Commit | Line | Data |
---|---|---|
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> | |
cb79295e AV |
13 | #include <linux/oom.h> |
14 | #include <linux/rcupdate.h> | |
9984de1a | 15 | #include <linux/export.h> |
e4cc2f87 | 16 | #include <linux/bug.h> |
1da177e4 LT |
17 | #include <linux/kthread.h> |
18 | #include <linux/stop_machine.h> | |
81615b62 | 19 | #include <linux/mutex.h> |
5a0e3ad6 | 20 | #include <linux/gfp.h> |
79cfbdfa | 21 | #include <linux/suspend.h> |
6fa3eb70 S |
22 | /******************************************************************************* |
23 | * 20131225 marc.huang * | |
24 | * CPU Hotplug debug mechanism * | |
25 | *******************************************************************************/ | |
26 | #include <linux/kallsyms.h> | |
27 | /******************************************************************************/ | |
28 | #ifdef CONFIG_MT_LOAD_BALANCE_PROFILER | |
29 | #include <mtlbprof/mtlbprof.h> | |
30 | #endif | |
1da177e4 | 31 | |
38498a67 TG |
32 | #include "smpboot.h" |
33 | ||
6fa3eb70 S |
34 | /******************************************************************************* |
35 | * 20131225 marc.huang * | |
36 | * CPU Hotplug and idle integration * | |
37 | *******************************************************************************/ | |
38 | atomic_t is_in_hotplug = ATOMIC_INIT(0); | |
39 | void __attribute__((weak)) spm_mcdi_wakeup_all_cores(void) {} | |
40 | /******************************************************************************/ | |
41 | ||
98a79d6a | 42 | #ifdef CONFIG_SMP |
b3199c02 | 43 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
aa953877 | 44 | static DEFINE_MUTEX(cpu_add_remove_lock); |
1da177e4 | 45 | |
79a6cdeb LJ |
46 | /* |
47 | * The following two API's must be used when attempting | |
48 | * to serialize the updates to cpu_online_mask, cpu_present_mask. | |
49 | */ | |
50 | void cpu_maps_update_begin(void) | |
51 | { | |
52 | mutex_lock(&cpu_add_remove_lock); | |
53 | } | |
54 | ||
55 | void cpu_maps_update_done(void) | |
56 | { | |
57 | mutex_unlock(&cpu_add_remove_lock); | |
58 | } | |
59 | ||
6fa3eb70 S |
60 | /******************************************************************************* |
61 | * 20131225 marc.huang * | |
62 | * CPU Hotplug debug mechanism * | |
63 | *******************************************************************************/ | |
64 | #if defined(MTK_CPU_HOTPLUG_DEBUG_1) || defined(MTK_CPU_HOTPLUG_DEBUG_2) | |
65 | RAW_NOTIFIER_HEAD(cpu_chain); | |
66 | #else | |
5c113fbe | 67 | static RAW_NOTIFIER_HEAD(cpu_chain); |
6fa3eb70 S |
68 | #endif |
69 | /******************************************************************************/ | |
1da177e4 | 70 | |
e3920fb4 RW |
71 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
72 | * Should always be manipulated under cpu_add_remove_lock | |
73 | */ | |
74 | static int cpu_hotplug_disabled; | |
75 | ||
79a6cdeb LJ |
76 | #ifdef CONFIG_HOTPLUG_CPU |
77 | ||
d221938c GS |
78 | static struct { |
79 | struct task_struct *active_writer; | |
80 | struct mutex lock; /* Synchronizes accesses to refcount, */ | |
81 | /* | |
82 | * Also blocks the new readers during | |
83 | * an ongoing cpu hotplug operation. | |
84 | */ | |
85 | int refcount; | |
31950eb6 LT |
86 | } cpu_hotplug = { |
87 | .active_writer = NULL, | |
88 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), | |
89 | .refcount = 0, | |
90 | }; | |
d221938c | 91 | |
86ef5c9a | 92 | void get_online_cpus(void) |
a9d9baa1 | 93 | { |
d221938c GS |
94 | might_sleep(); |
95 | if (cpu_hotplug.active_writer == current) | |
aa953877 | 96 | return; |
d221938c GS |
97 | mutex_lock(&cpu_hotplug.lock); |
98 | cpu_hotplug.refcount++; | |
99 | mutex_unlock(&cpu_hotplug.lock); | |
100 | ||
a9d9baa1 | 101 | } |
86ef5c9a | 102 | EXPORT_SYMBOL_GPL(get_online_cpus); |
90d45d17 | 103 | |
86ef5c9a | 104 | void put_online_cpus(void) |
