mm: Get rid of __ZONE_COUNT

It was used to compensate because MAX_NR_ZONES was not available to the
#ifdefs.  Export MAX_NR_ZONES via the new mechanism and get rid of
__ZONE_COUNT.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/mmzone.h

@@ -3,6 +3,7 @@
 
 #ifdef __KERNEL__
 #ifndef __ASSEMBLY__
+#ifndef __GENERATING_BOUNDS_H
 
 #include <linux/spinlock.h>
 #include <linux/list.h>
@@ -15,6 +16,7 @@
 #include <linux/seqlock.h>
 #include <linux/nodemask.h>
 #include <linux/pageblock-flags.h>
+#include <linux/bounds.h>
 #include <asm/atomic.h>
 #include <asm/page.h>
 
@@ -129,6 +131,8 @@ struct per_cpu_pageset {
 #define zone_pcp(__z, __cpu) (&(__z)->pageset[(__cpu)])
 #endif
 
+#endif /* !__GENERATING_BOUNDS.H */
+
 enum zone_type {
 #ifdef CONFIG_ZONE_DMA
 	/*
@@ -177,9 +181,11 @@ enum zone_type {
 	ZONE_HIGHMEM,
 #endif
 	ZONE_MOVABLE,
-	MAX_NR_ZONES
+	__MAX_NR_ZONES
 };
 
+#ifndef __GENERATING_BOUNDS_H
+
 /*
  * When a memory allocation must conform to specific limitations (such
  * as being suitable for DMA) the caller will pass in hints to the
@@ -188,28 +194,15 @@ enum zone_type {
  * match the requested limits. See gfp_zone() in include/linux/gfp.h
  */
 
-/*
+#if MAX_NR_ZONES < 2
- * Count the active zones.  Note that the use of defined(X) outside
- * #if and family is not necessarily defined so ensure we cannot use
- * it later.  Use __ZONE_COUNT to work out how many shift bits we need.
- */
-#define __ZONE_COUNT (			\
-	  defined(CONFIG_ZONE_DMA)	\
-	+ defined(CONFIG_ZONE_DMA32)	\
-	+ 1				\
-	+ defined(CONFIG_HIGHMEM)	\
-	+ 1				\
-)
-#if __ZONE_COUNT < 2
 #define ZONES_SHIFT 0
-#elif __ZONE_COUNT <= 2
+#elif MAX_NR_ZONES <= 2
 #define ZONES_SHIFT 1
-#elif __ZONE_COUNT <= 4
+#elif MAX_NR_ZONES <= 4
 #define ZONES_SHIFT 2
 #else
 #error ZONES_SHIFT -- too many zones configured adjust calculation
 #endif
-#undef __ZONE_COUNT
 
 struct zone {
 	/* Fields commonly accessed by the page allocator */
@@ -1008,6 +1001,7 @@ unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
 #define pfn_valid_within(pfn) (1)
 #endif
 
+#endif /* !__GENERATING_BOUNDS.H */
 #endif /* !__ASSEMBLY__ */
 #endif /* __KERNEL__ */
 #endif /* _LINUX_MMZONE_H */

kernel/bounds.c

@@ -7,6 +7,7 @@
 #define __GENERATING_BOUNDS_H
 /* Include headers that define the enum constants of interest */
 #include <linux/page-flags.h>
+#include <linux/mmzone.h>
 
 #define DEFINE(sym, val) \
         asm volatile("\n->" #sym " %0 " #val : : "i" (val))
@@ -17,5 +18,6 @@ void foo(void)
 {
 	/* The enum constants to put into include/linux/bounds.h */
 	DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS);
+	DEFINE(MAX_NR_ZONES, __MAX_NR_ZONES);
 	/* End of constants */
 }