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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> | |
3f07c014 | 10 | #include <linux/sched/signal.h> |
ef8bd77f | 11 | #include <linux/sched/hotplug.h> |
29930025 | 12 | #include <linux/sched/task.h> |
1da177e4 LT |
13 | #include <linux/unistd.h> |
14 | #include <linux/cpu.h> | |
cb79295e AV |
15 | #include <linux/oom.h> |
16 | #include <linux/rcupdate.h> | |
9984de1a | 17 | #include <linux/export.h> |
e4cc2f87 | 18 | #include <linux/bug.h> |
1da177e4 LT |
19 | #include <linux/kthread.h> |
20 | #include <linux/stop_machine.h> | |
81615b62 | 21 | #include <linux/mutex.h> |
5a0e3ad6 | 22 | #include <linux/gfp.h> |
79cfbdfa | 23 | #include <linux/suspend.h> |
a19423b9 | 24 | #include <linux/lockdep.h> |
345527b1 | 25 | #include <linux/tick.h> |
a8994181 | 26 | #include <linux/irq.h> |
4cb28ced | 27 | #include <linux/smpboot.h> |
e6d4989a | 28 | #include <linux/relay.h> |
6731d4f1 | 29 | #include <linux/slab.h> |
fc8dffd3 | 30 | #include <linux/percpu-rwsem.h> |
cff7d378 | 31 | |
bb3632c6 | 32 | #include <trace/events/power.h> |
cff7d378 TG |
33 | #define CREATE_TRACE_POINTS |
34 | #include <trace/events/cpuhp.h> | |
1da177e4 | 35 | |
38498a67 TG |
36 | #include "smpboot.h" |
37 | ||
cff7d378 TG |
38 | /** |
39 | * cpuhp_cpu_state - Per cpu hotplug state storage | |
40 | * @state: The current cpu state | |
41 | * @target: The target state | |
4cb28ced TG |
42 | * @thread: Pointer to the hotplug thread |
43 | * @should_run: Thread should execute | |
3b9d6da6 | 44 | * @rollback: Perform a rollback |
a724632c TG |
45 | * @single: Single callback invocation |
46 | * @bringup: Single callback bringup or teardown selector | |
47 | * @cb_state: The state for a single callback (install/uninstall) | |
4cb28ced | 48 | * @result: Result of the operation |
5ebe7742 PZ |
49 | * @done_up: Signal completion to the issuer of the task for cpu-up |
50 | * @done_down: Signal completion to the issuer of the task for cpu-down | |
cff7d378 TG |
51 | */ |
52 | struct cpuhp_cpu_state { | |
53 | enum cpuhp_state state; | |
54 | enum cpuhp_state target; | |
1db49484 | 55 | enum cpuhp_state fail; |
4cb28ced TG |
56 | #ifdef CONFIG_SMP |
57 | struct task_struct *thread; | |
58 | bool should_run; | |
3b9d6da6 | 59 | bool rollback; |
a724632c TG |
60 | bool single; |
61 | bool bringup; | |
cf392d10 | 62 | struct hlist_node *node; |
4dddfb5f | 63 | struct hlist_node *last; |
4cb28ced | 64 | enum cpuhp_state cb_state; |
4cb28ced | 65 | int result; |
5ebe7742 PZ |
66 | struct completion done_up; |
67 | struct completion done_down; | |
4cb28ced | 68 | #endif |
cff7d378 TG |
69 | }; |
70 | ||
1db49484 PZ |
71 | static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state) = { |
72 | .fail = CPUHP_INVALID, | |
73 | }; | |
cff7d378 | 74 | |
49dfe2a6 | 75 | #if defined(CONFIG_LOCKDEP) && defined(CONFIG_SMP) |
5f4b55e1 PZ |
76 | static struct lockdep_map cpuhp_state_up_map = |
77 | STATIC_LOCKDEP_MAP_INIT("cpuhp_state-up", &cpuhp_state_up_map); | |
78 | static struct lockdep_map cpuhp_state_down_map = | |
79 | STATIC_LOCKDEP_MAP_INIT("cpuhp_state-down", &cpuhp_state_down_map); | |
80 | ||
81 | ||
82 | static void inline cpuhp_lock_acquire(bool bringup) | |
83 | { | |
84 | lock_map_acquire(bringup ? &cpuhp_state_up_map : &cpuhp_state_down_map); | |
85 | } | |
86 | ||
87 | static void inline cpuhp_lock_release(bool bringup) | |
88 | { | |
89 | lock_map_release(bringup ? &cpuhp_state_up_map : &cpuhp_state_down_map); | |
90 | } | |
91 | #else | |
92 | ||
93 | static void inline cpuhp_lock_acquire(bool bringup) { } | |
94 | static void inline cpuhp_lock_release(bool bringup) { } | |
95 | ||
49dfe2a6 TG |
96 | #endif |
97 | ||
cff7d378 TG |
98 | /** |
99 | * cpuhp_step - Hotplug state machine step | |
100 | * @name: Name of the step | |
101 | * @startup: Startup function of the step | |
102 | * @teardown: Teardown function of the step | |
103 | * @skip_onerr: Do not invoke the functions on error rollback | |
104 | * Will go away once the notifiers are gone | |
757c989b | 105 | * @cant_stop: Bringup/teardown can't be stopped at this step |
cff7d378 TG |
106 | */ |
107 | struct cpuhp_step { | |
cf392d10 TG |
108 | const char *name; |
109 | union { | |
3c1627e9 TG |
110 | int (*single)(unsigned int cpu); |
111 | int (*multi)(unsigned int cpu, | |
112 | struct hlist_node *node); | |
113 | } startup; | |
cf392d10 | 114 | union { |
3c1627e9 TG |
115 | int (*single)(unsigned int cpu); |
116 | int (*multi)(unsigned int cpu, | |
117 | struct hlist_node *node); | |
118 | } teardown; | |
cf392d10 TG |
119 | struct hlist_head list; |
120 | bool skip_onerr; | |
121 | bool cant_stop; | |
122 | bool multi_instance; | |
cff7d378 TG |
123 | }; |
124 | ||
98f8cdce | 125 | static DEFINE_MUTEX(cpuhp_state_mutex); |
cff7d378 | 126 | static struct cpuhp_step cpuhp_bp_states[]; |
4baa0afc | 127 | static struct cpuhp_step cpuhp_ap_states[]; |
cff7d378 | 128 | |
a724632c TG |
129 | static bool cpuhp_is_ap_state(enum cpuhp_state state) |
130 | { | |
131 | /* | |
132 | * The extra check for CPUHP_TEARDOWN_CPU is only for documentation | |
133 | * purposes as that state is handled explicitly in cpu_down. | |
134 | */ | |
135 | return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU; | |
136 | } | |
137 | ||
138 | static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state) | |
139 | { | |
140 | struct cpuhp_step *sp; | |
141 | ||
142 | sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states; | |
143 | return sp + state; | |
144 | } | |
145 | ||
cff7d378 TG |
146 | /** |
147 | * cpuhp_invoke_callback _ Invoke the callbacks for a given state | |
148 | * @cpu: The cpu for which the callback should be invoked | |
96abb968 | 149 | * @state: The state to do callbacks for |
a724632c | 150 | * @bringup: True if the bringup callback should be invoked |
96abb968 PZ |
151 | * @node: For multi-instance, do a single entry callback for install/remove |
152 | * @lastp: For multi-instance rollback, remember how far we got | |
cff7d378 | 153 | * |
cf392d10 | 154 | * Called from cpu hotplug and from the state register machinery. |
cff7d378 | 155 | */ |
a724632c | 156 | static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state, |
96abb968 PZ |
157 | bool bringup, struct hlist_node *node, |
158 | struct hlist_node **lastp) | |
cff7d378 TG |
159 | { |
160 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
a724632c | 161 | struct cpuhp_step *step = cpuhp_get_step(state); |
cf392d10 TG |
162 | int (*cbm)(unsigned int cpu, struct hlist_node *node); |
163 | int (*cb)(unsigned int cpu); | |
164 | int ret, cnt; | |
165 | ||
1db49484 PZ |
166 | if (st->fail == state) { |
167 | st->fail = CPUHP_INVALID; | |
168 | ||
169 | if (!(bringup ? step->startup.single : step->teardown.single)) | |
170 | return 0; | |
171 | ||
172 | return -EAGAIN; | |
173 | } | |
174 | ||
cf392d10 | 175 | if (!step->multi_instance) { |
96abb968 | 176 | WARN_ON_ONCE(lastp && *lastp); |
3c1627e9 | 177 | cb = bringup ? step->startup.single : step->teardown.single; |
cf392d10 TG |
178 | if (!cb) |
179 | return 0; | |
a724632c | 180 | trace_cpuhp_enter(cpu, st->target, state, cb); |
cff7d378 | 181 | ret = cb(cpu); |
a724632c | 182 | trace_cpuhp_exit(cpu, st->state, state, ret); |
cf392d10 TG |
183 | return ret; |
184 | } | |
3c1627e9 | 185 | cbm = bringup ? step->startup.multi : step->teardown.multi; |
cf392d10 TG |
186 | if (!cbm) |
187 | return 0; | |
188 | ||
189 | /* Single invocation for instance add/remove */ | |
190 | if (node) { | |
96abb968 | 191 | WARN_ON_ONCE(lastp && *lastp); |
cf392d10 TG |
192 | trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node); |
193 | ret = cbm(cpu, node); | |
194 | trace_cpuhp_exit(cpu, st->state, state, ret); | |
195 | return ret; | |
196 | } | |
197 | ||
198 | /* State transition. Invoke on all instances */ | |
199 | cnt = 0; | |
200 | hlist_for_each(node, &step->list) { | |
96abb968 PZ |
201 | if (lastp && node == *lastp) |
202 | break; | |
203 | ||
cf392d10 TG |
204 | trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node); |
205 | ret = cbm(cpu, node); | |
206 | trace_cpuhp_exit(cpu, st->state, state, ret); | |
96abb968 PZ |
207 | if (ret) { |
208 | if (!lastp) | |
209 | goto err; | |
210 | ||
211 | *lastp = node; | |
212 | return ret; | |
213 | } | |
cf392d10 TG |
214 | cnt++; |
215 | } | |
96abb968 PZ |
216 | if (lastp) |
217 | *lastp = NULL; | |
cf392d10 TG |
218 | return 0; |
219 | err: | |
220 | /* Rollback the instances if one failed */ | |
3c1627e9 | 221 | cbm = !bringup ? step->startup.multi : step->teardown.multi; |
cf392d10 TG |
222 | if (!cbm) |
223 | return ret; | |
224 | ||
225 | hlist_for_each(node, &step->list) { | |
226 | if (!cnt--) | |
227 | break; | |
724a8688 PZ |
228 | |
229 | trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node); | |
230 | ret = cbm(cpu, node); | |
231 | trace_cpuhp_exit(cpu, st->state, state, ret); | |
232 | /* | |
233 | * Rollback must not fail, | |
234 | */ | |
235 | WARN_ON_ONCE(ret); | |
cff7d378 TG |
236 | } |
237 | return ret; | |
238 | } | |
239 | ||
98a79d6a | 240 | #ifdef CONFIG_SMP |
5ebe7742 PZ |
241 | static inline void wait_for_ap_thread(struct cpuhp_cpu_state *st, bool bringup) |
242 | { | |
243 | struct completion *done = bringup ? &st->done_up : &st->done_down; | |
