On 06/02/2025 08:23, Atish Patra wrote:
> 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 <atishp@xxxxxxxxxxxx>
> ---
> 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 3d6e706fc5b2..b4eddcb57842 100644
> --- a/arch/riscv/include/asm/hwcap.h
> +++ b/arch/riscv/include/asm/hwcap.h
> @@ -102,6 +102,7 @@
> #define RISCV_ISA_EXT_SVADU 93
> #define RISCV_ISA_EXT_SSCSRIND 94
> #define RISCV_ISA_EXT_SMCSRIND 95
> +#define RISCV_ISA_EXT_SMCNTRPMF 96
>
> #define RISCV_ISA_EXT_XLINUXENVCFG 127
>
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index c6da81aa48aa..8f225c9c3055 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -390,6 +390,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
> __RISCV_ISA_EXT_BUNDLE(zvksg, riscv_zvksg_bundled_exts),
> __RISCV_ISA_EXT_DATA(zvkt, RISCV_ISA_EXT_ZVKT),
> __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),
>
Looks good to me.
Reviewed-by: Clément Léger <cleger@xxxxxxxxxxxx>
Thanks,
Clément
