linux-kernel - Re: [PATCH v2 4/5] ARM: Add basic support for Airoha EN7523 SoC

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAFr9PX=Oi-HJYUFBfJn4pHUSk=drf7otyx473hvq1UC5_gaTHQ@mail.gmail.com>
Date:   Tue, 7 Sep 2021 23:32:20 +0900
From:   Daniel Palmer <daniel@...f.com>
To:     Arnd Bergmann <arnd@...db.de>
Cc:     Bert Vermeulen <bert@...t.com>,
        Russell King <linux@...linux.org.uk>,
        Linus Walleij <linus.walleij@...aro.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        Anshuman Khandual <anshuman.khandual@....com>,
        Marc Zyngier <maz@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        John Crispin <john@...ozen.org>,
        Ard Biesheuvel <ardb@...nel.org>,
        YiFei Zhu <yifeifz2@...inois.edu>,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>, Mike Rapoport <rppt@...nel.org>,
        linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        DTML <devicetree@...r.kernel.org>
Subject: Re: [PATCH v2 4/5] ARM: Add basic support for Airoha EN7523 SoC

Hi Arnd,

On Tue, 7 Sept 2021 at 23:12, Arnd Bergmann <arnd@...db.de> wrote:

> > I think the broken memory controller is still there so somehow I'd
> > need to get the heavy barrier to work in arm64. I haven't yet worked
> > out if that's even possible.
>I think I missed that part of the discussion, or I forgot about it already.
>What is the issue you are referring to here?

Sorry. I should have put a bit more context. This is for the SSD268G
not the original target of this series. But a similar situation.
The SSD268G (according to the decompiled device tree) is the same
hardware as the MSTAR_V7 chips but with a Cortex A53 instead of the
Cortex A7.
So it probably has the same memory controller as the MSTAR_V7 stuff
and that memory controller is not coherent so it needs the kernel to
make sure memory requests are flushed out to memory before DMA
happens[0]. For arm I fixed that with the heavy mb callback. With
arm64 I have no idea how to fix that.

I'm interested to see how this Airoha EN7523 series goes as if/when I
push anything for the SSD268G it'll probably only be for a 32bit
kernel.

0 - https://elixir.bootlin.com/linux/latest/source/arch/arm/mach-mstar/mstarv7.c#L61