244 | wait_for_completion(done); | |
245 | } | |
246 | ||
247 | static inline void complete_ap_thread(struct cpuhp_cpu_state *st, bool bringup) | |
248 | { | |
249 | struct completion *done = bringup ? &st->done_up : &st->done_down; | |
250 | complete(done); | |
251 | } | |
252 | ||
253 | /* | |
254 | * The former STARTING/DYING states, ran with IRQs disabled and must not fail. | |
255 | */ | |
256 | static bool cpuhp_is_atomic_state(enum cpuhp_state state) | |
257 | { | |
258 | return CPUHP_AP_IDLE_DEAD <= state && state < CPUHP_AP_ONLINE; | |
259 | } | |
260 | ||
b3199c02 | 261 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
aa953877 | 262 | static DEFINE_MUTEX(cpu_add_remove_lock); |
090e77c3 TG |
263 | bool cpuhp_tasks_frozen; |
264 | EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen); | |
1da177e4 | 265 | |
79a6cdeb | 266 | /* |
93ae4f97 SB |
267 | * The following two APIs (cpu_maps_update_begin/done) must be used when |
268 | * attempting to serialize the updates to cpu_online_mask & cpu_present_mask. | |
79a6cdeb LJ |
269 | */ |
270 | void cpu_maps_update_begin(void) | |
271 | { | |
272 | mutex_lock(&cpu_add_remove_lock); | |
273 | } | |
274 | ||
275 | void cpu_maps_update_done(void) | |
276 | { | |
277 | mutex_unlock(&cpu_add_remove_lock); | |
278 | } | |
1da177e4 | 279 | |
fc8dffd3 TG |
280 | /* |
281 | * If set, cpu_up and cpu_down will return -EBUSY and do nothing. | |
e3920fb4 RW |
282 | * Should always be manipulated under cpu_add_remove_lock |
283 | */ | |
284 | static int cpu_hotplug_disabled; | |
285 | ||
79a6cdeb LJ |
286 | #ifdef CONFIG_HOTPLUG_CPU |
287 | ||
fc8dffd3 | 288 | DEFINE_STATIC_PERCPU_RWSEM(cpu_hotplug_lock); |
a19423b9 | 289 | |
8f553c49 | 290 | void cpus_read_lock(void) |
a9d9baa1 | 291 | { |
fc8dffd3 | 292 | percpu_down_read(&cpu_hotplug_lock); |
a9d9baa1 | 293 | } |
8f553c49 | 294 | EXPORT_SYMBOL_GPL(cpus_read_lock); |
90d45d17 | 295 | |
8f553c49 | 296 | void cpus_read_unlock(void) |
a9d9baa1 | 297 | { |
fc8dffd3 | 298 | percpu_up_read(&cpu_hotplug_lock); |
a9d9baa1 | 299 | } |
8f553c49 | 300 | EXPORT_SYMBOL_GPL(cpus_read_unlock); |
a9d9baa1 | 301 | |
8f553c49 | 302 | void cpus_write_lock(void) |
d221938c | 303 | { |
fc8dffd3 | 304 | percpu_down_write(&cpu_hotplug_lock); |
d221938c | 305 | } |
87af9e7f | 306 | |
8f553c49 | 307 | void cpus_write_unlock(void) |
d221938c | 308 | { |
fc8dffd3 | 309 | percpu_up_write(&cpu_hotplug_lock); |
d221938c GS |
310 | } |
311 | ||
fc8dffd3 | 312 | void lockdep_assert_cpus_held(void) |
d221938c | 313 | { |
fc8dffd3 | 314 | percpu_rwsem_assert_held(&cpu_hotplug_lock); |
d221938c | 315 | } |
79a6cdeb | 316 | |
16e53dbf SB |
317 | /* |
318 | * Wait for currently running CPU hotplug operations to complete (if any) and | |
319 | * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects | |
320 | * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the | |
321 | * hotplug path before performing hotplug operations. So acquiring that lock | |
322 | * guarantees mutual exclusion from any currently running hotplug operations. | |
323 | */ | |
324 | void cpu_hotplug_disable(void) | |
325 | { | |
326 | cpu_maps_update_begin(); | |
89af7ba5 | 327 | cpu_hotplug_disabled++; |
16e53dbf SB |
328 | cpu_maps_update_done(); |
329 | } | |
32145c46 | 330 | EXPORT_SYMBOL_GPL(cpu_hotplug_disable); |
16e53dbf | 331 | |
01b41159 LW |
332 | static void __cpu_hotplug_enable(void) |
333 | { | |
334 | if (WARN_ONCE(!cpu_hotplug_disabled, "Unbalanced cpu hotplug enable\n")) | |
335 | return; | |
336 | cpu_hotplug_disabled--; | |
337 | } | |
338 | ||
16e53dbf SB |
339 | void cpu_hotplug_enable(void) |
340 | { | |
341 | cpu_maps_update_begin(); | |
01b41159 | 342 | __cpu_hotplug_enable(); |
16e53dbf SB |
343 | cpu_maps_update_done(); |
344 | } | |
32145c46 | 345 | EXPORT_SYMBOL_GPL(cpu_hotplug_enable); |
b9d10be7 | 346 | #endif /* CONFIG_HOTPLUG_CPU */ |
79a6cdeb | 347 | |
4dddfb5f PZ |
348 | static inline enum cpuhp_state |
349 | cpuhp_set_state(struct cpuhp_cpu_state *st, enum cpuhp_state target) | |
350 | { | |
351 | enum cpuhp_state prev_state = st->state; | |
352 | ||
353 | st->rollback = false; | |
354 | st->last = NULL; | |
355 | ||
356 | st->target = target; | |
357 | st->single = false; | |
358 | st->bringup = st->state < target; | |
359 | ||
360 | return prev_state; | |
361 | } | |
362 | ||
363 | static inline void | |
364 | cpuhp_reset_state(struct cpuhp_cpu_state *st, enum cpuhp_state prev_state) | |
365 | { | |
366 | st->rollback = true; | |
367 | ||
368 | /* | |
369 | * If we have st->last we need to undo partial multi_instance of this | |
370 | * state first. Otherwise start undo at the previous state. | |
371 | */ | |
372 | if (!st->last) { | |
373 | if (st->bringup) | |
374 | st->state--; | |
375 | else | |
376 | st->state++; | |
377 | } | |
378 | ||
379 | st->target = prev_state; | |
380 | st->bringup = !st->bringup; | |
381 | } | |
382 | ||
383 | /* Regular hotplug invocation of the AP hotplug thread */ | |
384 | static void __cpuhp_kick_ap(struct cpuhp_cpu_state *st) | |
385 | { | |
386 | if (!st->single && st->state == st->target) | |
387 | return; | |
388 | ||
389 | st->result = 0; | |
390 | /* | |
391 | * Make sure the above stores are visible before should_run becomes | |
392 | * true. Paired with the mb() above in cpuhp_thread_fun() | |
393 | */ | |
394 | smp_mb(); | |
395 | st->should_run = true; | |
396 | wake_up_process(st->thread); | |
5ebe7742 | 397 | wait_for_ap_thread(st, st->bringup); |
4dddfb5f PZ |
398 | } |
399 | ||
400 | static int cpuhp_kick_ap(struct cpuhp_cpu_state *st, enum cpuhp_state target) | |
401 | { | |
402 | enum cpuhp_state prev_state; | |
403 | int ret; | |
404 | ||
405 | prev_state = cpuhp_set_state(st, target); | |
406 | __cpuhp_kick_ap(st); | |
407 | if ((ret = st->result)) { | |
408 | cpuhp_reset_state(st, prev_state); | |
409 | __cpuhp_kick_ap(st); | |
410 | } | |
411 | ||
412 | return ret; | |
413 | } | |
9cd4f1a4 | 414 | |
8df3e07e TG |
415 | static int bringup_wait_for_ap(unsigned int cpu) |
416 | { | |
417 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
418 | ||
9cd4f1a4 | 419 | /* Wait for the CPU to reach CPUHP_AP_ONLINE_IDLE */ |
5ebe7742 | 420 | wait_for_ap_thread(st, true); |
dea1d0f5 TG |
421 | if (WARN_ON_ONCE((!cpu_online(cpu)))) |
422 | return -ECANCELED; | |
9cd4f1a4 TG |
423 | |
424 | /* Unpark the stopper thread and the hotplug thread of the target cpu */ | |
425 | stop_machine_unpark(cpu); | |
426 | kthread_unpark(st->thread); | |
427 | ||
4dddfb5f PZ |
428 | if (st->target <= CPUHP_AP_ONLINE_IDLE) |
429 | return 0; | |
430 | ||
431 | return cpuhp_kick_ap(st, st->target); | |
8df3e07e TG |
432 | } |
433 | ||
ba997462 TG |
434 | static int bringup_cpu(unsigned int cpu) |
435 | { | |
436 | struct task_struct *idle = idle_thread_get(cpu); | |
437 | int ret; | |
438 | ||
aa877175 BO |
439 | /* |
440 | * Some architectures have to walk the irq descriptors to | |
441 | * setup the vector space for the cpu which comes online. | |
442 | * Prevent irq alloc/free across the bringup. | |
443 | */ | |
444 | irq_lock_sparse(); | |
445 | ||
ba997462 TG |
446 | /* Arch-specific enabling code. */ |
447 | ret = __cpu_up(cpu, idle); | |
aa877175 | 448 | irq_unlock_sparse(); |
530e9b76 | 449 | if (ret) |
ba997462 | 450 | return ret; |
9cd4f1a4 | 451 | return bringup_wait_for_ap(cpu); |
ba997462 TG |
452 | } |
453 | ||
2e1a3483 TG |
454 | /* |
455 | * Hotplug state machine related functions | |
456 | */ | |
2e1a3483 | 457 | |
a724632c | 458 | static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st) |
2e1a3483 TG |
459 | { |
460 | for (st->state--; st->state > st->target; st->state--) { | |
a724632c | 461 | struct cpuhp_step *step = cpuhp_get_step(st->state); |
2e1a3483 TG |
462 | |
463 | if (!step->skip_onerr) | |
96abb968 | 464 | cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL); |
2e1a3483 TG |
465 | } |
466 | } | |
467 | ||
468 | static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, | |
a724632c | 469 | enum cpuhp_state target) |
2e1a3483 TG |
470 | { |
471 | enum cpuhp_state prev_state = st->state; | |
472 | int ret = 0; | |
473 | ||
474 | while (st->state < target) { | |
2e1a3483 | 475 | st->state++; |
96abb968 | 476 | ret = cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL); |
2e1a3483 TG |
477 | if (ret) { |
478 | st->target = prev_state; | |
a724632c | 479 | undo_cpu_up(cpu, st); |
2e1a3483 TG |
480 | break; |
481 | } | |
482 | } | |
483 | return ret; | |
484 | } | |
485 | ||
4cb28ced TG |
486 | /* |
487 | * The cpu hotplug threads manage the bringup and teardown of the cpus | |
488 | */ | |
489 | static void cpuhp_create(unsigned int cpu) | |
490 | { | |
491 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
492 | ||
5ebe7742 PZ |
493 | init_completion(&st->done_up); |
494 | init_completion(&st->done_down); | |
4cb28ced TG |
495 | } |
496 | ||
497 | static int cpuhp_should_run(unsigned int cpu) | |
498 | { | |
499 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); | |
500 | ||
501 | return st->should_run; | |
502 | } | |
503 | ||
4cb28ced TG |
504 | /* |
505 | * Execute teardown/startup callbacks on the plugged cpu. Also used to invoke | |
506 | * callbacks when a state gets [un]installed at runtime. | |
4dddfb5f PZ |
507 | * |
508 | * Each invocation of this function by the smpboot thread does a single AP | |
