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 /*
  36  * Provide __deprecated wrappers for the new interface, avoid flag day changes.
  37  * We need the ugly external functions to break header recursion hell.
  38  */
  39 #ifndef smp_mb__before_clear_bit
  40 static inline void __deprecated smp_mb__before_clear_bit(void)
  41 {
  42         extern void __smp_mb__before_atomic(void);
  43         __smp_mb__before_atomic();
  44 }
  45 #endif
  46
  47 #ifndef smp_mb__after_clear_bit
  48 static inline void __deprecated smp_mb__after_clear_bit(void)
  49 {
  50         extern void __smp_mb__after_atomic(void);
  51         __smp_mb__after_atomic();
  52 }
  53 #endif
  54
  55 #define for_each_set_bit(bit, addr, size) \
  56         for ((bit) = find_first_bit((addr), (size));            \
  57              (bit) < (size);                                    \
  58              (bit) = find_next_bit((addr), (size), (bit) + 1))
  59
  60 /* same as for_each_set_bit() but use bit as value to start with */
  61 #define for_each_set_bit_from(bit, addr, size) \
  62         for ((bit) = find_next_bit((addr), (size), (bit));      \
  63              (bit) < (size);                                    \
  64              (bit) = find_next_bit((addr), (size), (bit) + 1))
  65
  66 #define for_each_clear_bit(bit, addr, size) \
  67         for ((bit) = find_first_zero_bit((addr), (size));       \
  68              (bit) < (size);                                    \
  69              (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
  70
  71 /* same as for_each_clear_bit() but use bit as value to start with */
  72 #define for_each_clear_bit_from(bit, addr, size) \
  73         for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
  74              (bit) < (size);                                    \
  75              (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
  76
  77 static __inline__ int get_bitmask_order(unsigned int count)
  78 {
  79         int order;
  80
  81         order = fls(count);
  82         return order;   /* We could be slightly more clever with -1 here... */
  83 }
  84
  85 static __inline__ int get_count_order(unsigned int count)
  86 {
  87         int order;
  88
  89         order = fls(count) - 1;
  90         if (count & (count - 1))
  91                 order++;
  92         return order;
  93 }
  94
  95 static 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 >> (32 - shift));
 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 static inline __s32 sign_extend32(__u32 value, int index)
 186 {
 187         __u8 shift = 31 - index;
 188         return (__s32)(value << shift) >> shift;
 189 }
 190
 191 static inline unsigned fls_long(unsigned long l)
 192 {
 193         if (sizeof(l) == 4)
 194                 return fls(l);
 195         return fls64(l);
 196 }
 197
 198 /**
 199  * __ffs64 - find first set bit in a 64 bit word
 200  * @word: The 64 bit word
 201  *
 202  * On 64 bit arches this is a synomyn for __ffs
 203  * The result is not defined if no bits are set, so check that @word
 204  * is non-zero before calling this.
 205  */
 206 static inline unsigned long __ffs64(u64 word)
 207 {
 208 #if BITS_PER_LONG == 32
 209         if (((u32)word) == 0UL)
 210                 return __ffs((u32)(word >> 32)) + 32;
 211 #elif BITS_PER_LONG != 64
 212 #error BITS_PER_LONG not 32 or 64
 213 #endif
 214         return __ffs((unsigned long)word);
 215 }
 216
 217 #ifdef __KERNEL__
 218
 219 #ifndef set_mask_bits
 220 #define set_mask_bits(ptr, _mask, _bits)        \
 221 ({                                                              \
 222         const typeof(*ptr) mask = (_mask), bits = (_bits);      \
 223         typeof(*ptr) old, new;                                  \
 224                                                                 \
 225         do {                                                    \
 226                 old = ACCESS_ONCE(*ptr);                        \
 227                 new = (old & ~mask) | bits;                     \
 228         } while (cmpxchg(ptr, old, new) != old);                \
 229                                                                 \
 230         new;                                                    \
 231 })
 232 #endif
 233
 234 #ifndef find_last_bit
 235 /**
 236  * find_last_bit - find the last set bit in a memory region
 237  * @addr: The address to start the search at
 238  * @size: The maximum size to search
 239  *
 240  * Returns the bit number of the first set bit, or size.
 241  */
 242 extern unsigned long find_last_bit(const unsigned long *addr,
 243                                    unsigned long size);
 244 #endif
 245
 246 #endif /* __KERNEL__ */
 247 #endif