libkern/libkern/machine/OSByteOrder.h

   1 /*
   2  * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * Copyright (c) 1999 Apple Computer, Inc.  All rights reserved.
  32  *
  33  * HISTORY
  34  *
  35  */
  36
  37
  38 #ifndef _OS_OSBYTEORDERMACHINE_H
  39 #define _OS_OSBYTEORDERMACHINE_H
  40
  41 #include <stdint.h>
  42
  43 #if !defined(OS_INLINE)
  44 #        define OS_INLINE static inline
  45 #endif
  46
  47 /* Functions for byte reversed loads. */
  48
  49 OS_INLINE
  50 uint16_t
  51 OSReadSwapInt16(
  52     volatile void               * base,
  53     uintptr_t                     offset
  54 )
  55 {
  56     union sconv {
  57         uint16_t us;
  58         uint8_t  uc[2];
  59     } *inp, outv;
  60     inp = (union sconv *)((uint8_t *)base + offset);
  61     outv.uc[0] = inp->uc[1];
  62     outv.uc[1] = inp->uc[0];
  63     return (outv.us);
  64 }
  65
  66 OS_INLINE
  67 uint32_t
  68 OSReadSwapInt32(
  69     volatile void               * base,
  70     uintptr_t                     offset
  71 )
  72 {
  73     union lconv {
  74         uint32_t ul;
  75         uint8_t  uc[4];
  76     } *inp, outv;
  77     inp = (union lconv *)((uint8_t *)base + offset);
  78     outv.uc[0] = inp->uc[3];
  79     outv.uc[1] = inp->uc[2];
  80     outv.uc[2] = inp->uc[1];
  81     outv.uc[3] = inp->uc[0];
  82     return (outv.ul);
  83 }
  84
  85 OS_INLINE
  86 uint64_t
  87 OSReadSwapInt64(
  88     volatile void               * base,
  89     uintptr_t                     offset
  90 )
  91 {
  92     union llconv {
  93         uint64_t ull;
  94         uint8_t  uc[8];
  95     } *inp, outv;
  96     inp = (union llconv *)((uint8_t *)base + offset);
  97     outv.uc[0] = inp->uc[7];
  98     outv.uc[1] = inp->uc[6];
  99     outv.uc[2] = inp->uc[5];
 100     outv.uc[3] = inp->uc[4];
 101     outv.uc[4] = inp->uc[3];
 102     outv.uc[5] = inp->uc[2];
 103     outv.uc[6] = inp->uc[1];
 104     outv.uc[7] = inp->uc[0];
 105     return (outv.ull);
 106 }
 107
 108 /* Functions for byte reversed stores. */
 109
 110 OS_INLINE
 111 void
 112 OSWriteSwapInt16(
 113     volatile void               * base,
 114     uintptr_t                     offset,
 115     uint16_t                      data
 116 )
 117 {
 118     union sconv {
 119         uint16_t us;
 120         uint8_t  uc[2];
 121     } *inp, *outp;
 122     inp  = (union sconv *)((uint8_t *)base + offset);
 123     outp = (union sconv *)&data;
 124     outp->uc[0] = inp->uc[1];
 125     outp->uc[1] = inp->uc[0];
 126 }
 127
 128 OS_INLINE
 129 void
 130 OSWriteSwapInt32(
 131     volatile void               * base,
 132     uintptr_t                     offset,
 133     uint32_t                      data
 134 )
 135 {
 136     union lconv {
 137         uint32_t ul;
 138         uint8_t  uc[4];
 139     } *inp, *outp;
 140     inp  = (union lconv *)((uint8_t *)base + offset);
 141     outp = (union lconv *)&data;
 142     outp->uc[0] = inp->uc[3];
 143     outp->uc[1] = inp->uc[2];
 144     outp->uc[2] = inp->uc[1];
 145     outp->uc[3] = inp->uc[0];
 146 }
 147
 148 OS_INLINE
 149 void
 150 OSWriteSwapInt64(
 151     volatile void               * base,
 152     uintptr_t                     offset,
 153     uint64_t                      data
 154 )
 155 {
 156     union llconv {
 157         uint64_t ull;
 158         uint8_t  uc[8];
 159     } *inp, *outp;
 160     inp = (union llconv *)((uint8_t *)base + offset);
 161     outp = (union llconv *)&data;
 162     outp->uc[0] = inp->uc[7];
 163     outp->uc[1] = inp->uc[6];
 164     outp->uc[2] = inp->uc[5];
 165     outp->uc[3] = inp->uc[4];
 166     outp->uc[4] = inp->uc[3];
 167     outp->uc[5] = inp->uc[2];
 168     outp->uc[6] = inp->uc[1];
 169     outp->uc[7] = inp->uc[0];
 170 }
 171
 172 /* Generic byte swapping functions. */
 173
 174 OS_INLINE
 175 uint16_t
 176 _OSSwapInt16(
 177     uint16_t                      data
 178 )
 179 {
 180     uint16_t temp = data;
 181     return OSReadSwapInt16(&temp, 0);
 182 }
 183
 184 OS_INLINE
 185 uint32_t
 186 _OSSwapInt32(
 187     uint32_t                      data
 188 )
 189 {
 190     uint32_t temp = data;
 191     return OSReadSwapInt32(&temp, 0);
 192 }
 193
 194 OS_INLINE
 195 uint64_t
 196 _OSSwapInt64(
 197     uint64_t                        data
 198 )
 199 {
 200     uint64_t temp = data;
 201     return OSReadSwapInt64(&temp, 0);
 202 }
 203
 204 #endif /* ! _OS_OSBYTEORDERMACHINE_H */