+++ /dev/null
-// Low-level functions for atomic operations: m68k version -*- C++ -*-
-
-// Copyright (C) 2001, 2002 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library. This library 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, or (at your option)
-// any later version.
-
-// This 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 General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING. If not, write to the Free
-// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
-// USA.
-
-// As a special exception, you may use this file as part of a free software
-// library without restriction. Specifically, if other files instantiate
-// templates or use macros or inline functions from this file, or you compile
-// this file and link it with other files to produce an executable, this
-// file does not by itself cause the resulting executable to be covered by
-// the GNU General Public License. This exception does not however
-// invalidate any other reasons why the executable file might be covered by
-// the GNU General Public License.
-
-#ifndef _BITS_ATOMICITY_H
-#define _BITS_ATOMICITY_H 1
-
-typedef int _Atomic_word;
-
-#if defined(__mc68020__) || defined(__mc68030__) \
- || defined(__mc68040__) || defined(__mc68060__)
-// These variants support compare-and-swap.
-
-static inline _Atomic_word
-__attribute__ ((__unused__))
-__exchange_and_add (volatile _Atomic_word *__mem, int __val)
-{
- register _Atomic_word __result = *__mem;
- register _Atomic_word __temp;
- __asm__ __volatile__ ("1: move%.l %0,%1\n\t"
- "add%.l %2,%1\n\t"
- "cas%.l %0,%1,%3\n\t"
- "jne 1b"
- : "=d" (__result), "=&d" (__temp)
- : "d" (__val), "m" (*__mem), "0" (__result)
- : "memory");
- return __result;
-}
-
-#elif defined(__rtems__)
- /*
- * TAS/JBNE is unsafe on systems with strict priority-based scheduling.
- * Disable interrupts, which we can do only from supervisor mode.
- */
-static inline _Atomic_word
-__attribute__ ((__unused__))
-__exchange_and_add (volatile _Atomic_word *__mem, int __val)
-{
- _Atomic_word __result;
- short __level, __tmpsr;
- __asm__ __volatile__ ("move%.w %%sr,%0\n\tor%.l %0,%1\n\tmove%.w %1,%%sr"
- : "=d"(__level), "=d"(__tmpsr) : "1"(0x700));
-
- __result = *__mem;
- *__mem = __result + __val;
-
- __asm__ __volatile__ ("move%.w %0,%%sr" : : "d"(__level));
-
- return __result;
-}
-
-#elif !defined(__mcf5200__) && !defined(__mcf5300__)
-// 68000, 68010, cpu32 and 5400 support test-and-set.
-
-template <int __inst>
-struct __Atomicity_lock
-{
- static volatile unsigned char _S_atomicity_lock;
-};
-
-template <int __inst>
-volatile unsigned char __Atomicity_lock<__inst>::_S_atomicity_lock = 0;
-
-template volatile unsigned char __Atomicity_lock<0>::_S_atomicity_lock;
-
-static inline _Atomic_word
-__attribute__ ((__unused__))
-__exchange_and_add (volatile _Atomic_word *__mem, int __val)
-{
- _Atomic_word __result;
-
- __asm__ __volatile__("1: tas %0\n\tjbne 1b"
- : "=m"(__Atomicity_lock<0>::_S_atomicity_lock)
- : "m"(__Atomicity_lock<0>::_S_atomicity_lock));
-
- __result = *__mem;
- *__mem = __result + __val;
-
- __Atomicity_lock<0>::_S_atomicity_lock = 0;
-
- return __result;
-}
-
-#elif defined(__vxWorks__) || defined(__embedded__)
-// The best we can hope for is to disable interrupts, which we
-// can only do from supervisor mode.
-
-static inline _Atomic_word
-__attribute__ ((__unused__))
-__exchange_and_add (volatile _Atomic_word *__mem, int __val)
-{
- _Atomic_word __result;
- short __level, __tmpsr;
- __asm__ __volatile__ ("move%.w %%sr,%0\n\tor%.l %0,%1\n\tmove%.w %1,%%sr"
- : "=d"(__level), "=d"(__tmpsr) : "1"(0x700));
-
- __result = *__mem;
- *__mem = __result + __val;
-
- __asm__ __volatile__ ("move%.w %0,%%sr" : : "d"(__level));
-
- return __result;
-}
-
-#else
-// These variants do not support any atomic operations at all.
-
-#warning "__exchange_and_add is not atomic for this target"
-
-static inline _Atomic_word
-__attribute__ ((__unused__))
-__exchange_and_add (volatile _Atomic_word *__mem, int __val)
-{
- _Atomic_word __result;
-
- __result = *__mem;
- *__mem = __result + __val;
-
- return __result;
-}
-
-#endif /* CAS / IRQ / TAS */
-
-static inline void
-__attribute__ ((__unused__))
-__atomic_add (volatile _Atomic_word* __mem, int __val)
-{
- // Careful: using add.l with a memory destination is not
- // architecturally guaranteed to be atomic.
- (void) __exchange_and_add (__mem, __val);
-}
-
-#endif /* atomicity.h */
projects / msp430-gcc.git / blobdiff