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#ifndef _ASM_IA64_ATOMIC_H
#define _ASM_IA64_ATOMIC_H
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*
* NOTE: don't mess with the types below! The "unsigned long" and
* "int" types were carefully placed so as to ensure proper operation
* of the macros.
*
* Copyright (C) 1998, 1999 Hewlett-Packard Co
* Copyright (C) 1998, 1999 David Mosberger-Tang <davidm@hpl.hp.com>
*/
#include <linux/types.h>
#include <asm/system.h>
/*
* Make sure gcc doesn't try to be clever and move things around
* on us. We need to use _exactly_ the address the user gave us,
* not some alias that contains the same information.
*/
#define __atomic_fool_gcc(x) (*(volatile struct { int a[100]; } *)x)
/*
* On IA-64, counter must always be volatile to ensure that that the
* memory accesses are ordered.
*/
typedef struct { volatile __s32 counter; } atomic_t;
#define ATOMIC_INIT(i) ((atomic_t) { (i) })
#define atomic_read(v) ((v)->counter)
#define atomic_set(v,i) (((v)->counter) = (i))
static __inline__ int
ia64_atomic_add (int i, atomic_t *v)
{
__s32 old, new;
CMPXCHG_BUGCHECK_DECL
do {
CMPXCHG_BUGCHECK(v);
old = atomic_read(v);
new = old + i;
} while (ia64_cmpxchg("acq", v, old, old + i, sizeof(atomic_t)) != old);
return new;
}
static __inline__ int
ia64_atomic_sub (int i, atomic_t *v)
{
__s32 old, new;
CMPXCHG_BUGCHECK_DECL
do {
CMPXCHG_BUGCHECK(v);
old = atomic_read(v);
new = old - i;
} while (ia64_cmpxchg("acq", v, old, new, sizeof(atomic_t)) != old);
return new;
}
/*
* Atomically add I to V and return TRUE if the resulting value is
* negative.
*/
static __inline__ int
atomic_add_negative (int i, atomic_t *v)
{
return ia64_atomic_add(i, v) < 0;
}
#define atomic_add_return(i,v) \
((__builtin_constant_p(i) && \
( (i == 1) || (i == 4) || (i == 8) || (i == 16) \
|| (i == -1) || (i == -4) || (i == -8) || (i == -16))) \
? ia64_fetch_and_add(i, &(v)->counter) \
: ia64_atomic_add(i, v))
#define atomic_sub_return(i,v) \
((__builtin_constant_p(i) && \
( (i == 1) || (i == 4) || (i == 8) || (i == 16) \
|| (i == -1) || (i == -4) || (i == -8) || (i == -16))) \
? ia64_fetch_and_add(-(i), &(v)->counter) \
: ia64_atomic_sub(i, v))
#define atomic_dec_return(v) atomic_sub_return(1, (v))
#define atomic_inc_return(v) atomic_add_return(1, (v))
#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) != 0)
#define atomic_add(i,v) atomic_add_return((i), (v))
#define atomic_sub(i,v) atomic_sub_return((i), (v))
#define atomic_inc(v) atomic_add(1, (v))
#define atomic_dec(v) atomic_sub(1, (v))
#endif /* _ASM_IA64_ATOMIC_H */
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