Dear Arnd Bergmann,
On Wed, 13 Feb 2013 10:37:02 +0000, Arnd Bergmann wrote:
> Yes, of course. And the ranges property tells you how to turn the
> first address space into the second address space. So the above
> property defines that the PCI bus I/O space range from 0 to 0x10000
> gets converted into the host MMIO range 0xc0000000 to 0xc0010000 on
> the host, and the PCI bus memory space range from 0 to 0x08000000
> gets converted to the host MMIO range 0xc1000000 to 0xc9000000.
>
> The output of your of_pci_process_ranges() function is the host MMIO
> range, not the range in the bus address space, so it has to be
> IORESOURCE_MEM.
I am sorry, but I don't get how this can work. My code currently relies
on the DT encoding one I/O resource and one MEM resource to find which
is one to use.
Right now, in the ranges property of my DT, I have:
0x81000000 0 0 0xc0000000 0 0x00010000 /* downstream I/O */
0x82000000 0 0 0xc1000000 0 0x08000000>; /* non-prefetchable memory */
And the code parsing this does:
/* Get the I/O and memory ranges from DT */
while ((range = of_pci_process_ranges(np, &res, range)) != NULL) {
if (resource_type(&res) == IORESOURCE_IO) {
memcpy(&pcie->io, &res, sizeof(res));
memcpy(&pcie->realio, &res, sizeof(res));
pcie->io.name = "I/O";
pcie->realio.start &= 0xFFFFF;
pcie->realio.end &= 0xFFFFF;
}
if (resource_type(&res) == IORESOURCE_MEM) {
memcpy(&pcie->mem, &res, sizeof(res));
pcie->mem.name = "MEM";
}
}
As you can see, it relies on one of the two ranges being for I/O
(address starts with 0x81), and another range being for MEM (address
starts with 0x82).
If I make both ranges start with 0x82, how can my code differentiate
between the range used for I/O and the range used for MEM?
Thanks,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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