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.
26 #include <linux/init.h>
28 #include <linux/cpu.h>
29 #include <linux/module.h>
30 #include <linux/hardirq.h>
31 #include <linux/topology.h>
33 #define define_one_ro_named(_name, _func) \
34 static DEVICE_ATTR(_name, 0444, _func, NULL)
36 #define define_one_ro(_name) \
37 static DEVICE_ATTR(_name, 0444, show_##_name, NULL)
39 #define define_id_show_func(name) \
40 static ssize_t show_##name(struct device *dev, \
41 struct device_attribute *attr, char *buf) \
43 return sprintf(buf, "%d\n", topology_##name(dev->id)); \
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 #ifdef arch_provides_topology_pointers
65 #define define_siblings_show_map(name) \
66 static ssize_t show_##name(struct device *dev, \
67 struct device_attribute *attr, char *buf) \
69 unsigned int cpu = dev->id; \
70 return show_cpumap(0, topology_##name(cpu), buf); \
73 #define define_siblings_show_list(name) \
74 static ssize_t show_##name##_list(struct device *dev, \
75 struct device_attribute *attr, \
78 unsigned int cpu = dev->id; \
79 return show_cpumap(1, topology_##name(cpu), buf); \
83 #define define_siblings_show_map(name) \
84 static ssize_t show_##name(struct device *dev, \
85 struct device_attribute *attr, char *buf) \
87 return show_cpumap(0, topology_##name(dev->id), buf); \
90 #define define_siblings_show_list(name) \
91 static ssize_t show_##name##_list(struct device *dev, \
92 struct device_attribute *attr, \
95 return show_cpumap(1, topology_##name(dev->id), buf); \
99 #define define_siblings_show_func(name) \
100 define_siblings_show_map(name); define_siblings_show_list(name)
102 define_id_show_func(physical_package_id);
103 define_one_ro(physical_package_id);
105 define_id_show_func(core_id);
106 define_one_ro(core_id);
108 define_siblings_show_func(thread_cpumask);
109 define_one_ro_named(thread_siblings, show_thread_cpumask);
110 define_one_ro_named(thread_siblings_list, show_thread_cpumask_list);
112 define_siblings_show_func(core_cpumask);
113 define_one_ro_named(core_siblings, show_core_cpumask);
114 define_one_ro_named(core_siblings_list, show_core_cpumask_list);
116 #ifdef CONFIG_SCHED_BOOK
117 define_id_show_func(book_id);
118 define_one_ro(book_id);
119 define_siblings_show_func(book_cpumask);
120 define_one_ro_named(book_siblings, show_book_cpumask);
121 define_one_ro_named(book_siblings_list, show_book_cpumask_list);
124 static struct attribute *default_attrs[] = {
125 &dev_attr_physical_package_id.attr,
126 &dev_attr_core_id.attr,
127 &dev_attr_thread_siblings.attr,
128 &dev_attr_thread_siblings_list.attr,
129 &dev_attr_core_siblings.attr,
130 &dev_attr_core_siblings_list.attr,
131 #ifdef CONFIG_SCHED_BOOK
132 &dev_attr_book_id.attr,
133 &dev_attr_book_siblings.attr,
134 &dev_attr_book_siblings_list.attr,
139 static struct attribute_group topology_attr_group = {
140 .attrs = default_attrs,
144 /* Add/Remove cpu_topology interface for CPU device */
145 static int __cpuinit topology_add_dev(unsigned int cpu)
147 struct device *dev = get_cpu_device(cpu);
149 return sysfs_create_group(&dev->kobj, &topology_attr_group);
152 static void __cpuinit topology_remove_dev(unsigned int cpu)
154 struct device *dev = get_cpu_device(cpu);
156 sysfs_remove_group(&dev->kobj, &topology_attr_group);
159 static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
160 unsigned long action, void *hcpu)
162 unsigned int cpu = (unsigned long)hcpu;
167 case CPU_UP_PREPARE_FROZEN:
168 rc = topology_add_dev(cpu);
170 case CPU_UP_CANCELED:
171 case CPU_UP_CANCELED_FROZEN:
173 case CPU_DEAD_FROZEN:
174 topology_remove_dev(cpu);
177 return notifier_from_errno(rc);
180 static int __cpuinit topology_sysfs_init(void)
185 for_each_online_cpu(cpu) {
186 rc = topology_add_dev(cpu);
190 hotcpu_notifier(topology_cpu_callback, 0);
195 device_initcall(topology_sysfs_init);