optimizer will get rid of most of this */
static inline unsigned long
__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
{
switch (size) {
case 4:
return __cmpxchg_u32((u32 *)ptr, (u32)old, (u32)new_);
default:
__cmpxchg_called_with_bad_pointer();
break;
}
return old;
}
#define cmpxchg(ptr, o, n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
(unsigned long)_n_, sizeof(*(ptr))); \
})
#include <asm-generic/cmpxchg-local.h>
/*
* cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
* them available.
*/
#define cmpxchg_local(ptr, o, n) \
((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
(unsigned long)(n), sizeof(*(ptr))))
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
extern void die_if_kernel(char *str, struct pt_regs *regs) __attribute__ ((noreturn));
#endif /* __KERNEL__ */