memory-hotplug: remove page table of x86_64 architecture

Search a page table about the removed memory, and clear page table for
x86_64 architecture.

[akpm@linux-foundation.org: make kernel_physical_mapping_remove() static]
Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>
Signed-off-by: NJianguo Wu <wujianguo@huawei.com>
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/x86/mm/init_64.c

@@ -1011,6 +1011,15 @@ remove_pagetable(unsigned long start, unsigned long end, bool direct)
 	flush_tlb_all();
 }
 
+static void __meminit
+kernel_physical_mapping_remove(unsigned long start, unsigned long end)
+{
+	start = (unsigned long)__va(start);
+	end = (unsigned long)__va(end);
+
+	remove_pagetable(start, end, true);
+}
+
 #ifdef CONFIG_MEMORY_HOTREMOVE
 int __ref arch_remove_memory(u64 start, u64 size)
 {
@@ -1020,6 +1029,7 @@ int __ref arch_remove_memory(u64 start, u64 size)
 	int ret;
 
 	zone = page_zone(pfn_to_page(start_pfn));
+	kernel_physical_mapping_remove(start, start + size);
 	ret = __remove_pages(zone, start_pfn, nr_pages);
 	WARN_ON_ONCE(ret);