Drivers which may pass hotplug policy down to DAX need MMOP_ symbols and the mhp_get_default_online_type function for hotplug use cases.
Some drivers (cxl) co-mingle their hotplug and devdax use-cases into the same driver code, and chose the dax_kmem path as the default driver path - making it difficult to require hotplug as a predicate to building the overall driver (it may break other non-hotplug use-cases). Export mhp_get_default_online_type function to allow these drivers to build when hotplug is disabled and still use the DAX use case. In the built-out case we simply return MMOP_OFFLINE as it's non-destructive. The internal function can never return -1 either, so we choose this to allow for defining the function with 'enum mmop'. Signed-off-by: Gregory Price <[email protected]> --- include/linux/memory_hotplug.h | 2 ++ mm/memory_hotplug.c | 1 + 2 files changed, 3 insertions(+) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 7c9d66729c60..f059025f8f8b 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -316,6 +316,8 @@ extern struct zone *zone_for_pfn_range(enum mmop online_type, extern int arch_create_linear_mapping(int nid, u64 start, u64 size, struct mhp_params *params); void arch_remove_linear_mapping(u64 start, u64 size); +#else +static inline enum mmop mhp_get_default_online_type(void) { return MMOP_OFFLINE; } #endif /* CONFIG_MEMORY_HOTPLUG */ #endif /* __LINUX_MEMORY_HOTPLUG_H */ diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 6833208cc17c..494257054095 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -239,6 +239,7 @@ enum mmop mhp_get_default_online_type(void) return mhp_default_online_type; } +EXPORT_SYMBOL_GPL(mhp_get_default_online_type); void mhp_set_default_online_type(enum mmop online_type) { -- 2.54.0
