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c0a31329 TG |
1 | /* |
2 | * linux/kernel/hrtimer.c | |
3 | * | |
3c8aa39d | 4 | * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de> |
79bf2bb3 | 5 | * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar |
54cdfdb4 | 6 | * Copyright(C) 2006-2007 Timesys Corp., Thomas Gleixner |
c0a31329 TG |
7 | * |
8 | * High-resolution kernel timers | |
9 | * | |
10 | * In contrast to the low-resolution timeout API implemented in | |
11 | * kernel/timer.c, hrtimers provide finer resolution and accuracy | |
12 | * depending on system configuration and capabilities. | |
13 | * | |
14 | * These timers are currently used for: | |
15 | * - itimers | |
16 | * - POSIX timers | |
17 | * - nanosleep | |
18 | * - precise in-kernel timing | |
19 | * | |
20 | * Started by: Thomas Gleixner and Ingo Molnar | |
21 | * | |
22 | * Credits: | |
23 | * based on kernel/timer.c | |
24 | * | |
66188fae TG |
25 | * Help, testing, suggestions, bugfixes, improvements were |
26 | * provided by: | |
27 | * | |
28 | * George Anzinger, Andrew Morton, Steven Rostedt, Roman Zippel | |
29 | * et. al. | |
30 | * | |
c0a31329 TG |
31 | * For licencing details see kernel-base/COPYING |
32 | */ | |
33 | ||
34 | #include <linux/cpu.h> | |
54cdfdb4 | 35 | #include <linux/irq.h> |
c0a31329 TG |
36 | #include <linux/module.h> |
37 | #include <linux/percpu.h> | |
38 | #include <linux/hrtimer.h> | |
39 | #include <linux/notifier.h> | |
40 | #include <linux/syscalls.h> | |
54cdfdb4 | 41 | #include <linux/kallsyms.h> |
c0a31329 | 42 | #include <linux/interrupt.h> |
79bf2bb3 | 43 | #include <linux/tick.h> |
54cdfdb4 TG |
44 | #include <linux/seq_file.h> |
45 | #include <linux/err.h> | |
237fc6e7 | 46 | #include <linux/debugobjects.h> |
c0a31329 TG |
47 | |
48 | #include <asm/uaccess.h> | |
49 | ||
50 | /** | |
51 | * ktime_get - get the monotonic time in ktime_t format | |
52 | * | |
53 | * returns the time in ktime_t format | |
54 | */ | |
d316c57f | 55 | ktime_t ktime_get(void) |
c0a31329 TG |
56 | { |
57 | struct timespec now; | |
58 | ||
59 | ktime_get_ts(&now); | |
60 | ||
61 | return timespec_to_ktime(now); | |
62 | } | |
641b9e0e | 63 | EXPORT_SYMBOL_GPL(ktime_get); |
c0a31329 TG |
64 | |
65 | /** | |
66 | * ktime_get_real - get the real (wall-) time in ktime_t format | |
67 | * | |
68 | * returns the time in ktime_t format | |
69 | */ | |
d316c57f | 70 | ktime_t ktime_get_real(void) |
c0a31329 TG |
71 | { |
72 | struct timespec now; | |
73 | ||
74 | getnstimeofday(&now); | |
75 | ||
76 | return timespec_to_ktime(now); | |
77 | } | |
78 | ||
79 | EXPORT_SYMBOL_GPL(ktime_get_real); | |
80 | ||
81 | /* | |
82 | * The timer bases: | |
7978672c GA |
83 | * |
84 | * Note: If we want to add new timer bases, we have to skip the two | |
85 | * clock ids captured by the cpu-timers. We do this by holding empty | |
86 | * entries rather than doing math adjustment of the clock ids. | |
87 | * This ensures that we capture erroneous accesses to these clock ids | |
88 | * rather than moving them into the range of valid clock id's. | |
c0a31329 | 89 | */ |
54cdfdb4 | 90 | DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = |
c0a31329 | 91 | { |
3c8aa39d TG |
92 | |
93 | .clock_base = | |
c0a31329 | 94 | { |
3c8aa39d TG |
95 | { |
96 | .index = CLOCK_REALTIME, | |
97 | .get_time = &ktime_get_real, | |
54cdfdb4 | 98 | .resolution = KTIME_LOW_RES, |
3c8aa39d TG |
99 | }, |
100 | { | |
101 | .index = CLOCK_MONOTONIC, | |
102 | .get_time = &ktime_get, | |
54cdfdb4 | 103 | .resolution = KTIME_LOW_RES, |
3c8aa39d TG |
104 | }, |
105 | } | |
c0a31329 TG |
106 | }; |
107 | ||
108 | /** | |
109 | * ktime_get_ts - get the monotonic clock in timespec format | |
c0a31329 TG |
110 | * @ts: pointer to timespec variable |
111 | * | |
112 | * The function calculates the monotonic clock from the realtime | |
113 | * clock and the wall_to_monotonic offset and stores the result | |
72fd4a35 | 114 | * in normalized timespec format in the variable pointed to by @ts. |
c0a31329 TG |
115 | */ |
116 | void ktime_get_ts(struct timespec *ts) | |
117 | { | |
118 | struct timespec tomono; | |
119 | unsigned long seq; | |
120 | ||
121 | do { | |
122 | seq = read_seqbegin(&xtime_lock); | |
123 | getnstimeofday(ts); | |
124 | tomono = wall_to_monotonic; | |
125 | ||
126 | } while (read_seqretry(&xtime_lock, seq)); | |
127 | ||
128 | set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, | |
129 | ts->tv_nsec + tomono.tv_nsec); | |
130 | } | |
69778e32 | 131 | EXPORT_SYMBOL_GPL(ktime_get_ts); |
c0a31329 | 132 | |
92127c7a TG |
133 | /* |
134 | * Get the coarse grained time at the softirq based on xtime and | |
135 | * wall_to_monotonic. | |
136 | */ | |
3c8aa39d | 137 | static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) |
92127c7a TG |
138 | { |
139 | ktime_t xtim, tomono; | |
ad28d94a | 140 | struct timespec xts, tom; |
92127c7a TG |
141 | unsigned long seq; |
142 | ||
143 | do { | |
144 | seq = read_seqbegin(&xtime_lock); | |
2c6b47de | 145 | xts = current_kernel_time(); |
ad28d94a | 146 | tom = wall_to_monotonic; |
92127c7a TG |
147 | } while (read_seqretry(&xtime_lock, seq)); |
148 | ||
f4304ab2 | 149 | xtim = timespec_to_ktime(xts); |
ad28d94a | 150 | tomono = timespec_to_ktime(tom); |
3c8aa39d TG |
151 | base->clock_base[CLOCK_REALTIME].softirq_time = xtim; |
152 | base->clock_base[CLOCK_MONOTONIC].softirq_time = | |
153 | ktime_add(xtim, tomono); | |
92127c7a TG |
154 | } |
155 | ||
c0a31329 TG |
156 | /* |
157 | * Functions and macros which are different for UP/SMP systems are kept in a | |
158 | * single place | |
159 | */ | |
160 | #ifdef CONFIG_SMP | |
161 | ||
c0a31329 TG |
162 | /* |
163 | * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock | |
164 | * means that all timers which are tied to this base via timer->base are | |
165 | * locked, and the base itself is locked too. | |
166 | * | |
167 | * So __run_timers/migrate_timers can safely modify all timers which could | |
168 | * be found on the lists/queues. | |
169 | * | |
170 | * When the timer's base is locked, and the timer removed from list, it is | |
171 | * possible to set timer->base = NULL and drop the lock: the timer remains | |
172 | * locked. | |
173 | */ | |
3c8aa39d TG |
174 | static |
175 | struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer, | |
176 | unsigned long *flags) | |
c0a31329 | 177 | { |
3c8aa39d | 178 | struct hrtimer_clock_base *base; |
c0a31329 TG |
179 | |
180 | for (;;) { | |
181 | base = timer->base; | |
182 | if (likely(base != NULL)) { | |
3c8aa39d | 183 | spin_lock_irqsave(&base->cpu_base->lock, *flags); |
c0a31329 TG |
184 | if (likely(base == timer->base)) |
185 | return base; | |
186 | /* The timer has migrated to another CPU: */ | |
3c8aa39d | 187 | spin_unlock_irqrestore(&base->cpu_base->lock, *flags); |
c0a31329 TG |
188 | } |
189 | cpu_relax(); | |
190 | } | |
191 | } | |
192 | ||
193 | /* | |
194 | * Switch the timer base to the current CPU when possible. | |
195 | */ | |
3c8aa39d TG |
196 | static inline struct hrtimer_clock_base * |
197 | switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base) | |
c0a31329 | 198 | { |
3c8aa39d TG |
199 | struct hrtimer_clock_base *new_base; |
200 | struct hrtimer_cpu_base *new_cpu_base; | |
c0a31329 | 201 | |
3c8aa39d TG |
202 | new_cpu_base = &__get_cpu_var(hrtimer_bases); |
203 | new_base = &new_cpu_base->clock_base[base->index]; | |
c0a31329 TG |
204 | |
205 | if (base != new_base) { | |
206 | /* | |
207 | * We are trying to schedule the timer on the local CPU. | |
208 | * However we can't change timer's base while it is running, | |
209 | * so we keep it on the same CPU. No hassle vs. reprogramming | |
210 | * the event source in the high resolution case. The softirq | |
211 | * code will take care of this when the timer function has | |
212 | * completed. There is no conflict as we hold the lock until | |
213 | * the timer is enqueued. | |
214 | */ | |
