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> | |
13 | #include <linux/module.h> | |
14 | #include <linux/kthread.h> | |
15 | #include <linux/stop_machine.h> | |
81615b62 | 16 | #include <linux/mutex.h> |
5a0e3ad6 | 17 | #include <linux/gfp.h> |
1da177e4 | 18 | |
98a79d6a | 19 | #ifdef CONFIG_SMP |
b3199c02 | 20 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
aa953877 | 21 | static DEFINE_MUTEX(cpu_add_remove_lock); |
1da177e4 | 22 | |
79a6cdeb LJ |
23 | /* |
24 | * The following two API's must be used when attempting | |
25 | * to serialize the updates to cpu_online_mask, cpu_present_mask. | |
26 | */ | |
27 | void cpu_maps_update_begin(void) | |
28 | { | |
29 | mutex_lock(&cpu_add_remove_lock); | |
30 | } | |
31 | ||
32 | void cpu_maps_update_done(void) | |
33 | { | |
34 | mutex_unlock(&cpu_add_remove_lock); | |
35 | } | |
36 | ||
5c113fbe | 37 | static RAW_NOTIFIER_HEAD(cpu_chain); |
1da177e4 | 38 | |
e3920fb4 RW |
39 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
40 | * Should always be manipulated under cpu_add_remove_lock | |
41 | */ | |
42 | static int cpu_hotplug_disabled; | |
43 | ||
79a6cdeb LJ |
44 | #ifdef CONFIG_HOTPLUG_CPU |
45 | ||
d221938c GS |
46 | static struct { |
47 | struct task_struct *active_writer; | |
48 | struct mutex lock; /* Synchronizes accesses to refcount, */ | |
49 | /* | |
50 | * Also blocks the new readers during | |
51 | * an ongoing cpu hotplug operation. | |
52 | */ | |
53 | int refcount; | |
31950eb6 LT |
54 | } cpu_hotplug = { |
55 | .active_writer = NULL, | |
56 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), | |
57 | .refcount = 0, | |
58 | }; | |
d221938c | 59 | |
86ef5c9a | 60 | void get_online_cpus(void) |
a9d9baa1 | 61 | { |
d221938c GS |
62 | might_sleep(); |
63 | if (cpu_hotplug.active_writer == current) | |
aa953877 | 64 | return; |
d221938c GS |
65 | mutex_lock(&cpu_hotplug.lock); |
66 | cpu_hotplug.refcount++; | |
67 | mutex_unlock(&cpu_hotplug.lock); | |
68 | ||
a9d9baa1 | 69 | } |
86ef5c9a | 70 | EXPORT_SYMBOL_GPL(get_online_cpus); |
90d45d17 | 71 | |
86ef5c9a | 72 | void put_online_cpus(void) |
a9d9baa1 | 73 | { |
d221938c | 74 | if (cpu_hotplug.active_writer == current) |
aa953877 | 75 | return; |
d221938c | 76 | mutex_lock(&cpu_hotplug.lock); |
d2ba7e2a ON |
77 | if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer)) |
78 | wake_up_process(cpu_hotplug.active_writer); | |
d221938c GS |
79 | mutex_unlock(&cpu_hotplug.lock); |
80 | ||
a9d9baa1 | 81 | } |
86ef5c9a | 82 | EXPORT_SYMBOL_GPL(put_online_cpus); |
a9d9baa1 | 83 | |
d221938c GS |
84 | /* |
85 | * This ensures that the hotplug operation can begin only when the | |
86 | * refcount goes to zero. | |
87 | * | |
88 | * Note that during a cpu-hotplug operation, the new readers, if any, | |
89 | * will be blocked by the cpu_hotplug.lock | |
90 | * | |
d2ba7e2a ON |
91 | * Since cpu_hotplug_begin() is always called after invoking |
92 | * cpu_maps_update_begin(), we can be sure that only one writer is active. | |
d221938c GS |
93 | * |
94 | * Note that theoretically, there is a possibility of a livelock: | |
95 | * - Refcount goes to zero, last reader wakes up the sleeping | |
96 | * writer. | |
97 | * - Last reader unlocks the cpu_hotplug.lock. | |
98 | * - A new reader arrives at this moment, bumps up the refcount. | |
99 | * - The writer acquires the cpu_hotplug.lock finds the refcount | |
100 | * non zero and goes to sleep again. | |
101 | * | |
102 | * However, this is very difficult to achieve in practice since | |
86ef5c9a | 103 | * get_online_cpus() not an api which is called all that often. |
