[0/2] OP-TEE FF-A notifications

  Hi all,

This patchset adds support for using FF-A notifications as a delivery
mechanism of asynchronous notifications from OP-TEE running in the secure
world. Support for asynchronous notifications via the SMC ABI was added in
[1], here we add the counterpart needed when using the the FF-A ABI.

Support for FF-A notifications is added with [2] and this patch set is based
on Sudeeps tree at [3].

[1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
[2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
[3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
    commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")

Thanks,
Jens

Jens Wiklander (2):
  optee: provide optee_do_bottom_half() as a common function
  optee: ffa_abi: add asynchronous notifications

 drivers/tee/optee/call.c          | 31 ++++++++++-
 drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
 drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
 drivers/tee/optee/optee_private.h |  9 ++-
 drivers/tee/optee/smc_abi.c       | 36 ++----------
 5 files changed, 153 insertions(+), 42 deletions(-)


base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
  

Hi Jens,

On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> Hi all,
>
> This patchset adds support for using FF-A notifications as a delivery
> mechanism of asynchronous notifications from OP-TEE running in the secure
> world. Support for asynchronous notifications via the SMC ABI was added in
> [1], here we add the counterpart needed when using the the FF-A ABI.
>
> Support for FF-A notifications is added with [2] and this patch set is based
> on Sudeeps tree at [3].

It's good to see FF-A notifications support coming through. The good
aspect here is that FF-A uses a common secure world SGI for
notifications and doesn't have to deal with platform specific reserved
SPI for notifications.

From OP-TEE point of view I think most of the secure SGI donation base
would be common, so can we switch the SMC ABI to use this donated
secure world SGI for notifications too?

-Sumit

>
> [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
>     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
>
> Thanks,
> Jens
>
> Jens Wiklander (2):
>   optee: provide optee_do_bottom_half() as a common function
>   optee: ffa_abi: add asynchronous notifications
>
>  drivers/tee/optee/call.c          | 31 ++++++++++-
>  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
>  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
>  drivers/tee/optee/optee_private.h |  9 ++-
>  drivers/tee/optee/smc_abi.c       | 36 ++----------
>  5 files changed, 153 insertions(+), 42 deletions(-)
>
>
> base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> --
> 2.34.1
>
  

Hi Sumit,

On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> Hi Jens,
> 
> On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> >
> > Hi all,
> >
> > This patchset adds support for using FF-A notifications as a delivery
> > mechanism of asynchronous notifications from OP-TEE running in the secure
> > world. Support for asynchronous notifications via the SMC ABI was added in
> > [1], here we add the counterpart needed when using the the FF-A ABI.
> >
> > Support for FF-A notifications is added with [2] and this patch set is based
> > on Sudeeps tree at [3].
> 
> It's good to see FF-A notifications support coming through. The good
> aspect here is that FF-A uses a common secure world SGI for
> notifications and doesn't have to deal with platform specific reserved
> SPI for notifications.
> 
> From OP-TEE point of view I think most of the secure SGI donation base
> would be common, so can we switch the SMC ABI to use this donated
> secure world SGI for notifications too?

The SMC ABI driver picks up the interrupt used for notification from
device-tree, so there's a chance that it just works if a donated SGI is
supplied instead. We'll need some changes in the secure world side of
OP-TEE, but they wouldn't affect the ABI.

Cheers,
Jens

> 
> -Sumit
> 
> >
> > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> >
> > Thanks,
> > Jens
> >
> > Jens Wiklander (2):
> >   optee: provide optee_do_bottom_half() as a common function
> >   optee: ffa_abi: add asynchronous notifications
> >
> >  drivers/tee/optee/call.c          | 31 ++++++++++-
> >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> >  drivers/tee/optee/optee_private.h |  9 ++-
> >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> >  5 files changed, 153 insertions(+), 42 deletions(-)
> >
> >
> > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > --
> > 2.34.1
> >
  

On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> Hi Sumit,
>
> On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > Hi Jens,
> >
> > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > >
> > > Hi all,
> > >
> > > This patchset adds support for using FF-A notifications as a delivery
> > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > >
> > > Support for FF-A notifications is added with [2] and this patch set is based
> > > on Sudeeps tree at [3].
> >
> > It's good to see FF-A notifications support coming through. The good
> > aspect here is that FF-A uses a common secure world SGI for
> > notifications and doesn't have to deal with platform specific reserved
> > SPI for notifications.
> >
> > From OP-TEE point of view I think most of the secure SGI donation base
> > would be common, so can we switch the SMC ABI to use this donated
> > secure world SGI for notifications too?
>
> The SMC ABI driver picks up the interrupt used for notification from
> device-tree, so there's a chance that it just works if a donated SGI is
> supplied instead. We'll need some changes in the secure world side of
> OP-TEE, but they wouldn't affect the ABI.

AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
The FF-A driver explicitly creates that mapping here [1]. Moreover
it's better to detect it via an SMC call rather than hard coded via DT
as FF-A driver does.

So the ABI should dynamically detect if there is a donated SGI then
use it otherwise fallback to SPI/PPI detection via DT. This would make
the notifications feature platform agnostic and we can drop legacy DT
methods from optee-os entirely but still need to maintain them in the
kernel for backwards compatibility.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
[2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275

-Sumit

>
> Cheers,
> Jens
>
> >
> > -Sumit
> >
> > >
> > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > >
> > > Thanks,
> > > Jens
> > >
> > > Jens Wiklander (2):
> > >   optee: provide optee_do_bottom_half() as a common function
> > >   optee: ffa_abi: add asynchronous notifications
> > >
> > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > >  drivers/tee/optee/optee_private.h |  9 ++-
> > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > >
> > >
> > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > --
> > > 2.34.1
> > >
  

On Thu, Nov 02, 2023 at 05:46:55PM +0530, Sumit Garg wrote:
> On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> >
> > Hi Sumit,
> >
> > On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > > Hi Jens,
> > >
> > > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > >
> > > > Hi all,
> > > >
> > > > This patchset adds support for using FF-A notifications as a delivery
> > > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > > >
> > > > Support for FF-A notifications is added with [2] and this patch set is based
> > > > on Sudeeps tree at [3].
> > >
> > > It's good to see FF-A notifications support coming through. The good
> > > aspect here is that FF-A uses a common secure world SGI for
> > > notifications and doesn't have to deal with platform specific reserved
> > > SPI for notifications.
> > >
> > > From OP-TEE point of view I think most of the secure SGI donation base
> > > would be common, so can we switch the SMC ABI to use this donated
> > > secure world SGI for notifications too?
> >
> > The SMC ABI driver picks up the interrupt used for notification from
> > device-tree, so there's a chance that it just works if a donated SGI is
> > supplied instead. We'll need some changes in the secure world side of
> > OP-TEE, but they wouldn't affect the ABI.
> 
> AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
> The FF-A driver explicitly creates that mapping here [1].

That looks a lot like what platform_get_irq() does via of_irq_get().

> Moreover
> it's better to detect it via an SMC call rather than hard coded via DT
> as FF-A driver does.

Typo? I guess you mean that you prefer that way the FF-A driver does it
rather than having it set in the DT.

Assuming that you only care about "arm,gic-v3". The SGI will likely
always be the same so it shouldn't be too hard to keep the correct
configuration in DT.

> 
> So the ABI should dynamically detect if there is a donated SGI then
> use it otherwise fallback to SPI/PPI detection via DT. This would make
> the notifications feature platform agnostic and we can drop legacy DT
> methods from optee-os entirely but still need to maintain them in the
> kernel for backwards compatibility.

We care about compatibility in both directions so we'd need to keep it
in OP-TEE too, but perhaps under a config flag.

Thanks,
Jens

> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275
> 
> -Sumit
> 
> >
> > Cheers,
> > Jens
> >
> > >
> > > -Sumit
> > >
> > > >
> > > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > > >
> > > > Thanks,
> > > > Jens
> > > >
> > > > Jens Wiklander (2):
> > > >   optee: provide optee_do_bottom_half() as a common function
> > > >   optee: ffa_abi: add asynchronous notifications
> > > >
> > > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > > >  drivers/tee/optee/optee_private.h |  9 ++-
> > > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > > >
> > > >
> > > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > > --
> > > > 2.34.1
> > > >
  

