Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
[linux-2.6] / drivers / base / topology.c
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/sysdev.h>
27 #include <linux/init.h>
28 #include <linux/mm.h>
29 #include <linux/cpu.h>
30 #include <linux/module.h>
31 #include <linux/topology.h>
32
33 #define define_one_ro(_name)            \
34 static SYSDEV_ATTR(_name, 0444, show_##_name, NULL)
35
36 #define define_id_show_func(name)                               \
37 static ssize_t show_##name(struct sys_device *dev, char *buf)   \
38 {                                                               \
39         unsigned int cpu = dev->id;                             \
40         return sprintf(buf, "%d\n", topology_##name(cpu));      \
41 }
42
43 #define define_siblings_show_func(name)                                 \
44 static ssize_t show_##name(struct sys_device *dev, char *buf)           \
45 {                                                                       \
46         ssize_t len = -1;                                               \
47         unsigned int cpu = dev->id;                                     \
48         len = cpumask_scnprintf(buf, NR_CPUS+1, topology_##name(cpu));  \
49         return (len + sprintf(buf + len, "\n"));                        \
50 }
51
52 #ifdef  topology_physical_package_id
53 define_id_show_func(physical_package_id);
54 define_one_ro(physical_package_id);
55 #define ref_physical_package_id_attr    &attr_physical_package_id.attr,
56 #else
57 #define ref_physical_package_id_attr
58 #endif
59
60 #ifdef topology_core_id
61 define_id_show_func(core_id);
62 define_one_ro(core_id);
63 #define ref_core_id_attr                &attr_core_id.attr,
64 #else
65 #define ref_core_id_attr
66 #endif
67
68 #ifdef topology_thread_siblings
69 define_siblings_show_func(thread_siblings);
70 define_one_ro(thread_siblings);
71 #define ref_thread_siblings_attr        &attr_thread_siblings.attr,
72 #else
73 #define ref_thread_siblings_attr
74 #endif
75
76 #ifdef topology_core_siblings
77 define_siblings_show_func(core_siblings);
78 define_one_ro(core_siblings);
79 #define ref_core_siblings_attr          &attr_core_siblings.attr,
80 #else
81 #define ref_core_siblings_attr
82 #endif
83
84 static struct attribute *default_attrs[] = {
85         ref_physical_package_id_attr
86         ref_core_id_attr
87         ref_thread_siblings_attr
88         ref_core_siblings_attr
89         NULL
90 };
91
92 static struct attribute_group topology_attr_group = {
93         .attrs = default_attrs,
94         .name = "topology"
95 };
96
97 /* Add/Remove cpu_topology interface for CPU device */
98 static int __cpuinit topology_add_dev(struct sys_device * sys_dev)
99 {
100         sysfs_create_group(&sys_dev->kobj, &topology_attr_group);
101         return 0;
102 }
103
104 static int __cpuinit topology_remove_dev(struct sys_device * sys_dev)
105 {
106         sysfs_remove_group(&sys_dev->kobj, &topology_attr_group);
107         return 0;
108 }
109
110 static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
111                 unsigned long action, void *hcpu)
112 {
113         unsigned int cpu = (unsigned long)hcpu;
114         struct sys_device *sys_dev;
115
116         sys_dev = get_cpu_sysdev(cpu);
117         switch (action) {
118         case CPU_ONLINE:
119                 topology_add_dev(sys_dev);
120                 break;
121         case CPU_DEAD:
122                 topology_remove_dev(sys_dev);
123                 break;
124         }
125         return NOTIFY_OK;
126 }
127
128 static struct notifier_block __cpuinitdata topology_cpu_notifier =
129 {
130         .notifier_call = topology_cpu_callback,
131 };
132
133 static int __cpuinit topology_sysfs_init(void)
134 {
135         int i;
136
137         for_each_online_cpu(i) {
138                 topology_cpu_callback(&topology_cpu_notifier, CPU_ONLINE,
139                                 (void *)(long)i);
140         }
141
142         register_hotcpu_notifier(&topology_cpu_notifier);
143
144         return 0;
145 }
146
147 device_initcall(topology_sysfs_init);
148