Merge branch 'core/topology' of git://git.kernel.org/pub/scm/linux/kernel/git/tip...
[sfrench/cifs-2.6.git] / 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 #if defined(topology_thread_siblings) || defined(topology_core_siblings)
44 static ssize_t show_cpumap(int type, cpumask_t *mask, char *buf)
45 {
46         ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
47         int n = 0;
48
49         if (len > 1) {
50                 n = type?
51                         cpulist_scnprintf(buf, len-2, *mask):
52                         cpumask_scnprintf(buf, len-2, *mask);
53                 buf[n++] = '\n';
54                 buf[n] = '\0';
55         }
56         return n;
57 }
58 #endif
59
60 #ifdef arch_provides_topology_pointers
61 #define define_siblings_show_map(name)                                  \
62 static ssize_t show_##name(struct sys_device *dev, char *buf)   \
63 {                                                                       \
64         unsigned int cpu = dev->id;                                     \
65         return show_cpumap(0, &(topology_##name(cpu)), buf);            \
66 }
67
68 #define define_siblings_show_list(name)                                 \
69 static ssize_t show_##name##_list(struct sys_device *dev, char *buf) \
70 {                                                                       \
71         unsigned int cpu = dev->id;                                     \
72         return show_cpumap(1, &(topology_##name(cpu)), buf);            \
73 }
74
75 #else
76 #define define_siblings_show_map(name)                                  \
77 static ssize_t show_##name(struct sys_device *dev, char *buf)   \
78 {                                                                       \
79         unsigned int cpu = dev->id;                                     \
80         cpumask_t mask = topology_##name(cpu);                          \
81         return show_cpumap(0, &mask, buf);                              \
82 }
83
84 #define define_siblings_show_list(name)                                 \
85 static ssize_t show_##name##_list(struct sys_device *dev, char *buf) \
86 {                                                                       \
87         unsigned int cpu = dev->id;                                     \
88         cpumask_t mask = topology_##name(cpu);                          \
89         return show_cpumap(1, &mask, buf);                              \
90 }
91 #endif
92
93 #define define_siblings_show_func(name)         \
94         define_siblings_show_map(name); define_siblings_show_list(name)
95
96 define_id_show_func(physical_package_id);
97 define_one_ro(physical_package_id);
98
99 define_id_show_func(core_id);
100 define_one_ro(core_id);
101
102 define_siblings_show_func(thread_siblings);
103 define_one_ro(thread_siblings);
104 define_one_ro(thread_siblings_list);
105
106 define_siblings_show_func(core_siblings);
107 define_one_ro(core_siblings);
108 define_one_ro(core_siblings_list);
109
110 static struct attribute *default_attrs[] = {
111         &attr_physical_package_id.attr,
112         &attr_core_id.attr,
113         &attr_thread_siblings.attr,
114         &attr_thread_siblings_list.attr,
115         &attr_core_siblings.attr,
116         &attr_core_siblings_list.attr,
117         NULL
118 };
119
120 static struct attribute_group topology_attr_group = {
121         .attrs = default_attrs,
122         .name = "topology"
123 };
124
125 /* Add/Remove cpu_topology interface for CPU device */
126 static int __cpuinit topology_add_dev(unsigned int cpu)
127 {
128         struct sys_device *sys_dev = get_cpu_sysdev(cpu);
129
130         return sysfs_create_group(&sys_dev->kobj, &topology_attr_group);
131 }
132
133 static void __cpuinit topology_remove_dev(unsigned int cpu)
134 {
135         struct sys_device *sys_dev = get_cpu_sysdev(cpu);
136
137         sysfs_remove_group(&sys_dev->kobj, &topology_attr_group);
138 }
139
140 static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
141                                            unsigned long action, void *hcpu)
142 {
143         unsigned int cpu = (unsigned long)hcpu;
144         int rc = 0;
145
146         switch (action) {
147         case CPU_UP_PREPARE:
148         case CPU_UP_PREPARE_FROZEN:
149                 rc = topology_add_dev(cpu);
150                 break;
151         case CPU_UP_CANCELED:
152         case CPU_UP_CANCELED_FROZEN:
153         case CPU_DEAD:
154         case CPU_DEAD_FROZEN:
155                 topology_remove_dev(cpu);
156                 break;
157         }
158         return rc ? NOTIFY_BAD : NOTIFY_OK;
159 }
160
161 static int __cpuinit topology_sysfs_init(void)
162 {
163         int cpu;
164         int rc;
165
166         for_each_online_cpu(cpu) {
167                 rc = topology_add_dev(cpu);
168                 if (rc)
169                         return rc;
170         }
171         hotcpu_notifier(topology_cpu_callback, 0);
172
173         return 0;
174 }
175
176 device_initcall(topology_sysfs_init);