| Message ID | 20230828192507.117334-6-bartosz.golaszewski@linaro.org (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | arm64: qcom: add and enable SHM Bridge support | expand |
On 28/08/2023 21:25, Bartosz Golaszewski wrote: > Add Device Tree bindings for Qualcomm TEE Shared Memory Brige - a > mechanism that allows sharing memory buffers between trustzone and the > kernel. Subject prefix: dt-bindings: firmware: > > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > --- > .../bindings/firmware/qcom,shm-bridge.yaml | 36 +++++++++++++++++++ > 1 file changed, 36 insertions(+) > create mode 100644 Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml > > diff --git a/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml > new file mode 100644 > index 000000000000..f660962b7b86 > --- /dev/null > +++ b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml > @@ -0,0 +1,36 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/firmware/qcom,shm-bridge.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: QCOM Shared Memory Bridge > + > +description: | Do not need '|' unless you need to preserve formatting. > + Qualcomm TEE Shared Memory Bridge allows sharing limited areas of kernel's > + virtual memory with the trustzone in order to avoid mapping the entire RAM. > + > +maintainers: > + - Bjorn Andersson <andersson@kernel.org> > + - Konrad Dybcio <konrad.dybcio@linaro.org> > + - Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > + > +properties: > + compatible: > + items: > + - enum: > + - qcom,shm-bridge-sa8775p > + - qcom,shm-bridge-sm8150 > + - qcom,shm-bridge-sm8450 > + - const: qcom,shm-bridge > + Looks quite empty... Why this cannot be part of qcom,scm? IOW, why do you need new binding if you do not have any resources here and the block is essentially feature of qcom,scm firmware? > +required: > + - compatible > + > +additionalProperties: false > + > +examples: > + - | > + firmware { > + compatible = "qcom,shm-bridge-sa8775p", "qcom,shm-bridge"; Use 4 spaces for example indentation. > + }; Best regards, Krzysztof
On 29.08.2023 10:02, Krzysztof Kozlowski wrote: > On 28/08/2023 21:25, Bartosz Golaszewski wrote: >> Add Device Tree bindings for Qualcomm TEE Shared Memory Brige - a >> mechanism that allows sharing memory buffers between trustzone and the >> kernel. > > Subject prefix: > dt-bindings: firmware: > > > >> >> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> >> --- >> .../bindings/firmware/qcom,shm-bridge.yaml | 36 +++++++++++++++++++ >> 1 file changed, 36 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml >> >> diff --git a/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml >> new file mode 100644 >> index 000000000000..f660962b7b86 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml >> @@ -0,0 +1,36 @@ >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >> +%YAML 1.2 >> +--- >> +$id: http://devicetree.org/schemas/firmware/qcom,shm-bridge.yaml# >> +$schema: http://devicetree.org/meta-schemas/core.yaml# >> + >> +title: QCOM Shared Memory Bridge >> + >> +description: | > > Do not need '|' unless you need to preserve formatting. > >> + Qualcomm TEE Shared Memory Bridge allows sharing limited areas of kernel's >> + virtual memory with the trustzone in order to avoid mapping the entire RAM. >> + >> +maintainers: >> + - Bjorn Andersson <andersson@kernel.org> >> + - Konrad Dybcio <konrad.dybcio@linaro.org> >> + - Bartosz Golaszewski <bartosz.golaszewski@linaro.org> >> + >> +properties: >> + compatible: >> + items: >> + - enum: >> + - qcom,shm-bridge-sa8775p >> + - qcom,shm-bridge-sm8150 >> + - qcom,shm-bridge-sm8450 >> + - const: qcom,shm-bridge >> + > > Looks quite empty... Why this cannot be part of qcom,scm? IOW, why do > you need new binding if you do not have any resources here and the block > is essentially feature of qcom,scm firmware? Since it's "discoverable" (via retval of an scm call), I'd second the idea of probing this from within the SCM driver. Konrad
