On Thu, Sep 16, 2021 at 11:15 AM Oliver Upton <oupton@xxxxxxxxxx> wrote:
>
> Introduce a new cpucap to indicate if the system supports full enhanced
> counter virtualization (i.e. ID_AA64MMFR0_EL1.ECV>=0x2).
>
> Signed-off-by: Oliver Upton <oupton@xxxxxxxxxx>
> ---
> arch/arm64/include/asm/sysreg.h | 1 +
> arch/arm64/kernel/cpufeature.c | 10 ++++++++++
> arch/arm64/tools/cpucaps | 1 +
> 3 files changed, 12 insertions(+)
>
> diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
> index b268082d67ed..3fa6b091384d 100644
> --- a/arch/arm64/include/asm/sysreg.h
> +++ b/arch/arm64/include/asm/sysreg.h
> @@ -849,6 +849,7 @@
> #define ID_AA64MMFR0_ASID_8 0x0
> #define ID_AA64MMFR0_ASID_16 0x2
>
> +#define ID_AA64MMFR0_ECV_PHYS 0x2
> #define ID_AA64MMFR0_TGRAN4_NI 0xf
> #define ID_AA64MMFR0_TGRAN4_SUPPORTED_MIN 0x0
> #define ID_AA64MMFR0_TGRAN4_SUPPORTED_MAX 0x7
> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
> index f8a3067d10c6..2f5042bb107c 100644
> --- a/arch/arm64/kernel/cpufeature.c
> +++ b/arch/arm64/kernel/cpufeature.c
> @@ -2328,6 +2328,16 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
> .matches = has_cpuid_feature,
> .min_field_value = 1,
> },
> + {
> + .desc = "Enhanced Counter Virtualization (Physical)",
> + .capability = ARM64_HAS_ECV2,
> + .type = ARM64_CPUCAP_SYSTEM_FEATURE,
> + .sys_reg = SYS_ID_AA64MMFR0_EL1,
> + .sign = FTR_UNSIGNED,
> + .field_pos = ID_AA64MMFR0_ECV_SHIFT,
> + .matches = has_cpuid_feature,
> + .min_field_value = ID_AA64MMFR0_ECV_PHYS,
> + },
> {},
> };
>
> diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
> index 49305c2e6dfd..f73a30d5fb1c 100644
> --- a/arch/arm64/tools/cpucaps
> +++ b/arch/arm64/tools/cpucaps
> @@ -18,6 +18,7 @@ HAS_CRC32
> HAS_DCPODP
> HAS_DCPOP
> HAS_E0PD
> +HAS_ECV2
> HAS_EPAN
> HAS_GENERIC_AUTH
> HAS_GENERIC_AUTH_ARCH
> --
Reviewed-by: Reiji Watanabe <reijiw@xxxxxxxxxx>
Personally, I would prefer a more descriptive name (e.g. ECV_PHYS)
rather than ECV2 though.
Thanks,
Reiji
