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Commit | Line | Data |
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1da177e4 LT |
1 | /* CPU control. |
2 | * (C) 2001, 2002, 2003, 2004 Rusty Russell | |
3 | * | |
4 | * This code is licenced under the GPL. | |
5 | */ | |
6 | #include <linux/proc_fs.h> | |
7 | #include <linux/smp.h> | |
8 | #include <linux/init.h> | |
9 | #include <linux/notifier.h> | |
10 | #include <linux/sched.h> | |
11 | #include <linux/unistd.h> | |
12 | #include <linux/cpu.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/kthread.h> | |
15 | #include <linux/stop_machine.h> | |
81615b62 | 16 | #include <linux/mutex.h> |
5a0e3ad6 | 17 | #include <linux/gfp.h> |
1da177e4 | 18 | |
98a79d6a | 19 | #ifdef CONFIG_SMP |
b3199c02 | 20 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
aa953877 | 21 | static DEFINE_MUTEX(cpu_add_remove_lock); |
1da177e4 | 22 | |
bd5349cf | 23 | static __cpuinitdata RAW_NOTIFIER_HEAD(cpu_chain); |
1da177e4 | 24 | |
e3920fb4 RW |
25 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
26 | * Should always be manipulated under cpu_add_remove_lock | |
27 | */ | |
28 | static int cpu_hotplug_disabled; | |
29 | ||
d221938c GS |
30 | static struct { |
31 | struct task_struct *active_writer; | |
32 | struct mutex lock; /* Synchronizes accesses to refcount, */ | |
33 | /* | |
34 | * Also blocks the new readers during | |
35 | * an ongoing cpu hotplug operation. | |
36 | */ | |
37 | int refcount; | |
31950eb6 LT |
38 | } cpu_hotplug = { |
39 | .active_writer = NULL, | |
40 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), | |
41 | .refcount = 0, | |
42 | }; | |
d221938c GS |
43 | |
44 | #ifdef CONFIG_HOTPLUG_CPU | |
90d45d17 | 45 | |
86ef5c9a | 46 | void get_online_cpus(void) |
a9d9baa1 | 47 | { |
d221938c GS |
48 | might_sleep(); |
49 | if (cpu_hotplug.active_writer == current) | |
aa953877 | 50 | return; |
d221938c GS |
51 | mutex_lock(&cpu_hotplug.lock); |
52 | cpu_hotplug.refcount++; | |
53 | mutex_unlock(&cpu_hotplug.lock); | |
54 | ||
a9d9baa1 | 55 | } |
86ef5c9a | 56 | EXPORT_SYMBOL_GPL(get_online_cpus); |
90d45d17 | 57 | |
86ef5c9a | 58 | void put_online_cpus(void) |
a9d9baa1 | 59 | { |
d221938c | 60 | if (cpu_hotplug.active_writer == current) |
aa953877 | 61 | return; |
d221938c | 62 | mutex_lock(&cpu_hotplug.lock); |
d2ba7e2a ON |
63 | if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer)) |
64 | wake_up_process(cpu_hotplug.active_writer); | |
d221938c GS |
65 | mutex_unlock(&cpu_hotplug.lock); |
66 | ||
a9d9baa1 | 67 | } |
86ef5c9a | 68 | EXPORT_SYMBOL_GPL(put_online_cpus); |
a9d9baa1 | 69 | |
a9d9baa1 | 70 | #endif /* CONFIG_HOTPLUG_CPU */ |
90d45d17 | 71 | |
d221938c GS |
72 | /* |
73 | * The following two API's must be used when attempting | |
b3199c02 | 74 | * to serialize the updates to cpu_online_mask, cpu_present_mask. |
d221938c GS |
75 | */ |
76 | void cpu_maps_update_begin(void) | |
77 | { | |
78 | mutex_lock(&cpu_add_remove_lock); | |
79 | } | |
80 | ||
81 | void cpu_maps_update_done(void) | |
82 | { | |
83 | mutex_unlock(&cpu_add_remove_lock); | |
84 | } | |
85 | ||
86 | /* | |
87 | * This ensures that the hotplug operation can begin only when the | |
88 | * refcount goes to zero. | |
89 | * | |
90 | * Note that during a cpu-hotplug operation, the new readers, if any, | |
91 | * will be blocked by the cpu_hotplug.lock | |
92 | * | |
d2ba7e2a ON |
93 | * Since cpu_hotplug_begin() is always called after invoking |
94 | * cpu_maps_update_begin(), we can be sure that only one writer is active. | |
d221938c GS |
95 | * |
96 | * Note that theoretically, there is a possibility of a livelock: | |
