Re: [PATCH v9 1/8] remoteproc: qcom: Add PRNG proxy clock

Dmitry Baryshkov
2024-06-27T13:35:40Z

On Thu, Jun 27, 2024 at 04:59:38PM GMT, Gokul Sriram P wrote:
>
> On 6/27/2024 4:38 PM, Dmitry Baryshkov wrote:
> > On Thu, Jun 27, 2024 at 03:31:01PM GMT, Gokul Sriram P wrote:
> > > On 6/27/2024 12:47 AM, Dmitry Baryshkov wrote:
> > > > On Tue, Jun 25, 2024 at 11:03:30AM GMT, Gokul Sriram P wrote:
> > > > > On 6/22/2024 2:38 AM, Dmitry Baryshkov wrote:
> > > > > > On Fri, Jun 21, 2024 at 05:16:52PM GMT, Gokul Sriram Palanisamy wrote:
> > > > > > > PRNG clock is needed by the secure PIL, support for the same
> > > > > > > is added in subsequent patches.
> > > > > > Which 'same'?
> > > > > > What is 'secure PIL'?
> > > > >   will elaborate in the updated version.
> > > > >   To answer your question, secure PIL is signed PIL image which only
> > > > > TrustZone can authenticate and load.
> > > > Fine. So, the current driver can not load WCSS firmware on IPQ8074, is
> > > > that correct? Or was there some kind of firmware interface change? The
> > > > driver was added in 2018, so I can only hope that at that point it
> > > > worked. Could you please explain, what happened?
> > > The existing wcss driver can load unsigned PIL images without the
> > > involvement of TrustZone. That works even now.
> > > With the current change, we are trying to add signed PIL as an option based
> > > on "wcss->need_mem_protection" if set. For signed PIL alone, we send a PAS
> > > request to TrustZone to authenticate and load.
> > I see that you are enabling it unconditionally for IPQ8074. How is it
> > going to work?
>
> Correct Dmitry. In this change, it is forcing secure PIL. With a separate
> driver for secure PIL, this will be sorted right?

That depends. How will the running system decide, which driver to use?
It can not be a compile-time decision.

>
> Regards,
>
> Gokul
>
> > > I also just noticed that Bjorn had suggested to submit a new driver for the
> > > PAS based IPQ WCSS instead of overloading this driver. Will also address
> > > that and post a new driver in updated revision.
> > >
> > > Regards,
> > > Gokul
> > > > > > > Signed-off-by: Nikhil Prakash V <quic_nprakash@quicinc.com>
> > > > > > > Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
> > > > > > > Signed-off-by: Gokul Sriram Palanisamy <quic_gokulsri@quicinc.com>
> > > > > > > ---
> > > > > > > drivers/remoteproc/qcom_q6v5_wcss.c | 65 +++++++++++++++++++++--------
> > > > > > > 1 file changed, 47 insertions(+), 18 deletions(-)

--
With best wishes
Dmitry