diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c
index ae823b4..0710179 100644
--- a/drivers/firmware/memmap.c
+++ b/drivers/firmware/memmap.c
@@ -53,6 +53,9 @@ static ssize_t start_show(struct firmware_map_entry *entry, char *buf);
 static ssize_t end_show(struct firmware_map_entry *entry, char *buf);
 static ssize_t type_show(struct firmware_map_entry *entry, char *buf);
 
+static struct firmware_map_entry * __meminit
+firmware_map_find_entry(u64 start, u64 end, const char *type);
+
 /*
  * Static data -----------------------------------------------------------------
  */
@@ -80,6 +83,19 @@ static const struct sysfs_ops memmap_attr_ops = {
 	.show = memmap_attr_show,
 };
 
+/* Firmware memory map entries. */
+static LIST_HEAD(map_entries);
+static DEFINE_SPINLOCK(map_entries_lock);
+
+/*
+ * For memory hotplug, there is no way to free memory map entries allocated
+ * by boot mem after the system is up. So when we hot-remove memory whose
+ * map entry is allocated by bootmem, we need to remember the storage and
+ * reuse it when the memory is hot-added again.
+ */
+static LIST_HEAD(map_entries_bootmem);
+static DEFINE_SPINLOCK(map_entries_bootmem_lock);
+
 
 static inline struct firmware_map_entry *
 to_memmap_entry(struct kobject *kobj)
@@ -91,9 +107,22 @@ static void release_firmware_map_entry(struct kobject *kobj)
 {
 	struct firmware_map_entry *entry = to_memmap_entry(kobj);
 
-	if (PageReserved(virt_to_page(entry)))
-		/* There is no way to free memory allocated from bootmem */
+	if (PageReserved(virt_to_page(entry))) {
+		/*
+		 * Remember the storage allocated by bootmem, and reuse it when
+		 * the memory is hot-added again. The entry will be added to
+		 * map_entries_bootmem here, and deleted from &map_entries in
+		 * firmware_map_remove_entry().
+		 */
+		if (firmware_map_find_entry(entry->start, entry->end,
+		    entry->type)) {
+			spin_lock(&map_entries_bootmem_lock);
+			list_add(&entry->list, &map_entries_bootmem);
+			spin_unlock(&map_entries_bootmem_lock);
+		}
+
 		return;
+	}
 
 	kfree(entry);
 }
@@ -108,10 +137,6 @@ static struct kobj_type memmap_ktype = {
  * Registration functions ------------------------------------------------------
  */
 
-/* Firmware memory map entries. */
-static LIST_HEAD(map_entries);
-static DEFINE_SPINLOCK(map_entries_lock);
-
 /**
  * firmware_map_add_entry() - Does the real work to add a firmware memmap entry.
  * @start: Start of the memory range.
@@ -184,23 +209,25 @@ static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry)
 }
 
 /*
- * firmware_map_find_entry: Search memmap entry.
+ * firmware_map_find_entry_in_list: Search memmap entry in a given list.
  * @start: Start of the memory range.
  * @end:   End of the memory range (exclusive).
  * @type:  Type of the memory range.
+ * @list:  In which to find the entry.
  *
- * This function is to find the memmap entey of a given memory range.
- * The caller must hold map_entries_lock, and must not release the lock
- * until the processing of the returned entry has completed.
+ * This function is to find the memmap entey of a given memory range in a
+ * given list. The caller must hold map_entries_lock, and must not release
+ * the lock until the processing of the returned entry has completed.
  *
  * Return pointer to the entry to be found on success, or NULL on failure.
  */
 static struct firmware_map_entry * __meminit
-firmware_map_find_entry(u64 start, u64 end, const char *type)
+firmware_map_find_entry_in_list(u64 start, u64 end, const char *type,
+				struct list_head *list)
 {
 	struct firmware_map_entry *entry;
 
-	list_for_each_entry(entry, &map_entries, list)
+	list_for_each_entry(entry, list, list)
 		if ((entry->start == start) && (entry->end == end) &&
 		    (!strcmp(entry->type, type))) {
 			return entry;
@@ -209,6 +236,42 @@ firmware_map_find_entry(u64 start, u64 end, const char *type)
 	return NULL;
 }
 
+/*
+ * firmware_map_find_entry: Search memmap entry in map_entries.
+ * @start: Start of the memory range.
+ * @end:   End of the memory range (exclusive).
+ * @type:  Type of the memory range.
+ *
+ * This function is to find the memmap entey of a given memory range.
+ * The caller must hold map_entries_lock, and must not release the lock
+ * until the processing of the returned entry has completed.
+ *
+ * Return pointer to the entry to be found on success, or NULL on failure.
+ */
+static struct firmware_map_entry * __meminit
+firmware_map_find_entry(u64 start, u64 end, const char *type)
+{
+	return firmware_map_find_entry_in_list(start, end, type, &map_entries);
+}
+
+/*
+ * firmware_map_find_entry_bootmem: Search memmap entry in map_entries_bootmem.
+ * @start: Start of the memory range.
+ * @end:   End of the memory range (exclusive).
+ * @type:  Type of the memory range.
+ *
+ * This function is similar to firmware_map_find_entry except that it find the
+ * given entry in map_entries_bootmem.
+ *
+ * Return pointer to the entry to be found on success, or NULL on failure.
+ */
+static struct firmware_map_entry * __meminit
+firmware_map_find_entry_bootmem(u64 start, u64 end, const char *type)
+{
+	return firmware_map_find_entry_in_list(start, end, type,
+					       &map_entries_bootmem);
+}
+
 /**
  * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
  * memory hotplug.
@@ -226,9 +289,19 @@ int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)
 {
 	struct firmware_map_entry *entry;
 
-	entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
-	if (!entry)
-		return -ENOMEM;
+	entry = firmware_map_find_entry_bootmem(start, end, type);
+	if (!entry) {
+		entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
+		if (!entry)
+			return -ENOMEM;
+	} else {
+		/* Reuse storage allocated by bootmem. */
+		spin_lock(&map_entries_bootmem_lock);
+		list_del(&entry->list);
+		spin_unlock(&map_entries_bootmem_lock);
+
+		memset(entry, 0, sizeof(*entry));
+	}
 
 	firmware_map_add_entry(start, end, type, entry);
 	/* create the memmap entry */