Commit | Line | Data |
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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> | |
35 | #include <linux/module.h> | |
36 | #include <linux/percpu.h> | |
37 | #include <linux/hrtimer.h> | |
38 | #include <linux/notifier.h> | |
39 | #include <linux/syscalls.h> | |
54cdfdb4 | 40 | #include <linux/kallsyms.h> |
c0a31329 | 41 | #include <linux/interrupt.h> |
79bf2bb3 | 42 | #include <linux/tick.h> |
54cdfdb4 TG |
43 | #include <linux/seq_file.h> |
44 | #include <linux/err.h> | |
237fc6e7 | 45 | #include <linux/debugobjects.h> |
eea08f32 AB |
46 | #include <linux/sched.h> |
47 | #include <linux/timer.h> | |
c0a31329 TG |
48 | |
49 | #include <asm/uaccess.h> | |
50 | ||
c6a2a177 XG |
51 | #include <trace/events/timer.h> |
52 | ||
c0a31329 TG |
53 | /* |
54 | * The timer bases: | |
7978672c | 55 | * |
e06383db JS |
56 | * There are more clockids then hrtimer bases. Thus, we index |
57 | * into the timer bases by the hrtimer_base_type enum. When trying | |
58 | * to reach a base using a clockid, hrtimer_clockid_to_base() | |
59 | * is used to convert from clockid to the proper hrtimer_base_type. | |
c0a31329 | 60 | */ |
54cdfdb4 | 61 | DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = |
c0a31329 | 62 | { |
3c8aa39d TG |
63 | |
64 | .clock_base = | |
c0a31329 | 65 | { |
3c8aa39d TG |
66 | { |
67 | .index = CLOCK_REALTIME, | |
68 | .get_time = &ktime_get_real, | |
54cdfdb4 | 69 | .resolution = KTIME_LOW_RES, |
3c8aa39d TG |
70 | }, |
71 | { | |
72 | .index = CLOCK_MONOTONIC, | |
73 | .get_time = &ktime_get, | |
54cdfdb4 | 74 | .resolution = KTIME_LOW_RES, |
3c8aa39d | 75 | }, |
70a08cca JS |
76 | { |
77 | .index = CLOCK_BOOTTIME, | |
78 | .get_time = &ktime_get_boottime, | |
79 | .resolution = KTIME_LOW_RES, | |
80 | }, | |
3c8aa39d | 81 | } |
c0a31329 TG |
82 | }; |
83 | ||
e06383db JS |
84 | static int hrtimer_clock_to_base_table[MAX_CLOCKS]; |
85 | ||
86 | static inline int hrtimer_clockid_to_base(clockid_t clock_id) | |
87 | { | |
88 | return hrtimer_clock_to_base_table[clock_id]; | |
89 | } | |
90 | ||
91 | ||
92127c7a TG |
92 | /* |
93 | * Get the coarse grained time at the softirq based on xtime and | |
94 | * wall_to_monotonic. | |
95 | */ | |
3c8aa39d | 96 | static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) |
92127c7a | 97 | { |
70a08cca | 98 | ktime_t xtim, mono, boot; |
314ac371 | 99 | struct timespec xts, tom, slp; |
92127c7a | 100 | |
314ac371 | 101 | get_xtime_and_monotonic_and_sleep_offset(&xts, &tom, &slp); |
92127c7a | 102 | |
f4304ab2 | 103 | xtim = timespec_to_ktime(xts); |
70a08cca JS |
104 | mono = ktime_add(xtim, timespec_to_ktime(tom)); |
105 | boot = ktime_add(mono, timespec_to_ktime(slp)); | |
e06383db | 106 | base->clock_base[HRTIMER_BASE_REALTIME].softirq_time = xtim; |
70a08cca JS |
107 | base->clock_base[HRTIMER_BASE_MONOTONIC].softirq_time = mono; |
108 | base->clock_base[HRTIMER_BASE_BOOTTIME].softirq_time = boot; | |
92127c7a TG |
109 | } |
110 | ||
c0a31329 TG |
111 | /* |
112 | * Functions and macros which are different for UP/SMP systems are kept in a | |
113 | * single place | |
114 | */ | |
115 | #ifdef CONFIG_SMP | |
116 | ||
c0a31329 TG |
117 | /* |
118 | * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock | |
119 | * means that all timers which are tied to this base via timer->base are | |
