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

From: Hanjun Guo
Date: Sun Oct 11 2015 - 22:41:48 EST


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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