Re: The IO problem on multiple PCI busses

Oliver Xymoron
2001-03-06T23:02:47Z

On Fri, 2 Mar 2001, David S. Miller wrote:

> > On PPC, we don't have an "IO" space neither, all we have is a range of
> > memory addresses that will cause IO cycles to happen on the PCI bus.
>
> This is precisely what the "next MMAP is XXX space" ioctl I've
> suggested is for. I think I've addressed this concern in my
> proposal already. Look:
>
> fd = open("/proc/bus/pci/${BUS}/${DEV}", ...);
> if (fd < 0)
> return -errno;
> err = ioctl(fd, PCI_MMAP_IO, 0);

I know I'm coming in on this late, but wouldn't it be cleaner to have
separate files for memory and io cycles, eg ${BUS}/${DEV}.(io|mem)?
They're logically different so they might as well be embodied separately.

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