linux-kernel - Re: [PATCH v9 11/17] platform/x86: dell-smbios-smm: test for WSMT

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Message-ID: <20171018190927.GA1097@fury>
Date:   Wed, 18 Oct 2017 12:09:27 -0700
From:   Darren Hart <dvhart@...radead.org>
To:     Pali Rohár <pali.rohar@...il.com>
Cc:     Mario Limonciello <mario.limonciello@...l.com>,
        Andy Shevchenko <andy.shevchenko@...il.com>,
        LKML <linux-kernel@...r.kernel.org>,
        platform-driver-x86@...r.kernel.org,
        Andy Lutomirski <luto@...nel.org>, quasisec@...gle.com,
        rjw@...ysocki.net, mjg59@...gle.com, hch@....de,
        Greg KH <greg@...ah.com>, Alan Cox <gnomes@...rguk.ukuu.org.uk>
Subject: Re: [PATCH v9 11/17] platform/x86: dell-smbios-smm: test for WSMT

On Tue, Oct 17, 2017 at 09:22:58PM +0200, Pali Rohár wrote:
> On Tuesday 17 October 2017 13:21:55 Mario Limonciello wrote:
> > +/* When enabled this indicates that SMM won't work */
> > +static int test_wsmt_enabled(void)
> > +{
> > +	struct calling_interface_token *token;
> > +
> > +	/* if token doesn't exist, SMM will work */
> > +	token = dell_smbios_find_token(WSMT_EN_TOKEN);
> > +	if (!token)
> > +		return 0;
> > +
> > +	/* if token exists, try to access over SMM */
> > +	buffer->class = CLASS_TOKEN_READ;
> > +	buffer->select = SELECT_TOKEN_STD;
> > +	memset(buffer, 0, sizeof(struct calling_interface_buffer));
> > +	buffer->input[0] = token->location;
> > +	dell_smbios_smm_call(buffer);
> > +
> > +	/* if lookup failed, we know WSMT was enabled */
> > +	if (buffer->output[0] != 0)
> > +		return 1;
> > +
> > +	/* query token status if it didn't fail */
> > +	return (buffer->output[1] == token->value);
> > +}
> 
> Maybe small suggestion... function returns only zero or one -- what is a
> good candidate to have return value boolean and not basic int.

Yes please.

-- 
Darren Hart
VMware Open Source Technology Center