linux-kernel - Re: [PATCH v3 08/10] 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] [day] [month] [year] [list]

Message-ID: <Z8IDM8jb-3i5jxYU@smile.fi.intel.com>
Date: Fri, 28 Feb 2025 20:40:51 +0200
From: Andy Shevchenko <andy@...nel.org>
To: Ferry Toth <fntoth@...il.com>
Cc: Arnd Bergmann <arnd@...nel.org>, 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>,
	Matthew Wilcox <willy@...radead.org>
Subject: Re: [PATCH v3 08/10] x86: document X86_INTEL_MID as 64-bit-only

On Fri, Feb 28, 2025 at 05:20:54PM +0100, Ferry Toth wrote:
> Hi,
> 
> On 26-02-2025 22:37, Arnd Bergmann 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 variants were added, but the final Morganfield
> > 14nm platform was canceled before it hit the market.
> > 
> > To help users understand what the option actually refers to, update the
> > help text, and add a dependency on 64-bit kernels.
> > 
> > Ferry confirmed that all the hardware can run 64-bit kernels these days,
> > but is still testing 32-bit kernels on the Intel Edison board, so this
> > remains possible, but is guarded by a CONFIG_EXPERT dependency now,
> > to gently push remaining users towards using CONFIG_64BIT.
> 
> That is a bit more than I said :-) I only know of Merrifield, as Andy
> removed the SFI bits and got ACPI working. For the other platforms I don't
> know the status. Additionally there are pieces of code where 32b runs
> substantially faster than 64b (I know of at least crc32c).
> 
> Maybe Andy can confirm the other platforms?

Listed SoCs are all capable of running 64-bit code.

Telling that they 64-bit only is a bit of a lie but it seems for good. :-)

OTOH I dunno if there is still a plan by community to resurrect Intel Medifield
and Clovertrail (there are phones in a working shape still around), but either
way they will need to switch to ACPI and U-boot to begin with and that's in my
knowledge not trivial and not easy task. That said, I don't think it will ever
happen.

-- 
With Best Regards,
Andy Shevchenko