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

[Marc Zyngier]

On 11/10/15 22:01, 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.
> 
> 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.

FWIW, I've rebased this on top of -rc5, with a couple of fixes to the
first patch (fixing missed of_node accessor conversions), but the series
is otherwise unchanged:

git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git
irq/irq-domain-fwnode-v2

I'd very much appreciate some feedback from the ACPI folks as well
(patch 8 is the potential point of contention, as it creates fwnodes
ex-nihilo).

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...
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