libkern/libkern/i386/OSByteOrder.h

   1 /*
   2  * Copyright (c) 1999-2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25
  26 #ifndef _OS_OSBYTEORDERI386_H
  27 #define _OS_OSBYTEORDERI386_H
  28
  29 #include <stdint.h>
  30
  31 #if !defined(OS_INLINE)
  32 #        define OS_INLINE static inline
  33 #endif
  34
  35 /* Generic byte swapping functions. */
  36
  37 OS_INLINE
  38 uint16_t
  39 _OSSwapInt16(
  40     uint16_t        data
  41 )
  42 {
  43     __asm__ ("xchgb %b0, %h0" : "+q" (data));
  44     return data;
  45 }
  46
  47 OS_INLINE
  48 uint32_t
  49 _OSSwapInt32(
  50     uint32_t        data
  51 )
  52 {
  53     __asm__ ("bswap %0" : "+r" (data));
  54     return data;
  55 }
  56
  57 OS_INLINE
  58 uint64_t
  59 _OSSwapInt64(
  60     uint64_t        data
  61 )
  62 {
  63     union {
  64         uint64_t ull;
  65         uint32_t ul[2];
  66     } u;
  67
  68     /* This actually generates the best code */
  69     u.ul[0] = data >> 32;
  70     u.ul[1] = data & 0xffffffff;
  71     u.ul[0] = _OSSwapInt32(u.ul[0]);
  72     u.ul[1] = _OSSwapInt32(u.ul[1]);
  73     return u.ull;
  74 }
  75
  76 /* Functions for byte reversed loads. */
  77
  78 OS_INLINE
  79 uint16_t
  80 OSReadSwapInt16(
  81     volatile void   * base,
  82     uintptr_t       offset
  83 )
  84 {
  85     uint16_t result;
  86
  87     result = *(uint16_t *)((uintptr_t)base + offset);
  88     return _OSSwapInt16(result);
  89 }
  90
  91 OS_INLINE
  92 uint32_t
  93 OSReadSwapInt32(
  94     volatile void   * base,
  95     uintptr_t       offset
  96 )
  97 {
  98     uint32_t result;
  99
 100     result = *(uint32_t *)((uintptr_t)base + offset);
 101     return _OSSwapInt32(result);
 102 }
 103
 104 OS_INLINE
 105 uint64_t
 106 OSReadSwapInt64(
 107     volatile void   * base,
 108     uintptr_t       offset
 109 )
 110 {
 111     uint32_t * inp;
 112     union ullc {
 113         uint64_t     ull;
 114         uint32_t     ul[2];
 115     } outv;
 116
 117     inp = (uint32_t *)((uintptr_t)base + offset);
 118     outv.ul[0] = inp[1];
 119     outv.ul[1] = inp[0];
 120     outv.ul[0] = _OSSwapInt32(outv.ul[0]);
 121     outv.ul[1] = _OSSwapInt32(outv.ul[1]);
 122     return outv.ull;
 123 }
 124
 125 /* Functions for byte reversed stores. */
 126
 127 OS_INLINE
 128 void
 129 OSWriteSwapInt16(
 130     volatile void   * base,
 131     uintptr_t       offset,
 132     uint16_t        data
 133 )
 134 {
 135     *(uint16_t *)((uintptr_t)base + offset) = _OSSwapInt16(data);
 136 }
 137
 138 OS_INLINE
 139 void
 140 OSWriteSwapInt32(
 141     volatile void   * base,
 142     uintptr_t       offset,
 143     uint32_t        data
 144 )
 145 {
 146     *(uint32_t *)((uintptr_t)base + offset) = _OSSwapInt32(data);
 147 }
 148
 149 OS_INLINE
 150 void
 151 OSWriteSwapInt64(
 152     volatile void    * base,
 153     uintptr_t        offset,
 154     uint64_t         data
 155 )
 156 {
 157     *(uint64_t *)((uintptr_t)base + offset) = _OSSwapInt64(data);
 158 }
 159
 160 #endif /* ! _OS_OSBYTEORDERI386_H */