/* * drivers/base/memory.c - basic Memory class support * * Written by Matt Tolentino <matthew.e.tolentino@intel.com> *            Dave Hansen <haveblue@us.ibm.com> * * This file provides the necessary infrastructure to represent * a SPARSEMEM-memory-model system's physical memory in /sysfs. * All arch-independent code that assumes MEMORY_HOTPLUG requires * SPARSEMEM should be contained here, or in mm/memory_hotplug.c. */ #include <linux/sysdev.h>#include <linux/module.h>#include <linux/init.h>#include <linux/topology.h>#include <linux/capability.h>#include <linux/device.h>#include <linux/memory.h>#include <linux/kobject.h>#include <linux/memory_hotplug.h>#include <linux/mm.h>#include <linux/mutex.h>#include <linux/stat.h> #include <asm/atomic.h>#include <asm/uaccess.h> #define MEMORY_CLASS_NAME	"memory" static struct sysdev_class memory_sysdev_class = {	.name = MEMORY_CLASS_NAME,}; static const char *memory_uevent_name(struct kset *kset, struct kobject *kobj){	return MEMORY_CLASS_NAME;} static int memory_uevent(struct kset *kset, struct kobject *obj, struct kobj_uevent_env *env){	int retval = 0; 	return retval;} static struct kset_uevent_ops memory_uevent_ops = {	.name		= memory_uevent_name,	.uevent		= memory_uevent,}; static BLOCKING_NOTIFIER_HEAD(memory_chain); int register_memory_notifier(struct notifier_block *nb){        return blocking_notifier_chain_register(&memory_chain, nb);}EXPORT_SYMBOL(register_memory_notifier); void unregister_memory_notifier(struct notifier_block *nb){        blocking_notifier_chain_unregister(&memory_chain, nb);}EXPORT_SYMBOL(unregister_memory_notifier); /* * register_memory - Setup a sysfs device for a memory block */staticint register_memory(struct memory_block *memory, struct mem_section *section){	int error; 	memory->sysdev.cls = &memory_sysdev_class;	memory->sysdev.id = __section_nr(section); 	error = sysdev_register(&memory->sysdev);	return error;} static voidunregister_memory(struct memory_block *memory, struct mem_section *section){	BUG_ON(memory->sysdev.cls != &memory_sysdev_class);	BUG_ON(memory->sysdev.id != __section_nr(section)); 	/* drop the ref. we got in remove_memory_block() */	kobject_put(&memory->sysdev.kobj);	sysdev_unregister(&memory->sysdev);} /* * use this as the physical section index that this memsection * uses. */ static ssize_t show_mem_phys_index(struct sys_device *dev,			struct sysdev_attribute *attr, char *buf){	struct memory_block *mem =		container_of(dev, struct memory_block, sysdev);	return sprintf(buf, "%08lx\n", mem->phys_index);} /* * Show whether the section of memory is likely to be hot-removable */static ssize_t show_mem_removable(struct sys_device *dev,			struct sysdev_attribute *attr, char *buf){	unsigned long start_pfn;	int ret;	struct memory_block *mem =		container_of(dev, struct memory_block, sysdev); 	start_pfn = section_nr_to_pfn(mem->phys_index);	ret = is_mem_section_removable(start_pfn, PAGES_PER_SECTION);	return sprintf(buf, "%d\n", ret);} /* * online, offline, going offline, etc. */static ssize_t show_mem_state(struct sys_device *dev,			struct sysdev_attribute *attr, char *buf){	struct memory_block *mem =		container_of(dev, struct memory_block, sysdev);	ssize_t len = 0; 	/*	 * We can probably put these states in a nice little array	 * so that they're not open-coded	 */	switch (mem->state) {		case MEM_ONLINE:			len = sprintf(buf, "online\n");			break;		case MEM_OFFLINE:			len = sprintf(buf, "offline\n");			break;		case MEM_GOING_OFFLINE:			len = sprintf(buf, "going-offline\n");			break;		default:			len = sprintf(buf, "ERROR-UNKNOWN-%ld\n",					mem->state);			WARN_ON(1);			break;	} 	return len;} int memory_notify(unsigned long val, void *v){	return blocking_notifier_call_chain(&memory_chain, val, v);} /* * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is * OK to have direct references to sparsemem variables in here. */static intmemory_block_action(struct memory_block *mem, unsigned long action){	int i;	unsigned long psection;	unsigned long start_pfn, start_paddr;	struct page *first_page;	int ret;	int old_state = mem->state; 	psection = mem->phys_index;	first_page = pfn_to_page(psection << PFN_SECTION_SHIFT); 	/*	 * The probe routines leave the pages reserved, just	 * as the bootmem code does.  