sys/arch/m68k/include/asm_single.h

   1 /*      $NetBSD: asm_single.h,v 1.8 2006/08/03 20:32:07 mhitch 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  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #ifndef _M68K_ASM_SINGLE_H
  29 #define _M68K_ASM_SINGLE_H
  30 /*
  31  * Provide bit manipulation macro's that resolve to a single instruction.
  32  * These can be considered atomic on single processor architectures when
  33  * no page faults can occur when acessing <var>.
  34  * There primary use is to avoid race conditions when manipulating device
  35  * registers.
  36  */
  37
  38 #define single_inst_bset_b(var, bit)    \
  39         __asm volatile ("orb %1,%0"     \
  40                 : "+m" (var)            \
  41                 : "di" ((u_char)bit))
  42
  43 #define single_inst_bclr_b(var, bit)    \
  44         __asm volatile ("andb %1,%0"    \
  45                 : "+m" (var)            \
  46                 : "di" ((u_char)~(bit)))
  47
  48
  49 #define single_inst_bset_w(var, bit)    \
  50         __asm volatile ("orw %1,%0"     \
  51                 : "+m" (var)            \
  52                 : "di" ((u_short)bit))
  53
  54 #define single_inst_bclr_w(var, bit)    \
  55         __asm volatile ("andw %1,%0"    \
  56                 : "+m" (var)            \
  57                 : "di" ((u_short)~(bit)))
  58
  59
  60 #define single_inst_bset_l(var, bit)    \
  61         __asm volatile ("orl %1,%0"     \
  62                 : "+m" (var)            \
  63                 : "di" ((u_long)bit))
  64
  65 #define single_inst_bclr_l(var, bit)    \
  66         __asm volatile ("andl %1,%0"    \
  67                 : "+m" (var)            \
  68                 : "di" ((u_long)~(bit)))
  69
  70 #endif /* _M68K_ASM_SINGLE_H */