powerpc: Fix lwsync patching code on 64bit
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / base / cpu.c
blob958bd1540c303d92f84cbcea016c7da4c0ce925c
1 /*
2 * drivers/base/cpu.c - basic CPU class support
3 */
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>
14 #include "base.h"
16 struct sysdev_class cpu_sysdev_class = {
17 .name = "cpu",
19 EXPORT_SYMBOL(cpu_sysdev_class);
21 static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices);
23 #ifdef CONFIG_HOTPLUG_CPU
24 static ssize_t show_online(struct sys_device *dev, struct sysdev_attribute *attr,
25 char *buf)
27 struct cpu *cpu = container_of(dev, struct cpu, sysdev);
29 return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id));
32 static ssize_t __ref store_online(struct sys_device *dev, struct sysdev_attribute *attr,
33 const char *buf, size_t count)
35 struct cpu *cpu = container_of(dev, struct cpu, sysdev);
36 ssize_t ret;
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;
53 cpu_hotplug_driver_unlock();
55 if (ret >= 0)
56 ret = count;
57 return ret;
59 static SYSDEV_ATTR(online, 0644, show_online, store_online);
61 static void __cpuinit register_cpu_control(struct cpu *cpu)
63 sysdev_create_file(&cpu->sysdev, &attr_online);
65 void unregister_cpu(struct cpu *cpu)
67 int logical_cpu = cpu->sysdev.id;
69 unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
71 sysdev_remove_file(&cpu->sysdev, &attr_online);
73 sysdev_unregister(&cpu->sysdev);
74 per_cpu(cpu_sys_devices, logical_cpu) = NULL;
75 return;
78 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
79 static ssize_t cpu_probe_store(struct class *class, const char *buf,
80 size_t count)
82 return arch_cpu_probe(buf, count);
85 static ssize_t cpu_release_store(struct class *class, const char *buf,
86 size_t count)
88 return arch_cpu_release(buf, count);
91 static CLASS_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
92 static CLASS_ATTR(release, S_IWUSR, NULL, cpu_release_store);
94 int __init cpu_probe_release_init(void)
96 int rc;
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);
104 return rc;
106 device_initcall(cpu_probe_release_init);
107 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
109 #else /* ... !CONFIG_HOTPLUG_CPU */
110 static inline void register_cpu_control(struct cpu *cpu)
113 #endif /* CONFIG_HOTPLUG_CPU */
115 #ifdef CONFIG_KEXEC
116 #include <linux/kexec.h>
118 static ssize_t show_crash_notes(struct sys_device *dev, struct sysdev_attribute *attr,
119 char *buf)
121 struct cpu *cpu = container_of(dev, struct cpu, sysdev);
122 ssize_t rc;
123 unsigned long long addr;
124 int cpunum;
126 cpunum = cpu->sysdev.id;
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.
134 addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
135 rc = sprintf(buf, "%Lx\n", addr);
136 return rc;
138 static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
139 #endif
142 * Print cpu online, possible, present, and system maps
144 static ssize_t print_cpus_map(char *buf, const struct cpumask *map)
146 int n = cpulist_scnprintf(buf, PAGE_SIZE-2, map);
148 buf[n++] = '\n';
149 buf[n] = '\0';
150 return n;
153 #define print_cpus_func(type) \
154 static ssize_t print_cpus_##type(struct sysdev_class *class, char *buf) \
156 return print_cpus_map(buf, cpu_##type##_mask); \
158 static struct sysdev_class_attribute attr_##type##_map = \
159 _SYSDEV_CLASS_ATTR(type, 0444, print_cpus_##type, NULL)
161 print_cpus_func(online);
162 print_cpus_func(possible);
163 print_cpus_func(present);
166 * Print values for NR_CPUS and offlined cpus
168 static ssize_t print_cpus_kernel_max(struct sysdev_class *class, char *buf)
170 int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
171 return n;
173 static SYSDEV_CLASS_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
175 /* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
176 unsigned int total_cpus;
178 static ssize_t print_cpus_offline(struct sysdev_class *class, char *buf)
180 int n = 0, len = PAGE_SIZE-2;
181 cpumask_var_t offline;
183 /* display offline cpus < nr_cpu_ids */
184 if (!alloc_cpumask_var(&offline, GFP_KERNEL))
185 return -ENOMEM;
186 cpumask_complement(offline, cpu_online_mask);
187 n = cpulist_scnprintf(buf, len, offline);
188 free_cpumask_var(offline);
190 /* display offline cpus >= nr_cpu_ids */
191 if (total_cpus && nr_cpu_ids < total_cpus) {
192 if (n && n < len)
193 buf[n++] = ',';
195 if (nr_cpu_ids == total_cpus-1)
196 n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids);
197 else
198 n += snprintf(&buf[n], len - n, "%d-%d",
199 nr_cpu_ids, total_cpus-1);
202 n += snprintf(&buf[n], len - n, "\n");
203 return n;
205 static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL);
207 static struct sysdev_class_attribute *cpu_state_attr[] = {
208 &attr_online_map,
209 &attr_possible_map,
210 &attr_present_map,
211 &attr_kernel_max,
212 &attr_offline,
215 static int cpu_states_init(void)
217 int i;
218 int err = 0;
220 for (i = 0; i < ARRAY_SIZE(cpu_state_attr); i++) {
221 int ret;
222 ret = sysdev_class_create_file(&cpu_sysdev_class,
223 cpu_state_attr[i]);
224 if (!err)
225 err = ret;
227 return err;
231 * register_cpu - Setup a sysfs device for a CPU.
232 * @cpu - cpu->hotpluggable field set to 1 will generate a control file in
233 * sysfs for this CPU.
234 * @num - CPU number to use when creating the device.
236 * Initialize and register the CPU device.
238 int __cpuinit register_cpu(struct cpu *cpu, int num)
240 int error;
241 cpu->node_id = cpu_to_node(num);
242 cpu->sysdev.id = num;
243 cpu->sysdev.cls = &cpu_sysdev_class;
245 error = sysdev_register(&cpu->sysdev);
247 if (!error && cpu->hotpluggable)
248 register_cpu_control(cpu);
249 if (!error)
250 per_cpu(cpu_sys_devices, num) = &cpu->sysdev;
251 if (!error)
252 register_cpu_under_node(num, cpu_to_node(num));
254 #ifdef CONFIG_KEXEC
255 if (!error)
256 error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes);
257 #endif
258 return error;
261 struct sys_device *get_cpu_sysdev(unsigned cpu)
263 if (cpu < nr_cpu_ids && cpu_possible(cpu))
264 return per_cpu(cpu_sys_devices, cpu);
265 else
266 return NULL;
268 EXPORT_SYMBOL_GPL(get_cpu_sysdev);
270 int __init cpu_dev_init(void)
272 int err;
274 err = sysdev_class_register(&cpu_sysdev_class);
275 if (!err)
276 err = cpu_states_init();
278 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
279 if (!err)
280 err = sched_create_sysfs_power_savings_entries(&cpu_sysdev_class);
281 #endif
283 return err;