Make sure they're still	 * that way.	 */	if (action == MEM_ONLINE) {		for (i = 0; i < PAGES_PER_SECTION; i++) {			if (PageReserved(first_page+i))				continue; 			printk(KERN_WARNING "section number %ld page number %d "				"not reserved, was it already online? \n",				psection, i);			return -EBUSY;		}	} 	switch (action) {		case MEM_ONLINE:			start_pfn = page_to_pfn(first_page);			ret = online_pages(start_pfn, PAGES_PER_SECTION);			break;		case MEM_OFFLINE:			mem->state = MEM_GOING_OFFLINE;			start_paddr = page_to_pfn(first_page) << PAGE_SHIFT;			ret = remove_memory(start_paddr,					    PAGES_PER_SECTION << PAGE_SHIFT);			if (ret) {				mem->state = old_state;				break;			}			break;		default:			WARN(1, KERN_WARNING "%s(%p, %ld) unknown action: %ld\n",					__func__, mem, action, action);			ret = -EINVAL;	} 	return ret;} static int memory_block_change_state(struct memory_block *mem,		unsigned long to_state, unsigned long from_state_req){	int ret = 0;	mutex_lock(&mem->state_mutex); 	if (mem->state != from_state_req) {		ret = -EINVAL;		goto out;	} 	ret = memory_block_action(mem, to_state);	if (!ret)		mem->state = to_state; out:	mutex_unlock(&mem->state_mutex);	return ret;} static ssize_tstore_mem_state(struct sys_device *dev,		struct sysdev_attribute *attr, const char *buf, size_t count){	struct memory_block *mem;	unsigned int phys_section_nr;	int ret = -EINVAL; 	mem = container_of(dev, struct memory_block, sysdev);	phys_section_nr = mem->phys_index; 	if (!present_section_nr(phys_section_nr))		goto out; 	if (!strncmp(buf, "online", min((int)count, 6)))		ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);	else if(!strncmp(buf, "offline", min((int)count, 7)))		ret = memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);out:	if (ret)		return ret;	return count;} /* * phys_device is a bad name for this.  What I really want * is a way to differentiate between memory ranges that * are part of physical devices that constitute * a complete removable unit or fru. * i.e. do these ranges belong to the same physical device, * s.t. if I offline all of these sections I can then * remove the physical device? */static ssize_t show_phys_device(struct sys_device *dev,				struct sysdev_attribute *attr, char *buf){	struct memory_block *mem =		container_of(dev, struct memory_block, sysdev);	return sprintf(buf, "%d\n", mem->phys_device);} static SYSDEV_ATTR(phys_index, 0444, show_mem_phys_index, NULL);static SYSDEV_ATTR(state, 0644, show_mem_state, store_mem_state);static SYSDEV_ATTR(phys_device, 0444, show_phys_device, NULL);static SYSDEV_ATTR(removable, 0444, show_mem_removable, NULL); #define mem_create_simple_file(mem, attr_name)	\	sysdev_create_file(&mem->sysdev, &attr_##attr_name)#define mem_remove_simple_file(mem, attr_name)	\	sysdev_remove_file(&mem->sysdev, &attr_##attr_name) /* * Block size attribute stuff */static ssize_tprint_block_size(struct class *class, char *buf){	return sprintf(buf, "%lx\n", (unsigned long)PAGES_PER_SECTION * PAGE_SIZE);} static CLASS_ATTR(block_size_bytes, 0444, print_block_size, NULL); static int block_size_init(void){	return sysfs_create_file(&memory_sysdev_class.kset.kobj,				&class_attr_block_size_bytes.attr);} /* * Some architectures will have custom drivers to do this, and * will not need to do it from userspace.  