[PATCH v2 1/2] arm64: tlb: Detect the ARMv8.4 TLBI RANGE feature

Zhenyu Ye
2020-07-10T09:44:43Z

ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
range of input addresses. This patch detect this feature.

Signed-off-by: Zhenyu Ye <yezhenyu2@huawei.com>
---
arch/arm64/include/asm/cpucaps.h | 3 ++-
arch/arm64/include/asm/sysreg.h | 3 +++
arch/arm64/kernel/cpufeature.c | 10 ++++++++++
3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index d44ba903d11d..8fe4aa1d372b 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -63,7 +63,8 @@
#define ARM64_HAS_32BIT_EL1 53
#define ARM64_BTI 54
#define ARM64_HAS_ARMv8_4_TTL 55
+#define ARM64_HAS_TLBI_RANGE 56

-#define ARM64_NCAPS 56
+#define ARM64_NCAPS 57

#endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 8c209aa17273..a5f24a26d86a 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -617,6 +617,9 @@
#define ID_AA64ISAR0_SHA1_SHIFT 8
#define ID_AA64ISAR0_AES_SHIFT 4

+#define ID_AA64ISAR0_TLBI_RANGE_NI 0x0
+#define ID_AA64ISAR0_TLBI_RANGE 0x2
+
/* id_aa64isar1 */
#define ID_AA64ISAR1_I8MM_SHIFT 52
#define ID_AA64ISAR1_DGH_SHIFT 48
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index e877f56ff1ab..ba0f0ce06fee 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2067,6 +2067,16 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.sign = FTR_UNSIGNED,
},
#endif
+ {
+ .desc = "TLB range maintenance instruction",
+ .capability = ARM64_HAS_TLBI_RANGE,
+ .type = ARM64_CPUCAP_SYSTEM_FEATURE,
+ .matches = has_cpuid_feature,
+ .sys_reg = SYS_ID_AA64ISAR0_EL1,
+ .field_pos = ID_AA64ISAR0_TLB_SHIFT,
+ .sign = FTR_UNSIGNED,
+ .min_field_value = ID_AA64ISAR0_TLBI_RANGE,
+ },
{},
};

--
2.19.1