120 | * locked, and the base itself is locked too. | |
121 | * | |
122 | * So __run_timers/migrate_timers can safely modify all timers which could | |
123 | * be found on the lists/queues. | |
124 | * | |
125 | * When the timer's base is locked, and the timer removed from list, it is | |
126 | * possible to set timer->base = NULL and drop the lock: the timer remains | |
127 | * locked. | |
128 | */ | |
3c8aa39d TG |
129 | static |
130 | struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer, | |
131 | unsigned long *flags) | |
c0a31329 | 132 | { |
3c8aa39d | 133 | struct hrtimer_clock_base *base; |
c0a31329 TG |
134 | |
135 | for (;;) { | |
136 | base = timer->base; | |
137 | if (likely(base != NULL)) { | |
ecb49d1a | 138 | raw_spin_lock_irqsave(&base->cpu_base->lock, *flags); |
c0a31329 TG |
139 | if (likely(base == timer->base)) |
140 | return base; | |
141 | /* The timer has migrated to another CPU: */ | |
ecb49d1a | 142 | raw_spin_unlock_irqrestore(&base->cpu_base->lock, *flags); |
c0a31329 TG |
143 | } |
144 | cpu_relax(); | |
145 | } | |
146 | } | |
147 | ||
6ff7041d TG |
148 | |
149 | /* | |
150 | * Get the preferred target CPU for NOHZ | |
151 | */ | |
152 | static int hrtimer_get_target(int this_cpu, int pinned) | |
153 | { | |
154 | #ifdef CONFIG_NO_HZ | |
83cd4fe2 VP |
155 | if (!pinned && get_sysctl_timer_migration() && idle_cpu(this_cpu)) |
156 | return get_nohz_timer_target(); | |
6ff7041d TG |
157 | #endif |
158 | return this_cpu; | |
159 | } | |
160 | ||
161 | /* | |
162 | * With HIGHRES=y we do not migrate the timer when it is expiring | |
163 | * before the next event on the target cpu because we cannot reprogram | |
164 | * the target cpu hardware and we would cause it to fire late. | |
165 | * | |
166 | * Called with cpu_base->lock of target cpu held. | |
167 | */ | |
168 | static int | |
169 | hrtimer_check_target(struct hrtimer *timer, struct hrtimer_clock_base *new_base) | |
170 | { | |
171 | #ifdef CONFIG_HIGH_RES_TIMERS | |
172 | ktime_t expires; | |
173 | ||
174 | if (!new_base->cpu_base->hres_active) | |
175 | return 0; | |
176 | ||
177 | expires = ktime_sub(hrtimer_get_expires(timer), new_base->offset); | |
178 | return expires.tv64 <= new_base->cpu_base->expires_next.tv64; | |
179 | #else | |
180 | return 0; | |
181 | #endif | |
182 | } | |
183 | ||
c0a31329 TG |
184 | /* |
185 | * Switch the timer base to the current CPU when possible. | |
186 | */ | |
3c8aa39d | 187 | static inline struct hrtimer_clock_base * |
597d0275 AB |
188 | switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base, |
189 | int pinned) | |
c0a31329 | 190 | { |
3c8aa39d TG |
191 | struct hrtimer_clock_base *new_base; |
192 | struct hrtimer_cpu_base *new_cpu_base; | |
6ff7041d TG |
193 | int this_cpu = smp_processor_id(); |
194 | int cpu = hrtimer_get_target(this_cpu, pinned); | |
e06383db | 195 | int basenum = hrtimer_clockid_to_base(base->index); |
c0a31329 | 196 | |
eea08f32 AB |
197 | again: |
198 | new_cpu_base = &per_cpu(hrtimer_bases, cpu); | |
e06383db | 199 | new_base = &new_cpu_base->clock_base[basenum]; |
c0a31329 TG |
200 | |
201 | if (base != new_base) { | |
202 | /* | |
6ff7041d | 203 | * We are trying to move timer to new_base. |
c0a31329 TG |
204 | * However we can't change timer's base while it is running, |
205 | * so we keep it on the same CPU. No hassle vs. reprogramming | |
