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Diffstat (limited to 'ports/sysdeps/am33/atomicity.h')
-rw-r--r-- | ports/sysdeps/am33/atomicity.h | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/ports/sysdeps/am33/atomicity.h b/ports/sysdeps/am33/atomicity.h new file mode 100644 index 0000000000..b0ba43db4b --- /dev/null +++ b/ports/sysdeps/am33/atomicity.h @@ -0,0 +1,86 @@ +/* Low-level functions for atomic operations. AM33 version. + Copyright 1999, 2001 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> + +#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 */ |