[PATCH] memory hotplug: sysfs and add/remove functions (3947be19) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/base/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -7,6 +7,7 @@ obj-y := core.o sys.o bus.o dd.o \
		obj-y += power/
		obj-$(CONFIG_FW_LOADER) += firmware_class.o
		obj-$(CONFIG_NUMA) += node.o
		obj-$(CONFIG_MEMORY_HOTPLUG) += memory.o

		ifeq ($(CONFIG_DEBUG_DRIVER),y)
		EXTRA_CFLAGS += -DDEBUG

drivers/base/init.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -9,6 +9,7 @@

		#include <linux/device.h>
		#include <linux/init.h>
		#include <linux/memory.h>

		#include "base.h"

		@@ -33,5 +34,6 @@ void __init driver_init(void)
		platform_bus_init();
		system_bus_init();
		cpu_dev_init();
		memory_dev_init();
		attribute_container_init();
		}

drivers/base/memory.c

0 → 100644

+455 −0

Original line number	Diff line number	Diff line
		/*
		* 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/sched.h> /* capable() */
		#include <linux/topology.h>
		#include <linux/device.h>
		#include <linux/memory.h>
		#include <linux/kobject.h>
		#include <linux/memory_hotplug.h>
		#include <linux/mm.h>
		#include <asm/atomic.h>
		#include <asm/uaccess.h>

		#define MEMORY_CLASS_NAME "memory"

		static struct sysdev_class memory_sysdev_class = {
		set_kset_name(MEMORY_CLASS_NAME),
		};
		EXPORT_SYMBOL(memory_sysdev_class);

		static char memory_hotplug_name(struct kset kset, struct kobject *kobj)
		{
		return MEMORY_CLASS_NAME;
		}

		static int memory_hotplug(struct kset kset, struct kobject kobj, char **envp,
		int num_envp, char *buffer, int buffer_size)
		{
		int retval = 0;

		return retval;
		}

		static struct kset_hotplug_ops memory_hotplug_ops = {
		.name = memory_hotplug_name,
		.hotplug = memory_hotplug,
		};

		static struct notifier_block *memory_chain;

		static int register_memory_notifier(struct notifier_block *nb)
		{
		return notifier_chain_register(&memory_chain, nb);
		}

		static void unregister_memory_notifier(struct notifier_block *nb)
		{
		notifier_chain_unregister(&memory_chain, nb);
		}

		/*
		* register_memory - Setup a sysfs device for a memory block
		*/
		static int
		register_memory(struct memory_block memory, struct mem_section section,
		struct node *root)
		{
		int error;

		memory->sysdev.cls = &memory_sysdev_class;
		memory->sysdev.id = __section_nr(section);

		error = sysdev_register(&memory->sysdev);

		if (root && !error)
		error = sysfs_create_link(&root->sysdev.kobj,
		&memory->sysdev.kobj,
		kobject_name(&memory->sysdev.kobj));

		return error;
		}

		static void
		unregister_memory(struct memory_block memory, struct mem_section section,
		struct node *root)
		{
		BUG_ON(memory->sysdev.cls != &memory_sysdev_class);
		BUG_ON(memory->sysdev.id != __section_nr(section));

		sysdev_unregister(&memory->sysdev);
		if (root)
		sysfs_remove_link(&root->sysdev.kobj,
		kobject_name(&memory->sysdev.kobj));
		}

		/*
		* use this as the physical section index that this memsection
		* uses.
		*/

		static ssize_t show_mem_phys_index(struct sys_device dev, char buf)
		{
		struct memory_block *mem =
		container_of(dev, struct memory_block, sysdev);
		return sprintf(buf, "%08lx\n", mem->phys_index);
		}

		/*
		* online, offline, going offline, etc.
		*/
		static ssize_t show_mem_state(struct sys_device dev, 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;
		}

		static inline int memory_notify(unsigned long val, void *v)
		{
		return 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 int
		memory_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;
		memory_notify(MEM_GOING_OFFLINE, NULL);
		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;
		}
		memory_notify(MEM_MAPPING_INVALID, NULL);
		break;
		default:
		printk(KERN_WARNING "%s(%p, %ld) unknown action: %ld\n",
		__FUNCTION__, mem, action, action);
		WARN_ON(1);
		ret = -EINVAL;
		}
		/*
		* For now, only notify on successful memory operations
		*/
		if (!ret)
		memory_notify(action, NULL);

		return ret;
		}

		static int memory_block_change_state(struct memory_block *mem,
		unsigned long to_state, unsigned long from_state_req)
		{
		int ret = 0;
		down(&mem->state_sem);

		if (mem->state != from_state_req) {
		ret = -EINVAL;
		goto out;
		}

		ret = memory_block_action(mem, to_state);
		if (!ret)
		mem->state = to_state;

		out:
		up(&mem->state_sem);
		return ret;
		}

		static ssize_t
		store_mem_state(struct sys_device dev, 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 (!valid_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, 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);

