linux-kernel - Re: [PATCH v3 09/10] firmware: arm_ffa: Set up 32bit execution mode flag using partiion property

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Date:   Thu, 8 Sep 2022 11:25:42 +0100
From:   Sudeep Holla <sudeep.holla@....com>
To:     Jens Wiklander <jens.wiklander@...aro.org>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        op-tee@...ts.trustedfirmware.org,
        Marc Bonnici <marc.bonnici@....com>,
        Achin Gupta <achin.gupta@....com>,
        Valentin Laurent <valentin.laurent@...stonic.com>,
        Lukas Hanel <lukas.hanel@...stonic.com>,
        Coboy Chen <coboy.chen@...iatek.com>
Subject: Re: [PATCH v3 09/10] firmware: arm_ffa: Set up 32bit execution mode
 flag using partiion property

On Thu, Sep 08, 2022 at 12:08:00PM +0200, Jens Wiklander wrote:
> On Wed, Sep 7, 2022 at 4:53 PM Sudeep Holla <sudeep.holla@....com> wrote:
> >
> > FF-A v1.1 adds a flag in the partition properties to indicate if the
> > partition runs in the AArch32 or AArch64 execution state. Use the same
> > to set-up the 32-bit execution flag mode in the ffa_dev automatically
> > and ignore any requests to do the same from the ffa_driver.
> >
> > Signed-off-by: Sudeep Holla <sudeep.holla@....com>
> > ---
> >  drivers/firmware/arm_ffa/driver.c | 13 ++++++++++++-
> >  include/linux/arm_ffa.h           |  2 ++
> >  2 files changed, 14 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
> > index 42bc22220c69..34e12a2a98fe 100644
> > --- a/drivers/firmware/arm_ffa/driver.c
> > +++ b/drivers/firmware/arm_ffa/driver.c
> > @@ -648,11 +648,19 @@ static int ffa_partition_info_get(const char *uuid_str,
> >         return 0;
> >  }
> >
> > -static void ffa_mode_32bit_set(struct ffa_device *dev)
> > +static void _ffa_mode_32bit_set(struct ffa_device *dev)
> >  {
> >         dev->mode_32bit = true;
> >  }
> >
> > +static void ffa_mode_32bit_set(struct ffa_device *dev)
> > +{
> > +       if (drv_info->version > FFA_VERSION_1_0)
> > +               return;
> > +
> > +       _ffa_mode_32bit_set(dev);
> > +}
> > +
> >  static int ffa_sync_send_receive(struct ffa_device *dev,
> >                                  struct ffa_send_direct_data *data)
> >  {
> > @@ -744,6 +752,9 @@ static void ffa_setup_partitions(void)
> >                                __func__, tpbuf->id);
> >                         continue;
> >                 }
> > +
> > +               if (!(tpbuf->properties & FFA_PARTITION_AARCH64_EXEC))
> > +                       _ffa_mode_32bit_set(ffa_dev);
> 
> For FF-A 1.0 it looks like we change the dev->mode_32bit default value
> from false to true. Or am I missing something?
>

You are right, was trying to avoid additional check on version but we
need that to keep the behaviour unchanged. I will add the check. Thanks
again for spotting this.

-- 
Regards,
Sudeep