mm: page_alloc: move is_check_pages_enabled() into page_alloc.c

The is_check_pages_enabled() only used in page_alloc.c, move it into
page_alloc.c, also use it in free_tail_page_prepare().

Link: https://lkml.kernel.org/r/20230516063821.121844-14-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/internal.h

@@ -208,11 +208,6 @@ extern char * const zone_names[MAX_NR_ZONES];
 /* perform sanity checks on struct pages being allocated or freed */
 DECLARE_STATIC_KEY_MAYBE(CONFIG_DEBUG_VM, check_pages_enabled);
 
-static inline bool is_check_pages_enabled(void)
-{
-	return static_branch_unlikely(&check_pages_enabled);
-}
-
 extern int min_free_kbytes;
 
 void setup_per_zone_wmarks(void);

mm/page_alloc.c

@@ -983,6 +983,11 @@ static inline bool free_page_is_bad(struct page *page)
 	return true;
 }
 
+static inline bool is_check_pages_enabled(void)
+{
+	return static_branch_unlikely(&check_pages_enabled);
+}
+
 static int free_tail_page_prepare(struct page *head_page, struct page *page)
 {
 	struct folio *folio = (struct folio *)head_page;
@@ -994,7 +999,7 @@ static int free_tail_page_prepare(struct page *head_page, struct page *page)
 	 */
 	BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
 
-	if (!static_branch_unlikely(&check_pages_enabled)) {
+	if (!is_check_pages_enabled()) {
 		ret = 0;
 		goto out;
 	}