509 | * state callback. | |
510 | * | |
511 | * It has 3 modes of operation: | |
512 | * - single: runs st->cb_state | |
513 | * - up: runs ++st->state, while st->state < st->target | |
514 | * - down: runs st->state--, while st->state > st->target | |
515 | * | |
516 | * When complete or on error, should_run is cleared and the completion is fired. | |
4cb28ced TG |
517 | */ |
518 | static void cpuhp_thread_fun(unsigned int cpu) | |
519 | { | |
520 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); | |
4dddfb5f PZ |
521 | bool bringup = st->bringup; |
522 | enum cpuhp_state state; | |
4cb28ced TG |
523 | |
524 | /* | |
4dddfb5f PZ |
525 | * ACQUIRE for the cpuhp_should_run() load of ->should_run. Ensures |
526 | * that if we see ->should_run we also see the rest of the state. | |
4cb28ced TG |
527 | */ |
528 | smp_mb(); | |
4cb28ced | 529 | |
4dddfb5f PZ |
530 | if (WARN_ON_ONCE(!st->should_run)) |
531 | return; | |
4cb28ced | 532 | |
5f4b55e1 | 533 | cpuhp_lock_acquire(bringup); |
4dddfb5f | 534 | |
a724632c | 535 | if (st->single) { |
4dddfb5f PZ |
536 | state = st->cb_state; |
537 | st->should_run = false; | |
538 | } else { | |
539 | if (bringup) { | |
540 | st->state++; | |
541 | state = st->state; | |
542 | st->should_run = (st->state < st->target); | |
543 | WARN_ON_ONCE(st->state > st->target); | |
4cb28ced | 544 | } else { |
4dddfb5f PZ |
545 | state = st->state; |
546 | st->state--; | |
547 | st->should_run = (st->state > st->target); | |
548 | WARN_ON_ONCE(st->state < st->target); | |
4cb28ced | 549 | } |
4dddfb5f PZ |
550 | } |
551 | ||
552 | WARN_ON_ONCE(!cpuhp_is_ap_state(state)); | |
553 | ||
554 | if (st->rollback) { | |
555 | struct cpuhp_step *step = cpuhp_get_step(state); | |
556 | if (step->skip_onerr) | |
557 | goto next; | |
558 | } | |
559 | ||
560 | if (cpuhp_is_atomic_state(state)) { | |
561 | local_irq_disable(); | |
562 | st->result = cpuhp_invoke_callback(cpu, state, bringup, st->node, &st->last); | |
563 | local_irq_enable(); | |
3b9d6da6 | 564 | |
4dddfb5f PZ |
565 | /* |
566 | * STARTING/DYING must not fail! | |
567 | */ | |
568 | WARN_ON_ONCE(st->result); | |
4cb28ced | 569 | } else { |
4dddfb5f PZ |
570 | st->result = cpuhp_invoke_callback(cpu, state, bringup, st->node, &st->last); |
571 | } | |
572 | ||
573 | if (st->result) { | |
574 | /* | |
575 | * If we fail on a rollback, we're up a creek without no | |
576 | * paddle, no way forward, no way back. We loose, thanks for | |
577 | * playing. | |
578 | */ | |
579 | WARN_ON_ONCE(st->rollback); | |
580 | st->should_run = false; | |
4cb28ced | 581 | } |
4dddfb5f PZ |
582 | |
583 | next: | |
5f4b55e1 | 584 | cpuhp_lock_release(bringup); |
4dddfb5f PZ |
585 | |
586 | if (!st->should_run) | |
5ebe7742 | 587 | complete_ap_thread(st, bringup); |
4cb28ced TG |
588 | } |
589 | ||
590 | /* Invoke a single callback on a remote cpu */ | |
a724632c | 591 | static int |
cf392d10 TG |
592 | cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, bool bringup, |
593 | struct hlist_node *node) | |
4cb28ced TG |
594 | { |
595 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
4dddfb5f | 596 | int ret; |
4cb28ced TG |
597 | |
598 | if (!cpu_online(cpu)) | |
599 | return 0; | |
600 | ||
5f4b55e1 PZ |
601 | cpuhp_lock_acquire(false); |
602 | cpuhp_lock_release(false); | |
603 | ||
604 | cpuhp_lock_acquire(true); | |
605 | cpuhp_lock_release(true); | |
49dfe2a6 | 606 | |
6a4e2451 TG |
607 | /* |
608 | * If we are up and running, use the hotplug thread. For early calls | |
609 | * we invoke the thread function directly. | |
610 | */ | |
611 | if (!st->thread) | |
96abb968 | 612 | return cpuhp_invoke_callback(cpu, state, bringup, node, NULL); |
6a4e2451 | 613 | |
4dddfb5f PZ |
614 | st->rollback = false; |
615 | st->last = NULL; | |
616 | ||
617 | st->node = node; | |
618 | st->bringup = bringup; | |
4cb28ced | 619 | st->cb_state = state; |
a724632c | 620 | st->single = true; |
a724632c | 621 | |
4dddfb5f | 622 | __cpuhp_kick_ap(st); |
4cb28ced | 623 | |
4cb28ced | 624 | /* |
4dddfb5f | 625 | * If we failed and did a partial, do a rollback. |
4cb28ced | 626 | */ |
4dddfb5f PZ |
627 | if ((ret = st->result) && st->last) { |
628 | st->rollback = true; | |
629 | st->bringup = !bringup; | |
630 | ||
631 | __cpuhp_kick_ap(st); | |
632 | } | |
633 | ||
634 | return ret; | |
1cf4f629 TG |
635 | } |
636 | ||
637 | static int cpuhp_kick_ap_work(unsigned int cpu) | |
638 | { | |
639 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
4dddfb5f PZ |
640 | enum cpuhp_state prev_state = st->state; |
641 | int ret; | |
1cf4f629 | 642 | |
5f4b55e1 PZ |
643 | cpuhp_lock_acquire(false); |
644 | cpuhp_lock_release(false); | |
645 | ||
646 | cpuhp_lock_acquire(true); | |
647 | cpuhp_lock_release(true); | |
4dddfb5f PZ |
648 | |
649 | trace_cpuhp_enter(cpu, st->target, prev_state, cpuhp_kick_ap_work); | |
650 | ret = cpuhp_kick_ap(st, st->target); | |
651 | trace_cpuhp_exit(cpu, st->state, prev_state, ret); | |
652 | ||
653 | return ret; | |
4cb28ced TG |
654 | } |
655 | ||
656 | static struct smp_hotplug_thread cpuhp_threads = { | |
657 | .store = &cpuhp_state.thread, | |
658 | .create = &cpuhp_create, | |
659 | .thread_should_run = cpuhp_should_run, | |
660 | .thread_fn = cpuhp_thread_fun, | |
661 | .thread_comm = "cpuhp/%u", | |
662 | .selfparking = true, | |
663 | }; | |
664 | ||
665 | void __init cpuhp_threads_init(void) | |
666 | { | |
667 | BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads)); | |
668 | kthread_unpark(this_cpu_read(cpuhp_state.thread)); | |
669 | } | |
670 | ||
777c6e0d | 671 | #ifdef CONFIG_HOTPLUG_CPU |
e4cc2f87 AV |
672 | /** |
673 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU | |
674 | * @cpu: a CPU id | |
675 | * | |
676 | * This function walks all processes, finds a valid mm struct for each one and | |
677 | * then clears a corresponding bit in mm's cpumask. While this all sounds | |
678 | * trivial, there are various non-obvious corner cases, which this function | |
679 | * tries to solve in a safe manner. | |
680 | * | |
681 | * Also note that the function uses a somewhat relaxed locking scheme, so it may | |
682 | * be called only for an already offlined CPU. | |
683 | */ | |
cb79295e AV |
684 | void clear_tasks_mm_cpumask(int cpu) |
685 | { | |
686 | struct task_struct *p; | |
687 | ||
688 | /* | |
689 | * This function is called after the cpu is taken down and marked | |
690 | * offline, so its not like new tasks will ever get this cpu set in | |
691 | * their mm mask. -- Peter Zijlstra | |
692 | * Thus, we may use rcu_read_lock() here, instead of grabbing | |
693 | * full-fledged tasklist_lock. | |
694 | */ | |
e4cc2f87 | 695 | WARN_ON(cpu_online(cpu)); |
cb79295e AV |
696 | rcu_read_lock(); |
697 | for_each_process(p) { | |
698 | struct task_struct *t; | |
699 | ||
e4cc2f87 AV |
700 | /* |
701 | * Main thread might exit, but other threads may still have | |
702 | * a valid mm. Find one. | |
703 | */ | |
cb79295e AV |
704 | t = find_lock_task_mm(p); |
705 | if (!t) | |
706 | continue; | |
707 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); | |
708 | task_unlock(t); | |
709 | } | |
710 | rcu_read_unlock(); | |
711 | } | |
712 | ||
1da177e4 | 713 | /* Take this CPU down. */ |
71cf5aee | 714 | static int take_cpu_down(void *_param) |
1da177e4 | 715 | { |
4baa0afc TG |
716 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
717 | enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE); | |
090e77c3 | 718 | int err, cpu = smp_processor_id(); |
724a8688 | 719 | int ret; |
1da177e4 | 720 | |
1da177e4 LT |
721 | /* Ensure this CPU doesn't handle any more interrupts. */ |
722 | err = __cpu_disable(); | |
723 | if (err < 0) | |
f3705136 | 724 | return err; |
1da177e4 | 725 | |
a724632c TG |
726 | /* |
727 | * We get here while we are in CPUHP_TEARDOWN_CPU state and we must not | |
728 | * do this step again. | |
729 | */ | |
730 | WARN_ON(st->state != CPUHP_TEARDOWN_CPU); | |
731 | st->state--; | |
4baa0afc | 732 | /* Invoke the former CPU_DYING callbacks */ |
724a8688 PZ |
733 | for (; st->state > target; st->state--) { |
734 | ret = cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL); | |
735 | /* | |
736 | * DYING must not fail! | |
737 | */ | |
738 | WARN_ON_ONCE(ret); | |
739 | } | |
4baa0afc | 740 | |
52c063d1 TG |
741 | /* Give up timekeeping duties */ |
742 | tick_handover_do_timer(); | |
14e568e7 | 743 | /* Park the stopper thread */ |
090e77c3 | 744 | stop_machine_park(cpu); |
f3705136 | 745 | return 0; |
1da177e4 LT |
746 | } |
747 | ||
98458172 | 748 | static int takedown_cpu(unsigned int cpu) |
1da177e4 | 749 | { |
e69aab13 | 750 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
98458172 | 751 | int err; |
1da177e4 | 752 | |
2a58c527 | 753 | /* Park the smpboot threads */ |
1cf4f629 | 754 | kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread); |
2a58c527 | 755 | smpboot_park_threads(cpu); |
1cf4f629 | 756 | |
6acce3ef | 757 | /* |
a8994181 TG |
758 | * Prevent irq alloc/free while the dying cpu reorganizes the |
759 | * interrupt affinities. | |
6acce3ef | 760 | */ |
a8994181 | 761 | irq_lock_sparse(); |
6acce3ef | 762 | |
a8994181 TG |
763 | /* |
764 | * So now all preempt/rcu users must observe !cpu_active(). | |
765 | */ | |
210e2133 | 766 | err = stop_machine_cpuslocked(take_cpu_down, NULL, cpumask_of(cpu)); |
