libkern/libkern/machine/OSByteOrder.h

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