linux-kernel - Re: [PATCH v3 2/4] i2c: piix4: Move SB800_PIIX4_FCH_PM_ADDR definition to amd

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: <5509f044-912b-4d10-bdeb-95ec52002b06@kernel.org>
Date: Sat, 12 Apr 2025 14:51:09 -0500
From: Mario Limonciello <superm1@...nel.org>
To: Ingo Molnar <mingo@...nel.org>, Borislav Petkov <bp@...en8.de>
Cc: Jean Delvare <jdelvare@...e.com>, Andi Shyti <andi.shyti@...nel.org>,
 Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
 Jonathan Corbet <corbet@....net>,
 Mario Limonciello <mario.limonciello@....com>,
 Yazen Ghannam <yazen.ghannam@....com>, Thomas Gleixner <tglx@...utronix.de>,
 Ingo Molnar <mingo@...hat.com>, Dave Hansen <dave.hansen@...ux.intel.com>,
 "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@...nel.org>,
 "H . Peter Anvin" <hpa@...or.com>,
 Shyam Sundar S K <Shyam-sundar.S-k@....com>,
 Hans de Goede <hdegoede@...hat.com>,
 "open list:DOCUMENTATION" <linux-doc@...r.kernel.org>,
 open list <linux-kernel@...r.kernel.org>,
 "open list:I2C/SMBUS CONTROLLER DRIVERS FOR PC" <linux-i2c@...r.kernel.org>,
 "open list:AMD PMC DRIVER" <platform-driver-x86@...r.kernel.org>
Subject: Re: [PATCH v3 2/4] i2c: piix4: Move SB800_PIIX4_FCH_PM_ADDR
 definition to amd_node.h

On 4/12/25 14:44, Ingo Molnar wrote:
> 
> * Borislav Petkov <bp@...en8.de> wrote:
> 
>> On Fri, Apr 11, 2025 at 07:09:56AM -0500, Mario Limonciello wrote:
>>> I was aiming for a header that we would conceivably use in all these places
>>> anyway.
>>>
>>> Can you suggest a more fitting existing header?  A new one felt too heavy
>>> for a single register define.
>>
>> No, the logic is: put it in the *right* header. Not in the "whatever-works"
>> header.
> 
> Yeah, it's the Linux kernel equivalent of: 'if you touch it, you own it',
> a.k.a. 'no good deed goes unpunished'. ;-)
> 

Ya.

>> So you can easily add a
>>
>> arch/x86/include/asm/platform.h
>>
>> header which contains exactly platform stuff. And FCH sounds like a platform
>> thing to me. Or at least southbridge or whatever that thing is called now. It
>> certainly ain't part of the CPU so platform should be more fitting.
>>
>> Unless someone has a better idea...
> 
> Yeah, so I think we can create a brand new <asm/amd_sb.h> header or so,
> because it's an AMD SB800 southbridge chipset register? We already have
> <asm/amd_nb.h>.
> 
> 'platform' might be a bit too generic and fungible I think: often the
> northbridge and the CPU is considered part of a 'platform' too.
> 
> Thanks,
> 
> 	Ingo

SB800 is pre-Zen stuff.  It's "before my time" - I guess that's the 
precursor to FCH being in the SoC but has the same functionality.

So I'm thinking <asm/amd_fch.h>.