On Thu, 2 Nov 2023 at 18:46, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> On Thu, Nov 02, 2023 at 05:46:55PM +0530, Sumit Garg wrote:
> > On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > >
> > > Hi Sumit,
> > >
> > > On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > > > Hi Jens,
> > > >
> > > > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > >
> > > > > Hi all,
> > > > >
> > > > > This patchset adds support for using FF-A notifications as a delivery
> > > > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > > > >
> > > > > Support for FF-A notifications is added with [2] and this patch set is based
> > > > > on Sudeeps tree at [3].
> > > >
> > > > It's good to see FF-A notifications support coming through. The good
> > > > aspect here is that FF-A uses a common secure world SGI for
> > > > notifications and doesn't have to deal with platform specific reserved
> > > > SPI for notifications.
> > > >
> > > > From OP-TEE point of view I think most of the secure SGI donation base
> > > > would be common, so can we switch the SMC ABI to use this donated
> > > > secure world SGI for notifications too?
> > >
> > > The SMC ABI driver picks up the interrupt used for notification from
> > > device-tree, so there's a chance that it just works if a donated SGI is
> > > supplied instead. We'll need some changes in the secure world side of
> > > OP-TEE, but they wouldn't affect the ABI.
> >
> > AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
> > The FF-A driver explicitly creates that mapping here [1].
>
> That looks a lot like what platform_get_irq() does via of_irq_get().
>

There is GIC_SPI or GIC_PPI but nothing like GIC_SGI in DT bindings [1].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/dt-bindings/interrupt-controller/arm-gic.h

> > Moreover
> > it's better to detect it via an SMC call rather than hard coded via DT
> > as FF-A driver does.
>
> Typo? I guess you mean that you prefer that way the FF-A driver does it
> rather than having it set in the DT.

Yeah sorry about that. We shouldn't use DT if OP-TEE features are discoverable.

>
> Assuming that you only care about "arm,gic-v3". The SGI will likely
> always be the same so it shouldn't be too hard to keep the correct
> configuration in DT.

See above, DT looks like it does not support SGI.

>
> >
> > So the ABI should dynamically detect if there is a donated SGI then
> > use it otherwise fallback to SPI/PPI detection via DT. This would make
> > the notifications feature platform agnostic and we can drop legacy DT
> > methods from optee-os entirely but still need to maintain them in the
> > kernel for backwards compatibility.
>
> We care about compatibility in both directions so we'd need to keep it
> in OP-TEE too, but perhaps under a config flag.

Isn't it just supported on Qemu right now in OP-TEE? I hope dropping a
feature won't be a problem there compared with the maintenance burden.

-Sumit

>
> Thanks,
> Jens
>
> >
> > [1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
> > [2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275
> >
> > -Sumit
> >
> > >
> > > Cheers,
> > > Jens
> > >
> > > >
> > > > -Sumit
> > > >
> > > > >
> > > > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > > > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > > > >
> > > > > Thanks,
> > > > > Jens
> > > > >
> > > > > Jens Wiklander (2):
> > > > >   optee: provide optee_do_bottom_half() as a common function
> > > > >   optee: ffa_abi: add asynchronous notifications
> > > > >
> > > > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > > > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > > > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > > > >  drivers/tee/optee/optee_private.h |  9 ++-
> > > > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > > > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > > > >
> > > > >
> > > > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > > > --
> > > > > 2.34.1
> > > > >
  

