page_to_phys
info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));
char new_bit_17 = page_to_phys(page) >> 17;
if (page_to_phys(page) & (1 << 17))
sg_dma_address(sg) = page_to_phys(sg_page(sg));