Re: [PATCH v13 1/2] ACPI / APEI: Add a notifier chain for unknown (vendor) CPER records

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Jul 22, 2020 at 11:39:51AM +0100, Shiju Jose wrote:
> CPER records describing a firmware-first error are identified by GUID.
> The ghes driver currently logs, but ignores any unknown CPER records.
> This prevents describing errors that can't be represented by a standard
> entry, that would otherwise allow a driver to recover from an error.
> The UEFI spec calls these 'Non-standard Section Body' (N.2.3 of
> version 2.8).

> +#ifdef CONFIG_ACPI_APEI_GHES
> +/**
> + * ghes_register_vendor_record_notifier - register a notifier for vendor
> + * records that the kernel would otherwise ignore.
> + * @nb: pointer to the notifier_block structure of the event handler.
> + *
> + * return 0 : SUCCESS, non-zero : FAIL
> + */
> +int ghes_register_vendor_record_notifier(struct notifier_block *nb);
> +
> +/**
> + * ghes_unregister_vendor_record_notifier - unregister the previously
> + * registered vendor record notifier.
> + * @nb: pointer to the notifier_block structure of the vendor record handler.
> + */
> +void ghes_unregister_vendor_record_notifier(struct notifier_block *nb);
> +#else
> +static inline int ghes_register_vendor_record_notifier(struct notifier_block *nb)
> +{
> +	return -ENODEV;
> +}
> +
> +static inline void ghes_unregister_vendor_record_notifier(struct notifier_block *nb)
> +{
> +}

If you made CONFIG_PCIE_HISI_ERR depend on CONFIG_ACPI_APEI_GHES,
you'd be able to get rid of these stubs, wouldn't you?  It doesn't
look like there's any point in building pcie-hisi-error.c at all
unless CONFIG_ACPI_APEI_GHES is enabled.

> +#endif
> +
>  int ghes_estatus_pool_init(int num_ghes);
>  
>  /* From drivers/edac/ghes_edac.c */
> -- 
> 2.17.1
> 
>