#ifndef _LINUX_BITOPS_H #define _LINUX_BITOPS_H #include #include #ifdef __KERNEL__ #define BIT(nr) (1 << (nr)) #define BIT_MASK(nr) (1 << ((nr) % BITS_PER_LONG)) #define BIT_WORD(nr) ((nr) / BITS_PER_LONG) #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_LONG) #define BITS_PER_BYTE 8 #endif /* * Include this here because some architectures need generic_ffs/fls in * scope */ /** * find_first_zero_bit - find the first zero bit in a memory region * @addr: The address to start the search at * @size: The maximum size to search * * Returns the bit number of the first zero bit, not the number of the byte * containing a bit. */ #define find_first_zero_bit(addr, size) find_next_zero_bit((addr), (size), 0) /** * find_next_zero_bit - find the first zero bit in a memory region * @addr: The address to base the search on * @offset: The bit number to start searching at * @size: The maximum size to search */ int find_next_zero_bit(const unsigned long *addr, int size, int offset); /** * __ffs - find first bit in word. * @word: The word to search * * Undefined if no bit exists, so code should check against 0 first. */ static inline unsigned long __ffs(unsigned long word) { int num = 0; #if BITS_PER_LONG == 64 if ((word & 0xffffffff) == 0) { num += 32; word >>= 32; } #endif if ((word & 0xffff) == 0) { num += 16; word >>= 16; } if ((word & 0xff) == 0) { num += 8; word >>= 8; } if ((word & 0xf) == 0) { num += 4; word >>= 4; } if ((word & 0x3) == 0) { num += 2; word >>= 2; } if ((word & 0x1) == 0) num += 1; return num; } /** * find_first_bit - find the first set bit in a memory region * @addr: The address to start the search at * @size: The maximum size to search * * Returns the bit number of the first set bit, not the number of the byte * containing a bit. */ static inline unsigned find_first_bit(const unsigned long *addr, unsigned size) { unsigned x = 0; while (x < size) { unsigned long val = *addr++; if (val) return __ffs(val) + x; x += (sizeof(*addr)<<3); } return x; } /** * find_next_bit - find the next set bit in a memory region * @addr: The address to base the search on * @offset: The bitnumber to start searching at * @size: The maximum size to search */ /* * ffz - find first zero in word. * @word: The word to search * * Undefined if no zero exists, so code should check against ~0UL first. */ #define ffz(x) __ffs(~(x)) /** * ffs - find first bit set * @x: the word to search * * 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 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 (most-significant) bit set * @x: the word to search * * This is defined the same way as ffs. * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. */ static inline int 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; } static inline int fls64(__u64 x) { __u32 h = (__u32) (x >> 32); if (h) return fls(h) + 32; return fls((int)x); } #define for_each_bit(bit, addr, size) \ for ((bit) = find_first_bit((addr), (size)); \ (bit) < (size); \ (bit) = find_next_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; } /** * 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)); } static inline unsigned fls_long(unsigned long l) { if (sizeof(l) == 4) return fls(l); return fls64(l); } /* * hweightN: returns the hamming weight (i.e. the number * of bits set) of a N-bit word */ static inline unsigned long hweight32(unsigned long 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 long hweight64(__u64 w) { #if BITS_PER_LONG < 64 return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w); #else u64 res; res = (w & 0x5555555555555555U) + ((w >> 1) & 0x5555555555555555U); res = (res & 0x3333333333333333U) + ((res >> 2) & 0x3333333333333333U); res = (res & 0x0F0F0F0F0F0F0F0FU) + ((res >> 4) & 0x0F0F0F0F0F0F0F0FU); res = (res & 0x00FF00FF00FF00FFU) + ((res >> 8) & 0x00FF00FF00FF00FFU); res = (res & 0x0000FFFF0000FFFFU) + ((res >> 16) & 0x0000FFFF0000FFFFU); return (res & 0x00000000FFFFFFFFU) + ((res >> 32) & 0x00000000FFFFFFFFU); #endif } static inline unsigned long hweight_long(unsigned long w) { return sizeof(w) == 4 ? hweight32(w) : hweight64(w); } #endif