x86, mm: use limit_pfn for end pfn

instead of shifting end to get that.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-39-git-send-email-yinghai@kernel.orgSigned-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/mm/init.c

@@ -203,10 +203,12 @@ static int __meminit split_mem_range(struct map_range *mr, int nr_range,
 				     unsigned long start,
 				     unsigned long end)
 {
-	unsigned long start_pfn, end_pfn;
+	unsigned long start_pfn, end_pfn, limit_pfn;
 	unsigned long pfn;
 	int i;
 
+	limit_pfn = PFN_DOWN(end);
+
 	/* head if not big page alignment ? */
 	pfn = start_pfn = PFN_DOWN(start);
 #ifdef CONFIG_X86_32
@@ -223,8 +225,8 @@ static int __meminit split_mem_range(struct map_range *mr, int nr_range,
 #else /* CONFIG_X86_64 */
 	end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
 #endif
-	if (end_pfn > PFN_DOWN(end))
-		end_pfn = PFN_DOWN(end);
+	if (end_pfn > limit_pfn)
+		end_pfn = limit_pfn;
 	if (start_pfn < end_pfn) {
 		nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
 		pfn = end_pfn;
@@ -233,11 +235,11 @@ static int __meminit split_mem_range(struct map_range *mr, int nr_range,
 	/* big page (2M) range */
 	start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
 #ifdef CONFIG_X86_32
-	end_pfn = PFN_DOWN(round_down(end, PMD_SIZE));
+	end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
 #else /* CONFIG_X86_64 */
 	end_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE));
-	if (end_pfn > PFN_DOWN(round_down(end, PMD_SIZE)))
-		end_pfn = PFN_DOWN(round_down(end, PMD_SIZE));
+	if (end_pfn > round_down(limit_pfn, PFN_DOWN(PMD_SIZE)))
+		end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
 #endif
 
 	if (start_pfn < end_pfn) {
@@ -249,7 +251,7 @@ static int __meminit split_mem_range(struct map_range *mr, int nr_range,
 #ifdef CONFIG_X86_64
 	/* big page (1G) range */
 	start_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE));
-	end_pfn = PFN_DOWN(round_down(end, PUD_SIZE));
+	end_pfn = round_down(limit_pfn, PFN_DOWN(PUD_SIZE));
 	if (start_pfn < end_pfn) {
 		nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
 				page_size_mask &
@@ -259,7 +261,7 @@ static int __meminit split_mem_range(struct map_range *mr, int nr_range,
 
 	/* tail is not big page (1G) alignment */
 	start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
-	end_pfn = PFN_DOWN(round_down(end, PMD_SIZE));
+	end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
 	if (start_pfn < end_pfn) {
 		nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
 				page_size_mask & (1<<PG_LEVEL_2M));
@@ -269,7 +271,7 @@ static int __meminit split_mem_range(struct map_range *mr, int nr_range,
 
 	/* tail is not big page (2M) alignment */
 	start_pfn = pfn;
-	end_pfn = PFN_DOWN(end);
+	end_pfn = limit_pfn;
 	nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
 
 	/* try to merge same page size and continuous */