fs/xfs/xfs_arch.h

   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)        ((__be16)(val))
  45 #define cpu_to_be32(val)        ((__be32)(val))
  46 #define cpu_to_be64(val)        ((__be64)(val))
  47 #define be16_to_cpu(val)        ((__uint16_t)(val))
  48 #define be32_to_cpu(val)        ((__uint32_t)(val))
  49 #define be64_to_cpu(val)        ((__uint64_t)(val))
  50 #else
  51 #define cpu_to_be16(val)        (__swab16((__uint16_t)(val)))
  52 #define cpu_to_be32(val)        (__swab32((__uint32_t)(val)))
  53 #define cpu_to_be64(val)        (__swab64((__uint64_t)(val)))
  54 #define be16_to_cpu(val)        (__swab16((__be16)(val)))
  55 #define be32_to_cpu(val)        (__swab32((__be32)(val)))
  56 #define be64_to_cpu(val)        (__swab64((__be64)(val)))
  57 #endif
  58
  59 #endif  /* __KERNEL__ */
  60
  61 /* do we need conversion? */
  62 #define ARCH_NOCONVERT 1
  63 #ifdef XFS_NATIVE_HOST
  64 # define ARCH_CONVERT   ARCH_NOCONVERT
  65 #else
  66 # define ARCH_CONVERT   0
  67 #endif
  68
  69 /* generic swapping macros */
  70
  71 #ifndef HAVE_SWABMACROS
  72 #define INT_SWAP16(type,var) ((typeof(type))(__swab16((__u16)(var))))
  73 #define INT_SWAP32(type,var) ((typeof(type))(__swab32((__u32)(var))))
  74 #define INT_SWAP64(type,var) ((typeof(type))(__swab64((__u64)(var))))
  75 #endif
  76
  77 #define INT_SWAP(type, var) \
  78     ((sizeof(type) == 8) ? INT_SWAP64(type,var) : \
  79     ((sizeof(type) == 4) ? INT_SWAP32(type,var) : \
  80     ((sizeof(type) == 2) ? INT_SWAP16(type,var) : \
  81     (var))))
  82
  83 /*
  84  * get and set integers from potentially unaligned locations
  85  */
  86
  87 #define INT_GET_UNALIGNED_16_BE(pointer) \
  88    ((__u16)((((__u8*)(pointer))[0] << 8) | (((__u8*)(pointer))[1])))
  89 #define INT_SET_UNALIGNED_16_BE(pointer,value) \
  90     { \
  91         ((__u8*)(pointer))[0] = (((value) >> 8) & 0xff); \
  92         ((__u8*)(pointer))[1] = (((value)     ) & 0xff); \
  93     }
  94
  95 /* does not return a value */
  96 #define INT_SET(reference,arch,valueref) \
  97     (__builtin_constant_p(valueref) ? \
  98         (void)( (reference) = ( ((arch) != ARCH_NOCONVERT) ? (INT_SWAP((reference),(valueref))) : (valueref)) ) : \
  99         (void)( \
 100             ((reference) = (valueref)), \
 101             ( ((arch) != ARCH_NOCONVERT) ? (reference) = INT_SWAP((reference),(reference)) : 0 ) \
 102         ) \
 103     )
 104
 105 /*
 106  * In directories inode numbers are stored as unaligned arrays of unsigned
 107  * 8bit integers on disk.
 108  *
 109  * For v1 directories or v2 directories that contain inode numbers that
 110  * do not fit into 32bit the array has eight members, but the first member
 111  * is always zero:
 112  *
 113  *  |unused|48-55|40-47|32-39|24-31|16-23| 8-15| 0- 7|
 114  *
 115  * For v2 directories that only contain entries with inode numbers that fit
 116  * into 32bits a four-member array is used:
 117  *
 118  *  |24-31|16-23| 8-15| 0- 7|
 119  */
 120
 121 #define XFS_GET_DIR_INO4(di) \
 122         (((__u32)(di).i[0] << 24) | ((di).i[1] << 16) | ((di).i[2] << 8) | ((di).i[3]))
 123
 124 #define XFS_PUT_DIR_INO4(from, di) \
 125 do { \
 126         (di).i[0] = (((from) & 0xff000000ULL) >> 24); \
 127         (di).i[1] = (((from) & 0x00ff0000ULL) >> 16); \
 128         (di).i[2] = (((from) & 0x0000ff00ULL) >> 8); \
 129         (di).i[3] = ((from) & 0x000000ffULL); \
 130 } while (0)
 131
 132 #define XFS_DI_HI(di) \
 133         (((__u32)(di).i[1] << 16) | ((di).i[2] << 8) | ((di).i[3]))
 134 #define XFS_DI_LO(di) \
 135         (((__u32)(di).i[4] << 24) | ((di).i[5] << 16) | ((di).i[6] << 8) | ((di).i[7]))
 136
 137 #define XFS_GET_DIR_INO8(di)        \
 138         (((xfs_ino_t)XFS_DI_LO(di) & 0xffffffffULL) | \
 139          ((xfs_ino_t)XFS_DI_HI(di) << 32))
 140
 141 #define XFS_PUT_DIR_INO8(from, di) \
 142 do { \
 143         (di).i[0] = 0; \
 144         (di).i[1] = (((from) & 0x00ff000000000000ULL) >> 48); \
 145         (di).i[2] = (((from) & 0x0000ff0000000000ULL) >> 40); \
 146         (di).i[3] = (((from) & 0x000000ff00000000ULL) >> 32); \
 147         (di).i[4] = (((from) & 0x00000000ff000000ULL) >> 24); \
 148         (di).i[5] = (((from) & 0x0000000000ff0000ULL) >> 16); \
 149         (di).i[6] = (((from) & 0x000000000000ff00ULL) >> 8); \
 150         (di).i[7] = ((from) & 0x00000000000000ffULL); \
 151 } while (0)
 152
 153 #endif  /* __XFS_ARCH_H__ */