54cdfdb4 | 215 | if (unlikely(hrtimer_callback_running(timer))) |
c0a31329 TG |
216 | return base; |
217 | ||
218 | /* See the comment in lock_timer_base() */ | |
219 | timer->base = NULL; | |
3c8aa39d TG |
220 | spin_unlock(&base->cpu_base->lock); |
221 | spin_lock(&new_base->cpu_base->lock); | |
c0a31329 TG |
222 | timer->base = new_base; |
223 | } | |
224 | return new_base; | |
225 | } | |
226 | ||
227 | #else /* CONFIG_SMP */ | |
228 | ||
3c8aa39d | 229 | static inline struct hrtimer_clock_base * |
c0a31329 TG |
230 | lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) |
231 | { | |
3c8aa39d | 232 | struct hrtimer_clock_base *base = timer->base; |
c0a31329 | 233 | |
3c8aa39d | 234 | spin_lock_irqsave(&base->cpu_base->lock, *flags); |
c0a31329 TG |
235 | |
236 | return base; | |
237 | } | |
238 | ||
54cdfdb4 | 239 | # define switch_hrtimer_base(t, b) (b) |
c0a31329 TG |
240 | |
241 | #endif /* !CONFIG_SMP */ | |
242 | ||
243 | /* | |
244 | * Functions for the union type storage format of ktime_t which are | |
245 | * too large for inlining: | |
246 | */ | |
247 | #if BITS_PER_LONG < 64 | |
248 | # ifndef CONFIG_KTIME_SCALAR | |
249 | /** | |
250 | * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable | |
c0a31329 TG |
251 | * @kt: addend |
252 | * @nsec: the scalar nsec value to add | |
253 | * | |
254 | * Returns the sum of kt and nsec in ktime_t format | |
255 | */ | |
256 | ktime_t ktime_add_ns(const ktime_t kt, u64 nsec) | |
257 | { | |
258 | ktime_t tmp; | |
259 | ||
260 | if (likely(nsec < NSEC_PER_SEC)) { | |
261 | tmp.tv64 = nsec; | |
262 | } else { | |
263 | unsigned long rem = do_div(nsec, NSEC_PER_SEC); | |
264 | ||
265 | tmp = ktime_set((long)nsec, rem); | |
266 | } | |
267 | ||
268 | return ktime_add(kt, tmp); | |
269 | } | |
b8b8fd2d DH |
270 | |
271 | EXPORT_SYMBOL_GPL(ktime_add_ns); | |
a272378d ACM |
272 | |
273 | /** | |
274 | * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable | |
275 | * @kt: minuend | |
276 | * @nsec: the scalar nsec value to subtract | |
277 | * | |
278 | * Returns the subtraction of @nsec from @kt in ktime_t format | |
279 | */ | |
280 | ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec) | |
281 | { | |
282 | ktime_t tmp; | |
283 | ||
284 | if (likely(nsec < NSEC_PER_SEC)) { | |
285 | tmp.tv64 = nsec; | |
286 | } else { | |
287 | unsigned long rem = do_div(nsec, NSEC_PER_SEC); | |
288 | ||
289 | tmp = ktime_set((long)nsec, rem); | |
290 | } | |
291 | ||
292 | return ktime_sub(kt, tmp); | |
293 | } | |
294 | ||
295 | EXPORT_SYMBOL_GPL(ktime_sub_ns); | |
c0a31329 TG |
296 | # endif /* !CONFIG_KTIME_SCALAR */ |
297 | ||
298 | /* | |
299 | * Divide a ktime value by a nanosecond value | |
300 | */ | |
4d672e7a | 301 | u64 ktime_divns(const ktime_t kt, s64 div) |
c0a31329 | 302 | { |
900cfa46 | 303 | u64 dclc; |
c0a31329 TG |
304 | int sft = 0; |
305 | ||
900cfa46 | 306 | dclc = ktime_to_ns(kt); |
c0a31329 TG |
307 | /* Make sure the divisor is less than 2^32: */ |
308 | while (div >> 32) { | |
309 | sft++; | |
310 | div >>= 1; | |
311 | } | |
312 | dclc >>= sft; | |
313 | do_div(dclc, (unsigned long) div); | |
314 | ||
4d672e7a | 315 | return dclc; |
c0a31329 | 316 | } |
c0a31329 TG |
317 | #endif /* BITS_PER_LONG >= 64 */ |
318 | ||
5a7780e7 TG |
319 | /* |
320 | * Add two ktime values and do a safety check for overflow: | |
321 | */ | |
322 | ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs) | |
323 | { | |
324 | ktime_t res = ktime_add(lhs, rhs); | |
325 | ||
326 | /* | |
327 | * We use KTIME_SEC_MAX here, the maximum timeout which we can | |
328 | * return to user space in a timespec: | |
329 | */ | |
330 | if (res.tv64 < 0 || res.tv64 < lhs.tv64 || res.tv64 < rhs.tv64) | |
331 | res = ktime_set(KTIME_SEC_MAX, 0); | |
332 | ||
333 | return res; | |
334 | } | |
335 | ||
237fc6e7 TG |
336 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS |
337 | ||
338 | static struct debug_obj_descr hrtimer_debug_descr; | |
339 | ||
340 | /* | |
341 | * fixup_init is called when: | |
342 | * - an active object is initialized | |
343 | */ | |
344 | static int hrtimer_fixup_init(void *addr, enum debug_obj_state state) | |
345 | { | |
346 | struct hrtimer *timer = addr; | |
347 | ||
348 | switch (state) { | |
349 | case ODEBUG_STATE_ACTIVE: | |
350 | hrtimer_cancel(timer); | |
351 | debug_object_init(timer, &hrtimer_debug_descr); | |
352 | return 1; | |
353 | default: | |
354 | return 0; | |
355 | } | |
356 | } | |
357 | ||
358 | /* | |
359 | * fixup_activate is called when: | |
360 | * - an active object is activated | |
361 | * - an unknown object is activated (might be a statically initialized object) | |
362 | */ | |
363 | static int hrtimer_fixup_activate(void *addr, enum debug_obj_state state) | |
364 | { | |
365 | switch (state) { | |
366 | ||
367 | case ODEBUG_STATE_NOTAVAILABLE: | |
368 | WARN_ON_ONCE(1); | |
369 | return 0; | |
370 | ||
371 | case ODEBUG_STATE_ACTIVE: | |
372 | WARN_ON(1); | |
373 | ||
374 | default: | |
375 | return 0; | |
376 | } | |
377 | } | |
378 | ||
379 | /* | |
380 | * fixup_free is called when: | |
381 | * - an active object is freed | |
382 | */ | |
383 | static int hrtimer_fixup_free(void *addr, enum debug_obj_state state) | |
384 | { | |
385 | struct hrtimer *timer = addr; | |
386 | ||
387 | switch (state) { | |
388 | case ODEBUG_STATE_ACTIVE: | |
389 | hrtimer_cancel(timer); | |
390 | debug_object_free(timer, &hrtimer_debug_descr); | |
391 | return 1; | |
392 | default: | |
393 | return 0; | |
394 | } | |
395 | } | |
396 | ||
397 | static struct debug_obj_descr hrtimer_debug_descr = { | |
398 | .name = "hrtimer", | |
399 | .fixup_init = hrtimer_fixup_init, | |
400 | .fixup_activate = hrtimer_fixup_activate, | |
401 | .fixup_free = hrtimer_fixup_free, | |
402 | }; | |
403 | ||
404 | static inline void debug_hrtimer_init(struct hrtimer *timer) | |
405 | { | |
406 | debug_object_init(timer, &hrtimer_debug_descr); | |
407 | } | |
408 | ||
409 | static inline void debug_hrtimer_activate(struct hrtimer *timer) | |
410 | { | |
411 | debug_object_activate(timer, &hrtimer_debug_descr); | |
412 | } | |
413 | ||
414 | static inline void debug_hrtimer_deactivate(struct hrtimer *timer) | |
415 | { | |
416 | debug_object_deactivate(timer, &hrtimer_debug_descr); | |
417 | } | |
418 | ||
419 | static inline void debug_hrtimer_free(struct hrtimer *timer) | |
420 | { | |
421 | debug_object_free(timer, &hrtimer_debug_descr); | |
422 | } | |
423 | ||
424 | static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, | |
425 | enum hrtimer_mode mode); | |
426 | ||
427 | void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id, | |
428 | enum hrtimer_mode mode) | |
429 | { | |
430 | debug_object_init_on_stack(timer, &hrtimer_debug_descr); | |
431 | __hrtimer_init(timer, clock_id, mode); | |
432 | } | |
433 | ||
434 | void destroy_hrtimer_on_stack(struct hrtimer *timer) | |
435 | { | |
436 | debug_object_free(timer, &hrtimer_debug_descr); | |
437 | } | |
438 | ||
439 | #else | |
440 | static inline void debug_hrtimer_init(struct hrtimer *timer) { } | |
441 | static inline void debug_hrtimer_activate(struct hrtimer *timer) { } | |
442 | static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { } | |
443 | #endif | |
444 | ||
d3d74453 PZ |
445 | /* |
446 | * Check, whether the timer is on the callback pending list | |
447 | */ | |
448 | static inline int hrtimer_cb_pending(const struct hrtimer *timer) | |
449 | { | |
450 | return timer->state & HRTIMER_STATE_PENDING; | |
451 | } | |
452 | ||
453 | /* | |
454 | * Remove a timer from the callback pending list | |
455 | */ | |
456 | static inline void hrtimer_remove_cb_pending(struct hrtimer *timer) | |
457 | { | |
458 | list_del_init(&timer->cb_entry); | |
459 | } | |
460 | ||
54cdfdb4 TG |
461 | /* High resolution timer related functions */ |
462 | #ifdef CONFIG_HIGH_RES_TIMERS | |
463 | ||
464 | /* | |
465 | * High resolution timer enabled ? | |
466 | */ | |
