Merge branch 'drm-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied...
[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 static cpumask_t topology_dev_map = CPU_MASK_NONE;
98
99 /* Add/Remove cpu_topology interface for CPU device */
100 static int __cpuinit topology_add_dev(unsigned int cpu)
101 {
102         int rc;
103         struct sys_device *sys_dev = get_cpu_sysdev(cpu);
104
105         rc = sysfs_create_group(&sys_dev->kobj, &topology_attr_group);
106         if (!rc)
107                 cpu_set(cpu, topology_dev_map);
108         return rc;
109 }
110
111 static void __cpuinit topology_remove_dev(unsigned int cpu)
112 {
113         struct sys_device *sys_dev = get_cpu_sysdev(cpu);
114
115         if (!cpu_isset(cpu, topology_dev_map))
116                 return;
117         cpu_clear(cpu, topology_dev_map);
118         sysfs_remove_group(&sys_dev->kobj, &topology_attr_group);
119 }
120
121 static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
122                                            unsigned long action, void *hcpu)
123 {
124         unsigned int cpu = (unsigned long)hcpu;
125         int rc = 0;
126
127         switch (action) {
128         case CPU_UP_PREPARE:
129                 rc = topology_add_dev(cpu);
130                 break;
131         case CPU_UP_CANCELED:
132         case CPU_DEAD:
133                 topology_remove_dev(cpu);
134                 break;
135         }
136         return rc ? NOTIFY_BAD : NOTIFY_OK;
137 }
138
139 static int __cpuinit topology_sysfs_init(void)
140 {
141         int cpu;
142         int rc;
143
144         for_each_online_cpu(cpu) {
145                 rc = topology_add_dev(cpu);
146                 if (rc)
147                         return rc;
148         }
149         hotcpu_notifier(topology_cpu_callback, 0);
150
151         return 0;
152 }
153
154 device_initcall(topology_sysfs_init);