[PATCH 1/7] RISC-V: Detect XVentanaCondOps from ISA string

[Anup Patel]

The Veyron-V1 CPU supports custom conditional arithmetic and
conditional-select/move operations referred to as XVentanaCondOps
extension. In fact, QEMU RISC-V also has support for emulating
XVentanaCondOps extension.

Let us detect XVentanaCondOps extension from ISA string available
through DT or ACPI.

Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
---
 Documentation/devicetree/bindings/riscv/extensions.yaml | 7 +++++++
 arch/riscv/include/asm/hwcap.h                          | 1 +
 arch/riscv/kernel/cpufeature.c                          | 1 +
 3 files changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
index 36ff6749fbba..cad8ef68eca7 100644
--- a/Documentation/devicetree/bindings/riscv/extensions.yaml
+++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
@@ -171,6 +171,13 @@ properties:
             memory types as ratified in the 20191213 version of the privileged
             ISA specification.
 
+        - const: xventanacondops
+          description: |
+            The Ventana specific XVentanaCondOps extension for conditional
+            arithmetic and conditional-select/move operations defined by the
+            Ventana custom extensions specification v1.0.1 (or higher) at
+            https://github.com/ventanamicro/ventana-custom-extensions/releases.
+
         - const: zba
           description: |
             The standard Zba bit-manipulation extension for address generation
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 0f520f7d058a..b7efe9e2fa89 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -59,6 +59,7 @@
 #define RISCV_ISA_EXT_ZIFENCEI		41
 #define RISCV_ISA_EXT_ZIHPM		42
 #define RISCV_ISA_EXT_SMSTATEEN		43
+#define RISCV_ISA_EXT_XVENTANACONDOPS	44
 
 #define RISCV_ISA_EXT_MAX		64
 
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 3755a8c2a9de..3a31d34fe709 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -182,6 +182,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL),
 	__RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT),
 	__RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT),
+	__RISCV_ISA_EXT_DATA(xventanacondops, RISCV_ISA_EXT_XVENTANACONDOPS),
 };
 
 const size_t riscv_isa_ext_count = ARRAY_SIZE(riscv_isa_ext);
-- 
2.34.1