467 | static int hrtimer_hres_enabled __read_mostly = 1; | |
468 | ||
469 | /* | |
470 | * Enable / Disable high resolution mode | |
471 | */ | |
472 | static int __init setup_hrtimer_hres(char *str) | |
473 | { | |
474 | if (!strcmp(str, "off")) | |
475 | hrtimer_hres_enabled = 0; | |
476 | else if (!strcmp(str, "on")) | |
477 | hrtimer_hres_enabled = 1; | |
478 | else | |
479 | return 0; | |
480 | return 1; | |
481 | } | |
482 | ||
483 | __setup("highres=", setup_hrtimer_hres); | |
484 | ||
485 | /* | |
486 | * hrtimer_high_res_enabled - query, if the highres mode is enabled | |
487 | */ | |
488 | static inline int hrtimer_is_hres_enabled(void) | |
489 | { | |
490 | return hrtimer_hres_enabled; | |
491 | } | |
492 | ||
493 | /* | |
494 | * Is the high resolution mode active ? | |
495 | */ | |
496 | static inline int hrtimer_hres_active(void) | |
497 | { | |
498 | return __get_cpu_var(hrtimer_bases).hres_active; | |
499 | } | |
500 | ||
501 | /* | |
502 | * Reprogram the event source with checking both queues for the | |
503 | * next event | |
504 | * Called with interrupts disabled and base->lock held | |
505 | */ | |
506 | static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base) | |
507 | { | |
508 | int i; | |
509 | struct hrtimer_clock_base *base = cpu_base->clock_base; | |
510 | ktime_t expires; | |
511 | ||
512 | cpu_base->expires_next.tv64 = KTIME_MAX; | |
513 | ||
514 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { | |
515 | struct hrtimer *timer; | |
516 | ||
517 | if (!base->first) | |
518 | continue; | |
519 | timer = rb_entry(base->first, struct hrtimer, node); | |
520 | expires = ktime_sub(timer->expires, base->offset); | |
521 | if (expires.tv64 < cpu_base->expires_next.tv64) | |
522 | cpu_base->expires_next = expires; | |
523 | } | |
524 | ||
525 | if (cpu_base->expires_next.tv64 != KTIME_MAX) | |
526 | tick_program_event(cpu_base->expires_next, 1); | |
527 | } | |
528 | ||
529 | /* | |
530 | * Shared reprogramming for clock_realtime and clock_monotonic | |
531 | * | |
532 | * When a timer is enqueued and expires earlier than the already enqueued | |
533 | * timers, we have to check, whether it expires earlier than the timer for | |
534 | * which the clock event device was armed. | |
535 | * | |
536 | * Called with interrupts disabled and base->cpu_base.lock held | |
537 | */ | |
538 | static int hrtimer_reprogram(struct hrtimer *timer, | |
539 | struct hrtimer_clock_base *base) | |
540 | { | |
541 | ktime_t *expires_next = &__get_cpu_var(hrtimer_bases).expires_next; | |
542 | ktime_t expires = ktime_sub(timer->expires, base->offset); | |
543 | int res; | |
544 | ||
63070a79 TG |
545 | WARN_ON_ONCE(timer->expires.tv64 < 0); |
546 | ||
54cdfdb4 TG |
547 | /* |
548 | * When the callback is running, we do not reprogram the clock event | |
549 | * device. The timer callback is either running on a different CPU or | |
3a4fa0a2 | 550 | * the callback is executed in the hrtimer_interrupt context. The |
54cdfdb4 TG |
551 | * reprogramming is handled either by the softirq, which called the |
552 | * callback or at the end of the hrtimer_interrupt. | |
553 | */ | |
554 | if (hrtimer_callback_running(timer)) | |
555 | return 0; | |
556 | ||
63070a79 TG |
557 | /* |
558 | * CLOCK_REALTIME timer might be requested with an absolute | |
559 | * expiry time which is less than base->offset. Nothing wrong | |
560 | * about that, just avoid to call into the tick code, which | |
561 | * has now objections against negative expiry values. | |
562 | */ | |
563 | if (expires.tv64 < 0) | |
564 | return -ETIME; | |
565 | ||
54cdfdb4 TG |
566 | if (expires.tv64 >= expires_next->tv64) |
567 | return 0; | |
568 | ||
569 | /* | |
570 | * Clockevents returns -ETIME, when the event was in the past. | |
571 | */ | |
572 | res = tick_program_event(expires, 0); | |
573 | if (!IS_ERR_VALUE(res)) | |
574 | *expires_next = expires; | |
575 | return res; | |
576 | } | |
577 | ||
578 | ||
579 | /* | |
580 | * Retrigger next event is called after clock was set | |
581 | * | |
582 | * Called with interrupts disabled via on_each_cpu() | |
583 | */ | |
584 | static void retrigger_next_event(void *arg) | |
585 | { | |
586 | struct hrtimer_cpu_base *base; | |
587 | struct timespec realtime_offset; | |
588 | unsigned long seq; | |
589 | ||
590 | if (!hrtimer_hres_active()) | |
591 | return; | |
592 | ||
593 | do { | |
594 | seq = read_seqbegin(&xtime_lock); | |
595 | set_normalized_timespec(&realtime_offset, | |
596 | -wall_to_monotonic.tv_sec, | |
597 | -wall_to_monotonic.tv_nsec); | |
598 | } while (read_seqretry(&xtime_lock, seq)); | |
599 | ||
600 | base = &__get_cpu_var(hrtimer_bases); | |
601 | ||
602 | /* Adjust CLOCK_REALTIME offset */ | |
603 | spin_lock(&base->lock); | |
604 | base->clock_base[CLOCK_REALTIME].offset = | |
605 | timespec_to_ktime(realtime_offset); | |
606 | ||
607 | hrtimer_force_reprogram(base); | |
608 | spin_unlock(&base->lock); | |
609 | } | |
610 | ||
611 | /* | |
612 | * Clock realtime was set | |
613 | * | |
614 | * Change the offset of the realtime clock vs. the monotonic | |
615 | * clock. | |
616 | * | |
617 | * We might have to reprogram the high resolution timer interrupt. On | |
618 | * SMP we call the architecture specific code to retrigger _all_ high | |
619 | * resolution timer interrupts. On UP we just disable interrupts and | |
620 | * call the high resolution interrupt code. | |
621 | */ | |
622 | void clock_was_set(void) | |
623 | { | |
624 | /* Retrigger the CPU local events everywhere */ | |
15c8b6c1 | 625 | on_each_cpu(retrigger_next_event, NULL, 1); |
54cdfdb4 TG |
626 | } |
627 | ||
995f054f IM |
628 | /* |
629 | * During resume we might have to reprogram the high resolution timer | |
630 | * interrupt (on the local CPU): | |
631 | */ | |
632 | void hres_timers_resume(void) | |
633 | { | |
995f054f IM |
634 | /* Retrigger the CPU local events: */ |
635 | retrigger_next_event(NULL); | |
636 | } | |
637 | ||
54cdfdb4 TG |
638 | /* |
639 | * Initialize the high resolution related parts of cpu_base | |
640 | */ | |
641 | static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) | |
642 | { | |
643 | base->expires_next.tv64 = KTIME_MAX; | |
644 | base->hres_active = 0; | |
54cdfdb4 TG |
645 | } |
646 | ||
647 | /* | |
648 | * Initialize the high resolution related parts of a hrtimer | |
649 | */ | |
650 | static inline void hrtimer_init_timer_hres(struct hrtimer *timer) | |
651 | { | |
54cdfdb4 TG |
652 | } |
653 | ||
654 | /* | |
655 | * When High resolution timers are active, try to reprogram. Note, that in case | |
656 | * the state has HRTIMER_STATE_CALLBACK set, no reprogramming and no expiry | |
657 | * check happens. The timer gets enqueued into the rbtree. The reprogramming | |
658 | * and expiry check is done in the hrtimer_interrupt or in the softirq. | |
659 | */ | |
660 | static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, | |
661 | struct hrtimer_clock_base *base) | |
662 | { | |
663 | if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) { | |
664 | ||
665 | /* Timer is expired, act upon the callback mode */ | |
666 | switch(timer->cb_mode) { | |
667 | case HRTIMER_CB_IRQSAFE_NO_RESTART: | |
237fc6e7 | 668 | debug_hrtimer_deactivate(timer); |
54cdfdb4 TG |
669 | /* |
670 | * We can call the callback from here. No restart | |
671 | * happens, so no danger of recursion | |
672 | */ | |
673 | BUG_ON(timer->function(timer) != HRTIMER_NORESTART); | |
674 | return 1; | |
ccc7dadf TG |
675 | case HRTIMER_CB_IRQSAFE_PERCPU: |
676 | case HRTIMER_CB_IRQSAFE_UNLOCKED: | |
54cdfdb4 TG |
677 | /* |
678 | * This is solely for the sched tick emulation with | |
679 | * dynamic tick support to ensure that we do not | |
680 | * restart the tick right on the edge and end up with | |
681 | * the tick timer in the softirq ! The calling site | |
ccc7dadf | 682 | * takes care of this. Also used for hrtimer sleeper ! |
54cdfdb4 | 683 | */ |
237fc6e7 | 684 | debug_hrtimer_deactivate(timer); |
