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/topology.h>
33 #define define_one_ro(_name) \
34 static SYSDEV_ATTR(_name, 0444, show_##_name, NULL)
36 #define define_id_show_func(name) \
37 static ssize_t show_##name(struct sys_device *dev, char *buf) \
39 unsigned int cpu = dev->id; \
40 return sprintf(buf, "%d\n", topology_##name(cpu)); \
43 static ssize_t show_cpumap(int type, cpumask_t *mask, char *buf)
45 ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
50 cpulist_scnprintf(buf, len-2, *mask):
51 cpumask_scnprintf(buf, len-2, *mask);
58 #define define_siblings_show_map(name) \
59 static inline ssize_t show_##name(struct sys_device *dev, char *buf) \
61 unsigned int cpu = dev->id; \
62 return show_cpumap(0, &(topology_##name(cpu)), buf); \
65 #define define_siblings_show_list(name) \
66 static inline ssize_t show_##name##_list(struct sys_device *dev, char *buf) \
68 unsigned int cpu = dev->id; \
69 return show_cpumap(1, &(topology_##name(cpu)), buf); \
72 #define define_siblings_show_func(name) \
73 define_siblings_show_map(name); define_siblings_show_list(name)
75 define_id_show_func(physical_package_id);
76 define_one_ro(physical_package_id);
78 define_id_show_func(core_id);
79 define_one_ro(core_id);
81 define_siblings_show_func(thread_siblings);
82 define_one_ro(thread_siblings);
83 define_one_ro(thread_siblings_list);
85 define_siblings_show_func(core_siblings);
86 define_one_ro(core_siblings);
87 define_one_ro(core_siblings_list);
89 static struct attribute *default_attrs[] = {
90 &attr_physical_package_id.attr,
92 &attr_thread_siblings.attr,
93 &attr_thread_siblings_list.attr,
94 &attr_core_siblings.attr,
95 &attr_core_siblings_list.attr,
99 static struct attribute_group topology_attr_group = {
100 .attrs = default_attrs,
104 /* Add/Remove cpu_topology interface for CPU device */
105 static int __cpuinit topology_add_dev(unsigned int cpu)
107 struct sys_device *sys_dev = get_cpu_sysdev(cpu);
109 return sysfs_create_group(&sys_dev->kobj, &topology_attr_group);
112 static void __cpuinit topology_remove_dev(unsigned int cpu)
114 struct sys_device *sys_dev = get_cpu_sysdev(cpu);
116 sysfs_remove_group(&sys_dev->kobj, &topology_attr_group);
119 static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
120 unsigned long action, void *hcpu)
122 unsigned int cpu = (unsigned long)hcpu;
127 case CPU_UP_PREPARE_FROZEN:
128 rc = topology_add_dev(cpu);
130 case CPU_UP_CANCELED:
131 case CPU_UP_CANCELED_FROZEN:
133 case CPU_DEAD_FROZEN:
134 topology_remove_dev(cpu);
137 return rc ? NOTIFY_BAD : NOTIFY_OK;
140 static int __cpuinit topology_sysfs_init(void)
145 for_each_online_cpu(cpu) {
146 rc = topology_add_dev(cpu);
150 hotcpu_notifier(topology_cpu_callback, 0);
155 device_initcall(topology_sysfs_init);