libkern/libkern/ppc/OSByteOrder.h

   1 /*
   2  * Copyright (c) 2000-2005 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 #ifndef _OS_OSBYTEORDERPPC_H
  30 #define _OS_OSBYTEORDERPPC_H
  31
  32 #include <stdint.h>
  33
  34 #if !defined(OS_INLINE)
  35 # if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
  36 #        define OS_INLINE static inline
  37 # elif defined(__MWERKS__) || defined(__cplusplus)
  38 #        define OS_INLINE static inline
  39 # else
  40 #        define OS_INLINE static __inline__
  41 # endif
  42 #endif
  43
  44 /* Functions for byte reversed loads. */
  45
  46 OS_INLINE
  47 uint16_t
  48 OSReadSwapInt16(
  49     const volatile void * base,
  50     uintptr_t             byteOffset
  51 )
  52 {
  53     uint16_t result;
  54     volatile uint16_t *addr = (volatile uint16_t *)((uintptr_t)base + byteOffset);
  55
  56 #if defined(__llvm__)
  57     result = *addr;
  58     result = ((result << 8) | (result >> 8));
  59 #else
  60     __asm__ ("lhbrx %0, %2, %1"
  61              : "=r" (result)
  62              : "r"  (base), "bO" (byteOffset), "m" (*addr));
  63 #endif
  64
  65     return result;
  66 }
  67
  68 OS_INLINE
  69 uint32_t
  70 OSReadSwapInt32(
  71     const volatile void * base,
  72     uintptr_t             byteOffset
  73 )
  74 {
  75     uint32_t result;
  76     volatile uint32_t *addr = (volatile uint32_t *)((uintptr_t)base + byteOffset);
  77
  78 #if defined(__llvm__)
  79     result = __builtin_bswap32(*addr);
  80 #else
  81     __asm__ ("lwbrx %0, %2, %1"
  82              : "=r" (result)
  83              : "r"  (base), "bO" (byteOffset), "m" (*addr));
  84 #endif
  85
  86     return result;
  87 }
  88
  89 OS_INLINE
  90 uint64_t
  91 OSReadSwapInt64(
  92     const volatile void * base,
  93     uintptr_t             byteOffset
  94 )
  95 {
  96     volatile uint64_t *addr = (volatile uint64_t *)((uintptr_t)base + byteOffset);
  97     union {
  98         uint64_t u64;
  99         uint32_t u32[2];
 100     } u;
 101
 102 #if defined(__llvm__)
 103     u.u64 = __builtin_bswap64(*addr);
 104 #else
 105     __asm__ ("lwbrx %0, %3, %2\n\t"
 106              "lwbrx %1, %4, %2"
 107              : "=&r" (u.u32[1]), "=r" (u.u32[0])
 108              : "r"  (base), "bO" (byteOffset), "b" (byteOffset + 4), "m" (*addr));
 109 #endif
 110
 111     return u.u64;
 112 }
 113
 114 /* Functions for byte reversed stores. */
 115
 116 OS_INLINE
 117 void
 118 OSWriteSwapInt16(
 119     volatile void * base,
 120     uintptr_t       byteOffset,
 121     uint16_t        data
 122 )
 123 {
 124     volatile uint16_t *addr = (volatile uint16_t *)((uintptr_t)base + byteOffset);
 125
 126 #if defined(__llvm__)
 127     *addr = ((data >> 8) | (data << 8));
 128 #else
 129     __asm__ ("sthbrx %1, %3, %2"
 130              : "=m" (*addr)
 131              : "r" (data), "r" (base), "bO" (byteOffset));
 132 #endif
 133 }
 134
 135 OS_INLINE
 136 void
 137 OSWriteSwapInt32(
 138     volatile void * base,
 139     uintptr_t       byteOffset,
 140     uint32_t        data
 141 )
 142 {
 143     volatile uint32_t *addr = (volatile uint32_t *)((uintptr_t)base + byteOffset);
 144
 145 #if defined(__llvm__)
 146     *addr = __builtin_bswap32(data);
 147 #else
 148     __asm__ ("stwbrx %1, %3, %2"
 149              : "=m" (*addr)
 150              : "r" (data), "r" (base), "bO" (byteOffset));
 151 #endif
 152 }
 153
 154 OS_INLINE
 155 void
 156 OSWriteSwapInt64(
 157     volatile void * base,
 158     uintptr_t       byteOffset,
 159     uint64_t        data
 160 )
 161 {
 162     volatile uint64_t *addr = (volatile uint64_t *)((uintptr_t)base + byteOffset);
 163
 164 #if defined(__llvm__)
 165     *addr = __builtin_bswap64(data);
 166 #else
 167     uint32_t hi = (uint32_t)(data >> 32);
 168     uint32_t lo = (uint32_t)(data & 0xffffffff);
 169
 170     __asm__ ("stwbrx %1, %4, %3\n\t"
 171              "stwbrx %2, %5, %3"
 172              : "=m" (*addr)
 173              : "r" (lo), "r" (hi), "r" (base), "bO" (byteOffset), "b" (byteOffset + 4));
 174 #endif
 175 }
 176
 177 /* Generic byte swapping functions. */
 178
 179 OS_INLINE
 180 uint16_t
 181 _OSSwapInt16(
 182     uint16_t data
 183 )
 184 {
 185     return OSReadSwapInt16(&data, 0);
 186 }
 187
 188 OS_INLINE
 189 uint32_t
 190 _OSSwapInt32(
 191     uint32_t data
 192 )
 193 {
 194     return OSReadSwapInt32(&data, 0);
 195 }
 196
 197 OS_INLINE
 198 uint64_t
 199 _OSSwapInt64(
 200     uint64_t data
 201 )
 202 {
 203     return OSReadSwapInt64(&data, 0);
 204 }
 205
 206 #endif /* ! _OS_OSBYTEORDERPPC_H */