54cdfdb4 TG |
685 | return 1; |
686 | case HRTIMER_CB_IRQSAFE: | |
687 | case HRTIMER_CB_SOFTIRQ: | |
688 | /* | |
689 | * Move everything else into the softirq pending list ! | |
690 | */ | |
691 | list_add_tail(&timer->cb_entry, | |
692 | &base->cpu_base->cb_pending); | |
693 | timer->state = HRTIMER_STATE_PENDING; | |
54cdfdb4 TG |
694 | return 1; |
695 | default: | |
696 | BUG(); | |
697 | } | |
698 | } | |
699 | return 0; | |
700 | } | |
701 | ||
702 | /* | |
703 | * Switch to high resolution mode | |
704 | */ | |
f8953856 | 705 | static int hrtimer_switch_to_hres(void) |
54cdfdb4 | 706 | { |
820de5c3 IM |
707 | int cpu = smp_processor_id(); |
708 | struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu); | |
54cdfdb4 TG |
709 | unsigned long flags; |
710 | ||
711 | if (base->hres_active) | |
f8953856 | 712 | return 1; |
54cdfdb4 TG |
713 | |
714 | local_irq_save(flags); | |
715 | ||
716 | if (tick_init_highres()) { | |
717 | local_irq_restore(flags); | |
820de5c3 IM |
718 | printk(KERN_WARNING "Could not switch to high resolution " |
719 | "mode on CPU %d\n", cpu); | |
f8953856 | 720 | return 0; |
54cdfdb4 TG |
721 | } |
722 | base->hres_active = 1; | |
723 | base->clock_base[CLOCK_REALTIME].resolution = KTIME_HIGH_RES; | |
724 | base->clock_base[CLOCK_MONOTONIC].resolution = KTIME_HIGH_RES; | |
725 | ||
726 | tick_setup_sched_timer(); | |
727 | ||
728 | /* "Retrigger" the interrupt to get things going */ | |
729 | retrigger_next_event(NULL); | |
730 | local_irq_restore(flags); | |
edfed66e | 731 | printk(KERN_DEBUG "Switched to high resolution mode on CPU %d\n", |
54cdfdb4 | 732 | smp_processor_id()); |
f8953856 | 733 | return 1; |
54cdfdb4 TG |
734 | } |
735 | ||
0c96c597 TG |
736 | static inline void hrtimer_raise_softirq(void) |
737 | { | |
738 | raise_softirq(HRTIMER_SOFTIRQ); | |
739 | } | |
740 | ||
54cdfdb4 TG |
741 | #else |
742 | ||
743 | static inline int hrtimer_hres_active(void) { return 0; } | |
744 | static inline int hrtimer_is_hres_enabled(void) { return 0; } | |
f8953856 | 745 | static inline int hrtimer_switch_to_hres(void) { return 0; } |
54cdfdb4 TG |
746 | static inline void hrtimer_force_reprogram(struct hrtimer_cpu_base *base) { } |
747 | static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, | |
748 | struct hrtimer_clock_base *base) | |
749 | { | |
750 | return 0; | |
751 | } | |
54cdfdb4 TG |
752 | static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { } |
753 | static inline void hrtimer_init_timer_hres(struct hrtimer *timer) { } | |
d3d74453 PZ |
754 | static inline int hrtimer_reprogram(struct hrtimer *timer, |
755 | struct hrtimer_clock_base *base) | |
756 | { | |
757 | return 0; | |
758 | } | |
0c96c597 | 759 | static inline void hrtimer_raise_softirq(void) { } |
54cdfdb4 TG |
760 | |
761 | #endif /* CONFIG_HIGH_RES_TIMERS */ | |
762 | ||
82f67cd9 IM |
763 | #ifdef CONFIG_TIMER_STATS |
764 | void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer, void *addr) | |
765 | { | |
766 | if (timer->start_site) | |
767 | return; | |
768 | ||
769 | timer->start_site = addr; | |
770 | memcpy(timer->start_comm, current->comm, TASK_COMM_LEN); | |
771 | timer->start_pid = current->pid; | |
772 | } | |
773 | #endif | |
774 | ||
c0a31329 | 775 | /* |
6506f2aa | 776 | * Counterpart to lock_hrtimer_base above: |
c0a31329 TG |
777 | */ |
778 | static inline | |
779 | void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) | |
780 | { | |
3c8aa39d | 781 | spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags); |
c0a31329 TG |
782 | } |
783 | ||
784 | /** | |
785 | * hrtimer_forward - forward the timer expiry | |
c0a31329 | 786 | * @timer: hrtimer to forward |
44f21475 | 787 | * @now: forward past this time |
c0a31329 TG |
788 | * @interval: the interval to forward |
789 | * | |
790 | * Forward the timer expiry so it will expire in the future. | |
8dca6f33 | 791 | * Returns the number of overruns. |
c0a31329 | 792 | */ |
4d672e7a | 793 | u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) |
c0a31329 | 794 | { |
4d672e7a | 795 | u64 orun = 1; |
44f21475 | 796 | ktime_t delta; |
c0a31329 TG |
797 | |
798 | delta = ktime_sub(now, timer->expires); | |
799 | ||
800 | if (delta.tv64 < 0) | |
801 | return 0; | |
802 | ||
c9db4fa1 TG |
803 | if (interval.tv64 < timer->base->resolution.tv64) |
804 | interval.tv64 = timer->base->resolution.tv64; | |
805 | ||
c0a31329 | 806 | if (unlikely(delta.tv64 >= interval.tv64)) { |
df869b63 | 807 | s64 incr = ktime_to_ns(interval); |
c0a31329 TG |
808 | |
809 | orun = ktime_divns(delta, incr); | |
810 | timer->expires = ktime_add_ns(timer->expires, incr * orun); | |
811 | if (timer->expires.tv64 > now.tv64) | |
812 | return orun; | |
813 | /* | |
814 | * This (and the ktime_add() below) is the | |
815 | * correction for exact: | |
816 | */ | |
817 | orun++; | |
818 | } | |
5a7780e7 | 819 | timer->expires = ktime_add_safe(timer->expires, interval); |
c0a31329 TG |
820 | |
821 | return orun; | |
822 | } | |
6bdb6b62 | 823 | EXPORT_SYMBOL_GPL(hrtimer_forward); |
c0a31329 TG |
824 | |
825 | /* | |
826 | * enqueue_hrtimer - internal function to (re)start a timer | |
827 | * | |
828 | * The timer is inserted in expiry order. Insertion into the | |
829 | * red black tree is O(log(n)). Must hold the base lock. | |
830 | */ | |
3c8aa39d | 831 | static void enqueue_hrtimer(struct hrtimer *timer, |
54cdfdb4 | 832 | struct hrtimer_clock_base *base, int reprogram) |
c0a31329 TG |
833 | { |
834 | struct rb_node **link = &base->active.rb_node; | |
c0a31329 TG |
835 | struct rb_node *parent = NULL; |
836 | struct hrtimer *entry; | |
99bc2fcb | 837 | int leftmost = 1; |
c0a31329 | 838 | |
237fc6e7 TG |
839 | debug_hrtimer_activate(timer); |
840 | ||
c0a31329 TG |
841 | /* |
842 | * Find the right place in the rbtree: | |
843 | */ | |
844 | while (*link) { | |
845 | parent = *link; | |
846 | entry = rb_entry(parent, struct hrtimer, node); | |
847 | /* | |
848 | * We dont care about collisions. Nodes with | |
849 | * the same expiry time stay together. | |
850 | */ | |
99bc2fcb | 851 | if (timer->expires.tv64 < entry->expires.tv64) { |
c0a31329 | 852 | link = &(*link)->rb_left; |
99bc2fcb | 853 | } else { |
c0a31329 | 854 | link = &(*link)->rb_right; |
99bc2fcb IM |
855 | leftmost = 0; |
856 | } | |
c0a31329 TG |
857 | } |
858 | ||
859 | /* | |
288867ec TG |
860 | * Insert the timer to the rbtree and check whether it |
861 | * replaces the first pending timer | |
c0a31329 | 862 | */ |
99bc2fcb | 863 | if (leftmost) { |
54cdfdb4 TG |
864 | /* |
865 | * Reprogram the clock event device. When the timer is already | |
866 | * expired hrtimer_enqueue_reprogram has either called the | |
867 | * callback or added it to the pending list and raised the | |
868 | * softirq. | |
869 | * | |
870 | * This is a NOP for !HIGHRES | |
871 | */ | |
872 | if (reprogram && hrtimer_enqueue_reprogram(timer, base)) | |
873 | return; | |
874 | ||
875 | base->first = &timer->node; | |
876 | } | |
877 | ||
c0a31329 TG |
878 | rb_link_node(&timer->node, parent, link); |
879 | rb_insert_color(&timer->node, &base->active); | |
303e967f TG |
880 | /* |
881 | * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the | |
882 | * state of a possibly running callback. | |
883 | */ | |
884 | timer->state |= HRTIMER_STATE_ENQUEUED; | |
288867ec | 885 | } |
c0a31329 TG |
886 | |
887 | /* | |
888 | * __remove_hrtimer - internal function to remove a timer | |
889 | * | |
890 | * Caller must hold the base lock. | |
54cdfdb4 TG |
891 | * |
892 | * High resolution timer mode reprograms the clock event device when the | |
893 | * timer is the one which expires next. The caller can disable this by setting | |
894 | * reprogram to zero. This is useful, when the context does a reprogramming | |
895 | * anyway (e.g. timer interrupt) | |
c0a31329 | 896 | */ |
3c8aa39d | 897 | static void __remove_hrtimer(struct hrtimer *timer, |
303e967f | 898 | struct hrtimer_clock_base *base, |
