[PATCH] x86: remove wrong -1 in calling init_memory_mapping

[Yinghai Lu <yinghai@kernel.org>]

From: Shaohua Li <shaohua.li@intel.com>

impact: make memory hot plug got last page mapped.

Shuahua Li found:
Round up address to a page, otherwise the last page isn't mapped.

No, I just did some experiments on a desktop for memory hotplug and this bug
triggered a crash in my test.
Yinghai's suggestion also fixed the bug. I just want to have safer method. Anyway, either approach is ok to me.

So acctually we don't need to round it.
just remove that extra -1

Signed-off-by: Yinghai <yinghai@kernel.org>

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index d59e4c9..2884b17 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -837,7 +837,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
 	unsigned long nr_pages = size >> PAGE_SHIFT;
 	int ret;
 
-	last_mapped_pfn = init_memory_mapping(start, start + size-1);
+	last_mapped_pfn = init_memory_mapping(start, start + size);
 	if (last_mapped_pfn > max_pfn_mapped)
 		max_pfn_mapped = last_mapped_pfn;