Re: [PATCH 02/16] arm64: Move errata work around check on boot CPU

From: Dave Martin
Date: Tue Jan 23 2018 - 09:59:43 EST


On Tue, Jan 23, 2018 at 12:27:55PM +0000, Suzuki K Poulose wrote:
> We trigger CPU errata work around check on the boot CPU from
> smp_prepare_boot_cpu() to make sure that we run the checks only
> after the CPU feature infrastructure is initialised.

On the surface of it, this sounds like a bug fix.

Should there be a Fixes tag if so?

If this reordering doesn't matter for upstream, it would be good to have
a quick explanation here as to why not.

Cheers
---Dave

>
> We can do this from init_cpu_features() which is called only
> on the boot CPU and does the initilisation of the infrastructure.
> As we are consolidating the cpu capability handling, let us
> move this to where it should belong. No functional changes.
>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> ---
> arch/arm64/kernel/cpufeature.c | 6 ++++++
> arch/arm64/kernel/smp.c | 6 ------
> 2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
> index 6a8dfdc532b1..ebb467340b9c 100644
> --- a/arch/arm64/kernel/cpufeature.c
> +++ b/arch/arm64/kernel/cpufeature.c
> @@ -545,6 +545,12 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
> init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
> sve_init_vq_map();
> }
> +
> + /*
> + * Run the errata work around checks on the boot CPU, once we have
> + * initialised the cpu feature infrastructure.
> + */
> + update_cpu_errata_workarounds();
> }
>
> static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> index 3b8ad7be9c33..5cef11450183 100644
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
> @@ -448,12 +448,6 @@ void __init smp_prepare_boot_cpu(void)
> jump_label_init();
> cpuinfo_store_boot_cpu();
> save_boot_cpu_run_el();
> - /*
> - * Run the errata work around checks on the boot CPU, once we have
> - * initialised the cpu feature infrastructure from
> - * cpuinfo_store_boot_cpu() above.
> - */
> - update_cpu_errata_workarounds();
> }
>
> static u64 __init of_get_cpu_mpidr(struct device_node *dn)
> --
> 2.13.6
>
>
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