54cdfdb4 | 899 | unsigned long newstate, int reprogram) |
c0a31329 | 900 | { |
54cdfdb4 TG |
901 | /* High res. callback list. NOP for !HIGHRES */ |
902 | if (hrtimer_cb_pending(timer)) | |
903 | hrtimer_remove_cb_pending(timer); | |
904 | else { | |
905 | /* | |
906 | * Remove the timer from the rbtree and replace the | |
907 | * first entry pointer if necessary. | |
908 | */ | |
909 | if (base->first == &timer->node) { | |
910 | base->first = rb_next(&timer->node); | |
911 | /* Reprogram the clock event device. if enabled */ | |
912 | if (reprogram && hrtimer_hres_active()) | |
913 | hrtimer_force_reprogram(base->cpu_base); | |
914 | } | |
915 | rb_erase(&timer->node, &base->active); | |
916 | } | |
303e967f | 917 | timer->state = newstate; |
c0a31329 TG |
918 | } |
919 | ||
920 | /* | |
921 | * remove hrtimer, called with base lock held | |
922 | */ | |
923 | static inline int | |
3c8aa39d | 924 | remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) |
c0a31329 | 925 | { |
303e967f | 926 | if (hrtimer_is_queued(timer)) { |
54cdfdb4 TG |
927 | int reprogram; |
928 | ||
929 | /* | |
930 | * Remove the timer and force reprogramming when high | |
931 | * resolution mode is active and the timer is on the current | |
932 | * CPU. If we remove a timer on another CPU, reprogramming is | |
933 | * skipped. The interrupt event on this CPU is fired and | |
934 | * reprogramming happens in the interrupt handler. This is a | |
935 | * rare case and less expensive than a smp call. | |
936 | */ | |
237fc6e7 | 937 | debug_hrtimer_deactivate(timer); |
82f67cd9 | 938 | timer_stats_hrtimer_clear_start_info(timer); |
54cdfdb4 TG |
939 | reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases); |
940 | __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE, | |
941 | reprogram); | |
c0a31329 TG |
942 | return 1; |
943 | } | |
944 | return 0; | |
945 | } | |
946 | ||
947 | /** | |
948 | * hrtimer_start - (re)start an relative timer on the current CPU | |
c0a31329 TG |
949 | * @timer: the timer to be added |
950 | * @tim: expiry time | |
951 | * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL) | |
952 | * | |
953 | * Returns: | |
954 | * 0 on success | |
955 | * 1 when the timer was active | |
956 | */ | |
957 | int | |
958 | hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) | |
959 | { | |
3c8aa39d | 960 | struct hrtimer_clock_base *base, *new_base; |
c0a31329 | 961 | unsigned long flags; |
0c96c597 | 962 | int ret, raise; |
c0a31329 TG |
963 | |
964 | base = lock_hrtimer_base(timer, &flags); | |
965 | ||
966 | /* Remove an active timer from the queue: */ | |
967 | ret = remove_hrtimer(timer, base); | |
968 | ||
969 | /* Switch the timer base, if necessary: */ | |
970 | new_base = switch_hrtimer_base(timer, base); | |
971 | ||
c9cb2e3d | 972 | if (mode == HRTIMER_MODE_REL) { |
5a7780e7 | 973 | tim = ktime_add_safe(tim, new_base->get_time()); |
06027bdd IM |
974 | /* |
975 | * CONFIG_TIME_LOW_RES is a temporary way for architectures | |
976 | * to signal that they simply return xtime in | |
977 | * do_gettimeoffset(). In this case we want to round up by | |
978 | * resolution when starting a relative timer, to avoid short | |
979 | * timeouts. This will go away with the GTOD framework. | |
980 | */ | |
981 | #ifdef CONFIG_TIME_LOW_RES | |
5a7780e7 | 982 | tim = ktime_add_safe(tim, base->resolution); |
06027bdd IM |
983 | #endif |
984 | } | |
237fc6e7 | 985 | |
c0a31329 TG |
986 | timer->expires = tim; |
987 | ||
82f67cd9 IM |
988 | timer_stats_hrtimer_set_start_info(timer); |
989 | ||
935c631d IM |
990 | /* |
991 | * Only allow reprogramming if the new base is on this CPU. | |
992 | * (it might still be on another CPU if the timer was pending) | |
993 | */ | |
994 | enqueue_hrtimer(timer, new_base, | |
995 | new_base->cpu_base == &__get_cpu_var(hrtimer_bases)); | |
c0a31329 | 996 | |
0c96c597 TG |
997 | /* |
998 | * The timer may be expired and moved to the cb_pending | |
999 | * list. We can not raise the softirq with base lock held due | |
1000 | * to a possible deadlock with runqueue lock. | |
1001 | */ | |
1002 | raise = timer->state == HRTIMER_STATE_PENDING; | |
1003 | ||
ee3ece83 SR |
1004 | /* |
1005 | * We use preempt_disable to prevent this task from migrating after | |
1006 | * setting up the softirq and raising it. Otherwise, if me migrate | |
1007 | * we will raise the softirq on the wrong CPU. | |
1008 | */ | |
1009 | preempt_disable(); | |
1010 | ||
c0a31329 TG |
1011 | unlock_hrtimer_base(timer, &flags); |
1012 | ||
0c96c597 TG |
1013 | if (raise) |
1014 | hrtimer_raise_softirq(); | |
ee3ece83 | 1015 | preempt_enable(); |
0c96c597 | 1016 | |
c0a31329 TG |
1017 | return ret; |
1018 | } | |
8d16b764 | 1019 | EXPORT_SYMBOL_GPL(hrtimer_start); |
c0a31329 TG |
1020 | |
1021 | /** | |
1022 | * hrtimer_try_to_cancel - try to deactivate a timer | |
c0a31329 TG |
1023 | * @timer: hrtimer to stop |
1024 | * | |
1025 | * Returns: | |
1026 | * 0 when the timer was not active | |
1027 | * 1 when the timer was active | |
1028 | * -1 when the timer is currently excuting the callback function and | |
fa9799e3 | 1029 | * cannot be stopped |
c0a31329 TG |
1030 | */ |
1031 | int hrtimer_try_to_cancel(struct hrtimer *timer) | |
1032 | { | |
3c8aa39d | 1033 | struct hrtimer_clock_base *base; |
c0a31329 TG |
1034 | unsigned long flags; |
1035 | int ret = -1; | |
1036 | ||
1037 | base = lock_hrtimer_base(timer, &flags); | |
1038 | ||
303e967f | 1039 | if (!hrtimer_callback_running(timer)) |
c0a31329 TG |
1040 | ret = remove_hrtimer(timer, base); |
1041 | ||
1042 | unlock_hrtimer_base(timer, &flags); | |
1043 | ||
1044 | return ret; | |
1045 | ||
1046 | } | |
8d16b764 | 1047 | EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel); |
c0a31329 TG |
1048 | |
1049 | /** | |
1050 | * hrtimer_cancel - cancel a timer and wait for the handler to finish. | |
c0a31329 TG |
1051 | * @timer: the timer to be cancelled |
1052 | * | |
1053 | * Returns: | |
1054 | * 0 when the timer was not active | |
1055 | * 1 when the timer was active | |
1056 | */ | |
1057 | int hrtimer_cancel(struct hrtimer *timer) | |
1058 | { | |
1059 | for (;;) { | |
1060 | int ret = hrtimer_try_to_cancel(timer); | |
1061 | ||
1062 | if (ret >= 0) | |
1063 | return ret; | |
5ef37b19 | 1064 | cpu_relax(); |
c0a31329 TG |
1065 | } |
1066 | } | |
8d16b764 | 1067 | EXPORT_SYMBOL_GPL(hrtimer_cancel); |
c0a31329 TG |
1068 | |
1069 | /** | |
1070 | * hrtimer_get_remaining - get remaining time for the timer | |
c0a31329 TG |
1071 | * @timer: the timer to read |
1072 | */ | |
1073 | ktime_t hrtimer_get_remaining(const struct hrtimer *timer) | |
1074 | { | |
3c8aa39d | 1075 | struct hrtimer_clock_base *base; |
c0a31329 TG |
1076 | unsigned long flags; |
1077 | ktime_t rem; | |
1078 | ||
1079 | base = lock_hrtimer_base(timer, &flags); | |
3c8aa39d | 1080 | rem = ktime_sub(timer->expires, base->get_time()); |
c0a31329 TG |
1081 | unlock_hrtimer_base(timer, &flags); |
1082 | ||
1083 | return rem; | |
1084 | } | |
8d16b764 | 1085 | EXPORT_SYMBOL_GPL(hrtimer_get_remaining); |
c0a31329 | 1086 | |
ee9c5785 | 1087 | #ifdef CONFIG_NO_HZ |
69239749 TL |
1088 | /** |
1089 | * hrtimer_get_next_event - get the time until next expiry event | |
1090 | * | |
1091 | * Returns the delta to the next expiry event or KTIME_MAX if no timer | |
1092 | * is pending. | |
1093 | */ | |
1094 | ktime_t hrtimer_get_next_event(void) | |
1095 | { | |
3c8aa39d TG |
1096 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); |
1097 | struct hrtimer_clock_base *base = cpu_base->clock_base; | |
69239749 TL |
1098 | ktime_t delta, mindelta = { .tv64 = KTIME_MAX }; |
1099 | unsigned long flags; | |
1100 | int i; | |
1101 | ||
3c8aa39d TG |
1102 | spin_lock_irqsave(&cpu_base->lock, flags); |
1103 | ||
54cdfdb4 TG |
1104 | if (!hrtimer_hres_active()) { |
1105 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { | |
1106 | struct hrtimer *timer; | |
69239749 | 1107 | |
