[PATCH v5 2/4] dt-bindings: riscv: Add Svade and Svadu Entries

Yong-Xuan Wang yongxuan.wang at sifive.com
Wed Jun 5 05:15:08 PDT 2024


Add entries for the Svade and Svadu extensions to the riscv,isa-extensions
property.

Signed-off-by: Yong-Xuan Wang <yongxuan.wang at sifive.com>
---
 .../devicetree/bindings/riscv/extensions.yaml | 30 +++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
index 468c646247aa..1e30988826b9 100644
--- a/Documentation/devicetree/bindings/riscv/extensions.yaml
+++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
@@ -153,6 +153,36 @@ properties:
             ratified at commit 3f9ed34 ("Add ability to manually trigger
             workflow. (#2)") of riscv-time-compare.
 
+        - const: svade
+          description: |
+            The standard Svade supervisor-level extension for raising page-fault
+            exceptions when PTE A/D bits need be set as ratified in the 20240213
+            version of the privileged ISA specification.
+
+            Both Svade and Svadu extensions control the hardware behavior when
+            the PTE A/D bits need to be set. The default behavior for the four
+            possible combinations of these extensions in the device tree are:
+            1. Neither svade nor svadu in DT: default to svade.
+            2. Only svade in DT: use svade.
+            3. Only svadu in DT: use svadu.
+            4. Both svade and svadu in DT: default to svade (Linux can switch to
+               svadu once the SBI FWFT extension is available).
+
+        - const: svadu
+          description: |
+            The standard Svadu supervisor-level extension for hardware updating
+            of PTE A/D bits as ratified at commit c1abccf ("Merge pull request
+            #25 from ved-rivos/ratified") of riscv-svadu.
+
+            Both Svade and Svadu extensions control the hardware behavior when
+            the PTE A/D bits need to be set. The default behavior for the four
+            possible combinations of these extensions in the device tree are:
+            1. Neither svade nor svadu in DT: default to svade.
+            2. Only svade in DT: use svade.
+            3. Only svadu in DT: use svadu.
+            4. Both svade and svadu in DT: default to svade (Linux can switch to
+               svadu once the SBI FWFT extension is available).
+
         - const: svinval
           description:
             The standard Svinval supervisor-level extension for fine-grained
-- 
2.17.1




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