Re: [PATCH 2/4] dt-bindings: remoteproc: add compatibility for TEE support

On 1/16/24 20:21, Rob Herring wrote:

On Mon, Jan 15, 2024 at 02:52:47PM +0100, Arnaud Pouliquen wrote:

...

The "st,stm32mp1-m4-tee" compatible is utilized in a system configuration where the Cortex-M4 firmware is loaded by the Trusted execution Environment (TEE). This compatible is used in both the Linux and OP-TEE device-tree.

• In OP-TEE, a node is defined in the device tree with the st,stm32mp1-m4-tee to support signed remoteproc firmware. Based on DT properties, OP-TEE authenticates, loads, starts, and stops the firmware.
• On Linux, when the compatibility is set, the Cortex-M resets should not be declared in the device tree.

Signed-off-by: Arnaud Pouliquen arnaud.pouliquen@foss.st.com

.../bindings/remoteproc/st,stm32-rproc.yaml | 53 +++++++++++++++---- 1 file changed, 44 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml index 370af61d8f28..9fdfa30eff20 100644 --- a/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml +++ b/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml @@ -16,7 +16,12 @@ maintainers: properties: compatible:

• const: st,stm32mp1-m4

• enum:

•  - st,stm32mp1-m4
  

•  - st,stm32mp1-m4-tee
  

• description:

•  Use "st,stm32mp1-m4" for the Cortex-M4 coprocessor management by Linux
  

What if other OSs want to manage the M4?

Right, for instance this compatibles are also used by U-boot. I will change "by Linux" by "by non secure context"

...

•  Use "st,stm32mp1-m4-tee" for the Cortex-M4 coprocessor management by secure context
  

reg: description: @@ -142,21 +147,41 @@ properties: required:

• compatible
• reg
• • resets

allOf:

• if: properties:

•    reset-names:
  

•      not:
  

•        contains:
  

•          const: hold_boot
  

•    compatible:
  

•      contains:
  

•        const: st,stm32mp1-m4
  

• then:

•  if:
  

•    properties:
  

•      reset-names:
  

•        not:
  

•          contains:
  

•            const: hold_boot
  

•  then:
  

•    required:
  

•      - st,syscfg-holdboot
  

•      - resets
  

•  else:
  

•    properties:
  

•      st,syscfg-holdboot: false
  

•    required:
  

•      - reset-names
  

Looks like a new required property.

I just realize that it does not make sense. We execute this only if "reset-names" contains "hold_boot". I will remove it

Thanks! Arnaud

...

•      - resets
  

• • if:

•  properties:
  

•    compatible:
  

•      contains:
  

•        const: st,stm32mp1-m4-tee
  

  then:

•  required:
  

•    - st,syscfg-holdboot
  

• else: properties: st,syscfg-holdboot: false

•    reset-names: false
  

•    resets: false
  

additionalProperties: false @@ -188,5 +213,15 @@ examples: st,syscfg-rsc-tbl = <&tamp 0x144 0xFFFFFFFF>; st,syscfg-m4-state = <&tamp 0x148 0xFFFFFFFF>; };

• • |
• #include <dt-bindings/reset/stm32mp1-resets.h>
• m4@10000000 {

•  compatible = "st,stm32mp1-m4-tee";
  

•  reg = <0x10000000 0x40000>,
  

•        <0x30000000 0x40000>,
  

•        <0x38000000 0x10000>;
  

•  st,syscfg-rsc-tbl = <&tamp 0x144 0xFFFFFFFF>;
  

•  st,syscfg-m4-state = <&tamp 0x148 0xFFFFFFFF>;
  

• };

... -- 2.25.1