On Sun, Mar 29, 2020 at 10:23 PM Alastair D'Silva <alastair@xxxxxxxxxxx> wrote:
>
> When setting up OpenCAPI connected persistent memory, the range check may
> not be performed until quite late (or perhaps not at all, if the user does
> not establish a DAX device).
>
> This patch makes the range check callable so we can perform the check while
> probing the OpenCAPI Persistent Memory device.
>
> Signed-off-by: Alastair D'Silva <alastair@xxxxxxxxxxx>
> Reviewed-by: Andrew Donnellan <ajd@xxxxxxxxxxxxx>
> ---
> include/linux/memory_hotplug.h | 5 +++++
> mm/memory_hotplug.c | 4 ++--
> 2 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index f4d59155f3d4..9a19ae0d7e31 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/include/linux/memory_hotplug.h
> @@ -337,6 +337,11 @@ static inline void __remove_memory(int nid, u64 start, u64 size) {}
> extern void set_zone_contiguous(struct zone *zone);
> extern void clear_zone_contiguous(struct zone *zone);
>
> +#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
> +int check_hotplug_memory_addressable(unsigned long pfn,
> + unsigned long nr_pages);
> +#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
Let's move this to include/linux/memory.h with the other
CONFIG_MEMORY_HOTPLUG_SPARSE declarations, and add a dummy
implementation for the CONFIG_MEMORY_HOTPLUG_SPARSE=n case.
Also, this patch can be squashed with the next one, no need for it to
be stand alone.
> +
> extern void __ref free_area_init_core_hotplug(int nid);
> extern int __add_memory(int nid, u64 start, u64 size);
> extern int add_memory(int nid, u64 start, u64 size);
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 0a54ffac8c68..14945f033594 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -276,8 +276,8 @@ static int check_pfn_span(unsigned long pfn, unsigned long nr_pages,
> return 0;
> }
>
> -static int check_hotplug_memory_addressable(unsigned long pfn,
> - unsigned long nr_pages)
> +int check_hotplug_memory_addressable(unsigned long pfn,
> + unsigned long nr_pages)
> {
> const u64 max_addr = PFN_PHYS(pfn + nr_pages) - 1;
>
> --
> 2.24.1
>
