Thread (9 messages) 9 messages, 4 authors, 2020-07-08
STALE2182d
Revisions (6)
  1. v3 [diff vs current]
  2. v3 current
  3. v5 [diff vs current]
  4. v1 [diff vs current]
  5. v2 [diff vs current]
  6. v3 [diff vs current]

[RFC PATCH v4 1/2] arm64: tlb: Detect the ARMv8.4 TLBI RANGE feature

From: Zhenyu Ye <hidden>
Date: 2020-06-01 14:47:42
Also in: linux-arch, linux-mm, lkml
Subsystem: arm64 port (aarch64 architecture), the rest · Maintainers: Catalin Marinas, Will Deacon, Linus Torvalds

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 <redacted>
---
 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 c4ac0ac25a00..4cc3efd633bc 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -594,6 +594,7 @@
 
 /* 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
@@ -607,6 +608,9 @@
 #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_HIDDEN, 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



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