blob: 7036e8e96ab89080231f3287f52cac1e801e6d0b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * drivers/base/cpu.c - basic CPU class support
3 */
4
5#include <linux/sysdev.h>
6#include <linux/module.h>
7#include <linux/init.h>
Al Virof6a57032006-10-18 01:47:25 -04008#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#include <linux/cpu.h>
10#include <linux/topology.h>
11#include <linux/device.h>
KAMEZAWA Hiroyuki76b67ed2006-06-27 02:53:41 -070012#include <linux/node.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013
Ben Dooksa1bdc7a2005-10-13 17:54:41 +010014#include "base.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070015
Andi Kleene1a7e292010-01-05 12:48:03 +010016static struct sysdev_class_attribute *cpu_sysdev_class_attrs[];
17
Linus Torvalds1da177e2005-04-16 15:20:36 -070018struct sysdev_class cpu_sysdev_class = {
Kay Sieversaf5ca3f2007-12-20 02:09:39 +010019 .name = "cpu",
Andi Kleene1a7e292010-01-05 12:48:03 +010020 .attrs = cpu_sysdev_class_attrs,
Linus Torvalds1da177e2005-04-16 15:20:36 -070021};
22EXPORT_SYMBOL(cpu_sysdev_class);
23
Mike Travise37d05d2008-05-01 04:35:16 -070024static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices);
Ashok Rajad745572005-10-30 14:59:49 -080025
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#ifdef CONFIG_HOTPLUG_CPU
Andi Kleen4a0b2b42008-07-01 18:48:41 +020027static ssize_t show_online(struct sys_device *dev, struct sysdev_attribute *attr,
28 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070029{
30 struct cpu *cpu = container_of(dev, struct cpu, sysdev);
31
32 return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id));
33}
34
Andi Kleen4a0b2b42008-07-01 18:48:41 +020035static ssize_t __ref store_online(struct sys_device *dev, struct sysdev_attribute *attr,
36 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -070037{
38 struct cpu *cpu = container_of(dev, struct cpu, sysdev);
39 ssize_t ret;
40
Gautham R Shenoy51badeb2009-11-26 09:59:05 +000041 cpu_hotplug_driver_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 switch (buf[0]) {
43 case '0':
44 ret = cpu_down(cpu->sysdev.id);
45 if (!ret)
Kay Sievers312c0042005-11-16 09:00:00 +010046 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 break;
48 case '1':
Ashok Raj34f361a2006-03-25 03:08:18 -080049 ret = cpu_up(cpu->sysdev.id);
Nathan Lynchfb69c392005-06-25 14:55:05 -070050 if (!ret)
Kay Sievers312c0042005-11-16 09:00:00 +010051 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 break;
53 default:
54 ret = -EINVAL;
55 }
Gautham R Shenoy51badeb2009-11-26 09:59:05 +000056 cpu_hotplug_driver_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58 if (ret >= 0)
59 ret = count;
60 return ret;
61}
Ulrich Drepper9eb3ff42007-07-31 00:38:16 -070062static SYSDEV_ATTR(online, 0644, show_online, store_online);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Sam Ravnborg6c847402008-03-04 15:09:05 -080064static void __cpuinit register_cpu_control(struct cpu *cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -070065{
66 sysdev_create_file(&cpu->sysdev, &attr_online);
67}
KAMEZAWA Hiroyuki76b67ed2006-06-27 02:53:41 -070068void unregister_cpu(struct cpu *cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -070069{
Ashok Rajad745572005-10-30 14:59:49 -080070 int logical_cpu = cpu->sysdev.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
KAMEZAWA Hiroyuki76b67ed2006-06-27 02:53:41 -070072 unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
73
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 sysdev_remove_file(&cpu->sysdev, &attr_online);
75
76 sysdev_unregister(&cpu->sysdev);
Mike Travise37d05d2008-05-01 04:35:16 -070077 per_cpu(cpu_sys_devices, logical_cpu) = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 return;
79}
Nathan Fontenot12633e82009-11-25 17:23:25 +000080
81#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
Greg Kroah-Hartman6c1733a2010-01-21 15:07:59 -080082static ssize_t cpu_probe_store(struct sys_device *dev,
