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Commit | Line | Data |
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1da177e4 LT |
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> | |
f6a57033 | 8 | #include <linux/sched.h> |
1da177e4 LT |
9 | #include <linux/cpu.h> |
10 | #include <linux/topology.h> | |
11 | #include <linux/device.h> | |
76b67ed9 | 12 | #include <linux/node.h> |
1da177e4 | 13 | |
a1bdc7aa | 14 | #include "base.h" |
1da177e4 LT |
15 | |
16 | struct sysdev_class cpu_sysdev_class = { | |
af5ca3f4 | 17 | .name = "cpu", |
1da177e4 LT |
18 | }; |
19 | EXPORT_SYMBOL(cpu_sysdev_class); | |
20 | ||
e37d05da | 21 | static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices); |
ad74557a | 22 | |
1da177e4 | 23 | #ifdef CONFIG_HOTPLUG_CPU |
4a0b2b4d AK |
24 | static ssize_t show_online(struct sys_device *dev, struct sysdev_attribute *attr, |
25 | char *buf) | |
1da177e4 LT |
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 | ||
4a0b2b4d AK |
32 | static ssize_t __ref store_online(struct sys_device *dev, struct sysdev_attribute *attr, |
33 | const char *buf, size_t count) | |
1da177e4 LT |
34 | { |
35 | struct cpu *cpu = container_of(dev, struct cpu, sysdev); | |
36 | ssize_t ret; | |
37 | ||
38 | switch (buf[0]) { | |
39 | case '0': | |
40 | ret = cpu_down(cpu->sysdev.id); | |
41 | if (!ret) | |
312c004d | 42 | kobject_uevent(&dev->kobj, KOBJ_OFFLINE); |
1da177e4 LT |
43 | break; |
44 | case '1': | |
34f361ad | 45 | ret = cpu_up(cpu->sysdev.id); |
fb69c390 | 46 | if (!ret) |
312c004d | 47 | kobject_uevent(&dev->kobj, KOBJ_ONLINE); |
1da177e4 LT |
48 | break; |
49 | default: | |
50 | ret = -EINVAL; | |
51 | } | |
52 | ||
53 | if (ret >= 0) | |
54 | ret = count; | |
55 | return ret; | |
56 | } | |
9eb3ff40 | 57 | static SYSDEV_ATTR(online, 0644, show_online, store_online); |
1da177e4 | 58 | |
6c847402 | 59 | static void __cpuinit register_cpu_control(struct cpu *cpu) |
1da177e4 LT |
60 | { |
61 | sysdev_create_file(&cpu->sysdev, &attr_online); | |
62 | } | |
76b67ed9 | 63 | void unregister_cpu(struct cpu *cpu) |
1da177e4 | 64 | { |
ad74557a | 65 | int logical_cpu = cpu->sysdev.id; |
1da177e4 | 66 | |
76b67ed9 KH |
67 | unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu)); |
68 | ||
1da177e4 LT |
69 | sysdev_remove_file(&cpu->sysdev, &attr_online); |
70 | ||
71 | sysdev_unregister(&cpu->sysdev); | |
e37d05da | 72 | per_cpu(cpu_sys_devices, logical_cpu) = NULL; |
1da177e4 LT |
73 | return; |
74 | } | |
75 | #else /* ... !CONFIG_HOTPLUG_CPU */ | |
76 | static inline void register_cpu_control(struct cpu *cpu) | |
77 | { | |
78 | } | |
79 | #endif /* CONFIG_HOTPLUG_CPU */ | |
80 | ||
51be5606 VG |
81 | #ifdef CONFIG_KEXEC |
82 | #include <linux/kexec.h> | |
83 | ||
4a0b2b4d AK |
84 | static ssize_t show_crash_notes(struct sys_device *dev, struct sysdev_attribute *attr, |
85 | char *buf) | |
51be5606 VG |
86 | { |
87 | struct cpu *cpu = container_of(dev, struct cpu, sysdev); | |
88 | ssize_t rc; | |
89 | unsigned long long addr; | |
90 | int cpunum; | |
91 | ||
92 | cpunum = cpu->sysdev.id; | |
93 | ||
94 | /* | |
95 | * Might be reading other cpu's data based on which cpu read thread | |
96 | * has been scheduled. But cpu data (memory) is allocated once during | |
97 | * boot up and this data does not change there after. Hence this | |
98 | * operation should be safe. No locking required. | |
99 | */ | |
51be5606 VG |
100 | addr = __pa(per_cpu_ptr(crash_notes, cpunum)); |
101 | rc = sprintf(buf, "%Lx\n", addr); | |
51be5606 VG |
102 | return rc; |
103 | } | |
104 | static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL); | |
105 | #endif | |
106 | ||
9d1fe323 MT |
107 | /* |
108 | * Print cpu online, possible, present, and system maps | |
109 | */ | |
110 | static ssize_t print_cpus_map(char *buf, cpumask_t *map) | |
111 | { | |
29c0177e | 112 | int n = cpulist_scnprintf(buf, PAGE_SIZE-2, map); |
9d1fe323 MT |
113 | |
114 | buf[n++] = '\n'; | |
115 | buf[n] = '\0'; | |
116 | return n; | |
117 | } | |
118 | ||
119 | #define print_cpus_func(type) \ | |
120 | static ssize_t print_cpus_##type(struct sysdev_class *class, char *buf) \ | |
121 | { \ | |
122 | return print_cpus_map(buf, &cpu_##type##_map); \ | |
123 | } \ | |
143aa5c5 | 124 | static struct sysdev_class_attribute attr_##type##_map = \ |
9d1fe323 MT |