97 | * - Refcount goes to zero, last reader wakes up the sleeping | |
98 | * writer. | |
99 | * - Last reader unlocks the cpu_hotplug.lock. | |
100 | * - A new reader arrives at this moment, bumps up the refcount. | |
101 | * - The writer acquires the cpu_hotplug.lock finds the refcount | |
102 | * non zero and goes to sleep again. | |
103 | * | |
104 | * However, this is very difficult to achieve in practice since | |
86ef5c9a | 105 | * get_online_cpus() not an api which is called all that often. |
d221938c GS |
106 | * |
107 | */ | |
108 | static void cpu_hotplug_begin(void) | |
109 | { | |
d221938c | 110 | cpu_hotplug.active_writer = current; |
d2ba7e2a ON |
111 | |
112 | for (;;) { | |
113 | mutex_lock(&cpu_hotplug.lock); | |
114 | if (likely(!cpu_hotplug.refcount)) | |
115 | break; | |
116 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
d221938c GS |
117 | mutex_unlock(&cpu_hotplug.lock); |
118 | schedule(); | |
d221938c | 119 | } |
d221938c GS |
120 | } |
121 | ||
122 | static void cpu_hotplug_done(void) | |
123 | { | |
124 | cpu_hotplug.active_writer = NULL; | |
125 | mutex_unlock(&cpu_hotplug.lock); | |
126 | } | |
1da177e4 | 127 | /* Need to know about CPUs going up/down? */ |
f7b16c10 | 128 | int __ref register_cpu_notifier(struct notifier_block *nb) |
1da177e4 | 129 | { |
bd5349cf | 130 | int ret; |
d221938c | 131 | cpu_maps_update_begin(); |
bd5349cf | 132 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
d221938c | 133 | cpu_maps_update_done(); |
bd5349cf | 134 | return ret; |
1da177e4 | 135 | } |
65edc68c | 136 | |
e9fb7631 AM |
137 | static int __cpu_notify(unsigned long val, void *v, int nr_to_call, |
138 | int *nr_calls) | |
139 | { | |
e6bde73b AM |
140 | int ret; |
141 | ||
142 | ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call, | |
e9fb7631 | 143 | nr_calls); |
e6bde73b AM |
144 | |
145 | return notifier_to_errno(ret); | |
e9fb7631 AM |
146 | } |
147 | ||
148 | static int cpu_notify(unsigned long val, void *v) | |
149 | { | |
150 | return __cpu_notify(val, v, -1, NULL); | |
151 | } | |
152 | ||
153 | static void cpu_notify_nofail(unsigned long val, void *v) | |
154 | { | |
155 | int err; | |
156 | ||
157 | err = cpu_notify(val, v); | |
e6bde73b | 158 | BUG_ON(err); |
e9fb7631 AM |
159 | } |
160 | ||
65edc68c CS |
161 | #ifdef CONFIG_HOTPLUG_CPU |
162 | ||
1da177e4 LT |
163 | EXPORT_SYMBOL(register_cpu_notifier); |
164 | ||
9647155f | 165 | void __ref unregister_cpu_notifier(struct notifier_block *nb) |
1da177e4 | 166 | { |
d221938c | 167 | cpu_maps_update_begin(); |
bd5349cf | 168 | raw_notifier_chain_unregister(&cpu_chain, nb); |
d221938c | 169 | cpu_maps_update_done(); |
1da177e4 LT |
170 | } |
171 | EXPORT_SYMBOL(unregister_cpu_notifier); | |
172 | ||
1da177e4 LT |
173 | static inline void check_for_tasks(int cpu) |
174 | { | |
175 | struct task_struct *p; | |
176 | ||
177 | write_lock_irq(&tasklist_lock); | |
178 | for_each_process(p) { | |
11854247 | 179 | if (task_cpu(p) == cpu && p->state == TASK_RUNNING && |
1da177e4 LT |
180 | (!cputime_eq(p->utime, cputime_zero) || |
181 | !cputime_eq(p->stime, cputime_zero))) | |
9d3cfc4c FP |
182 | printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d " |
183 | "(state = %ld, flags = %x)\n", | |
184 | p->comm, task_pid_nr(p), cpu, | |
185 | p->state, p->flags); | |
1da177e4 LT |
186 | } |
187 | write_unlock_irq(&tasklist_lock); | |
188 | } | |
189 | ||
db912f96 | 190 | struct take_cpu_down_param { |
6a1bdc1b | 191 | struct task_struct *caller; |
db912f96 AK |
192 | unsigned long mod; |
193 | void *hcpu; | |
194 | }; | |
195 | ||
1da177e4 | 196 | /* Take this CPU down. */ |
