[PATCH v3 1/6] arm64: Detect the ARMv8.4 TTL feature
From: Zhenyu Ye <hidden>
Date: 2020-05-25 12:53:33
Also in:
linux-arch, linux-mm, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
From: Marc Zyngier <maz@kernel.org> In order to reduce the cost of TLB invalidation, the ARMv8.4 TTL feature allows TLBs to be issued with a level allowing for quicker invalidation. Let's detect the feature for now. Further patches will implement its actual usage. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Zhenyu Ye <redacted> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> --- arch/arm64/include/asm/cpucaps.h | 3 ++- arch/arm64/include/asm/sysreg.h | 1 + arch/arm64/kernel/cpufeature.c | 11 +++++++++++ 3 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index 8eb5a088ae65..cabb0c49a1d1 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h@@ -61,7 +61,8 @@ #define ARM64_HAS_AMU_EXTN 51 #define ARM64_HAS_ADDRESS_AUTH 52 #define ARM64_HAS_GENERIC_AUTH 53 +#define ARM64_HAS_ARMv8_4_TTL 54 -#define ARM64_NCAPS 54 +#define ARM64_NCAPS 55 #endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index c4ac0ac25a00..477d84ba1056 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h@@ -725,6 +725,7 @@ /* id_aa64mmfr2 */ #define ID_AA64MMFR2_E0PD_SHIFT 60 +#define ID_AA64MMFR2_TTL_SHIFT 48 #define ID_AA64MMFR2_FWB_SHIFT 40 #define ID_AA64MMFR2_AT_SHIFT 32 #define ID_AA64MMFR2_LVA_SHIFT 16
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 9fac745aa7bb..d993dc6dc7d5 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -244,6 +244,7 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = { static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_E0PD_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_TTL_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_FWB_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_AT_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0),
@@ -1622,6 +1623,16 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = has_cpuid_feature, .cpu_enable = cpu_has_fwb, }, + { + .desc = "ARMv8.4 Translation Table Level", + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .capability = ARM64_HAS_ARMv8_4_TTL, + .sys_reg = SYS_ID_AA64MMFR2_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64MMFR2_TTL_SHIFT, + .min_field_value = 1, + .matches = has_cpuid_feature, + }, #ifdef CONFIG_ARM64_HW_AFDBM { /*
--
2.19.1
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