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  * The same as get_count_order() but accepts a long type parameter
  83  * or 0 is returned if @l == 0UL
  84  */
  85 static inline int get_count_order_long(unsigned long l)
  86 {
  87         if (l == 0UL)
  88                 return 0;
  89         else if (l & (l - 1UL))
  90                 return fls_long(l);
  91         else
  92                 return fls_long(l) - 1;
  93 }
  94
  95 static __always_inline unsigned long hweight_long(unsigned long w)
  96 {
  97         return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
  98 }
  99
 100 /**
 101  * rol64 - rotate a 64-bit value left
 102  * @word: value to rotate
 103  * @shift: bits to roll
 104  */
 105 static inline __u64 rol64(__u64 word, unsigned int shift)
 106 {
 107         return (word << shift) | (word >> (64 - shift));
 108 }
 109
 110 /**
 111  * ror64 - rotate a 64-bit value right
 112  * @word: value to rotate
 113  * @shift: bits to roll
 114  */
 115 static inline __u64 ror64(__u64 word, unsigned int shift)
 116 {
 117         return (word >> shift) | (word << (64 - shift));
 118 }
 119
 120 /**
 121  * rol32 - rotate a 32-bit value left
 122  * @word: value to rotate
 123  * @shift: bits to roll
 124  */
 125 static inline __u32 rol32(__u32 word, unsigned int shift)
 126 {
 127         return (word << shift) | (word >> ((-shift) & 31));
 128 }
 129
 130 /**
 131  * ror32 - rotate a 32-bit value right
 132  * @word: value to rotate
 133  * @shift: bits to roll
 134  */
 135 static inline __u32 ror32(__u32 word, unsigned int shift)
 136 {
 137         return (word >> shift) | (word << (32 - shift));
 138 }
 139
 140 /**
 141  * rol16 - rotate a 16-bit value left
 142  * @word: value to rotate
 143  * @shift: bits to roll
 144  */
 145 static inline __u16 rol16(__u16 word, unsigned int shift)
 146 {
 147         return (word << shift) | (word >> (16 - shift));
 148 }
 149
 150 /**
 151  * ror16 - rotate a 16-bit value right
 152  * @word: value to rotate
 153  * @shift: bits to roll
 154  */
 155 static inline __u16 ror16(__u16 word, unsigned int shift)
 156 {
 157         return (word >> shift) | (word << (16 - shift));
 158 }
 159
 160 /**
 161  * rol8 - rotate an 8-bit value left
 162  * @word: value to rotate
 163  * @shift: bits to roll
 164  */
 165 static inline __u8 rol8(__u8 word, unsigned int shift)
 166 {
 167         return (word << shift) | (word >> (8 - shift));
 168 }
 169
 170 /**
 171  * ror8 - rotate an 8-bit value right
 172  * @word: value to rotate
 173  * @shift: bits to roll
 174  */
 175 static inline __u8 ror8(__u8 word, unsigned int shift)
 176 {
 177         return (word >> shift) | (word << (8 - shift));
 178 }
 179
 180 /**
 181  * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
 182  * @value: value to sign extend
 183  * @index: 0 based bit index (0<=index<32) to sign bit
 184  *
 185  * This is safe to use for 16- and 8-bit types as well.
 186  */
 187 static inline __s32 sign_extend32(__u32 value, int index)
 188 {
 189         __u8 shift = 31 - index;
 190         return (__s32)(value << shift) >> shift;
 191 }
 192
 193 /**
 194  * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
 195  * @value: value to sign extend
 196  * @index: 0 based bit index (0<=index<64) to sign bit
 197  */
 198 static inline __s64 sign_extend64(__u64 value, int index)
 199 {
 200         __u8 shift = 63 - index;
 201         return (__s64)(value << shift) >> shift;
 202 }
 203
 204 static inline unsigned fls_long(unsigned long l)
 205 {
 206         if (sizeof(l) == 4)
 207                 return fls(l);
 208         return fls64(l);
 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