diff mbox series

[v5,01/11] dt-bindings: document generic access controller

Message ID 20230929142852.578394-2-gatien.chevallier@foss.st.com (mailing list archive)
State New, archived
Headers show
Series Introduce STM32 Firewall framework | expand

Commit Message

Gatien CHEVALLIER Sept. 29, 2023, 2:28 p.m. UTC
From: Oleksii Moisieiev <Oleksii_Moisieiev@epam.com>

Introducing of the generic access controller bindings for the
access controller provider and consumer devices. Those bindings are
intended to allow a better handling of accesses to resources in a
hardware architecture supporting several compartments.

This patch is based on [1]. It is integrated in this patchset as it
provides a use-case for it.

Diffs with [1]:
	- Rename feature-domain* properties to access-control* to narrow
	  down the scope of the binding
	- YAML errors and typos corrected.
	- Example updated
	- Some rephrasing in the binding description

[1]: https://lore.kernel.org/lkml/0c0a82bb-18ae-d057-562b

Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com>
Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>

---
Changes in V5:
	- Diffs with [1]
	- Discarded the [IGNORE] tag as the patch is now part of the
	  patchset

 .../access-controllers/access-controller.yaml | 90 +++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/access-controllers/access-controller.yaml

Comments

Gatien CHEVALLIER Oct. 2, 2023, 9:10 a.m. UTC | #1
On 9/29/23 17:35, Rob Herring wrote:
> 
> On Fri, 29 Sep 2023 16:28:42 +0200, Gatien Chevallier wrote:
>> From: Oleksii Moisieiev <Oleksii_Moisieiev@epam.com>
>>
>> Introducing of the generic access controller bindings for the
>> access controller provider and consumer devices. Those bindings are
>> intended to allow a better handling of accesses to resources in a
>> hardware architecture supporting several compartments.
>>
>> This patch is based on [1]. It is integrated in this patchset as it
>> provides a use-case for it.
>>
>> Diffs with [1]:
>> 	- Rename feature-domain* properties to access-control* to narrow
>> 	  down the scope of the binding
>> 	- YAML errors and typos corrected.
>> 	- Example updated
>> 	- Some rephrasing in the binding description
>>
>> [1]: https://lore.kernel.org/lkml/0c0a82bb-18ae-d057-562b
>>
>> Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com>
>> Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
>>
>> ---
>> Changes in V5:
>> 	- Diffs with [1]
>> 	- Discarded the [IGNORE] tag as the patch is now part of the
>> 	  patchset
>>
>>   .../access-controllers/access-controller.yaml | 90 +++++++++++++++++++
>>   1 file changed, 90 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/access-controllers/access-controller.yaml
>>
> 
> My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
> on your patch (DT_CHECKER_FLAGS is new in v5.13):
> 
> yamllint warnings/errors:
> 
> dtschema/dtc warnings/errors:
> /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/access-controllers/access-controller.yaml: access-control-provider: missing type definition
> 
> doc reference errors (make refcheckdocs):
> 
> See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20230929142852.578394-2-gatien.chevallier@foss.st.com
> 
> The base for the series is generally the latest rc1. A different dependency
> should be noted in *this* patch.
> 
> If you already ran 'make dt_binding_check' and didn't see the above
> error(s), then make sure 'yamllint' is installed and dt-schema is up to
> date:
> 
> pip3 install dtschema --upgrade
> 
> Please check and re-submit after running the above command yourself. Note
> that DT_SCHEMA_FILES can be set to your schema file to speed up checking
> your schema. However, it must be unset to test all examples with your schema.
> 

Hi Rob,

Running:
1- make dt_binding_check | grep access-control
2- make dt_binding_check 
DT_SCHEMA_FILES=Documentation/devicetree/bindings/access-controllers/access-controller.yaml
from Krzysztof's slideset

with

pip3 show dtschema
Name: dtschema
Version: 2023.9

and

pip3 show yamllint
Name: yamllint
Version: 1.32.0

I don't see any of the errors reported by the robot. I have to clone
your repository to reproduce it.

Should I resubmit with a clean dt-check using the latest dtschema?