On Thu, Nov 2, 2023 at 3:05 PM Sumit Garg <sumit.garg@linaro.org> wrote:
>
> On Thu, 2 Nov 2023 at 18:46, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> >
> > On Thu, Nov 02, 2023 at 05:46:55PM +0530, Sumit Garg wrote:
> > > On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > >
> > > > Hi Sumit,
> > > >
> > > > On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > > > > Hi Jens,
> > > > >
> > > > > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > > >
> > > > > > Hi all,
> > > > > >
> > > > > > This patchset adds support for using FF-A notifications as a delivery
> > > > > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > > > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > > > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > > > > >
> > > > > > Support for FF-A notifications is added with [2] and this patch set is based
> > > > > > on Sudeeps tree at [3].
> > > > >
> > > > > It's good to see FF-A notifications support coming through. The good
> > > > > aspect here is that FF-A uses a common secure world SGI for
> > > > > notifications and doesn't have to deal with platform specific reserved
> > > > > SPI for notifications.
> > > > >
> > > > > From OP-TEE point of view I think most of the secure SGI donation base
> > > > > would be common, so can we switch the SMC ABI to use this donated
> > > > > secure world SGI for notifications too?
> > > >
> > > > The SMC ABI driver picks up the interrupt used for notification from
> > > > device-tree, so there's a chance that it just works if a donated SGI is
> > > > supplied instead. We'll need some changes in the secure world side of
> > > > OP-TEE, but they wouldn't affect the ABI.
> > >
> > > AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
> > > The FF-A driver explicitly creates that mapping here [1].
> >
> > That looks a lot like what platform_get_irq() does via of_irq_get().
> >
>
> There is GIC_SPI or GIC_PPI but nothing like GIC_SGI in DT bindings [1].
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/dt-bindings/interrupt-controller/arm-gic.h
>
> > > Moreover
> > > it's better to detect it via an SMC call rather than hard coded via DT
> > > as FF-A driver does.
> >
> > Typo? I guess you mean that you prefer that way the FF-A driver does it
> > rather than having it set in the DT.
>
> Yeah sorry about that. We shouldn't use DT if OP-TEE features are discoverable.
>
> >
> > Assuming that you only care about "arm,gic-v3". The SGI will likely
> > always be the same so it shouldn't be too hard to keep the correct
> > configuration in DT.
>
> See above, DT looks like it does not support SGI.

You're right.

>
> >
> > >
> > > So the ABI should dynamically detect if there is a donated SGI then
> > > use it otherwise fallback to SPI/PPI detection via DT. This would make
> > > the notifications feature platform agnostic and we can drop legacy DT
> > > methods from optee-os entirely but still need to maintain them in the
> > > kernel for backwards compatibility.
> >
> > We care about compatibility in both directions so we'd need to keep it
> > in OP-TEE too, but perhaps under a config flag.
>
> Isn't it just supported on Qemu right now in OP-TEE? I hope dropping a
> feature won't be a problem there compared with the maintenance burden.

I'd rather not remove this since I believe it can support more
configurations (different interrupt controllers), but feel free to
propose a patch with the new ABI.

Cheers,
Jens

>
> -Sumit
>
> >
> > Thanks,
> > Jens
> >
> > >
> > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
> > > [2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275
> > >
> > > -Sumit
> > >
> > > >
> > > > Cheers,
> > > > Jens
> > > >
> > > > >
> > > > > -Sumit
> > > > >
> > > > > >
> > > > > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > > > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > > > > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > > > > >
> > > > > > Thanks,
> > > > > > Jens
> > > > > >
> > > > > > Jens Wiklander (2):
> > > > > >   optee: provide optee_do_bottom_half() as a common function
> > > > > >   optee: ffa_abi: add asynchronous notifications
> > > > > >
> > > > > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > > > > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > > > > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > > > > >  drivers/tee/optee/optee_private.h |  9 ++-
> > > > > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > > > > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > > > > >
> > > > > >
> > > > > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > > > > --
> > > > > > 2.34.1
> > > > > >
  

