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Date:   Thu, 23 Nov 2023 15:07:09 +0000
From:   "Jiaxun Yang" <jiaxun.yang@flygoat.com>
To:     "Thomas Bogendoerfer" <tsbogend@alpha.franken.de>
Cc:     "Serge Semin" <fancer.lancer@gmail.com>,
        "Arnd Bergmann" <arnd@arndb.de>,
        "Andrew Morton" <akpm@linux-foundation.org>,
        "Mike Rapoport" <rppt@kernel.org>,
        "Matthew Wilcox" <willy@infradead.org>,
        "Tiezhu Yang" <yangtiezhu@loongson.cn>,
        "Huacai Chen" <chenhuacai@kernel.org>,
        "Yinglu Yang" <yangyinglu@loongson.cn>,
        "Alexey Malahov" <Alexey.Malahov@baikalelectronics.ru>,
        "Aleksandar Rikalo" <aleksandar.rikalo@syrmia.com>,
        "Aleksandar Rikalo" <arikalo@gmail.com>,
        "Dragan Mladjenovic" <dragan.mladjenovic@syrmia.com>,
        "Chao-ying Fu" <cfu@wavecomp.com>, "Marc Zyngier" <maz@kernel.org>,
        "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/7] mips: dmi: Fix early remap on MIPS32
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=E5=9C=A82023=E5=B9=B411=E6=9C=8823=E6=97=A5=E5=8D=81=E4=B8=80=E6=9C=88 =
=E4=B8=8B=E5=8D=8812:29=EF=BC=8CThomas Bogendoerfer=E5=86=99=E9=81=93=EF=
=BC=9A
> On Thu, Nov 23, 2023 at 12:13:11PM +0000, Jiaxun Yang wrote:
>> > Ok. Thanks for the heads up. I'll fix the patch to be using ioremap=
()
>> > in v2. ioremap_uc() is just an macro-alias of ioremap() on MIPS.
>>=20
>> Perhaps we need to fix ioremap_cache so it can give a KSEG1 address?
>
> KSEG0 ?

Ah yes it's KSEG0.

>
>> AFAIK for Loongson DMI is located at cached memory so using ioremap_uc
>> blindly will cause inconsistency.
>
> why ?

Firmware sometimes does not flush those tables from cache back to memory.
For Loongson systems (as well as most MTI systems) cache is enabled by
firmware.

Thanks.
>
> Thomas.
>
> --=20
> Crap can work. Given enough thrust pigs will fly, but it's not necessa=
rily a
> good idea.                                                [ RFC1925, 2=
.3 ]

--=20
- Jiaxun