04321587 | 767 | if (err) { |
3b9d6da6 | 768 | /* CPU refused to die */ |
a8994181 | 769 | irq_unlock_sparse(); |
3b9d6da6 SAS |
770 | /* Unpark the hotplug thread so we can rollback there */ |
771 | kthread_unpark(per_cpu_ptr(&cpuhp_state, cpu)->thread); | |
98458172 | 772 | return err; |
8fa1d7d3 | 773 | } |
04321587 | 774 | BUG_ON(cpu_online(cpu)); |
1da177e4 | 775 | |
48c5ccae | 776 | /* |
ee1e714b | 777 | * The CPUHP_AP_SCHED_MIGRATE_DYING callback will have removed all |
48c5ccae PZ |
778 | * runnable tasks from the cpu, there's only the idle task left now |
779 | * that the migration thread is done doing the stop_machine thing. | |
51a96c77 PZ |
780 | * |
781 | * Wait for the stop thread to go away. | |
48c5ccae | 782 | */ |
5ebe7742 | 783 | wait_for_ap_thread(st, false); |
e69aab13 | 784 | BUG_ON(st->state != CPUHP_AP_IDLE_DEAD); |
1da177e4 | 785 | |
a8994181 TG |
786 | /* Interrupts are moved away from the dying cpu, reenable alloc/free */ |
787 | irq_unlock_sparse(); | |
788 | ||
345527b1 | 789 | hotplug_cpu__broadcast_tick_pull(cpu); |
1da177e4 LT |
790 | /* This actually kills the CPU. */ |
791 | __cpu_die(cpu); | |
792 | ||
a49b116d | 793 | tick_cleanup_dead_cpu(cpu); |
a58163d8 | 794 | rcutree_migrate_callbacks(cpu); |
98458172 TG |
795 | return 0; |
796 | } | |
1da177e4 | 797 | |
71f87b2f TG |
798 | static void cpuhp_complete_idle_dead(void *arg) |
799 | { | |
800 | struct cpuhp_cpu_state *st = arg; | |
801 | ||
5ebe7742 | 802 | complete_ap_thread(st, false); |
71f87b2f TG |
803 | } |
804 | ||
e69aab13 TG |
805 | void cpuhp_report_idle_dead(void) |
806 | { | |
807 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); | |
808 | ||
809 | BUG_ON(st->state != CPUHP_AP_OFFLINE); | |
27d50c7e | 810 | rcu_report_dead(smp_processor_id()); |
71f87b2f TG |
811 | st->state = CPUHP_AP_IDLE_DEAD; |
812 | /* | |
813 | * We cannot call complete after rcu_report_dead() so we delegate it | |
814 | * to an online cpu. | |
815 | */ | |
816 | smp_call_function_single(cpumask_first(cpu_online_mask), | |
817 | cpuhp_complete_idle_dead, st, 0); | |
e69aab13 TG |
818 | } |
819 | ||
4dddfb5f PZ |
820 | static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st) |
821 | { | |
822 | for (st->state++; st->state < st->target; st->state++) { | |
823 | struct cpuhp_step *step = cpuhp_get_step(st->state); | |
cff7d378 | 824 | |
4dddfb5f PZ |
825 | if (!step->skip_onerr) |
826 | cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL); | |
827 | } | |
828 | } | |
829 | ||
830 | static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, | |
831 | enum cpuhp_state target) | |
832 | { | |
833 | enum cpuhp_state prev_state = st->state; | |
834 | int ret = 0; | |
835 | ||
836 | for (; st->state > target; st->state--) { | |
837 | ret = cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL); | |
838 | if (ret) { | |
839 | st->target = prev_state; | |
840 | undo_cpu_down(cpu, st); | |
841 | break; | |
842 | } | |
843 | } | |
844 | return ret; | |
845 | } | |
cff7d378 | 846 | |
98458172 | 847 | /* Requires cpu_add_remove_lock to be held */ |
af1f4045 TG |
848 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, |
849 | enum cpuhp_state target) | |
98458172 | 850 | { |
cff7d378 TG |
851 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
852 | int prev_state, ret = 0; | |
98458172 TG |
853 | |
854 | if (num_online_cpus() == 1) | |
855 | return -EBUSY; | |
856 | ||
757c989b | 857 | if (!cpu_present(cpu)) |
98458172 TG |
858 | return -EINVAL; |
859 | ||
8f553c49 | 860 | cpus_write_lock(); |
98458172 TG |
861 | |
862 | cpuhp_tasks_frozen = tasks_frozen; | |
863 | ||
4dddfb5f | 864 | prev_state = cpuhp_set_state(st, target); |
1cf4f629 TG |
865 | /* |
866 | * If the current CPU state is in the range of the AP hotplug thread, | |
867 | * then we need to kick the thread. | |
868 | */ | |
8df3e07e | 869 | if (st->state > CPUHP_TEARDOWN_CPU) { |
4dddfb5f | 870 | st->target = max((int)target, CPUHP_TEARDOWN_CPU); |
1cf4f629 TG |
871 | ret = cpuhp_kick_ap_work(cpu); |
872 | /* | |
873 | * The AP side has done the error rollback already. Just | |
874 | * return the error code.. | |
875 | */ | |
876 | if (ret) | |
877 | goto out; | |
878 | ||
879 | /* | |
880 | * We might have stopped still in the range of the AP hotplug | |
881 | * thread. Nothing to do anymore. | |
882 | */ | |
8df3e07e | 883 | if (st->state > CPUHP_TEARDOWN_CPU) |
1cf4f629 | 884 | goto out; |
4dddfb5f PZ |
885 | |
886 | st->target = target; | |
1cf4f629 TG |
887 | } |
888 | /* | |
8df3e07e | 889 | * The AP brought itself down to CPUHP_TEARDOWN_CPU. So we need |
1cf4f629 TG |
890 | * to do the further cleanups. |
891 | */ | |
a724632c | 892 | ret = cpuhp_down_callbacks(cpu, st, target); |
3b9d6da6 | 893 | if (ret && st->state > CPUHP_TEARDOWN_CPU && st->state < prev_state) { |
4dddfb5f PZ |
894 | cpuhp_reset_state(st, prev_state); |
895 | __cpuhp_kick_ap(st); | |
3b9d6da6 | 896 | } |
98458172 | 897 | |
1cf4f629 | 898 | out: |
8f553c49 | 899 | cpus_write_unlock(); |
cff7d378 | 900 | return ret; |
e3920fb4 RW |
901 | } |
902 | ||
af1f4045 | 903 | static int do_cpu_down(unsigned int cpu, enum cpuhp_state target) |
e3920fb4 | 904 | { |
9ea09af3 | 905 | int err; |
e3920fb4 | 906 | |
d221938c | 907 | cpu_maps_update_begin(); |
e761b772 MK |
908 | |
909 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 910 | err = -EBUSY; |
e761b772 MK |
911 | goto out; |
912 | } | |
913 | ||
af1f4045 | 914 | err = _cpu_down(cpu, 0, target); |
e3920fb4 | 915 | |
e761b772 | 916 | out: |
d221938c | 917 | cpu_maps_update_done(); |
1da177e4 LT |
918 | return err; |
919 | } | |
4dddfb5f | 920 | |
af1f4045 TG |
921 | int cpu_down(unsigned int cpu) |
922 | { | |
923 | return do_cpu_down(cpu, CPUHP_OFFLINE); | |
924 | } | |
b62b8ef9 | 925 | EXPORT_SYMBOL(cpu_down); |
4dddfb5f PZ |
926 | |
927 | #else | |
928 | #define takedown_cpu NULL | |
1da177e4 LT |
929 | #endif /*CONFIG_HOTPLUG_CPU*/ |
930 | ||
4baa0afc | 931 | /** |
ee1e714b | 932 | * notify_cpu_starting(cpu) - Invoke the callbacks on the starting CPU |
4baa0afc TG |
933 | * @cpu: cpu that just started |
934 | * | |
4baa0afc TG |
935 | * It must be called by the arch code on the new cpu, before the new cpu |
936 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). | |
937 | */ | |
938 | void notify_cpu_starting(unsigned int cpu) | |
939 | { | |
940 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
941 | enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE); | |
724a8688 | 942 | int ret; |
4baa0afc | 943 | |
0c6d4576 | 944 | rcu_cpu_starting(cpu); /* Enables RCU usage on this CPU. */ |
4baa0afc | 945 | while (st->state < target) { |
4baa0afc | 946 | st->state++; |
724a8688 PZ |
947 | ret = cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL); |
948 | /* | |
949 | * STARTING must not fail! | |
950 | */ | |
951 | WARN_ON_ONCE(ret); | |
4baa0afc TG |
952 | } |
953 | } | |
954 | ||
949338e3 | 955 | /* |
9cd4f1a4 TG |
956 | * Called from the idle task. Wake up the controlling task which brings the |
957 | * stopper and the hotplug thread of the upcoming CPU up and then delegates | |
958 | * the rest of the online bringup to the hotplug thread. | |
949338e3 | 959 | */ |
8df3e07e | 960 | void cpuhp_online_idle(enum cpuhp_state state) |
949338e3 | 961 | { |
8df3e07e | 962 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
8df3e07e TG |
963 | |
964 | /* Happens for the boot cpu */ | |
965 | if (state != CPUHP_AP_ONLINE_IDLE) | |
966 | return; | |
967 | ||
968 | st->state = CPUHP_AP_ONLINE_IDLE; | |
5ebe7742 | 969 | complete_ap_thread(st, true); |
949338e3 TG |
970 | } |
971 | ||
e3920fb4 | 972 | /* Requires cpu_add_remove_lock to be held */ |
af1f4045 | 973 | static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target) |
1da177e4 | 974 | { |
cff7d378 | 975 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
3bb5d2ee | 976 | struct task_struct *idle; |
2e1a3483 | 977 | int ret = 0; |
1da177e4 | 978 | |
8f553c49 | 979 | cpus_write_lock(); |
38498a67 | 980 | |
757c989b | 981 | if (!cpu_present(cpu)) { |
5e5041f3 YI |
982 | ret = -EINVAL; |
983 | goto out; | |
984 | } | |
985 | ||
757c989b TG |
986 | /* |
987 | * The caller of do_cpu_up might have raced with another | |
988 | * caller. Ignore it for now. | |
989 | */ | |
990 | if (st->state >= target) | |
38498a67 | 991 | goto out; |
757c989b TG |
992 | |
993 | if (st->state == CPUHP_OFFLINE) { | |
994 | /* Let it fail before we try to bring the cpu up */ | |
995 | idle = idle_thread_get(cpu); | |
996 | if (IS_ERR(idle)) { | |
997 | ret = PTR_ERR(idle); | |
998 | goto out; | |
999 | } | |
3bb5d2ee | 1000 | } |
38498a67 | 1001 | |
ba997462 TG |
1002 | cpuhp_tasks_frozen = tasks_frozen; |
1003 | ||
4dddfb5f | 1004 | cpuhp_set_state(st, target); |
1cf4f629 TG |
1005 | /* |
1006 | * If the current CPU state is in the range of the AP hotplug thread, | |
1007 | * then we need to kick the thread once more. | |
1008 | */ | |
8df3e07e | 1009 | if (st->state > CPUHP_BRINGUP_CPU) { |
1cf4f629 TG |
1010 | ret = cpuhp_kick_ap_work(cpu); |
1011 | /* | |
1012 | * The AP side has done the error rollback already. Just | |
1013 | * return the error code.. | |
1014 | */ | |
1015 | if (ret) | |
1016 | goto out; | |
1017 | } | |
1018 | ||
1019 | /* | |
1020 | * Try to reach the target state. We max out on the BP at | |
