Re: [PATCH v9 03/12] PCI: Introduce helper functions to deal with PCI I/O ranges.

Catalin Marinas
2014-08-18T21:52:44Z

On Mon, Aug 18, 2014 at 10:34:46PM +0100, Liviu Dudau wrote:
> On Mon, Aug 18, 2014 at 03:26:04PM +0100, Catalin Marinas wrote:
> > On Tue, Aug 12, 2014 at 05:25:16PM +0100, Liviu Dudau wrote:
> > > Some architectures do not have a simple view of the PCI I/O space
> > > and instead use a range of CPU addresses that map to bus addresses.
> > > For some architectures these ranges will be expressed by OF bindings
> > > in a device tree file.
> > >
> > > This patch introduces a pci_register_io_range() helper function with
> > > a generic implementation that can be used by such architectures to
> > > keep track of the I/O ranges described by the PCI bindings. If the
> > > PCI_IOBASE macro is not defined that signals lack of support for PCI
> > > and we return an error.
> > >
> > > In order to retrieve the CPU address associated with an I/O port, a
> > > new helper function pci_pio_to_address() is introduced. This will
> > > search in the list of ranges registered with pci_register_io_range()
> > > and return the CPU address that corresponds to the given port.
> > >
> > > Cc: Grant Likely <grant.likely@linaro.org>
> > > Cc: Rob Herring <robh+dt@kernel.org>
> > > Cc: Arnd Bergmann <arnd@arndb.de>
> > > Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
> > > ---
> > > drivers/of/address.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++
> > > include/linux/of_address.h | 2 +
> > > 2 files changed, 97 insertions(+)
> >
> > Actually, I think we moved too much code into drivers/of/. Is there
> > anything OF specific about this code to live here (apart from
> > OF_BAD_ADDR)? I think driver/pci/ more appropriate?
>
> I have no strong preference for one place vs the other. While this does
> not use any OF specific code, it should be called only from OF enabled
> code. So the relationship is not one of depending on of_* but on being
> dependent on.

In this case it's probably ok to keep them here for the time being.

I wonder whether it would also be useful for ACPI. But I have no idea
how ACPI would fit with the ACPI patches.

--
Catalin