On Fri, 3 Nov 2023 at 13:32, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> On Thu, Nov 2, 2023 at 3:05 PM Sumit Garg <sumit.garg@linaro.org> wrote:
> >
> > On Thu, 2 Nov 2023 at 18:46, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > >
> > > On Thu, Nov 02, 2023 at 05:46:55PM +0530, Sumit Garg wrote:
> > > > On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > >
> > > > > Hi Sumit,
> > > > >
> > > > > On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > > > > > Hi Jens,
> > > > > >
> > > > > > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > > > >
> > > > > > > Hi all,
> > > > > > >
> > > > > > > This patchset adds support for using FF-A notifications as a delivery
> > > > > > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > > > > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > > > > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > > > > > >
> > > > > > > Support for FF-A notifications is added with [2] and this patch set is based
> > > > > > > on Sudeeps tree at [3].
> > > > > >
> > > > > > It's good to see FF-A notifications support coming through. The good
> > > > > > aspect here is that FF-A uses a common secure world SGI for
> > > > > > notifications and doesn't have to deal with platform specific reserved
> > > > > > SPI for notifications.
> > > > > >
> > > > > > From OP-TEE point of view I think most of the secure SGI donation base
> > > > > > would be common, so can we switch the SMC ABI to use this donated
> > > > > > secure world SGI for notifications too?
> > > > >
> > > > > The SMC ABI driver picks up the interrupt used for notification from
> > > > > device-tree, so there's a chance that it just works if a donated SGI is
> > > > > supplied instead. We'll need some changes in the secure world side of
> > > > > OP-TEE, but they wouldn't affect the ABI.
> > > >
> > > > AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
> > > > The FF-A driver explicitly creates that mapping here [1].
> > >
> > > That looks a lot like what platform_get_irq() does via of_irq_get().
> > >
> >
> > There is GIC_SPI or GIC_PPI but nothing like GIC_SGI in DT bindings [1].
> >
> > [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/dt-bindings/interrupt-controller/arm-gic.h
> >
> > > > Moreover
> > > > it's better to detect it via an SMC call rather than hard coded via DT
> > > > as FF-A driver does.
> > >
> > > Typo? I guess you mean that you prefer that way the FF-A driver does it
> > > rather than having it set in the DT.
> >
> > Yeah sorry about that. We shouldn't use DT if OP-TEE features are discoverable.
> >
> > >
> > > Assuming that you only care about "arm,gic-v3". The SGI will likely
> > > always be the same so it shouldn't be too hard to keep the correct
> > > configuration in DT.
> >
> > See above, DT looks like it does not support SGI.
>
> You're right.
>
> >
> > >
> > > >
> > > > So the ABI should dynamically detect if there is a donated SGI then
> > > > use it otherwise fallback to SPI/PPI detection via DT. This would make
> > > > the notifications feature platform agnostic and we can drop legacy DT
> > > > methods from optee-os entirely but still need to maintain them in the
> > > > kernel for backwards compatibility.
> > >
> > > We care about compatibility in both directions so we'd need to keep it
> > > in OP-TEE too, but perhaps under a config flag.
> >
> > Isn't it just supported on Qemu right now in OP-TEE? I hope dropping a
> > feature won't be a problem there compared with the maintenance burden.
>
> I'd rather not remove this since I believe it can support more
> configurations (different interrupt controllers), but feel free to
> propose a patch with the new ABI.

Having a second thought here, I think adding further ABIs (redundant
ABIs become maintenance burden overtime) don't make sense until we see
real users of notifications. Have you been able to discover real users
of this asynchronous notifications feature in OP-TEE?

-Sumit

>
> Cheers,
> Jens
>
> >
> > -Sumit
> >
> > >
> > > Thanks,
> > > Jens
> > >
> > > >
> > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
> > > > [2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275
> > > >
> > > > -Sumit
> > > >
> > > > >
> > > > > Cheers,
> > > > > Jens
> > > > >
> > > > > >
> > > > > > -Sumit
> > > > > >
> > > > > > >
> > > > > > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > > > > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > > > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > > > > > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > > > > > >
> > > > > > > Thanks,
> > > > > > > Jens
> > > > > > >
> > > > > > > Jens Wiklander (2):
> > > > > > >   optee: provide optee_do_bottom_half() as a common function
> > > > > > >   optee: ffa_abi: add asynchronous notifications
> > > > > > >
> > > > > > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > > > > > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > > > > > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > > > > > >  drivers/tee/optee/optee_private.h |  9 ++-
> > > > > > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > > > > > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > > > > > >
> > > > > > >
> > > > > > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > > > > > --
> > > > > > > 2.34.1
> > > > > > >
  

