Re: [PATCH v10 02/14] dt-bindings: cpus: add a thead vlen register length property

Charlie Jenkins charlie@rivosinc.com 於 2024年9月12日 週四 下午1:57寫道：

Add a property analogous to the vlenb CSR so that software can detect the vector length of each CPU prior to it being brought online. Currently software has to assume that the vector length read from the boot CPU applies to all possible CPUs. On T-Head CPUs implementing pre-ratification vector, reading the th.vlenb CSR may produce an illegal instruction trap, so this property is required on such systems.

Signed-off-by: Charlie Jenkins charlie@rivosinc.com Reviewed-by: Conor Dooley conor.dooley@microchip.com

Reviewed-by: Andy Chiu andybnac@gmail.com

---

Documentation/devicetree/bindings/riscv/cpus.yaml | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)

diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml index 8edc8261241a..c0cf6cf56749 100644 --- a/Documentation/devicetree/bindings/riscv/cpus.yaml +++ b/Documentation/devicetree/bindings/riscv/cpus.yaml @@ -26,6 +26,18 @@ description: | allOf:

• $ref: /schemas/cpu.yaml#
• $ref: extensions.yaml

• • if:

•  not:
  

•    properties:
  

•      compatible:
  

•        contains:
  

•          enum:
  

•            - thead,c906
  

•            - thead,c910
  

•            - thead,c920
  

• then:

•  properties:
  

•    thead,vlenb: false
  
  

properties: compatible: @@ -95,6 +107,13 @@ properties: description: The blocksize in bytes for the Zicboz cache operations.

• thead,vlenb:
• $ref: /schemas/types.yaml#/definitions/uint32
• description:

•  VLEN/8, the vector register length in bytes. This property is required on
  

•  thead systems where the vector register length is not identical on all harts, or
  

•  the vlenb CSR is not available.
  

• # RISC-V has multiple properties for cache op block sizes as the sizes # differ between individual CBO extensions cache-op-block-size: false

-- 2.45.0

---

linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv