1 files changed, 15 insertions, 2 deletions

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index a2bb18e02839..468e98dfd44e 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -920,8 +920,21 @@ void __init setup_arch(char **cmdline_p)
 
 #ifdef CONFIG_X86_64
         if (max_pfn > max_low_pfn) {
-                max_pfn_mapped = init_memory_mapping(1UL<<32,
-                                                     max_pfn<<PAGE_SHIFT);
+                int i;
+                for (i = 0; i < e820.nr_map; i++) {
+                        struct e820entry *ei = &e820.map[i];
+
+                        if (ei->addr + ei->size <= 1UL << 32)
+                                continue;
+
+                        if (ei->type == E820_RESERVED)
+                                continue;
+
+                        max_pfn_mapped = init_memory_mapping(
+                                ei->addr < 1UL << 32 ? 1UL << 32 : ei->addr,
+                                ei->addr + ei->size);
+                }
+
                 /* can we preseve max_low_pfn ?*/
                 max_low_pfn = max_pfn;
         }