sysdev: Pass attribute in sysdev_class attributes show/store
[linux-2.6.git] / drivers / base / cpu.c
1 /*
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>
8 #include <linux/sched.h>
9 #include <linux/cpu.h>
10 #include <linux/topology.h>
11 #include <linux/device.h>
12 #include <linux/node.h>
13
14 #include "base.h"
15
16 struct sysdev_class cpu_sysdev_class = {
17         .name = "cpu",
18 };
19 EXPORT_SYMBOL(cpu_sysdev_class);
20
21 static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices);
22
23 #ifdef CONFIG_HOTPLUG_CPU
24 static ssize_t show_online(struct sys_device *dev, struct sysdev_attribute *attr,
25                            char *buf)
26 {
27         struct cpu *cpu = container_of(dev, struct cpu, sysdev);
28
29         return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id));
30 }
31
32 static ssize_t __ref store_online(struct sys_device *dev, struct sysdev_attribute *attr,
33                                  const char *buf, size_t count)
34 {
35         struct cpu *cpu = container_of(dev, struct cpu, sysdev);
36         ssize_t ret;
37
38         cpu_hotplug_driver_lock();
39         switch (buf[0]) {
40         case '0':
41                 ret = cpu_down(cpu->sysdev.id);
42                 if (!ret)
43                         kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
44                 break;
45         case '1':
46                 ret = cpu_up(cpu->sysdev.id);
47                 if (!ret)
48                         kobject_uevent(&dev->kobj, KOBJ_ONLINE);
49                 break;
50         default:
51                 ret = -EINVAL;
52         }
53         cpu_hotplug_driver_unlock();
54
55         if (ret >= 0)
56                 ret = count;
57         return ret;
58 }
59 static SYSDEV_ATTR(online, 0644, show_online, store_online);
60
61 static void __cpuinit register_cpu_control(struct cpu *cpu)
62 {
63         sysdev_create_file(&cpu->sysdev, &attr_online);
64 }
65 void unregister_cpu(struct cpu *cpu)
66 {
67         int logical_cpu = cpu->sysdev.id;
68
69         unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
70
71         sysdev_remove_file(&cpu->sysdev, &attr_online);
72
73         sysdev_unregister(&cpu->sysdev);
74         per_cpu(cpu_sys_devices, logical_cpu) = NULL;
75         return;
76 }
77
78 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
79 static ssize_t cpu_probe_store(struct class *class, const char *buf,
80                                size_t count)
81 {
82         return arch_cpu_probe(buf, count);
83 }
84
85 static ssize_t cpu_release_store(struct class *class, const char *buf,
86                                  size_t count)
87 {
88         return arch_cpu_release(buf, count);
89 }
90
91 static CLASS_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
92 static CLASS_ATTR(release, S_IWUSR, NULL, cpu_release_store);
93
94 int __init cpu_probe_release_init(void)
95 {
96         int rc;
97
98         rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
99                                &class_attr_probe.attr);
100         if (!rc)
101                 rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
102                                        &class_attr_release.attr);
103
104         return rc;
105 }
106 device_initcall(cpu_probe_release_init);
107 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
108
109 #else /* ... !CONFIG_HOTPLUG_CPU */
110 static inline void register_cpu_control(struct cpu *cpu)
111 {
112 }
113 #endif /* CONFIG_HOTPLUG_CPU */
114
115 #ifdef CONFIG_KEXEC
116 #include <linux/kexec.h>
117
118 static ssize_t show_crash_notes(struct sys_device *dev, struct sysdev_attribute *attr,
119                                 char *buf)
120 {
121         struct cpu *cpu = container_of(dev, struct cpu, sysdev);
122         ssize_t rc;
123         unsigned long long addr;
124         int cpunum;
125
126         cpunum = cpu->sysdev.id;
127
128         /*
129          * Might be reading other cpu's data based on which cpu read thread
130          * has been scheduled. But cpu data (memory) is allocated once during
131          * boot up and this data does not change there after. Hence this
132          * operation should be safe. No locking required.
