#ifndef _I386_BITOPS_H #define _I386_BITOPS_H #include #include /* * Copyright 1992, Linus Torvalds. */ /* * These have to be done with inline assembly: that way the bit-setting * is guaranteed to be atomic. All bit operations return 0 if the bit * was cleared before the operation and != 0 if it was not. * * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). */ /* * Function prototypes to keep gcc -Wall happy */ #include #define smp_mb__after_clear_bit() unsigned int hweight32(unsigned int w); /** * find_first_bit - find the first set bit in a memory region * @addr: The address to start the search at * @size: The maximum number of bits to search * * Returns the bit number of the first set bit. * If no bits are set, returns @size. */ extern unsigned long find_first_bit(const unsigned long *addr, unsigned long size); /** * __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; } /** * __fls - find last (most-significant) set bit in a long word * @word: the word to search * * Undefined if no set bit exists, so code should check against 0 first. */ static inline unsigned long __fls(unsigned long word) { int num = BITS_PER_LONG - 1; #if BITS_PER_LONG == 64 if (!(word & (~0ul << 32))) { num -= 32; word <<= 32; } #endif if (!(word & (~0ul << (BITS_PER_LONG-16)))) { num -= 16; word <<= 16; } if (!(word & (~0ul << (BITS_PER_LONG-8)))) { num -= 8; word <<= 8; } if (!(word & (~0ul << (BITS_PER_LONG-4)))) { num -= 4; word <<= 4; } if (!(word & (~0ul << (BITS_PER_LONG-2)))) { num -= 2; word <<= 2; } if (!(word & (~0ul << (BITS_PER_LONG-1)))) num -= 1; return num; } /* 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)) /** * 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; } #define BIT(nr) (1UL << (nr)) #define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) #define BIT_WORD(nr) ((nr) / BITS_PER_LONG) #define BITS_PER_BYTE 8 #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) /* * Create a contiguous bitmask starting at bit position @l and ending at * position @h. For example * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000. */ #define GENMASK(h, l) \ (((~0UL) << (l)) & (~0UL >> (BITS_PER_LONG - 1 - (h)))) #define GENMASK_ULL(h, l) \ (((~0ULL) << (l)) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (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)) 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 inline unsigned fls_long(unsigned long l) { return fls(l); } static inline unsigned long hweight_long(unsigned long w) { return hweight32(w); } #endif /* _I386_BITOPS_H */