diff options
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r-- | kernel/cpu.c | 157 |
1 files changed, 110 insertions, 47 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 8ea32e8d68b0..79e40f00dcb8 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c | |||
@@ -15,29 +15,8 @@ | |||
15 | #include <linux/stop_machine.h> | 15 | #include <linux/stop_machine.h> |
16 | #include <linux/mutex.h> | 16 | #include <linux/mutex.h> |
17 | 17 | ||
18 | /* | 18 | #ifdef CONFIG_SMP |
19 | * Represents all cpu's present in the system | 19 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
20 | * In systems capable of hotplug, this map could dynamically grow | ||
21 | * as new cpu's are detected in the system via any platform specific | ||
22 | * method, such as ACPI for e.g. | ||
23 | */ | ||
24 | cpumask_t cpu_present_map __read_mostly; | ||
25 | EXPORT_SYMBOL(cpu_present_map); | ||
26 | |||
27 | #ifndef CONFIG_SMP | ||
28 | |||
29 | /* | ||
30 | * Represents all cpu's that are currently online. | ||
31 | */ | ||
32 | cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL; | ||
33 | EXPORT_SYMBOL(cpu_online_map); | ||
34 | |||
35 | cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL; | ||
36 | EXPORT_SYMBOL(cpu_possible_map); | ||
37 | |||
38 | #else /* CONFIG_SMP */ | ||
39 | |||
40 | /* Serializes the updates to cpu_online_map, cpu_present_map */ | ||
41 | static DEFINE_MUTEX(cpu_add_remove_lock); | 20 | static DEFINE_MUTEX(cpu_add_remove_lock); |
42 | 21 | ||
43 | static __cpuinitdata RAW_NOTIFIER_HEAD(cpu_chain); | 22 | static __cpuinitdata RAW_NOTIFIER_HEAD(cpu_chain); |
@@ -64,8 +43,6 @@ void __init cpu_hotplug_init(void) | |||
64 | cpu_hotplug.refcount = 0; | 43 | cpu_hotplug.refcount = 0; |
65 | } | 44 | } |
66 | 45 | ||
67 | cpumask_t cpu_active_map; | ||
68 | |||
69 | #ifdef CONFIG_HOTPLUG_CPU | 46 | #ifdef CONFIG_HOTPLUG_CPU |
70 | 47 | ||
71 | void get_online_cpus(void) | 48 | void get_online_cpus(void) |
@@ -96,7 +73,7 @@ EXPORT_SYMBOL_GPL(put_online_cpus); | |||
96 | 73 | ||
97 | /* | 74 | /* |
98 | * The following two API's must be used when attempting | 75 | * The following two API's must be used when attempting |
99 | * to serialize the updates to cpu_online_map, cpu_present_map. | 76 | * to serialize the updates to cpu_online_mask, cpu_present_mask. |
100 | */ | 77 | */ |
101 | void cpu_maps_update_begin(void) | 78 | void cpu_maps_update_begin(void) |
102 | { | 79 | { |
@@ -217,7 +194,7 @@ static int __ref take_cpu_down(void *_param) | |||
217 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) | 194 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) |
218 | { | 195 | { |
219 | int err, nr_calls = 0; | 196 | int err, nr_calls = 0; |
220 | cpumask_t old_allowed, tmp; | 197 | cpumask_var_t old_allowed; |
221 | void *hcpu = (void *)(long)cpu; | 198 | void *hcpu = (void *)(long)cpu; |
222 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; | 199 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
223 | struct take_cpu_down_param tcd_param = { | 200 | struct take_cpu_down_param tcd_param = { |
@@ -231,6 +208,9 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) | |||
231 | if (!cpu_online(cpu)) | 208 | if (!cpu_online(cpu)) |
232 | return -EINVAL; | 209 | return -EINVAL; |
233 | 210 | ||
211 | if (!alloc_cpumask_var(&old_allowed, GFP_KERNEL)) | ||
212 | return -ENOMEM; | ||
213 | |||
234 | cpu_hotplug_begin(); | 214 | cpu_hotplug_begin(); |
235 | err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod, | 215 | err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod, |
236 | hcpu, -1, &nr_calls); | 216 | hcpu, -1, &nr_calls); |
@@ -245,13 +225,11 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) | |||
245 | } | 225 | } |
246 | 226 | ||
247 | /* Ensure that we are not runnable on dying cpu */ | 227 | /* Ensure that we are not runnable on dying cpu */ |
