mm: implement new zone specific memblock iterator

Introduce a new iterator for_each_free_mem_pfn_range_in_zone.

This iterator will take care of making sure a given memory range provided
is in fact contained within a zone.  It takes are of all the bounds
checking we were doing in deferred_grow_zone, and deferred_init_memmap.
In addition it should help to speed up the search a bit by iterating until
the end of a range is greater than the start of the zone pfn range, and
will exit completely if the start is beyond the end of the zone.

Link: http://lkml.kernel.org/r/20190405221225.12227.22573.stgit@localhost.localdomain
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <yi.z.zhang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 25b82be..fd42321 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1631,11 +1631,9 @@ static unsigned long  __init deferred_init_pages(struct zone *zone,
 static int __init deferred_init_memmap(void *data)
 {
 	pg_data_t *pgdat = data;
-	int nid = pgdat->node_id;
 	unsigned long start = jiffies;
 	unsigned long nr_pages = 0;
 	unsigned long spfn, epfn, first_init_pfn, flags;
-	phys_addr_t spa, epa;
 	int zid;
 	struct zone *zone;
 	const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
@@ -1672,14 +1670,12 @@ static int __init deferred_init_memmap(void *data)
 	 * freeing pages we can access pages that are ahead (computing buddy
 	 * page in __free_one_page()).
 	 */
-	for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
-		spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
-		epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
+	for_each_free_mem_pfn_range_in_zone(i, zone, &spfn, &epfn) {
+		spfn = max_t(unsigned long, first_init_pfn, spfn);
 		nr_pages += deferred_init_pages(zone, spfn, epfn);
 	}
-	for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
-		spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
-		epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
+	for_each_free_mem_pfn_range_in_zone(i, zone, &spfn, &epfn) {
+		spfn = max_t(unsigned long, first_init_pfn, spfn);
 		deferred_free_pages(spfn, epfn);
 	}
 	pgdat_resize_unlock(pgdat, &flags);
@@ -1687,8 +1683,8 @@ static int __init deferred_init_memmap(void *data)
 	/* Sanity check that the next zone really is unpopulated */
 	WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
 
-	pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
-					jiffies_to_msecs(jiffies - start));
+	pr_info("node %d initialised, %lu pages in %ums\n",
+		pgdat->node_id,	nr_pages, jiffies_to_msecs(jiffies - start));
 
 	pgdat_init_report_one_done();
 	return 0;
@@ -1712,13 +1708,11 @@ static int __init deferred_init_memmap(void *data)
 static noinline bool __init
 deferred_grow_zone(struct zone *zone, unsigned int order)
 {
-	int nid = zone_to_nid(zone);
-	pg_data_t *pgdat = NODE_DATA(nid);
 	unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION);
+	pg_data_t *pgdat = zone->zone_pgdat;
 	unsigned long nr_pages = 0;
 	unsigned long first_init_pfn, spfn, epfn, t, flags;
 	unsigned long first_deferred_pfn = pgdat->first_deferred_pfn;
-	phys_addr_t spa, epa;
 	u64 i;
 
 	/* Only the last zone may have deferred pages */
@@ -1754,9 +1748,8 @@ deferred_grow_zone(struct zone *zone, unsigned int order)
 		return false;
 	}
 
-	for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
-		spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
-		epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
+	for_each_free_mem_pfn_range_in_zone(i, zone, &spfn, &epfn) {
+		spfn = max_t(unsigned long, first_init_pfn, spfn);
 
 		while (spfn < epfn && nr_pages < nr_pages_needed) {
 			t = ALIGN(spfn + PAGES_PER_SECTION, PAGES_PER_SECTION);
@@ -1770,9 +1763,9 @@ deferred_grow_zone(struct zone *zone, unsigned int order)
 			break;
 	}
 
-	for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
-		spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
-		epfn = min_t(unsigned long, first_deferred_pfn, PFN_DOWN(epa));
+	for_each_free_mem_pfn_range_in_zone(i, zone, &spfn, &epfn) {
+		spfn = max_t(unsigned long, first_init_pfn, spfn);
+		epfn = min_t(unsigned long, first_deferred_pfn, epfn);
 		deferred_free_pages(spfn, epfn);
 
 		if (first_deferred_pfn == epfn)