54cdfdb4 TG |
1108 | if (!base->first) |
1109 | continue; | |
3c8aa39d | 1110 | |
54cdfdb4 TG |
1111 | timer = rb_entry(base->first, struct hrtimer, node); |
1112 | delta.tv64 = timer->expires.tv64; | |
1113 | delta = ktime_sub(delta, base->get_time()); | |
1114 | if (delta.tv64 < mindelta.tv64) | |
1115 | mindelta.tv64 = delta.tv64; | |
1116 | } | |
69239749 | 1117 | } |
3c8aa39d TG |
1118 | |
1119 | spin_unlock_irqrestore(&cpu_base->lock, flags); | |
1120 | ||
69239749 TL |
1121 | if (mindelta.tv64 < 0) |
1122 | mindelta.tv64 = 0; | |
1123 | return mindelta; | |
1124 | } | |
1125 | #endif | |
1126 | ||
237fc6e7 TG |
1127 | static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, |
1128 | enum hrtimer_mode mode) | |
c0a31329 | 1129 | { |
3c8aa39d | 1130 | struct hrtimer_cpu_base *cpu_base; |
c0a31329 | 1131 | |
7978672c GA |
1132 | memset(timer, 0, sizeof(struct hrtimer)); |
1133 | ||
3c8aa39d | 1134 | cpu_base = &__raw_get_cpu_var(hrtimer_bases); |
c0a31329 | 1135 | |
c9cb2e3d | 1136 | if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS) |
7978672c GA |
1137 | clock_id = CLOCK_MONOTONIC; |
1138 | ||
3c8aa39d | 1139 | timer->base = &cpu_base->clock_base[clock_id]; |
d3d74453 | 1140 | INIT_LIST_HEAD(&timer->cb_entry); |
54cdfdb4 | 1141 | hrtimer_init_timer_hres(timer); |
82f67cd9 IM |
1142 | |
1143 | #ifdef CONFIG_TIMER_STATS | |
1144 | timer->start_site = NULL; | |
1145 | timer->start_pid = -1; | |
1146 | memset(timer->start_comm, 0, TASK_COMM_LEN); | |
1147 | #endif | |
c0a31329 | 1148 | } |
237fc6e7 TG |
1149 | |
1150 | /** | |
1151 | * hrtimer_init - initialize a timer to the given clock | |
1152 | * @timer: the timer to be initialized | |
1153 | * @clock_id: the clock to be used | |
1154 | * @mode: timer mode abs/rel | |
1155 | */ | |
1156 | void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, | |
1157 | enum hrtimer_mode mode) | |
1158 | { | |
1159 | debug_hrtimer_init(timer); | |
1160 | __hrtimer_init(timer, clock_id, mode); | |
1161 | } | |
8d16b764 | 1162 | EXPORT_SYMBOL_GPL(hrtimer_init); |
c0a31329 TG |
1163 | |
1164 | /** | |
1165 | * hrtimer_get_res - get the timer resolution for a clock | |
c0a31329 TG |
1166 | * @which_clock: which clock to query |
1167 | * @tp: pointer to timespec variable to store the resolution | |
1168 | * | |
72fd4a35 RD |
1169 | * Store the resolution of the clock selected by @which_clock in the |
1170 | * variable pointed to by @tp. | |
c0a31329 TG |
1171 | */ |
1172 | int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) | |
1173 | { | |
3c8aa39d | 1174 | struct hrtimer_cpu_base *cpu_base; |
c0a31329 | 1175 | |
3c8aa39d TG |
1176 | cpu_base = &__raw_get_cpu_var(hrtimer_bases); |
1177 | *tp = ktime_to_timespec(cpu_base->clock_base[which_clock].resolution); | |
c0a31329 TG |
1178 | |
1179 | return 0; | |
1180 | } | |
8d16b764 | 1181 | EXPORT_SYMBOL_GPL(hrtimer_get_res); |
c0a31329 | 1182 | |
d3d74453 PZ |
1183 | static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base) |
1184 | { | |
1185 | spin_lock_irq(&cpu_base->lock); | |
1186 | ||
1187 | while (!list_empty(&cpu_base->cb_pending)) { | |
1188 | enum hrtimer_restart (*fn)(struct hrtimer *); | |
1189 | struct hrtimer *timer; | |
1190 | int restart; | |
1191 | ||
1192 | timer = list_entry(cpu_base->cb_pending.next, | |
1193 | struct hrtimer, cb_entry); | |
1194 | ||
237fc6e7 | 1195 | debug_hrtimer_deactivate(timer); |
d3d74453 PZ |
1196 | timer_stats_account_hrtimer(timer); |
1197 | ||
1198 | fn = timer->function; | |
1199 | __remove_hrtimer(timer, timer->base, HRTIMER_STATE_CALLBACK, 0); | |
1200 | spin_unlock_irq(&cpu_base->lock); | |
1201 | ||
1202 | restart = fn(timer); | |
1203 | ||
1204 | spin_lock_irq(&cpu_base->lock); | |
1205 | ||
1206 | timer->state &= ~HRTIMER_STATE_CALLBACK; | |
1207 | if (restart == HRTIMER_RESTART) { | |
1208 | BUG_ON(hrtimer_active(timer)); | |
1209 | /* | |
1210 | * Enqueue the timer, allow reprogramming of the event | |
1211 | * device | |
1212 | */ | |
1213 | enqueue_hrtimer(timer, timer->base, 1); | |
1214 | } else if (hrtimer_active(timer)) { | |
1215 | /* | |
1216 | * If the timer was rearmed on another CPU, reprogram | |
1217 | * the event device. | |
1218 | */ | |
d7b41a24 BS |
1219 | struct hrtimer_clock_base *base = timer->base; |
1220 | ||
1221 | if (base->first == &timer->node && | |
1222 | hrtimer_reprogram(timer, base)) { | |
1223 | /* | |
1224 | * Timer is expired. Thus move it from tree to | |
1225 | * pending list again. | |
1226 | */ | |
1227 | __remove_hrtimer(timer, base, | |
1228 | HRTIMER_STATE_PENDING, 0); | |
1229 | list_add_tail(&timer->cb_entry, | |
1230 | &base->cpu_base->cb_pending); | |
1231 | } | |
d3d74453 PZ |
1232 | } |
1233 | } | |
1234 | spin_unlock_irq(&cpu_base->lock); | |
1235 | } | |
1236 | ||
1237 | static void __run_hrtimer(struct hrtimer *timer) | |
1238 | { | |
1239 | struct hrtimer_clock_base *base = timer->base; | |
1240 | struct hrtimer_cpu_base *cpu_base = base->cpu_base; | |
1241 | enum hrtimer_restart (*fn)(struct hrtimer *); | |
1242 | int restart; | |
1243 | ||
237fc6e7 | 1244 | debug_hrtimer_deactivate(timer); |
d3d74453 PZ |
1245 | __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0); |
1246 | timer_stats_account_hrtimer(timer); | |
1247 | ||
1248 | fn = timer->function; | |
ccc7dadf TG |
1249 | if (timer->cb_mode == HRTIMER_CB_IRQSAFE_PERCPU || |
1250 | timer->cb_mode == HRTIMER_CB_IRQSAFE_UNLOCKED) { | |
d3d74453 PZ |
1251 | /* |
1252 | * Used for scheduler timers, avoid lock inversion with | |
1253 | * rq->lock and tasklist_lock. | |
1254 | * | |
1255 | * These timers are required to deal with enqueue expiry | |
1256 | * themselves and are not allowed to migrate. | |
1257 | */ | |
1258 | spin_unlock(&cpu_base->lock); | |
1259 | restart = fn(timer); | |
1260 | spin_lock(&cpu_base->lock); | |
1261 | } else | |
1262 | restart = fn(timer); | |
1263 | ||
1264 | /* | |
1265 | * Note: We clear the CALLBACK bit after enqueue_hrtimer to avoid | |
1266 | * reprogramming of the event hardware. This happens at the end of this | |
1267 | * function anyway. | |
1268 | */ | |
1269 | if (restart != HRTIMER_NORESTART) { | |
1270 | BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); | |
1271 | enqueue_hrtimer(timer, base, 0); | |
1272 | } | |
1273 | timer->state &= ~HRTIMER_STATE_CALLBACK; | |
1274 | } | |
1275 | ||
54cdfdb4 TG |
1276 | #ifdef CONFIG_HIGH_RES_TIMERS |
1277 | ||
1278 | /* | |
1279 | * High resolution timer interrupt | |
1280 | * Called with interrupts disabled | |
1281 | */ | |
1282 | void hrtimer_interrupt(struct clock_event_device *dev) | |
1283 | { | |
1284 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); | |
1285 | struct hrtimer_clock_base *base; | |
1286 | ktime_t expires_next, now; | |
1287 | int i, raise = 0; | |
1288 | ||
1289 | BUG_ON(!cpu_base->hres_active); | |
1290 | cpu_base->nr_events++; | |
1291 | dev->next_event.tv64 = KTIME_MAX; | |
1292 | ||
1293 | retry: | |
1294 | now = ktime_get(); | |
1295 | ||
1296 | expires_next.tv64 = KTIME_MAX; | |
1297 | ||
1298 | base = cpu_base->clock_base; | |
1299 | ||
1300 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { | |
1301 | ktime_t basenow; | |
1302 | struct rb_node *node; | |
1303 | ||
1304 | spin_lock(&cpu_base->lock); | |
1305 | ||
1306 | basenow = ktime_add(now, base->offset); | |
1307 | ||
1308 | while ((node = base->first)) { | |
1309 | struct hrtimer *timer; | |
1310 | ||
1311 | timer = rb_entry(node, struct hrtimer, node); | |
1312 | ||
1313 | if (basenow.tv64 < timer->expires.tv64) { | |
1314 | ktime_t expires; | |
1315 | ||
1316 | expires = ktime_sub(timer->expires, | |
1317 | base->offset); | |
1318 | if (expires.tv64 < expires_next.tv64) | |
1319 | expires_next = expires; | |
1320 | break; | |
1321 | } | |
1322 | ||
1323 | /* Move softirq callbacks to the pending list */ | |
1324 | if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) { | |
1325 | __remove_hrtimer(timer, base, | |
