[PATCH v1 3/5] dt-bindings: Add RISC-V misaligned access performance

Palmer Dabbelt palmer at rivosinc.com
Thu Oct 13 09:35:49 PDT 2022


This key allows device trees to specify the performance of misaligned
accesses to main memory regions from each CPU in the system.

Signed-off-by: Palmer Dabbelt <palmer at rivosinc.com>
---
 Documentation/devicetree/bindings/riscv/cpus.yaml | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml
index 873dd12f6e89..832ae9101d05 100644
--- a/Documentation/devicetree/bindings/riscv/cpus.yaml
+++ b/Documentation/devicetree/bindings/riscv/cpus.yaml
@@ -83,6 +83,21 @@ properties:
       - rv64imac
       - rv64imafdc
 
+  riscv,misaligned-access-performance:
+    description:
+      Identifies the performance of misaligned memory accesses to main memory
+      regions.  There are three flavors of unaligned access performance: "emulated"
+      means that misaligned accesses are emulated via software and thus
+      extremely slow, "slow" means that misaligned accesses are supported by
+      hardware but still slower that aligned accesses sequences, and "fast"
+      means that misaligned accesses are as fast or faster than the
+      cooresponding aligned accesses sequences.
+    $ref: "/schemas/types.yaml#/definitions/string"
+    enum:
+      - emulated
+      - slow
+      - fast
+
   # RISC-V requires 'timebase-frequency' in /cpus, so disallow it here
   timebase-frequency: false
 
-- 
2.38.0




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