mm/memory_hotplug: use "unsigned long" for PFN in zone_for_pfn_range()

Patch series "mm/memory_hotplug: preparatory patches for new online policy and memory"

These are all cleanups and one fix previously sent as part of [1]:
[PATCH v1 00/12] mm/memory_hotplug: "auto-movable" online policy and memory
groups.

These patches make sense even without the other series, therefore I pulled
them out to make the other series easier to digest.

[1] https://lkml.kernel.org/r/[email protected]

This patch (of 4):

Checkpatch complained on a follow-up patch that we are using "unsigned"
here, which defaults to "unsigned int" and checkpatch is correct.

As we will search for a fitting zone using the wrong pfn, we might end
up onlining memory to one of the special kernel zones, such as ZONE_DMA,
which can end badly as the onlined memory does not satisfy properties of
these zones.

Use "unsigned long" instead, just as we do in other places when handling
PFNs.  This can bite us once we have physical addresses in the range of
multiple TB.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: e5e6893 ("mm, memory_hotplug: display allowed zones in the preferred ordering")
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Pankaj Gupta <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Reviewed-by: Oscar Salvador <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: Pankaj Gupta <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: [email protected]
Cc: Andy Lutomirski <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: Anton Blanchard <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jia He <[email protected]>
Cc: Joe Perches <[email protected]>
Cc: Kefeng Wang <[email protected]>
Cc: Laurent Dufour <[email protected]>
Cc: Michel Lespinasse <[email protected]>
Cc: Nathan Lynch <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Pierre Morel <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Scott Cheloha <[email protected]>
Cc: Sergei Trofimovich <[email protected]>
Cc: Thiago Jung Bauermann <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

include/linux/memory_hotplug.h

@@ -339,8 +339,8 @@ extern void sparse_remove_section(struct mem_section *ms,
 		unsigned long map_offset, struct vmem_altmap *altmap);
 extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
 					  unsigned long pnum);
-extern struct zone *zone_for_pfn_range(int online_type, int nid, unsigned start_pfn,
-		unsigned long nr_pages);
+extern struct zone *zone_for_pfn_range(int online_type, int nid,
+		unsigned long start_pfn, unsigned long nr_pages);
 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);

mm/memory_hotplug.c

@@ -708,8 +708,8 @@ static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn
 	return movable_node_enabled ? movable_zone : kernel_zone;
 }
 
-struct zone *zone_for_pfn_range(int online_type, int nid, unsigned start_pfn,
-		unsigned long nr_pages)
+struct zone *zone_for_pfn_range(int online_type, int nid,
+		unsigned long start_pfn, unsigned long nr_pages)
 {
 	if (online_type == MMOP_ONLINE_KERNEL)
 		return default_kernel_zone_for_pfn(nid, start_pfn, nr_pages);