8df3e07e | 1021 | * CPUHP_BRINGUP_CPU. After that the AP hotplug thread is |
1cf4f629 TG |
1022 | * responsible for bringing it up to the target state. |
1023 | */ | |
8df3e07e | 1024 | target = min((int)target, CPUHP_BRINGUP_CPU); |
a724632c | 1025 | ret = cpuhp_up_callbacks(cpu, st, target); |
38498a67 | 1026 | out: |
8f553c49 | 1027 | cpus_write_unlock(); |
e3920fb4 RW |
1028 | return ret; |
1029 | } | |
1030 | ||
af1f4045 | 1031 | static int do_cpu_up(unsigned int cpu, enum cpuhp_state target) |
e3920fb4 RW |
1032 | { |
1033 | int err = 0; | |
cf23422b | 1034 | |
e0b582ec | 1035 | if (!cpu_possible(cpu)) { |
84117da5 FF |
1036 | pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n", |
1037 | cpu); | |
87d5e023 | 1038 | #if defined(CONFIG_IA64) |
84117da5 | 1039 | pr_err("please check additional_cpus= boot parameter\n"); |
73e753a5 KH |
1040 | #endif |
1041 | return -EINVAL; | |
1042 | } | |
e3920fb4 | 1043 | |
01b0f197 TK |
1044 | err = try_online_node(cpu_to_node(cpu)); |
1045 | if (err) | |
1046 | return err; | |
cf23422b | 1047 | |
d221938c | 1048 | cpu_maps_update_begin(); |
e761b772 MK |
1049 | |
1050 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 1051 | err = -EBUSY; |
e761b772 MK |
1052 | goto out; |
1053 | } | |
1054 | ||
af1f4045 | 1055 | err = _cpu_up(cpu, 0, target); |
e761b772 | 1056 | out: |
d221938c | 1057 | cpu_maps_update_done(); |
e3920fb4 RW |
1058 | return err; |
1059 | } | |
af1f4045 TG |
1060 | |
1061 | int cpu_up(unsigned int cpu) | |
1062 | { | |
1063 | return do_cpu_up(cpu, CPUHP_ONLINE); | |
1064 | } | |
a513f6ba | 1065 | EXPORT_SYMBOL_GPL(cpu_up); |
e3920fb4 | 1066 | |
f3de4be9 | 1067 | #ifdef CONFIG_PM_SLEEP_SMP |
e0b582ec | 1068 | static cpumask_var_t frozen_cpus; |
e3920fb4 | 1069 | |
d391e552 | 1070 | int freeze_secondary_cpus(int primary) |
e3920fb4 | 1071 | { |
d391e552 | 1072 | int cpu, error = 0; |
e3920fb4 | 1073 | |
d221938c | 1074 | cpu_maps_update_begin(); |
d391e552 JM |
1075 | if (!cpu_online(primary)) |
1076 | primary = cpumask_first(cpu_online_mask); | |
9ee349ad XF |
1077 | /* |
1078 | * We take down all of the non-boot CPUs in one shot to avoid races | |
e3920fb4 RW |
1079 | * with the userspace trying to use the CPU hotplug at the same time |
1080 | */ | |
e0b582ec | 1081 | cpumask_clear(frozen_cpus); |
6ad4c188 | 1082 | |
84117da5 | 1083 | pr_info("Disabling non-boot CPUs ...\n"); |
e3920fb4 | 1084 | for_each_online_cpu(cpu) { |
d391e552 | 1085 | if (cpu == primary) |
e3920fb4 | 1086 | continue; |
bb3632c6 | 1087 | trace_suspend_resume(TPS("CPU_OFF"), cpu, true); |
af1f4045 | 1088 | error = _cpu_down(cpu, 1, CPUHP_OFFLINE); |
bb3632c6 | 1089 | trace_suspend_resume(TPS("CPU_OFF"), cpu, false); |
feae3203 | 1090 | if (!error) |
e0b582ec | 1091 | cpumask_set_cpu(cpu, frozen_cpus); |
feae3203 | 1092 | else { |
84117da5 | 1093 | pr_err("Error taking CPU%d down: %d\n", cpu, error); |
e3920fb4 RW |
1094 | break; |
1095 | } | |
1096 | } | |
86886e55 | 1097 | |
89af7ba5 | 1098 | if (!error) |
e3920fb4 | 1099 | BUG_ON(num_online_cpus() > 1); |
89af7ba5 | 1100 | else |
84117da5 | 1101 | pr_err("Non-boot CPUs are not disabled\n"); |
89af7ba5 VK |
1102 | |
1103 | /* | |
1104 | * Make sure the CPUs won't be enabled by someone else. We need to do | |
1105 | * this even in case of failure as all disable_nonboot_cpus() users are | |
1106 | * supposed to do enable_nonboot_cpus() on the failure path. | |
1107 | */ | |
1108 | cpu_hotplug_disabled++; | |
1109 | ||
d221938c | 1110 | cpu_maps_update_done(); |
e3920fb4 RW |
1111 | return error; |
1112 | } | |
1113 | ||
d0af9eed SS |
1114 | void __weak arch_enable_nonboot_cpus_begin(void) |
1115 | { | |
1116 | } | |
1117 | ||
1118 | void __weak arch_enable_nonboot_cpus_end(void) | |
1119 | { | |
1120 | } | |
1121 | ||
71cf5aee | 1122 | void enable_nonboot_cpus(void) |
e3920fb4 RW |
1123 | { |
1124 | int cpu, error; | |
1125 | ||
1126 | /* Allow everyone to use the CPU hotplug again */ | |
d221938c | 1127 | cpu_maps_update_begin(); |
01b41159 | 1128 | __cpu_hotplug_enable(); |
e0b582ec | 1129 | if (cpumask_empty(frozen_cpus)) |
1d64b9cb | 1130 | goto out; |
e3920fb4 | 1131 | |
84117da5 | 1132 | pr_info("Enabling non-boot CPUs ...\n"); |
d0af9eed SS |
1133 | |
1134 | arch_enable_nonboot_cpus_begin(); | |
1135 | ||
e0b582ec | 1136 | for_each_cpu(cpu, frozen_cpus) { |
bb3632c6 | 1137 | trace_suspend_resume(TPS("CPU_ON"), cpu, true); |
af1f4045 | 1138 | error = _cpu_up(cpu, 1, CPUHP_ONLINE); |
bb3632c6 | 1139 | trace_suspend_resume(TPS("CPU_ON"), cpu, false); |
e3920fb4 | 1140 | if (!error) { |
84117da5 | 1141 | pr_info("CPU%d is up\n", cpu); |
e3920fb4 RW |
1142 | continue; |
1143 | } | |
84117da5 | 1144 | pr_warn("Error taking CPU%d up: %d\n", cpu, error); |
e3920fb4 | 1145 | } |
d0af9eed SS |
1146 | |
1147 | arch_enable_nonboot_cpus_end(); | |
1148 | ||
e0b582ec | 1149 | cpumask_clear(frozen_cpus); |
1d64b9cb | 1150 | out: |
d221938c | 1151 | cpu_maps_update_done(); |
1da177e4 | 1152 | } |
e0b582ec | 1153 | |
d7268a31 | 1154 | static int __init alloc_frozen_cpus(void) |
e0b582ec RR |
1155 | { |
1156 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) | |
1157 | return -ENOMEM; | |
1158 | return 0; | |
1159 | } | |
1160 | core_initcall(alloc_frozen_cpus); | |
79cfbdfa | 1161 | |
79cfbdfa SB |
1162 | /* |
1163 | * When callbacks for CPU hotplug notifications are being executed, we must | |
1164 | * ensure that the state of the system with respect to the tasks being frozen | |
1165 | * or not, as reported by the notification, remains unchanged *throughout the | |
1166 | * duration* of the execution of the callbacks. | |
1167 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. | |
1168 | * | |
1169 | * This synchronization is implemented by mutually excluding regular CPU | |
1170 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ | |
1171 | * Hibernate notifications. | |
1172 | */ | |
1173 | static int | |
1174 | cpu_hotplug_pm_callback(struct notifier_block *nb, | |
1175 | unsigned long action, void *ptr) | |
1176 | { | |
1177 | switch (action) { | |
1178 | ||
1179 | case PM_SUSPEND_PREPARE: | |
1180 | case PM_HIBERNATION_PREPARE: | |
16e53dbf | 1181 | cpu_hotplug_disable(); |
79cfbdfa SB |
1182 | break; |
1183 | ||
1184 | case PM_POST_SUSPEND: | |
1185 | case PM_POST_HIBERNATION: | |
16e53dbf | 1186 | cpu_hotplug_enable(); |
79cfbdfa SB |
1187 | break; |
1188 | ||
1189 | default: | |
1190 | return NOTIFY_DONE; | |
1191 | } | |
1192 | ||
1193 | return NOTIFY_OK; | |
1194 | } | |
1195 | ||
1196 | ||
d7268a31 | 1197 | static int __init cpu_hotplug_pm_sync_init(void) |
79cfbdfa | 1198 | { |
6e32d479 FY |
1199 | /* |
1200 | * cpu_hotplug_pm_callback has higher priority than x86 | |
1201 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback | |
1202 | * to disable cpu hotplug to avoid cpu hotplug race. | |
1203 | */ | |
79cfbdfa SB |
1204 | pm_notifier(cpu_hotplug_pm_callback, 0); |
1205 | return 0; | |
1206 | } | |
1207 | core_initcall(cpu_hotplug_pm_sync_init); | |
1208 | ||
f3de4be9 | 1209 | #endif /* CONFIG_PM_SLEEP_SMP */ |
68f4f1ec | 1210 | |
8ce371f9 PZ |
1211 | int __boot_cpu_id; |
1212 | ||
68f4f1ec | 1213 | #endif /* CONFIG_SMP */ |
b8d317d1 | 1214 | |
cff7d378 TG |
1215 | /* Boot processor state steps */ |
1216 | static struct cpuhp_step cpuhp_bp_states[] = { | |
1217 | [CPUHP_OFFLINE] = { | |
1218 | .name = "offline", | |
3c1627e9 TG |
1219 | .startup.single = NULL, |
1220 | .teardown.single = NULL, | |
cff7d378 TG |
1221 | }, |
1222 | #ifdef CONFIG_SMP | |
1223 | [CPUHP_CREATE_THREADS]= { | |
677f6646 | 1224 | .name = "threads:prepare", |
3c1627e9 TG |
1225 | .startup.single = smpboot_create_threads, |
1226 | .teardown.single = NULL, | |
757c989b | 1227 | .cant_stop = true, |
cff7d378 | 1228 | }, |
00e16c3d | 1229 | [CPUHP_PERF_PREPARE] = { |
3c1627e9 TG |
1230 | .name = "perf:prepare", |
1231 | .startup.single = perf_event_init_cpu, | |
1232 | .teardown.single = perf_event_exit_cpu, | |
00e16c3d | 1233 | }, |
7ee681b2 | 1234 | [CPUHP_WORKQUEUE_PREP] = { |
3c1627e9 TG |
1235 | .name = "workqueue:prepare", |
1236 | .startup.single = workqueue_prepare_cpu, | |
1237 | .teardown.single = NULL, | |
7ee681b2 | 1238 | }, |
27590dc1 | 1239 | [CPUHP_HRTIMERS_PREPARE] = { |
3c1627e9 TG |
1240 | .name = "hrtimers:prepare", |
1241 | .startup.single = hrtimers_prepare_cpu, | |
1242 | .teardown.single = hrtimers_dead_cpu, | |
27590dc1 | 1243 | }, |
31487f83 | 1244 | [CPUHP_SMPCFD_PREPARE] = { |
677f6646 | 1245 | .name = "smpcfd:prepare", |
3c1627e9 TG |
1246 | .startup.single = smpcfd_prepare_cpu, |
1247 | .teardown.single = smpcfd_dead_cpu, | |
31487f83 | 1248 | }, |
e6d4989a RW |
1249 | [CPUHP_RELAY_PREPARE] = { |
1250 | .name = "relay:prepare", | |
1251 | .startup.single = relay_prepare_cpu, | |
1252 | .teardown.single = NULL, | |
1253 | }, | |
6731d4f1 SAS |
1254 | [CPUHP_SLAB_PREPARE] = { |
1255 | .name = "slab:prepare", | |
1256 | .startup.single = slab_prepare_cpu, | |
1257 | .teardown.single = slab_dead_cpu, | |
31487f83 | 1258 | }, |
4df83742 | 1259 | [CPUHP_RCUTREE_PREP] = { |
677f6646 | 1260 | .name = "RCU/tree:prepare", |
3c1627e9 TG |
1261 | .startup.single = rcutree_prepare_cpu, |
1262 | .teardown.single = rcutree_dead_cpu, | |
4df83742 | 1263 | }, |
4fae16df RC |
1264 | /* |
1265 | * On the tear-down path, timers_dead_cpu() must be invoked | |
