[RFC PATCH 04/11] mm: Create FolioFlags

[Matthew Wilcox (Oracle)]

These new functions are the folio analogues of the PageFlags functions.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 include/linux/page-flags.h | 36 +++++++++++++++++++++++++++++++++---
 1 file changed, 33 insertions(+), 3 deletions(-)

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index ec5d0290e0ee..2c51cd4b3630 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -212,6 +212,12 @@ static inline void page_init_poison(struct page *page, size_t size)
 }
 #endif
 
+static unsigned long *folio_flags(struct folio *folio)
+{
+	VM_BUG_ON_PGFLAGS(PagePoisoned(&folio->page), &folio->page);
+	return &folio->page.flags;
+}
+
 /*
  * Page flags policies wrt compound pages
  *
@@ -260,30 +266,44 @@ static inline void page_init_poison(struct page *page, size_t size)
  * Macros to create function definitions for page flags
  */
 #define TESTPAGEFLAG(uname, lname, policy)				\
+static __always_inline int Folio##uname(struct folio *folio)		\
+	{ return test_bit(PG_##lname, folio_flags(folio)); }		\
 static __always_inline int Page##uname(struct page *page)		\
 	{ return test_bit(PG_##lname, &policy(page, 0)->flags); }
 
 #define SETPAGEFLAG(uname, lname, policy)				\
+static __always_inline void SetFolio##uname(struct folio *folio)	\
+	{ set_bit(PG_##lname, folio_flags(folio)); }			\
 static __always_inline void SetPage##uname(struct page *page)		\
 	{ set_bit(PG_##lname, &policy(page, 1)->flags); }
 
 #define CLEARPAGEFLAG(uname, lname, policy)				\
+static __always_inline void ClearFolio##uname(struct folio *folio)	\
+	{ clear_bit(PG_##lname, folio_flags(folio)); }			\
 static __always_inline void ClearPage##uname(struct page *page)		\
 	{ clear_bit(PG_##lname, &policy(page, 1)->flags); }
 
 #define __SETPAGEFLAG(uname, lname, policy)				\
+static __always_inline void __SetFolio##uname(struct folio *folio)	\
+	{ __set_bit(PG_##lname, folio_flags(folio)); }			\
 static __always_inline void __SetPage##uname(struct page *page)		\
 	{ __set_bit(PG_##lname, &policy(page, 1)->flags); }
 
 #define __CLEARPAGEFLAG(uname, lname, policy)				\
+static __always_inline void __ClearFolio##uname(struct folio *folio)	\
+	{ __clear_bit(PG_##lname, folio_flags(folio)); }		\
 static __always_inline void __ClearPage##uname(struct page *page)	\
 	{ __clear_bit(PG_##lname, &policy(page, 1)->flags); }
 
 #define TESTSETFLAG(uname, lname, policy)				\
+static __always_inline int TestSetFolio##uname(struct folio *folio)	\
+	{ return test_and_set_bit(PG_##lname, folio_flags(folio)); }	\
 static __always_inline int TestSetPage##uname(struct page *page)	\
 	{ return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); }
 
 #define TESTCLEARFLAG(uname, lname, policy)				\
+static __always_inline int TestClearFolio##uname(struct folio *folio)	\
+	{ return test_and_clear_bit(PG_##lname, folio_flags(folio)); }	\
 static __always_inline int TestClearPage##uname(struct page *page)	\
 	{ return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); }
 
@@ -302,21 +322,27 @@ static __always_inline int TestClearPage##uname(struct page *page)	\
 	TESTCLEARFLAG(uname, lname, policy)
 
 #define TESTPAGEFLAG_FALSE(uname)					\
+static inline int Folio##uname(const struct folio *folio) { return 0; }	\
 static inline int Page##uname(const struct page *page) { return 0; }
 
 #define SETPAGEFLAG_NOOP(uname)						\
+static inline void SetFolio##uname(struct folio *folio) { }		\
 static inline void SetPage##uname(struct page *page) {  }
 
 #define CLEARPAGEFLAG_NOOP(uname)					\
+static inline void ClearFolio##uname(struct folio *folio) { }		\
 static inline void ClearPage##uname(struct page *page) {  }
 
 #define __CLEARPAGEFLAG_NOOP(uname)					\
+static inline void __ClearFolio##uname(struct folio *folio) { }		\
 static inline void __ClearPage##uname(struct page *page) {  }
 
 #define TESTSETFLAG_FALSE(uname)					\
+static inline int TestSetFolio##uname(struct folio *folio) { return 0; } \
 static inline int TestSetPage##uname(struct page *page) { return 0; }
 
 #define TESTCLEARFLAG_FALSE(uname)					\
+static inline int TestClearFolio##uname(struct folio *folio) { return 0; } \
 static inline int TestClearPage##uname(struct page *page) { return 0; }
 
 #define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname)			\
@@ -509,11 +535,10 @@ TESTPAGEFLAG_FALSE(Ksm)
 
 u64 stable_page_flags(struct page *page);
 
-static inline int PageUptodate(struct page *page)
+static inline int FolioUptodate(struct folio *folio)
 {
 	int ret;
-	page = compound_head(page);
-	ret = test_bit(PG_uptodate, &(page)->flags);
+	ret = test_bit(PG_uptodate, folio_flags(folio));
 	/*
 	 * Must ensure that the data we read out of the page is loaded
 	 * _after_ we've loaded page->flags to check for PageUptodate.
@@ -528,6 +553,11 @@ static inline int PageUptodate(struct page *page)
 	return ret;
 }
 
+static inline int PageUptodate(struct page *page)
+{
+	return FolioUptodate(page_folio(page));
+}
+
 static __always_inline void __SetPageUptodate(struct page *page)
 {
 	VM_BUG_ON_PAGE(PageTail(page), page);
-- 
2.29.2