From: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start, type}
sysfs files are created. But there is no code to remove these files. The patch
implements the function to remove them.
Note: The code does not free firmware_map_entry which is allocated by bootmem.
So the patch makes memory leak. But I think the memory leak size is
very samll. And it does not affect the system.
Signed-off-by: Wen Congyang we...@cn.fujitsu.com
Signed-off-by: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
---
drivers/firmware/memmap.c| 98 +-
include/linux/firmware-map.h |6 +++
mm/memory_hotplug.c |5 ++-
3 files changed, 106 insertions(+), 3 deletions(-)
diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c
index 90723e6..49be12a 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
--
@@ -41,6 +42,7 @@ struct firmware_map_entry {
const char *type; /* type of the memory range */
struct list_headlist; /* entry for the linked list */
struct kobject kobj; /* kobject for each entry */
+ unsigned intbootmem:1; /* allocated from bootmem */
};
/*
@@ -79,7 +81,26 @@ static const struct sysfs_ops memmap_attr_ops = {
.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 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.
+ **/
+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
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);
+}
+
+/*
+ * 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 start, u64 end,
const char *type)
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
