[RESEND,1/2] firmware: qcom: scm: Add SDI disable support

  Some SoC-s like IPQ5018 require SDI(Secure Debug Image) to be disabled
before trying to reboot, otherwise board will just hang after reboot has
been issued via PSCI.

So, provide a call to SCM that allows disabling it.

Signed-off-by: Robert Marko <robimarko@gmail.com>
---
 drivers/firmware/qcom_scm.c | 23 +++++++++++++++++++++++
 drivers/firmware/qcom_scm.h |  1 +
 2 files changed, 24 insertions(+)
  

On 5/18/2023 7:32 PM, Robert Marko wrote:
> Some SoC-s like IPQ5018 require SDI(Secure Debug Image) to be disabled
> before trying to reboot, otherwise board will just hang after reboot has
> been issued via PSCI.
> 
> So, provide a call to SCM that allows disabling it.
> 
> Signed-off-by: Robert Marko <robimarko@gmail.com>

This scm call support indeed needed for reboot cases, but i am not sure
about target specific check in the later patch.

Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>

-- Mukesh

> ---
>   drivers/firmware/qcom_scm.c | 23 +++++++++++++++++++++++
>   drivers/firmware/qcom_scm.h |  1 +
>   2 files changed, 24 insertions(+)
> 
> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> index fde33acd46b7..bdc9324d4e62 100644
> --- a/drivers/firmware/qcom_scm.c
> +++ b/drivers/firmware/qcom_scm.c
> @@ -407,6 +407,29 @@ int qcom_scm_set_remote_state(u32 state, u32 id)
>   }
>   EXPORT_SYMBOL(qcom_scm_set_remote_state);
>   
> +static int qcom_scm_disable_sdi(void)
> +{
> +	int ret;
> +	struct qcom_scm_desc desc = {
> +		.svc = QCOM_SCM_SVC_BOOT,
> +		.cmd = QCOM_SCM_BOOT_SDI_CONFIG,
> +		.args[0] = 1, /* Disable watchdog debug */
> +		.args[1] = 0, /* Disable SDI */
> +		.arginfo = QCOM_SCM_ARGS(2),
> +		.owner = ARM_SMCCC_OWNER_SIP,
> +	};
> +	struct qcom_scm_res res;
> +
> +	ret = qcom_scm_clk_enable();
> +	if (ret)
> +		return ret;
> +	ret = qcom_scm_call(__scm->dev, &desc, &res);
> +
> +	qcom_scm_clk_disable();
> +
> +	return ret ? : res.result[0];
> +}
> +
>   static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
>   {
>   	struct qcom_scm_desc desc = {
> diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
> index e6e512bd57d1..7b68fa820495 100644
> --- a/drivers/firmware/qcom_scm.h
> +++ b/drivers/firmware/qcom_scm.h
> @@ -80,6 +80,7 @@ extern int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc,
>   #define QCOM_SCM_SVC_BOOT		0x01
>   #define QCOM_SCM_BOOT_SET_ADDR		0x01
>   #define QCOM_SCM_BOOT_TERMINATE_PC	0x02
> +#define QCOM_SCM_BOOT_SDI_CONFIG	0x09
>   #define QCOM_SCM_BOOT_SET_DLOAD_MODE	0x10
>   #define QCOM_SCM_BOOT_SET_ADDR_MC	0x11
>   #define QCOM_SCM_BOOT_SET_REMOTE_STATE	0x0a
  

On Thu, 18 May 2023 at 16:25, Mukesh Ojha <quic_mojha@quicinc.com> wrote:
>
>
>
> On 5/18/2023 7:32 PM, Robert Marko wrote:
> > Some SoC-s like IPQ5018 require SDI(Secure Debug Image) to be disabled
> > before trying to reboot, otherwise board will just hang after reboot has
> > been issued via PSCI.
> >
> > So, provide a call to SCM that allows disabling it.
> >
> > Signed-off-by: Robert Marko <robimarko@gmail.com>
>
> This scm call support indeed needed for reboot cases, but i am not sure
> about target specific check in the later patch.

I am not really sure where to put it, maybe as part of qcom_scm_shutdown?
Yesterday I found out that in OpenWrt we also have a Google IPQ4019 board that
has been needing SDI to be disabled as well.

