diff mbox series

[v3,1/7] dt-bindings: Arm: Add Firmware Framework for Armv8-A (FF-A) binding

Message ID 20201204121137.2966778-2-sudeep.holla@arm.com
State Superseded
Headers show
Series firmware: Add initial support for Arm FF-A | expand

Commit Message

Sudeep Holla Dec. 4, 2020, 12:11 p.m. UTC
Since the FF-A v1.0 specification doesn't list the UUID of all the
partitions in the discovery API, we need to specify the UUID of the
partitions that need to be accessed by drivers within the kernel.

This binding to provide the list of partitions that kernel drivers
may need to access.

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

---
 .../devicetree/bindings/arm/arm,ffa.yaml      | 58 +++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/arm,ffa.yaml

-- 
2.25.1

Comments

Rob Herring (Arm) Dec. 14, 2020, 10:01 p.m. UTC | #1
On Fri, Dec 04, 2020 at 12:11:31PM +0000, Sudeep Holla wrote:
> Since the FF-A v1.0 specification doesn't list the UUID of all the

> partitions in the discovery API, we need to specify the UUID of the

> partitions that need to be accessed by drivers within the kernel.

> 

> This binding to provide the list of partitions that kernel drivers

> may need to access.

> 

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

> ---

>  .../devicetree/bindings/arm/arm,ffa.yaml      | 58 +++++++++++++++++++

>  1 file changed, 58 insertions(+)

>  create mode 100644 Documentation/devicetree/bindings/arm/arm,ffa.yaml

> 

> diff --git a/Documentation/devicetree/bindings/arm/arm,ffa.yaml b/Documentation/devicetree/bindings/arm/arm,ffa.yaml

> new file mode 100644

> index 000000000000..a014a5801c34

> --- /dev/null

> +++ b/Documentation/devicetree/bindings/arm/arm,ffa.yaml

> @@ -0,0 +1,58 @@

> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

> +%YAML 1.2

> +---

> +$id: http://devicetree.org/schemas/arm/arm,ffa.yaml#

> +$schema: http://devicetree.org/meta-schemas/core.yaml#

> +

> +title: Arm Firmware Framework for Arm v8-A (in-kernel users)

> +

> +maintainers:

> +  - Sudeep Holla <sudeep.holla@arm.com>

> +

> +description: |

> +  Firmware frameworks implementing partition according to the FF-A

> +  specification defined by ARM document number ARM DEN 0077A ("Arm Firmware

> +  Framework for Arm v8-A") [0], providing services to be used by other

> +  partitions.

> +

> +  [0] https://developer.arm.com/docs/den0077/latest

> +

> +properties:

> +  $nodename:

> +    const: ffa

> +

> +  compatible:

> +    oneOf:

> +      - const: arm,ffa-1.0

> +

> +patternProperties:

> +  "^ffa_partition[0-9]+$":

> +    type: object

> +    description: One or more child nodes, each describing an FFA partition.

> +    properties:

> +      $nodename:

> +        const: ffa_partition

> +

> +      compatible:

> +        oneOf:

> +          - const: arm,ffa-1.0-partition

> +

> +      uuid:

> +        $ref: '/schemas/types.yaml#definitions/string'

> +        description: |

> +          The 128-bit UUID [2] of the service implemented by this partition.

> +

> +          [2] https://tools.ietf.org/html/rfc4122


UUIDs are actually a known thing in json-schema with 'format: uuid'. 
The meta-schema will probably reject that, so we'll need to add support 
to dtschema. Maybe it should be a new definition to reference.

> +

> +additionalProperties: false

> +

> +examples:

> +  - |

> +    ffa {

> +      compatible = "arm,ffa-1.0";

> +

> +      ffa_partition0 {

> +        compatible = "arm,ffa-1.0-partition";

> +        uuid = "12345678-9abc-def0-1234-56789abcdef0";

> +      };

> +    };


This could all be simplified down to just a single property:

arm,ffa-partitions = "12345678-9abc-def0-1234-56789abcdef0", 
	"12345678-9abc-def0-1234-56789abcdef1"
	"12345678-9abc-def0-1234-56789abcdef2";

Obviously, that's not extensible, but do we need it to be?

