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

From: Mario.Limonciello
Date: Wed Oct 18 2017 - 15:11:13 EST


> -----Original Message-----
> From: Darren Hart [mailto:dvhart@xxxxxxxxxxxxx]
> Sent: Wednesday, October 18, 2017 2:09 PM
> To: Pali Rohár <pali.rohar@xxxxxxxxx>
> Cc: Limonciello, Mario <Mario_Limonciello@xxxxxxxx>; Andy Shevchenko
> <andy.shevchenko@xxxxxxxxx>; LKML <linux-kernel@xxxxxxxxxxxxxxx>; platform-
> driver-x86@xxxxxxxxxxxxxxx; Andy Lutomirski <luto@xxxxxxxxxx>;
> quasisec@xxxxxxxxxx; rjw@xxxxxxxxxxxxx; mjg59@xxxxxxxxxx; hch@xxxxxx; Greg
> KH <greg@xxxxxxxxx>; Alan Cox <gnomes@xxxxxxxxxxxxxxxxxxx>
> 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.
>

OK I'll adjust this (and the other things Pali sent recently) in the next submission.

Just waiting on feedback for some of the other areas before sending off again.