linux-kernel - Re: [PATCH -next 1/2] i2c: designware: Switch from using MMIO access to SMN access

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]

Date:   Tue, 20 Sep 2022 18:27:41 +0200
From:   Jan Dąbroś <jsd@...ihalf.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:     linux-kernel@...r.kernel.org, linux-i2c@...r.kernel.org,
        jarkko.nikula@...ux.intel.com, wsa@...nel.org,
        rrangel@...omium.org, upstream@...ihalf.com,
        mario.limonciello@....com
Subject: Re: [PATCH -next 1/2] i2c: designware: Switch from using MMIO access
 to SMN access

Hi Andy,

pon., 19 wrz 2022 o 15:59 Andy Shevchenko
<andriy.shevchenko@...ux.intel.com> napisał(a):
>
> On Fri, Sep 16, 2022 at 03:18:53PM +0200, Jan Dabros wrote:
> > Due to a change in silicon compared to Cezanne, in future revisions MSR
> > access can't be used to get the base address of the PSP MMIO region that
> > contains the PSP mailbox interface.
> >
> > Modify driver to use SMN access also for Cezanne platforms (it is
> > working there) in order to simplify codebase when adding support for new
> > SoC versions.
> >
> > Export amd_cache_northbridges() which was unexported by
>
> > e1907d3: "x86/amd_nb: Unexport amd_cache_northbridges()"
>
> Please, use standard format of referring to the commits in the history
> (basically the same as for Fixes tags).

Sure.

>
> > since function which registers i2c-designware-platdrv is a
> > subsys_initcall that is executed before fs_initcall (when enumeration of
> > NB descriptors occurs). Thus in order to use SMN accesses it's necessary
> > to explicitly call amd_cache_northrbidges() from within this driver.
>
> Also it doesn't clarify if this commit a full revert of that (rebased for
> new kernel versions) or partial or functional?

This is a partial revert, I will mention this in the commit msg.

Best Regards,
Jan