a9d9baa1 | 105 | { |
d221938c | 106 | if (cpu_hotplug.active_writer == current) |
aa953877 | 107 | return; |
d221938c | 108 | mutex_lock(&cpu_hotplug.lock); |
075663d1 SB |
109 | |
110 | if (WARN_ON(!cpu_hotplug.refcount)) | |
111 | cpu_hotplug.refcount++; /* try to fix things up */ | |
112 | ||
d2ba7e2a ON |
113 | if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer)) |
114 | wake_up_process(cpu_hotplug.active_writer); | |
d221938c GS |
115 | mutex_unlock(&cpu_hotplug.lock); |
116 | ||
a9d9baa1 | 117 | } |
86ef5c9a | 118 | EXPORT_SYMBOL_GPL(put_online_cpus); |
a9d9baa1 | 119 | |
d221938c GS |
120 | /* |
121 | * This ensures that the hotplug operation can begin only when the | |
122 | * refcount goes to zero. | |
123 | * | |
124 | * Note that during a cpu-hotplug operation, the new readers, if any, | |
125 | * will be blocked by the cpu_hotplug.lock | |
126 | * | |
d2ba7e2a ON |
127 | * Since cpu_hotplug_begin() is always called after invoking |
128 | * cpu_maps_update_begin(), we can be sure that only one writer is active. | |
d221938c GS |
129 | * |
130 | * Note that theoretically, there is a possibility of a livelock: | |
131 | * - Refcount goes to zero, last reader wakes up the sleeping | |
132 | * writer. | |
133 | * - Last reader unlocks the cpu_hotplug.lock. | |
134 | * - A new reader arrives at this moment, bumps up the refcount. | |
135 | * - The writer acquires the cpu_hotplug.lock finds the refcount | |
136 | * non zero and goes to sleep again. | |
137 | * | |
138 | * However, this is very difficult to achieve in practice since | |
86ef5c9a | 139 | * get_online_cpus() not an api which is called all that often. |
d221938c GS |
140 | * |
141 | */ | |
142 | static void cpu_hotplug_begin(void) | |
143 | { | |
d221938c | 144 | cpu_hotplug.active_writer = current; |
d2ba7e2a ON |
145 | |
146 | for (;;) { | |
147 | mutex_lock(&cpu_hotplug.lock); | |
148 | if (likely(!cpu_hotplug.refcount)) | |
149 | break; | |
150 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
d221938c GS |
151 | mutex_unlock(&cpu_hotplug.lock); |
152 | schedule(); | |
d221938c | 153 | } |
6fa3eb70 S |
154 | |
155 | /******************************************************************************* | |
156 | * 20131225 marc.huang * | |
157 | * CPU Hotplug and idle integration * | |
158 | *******************************************************************************/ | |
159 | atomic_inc(&is_in_hotplug); | |
160 | spm_mcdi_wakeup_all_cores(); | |
161 | /******************************************************************************/ | |
d221938c GS |
162 | } |
163 | ||
164 | static void cpu_hotplug_done(void) | |
165 | { | |
6fa3eb70 S |
166 | /******************************************************************************* |
167 | * 20131225 marc.huang * | |
168 | * CPU Hotplug and idle integration * | |
169 | *******************************************************************************/ | |
170 | atomic_dec(&is_in_hotplug); | |
171 | /******************************************************************************/ | |
172 | ||
d221938c GS |
173 | cpu_hotplug.active_writer = NULL; |
174 | mutex_unlock(&cpu_hotplug.lock); | |
175 | } | |
79a6cdeb | 176 | |
16e53dbf SB |
177 | /* |
178 | * Wait for currently running CPU hotplug operations to complete (if any) and | |
179 | * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects | |
180 | * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the | |
181 | * hotplug path before performing hotplug operations. So acquiring that lock | |
182 | * guarantees mutual exclusion from any currently running hotplug operations. | |
183 | */ | |
184 | void cpu_hotplug_disable(void) | |
185 | { | |
186 | cpu_maps_update_begin(); | |
187 | cpu_hotplug_disabled = 1; | |
188 | cpu_maps_update_done(); | |
189 | } | |
190 | ||
191 | void cpu_hotplug_enable(void) | |
192 | { | |
193 | cpu_maps_update_begin(); | |