83 struct sysdev_attribute *attr,
Andi Kleen28812fe2010-01-05 12:48:07 +010084 const char *buf,
Nathan Fontenot12633e82009-11-25 17:23:25 +000085 size_t count)
86{
87 return arch_cpu_probe(buf, count);
88}
89
Greg Kroah-Hartman6c1733a2010-01-21 15:07:59 -080090static ssize_t cpu_release_store(struct sys_device *dev,
91 struct sysdev_attribute *attr,
Andi Kleen28812fe2010-01-05 12:48:07 +010092 const char *buf,
Nathan Fontenot12633e82009-11-25 17:23:25 +000093 size_t count)
94{
95 return arch_cpu_release(buf, count);
96}
97
Greg Kroah-Hartman6c1733a2010-01-21 15:07:59 -080098static SYSDEV_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
99static SYSDEV_ATTR(release, S_IWUSR, NULL, cpu_release_store);
Nathan Fontenot12633e82009-11-25 17:23:25 +0000100#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
101
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102#else /* ... !CONFIG_HOTPLUG_CPU */
103static inline void register_cpu_control(struct cpu *cpu)
104{
105}
106#endif /* CONFIG_HOTPLUG_CPU */
107
Vivek Goyal51be5602006-01-09 20:51:42 -0800108#ifdef CONFIG_KEXEC
109#include <linux/kexec.h>
110
Andi Kleen4a0b2b42008-07-01 18:48:41 +0200111static ssize_t show_crash_notes(struct sys_device *dev, struct sysdev_attribute *attr,
112 char *buf)
Vivek Goyal51be5602006-01-09 20:51:42 -0800113{
114 struct cpu *cpu = container_of(dev, struct cpu, sysdev);
115 ssize_t rc;
116 unsigned long long addr;
117 int cpunum;
118
119 cpunum = cpu->sysdev.id;
120
121 /*
122 * Might be reading other cpu's data based on which cpu read thread
123 * has been scheduled. But cpu data (memory) is allocated once during
124 * boot up and this data does not change there after. Hence this
125 * operation should be safe. No locking required.
126 */
Vivek Goyal3b034b02009-11-24 15:50:03 +0900127 addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
Vivek Goyal51be5602006-01-09 20:51:42 -0800128 rc = sprintf(buf, "%Lx\n", addr);
Vivek Goyal51be5602006-01-09 20:51:42 -0800129 return rc;
130}
131static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
132#endif
133
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134/*
Mike Travis9d1fe3232008-04-08 11:43:04 -0700135 * Print cpu online, possible, present, and system maps
136 */
Andi Kleen265d2e22010-01-05 12:48:00 +0100137
138struct cpu_attr {
139 struct sysdev_class_attribute attr;
140 const struct cpumask *const * const map;
141};
142
143static ssize_t show_cpus_attr(struct sysdev_class *class,
144 struct sysdev_class_attribute *attr,
145 char *buf)
Mike Travis9d1fe3232008-04-08 11:43:04 -0700146{
Andi Kleen265d2e22010-01-05 12:48:00 +0100147 struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr);
148 int n = cpulist_scnprintf(buf, PAGE_SIZE-2, *(ca->map));
Mike Travis9d1fe3232008-04-08 11:43:04 -0700149
150 buf[n++] = '\n';
151 buf[n] = '\0';
152 return n;
153}
154
Andi Kleen265d2e22010-01-05 12:48:00 +0100155#define _CPU_ATTR(name, map) \
156 { _SYSDEV_CLASS_ATTR(name, 0444, show_cpus_attr, NULL), map }
Mike Travis9d1fe3232008-04-08 11:43:04 -0700157
Andi Kleene1a7e292010-01-05 12:48:03 +0100158/* Keep in sync with cpu_sysdev_class_attrs */
Andi Kleen265d2e22010-01-05 12:48:00 +0100159static struct cpu_attr cpu_attrs[] = {
160 _CPU_ATTR(online, &cpu_online_mask),
161 _CPU_ATTR(possible, &cpu_possible_mask),
162 _CPU_ATTR(present, &cpu_present_mask),
163};
Mike Travis9d1fe3232008-04-08 11:43:04 -0700164
Mike Travise057d7a2008-12-15 20:26:48 -0800165/*
166 * Print values for NR_CPUS and offlined cpus
167 */
Andi Kleenc9be0a32010-01-05 12:47:58 +0100168static ssize_t print_cpus_kernel_max(struct sysdev_class *class,
169 struct sysdev_class_attribute *attr, char *buf)
Mike Travise057d7a2008-12-15 20:26:48 -0800170{
Mike Travis8fd2d2d2008-12-31 18:08:48 -0800171 int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
Mike Travise057d7a2008-12-15 20:26:48 -0800172 return n;
173}
