5 files changed, 31 insertions, 31 deletions

diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c
index 177d8aaeec42..8c2b50e8abc6 100644
--- a/arch/sparc64/mm/init.c
+++ b/arch/sparc64/mm/init.c
@@ -1699,9 +1699,21 @@ void __init paging_init(void)
          * functions like clear_dcache_dirty_cpu use the cpu mask
          * in 13-bit signed-immediate instruction fields.
          */
-        BUILD_BUG_ON(FLAGS_RESERVED != 32);
+
+        /*
+         * Page flags must not reach into upper 32 bits that are used
+         * for the cpu number
+         */
+        BUILD_BUG_ON(NR_PAGEFLAGS > 32);
+
+        /*
+         * The bit fields placed in the high range must not reach below
+         * the 32 bit boundary. Otherwise we cannot place the cpu field
+         * at the 32 bit boundary.
+         */
         BUILD_BUG_ON(SECTIONS_WIDTH + NODES_WIDTH + ZONES_WIDTH +
-                     ilog2(roundup_pow_of_two(NR_CPUS)) > FLAGS_RESERVED);
+                ilog2(roundup_pow_of_two(NR_CPUS)) > 32);
+
         BUILD_BUG_ON(NR_CPUS > 4096);
 
         kern_base = (prom_boot_mapping_phys_low >> 22UL) << 22UL;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 4f3c1b2f44de..526f810367d9 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -407,7 +407,7 @@ static inline void set_compound_order(struct page *page, unsigned long order)
 
 #define ZONES_WIDTH             ZONES_SHIFT
 
-#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= FLAGS_RESERVED
+#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
 #define NODES_WIDTH             NODES_SHIFT
 #else
 #ifdef CONFIG_SPARSEMEM_VMEMMAP
@@ -455,8 +455,8 @@ static inline void set_compound_order(struct page *page, unsigned long order)
 
 #define ZONEID_PGSHIFT          (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
 
-#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
-#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
+#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
+#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
 #endif
 
 #define ZONES_MASK              ((1UL << ZONES_WIDTH) - 1)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 0aece6d8937e..c7a51dac441d 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -820,25 +820,6 @@ static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
 #include <asm/sparsemem.h>
 #endif
 
-#if BITS_PER_LONG == 32
-/*
- * with 32 bit page->flags field, we reserve 9 bits for node/zone info.
- * there are 4 zones (3 bits) and this leaves 9-3=6 bits for nodes.
- */
-#define FLAGS_RESERVED          9
-
-#elif BITS_PER_LONG == 64
-/*
- * with 64 bit flags field, there's plenty of room.
- */
-#define FLAGS_RESERVED          32
-
-#else
-
-#error BITS_PER_LONG not defined
-
-#endif
-
 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
         !defined(CONFIG_ARCH_POPULATES_NODE_MAP)
 static inline unsigned long early_pfn_to_nid(unsigned long pfn)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index d66971530caa..00e55e23b777 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -6,7 +6,10 @@
 #define PAGE_FLAGS_H
 
 #include <linux/types.h>
+#ifndef __GENERATING_BOUNDS_H
 #include <linux/mm_types.h>
+#include <linux/bounds.h>
+#endif /* !__GENERATING_BOUNDS_H */
 
 /*
  * Various page->flags bits:
@@ -59,13 +62,12 @@
  * extends from the high bits downwards.
  *
  *  | FIELD | ... | FLAGS |
- *  N-1     ^             0
- *          (N-FLAGS_RESERVED)
+ *  N-1           ^       0
+ *               (NR_PAGEFLAGS)
  *
- * The fields area is reserved for fields mapping zone, node and SPARSEMEM
- * section.  The boundry between these two areas is defined by
- * FLAGS_RESERVED which defines the width of the fields section
- * (see linux/mmzone.h).  New flags must _not_ overlap with this area.
+ * The fields area is reserved for fields mapping zone, node (for NUMA) and
+ * SPARSEMEM section (for variants of SPARSEMEM that require section ids like
+ * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP).
  */
 enum pageflags {
         PG_locked,              /* Page is locked. Don't touch. */
@@ -101,9 +103,11 @@ enum pageflags {
  */
         PG_uncached = 31,               /* Page has been mapped as uncached */
 #endif
-        NR_PAGEFLAGS
+        __NR_PAGEFLAGS
 };
 
+#ifndef __GENERATING_BOUNDS_H
+
 /*
  * Manipulation of page state flags
  */
@@ -304,4 +308,5 @@ static inline void set_page_writeback(struct page *page)
         test_set_page_writeback(page);
 }
 
+#endif /* !__GENERATING_BOUNDS_H */
 #endif  /* PAGE_FLAGS_H */
diff --git a/kernel/bounds.c b/kernel/bounds.c
index 85bb281858cb..9ca2bb30243c 100644
--- a/kernel/bounds.c
+++ b/kernel/bounds.c
@@ -6,6 +6,7 @@
 
 #define __GENERATING_BOUNDS_H
 /* Include headers that define the enum constants of interest */
+#include <linux/page-flags.h>
 
 #define DEFINE(sym, val) \
         asm volatile("\n->" #sym " %0 " #val : : "i" (val))
@@ -15,5 +16,6 @@
 void foo(void)
 {
         /* The enum constants to put into include/linux/bounds.h */
+        DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS);
         /* End of constants */
 }