206 | * the event source in the high resolution case. The softirq | |
207 | * code will take care of this when the timer function has | |
208 | * completed. There is no conflict as we hold the lock until | |
209 | * the timer is enqueued. | |
210 | */ | |
54cdfdb4 | 211 | if (unlikely(hrtimer_callback_running(timer))) |
c0a31329 TG |
212 | return base; |
213 | ||
214 | /* See the comment in lock_timer_base() */ | |
215 | timer->base = NULL; | |
ecb49d1a TG |
216 | raw_spin_unlock(&base->cpu_base->lock); |
217 | raw_spin_lock(&new_base->cpu_base->lock); | |
eea08f32 | 218 | |
6ff7041d TG |
219 | if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) { |
220 | cpu = this_cpu; | |
ecb49d1a TG |
221 | raw_spin_unlock(&new_base->cpu_base->lock); |
222 | raw_spin_lock(&base->cpu_base->lock); | |
6ff7041d TG |
223 | timer->base = base; |
224 | goto again; | |
eea08f32 | 225 | } |
c0a31329 TG |
226 | timer->base = new_base; |
227 | } | |
228 | return new_base; | |
229 | } | |
230 | ||
231 | #else /* CONFIG_SMP */ | |
232 | ||
3c8aa39d | 233 | static inline struct hrtimer_clock_base * |
c0a31329 TG |
234 | lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) |
235 | { | |
3c8aa39d | 236 | struct hrtimer_clock_base *base = timer->base; |
c0a31329 | 237 | |
ecb49d1a | 238 | raw_spin_lock_irqsave(&base->cpu_base->lock, *flags); |
c0a31329 TG |
239 | |
240 | return base; | |
241 | } | |
242 | ||
eea08f32 | 243 | # define switch_hrtimer_base(t, b, p) (b) |
c0a31329 TG |
244 | |
245 | #endif /* !CONFIG_SMP */ | |
246 | ||
247 | /* | |
248 | * Functions for the union type storage format of ktime_t which are | |
249 | * too large for inlining: | |
250 | */ | |
251 | #if BITS_PER_LONG < 64 | |
252 | # ifndef CONFIG_KTIME_SCALAR | |
253 | /** | |
254 | * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable | |
c0a31329 TG |
255 | * @kt: addend |
256 | * @nsec: the scalar nsec value to add | |
257 | * | |
258 | * Returns the sum of kt and nsec in ktime_t format | |
259 | */ | |
260 | ktime_t ktime_add_ns(const ktime_t kt, u64 nsec) | |
261 | { | |
262 | ktime_t tmp; | |
263 | ||
264 | if (likely(nsec < NSEC_PER_SEC)) { | |
265 | tmp.tv64 = nsec; | |
266 | } else { | |
267 | unsigned long rem = do_div(nsec, NSEC_PER_SEC); | |
268 | ||
269 | tmp = ktime_set((long)nsec, rem); | |
270 | } | |
271 | ||
272 | return ktime_add(kt, tmp); | |
273 | } | |
b8b8fd2d DH |
274 | |
275 | EXPORT_SYMBOL_GPL(ktime_add_ns); | |
a272378d ACM |
276 | |
277 | /** | |
278 | * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable | |
279 | * @kt: minuend | |
280 | * @nsec: the scalar nsec value to subtract | |
281 | * | |
282 | * Returns the subtraction of @nsec from @kt in ktime_t format | |
283 | */ | |
284 | ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec) | |
285 | { | |
286 | ktime_t tmp; | |
287 | ||
288 | if (likely(nsec < NSEC_PER_SEC)) { | |
289 | tmp.tv64 = nsec; | |
290 | } else { | |
291 | unsigned long rem = do_div(nsec, NSEC_PER_SEC); | |
292 | ||
293 | tmp = ktime_set((long)nsec, rem); | |
294 | } | |
295 | ||
296 | return ktime_sub(kt, tmp); | |
297 | } | |
298 | ||
299 | EXPORT_SYMBOL_GPL(ktime_sub_ns); | |
c0a31329 TG |
300 | # endif /* !CONFIG_KTIME_SCALAR */ |
301 | ||
302 | /* | |
303 | * Divide a ktime value by a nanosecond value | |
304 | */ | |
4d672e7a | 305 | u64 ktime_divns(const ktime_t kt, s64 div) |
c0a31329 | 306 | { |
