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/sysdev.h>
27 #include <linux/init.h>
29 #include <linux/cpu.h>
30 #include <linux/module.h>
31 #include <linux/hardirq.h>
32 #include <linux/topology.h>
34 #define define_one_ro_named(_name, _func) \
35 static SYSDEV_ATTR(_name, 0444, _func, NULL)
37 #define define_one_ro(_name) \
38 static SYSDEV_ATTR(_name, 0444, show_##_name, NULL)
40 #define define_id_show_func(name) \
41 static ssize_t show_##name(struct sys_device *dev, \
42 struct sysdev_attribute *attr, char *buf) \
44 unsigned int cpu = dev->id; \
45 return sprintf(buf, "%d\n", topology_##name(cpu)); \
48 #if defined(topology_thread_cpumask) || defined(topology_core_cpumask)
49 static ssize_t show_cpumap(int type, const struct cpumask *mask, char *buf)
51 ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
56 cpulist_scnprintf(buf, len-2, mask) :
57 cpumask_scnprintf(buf, len-2, mask);
65 #ifdef arch_provides_topology_pointers
66 #define define_siblings_show_map(name) \
67 static ssize_t show_##name(struct sys_device *dev, \
68 struct sysdev_attribute *attr, char *buf) \
70 unsigned int cpu = dev->id; \
71 return show_cpumap(0, topology_##name(cpu), buf); \
74 #define define_siblings_show_list(name) \
75 static ssize_t show_##name##_list(struct sys_device *dev, \
76 struct sysdev_attribute *attr, \
79 unsigned int cpu = dev->id; \
80 return show_cpumap(1, topology_##name(cpu), buf); \
84 #define define_siblings_show_map(name) \
85 static ssize_t show_##name(struct sys_device *dev, \
86 struct sysdev_attribute *attr, char *buf) \
88 return show_cpumap(0, topology_##name(dev->id), buf); \
91 #define define_siblings_show_list(name) \
92 static ssize_t show_##name##_list(struct sys_device *dev, \
93 struct sysdev_attribute *attr, \
96 return show_cpumap(1, topology_##name(dev->id), buf); \
100 #define define_siblings_show_func(name) \
101 define_siblings_show_map(name); define_siblings_show_list(name)
103 define_id_show_func(physical_package_id);
104 define_one_ro(physical_package_id);
106 define_id_show_func(core_id);
107 define_one_ro(core_id);
109 define_siblings_show_func(thread_cpumask);
110 define_one_ro_named(thread_siblings, show_thread_cpumask);
111 define_one_ro_named(thread_siblings_list, show_thread_cpumask_list);
113 define_siblings_show_func(core_cpumask);
114 define_one_ro_named(core_siblings, show_core_cpumask);
115 define_one_ro_named(core_siblings_list, show_core_cpumask_list);
117 static struct attribute *default_attrs[] = {
118 &attr_physical_package_id.attr,
120 &attr_thread_siblings.attr,
121 &attr_thread_siblings_list.attr,
122 &attr_core_siblings.attr,
123 &attr_core_siblings_list.attr,
127 static struct attribute_group topology_attr_group = {
128 .attrs = default_attrs,
132 /* Add/Remove cpu_topology interface for CPU device */
133 static int __cpuinit topology_add_dev(unsigned int cpu)
135 struct sys_device *sys_dev = get_cpu_sysdev(cpu);
137 return sysfs_create_group(&sys_dev->kobj, &topology_attr_group);
140 static void __cpuinit topology_remove_dev(unsigned int cpu)
142 struct sys_device *sys_dev = get_cpu_sysdev(cpu);
144 sysfs_remove_group(&sys_dev->kobj, &topology_attr_group);
147 static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
148 unsigned long action, void *hcpu)
150 unsigned int cpu = (unsigned long)hcpu;
155 case CPU_UP_PREPARE_FROZEN:
156 rc = topology_add_dev(cpu);
158 case CPU_UP_CANCELED:
159 case CPU_UP_CANCELED_FROZEN:
161 case CPU_DEAD_FROZEN:
162 topology_remove_dev(cpu);
165 return rc ? NOTIFY_BAD : NOTIFY_OK;
168 static int __cpuinit topology_sysfs_init(void)
173 for_each_online_cpu(cpu) {
174 rc = topology_add_dev(cpu);
178 hotcpu_notifier(topology_cpu_callback, 0);
183 device_initcall(topology_sysfs_init);