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  * 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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Copyright (c) 1999 Apple Computer, Inc.  All rights reserved.
  25  *
  26  * HISTORY
  27  *
  28  */
  29
  30
  31 #ifndef _OS_OSBYTEORDERMACHINE_H
  32 #define _OS_OSBYTEORDERMACHINE_H
  33
  34 #include <stdint.h>
  35
  36 #if !defined(OS_INLINE)
  37 #        define OS_INLINE static inline
  38 #endif
  39
  40 /* Functions for byte reversed loads. */
  41
  42 OS_INLINE
  43 uint16_t
  44 OSReadSwapInt16(
  45     volatile void               * base,
  46     uintptr_t                     offset
  47 )
  48 {
  49     union sconv {
  50         uint16_t us;
  51         uint8_t  uc[2];
  52     } *inp, outv;
  53     inp = (union sconv *)((uint8_t *)base + offset);
  54     outv.uc[0] = inp->uc[1];
  55     outv.uc[1] = inp->uc[0];
  56     return (outv.us);
  57 }
  58
  59 OS_INLINE
  60 uint32_t
  61 OSReadSwapInt32(
  62     volatile void               * base,
  63     uintptr_t                     offset
  64 )
  65 {
  66     union lconv {
  67         uint32_t ul;
  68         uint8_t  uc[4];
  69     } *inp, outv;
  70     inp = (union lconv *)((uint8_t *)base + offset);
  71     outv.uc[0] = inp->uc[3];
  72     outv.uc[1] = inp->uc[2];
  73     outv.uc[2] = inp->uc[1];
  74     outv.uc[3] = inp->uc[0];
  75     return (outv.ul);
  76 }
  77
  78 OS_INLINE
  79 uint64_t
  80 OSReadSwapInt64(
  81     volatile void               * base,
  82     uintptr_t                     offset
  83 )
  84 {
  85     union llconv {
  86         uint64_t ull;
  87         uint8_t  uc[8];
  88     } *inp, outv;
  89     inp = (union llconv *)((uint8_t *)base + offset);
  90     outv.uc[0] = inp->uc[7];
  91     outv.uc[1] = inp->uc[6];
  92     outv.uc[2] = inp->uc[5];
  93     outv.uc[3] = inp->uc[4];
  94     outv.uc[4] = inp->uc[3];
  95     outv.uc[5] = inp->uc[2];
  96     outv.uc[6] = inp->uc[1];
  97     outv.uc[7] = inp->uc[0];
  98     return (outv.ull);
  99 }
 100
 101 /* Functions for byte reversed stores. */
 102
 103 OS_INLINE
 104 void
 105 OSWriteSwapInt16(
 106     volatile void               * base,
 107     uintptr_t                     offset,
 108     uint16_t                      data
 109 )
 110 {
 111     union sconv {
 112         uint16_t us;
 113         uint8_t  uc[2];
 114     } *inp, *outp;
 115     inp  = (union sconv *)((uint8_t *)base + offset);
 116     outp = (union sconv *)&data;
 117     outp->uc[0] = inp->uc[1];
 118     outp->uc[1] = inp->uc[0];
 119 }
 120
 121 OS_INLINE
 122 void
 123 OSWriteSwapInt32(
 124     volatile void               * base,
 125     uintptr_t                     offset,
 126     uint32_t                      data
 127 )
 128 {
 129     union lconv {
 130         uint32_t ul;
 131         uint8_t  uc[4];
 132     } *inp, *outp;
 133     inp  = (union lconv *)((uint8_t *)base + offset);
 134     outp = (union lconv *)&data;
 135     outp->uc[0] = inp->uc[3];
 136     outp->uc[1] = inp->uc[2];
 137     outp->uc[2] = inp->uc[1];
 138     outp->uc[3] = inp->uc[0];
 139 }
 140
 141 OS_INLINE
 142 void
 143 OSWriteSwapInt64(
 144     volatile void               * base,
 145     uintptr_t                     offset,
 146     uint64_t                      data
 147 )
 148 {
 149     union llconv {
 150         uint64_t ull;
 151         uint8_t  uc[8];
 152     } *inp, *outp;
 153     inp = (union llconv *)((uint8_t *)base + offset);
 154     outp = (union llconv *)&data;
 155     outp->uc[0] = inp->uc[7];
 156     outp->uc[1] = inp->uc[6];
 157     outp->uc[2] = inp->uc[5];
 158     outp->uc[3] = inp->uc[4];
 159     outp->uc[4] = inp->uc[3];
 160     outp->uc[5] = inp->uc[2];
 161     outp->uc[6] = inp->uc[1];
 162     outp->uc[7] = inp->uc[0];
 163 }
 164
 165 /* Generic byte swapping functions. */
 166
 167 OS_INLINE
 168 uint16_t
 169 _OSSwapInt16(
 170     uint16_t                      data
 171 )
 172 {
 173     uint16_t temp = data;
 174     return OSReadSwapInt16(&temp, 0);
 175 }
 176
 177 OS_INLINE
 178 uint32_t
 179 _OSSwapInt32(
 180     uint32_t                      data
 181 )
 182 {
 183     uint32_t temp = data;
 184     return OSReadSwapInt32(&temp, 0);
 185 }
 186
 187 OS_INLINE
 188 uint64_t
 189 _OSSwapInt64(
 190     uint64_t                        data
 191 )
 192 {
 193     uint64_t temp = data;
 194     return OSReadSwapInt64(&temp, 0);
 195 }
 196
 197 #endif /* ! _OS_OSBYTEORDERMACHINE_H */