2 files changed, 70 insertions, 0 deletions

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 9a805ec6e794..b788faa71563 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -19,6 +19,9 @@
 
 #define INIT_MEMBLOCK_REGIONS   128
 
+/* Definition of memblock flags. */
+#define MEMBLOCK_HOTPLUG        0x1     /* hotpluggable region */
+
 struct memblock_region {
         phys_addr_t base;
         phys_addr_t size;
@@ -60,6 +63,8 @@ int memblock_remove(phys_addr_t base, phys_addr_t size);
 int memblock_free(phys_addr_t base, phys_addr_t size);
 int memblock_reserve(phys_addr_t base, phys_addr_t size);
 void memblock_trim_memory(phys_addr_t align);
+int memblock_mark_hotplug(phys_addr_t base, phys_addr_t size);
+int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size);
 
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn,
@@ -122,6 +127,18 @@ void __next_free_mem_range_rev(u64 *idx, int nid, phys_addr_t *out_start,
              i != (u64)ULLONG_MAX;                                      \
              __next_free_mem_range_rev(&i, nid, p_start, p_end, p_nid))
 
+static inline void memblock_set_region_flags(struct memblock_region *r,
+                                             unsigned long flags)
+{
+        r->flags |= flags;
+}
+
+static inline void memblock_clear_region_flags(struct memblock_region *r,
+                                               unsigned long flags)
+{
+        r->flags &= ~flags;
+}
+
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 int memblock_set_node(phys_addr_t base, phys_addr_t size, int nid);
 
diff --git a/mm/memblock.c b/mm/memblock.c
index 270b005ca964..2121ec4c7fa0 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -683,6 +683,59 @@ int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
 }
 
 /**
+ * memblock_mark_hotplug - Mark hotpluggable memory with flag MEMBLOCK_HOTPLUG.
+ * @base: the base phys addr of the region
+ * @size: the size of the region
+ *
+ * This function isolates region [@base, @base + @size), and mark it with flag
+ * MEMBLOCK_HOTPLUG.
+ *
+ * Return 0 on succees, -errno on failure.
+ */
+int __init_memblock memblock_mark_hotplug(phys_addr_t base, phys_addr_t size)
+{
+        struct memblock_type *type = &memblock.memory;
+        int i, ret, start_rgn, end_rgn;
+
+        ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
+        if (ret)
+                return ret;
+
+        for (i = start_rgn; i < end_rgn; i++)
+                memblock_set_region_flags(&type->regions[i], MEMBLOCK_HOTPLUG);
+
+        memblock_merge_regions(type);
+        return 0;
+}
+
+/**
+ * memblock_clear_hotplug - Clear flag MEMBLOCK_HOTPLUG for a specified region.
+ * @base: the base phys addr of the region
+ * @size: the size of the region
+ *
+ * This function isolates region [@base, @base + @size), and clear flag
+ * MEMBLOCK_HOTPLUG for the isolated regions.
+ *
+ * Return 0 on succees, -errno on failure.
+ */
+int __init_memblock memblock_clear_hotplug(phys_addr_t base, phys_addr_t size)
+{
+        struct memblock_type *type = &memblock.memory;
+        int i, ret, start_rgn, end_rgn;
+
+        ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
+        if (ret)
+                return ret;
+
+        for (i = start_rgn; i < end_rgn; i++)
+                memblock_clear_region_flags(&type->regions[i],
+                                            MEMBLOCK_HOTPLUG);
+
+        memblock_merge_regions(type);
+        return 0;
+}
+
+/**
  * __next_free_mem_range - next function for for_each_free_mem_range()
  * @idx: pointer to u64 loop variable
  * @nid: node selector, %MAX_NUMNODES for all nodes