/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*
* Atomic primitives.
*/
#ifndef _ASM_TILE_ATOMIC_H
#define _ASM_TILE_ATOMIC_H
#include <asm/cmpxchg.h>
#ifndef __ASSEMBLY__
#include <linux/compiler.h>
#include <linux/types.h>
#define ATOMIC_INIT(i) { (i) }
/**
* atomic_read - read atomic variable
* @v: pointer of type atomic_t
*
* Atomically reads the value of @v.
*/
static inline int atomic_read(const atomic_t *v)
{
return ACCESS_ONCE(v->counter);
}
/**
* atomic_sub_return - subtract integer and return
* @v: pointer of type atomic_t
* @i: integer value to subtract
*
* Atomically subtracts @i from @v and returns @v - @i
*/
#define atomic_sub_return(i, v) atomic_add_return((int)(-(i)), (v))
/**
* atomic_sub - subtract integer from atomic variable
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v.
*/
#define atomic_sub(i, v) atomic_add((int)(-(i)), (v))
/**
* atomic_sub_and_test - subtract value from variable and test result
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v and returns true if the result is
* zero, or false for all other cases.
*/
#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
/**
* atomic_inc_return - increment memory and return
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1 and returns the new value.
*/
#define atomic_inc_return(v) atomic_add_return(1, (v))
/**
* atomic_dec_return - decrement memory and return
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1 and returns the new value.
*/
#define atomic_dec_return(v) atomic_sub_return(1, (v))
/**
* atomic_inc - increment atomic variable
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1.
*/
#define atomic_inc(v) atomic_add(1, (v))
/**
* atomic_dec - decrement atomic variable
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1.
*/
#define atomic_dec(v) atomic_sub(1, (v))
/**
* atomic_dec_and_test - decrement and test
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1 and returns true if the result is 0.
*/
#define atomic_dec_and_test(v) (atomic_dec_return(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 0.
*/
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
/**
* atomic_xchg - atomically exchange contents of memory with a new value
* @v: pointer of type atomic_t
* @i: integer value to store in memory
*
* Atomically sets @v to @i and returns old @v
*/
static inline int atomic_xchg(atomic_t *v, int n)
{
return xchg(&v->counter, n);
}
/**
* atomic_cmpxchg - atomically exchange contents of memory if it matches
* @v: pointer of type atomic_t
* @o: old value that memory should have
* @n: new value to write to memory if it matches
*
* Atomically checks if @v holds @o and replaces it with @n if so.
* Returns the old value at @v.
*/
static inline int atomic_cmpxchg(atomic_t *v, int o, int n)
{
return cmpxchg(&v->counter, o, n);
}
/**
* atomic_add_negative - add and test if negative
* @v: pointer of type atomic_t
* @i: integer value to add
*
* Atomically adds @i to @v and returns true if the result is
* negative, or false when result is greater than or equal to zero.
*/
#define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0)
#endif /* __ASSEMBLY__ */
#ifndef __tilegx__
#include <asm/atomic_32.h>
#else
#include <asm/atomic_64.h>
#endif
#ifndef __ASSEMBLY__
/**
* atomic64_xchg - atomically exchange contents of memory with a new value
* @v: pointer of type atomic64_t
* @i: integer value to store in memory
*
* Atomically sets @v to @i and returns old @v
*/
static inline u64 atomic64_xchg(atomic64_t *v, u64 n)
{
return xchg64(&v->counter, n);
}
/**
* atomic64_cmpxchg - atomically exchange contents of memory if it matches
* @v: pointer of type atomic64_t
* @o: old value that memory should have
* @n: new value to write to memory if it matches
*
* Atomically checks if @v holds @o and replaces it with @n if so.
* Returns the old value at @v.
*/
static inline u64 atomic64_cmpxchg(atomic64_t *v, u64 o, u64 n)
{
return cmpxchg64(&v->counter, o, n);
}
static inline long long atomic64_dec_if_positive(atomic64_t *v)
{
long long c, old, dec;
c = atomic64_read(v);
for (;;) {
dec = c - 1;
if (unlikely(dec < 0))
break;
old = atomic64_cmpxchg((v), c, dec);
if (likely(old == c))
break;
c = old;
}
return dec;
}
#endif /* __ASSEMBLY__ */
#endif /* _ASM_TILE_ATOMIC_H */
