1a17fdc4f4
Atomicity between xchg and cmpxchg cannot be guaranteed when xchg is implemented with a swap and cmpxchg is implemented with locks. Without this, e.g. mcs_spin_lock and mcs_spin_unlock are broken. Signed-off-by: Andreas Larsson <andreas@gaisler.com> Signed-off-by: David S. Miller <davem@davemloft.net>
55 lines
1.8 KiB
C
55 lines
1.8 KiB
C
/* atomic.h: These still suck, but the I-cache hit rate is higher.
|
|
*
|
|
* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
|
|
* Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com.au)
|
|
* Copyright (C) 2007 Kyle McMartin (kyle@parisc-linux.org)
|
|
*
|
|
* Additions by Keith M Wesolowski (wesolows@foobazco.org) based
|
|
* on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>.
|
|
*/
|
|
|
|
#ifndef __ARCH_SPARC_ATOMIC__
|
|
#define __ARCH_SPARC_ATOMIC__
|
|
|
|
#include <linux/types.h>
|
|
|
|
#include <asm/cmpxchg.h>
|
|
#include <asm/barrier.h>
|
|
#include <asm-generic/atomic64.h>
|
|
|
|
|
|
#define ATOMIC_INIT(i) { (i) }
|
|
|
|
int atomic_add_return(int, atomic_t *);
|
|
int atomic_cmpxchg(atomic_t *, int, int);
|
|
int atomic_xchg(atomic_t *, int);
|
|
int __atomic_add_unless(atomic_t *, int, int);
|
|
void atomic_set(atomic_t *, int);
|
|
|
|
#define atomic_read(v) ACCESS_ONCE((v)->counter)
|
|
|
|
#define atomic_add(i, v) ((void)atomic_add_return( (int)(i), (v)))
|
|
#define atomic_sub(i, v) ((void)atomic_add_return(-(int)(i), (v)))
|
|
#define atomic_inc(v) ((void)atomic_add_return( 1, (v)))
|
|
#define atomic_dec(v) ((void)atomic_add_return( -1, (v)))
|
|
|
|
#define atomic_sub_return(i, v) (atomic_add_return(-(int)(i), (v)))
|
|
#define atomic_inc_return(v) (atomic_add_return( 1, (v)))
|
|
#define atomic_dec_return(v) (atomic_add_return( -1, (v)))
|
|
|
|
#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
|
|
|
|
/*
|
|
* atomic_inc_and_test - increment and test
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically increments @v by 1
|
|
* and returns true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
|
|
|
|
#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
|
|
#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
|
|
|
|
#endif /* !(__ARCH_SPARC_ATOMIC__) */
|