80 lines
1.7 KiB
C
80 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/******************************************************************************
|
|
*
|
|
* Copyright © International Business Machines Corp., 2009
|
|
*
|
|
* DESCRIPTION
|
|
* GCC atomic builtin wrappers
|
|
* http://gcc.gnu.org/onlinedocs/gcc-4.1.0/gcc/Atomic-Builtins.html
|
|
*
|
|
* AUTHOR
|
|
* Darren Hart <dvhart@linux.intel.com>
|
|
*
|
|
* HISTORY
|
|
* 2009-Nov-17: Initial version by Darren Hart <dvhart@linux.intel.com>
|
|
*
|
|
*****************************************************************************/
|
|
|
|
#ifndef _ATOMIC_H
|
|
#define _ATOMIC_H
|
|
|
|
typedef struct {
|
|
volatile int val;
|
|
} atomic_t;
|
|
|
|
#define ATOMIC_INITIALIZER { 0 }
|
|
|
|
/**
|
|
* atomic_cmpxchg() - Atomic compare and exchange
|
|
* @uaddr: The address of the futex to be modified
|
|
* @oldval: The expected value of the futex
|
|
* @newval: The new value to try and assign the futex
|
|
*
|
|
* Return the old value of addr->val.
|
|
*/
|
|
static inline int
|
|
atomic_cmpxchg(atomic_t *addr, int oldval, int newval)
|
|
{
|
|
return __sync_val_compare_and_swap(&addr->val, oldval, newval);
|
|
}
|
|
|
|
/**
|
|
* atomic_inc() - Atomic incrememnt
|
|
* @addr: Address of the variable to increment
|
|
*
|
|
* Return the new value of addr->val.
|
|
*/
|
|
static inline int
|
|
atomic_inc(atomic_t *addr)
|
|
{
|
|
return __sync_add_and_fetch(&addr->val, 1);
|
|
}
|
|
|
|
/**
|
|
* atomic_dec() - Atomic decrement
|
|
* @addr: Address of the variable to decrement
|
|
*
|
|
* Return the new value of addr-val.
|
|
*/
|
|
static inline int
|
|
atomic_dec(atomic_t *addr)
|
|
{
|
|
return __sync_sub_and_fetch(&addr->val, 1);
|
|
}
|
|
|
|
/**
|
|
* atomic_set() - Atomic set
|
|
* @addr: Address of the variable to set
|
|
* @newval: New value for the atomic_t
|
|
*
|
|
* Return the new value of addr->val.
|
|
*/
|
|
static inline int
|
|
atomic_set(atomic_t *addr, int newval)
|
|
{
|
|
addr->val = newval;
|
|
return newval;
|
|
}
|
|
|
|
#endif
|