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