1 /* $NetBSD: asm_single.h,v 1.4 2002/01/25 16:42:22 thorpej 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 %1,%0" \ 45 : "=m" (var) \ 46 : "di" ((u_char)bit), "0" (var)) 47 48 #define single_inst_bclr_b(var, bit) \ 49 __asm __volatile ("andb %1,%0" \ 50 : "=m" (var) \ 51 : "di" ((u_char)~(bit)), "0" (var)) 52 53 54 #define single_inst_bset_w(var, bit) \ 55 __asm __volatile ("orw %1,%0" \ 56 : "=m" (var) \ 57 : "di" ((u_short)bit), "0" (var)) 58 59 #define single_inst_bclr_w(var, bit) \ 60 __asm __volatile ("andw %1,%0" \ 61 : "=m" (var) \ 62 : "di" ((u_short)~(bit)), "0" (var)) 63 64 65 #define single_inst_bset_l(var, bit) \ 66 __asm __volatile ("orl %1,%0" \ 67 : "=m" (var) \ 68 : "di" ((u_long)bit), "0" (var)) 69 70 #define single_inst_bclr_l(var, bit) \ 71 __asm __volatile ("andl %1,%0" \ 72 : "=m" (var) \ 73 : "di" ((u_long)~(bit)), "0" (var)) 74 75 #endif /* _M68K_ASM_SINGLE_H */ 76