/* The mapping is cacheline aligned, so there's no information in the bottom few bits of the address. We're looking for 10 bits (4MB / 4k), so let's drop the bottom 8 bits and use bits 8-17.  */
static int get_offset(struct address_space *mapping)
/* The mapping is cacheline aligned, so there's no information in the bottom few bits of the address. We're looking for 10 bits (4MB / 4k), so let's drop the bottom 8 bits and use bits 8-17.  */
static int get_offset(struct address_space *mapping)
{
	int offset = (unsigned long) mapping << (PAGE_SHIFT - 8);
	return offset & 0x3FF000;
}