194 | cpu_hotplug_disabled = 0; | |
195 | cpu_maps_update_done(); | |
196 | } | |
197 | ||
79a6cdeb LJ |
198 | #else /* #if CONFIG_HOTPLUG_CPU */ |
199 | static void cpu_hotplug_begin(void) {} | |
200 | static void cpu_hotplug_done(void) {} | |
25985edc | 201 | #endif /* #else #if CONFIG_HOTPLUG_CPU */ |
79a6cdeb | 202 | |
1da177e4 | 203 | /* Need to know about CPUs going up/down? */ |
f7b16c10 | 204 | int __ref register_cpu_notifier(struct notifier_block *nb) |
1da177e4 | 205 | { |
bd5349cf | 206 | int ret; |
6fa3eb70 S |
207 | |
208 | /******************************************************************************* | |
209 | * 20131225 marc.huang * | |
210 | * CPU Hotplug debug mechanism * | |
211 | *******************************************************************************/ | |
212 | #ifdef MTK_CPU_HOTPLUG_DEBUG_0 | |
213 | static int index = 0; | |
214 | #ifdef CONFIG_KALLSYMS | |
215 | char namebuf[128] = {0}; | |
216 | const char *symname; | |
217 | ||
218 | symname = kallsyms_lookup((unsigned long)nb->notifier_call, NULL, NULL, NULL, namebuf); | |
219 | if (symname) | |
220 | printk("[cpu_ntf] <%02d>%08lx (%s)\n", index++, (unsigned long)nb->notifier_call, symname); | |
221 | else | |
222 | printk("[cpu_ntf] <%02d>%08lx\n", index++, (unsigned long)nb->notifier_call); | |
223 | #else //#ifdef CONFIG_KALLSYMS | |
224 | printk("[cpu_ntf] <%02d>%08lx\n", index++, (unsigned long)nb->notifier_call); | |
225 | #endif //#ifdef CONFIG_KALLSYMS | |
226 | #endif //#ifdef MTK_CPU_HOTPLUG_DEBUG_0 | |
227 | /******************************************************************************/ | |
228 | ||
d221938c | 229 | cpu_maps_update_begin(); |
bd5349cf | 230 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
d221938c | 231 | cpu_maps_update_done(); |
bd5349cf | 232 | return ret; |
1da177e4 | 233 | } |
65edc68c | 234 | |
e9fb7631 AM |
235 | static int __cpu_notify(unsigned long val, void *v, int nr_to_call, |
236 | int *nr_calls) | |
237 | { | |
e6bde73b AM |
238 | int ret; |
239 | ||
240 | ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call, | |
e9fb7631 | 241 | nr_calls); |
e6bde73b AM |
242 | |
243 | return notifier_to_errno(ret); | |
e9fb7631 AM |
244 | } |
245 | ||
246 | static int cpu_notify(unsigned long val, void *v) | |
247 | { | |
248 | return __cpu_notify(val, v, -1, NULL); | |
249 | } | |
250 | ||
251 | static void cpu_notify_nofail(unsigned long val, void *v) | |
252 | { | |
00b9b0af | 253 | BUG_ON(cpu_notify(val, v)); |
e9fb7631 | 254 | } |
1da177e4 LT |
255 | EXPORT_SYMBOL(register_cpu_notifier); |
256 | ||
9647155f | 257 | void __ref unregister_cpu_notifier(struct notifier_block *nb) |
1da177e4 | 258 | { |
d221938c | 259 | cpu_maps_update_begin(); |
bd5349cf | 260 | raw_notifier_chain_unregister(&cpu_chain, nb); |
d221938c | 261 | cpu_maps_update_done(); |
1da177e4 LT |
262 | } |
263 | EXPORT_SYMBOL(unregister_cpu_notifier); | |
264 | ||
57bf12f4 | 265 | #ifdef CONFIG_HOTPLUG_CPU |
e4cc2f87 AV |
266 | /** |
267 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU | |
268 | * @cpu: a CPU id | |
269 | * | |
270 | * This function walks all processes, finds a valid mm struct for each one and | |
271 | * then clears a corresponding bit in mm's cpumask. While this all sounds | |
272 | * trivial, there are various non-obvious corner cases, which this function | |
273 | * tries to solve in a safe manner. | |
274 | * | |
275 | * Also note that the function uses a somewhat relaxed locking scheme, so it may | |
276 | * be called only for an already offlined CPU. | |
277 | */ | |
cb79295e AV |
278 | void clear_tasks_mm_cpumask(int cpu) |
279 | { | |
280 | struct task_struct *p; | |
281 | ||
282 | /* | |
283 | * This function is called after the cpu is taken down and marked | |
284 | * offline, so its not like new tasks will ever get this cpu set in | |
285 | * their mm mask. -- Peter Zijlstra | |
