linux-kernel - Re: [PATCH -fixes v2 3/3] riscv: No need to relocate the dtb as it lies in the fixmap region

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Message-ID: <mhng-4113481b-4c71-4b5c-ab7e-6896058f074b@palmer-ri-x1c9a>
Date:   Thu, 13 Apr 2023 18:17:00 -0700 (PDT)
From:   Palmer Dabbelt <palmer@...belt.com>
To:     Conor Dooley <conor@...nel.org>
CC:     alexghiti@...osinc.com, corbet@....net,
        Paul Walmsley <paul.walmsley@...ive.com>,
        aou@...s.berkeley.edu, Conor Dooley <conor.dooley@...rochip.com>,
        linux-doc@...r.kernel.org, linux-riscv@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Subject:     Re: [PATCH -fixes v2 3/3] riscv: No need to relocate the dtb as it lies in the fixmap region

On Wed, 29 Mar 2023 08:33:45 PDT (-0700), Conor Dooley wrote:
> On Wed, Mar 29, 2023 at 04:40:18PM +0200, Alexandre Ghiti wrote:
>> On Wed, Mar 29, 2023 at 3:56 PM Conor Dooley <conor@...nel.org> wrote:
>> >
>> > On Wed, Mar 29, 2023 at 10:19:32AM +0200, Alexandre Ghiti wrote:
>> > > We used to access the dtb via its linear mapping address but now that the
>> > > dtb early mapping was moved in the fixmap region, we can keep using this
>> > > address since it is present in swapper_pg_dir, and remove the dtb
>> > > relocation.
>> > >
>> > > Note that the relocation was wrong anyway since early_memremap() is
>> > > restricted to 256K whereas the maximum fdt size is 2MB.
>> >
>> > So, should this be marked as a fix, and backported along with 1/3?
>> 
>> Hmmm the whole series should be backported, it does not make sense to
>> move the dtb mapping and keep accessing it using its linear mapping
>> address since it could fail for the exact reason the relocation was
>> implemented in the first place and the relocation is wrong.
>> 
>> Maybe we should simply add a "Cc: stable@...r.kernel.org" on all the patches?
>
> Yup, although hopefully Palmer can handle that if nothing else needs
> changing.

The bots usually pick it up anyway, but in general I try and put the 
stable CC on there when I see stuff go by.  I actually missed it this 
time until seeing the comment, though...