1266 | * before blk_mq_queue_reinit_notify() from notify_dead(), | |
1267 | * otherwise a RCU stall occurs. | |
1268 | */ | |
1269 | [CPUHP_TIMERS_DEAD] = { | |
3c1627e9 TG |
1270 | .name = "timers:dead", |
1271 | .startup.single = NULL, | |
1272 | .teardown.single = timers_dead_cpu, | |
4fae16df | 1273 | }, |
d10ef6f9 | 1274 | /* Kicks the plugged cpu into life */ |
cff7d378 TG |
1275 | [CPUHP_BRINGUP_CPU] = { |
1276 | .name = "cpu:bringup", | |
3c1627e9 TG |
1277 | .startup.single = bringup_cpu, |
1278 | .teardown.single = NULL, | |
757c989b | 1279 | .cant_stop = true, |
4baa0afc | 1280 | }, |
31487f83 | 1281 | [CPUHP_AP_SMPCFD_DYING] = { |
677f6646 | 1282 | .name = "smpcfd:dying", |
3c1627e9 TG |
1283 | .startup.single = NULL, |
1284 | .teardown.single = smpcfd_dying_cpu, | |
31487f83 | 1285 | }, |
d10ef6f9 TG |
1286 | /* |
1287 | * Handled on controll processor until the plugged processor manages | |
1288 | * this itself. | |
1289 | */ | |
4baa0afc TG |
1290 | [CPUHP_TEARDOWN_CPU] = { |
1291 | .name = "cpu:teardown", | |
3c1627e9 TG |
1292 | .startup.single = NULL, |
1293 | .teardown.single = takedown_cpu, | |
757c989b | 1294 | .cant_stop = true, |
cff7d378 | 1295 | }, |
a7c73414 TG |
1296 | #else |
1297 | [CPUHP_BRINGUP_CPU] = { }, | |
cff7d378 | 1298 | #endif |
cff7d378 TG |
1299 | }; |
1300 | ||
4baa0afc TG |
1301 | /* Application processor state steps */ |
1302 | static struct cpuhp_step cpuhp_ap_states[] = { | |
1303 | #ifdef CONFIG_SMP | |
d10ef6f9 TG |
1304 | /* Final state before CPU kills itself */ |
1305 | [CPUHP_AP_IDLE_DEAD] = { | |
1306 | .name = "idle:dead", | |
1307 | }, | |
1308 | /* | |
1309 | * Last state before CPU enters the idle loop to die. Transient state | |
1310 | * for synchronization. | |
1311 | */ | |
1312 | [CPUHP_AP_OFFLINE] = { | |
1313 | .name = "ap:offline", | |
1314 | .cant_stop = true, | |
1315 | }, | |
9cf7243d TG |
1316 | /* First state is scheduler control. Interrupts are disabled */ |
1317 | [CPUHP_AP_SCHED_STARTING] = { | |
1318 | .name = "sched:starting", | |
3c1627e9 TG |
1319 | .startup.single = sched_cpu_starting, |
1320 | .teardown.single = sched_cpu_dying, | |
9cf7243d | 1321 | }, |
4df83742 | 1322 | [CPUHP_AP_RCUTREE_DYING] = { |
677f6646 | 1323 | .name = "RCU/tree:dying", |
3c1627e9 TG |
1324 | .startup.single = NULL, |
1325 | .teardown.single = rcutree_dying_cpu, | |
4baa0afc | 1326 | }, |
d10ef6f9 TG |
1327 | /* Entry state on starting. Interrupts enabled from here on. Transient |
1328 | * state for synchronsization */ | |
1329 | [CPUHP_AP_ONLINE] = { | |
1330 | .name = "ap:online", | |
1331 | }, | |
1332 | /* Handle smpboot threads park/unpark */ | |
1cf4f629 | 1333 | [CPUHP_AP_SMPBOOT_THREADS] = { |
677f6646 | 1334 | .name = "smpboot/threads:online", |
3c1627e9 TG |
1335 | .startup.single = smpboot_unpark_threads, |
1336 | .teardown.single = NULL, | |
1cf4f629 | 1337 | }, |
c5cb83bb TG |
1338 | [CPUHP_AP_IRQ_AFFINITY_ONLINE] = { |
1339 | .name = "irq/affinity:online", | |
1340 | .startup.single = irq_affinity_online_cpu, | |
1341 | .teardown.single = NULL, | |
1342 | }, | |
00e16c3d | 1343 | [CPUHP_AP_PERF_ONLINE] = { |
3c1627e9 TG |
1344 | .name = "perf:online", |
1345 | .startup.single = perf_event_init_cpu, | |
1346 | .teardown.single = perf_event_exit_cpu, | |
00e16c3d | 1347 | }, |
7ee681b2 | 1348 | [CPUHP_AP_WORKQUEUE_ONLINE] = { |
3c1627e9 TG |
1349 | .name = "workqueue:online", |
1350 | .startup.single = workqueue_online_cpu, | |
1351 | .teardown.single = workqueue_offline_cpu, | |
7ee681b2 | 1352 | }, |
4df83742 | 1353 | [CPUHP_AP_RCUTREE_ONLINE] = { |
677f6646 | 1354 | .name = "RCU/tree:online", |
3c1627e9 TG |
1355 | .startup.single = rcutree_online_cpu, |
1356 | .teardown.single = rcutree_offline_cpu, | |
4df83742 | 1357 | }, |
4baa0afc | 1358 | #endif |
d10ef6f9 TG |
1359 | /* |
1360 | * The dynamically registered state space is here | |
1361 | */ | |
1362 | ||
aaddd7d1 TG |
1363 | #ifdef CONFIG_SMP |
1364 | /* Last state is scheduler control setting the cpu active */ | |
1365 | [CPUHP_AP_ACTIVE] = { | |
1366 | .name = "sched:active", | |
3c1627e9 TG |
1367 | .startup.single = sched_cpu_activate, |
1368 | .teardown.single = sched_cpu_deactivate, | |
aaddd7d1 TG |
1369 | }, |
1370 | #endif | |
1371 | ||
d10ef6f9 | 1372 | /* CPU is fully up and running. */ |
4baa0afc TG |
1373 | [CPUHP_ONLINE] = { |
1374 | .name = "online", | |
3c1627e9 TG |
1375 | .startup.single = NULL, |
1376 | .teardown.single = NULL, | |
4baa0afc TG |
1377 | }, |
1378 | }; | |
1379 | ||
5b7aa87e TG |
1380 | /* Sanity check for callbacks */ |
1381 | static int cpuhp_cb_check(enum cpuhp_state state) | |
1382 | { | |
1383 | if (state <= CPUHP_OFFLINE || state >= CPUHP_ONLINE) | |
1384 | return -EINVAL; | |
1385 | return 0; | |
1386 | } | |
1387 | ||
dc280d93 TG |
1388 | /* |
1389 | * Returns a free for dynamic slot assignment of the Online state. The states | |
1390 | * are protected by the cpuhp_slot_states mutex and an empty slot is identified | |
1391 | * by having no name assigned. | |
1392 | */ | |
1393 | static int cpuhp_reserve_state(enum cpuhp_state state) | |
1394 | { | |
4205e478 TG |
1395 | enum cpuhp_state i, end; |
1396 | struct cpuhp_step *step; | |
dc280d93 | 1397 | |
4205e478 TG |
1398 | switch (state) { |
1399 | case CPUHP_AP_ONLINE_DYN: | |
1400 | step = cpuhp_ap_states + CPUHP_AP_ONLINE_DYN; | |
1401 | end = CPUHP_AP_ONLINE_DYN_END; | |
1402 | break; | |
1403 | case CPUHP_BP_PREPARE_DYN: | |
1404 | step = cpuhp_bp_states + CPUHP_BP_PREPARE_DYN; | |
1405 | end = CPUHP_BP_PREPARE_DYN_END; | |
1406 | break; | |
1407 | default: | |
1408 | return -EINVAL; | |
1409 | } | |
1410 | ||
1411 | for (i = state; i <= end; i++, step++) { | |
1412 | if (!step->name) | |
dc280d93 TG |
1413 | return i; |
1414 | } | |
1415 | WARN(1, "No more dynamic states available for CPU hotplug\n"); | |
1416 | return -ENOSPC; | |
1417 | } | |
1418 | ||
1419 | static int cpuhp_store_callbacks(enum cpuhp_state state, const char *name, | |
1420 | int (*startup)(unsigned int cpu), | |
1421 | int (*teardown)(unsigned int cpu), | |
1422 | bool multi_instance) | |
5b7aa87e TG |
1423 | { |
1424 | /* (Un)Install the callbacks for further cpu hotplug operations */ | |
1425 | struct cpuhp_step *sp; | |
dc280d93 | 1426 | int ret = 0; |
5b7aa87e | 1427 | |
0c96b273 EB |
1428 | /* |
1429 | * If name is NULL, then the state gets removed. | |
1430 | * | |
1431 | * CPUHP_AP_ONLINE_DYN and CPUHP_BP_PREPARE_DYN are handed out on | |
1432 | * the first allocation from these dynamic ranges, so the removal | |
1433 | * would trigger a new allocation and clear the wrong (already | |
1434 | * empty) state, leaving the callbacks of the to be cleared state | |
1435 | * dangling, which causes wreckage on the next hotplug operation. | |
1436 | */ | |
1437 | if (name && (state == CPUHP_AP_ONLINE_DYN || | |
1438 | state == CPUHP_BP_PREPARE_DYN)) { | |
dc280d93 TG |
1439 | ret = cpuhp_reserve_state(state); |
1440 | if (ret < 0) | |
dc434e05 | 1441 | return ret; |
dc280d93 TG |
1442 | state = ret; |
1443 | } | |
5b7aa87e | 1444 | sp = cpuhp_get_step(state); |
dc434e05 SAS |
1445 | if (name && sp->name) |
1446 | return -EBUSY; | |
1447 | ||
3c1627e9 TG |
1448 | sp->startup.single = startup; |
1449 | sp->teardown.single = teardown; | |
5b7aa87e | 1450 | sp->name = name; |
cf392d10 TG |
1451 | sp->multi_instance = multi_instance; |
1452 | INIT_HLIST_HEAD(&sp->list); | |
dc280d93 | 1453 | return ret; |
5b7aa87e TG |
1454 | } |
1455 | ||
1456 | static void *cpuhp_get_teardown_cb(enum cpuhp_state state) | |
1457 | { | |
3c1627e9 | 1458 | return cpuhp_get_step(state)->teardown.single; |
5b7aa87e TG |
1459 | } |
1460 | ||
5b7aa87e TG |
1461 | /* |
1462 | * Call the startup/teardown function for a step either on the AP or | |
1463 | * on the current CPU. | |
1464 | */ | |
cf392d10 TG |
1465 | static int cpuhp_issue_call(int cpu, enum cpuhp_state state, bool bringup, |
1466 | struct hlist_node *node) | |
5b7aa87e | 1467 | { |
a724632c | 1468 | struct cpuhp_step *sp = cpuhp_get_step(state); |
5b7aa87e TG |
1469 | int ret; |
1470 | ||
4dddfb5f PZ |
1471 | /* |
1472 | * If there's nothing to do, we done. | |
1473 | * Relies on the union for multi_instance. | |
1474 | */ | |
3c1627e9 TG |
1475 | if ((bringup && !sp->startup.single) || |
1476 | (!bringup && !sp->teardown.single)) | |
5b7aa87e | 1477 | return 0; |
5b7aa87e TG |
1478 | /* |
1479 | * The non AP bound callbacks can fail on bringup. On teardown | |
1480 | * e.g. module removal we crash for now. | |
1481 | */ | |
1cf4f629 TG |
1482 | #ifdef CONFIG_SMP |
1483 | if (cpuhp_is_ap_state(state)) | |
cf392d10 | 1484 | ret = cpuhp_invoke_ap_callback(cpu, state, bringup, node); |
1cf4f629 | 1485 | else |
96abb968 | 1486 | ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL); |
1cf4f629 | 1487 | #else |
96abb968 | 1488 | ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL); |
1cf4f629 | 1489 | #endif |
5b7aa87e TG |
1490 | BUG_ON(ret && !bringup); |
1491 | return ret; | |
1492 | } | |
1493 | ||
1494 | /* | |
1495 | * Called from __cpuhp_setup_state on a recoverable failure. | |
1496 | * | |
1497 | * Note: The teardown callbacks for rollback are not allowed to fail! | |
1498 | */ | |
1499 | static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state, | |
cf392d10 | 1500 | struct hlist_node *node) |
5b7aa87e TG |
