linux-kernel - Re: [PATCH v4 04/10] platform/x86/intel/ifs: Read IFS firmware image

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Message-ID: <YmgfnhhCQHWPHxAw@kroah.com>
Date:   Tue, 26 Apr 2022 18:36:46 +0200
From:   Greg KH <gregkh@...uxfoundation.org>
To:     "Luck, Tony" <tony.luck@...el.com>
Cc:     hdegoede@...hat.com, markgross@...nel.org, tglx@...utronix.de,
        mingo@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com,
        x86@...nel.org, hpa@...or.com, corbet@....net,
        andriy.shevchenko@...ux.intel.com, jithu.joseph@...el.com,
        ashok.raj@...el.com, rostedt@...dmis.org, dan.j.williams@...el.com,
        linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org,
        platform-driver-x86@...r.kernel.org, patches@...ts.linux.dev,
        ravi.v.shankar@...el.com
Subject: Re: [PATCH v4 04/10] platform/x86/intel/ifs: Read IFS firmware image

On Tue, Apr 26, 2022 at 09:12:37AM -0700, Luck, Tony wrote:
> On Tue, Apr 26, 2022 at 12:45:40PM +0200, Greg KH wrote:
> > On Fri, Apr 22, 2022 at 01:02:13PM -0700, Tony Luck wrote:
> > >  drivers/platform/x86/intel/ifs/Makefile |  2 +-
> > >  drivers/platform/x86/intel/ifs/core.c   | 36 ++++++++++++++++++++++++-
> > >  drivers/platform/x86/intel/ifs/ifs.h    | 25 +++++++++++++++++
> > >  drivers/platform/x86/intel/ifs/load.c   | 28 +++++++++++++++++++
> 
> You haven't commented on the source tree location. With the change
> to use misc_register() this isn't a "platform" device anymore.
> 
> Should I move to "drivers/misc/"? Or is there some better spot that
> preseves the detail that this is an x86/intel driver in the path?

There's misc_register() users all over the tree, no need for it to be in
drivers/misc/ at all, especially if this really is a platform device as
this one is.  It's fine here.

> > > +static struct ifs_device ifs_devices[] = {
> > > +	[IFS_SAF] = {
> > > +		.data = {
> > > +			.integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT,
> > > +		},
> > > +		.misc = {
> > > +			.name = "intel_ifs_0",
> > > +			.nodename = "intel_ifs/0",
> > > +			.minor = MISC_DYNAMIC_MINOR,
> > > +		},
> > > +	},
> > > +};
> > > +
> > > +#define IFS_NUMTESTS ARRAY_SIZE(ifs_devices)
> > 
> > Cute way to do this, but I don't see you ever have any more devices
> > added to this list in this series.  Did I miss them?
> 
> That's in part 11/10 ... I have hardware, so I'm pretty sure that this
> is a real thing. Just not ready to post until Intel announces the
> details of the new test type.

Let's not over-engineer for anything we can not review today please.

> > If not, why all the overhead and complexity involved here for just a
> > single misc device?
> 
> It didn't seem like a lot of complexity here. It makes the changes to
> this file to add an extra test trivial (just a new name in the "enum"
> and a new initializer in ifs_devices[]).
> 
> Obviously some more code in load.c and runtest.c to handle the new
> test type.
> 
> If it really is too much now, I can rip it out from this submission
> and add it back when the second test is ready for public view.

Please do, thanks.

greg k-h