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 #endif  /* __KERNEL__ */
  44
  45 /* do we need conversion? */
  46 #define ARCH_NOCONVERT 1
  47 #ifdef XFS_NATIVE_HOST
  48 # define ARCH_CONVERT   ARCH_NOCONVERT
  49 #else
  50 # define ARCH_CONVERT   0
  51 #endif
  52
  53 /* generic swapping macros */
  54
  55 #ifndef HAVE_SWABMACROS
  56 #define INT_SWAP16(type,var) ((typeof(type))(__swab16((__u16)(var))))
  57 #define INT_SWAP32(type,var) ((typeof(type))(__swab32((__u32)(var))))
  58 #define INT_SWAP64(type,var) ((typeof(type))(__swab64((__u64)(var))))
  59 #endif
  60
  61 #define INT_SWAP(type, var) \
  62     ((sizeof(type) == 8) ? INT_SWAP64(type,var) : \
  63     ((sizeof(type) == 4) ? INT_SWAP32(type,var) : \
  64     ((sizeof(type) == 2) ? INT_SWAP16(type,var) : \
  65     (var))))
  66
  67 /*
  68  * get and set integers from potentially unaligned locations
  69  */
  70
  71 #define INT_GET_UNALIGNED_16_BE(pointer) \
  72    ((__u16)((((__u8*)(pointer))[0] << 8) | (((__u8*)(pointer))[1])))
  73 #define INT_SET_UNALIGNED_16_BE(pointer,value) \
  74     { \
  75         ((__u8*)(pointer))[0] = (((value) >> 8) & 0xff); \
  76         ((__u8*)(pointer))[1] = (((value)     ) & 0xff); \
  77     }
  78
  79 /* define generic INT_ macros */
  80
  81 #define INT_GET(reference,arch) \
  82     (((arch) == ARCH_NOCONVERT) \
  83         ? \
  84             (reference) \
  85         : \
  86             INT_SWAP((reference),(reference)) \
  87     )
  88
  89 /* does not return a value */
  90 #define INT_SET(reference,arch,valueref) \
  91     (__builtin_constant_p(valueref) ? \
  92         (void)( (reference) = ( ((arch) != ARCH_NOCONVERT) ? (INT_SWAP((reference),(valueref))) : (valueref)) ) : \
  93         (void)( \
  94             ((reference) = (valueref)), \
  95             ( ((arch) != ARCH_NOCONVERT) ? (reference) = INT_SWAP((reference),(reference)) : 0 ) \
  96         ) \
  97     )
  98
  99 /* does not return a value */
 100 #define INT_MOD_EXPR(reference,arch,code) \
 101     (((arch) == ARCH_NOCONVERT) \
 102         ? \
 103             (void)((reference) code) \
 104         : \
 105             (void)( \
 106                 (reference) = INT_GET((reference),arch) , \
 107                 ((reference) code), \
 108                 INT_SET(reference, arch, reference) \
 109             ) \
 110     )
 111
 112 /* does not return a value */
 113 #define INT_MOD(reference,arch,delta) \
 114     (void)( \
 115         INT_MOD_EXPR(reference,arch,+=(delta)) \
 116     )
 117
 118 /*
 119  * INT_COPY - copy a value between two locations with the
 120  *            _same architecture_ but _potentially different sizes_
 121  *
 122  *          if the types of the two parameters are equal or they are
 123  *              in native architecture, a simple copy is done
 124  *
 125  *          otherwise, architecture conversions are done
 126  *
 127  */
 128
 129 /* does not return a value */
 130 #define INT_COPY(dst,src,arch) \
 131     ( \
 132         ((sizeof(dst) == sizeof(src)) || ((arch) == ARCH_NOCONVERT)) \
