[PATCH] asm-i386/mmzone.h macro paren/eval fixes

Patch from William Lee Irwin III <wli@holomorphy.com>

Okay, this one looks ugly because we're missing some of the definitions
available with which to convert to inline functions (esp. struct page).
A lot of these introduce temporaries and sort of hope names won't clash,
which might be important to whoever cares about -Wshadow.

 - node_end_pfn() evaluates nid twice
 - local_mapnr() evaluates kvaddr twice
 - kern_addr_valid() evaluates kaddr twice
 - pfn_to_page() evaluates pfn multiple times
 - page_to_pfn() evaluates page thrice
 - pfn_valid() doesn't parenthesize its argument

include/asm-i386/mmzone.h

@@ -57,25 +57,47 @@ extern struct pglist_data *node_data[];
 
 #define node_mem_map(nid)	(NODE_DATA(nid)->node_mem_map)
 #define node_start_pfn(nid)	(NODE_DATA(nid)->node_start_pfn)
-#define node_end_pfn(nid)       (NODE_DATA(nid)->node_start_pfn + \
-				 NODE_DATA(nid)->node_size)
+#define node_end_pfn(nid)						\
+({									\
+	pg_data_t *__pgdat = NODE_DATA(nid);				\
+	__pgdat->node_start_pfn + __pgdat->node_size;			\
+})
 
 #define local_mapnr(kvaddr)						\
-	( (__pa(kvaddr) >> PAGE_SHIFT) - node_start_pfn(kvaddr_to_nid(kvaddr)) )
+({									\
+	unsigned long __pfn = __pa(kvaddr) >> PAGE_SHIFT;		\
+	(__pfn - node_start_pfn(pfn_to_nid(__pfn)));			\
+})
 
-#define kern_addr_valid(kaddr)	test_bit(local_mapnr(kaddr), \
-		 NODE_DATA(kvaddr_to_nid(kaddr))->valid_addr_bitmap)
+#define kern_addr_valid(kaddr)						\
+({									\
+	unsigned long __kaddr = (unsigned long)(kaddr);			\
+	pg_data_t *__pgdat = NODE_DATA(kvaddr_to_nid(__kaddr));		\
+	test_bit(local_mapnr(__kaddr), __pgdat->valid_addr_bitmap);	\
+})
 
-#define pfn_to_page(pfn)	(node_mem_map(pfn_to_nid(pfn)) + node_localnr(pfn, pfn_to_nid(pfn)))
-#define page_to_pfn(page)	((page - page_zone(page)->zone_mem_map) + page_zone(page)->zone_start_pfn)
+#define pfn_to_page(pfn)						\
+({									\
+	unsigned long __pfn = pfn;					\
+	int __node  = pfn_to_nid(__pfn);				\
+	&node_mem_map(__node)[node_localnr(__pfn,__node)];		\
+})
+
+#define page_to_pfn(pg)							\
+({									\
+	struct page *__page = pg;					\
+	struct zone *__zone = page_zone(__page);			\
+	(unsigned long)(__page - __zone->zone_mem_map)			\
+		+ __zone->zone_start_pfn;				\
+})
 #define pmd_page(pmd)		(pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
 /*
  * pfn_valid should be made as fast as possible, and the current definition 
  * is valid for machines that are NUMA, but still contiguous, which is what
  * is currently supported. A more generalised, but slower definition would
  * be something like this - mbligh:
- * ( pfn_to_pgdat(pfn) && (pfn < node_end_pfn(pfn_to_nid(pfn))) ) 
+ * ( pfn_to_pgdat(pfn) && ((pfn) < node_end_pfn(pfn_to_nid(pfn))) ) 
  */ 
-#define pfn_valid(pfn)          (pfn < num_physpages)
+#define pfn_valid(pfn)          ((pfn) < num_physpages)
 #endif /* CONFIG_DISCONTIGMEM */
 #endif /* _ASM_MMZONE_H_ */