286 | * Thus, we may use rcu_read_lock() here, instead of grabbing | |
287 | * full-fledged tasklist_lock. | |
288 | */ | |
e4cc2f87 | 289 | WARN_ON(cpu_online(cpu)); |
cb79295e AV |
290 | rcu_read_lock(); |
291 | for_each_process(p) { | |
292 | struct task_struct *t; | |
293 | ||
e4cc2f87 AV |
294 | /* |
295 | * Main thread might exit, but other threads may still have | |
296 | * a valid mm. Find one. | |
297 | */ | |
cb79295e AV |
298 | t = find_lock_task_mm(p); |
299 | if (!t) | |
300 | continue; | |
301 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); | |
302 | task_unlock(t); | |
303 | } | |
304 | rcu_read_unlock(); | |
305 | } | |
306 | ||
1da177e4 LT |
307 | static inline void check_for_tasks(int cpu) |
308 | { | |
309 | struct task_struct *p; | |
6fac4829 | 310 | cputime_t utime, stime; |
1da177e4 LT |
311 | |
312 | write_lock_irq(&tasklist_lock); | |
313 | for_each_process(p) { | |
6fac4829 | 314 | task_cputime(p, &utime, &stime); |
11854247 | 315 | if (task_cpu(p) == cpu && p->state == TASK_RUNNING && |
6fac4829 | 316 | (utime || stime)) |
9d3cfc4c FP |
317 | printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d " |
318 | "(state = %ld, flags = %x)\n", | |
319 | p->comm, task_pid_nr(p), cpu, | |
320 | p->state, p->flags); | |
1da177e4 LT |
321 | } |
322 | write_unlock_irq(&tasklist_lock); | |
323 | } | |
324 | ||
db912f96 AK |
325 | struct take_cpu_down_param { |
326 | unsigned long mod; | |
327 | void *hcpu; | |
328 | }; | |
329 | ||
1da177e4 | 330 | /* Take this CPU down. */ |
514a20a5 | 331 | static int __ref take_cpu_down(void *_param) |
1da177e4 | 332 | { |
db912f96 | 333 | struct take_cpu_down_param *param = _param; |
1da177e4 LT |
334 | int err; |
335 | ||
1da177e4 LT |
336 | /* Ensure this CPU doesn't handle any more interrupts. */ |
337 | err = __cpu_disable(); | |
338 | if (err < 0) | |
f3705136 | 339 | return err; |
1da177e4 | 340 | |
e9fb7631 | 341 | cpu_notify(CPU_DYING | param->mod, param->hcpu); |
14e568e7 TG |
342 | /* Park the stopper thread */ |
343 | kthread_park(current); | |
f3705136 | 344 | return 0; |
1da177e4 LT |
345 | } |
346 | ||
e3920fb4 | 347 | /* Requires cpu_add_remove_lock to be held */ |
514a20a5 | 348 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) |
1da177e4 | 349 | { |
e7407dcc | 350 | int err, nr_calls = 0; |
e7407dcc | 351 | void *hcpu = (void *)(long)cpu; |
8bb78442 | 352 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
db912f96 AK |
353 | struct take_cpu_down_param tcd_param = { |
354 | .mod = mod, | |
355 | .hcpu = hcpu, | |
356 | }; | |
1da177e4 | 357 | |
e3920fb4 RW |
358 | if (num_online_cpus() == 1) |
359 | return -EBUSY; | |
1da177e4 | 360 | |
e3920fb4 RW |
361 | if (!cpu_online(cpu)) |
362 | return -EINVAL; | |
1da177e4 | 363 | |
d221938c | 364 | cpu_hotplug_begin(); |
4d51985e | 365 | |
e9fb7631 | 366 | err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls); |
e6bde73b | 367 | if (err) { |
a0d8cdb6 | 368 | nr_calls--; |
e9fb7631 | 369 | __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL); |
1da177e4 | 370 | printk("%s: attempt to take down CPU %u failed\n", |
af1f16d0 | 371 | __func__, cpu); |
baaca49f | 372 | goto out_release; |
1da177e4 | 373 | } |
f97f8f06 | 374 | smpboot_park_threads(cpu); |
1da177e4 | 375 | |
e0b582ec | 376 | err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); |
04321587 | 377 | if (err) { |
1da177e4 | 378 | /* CPU didn't die: tell everyone. Can't complain. */ |
f97f8f06 | 379 | smpboot_unpark_threads(cpu); |
e9fb7631 | 380 | cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu); |
6a1bdc1b | 381 | goto out_release; |
8fa1d7d3 | 382 | } |
04321587 | 383 | BUG_ON(cpu_online(cpu)); |
1da177e4 | 384 | |
48c5ccae PZ |
385 | /* |
386 | * The migration_call() CPU_DYING callback will have removed all | |
387 | * runnable tasks from the cpu, there's only the idle task left now | |
388 | * that the migration thread is done doing the stop_machine thing. | |
