Re: [PATCH 1/6] of: Add basic infrastructure to create early probe arrays

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Sat 12 Sep 07:51 CDT 2020, Marc Zyngier wrote:

> We currently probe interrupt controller and timers that need
> to be available very early using an infratstructure that creates

s/infratstructure/infrastructure/

> struct of_device_id instances in a special section. These are
> individual structures that are ultimately collated by the linker.
> 
> In order to facilitate further use of this infrastructure for
> drivers that can either be built modular or as an early driver,
> let's add a couple of helpers that will make it look like a
> "normal" device_id array, like this:
> 
> _OF_DECLARE_ARRAY_START(table, name)
> _OF_DECLARE_ELMT("compat-1", probe, type)
> _OF_DECLARE_ELMT("compat-2", probe, type)
> _OF_DECLARE_ELMT("compat-3", other_probe, type)
> _OF_DECLARE_ARRAY_END
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>  include/linux/of.h | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 5cf7ae0465d1..08f78da95378 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -1291,20 +1291,35 @@ static inline int of_get_available_child_count(const struct device_node *np)
>  	return num;
>  }
>  
> +#define __OF_DECLARE_ARRAY_START(name, section)				\
> +	static const struct of_device_id __of_table_##name[]		\
> +		__used __section(section) = {
> +
>  #if defined(CONFIG_OF) && !defined(MODULE)
>  #define _OF_DECLARE(table, name, compat, fn, fn_type)			\
>  	static const struct of_device_id __of_table_##name		\
>  		__used __section(__##table##_of_table)			\
>  		 = { .compatible = compat,				\
>  		     .data = (fn == (fn_type)NULL) ? fn : fn  }
> +#define _OF_DECLARE_ARRAY_START(table, name)				\
> +	__OF_DECLARE_ARRAY_START(name, __##table##_of_table)
>  #else
>  #define _OF_DECLARE(table, name, compat, fn, fn_type)			\
>  	static const struct of_device_id __of_table_##name		\
>  		__attribute__((unused))					\
>  		 = { .compatible = compat,				\
>  		     .data = (fn == (fn_type)NULL) ? fn : fn }
> +#define _OF_DECLARE_ARRAY_START(table, name)				\
> +	__OF_DECLARE_ARRAY_START(name, unused)
>  #endif
>  
> +#define _OF_DECLARE_ARRAY_END	}
> +#define _OF_DECLARE_ELMT(compat, fn, fn_type)				\
> +	{								\
> +		.compatible = compat,					\
> +		.data = (fn == (fn_type)NULL) ? fn : fn,		\
> +	},
> +
>  typedef int (*of_init_fn_2)(struct device_node *, struct device_node *);
>  typedef int (*of_init_fn_1_ret)(struct device_node *);
>  typedef void (*of_init_fn_1)(struct device_node *);
> -- 
> 2.28.0
>