linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Memory subsystem 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/module.h>

#include <linux/init.h>

#include <linux/topology.h>

#include <linux/capability.h>

#include <linux/device.h>

#include <linux/memory.h>

#include <linux/memory_hotplug.h>

#include <linux/mm.h>

#include <linux/mutex.h>

#include <linux/stat.h>

#include <linux/slab.h>

​

#include <linux/atomic.h>

#include <linux/uaccess.h>

​

static DEFINE_MUTEX(mem_sysfs_mutex);

​

#define MEMORY_CLASS_NAME   "memory"

​

#define to_memory_block(dev) container_of(dev, struct memory_block, dev)

​

static int sections_per_block;

​

static inline int base_memory_block_id(int section_nr)

{

    return section_nr / sections_per_block;

}

​

static int memory_subsys_online(struct device *dev);

static int memory_subsys_offline(struct device *dev);

​

static struct bus_type memory_subsys = {

    .name = MEMORY_CLASS_NAME,

    .dev_name = MEMORY_CLASS_NAME,

    .online = memory_subsys_online,

    .offline = memory_subsys_offline,

};

​

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);

}