d356b595e5
This adds the volatile cast which forces the compiler to emit the load. Suggested by Peter Zijlstra <peterz@infradead.org>. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
160 lines
4.1 KiB
C
160 lines
4.1 KiB
C
/*
|
|
* 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
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#include <linux/compiler.h>
|
|
#include <asm/system.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_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)
|
|
|
|
/**
|
|
* atomic_inc_not_zero - increment unless the number is zero
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically increments @v by 1, so long as @v is non-zero.
|
|
* Returns non-zero if @v was non-zero, and zero otherwise.
|
|
*/
|
|
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
|
|
|
|
|
|
/*
|
|
* We define xchg() and cmpxchg() in the included headers.
|
|
* Note that we do not define __HAVE_ARCH_CMPXCHG, since that would imply
|
|
* that cmpxchg() is an efficient operation, which is not particularly true.
|
|
*/
|
|
|
|
/* Nonexistent functions intended to cause link errors. */
|
|
extern unsigned long __xchg_called_with_bad_pointer(void);
|
|
extern unsigned long __cmpxchg_called_with_bad_pointer(void);
|
|
|
|
#define tas(ptr) (xchg((ptr), 1))
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
|
|
#ifndef __tilegx__
|
|
#include <asm/atomic_32.h>
|
|
#else
|
|
#include <asm/atomic_64.h>
|
|
#endif
|
|
|
|
/* Provide the appropriate atomic_long_t definitions. */
|
|
#ifndef __ASSEMBLY__
|
|
#include <asm-generic/atomic-long.h>
|
|
#endif
|
|
|
|
#endif /* _ASM_TILE_ATOMIC_H */
|