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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/string.h>#include <linux/firmware-map.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/types.h>#include <linux/memblock.h>#include <linux/slab.h>#include <linux/mm.h>
/* * Data types ------------------------------------------------------------------ */
/* * Firmware map entry. Because firmware memory maps are flat and not * hierarchical, it's ok to organise them in a linked list. No parent * information is necessary as for the resource tree. */struct firmware_map_entry { /* * start and end must be u64 rather than resource_size_t, because e820 * resources can lie at addresses above 4G. */ u64 start; /* start of the memory range */ u64 end; /* end of the memory range (incl.) */ const char *type; /* type of the memory range */ struct list_head list; /* entry for the linked list */ struct kobject kobj; /* kobject for each entry */};
/* * Forward declarations -------------------------------------------------------- */static ssize_t memmap_attr_show(struct kobject *kobj, struct attribute *attr, char *buf);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 * __meminitfirmware_map_find_entry(u64 start, u64 end, const char *type);
/* * Static data ----------------------------------------------------------------- */
struct memmap_attribute { struct attribute attr; ssize_t (*show)(struct firmware_map_entry *entry, char *buf);};
static struct memmap_attribute memmap_start_attr = __ATTR_RO(start);static struct memmap_attribute memmap_end_attr = __ATTR_RO(end);static struct memmap_attribute memmap_type_attr = __ATTR_RO(type);
/* * These are default attributes that are added for every memmap entry. */static struct attribute *def_attrs[] = { &memmap_start_attr.attr, &memmap_end_attr.attr, &memmap_type_attr.attr, NULL};ATTRIBUTE_GROUPS(def);
static const struct sysfs_ops memmap_attr_ops = { .show = memmap_attr_show,};
/* 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(). */ spin_lock(&map_entries_bootmem_lock); list_add(&entry->list, &map_entries_bootmem); spin_unlock(&map_entries_bootmem_lock);
return; }
kfree(entry);}
static const struct kobj_type memmap_ktype = { .release = release_firmware_map_entry, .sysfs_ops = &memmap_attr_ops, .default_groups = def_groups,};
/* * Registration functions ------------------------------------------------------ */
/** * firmware_map_add_entry() - Does the real work to add a firmware memmap entry. * @start: Start of the memory range. * @end: End of the memory range (exclusive). * @type: Type of the memory range. * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised * entry. * * Common implementation of firmware_map_add() and firmware_map_add_early() * which expects a pre-allocated struct firmware_map_entry. * * Return: 0 always */static int firmware_map_add_entry(u64 start, u64 end, const char *type, struct firmware_map_entry *entry){ BUG_ON(start > end);
entry->start = start; entry->end = end - 1; entry->type = type; 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 */static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry){ static int map_entries_nr; static struct kset *mmap_kset;
if (entry->kobj.state_in_sysfs) return -EEXIST;
if (!mmap_kset) { mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj); if (!mmap_kset) return -ENOMEM; }
entry->kobj.kset = mmap_kset; if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++)) kobject_put(&entry->kobj);
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 * __meminitfirmware_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 * __meminitfirmware_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 * __meminitfirmware_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. * @start: Start of the memory range. * @end: End of the memory range (exclusive) * @type: Type of the memory range. * * Adds a firmware mapping entry. This function is for memory hotplug, it is * similar to function firmware_map_add_early(). The only difference is that * it will create the syfs entry dynamically. * * Return: 0 on success, or -ENOMEM if no memory could be allocated. */int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type){ struct firmware_map_entry *entry;
entry = firmware_map_find_entry(start, end - 1, type); if (entry) return 0;
entry = firmware_map_find_entry_bootmem(start, end - 1, type); if (!entry) { entry = kzalloc_obj(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 */ add_sysfs_fw_map_entry(entry);
return 0;}
/** * firmware_map_add_early() - Adds a firmware mapping entry. * @start: Start of the memory range. * @end: End of the memory range. * @type: Type of the memory range. * * Adds a firmware mapping entry. This function uses the bootmem allocator * for memory allocation. * * That function must be called before late_initcall. * * Return: 0 on success, or -ENOMEM if no memory could be allocated. */int __init firmware_map_add_early(u64 start, u64 end, const char *type){ struct firmware_map_entry *entry;
entry = memblock_alloc(sizeof(struct firmware_map_entry), SMP_CACHE_BYTES); if (WARN_ON(!entry)) return -ENOMEM;
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. * * Return: 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 ------------------------------------------------------------- */
static ssize_t start_show(struct firmware_map_entry *entry, char *buf){ return snprintf(buf, PAGE_SIZE, "0x%llx\n", (unsigned long long)entry->start);}
static ssize_t end_show(struct firmware_map_entry *entry, char *buf){ return snprintf(buf, PAGE_SIZE, "0x%llx\n", (unsigned long long)entry->end);}
static ssize_t type_show(struct firmware_map_entry *entry, char *buf){ return snprintf(buf, PAGE_SIZE, "%s\n", entry->type);}
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){ struct firmware_map_entry *entry = to_memmap_entry(kobj); struct memmap_attribute *memmap_attr = to_memmap_attr(attr);
return memmap_attr->show(entry, buf);}
/* * Initialises stuff and adds the entries in the map_entries list to * sysfs. Important is that firmware_map_add() and firmware_map_add_early() * must be called before late_initcall. That's just because that function * is called as late_initcall() function, which means that if you call * firmware_map_add() or firmware_map_add_early() afterwards, the entries * are not added to sysfs. */static int __init firmware_memmap_init(void){ struct firmware_map_entry *entry;
list_for_each_entry(entry, &map_entries, list) add_sysfs_fw_map_entry(entry);
return 0;}late_initcall(firmware_memmap_init);