#ifndef _LINUX_BITOPS_H #define _LINUX_BITOPS_H #include <asm/types.h> /* * ffs: find first bit set. This is defined the same way as * the libc and compiler builtin ffs routines, therefore * differs in spirit from the above ffz (man ffs). */ static inline int generic_ffs(int x) { int r = 1; if (!x) return 0; if (!(x & 0xffff)) { x >>= 16; r += 16; } if (!(x & 0xff)) { x >>= 8; r += 8; } if (!(x & 0xf)) { x >>= 4; r += 4; } if (!(x & 3)) { x >>= 2; r += 2; } if (!(x & 1)) { x >>= 1; r += 1; } return r; } /* * fls: find last bit set. */ static __inline__ int generic_fls(int x) { int r = 32; if (!x) return 0; if (!(x & 0xffff0000u)) { x <<= 16; r -= 16; } if (!(x & 0xff000000u)) { x <<= 8; r -= 8; } if (!(x & 0xf0000000u)) { x <<= 4; r -= 4; } if (!(x & 0xc0000000u)) { x <<= 2; r -= 2; } if (!(x & 0x80000000u)) { x <<= 1; r -= 1; } return r; } /* * Include this here because some architectures need generic_ffs/fls in * scope */ #include <asm/bitops.h> 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... */ } /* * hweightN: returns the hamming weight (i.e. the number * of bits set) of a N-bit word */ static inline unsigned int generic_hweight32(unsigned int w) { unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555); res = (res & 0x33333333) + ((res >> 2) & 0x33333333); res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F); res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF); return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF); } static inline unsigned int generic_hweight16(unsigned int w) { unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555); res = (res & 0x3333) + ((res >> 2) & 0x3333); res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F); return (res & 0x00FF) + ((res >> 8) & 0x00FF); } static inline unsigned int generic_hweight8(unsigned int w) { unsigned int res = (w & 0x55) + ((w >> 1) & 0x55); res = (res & 0x33) + ((res >> 2) & 0x33); return (res & 0x0F) + ((res >> 4) & 0x0F); } static inline unsigned long generic_hweight64(__u64 w) { #if BITS_PER_LONG < 64 return generic_hweight32((unsigned int)(w >> 32)) + generic_hweight32((unsigned int)w); #else u64 res; res = (w & 0x5555555555555555ul) + ((w >> 1) & 0x5555555555555555ul); res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul); res = (res & 0x0F0F0F0F0F0F0F0Ful) + ((res >> 4) & 0x0F0F0F0F0F0F0F0Ful); res = (res & 0x00FF00FF00FF00FFul) + ((res >> 8) & 0x00FF00FF00FF00FFul); res = (res & 0x0000FFFF0000FFFFul) + ((res >> 16) & 0x0000FFFF0000FFFFul); return (res & 0x00000000FFFFFFFFul) + ((res >> 32) & 0x00000000FFFFFFFFul); #endif } static inline unsigned long hweight_long(unsigned long w) { return sizeof(w) == 4 ? generic_hweight32(w) : generic_hweight64(w); } /* * 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) | (word >> (32 - shift)); } /* * 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) | (word << (32 - shift)); } #endif