kho: use unsigned long for nr_pages

Patch series "kho: clean up page initialization logic", v2.

This series simplifies the page initialization logic in
kho_restore_page().  It was originally only a single patch [0], but on
Pasha's suggestion, I added another patch to use unsigned long for
nr_pages.

Technically speaking, the patches aren't related and can be applied
independently, but bundling them together since patch 2 relies on 1 and it
is easier to manage them this way.


This patch (of 2):

With 4k pages, a 32-bit nr_pages can span up to 16 TiB.  While it is a
lot, there exist systems with terabytes of RAM.  gup is also moving to
using long for nr_pages.  Use unsigned long and make KHO future-proof.

Link: https://lkml.kernel.org/r/20260116112217.915803-1-pratyush@kernel.org
Link: https://lkml.kernel.org/r/20260116112217.915803-2-pratyush@kernel.org
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Suggested-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/include/linux/kexec_handover.h b/include/linux/kexec_handover.h
index a56ff3ffaf17..ac4129d1d741 100644
--- a/include/linux/kexec_handover.h
+++ b/include/linux/kexec_handover.h
@@ -22,15 +22,15 @@ bool is_kho_boot(void);
 
 int kho_preserve_folio(struct folio *folio);
 void kho_unpreserve_folio(struct folio *folio);
-int kho_preserve_pages(struct page *page, unsigned int nr_pages);
-void kho_unpreserve_pages(struct page *page, unsigned int nr_pages);
+int kho_preserve_pages(struct page *page, unsigned long nr_pages);
+void kho_unpreserve_pages(struct page *page, unsigned long nr_pages);
 int kho_preserve_vmalloc(void *ptr, struct kho_vmalloc *preservation);
 void kho_unpreserve_vmalloc(struct kho_vmalloc *preservation);
 void *kho_alloc_preserve(size_t size);
 void kho_unpreserve_free(void *mem);
 void kho_restore_free(void *mem);
 struct folio *kho_restore_folio(phys_addr_t phys);
-struct page *kho_restore_pages(phys_addr_t phys, unsigned int nr_pages);
+struct page *kho_restore_pages(phys_addr_t phys, unsigned long nr_pages);
 void *kho_restore_vmalloc(const struct kho_vmalloc *preservation);
 int kho_add_subtree(const char *name, void *fdt);
 void kho_remove_subtree(void *fdt);