On Thu, Jul 21, 2016 at 11:12:55AM +0100, Suzuki K Poulose wrote:
> In smp_prepare_boot_cpu(), we invoke cpuinfo_store_boot_cpu to store
> the cpuinfo in a per-cpu ptr, before initialising the per-cpu offset for
> the boot CPU. This patch reorders the sequence to make sure we initialise
> the per-cpu offset before accessing the per-cpu area.
>
> Commit 4b998ff1885eec ("arm64: Delay cpuinfo_store_boot_cpu") fixed the
> issue where we modified the per-cpu area even before the kernel initialises
> the per-cpu areas, but failed to wait until the boot cpu updated it's
> offset.
>
> Fixes: commit 4b998ff1885eec ("arm64: Delay cpuinfo_store_boot_cpu")
> Cc: <[email protected]>
> Cc: Will Deacon <[email protected]>
> Cc: Catalin Marinas <[email protected]>
> Signed-off-by: Suzuki K Poulose <[email protected]>
Acked-by: Mark Rutland <[email protected]>
Mark.
> ---
> arch/arm64/kernel/smp.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> index 62ff3c0..d242e81 100644
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
> @@ -437,9 +437,9 @@ void __init smp_cpus_done(unsigned int max_cpus)
>
> void __init smp_prepare_boot_cpu(void)
> {
> + set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
> cpuinfo_store_boot_cpu();
> save_boot_cpu_run_el();
> - set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
> }
>
> static u64 __init of_get_cpu_mpidr(struct device_node *dn)
> --
> 2.7.4
>
