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/* MN10300 Atomic counter operations
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _ASM_ATOMIC_H
#define _ASM_ATOMIC_H
#include <asm/irqflags.h>
#include <asm/cmpxchg.h>
#include <asm/barrier.h>
#ifndef CONFIG_SMP
#include <asm-generic/atomic.h>
#else
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*/
#define ATOMIC_INIT(i) { (i) }
#ifdef __KERNEL__
/**
* atomic_read - read atomic variable
* @v: pointer of type atomic_t
*
* Atomically reads the value of @v. Note that the guaranteed
*/
#define atomic_read(v) (ACCESS_ONCE((v)->counter))
/**
* atomic_set - set atomic variable
* @v: pointer of type atomic_t
* @i: required value
*
* Atomically sets the value of @v to @i. Note that the guaranteed
*/
#define atomic_set(v, i) (((v)->counter) = (i))
#define ATOMIC_OP(op) \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
int retval, status; \
\
asm volatile( \
"1: mov %4,(_AAR,%3) \n" \
" mov (_ADR,%3),%1 \n" \
" " #op " %5,%1 \n" \
" mov %1,(_ADR,%3) \n" \
" mov (_ADR,%3),%0 \n" /* flush */ \
" mov (_ASR,%3),%0 \n" \
" or %0,%0 \n" \
" bne 1b \n" \
: "=&r"(status), "=&r"(retval), "=m"(v->counter) \
: "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i) \
: "memory", "cc"); \
}
#define ATOMIC_OP_RETURN(op) \
static inline int atomic_##op##_return(int i, atomic_t *v) \
{ \
int retval, status; \
\
asm volatile( \
"1: mov %4,(_AAR,%3) \n" \
" mov (_ADR,%3),%1 \n" \
" " #op " %5,%1 \n" \
" mov %1,(_ADR,%3) \n" \
" mov (_ADR,%3),%0 \n" /* flush */ \
" mov (_ASR,%3),%0 \n" \
" or %0,%0 \n" \
" bne 1b \n" \
: "=&r"(status), "=&r"(retval), "=m"(v->counter) \
: "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i) \
: "memory", "cc"); \
return retval; \
}
#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
ATOMIC_OPS(add)
ATOMIC_OPS(sub)
ATOMIC_OP(and)
ATOMIC_OP(or)
ATOMIC_OP(xor)
#undef ATOMIC_OPS
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
static inline int atomic_add_negative(int i, atomic_t *v)
{
return atomic_add_return(i, v) < 0;
}
static inline void atomic_inc(atomic_t *v)
{
atomic_add_return(1, v);
}
static inline void atomic_dec(atomic_t *v)
{
atomic_sub_return(1, 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_unless(v, a, u) \
({ \
int c, old; \
c = atomic_read(v); \
while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
c = old; \
c; \
})
#define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v)))
#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
#endif /* __KERNEL__ */
#endif /* CONFIG_SMP */
#endif /* _ASM_ATOMIC_H */
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