[PATCH v3 14/14] arm64: Enable IMP DEF PMUv3 traps on Apple M*
From: Oliver Upton <hidden>
Date: 2025-03-05 20:30:53
Also in:
kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Apple M1 and M2 CPUs support IMPDEF traps of the PMUv3 sysregs, allowing a hypervisor to virtualize an architectural PMU for a VM. Flip the appropriate bit in HACR_EL2 on supporting hardware. Tested-by: Janne Grunau <j@jannau.net> Signed-off-by: Oliver Upton <redacted> --- arch/arm64/kernel/cpu_errata.c | 44 ++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+)
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 7ce555862895..a1e16b156fab 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c@@ -194,6 +194,43 @@ has_neoverse_n1_erratum_1542419(const struct arm64_cpu_capabilities *entry, return is_midr_in_range(midr, &range) && has_dic; } +static const struct midr_range impdef_pmuv3_cpus[] = { + MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM), + MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM), + MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM_PRO), + MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM_PRO), + MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM_MAX), + MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM_MAX), + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD), + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE), + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD_PRO), + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE_PRO), + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD_MAX), + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE_MAX), + {}, +}; + +static bool has_impdef_pmuv3(const struct arm64_cpu_capabilities *entry, int scope) +{ + u64 dfr0 = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1); + unsigned int pmuver; + + if (!is_kernel_in_hyp_mode()) + return false; + + pmuver = cpuid_feature_extract_unsigned_field(dfr0, + ID_AA64DFR0_EL1_PMUVer_SHIFT); + if (pmuver != ID_AA64DFR0_EL1_PMUVer_IMP_DEF) + return false; + + return is_midr_in_range_list(read_cpuid_id(), impdef_pmuv3_cpus); +} + +static void cpu_enable_impdef_pmuv3_traps(const struct arm64_cpu_capabilities *__unused) +{ + sysreg_clear_set_s(SYS_HACR_EL2, 0, BIT(56)); +} + #ifdef CONFIG_ARM64_WORKAROUND_REPEAT_TLBI static const struct arm64_cpu_capabilities arm64_repeat_tlbi_list[] = { #ifdef CONFIG_QCOM_FALKOR_ERRATUM_1009
@@ -794,6 +831,13 @@ const struct arm64_cpu_capabilities arm64_errata[] = { {} })), }, + { + .desc = "Apple IMPDEF PMUv3 Traps", + .capability = ARM64_WORKAROUND_PMUV3_IMPDEF_TRAPS, + .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, + .matches = has_impdef_pmuv3, + .cpu_enable = cpu_enable_impdef_pmuv3_traps, + }, { } };
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2.39.5