On Tue, 29 Aug 2023 at 11:30, Konrad Dybcio <konrad.dybcio@linaro.org> wrote: > > On 29.08.2023 10:02, Krzysztof Kozlowski wrote: > > On 28/08/2023 21:25, Bartosz Golaszewski wrote: > >> Add Device Tree bindings for Qualcomm TEE Shared Memory Brige - a > >> mechanism that allows sharing memory buffers between trustzone and the > >> kernel. > > > > Subject prefix: > > dt-bindings: firmware: > > > > > > > >> > >> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > >> --- > >> .../bindings/firmware/qcom,shm-bridge.yaml | 36 +++++++++++++++++++ > >> 1 file changed, 36 insertions(+) > >> create mode 100644 Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml > >> > >> diff --git a/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml > >> new file mode 100644 > >> index 000000000000..f660962b7b86 > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml > >> @@ -0,0 +1,36 @@ > >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > >> +%YAML 1.2 > >> +--- > >> +$id: http://devicetree.org/schemas/firmware/qcom,shm-bridge.yaml# > >> +$schema: http://devicetree.org/meta-schemas/core.yaml# > >> + > >> +title: QCOM Shared Memory Bridge > >> + > >> +description: | > > > > Do not need '|' unless you need to preserve formatting. > > > >> + Qualcomm TEE Shared Memory Bridge allows sharing limited areas of kernel's > >> + virtual memory with the trustzone in order to avoid mapping the entire RAM. > >> + > >> +maintainers: > >> + - Bjorn Andersson <andersson@kernel.org> > >> + - Konrad Dybcio <konrad.dybcio@linaro.org> > >> + - Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > >> + > >> +properties: > >> + compatible: > >> + items: > >> + - enum: > >> + - qcom,shm-bridge-sa8775p > >> + - qcom,shm-bridge-sm8150 > >> + - qcom,shm-bridge-sm8450 > >> + - const: qcom,shm-bridge > >> + > > > > Looks quite empty... Why this cannot be part of qcom,scm? IOW, why do > > you need new binding if you do not have any resources here and the block > > is essentially feature of qcom,scm firmware? > Since it's "discoverable" (via retval of an scm call), I'd second the > idea of probing this from within the SCM driver. > > Konrad Downstream has a bunch of DT switches that we don't support for now upstream. I disagree about shoehorning this into the SCM driver. It really is a layer on top of SCM but also SCM is a user of this interface. I will send a v2 with QCom ICE as a second user so that exporting symbols pointed out by Krzysztof as having no users make more sense. Hopefully keeping it separate will make more sense too. If anything, the SHM Bridge code should stay in a separate compilation unit even as part of SCM. Bart
On 30/08/2023 15:48, Bartosz Golaszewski wrote: > On Tue, 29 Aug 2023 at 11:30, Konrad Dybcio <konrad.dybcio@linaro.org> wrote: >> >> On 29.08.2023 10:02, Krzysztof Kozlowski wrote: >>> On 28/08/2023 21:25, Bartosz Golaszewski wrote: >>>> Add Device Tree bindings for Qualcomm TEE Shared Memory Brige - a >>>> mechanism that allows sharing memory buffers between trustzone and the >>>> kernel. >>> >>> Subject prefix: >>> dt-bindings: firmware: >>> >>> >>> >>>> >>>> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> >>>> --- >>>> .../bindings/firmware/qcom,shm-bridge.yaml | 36 +++++++++++++++++++ >>>> 1 file changed, 36 insertions(+) >>>> create mode 100644 Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml >>>> >>>> diff --git a/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml >>>> new file mode 100644 >>>> index 000000000000..f660962b7b86 >>>> --- /dev/null >>>> +++ b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml >>>> @@ -0,0 +1,36 @@ >>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >>>> +%YAML 1.2 >>>> +--- >>>> +$id: http://devicetree.org/schemas/firmware/qcom,shm-bridge.yaml# >>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>>> + >>>> +title: QCOM Shared Memory Bridge >>>> + >>>> +description: | >>> >>> Do not need '|' unless you need to preserve formatting. >>> >>>> + Qualcomm TEE Shared Memory Bridge allows sharing limited areas of kernel's >>>> + virtual memory with the trustzone in order to avoid mapping the entire RAM. >>>> + >>>> +maintainers: >>>> + - Bjorn Andersson <andersson@kernel.org> >>>> + - Konrad Dybcio <konrad.dybcio@linaro.org> >>>> + - Bartosz Golaszewski <bartosz.golaszewski@linaro.org> >>>> + >>>> +properties: >>>> + compatible: >>>> + items: >>>> + - enum: >>>> + - qcom,shm-bridge-sa8775p >>>> + - qcom,shm-bridge-sm8150 >>>> + - qcom,shm-bridge-sm8450 >>>> + - const: qcom,shm-bridge >>>> + >>> >>> Looks quite empty... Why this cannot be part of qcom,scm? IOW, why do >>> you need new binding if you do not have any resources here and the block >>> is essentially feature of qcom,scm firmware? >> Since it's "discoverable" (via retval of an scm call), I'd second the >> idea of probing this from within the SCM driver. >> >> Konrad > > Downstream has a bunch of DT switches that we don't support for now > upstream. I disagree about shoehorning this into the SCM driver. It > really is a layer on top of SCM but also SCM is a user of this > interface. Sure, for the driver makes sense, but it does not really explain why DT node is needed. It is not separate hardware. I doubt it is even separate firmware, but part of SCM. Best regards, Krzysztof
On Wed, 30 Aug 2023 at 16:31, Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote: > > On 30/08/2023 15:48, Bartosz Golaszewski wrote: > > On Tue, 29 Aug 2023 at 11:30, Konrad Dybcio <konrad.dybcio@linaro.org> wrote: > >> > >> On 29.08.2023 10:02, Krzysztof Kozlowski wrote: > >>> On 28/08/2023 21:25, Bartosz Golaszewski wrote: > >>>> Add Device Tree bindings for Qualcomm TEE Shared Memory Brige - a > >>>> mechanism that allows sharing memory buffers between trustzone and the > >>>> kernel. > >>> > >>> Subject prefix: > >>> dt-bindings: firmware: > >>> > >>> > >>> > >>>> > >>>> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > >>>> --- > >>>> .../bindings/firmware/qcom,shm-bridge.yaml | 36 +++++++++++++++++++ > >>>> 1 file changed, 36 insertions(+) > >>>> create mode 100644 Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml > >>>> > >>>> diff --git a/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml > >>>> new file mode 100644 > >>>> index 000000000000..f660962b7b86 > >>>> --- /dev/null > >>>> +++ b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml > >>>> @@ -0,0 +1,36 @@ > >>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > >>>> +%YAML 1.2 > >>>> +--- > >>>> +$id: http://devicetree.org/schemas/firmware/qcom,shm-bridge.yaml# > >>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# > >>>> + > >>>> +title: QCOM Shared Memory Bridge > >>>> + > >>>> +description: | > >>> > >>> Do not need '|' unless you need to preserve formatting. > >>> > >>>> + Qualcomm TEE Shared Memory Bridge allows sharing limited areas of kernel's > >>>> + virtual memory with the trustzone in order to avoid mapping the entire RAM. > >>>> + > >>>> +maintainers: > >>>> + - Bjorn Andersson <andersson@kernel.org> > >>>> + - Konrad Dybcio <konrad.dybcio@linaro.org> > >>>> + - Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > >>>> + > >>>> +properties: > >>>> + compatible: > >>>> + items: > >>>> + - enum: > >>>> + - qcom,shm-bridge-sa8775p > >>>> + - qcom,shm-bridge-sm8150 > >>>> + - qcom,shm-bridge-sm8450 > >>>> + - const: qcom,shm-bridge > >>>> + > >>> > >>> Looks quite empty... Why this cannot be part of qcom,scm? IOW, why do > >>> you need new binding if you do not have any resources here and the block > >>> is essentially feature of qcom,scm firmware? > >> Since it's "discoverable" (via retval of an scm call), I'd second the > >> idea of probing this from within the SCM driver. > >> > >> Konrad > > > > Downstream has a bunch of DT switches that we don't support for now > > upstream. I disagree about shoehorning this into the SCM driver. It > > really is a layer on top of SCM but also SCM is a user of this > > interface. > > Sure, for the driver makes sense, but it does not really explain why DT > node is needed. It is not separate hardware. I doubt it is even separate > firmware, but part of SCM. > > Best regards, > Krzysztof > Because not all platforms support it and it's the simplest way of marking the ones that do. Both SHM and SCM nodes sit on the firmware node anyway. What do you recommend? A property of the SCM node? Like 'qcom,shm-bridge` or something? Bart