On Fri, Nov 3, 2023 at 9:53 AM Sumit Garg <sumit.garg@linaro.org> wrote:
>
> On Fri, 3 Nov 2023 at 13:32, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> >
> > On Thu, Nov 2, 2023 at 3:05 PM Sumit Garg <sumit.garg@linaro.org> wrote:
> > >
> > > On Thu, 2 Nov 2023 at 18:46, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > >
> > > > On Thu, Nov 02, 2023 at 05:46:55PM +0530, Sumit Garg wrote:
> > > > > On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > > >
> > > > > > Hi Sumit,
> > > > > >
> > > > > > On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > > > > > > Hi Jens,
> > > > > > >
> > > > > > > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > > > > >
> > > > > > > > Hi all,
> > > > > > > >
> > > > > > > > This patchset adds support for using FF-A notifications as a delivery
> > > > > > > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > > > > > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > > > > > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > > > > > > >
> > > > > > > > Support for FF-A notifications is added with [2] and this patch set is based
> > > > > > > > on Sudeeps tree at [3].
> > > > > > >
> > > > > > > It's good to see FF-A notifications support coming through. The good
> > > > > > > aspect here is that FF-A uses a common secure world SGI for
> > > > > > > notifications and doesn't have to deal with platform specific reserved
> > > > > > > SPI for notifications.
> > > > > > >
> > > > > > > From OP-TEE point of view I think most of the secure SGI donation base
> > > > > > > would be common, so can we switch the SMC ABI to use this donated
> > > > > > > secure world SGI for notifications too?
> > > > > >
> > > > > > The SMC ABI driver picks up the interrupt used for notification from
> > > > > > device-tree, so there's a chance that it just works if a donated SGI is
> > > > > > supplied instead. We'll need some changes in the secure world side of
> > > > > > OP-TEE, but they wouldn't affect the ABI.
> > > > >
> > > > > AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
> > > > > The FF-A driver explicitly creates that mapping here [1].
> > > >
> > > > That looks a lot like what platform_get_irq() does via of_irq_get().
> > > >
> > >
> > > There is GIC_SPI or GIC_PPI but nothing like GIC_SGI in DT bindings [1].
> > >
> > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/dt-bindings/interrupt-controller/arm-gic.h
> > >
> > > > > Moreover
> > > > > it's better to detect it via an SMC call rather than hard coded via DT
> > > > > as FF-A driver does.
> > > >
> > > > Typo? I guess you mean that you prefer that way the FF-A driver does it
> > > > rather than having it set in the DT.
> > >
> > > Yeah sorry about that. We shouldn't use DT if OP-TEE features are discoverable.
> > >
> > > >
> > > > Assuming that you only care about "arm,gic-v3". The SGI will likely
> > > > always be the same so it shouldn't be too hard to keep the correct
> > > > configuration in DT.
> > >
> > > See above, DT looks like it does not support SGI.
> >
> > You're right.
> >
> > >
> > > >
> > > > >
> > > > > So the ABI should dynamically detect if there is a donated SGI then
> > > > > use it otherwise fallback to SPI/PPI detection via DT. This would make
> > > > > the notifications feature platform agnostic and we can drop legacy DT
> > > > > methods from optee-os entirely but still need to maintain them in the
> > > > > kernel for backwards compatibility.
> > > >
> > > > We care about compatibility in both directions so we'd need to keep it
> > > > in OP-TEE too, but perhaps under a config flag.
> > >
> > > Isn't it just supported on Qemu right now in OP-TEE? I hope dropping a
> > > feature won't be a problem there compared with the maintenance burden.
> >
> > I'd rather not remove this since I believe it can support more
> > configurations (different interrupt controllers), but feel free to
> > propose a patch with the new ABI.
>
> Having a second thought here, I think adding further ABIs (redundant
> ABIs become maintenance burden overtime) don't make sense until we see
> real users of notifications. Have you been able to discover real users
> of this asynchronous notifications feature in OP-TEE?

No, not upstream. There have been questions about a feature like this
from time to time in the past and I guess non-trivial interrupt
handling will soon need it.

Cheers,
Jens

>
> -Sumit
>
> >
> > Cheers,
> > Jens
> >
> > >
> > > -Sumit
> > >
> > > >
> > > > Thanks,
> > > > Jens
> > > >
> > > > >
> > > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
> > > > > [2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275
> > > > >
> > > > > -Sumit
> > > > >
> > > > > >
> > > > > > Cheers,
> > > > > > Jens
> > > > > >
> > > > > > >
> > > > > > > -Sumit
> > > > > > >
> > > > > > > >
> > > > > > > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > > > > > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > > > > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > > > > > > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > > > > > > >
> > > > > > > > Thanks,
> > > > > > > > Jens
> > > > > > > >
> > > > > > > > Jens Wiklander (2):
> > > > > > > >   optee: provide optee_do_bottom_half() as a common function
> > > > > > > >   optee: ffa_abi: add asynchronous notifications
> > > > > > > >
> > > > > > > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > > > > > > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > > > > > > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > > > > > > >  drivers/tee/optee/optee_private.h |  9 ++-
> > > > > > > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > > > > > > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > > > > > > >
> > > > > > > >
> > > > > > > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > > > > > > --
> > > > > > > > 2.34.1
> > > > > > > >
  

