Re: [PATCH 00/16] Divorcing irqdomain and device_node

[Hanjun Guo]

On 10/12/2015 05:01 AM, Thomas Gleixner wrote:
> On Tue, 6 Oct 2015, Marc Zyngier wrote:
> > [This patch series used to be called "Making the generic ACPI GSI
> > layer irqdomain aware", but as I've radically changed my approach to
> > this problem, I've decided to reset the counters...]
> >
> > The irqdomain code is not entierely ACPI friendly, as it has some
> > built-in knowledge of the device-tree. Nothing too harmful, but enough
> > to scare the ARM ACPI developpers which end up with their own version
> > of the square wheel. And some of the ramifications actually run deeper
> > than initially expected.
> >
> > This series adapts the irqdomain code to use 'struct fwnode_handle'
> > instead of 'struct device_node' as the identifier for a domain
> > (compatibility interfaces are of course added). It also introduces a
> > generic IRQ specifier that firmware interfaces (DT or ACPI) can
> > directly use to configure interrupts, and allow the ACPI GSI code to
> > be plugged into this.
> >
> > As examples, we convert the ARM GIC ACPI support to use irqdomains as
> > originally intended, and rework the MSI code to also move away from
> > using device nodes when using irqdomains.
> >
> > Overall, this gives us a way to use irqdomains on both DT and ACPI
> > enabled platforms, having very little changes made to the actual
> > drivers (other than the probing infrastructure). Because we keep the
> > flow of information between the various layers identical between ACPI
> > and DT, we immediately benefit from the existing infrastructure.
> >
> > This has been test-booted on Juno, is based on 4.3-rc4, and available at:
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git irq/irq-domain-fwnode-v1
> >
> > Marc Zyngier (16):
> >    irqdomain: Use an accessor for the of_node field
> >    irqdomain: Convert irqdomain->of_node to fwnode
> >    irqdomain: Allow irq domain lookup by fwnode
> >    irqdomain: Introduce a firmware-specific IRQ specifier structure
> >    irqchip: Convert all alloc/xlate users from of_node to fwnode
> >    irqdomain: Introduce irq_create_fwspec_mapping
> >    irqdomain: Introduce irq_domain_create_{linear,tree}
> >    irqdomain: Add a fwnode_handle allocator
> >    acpi/gsi: Always perform an irq domain lookup
> >    acpi/gsi: Add acpi_set_irq_model to initialize the GSI layer
> >    irqchip/gic: Get rid of gic_init_bases()
> >    irqchip/gic: Switch ACPI support to stacked domains
> >    irqchip/gic: Kill the xlate method
> >    acpi/gsi: Cleanup acpi_register_gsi
> >    irqdomain: Introduce irq_domain_create_hierarchy
> >    irqdomain/msi: Use fwnode instead of of_node
>
> I really like this one way better than the previous attempts and I
> couldn't find any real issue when going through them with a fine comb.

Fully agree, this version removes the dependency on DT for ACPI.

> I'd like to get that into 4.4, so I have to ask for the opinion of
> ACPI folks. Having an ack on those patches would be nice.

I'm reviewing this patch set, and will have a test today.

Thanks
Hanjun
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