reactos/drivers/filesystems/ext2_new/inc/linux/bitops.h

   1 #ifndef _LINUX_BITOPS_H
   2 #define _LINUX_BITOPS_H
   3
   4 #include <ntifs.h>
   5 #include <linux/types.h>
   6
   7 #ifdef  __KERNEL__
   8 #define BIT(nr)                     (1 << (nr))
   9 #define BIT_MASK(nr)            (1 << ((nr) % BITS_PER_LONG))
  10 #define BIT_WORD(nr)            ((nr) / BITS_PER_LONG)
  11 #define BITS_TO_LONGS(nr)       DIV_ROUND_UP(nr, BITS_PER_LONG)
  12 #define BITS_PER_BYTE           8
  13 #endif
  14
  15 /*
  16  * Include this here because some architectures need generic_ffs/fls in
  17  * scope
  18  */
  19
  20 /**
  21  * find_first_zero_bit - find the first zero bit in a memory region
  22  * @addr: The address to start the search at
  23  * @size: The maximum size to search
  24  *
  25  * Returns the bit number of the first zero bit, not the number of the byte
  26  * containing a bit.
  27  */
  28 #define find_first_zero_bit(addr, size) find_next_zero_bit((addr), (size), 0)
  29
  30 /**
  31  * find_next_zero_bit - find the first zero bit in a memory region
  32  * @addr: The address to base the search on
  33  * @offset: The bit number to start searching at
  34  * @size: The maximum size to search
  35  */
  36 int find_next_zero_bit(const unsigned long *addr, int size, int offset);
  37
  38 /**
  39  * __ffs - find first bit in word.
  40  * @word: The word to search
  41  *
  42  * Undefined if no bit exists, so code should check against 0 first.
  43  */
  44 static inline unsigned long __ffs(unsigned long word)
  45 {
  46     int num = 0;
  47
  48 #if BITS_PER_LONG == 64
  49     if ((word & 0xffffffff) == 0) {
  50         num += 32;
  51         word >>= 32;
  52     }
  53 #endif
  54     if ((word & 0xffff) == 0) {
  55         num += 16;
  56         word >>= 16;
  57     }
  58     if ((word & 0xff) == 0) {
  59         num += 8;
  60         word >>= 8;
  61     }
  62     if ((word & 0xf) == 0) {
  63         num += 4;
  64         word >>= 4;
  65     }
  66     if ((word & 0x3) == 0) {
  67         num += 2;
  68         word >>= 2;
  69     }
  70     if ((word & 0x1) == 0)
  71         num += 1;
  72     return num;
  73 }
  74
  75 /**
  76  * find_first_bit - find the first set bit in a memory region
  77  * @addr: The address to start the search at
  78  * @size: The maximum size to search
  79  *
  80  * Returns the bit number of the first set bit, not the number of the byte
  81  * containing a bit.
  82  */
  83 static inline unsigned find_first_bit(const unsigned long *addr, unsigned size)
  84 {
  85     unsigned x = 0;
  86
  87     while (x < size) {
  88         unsigned long val = *addr++;
  89         if (val)
  90             return __ffs(val) + x;
  91         x += (sizeof(*addr)<<3);
  92     }
  93     return x;
  94 }
  95
  96 /**
  97  * find_next_bit - find the next set bit in a memory region
  98  * @addr: The address to base the search on
  99  * @offset: The bitnumber to start searching at
 100  * @size: The maximum size to search
 101  */
 102
 103 /*
 104  * ffz - find first zero in word.
 105  * @word: The word to search
 106  *
 107  * Undefined if no zero exists, so code should check against ~0UL first.
 108  */
 109 #define ffz(x)  __ffs(~(x))
 110
 111
 112 /**
 113  * ffs - find first bit set
 114  * @x: the word to search
 115  *
 116  * This is defined the same way as
 117  * the libc and compiler builtin ffs routines, therefore
 118  * differs in spirit from the above ffz (man ffs).
