[PATCH 2/2] arm64: dts: juno: Describe the full GICv2m region

Robin Murphy robin.murphy at arm.com
Mon Feb 12 10:22:55 PST 2018


On 12/02/18 18:17, Sudeep Holla wrote:
> 
> 
> On 07/02/18 14:32, Marc Zyngier wrote:
>> From: Robin Murphy <robin.murphy at arm.com>
>>
>> Juno's GICv2m implementation consists of four frames providing 32
>> interrupts each. Since it is possible to plug in enough PCIe endpoints
>> to consume more than 32 MSIs, and the driver already has a bodge to
>> handle multiple frames, let's expose the other three as well.
>>
> 
> Change on it own looks good. So if you want to merge via your tree:
> 
> Acked-by: Sudeep Holla <sudeep.holla at arm.com>
> 
> Let me know if you decide not to take it via your tree and you want me
> to send it to arm-soc.
> 
> On the side note I just noticed the Juno TRM[1] has 64k for each of
> these MSI frames(page 3-24 section 3.3.5 Application memory map summary)
> 
> I am not sure if TRM is wrong. This patch is just copying the 4k size
> from frame 0 which got added with initial Juno DTS.

Depends what your point of view is: The address map allocates 64KB worth 
of space for the device, but the device itself only decodes the first 
4KB of that. My view is that the DT is describing the actual devices, 
not the interconnect routing between them, so there's really no need to 
tell consumers to map known-useless empty space.

Robin.



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