On Mon, 6 Nov 2023 at 14:09, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> On Fri, Nov 3, 2023 at 9:53 AM Sumit Garg <sumit.garg@linaro.org> wrote:
> >
> > On Fri, 3 Nov 2023 at 13:32, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > >
> > > On Thu, Nov 2, 2023 at 3:05 PM Sumit Garg <sumit.garg@linaro.org> wrote:
> > > >
> > > > On Thu, 2 Nov 2023 at 18:46, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > >
> > > > > On Thu, Nov 02, 2023 at 05:46:55PM +0530, Sumit Garg wrote:
> > > > > > On Thu, 2 Nov 2023 at 17:29, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > > > >
> > > > > > > Hi Sumit,
> > > > > > >
> > > > > > > On Mon, Oct 30, 2023 at 11:32:47AM +0530, Sumit Garg wrote:
> > > > > > > > Hi Jens,
> > > > > > > >
> > > > > > > > On Thu, 26 Oct 2023 at 13:34, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> > > > > > > > >
> > > > > > > > > Hi all,
> > > > > > > > >
> > > > > > > > > This patchset adds support for using FF-A notifications as a delivery
> > > > > > > > > mechanism of asynchronous notifications from OP-TEE running in the secure
> > > > > > > > > world. Support for asynchronous notifications via the SMC ABI was added in
> > > > > > > > > [1], here we add the counterpart needed when using the the FF-A ABI.
> > > > > > > > >
> > > > > > > > > Support for FF-A notifications is added with [2] and this patch set is based
> > > > > > > > > on Sudeeps tree at [3].
> > > > > > > >
> > > > > > > > It's good to see FF-A notifications support coming through. The good
> > > > > > > > aspect here is that FF-A uses a common secure world SGI for
> > > > > > > > notifications and doesn't have to deal with platform specific reserved
> > > > > > > > SPI for notifications.
> > > > > > > >
> > > > > > > > From OP-TEE point of view I think most of the secure SGI donation base
> > > > > > > > would be common, so can we switch the SMC ABI to use this donated
> > > > > > > > secure world SGI for notifications too?
> > > > > > >
> > > > > > > The SMC ABI driver picks up the interrupt used for notification from
> > > > > > > device-tree, so there's a chance that it just works if a donated SGI is
> > > > > > > supplied instead. We'll need some changes in the secure world side of
> > > > > > > OP-TEE, but they wouldn't affect the ABI.
> > > > > >
> > > > > > AFAIK, a secure world donated SGIs doesn't support IRQ mapping via DT.
> > > > > > The FF-A driver explicitly creates that mapping here [1].
> > > > >
> > > > > That looks a lot like what platform_get_irq() does via of_irq_get().
> > > > >
> > > >
> > > > There is GIC_SPI or GIC_PPI but nothing like GIC_SGI in DT bindings [1].
> > > >
> > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/dt-bindings/interrupt-controller/arm-gic.h
> > > >
> > > > > > Moreover
> > > > > > it's better to detect it via an SMC call rather than hard coded via DT
> > > > > > as FF-A driver does.
> > > > >
> > > > > Typo? I guess you mean that you prefer that way the FF-A driver does it
> > > > > rather than having it set in the DT.
> > > >
> > > > Yeah sorry about that. We shouldn't use DT if OP-TEE features are discoverable.
> > > >
> > > > >
> > > > > Assuming that you only care about "arm,gic-v3". The SGI will likely
> > > > > always be the same so it shouldn't be too hard to keep the correct
> > > > > configuration in DT.
> > > >
> > > > See above, DT looks like it does not support SGI.
> > >
> > > You're right.
> > >
> > > >
> > > > >
> > > > > >
> > > > > > So the ABI should dynamically detect if there is a donated SGI then
> > > > > > use it otherwise fallback to SPI/PPI detection via DT. This would make
> > > > > > the notifications feature platform agnostic and we can drop legacy DT
> > > > > > methods from optee-os entirely but still need to maintain them in the
> > > > > > kernel for backwards compatibility.
> > > > >
> > > > > We care about compatibility in both directions so we'd need to keep it
> > > > > in OP-TEE too, but perhaps under a config flag.
> > > >
> > > > Isn't it just supported on Qemu right now in OP-TEE? I hope dropping a
> > > > feature won't be a problem there compared with the maintenance burden.
> > >
> > > I'd rather not remove this since I believe it can support more
> > > configurations (different interrupt controllers), but feel free to
> > > propose a patch with the new ABI.
> >
> > Having a second thought here, I think adding further ABIs (redundant
> > ABIs become maintenance burden overtime) don't make sense until we see
> > real users of notifications. Have you been able to discover real users
> > of this asynchronous notifications feature in OP-TEE?
>
> No, not upstream. There have been questions about a feature like this
> from time to time in the past and I guess non-trivial interrupt
> handling will soon need it.

