From a6dc3cd718ec2a19b8ca812087666899852af78f Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Mon, 18 Apr 2016 10:28:35 +0100 Subject: arm64: cpufeature: Check availability of AArch32 On ARMv8 support for AArch32 state is optional. Hence it is not safe to check the AArch32 ID registers for sanity, which could lead to false warnings. This patch makes sure that the AArch32 state is implemented before we keep track of the 32bit ID registers. As per ARM ARM (D.1.21.2 - Support for Exception Levels and Execution States, DDI0487A.h), checking the support for AArch32 at EL0 is good enough to check the support for AArch32 (i.e, AArch32 at EL1 => AArch32 at EL0, but not vice versa). Tested-by: Yury Norov Signed-off-by: Suzuki K Poulose Signed-off-by: Will Deacon --- arch/arm64/kernel/cpuinfo.c | 37 ++++++++++++++++++++----------------- 1 file changed, 20 insertions(+), 17 deletions(-) (limited to 'arch/arm64/kernel/cpuinfo.c') diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 84c8684431c7..92189e2875f2 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -216,23 +216,26 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info) info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1); info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1); - info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1); - info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1); - info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1); - info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1); - info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1); - info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1); - info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1); - info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1); - info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1); - info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1); - info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1); - info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1); - info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1); - - info->reg_mvfr0 = read_cpuid(MVFR0_EL1); - info->reg_mvfr1 = read_cpuid(MVFR1_EL1); - info->reg_mvfr2 = read_cpuid(MVFR2_EL1); + /* Update the 32bit ID registers only if AArch32 is implemented */ + if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) { + info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1); + info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1); + info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1); + info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1); + info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1); + info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1); + info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1); + info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1); + info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1); + info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1); + info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1); + info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1); + info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1); + + info->reg_mvfr0 = read_cpuid(MVFR0_EL1); + info->reg_mvfr1 = read_cpuid(MVFR1_EL1); + info->reg_mvfr2 = read_cpuid(MVFR2_EL1); + } cpuinfo_detect_icache_policy(info); -- cgit v1.2.1