900cfa46 | 307 | u64 dclc; |
c0a31329 TG |
308 | int sft = 0; |
309 | ||
900cfa46 | 310 | dclc = ktime_to_ns(kt); |
c0a31329 TG |
311 | /* Make sure the divisor is less than 2^32: */ |
312 | while (div >> 32) { | |
313 | sft++; | |
314 | div >>= 1; | |
315 | } | |
316 | dclc >>= sft; | |
317 | do_div(dclc, (unsigned long) div); | |
318 | ||
4d672e7a | 319 | return dclc; |
c0a31329 | 320 | } |
c0a31329 TG |
321 | #endif /* BITS_PER_LONG >= 64 */ |
322 | ||
5a7780e7 TG |
323 | /* |
324 | * Add two ktime values and do a safety check for overflow: | |
325 | */ | |
326 | ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs) | |
327 | { | |
328 | ktime_t res = ktime_add(lhs, rhs); | |
329 | ||
330 | /* | |
331 | * We use KTIME_SEC_MAX here, the maximum timeout which we can | |
332 | * return to user space in a timespec: | |
333 | */ | |
334 | if (res.tv64 < 0 || res.tv64 < lhs.tv64 || res.tv64 < rhs.tv64) | |
335 | res = ktime_set(KTIME_SEC_MAX, 0); | |
336 | ||
337 | return res; | |
338 | } | |
339 | ||
8daa21e6 AB |
340 | EXPORT_SYMBOL_GPL(ktime_add_safe); |
341 | ||
237fc6e7 TG |
342 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS |
343 | ||
344 | static struct debug_obj_descr hrtimer_debug_descr; | |
345 | ||
99777288 SG |
346 | static void *hrtimer_debug_hint(void *addr) |
347 | { | |
348 | return ((struct hrtimer *) addr)->function; | |
349 | } | |
350 | ||
237fc6e7 TG |
351 | /* |
352 | * fixup_init is called when: | |
353 | * - an active object is initialized | |
354 | */ | |
355 | static int hrtimer_fixup_init(void *addr, enum debug_obj_state state) | |
356 | { | |
357 | struct hrtimer *timer = addr; | |
358 | ||
359 | switch (state) { | |
360 | case ODEBUG_STATE_ACTIVE: | |
361 | hrtimer_cancel(timer); | |
362 | debug_object_init(timer, &hrtimer_debug_descr); | |
363 | return 1; | |
364 | default: | |
365 | return 0; | |
366 | } | |
367 | } | |
368 | ||
369 | /* | |
370 | * fixup_activate is called when: | |
371 | * - an active object is activated | |
372 | * - an unknown object is activated (might be a statically initialized object) | |
373 | */ | |
374 | static int hrtimer_fixup_activate(void *addr, enum debug_obj_state state) | |
375 | { | |
376 | switch (state) { | |
377 | ||
378 | case ODEBUG_STATE_NOTAVAILABLE: | |
379 | WARN_ON_ONCE(1); | |
380 | return 0; | |
381 | ||
382 | case ODEBUG_STATE_ACTIVE: | |
383 | WARN_ON(1); | |
384 | ||
385 | default: | |
386 | return 0; | |
387 | } | |
388 | } | |
389 | ||
390 | /* | |
391 | * fixup_free is called when: | |
392 | * - an active object is freed | |
393 | */ | |
394 | static int hrtimer_fixup_free(void *addr, enum debug_obj_state state) | |
395 | { | |
396 | struct hrtimer *timer = addr; | |
397 | ||
398 | switch (state) { | |
399 | case ODEBUG_STATE_ACTIVE: | |
400 | hrtimer_cancel(timer); | |
401 | debug_object_free(timer, &hrtimer_debug_descr); | |
402 | return 1; | |
403 | default: | |
404 | return 0; | |
405 | } | |
406 | } | |
407 | ||
408 | static struct debug_obj_descr hrtimer_debug_descr = { | |
409 | .name = "hrtimer", | |
99777288 | 410 | .debug_hint = hrtimer_debug_hint, |
237fc6e7 TG |
411 | .fixup_init = hrtimer_fixup_init, |
412 | .fixup_activate = hrtimer_fixup_activate, | |
413 | .fixup_free = hrtimer_fixup_free, | |
414 | }; | |
415 | ||
416 | static inline void debug_hrtimer_init(struct hrtimer *timer) | |
417 | { | |
