include/linux/bitops.h

   1 #ifndef _LINUX_BITOPS_H
   2 #define _LINUX_BITOPS_H
   3 #include <asm/types.h>
   4
   5 #ifdef  __KERNEL__
   6 #define BIT(nr)                 (1UL << (nr))
   7 #define BIT_ULL(nr)             (1ULL << (nr))
   8 #define BIT_MASK(nr)            (1UL << ((nr) % BITS_PER_LONG))
   9 #define BIT_WORD(nr)            ((nr) / BITS_PER_LONG)
  10 #define BIT_ULL_MASK(nr)        (1ULL << ((nr) % BITS_PER_LONG_LONG))
  11 #define BIT_ULL_WORD(nr)        ((nr) / BITS_PER_LONG_LONG)
  12 #define BITS_PER_BYTE           8
  13 #define BITS_TO_LONGS(nr)       DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
  14 #endif
  15
  16 /*
  17  * Create a contiguous bitmask starting at bit position @l and ending at
  18  * position @h. For example
  19  * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
  20  */
  21 #define GENMASK(h, l) \
  22         (((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
  23
  24 #define GENMASK_ULL(h, l) \
  25         (((~0ULL) - (1ULL << (l)) + 1) & \
  26          (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
  27
  28 extern unsigned int __sw_hweight8(unsigned int w);
  29 extern unsigned int __sw_hweight16(unsigned int w);
  30 extern unsigned int __sw_hweight32(unsigned int w);
  31 extern unsigned long __sw_hweight64(__u64 w);
  32
  33 /*
  34  * Include this here because some architectures need generic_ffs/fls in
  35  * scope
  36  */
  37 #include <asm/bitops.h>
  38
  39 #define for_each_set_bit(bit, addr, size) \
  40         for ((bit) = find_first_bit((addr), (size));            \
  41              (bit) < (size);                                    \
  42              (bit) = find_next_bit((addr), (size), (bit) + 1))
  43
  44 /* same as for_each_set_bit() but use bit as value to start with */
  45 #define for_each_set_bit_from(bit, addr, size) \
  46         for ((bit) = find_next_bit((addr), (size), (bit));      \
  47              (bit) < (size);                                    \
  48              (bit) = find_next_bit((addr), (size), (bit) + 1))
  49
  50 #define for_each_clear_bit(bit, addr, size) \
  51         for ((bit) = find_first_zero_bit((addr), (size));       \
  52              (bit) < (size);                                    \
  53              (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
  54
  55 /* same as for_each_clear_bit() but use bit as value to start with */
  56 #define for_each_clear_bit_from(bit, addr, size) \
  57         for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
  58              (bit) < (size);                                    \
  59              (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
  60
  61 static inline int get_bitmask_order(unsigned int count)
  62 {
  63         int order;
  64
  65         order = fls(count);
  66         return order;   /* We could be slightly more clever with -1 here... */
  67 }
  68
  69 static __always_inline unsigned long hweight_long(unsigned long w)
  70 {
  71         return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
  72 }
  73
  74 /**
  75  * rol64 - rotate a 64-bit value left
  76  * @word: value to rotate
  77  * @shift: bits to roll
  78  */
  79 static inline __u64 rol64(__u64 word, unsigned int shift)
  80 {
  81         return (word << shift) | (word >> (64 - shift));
  82 }
  83
  84 /**
  85  * ror64 - rotate a 64-bit value right
  86  * @word: value to rotate
  87  * @shift: bits to roll
  88  */
  89 static inline __u64 ror64(__u64 word, unsigned int shift)
  90 {
  91         return (word >> shift) | (word << (64 - shift));
  92 }
  93
  94 /**
  95  * rol32 - rotate a 32-bit value left
  96  * @word: value to rotate
  97  * @shift: bits to roll
  98  */
  99 static inline __u32 rol32(__u32 word, unsigned int shift)
 100 {
 101         return (word << shift) | (word >> ((-shift) & 31));
 102 }
 103
 104 /**
 105  * ror32 - rotate a 32-bit value right
 106  * @word: value to rotate
 107  * @shift: bits to roll
 108  */
 109 static inline __u32 ror32(__u32 word, unsigned int shift)
 110 {
 111         return (word >> shift) | (word << (32 - shift));
 112 }
 113
 114 /**
 115  * rol16 - rotate a 16-bit value left
 116  * @word: value to rotate
 117  * @shift: bits to roll
 118  */
 119 static inline __u16 rol16(__u16 word, unsigned int shift)
 120 {
 121         return (word << shift) | (word >> (16 - shift));
 122 }
 123
 124 /**
 125  * ror16 - rotate a 16-bit value right
 126  * @word: value to rotate
 127  * @shift: bits to roll
 128  */
 129 static inline __u16 ror16(__u16 word, unsigned int shift)
 130 {
 131         return (word >> shift) | (word << (16 - shift));
 132 }
 133
 134 /**
 135  * rol8 - rotate an 8-bit value left
 136  * @word: value to rotate
 137  * @shift: bits to roll
 138  */
 139 static inline __u8 rol8(__u8 word, unsigned int shift)
 140 {
 141         return (word << shift) | (word >> (8 - shift));
 142 }
 143
 144 /**
 145  * ror8 - rotate an 8-bit value right
 146  * @word: value to rotate
 147  * @shift: bits to roll
 148  */
 149 static inline __u8 ror8(__u8 word, unsigned int shift)
 150 {
 151         return (word >> shift) | (word << (8 - shift));
 152 }
 153
 154 /**
 155  * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
 156  * @value: value to sign extend
 157  * @index: 0 based bit index (0<=index<32) to sign bit
 158  *
 159  * This is safe to use for 16- and 8-bit types as well.