51a96c77 PZ |
389 | * |
390 | * Wait for the stop thread to go away. | |
48c5ccae | 391 | */ |
51a96c77 PZ |
392 | while (!idle_cpu(cpu)) |
393 | cpu_relax(); | |
1da177e4 | 394 | |
6fa3eb70 S |
395 | #ifdef CONFIG_MT_LOAD_BALANCE_PROFILER |
396 | mt_lbprof_update_state(cpu, MT_LBPROF_HOTPLUG_STATE); | |
397 | #endif | |
398 | ||
1da177e4 LT |
399 | /* This actually kills the CPU. */ |
400 | __cpu_die(cpu); | |
401 | ||
1da177e4 | 402 | /* CPU is completely dead: tell everyone. Too late to complain. */ |
e9fb7631 | 403 | cpu_notify_nofail(CPU_DEAD | mod, hcpu); |
1da177e4 LT |
404 | |
405 | check_for_tasks(cpu); | |
406 | ||
baaca49f | 407 | out_release: |
d221938c | 408 | cpu_hotplug_done(); |
e9fb7631 AM |
409 | if (!err) |
410 | cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu); | |
e3920fb4 RW |
411 | return err; |
412 | } | |
413 | ||
514a20a5 | 414 | int __ref cpu_down(unsigned int cpu) |
e3920fb4 | 415 | { |
9ea09af3 | 416 | int err; |
e3920fb4 | 417 | |
d221938c | 418 | cpu_maps_update_begin(); |
e761b772 MK |
419 | |
420 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 421 | err = -EBUSY; |
e761b772 MK |
422 | goto out; |
423 | } | |
424 | ||
e761b772 | 425 | err = _cpu_down(cpu, 0); |
e3920fb4 | 426 | |
e761b772 | 427 | out: |
d221938c | 428 | cpu_maps_update_done(); |
1da177e4 LT |
429 | return err; |
430 | } | |
b62b8ef9 | 431 | EXPORT_SYMBOL(cpu_down); |
1da177e4 LT |
432 | #endif /*CONFIG_HOTPLUG_CPU*/ |
433 | ||
e3920fb4 | 434 | /* Requires cpu_add_remove_lock to be held */ |
8bb78442 | 435 | static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) |
1da177e4 | 436 | { |
baaca49f | 437 | int ret, nr_calls = 0; |
1da177e4 | 438 | void *hcpu = (void *)(long)cpu; |
8bb78442 | 439 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
3bb5d2ee | 440 | struct task_struct *idle; |
1da177e4 | 441 | |
d221938c | 442 | cpu_hotplug_begin(); |
38498a67 | 443 | |
5e5041f3 YI |
444 | if (cpu_online(cpu) || !cpu_present(cpu)) { |
445 | ret = -EINVAL; | |
446 | goto out; | |
447 | } | |
448 | ||
3bb5d2ee SS |
449 | idle = idle_thread_get(cpu); |
450 | if (IS_ERR(idle)) { | |
451 | ret = PTR_ERR(idle); | |
38498a67 | 452 | goto out; |
3bb5d2ee | 453 | } |
38498a67 | 454 | |
f97f8f06 TG |
455 | ret = smpboot_create_threads(cpu); |
456 | if (ret) | |
457 | goto out; | |
458 | ||
e9fb7631 | 459 | ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls); |
e6bde73b | 460 | if (ret) { |
a0d8cdb6 | 461 | nr_calls--; |
4d51985e | 462 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", |
af1f16d0 | 463 | __func__, cpu); |
1da177e4 LT |
464 | goto out_notify; |
465 | } | |
466 | ||
467 | /* Arch-specific enabling code. */ | |
3bb5d2ee | 468 | ret = __cpu_up(cpu, idle); |
1da177e4 LT |
469 | if (ret != 0) |
470 | goto out_notify; | |
6978c705 | 471 | BUG_ON(!cpu_online(cpu)); |
1da177e4 | 472 | |
f97f8f06 TG |
473 | /* Wake the per cpu threads */ |
474 | smpboot_unpark_threads(cpu); | |
475 | ||
1da177e4 | 476 | /* Now call notifier in preparation. */ |
e9fb7631 | 477 | cpu_notify(CPU_ONLINE | mod, hcpu); |
1da177e4 LT |
478 | |
479 | out_notify: | |
480 | if (ret != 0) | |
e9fb7631 | 481 | __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL); |
38498a67 | 482 | out: |
d221938c | 483 | cpu_hotplug_done(); |
e3920fb4 RW |
484 | |
485 | return ret; | |
486 | } | |
487 | ||
b282b6f8 | 488 | int __cpuinit cpu_up(unsigned int cpu) |
e3920fb4 RW |
489 | { |
490 | int err = 0; | |
cf23422b | 491 | |
492 | #ifdef CONFIG_MEMORY_HOTPLUG | |
493 | int nid; | |
494 | pg_data_t *pgdat; | |
495 | #endif | |
496 | ||
e0b582ec | 497 | if (!cpu_possible(cpu)) { |
73e753a5 KH |
498 | printk(KERN_ERR "can't online cpu %d because it is not " |
499 | "configured as may-hotadd at boot time\n", cpu); | |
87d5e023 | 500 | #if defined(CONFIG_IA64) |
73e753a5 KH |
501 | printk(KERN_ERR "please check additional_cpus= boot " |
