acpi, memory-hotplug: extend movablemem_map ranges to the end of node

When implementing movablemem_map boot option, we introduced an array
movablemem_map.map[] to store the memory ranges to be set as
ZONE_MOVABLE.

Since ZONE_MOVABLE is the latst zone of a node, if user didn't specify
the whole node memory range, we need to extend it to the node end so
that we can use it to prevent memblock from allocating memory in the
ranges user didn't specify.

We now implement movablemem_map boot option like this:

        /*
         * For movablemem_map=nn[KMG]@ss[KMG]:
         *
         * SRAT:                |_____| |_____| |_________| |_________| ......
         * node id:                0       1         1           2
         * user specified:                |__|                 |___|
         * movablemem_map:                |___| |_________|    |______| ......
         *
         * Using movablemem_map, we can prevent memblock from allocating memory
         * on ZONE_MOVABLE at boot time.
         *
         * NOTE: In this case, SRAT info will be ingored.
         */

[akpm@linux-foundation.org: clean up code, fix build warning]
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.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>
Cc: Len Brown <lenb@kernel.org>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 32 insertions, 2 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 88b9962c99b..7ea9a003ad5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5176,6 +5176,36 @@ early_param("kernelcore", cmdline_parse_kernelcore);
 early_param("movablecore", cmdline_parse_movablecore);
 
 /**
+ * movablemem_map_overlap() - Check if a range overlaps movablemem_map.map[].
+ * @start_pfn:	start pfn of the range to be checked
+ * @end_pfn: 	end pfn of the range to be checked (exclusive)
+ *
+ * This function checks if a given memory range [start_pfn, end_pfn) overlaps
+ * the movablemem_map.map[] array.
+ *
+ * Return: index of the first overlapped element in movablemem_map.map[]
+ *         or -1 if they don't overlap each other.
+ */
+int __init movablemem_map_overlap(unsigned long start_pfn,
+				   unsigned long end_pfn)
+{
+	int overlap;
+
+	if (!movablemem_map.nr_map)
+		return -1;
+
+	for (overlap = 0; overlap < movablemem_map.nr_map; overlap++)
+		if (start_pfn < movablemem_map.map[overlap].end_pfn)
+			break;
+
+	if (overlap == movablemem_map.nr_map ||
+	    end_pfn <= movablemem_map.map[overlap].start_pfn)
+		return -1;
+
+	return overlap;
+}
+
+/**
  * insert_movablemem_map - Insert a memory range in to movablemem_map.map.
  * @start_pfn:	start pfn of the range
  * @end_pfn:	end pfn of the range
@@ -5183,8 +5213,8 @@ early_param("movablecore", cmdline_parse_movablecore);
  * This function will also merge the overlapped ranges, and sort the array
  * by start_pfn in monotonic increasing order.
  */
-static void __init insert_movablemem_map(unsigned long start_pfn,
-					  unsigned long end_pfn)
+void __init insert_movablemem_map(unsigned long start_pfn,
+				  unsigned long end_pfn)
 {
 	int pos, overlap;