/* * linux/drivers/firmware/memmap.c *  Copyright (C) 2008 SUSE LINUX Products GmbH *  by Bernhard Walle <bernhard.walle@gmx.de> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License v2.0 as published by * the Free Software Foundation * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * */ #include <linux/string.h>#include <linux/firmware-map.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/types.h>#include <linux/bootmem.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}; 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 struct kobj_type __refdata memmap_ktype = {	.release	= release_firmware_map_entry,	.sysfs_ops	= &memmap_attr_ops,	.default_attrs	= def_attrs,}; /* * 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(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 */	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_virt_alloc(sizeof(struct firmware_map_entry), 0);	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);