502 | "parameter\n"); | |
503 | #endif | |
504 | return -EINVAL; | |
505 | } | |
e3920fb4 | 506 | |
cf23422b | 507 | #ifdef CONFIG_MEMORY_HOTPLUG |
508 | nid = cpu_to_node(cpu); | |
509 | if (!node_online(nid)) { | |
510 | err = mem_online_node(nid); | |
511 | if (err) | |
512 | return err; | |
513 | } | |
514 | ||
515 | pgdat = NODE_DATA(nid); | |
516 | if (!pgdat) { | |
517 | printk(KERN_ERR | |
518 | "Can't online cpu %d due to NULL pgdat\n", cpu); | |
519 | return -ENOMEM; | |
520 | } | |
521 | ||
4eaf3f64 HL |
522 | if (pgdat->node_zonelists->_zonerefs->zone == NULL) { |
523 | mutex_lock(&zonelists_mutex); | |
9adb62a5 | 524 | build_all_zonelists(NULL, NULL); |
4eaf3f64 HL |
525 | mutex_unlock(&zonelists_mutex); |
526 | } | |
cf23422b | 527 | #endif |
528 | ||
d221938c | 529 | cpu_maps_update_begin(); |
e761b772 MK |
530 | |
531 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 532 | err = -EBUSY; |
e761b772 MK |
533 | goto out; |
534 | } | |
535 | ||
536 | err = _cpu_up(cpu, 0); | |
537 | ||
e761b772 | 538 | out: |
d221938c | 539 | cpu_maps_update_done(); |
e3920fb4 RW |
540 | return err; |
541 | } | |
a513f6ba | 542 | EXPORT_SYMBOL_GPL(cpu_up); |
e3920fb4 | 543 | |
f3de4be9 | 544 | #ifdef CONFIG_PM_SLEEP_SMP |
e0b582ec | 545 | static cpumask_var_t frozen_cpus; |
e3920fb4 RW |
546 | |
547 | int disable_nonboot_cpus(void) | |
548 | { | |
e9a5f426 | 549 | int cpu, first_cpu, error = 0; |
e3920fb4 | 550 | |
d221938c | 551 | cpu_maps_update_begin(); |
e0b582ec | 552 | first_cpu = cpumask_first(cpu_online_mask); |
9ee349ad XF |
553 | /* |
554 | * We take down all of the non-boot CPUs in one shot to avoid races | |
e3920fb4 RW |
555 | * with the userspace trying to use the CPU hotplug at the same time |
556 | */ | |
e0b582ec | 557 | cpumask_clear(frozen_cpus); |
6ad4c188 | 558 | |
e3920fb4 RW |
559 | printk("Disabling non-boot CPUs ...\n"); |
560 | for_each_online_cpu(cpu) { | |
561 | if (cpu == first_cpu) | |
562 | continue; | |
8bb78442 | 563 | error = _cpu_down(cpu, 1); |
feae3203 | 564 | if (!error) |
e0b582ec | 565 | cpumask_set_cpu(cpu, frozen_cpus); |
feae3203 | 566 | else { |
e3920fb4 RW |
567 | printk(KERN_ERR "Error taking CPU%d down: %d\n", |
568 | cpu, error); | |
569 | break; | |
570 | } | |
571 | } | |
86886e55 | 572 | |
e3920fb4 RW |
573 | if (!error) { |
574 | BUG_ON(num_online_cpus() > 1); | |
575 | /* Make sure the CPUs won't be enabled by someone else */ | |
576 | cpu_hotplug_disabled = 1; | |
577 | } else { | |
e1d9fd2e | 578 | printk(KERN_ERR "Non-boot CPUs are not disabled\n"); |
e3920fb4 | 579 | } |
d221938c | 580 | cpu_maps_update_done(); |
e3920fb4 RW |
581 | return error; |
582 | } | |
6fa3eb70 | 583 | EXPORT_SYMBOL_GPL(disable_nonboot_cpus); |
e3920fb4 | 584 | |
d0af9eed SS |
585 | void __weak arch_enable_nonboot_cpus_begin(void) |
586 | { | |
587 | } | |
588 | ||
589 | void __weak arch_enable_nonboot_cpus_end(void) | |
590 | { | |
591 | } | |
592 | ||
fa7303e2 | 593 | void __ref enable_nonboot_cpus(void) |
e3920fb4 RW |
594 | { |
595 | int cpu, error; | |
596 | ||
597 | /* Allow everyone to use the CPU hotplug again */ | |
d221938c | 598 | cpu_maps_update_begin(); |
e3920fb4 | 599 | cpu_hotplug_disabled = 0; |
e0b582ec | 600 | if (cpumask_empty(frozen_cpus)) |
1d64b9cb | 601 | goto out; |
e3920fb4 | 602 | |
4d51985e | 603 | printk(KERN_INFO "Enabling non-boot CPUs ...\n"); |
d0af9eed SS |
604 | |
605 | arch_enable_nonboot_cpus_begin(); | |
606 | ||
e0b582ec | 607 | for_each_cpu(cpu, frozen_cpus) { |
8bb78442 | 608 | error = _cpu_up(cpu, 1); |
e3920fb4 | 609 | if (!error) { |
4d51985e | 610 | printk(KERN_INFO "CPU%d is up\n", cpu); |
e3920fb4 RW |
611 | continue; |
612 | } | |
1d64b9cb | 613 | printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error); |
e3920fb4 | 614 | } |
d0af9eed SS |
615 | |
616 | arch_enable_nonboot_cpus_end(); | |
617 | ||
e0b582ec | 618 | cpumask_clear(frozen_cpus); |
