pageflags: introduce macros to generate page flag functions

Introduce a set of macros that generate functions to handle page flags.

A page flag function group typically starts with either

	SETPAGEFLAG(<part of function name>,<part of PG_ flagname>)

to create a set of page flag operations that are atomic. Or

	__SETPAGEFLAG(<part of function name>,<part of PG_ flagname)

to create a set of page flag operations that are not atomic.

Then additional operations can be added using the following macros

TESTSCFLAG		Create additional atomic test-and-set and
			test-and-clear functions

TESTSETFLAG		Create additional test and set function
TESTCLEARFLAG		Create additional test and clear function
SETPAGEFLAG		Create additional atomic set function
CLEARPAGEFLAG		Create additional atomic clear function
__TESTPAGEFLAG		Create additional non atomic set function
__SETPAGEFLAG		Create additional non atomic clear function

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 41 insertions, 0 deletions

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 00e55e23b777..e5bddbfcf7ae 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -109,6 +109,47 @@ enum pageflags {
 #ifndef __GENERATING_BOUNDS_H
 
 /*
+ * Macros to create function definitions for page flags
+ */
+#define TESTPAGEFLAG(uname, lname)                                      \
+static inline int Page##uname(struct page *page)                        \
+                        { return test_bit(PG_##lname, &page->flags); }
+
+#define SETPAGEFLAG(uname, lname)                                       \
+static inline void SetPage##uname(struct page *page)                    \
+                        { set_bit(PG_##lname, &page->flags); }
+
+#define CLEARPAGEFLAG(uname, lname)                                     \
+static inline void ClearPage##uname(struct page *page)                  \
+                        { clear_bit(PG_##lname, &page->flags); }
+
+#define __SETPAGEFLAG(uname, lname)                                     \
+static inline void __SetPage##uname(struct page *page)                  \
+                        { __set_bit(PG_##lname, &page->flags); }
+
+#define __CLEARPAGEFLAG(uname, lname)                                   \
+static inline void __ClearPage##uname(struct page *page)                \
+                        { __clear_bit(PG_##lname, &page->flags); }
+
+#define TESTSETFLAG(uname, lname)                                       \
+static inline int TestSetPage##uname(struct page *page)                 \
+                { return test_and_set_bit(PG_##lname, &page->flags); }
+
+#define TESTCLEARFLAG(uname, lname)                                     \
+static inline int TestClearPage##uname(struct page *page)               \
+                { return test_and_clear_bit(PG_##lname, &page->flags); }
+
+
+#define PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname)               \
+        SETPAGEFLAG(uname, lname) CLEARPAGEFLAG(uname, lname)
+
+#define __PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname)             \
+        __SETPAGEFLAG(uname, lname)  __CLEARPAGEFLAG(uname, lname)
+
+#define TESTSCFLAG(uname, lname)                                        \
+        TESTSETFLAG(uname, lname) TESTCLEARFLAG(uname, lname)
+
+/*
  * Manipulation of page state flags
  */
 #define PageLocked(page)                \