174static SYSDEV_CLASS_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
175
176/* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
177unsigned int total_cpus;
178
Andi Kleenc9be0a32010-01-05 12:47:58 +0100179static ssize_t print_cpus_offline(struct sysdev_class *class,
180 struct sysdev_class_attribute *attr, char *buf)
Mike Travise057d7a2008-12-15 20:26:48 -0800181{
182 int n = 0, len = PAGE_SIZE-2;
183 cpumask_var_t offline;
184
185 /* display offline cpus < nr_cpu_ids */
186 if (!alloc_cpumask_var(&offline, GFP_KERNEL))
187 return -ENOMEM;
188 cpumask_complement(offline, cpu_online_mask);
189 n = cpulist_scnprintf(buf, len, offline);
190 free_cpumask_var(offline);
191
192 /* display offline cpus >= nr_cpu_ids */
193 if (total_cpus && nr_cpu_ids < total_cpus) {
194 if (n && n < len)
195 buf[n++] = ',';
196
197 if (nr_cpu_ids == total_cpus-1)
198 n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids);
199 else
200 n += snprintf(&buf[n], len - n, "%d-%d",
201 nr_cpu_ids, total_cpus-1);
202 }
203
204 n += snprintf(&buf[n], len - n, "\n");
205 return n;
206}
207static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL);
208
Mike Travis9d1fe3232008-04-08 11:43:04 -0700209/*
Robert P. J. Day405ae7d2007-02-17 19:13:42 +0100210 * register_cpu - Setup a sysfs device for a CPU.
Siddha, Suresh B72486f12006-12-07 02:14:10 +0100211 * @cpu - cpu->hotpluggable field set to 1 will generate a control file in
212 * sysfs for this CPU.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 * @num - CPU number to use when creating the device.
214 *
215 * Initialize and register the CPU device.
216 */
Randy Dunlap33b5f312008-02-06 01:36:28 -0800217int __cpuinit register_cpu(struct cpu *cpu, int num)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218{
219 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 cpu->node_id = cpu_to_node(num);
221 cpu->sysdev.id = num;
222 cpu->sysdev.cls = &cpu_sysdev_class;
223
224 error = sysdev_register(&cpu->sysdev);
KAMEZAWA Hiroyuki76b67ed2006-06-27 02:53:41 -0700225
Siddha, Suresh B72486f12006-12-07 02:14:10 +0100226 if (!error && cpu->hotpluggable)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 register_cpu_control(cpu);
Ashok Rajad745572005-10-30 14:59:49 -0800228 if (!error)
Mike Travise37d05d2008-05-01 04:35:16 -0700229 per_cpu(cpu_sys_devices, num) = &cpu->sysdev;
KAMEZAWA Hiroyuki76b67ed2006-06-27 02:53:41 -0700230 if (!error)
231 register_cpu_under_node(num, cpu_to_node(num));
Vivek Goyal51be5602006-01-09 20:51:42 -0800232
233#ifdef CONFIG_KEXEC
234 if (!error)
235 error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes);
236#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 return error;
238}
239
Andrew Mortona29d6422006-03-07 23:53:25 -0800240struct sys_device *get_cpu_sysdev(unsigned cpu)
Ashok Rajad745572005-10-30 14:59:49 -0800241{
Mike Travise37d05d2008-05-01 04:35:16 -0700242 if (cpu < nr_cpu_ids && cpu_possible(cpu))
243 return per_cpu(cpu_sys_devices, cpu);
Ashok Rajad745572005-10-30 14:59:49 -0800244 else
245 return NULL;
246}
247EXPORT_SYMBOL_GPL(get_cpu_sysdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
249int __init cpu_dev_init(void)
250{
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -0700251 int err;
252
253 err = sysdev_class_register(&cpu_sysdev_class);
254#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
255 if (!err)
256 err = sched_create_sysfs_power_savings_entries(&cpu_sysdev_class);
257#endif
258
259 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260}
Andi Kleene1a7e292010-01-05 12:48:03 +0100261
262static struct sysdev_class_attribute *cpu_sysdev_class_attrs[] = {
263#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
Greg Kroah-Hartman6c1733a2010-01-21 15:07:59 -0800264 &attr_probe,
265 &attr_release,
Andi Kleene1a7e292010-01-05 12:48:03 +0100266#endif
267 &cpu_attrs[0].attr,
268 &cpu_attrs[1].attr,
269 &cpu_attrs[2].attr,
270 &attr_kernel_max,
271 &attr_offline,
272 NULL
273};