[PATCH v7 03/11] dt-bindings: riscv: Add Zic64b extension description

Zic64b mandates that cache blocks are 64 bytes in size and naturally
aligned in the address space. It is a mandatory extension of both the
RVA22 (U64/S64) and RVA23 (U64/S64) profiles, ratified with RISC-V
Profiles Version 1.0.

Document it so it can be described in the riscv,isa-extensions property,
alongside the related Zicbom/Zicbop/Zicboz cache-block extensions. Since
Zic64b fixes the cache block size at 64 bytes, also add a schema check
requiring any present cbom/cbop/cboz block size to be 64. The check
matches only nodes that use riscv,isa-extensions, so nodes carrying
just the deprecated riscv,isa string are not affected.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Guodong Xu <redacted>
---
v7: Collected Acked-by from Conor Dooley.
v6: Guard the zic64b rule with required: riscv,isa-extensions so it
    cannot match nodes using only the deprecated riscv,isa string
    (same defect class as Rob's bot reported against the Zicbo*
    block-size patch).
v5: Commit message clean up, fix a double space (Conor).
v4: Insert zic64b at its sorted position (before zicbom).
    Update the commit message.
v3: New patch.
---
 .../devicetree/bindings/riscv/extensions.yaml      | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
index d4cde2a7b8b2..79491ef8f86a 100644
--- a/Documentation/devicetree/bindings/riscv/extensions.yaml
+++ b/Documentation/devicetree/bindings/riscv/extensions.yaml

@@ -537,6 +537,12 @@   riscv,isa-extensions:
             in commit 64074bc ("Update version numbers for Zfh/Zfinx") of
             riscv-isa-manual.
 
+        - const: zic64b
+          description:
+            The standard Zic64b extension for 64-byte naturally aligned cache
+            blocks, as ratified in RISC-V Profiles Version 1.0, with commit
+            b1d806605f87 ("Updated to ratified state.")
+
         - const: zicbom
           description:
             The standard Zicbom extension for base cache management operations as

@@ -1211,6 +1217,22 @@   - if:
           not:
             contains:
               const: zilsd
+  # Zic64b mandates 64-byte naturally aligned cache blocks
+  - if:
+      properties:
+        riscv,isa-extensions:
+          contains:
+            const: zic64b
+      required:
+        - riscv,isa-extensions
+    then:
+      properties:
+        riscv,cbom-block-size:
+          const: 64
+        riscv,cbop-block-size:
+          const: 64
+        riscv,cboz-block-size:
+          const: 64
   # All three Zicbo* extensions require their block size property as there's no
   # default.
   - if:

-- 
2.43.0