79 lines
2.7 KiB
C
79 lines
2.7 KiB
C
/* SPDX-License-Identifier: BSD-3-Clause */
|
|
/* See the end of this file for copyright, licensing, and warranty information. */
|
|
|
|
#include <ardix/atom.h>
|
|
|
|
void atom_init(atom_t *atom)
|
|
{
|
|
atom->count = 0;
|
|
}
|
|
|
|
int atom_get(atom_t *atom)
|
|
{
|
|
int tmp;
|
|
int newval;
|
|
atom_t atom_val;
|
|
|
|
__asm__ volatile(
|
|
"1: ldrex %0, [%3] \n" /* atom_val = *atom */
|
|
" add %1, %0, #1 \n" /* newval = atom_val.count + 1 */
|
|
" strex %2, %1, [%3] \n" /* *atom = newval */
|
|
" teq %2, #0 \n" /* store successful? */
|
|
" bne 1b \n" /* -> goto 1 if not */
|
|
" dmb " /* memory barrier */
|
|
: "=&r" (atom_val), "=&r" (newval), "=&r" (tmp)
|
|
: "r" (atom)
|
|
: "cc");
|
|
|
|
return newval;
|
|
}
|
|
|
|
int atom_put(atom_t *atom)
|
|
{
|
|
int tmp;
|
|
int newval;
|
|
atom_t atom_val;
|
|
|
|
__asm__ volatile(
|
|
"1: ldrex %0, [%3] \n" /* atom_val = *atom */
|
|
" sub %1, %0, #1 \n" /* newval = atom_val.count - 1 */
|
|
" strex %2, %1, [%3] \n" /* *atom = newval */
|
|
" teq %2, #0 \n" /* store successful? */
|
|
" bne 1b \n" /* -> goto 1 if not */
|
|
" dmb " /* memory barrier */
|
|
: "=&r" (atom_val), "=&r" (newval), "=&r" (tmp)
|
|
: "r" (atom)
|
|
: "cc");
|
|
|
|
return newval;
|
|
}
|
|
|
|
int atom_count(atom_t *atom)
|
|
{
|
|
return atom->count;
|
|
}
|
|
|
|
/*
|
|
* Copyright (c) 2020 Felix Kopp <sandtler@sandtler.club>
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without modification, are permitted
|
|
* provided that the following conditions are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright notice, this list of
|
|
* conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright notice, this list of
|
|
* conditions and the following disclaimer in the documentation and/or other materials
|
|
* provided with the distribution.
|
|
* 3. Neither the name of the copyright holder nor the names of its contributors may be
|
|
* used to endorse or promote products derived from this software without specific prior
|
|
* written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
|
|
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
|
|
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
|
|
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
|
|
* WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|