Merge branch 'mm-hotfixes-stable' into mm-stable to be able to merge "mm:

introduce deferred freeing for kernel page tables" into mm-stable.

3 files changed, 36 insertions, 35 deletions

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 0ceb4e09306c..623bee335383 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -7,6 +7,7 @@
 #include <linux/mmzone.h>
 #include <linux/topology.h>
 #include <linux/alloc_tag.h>
+#include <linux/cleanup.h>
 #include <linux/sched.h>
 
 struct vm_area_struct;
@@ -463,4 +464,6 @@ static inline struct folio *folio_alloc_gigantic_noprof(int order, gfp_t gfp,
 /* This should be paired with folio_put() rather than free_contig_range(). */
 #define folio_alloc_gigantic(...) alloc_hooks(folio_alloc_gigantic_noprof(__VA_ARGS__))
 
+DEFINE_FREE(free_page, void *, free_page((unsigned long)_T))
+
 #endif /* __LINUX_GFP_H */
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index f327d62fc985..71ac78b9f834 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -376,45 +376,30 @@ bool non_uniform_split_supported(struct folio *folio, unsigned int new_order,
 int folio_split(struct folio *folio, unsigned int new_order, struct page *page,
 		struct list_head *list);
 /*
- * try_folio_split - try to split a @folio at @page using non uniform split.
+ * try_folio_split_to_order - try to split a @folio at @page to @new_order using
+ * non uniform split.
  * @folio: folio to be split
- * @page: split to order-0 at the given page
- * @list: store the after-split folios
+ * @page: split to @new_order at the given page
+ * @new_order: the target split order
  *
- * Try to split a @folio at @page using non uniform split to order-0, if
- * non uniform split is not supported, fall back to uniform split.
+ * Try to split a @folio at @page using non uniform split to @new_order, if
+ * non uniform split is not supported, fall back to uniform split. After-split
+ * folios are put back to LRU list. Use min_order_for_split() to get the lower
+ * bound of @new_order.
  *
  * Return: 0: split is successful, otherwise split failed.
  */
-static inline int try_folio_split(struct folio *folio, struct page *page,
-		struct list_head *list)
+static inline int try_folio_split_to_order(struct folio *folio,
+		struct page *page, unsigned int new_order)
 {
-	int ret = min_order_for_split(folio);
-
-	if (ret < 0)
-		return ret;
-
-	if (!non_uniform_split_supported(folio, 0, false))
-		return split_huge_page_to_list_to_order(&folio->page, list,
-				ret);
-	return folio_split(folio, ret, page, list);
+	if (!non_uniform_split_supported(folio, new_order, /* warns= */ false))
+		return split_huge_page_to_list_to_order(&folio->page, NULL,
+				new_order);
+	return folio_split(folio, new_order, page, NULL);
 }
 static inline int split_huge_page(struct page *page)
 {
-	struct folio *folio = page_folio(page);
-	int ret = min_order_for_split(folio);
-
-	if (ret < 0)
-		return ret;
-
-	/*
-	 * split_huge_page() locks the page before splitting and
-	 * expects the same page that has been split to be locked when
-	 * returned. split_folio(page_folio(page)) cannot be used here
-	 * because it converts the page to folio and passes the head
-	 * page to be split.
-	 */
-	return split_huge_page_to_list_to_order(page, NULL, ret);
+	return split_huge_page_to_list_to_order(page, NULL, 0);
 }
 void deferred_split_folio(struct folio *folio, bool partially_mapped);
 
@@ -597,14 +582,20 @@ static inline int split_huge_page(struct page *page)
 	return -EINVAL;
 }
 
+static inline int min_order_for_split(struct folio *folio)
+{
+	VM_WARN_ON_ONCE_FOLIO(1, folio);
+	return -EINVAL;
+}
+
 static inline int split_folio_to_list(struct folio *folio, struct list_head *list)
 {
 	VM_WARN_ON_ONCE_FOLIO(1, folio);
 	return -EINVAL;
 }
 
-static inline int try_folio_split(struct folio *folio, struct page *page,
-		struct list_head *list)
+static inline int try_folio_split_to_order(struct folio *folio,
+		struct page *page, unsigned int new_order)
 {
 	VM_WARN_ON_ONCE_FOLIO(1, folio);
 	return -EINVAL;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index d16b33bacc32..7c79b3369b82 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2074,7 +2074,7 @@ static inline unsigned long folio_nr_pages(const struct folio *folio)
 	return folio_large_nr_pages(folio);
 }
 
-#if !defined(CONFIG_ARCH_HAS_GIGANTIC_PAGE)
+#if !defined(CONFIG_HAVE_GIGANTIC_FOLIOS)
 /*
  * We don't expect any folios that exceed buddy sizes (and consequently
  * memory sections).
@@ -2087,10 +2087,17 @@ static inline unsigned long folio_nr_pages(const struct folio *folio)
  * pages are guaranteed to be contiguous.
  */
 #define MAX_FOLIO_ORDER		PFN_SECTION_SHIFT
-#else
+#elif defined(CONFIG_HUGETLB_PAGE)
 /*
  * There is no real limit on the folio size. We limit them to the maximum we
- * currently expect (e.g., hugetlb, dax).
+ * currently expect (see CONFIG_HAVE_GIGANTIC_FOLIOS): with hugetlb, we expect
+ * no folios larger than 16 GiB on 64bit and 1 GiB on 32bit.
+ */
+#define MAX_FOLIO_ORDER		get_order(IS_ENABLED(CONFIG_64BIT) ? SZ_16G : SZ_1G)
+#else
+/*
+ * Without hugetlb, gigantic folios that are bigger than a single PUD are
+ * currently impossible.
  */
 #define MAX_FOLIO_ORDER		PUD_ORDER
 #endif