 160  */
 161 static inline __s32 sign_extend32(__u32 value, int index)
 162 {
 163         __u8 shift = 31 - index;
 164         return (__s32)(value << shift) >> shift;
 165 }
 166
 167 /**
 168  * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
 169  * @value: value to sign extend
 170  * @index: 0 based bit index (0<=index<64) to sign bit
 171  */
 172 static inline __s64 sign_extend64(__u64 value, int index)
 173 {
 174         __u8 shift = 63 - index;
 175         return (__s64)(value << shift) >> shift;
 176 }
 177
 178 static inline unsigned fls_long(unsigned long l)
 179 {
 180         if (sizeof(l) == 4)
 181                 return fls(l);
 182         return fls64(l);
 183 }
 184
 185 static inline int get_count_order(unsigned int count)
 186 {
 187         int order;
 188
 189         order = fls(count) - 1;
 190         if (count & (count - 1))
 191                 order++;
 192         return order;
 193 }
 194
 195 /**
 196  * get_count_order_long - get order after rounding @l up to power of 2
 197  * @l: parameter
 198  *
 199  * it is same as get_count_order() but with long type parameter
 200  */
 201 static inline int get_count_order_long(unsigned long l)
 202 {
 203         if (l == 0UL)
 204                 return -1;
 205         else if (l & (l - 1UL))
 206                 return (int)fls_long(l);
 207         else
 208                 return (int)fls_long(l) - 1;
 209 }
 210
 211 /**
 212  * __ffs64 - find first set bit in a 64 bit word
 213  * @word: The 64 bit word
 214  *
 215  * On 64 bit arches this is a synomyn for __ffs
 216  * The result is not defined if no bits are set, so check that @word
 217  * is non-zero before calling this.
 218  */
 219 static inline unsigned long __ffs64(u64 word)
 220 {
 221 #if BITS_PER_LONG == 32
 222         if (((u32)word) == 0UL)
 223                 return __ffs((u32)(word >> 32)) + 32;
 224 #elif BITS_PER_LONG != 64
 225 #error BITS_PER_LONG not 32 or 64
 226 #endif
 227         return __ffs((unsigned long)word);
 228 }
 229
 230 #ifdef __KERNEL__
 231
 232 #ifndef set_mask_bits
 233 #define set_mask_bits(ptr, _mask, _bits)        \
 234 ({                                                              \
 235         const typeof(*ptr) mask = (_mask), bits = (_bits);      \
 236         typeof(*ptr) old, new;                                  \
 237                                                                 \
 238         do {                                                    \
 239                 old = ACCESS_ONCE(*ptr);                        \
 240                 new = (old & ~mask) | bits;                     \
 241         } while (cmpxchg(ptr, old, new) != old);                \
 242                                                                 \
 243         new;                                                    \
 244 })
 245 #endif
 246
 247 #ifndef bit_clear_unless
 248 #define bit_clear_unless(ptr, _clear, _test)    \
 249 ({                                                              \
 250         const typeof(*ptr) clear = (_clear), test = (_test);    \
 251         typeof(*ptr) old, new;                                  \
 252                                                                 \
 253         do {                                                    \
 254                 old = ACCESS_ONCE(*ptr);                        \
 255                 new = old & ~clear;                             \
 256         } while (!(old & test) &&                               \
 257                  cmpxchg(ptr, old, new) != old);                \
 258                                                                 \
 259         !(old & test);                                          \
 260 })
 261 #endif
 262
 263 #ifndef find_last_bit
 264 /**
 265  * find_last_bit - find the last set bit in a memory region
 266  * @addr: The address to start the search at
 267  * @size: The number of bits to search
 268  *
 269  * Returns the bit number of the last set bit, or size.
 270  */
 271 extern unsigned long find_last_bit(const unsigned long *addr,
 272                                    unsigned long size);
 273 #endif
 274
 275 #endif /* __KERNEL__ */
 276 #endif