[PATCH 02/62] mm: Add pgflags_nid()

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

Convert page_to_nid() into a wrapper around pgflags_nid().  This is
in preparation for splitting struct page into separate types.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 include/linux/mm.h | 12 ++++++++----
 mm/sparse.c        |  6 +++---
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index db63653f403c..adc7e843148b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1369,16 +1369,20 @@ static inline int page_zone_id(struct page *page)
 }
 
 #ifdef NODE_NOT_IN_PAGE_FLAGS
-extern int page_to_nid(const struct page *page);
+extern int pgflags_nid(unsigned long pgflags);
 #else
+static inline int pgflags_nid(unsigned long pgflags)
+{
+	return (pgflags >> NODES_PGSHIFT) & NODES_MASK;
+}
+#endif
+
 static inline int page_to_nid(const struct page *page)
 {
 	struct page *p = (struct page *)page;
 
-	return (PF_POISONED_CHECK(p)->flags >> NODES_PGSHIFT) & NODES_MASK;
+	return pgflags_nid(PF_POISONED_CHECK(p)->flags);
 }
-#endif
-
 #ifdef CONFIG_NUMA_BALANCING
 static inline int cpu_pid_to_cpupid(int cpu, int pid)
 {
diff --git a/mm/sparse.c b/mm/sparse.c
index 4c59ed8c1d5a..818bdb84be99 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 pgflags_nid(unsigned long pgflags)
 {
-	return section_to_node_table[pgflags_section(page->flags)];
+	return section_to_node_table[pgflags_section(pgflags)];
 }
-EXPORT_SYMBOL(page_to_nid);
+EXPORT_SYMBOL(pgflags_nid);
 
 static void set_section_nid(unsigned long section_nr, int nid)
 {
-- 
2.32.0