 119  */
 120 static inline int ffs(int x)
 121 {
 122     int r = 1;
 123
 124     if (!x)
 125         return 0;
 126     if (!(x & 0xffff)) {
 127         x >>= 16;
 128         r += 16;
 129     }
 130     if (!(x & 0xff)) {
 131         x >>= 8;
 132         r += 8;
 133     }
 134     if (!(x & 0xf)) {
 135         x >>= 4;
 136         r += 4;
 137     }
 138     if (!(x & 3)) {
 139         x >>= 2;
 140         r += 2;
 141     }
 142     if (!(x & 1)) {
 143         x >>= 1;
 144         r += 1;
 145     }
 146     return r;
 147 }
 148
 149 /**
 150  * fls - find last (most-significant) bit set
 151  * @x: the word to search
 152  *
 153  * This is defined the same way as ffs.
 154  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 155  */
 156
 157 static inline int fls(int x)
 158 {
 159     int r = 32;
 160
 161     if (!x)
 162         return 0;
 163     if (!(x & 0xffff0000u)) {
 164         x <<= 16;
 165         r -= 16;
 166     }
 167     if (!(x & 0xff000000u)) {
 168         x <<= 8;
 169         r -= 8;
 170     }
 171     if (!(x & 0xf0000000u)) {
 172         x <<= 4;
 173         r -= 4;
 174     }
 175     if (!(x & 0xc0000000u)) {
 176         x <<= 2;
 177         r -= 2;
 178     }
 179     if (!(x & 0x80000000u)) {
 180         x <<= 1;
 181         r -= 1;
 182     }
 183     return r;
 184 }
 185
 186 static inline int fls64(__u64 x)
 187 {
 188     __u32 h = (__u32) (x >> 32);
 189     if (h)
 190         return fls(h) + 32;
 191     return fls((int)x);
 192 }
 193
 194 #define for_each_bit(bit, addr, size) \
 195         for ((bit) = find_first_bit((addr), (size)); \
 196              (bit) < (size); \
 197              (bit) = find_next_bit((addr), (size), (bit) + 1))
 198
 199
 200 static __inline int get_bitmask_order(unsigned int count)
 201 {
 202     int order;
 203
 204     order = fls(count);
 205     return order;       /* We could be slightly more clever with -1 here... */
 206 }
 207
 208 static __inline int get_count_order(unsigned int count)
 209 {
 210     int order;
 211
 212     order = fls(count) - 1;
 213     if (count & (count - 1))
 214         order++;
 215     return order;
 216 }
 217
 218
 219 /**
 220  * rol32 - rotate a 32-bit value left
 221  * @word: value to rotate
 222  * @shift: bits to roll
 223  */
 224 static inline __u32 rol32(__u32 word, unsigned int shift)
 225 {
 226     return (word << shift) | (word >> (32 - shift));
 227 }
 228
 229 /**
 230  * ror32 - rotate a 32-bit value right
 231  * @word: value to rotate
 232  * @shift: bits to roll
 233  */
 234 static inline __u32 ror32(__u32 word, unsigned int shift)
 235 {
 236     return (word >> shift) | (word << (32 - shift));
 237 }
 238
 239 static inline unsigned fls_long(unsigned long l)
 240 {
 241     if (sizeof(l) == 4)
 242         return fls(l);
 243     return fls64(l);
 244 }
 245
 246 /*
 247  * hweightN: returns the hamming weight (i.e. the number
 248  * of bits set) of a N-bit word
 249  */
 250
 251 static inline unsigned long hweight32(unsigned long w)
 252 {
 253     unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555);
 254     res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
 255     res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F);
 256     res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF);
 257     return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF);
 258 }
 259
 260 static inline unsigned long hweight64(__u64 w)
 261 {
 262 #if BITS_PER_LONG < 64
 263     return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w);
 264 #else
 265     u64 res;
 266     res = (w & 0x5555555555555555U) + ((w >> 1) & 0x5555555555555555U);
 267     res = (res & 0x3333333333333333U) + ((res >> 2) & 0x3333333333333333U);
 268     res = (res & 0x0F0F0F0F0F0F0F0FU) + ((res >> 4) & 0x0F0F0F0F0F0F0F0FU);
 269     res = (res & 0x00FF00FF00FF00FFU) + ((res >> 8) & 0x00FF00FF00FF00FFU);
 270     res = (res & 0x0000FFFF0000FFFFU) + ((res >> 16) & 0x0000FFFF0000FFFFU);
 271     return (res & 0x00000000FFFFFFFFU) + ((res >> 32) & 0x00000000FFFFFFFFU);
 272 #endif
 273 }
 274
 275 static inline unsigned long hweight_long(unsigned long w)
 276 {
 277     return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
 278 }
 279
 280 #endif