Rob
Sudeep Holla Dec. 16, 2020, 12:24 p.m. UTC | #2
On Mon, Dec 14, 2020 at 04:01:07PM -0600, Rob Herring wrote:
> On Fri, Dec 04, 2020 at 12:11:31PM +0000, Sudeep Holla wrote:

> > Since the FF-A v1.0 specification doesn't list the UUID of all the

> > partitions in the discovery API, we need to specify the UUID of the

> > partitions that need to be accessed by drivers within the kernel.

> > 

> > This binding to provide the list of partitions that kernel drivers

> > may need to access.

> > 

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

> > ---

> >  .../devicetree/bindings/arm/arm,ffa.yaml      | 58 +++++++++++++++++++

> >  1 file changed, 58 insertions(+)

> >  create mode 100644 Documentation/devicetree/bindings/arm/arm,ffa.yaml

> > 

> > diff --git a/Documentation/devicetree/bindings/arm/arm,ffa.yaml b/Documentation/devicetree/bindings/arm/arm,ffa.yaml

> > new file mode 100644

> > index 000000000000..a014a5801c34

> > --- /dev/null

> > +++ b/Documentation/devicetree/bindings/arm/arm,ffa.yaml

> > @@ -0,0 +1,58 @@

> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

> > +%YAML 1.2

> > +---

> > +$id: http://devicetree.org/schemas/arm/arm,ffa.yaml#

> > +$schema: http://devicetree.org/meta-schemas/core.yaml#

> > +

> > +title: Arm Firmware Framework for Arm v8-A (in-kernel users)

> > +

> > +maintainers:

> > +  - Sudeep Holla <sudeep.holla@arm.com>

> > +

> > +description: |

> > +  Firmware frameworks implementing partition according to the FF-A

> > +  specification defined by ARM document number ARM DEN 0077A ("Arm Firmware

> > +  Framework for Arm v8-A") [0], providing services to be used by other

> > +  partitions.

> > +

> > +  [0] https://developer.arm.com/docs/den0077/latest

> > +

> > +properties:

> > +  $nodename:

> > +    const: ffa

> > +

> > +  compatible:

> > +    oneOf:

> > +      - const: arm,ffa-1.0

> > +

> > +patternProperties:

> > +  "^ffa_partition[0-9]+$":

> > +    type: object

> > +    description: One or more child nodes, each describing an FFA partition.

> > +    properties:

> > +      $nodename:

> > +        const: ffa_partition

> > +

> > +      compatible:

> > +        oneOf:

> > +          - const: arm,ffa-1.0-partition

> > +

> > +      uuid:

> > +        $ref: '/schemas/types.yaml#definitions/string'

> > +        description: |

> > +          The 128-bit UUID [2] of the service implemented by this partition.

> > +

> > +          [2] https://tools.ietf.org/html/rfc4122

> 

> UUIDs are actually a known thing in json-schema with 'format: uuid'. 

> The meta-schema will probably reject that, so we'll need to add support 

> to dtschema. Maybe it should be a new definition to reference.

>


Ah OK, I will try that and ask for help if I am stuck as I am still trying
to learn these, not there yet 😄 

> > +

> > +additionalProperties: false

> > +

> > +examples:

> > +  - |

> > +    ffa {

> > +      compatible = "arm,ffa-1.0";

> > +

> > +      ffa_partition0 {

> > +        compatible = "arm,ffa-1.0-partition";

> > +        uuid = "12345678-9abc-def0-1234-56789abcdef0";

> > +      };

> > +    };

>

> This could all be simplified down to just a single property:

>


Thanks for the suggestion, I would love this to force spec authors to
stop relying on DT and add whatever needed in future to the spec as part
of discovery APIs.