d221938c GS |
104 | * |
105 | */ | |
106 | static void cpu_hotplug_begin(void) | |
107 | { | |
d221938c | 108 | cpu_hotplug.active_writer = current; |
d2ba7e2a ON |
109 | |
110 | for (;;) { | |
111 | mutex_lock(&cpu_hotplug.lock); | |
112 | if (likely(!cpu_hotplug.refcount)) | |
113 | break; | |
114 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
d221938c GS |
115 | mutex_unlock(&cpu_hotplug.lock); |
116 | schedule(); | |
d221938c | 117 | } |
d221938c GS |
118 | } |
119 | ||
120 | static void cpu_hotplug_done(void) | |
121 | { | |
122 | cpu_hotplug.active_writer = NULL; | |
123 | mutex_unlock(&cpu_hotplug.lock); | |
124 | } | |
79a6cdeb LJ |
125 | |
126 | #else /* #if CONFIG_HOTPLUG_CPU */ | |
127 | static void cpu_hotplug_begin(void) {} | |
128 | static void cpu_hotplug_done(void) {} | |
129 | #endif /* #esle #if CONFIG_HOTPLUG_CPU */ | |
130 | ||
1da177e4 | 131 | /* Need to know about CPUs going up/down? */ |
f7b16c10 | 132 | int __ref register_cpu_notifier(struct notifier_block *nb) |
1da177e4 | 133 | { |
bd5349cf | 134 | int ret; |
d221938c | 135 | cpu_maps_update_begin(); |
bd5349cf | 136 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
d221938c | 137 | cpu_maps_update_done(); |
bd5349cf | 138 | return ret; |
1da177e4 | 139 | } |
65edc68c | 140 | |
e9fb7631 AM |
141 | static int __cpu_notify(unsigned long val, void *v, int nr_to_call, |
142 | int *nr_calls) | |
143 | { | |
e6bde73b AM |
144 | int ret; |
145 | ||
146 | ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call, | |
e9fb7631 | 147 | nr_calls); |
e6bde73b AM |
148 | |
149 | return notifier_to_errno(ret); | |
e9fb7631 AM |
150 | } |
151 | ||
152 | static int cpu_notify(unsigned long val, void *v) | |
153 | { | |
154 | return __cpu_notify(val, v, -1, NULL); | |
155 | } | |
156 | ||
00b9b0af LT |
157 | #ifdef CONFIG_HOTPLUG_CPU |
158 | ||
e9fb7631 AM |
159 | static void cpu_notify_nofail(unsigned long val, void *v) |
160 | { | |
00b9b0af | 161 | BUG_ON(cpu_notify(val, v)); |
e9fb7631 AM |
162 | } |
163 | ||
1da177e4 LT |
164 | EXPORT_SYMBOL(register_cpu_notifier); |
165 | ||
9647155f | 166 | void __ref unregister_cpu_notifier(struct notifier_block *nb) |
1da177e4 | 167 | { |
d221938c | 168 | cpu_maps_update_begin(); |
bd5349cf | 169 | raw_notifier_chain_unregister(&cpu_chain, nb); |
d221938c | 170 | cpu_maps_update_done(); |
1da177e4 LT |
171 | } |
172 | EXPORT_SYMBOL(unregister_cpu_notifier); | |
173 | ||
1da177e4 LT |
174 | static inline void check_for_tasks(int cpu) |
175 | { | |
176 | struct task_struct *p; | |
177 | ||
178 | write_lock_irq(&tasklist_lock); | |
179 | for_each_process(p) { | |
11854247 | 180 | if (task_cpu(p) == cpu && p->state == TASK_RUNNING && |
1da177e4 LT |
181 | (!cputime_eq(p->utime, cputime_zero) || |
182 | !cputime_eq(p->stime, cputime_zero))) | |
9d3cfc4c FP |
183 | printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d " |
184 | "(state = %ld, flags = %x)\n", | |
185 | p->comm, task_pid_nr(p), cpu, | |
186 | p->state, p->flags); | |
1da177e4 LT |
187 | } |
188 | write_unlock_irq(&tasklist_lock); | |
189 | } | |
190 | ||
db912f96 | 191 | struct take_cpu_down_param { |
6a1bdc1b | 192 | struct task_struct *caller; |
db912f96 AK |
193 | unsigned long mod; |
194 | void *hcpu; | |
195 | }; | |
196 | ||
1da177e4 | 197 | /* Take this CPU down. */ |
514a20a5 | 198 | static int __ref take_cpu_down(void *_param) |
1da177e4 | 199 | { |
db912f96 | 200 | struct take_cpu_down_param *param = _param; |
6a1bdc1b | 201 | unsigned int cpu = (unsigned long)param->hcpu; |
1da177e4 LT |
202 | int err; |
203 | ||
