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, 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) \
44static 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
53define_id_show_func(physical_package_id);
54define_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
61define_id_show_func(core_id);
62define_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
69define_siblings_show_func(thread_siblings);
70define_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
77define_siblings_show_func(core_siblings);
78define_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
84static 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
92static struct attribute_group topology_attr_group = {
93 .attrs = default_attrs,
94 .name = "topology"
95};
96
97static cpumask_t topology_dev_map = CPU_MASK_NONE;
98
99/* Add/Remove cpu_topology interface for CPU device */
100static 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
111static 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
121static 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 case CPU_UP_PREPARE_FROZEN:
130 rc = topology_add_dev(cpu);
131 break;
132 case CPU_UP_CANCELED:
133 case CPU_UP_CANCELED_FROZEN:
134 case CPU_DEAD:
135 case CPU_DEAD_FROZEN:
136 topology_remove_dev(cpu);
137 break;
138 }
139 return rc ? NOTIFY_BAD : NOTIFY_OK;
140}
141
142static int __cpuinit topology_sysfs_init(void)
143{
144 int cpu;
145 int rc;
146
147 for_each_online_cpu(cpu) {
148 rc = topology_add_dev(cpu);
149 if (rc)
150 return rc;
151 }
152 hotcpu_notifier(topology_cpu_callback, 0);
153
154 return 0;
155}
156
157device_initcall(topology_sysfs_init);