Re: [PATCH 2/3] irqchip: irq-mips-gic: Provide function to map GIC user section

From: Qais Yousef
Date: Mon Sep 28 2015 - 10:16:51 EST

On 09/28/2015 11:55 AM, Marc Zyngier wrote:
On 28/09/15 11:11, Markos Chandras wrote:

+ pfn = (gic_base_addr + USM_VISIBLE_SECTION_OFS) >> PAGE_SHIFT;
+ return io_remap_pfn_range(vma, base, pfn, size,
+ pgprot_noncached(PAGE_READONLY));

- Does this code have to be in the irqchip driver? It really feels out
of place, and I'd rather see a function that returns the mappable range
to the VDSO code, where the mapping would occur.

I don't think it's a good idea either for the VDSO code to know about gic_base_addr. Maybe this function could be split to return the pfn and let the caller do io_remap_pfn_range(). Though I think it's nice to have it all there. USM stands for USer Mode - GIC wants to make some stuff visible to user mode and it puts them in that special section. So it makes sense to do it all there IMO.

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