Re: [PATCH v8 01/19] arm64: cpuinfo: Split AArch32 registers out into a separate struct

Mark Rutland
2021-06-03T12:41:24Z

On Wed, Jun 02, 2021 at 05:47:01PM +0100, Will Deacon wrote:
> In preparation for late initialisation of the "sanitised" AArch32 register
> state, move the AArch32 registers out of 'struct cpuinfo' and into their
> own struct definition.
>
> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Will Deacon <will@kernel.org>

Makes sense to me; if it's not too painful to change, I'd suggest
`aarch32` rather than `32bit` in the name, but either way:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Mark.

> ---
> arch/arm64/include/asm/cpu.h | 44 +++++++++++----------
> arch/arm64/kernel/cpufeature.c | 71 ++++++++++++++++++----------------
> arch/arm64/kernel/cpuinfo.c | 53 +++++++++++++------------
> 3 files changed, 89 insertions(+), 79 deletions(-)
>
> diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h
> index 7faae6ff3ab4..f4e01aa0f442 100644
> --- a/arch/arm64/include/asm/cpu.h
> +++ b/arch/arm64/include/asm/cpu.h
> @@ -12,26 +12,7 @@
> /*
> * Records attributes of an individual CPU.
> */
> -struct cpuinfo_arm64 {
> - struct cpu cpu;
> - struct kobject kobj;
> - u32 reg_ctr;
> - u32 reg_cntfrq;
> - u32 reg_dczid;
> - u32 reg_midr;
> - u32 reg_revidr;
> -
> - u64 reg_id_aa64dfr0;
> - u64 reg_id_aa64dfr1;
> - u64 reg_id_aa64isar0;
> - u64 reg_id_aa64isar1;
> - u64 reg_id_aa64mmfr0;
> - u64 reg_id_aa64mmfr1;
> - u64 reg_id_aa64mmfr2;
> - u64 reg_id_aa64pfr0;
> - u64 reg_id_aa64pfr1;
> - u64 reg_id_aa64zfr0;
> -
> +struct cpuinfo_32bit {
> u32 reg_id_dfr0;
> u32 reg_id_dfr1;
> u32 reg_id_isar0;
> @@ -54,6 +35,29 @@ struct cpuinfo_arm64 {
> u32 reg_mvfr0;
> u32 reg_mvfr1;
> u32 reg_mvfr2;
> +};
> +
> +struct cpuinfo_arm64 {
> + struct cpu cpu;
> + struct kobject kobj;
> + u32 reg_ctr;
> + u32 reg_cntfrq;
> + u32 reg_dczid;
> + u32 reg_midr;
> + u32 reg_revidr;
> +
> + u64 reg_id_aa64dfr0;
> + u64 reg_id_aa64dfr1;
> + u64 reg_id_aa64isar0;
> + u64 reg_id_aa64isar1;
> + u64 reg_id_aa64mmfr0;
> + u64 reg_id_aa64mmfr1;
> + u64 reg_id_aa64mmfr2;
> + u64 reg_id_aa64pfr0;
> + u64 reg_id_aa64pfr1;
> + u64 reg_id_aa64zfr0;
> +
> + struct cpuinfo_32bit aarch32;
>
> /* pseudo-ZCR for recording maximum ZCR_EL1 LEN value: */
> u64 reg_zcr;
> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
> index efed2830d141..a4db25cd7122 100644
> --- a/arch/arm64/kernel/cpufeature.c
> +++ b/arch/arm64/kernel/cpufeature.c
> @@ -863,6 +863,31 @@ static void __init init_cpu_hwcaps_indirect_list(void)
>
> static void __init setup_boot_cpu_capabilities(void);
>
> +static void __init init_32bit_cpu_features(struct cpuinfo_32bit *info)
> +{
> + 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);
> + init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
> + init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
> + init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
> + init_cpu_ftr_reg(SYS_ID_ISAR6_EL1, info->reg_id_isar6);
> + init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
> + init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
> + init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
> + init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
> + init_cpu_ftr_reg(SYS_ID_MMFR4_EL1, info->reg_id_mmfr4);
> + init_cpu_ftr_reg(SYS_ID_MMFR5_EL1, info->reg_id_mmfr5);
> + init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
> + init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
> + init_cpu_ftr_reg(SYS_ID_PFR2_EL1, info->reg_id_pfr2);
> + init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
> + init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
> + init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
> +}
> +
> void __init init_cpu_features(struct cpuinfo_arm64 *info)
> {
> /* Before we start using the tables, make sure it is sorted */
> @@ -882,29 +907,8 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
> init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
> init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);
>
> - 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);
> - init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
> - init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
> - init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
> - init_cpu_ftr_reg(SYS_ID_ISAR6_EL1, info->reg_id_isar6);
> - init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
