s390/mm: make arch_add_memory() NUMA aware

With NUMA support for s390, arch_add_memory() needs to respect the nid
parameter.

Signed-off-by: Gerald Schaefer <[e-mail]>
Signed-off-by: Martin Schwidefsky <[e-mail]>

arch/s390/mm/init.c

···
 #include <linux/initrd.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
+#include <linux/memblock.h>
 #include <asm/processor.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
···
 #ifdef CONFIG_MEMORY_HOTPLUG
 int arch_add_memory(int nid, u64 start, u64 size)
 {
-	unsigned long zone_start_pfn, zone_end_pfn, nr_pages;
+	unsigned long normal_end_pfn = PFN_DOWN(memblock_end_of_DRAM());
+	unsigned long dma_end_pfn = PFN_DOWN(MAX_DMA_ADDRESS);
 	unsigned long start_pfn = PFN_DOWN(start);
 	unsigned long size_pages = PFN_DOWN(size);
-	struct zone *zone;
-	int rc;
+	unsigned long nr_pages;
+	int rc, zone_enum;
 
 	rc = vmem_add_mapping(start, size);
 	if (rc)
 		return rc;
-	for_each_zone(zone) {
-		if (zone_idx(zone) != ZONE_MOVABLE) {
-			/* Add range within existing zone limits */
-			zone_start_pfn = zone->zone_start_pfn;
-			zone_end_pfn = zone->zone_start_pfn +
-				       zone->spanned_pages;
+
+	while (size_pages > 0) {
+		if (start_pfn < dma_end_pfn) {
+			nr_pages = (start_pfn + size_pages > dma_end_pfn) ?
+				   dma_end_pfn - start_pfn : size_pages;
+			zone_enum = ZONE_DMA;
+		} else if (start_pfn < normal_end_pfn) {
+			nr_pages = (start_pfn + size_pages > normal_end_pfn) ?
+				   normal_end_pfn - start_pfn : size_pages;
+			zone_enum = ZONE_NORMAL;
 		} else {
-			/* Add remaining range to ZONE_MOVABLE */
-			zone_start_pfn = start_pfn;
-			zone_end_pfn = start_pfn + size_pages;
+			nr_pages = size_pages;
+			zone_enum = ZONE_MOVABLE;
 		}
-		if (start_pfn < zone_start_pfn || start_pfn >= zone_end_pfn)
-			continue;
-		nr_pages = (start_pfn + size_pages > zone_end_pfn) ?
-			   zone_end_pfn - start_pfn : size_pages;
-		rc = __add_pages(nid, zone, start_pfn, nr_pages);
+		rc = __add_pages(nid, NODE_DATA(nid)->node_zones + zone_enum,
+				 start_pfn, size_pages);
 		if (rc)
 			break;
 		start_pfn += nr_pages;
 		size_pages -= nr_pages;
-		if (!size_pages)
-			break;
 	}
 	if (rc)
 		vmem_remove_mapping(start, size);