diff mbox series

[2/2] firmware: arm_scmi: optee: use optee system invocation

Message ID 20230130094157.1082712-2-etienne.carriere@linaro.org
State New
Headers
Series [1/2] tee: system invocation |

Commit Message

Etienne Carriere Jan. 30, 2023, 9:41 a.m. UTC 
  Changes SCMI optee transport to enable sys_service capability of
its tee context to leverage provisioned system resources in OP-TEE
preventing possible deadlock.

Such deadlock could happen when many Linux clients invoke OP-TEE are
are all suspended waiting for an OP-TEE RPC request access an SCMI
resource through the SCMI OP-TEE PTA service.

Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
---
 drivers/firmware/arm_scmi/optee.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Cristian Marussi Feb. 3, 2023, 2:36 p.m. UTC | #1 
On Mon, Jan 30, 2023 at 10:41:57AM +0100, Etienne Carriere wrote:
> Changes SCMI optee transport to enable sys_service capability of
> its tee context to leverage provisioned system resources in OP-TEE
> preventing possible deadlock.
> 
> Such deadlock could happen when many Linux clients invoke OP-TEE are
> are all suspended waiting for an OP-TEE RPC request access an SCMI
> resource through the SCMI OP-TEE PTA service.
> 
> Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> ---
>  drivers/firmware/arm_scmi/optee.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
> index 2a7aeab40e54..91840345e946 100644
> --- a/drivers/firmware/arm_scmi/optee.c
> +++ b/drivers/firmware/arm_scmi/optee.c
> @@ -559,6 +559,9 @@ static int scmi_optee_service_probe(struct device *dev)
>  	if (IS_ERR(tee_ctx))
>  		return -ENODEV;
>  
> +	/* SCMI agent can used TEE system service resources */
> +	tee_ctx->sys_service = true;
> +
>  	agent = devm_kzalloc(dev, sizeof(*agent), GFP_KERNEL);
>  	if (!agent) {
>  		ret = -ENOMEM;

LGTM.

I suppose you'll sync-up with Sudeep for how to queue this whole series.

Thanks,
Cristian
Sudeep Holla Feb. 3, 2023, 5:04 p.m. UTC | #2 
On Fri, Feb 03, 2023 at 02:36:26PM +0000, Cristian Marussi wrote:
> On Mon, Jan 30, 2023 at 10:41:57AM +0100, Etienne Carriere wrote:
> > Changes SCMI optee transport to enable sys_service capability of
> > its tee context to leverage provisioned system resources in OP-TEE
> > preventing possible deadlock.
> > 
> > Such deadlock could happen when many Linux clients invoke OP-TEE are
> > are all suspended waiting for an OP-TEE RPC request access an SCMI
> > resource through the SCMI OP-TEE PTA service.
> > 
> > Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> > ---
> >  drivers/firmware/arm_scmi/optee.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
> > index 2a7aeab40e54..91840345e946 100644
> > --- a/drivers/firmware/arm_scmi/optee.c
> > +++ b/drivers/firmware/arm_scmi/optee.c
> > @@ -559,6 +559,9 @@ static int scmi_optee_service_probe(struct device *dev)
> >  	if (IS_ERR(tee_ctx))
> >  		return -ENODEV;
> >  
> > +	/* SCMI agent can used TEE system service resources */
> > +	tee_ctx->sys_service = true;
> > +
> >  	agent = devm_kzalloc(dev, sizeof(*agent), GFP_KERNEL);
> >  	if (!agent) {
> >  		ret = -ENOMEM;
> 
> LGTM.
> 
> I suppose you'll sync-up with Sudeep for how to queue this whole series.
> 

I thought I had responded to this but not. Anyways since TEE changes are
significant than SCMI, you can route it via TEE tree. In that case,

Acked-by: Sudeep Holla <sudeep.holla@arm.com>

Let me know if that was not your plan.
Etienne Carriere Feb. 3, 2023, 6:43 p.m. UTC | #3 
Hello Sudeep,