Regards,
Robert
>
> Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
>
> -- Mukesh
>
> > ---
> >   drivers/firmware/qcom_scm.c | 23 +++++++++++++++++++++++
> >   drivers/firmware/qcom_scm.h |  1 +
> >   2 files changed, 24 insertions(+)
> >
> > diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> > index fde33acd46b7..bdc9324d4e62 100644
> > --- a/drivers/firmware/qcom_scm.c
> > +++ b/drivers/firmware/qcom_scm.c
> > @@ -407,6 +407,29 @@ int qcom_scm_set_remote_state(u32 state, u32 id)
> >   }
> >   EXPORT_SYMBOL(qcom_scm_set_remote_state);
> >
> > +static int qcom_scm_disable_sdi(void)
> > +{
> > +     int ret;
> > +     struct qcom_scm_desc desc = {
> > +             .svc = QCOM_SCM_SVC_BOOT,
> > +             .cmd = QCOM_SCM_BOOT_SDI_CONFIG,
> > +             .args[0] = 1, /* Disable watchdog debug */
> > +             .args[1] = 0, /* Disable SDI */
> > +             .arginfo = QCOM_SCM_ARGS(2),
> > +             .owner = ARM_SMCCC_OWNER_SIP,
> > +     };
> > +     struct qcom_scm_res res;
> > +
> > +     ret = qcom_scm_clk_enable();
> > +     if (ret)
> > +             return ret;
> > +     ret = qcom_scm_call(__scm->dev, &desc, &res);
> > +
> > +     qcom_scm_clk_disable();
> > +
> > +     return ret ? : res.result[0];
> > +}
> > +
> >   static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
> >   {
> >       struct qcom_scm_desc desc = {
> > diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
> > index e6e512bd57d1..7b68fa820495 100644
> > --- a/drivers/firmware/qcom_scm.h
> > +++ b/drivers/firmware/qcom_scm.h
> > @@ -80,6 +80,7 @@ extern int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc,
> >   #define QCOM_SCM_SVC_BOOT           0x01
> >   #define QCOM_SCM_BOOT_SET_ADDR              0x01
> >   #define QCOM_SCM_BOOT_TERMINATE_PC  0x02
> > +#define QCOM_SCM_BOOT_SDI_CONFIG     0x09
> >   #define QCOM_SCM_BOOT_SET_DLOAD_MODE        0x10
> >   #define QCOM_SCM_BOOT_SET_ADDR_MC   0x11
> >   #define QCOM_SCM_BOOT_SET_REMOTE_STATE      0x0a
  

On Fri, May 19, 2023 at 01:16:56PM +0200, Robert Marko wrote:
> On Thu, 18 May 2023 at 16:25, Mukesh Ojha <quic_mojha@quicinc.com> wrote:
> > On 5/18/2023 7:32 PM, Robert Marko wrote:
> > > Some SoC-s like IPQ5018 require SDI(Secure Debug Image) to be disabled
> > > before trying to reboot, otherwise board will just hang after reboot has
> > > been issued via PSCI.
> > >
> > > So, provide a call to SCM that allows disabling it.
> > >
> > > Signed-off-by: Robert Marko <robimarko@gmail.com>
> >
> > This scm call support indeed needed for reboot cases, but i am not sure
> > about target specific check in the later patch.
> 
> I am not really sure where to put it, maybe as part of qcom_scm_shutdown?

I would suggest not waiting until shutdown. In fact, I suggest the
opposite -- that this needs to be done as early as possible. Any delay
leaves room for hanging the system -- because a watchdog reset, for
instance, might not be able to trigger an shutdown handler.

And I also imagine that's not the complain Mukesh had; I expect his
reservation was about using the SoC compatible property. But I'd prefer
having that conversation on patch 2.

> Yesterday I found out that in OpenWrt we also have a Google IPQ4019 board that
> has been needing SDI to be disabled as well.

That's me [1] :)

Feel free to CC me on such occasions. I would have loved to have
engaged with this earlier. Anyway, I replied directly to patch 2, since
I think that's a more appropriate place for the discussion.

Brian

[1] Subject: [RFC PATCH] firmware: qcom_scm: disable SDI at boot
    https://lore.kernel.org/all/20200721080054.2803881-1-computersforpeace@gmail.com/