Re: [RFC PATCH 2/4] ARM: kernel: add cpu logical map DT init in setup_arch

[Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>]

On Tue, Oct 16, 2012 at 02:21:46PM +0100, Lorenzo Pieralisi wrote:
> As soon as the device tree is unflattened the cpu logical to physical
> mapping is carried out in setup_arch to build a proper array of MPIDR and
> corresponding logical indexes.
> 
> The mapping could have been carried out using the flattened DT blob and
> related primitives, but since the mapping is not needed by early boot
> code it can safely be executed when the device tree has been uncompressed to
> its tree data structure.
> 
> This patch adds the arm_dt_init_cpu maps() function call in setup_arch().
> 
> If the kernel is not compiled with DT support the function is empty and
> no logical mapping takes place through it; the mapping carried out in
> smp_setup_processor_id() is left unchanged.
> If DT is supported the mapping created in smp_setup_processor_id() is overriden.
> The DT mapping also sets the possible cpus mask, hence platform
> code need not set it again in the respective smp_init_cpus() functions.
> 
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org>
> ---
>  arch/arm/kernel/setup.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
> index da1d1aa..20c530b 100644
> --- a/arch/arm/kernel/setup.c
> +++ b/arch/arm/kernel/setup.c
> @@ -758,6 +758,7 @@ void __init setup_arch(char **cmdline_p)
>  
>  	unflatten_device_tree();
>  
> +	arm_dt_init_cpu_maps();
>  #ifdef CONFIG_SMP
>  	if (is_smp()) {
>  		smp_set_ops(mdesc->smp);
> -- 
> 1.7.12

Acked-by: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>

Will