Re: [PATCH 5/5] x86/sysfs: Add PPIN in sysfs under cpu topology

From: "Luck, Tony" <tony.luck@intel.com>
To: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Smita Koralahalli Channabasappa
	<smita.koralahallichannabasappa@amd.com>,
	Wei Huang <wei.huang2@amd.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	patches@lists.linux.dev
Subject: Re: [PATCH 5/5] x86/sysfs: Add PPIN in sysfs under cpu topology
Date: Thu, 20 Jan 2022 10:01:51 -0800	[thread overview]
Message-ID: <Yemjj26elXuOcegg@agluck-desk2.amr.corp.intel.com> (raw)
In-Reply-To: <YellN/3VCasDI3OD@zn.tnic>

On Thu, Jan 20, 2022 at 02:35:51PM +0100, Borislav Petkov wrote:
> On Fri, Jan 07, 2022 at 02:54:42PM -0800, Tony Luck wrote:
> > +#define topology_ppin(cpu)			(cpu_data(cpu).ppin)
> 
> That looks unused. No need to add it.

It "looks" unused, But thanks to the obscurity of CPP macros using ## to
concatenate tokens it is needed.

This harmless looking line:

define_id_show_func(ppin, "%llx");

is transmogrified by this:

#define define_id_show_func(name, fmt)					\
static ssize_t name##_show(struct device *dev,				\
			   struct device_attribute *attr, char *buf)	\
{									\
	return sysfs_emit(buf, fmt "\n", topology_##name(dev->id));	\
                                         ^^^^^^^^^^^^^^^

                                         This becomes topology_ppin
}

Will fix the other stuff and rebase to latest so part 4 applies.

Thanks for the review.

-Tony