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 since there is no way to free memory which is allocated by bootmem. CC: David Rientjes <rient...@google.com> CC: Jiang Liu <liu...@gmail.com> CC: Len Brown <len.br...@intel.com> CC: Christoph Lameter <c...@linux.com> Cc: Minchan Kim <minchan....@gmail.com> CC: Andrew Morton <a...@linux-foundation.org> CC: KOSAKI Motohiro <kosaki.motoh...@jp.fujitsu.com> 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 | 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; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/