On 30/08/2023 16:39, Bartosz Golaszewski wrote: > On Wed, 30 Aug 2023 at 16:31, Krzysztof Kozlowski > <krzysztof.kozlowski@linaro.org> wrote: >> >> On 30/08/2023 15:48, Bartosz Golaszewski wrote: >>> On Tue, 29 Aug 2023 at 11:30, Konrad Dybcio <konrad.dybcio@linaro.org> wrote: >>>> >>>> On 29.08.2023 10:02, Krzysztof Kozlowski wrote: >>>>> On 28/08/2023 21:25, Bartosz Golaszewski wrote: >>>>>> Add Device Tree bindings for Qualcomm TEE Shared Memory Brige - a >>>>>> mechanism that allows sharing memory buffers between trustzone and the >>>>>> kernel. >>>>> >>>>> Subject prefix: >>>>> dt-bindings: firmware: >>>>> >>>>> >>>>> >>>>>> >>>>>> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> >>>>>> --- >>>>>> .../bindings/firmware/qcom,shm-bridge.yaml | 36 +++++++++++++++++++ >>>>>> 1 file changed, 36 insertions(+) >>>>>> create mode 100644 Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml >>>>>> >>>>>> diff --git a/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml >>>>>> new file mode 100644 >>>>>> index 000000000000..f660962b7b86 >>>>>> --- /dev/null >>>>>> +++ b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml >>>>>> @@ -0,0 +1,36 @@ >>>>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >>>>>> +%YAML 1.2 >>>>>> +--- >>>>>> +$id: http://devicetree.org/schemas/firmware/qcom,shm-bridge.yaml# >>>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>>>>> + >>>>>> +title: QCOM Shared Memory Bridge >>>>>> + >>>>>> +description: | >>>>> >>>>> Do not need '|' unless you need to preserve formatting. >>>>> >>>>>> + Qualcomm TEE Shared Memory Bridge allows sharing limited areas of kernel's >>>>>> + virtual memory with the trustzone in order to avoid mapping the entire RAM. >>>>>> + >>>>>> +maintainers: >>>>>> + - Bjorn Andersson <andersson@kernel.org> >>>>>> + - Konrad Dybcio <konrad.dybcio@linaro.org> >>>>>> + - Bartosz Golaszewski <bartosz.golaszewski@linaro.org> >>>>>> + >>>>>> +properties: >>>>>> + compatible: >>>>>> + items: >>>>>> + - enum: >>>>>> + - qcom,shm-bridge-sa8775p >>>>>> + - qcom,shm-bridge-sm8150 >>>>>> + - qcom,shm-bridge-sm8450 >>>>>> + - const: qcom,shm-bridge >>>>>> + >>>>> >>>>> Looks quite empty... Why this cannot be part of qcom,scm? IOW, why do >>>>> you need new binding if you do not have any resources here and the block >>>>> is essentially feature of qcom,scm firmware? >>>> Since it's "discoverable" (via retval of an scm call), I'd second the >>>> idea of probing this from within the SCM driver. >>>> >>>> Konrad >>> >>> Downstream has a bunch of DT switches that we don't support for now >>> upstream. I disagree about shoehorning this into the SCM driver. It >>> really is a layer on top of SCM but also SCM is a user of this >>> interface. >> >> Sure, for the driver makes sense, but it does not really explain why DT >> node is needed. It is not separate hardware. I doubt it is even separate >> firmware, but part of SCM. >> >> Best regards, >> Krzysztof >> > > Because not all platforms support it and it's the simplest way of Platforms like SoCs or boards? > marking the ones that do. Both SHM and SCM nodes sit on the firmware > node anyway. What do you recommend? A property of the SCM node? Like > 'qcom,shm-bridge` or something? If the first - you talk about SoCs - then you have everything needed already: SCM compatibles. This defines it fully. If it varies by boards with one SoC, would be different case, but I really doubt it. Best regards, Krzysztof
On Wed, 30 Aug 2023 at 16:58, Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote: > > On 30/08/2023 16:39, Bartosz Golaszewski wrote: > > On Wed, 30 Aug 2023 at 16:31, Krzysztof Kozlowski > > <krzysztof.kozlowski@linaro.org> wrote: > >> > >> On 30/08/2023 15:48, Bartosz Golaszewski wrote: > >>> On Tue, 29 Aug 2023 at 11:30, Konrad Dybcio <konrad.dybcio@linaro.org> wrote: > >>>> > >>>> On 29.08.2023 10:02, Krzysztof Kozlowski wrote: > >>>>> On 28/08/2023 21:25, Bartosz Golaszewski wrote: > >>>>>> Add Device Tree bindings for Qualcomm TEE Shared Memory Brige - a > >>>>>> mechanism that allows sharing memory buffers between trustzone and the > >>>>>> kernel. > >>>>> > >>>>> Subject prefix: > >>>>> dt-bindings: firmware: > >>>>> > >>>>> > >>>>> > >>>>>> > >>>>>> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > >>>>>> --- > >>>>>> .../bindings/firmware/qcom,shm-bridge.yaml | 36 +++++++++++++++++++ > >>>>>> 1 file changed, 