1/*
2 * driver/base/topology.c - Populate sysfs with cpu topology information
3 *
4 * Written by: Zhang Yanmin, Intel Corporation
5 *
6 * Copyright (C) 2006, Intel Corp.
7 *
8 * All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
18 * NON INFRINGEMENT.  See the GNU General Public License for more
19 * details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 *
25 */
26#include <linux/mm.h>
27#include <linux/cpu.h>
28#include <linux/module.h>
29#include <linux/hardirq.h>
30#include <linux/topology.h>
31
32#define define_id_show_func(name)				\
33static ssize_t name##_show(struct device *dev,			\
34		struct device_attribute *attr, char *buf)	\
35{								\
36	return sprintf(buf, "%d\n", topology_##name(dev->id));	\
37}
38
39#define define_siblings_show_map(name, mask)				\
40static ssize_t name##_show(struct device *dev,				\
41			   struct device_attribute *attr, char *buf)	\
42{									\
43	return cpumap_print_to_pagebuf(false, buf, topology_##mask(dev->id));\
44}
45
46#define define_siblings_show_list(name, mask)				\
47static ssize_t name##_list_show(struct device *dev,			\
48				struct device_attribute *attr,		\
49				char *buf)				\
50{									\
51	return cpumap_print_to_pagebuf(true, buf, topology_##mask(dev->id));\
52}
53
54#define define_siblings_show_func(name, mask)	\
55	define_siblings_show_map(name, mask);	\
56	define_siblings_show_list(name, mask)
57
58define_id_show_func(physical_package_id);
59static DEVICE_ATTR_RO(physical_package_id);
60
61define_id_show_func(core_id);
62static DEVICE_ATTR_RO(core_id);
63
64define_siblings_show_func(thread_siblings, sibling_cpumask);
65static DEVICE_ATTR_RO(thread_siblings);
66static DEVICE_ATTR_RO(thread_siblings_list);
67
68define_siblings_show_func(core_siblings, core_cpumask);
69static DEVICE_ATTR_RO(core_siblings);
70static DEVICE_ATTR_RO(core_siblings_list);
71
72#ifdef CONFIG_SCHED_BOOK
73define_id_show_func(book_id);
74static DEVICE_ATTR_RO(book_id);
75define_siblings_show_func(book_siblings, book_cpumask);
76static DEVICE_ATTR_RO(book_siblings);
77static DEVICE_ATTR_RO(book_siblings_list);
78#endif
79
80static struct attribute *default_attrs[] = {
81	&dev_attr_physical_package_id.attr,
82	&dev_attr_core_id.attr,
83	&dev_attr_thread_siblings.attr,
84	&dev_attr_thread_siblings_list.attr,
85	&dev_attr_core_siblings.attr,
86	&dev_attr_core_siblings_list.attr,
87#ifdef CONFIG_SCHED_BOOK
88	&dev_attr_book_id.attr,
89	&dev_attr_book_siblings.attr,
90	&dev_attr_book_siblings_list.attr,
91#endif
92	NULL
93};
94
95static struct attribute_group topology_attr_group = {
96	.attrs = default_attrs,
97	.name = "topology"
98};
99
100/* Add/Remove cpu_topology interface for CPU device */
101static int topology_add_dev(unsigned int cpu)
102{
103	struct device *dev = get_cpu_device(cpu);
104
105	return sysfs_create_group(&dev->kobj, &topology_attr_group);
106}
107
108static void topology_remove_dev(unsigned int cpu)
109{
110	struct device *dev = get_cpu_device(cpu);
111
112	sysfs_remove_group(&dev->kobj, &topology_attr_group);
113}
114
115static int topology_cpu_callback(struct notifier_block *nfb,
116				 unsigned long action, void *hcpu)
117{
118	unsigned int cpu = (unsigned long)hcpu;
119	int rc = 0;
120
121	switch (action) {
122	case CPU_UP_PREPARE:
123	case CPU_UP_PREPARE_FROZEN:
124		rc = topology_add_dev(cpu);
125		break;
126	case CPU_UP_CANCELED:
127	case CPU_UP_CANCELED_FROZEN:
128	case CPU_DEAD:
129	case CPU_DEAD_FROZEN:
130		topology_remove_dev(cpu);
131		break;
132	}
133	return notifier_from_errno(rc);
134}
135
136static int topology_sysfs_init(void)
137{
138	int cpu;
139	int rc = 0;
140
141	cpu_notifier_register_begin();
142
143	for_each_online_cpu(cpu) {
144		rc = topology_add_dev(cpu);
145		if (rc)
146			goto out;
147	}
148	__hotcpu_notifier(topology_cpu_callback, 0);
149
150out:
151	cpu_notifier_register_done();
152	return rc;
153}
154
155device_initcall(topology_sysfs_init);
156