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)        ((__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
  59 static inline void be16_add_cpu(__be16 *a, __s16 b)
  60 {
  61         *a = cpu_to_be16(be16_to_cpu(*a) + b);
  62 }
  63
  64 static inline void be32_add_cpu(__be32 *a, __s32 b)
  65 {
  66         *a = cpu_to_be32(be32_to_cpu(*a) + b);
  67 }
  68
  69 static 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 /* do we need conversion? */
  77 #define ARCH_NOCONVERT 1
  78 #ifdef XFS_NATIVE_HOST
  79 # define ARCH_CONVERT   ARCH_NOCONVERT
  80 #else
  81 # define ARCH_CONVERT   0
  82 #endif
  83
  84 /* generic swapping macros */
  85
  86 #ifndef HAVE_SWABMACROS
  87 #define INT_SWAP16(type,var) ((typeof(type))(__swab16((__u16)(var))))
  88 #define INT_SWAP32(type,var) ((typeof(type))(__swab32((__u32)(var))))
  89 #define INT_SWAP64(type,var) ((typeof(type))(__swab64((__u64)(var))))
  90 #endif
  91
  92 #define INT_SWAP(type, var) \
  93     ((sizeof(type) == 8) ? INT_SWAP64(type,var) : \
  94     ((sizeof(type) == 4) ? INT_SWAP32(type,var) : \
  95     ((sizeof(type) == 2) ? INT_SWAP16(type,var) : \
  96     (var))))
  97
  98 /*
  99  * get and set integers from potentially unaligned locations
 100  */
 101
 102 #define INT_GET_UNALIGNED_16_BE(pointer) \
 103    ((__u16)((((__u8*)(pointer))[0] << 8) | (((__u8*)(pointer))[1])))
 104 #define INT_SET_UNALIGNED_16_BE(pointer,value) \
 105     { \
 106         ((__u8*)(pointer))[0] = (((value) >> 8) & 0xff); \
 107         ((__u8*)(pointer))[1] = (((value)     ) & 0xff); \
 108     }
 109
 110 /* does not return a value */
 111 #define INT_SET(reference,arch,valueref) \
 112     (__builtin_constant_p(valueref) ? \
 113         (void)( (reference) = ( ((arch) != ARCH_NOCONVERT) ? (INT_SWAP((reference),(valueref))) : (valueref)) ) : \
 114         (void)( \
 115             ((reference) = (valueref)), \
 116             ( ((arch) != ARCH_NOCONVERT) ? (reference) = INT_SWAP((reference),(reference)) : 0 ) \
 117         ) \
 118     )
 119
 120 /*
 121  * In directories inode numbers are stored as unaligned arrays of unsigned
 122  * 8bit integers on disk.
 123  *
 124  * For v1 directories or v2 directories that contain inode numbers that
 125  * do not fit into 32bit the array has eight members, but the first member
 126  * is always zero:
 127  *
 128  *  |unused|48-55|40-47|32-39|24-31|16-23| 8-15| 0- 7|
 129  *
 130  * For v2 directories that only contain entries with inode numbers that fit
 131  * into 32bits a four-member array is used:
 132  *
 133  *  |24-31|16-23| 8-15| 0- 7|
 134  */
 135
 136 #define XFS_GET_DIR_INO4(di) \
 137         (((__u32)(di).i[0] << 24) | ((di).i[1] << 16) | ((di).i[2] << 8) | ((di).i[3]))
 138
 139 #define XFS_PUT_DIR_INO4(from, di) \
 140 do { \
 141         (di).i[0] = (((from) & 0xff000000ULL) >> 24); \
 142         (di).i[1] = (((from) & 0x00ff0000ULL) >> 16); \
 143         (di).i[2] = (((from) & 0x0000ff00ULL) >> 8); \
 144         (di).i[3] = ((from) & 0x000000ffULL); \
 145 } while (0)
 146
 147 #define XFS_DI_HI(di) \
 148         (((__u32)(di).i[1] << 16) | ((di).i[2] << 8) | ((di).i[3]))
 149 #define XFS_DI_LO(di) \
 150         (((__u32)(di).i[4] << 24) | ((di).i[5] << 16) | ((di).i[6] << 8) | ((di).i[7]))
 151
 152 #define XFS_GET_DIR_INO8(di)        \
 153         (((xfs_ino_t)XFS_DI_LO(di) & 0xffffffffULL) | \
 154          ((xfs_ino_t)XFS_DI_HI(di) << 32))
 155
 156 #define XFS_PUT_DIR_INO8(from, di) \
 157 do { \
 158         (di).i[0] = 0; \
 159         (di).i[1] = (((from) & 0x00ff000000000000ULL) >> 48); \
 160         (di).i[2] = (((from) & 0x0000ff0000000000ULL) >> 40); \
 161         (di).i[3] = (((from) & 0x000000ff00000000ULL) >> 32); \
 162         (di).i[4] = (((from) & 0x00000000ff000000ULL) >> 24); \
 163         (di).i[5] = (((from) & 0x0000000000ff0000ULL) >> 16); \
 164         (di).i[6] = (((from) & 0x000000000000ff00ULL) >> 8); \
 165         (di).i[7] = ((from) & 0x00000000000000ffULL); \
 166 } while (0)
 167
 168 #endif  /* __XFS_ARCH_H__ */