1326 | HRTIMER_STATE_PENDING, 0); | |
1327 | list_add_tail(&timer->cb_entry, | |
1328 | &base->cpu_base->cb_pending); | |
1329 | raise = 1; | |
1330 | continue; | |
1331 | } | |
1332 | ||
d3d74453 | 1333 | __run_hrtimer(timer); |
54cdfdb4 TG |
1334 | } |
1335 | spin_unlock(&cpu_base->lock); | |
1336 | base++; | |
1337 | } | |
1338 | ||
1339 | cpu_base->expires_next = expires_next; | |
1340 | ||
1341 | /* Reprogramming necessary ? */ | |
1342 | if (expires_next.tv64 != KTIME_MAX) { | |
1343 | if (tick_program_event(expires_next, 0)) | |
1344 | goto retry; | |
1345 | } | |
1346 | ||
1347 | /* Raise softirq ? */ | |
1348 | if (raise) | |
1349 | raise_softirq(HRTIMER_SOFTIRQ); | |
1350 | } | |
1351 | ||
1352 | static void run_hrtimer_softirq(struct softirq_action *h) | |
1353 | { | |
d3d74453 PZ |
1354 | run_hrtimer_pending(&__get_cpu_var(hrtimer_bases)); |
1355 | } | |
54cdfdb4 | 1356 | |
d3d74453 | 1357 | #endif /* CONFIG_HIGH_RES_TIMERS */ |
82f67cd9 | 1358 | |
d3d74453 PZ |
1359 | /* |
1360 | * Called from timer softirq every jiffy, expire hrtimers: | |
1361 | * | |
1362 | * For HRT its the fall back code to run the softirq in the timer | |
1363 | * softirq context in case the hrtimer initialization failed or has | |
1364 | * not been done yet. | |
1365 | */ | |
1366 | void hrtimer_run_pending(void) | |
1367 | { | |
1368 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); | |
54cdfdb4 | 1369 | |
d3d74453 PZ |
1370 | if (hrtimer_hres_active()) |
1371 | return; | |
54cdfdb4 | 1372 | |
d3d74453 PZ |
1373 | /* |
1374 | * This _is_ ugly: We have to check in the softirq context, | |
1375 | * whether we can switch to highres and / or nohz mode. The | |
1376 | * clocksource switch happens in the timer interrupt with | |
1377 | * xtime_lock held. Notification from there only sets the | |
1378 | * check bit in the tick_oneshot code, otherwise we might | |
1379 | * deadlock vs. xtime_lock. | |
1380 | */ | |
1381 | if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())) | |
1382 | hrtimer_switch_to_hres(); | |
54cdfdb4 | 1383 | |
d3d74453 | 1384 | run_hrtimer_pending(cpu_base); |
54cdfdb4 TG |
1385 | } |
1386 | ||
c0a31329 | 1387 | /* |
d3d74453 | 1388 | * Called from hardirq context every jiffy |
c0a31329 | 1389 | */ |
833883d9 | 1390 | void hrtimer_run_queues(void) |
c0a31329 | 1391 | { |
288867ec | 1392 | struct rb_node *node; |
833883d9 DS |
1393 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); |
1394 | struct hrtimer_clock_base *base; | |
1395 | int index, gettime = 1; | |
c0a31329 | 1396 | |
833883d9 | 1397 | if (hrtimer_hres_active()) |
3055adda DS |
1398 | return; |
1399 | ||
833883d9 DS |
1400 | for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) { |
1401 | base = &cpu_base->clock_base[index]; | |
c0a31329 | 1402 | |
833883d9 | 1403 | if (!base->first) |
d3d74453 | 1404 | continue; |
833883d9 | 1405 | |
259aae86 TG |
1406 | if (base->get_softirq_time) |
1407 | base->softirq_time = base->get_softirq_time(); | |
1408 | else if (gettime) { | |
833883d9 DS |
1409 | hrtimer_get_softirq_time(cpu_base); |
1410 | gettime = 0; | |
b75f7a51 | 1411 | } |
d3d74453 | 1412 | |
833883d9 | 1413 | spin_lock(&cpu_base->lock); |
c0a31329 | 1414 | |
833883d9 DS |
1415 | while ((node = base->first)) { |
1416 | struct hrtimer *timer; | |
54cdfdb4 | 1417 | |
833883d9 DS |
1418 | timer = rb_entry(node, struct hrtimer, node); |
1419 | if (base->softirq_time.tv64 <= timer->expires.tv64) | |
1420 | break; | |
1421 | ||
1422 | if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) { | |
1423 | __remove_hrtimer(timer, base, | |
1424 | HRTIMER_STATE_PENDING, 0); | |
1425 | list_add_tail(&timer->cb_entry, | |
1426 | &base->cpu_base->cb_pending); | |
1427 | continue; | |
1428 | } | |
92127c7a | 1429 | |
833883d9 DS |
1430 | __run_hrtimer(timer); |
1431 | } | |
1432 | spin_unlock(&cpu_base->lock); | |
1433 | } | |
c0a31329 TG |
1434 | } |
1435 | ||
10c94ec1 TG |
1436 | /* |
1437 | * Sleep related functions: | |
1438 | */ | |
c9cb2e3d | 1439 | static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer) |
00362e33 TG |
1440 | { |
1441 | struct hrtimer_sleeper *t = | |
1442 | container_of(timer, struct hrtimer_sleeper, timer); | |
1443 | struct task_struct *task = t->task; | |
1444 | ||
1445 | t->task = NULL; | |
1446 | if (task) | |
1447 | wake_up_process(task); | |
1448 | ||
1449 | return HRTIMER_NORESTART; | |
1450 | } | |
1451 | ||
36c8b586 | 1452 | void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) |
00362e33 TG |
1453 | { |
1454 | sl->timer.function = hrtimer_wakeup; | |
1455 | sl->task = task; | |
54cdfdb4 | 1456 | #ifdef CONFIG_HIGH_RES_TIMERS |
ccc7dadf | 1457 | sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_UNLOCKED; |
54cdfdb4 | 1458 | #endif |
00362e33 TG |
1459 | } |
1460 | ||
669d7868 | 1461 | static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode) |
432569bb | 1462 | { |
669d7868 | 1463 | hrtimer_init_sleeper(t, current); |
10c94ec1 | 1464 | |
432569bb RZ |
1465 | do { |
1466 | set_current_state(TASK_INTERRUPTIBLE); | |
1467 | hrtimer_start(&t->timer, t->timer.expires, mode); | |
37bb6cb4 PZ |
1468 | if (!hrtimer_active(&t->timer)) |
1469 | t->task = NULL; | |
432569bb | 1470 | |
54cdfdb4 TG |
1471 | if (likely(t->task)) |
1472 | schedule(); | |
432569bb | 1473 | |
669d7868 | 1474 | hrtimer_cancel(&t->timer); |
c9cb2e3d | 1475 | mode = HRTIMER_MODE_ABS; |
669d7868 TG |
1476 | |
1477 | } while (t->task && !signal_pending(current)); | |
432569bb | 1478 | |
3588a085 PZ |
1479 | __set_current_state(TASK_RUNNING); |
1480 | ||
669d7868 | 1481 | return t->task == NULL; |
10c94ec1 TG |
1482 | } |
1483 | ||
080344b9 ON |
1484 | static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp) |
1485 | { | |
1486 | struct timespec rmt; | |
1487 | ktime_t rem; | |
1488 | ||
1489 | rem = ktime_sub(timer->expires, timer->base->get_time()); | |
1490 | if (rem.tv64 <= 0) | |
1491 | return 0; | |
1492 | rmt = ktime_to_timespec(rem); | |
1493 | ||
1494 | if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) | |
1495 | return -EFAULT; | |
1496 | ||
1497 | return 1; | |
1498 | } | |
1499 | ||
1711ef38 | 1500 | long __sched hrtimer_nanosleep_restart(struct restart_block *restart) |
10c94ec1 | 1501 | { |
669d7868 | 1502 | struct hrtimer_sleeper t; |
080344b9 | 1503 | struct timespec __user *rmtp; |
237fc6e7 | 1504 | int ret = 0; |
10c94ec1 | 1505 | |
237fc6e7 TG |
1506 | hrtimer_init_on_stack(&t.timer, restart->nanosleep.index, |
1507 | HRTIMER_MODE_ABS); | |
029a07e0 | 1508 | t.timer.expires.tv64 = restart->nanosleep.expires; |
10c94ec1 | 1509 | |
c9cb2e3d | 1510 | if (do_nanosleep(&t, HRTIMER_MODE_ABS)) |
237fc6e7 | 1511 | goto out; |
10c94ec1 | 1512 | |
029a07e0 | 1513 | rmtp = restart->nanosleep.rmtp; |
432569bb | 1514 | if (rmtp) { |
237fc6e7 | 1515 | ret = update_rmtp(&t.timer, rmtp); |
080344b9 | 1516 | if (ret <= 0) |
237fc6e7 | 1517 | goto out; |
432569bb | 1518 | } |
10c94ec1 | 1519 | |
10c94ec1 | 1520 | /* The other values in restart are already filled in */ |
237fc6e7 TG |
1521 | ret = -ERESTART_RESTARTBLOCK; |
1522 | out: | |
1523 | destroy_hrtimer_on_stack(&t.timer); | |
1524 | return ret; | |
10c94ec1 TG |
1525 | } |
1526 | ||
080344b9 | 1527 | long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, |
10c94ec1 TG |
1528 | const enum hrtimer_mode mode, const clockid_t clockid) |
1529 | { | |
1530 | struct restart_block *restart; | |
669d7868 | 1531 | struct hrtimer_sleeper t; |
237fc6e7 | 1532 | int ret = 0; |
10c94ec1 | 1533 | |
237fc6e7 | 1534 | hrtimer_init_on_stack(&t.timer, clockid, mode); |
432569bb RZ |
1535 | t.timer.expires = timespec_to_ktime(*rqtp); |
1536 | if (do_nanosleep(&t, mode)) | |
237fc6e7 | 1537 | goto out; |
10c94ec1 | 1538 | |
7978672c | 1539 | /* Absolute timers do not update the rmtp value and restart: */ |
237fc6e7 TG |
1540 | if (mode == HRTIMER_MODE_ABS) { |
1541 | ret = -ERESTARTNOHAND; | |
1542 | goto out; | |
1543 | } | |
10c94ec1 | 1544 | |
432569bb | 1545 | if (rmtp) { |
