Add basic feature detection for SME2, detecting that the feature is present and disabling traps for ZT0.
Signed-off-by: Mark Brown broonie@kernel.org --- arch/arm64/include/asm/cpufeature.h | 6 ++++++ arch/arm64/include/asm/fpsimd.h | 1 + arch/arm64/kernel/cpufeature.c | 14 ++++++++++++++ arch/arm64/kernel/fpsimd.c | 11 +++++++++++ arch/arm64/tools/cpucaps | 1 + 5 files changed, 33 insertions(+)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index f73f11b55042..3ad41c26c9e7 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -769,6 +769,12 @@ static __always_inline bool system_supports_sme(void) cpus_have_const_cap(ARM64_SME); }
+static __always_inline bool system_supports_sme2(void) +{ + return IS_ENABLED(CONFIG_ARM64_SME) && + cpus_have_const_cap(ARM64_SME2); +} + static __always_inline bool system_supports_fa64(void) { return IS_ENABLED(CONFIG_ARM64_SME) && diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index a18a86ccfd82..f2bda963cfe5 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -109,6 +109,7 @@ extern void za_load_state(void const *state); struct arm64_cpu_capabilities; extern void sve_kernel_enable(const struct arm64_cpu_capabilities *__unused); extern void sme_kernel_enable(const struct arm64_cpu_capabilities *__unused); +extern void sme2_kernel_enable(const struct arm64_cpu_capabilities *__unused); extern void fa64_kernel_enable(const struct arm64_cpu_capabilities *__unused);
extern u64 read_zcr_features(void); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 3e3af6b8cc85..5b0d79f026aa 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -282,6 +282,8 @@ static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = { static const struct arm64_ftr_bits ftr_id_aa64smfr0[] = { ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME), FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_FA64_SHIFT, 1, 0), + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME), + FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_SMEver_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME), FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_EL1_I16I64_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME), @@ -2647,6 +2649,18 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = has_cpuid_feature, .cpu_enable = fa64_kernel_enable, }, + { + .desc = "SME2", + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .capability = ARM64_SME2, + .sys_reg = SYS_ID_AA64SMFR0_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64SMFR0_EL1_SMEver_SHIFT, + .field_width = ID_AA64SMFR0_EL1_SMEver_WIDTH, + .min_field_value = ID_AA64SMFR0_EL1_SMEver_SME2, + .matches = has_cpuid_feature, + .cpu_enable = sme2_kernel_enable, + }, #endif /* CONFIG_ARM64_SME */ { .desc = "WFx with timeout", diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index b677b5a3e0f6..73ec8850a402 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1254,6 +1254,17 @@ void sme_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p) isb(); }
+/* + * This must be called after sme_kernel_enable(), we rely on the + * feature table being sorted to ensure this. + */ +void sme2_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p) +{ + /* Allow use of ZT0 */ + write_sysreg_s(read_sysreg_s(SYS_SMCR_EL1) | SMCR_ELx_EZT0_MASK, + SYS_SMCR_EL1); +} + /* * This must be called after sme_kernel_enable(), we rely on the * feature table being sorted to ensure this. diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index a86ee376920a..1222b0ed63a2 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -50,6 +50,7 @@ MTE MTE_ASYMM SME SME_FA64 +SME2 SPECTRE_V2 SPECTRE_V3A SPECTRE_V4