Armv9.5 introduces the Hardware dirty state tracking structure (HDBSS), indicated by ID_AA64MMFR1_EL1.HAFDBS == 0b0100.
Add CPU capability detection for HDBSS. The capability is restricted to VHE systems, as the buffer registers HDBSSBR_EL2 and HDBSSPROD_EL2 are EL2-only and are programmed directly from host context. A system_supports_hdbss() helper is provided for the rest of the series. Suggested-by: Zhou Wang <[email protected]> Co-developed-by: Eillon <[email protected]> Signed-off-by: Eillon <[email protected]> Signed-off-by: Tian Zheng <[email protected]> --- arch/arm64/include/asm/cpufeature.h | 5 +++++ arch/arm64/kernel/cpufeature.c | 12 ++++++++++++ arch/arm64/tools/cpucaps | 1 + 3 files changed, 18 insertions(+) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 4f04ad82ea34..0592e6f6b4d7 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -856,6 +856,11 @@ static inline bool system_supports_haft(void) return cpus_have_final_cap(ARM64_HAFT); } +static inline bool system_supports_hdbss(void) +{ + return cpus_have_final_cap(ARM64_HAS_HDBSS); +} + static __always_inline bool system_supports_mpam(void) { return alternative_has_cap_unlikely(ARM64_MPAM); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 32102c3912fa..12fa37328dd2 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2158,6 +2158,11 @@ static bool hvhe_possible(const struct arm64_cpu_capabilities *entry, return arm64_test_sw_feature_override(ARM64_SW_FEATURE_OVERRIDE_HVHE); } +static bool has_vhe_hdbss(const struct arm64_cpu_capabilities *entry, int scope) +{ + return is_kernel_in_hyp_mode() && has_cpuid_feature(entry, scope); +} + bool cpu_supports_bbml3(void) { /* CPUs that support BBML3 but dont advertise through ID_AA64MMFR2_EL1 */ @@ -2816,6 +2821,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = { ARM64_CPUID_FIELDS(ID_AA64MMFR1_EL1, HAFDBS, HAFT) }, #endif + { + .desc = "Hardware dirty state tracking structure (HDBSS)", + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .capability = ARM64_HAS_HDBSS, + .matches = has_vhe_hdbss, + ARM64_CPUID_FIELDS(ID_AA64MMFR1_EL1, HAFDBS, HDBSS) + }, { .desc = "CRC32 instructions", .capability = ARM64_HAS_CRC32, diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index 2775ba3359cf..8acb3db980c9 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -71,6 +71,7 @@ HAS_VA52 HAS_VIRT_HOST_EXTN HAS_WFXT HAS_XNX +HAS_HDBSS HAFT HW_DBM KVM_HVHE -- 2.43.0