> - init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
> - init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
> - init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
> - init_cpu_ftr_reg(SYS_ID_MMFR4_EL1, info->reg_id_mmfr4);
> - init_cpu_ftr_reg(SYS_ID_MMFR5_EL1, info->reg_id_mmfr5);
> - init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
> - init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
> - init_cpu_ftr_reg(SYS_ID_PFR2_EL1, info->reg_id_pfr2);
> - init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
> - init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
> - init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
> - }
> + if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0))
> + init_32bit_cpu_features(&info->aarch32);
>
> if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
> init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
> @@ -975,20 +979,12 @@ static void relax_cpu_ftr_reg(u32 sys_id, int field)
> WARN_ON(!ftrp->width);
> }
>
> -static int update_32bit_cpu_features(int cpu, struct cpuinfo_arm64 *info,
> - struct cpuinfo_arm64 *boot)
> +static int update_32bit_cpu_features(int cpu, struct cpuinfo_32bit *info,
> + struct cpuinfo_32bit *boot)
> {
> int taint = 0;
> u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
>
> - /*
> - * 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
> - * using them for anything.
> - */
> - if (!id_aa64pfr0_32bit_el0(pfr0))
> - return taint;
> -
> /*
> * If we don't have AArch32 at EL1, then relax the strictness of
> * EL1-dependent register fields to avoid spurious sanity check fails.
> @@ -1135,10 +1131,17 @@ void update_cpu_features(int cpu,
> }
>
> /*
> + * 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
> + * using them for anything.
> + *
> * This relies on a sanitised view of the AArch64 ID registers
> * (e.g. SYS_ID_AA64PFR0_EL1), so we call it last.
> */
> - taint |= update_32bit_cpu_features(cpu, info, boot);
> + if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
> + taint |= update_32bit_cpu_features(cpu, &info->aarch32,
> + &boot->aarch32);
> + }
>
> /*
> * Mismatched CPU features are a recipe for disaster. Don't even
> diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
> index 51fcf99d5351..264c119a6cae 100644
> --- a/arch/arm64/kernel/cpuinfo.c
> +++ b/arch/arm64/kernel/cpuinfo.c
> @@ -344,6 +344,32 @@ static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
> pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
> }
>
> +static void __cpuinfo_store_cpu_32bit(struct cpuinfo_32bit *info)
> +{
> + info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1);
> + info->reg_id_dfr1 = read_cpuid(ID_DFR1_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_isar6 = read_cpuid(ID_ISAR6_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_mmfr4 = read_cpuid(ID_MMFR4_EL1);
> + info->reg_id_mmfr5 = read_cpuid(ID_MMFR5_EL1);
> + info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
> + info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
> + info->reg_id_pfr2 = read_cpuid(ID_PFR2_EL1);
> +
> + info->reg_mvfr0 = read_cpuid(MVFR0_EL1);
> + info->reg_mvfr1 = read_cpuid(MVFR1_EL1);
> + info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
> +}
> +
> static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
> {
> info->reg_cntfrq = arch_timer_get_cntfrq();
> @@ -371,31 +397,8 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
> info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
> info->reg_id_aa64zfr0 = read_cpuid(ID_AA64ZFR0_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_dfr1 = read_cpuid(ID_DFR1_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_isar6 = read_cpuid(ID_ISAR6_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_mmfr4 = read_cpuid(ID_MMFR4_EL1);
> - info->reg_id_mmfr5 = read_cpuid(ID_MMFR5_EL1);
> - info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
> - info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
> - info->reg_id_pfr2 = read_cpuid(ID_PFR2_EL1);
> -
> - info->reg_mvfr0 = read_cpuid(MVFR0_EL1);
> - info->reg_mvfr1 = read_cpuid(MVFR1_EL1);
> - info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
> - }
> + if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0))
> + __cpuinfo_store_cpu_32bit(&info->aarch32);
>
> if (IS_ENABLED(CONFIG_ARM64_SVE) &&
> id_aa64pfr0_sve(info->reg_id_aa64pfr0))
> --
> 2.32.0.rc0.204.g9fa02ecfa5-goog