1da177e4 LT |
204 | /* Ensure this CPU doesn't handle any more interrupts. */ |
205 | err = __cpu_disable(); | |
206 | if (err < 0) | |
f3705136 | 207 | return err; |
1da177e4 | 208 | |
e9fb7631 | 209 | cpu_notify(CPU_DYING | param->mod, param->hcpu); |
3ba35573 | 210 | |
6a1bdc1b ON |
211 | if (task_cpu(param->caller) == cpu) |
212 | move_task_off_dead_cpu(cpu, param->caller); | |
f3705136 ZM |
213 | /* Force idle task to run as soon as we yield: it should |
214 | immediately notice cpu is offline and die quickly. */ | |
215 | sched_idle_next(); | |
216 | return 0; | |
1da177e4 LT |
217 | } |
218 | ||
e3920fb4 | 219 | /* Requires cpu_add_remove_lock to be held */ |
514a20a5 | 220 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) |
1da177e4 | 221 | { |
e7407dcc | 222 | int err, nr_calls = 0; |
e7407dcc | 223 | void *hcpu = (void *)(long)cpu; |
8bb78442 | 224 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
db912f96 | 225 | struct take_cpu_down_param tcd_param = { |
6a1bdc1b | 226 | .caller = current, |
db912f96 AK |
227 | .mod = mod, |
228 | .hcpu = hcpu, | |
229 | }; | |
1da177e4 | 230 | |
e3920fb4 RW |
231 | if (num_online_cpus() == 1) |
232 | return -EBUSY; | |
1da177e4 | 233 | |
e3920fb4 RW |
234 | if (!cpu_online(cpu)) |
235 | return -EINVAL; | |
1da177e4 | 236 | |
d221938c | 237 | cpu_hotplug_begin(); |
9ee349ad | 238 | set_cpu_active(cpu, false); |
e9fb7631 | 239 | err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls); |
e6bde73b | 240 | if (err) { |
6ad4c188 PZ |
241 | set_cpu_active(cpu, true); |
242 | ||
a0d8cdb6 | 243 | nr_calls--; |
e9fb7631 | 244 | __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL); |
1da177e4 | 245 | printk("%s: attempt to take down CPU %u failed\n", |
af1f16d0 | 246 | __func__, cpu); |
baaca49f | 247 | goto out_release; |
1da177e4 LT |
248 | } |
249 | ||
e0b582ec | 250 | err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); |
04321587 | 251 | if (err) { |
6ad4c188 | 252 | set_cpu_active(cpu, true); |
1da177e4 | 253 | /* CPU didn't die: tell everyone. Can't complain. */ |
e9fb7631 | 254 | cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu); |
1da177e4 | 255 | |
6a1bdc1b | 256 | goto out_release; |
8fa1d7d3 | 257 | } |
04321587 | 258 | BUG_ON(cpu_online(cpu)); |
1da177e4 LT |
259 | |
260 | /* Wait for it to sleep (leaving idle task). */ | |
261 | while (!idle_cpu(cpu)) | |
262 | yield(); | |
263 | ||
264 | /* This actually kills the CPU. */ | |
265 | __cpu_die(cpu); | |
266 | ||
1da177e4 | 267 | /* CPU is completely dead: tell everyone. Too late to complain. */ |
e9fb7631 | 268 | cpu_notify_nofail(CPU_DEAD | mod, hcpu); |
1da177e4 LT |
269 | |
270 | check_for_tasks(cpu); | |
271 | ||
baaca49f | 272 | out_release: |
d221938c | 273 | cpu_hotplug_done(); |
e9fb7631 AM |
274 | if (!err) |
275 | cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu); | |
e3920fb4 RW |
276 | return err; |
277 | } | |
278 | ||
514a20a5 | 279 | int __ref cpu_down(unsigned int cpu) |
e3920fb4 | 280 | { |
9ea09af3 | 281 | int err; |
e3920fb4 | 282 | |
d221938c | 283 | cpu_maps_update_begin(); |
e761b772 MK |
284 | |
285 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 286 | err = -EBUSY; |
e761b772 MK |
287 | goto out; |
288 | } | |
289 | ||
e761b772 | 290 | err = _cpu_down(cpu, 0); |
e3920fb4 | 291 | |
e761b772 | 292 | out: |
d221938c | 293 | cpu_maps_update_done(); |
1da177e4 LT |
294 | return err; |
295 | } | |
b62b8ef9 | 296 | EXPORT_SYMBOL(cpu_down); |
1da177e4 LT |
297 | #endif /*CONFIG_HOTPLUG_CPU*/ |
298 | ||
e3920fb4 | 299 | /* Requires cpu_add_remove_lock to be held */ |