418 | debug_object_init(timer, &hrtimer_debug_descr); | |
419 | } | |
420 | ||
421 | static inline void debug_hrtimer_activate(struct hrtimer *timer) | |
422 | { | |
423 | debug_object_activate(timer, &hrtimer_debug_descr); | |
424 | } | |
425 | ||
426 | static inline void debug_hrtimer_deactivate(struct hrtimer *timer) | |
427 | { | |
428 | debug_object_deactivate(timer, &hrtimer_debug_descr); | |
429 | } | |
430 | ||
431 | static inline void debug_hrtimer_free(struct hrtimer *timer) | |
432 | { | |
433 | debug_object_free(timer, &hrtimer_debug_descr); | |
434 | } | |
435 | ||
436 | static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, | |
437 | enum hrtimer_mode mode); | |
438 | ||
439 | void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id, | |
440 | enum hrtimer_mode mode) | |
441 | { | |
442 | debug_object_init_on_stack(timer, &hrtimer_debug_descr); | |
443 | __hrtimer_init(timer, clock_id, mode); | |
444 | } | |
2bc481cf | 445 | EXPORT_SYMBOL_GPL(hrtimer_init_on_stack); |
237fc6e7 TG |
446 | |
447 | void destroy_hrtimer_on_stack(struct hrtimer *timer) | |
448 | { | |
449 | debug_object_free(timer, &hrtimer_debug_descr); | |
450 | } | |
451 | ||
452 | #else | |
453 | static inline void debug_hrtimer_init(struct hrtimer *timer) { } | |
454 | static inline void debug_hrtimer_activate(struct hrtimer *timer) { } | |
455 | static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { } | |
456 | #endif | |
457 | ||
c6a2a177 XG |
458 | static inline void |
459 | debug_init(struct hrtimer *timer, clockid_t clockid, | |
460 | enum hrtimer_mode mode) | |
461 | { | |
462 | debug_hrtimer_init(timer); | |
463 | trace_hrtimer_init(timer, clockid, mode); | |
464 | } | |
465 | ||
466 | static inline void debug_activate(struct hrtimer *timer) | |
467 | { | |
468 | debug_hrtimer_activate(timer); | |
469 | trace_hrtimer_start(timer); | |
470 | } | |
471 | ||
472 | static inline void debug_deactivate(struct hrtimer *timer) | |
473 | { | |
474 | debug_hrtimer_deactivate(timer); | |
475 | trace_hrtimer_cancel(timer); | |
476 | } | |
477 | ||
54cdfdb4 TG |
478 | /* High resolution timer related functions */ |
479 | #ifdef CONFIG_HIGH_RES_TIMERS | |
480 | ||
481 | /* | |
482 | * High resolution timer enabled ? | |
483 | */ | |
484 | static int hrtimer_hres_enabled __read_mostly = 1; | |
485 | ||
486 | /* | |
487 | * Enable / Disable high resolution mode | |
488 | */ | |
489 | static int __init setup_hrtimer_hres(char *str) | |
490 | { | |
491 | if (!strcmp(str, "off")) | |
492 | hrtimer_hres_enabled = 0; | |
493 | else if (!strcmp(str, "on")) | |
494 | hrtimer_hres_enabled = 1; | |
495 | else | |
496 | return 0; | |
497 | return 1; | |
498 | } | |
499 | ||
500 | __setup("highres=", setup_hrtimer_hres); | |
501 | ||
502 | /* | |
503 | * hrtimer_high_res_enabled - query, if the highres mode is enabled | |
504 | */ | |
505 | static inline int hrtimer_is_hres_enabled(void) | |
506 | { | |
507 | return hrtimer_hres_enabled; | |
508 | } | |
509 | ||
510 | /* | |
511 | * Is the high resolution mode active ? | |
512 | */ | |
513 | static inline int hrtimer_hres_active(void) | |
514 | { | |
909ea964 | 515 | return __this_cpu_read(hrtimer_bases.hres_active); |
54cdfdb4 TG |
516 | } |
517 | ||
518 | /* | |
519 | * Reprogram the event source with checking both queues for the | |
520 | * next event | |
521 | * Called with interrupts disabled and base->lock held | |
