Re: [PATCH v1 1/3] ACPI / x86: boot: Not all platforms require acpi_reduced_hw_init()

[Rafael J. Wysocki]

On Wednesday, January 17, 2018 6:34:07 PM CET Andy Shevchenko wrote:
> Some platforms might take care of legacy devices on theirs own.
> Let's allow them to do that by exporting a weak function.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
>  arch/x86/kernel/acpi/boot.c | 2 +-
>  include/linux/acpi.h        | 3 +++
>  2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> index ec3a286163c3..9a714b79ebed 100644
> --- a/arch/x86/kernel/acpi/boot.c
> +++ b/arch/x86/kernel/acpi/boot.c
> @@ -1375,7 +1375,7 @@ static int __init dmi_ignore_irq0_timer_override(const struct dmi_system_id *d)
>   *
>   * We initialize the Hardware-reduced ACPI model here:
>   */
> -static void __init acpi_reduced_hw_init(void)
> +void __init __weak acpi_reduced_hw_init(void)
>  {
>  	if (acpi_gbl_reduced_hardware) {
>  		/*
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index f0ea50ba0550..eb881516bce6 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -226,6 +226,8 @@ struct acpi_subtable_proc {
>  
>  void __iomem *__acpi_map_table(unsigned long phys, unsigned long size);
>  void __acpi_unmap_table(void __iomem *map, unsigned long size);
> +
> +void acpi_reduced_hw_init(void);
>  int early_acpi_boot_init(void);
>  int acpi_boot_init (void);
>  void acpi_boot_table_init (void);
> @@ -707,6 +709,7 @@ static inline struct device *acpi_get_first_physical_node(struct acpi_device *ad
>  static inline void acpi_early_init(void) { }
>  static inline void acpi_subsystem_init(void) { }
>  
> +static inline void acpi_reduced_hw_init(void) { }
>  static inline int early_acpi_boot_init(void)
>  {
>  	return 0;

May I suggest folding this into the [3/3]?

It would be clear why you need the __weak thing then.

OTOH, I guess you'll go for the new init callbacks rather.