RE: Right Semantics for ioremap, remap_page_range

Martin Frey (frey@scs.ch)
Wed, 18 Jul 2001 10:34:17 -0400


Hi,

>What I now do is ioremap_nocache and do writel's, readl's on it.
>For the mmap stuff, I just call remap_page_range with the physical
>address that I get from pci_resource_start(). Is that alright?
>I mean it's working for me now, thats most important :)
>
That does not work on an Alpha. The Alpha (at leat my DS20 and
ES40) is happy with result of ioremap feeded into remap_page_range,
or the real CPU physical address (pci_resource_start + 0x80000000000
on Tsunami chipset).
There is an io_remap_page_range, which does a
remap_page_range(virt_to_phys(ioremap(pci_resource_start()))) on
Alpha, but this does not work either.

There must be a portable way to export PCI memory space to user space,
since e.g. the X servers are using that.

Any hints?

Thanks & regards,

Martin
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/