Re: [PATCH 2/2] firmware: psci: support SMCCC v1.2 for SMCCC conduit

From: Sudeep Holla <sudeep.holla@arm.com>
To: Etienne Carriere <etienne.carriere@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
	lorenzo.pieralisi@arm.com, maz@kernel.org,
	linux-kernel@vger.kernel.org, Steven Price <steven.price@arm.com>,
	alexios.zavras@intel.com, Thomas Gleixner <tglx@linutronix.de>,
	will@kernel.org,
	"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 2/2] firmware: psci: support SMCCC v1.2 for SMCCC conduit
Date: Fri, 15 May 2020 10:24:57 +0100	[thread overview]
Message-ID: <20200515092457.GB23671@bogus> (raw)
In-Reply-To: <CAN5uoS9gZ7820Fg-6dmm4BO5GW+Y6D3O5Xt3gUQtYVZGafm_XA@mail.gmail.com>

On Thu, May 14, 2020 at 04:56:53PM +0200, Etienne Carriere wrote:
> On Thu, 14 May 2020 at 16:24, Sudeep Holla <sudeep.holla@arm.com> wrote:
> >
> > On Thu, May 14, 2020 at 10:21:09AM +0200, Etienne Carriere wrote:
> > > Update PSCI driver to support SMCCC v1.2 reported by secure firmware
> > > and indirectly make SMCCC conduit properly set when so. TF-A release
> > > v2.3 implements and reports SMCCC v1.2 since commit [1].
> > >
> > > Link: [1] https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=e34cc0cedca6e229847c232fe58d37fad2610ce9
> > > Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> > > ---
> > >  drivers/firmware/psci/psci.c | 14 ++++++++++----
> > >  include/linux/psci.h         |  1 +
> > >  2 files changed, 11 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
> > > index 2937d44b5df4..80cf73bea4b0 100644
> > > --- a/drivers/firmware/psci/psci.c
> > > +++ b/drivers/firmware/psci/psci.c
> > > @@ -409,11 +409,17 @@ static void __init psci_init_smccc(void)
> > >       feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
> > >
> > >       if (feature != PSCI_RET_NOT_SUPPORTED) {
> > > -             u32 ret;
> > > -             ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
> > > -             if (ret == ARM_SMCCC_VERSION_1_1) {
> > > +             ver = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
> > > +
> > > +             switch (ver) {
> > > +             case ARM_SMCCC_VERSION_1_1:
> > >                       psci_ops.smccc_version = SMCCC_VERSION_1_1;
> > > -                     ver = ret;
> > > +                     break;
> > > +             case ARM_SMCCC_VERSION_1_2:
> > > +                     psci_ops.smccc_version = SMCCC_VERSION_1_2;
> > > +                     break;
> > > +             default:
> > > +                     break;
> > >               }
> > >       }
> > >
> > > diff --git a/include/linux/psci.h b/include/linux/psci.h
> > > index a67712b73b6c..c7d99b7f34ed 100644
> > > --- a/include/linux/psci.h
> > > +++ b/include/linux/psci.h
> > > @@ -24,6 +24,7 @@ bool psci_has_osi_support(void);
> > >  enum smccc_version {
> > >       SMCCC_VERSION_1_0,
> > >       SMCCC_VERSION_1_1,
> > > +     SMCCC_VERSION_1_2,
> >
> > I took approach to kill this completely [1] instead of having to keep
> > expanding it for ever.
>
> Yes, I've been pointed to [1]. Discard this change. Sorry for the
> (little) noise.
>

No worries, it's not a noise, just different approach.

--
Regards,
Sudeep

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