tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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) \
34static SYSDEV_ATTR(_name, 0444, show_##_name, NULL)
35
36#define define_id_show_func(name) \
37static ssize_t show_##name(struct sys_device *dev, \
38 struct sysdev_attribute *attr, char *buf) \
39{ \
40 unsigned int cpu = dev->id; \
41 return sprintf(buf, "%d\n", topology_##name(cpu)); \
42}
43
44#if defined(topology_thread_siblings) || defined(topology_core_siblings)
45static ssize_t show_cpumap(int type, cpumask_t *mask, char *buf)
46{
47 ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
48 int n = 0;
49
50 if (len > 1) {
51 n = type?
52 cpulist_scnprintf(buf, len-2, *mask):
53 cpumask_scnprintf(buf, len-2, *mask);
54 buf[n++] = '\n';
55 buf[n] = '\0';
56 }
57 return n;
58}
59#endif
60
61#ifdef arch_provides_topology_pointers
62#define define_siblings_show_map(name) \
63static ssize_t show_##name(struct sys_device *dev, \
64 struct sysdev_attribute *attr, char *buf) \
65{ \
66 unsigned int cpu = dev->id; \
67 return show_cpumap(0, &(topology_##name(cpu)), buf); \
68}
69
70#define define_siblings_show_list(name) \
71static ssize_t show_##name##_list(struct sys_device *dev, \
72 struct sysdev_attribute *attr, \
73 char *buf) \
74{ \
75 unsigned int cpu = dev->id; \
76 return show_cpumap(1, &(topology_##name(cpu)), buf); \
77}
78
79#else
80#define define_siblings_show_map(name) \
81static ssize_t show_##name(struct sys_device *dev, \
82 struct sysdev_attribute *attr, char *buf) \
83{ \
84 unsigned int cpu = dev->id; \
85 cpumask_t mask = topology_##name(cpu); \
86 return show_cpumap(0, &mask, buf); \
87}
88
89#define define_siblings_show_list(name) \
90static ssize_t show_##name##_list(struct sys_device *dev, \
91 struct sysdev_attribute *attr, \
92 char *buf) \
93{ \
94 unsigned int cpu = dev->id; \
95 cpumask_t mask = topology_##name(cpu); \
96 return show_cpumap(1, &mask, buf); \
97}
98#endif
99
100#define define_siblings_show_func(name) \
101 define_siblings_show_map(name); define_siblings_show_list(name)
102
103define_id_show_func(physical_package_id);
104define_one_ro(physical_package_id);
105
106define_id_show_func(core_id);
107define_one_ro(core_id);
108
109define_siblings_show_func(thread_siblings);
110define_one_ro(thread_siblings);
111define_one_ro(thread_siblings_list);
112
113define_siblings_show_func(core_siblings);
114define_one_ro(core_siblings);
115define_one_ro(core_siblings_list);
116
117static struct attribute *default_attrs[] = {
118 &attr_physical_package_id.attr,
119 &attr_core_id.attr,
120 &attr_thread_siblings.attr,
121 &attr_thread_siblings_list.attr,
122 &attr_core_siblings.attr,
123 &attr_core_siblings_list.attr,
124 NULL
125};
126
127static struct attribute_group topology_attr_group = {
128 .attrs = default_attrs,
129 .name = "topology"
130};
131
132/* Add/Remove cpu_topology interface for CPU device */
133static int __cpuinit topology_add_dev(unsigned int cpu)
134{
135 struct sys_device *sys_dev = get_cpu_sysdev(cpu);
136
137 return sysfs_create_group(&sys_dev->kobj, &topology_attr_group);
138}
139
140static void __cpuinit topology_remove_dev(unsigned int cpu)
141{
142 struct sys_device *sys_dev = get_cpu_sysdev(cpu);
143
144 sysfs_remove_group(&sys_dev->kobj, &topology_attr_group);
145}
146
147static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
148 unsigned long action, void *hcpu)
149{
150 unsigned int cpu = (unsigned long)hcpu;
151 int rc = 0;
152
153 switch (action) {
154 case CPU_UP_PREPARE:
155 case CPU_UP_PREPARE_FROZEN:
156 rc = topology_add_dev(cpu);
157 break;
158 case CPU_UP_CANCELED:
159 case CPU_UP_CANCELED_FROZEN:
160 case CPU_DEAD:
161 case CPU_DEAD_FROZEN:
162 topology_remove_dev(cpu);
163 break;
164 }
165 return rc ? NOTIFY_BAD : NOTIFY_OK;
166}
167
168static int __cpuinit topology_sysfs_init(void)
169{
170 int cpu;
171 int rc;
172
173 for_each_online_cpu(cpu) {
174 rc = topology_add_dev(cpu);
175 if (rc)
176 return rc;
177 }
178 hotcpu_notifier(topology_cpu_callback, 0);
179
180 return 0;
181}
182
183device_initcall(topology_sysfs_init);