2 * driver/base/topology.c - Populate sysfs with cpu topology information
4 * Written by: Zhang Yanmin, Intel Corporation
6 * Copyright (C) 2006, Intel Corp.
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.
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
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.
27 #include <linux/cpu.h>
28 #include <linux/module.h>
29 #include <linux/hardirq.h>
30 #include <linux/topology.h>
32 #define define_one_ro_named(_name, _func) \
33 static DEVICE_ATTR(_name, 0444, _func, NULL)
35 #define define_one_ro(_name) \
36 static DEVICE_ATTR(_name, 0444, show_##_name, NULL)
38 #define define_id_show_func(name) \
39 static ssize_t show_##name(struct device *dev, \
40 struct device_attribute *attr, char *buf) \
42 unsigned int cpu = dev->id; \
43 return sprintf(buf, "%d\n", topology_##name(cpu)); \
46 #if defined(topology_thread_cpumask) || defined(topology_core_cpumask) || \
47 defined(topology_book_cpumask)
48 static ssize_t show_cpumap(int type, const struct cpumask *mask, char *buf)
50 ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
55 cpulist_scnprintf(buf, len-2, mask) :
56 cpumask_scnprintf(buf, len-2, mask);
64 #define define_siblings_show_map(name) \
65 static ssize_t show_##name(struct device *dev, \
66 struct device_attribute *attr, char *buf) \
68 return show_cpumap(0, topology_##name(dev->id), buf); \
71 #define define_siblings_show_list(name) \
72 static ssize_t show_##name##_list(struct device *dev, \
73 struct device_attribute *attr, \
76 return show_cpumap(1, topology_##name(dev->id), buf); \
79 #define define_siblings_show_func(name) \
80 define_siblings_show_map(name); define_siblings_show_list(name)
82 define_id_show_func(physical_package_id);
83 define_one_ro(physical_package_id);
85 define_id_show_func(core_id);
86 define_one_ro(core_id);
88 define_siblings_show_func(thread_cpumask);
89 define_one_ro_named(thread_siblings, show_thread_cpumask);
90 define_one_ro_named(thread_siblings_list, show_thread_cpumask_list);
92 define_siblings_show_func(core_cpumask);
93 define_one_ro_named(core_siblings, show_core_cpumask);
94 define_one_ro_named(core_siblings_list, show_core_cpumask_list);
96 #ifdef CONFIG_SCHED_BOOK
97 define_id_show_func(book_id);
98 define_one_ro(book_id);
99 define_siblings_show_func(book_cpumask);
100 define_one_ro_named(book_siblings, show_book_cpumask);
101 define_one_ro_named(book_siblings_list, show_book_cpumask_list);
104 static struct attribute *default_attrs[] = {
105 &dev_attr_physical_package_id.attr,
106 &dev_attr_core_id.attr,
107 &dev_attr_thread_siblings.attr,
108 &dev_attr_thread_siblings_list.attr,
109 &dev_attr_core_siblings.attr,
110 &dev_attr_core_siblings_list.attr,
111 #ifdef CONFIG_SCHED_BOOK
112 &dev_attr_book_id.attr,
113 &dev_attr_book_siblings.attr,
114 &dev_attr_book_siblings_list.attr,
119 static struct attribute_group topology_attr_group = {
120 .attrs = default_attrs,
124 /* Add/Remove cpu_topology interface for CPU device */
125 static int topology_add_dev(unsigned int cpu)
127 struct device *dev = get_cpu_device(cpu);
129 return sysfs_create_group(&dev->kobj, &topology_attr_group);
132 static void topology_remove_dev(unsigned int cpu)
134 struct device *dev = get_cpu_device(cpu);
136 sysfs_remove_group(&dev->kobj, &topology_attr_group);
139 static int topology_cpu_callback(struct notifier_block *nfb,
140 unsigned long action, void *hcpu)
142 unsigned int cpu = (unsigned long)hcpu;
147 case CPU_UP_PREPARE_FROZEN:
148 rc = topology_add_dev(cpu);
150 case CPU_UP_CANCELED:
151 case CPU_UP_CANCELED_FROZEN:
153 case CPU_DEAD_FROZEN:
154 topology_remove_dev(cpu);
157 return notifier_from_errno(rc);
160 static int topology_sysfs_init(void)
165 cpu_notifier_register_begin();
167 for_each_online_cpu(cpu) {
168 rc = topology_add_dev(cpu);
172 __hotcpu_notifier(topology_cpu_callback, 0);
175 cpu_notifier_register_done();
179 device_initcall(topology_sysfs_init);