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)           (((U32_C(1) << ((h) - (l) + 1)) - 1) << (l))
  22 #define GENMASK_ULL(h, l)       (((U64_C(1) << ((h) - (l) + 1)) - 1) << (l))
  23
  24 extern unsigned int __sw_hweight8(unsigned int w);
  25 extern unsigned int __sw_hweight16(unsigned int w);
  26 extern unsigned int __sw_hweight32(unsigned int w);
  27 extern unsigned long __sw_hweight64(__u64 w);
  28
  29 /*
  30  * Include this here because some architectures need generic_ffs/fls in
  31  * scope
  32  */
  33 #include <asm/bitops.h>
  34
  35 #define for_each_set_bit(bit, addr, size) \
  36         for ((bit) = find_first_bit((addr), (size));            \
  37              (bit) < (size);                                    \
  38              (bit) = find_next_bit((addr), (size), (bit) + 1))
  39
  40 /* same as for_each_set_bit() but use bit as value to start with */
  41 #define for_each_set_bit_from(bit, addr, size) \
  42         for ((bit) = find_next_bit((addr), (size), (bit));      \
  43              (bit) < (size);                                    \
  44              (bit) = find_next_bit((addr), (size), (bit) + 1))
  45
  46 #define for_each_clear_bit(bit, addr, size) \
  47         for ((bit) = find_first_zero_bit((addr), (size));       \
  48              (bit) < (size);                                    \
  49              (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
  50
  51 /* same as for_each_clear_bit() but use bit as value to start with */
  52 #define for_each_clear_bit_from(bit, addr, size) \
  53         for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
  54              (bit) < (size);                                    \
  55              (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
  56
  57 static __inline__ int get_bitmask_order(unsigned int count)
  58 {
  59         int order;
  60
  61         order = fls(count);
  62         return order;   /* We could be slightly more clever with -1 here... */
  63 }
  64
  65 static __inline__ int get_count_order(unsigned int count)
  66 {
  67         int order;
  68
  69         order = fls(count) - 1;
  70         if (count & (count - 1))
  71                 order++;
  72         return order;
  73 }
  74
  75 static inline unsigned long hweight_long(unsigned long w)
  76 {
  77         return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
  78 }
  79
  80 /**
  81  * rol64 - rotate a 64-bit value left
  82  * @word: value to rotate
  83  * @shift: bits to roll
  84  */
  85 static inline __u64 rol64(__u64 word, unsigned int shift)
  86 {
  87         return (word << shift) | (word >> (64 - shift));
  88 }
  89
  90 /**
  91  * ror64 - rotate a 64-bit value right
  92  * @word: value to rotate
  93  * @shift: bits to roll
  94  */
  95 static inline __u64 ror64(__u64 word, unsigned int shift)
  96 {
  97         return (word >> shift) | (word << (64 - shift));
  98 }
  99
 100 /**
 101  * rol32 - rotate a 32-bit value left
 102  * @word: value to rotate
 103  * @shift: bits to roll
 104  */
 105 static inline __u32 rol32(__u32 word, unsigned int shift)
 106 {
 107         return (word << shift) | (word >> (32 - shift));
 108 }
 109
 110 /**
 111  * ror32 - rotate a 32-bit value right
 112  * @word: value to rotate
 113  * @shift: bits to roll
 114  */
 115 static inline __u32 ror32(__u32 word, unsigned int shift)
 116 {
 117         return (word >> shift) | (word << (32 - shift));
 118 }
 119
 120 /**
 121  * rol16 - rotate a 16-bit value left
 122  * @word: value to rotate
 123  * @shift: bits to roll
 124  */
 125 static inline __u16 rol16(__u16 word, unsigned int shift)
 126 {
 127         return (word << shift) | (word >> (16 - shift));
 128 }
 129
 130 /**
 131  * ror16 - rotate a 16-bit value right
 132  * @word: value to rotate
 133  * @shift: bits to roll
 134  */
 135 static inline __u16 ror16(__u16 word, unsigned int shift)
 136 {
 137         return (word >> shift) | (word << (16 - shift));
 138 }
 139
 140 /**
 141  * rol8 - rotate an 8-bit value left
 142  * @word: value to rotate
 143  * @shift: bits to roll
 144  */
 145 static inline __u8 rol8(__u8 word, unsigned int shift)
 146 {
 147         return (word << shift) | (word >> (8 - shift));
 148 }
 149
 150 /**
 151  * ror8 - rotate an 8-bit value right
 152  * @word: value to rotate
 153  * @shift: bits to roll
 154  */
 155 static inline __u8 ror8(__u8 word, unsigned int shift)
 156 {
 157         return (word >> shift) | (word << (8 - shift));
 158 }
 159
 160 /**
 161  * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
 162  * @value: value to sign extend
 163  * @index: 0 based bit index (0<=index<32) to sign bit
 164  */
 165 static inline __s32 sign_extend32(__u32 value, int index)
 166 {
 167         __u8 shift = 31 - index;
 168         return (__s32)(value << shift) >> shift;
 169 }
 170
 171 static inline unsigned fls_long(unsigned long l)
 172 {
 173         if (sizeof(l) == 4)
 174                 return fls(l);
 175         return fls64(l);
 176 }
 177
 178 /**
 179  * __ffs64 - find first set bit in a 64 bit word
 180  * @word: The 64 bit word
 181  *
 182  * On 64 bit arches this is a synomyn for __ffs
 183  * The result is not defined if no bits are set, so check that @word
 184  * is non-zero before calling this.
 185  */
 186 static inline unsigned long __ffs64(u64 word)
 187 {
 188 #if BITS_PER_LONG == 32
 189         if (((u32)word) == 0UL)
 190                 return __ffs((u32)(word >> 32)) + 32;
 191 #elif BITS_PER_LONG != 64
 192 #error BITS_PER_LONG not 32 or 64
 193 #endif
 194         return __ffs((unsigned long)word);
 195 }
 196
 197 #ifdef __KERNEL__
 198
 199 #ifndef set_mask_bits
 200 #define set_mask_bits(ptr, _mask, _bits)        \
 201 ({                                                              \
 202         const typeof(*ptr) mask = (_mask), bits = (_bits);      \
 203         typeof(*ptr) old, new;                                  \
 204                                                                 \
 205         do {                                                    \
 206                 old = ACCESS_ONCE(*ptr);                        \
 207                 new = (old & ~mask) | bits;                     \
 208         } while (cmpxchg(ptr, old, new) != old);                \
 209                                                                 \
 210         new;                                                    \
 211 })
 212 #endif
 213
 214 #ifndef find_last_bit
 215 /**
 216  * find_last_bit - find the last set bit in a memory region
 217  * @addr: The address to start the search at
 218  * @size: The maximum size to search
 219  *
 220  * Returns the bit number of the first set bit, or size.
 221  */
 222 extern unsigned long find_last_bit(const unsigned long *addr,
 223                                    unsigned long size);
 224 #endif
 225
 226 #endif /* __KERNEL__ */
 227 #endif