248 | old_allowed = current->cpus_allowed; | 228 | cpumask_copy(old_allowed, ¤t->cpus_allowed); |
249 | cpus_setall(tmp); | 229 | set_cpus_allowed_ptr(current, |
250 | cpu_clear(cpu, tmp); | 230 | cpumask_of(cpumask_any_but(cpu_online_mask, cpu))); |
251 | set_cpus_allowed_ptr(current, &tmp); | ||
252 | tmp = cpumask_of_cpu(cpu); | ||
253 | 231 | ||
254 | err = __stop_machine(take_cpu_down, &tcd_param, &tmp); | 232 | err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); |
255 | if (err) { | 233 | if (err) { |
256 | /* CPU didn't die: tell everyone. Can't complain. */ | 234 | /* CPU didn't die: tell everyone. Can't complain. */ |
257 | if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod, | 235 | if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod, |
@@ -277,7 +255,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) | |||
277 | check_for_tasks(cpu); | 255 | check_for_tasks(cpu); |
278 | 256 | ||
279 | out_allowed: | 257 | out_allowed: |
280 | set_cpus_allowed_ptr(current, &old_allowed); | 258 | set_cpus_allowed_ptr(current, old_allowed); |
281 | out_release: | 259 | out_release: |
282 | cpu_hotplug_done(); | 260 | cpu_hotplug_done(); |
283 | if (!err) { | 261 | if (!err) { |
@@ -285,13 +263,17 @@ out_release: | |||
285 | hcpu) == NOTIFY_BAD) | 263 | hcpu) == NOTIFY_BAD) |
286 | BUG(); | 264 | BUG(); |
287 | } | 265 | } |
266 | free_cpumask_var(old_allowed); | ||
288 | return err; | 267 | return err; |
289 | } | 268 | } |
290 | 269 | ||
291 | int __ref cpu_down(unsigned int cpu) | 270 | int __ref cpu_down(unsigned int cpu) |
292 | { | 271 | { |
293 | int err = 0; | 272 | int err; |
294 | 273 | ||
274 | err = stop_machine_create(); | ||
275 | if (err) | ||
276 | return err; | ||
295 | cpu_maps_update_begin(); | 277 | cpu_maps_update_begin(); |
296 | 278 | ||
297 | if (cpu_hotplug_disabled) { | 279 | if (cpu_hotplug_disabled) { |
@@ -303,7 +285,7 @@ int __ref cpu_down(unsigned int cpu) | |||
303 | 285 | ||
304 | /* | 286 | /* |
305 | * Make sure the all cpus did the reschedule and are not | 287 | * Make sure the all cpus did the reschedule and are not |
306 | * using stale version of the cpu_active_map. | 288 | * using stale version of the cpu_active_mask. |
307 | * This is not strictly necessary becuase stop_machine() | 289 | * This is not strictly necessary becuase stop_machine() |
308 | * that we run down the line already provides the required | 290 | * that we run down the line already provides the required |
309 | * synchronization. But it's really a side effect and we do not | 291 | * synchronization. But it's really a side effect and we do not |
@@ -318,6 +300,7 @@ int __ref cpu_down(unsigned int cpu) | |||
318 | 300 | ||
319 | out: | 301 | out: |
320 | cpu_maps_update_done(); | 302 | cpu_maps_update_done(); |
303 | stop_machine_destroy(); | ||
321 | return err; | 304 | return err; |
322 | } | 305 | } |
323 | EXPORT_SYMBOL(cpu_down); | 306 | EXPORT_SYMBOL(cpu_down); |
@@ -367,7 +350,7 @@ out_notify: | |||
367 | int __cpuinit cpu_up(unsigned int cpu) | 350 | int __cpuinit cpu_up(unsigned int cpu) |
368 | { | 351 | { |
369 | int err = 0; | 352 | int err = 0; |
370 | if (!cpu_isset(cpu, cpu_possible_map)) { | 353 | if (!cpu_possible(cpu)) { |
371 | printk(KERN_ERR "can't online cpu %d because it is not " | 354 | printk(KERN_ERR "can't online cpu %d because it is not " |
372 | "configured as may-hotadd at boot time\n", cpu); | 355 | "configured as may-hotadd at boot time\n", cpu); |
373 | #if defined(CONFIG_IA64) || defined(CONFIG_X86_64) | 356 | #if defined(CONFIG_IA64) || defined(CONFIG_X86_64) |
@@ -392,25 +375,28 @@ out: | |||
392 | } | 375 | } |
393 | 376 | ||
394 | #ifdef CONFIG_PM_SLEEP_SMP | 377 | #ifdef CONFIG_PM_SLEEP_SMP |
395 | static cpumask_t frozen_cpus; | 378 | static cpumask_var_t frozen_cpus; |
