Re: [PATCH RFC] UIO: Pass information about ioports to userspace

Greg KH
2008-11-24T01:45:42Z

On Sun, Nov 23, 2008 at 01:14:20PM +0100, Hans J. Koch wrote:
> Devices sometimes have memory where all or parts of it can not be mapped to
> userspace. But it might still be possible to access this memory from
> userspace by other means. An example are PCI cards that advertise not only
> mappable memory but also ioport ranges. On x86 architectures, these can be
> accessed with ioperm, iopl, inb, outb, and friends. Mike Frysinger (CCed)
> reported a similar problem on Blackfin arch where it doesn't seem to be easy
> to mmap non-cached memory but it can still be accessed from userspace.
>
> This patch allows kernel drivers to pass information about such ports to
> userspace. Similar to the existing mem[] array, it adds a port[] array to
> struct uio_info. Each port range is described by start, size, and porttype.

Looks good, but I think you also forgot the documentation update :)

thanks,

greg k-h