[PATCH] PG_uncached is ia64 only
As Nick points out, only ia64 uses PG_uncached. So we can push it up into the
higher bits of the lower half of page->flags and make room for another flag on
32-bit machines.
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jesse Barnes <jbarnes@sgi.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index d276a4e..0c076d5 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -7,6 +7,8 @@
#include <linux/percpu.h>
#include <linux/cache.h>
+#include <linux/types.h>
+
#include <asm/pgtable.h>
/*
@@ -88,7 +90,17 @@
#define PG_nosave_free 18 /* Free, should not be written */
#define PG_buddy 19 /* Page is free, on buddy lists */
-#define PG_uncached 20 /* Page has been mapped as uncached */
+
+#if (BITS_PER_LONG > 32)
+/*
+ * 64-bit-only flags build down from bit 31
+ *
+ * 32 bit -------------------------------| FIELDS | FLAGS |
+ * 64 bit | FIELDS | ?????? FLAGS |
+ * 63 32 0
+ */
+#define PG_uncached 31 /* Page has been mapped as uncached */
+#endif
/*
* Global page accounting. One instance per CPU. Only unsigned longs are