396 | 379 | ||
397 | int disable_nonboot_cpus(void) | 380 | int disable_nonboot_cpus(void) |
398 | { | 381 | { |
399 | int cpu, first_cpu, error = 0; | 382 | int cpu, first_cpu, error; |
400 | 383 | ||
384 | error = stop_machine_create(); | ||
385 | if (error) | ||
386 | return error; | ||
401 | cpu_maps_update_begin(); | 387 | cpu_maps_update_begin(); |
402 | first_cpu = first_cpu(cpu_online_map); | 388 | first_cpu = cpumask_first(cpu_online_mask); |
403 | /* We take down all of the non-boot CPUs in one shot to avoid races | 389 | /* We take down all of the non-boot CPUs in one shot to avoid races |
404 | * with the userspace trying to use the CPU hotplug at the same time | 390 | * with the userspace trying to use the CPU hotplug at the same time |
405 | */ | 391 | */ |
406 | cpus_clear(frozen_cpus); | 392 | cpumask_clear(frozen_cpus); |
407 | printk("Disabling non-boot CPUs ...\n"); | 393 | printk("Disabling non-boot CPUs ...\n"); |
408 | for_each_online_cpu(cpu) { | 394 | for_each_online_cpu(cpu) { |
409 | if (cpu == first_cpu) | 395 | if (cpu == first_cpu) |
410 | continue; | 396 | continue; |
411 | error = _cpu_down(cpu, 1); | 397 | error = _cpu_down(cpu, 1); |
412 | if (!error) { | 398 | if (!error) { |
413 | cpu_set(cpu, frozen_cpus); | 399 | cpumask_set_cpu(cpu, frozen_cpus); |
414 | printk("CPU%d is down\n", cpu); | 400 | printk("CPU%d is down\n", cpu); |
415 | } else { | 401 | } else { |
416 | printk(KERN_ERR "Error taking CPU%d down: %d\n", | 402 | printk(KERN_ERR "Error taking CPU%d down: %d\n", |
@@ -426,6 +412,7 @@ int disable_nonboot_cpus(void) | |||
426 | printk(KERN_ERR "Non-boot CPUs are not disabled\n"); | 412 | printk(KERN_ERR "Non-boot CPUs are not disabled\n"); |
427 | } | 413 | } |
428 | cpu_maps_update_done(); | 414 | cpu_maps_update_done(); |
415 | stop_machine_destroy(); | ||
429 | return error; | 416 | return error; |
430 | } | 417 | } |
431 | 418 | ||
@@ -436,11 +423,11 @@ void __ref enable_nonboot_cpus(void) | |||
436 | /* Allow everyone to use the CPU hotplug again */ | 423 | /* Allow everyone to use the CPU hotplug again */ |
437 | cpu_maps_update_begin(); | 424 | cpu_maps_update_begin(); |
438 | cpu_hotplug_disabled = 0; | 425 | cpu_hotplug_disabled = 0; |
439 | if (cpus_empty(frozen_cpus)) | 426 | if (cpumask_empty(frozen_cpus)) |
440 | goto out; | 427 | goto out; |
441 | 428 | ||
442 | printk("Enabling non-boot CPUs ...\n"); | 429 | printk("Enabling non-boot CPUs ...\n"); |
443 | for_each_cpu_mask_nr(cpu, frozen_cpus) { | 430 | for_each_cpu(cpu, frozen_cpus) { |
444 | error = _cpu_up(cpu, 1); | 431 | error = _cpu_up(cpu, 1); |
445 | if (!error) { | 432 | if (!error) { |
446 | printk("CPU%d is up\n", cpu); | 433 | printk("CPU%d is up\n", cpu); |
@@ -448,10 +435,18 @@ void __ref enable_nonboot_cpus(void) | |||
448 | } | 435 | } |
449 | printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error); | 436 | printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error); |
450 | } | 437 | } |
451 | cpus_clear(frozen_cpus); | 438 | cpumask_clear(frozen_cpus); |
452 | out: | 439 | out: |
453 | cpu_maps_update_done(); | 440 | cpu_maps_update_done(); |
454 | } | 441 | } |
442 | |||
443 | static int alloc_frozen_cpus(void) | ||
444 | { | ||
445 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) | ||
446 | return -ENOMEM; | ||
447 | return 0; | ||
448 | } | ||
449 | core_initcall(alloc_frozen_cpus); | ||
455 | #endif /* CONFIG_PM_SLEEP_SMP */ | 450 | #endif /* CONFIG_PM_SLEEP_SMP */ |
456 | 451 | ||
457 | /** | 452 | /** |
@@ -467,7 +462,7 @@ void __cpuinit notify_cpu_starting(unsigned int cpu) | |||
467 | unsigned long val = CPU_STARTING; | 462 | unsigned long val = CPU_STARTING; |
468 | 463 | ||
469 | #ifdef CONFIG_PM_SLEEP_SMP | 464 | #ifdef CONFIG_PM_SLEEP_SMP |
470 | if (cpu_isset(cpu, frozen_cpus)) | 465 | if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus)) |