 133             ? \
 134                 (void)((dst) = (src)) \
 135             : \
 136                 INT_SET(dst, arch, INT_GET(src, arch)) \
 137     )
 138
 139 /*
 140  * INT_XLATE - copy a value in either direction between two locations
 141  *             with different architectures
 142  *
 143  *                  dir < 0     - copy from memory to buffer (native to arch)
 144  *                  dir > 0     - copy from buffer to memory (arch to native)
 145  */
 146
 147 /* does not return a value */
 148 #define INT_XLATE(buf,mem,dir,arch) {\
 149     ASSERT(dir); \
 150     if (dir>0) { \
 151         (mem)=INT_GET(buf, arch); \
 152     } else { \
 153         INT_SET(buf, arch, mem); \
 154     } \
 155 }
 156
 157 static inline void be16_add(__be16 *a, __s16 b)
 158 {
 159         *a = cpu_to_be16(be16_to_cpu(*a) + b);
 160 }
 161
 162 static inline void be32_add(__be32 *a, __s32 b)
 163 {
 164         *a = cpu_to_be32(be32_to_cpu(*a) + b);
 165 }
 166
 167 static inline void be64_add(__be64 *a, __s64 b)
 168 {
 169         *a = cpu_to_be64(be64_to_cpu(*a) + b);
 170 }
 171
 172 /*
 173  * In directories inode numbers are stored as unaligned arrays of unsigned
 174  * 8bit integers on disk.
 175  *
 176  * For v1 directories or v2 directories that contain inode numbers that
 177  * do not fit into 32bit the array has eight members, but the first member
 178  * is always zero:
 179  *
 180  *  |unused|48-55|40-47|32-39|24-31|16-23| 8-15| 0- 7|
 181  *
 182  * For v2 directories that only contain entries with inode numbers that fit
 183  * into 32bits a four-member array is used:
 184  *
 185  *  |24-31|16-23| 8-15| 0- 7|
 186  */
 187
 188 #define XFS_GET_DIR_INO4(di) \
 189         (((u32)(di).i[0] << 24) | ((di).i[1] << 16) | ((di).i[2] << 8) | ((di).i[3]))
 190
 191 #define XFS_PUT_DIR_INO4(from, di) \
 192 do { \
 193         (di).i[0] = (((from) & 0xff000000ULL) >> 24); \
 194         (di).i[1] = (((from) & 0x00ff0000ULL) >> 16); \
 195         (di).i[2] = (((from) & 0x0000ff00ULL) >> 8); \
 196         (di).i[3] = ((from) & 0x000000ffULL); \
 197 } while (0)
 198
 199 #define XFS_DI_HI(di) \
 200         (((u32)(di).i[1] << 16) | ((di).i[2] << 8) | ((di).i[3]))
 201 #define XFS_DI_LO(di) \
 202         (((u32)(di).i[4] << 24) | ((di).i[5] << 16) | ((di).i[6] << 8) | ((di).i[7]))
 203
 204 #define XFS_GET_DIR_INO8(di)        \
 205         (((xfs_ino_t)XFS_DI_LO(di) & 0xffffffffULL) | \
 206          ((xfs_ino_t)XFS_DI_HI(di) << 32))
 207
 208 #define XFS_PUT_DIR_INO8(from, di) \
 209 do { \
 210         (di).i[0] = 0; \
 211         (di).i[1] = (((from) & 0x00ff000000000000ULL) >> 48); \
 212         (di).i[2] = (((from) & 0x0000ff0000000000ULL) >> 40); \
 213         (di).i[3] = (((from) & 0x000000ff00000000ULL) >> 32); \
 214         (di).i[4] = (((from) & 0x00000000ff000000ULL) >> 24); \
 215         (di).i[5] = (((from) & 0x0000000000ff0000ULL) >> 16); \
 216         (di).i[6] = (((from) & 0x000000000000ff00ULL) >> 8); \
 217         (di).i[7] = ((from) & 0x00000000000000ffULL); \
 218 } while (0)
 219
 220 #endif  /* __XFS_ARCH_H__ */