diff options
Diffstat (limited to 'drivers/firmware/memmap.c')
| -rw-r--r-- | drivers/firmware/memmap.c | 196 |
1 files changed, 183 insertions, 13 deletions
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) |