> arm,ffa-partitions = "12345678-9abc-def0-1234-56789abcdef0", 

> 	"12345678-9abc-def0-1234-56789abcdef1"

> 	"12345678-9abc-def0-1234-56789abcdef2";

>

> Obviously, that's not extensible, but do we need it to be?

>


I prefer if we don't, but I will run this through spec authors so that
they are aware of what we will do in DT which means they *have* to
incorporate any future needs into the spec discovery apis.

Ah I forgot the spec author is cc-ed. @Achin please shout if you see
issues with this approach.

--
Regards,
Sudeep
Jens Wiklander Dec. 16, 2020, 1:46 p.m. UTC | #3
On Wed, Dec 16, 2020 at 12:24:08PM +0000, Sudeep Holla wrote:
> On Mon, Dec 14, 2020 at 04:01:07PM -0600, Rob Herring wrote:

> > On Fri, Dec 04, 2020 at 12:11:31PM +0000, Sudeep Holla wrote:

> > > Since the FF-A v1.0 specification doesn't list the UUID of all the

> > > partitions in the discovery API, we need to specify the UUID of the

> > > partitions that need to be accessed by drivers within the kernel.

> > > 

> > > This binding to provide the list of partitions that kernel drivers

> > > may need to access.

> > > 

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

> > > ---

> > >  .../devicetree/bindings/arm/arm,ffa.yaml      | 58 +++++++++++++++++++

> > >  1 file changed, 58 insertions(+)

> > >  create mode 100644 Documentation/devicetree/bindings/arm/arm,ffa.yaml

> > > 

> > > diff --git a/Documentation/devicetree/bindings/arm/arm,ffa.yaml b/Documentation/devicetree/bindings/arm/arm,ffa.yaml

> > > new file mode 100644

> > > index 000000000000..a014a5801c34

> > > --- /dev/null

> > > +++ b/Documentation/devicetree/bindings/arm/arm,ffa.yaml

> > > @@ -0,0 +1,58 @@

> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

> > > +%YAML 1.2

> > > +---

> > > +$id: http://devicetree.org/schemas/arm/arm,ffa.yaml#

> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#

> > > +

> > > +title: Arm Firmware Framework for Arm v8-A (in-kernel users)

> > > +

> > > +maintainers:

> > > +  - Sudeep Holla <sudeep.holla@arm.com>

> > > +

> > > +description: |

> > > +  Firmware frameworks implementing partition according to the FF-A

> > > +  specification defined by ARM document number ARM DEN 0077A ("Arm Firmware

> > > +  Framework for Arm v8-A") [0], providing services to be used by other

> > > +  partitions.

> > > +

> > > +  [0] https://developer.arm.com/docs/den0077/latest

> > > +

> > > +properties:

> > > +  $nodename:

> > > +    const: ffa

> > > +

> > > +  compatible:

> > > +    oneOf:

> > > +      - const: arm,ffa-1.0

> > > +

> > > +patternProperties:

> > > +  "^ffa_partition[0-9]+$":

> > > +    type: object

> > > +    description: One or more child nodes, each describing an FFA partition.

> > > +    properties:

> > > +      $nodename:

> > > +        const: ffa_partition

> > > +

> > > +      compatible:

> > > +        oneOf:

> > > +          - const: arm,ffa-1.0-partition

> > > +

> > > +      uuid:

> > > +        $ref: '/schemas/types.yaml#definitions/string'

> > > +        description: |

> > > +          The 128-bit UUID [2] of the service implemented by this partition.

> > > +

> > > +          [2] https://tools.ietf.org/html/rfc4122

> > 

> > UUIDs are actually a known thing in json-schema with 'format: uuid'. 

> > The meta-schema will probably reject that, so we'll need to add support 

> > to dtschema. Maybe it should be a new definition to reference.

