Re: The IO problem on multiple PCI busses

Benjamin Herrenschmidt
2001-03-03T17:29:00Z

>I/O is not supposed to be fast, that's what MMIO is for. :) Just do
>
>void outb (u8 val, u16 addr)
>{
> void *addr = ioremap (ISA_IO_BASE + addr);
> if (addr) {
> writeb (val, addr);
> iounmap (addr);
> }
>}
>
>You can map and unmap for each call :) Ugly and slow, but hey, it's
>I/O...

Well, that would really suck ;) And I don't think it would be necessary
as we can probably limit each IO bus to 64k without much problem, and
have them permanently ioremap'ed.

Ben.