On Fri, 3 Feb 2023 at 18:04, Sudeep Holla <sudeep.holla@arm.com> wrote:
>
> On Fri, Feb 03, 2023 at 02:36:26PM +0000, Cristian Marussi wrote:
> > On Mon, Jan 30, 2023 at 10:41:57AM +0100, Etienne Carriere wrote:
> > > Changes SCMI optee transport to enable sys_service capability of
> > > its tee context to leverage provisioned system resources in OP-TEE
> > > preventing possible deadlock.
> > >
> > > Such deadlock could happen when many Linux clients invoke OP-TEE are
> > > are all suspended waiting for an OP-TEE RPC request access an SCMI
> > > resource through the SCMI OP-TEE PTA service.
> > >
> > > Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> > > ---
> > >  drivers/firmware/arm_scmi/optee.c | 3 +++
> > >  1 file changed, 3 insertions(+)
> > >
> > > diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
> > > index 2a7aeab40e54..91840345e946 100644
> > > --- a/drivers/firmware/arm_scmi/optee.c
> > > +++ b/drivers/firmware/arm_scmi/optee.c
> > > @@ -559,6 +559,9 @@ static int scmi_optee_service_probe(struct device *dev)
> > >     if (IS_ERR(tee_ctx))
> > >             return -ENODEV;
> > >
> > > +   /* SCMI agent can used TEE system service resources */
> > > +   tee_ctx->sys_service = true;
> > > +
> > >     agent = devm_kzalloc(dev, sizeof(*agent), GFP_KERNEL);
> > >     if (!agent) {
> > >             ret = -ENOMEM;
> >
> > LGTM.
> >
> > I suppose you'll sync-up with Sudeep for how to queue this whole series.
> >
>
> I thought I had responded to this but not. Anyways since TEE changes are
> significant than SCMI, you can route it via TEE tree. In that case,
>
> Acked-by: Sudeep Holla <sudeep.holla@arm.com>
>
> Let me know if that was not your plan.

That's fine. Thanks. I'll ask Jens to apply it next to the optee commit.

Regards,
Etienne

>
> --
> Regards,
> Sudeep
Sumit Garg Feb. 7, 2023, 9:59 a.m. UTC | #4 
On Mon, 30 Jan 2023 at 15:12, Etienne Carriere
<etienne.carriere@linaro.org> wrote:
>
> Changes SCMI optee transport to enable sys_service capability of
> its tee context to leverage provisioned system resources in OP-TEE
> preventing possible deadlock.
>
> Such deadlock could happen when many Linux clients invoke OP-TEE are
> are all suspended waiting for an OP-TEE RPC request access an SCMI
> resource through the SCMI OP-TEE PTA service.
>
> Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> ---
>  drivers/firmware/arm_scmi/optee.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
> index 2a7aeab40e54..91840345e946 100644
> --- a/drivers/firmware/arm_scmi/optee.c
> +++ b/drivers/firmware/arm_scmi/optee.c
> @@ -559,6 +559,9 @@ static int scmi_optee_service_probe(struct device *dev)
>         if (IS_ERR(tee_ctx))
>                 return -ENODEV;
>
> +       /* SCMI agent can used TEE system service resources */
> +       tee_ctx->sys_service = true;
> +

As per the other thread for patch #1, this feature will only be
available with OP-TEE supporting TEE_GEN_CAP_REG_MEM. Can we add a
corresponding conditional check here?

-Sumit

>         agent = devm_kzalloc(dev, sizeof(*agent), GFP_KERNEL);
>         if (!agent) {
>                 ret = -ENOMEM;
> --
> 2.25.1
>
Jens Wiklander Feb. 7, 2023, 10:39 a.m. UTC | #5 
On Tue, Feb 7, 2023 at 10:59 AM Sumit Garg <sumit.garg@linaro.org> wrote:
>
> On Mon, 30 Jan 2023 at 15:12, Etienne Carriere
> <etienne.carriere@linaro.org> wrote:
> >
> > Changes SCMI optee transport to enable sys_service capability of
> > its tee context to leverage provisioned system resources in OP-TEE
> > preventing possible deadlock.
> >
> > Such deadlock could happen when many Linux clients invoke OP-TEE are
> > are all suspended waiting for an OP-TEE RPC request access an SCMI
> > resource through the SCMI OP-TEE PTA service.
> >
> > Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> > ---
> >  drivers/firmware/arm_scmi/optee.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
> > index 2a7aeab40e54..91840345e946 100644
> > --- a/drivers/firmware/arm_scmi/optee.c
> > +++ b/drivers/firmware/arm_scmi/optee.c
> > @@ -559,6 +559,9 @@ static int scmi_optee_service_probe(struct device *dev)
> >         if (IS_ERR(tee_ctx))
> >                 return -ENODEV;
> >
> > +       /* SCMI agent can used TEE system service resources */
> > +       tee_ctx->sys_service = true;
> > +
>
> As per the other thread for patch #1, this feature will only be
> available with OP-TEE supporting TEE_GEN_CAP_REG_MEM. Can we add a
> corresponding conditional check here?

