Hi Suravee, On 13/07/15 10:14, Suravee Suthikulpanit wrote: > ACPI core patches for ARM64 are now upstreamed in 4.1. The PCI support > patches for ARM64 ACPI are also in progress. I am sending out this RFC to > introduce ACPI support for GICv2m. This would allow MSI to work when > booting ACPI. > > There are some modifications to the irq_domain and acpi/gsi code. > > Due to a large number of prerequisite patches, I have put together a branch > on GitHub for review and testing: > > https://github.com/ssuthiku/linux.git acpi-pci-msi-rfc2 > > This branch has been tested on AMD Seattle Platform. Any feedback and > comments are appreciated. I've had a look at this, and mostly the init_alloc_info method you introduce. I have a few issues with the concept: - The first thing that annoys me a tiny bit is that the bottom irqchip (the GIC in your case) is allocating memory on the behalf of all the others in the stack, while the actual users are sitting on top. It feels really backward. Why can't this allocation be performed at the top of the stack? The order of the request goes from top to bottom anyway, so what am I missing? - This gic_irq_alloc_info structure is completely GIC specific, and contains things that don't make much sense to most domains. Here, it is only useful to the GICv2m driver, but not to the top MSI layer. So why should this structure be passed around across domains that don't care? So I'd like to get back to the intent: why do you need to turn the logic around? I understand that of_phandle_args is not ideal for ACPI, and I'm happy to find ways around its limitations. But why do we need to reverse the allocation logic and make this structure global along the stack, rather than keeping it for local interaction at the frontier of two domains? Thanks, M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
