linux_dsm_epyc7002/tools/testing/selftests/futex/include/atomic.h
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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 either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

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