[PATCH 2/7] RISC-V: Detect Zicond from ISA string

Anup Patel
2023-09-19T03:54:18Z

The RISC-V integer conditional (Zicond) operation extension defines
standard conditional arithmetic and conditional-select/move operations
which are inspired from the XVentanaCondOps extension. In fact, QEMU
RISC-V also has support for emulating Zicond extension.

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

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
Documentation/devicetree/bindings/riscv/extensions.yaml | 6 ++++++
arch/riscv/include/asm/hwcap.h | 1 +
arch/riscv/kernel/cpufeature.c | 1 +
3 files changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
index cad8ef68eca7..7ea90e2dbc5b 100644
--- a/Documentation/devicetree/bindings/riscv/extensions.yaml
+++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
@@ -225,6 +225,12 @@ properties:
ratified in the 20191213 version of the unprivileged ISA
specification.

+ - const: zicond
+ description:
+ The standard Zicond extension for conditional arithmetic and
+ conditional-select/move operations as ratified in commit 8fb6694
+ ("Update Gemfile") of riscv-zicond.
+
- const: zicsr
description: |
The standard Zicsr extension for control and status register
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index b7efe9e2fa89..15bafc02ffd4 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -60,6 +60,7 @@
#define RISCV_ISA_EXT_ZIHPM 42
#define RISCV_ISA_EXT_SMSTATEEN 43
#define RISCV_ISA_EXT_XVENTANACONDOPS 44
+#define RISCV_ISA_EXT_ZICOND 45

#define RISCV_ISA_EXT_MAX 64

diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 3a31d34fe709..49b6551f3347 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -174,6 +174,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
__RISCV_ISA_EXT_DATA(zba, RISCV_ISA_EXT_ZBA),
__RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB),
__RISCV_ISA_EXT_DATA(zbs, RISCV_ISA_EXT_ZBS),
+ __RISCV_ISA_EXT_DATA(zicond, RISCV_ISA_EXT_ZICOND),
__RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
__RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN),
__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
--
2.34.1