Files
Linux_Drivers/linux_5.10/tools/testing/selftests/futex/include/atomic.h
sam.xiang 5c7dd7acc3 [linux] create linux_5.10.4 from T-head official:
repo: https://github.com/T-head-Semi/linux
	commit: b1313fe517ca3703119dcc99ef3bbf75ab42bcfb

Change-Id: I6cbb35294024ea3a66140e311f4bb705fd7fd626
2023-03-10 20:32:41 +08:00

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