sys/arch/powerpc/include/lock.h

   1 /*      $NetBSD: lock.h,v 1.11 2007/10/17 19:56:41 garbled Exp $        */
   2
   3 /*-
   4  * Copyright (c) 2000, 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 /*
  33  * Machine-dependent spin lock operations.
  34  */
  35
  36 #ifndef _POWERPC_LOCK_H_
  37 #define _POWERPC_LOCK_H_
  38
  39 static __inline int
  40 __SIMPLELOCK_LOCKED_P(__cpu_simple_lock_t *__ptr)
  41 {
  42         return *__ptr == __SIMPLELOCK_LOCKED;
  43 }
  44
  45 static __inline int
  46 __SIMPLELOCK_UNLOCKED_P(__cpu_simple_lock_t *__ptr)
  47 {
  48         return *__ptr == __SIMPLELOCK_UNLOCKED;
  49 }
  50
  51 static __inline void
  52 __cpu_simple_lock_clear(__cpu_simple_lock_t *__ptr)
  53 {
  54         *__ptr = __SIMPLELOCK_UNLOCKED;
  55 }
  56
  57 static __inline void
  58 __cpu_simple_lock_set(__cpu_simple_lock_t *__ptr)
  59 {
  60         *__ptr = __SIMPLELOCK_LOCKED;
  61 }
  62
  63 static __inline void
  64 __cpu_simple_lock_init(__cpu_simple_lock_t *alp)
  65 {
  66         *alp = __SIMPLELOCK_UNLOCKED;
  67         __asm volatile ("sync");
  68 }
  69
  70 static __inline void
  71 __cpu_simple_lock(__cpu_simple_lock_t *alp)
  72 {
  73         int old;
  74
  75         __asm volatile ("       \
  76                                 \n\
  77 1:      lwarx   %0,0,%1         \n\
  78         cmpwi   %0,%2           \n\
  79         beq+    3f              \n\
  80 2:      lwzx    %0,0,%1         \n\
  81         cmpwi   %0,%2           \n\
  82         beq+    1b              \n\
  83         b       2b              \n\
  84 3:      stwcx.  %3,0,%1         \n\
  85         bne-    1b              \n\
  86         isync                   \n\
  87                                 \n"
  88         : "=&r"(old)
  89         : "r"(alp), "I"(__SIMPLELOCK_UNLOCKED), "r"(__SIMPLELOCK_LOCKED)
  90         : "memory");
  91 }
  92
  93 static __inline int
  94 __cpu_simple_lock_try(__cpu_simple_lock_t *alp)
  95 {
  96         int old, dummy;
  97
  98         __asm volatile ("       \
  99                                 \n\
 100 1:      lwarx   %0,0,%1         \n\
 101         cmpwi   %0,%2           \n\
 102         bne     2f              \n\
 103         stwcx.  %3,0,%1         \n\
 104         bne-    1b              \n\
 105 2:      stwcx.  %3,0,%4         \n\
 106         isync                   \n\
 107                                 \n"
 108         : "=&r"(old)
 109         : "r"(alp), "I"(__SIMPLELOCK_UNLOCKED), "r"(__SIMPLELOCK_LOCKED),
 110           "r"(&dummy)
 111         : "memory");
 112
 113         return (old == __SIMPLELOCK_UNLOCKED);
 114 }
 115
 116 static __inline void
 117 __cpu_simple_unlock(__cpu_simple_lock_t *alp)
 118 {
 119         __asm volatile ("sync");
 120         *alp = __SIMPLELOCK_UNLOCKED;
 121 }
 122
 123 static __inline void
 124 mb_read(void)
 125 {
 126         __asm volatile ("isync" ::: "memory");
 127 }
 128
 129 static __inline void
 130 mb_write(void)
 131 {
 132         __asm volatile ("sync" ::: "memory");
 133 }
 134
 135 static __inline void
 136 mb_memory(void)
 137 {
 138         __asm volatile ("sync" ::: "memory");
 139 }
 140
 141 #endif /* _POWERPC_LOCK_H_ */