bitops.h 5.1 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217
  1. #ifndef _LINUX_BITOPS_H
  2. #define _LINUX_BITOPS_H
  3. #include <asm/types.h>
  4. #ifdef __KERNEL__
  5. #define BIT(nr) (1UL << (nr))
  6. #define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
  7. #define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
  8. #define BITS_PER_BYTE 8
  9. #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
  10. #endif
  11. extern unsigned int __sw_hweight8(unsigned int w);
  12. extern unsigned int __sw_hweight16(unsigned int w);
  13. extern unsigned int __sw_hweight32(unsigned int w);
  14. extern unsigned long __sw_hweight64(__u64 w);
  15. /*
  16. * Include this here because some architectures need generic_ffs/fls in
  17. * scope
  18. */
  19. #include <asm/bitops.h>
  20. #define for_each_set_bit(bit, addr, size) \
  21. for ((bit) = find_first_bit((addr), (size)); \
  22. (bit) < (size); \
  23. (bit) = find_next_bit((addr), (size), (bit) + 1))
  24. /* same as for_each_set_bit() but use bit as value to start with */
  25. #define for_each_set_bit_from(bit, addr, size) \
  26. for ((bit) = find_next_bit((addr), (size), (bit)); \
  27. (bit) < (size); \
  28. (bit) = find_next_bit((addr), (size), (bit) + 1))
  29. #define for_each_clear_bit(bit, addr, size) \
  30. for ((bit) = find_first_zero_bit((addr), (size)); \
  31. (bit) < (size); \
  32. (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
  33. /* same as for_each_clear_bit() but use bit as value to start with */
  34. #define for_each_clear_bit_from(bit, addr, size) \
  35. for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
  36. (bit) < (size); \
  37. (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
  38. static __inline__ int get_bitmask_order(unsigned int count)
  39. {
  40. int order;
  41. order = fls(count);
  42. return order; /* We could be slightly more clever with -1 here... */
  43. }
  44. static __inline__ int get_count_order(unsigned int count)
  45. {
  46. int order;
  47. order = fls(count) - 1;
  48. if (count & (count - 1))
  49. order++;
  50. return order;
  51. }
  52. static inline unsigned long hweight_long(unsigned long w)
  53. {
  54. return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
  55. }
  56. /**
  57. * rol64 - rotate a 64-bit value left
  58. * @word: value to rotate
  59. * @shift: bits to roll
  60. */
  61. static inline __u64 rol64(__u64 word, unsigned int shift)
  62. {
  63. return (word << shift) | (word >> (64 - shift));
  64. }
  65. /**
  66. * ror64 - rotate a 64-bit value right
  67. * @word: value to rotate
  68. * @shift: bits to roll
  69. */
  70. static inline __u64 ror64(__u64 word, unsigned int shift)
  71. {
  72. return (word >> shift) | (word << (64 - shift));
  73. }
  74. /**
  75. * rol32 - rotate a 32-bit value left
  76. * @word: value to rotate
  77. * @shift: bits to roll
  78. */
  79. static inline __u32 rol32(__u32 word, unsigned int shift)
  80. {
  81. return (word << shift) | (word >> (32 - shift));
  82. }
  83. /**
  84. * ror32 - rotate a 32-bit value right
  85. * @word: value to rotate
  86. * @shift: bits to roll
  87. */
  88. static inline __u32 ror32(__u32 word, unsigned int shift)
  89. {
  90. return (word >> shift) | (word << (32 - shift));
  91. }
  92. /**
  93. * rol16 - rotate a 16-bit value left
  94. * @word: value to rotate
  95. * @shift: bits to roll
  96. */
  97. static inline __u16 rol16(__u16 word, unsigned int shift)
  98. {
  99. return (word << shift) | (word >> (16 - shift));
  100. }
  101. /**
  102. * ror16 - rotate a 16-bit value right
  103. * @word: value to rotate
  104. * @shift: bits to roll
  105. */
  106. static inline __u16 ror16(__u16 word, unsigned int shift)
  107. {
  108. return (word >> shift) | (word << (16 - shift));
  109. }
  110. /**
  111. * rol8 - rotate an 8-bit value left
  112. * @word: value to rotate
  113. * @shift: bits to roll
  114. */
  115. static inline __u8 rol8(__u8 word, unsigned int shift)
  116. {
  117. return (word << shift) | (word >> (8 - shift));
  118. }
  119. /**
  120. * ror8 - rotate an 8-bit value right
  121. * @word: value to rotate
  122. * @shift: bits to roll
  123. */
  124. static inline __u8 ror8(__u8 word, unsigned int shift)
  125. {
  126. return (word >> shift) | (word << (8 - shift));
  127. }
  128. /**
  129. * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
  130. * @value: value to sign extend
  131. * @index: 0 based bit index (0<=index<32) to sign bit
  132. */
  133. static inline __s32 sign_extend32(__u32 value, int index)
  134. {
  135. __u8 shift = 31 - index;
  136. return (__s32)(value << shift) >> shift;
  137. }
  138. static inline unsigned fls_long(unsigned long l)
  139. {
  140. if (sizeof(l) == 4)
  141. return fls(l);
  142. return fls64(l);
  143. }
  144. /**
  145. * __ffs64 - find first set bit in a 64 bit word
  146. * @word: The 64 bit word
  147. *
  148. * On 64 bit arches this is a synomyn for __ffs
  149. * The result is not defined if no bits are set, so check that @word
  150. * is non-zero before calling this.
  151. */
  152. static inline unsigned long __ffs64(u64 word)
  153. {
  154. #if BITS_PER_LONG == 32
  155. if (((u32)word) == 0UL)
  156. return __ffs((u32)(word >> 32)) + 32;
  157. #elif BITS_PER_LONG != 64
  158. #error BITS_PER_LONG not 32 or 64
  159. #endif
  160. return __ffs((unsigned long)word);
  161. }
  162. #ifdef __KERNEL__
  163. #ifndef set_mask_bits
  164. #define set_mask_bits(ptr, _mask, _bits) \
  165. ({ \
  166. const typeof(*ptr) mask = (_mask), bits = (_bits); \
  167. typeof(*ptr) old, new; \
  168. \
  169. do { \
  170. old = ACCESS_ONCE(*ptr); \
  171. new = (old & ~mask) | bits; \
  172. } while (cmpxchg(ptr, old, new) != old); \
  173. \
  174. new; \
  175. })
  176. #endif
  177. #ifndef find_last_bit
  178. /**
  179. * find_last_bit - find the last set bit in a memory region
  180. * @addr: The address to start the search at
  181. * @size: The maximum size to search
  182. *
  183. * Returns the bit number of the first set bit, or size.
  184. */
  185. extern unsigned long find_last_bit(const unsigned long *addr,
  186. unsigned long size);
  187. #endif
  188. #endif /* __KERNEL__ */
  189. #endif