[RFC PATCH v3 1/2] arm64: tlb: Detect the ARMv8.4 TLBI RANGE feature

Zhenyu Ye
2020-04-14T11:28:34Z

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 | 4 ++++
arch/arm64/kernel/cpufeature.c | 11 +++++++++++
3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index 8eb5a088ae65..950095a72617 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_TLBI_RANGE 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 ebc622432831..ac1b98650234 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -592,6 +592,7 @@

/* id_aa64isar0 */
#define ID_AA64ISAR0_RNDR_SHIFT 60
+#define ID_AA64ISAR0_TLBI_RANGE_SHIFT 56
#define ID_AA64ISAR0_TS_SHIFT 52
#define ID_AA64ISAR0_FHM_SHIFT 48
#define ID_AA64ISAR0_DP_SHIFT 44
@@ -605,6 +606,9 @@
#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 9fac745aa7bb..31bcfd0722b5 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -124,6 +124,7 @@ static bool __system_matches_cap(unsigned int n);
*/
static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RNDR_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TLBI_RANGE_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TS_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_FHM_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_DP_SHIFT, 4, 0),
@@ -1779,6 +1780,16 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.min_field_value = 1,
},
#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_TLBI_RANGE_SHIFT,
+ .sign = FTR_UNSIGNED,
+ .min_field_value = ID_AA64ISAR0_TLBI_RANGE,
+ },
{},
};

--
2.19.1