125 | _SYSDEV_CLASS_ATTR(type, 0444, print_cpus_##type, NULL) |
126 | ||
127 | print_cpus_func(online); | |
128 | print_cpus_func(possible); | |
129 | print_cpus_func(present); | |
130 | ||
e057d7ae MT |
131 | /* |
132 | * Print values for NR_CPUS and offlined cpus | |
133 | */ | |
134 | static ssize_t print_cpus_kernel_max(struct sysdev_class *class, char *buf) | |
135 | { | |
8fd2d2d5 | 136 | int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1); |
e057d7ae MT |
137 | return n; |
138 | } | |
139 | static SYSDEV_CLASS_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL); | |
140 | ||
141 | /* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */ | |
142 | unsigned int total_cpus; | |
143 | ||
144 | static ssize_t print_cpus_offline(struct sysdev_class *class, char *buf) | |
145 | { | |
146 | int n = 0, len = PAGE_SIZE-2; | |
147 | cpumask_var_t offline; | |
148 | ||
149 | /* display offline cpus < nr_cpu_ids */ | |
150 | if (!alloc_cpumask_var(&offline, GFP_KERNEL)) | |
151 | return -ENOMEM; | |
152 | cpumask_complement(offline, cpu_online_mask); | |
153 | n = cpulist_scnprintf(buf, len, offline); | |
154 | free_cpumask_var(offline); | |
155 | ||
156 | /* display offline cpus >= nr_cpu_ids */ | |
157 | if (total_cpus && nr_cpu_ids < total_cpus) { | |
158 | if (n && n < len) | |
159 | buf[n++] = ','; | |
160 | ||
161 | if (nr_cpu_ids == total_cpus-1) | |
162 | n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids); | |
163 | else | |
164 | n += snprintf(&buf[n], len - n, "%d-%d", | |
165 | nr_cpu_ids, total_cpus-1); | |
166 | } | |
167 | ||
168 | n += snprintf(&buf[n], len - n, "\n"); | |
169 | return n; | |
170 | } | |
171 | static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL); | |
172 | ||
143aa5c5 | 173 | static struct sysdev_class_attribute *cpu_state_attr[] = { |
9d1fe323 MT |
174 | &attr_online_map, |
175 | &attr_possible_map, | |
176 | &attr_present_map, | |
e057d7ae MT |
177 | &attr_kernel_max, |
178 | &attr_offline, | |
9d1fe323 MT |
179 | }; |
180 | ||
181 | static int cpu_states_init(void) | |
182 | { | |
183 | int i; | |
184 | int err = 0; | |
185 | ||
186 | for (i = 0; i < ARRAY_SIZE(cpu_state_attr); i++) { | |
187 | int ret; | |
188 | ret = sysdev_class_create_file(&cpu_sysdev_class, | |
189 | cpu_state_attr[i]); | |
190 | if (!err) | |
191 | err = ret; | |
192 | } | |
193 | return err; | |
194 | } | |
195 | ||
1da177e4 | 196 | /* |
405ae7d3 | 197 | * register_cpu - Setup a sysfs device for a CPU. |
72486f1f SS |
198 | * @cpu - cpu->hotpluggable field set to 1 will generate a control file in |
199 | * sysfs for this CPU. | |
1da177e4 LT |
200 | * @num - CPU number to use when creating the device. |
201 | * | |
202 | * Initialize and register the CPU device. | |
203 | */ | |
33b5f31b | 204 | int __cpuinit register_cpu(struct cpu *cpu, int num) |
1da177e4 LT |
205 | { |
206 | int error; | |
1da177e4 LT |
207 | cpu->node_id = cpu_to_node(num); |
208 | cpu->sysdev.id = num; | |
209 | cpu->sysdev.cls = &cpu_sysdev_class; | |
210 | ||
211 | error = sysdev_register(&cpu->sysdev); | |
76b67ed9 | 212 | |
72486f1f | 213 | if (!error && cpu->hotpluggable) |
1da177e4 | 214 | register_cpu_control(cpu); |
ad74557a | 215 | if (!error) |
e37d05da | 216 | per_cpu(cpu_sys_devices, num) = &cpu->sysdev; |
76b67ed9 KH |
217 | if (!error) |
218 | register_cpu_under_node(num, cpu_to_node(num)); | |
51be5606 VG |
219 | |
220 | #ifdef CONFIG_KEXEC | |
221 | if (!error) | |
222 | error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes); | |
223 | #endif | |
1da177e4 LT |
224 | return error; |
225 | } | |
226 | ||
a29d642a | 227 | struct sys_device *get_cpu_sysdev(unsigned cpu) |
ad74557a | 228 | { |
e37d05da MT |
229 | if (cpu < nr_cpu_ids && cpu_possible(cpu)) |
230 | return per_cpu(cpu_sys_devices, cpu); | |
ad74557a AR |
231 | else |
232 | return NULL; | |
233 | } | |
234 | EXPORT_SYMBOL_GPL(get_cpu_sysdev); | |
1da177e4 LT |
235 | |
236 | int __init cpu_dev_init(void) | |
237 | { | |
5c45bf27 SS |
238 | int err; |
239 | ||
240 | err = sysdev_class_register(&cpu_sysdev_class); | |
9d1fe323 MT |
241 | if (!err) |
242 | err = cpu_states_init(); | |
243 | ||
5c45bf27 SS |
244 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
245 | if (!err) | |
246 | err = sched_create_sysfs_power_savings_entries(&cpu_sysdev_class); | |
247 | #endif | |
248 | ||
249 | return err; | |
1da177e4 | 250 | } |