sys/arch/acorn32/include/lock.h

   1 /*      $NetBSD: lock.h,v 1.8 2008/10/12 20:52:56 pooka Exp $   */
   2
   3 /*-
   4  * Copyright (c) 2000, 2001 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Jason R. Thorpe.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #ifndef _ACORN32_LOCK_H_
  33 #define _ACORN32_LOCK_H_
  34
  35 #include <sys/param.h>
  36
  37 #ifdef _KERNEL_OPT
  38 #include "opt_multiprocessor.h"
  39 #endif
  40
  41 #if defined(_HARDKERNEL) && defined(MULTIPROCESSOR)
  42
  43 #include <arm/cpufunc.h>
  44
  45 static __inline int
  46 __swp(int __val, volatile unsigned char *__ptr)
  47 {
  48
  49         __asm volatile("swpb %0, %1, [%2]"
  50             : "=r" (__val) : "r" (__val), "r" (__ptr) : "memory");
  51         return __val;
  52 }
  53
  54 static __inline void __attribute__((__unused__))
  55 __cpu_simple_lock_init(__cpu_simple_lock_t *alp)
  56 {
  57
  58         *alp = __SIMPLELOCK_UNLOCKED;
  59 }
  60
  61 static __inline void __attribute__((__unused__))
  62 __cpu_simple_lock(__cpu_simple_lock_t *alp)
  63 {
  64
  65         while (__swp(__SIMPLELOCK_LOCKED, alp) != __SIMPLELOCK_UNLOCKED)
  66                 continue;
  67         cpu_idcache_wbinv_all();
  68 }
  69
  70 static __inline int __attribute__((__unused__))
  71 __cpu_simple_lock_try(__cpu_simple_lock_t *alp)
  72 {
  73         int __result;
  74
  75         __result = __swp(__SIMPLELOCK_LOCKED, alp) == __SIMPLELOCK_UNLOCKED;
  76         if (__result)
  77                 cpu_idcache_wbinv_all();
  78         return __result;
  79 }
  80
  81 static __inline void __attribute__((__unused__))
  82 __cpu_simple_unlock(__cpu_simple_lock_t *alp)
  83 {
  84
  85         *alp = __SIMPLELOCK_UNLOCKED;
  86 }
  87
  88 #else /* !(_HARDKERNEL && MULTIPROCESSOR) */
  89 #include <arm/lock.h>
  90 #endif /* !(_HARDKERNEL && MULTIPROCESSOR) */
  91 #endif