8bb78442 | 300 | static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) |
1da177e4 | 301 | { |
baaca49f | 302 | int ret, nr_calls = 0; |
1da177e4 | 303 | void *hcpu = (void *)(long)cpu; |
8bb78442 | 304 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
1da177e4 | 305 | |
e3920fb4 RW |
306 | if (cpu_online(cpu) || !cpu_present(cpu)) |
307 | return -EINVAL; | |
90d45d17 | 308 | |
d221938c | 309 | cpu_hotplug_begin(); |
e9fb7631 | 310 | ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls); |
e6bde73b | 311 | if (ret) { |
a0d8cdb6 | 312 | nr_calls--; |
1da177e4 | 313 | printk("%s: attempt to bring up CPU %u failed\n", |
af1f16d0 | 314 | __func__, cpu); |
1da177e4 LT |
315 | goto out_notify; |
316 | } | |
317 | ||
318 | /* Arch-specific enabling code. */ | |
319 | ret = __cpu_up(cpu); | |
320 | if (ret != 0) | |
321 | goto out_notify; | |
6978c705 | 322 | BUG_ON(!cpu_online(cpu)); |
1da177e4 | 323 | |
2b17fa50 | 324 | set_cpu_active(cpu, true); |
279ef6bb | 325 | |
1da177e4 | 326 | /* Now call notifier in preparation. */ |
e9fb7631 | 327 | cpu_notify(CPU_ONLINE | mod, hcpu); |
1da177e4 LT |
328 | |
329 | out_notify: | |
330 | if (ret != 0) | |
e9fb7631 | 331 | __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL); |
d221938c | 332 | cpu_hotplug_done(); |
e3920fb4 RW |
333 | |
334 | return ret; | |
335 | } | |
336 | ||
b282b6f8 | 337 | int __cpuinit cpu_up(unsigned int cpu) |
e3920fb4 RW |
338 | { |
339 | int err = 0; | |
cf23422b | 340 | |
341 | #ifdef CONFIG_MEMORY_HOTPLUG | |
342 | int nid; | |
343 | pg_data_t *pgdat; | |
344 | #endif | |
345 | ||
e0b582ec | 346 | if (!cpu_possible(cpu)) { |
73e753a5 KH |
347 | printk(KERN_ERR "can't online cpu %d because it is not " |
348 | "configured as may-hotadd at boot time\n", cpu); | |
87d5e023 | 349 | #if defined(CONFIG_IA64) |
73e753a5 KH |
350 | printk(KERN_ERR "please check additional_cpus= boot " |
351 | "parameter\n"); | |
352 | #endif | |
353 | return -EINVAL; | |
354 | } | |
e3920fb4 | 355 | |
cf23422b | 356 | #ifdef CONFIG_MEMORY_HOTPLUG |
357 | nid = cpu_to_node(cpu); | |
358 | if (!node_online(nid)) { | |
359 | err = mem_online_node(nid); | |
360 | if (err) | |
361 | return err; | |
362 | } | |
363 | ||
364 | pgdat = NODE_DATA(nid); | |
365 | if (!pgdat) { | |
366 | printk(KERN_ERR | |
367 | "Can't online cpu %d due to NULL pgdat\n", cpu); | |
368 | return -ENOMEM; | |
369 | } | |
370 | ||
4eaf3f64 HL |
371 | if (pgdat->node_zonelists->_zonerefs->zone == NULL) { |
372 | mutex_lock(&zonelists_mutex); | |
1f522509 | 373 | build_all_zonelists(NULL); |
4eaf3f64 HL |
374 | mutex_unlock(&zonelists_mutex); |
375 | } | |
cf23422b | 376 | #endif |
377 | ||
d221938c | 378 | cpu_maps_update_begin(); |
e761b772 MK |
379 | |
380 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 381 | err = -EBUSY; |
e761b772 MK |
382 | goto out; |
383 | } | |
384 | ||
385 | err = _cpu_up(cpu, 0); | |
386 | ||
e761b772 | 387 | out: |
d221938c | 388 | cpu_maps_update_done(); |
e3920fb4 RW |
389 | return err; |
390 | } | |
391 | ||
f3de4be9 | 392 | #ifdef CONFIG_PM_SLEEP_SMP |
e0b582ec | 393 | static cpumask_var_t frozen_cpus; |
e3920fb4 RW |
394 | |
395 | int disable_nonboot_cpus(void) | |
396 | { | |
e9a5f426 | 397 | int cpu, first_cpu, error = 0; |
e3920fb4 | 398 | |
d221938c | 399 | cpu_maps_update_begin(); |
e0b582ec | 400 | first_cpu = cpumask_first(cpu_online_mask); |
9ee349ad XF |
401 | /* |
402 | * We take down all of the non-boot CPUs in one shot to avoid races | |
e3920fb4 RW |
403 | * with the userspace trying to use the CPU hotplug at the same time |
404 | */ | |