522 | */ | |
7403f41f AC |
523 | static void |
524 | hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal) | |
54cdfdb4 TG |
525 | { |
526 | int i; | |
527 | struct hrtimer_clock_base *base = cpu_base->clock_base; | |
7403f41f | 528 | ktime_t expires, expires_next; |
54cdfdb4 | 529 | |
7403f41f | 530 | expires_next.tv64 = KTIME_MAX; |
54cdfdb4 TG |
531 | |
532 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { | |
533 | struct hrtimer *timer; | |
998adc3d | 534 | struct timerqueue_node *next; |
54cdfdb4 | 535 | |
998adc3d JS |
536 | next = timerqueue_getnext(&base->active); |
537 | if (!next) | |
54cdfdb4 | 538 | continue; |
998adc3d JS |
539 | timer = container_of(next, struct hrtimer, node); |
540 | ||
cc584b21 | 541 | expires = ktime_sub(hrtimer_get_expires(timer), base->offset); |
b0a9b511 TG |
542 | /* |
543 | * clock_was_set() has changed base->offset so the | |
544 | * result might be negative. Fix it up to prevent a | |
545 | * false positive in clockevents_program_event() | |
546 | */ | |
547 | if (expires.tv64 < 0) | |
548 | expires.tv64 = 0; | |
7403f41f AC |
549 | if (expires.tv64 < expires_next.tv64) |
550 | expires_next = expires; | |
54cdfdb4 TG |
551 | } |
552 | ||
7403f41f AC |
553 | if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64) |
554 | return; | |
555 | ||
556 | cpu_base->expires_next.tv64 = expires_next.tv64; | |
557 | ||
54cdfdb4 TG |
558 | if (cpu_base->expires_next.tv64 != KTIME_MAX) |
559 | tick_program_event(cpu_base->expires_next, 1); | |
560 | } | |
561 | ||
562 | /* | |
563 | * Shared reprogramming for clock_realtime and clock_monotonic | |
564 | * | |
565 | * When a timer is enqueued and expires earlier than the already enqueued | |
566 | * timers, we have to check, whether it expires earlier than the timer for | |
567 | * which the clock event device was armed. | |
568 | * | |
569 | * Called with interrupts disabled and base->cpu_base.lock held | |
570 | */ | |
571 | static int hrtimer_reprogram(struct hrtimer *timer, | |
572 | struct hrtimer_clock_base *base) | |
573 | { | |
41d2e494 | 574 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); |
cc584b21 | 575 | ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset); |
54cdfdb4 TG |
576 | int res; |
577 | ||
cc584b21 | 578 | WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0); |
63070a79 | 579 | |
54cdfdb4 TG |
580 | /* |
581 | * When the callback is running, we do not reprogram the clock event | |
582 | * device. The timer callback is either running on a different CPU or | |
3a4fa0a2 | 583 | * the callback is executed in the hrtimer_interrupt context. The |
54cdfdb4 TG |
584 | * reprogramming is handled either by the softirq, which called the |
585 | * callback or at the end of the hrtimer_interrupt. | |
586 | */ | |
587 | if (hrtimer_callback_running(timer)) | |
588 | return 0; | |
589 | ||
63070a79 TG |
590 | /* |
591 | * CLOCK_REALTIME timer might be requested with an absolute | |
592 | * expiry time which is less than base->offset. Nothing wrong | |
593 | * about that, just avoid to call into the tick code, which | |
594 | * has now objections against negative expiry values. | |
595 | */ | |
596 | if (expires.tv64 < 0) | |
597 | return -ETIME; | |
598 | ||
41d2e494 TG |
599 | if (expires.tv64 >= cpu_base->expires_next.tv64) |
600 | return 0; | |
601 | ||
602 | /* | |