1d64b9cb | 619 | out: |
d221938c | 620 | cpu_maps_update_done(); |
1da177e4 | 621 | } |
6fa3eb70 | 622 | EXPORT_SYMBOL_GPL(enable_nonboot_cpus); |
e0b582ec | 623 | |
d7268a31 | 624 | static int __init alloc_frozen_cpus(void) |
e0b582ec RR |
625 | { |
626 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) | |
627 | return -ENOMEM; | |
628 | return 0; | |
629 | } | |
630 | core_initcall(alloc_frozen_cpus); | |
79cfbdfa | 631 | |
79cfbdfa SB |
632 | /* |
633 | * When callbacks for CPU hotplug notifications are being executed, we must | |
634 | * ensure that the state of the system with respect to the tasks being frozen | |
635 | * or not, as reported by the notification, remains unchanged *throughout the | |
636 | * duration* of the execution of the callbacks. | |
637 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. | |
638 | * | |
639 | * This synchronization is implemented by mutually excluding regular CPU | |
640 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ | |
641 | * Hibernate notifications. | |
642 | */ | |
643 | static int | |
644 | cpu_hotplug_pm_callback(struct notifier_block *nb, | |
645 | unsigned long action, void *ptr) | |
646 | { | |
647 | switch (action) { | |
648 | ||
649 | case PM_SUSPEND_PREPARE: | |
650 | case PM_HIBERNATION_PREPARE: | |
16e53dbf | 651 | cpu_hotplug_disable(); |
79cfbdfa SB |
652 | break; |
653 | ||
654 | case PM_POST_SUSPEND: | |
655 | case PM_POST_HIBERNATION: | |
16e53dbf | 656 | cpu_hotplug_enable(); |
79cfbdfa SB |
657 | break; |
658 | ||
659 | default: | |
660 | return NOTIFY_DONE; | |
661 | } | |
662 | ||
663 | return NOTIFY_OK; | |
664 | } | |
665 | ||
666 | ||
d7268a31 | 667 | static int __init cpu_hotplug_pm_sync_init(void) |
79cfbdfa | 668 | { |
6e32d479 FY |
669 | /* |
670 | * cpu_hotplug_pm_callback has higher priority than x86 | |
671 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback | |
672 | * to disable cpu hotplug to avoid cpu hotplug race. | |
673 | */ | |
79cfbdfa SB |
674 | pm_notifier(cpu_hotplug_pm_callback, 0); |
675 | return 0; | |
676 | } | |
677 | core_initcall(cpu_hotplug_pm_sync_init); | |
678 | ||
f3de4be9 | 679 | #endif /* CONFIG_PM_SLEEP_SMP */ |
68f4f1ec | 680 | |
e545a614 MS |
681 | /** |
682 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers | |
683 | * @cpu: cpu that just started | |
684 | * | |
685 | * This function calls the cpu_chain notifiers with CPU_STARTING. | |
686 | * It must be called by the arch code on the new cpu, before the new cpu | |
687 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). | |
688 | */ | |
84196414 | 689 | void __cpuinit notify_cpu_starting(unsigned int cpu) |
e545a614 MS |
690 | { |
691 | unsigned long val = CPU_STARTING; | |
692 | ||
693 | #ifdef CONFIG_PM_SLEEP_SMP | |
e0b582ec | 694 | if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus)) |
e545a614 MS |
695 | val = CPU_STARTING_FROZEN; |
696 | #endif /* CONFIG_PM_SLEEP_SMP */ | |
e9fb7631 | 697 | cpu_notify(val, (void *)(long)cpu); |
e545a614 MS |
698 | } |
699 | ||
68f4f1ec | 700 | #endif /* CONFIG_SMP */ |
b8d317d1 | 701 | |
e56b3bc7 LT |
702 | /* |
703 | * cpu_bit_bitmap[] is a special, "compressed" data structure that | |
704 | * represents all NR_CPUS bits binary values of 1<<nr. | |
705 | * | |
e0b582ec | 706 | * It is used by cpumask_of() to get a constant address to a CPU |
e56b3bc7 LT |
707 | * mask value that has a single bit set only. |
708 | */ | |
b8d317d1 | 709 | |
e56b3bc7 | 710 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
4d51985e | 711 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
e56b3bc7 LT |
712 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
713 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) | |
714 | #define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) | |
b8d317d1 | 715 | |
e56b3bc7 LT |
716 | const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { |
717 | ||
