[PATCH 70/75] mm: Support arbitrary THP sizes

[Matthew Wilcox (Oracle)]

For code which has not yet been converted from THP to folios, use the
compound size of the page instead of assuming PTE or PMD size.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 include/linux/huge_mm.h | 47 -----------------------------------------
 include/linux/mm.h      | 31 +++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 47 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index e0348bca3d66..0734aff8fa19 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -250,30 +250,6 @@ static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
 		return NULL;
 }
 
-/**
- * thp_order - Order of a transparent huge page.
- * @page: Head page of a transparent huge page.
- */
-static inline unsigned int thp_order(struct page *page)
-{
-	VM_BUG_ON_PGFLAGS(PageTail(page), page);
-	if (PageHead(page))
-		return HPAGE_PMD_ORDER;
-	return 0;
-}
-
-/**
- * thp_nr_pages - The number of regular pages in this huge page.
- * @page: The head page of a huge page.
- */
-static inline int thp_nr_pages(struct page *page)
-{
-	VM_BUG_ON_PGFLAGS(PageTail(page), page);
-	if (PageHead(page))
-		return HPAGE_PMD_NR;
-	return 1;
-}
-
 /**
  * folio_test_pmd_mappable - Can we map this folio with a PMD?
  * @folio: The folio to test
@@ -336,18 +312,6 @@ static inline struct list_head *page_deferred_list(struct page *page)
 #define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; })
 #define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; })
 
-static inline unsigned int thp_order(struct page *page)
-{
-	VM_BUG_ON_PGFLAGS(PageTail(page), page);
-	return 0;
-}
-
-static inline int thp_nr_pages(struct page *page)
-{
-	VM_BUG_ON_PGFLAGS(PageTail(page), page);
-	return 1;
-}
-
 static inline bool folio_test_pmd_mappable(struct folio *folio)
 {
 	return false;
@@ -489,15 +453,4 @@ static inline int split_folio_to_list(struct folio *folio,
 	return split_huge_page_to_list(&folio->page, list);
 }
 
-/**
- * thp_size - Size of a transparent huge page.
- * @page: Head page of a transparent huge page.
- *
- * Return: Number of bytes in this page.
- */
-static inline unsigned long thp_size(struct page *page)
-{
-	return PAGE_SIZE << thp_order(page);
-}
-
 #endif /* _LINUX_HUGE_MM_H */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 74d9cda7cfd6..0c2a0f4bda1b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -945,6 +945,37 @@ static inline unsigned int page_shift(struct page *page)
 	return PAGE_SHIFT + compound_order(page);
 }
 
+/**
+ * thp_order - Order of a transparent huge page.
+ * @page: Head page of a transparent huge page.
+ */
+static inline unsigned int thp_order(struct page *page)
+{
+	VM_BUG_ON_PGFLAGS(PageTail(page), page);
+	return compound_order(page);
+}
+
+/**
+ * thp_nr_pages - The number of regular pages in this huge page.
+ * @page: The head page of a huge page.
+ */
+static inline int thp_nr_pages(struct page *page)
+{
+	VM_BUG_ON_PGFLAGS(PageTail(page), page);
+	return compound_nr(page);
+}
+
+/**
+ * thp_size - Size of a transparent huge page.
+ * @page: Head page of a transparent huge page.
+ *
+ * Return: Number of bytes in this page.
+ */
+static inline unsigned long thp_size(struct page *page)
+{
+	return PAGE_SIZE << thp_order(page);
+}
+
 void free_compound_page(struct page *page);
 
 #ifdef CONFIG_MMU
-- 
2.34.1