sys/arch/sh3/include/mutex.h

   1 /*      $NetBSD: mutex.h,v 1.8 2007/11/29 17:33:09 ad Exp $     */
   2
   3 /*-
   4  * Copyright (c) 2002, 2007 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 and Andrew Doran.
   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 _SH3_MUTEX_H_
  33 #define _SH3_MUTEX_H_
  34
  35 #ifndef __MUTEX_PRIVATE
  36
  37 struct kmutex {
  38         uintptr_t       mtx_pad1;
  39 };
  40
  41 #else   /* __MUTEX_PRIVATE */
  42
  43 struct kmutex {
  44         union {
  45                 /* Adaptive mutex */
  46                 volatile uintptr_t      mtxa_owner;     /* 0-3 */
  47
  48                 /* Spin mutex */
  49                 struct {
  50                         volatile uint8_t        mtxs_dummy;
  51                         ipl_cookie_t            mtxs_ipl;
  52                         __cpu_simple_lock_t     mtxs_lock;
  53                         volatile uint8_t        mtxs_unused;
  54                 } s;
  55         } u;
  56 };
  57
  58 #define mtx_owner               u.mtxa_owner
  59 #define mtx_ipl                 u.s.mtxs_ipl
  60 #define mtx_lock                u.s.mtxs_lock
  61
  62 #define __HAVE_SIMPLE_MUTEXES           1
  63 #define __HAVE_MUTEX_STUBS              1
  64
  65 /*
  66  * MUTEX_RECEIVE: no memory barrier required; we're synchronizing against
  67  * interrupts, not multiple processors.
  68  */
  69 #define MUTEX_RECEIVE(mtx)              /* nothing */
  70
  71 /*
  72  * MUTEX_GIVE: no memory barrier required; same reason.
  73  */
  74 #define MUTEX_GIVE(mtx)                 /* nothing */
  75
  76 uintptr_t       _lock_cas(volatile uintptr_t *, uintptr_t, uintptr_t);
  77
  78 #define MUTEX_CAS(p, o, n)              (_lock_cas((p), (o), (n)) == (o))
  79
  80 #endif  /* __MUTEX_PRIVATE */
  81
  82 #endif /* _SH3_MUTEX_H_ */