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/mm.h>
27#include <linux/cpu.h>
28#include <linux/module.h>
29#include <linux/hardirq.h>
30#include <linux/topology.h>
31
32#define define_one_ro_named(_name, _func) \
33 static DEVICE_ATTR(_name, 0444, _func, NULL)
34
35#define define_one_ro(_name) \
36 static DEVICE_ATTR(_name, 0444, show_##_name, NULL)
37
38#define define_id_show_func(name) \
39static ssize_t show_##name(struct device *dev, \
40 struct device_attribute *attr, char *buf) \
41{ \
42 return sprintf(buf, "%d\n", topology_##name(dev->id)); \
43}
44
45#if defined(topology_thread_cpumask) || defined(topology_core_cpumask) || \
46 defined(topology_book_cpumask)
47static ssize_t show_cpumap(int type, const struct cpumask *mask, char *buf)
48{
49 ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
50 int n = 0;
51
52 if (len > 1) {
53 n = type?
54 cpulist_scnprintf(buf, len-2, mask) :
55 cpumask_scnprintf(buf, len-2, mask);
56 buf[n++] = '\n';
57 buf[n] = '\0';
58 }
59 return n;
60}
61#endif
62
63#define define_siblings_show_map(name) \
64static ssize_t show_##name(struct device *dev, \
65 struct device_attribute *attr, char *buf) \
66{ \
67 return show_cpumap(0, topology_##name(dev->id), buf); \
68}
69
70#define define_siblings_show_list(name) \
71static ssize_t show_##name##_list(struct device *dev, \
72 struct device_attribute *attr, \
73 char *buf) \
74{ \
75 return show_cpumap(1, topology_##name(dev->id), buf); \
76}
77
78#define define_siblings_show_func(name) \
79 define_siblings_show_map(name); define_siblings_show_list(name)
80
81define_id_show_func(physical_package_id);
82define_one_ro(physical_package_id);
83
84define_id_show_func(core_id);
85define_one_ro(core_id);
86
87define_siblings_show_func(thread_cpumask);
88define_one_ro_named(thread_siblings, show_thread_cpumask);
89define_one_ro_named(thread_siblings_list, show_thread_cpumask_list);
90
91define_siblings_show_func(core_cpumask);
92define_one_ro_named(core_siblings, show_core_cpumask);
93define_one_ro_named(core_siblings_list, show_core_cpumask_list);
94
95#ifdef CONFIG_SCHED_BOOK
96define_id_show_func(book_id);
97define_one_ro(book_id);
98define_siblings_show_func(book_cpumask);
99define_one_ro_named(book_siblings, show_book_cpumask);
100define_one_ro_named(book_siblings_list, show_book_cpumask_list);
101#endif
102
103static struct attribute *default_attrs[] = {
104 &dev_attr_physical_package_id.attr,
105 &dev_attr_core_id.attr,
106 &dev_attr_thread_siblings.attr,
107 &dev_attr_thread_siblings_list.attr,
108 &dev_attr_core_siblings.attr,
109 &dev_attr_core_siblings_list.attr,
110#ifdef CONFIG_SCHED_BOOK
111 &dev_attr_book_id.attr,
112 &dev_attr_book_siblings.attr,
113 &dev_attr_book_siblings_list.attr,
114#endif
115 NULL
116};
117
118static struct attribute_group topology_attr_group = {
119 .attrs = default_attrs,
120 .name = "topology"
121};
122
123/* Add/Remove cpu_topology interface for CPU device */
124static int topology_add_dev(unsigned int cpu)
125{
126 struct device *dev = get_cpu_device(cpu);
127
128 return sysfs_create_group(&dev->kobj, &topology_attr_group);
129}
130
131static void topology_remove_dev(unsigned int cpu)
132{
133 struct device *dev = get_cpu_device(cpu);
134
135 sysfs_remove_group(&dev->kobj, &topology_attr_group);
136}
137
138static int topology_cpu_callback(struct notifier_block *nfb,
139 unsigned long action, void *hcpu)
140{
141 unsigned int cpu = (unsigned long)hcpu;
142 int rc = 0;
143
144 switch (action) {
145 case CPU_UP_PREPARE:
146 case CPU_UP_PREPARE_FROZEN:
147 rc = topology_add_dev(cpu);
148 break;
149 case CPU_UP_CANCELED:
150 case CPU_UP_CANCELED_FROZEN:
151 case CPU_DEAD:
152 case CPU_DEAD_FROZEN:
153 topology_remove_dev(cpu);
154 break;
155 }
156 return notifier_from_errno(rc);
157}
158
159static int topology_sysfs_init(void)
160{
161 int cpu;
162 int rc = 0;
163
164 cpu_notifier_register_begin();
165
166 for_each_online_cpu(cpu) {
167 rc = topology_add_dev(cpu);
168 if (rc)
169 goto out;
170 }
171 __hotcpu_notifier(topology_cpu_callback, 0);
172
173out:
174 cpu_notifier_register_done();
175 return rc;
176}
177
178device_initcall(topology_sysfs_init);