> >

> 

> Ah OK, I will try that and ask for help if I am stuck as I am still trying

> to learn these, not there yet 😄 

> 

> > > +

> > > +additionalProperties: false

> > > +

> > > +examples:

> > > +  - |

> > > +    ffa {

> > > +      compatible = "arm,ffa-1.0";

> > > +

> > > +      ffa_partition0 {

> > > +        compatible = "arm,ffa-1.0-partition";

> > > +        uuid = "12345678-9abc-def0-1234-56789abcdef0";

> > > +      };

> > > +    };

> >

> > This could all be simplified down to just a single property:

> >

> 

> Thanks for the suggestion, I would love this to force spec authors to

> stop relying on DT and add whatever needed in future to the spec as part

> of discovery APIs.

> 

> > arm,ffa-partitions = "12345678-9abc-def0-1234-56789abcdef0", 

> > 	"12345678-9abc-def0-1234-56789abcdef1"

> > 	"12345678-9abc-def0-1234-56789abcdef2";

> >

> > Obviously, that's not extensible, but do we need it to be?

> >

> 

> I prefer if we don't, but I will run this through spec authors so that

> they are aware of what we will do in DT which means they *have* to

> incorporate any future needs into the spec discovery apis.


Speaking of discovery apis, doesn't the FF-A spec already have that?
Or am I missing something?

Cheers,
Jens

> 

> Ah I forgot the spec author is cc-ed. @Achin please shout if you see

> issues with this approach.

> 

> --

> Regards,

> Sudeep
Sudeep Holla Jan. 13, 2021, 10 a.m. UTC | #4
On Wed, Dec 16, 2020 at 12:24:08PM +0000, Sudeep Holla wrote:
> On Mon, Dec 14, 2020 at 04:01:07PM -0600, Rob Herring wrote:

> > On Fri, Dec 04, 2020 at 12:11:31PM +0000, Sudeep Holla wrote:

> > > Since the FF-A v1.0 specification doesn't list the UUID of all the

> > > partitions in the discovery API, we need to specify the UUID of the

> > > partitions that need to be accessed by drivers within the kernel.

> > > 

> > > This binding to provide the list of partitions that kernel drivers

> > > may need to access.

> > > 

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

> > > ---

> > >  .../devicetree/bindings/arm/arm,ffa.yaml      | 58 +++++++++++++++++++

> > >  1 file changed, 58 insertions(+)

> > >  create mode 100644 Documentation/devicetree/bindings/arm/arm,ffa.yaml

> > > 

> > > diff --git a/Documentation/devicetree/bindings/arm/arm,ffa.yaml b/Documentation/devicetree/bindings/arm/arm,ffa.yaml

> > > new file mode 100644

> > > index 000000000000..a014a5801c34

> > > --- /dev/null

> > > +++ b/Documentation/devicetree/bindings/arm/arm,ffa.yaml

> > > @@ -0,0 +1,58 @@

> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

> > > +%YAML 1.2

> > > +---

> > > +$id: http://devicetree.org/schemas/arm/arm,ffa.yaml#

> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#

> > > +

> > > +title: Arm Firmware Framework for Arm v8-A (in-kernel users)

> > > +

> > > +maintainers:

> > > +  - Sudeep Holla <sudeep.holla@arm.com>

> > > +

> > > +description: |

> > > +  Firmware frameworks implementing partition according to the FF-A

> > > +  specification defined by ARM document number ARM DEN 0077A ("Arm Firmware

> > > +  Framework for Arm v8-A") [0], providing services to be used by other

> > > +  partitions.

> > > +

> > > +  [0] https://developer.arm.com/docs/den0077/latest

> > > +

> > > +properties:

> > > +  $nodename:

> > > +    const: ffa

> > > +

> > > +  compatible:

> > > +    oneOf:

> > > +      - const: arm,ffa-1.0

> > > +

> > > +patternProperties:

> > > +  "^ffa_partition[0-9]+$":

> > > +    type: object

> > > +    description: One or more child nodes, each describing an FFA partition.

> > > +    properties:

> > > +      $nodename:

> > > +        const: ffa_partition

> > > +

> > > +      compatible:

> > > +        oneOf:

> > > +          - const: arm,ffa-1.0-partition

> > > +

> > > +      uuid:

> > > +        $ref: '/schemas/types.yaml#definitions/string'

> > > +        description: |

> > > +          The 128-bit UUID [2] of the service implemented by this partition.

