This patch adds functions to parse movablecore_map boot option. Since the
option could be specified more then once, all the maps will be stored in
the global variable movablecore_map.map array.
And also, we keep the array in monotonic increasing order by start_pfn.
And merge all overlapped ranges.
Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
Reviewed-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
Tested-by: Lin Feng <linfeng@xxxxxxxxxxxxxx>
---
Documentation/kernel-parameters.txt | 17 ++++
include/linux/mm.h | 11 +++
mm/page_alloc.c | 146 +++++++++++++++++++++++++++++++++++
3 files changed, 174 insertions(+), 0 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9776f06..0718976 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1620,6 +1620,23 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
that the amount of memory usable for all allocations
is not too small.
+ movablecore_map=nn[KMG]@ss[KMG]
+ [KNL,X86,IA-64,PPC] This parameter is similar to
+ memmap except it specifies the memory map of
+ ZONE_MOVABLE.
+ If more areas are all within one node, then from
+ lowest ss to the end of the node will be ZONE_MOVABLE.
+ If an area covers two or more nodes, the area from
+ ss to the end of the 1st node will be ZONE_MOVABLE,
+ and all the rest nodes will only have ZONE_MOVABLE.
+ If memmap is specified at the same time, the
+ movablecore_map will be limited within the memmap
+ areas. If kernelcore or movablecore is also specified,
+ movablecore_map will have higher priority to be
+ satisfied. So the administrator should be careful that
+ the amount of movablecore_map areas are not too large.
+ Otherwise kernel won't have enough memory to start.
+
MTD_Partition= [MTD]
Format: <name>,<region-number>,<size>,<offset>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index fa06804..e4541b4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1328,6 +1328,17 @@ extern void free_bootmem_with_active_regions(int nid,
unsigned long max_low_pfn);
extern void sparse_memory_present_with_active_regions(int nid);
+#define MOVABLECORE_MAP_MAX MAX_NUMNODES
+struct movablecore_entry {
+ unsigned long start; /* start pfn of memory segment */
+ unsigned long end; /* end pfn of memory segment */
+};
+
+struct movablecore_map {
+ __u32 nr_map;
+ struct movablecore_entry map[MOVABLECORE_MAP_MAX];
+};
+
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
#if !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) && \
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5b74de6..198106f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -198,6 +198,9 @@ static unsigned long __meminitdata nr_all_pages;
static unsigned long __meminitdata dma_reserve;
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+/* Movable memory segments, will also be used by memblock subsystem. */
+struct movablecore_map movablecore_map;
+
static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
static unsigned long __initdata required_kernelcore;
@@ -4986,6 +4989,149 @@ static int __init cmdline_parse_movablecore(char *p)
early_param("kernelcore", cmdline_parse_kernelcore);
early_param("movablecore", cmdline_parse_movablecore);
+/**
+ * insert_movablecore_map - Insert a memory range in to movablecore_map.map.
+ * @start_pfn: start pfn of the range
+ * @end_pfn: end pfn of the range
+ *
+ * This function will also merge the overlapped ranges, and sort the array
+ * by start_pfn in monotonic increasing order.
+ */
+static void __init insert_movablecore_map(unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ int i, pos_start, pos_end, remove;
+ bool merge = true;
+
+ if (!movablecore_map.nr_map) {
+ movablecore_map.map[0].start = start_pfn;
+ movablecore_map.map[0].end = end_pfn;
+ movablecore_map.nr_map++;
+ return;
+ }
+
+ /*
+ * pos_start at the 1st overlapped segment if merge_start is true,
+ * or at the next unoverlapped segment if merge_start is false.
+ */
+ for (pos_start = 0; pos_start < movablecore_map.nr_map; pos_start++)
+ if (start_pfn <= movablecore_map.map[pos_start].end) {
+ if (end_pfn < movablecore_map.map[pos_start].start)
+ merge = false;
+ break;
+ }
+
+ /*
+ * pos_end at the last overlapped segment if merge_end is true,
+ * or at the next unoverlapped segment if merge_start is false.
+ */
+ for (pos_end = pos_start; pos_end < movablecore_map.nr_map; pos_end++) {
+ if (end_pfn < movablecore_map.map[pos_end].start) {
+ if (pos_end > 0 && start_pfn > movablecore_map.map[pos_end-1].end)
+ merge = false;
+ else
+ pos_end--;
+ break;
+ }
+ }
+ if (pos_end == movablecore_map.nr_map && merge)
+ pos_end--;
+
+ if (pos_start == movablecore_map.nr_map)
+ merge = false;
+
+ if (merge) {
+ remove = pos_end - pos_start;
+
+ movablecore_map.map[pos_start].start =
+ min(start_pfn, movablecore_map.map[pos_start].start);
+ movablecore_map.map[pos_start].end =
+ max(end_pfn, movablecore_map.map[pos_end].end);
+
+ if (remove == 0)
+ goto out;
+
+ for (i = pos_start+1; i < movablecore_map.nr_map; i++) {
+ movablecore_map.map[i].start =
+ movablecore_map.map[i+remove].start;
+ movablecore_map.map[i].end =
+ movablecore_map.map[i+remove].end;
+ }
+
+ movablecore_map.nr_map -= remove;
+ } else {
+ for (i = movablecore_map.nr_map; i > pos_start; i--) {
+ movablecore_map.map[i].start =
+ movablecore_map.map[i-1].start;
+ movablecore_map.map[i].end =
+ movablecore_map.map[i-1].end;
+ }
+
+ movablecore_map.map[pos_start].start = start_pfn;
+ movablecore_map.map[pos_start].end = end_pfn;
+ movablecore_map.nr_map++;
+ }
+}
+
+/**
+ * movablecore_map_add_region - Add a memory range into movablecore_map.
+ * @start: physical start address of range
+ * @end: physical end address of range
+ *
+ * This function transform the physical address into pfn, and then add the
+ * range into movablecore_map by calling insert_movablecore_map().
+ */
+static void __init movablecore_map_add_region(u64 start, u64 size)
+{
+ unsigned long start_pfn, end_pfn;
+
+ if (start + size <= start)
+ return;
+
+ if (movablecore_map.nr_map >= ARRAY_SIZE(movablecore_map.map)) {
+ pr_err("movable_memory_map: too many entries;"
+ " ignoring [mem %#010llx-%#010llx]\n",
+ (unsigned long long) start,
+ (unsigned long long) (start + size - 1));
+ return;
+ }
+
+ start_pfn = PFN_DOWN(start);
+ end_pfn = PFN_UP(start + size);
+ insert_movablecore_map(start_pfn, end_pfn);
+}
+
+/*
+ * movablecore_map=nn[KMG]@ss[KMG] sets the region of memory to be used as
+ * movable memory.
+ */
+static int __init cmdline_parse_movablecore_map(char *p)
+{
+ char *oldp;
+ u64 start_at, mem_size;
+
+ if (!p)
+ goto err;
+
+ oldp = p;
+ mem_size = memparse(p, &p);
+ if (p == oldp)
+ goto err;
+
+ if (*p == '@') {
+ oldp = p + 1;
+ start_at = memparse(p+1, &p);
+ if (p == oldp || *p != '\0')
+ goto err;
+
+ movablecore_map_add_region(start_at, mem_size);
+ return 0;
+ }
+err:
+ return -EINVAL;
+}
+early_param("movablecore_map", cmdline_parse_movablecore_map);
+
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
/**
--
1.7.1
--
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