CC: David Rientjes <rientjes@google.com>
CC: Jiang Liu <redacted>
CC: Len Brown <redacted>
CC: Christoph Lameter <redacted>
Cc: Minchan Kim <redacted>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: KOSAKI Motohiro <redacted>
Signed-off-by: Wen Congyang <redacted>
Signed-off-by: Yasuaki Ishimatsu <redacted>

---
 drivers/firmware/memmap.c    |   98 ++++++++++++++++++++++++++++++++++++++++++-
 include/linux/firmware-map.h |    6 ++
 mm/memory_hotplug.c          |    7 ++-
 3 files changed, 108 insertions(+), 3 deletions(-)

Index: linux-3.6/drivers/firmware/memmap.c
===================================================================

--- linux-3.6.orig/drivers/firmware/memmap.c    2012-10-04 18:27:05.195500420 +0900
+++ linux-3.6/drivers/firmware/memmap.c 2012-10-04 18:27:18.901514330 +0900

@@ -21,6 +21,7 @@
 #include <linux/types.h>
 #include <linux/bootmem.h>
 #include <linux/slab.h>
+#include <linux/mm.h>

 /*
  * Data types ------------------------------------------------------------------

@@ -41,6 +42,7 @@ struct firmware_map_entry {
        const char              *type;  /* type of the memory range */
        struct list_head        list;   /* entry for the linked list */
        struct kobject          kobj;   /* kobject for each entry */
+       unsigned int            bootmem:1; /* allocated from bootmem */

 };

 /*

@@ -79,7 +81,26 @@ static const struct sysfs_ops memmap_att
        .show = memmap_attr_show,
 };

+
+static inline struct firmware_map_entry *
+to_memmap_entry(struct kobject *kobj)
+{
+       return container_of(kobj, struct firmware_map_entry, kobj);
+}
+
+static void release_firmware_map_entry(struct kobject *kobj)
+{
+       struct firmware_map_entry *entry = to_memmap_entry(kobj);
+
+       if (entry->bootmem)
+               /* There is no way to free memory allocated from bootmem */
+               return;
+
+       kfree(entry);
+}
+
 static struct kobj_type memmap_ktype = {
+       .release        = release_firmware_map_entry,
        .sysfs_ops      = &memmap_attr_ops,
        .default_attrs  = def_attrs,
 };

@@ -94,6 +115,7 @@ static struct kobj_type memmap_ktype = {
  * in firmware initialisation code in one single thread of execution.
  */
 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.

@@ -118,11 +140,25 @@ static int firmware_map_add_entry(u64 st
        INIT_LIST_HEAD(&entry->list);
        kobject_init(&entry->kobj, &memmap_ktype);

+       spin_lock(&map_entries_lock);
        list_add_tail(&entry->list, &map_entries);
+       spin_unlock(&map_entries_lock);

        return 0;
 }

+/**
+ * firmware_map_remove_entry() - Does the real work to remove a firmware
+ * memmap entry.
+ * @entry: removed entry.
+ **/
+static inline void firmware_map_remove_entry(struct firmware_map_entry *entry)

+{
+       spin_lock(&map_entries_lock);
+       list_del(&entry->list);
+       spin_unlock(&map_entries_lock);
+}
+
 /*
  * Add memmap entry on sysfs
  */

@@ -144,6 +180,35 @@ static int add_sysfs_fw_map_entry(struct
        return 0;
 }

+/*
+ * Remove memmap entry on sysfs
+ */
+static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry)
+{
+       kobject_put(&entry->kobj);
+}
+
+/*
+ * Search memmap entry
+ */
+
+static struct firmware_map_entry * __meminit
+firmware_map_find_entry(u64 start, u64 end, const char *type)
+{
+       struct firmware_map_entry *entry;
+
+       spin_lock(&map_entries_lock);
+       list_for_each_entry(entry, &map_entries, list)
+               if ((entry->start == start) && (entry->end == end) &&
+                   (!strcmp(entry->type, type))) {
+                       spin_unlock(&map_entries_lock);
+                       return entry;
+               }
+
+       spin_unlock(&map_entries_lock);
+       return NULL;
+}
+
 /**
  * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
  * memory hotplug.

@@ -193,9 +258,36 @@ int __init firmware_map_add_early(u64 st
        if (WARN_ON(!entry))
                return -ENOMEM;

+       entry->bootmem = 1;
        return firmware_map_add_entry(start, end, type, entry);
 }

+/**
+ * firmware_map_remove() - remove a firmware mapping entry
+ * @start: Start of the memory range.
+ * @end:   End of the memory range.
+ * @type:  Type of the memory range.
+ *
+ * removes a firmware mapping entry.
+ *
+ * Returns 0 on success, or -EINVAL if no entry.
+ **/
+int __meminit firmware_map_remove(u64 start, u64 end, const char *type)

+{
+       struct firmware_map_entry *entry;
+
+       entry = firmware_map_find_entry(start, end - 1, type);
+       if (!entry)
+               return -EINVAL;
+
+       firmware_map_remove_entry(entry);
+
+       /* remove the memmap entry */
+       remove_sysfs_fw_map_entry(entry);
+
+       return 0;
+}
+
 /*
  * Sysfs functions -------------------------------------------------------------
  */

@@ -217,8 +309,10 @@ static ssize_t type_show(struct firmware
        return snprintf(buf, PAGE_SIZE, "%s\n", entry->type);
 }

-#define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr)
-#define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj)
+static inline struct memmap_attribute *to_memmap_attr(struct attribute *attr)
+{
+       return container_of(attr, struct memmap_attribute, attr);
+}

 static ssize_t memmap_attr_show(struct kobject *kobj,
                                struct attribute *attr, char *buf)

Index: linux-3.6/include/linux/firmware-map.h
===================================================================

--- linux-3.6.orig/include/linux/firmware-map.h 2012-10-04 18:27:05.197500422 +0900
+++ linux-3.6/include/linux/firmware-map.h      2012-10-04 18:27:18.904514333 +0900

@@ -25,6 +25,7 @@

 int firmware_map_add_early(u64 start, u64 end, const char *type);
 int firmware_map_add_hotplug(u64 start, u64 end, const char *type);
+int firmware_map_remove(u64 start, u64 end, const char *type);

 #else /* CONFIG_FIRMWARE_MEMMAP */

@@ -38,6 +39,11 @@ static inline int firmware_map_add_hotpl
        return 0;
 }

+static inline int firmware_map_remove(u64 start, u64 end, const char *type)
+{
+       return 0;
+}
+
 #endif /* CONFIG_FIRMWARE_MEMMAP */

 #endif /* _LINUX_FIRMWARE_MAP_H */

Index: linux-3.6/mm/memory_hotplug.c
===================================================================

--- linux-3.6.orig/mm/memory_hotplug.c  2012-10-04 18:27:03.000000000 +0900
+++ linux-3.6/mm/memory_hotplug.c       2012-10-04 18:28:42.851599524 +0900

@@ -1043,7 +1043,7 @@ int offline_memory(u64 start, u64 size)
        return 0;
 }

-int remove_memory(int nid, u64 start, u64 size)
+int __ref remove_memory(int nid, u64 start, u64 size)
 {
        int ret = 0;
        lock_memory_hotplug();

@@ -1056,8 +1056,13 @@ int remove_memory(int nid, u64 start, u6
                        "because the memmory range is online\n",
                        start, start + size);
                ret = -EAGAIN;
+               goto out;
        }

+       /* remove memmap entry */
+       firmware_map_remove(start, start + size, "System RAM");
+
+out:
        unlock_memory_hotplug();
        return ret;
 }