> > > +

> > > +          [2] https://tools.ietf.org/html/rfc4122

> > 

> > UUIDs are actually a known thing in json-schema with 'format: uuid'. 

> > The meta-schema will probably reject that, so we'll need to add support 

> > to dtschema. Maybe it should be a new definition to reference.

> >

> 

> Ah OK, I will try that and ask for help if I am stuck as I am still trying

> to learn these, not there yet 😄 

> 

> > > +

> > > +additionalProperties: false

> > > +

> > > +examples:

> > > +  - |

> > > +    ffa {

> > > +      compatible = "arm,ffa-1.0";

> > > +

> > > +      ffa_partition0 {

> > > +        compatible = "arm,ffa-1.0-partition";

> > > +        uuid = "12345678-9abc-def0-1234-56789abcdef0";

> > > +      };

> > > +    };

> >

> > This could all be simplified down to just a single property:

> >

> 

> Thanks for the suggestion, I would love this to force spec authors to

> stop relying on DT and add whatever needed in future to the spec as part

> of discovery APIs.

> 

> > arm,ffa-partitions = "12345678-9abc-def0-1234-56789abcdef0", 

> > 	"12345678-9abc-def0-1234-56789abcdef1"

> > 	"12345678-9abc-def0-1234-56789abcdef2";

> >

> > Obviously, that's not extensible, but do we need it to be?

> >

> 

> I prefer if we don't, but I will run this through spec authors so that

> they are aware of what we will do in DT which means they *have* to

> incorporate any future needs into the spec discovery apis.

> 


OK we found some usecase which may require separate nodes. I am sure they
could be alternative solution even with above style of array of UUID strings.

If you remember use of SMC/HVC as SCMI transport[1], it just provides one
way(a2p) communication. P2A is not possible with that, i.e platform
notifications to OSPM is not possible. FFA aims to replace native SMC/HVC
transport there to provide bi-directional support. For such usecase,
where one partition running SCMI server might provide multiple channels
for SCMI communication and we may need to provide the link using phandle
or something in DT.

Let me know your thoughts on those.

--
Regards,
Sudeep

[1] https://lore.kernel.org/r/20201222145603.40192-2-jim2101024@gmail.com
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/arm/arm,ffa.yaml b/Documentation/devicetree/bindings/arm/arm,ffa.yaml
new file mode 100644
index 000000000000..a014a5801c34
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/arm,ffa.yaml
@@ -0,0 +1,58 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/arm,ffa.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Arm Firmware Framework for Arm v8-A (in-kernel users)
+
+maintainers:
+  - Sudeep Holla <sudeep.holla@arm.com>
+
+description: |
+  Firmware frameworks implementing partition according to the FF-A
+  specification defined by ARM document number ARM DEN 0077A ("Arm Firmware
+  Framework for Arm v8-A") [0], providing services to be used by other
+  partitions.
+
+  [0] https://developer.arm.com/docs/den0077/latest
+
+properties:
+  $nodename:
+    const: ffa
+
+  compatible:
+    oneOf:
+      - const: arm,ffa-1.0
+
+patternProperties:
+  "^ffa_partition[0-9]+$":
+    type: object
+    description: One or more child nodes, each describing an FFA partition.
+    properties:
+      $nodename:
+        const: ffa_partition
+
+      compatible:
+        oneOf:
+          - const: arm,ffa-1.0-partition
+
+      uuid:
+        $ref: '/schemas/types.yaml#definitions/string'
+        description: |
+          The 128-bit UUID [2] of the service implemented by this partition.
+
+          [2] https://tools.ietf.org/html/rfc4122
+
+additionalProperties: false
+
+examples:
+  - |
+    ffa {
+      compatible = "arm,ffa-1.0";
+
+      ffa_partition0 {
+        compatible = "arm,ffa-1.0-partition";
+        uuid = "12345678-9abc-def0-1234-56789abcdef0";
+      };
+    };