514a20a5 | 197 | static int __ref take_cpu_down(void *_param) |
1da177e4 | 198 | { |
db912f96 | 199 | struct take_cpu_down_param *param = _param; |
6a1bdc1b | 200 | unsigned int cpu = (unsigned long)param->hcpu; |
1da177e4 LT |
201 | int err; |
202 | ||
1da177e4 LT |
203 | /* Ensure this CPU doesn't handle any more interrupts. */ |
204 | err = __cpu_disable(); | |
205 | if (err < 0) | |
f3705136 | 206 | return err; |
1da177e4 | 207 | |
e9fb7631 | 208 | cpu_notify(CPU_DYING | param->mod, param->hcpu); |
3ba35573 | 209 | |
6a1bdc1b ON |
210 | if (task_cpu(param->caller) == cpu) |
211 | move_task_off_dead_cpu(cpu, param->caller); | |
f3705136 ZM |
212 | /* Force idle task to run as soon as we yield: it should |
213 | immediately notice cpu is offline and die quickly. */ | |
214 | sched_idle_next(); | |
215 | return 0; | |
1da177e4 LT |
216 | } |
217 | ||
e3920fb4 | 218 | /* Requires cpu_add_remove_lock to be held */ |
514a20a5 | 219 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) |
1da177e4 | 220 | { |
e7407dcc | 221 | int err, nr_calls = 0; |
e7407dcc | 222 | void *hcpu = (void *)(long)cpu; |
8bb78442 | 223 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
db912f96 | 224 | struct take_cpu_down_param tcd_param = { |
6a1bdc1b | 225 | .caller = current, |
db912f96 AK |
226 | .mod = mod, |
227 | .hcpu = hcpu, | |
228 | }; | |
1da177e4 | 229 | |
e3920fb4 RW |
230 | if (num_online_cpus() == 1) |
231 | return -EBUSY; | |
1da177e4 | 232 | |
e3920fb4 RW |
233 | if (!cpu_online(cpu)) |
234 | return -EINVAL; | |
1da177e4 | 235 | |
d221938c | 236 | cpu_hotplug_begin(); |
9ee349ad | 237 | set_cpu_active(cpu, false); |
e9fb7631 | 238 | err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls); |
e6bde73b | 239 | if (err) { |
6ad4c188 PZ |
240 | set_cpu_active(cpu, true); |
241 | ||
a0d8cdb6 | 242 | nr_calls--; |
e9fb7631 | 243 | __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL); |
1da177e4 | 244 | printk("%s: attempt to take down CPU %u failed\n", |
af1f16d0 | 245 | __func__, cpu); |
baaca49f | 246 | goto out_release; |
1da177e4 LT |
247 | } |
248 | ||
e0b582ec | 249 | err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); |
04321587 | 250 | if (err) { |
6ad4c188 | 251 | set_cpu_active(cpu, true); |
1da177e4 | 252 | /* CPU didn't die: tell everyone. Can't complain. */ |
e9fb7631 | 253 | cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu); |
1da177e4 | 254 | |
6a1bdc1b | 255 | goto out_release; |
8fa1d7d3 | 256 | } |
04321587 | 257 | BUG_ON(cpu_online(cpu)); |
1da177e4 LT |
258 | |
259 | /* Wait for it to sleep (leaving idle task). */ | |
260 | while (!idle_cpu(cpu)) | |
261 | yield(); | |
262 | ||
263 | /* This actually kills the CPU. */ | |
264 | __cpu_die(cpu); | |
265 | ||
1da177e4 | 266 | /* CPU is completely dead: tell everyone. Too late to complain. */ |
e9fb7631 | 267 | cpu_notify_nofail(CPU_DEAD | mod, hcpu); |
1da177e4 LT |
268 | |
269 | check_for_tasks(cpu); | |
270 | ||
baaca49f | 271 | out_release: |
d221938c | 272 | cpu_hotplug_done(); |
e9fb7631 AM |
273 | if (!err) |
274 | cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu); | |
e3920fb4 RW |
275 | return err; |
276 | } | |
277 | ||
514a20a5 | 278 | int __ref cpu_down(unsigned int cpu) |
e3920fb4 | 279 | { |
9ea09af3 | 280 | int err; |
e3920fb4 | 281 | |
d221938c | 282 | cpu_maps_update_begin(); |
e761b772 MK |
283 | |
284 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 285 | err = -EBUSY; |
e761b772 MK |
286 | goto out; |
287 | } | |
288 | ||
e761b772 | 289 | err = _cpu_down(cpu, 0); |
e3920fb4 | 290 | |
e761b772 | 291 | out: |
d221938c | 292 | cpu_maps_update_done(); |
1da177e4 LT |
293 | return err; |
