[RFC 02/12] arm64: Detect FEAT_TLBID
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From: Kristina Martšenko <hidden>
Date: 2026-10-01 11:07:36
Also in:
kvmarm, linux-acpi, linux-efi
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Detect if FEAT_TLBID is supported by the system. Detect TLBID configuration from TLBIDIDR_EL1. This information will be used in later patches. Set HFGRTR2_EL2.nTLBIDIDR_EL1 so that the kernel can access TLBIDIDR_EL1 at EL1 (in case of nVHE/hVHE). Signed-off-by: Kristina Martšenko <redacted> --- arch/arm64/include/asm/cpu.h | 1 + arch/arm64/include/asm/cpufeature.h | 7 +++++++ arch/arm64/include/asm/el2_setup.h | 9 ++++++++- arch/arm64/kernel/cpufeature.c | 25 +++++++++++++++++++++++++ arch/arm64/kernel/cpuinfo.c | 3 +++ arch/arm64/tools/cpucaps | 1 + 6 files changed, 45 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h
index 3c008821219c..967ccdedf526 100644
--- a/arch/arm64/include/asm/cpu.h
+++ b/arch/arm64/include/asm/cpu.h@@ -48,6 +48,7 @@ struct cpuinfo_arm64 { u64 reg_gmid; u64 reg_smidr; u64 reg_mpamidr; + u64 reg_tlbididr; u64 reg_id_aa64dfr0; u64 reg_id_aa64dfr1;
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 4f04ad82ea34..d4e7497143b2 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h@@ -627,6 +627,13 @@ static inline bool id_aa64pfr1_mpamfrac(u64 pfr1) return val > 0; } +static inline bool id_aa64mmfr4_tlbid(u64 mmfr4) +{ + u32 val = cpuid_feature_extract_unsigned_field(mmfr4, ID_AA64MMFR4_EL1_TLBID_SHIFT); + + return val > 0; +} + void __init setup_boot_cpu_features(void); void __init setup_system_features(void); void __init setup_user_features(void);
diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
index aa8ec9df8024..bd70a470596c 100644
--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h@@ -438,9 +438,16 @@ orr x0, x0, #HDFGRTR2_EL2_nPMSDSFR_EL1 .Lskip_spefds_\@: + mov x1, xzr + mrs_s x2, SYS_ID_AA64MMFR4_EL1 + ubfx x2, x2, #ID_AA64MMFR4_EL1_TLBID_SHIFT, #ID_AA64MMFR4_EL1_TLBID_WIDTH + cbz x2, .Lskip_tlbid_\@ + orr x1, x1, #HFGRTR2_EL2_nTLBIDIDR_EL1 + +.Lskip_tlbid_\@: msr_s SYS_HDFGRTR2_EL2, x0 msr_s SYS_HDFGWTR2_EL2, x0 - msr_s SYS_HFGRTR2_EL2, xzr + msr_s SYS_HFGRTR2_EL2, x1 msr_s SYS_HFGWTR2_EL2, xzr msr_s SYS_HFGITR2_EL2, xzr .Lskip_fgt2_\@:
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 32102c3912fa..39a30226ccca 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -521,6 +521,7 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr3[] = { }; static const struct arm64_ftr_bits ftr_id_aa64mmfr4[] = { + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR4_EL1_TLBID_SHIFT, 4, 0), S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR4_EL1_E2H0_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR4_EL1_NV_frac_SHIFT, 4, 0), ARM64_FTR_END,
@@ -740,6 +741,14 @@ static const struct arm64_ftr_bits ftr_mpamidr[] = { ARM64_FTR_END, }; +static const struct arm64_ftr_bits ftr_tlbididr[] = { + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, TLBIDIDR_EL1_NVOS_SHIFT, TLBIDIDR_EL1_NVOS_WIDTH, 0), + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, TLBIDIDR_EL1_NOS_SHIFT, TLBIDIDR_EL1_NOS_WIDTH, 0), + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, TLBIDIDR_EL1_NVIS_SHIFT, TLBIDIDR_EL1_NVIS_WIDTH, 0), + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, TLBIDIDR_EL1_NIS_SHIFT, TLBIDIDR_EL1_NIS_WIDTH, 0), + ARM64_FTR_END, +}; + /* * Common ftr bits for a 32bit register with all hidden, strict * attributes, with 4bit feature fields and a default safe value of
@@ -864,6 +873,7 @@ static const struct __ftr_reg_entry { /* Op1 = 0, CRn = 10, CRm = 4 */ ARM64_FTR_REG(SYS_MPAMIDR_EL1, ftr_mpamidr), + ARM64_FTR_REG(SYS_TLBIDIDR_EL1, ftr_tlbididr), /* Op1 = 1, CRn = 0, CRm = 0 */ ARM64_FTR_REG(SYS_GMID_EL1, ftr_gmid),
@@ -1259,6 +1269,9 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info) if (gmid_el1_accessible(info)) init_cpu_ftr_reg(SYS_GMID_EL1, info->reg_gmid); + + if (id_aa64mmfr4_tlbid(info->reg_id_aa64mmfr4)) + init_cpu_ftr_reg(SYS_TLBIDIDR_EL1, info->reg_tlbididr); } static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
@@ -1523,6 +1536,11 @@ void update_cpu_features(int cpu, taint |= check_update_ftr_reg(SYS_GMID_EL1, cpu, info->reg_gmid, boot->reg_gmid); + if (id_aa64mmfr4_tlbid(info->reg_id_aa64mmfr4)) { + taint |= check_update_ftr_reg(SYS_TLBIDIDR_EL1, cpu, + info->reg_tlbididr, boot->reg_tlbididr); + } + /* * If we don't have AArch32 at all then skip the checks entirely * as the register values may be UNKNOWN and we're not going to be
@@ -3234,6 +3252,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = { ARM64_CPUID_FIELDS(ID_AA64ISAR3_EL1, LSUI, IMP) }, #endif + { + .desc = "TLBI domains (TLBID)", + .capability = ARM64_HAS_TLBID, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_cpuid_feature, + ARM64_CPUID_FIELDS(ID_AA64MMFR4_EL1, TLBID, IMP) + }, {}, };
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 45c63f3d75c5..2d4fc664231c 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c@@ -524,6 +524,9 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info) info->reg_smidr = read_cpuid(SMIDR_EL1) & ~SMIDR_EL1_SMPS; } + if (id_aa64mmfr4_tlbid(info->reg_id_aa64mmfr4)) + info->reg_tlbididr = read_cpuid(TLBIDIDR_EL1); + cpuinfo_detect_icache_policy(info); }
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 2775ba3359cf..d9ed599dee70 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps@@ -67,6 +67,7 @@ HAS_STAGE2_FWB HAS_TCR2 HAS_TIDCP1 HAS_TLB_RANGE +HAS_TLBID HAS_VA52 HAS_VIRT_HOST_EXTN HAS_WFXT
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2.43.0