LXR linux/fs/xfs/xfs

   1/*
   2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
   3 * All Rights Reserved.
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it would be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write the Free Software Foundation,
  16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18#ifndef __XFS_ARCH_H__
  19#define __XFS_ARCH_H__
  20
  21#ifndef XFS_BIG_INUMS
  22# error XFS_BIG_INUMS must be defined true or false
  23#endif
  24
  25#ifdef __KERNEL__
  26
  27#include <asm/byteorder.h>
  28
  29#ifdef __BIG_ENDIAN
  30#define XFS_NATIVE_HOST 1
  31#else
  32#undef XFS_NATIVE_HOST
  33#endif
  34
  35#else /* __KERNEL__ */
  36
  37#if __BYTE_ORDER == __BIG_ENDIAN
  38#define XFS_NATIVE_HOST 1
  39#else
  40#undef XFS_NATIVE_HOST
  41#endif
  42
  43#ifdef XFS_NATIVE_HOST
  44#define cpu_to_be16(val)        ((__force __be16)(__u16)(val))
  45#define cpu_to_be32(val)        ((__force __be32)(__u32)(val))
  46#define cpu_to_be64(val)        ((__force __be64)(__u64)(val))
  47#define be16_to_cpu(val)        ((__force __u16)(__be16)(val))
  48#define be32_to_cpu(val)        ((__force __u32)(__be32)(val))
  49#define be64_to_cpu(val)        ((__force __u64)(__be64)(val))
  50#else
  51#define cpu_to_be16(val)        ((__force __be16)__swab16((__u16)(val)))
  52#define cpu_to_be32(val)        ((__force __be32)__swab32((__u32)(val)))
  53#define cpu_to_be64(val)        ((__force __be64)__swab64((__u64)(val)))
  54#define be16_to_cpu(val)        (__swab16((__force __u16)(__be16)(val)))
  55#define be32_to_cpu(val)        (__swab32((__force __u32)(__be32)(val)))
  56#define be64_to_cpu(val)        (__swab64((__force __u64)(__be64)(val)))
  57#endif
  58
  59static inline void be16_add_cpu(__be16 *a, __s16 b)
  60{
  61        *a = cpu_to_be16(be16_to_cpu(*a) + b);
  62}
  63
  64static inline void be32_add_cpu(__be32 *a, __s32 b)
  65{
  66        *a = cpu_to_be32(be32_to_cpu(*a) + b);
  67}
  68
  69static inline void be64_add_cpu(__be64 *a, __s64 b)
  70{
  71        *a = cpu_to_be64(be64_to_cpu(*a) + b);
  72}
  73
  74#endif  /* __KERNEL__ */
  75
  76/*
  77 * get and set integers from potentially unaligned locations
  78 */
  79
  80#define INT_GET_UNALIGNED_16_BE(pointer) \
  81   ((__u16)((((__u8*)(pointer))[0] << 8) | (((__u8*)(pointer))[1])))
  82#define INT_SET_UNALIGNED_16_BE(pointer,value) \
  83    { \
  84        ((__u8*)(pointer))[0] = (((value) >> 8) & 0xff); \
  85        ((__u8*)(pointer))[1] = (((value)     ) & 0xff); \
  86    }
  87
  88/*
  89 * In directories inode numbers are stored as unaligned arrays of unsigned
  90 * 8bit integers on disk.
  91 *
  92 * For v1 directories or v2 directories that contain inode numbers that
  93 * do not fit into 32bit the array has eight members, but the first member
  94 * is always zero:
  95 *
  96 *  |unused|48-55|40-47|32-39|24-31|16-23| 8-15| 0- 7|
  97 *
  98 * For v2 directories that only contain entries with inode numbers that fit
  99 * into 32bits a four-member array is used:
 100 *
 101 *  |24-31|16-23| 8-15| 0- 7|
 102 */ 
 103
 104#define XFS_GET_DIR_INO4(di) \
 105        (((__u32)(di).i[0] << 24) | ((di).i[1] << 16) | ((di).i[2] << 8) | ((di).i[3]))
 106
 107#define XFS_PUT_DIR_INO4(from, di) \
 108do { \
 109        (di).i[0] = (((from) & 0xff000000ULL) >> 24); \
 110        (di).i[1] = (((from) & 0x00ff0000ULL) >> 16); \
 111        (di).i[2] = (((from) & 0x0000ff00ULL) >> 8); \
 112        (di).i[3] = ((from) & 0x000000ffULL); \
 113} while (0)
 114
 115#define XFS_DI_HI(di) \
 116        (((__u32)(di).i[1] << 16) | ((di).i[2] << 8) | ((di).i[3]))
 117#define XFS_DI_LO(di) \
 118        (((__u32)(di).i[4] << 24) | ((di).i[5] << 16) | ((di).i[6] << 8) | ((di).i[7]))
 119
 120#define XFS_GET_DIR_INO8(di)        \
 121        (((xfs_ino_t)XFS_DI_LO(di) & 0xffffffffULL) | \
 122         ((xfs_ino_t)XFS_DI_HI(di) << 32))
 123
 124#define XFS_PUT_DIR_INO8(from, di) \
 125do { \
 126        (di).i[0] = 0; \
 127        (di).i[1] = (((from) & 0x00ff000000000000ULL) >> 48); \
 128        (di).i[2] = (((from) & 0x0000ff0000000000ULL) >> 40); \
 129        (di).i[3] = (((from) & 0x000000ff00000000ULL) >> 32); \
 130        (di).i[4] = (((from) & 0x00000000ff000000ULL) >> 24); \
 131        (di).i[5] = (((from) & 0x0000000000ff0000ULL) >> 16); \
 132        (di).i[6] = (((from) & 0x000000000000ff00ULL) >> 8); \
 133        (di).i[7] = ((from) & 0x00000000000000ffULL); \
 134} while (0)
 135        
 136#endif  /* __XFS_ARCH_H__ */
 137