x86, mm: Use memblock memory loop instead of e820_RAM

We need to handle E820_RAM and E820_RESERVED_KERNEL at the same time.

Also memblock has page aligned range for ram, so we could avoid mapping
partial pages.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/CAE9FiQVZirvaBMFYRfXMmWEcHbKSicQEHz4VAwUv0xFCk51ZNw@mail.gmail.com
Acked-by: Jacob Shin <jacob.shin@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>

arch/x86/kernel/setup.c

@@ -921,18 +921,19 @@ void __init setup_arch(char **cmdline_p)
 #ifdef CONFIG_X86_64
 	if (max_pfn > max_low_pfn) {
 		int i;
-		for (i = 0; i < e820.nr_map; i++) {
-			struct e820entry *ei = &e820.map[i];
+		unsigned long start, end;
+		unsigned long start_pfn, end_pfn;
 
-			if (ei->addr + ei->size <= 1UL << 32)
-				continue;
+		for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn,
+							 NULL) {
 
-			if (ei->type == E820_RESERVED)
+			end = PFN_PHYS(end_pfn);
+			if (end <= (1UL<<32))
 				continue;
 
+			start = PFN_PHYS(start_pfn);
 			max_pfn_mapped = init_memory_mapping(
-				ei->addr < 1UL << 32 ? 1UL << 32 : ei->addr,
-				ei->addr + ei->size);
+						max((1UL<<32), start), end);
 		}
 
 		/* can we preseve max_low_pfn ?*/