The fake hot-add code * as well as ppc64 will do all of their discovery in userspace * and will require this interface. */#ifdef CONFIG_ARCH_MEMORY_PROBEstatic ssize_tmemory_probe_store(struct class *class, const char *buf, size_t count){	u64 phys_addr;	int nid;	int ret; 	phys_addr = simple_strtoull(buf, NULL, 0); 	nid = memory_add_physaddr_to_nid(phys_addr);	ret = add_memory(nid, phys_addr, PAGES_PER_SECTION << PAGE_SHIFT); 	if (ret)		count = ret; 	return count;}static CLASS_ATTR(probe, S_IWUSR, NULL, memory_probe_store); static int memory_probe_init(void){	return sysfs_create_file(&memory_sysdev_class.kset.kobj,				&class_attr_probe.attr);}#elsestatic inline int memory_probe_init(void){	return 0;}#endif /* * Note that phys_device is optional.  It is here to allow for * differentiation between which *physical* devices each * section belongs to... */ static int add_memory_block(int nid, struct mem_section *section,			unsigned long state, int phys_device,			enum mem_add_context context){	struct memory_block *mem = kzalloc(sizeof(*mem), GFP_KERNEL);	int ret = 0; 	if (!mem)		return -ENOMEM; 	mem->phys_index = __section_nr(section);	mem->state = state;	mutex_init(&mem->state_mutex);	mem->phys_device = phys_device; 	ret = register_memory(mem, section);	if (!ret)		ret = mem_create_simple_file(mem, phys_index);	if (!ret)		ret = mem_create_simple_file(mem, state);	if (!ret)		ret = mem_create_simple_file(mem, phys_device);	if (!ret)		ret = mem_create_simple_file(mem, removable);	if (!ret) {		if (context == HOTPLUG)			ret = register_mem_sect_under_node(mem, nid);	} 	return ret;} /* * For now, we have a linear search to go find the appropriate * memory_block corresponding to a particular phys_index. If * this gets to be a real problem, we can always use a radix * tree or something here. * * This could be made generic for all sysdev classes. */struct memory_block *find_memory_block(struct mem_section *section){	struct kobject *kobj;	struct sys_device *sysdev;	struct memory_block *mem;	char name[sizeof(MEMORY_CLASS_NAME) + 9 + 1]; 	/*	 * This only works because we know that section == sysdev->id	 * slightly redundant with sysdev_register()	 */	sprintf(&name[0], "%s%d", MEMORY_CLASS_NAME, __section_nr(section)); 	kobj = kset_find_obj(&memory_sysdev_class.kset, name);	if (!kobj)		return NULL; 	sysdev = container_of(kobj, struct sys_device, kobj);	mem = container_of(sysdev, struct memory_block, sysdev); 	return mem;} int remove_memory_block(unsigned long node_id, struct mem_section *section,		int phys_device){	struct memory_block *mem; 	mem = find_memory_block(section);	unregister_mem_sect_under_nodes(mem);	mem_remove_simple_file(mem, phys_index);	mem_remove_simple_file(mem, state);	mem_remove_simple_file(mem, phys_device);	mem_remove_simple_file(mem, removable);	unregister_memory(mem, section); 	return 0;} /* * need an interface for the VM to add new memory regions, * but without onlining it. */int register_new_memory(int nid, struct mem_section *section){	return add_memory_block(nid, section, MEM_OFFLINE, 0, HOTPLUG);} int unregister_memory_section(struct mem_section *section){	if (!present_section(section))		return -EINVAL; 	return remove_memory_block(0, section, 0);} /* * Initialize the sysfs support for memory devices... */int __init memory_dev_init(void){	unsigned int i;	int ret;	int err; 	memory_sysdev_class.kset.uevent_ops = &memory_uevent_ops;	ret = sysdev_class_register(&memory_sysdev_class);	if (ret)		goto out; 	/*	 * Create entries for memory sections that were found	 * during boot and have been initialized	 */	for (i = 0; i < NR_MEM_SECTIONS; i++) {		if (!present_section_nr(i))			continue;		err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE,					0, BOOT);		if (!ret)			ret = err;	} 	err = memory_probe_init();	if (!ret)		ret = err;	err = block_size_init();	if (!ret)		ret = err;out:	if (ret)		printk(KERN_ERR "%s() failed: %d\n", __func__, ret);	return ret;}