[RFC 1/6] powerpc:/drc Define interface to acquire arch-specific drc info

[Tyrel Datwyler]

On 12/14/2018 12:50 PM, Michael Bringmann wrote:
> Define interface to acquire arch-specific drc info to match against
> hotpluggable devices.  The current implementation exposes several
> pseries-specific dynamic memory properties in generic kernel code.
> This patch set provides an interface to pull that code out of the
> generic kernel.
> 
> Signed-off-by: Michael Bringmann <mwb at linux.vnet.ibm.com>
> ---
>  include/linux/topology.h |    9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/include/linux/topology.h b/include/linux/topology.h
> index cb0775e..df97f5f 100644
> --- a/include/linux/topology.h
> +++ b/include/linux/topology.h
> @@ -44,6 +44,15 @@

As far as I know pseries is the only platform that uses DR connectors, and I
highly doubt that any other powerpc platform or arch ever will. So, I'm not sure
that this is really generic enough to belong in topology.h. If anything I would
suggest putting this in an include in arch/powerpc/include/ named something like
drcinfo.h or pseries-drc.h. That will make it visible to modules like rpaphp
that want/need to use this functionality.

-Tyrel

>  
>  int arch_update_cpu_topology(void);
>  
> +int arch_find_drc_match(struct device_node *dn,
> +			bool (*usercb)(struct device_node *dn,
> +				u32 drc_index, char *drc_name,
> +				char *drc_type, u32 drc_power_domain,
> +				void *data),
> +			char *opt_drc_type, char *opt_drc_name,
> +			bool match_drc_index, bool ck_php_type,
> +			void *data);
> +
>  /* Conform to ACPI 2.0 SLIT distance definitions */
>  #define LOCAL_DISTANCE		10
>  #define REMOTE_DISTANCE		20
>