e0b582ec | 405 | cpumask_clear(frozen_cpus); |
6ad4c188 | 406 | |
e3920fb4 RW |
407 | printk("Disabling non-boot CPUs ...\n"); |
408 | for_each_online_cpu(cpu) { | |
409 | if (cpu == first_cpu) | |
410 | continue; | |
8bb78442 | 411 | error = _cpu_down(cpu, 1); |
feae3203 | 412 | if (!error) |
e0b582ec | 413 | cpumask_set_cpu(cpu, frozen_cpus); |
feae3203 | 414 | else { |
e3920fb4 RW |
415 | printk(KERN_ERR "Error taking CPU%d down: %d\n", |
416 | cpu, error); | |
417 | break; | |
418 | } | |
419 | } | |
86886e55 | 420 | |
e3920fb4 RW |
421 | if (!error) { |
422 | BUG_ON(num_online_cpus() > 1); | |
423 | /* Make sure the CPUs won't be enabled by someone else */ | |
424 | cpu_hotplug_disabled = 1; | |
425 | } else { | |
e1d9fd2e | 426 | printk(KERN_ERR "Non-boot CPUs are not disabled\n"); |
e3920fb4 | 427 | } |
d221938c | 428 | cpu_maps_update_done(); |
e3920fb4 RW |
429 | return error; |
430 | } | |
431 | ||
d0af9eed SS |
432 | void __weak arch_enable_nonboot_cpus_begin(void) |
433 | { | |
434 | } | |
435 | ||
436 | void __weak arch_enable_nonboot_cpus_end(void) | |
437 | { | |
438 | } | |
439 | ||
fa7303e2 | 440 | void __ref enable_nonboot_cpus(void) |
e3920fb4 RW |
441 | { |
442 | int cpu, error; | |
443 | ||
444 | /* Allow everyone to use the CPU hotplug again */ | |
d221938c | 445 | cpu_maps_update_begin(); |
e3920fb4 | 446 | cpu_hotplug_disabled = 0; |
e0b582ec | 447 | if (cpumask_empty(frozen_cpus)) |
1d64b9cb | 448 | goto out; |
e3920fb4 RW |
449 | |
450 | printk("Enabling non-boot CPUs ...\n"); | |
d0af9eed SS |
451 | |
452 | arch_enable_nonboot_cpus_begin(); | |
453 | ||
e0b582ec | 454 | for_each_cpu(cpu, frozen_cpus) { |
8bb78442 | 455 | error = _cpu_up(cpu, 1); |
e3920fb4 RW |
456 | if (!error) { |
457 | printk("CPU%d is up\n", cpu); | |
458 | continue; | |
459 | } | |
1d64b9cb | 460 | printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error); |
e3920fb4 | 461 | } |
d0af9eed SS |
462 | |
463 | arch_enable_nonboot_cpus_end(); | |
464 | ||
e0b582ec | 465 | cpumask_clear(frozen_cpus); |
1d64b9cb | 466 | out: |
d221938c | 467 | cpu_maps_update_done(); |
1da177e4 | 468 | } |
e0b582ec RR |
469 | |
470 | static int alloc_frozen_cpus(void) | |
471 | { | |
472 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) | |
473 | return -ENOMEM; | |
474 | return 0; | |
475 | } | |
476 | core_initcall(alloc_frozen_cpus); | |
f3de4be9 | 477 | #endif /* CONFIG_PM_SLEEP_SMP */ |
68f4f1ec | 478 | |
e545a614 MS |
479 | /** |
480 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers | |
481 | * @cpu: cpu that just started | |
482 | * | |
483 | * This function calls the cpu_chain notifiers with CPU_STARTING. | |
484 | * It must be called by the arch code on the new cpu, before the new cpu | |
485 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). | |
486 | */ | |
84196414 | 487 | void __cpuinit notify_cpu_starting(unsigned int cpu) |
e545a614 MS |
488 | { |
489 | unsigned long val = CPU_STARTING; | |
490 | ||
491 | #ifdef CONFIG_PM_SLEEP_SMP | |
e0b582ec | 492 | if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus)) |
e545a614 MS |
493 | val = CPU_STARTING_FROZEN; |
494 | #endif /* CONFIG_PM_SLEEP_SMP */ | |
e9fb7631 | 495 | cpu_notify(val, (void *)(long)cpu); |
e545a614 MS |
496 | } |
497 | ||
68f4f1ec | 498 | #endif /* CONFIG_SMP */ |
b8d317d1 | 499 | |
e56b3bc7 LT |
500 | /* |
501 | * cpu_bit_bitmap[] is a special, "compressed" data structure that | |
502 | * represents all NR_CPUS bits binary values of 1<<nr. | |
503 | * | |
e0b582ec | 504 | * It is used by cpumask_of() to get a constant address to a CPU |
