[v2,09/21] RISC-V: Add Smcntrpmf extension parsing

Commit Message

Atish Patra Jan. 14, 2025, 10:57 p.m. UTC

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

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

Signed-off-by: Atish Patra <[e-mail]>
---
 arch/riscv/include/asm/hwcap.h | 1 +
 arch/riscv/kernel/cpufeature.c | 1 +
 2 files changed, 2 insertions(+)

Patch

diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 2f5ef1dee7ac..42b34e2f80e8 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -104,6 +104,7 @@ 
 #define RISCV_ISA_EXT_SMCSRIND		95
 #define RISCV_ISA_EXT_SSCCFG            96
 #define RISCV_ISA_EXT_SMCDELEG          97
+#define RISCV_ISA_EXT_SMCNTRPMF         98
 
 #define RISCV_ISA_EXT_XLINUXENVCFG	127
 
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index b584aa2d5bc3..ec068c9130e5 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -394,6 +394,7 @@  const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_DATA(smmpm, RISCV_ISA_EXT_SMMPM),
 	__RISCV_ISA_EXT_SUPERSET(smnpm, RISCV_ISA_EXT_SMNPM, riscv_xlinuxenvcfg_exts),
 	__RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN),
+	__RISCV_ISA_EXT_DATA(smcntrpmf, RISCV_ISA_EXT_SMCNTRPMF),
 	__RISCV_ISA_EXT_DATA(smcsrind, RISCV_ISA_EXT_SMCSRIND),
 	__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
 	__RISCV_ISA_EXT_DATA(sscsrind, RISCV_ISA_EXT_SSCSRIND),