294 | } | |
b62b8ef9 | 295 | EXPORT_SYMBOL(cpu_down); |
1da177e4 LT |
296 | #endif /*CONFIG_HOTPLUG_CPU*/ |
297 | ||
e3920fb4 | 298 | /* Requires cpu_add_remove_lock to be held */ |
8bb78442 | 299 | static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) |
1da177e4 | 300 | { |
baaca49f | 301 | int ret, nr_calls = 0; |
1da177e4 | 302 | void *hcpu = (void *)(long)cpu; |
8bb78442 | 303 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
1da177e4 | 304 | |
e3920fb4 RW |
305 | if (cpu_online(cpu) || !cpu_present(cpu)) |
306 | return -EINVAL; | |
90d45d17 | 307 | |
d221938c | 308 | cpu_hotplug_begin(); |
e9fb7631 | 309 | ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls); |
e6bde73b | 310 | if (ret) { |
a0d8cdb6 | 311 | nr_calls--; |
1da177e4 | 312 | printk("%s: attempt to bring up CPU %u failed\n", |
af1f16d0 | 313 | __func__, cpu); |
1da177e4 LT |
314 | goto out_notify; |
315 | } | |
316 | ||
317 | /* Arch-specific enabling code. */ | |
318 | ret = __cpu_up(cpu); | |
319 | if (ret != 0) | |
320 | goto out_notify; | |
6978c705 | 321 | BUG_ON(!cpu_online(cpu)); |
1da177e4 | 322 | |
2b17fa50 | 323 | set_cpu_active(cpu, true); |
279ef6bb | 324 | |
1da177e4 | 325 | /* Now call notifier in preparation. */ |
e9fb7631 | 326 | cpu_notify(CPU_ONLINE | mod, hcpu); |
1da177e4 LT |
327 | |
328 | out_notify: | |
329 | if (ret != 0) | |
e9fb7631 | 330 | __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL); |
d221938c | 331 | cpu_hotplug_done(); |
e3920fb4 RW |
332 | |
333 | return ret; | |
334 | } | |
335 | ||
b282b6f8 | 336 | int __cpuinit cpu_up(unsigned int cpu) |
e3920fb4 RW |
337 | { |
338 | int err = 0; | |
cf23422b | 339 | |
340 | #ifdef CONFIG_MEMORY_HOTPLUG | |
341 | int nid; | |
342 | pg_data_t *pgdat; | |
343 | #endif | |
344 | ||
e0b582ec | 345 | if (!cpu_possible(cpu)) { |
73e753a5 KH |
346 | printk(KERN_ERR "can't online cpu %d because it is not " |
347 | "configured as may-hotadd at boot time\n", cpu); | |
87d5e023 | 348 | #if defined(CONFIG_IA64) |
73e753a5 KH |
349 | printk(KERN_ERR "please check additional_cpus= boot " |
350 | "parameter\n"); | |
351 | #endif | |
352 | return -EINVAL; | |
353 | } | |
e3920fb4 | 354 | |
cf23422b | 355 | #ifdef CONFIG_MEMORY_HOTPLUG |
356 | nid = cpu_to_node(cpu); | |
357 | if (!node_online(nid)) { | |
358 | err = mem_online_node(nid); | |
359 | if (err) | |
360 | return err; | |
361 | } | |
362 | ||
363 | pgdat = NODE_DATA(nid); | |
364 | if (!pgdat) { | |
365 | printk(KERN_ERR | |
366 | "Can't online cpu %d due to NULL pgdat\n", cpu); | |
367 | return -ENOMEM; | |
368 | } | |
369 | ||
4eaf3f64 HL |
370 | if (pgdat->node_zonelists->_zonerefs->zone == NULL) { |
371 | mutex_lock(&zonelists_mutex); | |
1f522509 | 372 | build_all_zonelists(NULL); |
4eaf3f64 HL |
373 | mutex_unlock(&zonelists_mutex); |
374 | } | |
cf23422b | 375 | #endif |
376 | ||
d221938c | 377 | cpu_maps_update_begin(); |
e761b772 MK |
378 | |
379 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 380 | err = -EBUSY; |
e761b772 MK |
381 | goto out; |
382 | } | |
383 | ||
384 | err = _cpu_up(cpu, 0); | |
385 | ||
e761b772 | 386 | out: |
d221938c | 387 | cpu_maps_update_done(); |
e3920fb4 RW |
388 | return err; |
389 | } | |
390 | ||
f3de4be9 | 391 | #ifdef CONFIG_PM_SLEEP_SMP |
e0b582ec | 392 | static cpumask_var_t frozen_cpus; |
e3920fb4 RW |
393 | |
394 | int disable_nonboot_cpus(void) | |
395 | { | |
69575d38 | 396 | int cpu, first_cpu, error; |
e3920fb4 | 397 | |
d221938c | 398 | cpu_maps_update_begin(); |
e0b582ec | 399 | first_cpu = cpumask_first(cpu_online_mask); |
9ee349ad XF |
400 | /* |
401 | * We take down all of the non-boot CPUs in one shot to avoid races | |
