Re: [PATCH v9 08/21] ARM64 / ACPI: Introduce PCI stub functions for ACPI

[Hanjun Guo]

On 2015å03æ09æ 23:01, Liviu Dudau wrote:
> On Wed, Feb 25, 2015 at 08:39:48AM +0000, Hanjun Guo wrote:
> > CONFIG_ACPI depends CONFIG_PCI on x86 and ia64, in ARM64 server
> > world we will have PCIe in most cases, but some of them may not,
> > make CONFIG_ACPI depend CONFIG_PCI on ARM64 will satisfy both.
> >
> > With that case, we need some arch dependent PCI functions to
> > access the config space before the PCI root bridge is created, and
> > pci_acpi_scan_root() to create the PCI root bus. So introduce
> > some stub function here to make ACPI core compile and revisit
> > them later when implemented on ARM64.
> >
> > CC: Liviu Dudau <Liviu.Dudau@xxxxxxx>
> > CC: Catalin Marinas <catalin.marinas@xxxxxxx>
> > CC: Will Deacon <will.deacon@xxxxxxx>
> > Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
> > Tested-by: Yijing Wang <wangyijing@xxxxxxxxxx>
> > Tested-by: Mark Langsdorf <mlangsdo@xxxxxxxxxx>
> > Tested-by: Jon Masters <jcm@xxxxxxxxxx>
> > Tested-by: Timur Tabi <timur@xxxxxxxxxxxxxx>
> > Tested-by: Robert Richter <rrichter@xxxxxxxxxx>
> > Acked-by: Robert Richter <rrichter@xxxxxxxxxx>
> > Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> > ---
> >   arch/arm64/include/asm/pci.h |  6 ++++++
> >   arch/arm64/kernel/pci.c      | 25 +++++++++++++++++++++++++
> >   2 files changed, 31 insertions(+)
> >
> > diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h
> > index 872ba93..fded096 100644
> > --- a/arch/arm64/include/asm/pci.h
> > +++ b/arch/arm64/include/asm/pci.h
> > @@ -24,6 +24,12 @@
> >    */
> >   #define PCI_DMA_BUS_IS_PHYS	(0)
>
> Hanjun,

Hi Liviu,

> > +static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
> > +{
> > +	/* no legacy IRQ on arm64 */
> > +	return -ENODEV;
> > +}
> > +
>
> Could you explain to me what situation you encountered where you needed
> to define this? I'm trying to figure out when this would be needed and the
> only thing I can come up with would be for drivers/pnp/resource.c, but that
> is guarded by #ifdef CONFIG_PCI, which would mean that you should move this
> a bit further down in the file,

Agreed, will move it to #ifdef CONFIG_PCI .. #endif.

> but also contradicts the last comment on
> this patch (i.e. PCI on ACPI is not really implemented, so presumably
> CONFIG_PCI is not enabled?)

CONFIG_ACPI depends on CONFIG_PCI in the Kconfig, so CONFIG_PCI will be
enabled even PCI on ACPI is not really implemented now, did I
understand your question correctly?

Thanks
Hanjun
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