arm64/cpufeature: Introduce ID_DFR1 CPU register
This adds basic building blocks required for ID_DFR1 CPU register which
provides top level information about the debug system in AArch32 state.
We hide the register from KVM guests, as we don't emulate the 'MTPMU'
feature.
This is added per ARM DDI 0487F.a specification.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: Will Deacon <will@kernel.org>
Reviewed-by : Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/1589881254-10082-6-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index b81b74d..7a7ddbd 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -457,6 +457,11 @@ static const struct arm64_ftr_bits ftr_id_dfr0[] = {
ARM64_FTR_END,
};
+static const struct arm64_ftr_bits ftr_id_dfr1[] = {
+ S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_DFR1_MTPMU_SHIFT, 4, 0),
+ ARM64_FTR_END,
+};
+
static const struct arm64_ftr_bits ftr_zcr[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_SIZE, 0), /* LEN */
@@ -527,6 +532,7 @@ static const struct __ftr_reg_entry {
ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
ARM64_FTR_REG(SYS_ID_PFR2_EL1, ftr_id_pfr2),
+ ARM64_FTR_REG(SYS_ID_DFR1_EL1, ftr_id_dfr1),
/* Op1 = 0, CRn = 0, CRm = 4 */
ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
@@ -720,6 +726,7 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
+ init_cpu_ftr_reg(SYS_ID_DFR1_EL1, info->reg_id_dfr1);
init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
@@ -835,6 +842,8 @@ static int update_32bit_cpu_features(int cpu, struct cpuinfo_arm64 *info,
taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
info->reg_id_dfr0, boot->reg_id_dfr0);
+ taint |= check_update_ftr_reg(SYS_ID_DFR1_EL1, cpu,
+ info->reg_id_dfr1, boot->reg_id_dfr1);
taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
info->reg_id_isar0, boot->reg_id_isar0);
taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
@@ -998,6 +1007,7 @@ static u64 __read_sysreg_by_encoding(u32 sys_id)
read_sysreg_case(SYS_ID_PFR1_EL1);
read_sysreg_case(SYS_ID_PFR2_EL1);
read_sysreg_case(SYS_ID_DFR0_EL1);
+ read_sysreg_case(SYS_ID_DFR1_EL1);
read_sysreg_case(SYS_ID_MMFR0_EL1);
read_sysreg_case(SYS_ID_MMFR1_EL1);
read_sysreg_case(SYS_ID_MMFR2_EL1);