e3920fb4 RW |
402 | * with the userspace trying to use the CPU hotplug at the same time |
403 | */ | |
e0b582ec | 404 | cpumask_clear(frozen_cpus); |
6ad4c188 | 405 | |
e3920fb4 RW |
406 | printk("Disabling non-boot CPUs ...\n"); |
407 | for_each_online_cpu(cpu) { | |
408 | if (cpu == first_cpu) | |
409 | continue; | |
8bb78442 | 410 | error = _cpu_down(cpu, 1); |
feae3203 | 411 | if (!error) |
e0b582ec | 412 | cpumask_set_cpu(cpu, frozen_cpus); |
feae3203 | 413 | else { |
e3920fb4 RW |
414 | printk(KERN_ERR "Error taking CPU%d down: %d\n", |
415 | cpu, error); | |
416 | break; | |
417 | } | |
418 | } | |
86886e55 | 419 | |
e3920fb4 RW |
420 | if (!error) { |
421 | BUG_ON(num_online_cpus() > 1); | |
422 | /* Make sure the CPUs won't be enabled by someone else */ | |
423 | cpu_hotplug_disabled = 1; | |
424 | } else { | |
e1d9fd2e | 425 | printk(KERN_ERR "Non-boot CPUs are not disabled\n"); |
e3920fb4 | 426 | } |
d221938c | 427 | cpu_maps_update_done(); |
e3920fb4 RW |
428 | return error; |
429 | } | |
430 | ||
d0af9eed SS |
431 | void __weak arch_enable_nonboot_cpus_begin(void) |
432 | { | |
433 | } | |
434 | ||
435 | void __weak arch_enable_nonboot_cpus_end(void) | |
436 | { | |
437 | } | |
438 | ||
fa7303e2 | 439 | void __ref enable_nonboot_cpus(void) |
e3920fb4 RW |
440 | { |
441 | int cpu, error; | |
442 | ||
443 | /* Allow everyone to use the CPU hotplug again */ | |
d221938c | 444 | cpu_maps_update_begin(); |
e3920fb4 | 445 | cpu_hotplug_disabled = 0; |
e0b582ec | 446 | if (cpumask_empty(frozen_cpus)) |
1d64b9cb | 447 | goto out; |
e3920fb4 RW |
448 | |
449 | printk("Enabling non-boot CPUs ...\n"); | |
d0af9eed SS |
450 | |
451 | arch_enable_nonboot_cpus_begin(); | |
452 | ||
e0b582ec | 453 | for_each_cpu(cpu, frozen_cpus) { |
8bb78442 | 454 | error = _cpu_up(cpu, 1); |
e3920fb4 RW |
455 | if (!error) { |
456 | printk("CPU%d is up\n", cpu); | |
457 | continue; | |
458 | } | |
1d64b9cb | 459 | printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error); |
e3920fb4 | 460 | } |
d0af9eed SS |
461 | |
462 | arch_enable_nonboot_cpus_end(); | |
463 | ||
e0b582ec | 464 | cpumask_clear(frozen_cpus); |
1d64b9cb | 465 | out: |
d221938c | 466 | cpu_maps_update_done(); |
1da177e4 | 467 | } |
e0b582ec RR |
468 | |
469 | static int alloc_frozen_cpus(void) | |
470 | { | |
471 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) | |
472 | return -ENOMEM; | |
473 | return 0; | |
474 | } | |
475 | core_initcall(alloc_frozen_cpus); | |
f3de4be9 | 476 | #endif /* CONFIG_PM_SLEEP_SMP */ |
68f4f1ec | 477 | |
e545a614 MS |
478 | /** |
479 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers | |
480 | * @cpu: cpu that just started | |
481 | * | |
482 | * This function calls the cpu_chain notifiers with CPU_STARTING. | |
483 | * It must be called by the arch code on the new cpu, before the new cpu | |
484 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). | |
485 | */ | |
84196414 | 486 | void __cpuinit notify_cpu_starting(unsigned int cpu) |
e545a614 MS |
487 | { |
488 | unsigned long val = CPU_STARTING; | |
489 | ||
490 | #ifdef CONFIG_PM_SLEEP_SMP | |
e0b582ec | 491 | if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus)) |
e545a614 MS |
492 | val = CPU_STARTING_FROZEN; |
493 | #endif /* CONFIG_PM_SLEEP_SMP */ | |
e9fb7631 | 494 | cpu_notify(val, (void *)(long)cpu); |
e545a614 MS |
495 | } |
496 | ||
68f4f1ec | 497 | #endif /* CONFIG_SMP */ |
b8d317d1 | 498 | |
e56b3bc7 LT |
499 | /* |
500 | * cpu_bit_bitmap[] is a special, "compressed" data structure that | |
501 | * represents all NR_CPUS bits binary values of 1<<nr. | |
502 | * | |
