Re: pci-sysfs resource mmap broken

From: Benjamin Herrenschmidt
Date: Tue Apr 26 2005 - 01:12:36 EST

On Tue, 2005-04-26 at 15:33 +1000, Benjamin Herrenschmidt wrote:

> In a similar vein, the "resource" is exposing directly to userland the
> content of "struct resource". This doesn't mean anything. The kernel is
> internally playing all sort of offset tricks on these values, so they
> can't be used for anything useful, either via /dev/mem, or for io port
> accesses, or whatever.
> Shouldn't we expose the BAR values & size rather here ? That is,
> reconsitutes non-offset'd resources, possibly with arch help, or just
> reading BAR to get base, and apply resource size & flags ?


Ok, after a bit more thinking, I think I'll go that way for now, please
let me know if you think I'm wrong:

rename "resource" to "resources" and make it contain a start address
that matches the BAR value, that is something that has at least some
sort of meaning in userland and can be passed to pci_mmap_page_range().
To do that "translation", I'll read the BAR value, and use it as start,
then use the resource size & flags.

The name change will also allow userland to "detect" the fixed


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