diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c
index 90723e65b081..0b5b5f619c75 100644
--- a/drivers/firmware/memmap.c
+++ b/drivers/firmware/memmap.c
@@ -21,6 +21,7 @@
#include <linux/types.h>
#include <linux/bootmem.h>
#include <linux/slab.h>
+#include <linux/mm.h>
/*
* Data types ------------------------------------------------------------------
@@ -52,6 +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 -----------------------------------------------------------------
*/
@@ -79,7 +83,52 @@ static const struct sysfs_ops memmap_attr_ops = {
.show = memmap_attr_show,
};
-static struct kobj_type memmap_ktype = {
+/* 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)
+{
+ return container_of(kobj, struct firmware_map_entry, kobj);
+}
+
+static void __meminit release_firmware_map_entry(struct kobject *kobj)
+{
+ struct firmware_map_entry *entry = to_memmap_entry(kobj);
+
+ 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);
+}
+
+static struct kobj_type __refdata memmap_ktype = {
+ .release = release_firmware_map_entry,
.sysfs_ops = &memmap_attr_ops,
.default_attrs = def_attrs,
};
@@ -88,13 +137,6 @@ static struct kobj_type memmap_ktype = {
* Registration functions ------------------------------------------------------
*/
-/*
- * Firmware memory map entries. No locking is needed because the
- * firmware_map_add() and firmware_map_add_early() functions are called
- * in firmware initialisation code in one single thread of execution.
- */
-static LIST_HEAD(map_entries);
-
/**
* firmware_map_add_entry() - Does the real work to add a firmware memmap entry.
* @start: Start of the memory range.
@@ -118,11 +160,25 @@ static int firmware_map_add_entry(u64 start, u64 end,
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.
+ *
+ * The caller must hold map_entries_lock, and release it properly.
+ **/
+static inline void firmware_map_remove_entry(struct firmware_map_entry *entry)
+{
+ list_del(&entry->list);
+}
+
/*
* Add memmap entry on sysfs
*/
@@ -144,6 +200,78 @@ static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry)
return 0;
}
+/*
+ * Remove memmap entry on sysfs
+ */
+static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry)
+{
+ kobject_put(&entry->kobj);
+}
+
+/*
+ * 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 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_in_list(u64 start, u64 end, const char *type,
+ struct list_head *list)
+{
+ struct firmware_map_entry *entry;
+
+ list_for_each_entry(entry, list, list)
+ if ((entry->start == start) && (entry->end == end) &&
+ (!strcmp(entry->type, type))) {
+ return entry;
+ }
+
+ 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.
@@ -161,9 +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 */
@@ -196,6 +334,36 @@ int __init firmware_map_add_early(u64 start, u64 end, const char *type)
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;
+
+ spin_lock(&map_entries_lock);
+ entry = firmware_map_find_entry(start, end - 1, type);
+ if (!entry) {
+ spin_unlock(&map_entries_lock);
+ return -EINVAL;
+ }
+
+ firmware_map_remove_entry(entry);
+ spin_unlock(&map_entries_lock);
+
+ /* remove the memmap entry */
+ remove_sysfs_fw_map_entry(entry);
+
+ return 0;
+}
+
/*
* Sysfs functions -------------------------------------------------------------
*/
@@ -217,8 +385,10 @@ static ssize_t type_show(struct firmware_map_entry *entry, char *buf)
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)
diff --git a/include/linux/firmware-map.h b/include/linux/firmware-map.h
index 43fe52fcef0f..71d4fa721db9 100644
--- a/include/linux/firmware-map.h
+++ b/include/linux/firmware-map.h
@@ -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_hotplug(u64 start, u64 end, const char *type)
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 */
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index e5b91b12cec3..a776dbf3fa00 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1460,7 +1460,7 @@ static int is_memblock_offlined_cb(struct memory_block *mem, void *arg)
return ret;
}
-int remove_memory(u64 start, u64 size)
+int __ref remove_memory(u64 start, u64 size)
{
unsigned long start_pfn, end_pfn;
int ret = 0;
@@ -1510,6 +1510,9 @@ repeat:
return ret;
}
+ /* remove memmap entry */
+ firmware_map_remove(start, start + size, "System RAM");
+
unlock_memory_hotplug();
return 0;