e0b582ec | 503 | * It is used by cpumask_of() to get a constant address to a CPU |
e56b3bc7 LT |
504 | * mask value that has a single bit set only. |
505 | */ | |
b8d317d1 | 506 | |
e56b3bc7 LT |
507 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
508 | #define MASK_DECLARE_1(x) [x+1][0] = 1UL << (x) | |
509 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) | |
510 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) | |
511 | #define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) | |
b8d317d1 | 512 | |
e56b3bc7 LT |
513 | const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { |
514 | ||
515 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), | |
516 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), | |
517 | #if BITS_PER_LONG > 32 | |
518 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), | |
519 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), | |
b8d317d1 MT |
520 | #endif |
521 | }; | |
e56b3bc7 | 522 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
2d3854a3 RR |
523 | |
524 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; | |
525 | EXPORT_SYMBOL(cpu_all_bits); | |
b3199c02 RR |
526 | |
527 | #ifdef CONFIG_INIT_ALL_POSSIBLE | |
528 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly | |
529 | = CPU_BITS_ALL; | |
530 | #else | |
531 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly; | |
532 | #endif | |
533 | const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits); | |
534 | EXPORT_SYMBOL(cpu_possible_mask); | |
535 | ||
536 | static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly; | |
537 | const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits); | |
538 | EXPORT_SYMBOL(cpu_online_mask); | |
539 | ||
540 | static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly; | |
541 | const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits); | |
542 | EXPORT_SYMBOL(cpu_present_mask); | |
543 | ||
544 | static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly; | |
545 | const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits); | |
546 | EXPORT_SYMBOL(cpu_active_mask); | |
3fa41520 RR |
547 | |
548 | void set_cpu_possible(unsigned int cpu, bool possible) | |
549 | { | |
550 | if (possible) | |
551 | cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits)); | |
552 | else | |
553 | cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits)); | |
554 | } | |
555 | ||
556 | void set_cpu_present(unsigned int cpu, bool present) | |
557 | { | |
558 | if (present) | |
559 | cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits)); | |
560 | else | |
561 | cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits)); | |
562 | } | |
563 | ||
564 | void set_cpu_online(unsigned int cpu, bool online) | |
565 | { | |
566 | if (online) | |
567 | cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits)); | |
568 | else | |
569 | cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits)); | |
570 | } | |
571 | ||
572 | void set_cpu_active(unsigned int cpu, bool active) | |
573 | { | |
574 | if (active) | |
575 | cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); | |
576 | else | |
577 | cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits)); | |
578 | } | |
579 | ||
580 | void init_cpu_present(const struct cpumask *src) | |
581 | { | |
582 | cpumask_copy(to_cpumask(cpu_present_bits), src); | |
583 | } | |
584 | ||
585 | void init_cpu_possible(const struct cpumask *src) | |
586 | { | |
587 | cpumask_copy(to_cpumask(cpu_possible_bits), src); | |
588 | } | |
589 | ||
590 | void init_cpu_online(const struct cpumask *src) | |
591 | { | |
592 | cpumask_copy(to_cpumask(cpu_online_bits), src); | |
593 | } |