Okay let's keep the way it is today unless we really need support for SGIs too.

-Sumit

>
> Cheers,
> Jens
>
> >
> > -Sumit
> >
> > >
> > > Cheers,
> > > Jens
> > >
> > > >
> > > > -Sumit
> > > >
> > > > >
> > > > > Thanks,
> > > > > Jens
> > > > >
> > > > > >
> > > > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1283
> > > > > > [2] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tree/drivers/firmware/arm_ffa/driver.c?h=ffa-updates-6.7#n1275
> > > > > >
> > > > > > -Sumit
> > > > > >
> > > > > > >
> > > > > > > Cheers,
> > > > > > > Jens
> > > > > > >
> > > > > > > >
> > > > > > > > -Sumit
> > > > > > > >
> > > > > > > > >
> > > > > > > > > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > > > > > > > > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > > > > > > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> > > > > > > > >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> > > > > > > > >
> > > > > > > > > Thanks,
> > > > > > > > > Jens
> > > > > > > > >
> > > > > > > > > Jens Wiklander (2):
> > > > > > > > >   optee: provide optee_do_bottom_half() as a common function
> > > > > > > > >   optee: ffa_abi: add asynchronous notifications
> > > > > > > > >
> > > > > > > > >  drivers/tee/optee/call.c          | 31 ++++++++++-
> > > > > > > > >  drivers/tee/optee/ffa_abi.c       | 91 ++++++++++++++++++++++++++++++-
> > > > > > > > >  drivers/tee/optee/optee_ffa.h     | 28 ++++++++--
> > > > > > > > >  drivers/tee/optee/optee_private.h |  9 ++-
> > > > > > > > >  drivers/tee/optee/smc_abi.c       | 36 ++----------
> > > > > > > > >  5 files changed, 153 insertions(+), 42 deletions(-)
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > base-commit: bcefd1bf63b1ec9bb08067021cf47f0fad96f395
> > > > > > > > > --
> > > > > > > > > 2.34.1
> > > > > > > > >
  

On Thu, Oct 26, 2023 at 10:04:07AM +0200, Jens Wiklander wrote:
> Hi all,
> 
> This patchset adds support for using FF-A notifications as a delivery
> mechanism of asynchronous notifications from OP-TEE running in the secure
> world. Support for asynchronous notifications via the SMC ABI was added in
> [1], here we add the counterpart needed when using the the FF-A ABI.
> 
> Support for FF-A notifications is added with [2] and this patch set is based
> on Sudeeps tree at [3].
> 
> [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
>     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> 

FWIW:

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

On Tue, Nov 7, 2023 at 12:48 PM Sudeep Holla <sudeep.holla@arm.com> wrote:
>
> On Thu, Oct 26, 2023 at 10:04:07AM +0200, Jens Wiklander wrote:
> > Hi all,
> >
> > This patchset adds support for using FF-A notifications as a delivery
> > mechanism of asynchronous notifications from OP-TEE running in the secure
> > world. Support for asynchronous notifications via the SMC ABI was added in
> > [1], here we add the counterpart needed when using the the FF-A ABI.
> >
> > Support for FF-A notifications is added with [2] and this patch set is based
> > on Sudeeps tree at [3].
> >
> > [1] https://lore.kernel.org/lkml/20211103090255.998070-1-jens.wiklander@linaro.org/
> > [2] https://lore.kernel.org/linux-arm-kernel/20231005-ffa_v1-1_notif-v4-0-cddd3237809c@arm.com/
> > [3] https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/tag/?h=ffa-updates-6.7
> >     commit bcefd1bf63b1 ("firmware: arm_ffa: Upgrade the driver version to v1.1")
> >
>
> FWIW:
>
> Tested-by: Sudeep Holla <sudeep.holla@arm.com>

Thanks, much appreciated.

Cheers,
Jens

>
> --
> Regards,
> Sudeep