237fc6e7 | 1546 | ret = update_rmtp(&t.timer, rmtp); |
080344b9 | 1547 | if (ret <= 0) |
237fc6e7 | 1548 | goto out; |
432569bb | 1549 | } |
10c94ec1 TG |
1550 | |
1551 | restart = ¤t_thread_info()->restart_block; | |
1711ef38 | 1552 | restart->fn = hrtimer_nanosleep_restart; |
029a07e0 TG |
1553 | restart->nanosleep.index = t.timer.base->index; |
1554 | restart->nanosleep.rmtp = rmtp; | |
1555 | restart->nanosleep.expires = t.timer.expires.tv64; | |
10c94ec1 | 1556 | |
237fc6e7 TG |
1557 | ret = -ERESTART_RESTARTBLOCK; |
1558 | out: | |
1559 | destroy_hrtimer_on_stack(&t.timer); | |
1560 | return ret; | |
10c94ec1 TG |
1561 | } |
1562 | ||
6ba1b912 TG |
1563 | asmlinkage long |
1564 | sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp) | |
1565 | { | |
080344b9 | 1566 | struct timespec tu; |
6ba1b912 TG |
1567 | |
1568 | if (copy_from_user(&tu, rqtp, sizeof(tu))) | |
1569 | return -EFAULT; | |
1570 | ||
1571 | if (!timespec_valid(&tu)) | |
1572 | return -EINVAL; | |
1573 | ||
080344b9 | 1574 | return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC); |
6ba1b912 TG |
1575 | } |
1576 | ||
c0a31329 TG |
1577 | /* |
1578 | * Functions related to boot-time initialization: | |
1579 | */ | |
0ec160dd | 1580 | static void __cpuinit init_hrtimers_cpu(int cpu) |
c0a31329 | 1581 | { |
3c8aa39d | 1582 | struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); |
c0a31329 TG |
1583 | int i; |
1584 | ||
3c8aa39d | 1585 | spin_lock_init(&cpu_base->lock); |
3c8aa39d TG |
1586 | |
1587 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) | |
1588 | cpu_base->clock_base[i].cpu_base = cpu_base; | |
1589 | ||
d3d74453 | 1590 | INIT_LIST_HEAD(&cpu_base->cb_pending); |
54cdfdb4 | 1591 | hrtimer_init_hres(cpu_base); |
c0a31329 TG |
1592 | } |
1593 | ||
1594 | #ifdef CONFIG_HOTPLUG_CPU | |
1595 | ||
41e1022e | 1596 | static int migrate_hrtimer_list(struct hrtimer_clock_base *old_base, |
ccc7dadf | 1597 | struct hrtimer_clock_base *new_base, int dcpu) |
c0a31329 TG |
1598 | { |
1599 | struct hrtimer *timer; | |
1600 | struct rb_node *node; | |
41e1022e | 1601 | int raise = 0; |
c0a31329 TG |
1602 | |
1603 | while ((node = rb_first(&old_base->active))) { | |
1604 | timer = rb_entry(node, struct hrtimer, node); | |
54cdfdb4 | 1605 | BUG_ON(hrtimer_callback_running(timer)); |
237fc6e7 | 1606 | debug_hrtimer_deactivate(timer); |
b00c1a99 | 1607 | |
ccc7dadf TG |
1608 | /* |
1609 | * Should not happen. Per CPU timers should be | |
1610 | * canceled _before_ the migration code is called | |
1611 | */ | |
1612 | if (timer->cb_mode == HRTIMER_CB_IRQSAFE_PERCPU) { | |
1613 | __remove_hrtimer(timer, old_base, | |
1614 | HRTIMER_STATE_INACTIVE, 0); | |
1615 | WARN(1, "hrtimer (%p %p)active but cpu %d dead\n", | |
1616 | timer, timer->function, dcpu); | |
1617 | continue; | |
1618 | } | |
1619 | ||
b00c1a99 TG |
1620 | /* |
1621 | * Mark it as STATE_MIGRATE not INACTIVE otherwise the | |
1622 | * timer could be seen as !active and just vanish away | |
1623 | * under us on another CPU | |
1624 | */ | |
1625 | __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0); | |
c0a31329 | 1626 | timer->base = new_base; |
54cdfdb4 TG |
1627 | /* |
1628 | * Enqueue the timer. Allow reprogramming of the event device | |
1629 | */ | |
1630 | enqueue_hrtimer(timer, new_base, 1); | |
41e1022e TG |
1631 | |
1632 | #ifdef CONFIG_HIGH_RES_TIMERS | |
1633 | /* | |
1634 | * Happens with high res enabled when the timer was | |
1635 | * already expired and the callback mode is | |
ccc7dadf TG |
1636 | * HRTIMER_CB_IRQSAFE_UNLOCKED (hrtimer_sleeper). The |
1637 | * enqueue code does not move them to the soft irq | |
1638 | * pending list for performance/latency reasons, but | |
1639 | * in the migration state, we need to do that | |
1640 | * otherwise we end up with a stale timer. | |
41e1022e | 1641 | */ |
b00c1a99 | 1642 | if (timer->state == HRTIMER_STATE_MIGRATE) { |
41e1022e TG |
1643 | timer->state = HRTIMER_STATE_PENDING; |
1644 | list_add_tail(&timer->cb_entry, | |
1645 | &new_base->cpu_base->cb_pending); | |
1646 | raise = 1; | |
1647 | } | |
1648 | #endif | |
b00c1a99 TG |
1649 | /* Clear the migration state bit */ |
1650 | timer->state &= ~HRTIMER_STATE_MIGRATE; | |
c0a31329 | 1651 | } |
41e1022e | 1652 | return raise; |
c0a31329 TG |
1653 | } |
1654 | ||
7659e349 TG |
1655 | #ifdef CONFIG_HIGH_RES_TIMERS |
1656 | static int migrate_hrtimer_pending(struct hrtimer_cpu_base *old_base, | |
1657 | struct hrtimer_cpu_base *new_base) | |
1658 | { | |
1659 | struct hrtimer *timer; | |
1660 | int raise = 0; | |
1661 | ||
1662 | while (!list_empty(&old_base->cb_pending)) { | |
1663 | timer = list_entry(old_base->cb_pending.next, | |
1664 | struct hrtimer, cb_entry); | |
1665 | ||
1666 | __remove_hrtimer(timer, timer->base, HRTIMER_STATE_PENDING, 0); | |
1667 | timer->base = &new_base->clock_base[timer->base->index]; | |
1668 | list_add_tail(&timer->cb_entry, &new_base->cb_pending); | |
1669 | raise = 1; | |
1670 | } | |
1671 | return raise; | |
1672 | } | |
1673 | #else | |
1674 | static int migrate_hrtimer_pending(struct hrtimer_cpu_base *old_base, | |
1675 | struct hrtimer_cpu_base *new_base) | |
1676 | { | |
1677 | return 0; | |
1678 | } | |
1679 | #endif | |
1680 | ||
c0a31329 TG |
1681 | static void migrate_hrtimers(int cpu) |
1682 | { | |
3c8aa39d | 1683 | struct hrtimer_cpu_base *old_base, *new_base; |
7659e349 | 1684 | int i, raise = 0; |
c0a31329 TG |
1685 | |
1686 | BUG_ON(cpu_online(cpu)); | |
3c8aa39d TG |
1687 | old_base = &per_cpu(hrtimer_bases, cpu); |
1688 | new_base = &get_cpu_var(hrtimer_bases); | |
c0a31329 | 1689 | |
54cdfdb4 TG |
1690 | tick_cancel_sched_timer(cpu); |
1691 | ||
c0a31329 | 1692 | local_irq_disable(); |
8e60e05f ON |
1693 | spin_lock(&new_base->lock); |
1694 | spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); | |
c0a31329 | 1695 | |
3c8aa39d | 1696 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { |
41e1022e | 1697 | if (migrate_hrtimer_list(&old_base->clock_base[i], |
ccc7dadf | 1698 | &new_base->clock_base[i], cpu)) |
41e1022e | 1699 | raise = 1; |
c0a31329 TG |
1700 | } |
1701 | ||
7659e349 TG |
1702 | if (migrate_hrtimer_pending(old_base, new_base)) |
1703 | raise = 1; | |
1704 | ||
8e60e05f ON |
1705 | spin_unlock(&old_base->lock); |
1706 | spin_unlock(&new_base->lock); | |
c0a31329 TG |
1707 | local_irq_enable(); |
1708 | put_cpu_var(hrtimer_bases); | |
7659e349 TG |
1709 | |
1710 | if (raise) | |
1711 | hrtimer_raise_softirq(); | |
c0a31329 TG |
1712 | } |
1713 | #endif /* CONFIG_HOTPLUG_CPU */ | |
1714 | ||
8c78f307 | 1715 | static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self, |
c0a31329 TG |
1716 | unsigned long action, void *hcpu) |
1717 | { | |
7713a7d1 | 1718 | unsigned int cpu = (long)hcpu; |
c0a31329 TG |
1719 | |
1720 | switch (action) { | |
1721 | ||
1722 | case CPU_UP_PREPARE: | |
8bb78442 | 1723 | case CPU_UP_PREPARE_FROZEN: |
c0a31329 TG |
1724 | init_hrtimers_cpu(cpu); |
1725 | break; | |
1726 | ||
1727 | #ifdef CONFIG_HOTPLUG_CPU | |
1728 | case CPU_DEAD: | |
8bb78442 | 1729 | case CPU_DEAD_FROZEN: |
d316c57f | 1730 | clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &cpu); |
c0a31329 TG |
1731 | migrate_hrtimers(cpu); |
1732 | break; | |
1733 | #endif | |
1734 | ||
1735 | default: | |
1736 | break; | |
1737 | } | |
1738 | ||
1739 | return NOTIFY_OK; | |
1740 | } | |
1741 | ||
8c78f307 | 1742 | static struct notifier_block __cpuinitdata hrtimers_nb = { |
c0a31329 TG |
1743 | .notifier_call = hrtimer_cpu_notify, |
1744 | }; | |
1745 | ||
1746 | void __init hrtimers_init(void) | |
1747 | { | |
1748 | hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE, | |
1749 | (void *)(long)smp_processor_id()); | |
1750 | register_cpu_notifier(&hrtimers_nb); | |
54cdfdb4 | 1751 | #ifdef CONFIG_HIGH_RES_TIMERS |
962cf36c | 1752 | open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq); |
54cdfdb4 | 1753 | #endif |
c0a31329 TG |
1754 | } |
1755 |