1501 | { |
1502 | int cpu; | |
1503 | ||
5b7aa87e TG |
1504 | /* Roll back the already executed steps on the other cpus */ |
1505 | for_each_present_cpu(cpu) { | |
1506 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
1507 | int cpustate = st->state; | |
1508 | ||
1509 | if (cpu >= failedcpu) | |
1510 | break; | |
1511 | ||
1512 | /* Did we invoke the startup call on that cpu ? */ | |
1513 | if (cpustate >= state) | |
cf392d10 | 1514 | cpuhp_issue_call(cpu, state, false, node); |
5b7aa87e TG |
1515 | } |
1516 | } | |
1517 | ||
9805c673 TG |
1518 | int __cpuhp_state_add_instance_cpuslocked(enum cpuhp_state state, |
1519 | struct hlist_node *node, | |
1520 | bool invoke) | |
cf392d10 TG |
1521 | { |
1522 | struct cpuhp_step *sp; | |
1523 | int cpu; | |
1524 | int ret; | |
1525 | ||
9805c673 TG |
1526 | lockdep_assert_cpus_held(); |
1527 | ||
cf392d10 TG |
1528 | sp = cpuhp_get_step(state); |
1529 | if (sp->multi_instance == false) | |
1530 | return -EINVAL; | |
1531 | ||
dc434e05 | 1532 | mutex_lock(&cpuhp_state_mutex); |
cf392d10 | 1533 | |
3c1627e9 | 1534 | if (!invoke || !sp->startup.multi) |
cf392d10 TG |
1535 | goto add_node; |
1536 | ||
1537 | /* | |
1538 | * Try to call the startup callback for each present cpu | |
1539 | * depending on the hotplug state of the cpu. | |
1540 | */ | |
1541 | for_each_present_cpu(cpu) { | |
1542 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
1543 | int cpustate = st->state; | |
1544 | ||
1545 | if (cpustate < state) | |
1546 | continue; | |
1547 | ||
1548 | ret = cpuhp_issue_call(cpu, state, true, node); | |
1549 | if (ret) { | |
3c1627e9 | 1550 | if (sp->teardown.multi) |
cf392d10 | 1551 | cpuhp_rollback_install(cpu, state, node); |
dc434e05 | 1552 | goto unlock; |
cf392d10 TG |
1553 | } |
1554 | } | |
1555 | add_node: | |
1556 | ret = 0; | |
cf392d10 | 1557 | hlist_add_head(node, &sp->list); |
dc434e05 | 1558 | unlock: |
cf392d10 | 1559 | mutex_unlock(&cpuhp_state_mutex); |
9805c673 TG |
1560 | return ret; |
1561 | } | |
1562 | ||
1563 | int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node, | |
1564 | bool invoke) | |
1565 | { | |
1566 | int ret; | |
1567 | ||
1568 | cpus_read_lock(); | |
1569 | ret = __cpuhp_state_add_instance_cpuslocked(state, node, invoke); | |
8f553c49 | 1570 | cpus_read_unlock(); |
cf392d10 TG |
1571 | return ret; |
1572 | } | |
1573 | EXPORT_SYMBOL_GPL(__cpuhp_state_add_instance); | |
1574 | ||
5b7aa87e | 1575 | /** |
71def423 | 1576 | * __cpuhp_setup_state_cpuslocked - Setup the callbacks for an hotplug machine state |
dc280d93 TG |
1577 | * @state: The state to setup |
1578 | * @invoke: If true, the startup function is invoked for cpus where | |
1579 | * cpu state >= @state | |
1580 | * @startup: startup callback function | |
1581 | * @teardown: teardown callback function | |
1582 | * @multi_instance: State is set up for multiple instances which get | |
1583 | * added afterwards. | |
5b7aa87e | 1584 | * |
71def423 | 1585 | * The caller needs to hold cpus read locked while calling this function. |
512f0980 BO |
1586 | * Returns: |
1587 | * On success: | |
1588 | * Positive state number if @state is CPUHP_AP_ONLINE_DYN | |
1589 | * 0 for all other states | |
1590 | * On failure: proper (negative) error code | |
5b7aa87e | 1591 | */ |
71def423 SAS |
1592 | int __cpuhp_setup_state_cpuslocked(enum cpuhp_state state, |
1593 | const char *name, bool invoke, | |
1594 | int (*startup)(unsigned int cpu), | |
1595 | int (*teardown)(unsigned int cpu), | |
1596 | bool multi_instance) | |
5b7aa87e TG |
1597 | { |
1598 | int cpu, ret = 0; | |
b9d9d691 | 1599 | bool dynstate; |
5b7aa87e | 1600 | |
71def423 SAS |
1601 | lockdep_assert_cpus_held(); |
1602 | ||
5b7aa87e TG |
1603 | if (cpuhp_cb_check(state) || !name) |
1604 | return -EINVAL; | |
1605 | ||
dc434e05 | 1606 | mutex_lock(&cpuhp_state_mutex); |
5b7aa87e | 1607 | |
dc280d93 TG |
1608 | ret = cpuhp_store_callbacks(state, name, startup, teardown, |
1609 | multi_instance); | |
5b7aa87e | 1610 | |
b9d9d691 TG |
1611 | dynstate = state == CPUHP_AP_ONLINE_DYN; |
1612 | if (ret > 0 && dynstate) { | |
1613 | state = ret; | |
1614 | ret = 0; | |
1615 | } | |
1616 | ||
dc280d93 | 1617 | if (ret || !invoke || !startup) |
5b7aa87e TG |
1618 | goto out; |
1619 | ||
1620 | /* | |
1621 | * Try to call the startup callback for each present cpu | |
1622 | * depending on the hotplug state of the cpu. | |
1623 | */ | |
1624 | for_each_present_cpu(cpu) { | |
1625 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
1626 | int cpustate = st->state; | |
1627 | ||
1628 | if (cpustate < state) | |
1629 | continue; | |
1630 | ||
cf392d10 | 1631 | ret = cpuhp_issue_call(cpu, state, true, NULL); |
5b7aa87e | 1632 | if (ret) { |
a724632c | 1633 | if (teardown) |
cf392d10 TG |
1634 | cpuhp_rollback_install(cpu, state, NULL); |
1635 | cpuhp_store_callbacks(state, NULL, NULL, NULL, false); | |
5b7aa87e TG |
1636 | goto out; |
1637 | } | |
1638 | } | |
1639 | out: | |
dc434e05 | 1640 | mutex_unlock(&cpuhp_state_mutex); |
dc280d93 TG |
1641 | /* |
1642 | * If the requested state is CPUHP_AP_ONLINE_DYN, return the | |
1643 | * dynamically allocated state in case of success. | |
1644 | */ | |
b9d9d691 | 1645 | if (!ret && dynstate) |
5b7aa87e TG |
1646 | return state; |
1647 | return ret; | |
1648 | } | |
71def423 SAS |
1649 | EXPORT_SYMBOL(__cpuhp_setup_state_cpuslocked); |
1650 | ||
1651 | int __cpuhp_setup_state(enum cpuhp_state state, | |
1652 | const char *name, bool invoke, | |
1653 | int (*startup)(unsigned int cpu), | |
1654 | int (*teardown)(unsigned int cpu), | |
1655 | bool multi_instance) | |
1656 | { | |
1657 | int ret; | |
1658 | ||
1659 | cpus_read_lock(); | |
1660 | ret = __cpuhp_setup_state_cpuslocked(state, name, invoke, startup, | |
1661 | teardown, multi_instance); | |
1662 | cpus_read_unlock(); | |
1663 | return ret; | |
1664 | } | |
5b7aa87e TG |
1665 | EXPORT_SYMBOL(__cpuhp_setup_state); |
1666 | ||
cf392d10 TG |
1667 | int __cpuhp_state_remove_instance(enum cpuhp_state state, |
1668 | struct hlist_node *node, bool invoke) | |
1669 | { | |
1670 | struct cpuhp_step *sp = cpuhp_get_step(state); | |
1671 | int cpu; | |
1672 | ||
1673 | BUG_ON(cpuhp_cb_check(state)); | |
1674 | ||
1675 | if (!sp->multi_instance) | |
1676 | return -EINVAL; | |
1677 | ||
8f553c49 | 1678 | cpus_read_lock(); |
dc434e05 SAS |
1679 | mutex_lock(&cpuhp_state_mutex); |
1680 | ||
cf392d10 TG |
1681 | if (!invoke || !cpuhp_get_teardown_cb(state)) |
1682 | goto remove; | |
1683 | /* | |
1684 | * Call the teardown callback for each present cpu depending | |
1685 | * on the hotplug state of the cpu. This function is not | |
1686 | * allowed to fail currently! | |
1687 | */ | |
1688 | for_each_present_cpu(cpu) { | |
1689 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
1690 | int cpustate = st->state; | |
1691 | ||
1692 | if (cpustate >= state) | |
1693 | cpuhp_issue_call(cpu, state, false, node); | |
1694 | } | |
1695 | ||
1696 | remove: | |
cf392d10 TG |
1697 | hlist_del(node); |
1698 | mutex_unlock(&cpuhp_state_mutex); | |
8f553c49 | 1699 | cpus_read_unlock(); |
cf392d10 TG |
1700 | |
1701 | return 0; | |
1702 | } | |
1703 | EXPORT_SYMBOL_GPL(__cpuhp_state_remove_instance); | |
dc434e05 | 1704 | |
5b7aa87e | 1705 | /** |
71def423 | 1706 | * __cpuhp_remove_state_cpuslocked - Remove the callbacks for an hotplug machine state |
5b7aa87e TG |
1707 | * @state: The state to remove |
1708 | * @invoke: If true, the teardown function is invoked for cpus where | |
1709 | * cpu state >= @state | |
1710 | * | |
71def423 | 1711 | * The caller needs to hold cpus read locked while calling this function. |
5b7aa87e TG |
1712 | * The teardown callback is currently not allowed to fail. Think |
1713 | * about module removal! | |
1714 | */ | |
71def423 | 1715 | void __cpuhp_remove_state_cpuslocked(enum cpuhp_state state, bool invoke) |
5b7aa87e | 1716 | { |
cf392d10 | 1717 | struct cpuhp_step *sp = cpuhp_get_step(state); |
5b7aa87e TG |
1718 | int cpu; |
1719 | ||
1720 | BUG_ON(cpuhp_cb_check(state)); | |
1721 | ||
71def423 | 1722 | lockdep_assert_cpus_held(); |
5b7aa87e | 1723 | |
dc434e05 | 1724 | mutex_lock(&cpuhp_state_mutex); |
cf392d10 TG |
1725 | if (sp->multi_instance) { |
1726 | WARN(!hlist_empty(&sp->list), | |
1727 | "Error: Removing state %d which has instances left.\n", | |
1728 | state); | |
1729 | goto remove; | |
1730 | } | |
1731 | ||
a724632c | 1732 | if (!invoke || !cpuhp_get_teardown_cb(state)) |
5b7aa87e TG |
1733 | goto remove; |
1734 | ||
1735 | /* | |
1736 | * Call the teardown callback for each present cpu depending | |
1737 | * on the hotplug state of the cpu. This function is not | |
1738 | * allowed to fail currently! | |
1739 | */ | |
1740 | for_each_present_cpu(cpu) { | |
1741 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
1742 | int cpustate = st->state; | |
1743 | ||
1744 | if (cpustate >= state) | |
cf392d10 | 1745 | cpuhp_issue_call(cpu, state, false, NULL); |
5b7aa87e TG |
1746 | } |
1747 | remove: | |
cf392d10 | 1748 | cpuhp_store_callbacks(state, NULL, NULL, NULL, false); |
dc434e05 | 1749 | mutex_unlock(&cpuhp_state_mutex); |
71def423 SAS |
1750 | } |
1751 | EXPORT_SYMBOL(__cpuhp_remove_state_cpuslocked); | |
1752 | ||
1753 | void __cpuhp_remove_state(enum cpuhp_state state, bool invoke) | |
1754 | { | |
1755 | cpus_read_lock(); | |
