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/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>

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


static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf)
{
	ssize_t n;
	cpumask_var_t mask;
	struct node *node_dev = to_node(dev);

	/* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
	BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));

	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_to_pagebuf(list, buf, mask);
	free_cpumask_var(mask);

	return n;
}

static inline ssize_t node_read_cpumask(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	return node_read_cpumap(dev, false, buf);
}
static inline ssize_t node_read_cpulist(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	return node_read_cpumap(dev, true, buf);
}

static DEVICE_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);

/**
 * 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
 * @hmem_attrs: Heterogeneous memory performance attributes
 */
struct node_access_nodes {
	struct device		dev;
	struct list_head	list_node;
	unsigned		access;
#ifdef CONFIG_HMEM_REPORTING
	struct node_hmem_attrs	hmem_attrs;
#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,
};

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,
						       unsigned access)
{
	struct node_access_nodes *access_node;
	struct device *dev;

	list_for_each_entry(access_node, &node->access_list, list_node)
		if (access_node->access == access)
			return access_node;

	access_node = kzalloc(sizeof(*access_node), GFP_KERNEL);
	if (!access_node)
		return NULL;

	access_node->access = access;
	dev = &access_node->dev;
	dev->parent = &node->dev;
	dev->release = node_access_release;
	dev->groups = node_access_node_groups;
	if (dev_set_name(dev, "access%u", access))
		goto free;

	if (device_register(dev))
		goto free_name;

	pm_runtime_no_callbacks(dev);
	list_add_tail(&access_node->list_node, &node->access_list);
	return access_node;
free_name:
	kfree_const(dev->kobj.name);
free:
	kfree(access_node);
	return NULL;
}

#ifdef CONFIG_HMEM_REPORTING
#define ACCESS_ATTR(name) 						   \
static ssize_t name##_show(struct device *dev,				   \
			   struct device_attribute *attr,		   \
			   char *buf)					   \
{									   \
	return sprintf(buf, "%u\n", to_access_nodes(dev)->hmem_attrs.name); \
}									   \
static DEVICE_ATTR_RO(name);

ACCESS_ATTR(read_bandwidth)
ACCESS_ATTR(read_latency)
ACCESS_ATTR(write_bandwidth)
ACCESS_ATTR(write_latency)

static struct attribute *access_attrs[] = {
	&dev_attr_read_bandwidth.attr,
	&dev_attr_read_latency.attr,
	&dev_attr_write_bandwidth.attr,
	&dev_attr_write_latency.attr,
	NULL,
};

/**
 * node_set_perf_attrs - Set the performance values for given access class
 * @nid: Node identifier to be set
 * @hmem_attrs: Heterogeneous memory performance attributes
 * @access: The access class the for the given attributes
 */
void node_set_perf_attrs(unsigned int nid, struct node_hmem_attrs *hmem_attrs,
			 unsigned access)
{
	struct node_access_nodes *c;
	struct node *node;
	int i;

	if (WARN_ON_ONCE(!node_online(nid)))
		return;

	node = node_devices[nid];
	c = node_init_node_access(node, access);
	if (!c)
		return;

	c->hmem_attrs = *hmem_attrs;
	for