linux-kernel - Re: [PATCH 08/11] x86: document X86_INTEL

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: <CAHp75VfzHmV2anw6C8iSCiwnJc2YNa+1aLDj6Frf9OZyGjD0MQ@mail.gmail.com>
Date: Wed, 4 Dec 2024 20:55:19 +0200
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: Arnd Bergmann <arnd@...nel.org>, Ferry Toth <fntoth@...il.com>
Cc: linux-kernel@...r.kernel.org, x86@...nel.org, 
	Arnd Bergmann <arnd@...db.de>, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, 
	Borislav Petkov <bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>, 
	"H. Peter Anvin" <hpa@...or.com>, Linus Torvalds <torvalds@...ux-foundation.org>, 
	Andy Shevchenko <andy@...nel.org>, Matthew Wilcox <willy@...radead.org>, 
	Sean Christopherson <seanjc@...gle.com>, Davide Ciminaghi <ciminaghi@...dd.com>, 
	Paolo Bonzini <pbonzini@...hat.com>, kvm@...r.kernel.org
Subject: Re: [PATCH 08/11] x86: document X86_INTEL_MID as 64-bit-only

+Cc: Ferry

On Wed, Dec 4, 2024 at 12:31 PM Arnd Bergmann <arnd@...nel.org> wrote:
>
> From: Arnd Bergmann <arnd@...db.de>
>
> The X86_INTEL_MID code was originally introduced for the
> 32-bit Moorestown/Medfield/Clovertrail platform, later the 64-bit
> Merrifield/Moorefield variant got added, but the final

variant got --> variants were

> Morganfield/Broxton 14nm chips were canceled before they hit
> the market.

Inaccurate. "Broxton for Mobile", and not "Broxton" in general.

> To help users understand what the option actually refers to,
> update the help text, and make it a hard dependency on 64-bit
> kernels. While they could theoretically run a 32-bit kernel,
> the devices originally shipped with 64-bit one in 2015, so that
> was proabably never tested.

probably

It's all other way around (from SW point of view). For unknown reasons
Intel decided to release only 32-bit SW and it became the only thing
that was heavily tested (despite misunderstanding by some developers
that pointed finger to the HW without researching the issue that
appears to be purely software in a few cases) _that_ time.  Starting
ca. 2017 I enabled 64-bit for Merrifield and from then it's being used
by both 32- and 64-bit builds.

I'm totally fine to drop 32-bit defaults for Merrifield/Moorefield,
but let's hear Ferry who might/may still have a use case for that.

...

> -               Moorestown MID devices

FTR, a year or so ago it was a (weak) interest to revive Medfield, but
I think it would require too much work even for the person who is
quite familiar with HW, U-Boot, and Linux kernel, so it is most
unlikely to happen.

...

>           Select to build a kernel capable of supporting Intel MID (Mobile
>           Internet Device) platform systems which do not have the PCI legacy
> -         interfaces. If you are building for a PC class system say N here.
> +         interfaces.
> +
> +         The only supported devices are the 22nm Merrified (Z34xx) and
> +         Moorefield (Z35xx) SoC used in Android devices such as the
> +         Asus Zenfone 2, Asus FonePad 8 and Dell Venue 7.

The list is missing the Intel Edison DIY platform which is probably
the main user of Intel MID kernels nowadays.

...

> -         Intel MID platforms are based on an Intel processor and chipset which
> -         consume less power than most of the x86 derivatives.

Why remove this? AFAIK it states the truth.

-- 
With Best Regards,
Andy Shevchenko