Revert "mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE"

This reverts the following commits that change CMA design in MM.

 3d2054ad8c2d ("ARM: CMA: avoid double mapping to the CMA area if CONFIG_HIGHMEM=y")

 1d47a3ec09b5 ("mm/cma: remove ALLOC_CMA")

 bad8c6c0b114 ("mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE")

Ville reported a following error on i386.

  Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
  microcode: microcode updated early to revision 0x4, date = 2013-06-28
  Initializing CPU#0
  Initializing HighMem for node 0 (000377fe:00118000)
  Initializing Movable for node 0 (00000001:00118000)
  BUG: Bad page state in process swapper  pfn:377fe
  page:f53effc0 count:0 mapcount:-127 mapping:00000000 index:0x0
  flags: 0x80000000()
  raw: 80000000 00000000 00000000 ffffff80 00000000 00000100 00000200 00000001
  page dumped because: nonzero mapcount
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper Not tainted 4.17.0-rc5-elk+ #145
  Hardware name: Dell Inc. Latitude E5410/03VXMC, BIOS A15 07/11/2013
  Call Trace:
   dump_stack+0x60/0x96
   bad_page+0x9a/0x100
   free_pages_check_bad+0x3f/0x60
   free_pcppages_bulk+0x29d/0x5b0
   free_unref_page_commit+0x84/0xb0
   free_unref_page+0x3e/0x70
   __free_pages+0x1d/0x20
   free_highmem_page+0x19/0x40
   add_highpages_with_active_regions+0xab/0xeb
   set_highmem_pages_init+0x66/0x73
   mem_init+0x1b/0x1d7
   start_kernel+0x17a/0x363
   i386_start_kernel+0x95/0x99
   startup_32_smp+0x164/0x168

The reason for this error is that the span of MOVABLE_ZONE is extended
to whole node span for future CMA initialization, and, normal memory is
wrongly freed here.  I submitted the fix and it seems to work, but,
another problem happened.

It's so late time to fix the later problem so I decide to reverting the
series.

Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/cma.c b/mm/cma.c
index aa40e6c..5809bbe 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -39,7 +39,6 @@
 #include <trace/events/cma.h>
 
 #include "cma.h"
-#include "internal.h"
 
 struct cma cma_areas[MAX_CMA_AREAS];
 unsigned cma_area_count;
@@ -110,25 +109,23 @@
 	if (!cma->bitmap)
 		return -ENOMEM;
 
+	WARN_ON_ONCE(!pfn_valid(pfn));
+	zone = page_zone(pfn_to_page(pfn));
+
 	do {
 		unsigned j;
 
 		base_pfn = pfn;
-		if (!pfn_valid(base_pfn))
-			goto err;
-
-		zone = page_zone(pfn_to_page(base_pfn));
 		for (j = pageblock_nr_pages; j; --j, pfn++) {
-			if (!pfn_valid(pfn))
-				goto err;
-
+			WARN_ON_ONCE(!pfn_valid(pfn));
 			/*
-			 * In init_cma_reserved_pageblock(), present_pages
-			 * is adjusted with assumption that all pages in
-			 * the pageblock come from a single zone.
+			 * alloc_contig_range requires the pfn range
+			 * specified to be in the same zone. Make this
+			 * simple by forcing the entire CMA resv range
+			 * to be in the same zone.
 			 */
 			if (page_zone(pfn_to_page(pfn)) != zone)
-				goto err;
+				goto not_in_zone;
 		}
 		init_cma_reserved_pageblock(pfn_to_page(base_pfn));
 	} while (--i);
@@ -142,7 +139,7 @@
 
 	return 0;
 
-err:
+not_in_zone:
 	pr_err("CMA area %s could not be activated\n", cma->name);
 	kfree(cma->bitmap);
 	cma->count = 0;
@@ -152,41 +149,6 @@
 static int __init cma_init_reserved_areas(void)
 {
 	int i;
-	struct zone *zone;
-	pg_data_t *pgdat;
-
-	if (!cma_area_count)
-		return 0;
-
-	for_each_online_pgdat(pgdat) {
-		unsigned long start_pfn = UINT_MAX, end_pfn = 0;
-
-		zone = &pgdat->node_zones[ZONE_MOVABLE];
-
-		/*
-		 * In this case, we cannot adjust the zone range
-		 * since it is now maximum node span and we don't
-		 * know original zone range.
-		 */
-		if (populated_zone(zone))
-			continue;
-
-		for (i = 0; i < cma_area_count; i++) {
-			if (pfn_to_nid(cma_areas[i].base_pfn) !=
-				pgdat->node_id)
-				continue;
-
-			start_pfn = min(start_pfn, cma_areas[i].base_pfn);
-			end_pfn = max(end_pfn, cma_areas[i].base_pfn +
-						cma_areas[i].count);
-		}
-
-		if (!end_pfn)
-			continue;
-
-		zone->zone_start_pfn = start_pfn;
-		zone->spanned_pages = end_pfn - start_pfn;
-	}
 
 	for (i = 0; i < cma_area_count; i++) {
 		int ret = cma_activate_area(&cma_areas[i]);
@@ -195,32 +157,9 @@
 			return ret;
 	}
 
-	/*
-	 * Reserved pages for ZONE_MOVABLE are now activated and
-	 * this would change ZONE_MOVABLE's managed page counter and
-	 * the other zones' present counter. We need to re-calculate
-	 * various zone information that depends on this initialization.
-	 */
-	build_all_zonelists(NULL);
-	for_each_populated_zone(zone) {
-		if (zone_idx(zone) == ZONE_MOVABLE) {
-			zone_pcp_reset(zone);
-			setup_zone_pageset(zone);
-		} else
-			zone_pcp_update(zone);
-
-		set_zone_contiguous(zone);
-	}
-
-	/*
-	 * We need to re-init per zone wmark by calling
-	 * init_per_zone_wmark_min() but doesn't call here because it is
-	 * registered on core_initcall and it will be called later than us.
-	 */
-
 	return 0;
 }
-pure_initcall(cma_init_reserved_areas);
+core_initcall(cma_init_reserved_areas);
 
 /**
  * cma_init_reserved_mem() - create custom contiguous area from reserved memory