mm: introduce memdesc_nid()

Remove a conversion from folio to page by passing the folio->flags (which
are a copy of the page->flags) to the new memdesc_nid() function.

Link: https://lkml.kernel.org/r/20250805172307.1302730-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

2 files changed, 16 insertions, 11 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 82617c4cfa24..00c8a54127d3 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1558,17 +1558,22 @@ static inline int page_zone_id(struct page *page)
 }
 
 #ifdef NODE_NOT_IN_PAGE_FLAGS
-int page_to_nid(const struct page *page);
+int memdesc_nid(memdesc_flags_t mdf);
 #else
-static inline int page_to_nid(const struct page *page)
+static inline int memdesc_nid(memdesc_flags_t mdf)
 {
-	return (PF_POISONED_CHECK(page)->flags.f >> NODES_PGSHIFT) & NODES_MASK;
+	return (mdf.f >> NODES_PGSHIFT) & NODES_MASK;
 }
 #endif
 
+static inline int page_to_nid(const struct page *page)
+{
+	return memdesc_nid(PF_POISONED_CHECK(page)->flags);
+}
+
 static inline int folio_nid(const struct folio *folio)
 {
-	return page_to_nid(&folio->page);
+	return memdesc_nid(folio->flags);
 }
 
 #ifdef CONFIG_NUMA_BALANCING
@@ -1791,14 +1796,14 @@ static inline pg_data_t *page_pgdat(const struct page *page)
 	return NODE_DATA(page_to_nid(page));
 }
 
-static inline struct zone *folio_zone(const struct folio *folio)
+static inline pg_data_t *folio_pgdat(const struct folio *folio)
 {
-	return page_zone(&folio->page);
+	return NODE_DATA(folio_nid(folio));
 }
 
-static inline pg_data_t *folio_pgdat(const struct folio *folio)
+static inline struct zone *folio_zone(const struct folio *folio)
 {
-	return page_pgdat(&folio->page);
+	return &folio_pgdat(folio)->node_zones[folio_zonenum(folio)];
 }
 
 #ifdef SECTION_IN_PAGE_FLAGS
diff --git a/mm/sparse.c b/mm/sparse.c
index 7cb42cbfc7f9..17c50a6415c2 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -43,11 +43,11 @@ static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
 static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
 #endif
 
-int page_to_nid(const struct page *page)
+int memdesc_nid(memdesc_flags_t mdf)
 {
-	return section_to_node_table[memdesc_section(page->flags)];
+	return section_to_node_table[memdesc_section(mdf)];
 }
-EXPORT_SYMBOL(page_to_nid);
+EXPORT_SYMBOL(memdesc_nid);
 
 static void set_section_nid(unsigned long section_nr, int nid)
 {