[PATCH v9 06/20] RISC-V: Add Smcntrpmf extension parsing

[Atish Patra <atish.patra@linux.dev>]

From: Atish Patra <atishp@rivosinc.com>

Smcntrpmf extension allows M-mode to enable privilege mode filtering
for cycle/instret counters. However, the cyclecfg/instretcfg CSRs are
available in Ssccfg only if Smcntrpmf is present.

That's why, kernel needs to detect presence of Smcntrpmf extension and
enable privilege mode filtering for cycle/instret counters.

Reviewed-by: Clément Léger <cleger@rivosinc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Charlie Jenkins <thecharlesjenkins@gmail.com>
Tested-by: Charlie Jenkins <thecharlesjenkins@gmail.com>
Link: https://patch.msgid.link/20260701-counter_delegation-v8-6-7909f863a645@meta.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
---
 arch/riscv/include/asm/hwcap.h | 1 +
 arch/riscv/kernel/cpufeature.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index d4a7b90e2d78..51ad55b9677a 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -114,6 +114,7 @@
 #define RISCV_ISA_EXT_ZICFISS		105
 #define RISCV_ISA_EXT_SSCSRIND		106
 #define RISCV_ISA_EXT_SMCSRIND		107
+#define RISCV_ISA_EXT_SMCNTRPMF		108
 
 #define RISCV_ISA_EXT_XLINUXENVCFG	127
 
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 3fa0a563fb21..1452521d740a 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -576,6 +576,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_BUNDLE_VALIDATE(zvksg, riscv_zvksg_bundled_exts, riscv_ext_vector_crypto_validate),
 	__RISCV_ISA_EXT_DATA_VALIDATE(zvkt, RISCV_ISA_EXT_ZVKT, riscv_ext_vector_crypto_validate),
 	__RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
+	__RISCV_ISA_EXT_DATA(smcntrpmf, RISCV_ISA_EXT_SMCNTRPMF),
 	__RISCV_ISA_EXT_DATA(smcsrind, RISCV_ISA_EXT_SMCSRIND),
 	__RISCV_ISA_EXT_DATA(smmpm, RISCV_ISA_EXT_SMMPM),
 	__RISCV_ISA_EXT_SUPERSET(smnpm, RISCV_ISA_EXT_SMNPM, riscv_xlinuxenvcfg_exts),

-- 
2.53.0-Meta