mirror of
https://github.com/torvalds/linux.git
synced 2024-11-05 03:21:32 +00:00
158 lines
3.7 KiB
C
158 lines
3.7 KiB
C
/* 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
|
|
|
|
#ifdef CONFIG_SMP
|
|
#error not SMP safe
|
|
#endif
|
|
|
|
/*
|
|
* 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
|
|
* useful range of an atomic_t is only 24 bits.
|
|
*/
|
|
#define atomic_read(v) ((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
|
|
* useful range of an atomic_t is only 24 bits.
|
|
*/
|
|
#define atomic_set(v, i) (((v)->counter) = (i))
|
|
|
|
#include <asm/system.h>
|
|
|
|
/**
|
|
* atomic_add_return - add integer to atomic variable
|
|
* @i: integer value to add
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically adds @i to @v and returns the result
|
|
* Note that the guaranteed useful range of an atomic_t is only 24 bits.
|
|
*/
|
|
static inline int atomic_add_return(int i, atomic_t *v)
|
|
{
|
|
unsigned long flags;
|
|
int temp;
|
|
|
|
local_irq_save(flags);
|
|
temp = v->counter;
|
|
temp += i;
|
|
v->counter = temp;
|
|
local_irq_restore(flags);
|
|
|
|
return temp;
|
|
}
|
|
|
|
/**
|
|
* atomic_sub_return - subtract integer from atomic variable
|
|
* @i: integer value to subtract
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically subtracts @i from @v and returns the result
|
|
* Note that the guaranteed useful range of an atomic_t is only 24 bits.
|
|
*/
|
|
static inline int atomic_sub_return(int i, atomic_t *v)
|
|
{
|
|
unsigned long flags;
|
|
int temp;
|
|
|
|
local_irq_save(flags);
|
|
temp = v->counter;
|
|
temp -= i;
|
|
v->counter = temp;
|
|
local_irq_restore(flags);
|
|
|
|
return temp;
|
|
}
|
|
|
|
static inline int atomic_add_negative(int i, atomic_t *v)
|
|
{
|
|
return atomic_add_return(i, v) < 0;
|
|
}
|
|
|
|
static inline void atomic_add(int i, atomic_t *v)
|
|
{
|
|
atomic_add_return(i, v);
|
|
}
|
|
|
|
static inline void atomic_sub(int i, atomic_t *v)
|
|
{
|
|
atomic_sub_return(i, v);
|
|
}
|
|
|
|
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 != (u); \
|
|
})
|
|
|
|
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
|
|
|
|
static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
|
|
{
|
|
unsigned long flags;
|
|
|
|
mask = ~mask;
|
|
local_irq_save(flags);
|
|
*addr &= mask;
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
#define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v)))
|
|
#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
|
|
|
|
/* Atomic operations are already serializing on MN10300??? */
|
|
#define smp_mb__before_atomic_dec() barrier()
|
|
#define smp_mb__after_atomic_dec() barrier()
|
|
#define smp_mb__before_atomic_inc() barrier()
|
|
#define smp_mb__after_atomic_inc() barrier()
|
|
|
|
#include <asm-generic/atomic.h>
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* _ASM_ATOMIC_H */
|