718 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), | |
719 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), | |
720 | #if BITS_PER_LONG > 32 | |
721 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), | |
722 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), | |
b8d317d1 MT |
723 | #endif |
724 | }; | |
e56b3bc7 | 725 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
2d3854a3 RR |
726 | |
727 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; | |
728 | EXPORT_SYMBOL(cpu_all_bits); | |
b3199c02 RR |
729 | |
730 | #ifdef CONFIG_INIT_ALL_POSSIBLE | |
731 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly | |
732 | = CPU_BITS_ALL; | |
733 | #else | |
734 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly; | |
735 | #endif | |
736 | const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits); | |
737 | EXPORT_SYMBOL(cpu_possible_mask); | |
738 | ||
739 | static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly; | |
740 | const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits); | |
741 | EXPORT_SYMBOL(cpu_online_mask); | |
742 | ||
743 | static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly; | |
744 | const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits); | |
745 | EXPORT_SYMBOL(cpu_present_mask); | |
746 | ||
747 | static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly; | |
748 | const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits); | |
749 | EXPORT_SYMBOL(cpu_active_mask); | |
3fa41520 RR |
750 | |
751 | void set_cpu_possible(unsigned int cpu, bool possible) | |
752 | { | |
753 | if (possible) | |
754 | cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits)); | |
755 | else | |
756 | cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits)); | |
757 | } | |
758 | ||
759 | void set_cpu_present(unsigned int cpu, bool present) | |
760 | { | |
761 | if (present) | |
762 | cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits)); | |
763 | else | |
764 | cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits)); | |
765 | } | |
766 | ||
767 | void set_cpu_online(unsigned int cpu, bool online) | |
768 | { | |
24d52daa | 769 | if (online) { |
3fa41520 | 770 | cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits)); |
24d52daa LJ |
771 | cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); |
772 | } else { | |
3fa41520 | 773 | cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits)); |
24d52daa | 774 | } |
3fa41520 RR |
775 | } |
776 | ||
777 | void set_cpu_active(unsigned int cpu, bool active) | |
778 | { | |
779 | if (active) | |
780 | cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); | |
781 | else | |
782 | cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits)); | |
783 | } | |
784 | ||
785 | void init_cpu_present(const struct cpumask *src) | |
786 | { | |
787 | cpumask_copy(to_cpumask(cpu_present_bits), src); | |
788 | } | |
789 | ||
790 | void init_cpu_possible(const struct cpumask *src) | |
791 | { | |
792 | cpumask_copy(to_cpumask(cpu_possible_bits), src); | |
793 | } | |
794 | ||
795 | void init_cpu_online(const struct cpumask *src) | |
796 | { | |
797 | cpumask_copy(to_cpumask(cpu_online_bits), src); | |
798 | } | |
6fa3eb70 S |
799 | |
800 | static ATOMIC_NOTIFIER_HEAD(idle_notifier); | |
801 | ||
802 | void idle_notifier_register(struct notifier_block *n) | |
803 | { | |
804 | atomic_notifier_chain_register(&idle_notifier, n); | |
805 | } | |
806 | EXPORT_SYMBOL_GPL(idle_notifier_register); | |
807 | ||
808 | void idle_notifier_unregister(struct notifier_block *n) | |
809 | { | |
810 | atomic_notifier_chain_unregister(&idle_notifier, n); | |
811 | } | |
812 | EXPORT_SYMBOL_GPL(idle_notifier_unregister); | |
813 | ||
814 | void idle_notifier_call_chain(unsigned long val) | |
815 | { | |
816 | atomic_notifier_call_chain(&idle_notifier, val, NULL); | |
817 | } | |
818 | EXPORT_SYMBOL_GPL(idle_notifier_call_chain); |