Re: [PATCH v4 2/2] RISC-V: Implement sparsemem

From: Paul Walmsley
Date: Tue Aug 13 2019 - 12:48:47 EST


On Tue, 13 Aug 2019, Paul Walmsley wrote:

> On Tue, 13 Aug 2019, Logan Gunthorpe wrote:
>
> > On 2019-08-13 12:04 a.m., Greentime Hu wrote:
> >
> > > Every architecture with mmu defines their own pfn_valid().
> >
> > Not true. Arm64, for example just uses the generic implementation in
> > mmzone.h.
>
> arm64 seems to define their own:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/Kconfig#n899
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/mm/init.c#n235
>
> While there are many architectures which have their own pfn_valid();
> oddly, almost none of them set HAVE_ARCH_PFN_VALID ?

(fixed the linux-mm@ address)


- Paul