ARM: 6093/1: Fix kernel memory printing for sparsemem

The show_mem() and mem_init() function are assuming that the page map is
contiguous and calculates the start and end page of a bank using (map +
pfn). This fails with SPARSEMEM where pfn_to_page() must be used.

Tested-by: Will Deacon <Will.Deacon@arm.com>
Tested-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/init.c

@@ -86,9 +86,6 @@ void show_mem(void)
 	printk("Mem-info:\n");
 	show_free_areas();
 	for_each_online_node(node) {
-		pg_data_t *n = NODE_DATA(node);
-		struct page *map = pgdat_page_nr(n, 0) - n->node_start_pfn;
-
 		for_each_nodebank (i,mi,node) {
 			struct membank *bank = &mi->bank[i];
 			unsigned int pfn1, pfn2;
@@ -97,8 +94,8 @@ void show_mem(void)
 			pfn1 = bank_pfn_start(bank);
 			pfn2 = bank_pfn_end(bank);
 
-			page = map + pfn1;
-			end  = map + pfn2;
+			page = pfn_to_page(pfn1);
+			end  = pfn_to_page(pfn2 - 1) + 1;
 
 			do {
 				total++;
@@ -603,9 +600,6 @@ void __init mem_init(void)
 	reserved_pages = free_pages = 0;
 
 	for_each_online_node(node) {
-		pg_data_t *n = NODE_DATA(node);
-		struct page *map = pgdat_page_nr(n, 0) - n->node_start_pfn;
-
 		for_each_nodebank(i, &meminfo, node) {
 			struct membank *bank = &meminfo.bank[i];
 			unsigned int pfn1, pfn2;
@@ -614,8 +608,8 @@ void __init mem_init(void)
 			pfn1 = bank_pfn_start(bank);
 			pfn2 = bank_pfn_end(bank);
 
-			page = map + pfn1;
-			end  = map + pfn2;
+			page = pfn_to_page(pfn1);
+			end  = pfn_to_page(pfn2 - 1) + 1;
 
 			do {
 				if (PageReserved(page))