[PATCH] dt-bindings: riscv: Add SiFive vendor extensions description

[Nick Hu]

Add description for SiFive vendor extensions "xsfcflushdlone",
"xsfpgflushdlone" and "xsfcease".

Signed-off-by: Nick Hu <nick.hu at sifive.com>
---
 .../devicetree/bindings/riscv/extensions.yaml  | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
index 72c1b063fdfe..10c37c61243d 100644
--- a/Documentation/devicetree/bindings/riscv/extensions.yaml
+++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
@@ -626,6 +626,24 @@ properties:
             https://www.andestech.com/wp-content/uploads/AX45MP-1C-Rev.-5.0.0-Datasheet.pdf
 
         # SiFive
+        - const: xsfcease
+          description:
+            SiFive CEASE Instruction Extensions Specification.
+            See more details in
+            https://www.sifive.com/document-file/freedom-u740-c000-manual
+
+        - const: xsfcflushdlone
+          description:
+            SiFive L1D Cache Flush Instruction Extensions Specification.
+            See more details in
+            https://www.sifive.com/document-file/freedom-u740-c000-manual
+
+        - const: xsfpgflushdlone
+          description:
+            SiFive PGFLUSH Instruction Extensions for the power management. The
+            CPU will flush the L1D and enter the cease state after executing
+            the instruction.
+
         - const: xsfqmaccdod
           description:
             SiFive Int8 Matrix Multiplication Extensions Specification.
-- 
2.17.1