path: root/drivers/base/node.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Basic Node interface support
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memory.h>
#include <linux/mempolicy.h>
#include <linux/vmstat.h>
#include <linux/notifier.h>
#include <linux/node.h>
#include <linux/hugetlb.h>
#include <linux/compaction.h>
#include <linux/cpumask.h>
#include <linux/topology.h>
#include <linux/nodemask.h>
#include <linux/cpu.h>
#include <linux/device.h>
#include <linux/pm_runtime.h>
#include <linux/swap.h>
#include <linux/slab.h>
#include <linux/memblock.h>

static const struct bus_type node_subsys = {
	.name = "node",
	.dev_name = "node",
};

static inline ssize_t cpumap_read(struct file *file, struct kobject *kobj,
				  const struct bin_attribute *attr, char *buf,
				  loff_t off, size_t count)
{
	struct device *dev = kobj_to_dev(kobj);
	struct node *node_dev = to_node(dev);
	cpumask_var_t mask;
	ssize_t n;

	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
		return 0;

	cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
	n = cpumap_print_bitmask_to_buf(buf, mask, off, count);
	free_cpumask_var(mask);

	return n;
}

static const BIN_ATTR_RO(cpumap, CPUMAP_FILE_MAX_BYTES);

static inline ssize_t cpulist_read(struct file *file, struct kobject *kobj,
				   const struct bin_attribute *attr, char *buf,
				   loff_t off, size_t count)
{
	struct device *dev = kobj_to_dev(kobj);
	struct node *node_dev = to_node(dev);
	cpumask_var_t mask;
	ssize_t n;

	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
		return 0;

	cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
	n = cpumap_print_list_to_buf(buf, mask, off, count);
	free_cpumask_var(mask);

	return n;
}

static const BIN_ATTR_RO(cpulist, CPULIST_FILE_MAX_BYTES);

/**
 * struct node_access_nodes - Access class device to hold user visible
 * 			      relationships to other nodes.
 * @dev:	Device for this memory access class
 * @list_node:	List element in the node's access list
 * @access:	The access class rank
 * @coord:	Heterogeneous memory performance coordinates
 */
struct node_access_nodes {
	struct device		dev;
	struct list_head	list_node;
	unsigned int		access;
#ifdef CONFIG_HMEM_REPORTING
	struct access_coordinate	coord;
#endif
};
#define to_access_nodes(dev) container_of(dev, struct node_access_nodes, dev)

static struct attribute *node_init_access_node_attrs[] = {
	NULL,
};

static struct attribute *node_targ_access_node_attrs[] = {
	NULL,
};

static const struct attribute_group initiators = {
	.name	= "initiators",
	.attrs	= node_init_access_node_attrs,
};

static const struct attribute_group targets = {
	.name	= "targets",
	.attrs	= node_targ_access_node_attrs,
};

static const struct attribute_group *node_access_node_groups[] = {
	&initiators,
	&targets,
	NULL,
};

#ifdef CONFIG_MEMORY_HOTPLUG
static BLOCKING_NOTIFIER_HEAD(node_chain);

int register_node_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_register(&node_chain, nb);
}
EXPORT_SYMBOL(register_node_notifier);

void unregister_node_notifier(struct notifier_block *nb)
{
	blocking_notifier_chain_unregister(&node_chain, nb);
}
EXPORT_SYMBOL(unregister_node_notifier);

int node_notify(unsigned long val, void *v)
{
	return blocking_notifier_call_chain(&node_chain, val, v);
}
#endif

static void node_remove_accesses(struct node *node)
{
	struct node_access_nodes *c, *cnext;

	list_for_each_entry_safe(c, cnext, &node->access_list, list_node) {
		list_del(&c->list_node);
		device_unregister(&c->dev);
	}
}

static void node_access_release(struct device *dev)
{
	kfree(to_access_nodes(dev));
}

static struct node_access_nodes *node_init_node_access(struct node *node,
						       enum access_coordinate_c