		#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_t
		print_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)
		{
		sysfs_create_file(&memory_sysdev_class.kset.kobj,
		&class_attr_block_size_bytes.attr);
		return 0;
		}

		/*
		* 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_PROBE
		static ssize_t
		memory_probe_store(struct class class, const char __user buf, size_t count)
		{
		u64 phys_addr;
		int ret;

		phys_addr = simple_strtoull(buf, NULL, 0);

		ret = add_memory(phys_addr, PAGES_PER_SECTION << PAGE_SHIFT);

		if (ret)
		count = ret;

		return count;
		}
		static CLASS_ATTR(probe, 0700, NULL, memory_probe_store);

		static int memory_probe_init(void)
		{
		sysfs_create_file(&memory_sysdev_class.kset.kobj,
		&class_attr_probe.attr);
		return 0;
		}
		#else
		#define memory_probe_init(...) do {} while (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(unsigned long node_id, struct mem_section *section,
		unsigned long state, int phys_device)
		{
		size_t size = sizeof(struct memory_block);
		struct memory_block *mem = kmalloc(size, GFP_KERNEL);
		int ret = 0;

		if (!mem)
		return -ENOMEM;

		memset(mem, 0, size);

		mem->phys_index = __section_nr(section);
		mem->state = state;
		init_MUTEX(&mem->state_sem);
		mem->phys_device = phys_device;

		ret = register_memory(mem, section, NULL);
		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);

		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.
		*/
		static 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);
		mem_remove_simple_file(mem, phys_index);
		mem_remove_simple_file(mem, state);
		mem_remove_simple_file(mem, phys_device);
		unregister_memory(mem, section, NULL);

		return 0;
		}

		/*
		* need an interface for the VM to add new memory regions,
		* but without onlining it.
		*/
		int register_new_memory(struct mem_section *section)
		{
		return add_memory_block(0, section, MEM_OFFLINE, 0);
		}

		int unregister_memory_section(struct mem_section *section)
		{
		if (!valid_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;

		memory_sysdev_class.kset.hotplug_ops = &memory_hotplug_ops;
		ret = sysdev_class_register(&memory_sysdev_class);

		/*
		* Create entries for memory sections that were found
		* during boot and have been initialized
		*/
		for (i = 0; i < NR_MEM_SECTIONS; i++) {
		if (!valid_section_nr(i))
		continue;
		add_memory_block(0, __nr_to_section(i), MEM_ONLINE, 0);
		}

		memory_probe_init();
		block_size_init();

		return ret;
		}

include/linux/memory.h

0 → 100644

+94 −0

Original line number	Diff line number	Diff line
		/*
		* include/linux/memory.h - generic memory definition
		*
		* This is mainly for topological representation. We define the
		* basic "struct memory_block" here, which can be embedded in per-arch
		* definitions or NUMA information.
		*
		* Basic handling of the devices is done in drivers/base/memory.c
		* and system devices are handled in drivers/base/sys.c.
		*
		* Memory block are exported via sysfs in the class/memory/devices/
		* directory.
		*
		*/
		#ifndef _LINUX_MEMORY_H_
		#define _LINUX_MEMORY_H_

		#include <linux/sysdev.h>
		#include <linux/node.h>
		#include <linux/compiler.h>

		#include <asm/semaphore.h>

		struct memory_block {
		unsigned long phys_index;
		unsigned long state;
		/*
		* This serializes all state change requests. It isn't
		* held during creation because the control files are
		* created long after the critical areas during
		* initialization.
		*/
		struct semaphore state_sem;
		int phys_device; /* to which fru does this belong? */
		void hw; / optional pointer to fw/hw data */
		int (phys_callback)(struct memory_block );
		struct sys_device sysdev;
		};

		/* These states are exposed to userspace as text strings in sysfs */
		#define MEM_ONLINE (1<<0) /* exposed to userspace */
		#define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */
		#define MEM_OFFLINE (1<<2) /* exposed to userspace */

		/*
		* All of these states are currently kernel-internal for notifying
		* kernel components and architectures.
		*
		* For MEM_MAPPING_INVALID, all notifier chains with priority >0
		* are called before pfn_to_page() becomes invalid. The priority=0
		* entry is reserved for the function that actually makes
		* pfn_to_page() stop working. Any notifiers that want to be called
		* after that should have priority <0.
		*/
		#define MEM_MAPPING_INVALID (1<<3)

		#ifndef CONFIG_MEMORY_HOTPLUG
		static inline int memory_dev_init(void)
		{
		return 0;
		}
		static inline int register_memory_notifier(struct notifier_block *nb)
		{
		return 0;
		}
		static inline void unregister_memory_notifier(struct notifier_block *nb)
		{
		}
		#else
		extern int register_memory(struct memory_block , struct mem_section section, struct node *);
		extern int register_new_memory(struct mem_section *);
		extern int unregister_memory_section(struct mem_section *);
		extern int memory_dev_init(void);
		extern int register_memory_notifier(struct notifier_block *nb);
		extern void unregister_memory_notifier(struct notifier_block *nb);

		#define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)

		extern int invalidate_phys_mapping(unsigned long, unsigned long);
		struct notifier_block;

		extern int register_memory_notifier(struct notifier_block *nb);
		extern void unregister_memory_notifier(struct notifier_block *nb);

		extern struct sysdev_class memory_sysdev_class;
		#endif /* CONFIG_MEMORY_HOTPLUG */

		#define hotplug_memory_notifier(fn, pri) { \
		static struct notifier_block fn##_mem_nb = \
		{ .notifier_call = fn, .priority = pri }; \
		register_memory_notifier(&fn##_mem_nb); \
		}

		#endif /* _LINUX_MEMORY_H_ */

include/linux/memory_hotplug.h

+35 −0

Original line number	Diff line number	Diff line
		@@ -3,6 +3,8 @@

		#include <linux/mmzone.h>
		#include <linux/spinlock.h>
		#include <linux/mmzone.h>
		#include <linux/notifier.h>

		#ifdef CONFIG_MEMORY_HOTPLUG
		/*
		@@ -46,6 +48,19 @@ static inline void zone_seqlock_init(struct zone *zone)
		{
		seqlock_init(&zone->span_seqlock);
		}
		extern int zone_grow_free_lists(struct zone *zone, unsigned long new_nr_pages);
		extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages);
		extern int add_one_highpage(struct page *page, int pfn, int bad_ppro);
		/* need some defines for these for archs that don't support it */
		extern void online_page(struct page *page);
		/* VM interface that may be used by firmware interface */
		extern int add_memory(u64 start, u64 size);
		extern int remove_memory(u64 start, u64 size);
		extern int online_pages(unsigned long, unsigned long);

		/* reasonably generic interface to expand the physical pages in a zone */
		extern int __add_pages(struct zone *zone, unsigned long start_pfn,
		unsigned long nr_pages);
		#else /* ! CONFIG_MEMORY_HOTPLUG */
		/*
		* Stub functions for when hotplug is off
		@@ -65,5 +80,25 @@ static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
		static inline void zone_span_writelock(struct zone *zone) {}
		static inline void zone_span_writeunlock(struct zone *zone) {}
		static inline void zone_seqlock_init(struct zone *zone) {}

		static inline int mhp_notimplemented(const char *func)
		{
		printk(KERN_WARNING "%s() called, with CONFIG_MEMORY_HOTPLUG disabled\n", func);
		dump_stack();
		return -ENOSYS;
		}

		static inline int __add_pages(struct zone *zone, unsigned long start_pfn,
		unsigned long nr_pages)
		{
		return mhp_notimplemented(__FUNCTION__);
		}
		#endif /* ! CONFIG_MEMORY_HOTPLUG */
		static inline int __remove_pages(struct zone *zone, unsigned long start_pfn,
		unsigned long nr_pages)
		{
		printk(KERN_WARNING "%s() called, not yet supported\n", __FUNCTION__);
		dump_stack();
		return -ENOSYS;
		}
		#endif /* __LINUX_MEMORY_HOTPLUG_H */