GIC v4.1 introduced changes to the GIC CPU interface; systems that integrate CPUs that do not support GIC v4.1 features (as reported in the ID_AA64PFR0_EL1.GIC bitfield) and a GIC v4.1 controller must disable in software virtual SGIs support since the CPUIF and GIC controller version mismatch results in CONSTRAINED UNPREDICTABLE behaviour at architectural level.
Add a cpufeature and related capability to detect GIC v4.1 CPUIF features so that the GIC driver can probe it to detect GIC CPUIF hardware configuration and take action accordingly. Signed-off-by: Lorenzo Pieralisi <[email protected]> Cc: Will Deacon <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Marc Zyngier <[email protected]> --- arch/arm64/include/asm/cpucaps.h | 3 ++- arch/arm64/kernel/cpufeature.c | 10 ++++++++++ 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index 42868dbd29fd..35ef0319f422 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -65,7 +65,8 @@ #define ARM64_HAS_ARMv8_4_TTL 55 #define ARM64_HAS_TLB_RANGE 56 #define ARM64_MTE 57 +#define ARM64_HAS_GIC_CPUIF_VSGI 58 -#define ARM64_NCAPS 58 +#define ARM64_NCAPS 59 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index dcc165b3fc04..9eabbaddfe5e 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2136,6 +2136,16 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .cpu_enable = cpu_enable_mte, }, #endif /* CONFIG_ARM64_MTE */ + { + .desc = "GIC CPUIF virtual SGI", + .capability = ARM64_HAS_GIC_CPUIF_VSGI, + .type = ARM64_CPUCAP_BOOT_CPU_FEATURE, + .matches = has_cpuid_feature, + .sys_reg = SYS_ID_AA64PFR0_EL1, + .field_pos = ID_AA64PFR0_GIC_SHIFT, + .sign = FTR_UNSIGNED, + .min_field_value = 3, + }, {}, }; -- 2.29.1