1756 | __cpuhp_remove_state_cpuslocked(state, invoke); | |
8f553c49 | 1757 | cpus_read_unlock(); |
5b7aa87e TG |
1758 | } |
1759 | EXPORT_SYMBOL(__cpuhp_remove_state); | |
1760 | ||
98f8cdce TG |
1761 | #if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU) |
1762 | static ssize_t show_cpuhp_state(struct device *dev, | |
1763 | struct device_attribute *attr, char *buf) | |
1764 | { | |
1765 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); | |
1766 | ||
1767 | return sprintf(buf, "%d\n", st->state); | |
1768 | } | |
1769 | static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL); | |
1770 | ||
757c989b TG |
1771 | static ssize_t write_cpuhp_target(struct device *dev, |
1772 | struct device_attribute *attr, | |
1773 | const char *buf, size_t count) | |
1774 | { | |
1775 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); | |
1776 | struct cpuhp_step *sp; | |
1777 | int target, ret; | |
1778 | ||
1779 | ret = kstrtoint(buf, 10, &target); | |
1780 | if (ret) | |
1781 | return ret; | |
1782 | ||
1783 | #ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL | |
1784 | if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE) | |
1785 | return -EINVAL; | |
1786 | #else | |
1787 | if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE) | |
1788 | return -EINVAL; | |
1789 | #endif | |
1790 | ||
1791 | ret = lock_device_hotplug_sysfs(); | |
1792 | if (ret) | |
1793 | return ret; | |
1794 | ||
1795 | mutex_lock(&cpuhp_state_mutex); | |
1796 | sp = cpuhp_get_step(target); | |
1797 | ret = !sp->name || sp->cant_stop ? -EINVAL : 0; | |
1798 | mutex_unlock(&cpuhp_state_mutex); | |
1799 | if (ret) | |
40da1b11 | 1800 | goto out; |
757c989b TG |
1801 | |
1802 | if (st->state < target) | |
1803 | ret = do_cpu_up(dev->id, target); | |
1804 | else | |
1805 | ret = do_cpu_down(dev->id, target); | |
40da1b11 | 1806 | out: |
757c989b TG |
1807 | unlock_device_hotplug(); |
1808 | return ret ? ret : count; | |
1809 | } | |
1810 | ||
98f8cdce TG |
1811 | static ssize_t show_cpuhp_target(struct device *dev, |
1812 | struct device_attribute *attr, char *buf) | |
1813 | { | |
1814 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); | |
1815 | ||
1816 | return sprintf(buf, "%d\n", st->target); | |
1817 | } | |
757c989b | 1818 | static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target); |
98f8cdce | 1819 | |
1db49484 PZ |
1820 | |
1821 | static ssize_t write_cpuhp_fail(struct device *dev, | |
1822 | struct device_attribute *attr, | |
1823 | const char *buf, size_t count) | |
1824 | { | |
1825 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); | |
1826 | struct cpuhp_step *sp; | |
1827 | int fail, ret; | |
1828 | ||
1829 | ret = kstrtoint(buf, 10, &fail); | |
1830 | if (ret) | |
1831 | return ret; | |
1832 | ||
1833 | /* | |
1834 | * Cannot fail STARTING/DYING callbacks. | |
1835 | */ | |
1836 | if (cpuhp_is_atomic_state(fail)) | |
1837 | return -EINVAL; | |
1838 | ||
1839 | /* | |
1840 | * Cannot fail anything that doesn't have callbacks. | |
1841 | */ | |
1842 | mutex_lock(&cpuhp_state_mutex); | |
1843 | sp = cpuhp_get_step(fail); | |
1844 | if (!sp->startup.single && !sp->teardown.single) | |
1845 | ret = -EINVAL; | |
1846 | mutex_unlock(&cpuhp_state_mutex); | |
1847 | if (ret) | |
1848 | return ret; | |
1849 | ||
1850 | st->fail = fail; | |
1851 | ||
1852 | return count; | |
1853 | } | |
1854 | ||
1855 | static ssize_t show_cpuhp_fail(struct device *dev, | |
1856 | struct device_attribute *attr, char *buf) | |
1857 | { | |
1858 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); | |
1859 | ||
1860 | return sprintf(buf, "%d\n", st->fail); | |
1861 | } | |
1862 | ||
1863 | static DEVICE_ATTR(fail, 0644, show_cpuhp_fail, write_cpuhp_fail); | |
1864 | ||
98f8cdce TG |
1865 | static struct attribute *cpuhp_cpu_attrs[] = { |
1866 | &dev_attr_state.attr, | |
1867 | &dev_attr_target.attr, | |
1db49484 | 1868 | &dev_attr_fail.attr, |
98f8cdce TG |
1869 | NULL |
1870 | }; | |
1871 | ||
993647a2 | 1872 | static const struct attribute_group cpuhp_cpu_attr_group = { |
98f8cdce TG |
1873 | .attrs = cpuhp_cpu_attrs, |
1874 | .name = "hotplug", | |
1875 | NULL | |
1876 | }; | |
1877 | ||
1878 | static ssize_t show_cpuhp_states(struct device *dev, | |
1879 | struct device_attribute *attr, char *buf) | |
1880 | { | |
1881 | ssize_t cur, res = 0; | |
1882 | int i; | |
1883 | ||
1884 | mutex_lock(&cpuhp_state_mutex); | |
757c989b | 1885 | for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) { |
98f8cdce TG |
1886 | struct cpuhp_step *sp = cpuhp_get_step(i); |
1887 | ||
1888 | if (sp->name) { | |
1889 | cur = sprintf(buf, "%3d: %s\n", i, sp->name); | |
1890 | buf += cur; | |
1891 | res += cur; | |
1892 | } | |
1893 | } | |
1894 | mutex_unlock(&cpuhp_state_mutex); | |
1895 | return res; | |
1896 | } | |
1897 | static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL); | |
1898 | ||
1899 | static struct attribute *cpuhp_cpu_root_attrs[] = { | |
1900 | &dev_attr_states.attr, | |
1901 | NULL | |
1902 | }; | |
1903 | ||
993647a2 | 1904 | static const struct attribute_group cpuhp_cpu_root_attr_group = { |
98f8cdce TG |
1905 | .attrs = cpuhp_cpu_root_attrs, |
1906 | .name = "hotplug", | |
1907 | NULL | |
1908 | }; | |
1909 | ||
1910 | static int __init cpuhp_sysfs_init(void) | |
1911 | { | |
1912 | int cpu, ret; | |
1913 | ||
1914 | ret = sysfs_create_group(&cpu_subsys.dev_root->kobj, | |
1915 | &cpuhp_cpu_root_attr_group); | |
1916 | if (ret) | |
1917 | return ret; | |
1918 | ||
1919 | for_each_possible_cpu(cpu) { | |
1920 | struct device *dev = get_cpu_device(cpu); | |
1921 | ||
1922 | if (!dev) | |
1923 | continue; | |
1924 | ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group); | |
1925 | if (ret) | |
1926 | return ret; | |
1927 | } | |
1928 | return 0; | |
1929 | } | |
1930 | device_initcall(cpuhp_sysfs_init); | |
1931 | #endif | |
1932 | ||
e56b3bc7 LT |
1933 | /* |
1934 | * cpu_bit_bitmap[] is a special, "compressed" data structure that | |
1935 | * represents all NR_CPUS bits binary values of 1<<nr. | |
1936 | * | |
e0b582ec | 1937 | * It is used by cpumask_of() to get a constant address to a CPU |
e56b3bc7 LT |
1938 | * mask value that has a single bit set only. |
1939 | */ | |
b8d317d1 | 1940 | |
e56b3bc7 | 1941 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
4d51985e | 1942 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
e56b3bc7 LT |
1943 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
1944 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) | |
1945 | #define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) | |
b8d317d1 | 1946 | |
e56b3bc7 LT |
1947 | const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { |
1948 | ||
1949 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), | |
1950 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), | |
1951 | #if BITS_PER_LONG > 32 | |
1952 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), | |
1953 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), | |
b8d317d1 MT |
1954 | #endif |
1955 | }; | |
e56b3bc7 | 1956 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
2d3854a3 RR |
1957 | |
1958 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; | |
1959 | EXPORT_SYMBOL(cpu_all_bits); | |
b3199c02 RR |
1960 | |
1961 | #ifdef CONFIG_INIT_ALL_POSSIBLE | |
4b804c85 | 1962 | struct cpumask __cpu_possible_mask __read_mostly |
c4c54dd1 | 1963 | = {CPU_BITS_ALL}; |
b3199c02 | 1964 | #else |
4b804c85 | 1965 | struct cpumask __cpu_possible_mask __read_mostly; |
b3199c02 | 1966 | #endif |
4b804c85 | 1967 | EXPORT_SYMBOL(__cpu_possible_mask); |
b3199c02 | 1968 | |
4b804c85 RV |
1969 | struct cpumask __cpu_online_mask __read_mostly; |
1970 | EXPORT_SYMBOL(__cpu_online_mask); | |
b3199c02 | 1971 | |
4b804c85 RV |
1972 | struct cpumask __cpu_present_mask __read_mostly; |
1973 | EXPORT_SYMBOL(__cpu_present_mask); | |
b3199c02 | 1974 | |
4b804c85 RV |
1975 | struct cpumask __cpu_active_mask __read_mostly; |
1976 | EXPORT_SYMBOL(__cpu_active_mask); | |
3fa41520 | 1977 | |
3fa41520 RR |
1978 | void init_cpu_present(const struct cpumask *src) |
1979 | { | |
c4c54dd1 | 1980 | cpumask_copy(&__cpu_present_mask, src); |
3fa41520 RR |
1981 | } |
1982 | ||
1983 | void init_cpu_possible(const struct cpumask *src) | |
1984 | { | |
c4c54dd1 | 1985 | cpumask_copy(&__cpu_possible_mask, src); |
3fa41520 RR |
1986 | } |
1987 | ||
1988 | void init_cpu_online(const struct cpumask *src) | |
1989 | { | |
c4c54dd1 | 1990 | cpumask_copy(&__cpu_online_mask, src); |
3fa41520 | 1991 | } |
cff7d378 TG |
1992 | |
1993 | /* | |
1994 | * Activate the first processor. | |
1995 | */ | |
1996 | void __init boot_cpu_init(void) | |
1997 | { | |
1998 | int cpu = smp_processor_id(); | |
1999 | ||
2000 | /* Mark the boot cpu "present", "online" etc for SMP and UP case */ | |
2001 | set_cpu_online(cpu, true); | |
2002 | set_cpu_active(cpu, true); | |
2003 | set_cpu_present(cpu, true); | |
2004 | set_cpu_possible(cpu, true); | |
8ce371f9 PZ |
2005 | |
2006 | #ifdef CONFIG_SMP | |
2007 | __boot_cpu_id = cpu; | |
2008 | #endif | |
cff7d378 TG |
2009 | } |
2010 | ||
2011 | /* | |
2012 | * Must be called _AFTER_ setting up the per_cpu areas | |
2013 | */ | |
2014 | void __init boot_cpu_state_init(void) | |
2015 | { | |
2016 | per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE; | |
2017 | } |