arm64: cpufeature: Add ID_AA64MMFR4_EL1 handling

Add ID_AA64MMFR4_EL1 to the list of idregs the kernel knows about,
and describe the E2H0 field.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20240122181344.258974-6-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h
index b1e43f56ee461eb8f36222412057e90c42d6f6bf..6c13fd47e170c6510553ba718354d07cf057a809 100644 (file)
--- a/arch/arm64/include/asm/cpu.h
+++ b/arch/arm64/include/asm/cpu.h
@@ -56,6 +56,7 @@ struct cpuinfo_arm64 {
        u64             reg_id_aa64mmfr1;
        u64             reg_id_aa64mmfr2;
        u64             reg_id_aa64mmfr3;
+       u64             reg_id_aa64mmfr4;
        u64             reg_id_aa64pfr0;
        u64             reg_id_aa64pfr1;
        u64             reg_id_aa64zfr0;

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index bae5d0655262e2a18094eda84c9ced169e0e99bc..ad3753fbdcb1a5eecee04c442622232c1b5e4fe7 100644 (file)
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -437,6 +437,11 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr3[] = {
        ARM64_FTR_END,
 };
 
+static const struct arm64_ftr_bits ftr_id_aa64mmfr4[] = {
+       S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR4_EL1_E2H0_SHIFT, 4, 0),
+       ARM64_FTR_END,
+};
+
 static const struct arm64_ftr_bits ftr_ctr[] = {
        ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RES1 */
        ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_EL0_DIC_SHIFT, 1, 1),
@@ -754,6 +759,7 @@ static const struct __ftr_reg_entry {
                               &id_aa64mmfr1_override),
        ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2),
        ARM64_FTR_REG(SYS_ID_AA64MMFR3_EL1, ftr_id_aa64mmfr3),
+       ARM64_FTR_REG(SYS_ID_AA64MMFR4_EL1, ftr_id_aa64mmfr4),
 
        /* Op1 = 1, CRn = 0, CRm = 0 */
        ARM64_FTR_REG(SYS_GMID_EL1, ftr_gmid),
@@ -1078,6 +1084,7 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
        init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
        init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2);
        init_cpu_ftr_reg(SYS_ID_AA64MMFR3_EL1, info->reg_id_aa64mmfr3);
+       init_cpu_ftr_reg(SYS_ID_AA64MMFR4_EL1, info->reg_id_aa64mmfr4);
        init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
        init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
        init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);

diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 47043c0d95ec3d5d1c4bcfba9766b57a8aca5266..7ca3fbd200f0f3ec1043e41226e326aaaec390f4 100644 (file)
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -447,6 +447,7 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
        info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
        info->reg_id_aa64mmfr2 = read_cpuid(ID_AA64MMFR2_EL1);
        info->reg_id_aa64mmfr3 = read_cpuid(ID_AA64MMFR3_EL1);
+       info->reg_id_aa64mmfr4 = read_cpuid(ID_AA64MMFR4_EL1);
        info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
        info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
        info->reg_id_aa64zfr0 = read_cpuid(ID_AA64ZFR0_EL1);