***********
However, I get:
warning: ignoring duplicate '$id' value 
'http://devicetree.org/schemas/reserved-memory/framebuffer.yaml#
warning: ignoring duplicate '$id' value 
'http://devicetree.org/schemas/reserved-memory/memory-region.yaml#
warning: ignoring duplicate '$id' value 
'http://devicetree.org/schemas/reserved-memory/shared-dma-pool.yaml#
warning: ignoring duplicate '$id' value 
'http://devicetree.org/schemas/reserved-memory/reserved-memory.yaml

Above warnings disappears when switching to:
pip3 show dtschema
Name: dtschema
Version: 2023.7

The above YAMLs seem to be duplicated in dtschema's latest version.
I guess it's a synchro that needs to be done since:
https://lore.kernel.org/all/20230830231758.2561402-2-sjg@chromium.org/
***********

Best regards,
Gatien
Gatien CHEVALLIER Oct. 3, 2023, 7:45 a.m. UTC | #2
Hi Rob,

On 10/2/23 19:30, Rob Herring wrote:
> On Fri, Sep 29, 2023 at 04:28:42PM +0200, Gatien Chevallier wrote:
>> From: Oleksii Moisieiev <Oleksii_Moisieiev@epam.com>
>>
>> Introducing of the generic access controller bindings for the
>> access controller provider and consumer devices. Those bindings are
>> intended to allow a better handling of accesses to resources in a
>> hardware architecture supporting several compartments.
>>
>> This patch is based on [1]. It is integrated in this patchset as it
>> provides a use-case for it.
>>
>> Diffs with [1]:
>> 	- Rename feature-domain* properties to access-control* to narrow
>> 	  down the scope of the binding
>> 	- YAML errors and typos corrected.
>> 	- Example updated
>> 	- Some rephrasing in the binding description
>>
>> [1]: https://lore.kernel.org/lkml/0c0a82bb-18ae-d057-562b
>>
>> Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com>
>> Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
>>
>> ---
>> Changes in V5:
>> 	- Diffs with [1]
>> 	- Discarded the [IGNORE] tag as the patch is now part of the
>> 	  patchset
>>
>>   .../access-controllers/access-controller.yaml | 90 +++++++++++++++++++
>>   1 file changed, 90 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/access-controllers/access-controller.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/access-controllers/access-controller.yaml b/Documentation/devicetree/bindings/access-controllers/access-controller.yaml
>> new file mode 100644
>> index 000000000000..9d305fccc333
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/access-controllers/access-controller.yaml
>> @@ -0,0 +1,90 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/access-controllers/access-controller.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Generic Domain Access Controller
>> +
>> +maintainers:
>> +  - Oleksii Moisieiev <oleksii_moisieiev@epam.com>
>> +
>> +description: |+
>> +  Common access controllers properties
>> +
>> +  Access controllers are in charge of stating which of the hardware blocks under
>> +  their responsibility (their domain) can be accesssed by which compartment. A
>> +  compartment can be a cluster of CPUs (or coprocessors), a range of addresses
>> +  or a group of hardware blocks. An access controller's domain is the set of
>> +  resources covered by the access controller.
>> +
>> +  This device tree bindings can be used to bind devices to their access
>> +  controller provided by access-controller property. In this case, the device is
>> +  a consumer and the access controller is the provider.
>> +
>> +  An access controller can be represented by any node in the device tree and
>> +  can provide one or more configuration parameters, needed to control parameters
>> +  of the consumer device. A consumer node can refer to the provider by phandle
>> +  and a set of phandle arguments, specified by '#access-controller-cells'
>> +  property in the access controller node.
>> +
>> +  Access controllers are typically used to set/read the permissions of a
>> +  hardware block and grant access to it. Any of which depends on the access
>> +  controller. The capabilities of each access controller are defined by the
>> +  binding of the access controller device.
>> +
>> +  Each node can be a consumer for the several access controllers.
>> +
>> +# always select the core schema
>> +select: true
>> +
>> +properties:
>> +  "#access-controller-cells":
>> +    $ref: /schemas/types.yaml#/definitions/uint32
> 
> Drop. "#.*-cells" already defines the type.
> 

Ok, I will drop it for V6

>> +    description:
>> +      Number of cells in a access-controller specifier;
>> +      Can be any value as specified by device tree binding documentation
>> +      of a particular provider.
>> +
>> +  access-control-provider:
>> +    description:
>> +      Indicates that the node is an access controller.
> 
> Drop. The presence of "#access-controller-cells" is enough to do that.
> 

Ok, I wasn't sure. I'll will drop it for V6

>> +
>> +  access-controller-names:
>> +    $ref: /schemas/types.yaml#/definitions/string-array
>> +    description:
>> +      A list of access-controller names, sorted in the same order as
>> +      access-controller entries. Consumer drivers will use
>> +      access-controller-names to match with existing access-controller entries.
>> +
>> +  access-controller:
> 
> For consistency with other provider bindings: access-controllers
> 