133          */
134         addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
135         rc = sprintf(buf, "%Lx\n", addr);
136         return rc;
137 }
138 static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
139 #endif
140
141 /*
142  * Print cpu online, possible, present, and system maps
143  */
144 static ssize_t print_cpus_map(char *buf, const struct cpumask *map)
145 {
146         int n = cpulist_scnprintf(buf, PAGE_SIZE-2, map);
147
148         buf[n++] = '\n';
149         buf[n] = '\0';
150         return n;
151 }
152
153 #define print_cpus_func(type) \
154 static ssize_t print_cpus_##type(struct sysdev_class *class,            \
155                         struct sysdev_class_attribute *attr, char *buf) \
156 {                                                                       \
157         return print_cpus_map(buf, cpu_##type##_mask);                  \
158 }                                                                       \
159 static struct sysdev_class_attribute attr_##type##_map =                \
160         _SYSDEV_CLASS_ATTR(type, 0444, print_cpus_##type, NULL)
161
162 print_cpus_func(online);
163 print_cpus_func(possible);
164 print_cpus_func(present);
165
166 /*
167  * Print values for NR_CPUS and offlined cpus
168  */
169 static ssize_t print_cpus_kernel_max(struct sysdev_class *class,
170                                      struct sysdev_class_attribute *attr, char *buf)
171 {
172         int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
173         return n;
174 }
175 static SYSDEV_CLASS_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
176
177 /* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
178 unsigned int total_cpus;
179
180 static ssize_t print_cpus_offline(struct sysdev_class *class,
181                                   struct sysdev_class_attribute *attr, char *buf)
182 {
183         int n = 0, len = PAGE_SIZE-2;
184         cpumask_var_t offline;
185
186         /* display offline cpus < nr_cpu_ids */
187         if (!alloc_cpumask_var(&offline, GFP_KERNEL))
188                 return -ENOMEM;
189         cpumask_complement(offline, cpu_online_mask);
190         n = cpulist_scnprintf(buf, len, offline);
191         free_cpumask_var(offline);
192
193         /* display offline cpus >= nr_cpu_ids */
194         if (total_cpus && nr_cpu_ids < total_cpus) {
195                 if (n && n < len)
196                         buf[n++] = ',';
197
198                 if (nr_cpu_ids == total_cpus-1)
199                         n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids);
200                 else
201                         n += snprintf(&buf[n], len - n, "%d-%d",
202                                                       nr_cpu_ids, total_cpus-1);
203         }
204
205         n += snprintf(&buf[n], len - n, "\n");
206         return n;
207 }
208 static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL);
209
210 static struct sysdev_class_attribute *cpu_state_attr[] = {
211         &attr_online_map,
212         &attr_possible_map,
213         &attr_present_map,
214         &attr_kernel_max,
215         &attr_offline,
216 };
217
218 static int cpu_states_init(void)
219 {
220         int i;
221         int err = 0;
222
223         for (i = 0;  i < ARRAY_SIZE(cpu_state_attr); i++) {
224                 int ret;
225                 ret = sysdev_class_create_file(&cpu_sysdev_class,
226                                                 cpu_state_attr[i]);
227                 if (!err)
228                         err = ret;
229         }
230         return err;
231 }
232
233 /*
234  * register_cpu - Setup a sysfs device for a CPU.
235  * @cpu - cpu->hotpluggable field set to 1 will generate a control file in
236  *        sysfs for this CPU.
237  * @num - CPU number to use when creating the device.
238  *
239  * Initialize and register the CPU device.
240  */
241 int __cpuinit register_cpu(struct cpu *cpu, int num)
242 {
243         int error;
244         cpu->node_id = cpu_to_node(num);
245         cpu->sysdev.id = num;
246         cpu->sysdev.cls = &cpu_sysdev_class;
247
248         error = sysdev_register(&cpu->sysdev);
249
250         if (!error && cpu->hotpluggable)
251                 register_cpu_control(cpu);
252         if (!error)
253                 per_cpu(cpu_sys_devices, num) = &cpu->sysdev;
254         if (!error)
255                 register_cpu_under_node(num, cpu_to_node(num));
256
257 #ifdef CONFIG_KEXEC
258         if (!error)
259                 error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes);
260 #endif
261         return error;
262 }
263
264 struct sys_device *get_cpu_sysdev(unsigned cpu)
265 {
266         if (cpu < nr_cpu_ids && cpu_possible(cpu))
267                 return per_cpu(cpu_sys_devices, cpu);
268         else
269                 return NULL;
270 }
271 EXPORT_SYMBOL_GPL(get_cpu_sysdev);
272
273 int __init cpu_dev_init(void)
274 {
275         int err;
276
277         err = sysdev_class_register(&cpu_sysdev_class);
278         if (!err)
279                 err = cpu_states_init();
280
281 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
282         if (!err)
283                 err = sched_create_sysfs_power_savings_entries(&cpu_sysdev_class);
284 #endif
285
286         return err;
287 }