e56b3bc7 LT |
505 | * mask value that has a single bit set only. |
506 | */ | |
b8d317d1 | 507 | |
e56b3bc7 LT |
508 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
509 | #define MASK_DECLARE_1(x) [x+1][0] = 1UL << (x) | |
510 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) | |
511 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) | |
512 | #define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) | |
b8d317d1 | 513 | |
e56b3bc7 LT |
514 | const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { |
515 | ||
516 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), | |
517 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), | |
518 | #if BITS_PER_LONG > 32 | |
519 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), | |
520 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), | |
b8d317d1 MT |
521 | #endif |
522 | }; | |
e56b3bc7 | 523 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
2d3854a3 RR |
524 | |
525 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; | |
526 | EXPORT_SYMBOL(cpu_all_bits); | |
b3199c02 RR |
527 | |
528 | #ifdef CONFIG_INIT_ALL_POSSIBLE | |
529 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly | |
530 | = CPU_BITS_ALL; | |
531 | #else | |
532 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly; | |
533 | #endif | |
534 | const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits); | |
535 | EXPORT_SYMBOL(cpu_possible_mask); | |
536 | ||
537 | static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly; | |
538 | const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits); | |
539 | EXPORT_SYMBOL(cpu_online_mask); | |
540 | ||
541 | static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly; | |
542 | const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits); | |
543 | EXPORT_SYMBOL(cpu_present_mask); | |
544 | ||
545 | static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly; | |
546 | const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits); | |
547 | EXPORT_SYMBOL(cpu_active_mask); | |
3fa41520 RR |
548 | |
549 | void set_cpu_possible(unsigned int cpu, bool possible) | |
550 | { | |
551 | if (possible) | |
552 | cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits)); | |
553 | else | |
554 | cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits)); | |
555 | } | |
556 | ||
557 | void set_cpu_present(unsigned int cpu, bool present) | |
558 | { | |
559 | if (present) | |
560 | cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits)); | |
561 | else | |
562 | cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits)); | |
563 | } | |
564 | ||
565 | void set_cpu_online(unsigned int cpu, bool online) | |
566 | { | |
567 | if (online) | |
568 | cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits)); | |
569 | else | |
570 | cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits)); | |
571 | } | |
572 | ||
573 | void set_cpu_active(unsigned int cpu, bool active) | |
574 | { | |
575 | if (active) | |
576 | cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); | |
577 | else | |
578 | cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits)); | |
579 | } | |
580 | ||
581 | void init_cpu_present(const struct cpumask *src) | |
582 | { | |
583 | cpumask_copy(to_cpumask(cpu_present_bits), src); | |
584 | } | |
585 | ||
586 | void init_cpu_possible(const struct cpumask *src) | |
587 | { | |
588 | cpumask_copy(to_cpumask(cpu_possible_bits), src); | |
589 | } | |
590 | ||
591 | void init_cpu_online(const struct cpumask *src) | |
592 | { | |
593 | cpumask_copy(to_cpumask(cpu_online_bits), src); | |
594 | } |