mm/page_alloc.c: cleanup add_active_range() related comments

add_active_range() has been repalced by memblock_set_node().  Clean up the
comments to comply with that change.
Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c

@@ -4387,9 +4387,6 @@ int __meminit init_currently_empty_zone(struct zone *zone,
 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
 /*
  * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
- * Architectures may implement their own version but if add_active_range()
- * was used and there are no special requirements, this is a convenient
- * alternative
  */
 int __meminit __early_pfn_to_nid(unsigned long pfn)
 {
@@ -4444,10 +4441,9 @@ bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
  * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
  * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
  *
- * If an architecture guarantees that all ranges registered with
- * add_active_ranges() contain no holes and may be freed, this
- * this function may be used instead of calling memblock_free_early_nid()
- * manually.
+ * If an architecture guarantees that all ranges registered contain no holes
+ * and may be freed, this this function may be used instead of calling
+ * memblock_free_early_nid() manually.
  */
 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
 {
@@ -4469,9 +4465,8 @@ void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
  * sparse_memory_present_with_active_regions - Call memory_present for each active range
  * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
  *
- * If an architecture guarantees that all ranges registered with
- * add_active_ranges() contain no holes and may be freed, this
- * function may be used instead of calling memory_present() manually.
+ * If an architecture guarantees that all ranges registered contain no holes and may
+ * be freed, this function may be used instead of calling memory_present() manually.
  */
 void __init sparse_memory_present_with_active_regions(int nid)
 {
@@ -4489,7 +4484,7 @@ void __init sparse_memory_present_with_active_regions(int nid)
  * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
  *
  * It returns the start and end page frame of a node based on information
- * provided by an arch calling add_active_range(). If called for a node
+ * provided by memblock_set_node(). If called for a node
  * with no available memory, a warning is printed and the start and end
  * PFNs will be 0.
  */
@@ -5066,7 +5061,7 @@ static unsigned long __init find_min_pfn_for_node(int nid)
  * find_min_pfn_with_active_regions - Find the minimum PFN registered
  *
  * It returns the minimum PFN based on information provided via
- * add_active_range().
+ * memblock_set_node().
  */
 unsigned long __init find_min_pfn_with_active_regions(void)
 {
@@ -5287,7 +5282,7 @@ static void check_for_memory(pg_data_t *pgdat, int nid)
  * @max_zone_pfn: an array of max PFNs for each zone
  *
  * This will call free_area_init_node() for each active node in the system.
- * Using the page ranges provided by add_active_range(), the size of each
+ * Using the page ranges provided by memblock_set_node(), the size of each
  * zone in each node and their holes is calculated. If the maximum PFN
  * between two adjacent zones match, it is assumed that the zone is empty.
  * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed