HelenOS sources

PORTS_PER_PAGE     70 kernel/arch/ia64/src/ddi/ddi.c 	uintptr_t iopage = ioaddr / PORTS_PER_PAGE;
PORTS_PER_PAGE     71 kernel/arch/ia64/src/ddi/ddi.c 	size = ALIGN_UP(size + ioaddr - 4 * iopage, PORTS_PER_PAGE);
PORTS_PER_PAGE     92 kernel/arch/ia64/src/ddi/ddi.c 	uintptr_t iopage = ioaddr / PORTS_PER_PAGE;
PORTS_PER_PAGE     93 kernel/arch/ia64/src/ddi/ddi.c 	size = ALIGN_UP(size + ioaddr - 4 * iopage, PORTS_PER_PAGE);
HelenOS homepage, sources at GitHub