1 /* $NetBSD: asm_single.h,v 1.3 1998/07/25 09:24:17 is Exp $ */ 2 3 /* 4 * Copyright (c) 1996 Leo Weppelman. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Leo Weppelman. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #ifndef _M68K_ASM_SINGLE_H 34 #define _M68K_ASM_SINGLE_H 35 /* 36 * Provide bit manipulation macro's that resolve to a single instruction. 37 * These can be considered atomic on single processor architectures when 38 * no page faults can occur when acessing <var>. 39 * There primary use is to avoid race conditions when manipulating device 40 * registers. 41 */ 42 43 #define single_inst_bset_b(var, bit) \ 44 __asm__ __volatile ("orb %0,%1" : : "di" ((u_char)bit), "g" (var)) 45 #define single_inst_bclr_b(var, bit) \ 46 __asm__ __volatile ("andb %0,%1" : : "di" ((u_char)~(bit)), "g" (var)) 47 48 #define single_inst_bset_w(var, bit) \ 49 __asm__ __volatile ("orw %0,%1" : : "di" ((u_short)bit), "g" (var)) 50 #define single_inst_bclr_w(var, bit) \ 51 __asm__ __volatile ("andw %0,%1" : : "di" ((u_short)~(bit)), "g" (var)) 52 53 #define single_inst_bset_l(var, bit) \ 54 __asm__ __volatile ("orl %0,%1" : : "di" ((u_long)bit), "g" (var)) 55 #define single_inst_bclr_l(var, bit) \ 56 __asm__ __volatile ("andl %0,%1" : : "di" ((u_long)~(bit)), "g" (var)) 57 58 #endif /* _M68K_ASM_SINGLE_H */ 59