unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, unsigned long offset) { const unsigned long *p = addr + BITOP_WORD(offset); unsigned long result = offset & ~(BITS_PER_LONG-1); unsigned long tmp; if (offset >= size) { return size; } size -= result; offset %= BITS_PER_LONG; if (offset) { tmp = *(p++); tmp |= ~0UL >> (BITS_PER_LONG - offset); if (size < BITS_PER_LONG) { goto found_first; } if (~tmp) { goto found_middle; } size -= BITS_PER_LONG; result += BITS_PER_LONG; } while (size & ~(BITS_PER_LONG-1)) { if (~(tmp = *(p++))) { goto found_middle; } result += BITS_PER_LONG; size -= BITS_PER_LONG; } if (!size) { return result; } tmp = *p; found_first: tmp |= ~0UL << size; if (tmp == ~0UL) { /* Are any bits zero? */ return result + size; /* Nope. */ } found_middle: return result + ffz(tmp); }