1 files changed, 19 insertions, 0 deletions

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 5198b9bb34ef..69ddfbd91135 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -49,6 +49,7 @@
 #include <asm/numa.h>
 #include <asm/cacheflush.h>
 #include <asm/init.h>
+#include <linux/bootmem.h>
 
 static unsigned long dma_reserve __initdata;
 
@@ -616,6 +617,21 @@ void __init paging_init(void)
  */
 #ifdef CONFIG_MEMORY_HOTPLUG
 /*
+ * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
+ * updating.
+ */
+static void  update_end_of_memory_vars(u64 start, u64 size)
+{
+        unsigned long end_pfn = PFN_UP(start + size);
+
+        if (end_pfn > max_pfn) {
+                max_pfn = end_pfn;
+                max_low_pfn = end_pfn;
+                high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
+        }
+}
+
+/*
  * Memory is added always to NORMAL zone. This means you will never get
  * additional DMA/DMA32 memory.
  */
@@ -634,6 +650,9 @@ int arch_add_memory(int nid, u64 start, u64 size)
         ret = __add_pages(nid, zone, start_pfn, nr_pages);
         WARN_ON_ONCE(ret);
 
+        /* update max_pfn, max_low_pfn and high_memory */
+        update_end_of_memory_vars(start, size);
+
         return ret;
 }
 EXPORT_SYMBOL_GPL(arch_add_memory);