#include <linux/bitops.h> #include <linux/module.h> /** * find_next_bit - find the first 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 */ int find_next_bit(const unsigned long *addr, int size, int offset) { const unsigned long *p = addr + (offset >> 5); int set = 0, bit = offset & 31, res; if (bit) { /* * Look for nonzero in the first 32 bits: */ __asm__("bsfl %1,%0\n\t" "jne 1f\n\t" "movl $32, %0\n" "1:" : "=r" (set) : "r" (*p >> bit)); if (set < (32 - bit)) return set + offset; set = 32 - bit; p++; } /* * No set bit yet, search remaining full words for a bit */ res = find_first_bit (p, size - 32 * (p - addr)); return (offset + set + res); } EXPORT_SYMBOL(find_next_bit); /** * find_next_zero_bit - find the first zero 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 */ int find_next_zero_bit(const unsigned long *addr, int size, int offset) { const unsigned long *p = addr + (offset >> 5); int set = 0, bit = offset & 31, res; if (bit) { /* * Look for zero in the first 32 bits. */ __asm__("bsfl %1,%0\n\t" "jne 1f\n\t" "movl $32, %0\n" "1:" : "=r" (set) : "r" (~(*p >> bit))); if (set < (32 - bit)) return set + offset; set = 32 - bit; p++; } /* * No zero yet, search remaining full bytes for a zero */ res = find_first_zero_bit(p, size - 32 * (p - addr)); return (offset + set + res); } EXPORT_SYMBOL(find_next_zero_bit);