NetBSD/sys/arch/m68k/include/asm_single.h

59 lines
2.7 KiB
C

/* $NetBSD: asm_single.h,v 1.1 1996/09/16 06:03:58 leo Exp $ */
/*
* Copyright (c) 1996 Leo Weppelman.
* All rights reserved.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Leo Weppelman.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#ifndef _M68K_ASM_SINGLE_H
#define _M68K_ASM_SINGLE_H
/*
* Provide bit manipulation macro's that resolve to a single instruction.
* These can be considered atomic on single processor architectures when
* no page faults can occur when acessing <var>.
* There primary use is to avoid race conditions when manipulating device
* registers.
*/
#define single_inst_bset_b(var, bit) \
asm volatile ("orb %0,%1" : : "di" ((u_char)bit), "g" (var))
#define single_inst_bclr_b(var, bit) \
asm volatile ("andb %0,%1" : : "di" ((u_char)~(bit)), "g" (var));
#define single_inst_bset_w(var, bit) \
asm volatile ("orw %0,%1" : : "di" ((u_short)bit), "g" (var))
#define single_inst_bclr_w(var, bit) \
asm volatile ("andw %0,%1" : : "di" ((u_short)~(bit)), "g" (var));
#define single_inst_bset_l(var, bit) \
asm volatile ("orl %0,%1" : : "di" ((u_long)bit), "g" (var))
#define single_inst_bclr_l(var, bit) \
asm volatile ("andl %0,%1" : : "di" ((u_long)~(bit)), "g" (var));
#endif /* _M68K_ASM_SINGLE_H */