Re: [PATCH v3 2/6] arm64/mirror: arm64 enabling - find mirrored memory ranges

From: Ard Biesheuvel <ardb@kernel.org>
To: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Wupeng Ma <mawupeng1@huawei.com>,
	Jonathan Corbet <corbet@lwn.net>, Will Deacon <will@kernel.org>,
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Subject: Re: [PATCH v3 2/6] arm64/mirror: arm64 enabling - find mirrored memory ranges
Date: Fri, 10 Jun 2022 13:17:38 +0200	[thread overview]
Message-ID: <CAMj1kXEGOmeaWhh6+LhtXTZ-M_cXz1rzTzbaGNrcmyshaSQP=Q@mail.gmail.com> (raw)
In-Reply-To: <174f988c-ea14-9f10-40e1-7bdddcef5d35@huawei.com>

On Fri, 10 Jun 2022 at 12:24, Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
>
>
> On 2022/6/10 17:34, Ard Biesheuvel wrote:
> > On Fri, 10 Jun 2022 at 11:27, Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
> >>
> >> On 2022/6/7 17:38, Wupeng Ma wrote:
> >>> From: Ma Wupeng <mawupeng1@huawei.com>
> >>>
> >>> Commit b05b9f5f9dcf ("x86, mirror: x86 enabling - find mirrored memory ranges")
> >>> introduced mirrored memory support for x86 and this could be used on arm64.
> >>>
> >>> Since we only support this feature on arm64, efi_find_mirror() won't be placed
> >>> into efi_init(), which is used by riscv/arm/arm64, it is added in setup_arch()
> >>> to scan the memory map and mark mirrored memory in memblock.
> >> Move into efi_init() looks better, it won't bring negative effects on
> >> arm/riscv.
> >>
> >> but let's maintainer to make a decision.
> >>
> >> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> >>
> > I don't disagree with that in principle, but x86 calls the efi fake
> > memmap stuff between efi_init() and efi_find_mirror(), and I already
> > indicated that I don't want to enable fake memmap on !X86.
>
> I mean move into efi_init() in drivers/firmware/efi/efi-init.c which
> only used
>
> in arm32/arm64/riscv.
>
> >
> > But I do think there is some room for improvement here: we could move
> > things like efi_mokvar_table_init() and efi_esrt_init() into
> > efi_init() as well, and make efi_fake_memmap() do nothing on !X86 so
> > we can move it into efi_init() too.
>
> x86 has own efi_init() in arch/x86/platform/efi/efi.c, it seams that all
> the above
>
> function could move into x86's own efi_init(), not sure, but we could do
> it later
>
> if it possible.
>

Yes, I see what you mean now. I agree that would be better.