| /* Low-level functions for atomic operations. AM33 version. |
| Copyright 1999-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Alexandre Oliva <aoliva@redhat.com>. |
| Based on ../sparc/sparc32/atomicity.h |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Library General Public License as |
| published by the Free Software Foundation; either version 2 of the |
| License, or (at your option) any later version. |
| |
| The GNU C Library 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. See the GNU |
| Library General Public License for more details. |
| |
| You should have received a copy of the GNU Library General Public |
| License along with the GNU C Library. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #ifndef _ATOMICITY_H |
| #define _ATOMICITY_H 1 |
| |
| #include <inttypes.h> |
| #include <stdint.h> |
| |
| #define __acquire_lock(lock) \ |
| __asm__ __volatile__("1: bset %1, (%0)\n\t" \ |
| " beq 1b" \ |
| : : "a" (&(lock)), "d" (1) \ |
| : "memory") |
| |
| #define __release_lock(lock) lock = 0 |
| |
| static int |
| __attribute__ ((unused)) |
| exchange_and_add (volatile uint32_t *mem, int val) |
| { |
| static unsigned char lock; |
| int result; |
| |
| __acquire_lock (lock); |
| |
| result = *mem; |
| *mem += val; |
| |
| __release_lock (lock); |
| |
| return result; |
| } |
| |
| static void |
| __attribute__ ((unused)) |
| atomic_add (volatile uint32_t *mem, int val) |
| { |
| static unsigned char lock; |
| |
| __acquire_lock (lock); |
| |
| *mem += val; |
| |
| __release_lock (lock); |
| } |
| |
| static int |
| __attribute__ ((unused)) |
| compare_and_swap (volatile long int *p, long int oldval, long int newval) |
| { |
| static unsigned char lock; |
| int ret; |
| |
| __acquire_lock (lock); |
| |
| if (*p != oldval) |
| ret = 0; |
| else |
| { |
| *p = newval; |
| ret = 1; |
| } |
| |
| __release_lock (lock); |
| |
| return ret; |
| } |
| |
| #endif /* atomicity.h */ |