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