libkern/libkern/machine/OSByteOrder.h

   1 /*
   2  * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1999 Apple Computer, Inc.  All rights reserved.
  24  *
  25  * HISTORY
  26  *
  27  */
  28
  29
  30 #ifndef _OS_OSBYTEORDERMACHINE_H
  31 #define _OS_OSBYTEORDERMACHINE_H
  32
  33 #include <stdint.h>
  34
  35 #if !defined(OS_INLINE)
  36 #        define OS_INLINE static inline
  37 #endif
  38
  39 /* Functions for byte reversed loads. */
  40
  41 OS_INLINE
  42 uint16_t
  43 OSReadSwapInt16(
  44     volatile void               * base,
  45     uintptr_t                     offset
  46 )
  47 {
  48     union sconv {
  49         uint16_t us;
  50         uint8_t  uc[2];
  51     } *inp, outv;
  52     inp = (union sconv *)((uint8_t *)base + offset);
  53     outv.uc[0] = inp->uc[1];
  54     outv.uc[1] = inp->uc[0];
  55     return (outv.us);
  56 }
  57
  58 OS_INLINE
  59 uint32_t
  60 OSReadSwapInt32(
  61     volatile void               * base,
  62     uintptr_t                     offset
  63 )
  64 {
  65     union lconv {
  66         uint32_t ul;
  67         uint8_t  uc[4];
  68     } *inp, outv;
  69     inp = (union lconv *)((uint8_t *)base + offset);
  70     outv.uc[0] = inp->uc[3];
  71     outv.uc[1] = inp->uc[2];
  72     outv.uc[2] = inp->uc[1];
  73     outv.uc[3] = inp->uc[0];
  74     return (outv.ul);
  75 }
  76
  77 OS_INLINE
  78 uint64_t
  79 OSReadSwapInt64(
  80     volatile void               * base,
  81     uintptr_t                     offset
  82 )
  83 {
  84     union llconv {
  85         uint64_t ull;
  86         uint8_t  uc[8];
  87     } *inp, outv;
  88     inp = (union llconv *)((uint8_t *)base + offset);
  89     outv.uc[0] = inp->uc[7];
  90     outv.uc[1] = inp->uc[6];
  91     outv.uc[2] = inp->uc[5];
  92     outv.uc[3] = inp->uc[4];
  93     outv.uc[4] = inp->uc[3];
  94     outv.uc[5] = inp->uc[2];
  95     outv.uc[6] = inp->uc[1];
  96     outv.uc[7] = inp->uc[0];
  97     return (outv.ull);
  98 }
  99
 100 /* Functions for byte reversed stores. */
 101
 102 OS_INLINE
 103 void
 104 OSWriteSwapInt16(
 105     volatile void               * base,
 106     uintptr_t                     offset,
 107     uint16_t                      data
 108 )
 109 {
 110     union sconv {
 111         uint16_t us;
 112         uint8_t  uc[2];
 113     } *inp, *outp;
 114     inp  = (union sconv *)((uint8_t *)base + offset);
 115     outp = (union sconv *)&data;
 116     outp->uc[0] = inp->uc[1];
 117     outp->uc[1] = inp->uc[0];
 118 }
 119
 120 OS_INLINE
 121 void
 122 OSWriteSwapInt32(
 123     volatile void               * base,
 124     uintptr_t                     offset,
 125     uint32_t                      data
 126 )
 127 {
 128     union lconv {
 129         uint32_t ul;
 130         uint8_t  uc[4];
 131     } *inp, *outp;
 132     inp  = (union lconv *)((uint8_t *)base + offset);
 133     outp = (union lconv *)&data;
 134     outp->uc[0] = inp->uc[3];
 135     outp->uc[1] = inp->uc[2];
 136     outp->uc[2] = inp->uc[1];
 137     outp->uc[3] = inp->uc[0];
 138 }
 139
 140 OS_INLINE
 141 void
 142 OSWriteSwapInt64(
 143     volatile void               * base,
 144     uintptr_t                     offset,
 145     uint64_t                      data
 146 )
 147 {
 148     union llconv {
 149         uint64_t ull;
 150         uint8_t  uc[8];
 151     } *inp, *outp;
 152     inp = (union llconv *)((uint8_t *)base + offset);
 153     outp = (union llconv *)&data;
 154     outp->uc[0] = inp->uc[7];
 155     outp->uc[1] = inp->uc[6];
 156     outp->uc[2] = inp->uc[5];
 157     outp->uc[3] = inp->uc[4];
 158     outp->uc[4] = inp->uc[3];
 159     outp->uc[5] = inp->uc[2];
 160     outp->uc[6] = inp->uc[1];
 161     outp->uc[7] = inp->uc[0];
 162 }
 163
 164 /* Generic byte swapping functions. */
 165
 166 OS_INLINE
 167 uint16_t
 168 _OSSwapInt16(
 169     uint16_t                      data
 170 )
 171 {
 172     uint16_t temp = data;
 173     return OSReadSwapInt16(&temp, 0);
 174 }
 175
 176 OS_INLINE
 177 uint32_t
 178 _OSSwapInt32(
 179     uint32_t                      data
 180 )
 181 {
 182     uint32_t temp = data;
 183     return OSReadSwapInt32(&temp, 0);
 184 }
 185
 186 OS_INLINE
 187 uint64_t
 188 _OSSwapInt64(
 189     uint64_t                        data
 190 )
 191 {
 192     uint64_t temp = data;
 193     return OSReadSwapInt64(&temp, 0);
 194 }
 195
 196 #endif /* ! _OS_OSBYTEORDERMACHINE_H */