bootmem: Replace work_with_active_regions() with for_each_mem_pfn_range()

Callback based iteration is cumbersome and much less useful than
for_each_*() iterator.  This patch implements for_each_mem_pfn_range()
which replaces work_with_active_regions().  All the current users of
work_with_active_regions() are converted.

This simplifies walking over early_node_map and will allow converting
internal logics in page_alloc to use iterator instead of walking
early_node_map directly, which in turn will enable moving node
information to memblock.

powerpc change is only compile tested.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20110714074610.GD3455@htj.dyndns.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index c70a326..57e4c9f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1327,9 +1327,27 @@
 				   int nr_range, int nid);
 u64 __init find_memory_core_early(int nid, u64 size, u64 align,
 					u64 goal, u64 limit);
-typedef int (*work_fn_t)(unsigned long, unsigned long, void *);
-extern void work_with_active_regions(int nid, work_fn_t work_fn, void *data);
 extern void sparse_memory_present_with_active_regions(int nid);
+
+extern void __next_mem_pfn_range(int *idx, int nid,
+				 unsigned long *out_start_pfn,
+				 unsigned long *out_end_pfn, int *out_nid);
+
+/**
+ * for_each_mem_pfn_range - early memory pfn range iterator
+ * @i: an integer used as loop variable
+ * @nid: node selector, %MAX_NUMNODES for all nodes
+ * @p_start: ptr to ulong for start pfn of the range, can be %NULL
+ * @p_end: ptr to ulong for end pfn of the range, can be %NULL
+ * @p_nid: ptr to int for nid of the range, can be %NULL
+ *
+ * Walks over configured memory ranges.  Available after early_node_map is
+ * populated.
+ */
+#define for_each_mem_pfn_range(i, nid, p_start, p_end, p_nid)		\
+	for (i = -1, __next_mem_pfn_range(&i, nid, p_start, p_end, p_nid); \
+	     i >= 0; __next_mem_pfn_range(&i, nid, p_start, p_end, p_nid))
+
 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
 
 #if !defined(CONFIG_ARCH_POPULATES_NODE_MAP) && \