36 insertions(+) > >>>>>> create mode 100644 Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml > >>>>>> > >>>>>> diff --git a/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml > >>>>>> new file mode 100644 > >>>>>> index 000000000000..f660962b7b86 > >>>>>> --- /dev/null > >>>>>> +++ b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml > >>>>>> @@ -0,0 +1,36 @@ > >>>>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > >>>>>> +%YAML 1.2 > >>>>>> +--- > >>>>>> +$id: http://devicetree.org/schemas/firmware/qcom,shm-bridge.yaml# > >>>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# > >>>>>> + > >>>>>> +title: QCOM Shared Memory Bridge > >>>>>> + > >>>>>> +description: | > >>>>> > >>>>> Do not need '|' unless you need to preserve formatting. > >>>>> > >>>>>> + Qualcomm TEE Shared Memory Bridge allows sharing limited areas of kernel's > >>>>>> + virtual memory with the trustzone in order to avoid mapping the entire RAM. > >>>>>> + > >>>>>> +maintainers: > >>>>>> + - Bjorn Andersson <andersson@kernel.org> > >>>>>> + - Konrad Dybcio <konrad.dybcio@linaro.org> > >>>>>> + - Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > >>>>>> + > >>>>>> +properties: > >>>>>> + compatible: > >>>>>> + items: > >>>>>> + - enum: > >>>>>> + - qcom,shm-bridge-sa8775p > >>>>>> + - qcom,shm-bridge-sm8150 > >>>>>> + - qcom,shm-bridge-sm8450 > >>>>>> + - const: qcom,shm-bridge > >>>>>> + > >>>>> > >>>>> Looks quite empty... Why this cannot be part of qcom,scm? IOW, why do > >>>>> you need new binding if you do not have any resources here and the block > >>>>> is essentially feature of qcom,scm firmware? > >>>> Since it's "discoverable" (via retval of an scm call), I'd second the > >>>> idea of probing this from within the SCM driver. > >>>> > >>>> Konrad > >>> > >>> Downstream has a bunch of DT switches that we don't support for now > >>> upstream. I disagree about shoehorning this into the SCM driver. It > >>> really is a layer on top of SCM but also SCM is a user of this > >>> interface. > >> > >> Sure, for the driver makes sense, but it does not really explain why DT > >> node is needed. It is not separate hardware. I doubt it is even separate > >> firmware, but part of SCM. > >> > >> Best regards, > >> Krzysztof > >> > > > > Because not all platforms support it and it's the simplest way of > > Platforms like SoCs or boards? > > > marking the ones that do. Both SHM and SCM nodes sit on the firmware > > node anyway. What do you recommend? A property of the SCM node? Like > > 'qcom,shm-bridge` or something? > > If the first - you talk about SoCs - then you have everything needed > already: SCM compatibles. This defines it fully. > > If it varies by boards with one SoC, would be different case, but I > really doubt it. > Ok, makes sense. Thanks. Bartosz
diff --git a/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml new file mode 100644 index 000000000000..f660962b7b86 --- /dev/null +++ b/Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml @@ -0,0 +1,36 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/firmware/qcom,shm-bridge.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: QCOM Shared Memory Bridge + +description: | + Qualcomm TEE Shared Memory Bridge allows sharing limited areas of kernel's + virtual memory with the trustzone in order to avoid mapping the entire RAM. + +maintainers: + - Bjorn Andersson <andersson@kernel.org> + - Konrad Dybcio <konrad.dybcio@linaro.org> + - Bartosz Golaszewski <bartosz.golaszewski@linaro.org> + +properties: + compatible: + items: + - enum: + - qcom,shm-bridge-sa8775p + - qcom,shm-bridge-sm8150 + - qcom,shm-bridge-sm8450 + - const: qcom,shm-bridge + +required: + - compatible + +additionalProperties: false + +examples: + - | + firmware { + compatible = "qcom,shm-bridge-sa8775p", "qcom,shm-bridge"; + };
Add Device Tree bindings for Qualcomm TEE Shared Memory Brige - a mechanism that allows sharing memory buffers between trustzone and the kernel. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> --- .../bindings/firmware/qcom,shm-bridge.yaml | 36 +++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 Documentation/devicetree/bindings/firmware/qcom,shm-bridge.yaml