471 | val = CPU_STARTING_FROZEN; | 466 | val = CPU_STARTING_FROZEN; |
472 | #endif /* CONFIG_PM_SLEEP_SMP */ | 467 | #endif /* CONFIG_PM_SLEEP_SMP */ |
473 | raw_notifier_call_chain(&cpu_chain, val, (void *)(long)cpu); | 468 | raw_notifier_call_chain(&cpu_chain, val, (void *)(long)cpu); |
@@ -479,7 +474,7 @@ void __cpuinit notify_cpu_starting(unsigned int cpu) | |||
479 | * cpu_bit_bitmap[] is a special, "compressed" data structure that | 474 | * cpu_bit_bitmap[] is a special, "compressed" data structure that |
480 | * represents all NR_CPUS bits binary values of 1<<nr. | 475 | * represents all NR_CPUS bits binary values of 1<<nr. |
481 | * | 476 | * |
482 | * It is used by cpumask_of_cpu() to get a constant address to a CPU | 477 | * It is used by cpumask_of() to get a constant address to a CPU |
483 | * mask value that has a single bit set only. | 478 | * mask value that has a single bit set only. |
484 | */ | 479 | */ |
485 | 480 | ||
@@ -502,3 +497,71 @@ EXPORT_SYMBOL_GPL(cpu_bit_bitmap); | |||
502 | 497 | ||
503 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; | 498 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; |
504 | EXPORT_SYMBOL(cpu_all_bits); | 499 | EXPORT_SYMBOL(cpu_all_bits); |
500 | |||
501 | #ifdef CONFIG_INIT_ALL_POSSIBLE | ||
502 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly | ||
503 | = CPU_BITS_ALL; | ||
504 | #else | ||
505 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly; | ||
506 | #endif | ||
507 | const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits); | ||
508 | EXPORT_SYMBOL(cpu_possible_mask); | ||
509 | |||
510 | static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly; | ||
511 | const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits); | ||
512 | EXPORT_SYMBOL(cpu_online_mask); | ||
513 | |||
514 | static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly; | ||
515 | const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits); | ||
516 | EXPORT_SYMBOL(cpu_present_mask); | ||
517 | |||
518 | static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly; | ||
519 | const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits); | ||
520 | EXPORT_SYMBOL(cpu_active_mask); | ||
521 | |||
522 | void set_cpu_possible(unsigned int cpu, bool possible) | ||
523 | { | ||
524 | if (possible) | ||
525 | cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits)); | ||
526 | else | ||
527 | cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits)); | ||
528 | } | ||
529 | |||
530 | void set_cpu_present(unsigned int cpu, bool present) | ||
531 | { | ||
532 | if (present) | ||
533 | cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits)); | ||
534 | else | ||
535 | cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits)); | ||
536 | } | ||
537 | |||
538 | void set_cpu_online(unsigned int cpu, bool online) | ||
539 | { | ||
540 | if (online) | ||
541 | cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits)); | ||
542 | else | ||
543 | cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits)); | ||
544 | } | ||
545 | |||
546 | void set_cpu_active(unsigned int cpu, bool active) | ||
547 | { | ||
548 | if (active) | ||
549 | cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); | ||
550 | else | ||
551 | cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits)); | ||
552 | } | ||
553 | |||
554 | void init_cpu_present(const struct cpumask *src) | ||
555 | { | ||
556 | cpumask_copy(to_cpumask(cpu_present_bits), src); | ||
557 | } | ||
558 | |||
559 | void init_cpu_possible(const struct cpumask *src) | ||
560 | { | ||
561 | cpumask_copy(to_cpumask(cpu_possible_bits), src); | ||
562 | } | ||
563 | |||
564 | void init_cpu_online(const struct cpumask *src) | ||
565 | { | ||
566 | cpumask_copy(to_cpumask(cpu_online_bits), src); | ||
567 | } | ||