Ack

>> +    $ref: /schemas/types.yaml#/definitions/phandle-array
>> +    description:
>> +      A list of access controller specifiers, as defined by the
>> +      bindings of the access-controller provider.
>> +
>> +additionalProperties: true
>> +
>> +examples:
>> +  - |
>> +    uart_controller: access-controller@50000 {
>> +        reg = <0x50000 0x10>;
>> +        access-control-provider;
>> +        #access-controller-cells = <2>;
>> +    };
>> +
>> +    bus_controller: bus@60000 {
>> +        reg = <0x60000 0x10000>;
>> +        #address-cells = <1>;
>> +        #size-cells = <1>;
>> +        ranges;
>> +        access-control-provider;
>> +        #access-controller-cells = <3>;
>> +
>> +        uart4: serial@60100 {
>> +            reg = <0x60100 0x400>;
>> +            access-controller = <&uart_controller 1 2>,
>> +                                <&bus_controller 1 3 5>;
>> +            access-controller-names = "controller", "bus-controller";
> 
> Not great names. It should indicate what access is being controlled
> locally. Perhaps "reg" for register access, "dma" or "bus" for bus
> master access. (Not sure what your uart_controller is controlling access
> to.)
> 
> Rob

Yes, I agree it's poor naming. I'll come up with something more
adequate. Thank you for the input.

Best regards,
Gatien
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/access-controllers/access-controller.yaml b/Documentation/devicetree/bindings/access-controllers/access-controller.yaml
new file mode 100644
index 000000000000..9d305fccc333
--- /dev/null
+++ b/Documentation/devicetree/bindings/access-controllers/access-controller.yaml
@@ -0,0 +1,90 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/access-controllers/access-controller.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic Domain Access Controller
+
+maintainers:
+  - Oleksii Moisieiev <oleksii_moisieiev@epam.com>
+
+description: |+
+  Common access controllers properties
+
+  Access controllers are in charge of stating which of the hardware blocks under
+  their responsibility (their domain) can be accesssed by which compartment. A
+  compartment can be a cluster of CPUs (or coprocessors), a range of addresses
+  or a group of hardware blocks. An access controller's domain is the set of
+  resources covered by the access controller.
+
+  This device tree bindings can be used to bind devices to their access
+  controller provided by access-controller property. In this case, the device is
+  a consumer and the access controller is the provider.
+
+  An access controller can be represented by any node in the device tree and
+  can provide one or more configuration parameters, needed to control parameters
+  of the consumer device. A consumer node can refer to the provider by phandle
+  and a set of phandle arguments, specified by '#access-controller-cells'
+  property in the access controller node.
+
+  Access controllers are typically used to set/read the permissions of a
+  hardware block and grant access to it. Any of which depends on the access
+  controller. The capabilities of each access controller are defined by the
+  binding of the access controller device.
+
+  Each node can be a consumer for the several access controllers.
+
+# always select the core schema
+select: true
+
+properties:
+  "#access-controller-cells":
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Number of cells in a access-controller specifier;
+      Can be any value as specified by device tree binding documentation
+      of a particular provider.
+
+  access-control-provider:
+    description:
+      Indicates that the node is an access controller.
+
+  access-controller-names:
+    $ref: /schemas/types.yaml#/definitions/string-array
+    description:
+      A list of access-controller names, sorted in the same order as
+      access-controller entries. Consumer drivers will use
+      access-controller-names to match with existing access-controller entries.
+
+  access-controller:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    description:
+      A list of access controller specifiers, as defined by the
+      bindings of the access-controller provider.
+
+additionalProperties: true
+
+examples:
+  - |
+    uart_controller: access-controller@50000 {
+        reg = <0x50000 0x10>;
+        access-control-provider;
+        #access-controller-cells = <2>;
+    };
+
+    bus_controller: bus@60000 {
+        reg = <0x60000 0x10000>;
+        #address-cells = <1>;
+        #size-cells = <1>;
+        ranges;
+        access-control-provider;
+        #access-controller-cells = <3>;
+
+        uart4: serial@60100 {
+            reg = <0x60100 0x400>;
+            access-controller = <&uart_controller 1 2>,
+                                <&bus_controller 1 3 5>;
+            access-controller-names = "controller", "bus-controller";
+        };
+    };