diff options
Diffstat (limited to 'include/linux/bitops.h')
| -rw-r--r-- | include/linux/bitops.h | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h new file mode 100644 index 000000000000..9b9711ea267a --- /dev/null +++ b/include/linux/bitops.h @@ -0,0 +1,225 @@ +#ifndef _LINUX_BITOPS_H +#define _LINUX_BITOPS_H +#include <asm/types.h> +#include <linux/bits.h> + +#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE) +#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(long)) + +extern unsigned int __sw_hweight8(unsigned int w); +extern unsigned int __sw_hweight16(unsigned int w); +extern unsigned int __sw_hweight32(unsigned int w); +extern unsigned long __sw_hweight64(__u64 w); + +/* + * Include this here because some architectures need generic_ffs/fls in + * scope + */ +#include <asm/bitops.h> + +#define for_each_set_bit(bit, addr, size) \ + for ((bit) = find_first_bit((addr), (size)); \ + (bit) < (size); \ + (bit) = find_next_bit((addr), (size), (bit) + 1)) + +/* same as for_each_set_bit() but use bit as value to start with */ +#define for_each_set_bit_from(bit, addr, size) \ + for ((bit) = find_next_bit((addr), (size), (bit)); \ + (bit) < (size); \ + (bit) = find_next_bit((addr), (size), (bit) + 1)) + +#define for_each_clear_bit(bit, addr, size) \ + for ((bit) = find_first_zero_bit((addr), (size)); \ + (bit) < (size); \ + (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) + +/* same as for_each_clear_bit() but use bit as value to start with */ +#define for_each_clear_bit_from(bit, addr, size) \ + for ((bit) = find_next_zero_bit((addr), (size), (bit)); \ + (bit) < (size); \ + (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) + +static inline int get_bitmask_order(unsigned int count) +{ + int order; + + order = fls(count); + return order; /* We could be slightly more clever with -1 here... */ +} + +static inline int get_count_order(unsigned int count) +{ + int order; + + order = fls(count) - 1; + if (count & (count - 1)) + order++; + return order; +} + +static __always_inline unsigned long hweight_long(unsigned long w) +{ + return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w); +} + +/** + * rol64 - rotate a 64-bit value left + * @word: value to rotate + * @shift: bits to roll + */ +static inline __u64 rol64(__u64 word, unsigned int shift) +{ + return (word << (shift & 63)) | (word >> ((-shift) & 63)); +} + +/** + * ror64 - rotate a 64-bit value right + * @word: value to rotate + * @shift: bits to roll + */ +static inline __u64 ror64(__u64 word, unsigned int shift) +{ + return (word >> (shift & 63)) | (word << ((-shift) & 63)); +} + +/** + * rol32 - rotate a 32-bit value left + * @word: value to rotate + * @shift: bits to roll + */ +static inline __u32 rol32(__u32 word, unsigned int shift) +{ + return (word << (shift & 31)) | (word >> ((-shift) & 31)); +} + +/** + * ror32 - rotate a 32-bit value right + * @word: value to rotate + * @shift: bits to roll + */ +static inline __u32 ror32(__u32 word, unsigned int shift) +{ + return (word >> (shift & 31)) | (word << ((-shift) & 31)); +} + +/** + * rol16 - rotate a 16-bit value left + * @word: value to rotate + * @shift: bits to roll + */ +static inline __u16 rol16(__u16 word, unsigned int shift) +{ + return (word << (shift & 15)) | (word >> ((-shift) & 15)); +} + +/** + * ror16 - rotate a 16-bit value right + * @word: value to rotate + * @shift: bits to roll + */ +static inline __u16 ror16(__u16 word, unsigned int shift) +{ + return (word >> (shift & 15)) | (word << ((-shift) & 15)); +} + +/** + * rol8 - rotate an 8-bit value left + * @word: value to rotate + * @shift: bits to roll + */ +static inline __u8 rol8(__u8 word, unsigned int shift) +{ + return (word << (shift & 7)) | (word >> ((-shift) & 7)); +} + +/** + * ror8 - rotate an 8-bit value right + * @word: value to rotate + * @shift: bits to roll + */ +static inline __u8 ror8(__u8 word, unsigned int shift) +{ + return (word >> (shift & 7)) | (word << ((-shift) & 7)); +} + +/** + * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit + * @value: value to sign extend + * @index: 0 based bit index (0<=index<32) to sign bit + * + * This is safe to use for 16- and 8-bit types as well. + */ +static inline __s32 sign_extend32(__u32 value, int index) +{ + __u8 shift = 31 - index; + return (__s32)(value << shift) >> shift; +} + +/** + * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit + * @value: value to sign extend + * @index: 0 based bit index (0<=index<64) to sign bit + */ +static inline __s64 sign_extend64(__u64 value, int index) +{ + __u8 shift = 63 - index; + return (__s64)(value << shift) >> shift; +} + +static inline unsigned fls_long(unsigned long l) +{ + if (sizeof(l) == 4) + return fls(l); + return fls64(l); +} + +/** + * __ffs64 - find first set bit in a 64 bit word + * @word: The 64 bit word + * + * On 64 bit arches this is a synomyn for __ffs + * The result is not defined if no bits are set, so check that @word + * is non-zero before calling this. + */ +static inline unsigned long __ffs64(u64 word) +{ +#if BITS_PER_LONG == 32 + if (((u32)word) == 0UL) + return __ffs((u32)(word >> 32)) + 32; +#elif BITS_PER_LONG != 64 +#error BITS_PER_LONG not 32 or 64 +#endif + return __ffs((unsigned long)word); +} + +#ifdef __KERNEL__ + +#ifndef set_mask_bits +#define set_mask_bits(ptr, _mask, _bits) \ +({ \ + const typeof(*ptr) mask = (_mask), bits = (_bits); \ + typeof(*ptr) old, new; \ + \ + do { \ + old = ACCESS_ONCE(*ptr); \ + new = (old & ~mask) | bits; \ + } while (cmpxchg(ptr, old, new) != old); \ + \ + new; \ +}) +#endif + +#ifndef find_last_bit +/** + * find_last_bit - find the last set bit in a memory region + * @addr: The address to start the search at + * @size: The number of bits to search + * + * Returns the bit number of the last set bit, or size. + */ +extern unsigned long find_last_bit(const unsigned long *addr, + unsigned long size); +#endif + +#endif /* __KERNEL__ */ +#endif |