What would be gained by that? If a system thread isn't available or
already is busy we're supposed to fall back to normal threads.

Cheers,
Jens

>
> -Sumit
>
> >         agent = devm_kzalloc(dev, sizeof(*agent), GFP_KERNEL);
> >         if (!agent) {
> >                 ret = -ENOMEM;
> > --
> > 2.25.1
> >
Sumit Garg Feb. 7, 2023, 11:11 a.m. UTC | #6 
On Tue, 7 Feb 2023 at 16:09, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> On Tue, Feb 7, 2023 at 10:59 AM Sumit Garg <sumit.garg@linaro.org> wrote:
> >
> > On Mon, 30 Jan 2023 at 15:12, Etienne Carriere
> > <etienne.carriere@linaro.org> wrote:
> > >
> > > Changes SCMI optee transport to enable sys_service capability of
> > > its tee context to leverage provisioned system resources in OP-TEE
> > > preventing possible deadlock.
> > >
> > > Such deadlock could happen when many Linux clients invoke OP-TEE are
> > > are all suspended waiting for an OP-TEE RPC request access an SCMI
> > > resource through the SCMI OP-TEE PTA service.
> > >
> > > Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> > > ---
> > >  drivers/firmware/arm_scmi/optee.c | 3 +++
> > >  1 file changed, 3 insertions(+)
> > >
> > > diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
> > > index 2a7aeab40e54..91840345e946 100644
> > > --- a/drivers/firmware/arm_scmi/optee.c
> > > +++ b/drivers/firmware/arm_scmi/optee.c
> > > @@ -559,6 +559,9 @@ static int scmi_optee_service_probe(struct device *dev)
> > >         if (IS_ERR(tee_ctx))
> > >                 return -ENODEV;
> > >
> > > +       /* SCMI agent can used TEE system service resources */
> > > +       tee_ctx->sys_service = true;
> > > +
> >
> > As per the other thread for patch #1, this feature will only be
> > available with OP-TEE supporting TEE_GEN_CAP_REG_MEM. Can we add a
> > corresponding conditional check here?
>
> What would be gained by that? If a system thread isn't available or
> already is busy we're supposed to fall back to normal threads.
>

Just to make the dependency explicit and probably warn users that the
system is missing a required capability. Earlier I went through a
similar dependency issue report for trusted keys driver. I ended with
a dependency fix [1] to make it easier while debugging when something
doesn't work as intended.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/security/keys/trusted-keys/trusted_tee.c#n223

-Sumit

> Cheers,
> Jens
>
> >
> > -Sumit
> >
> > >         agent = devm_kzalloc(dev, sizeof(*agent), GFP_KERNEL);
> > >         if (!agent) {
> > >                 ret = -ENOMEM;
> > > --
> > > 2.25.1
> > >
diff mbox series

Patch

diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
index 2a7aeab40e54..91840345e946 100644
--- a/drivers/firmware/arm_scmi/optee.c
+++ b/drivers/firmware/arm_scmi/optee.c
@@ -559,6 +559,9 @@  static int scmi_optee_service_probe(struct device *dev)
 	if (IS_ERR(tee_ctx))
 		return -ENODEV;
 
+	/* SCMI agent can used TEE system service resources */
+	tee_ctx->sys_service = true;
+
 	agent = devm_kzalloc(dev, sizeof(*agent), GFP_KERNEL);
 	if (!agent) {
 		ret = -ENOMEM;