603 | * If a hang was detected in the last timer interrupt then we | |
604 | * do not schedule a timer which is earlier than the expiry | |
605 | * which we enforced in the hang detection. We want the system | |
606 | * to make progress. | |
607 | */ | |
608 | if (cpu_base->hang_detected) | |
54cdfdb4 TG |
609 | return 0; |
610 | ||
611 | /* | |
612 | * Clockevents returns -ETIME, when the event was in the past. | |
613 | */ | |
614 | res = tick_program_event(expires, 0); | |
615 | if (!IS_ERR_VALUE(res)) | |
41d2e494 | 616 | cpu_base->expires_next = expires; |
54cdfdb4 TG |
617 | return res; |
618 | } | |
619 | ||
620 | ||
621 | /* | |
622 | * Retrigger next event is called after clock was set | |
623 | * | |
624 | * Called with interrupts disabled via on_each_cpu() | |
625 | */ | |
626 | static void retrigger_next_event(void *arg) | |
627 | { | |
628 | struct hrtimer_cpu_base *base; | |
314ac371 | 629 | struct timespec realtime_offset, wtm, sleep; |
54cdfdb4 TG |
630 | |
631 | if (!hrtimer_hres_active()) | |
632 | return; | |
633 | ||
314ac371 JS |
634 | get_xtime_and_monotonic_and_sleep_offset(&realtime_offset, &wtm, |
635 | &sleep); | |
8ab4351a | 636 | set_normalized_timespec(&realtime_offset, -wtm.tv_sec, -wtm.tv_nsec); |
54cdfdb4 TG |
637 | |
638 | base = &__get_cpu_var(hrtimer_bases); | |
639 | ||
640 | /* Adjust CLOCK_REALTIME offset */ | |
ecb49d1a | 641 | raw_spin_lock(&base->lock); |
e06383db | 642 | base->clock_base[HRTIMER_BASE_REALTIME].offset = |
54cdfdb4 | 643 | timespec_to_ktime(realtime_offset); |
5cd10e79 TG |
644 | base->clock_base[HRTIMER_BASE_BOOTTIME].offset = |
645 | timespec_to_ktime(sleep); | |
54cdfdb4 | 646 | |
7403f41f | 647 | hrtimer_force_reprogram(base, 0); |
ecb49d1a | 648 | raw_spin_unlock(&base->lock); |
54cdfdb4 TG |
649 | } |
650 | ||
651 | /* | |
652 | * Clock realtime was set | |
653 | * | |
654 | * Change the offset of the realtime clock vs. the monotonic | |
655 | * clock. | |
656 | * | |
657 | * We might have to reprogram the high resolution timer interrupt. On | |
658 | * SMP we call the architecture specific code to retrigger _all_ high | |
659 | * resolution timer interrupts. On UP we just disable interrupts and | |
660 | * call the high resolution interrupt code. | |
661 | */ | |
662 | void clock_was_set(void) | |
663 | { | |
664 | /* Retrigger the CPU local events everywhere */ | |
15c8b6c1 | 665 | on_each_cpu(retrigger_next_event, NULL, 1); |
54cdfdb4 TG |
666 | } |
667 | ||
995f054f IM |
668 | /* |
669 | * During resume we might have to reprogram the high resolution timer | |
670 | * interrupt (on the local CPU): | |
671 | */ | |
672 | void hres_timers_resume(void) | |
673 | { | |
1d4a7f1c PZ |
674 | WARN_ONCE(!irqs_disabled(), |
675 | KERN_INFO "hres_timers_resume() called with IRQs enabled!"); | |
676 | ||
995f054f IM |
677 | retrigger_next_event(NULL); |
678 | } | |
679 | ||
54cdfdb4 TG |
680 | /* |
681 | * Initialize the high resolution related parts of cpu_base | |
682 | */ | |
683 | static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) | |
684 | { | |
685 | base->expires_next.tv64 = KTIME_MAX; | |
686 | base->hres_active = 0; | |
54cdfdb4 TG |
687 | } |
688 | ||
54cdfdb4 TG |
689 | /* |
690 | * When High resolution timers are active, try to reprogram. Note, that in case | |
691 | * the state has HRTIMER_STATE_CALLBACK set, no reprogramming and no expiry | |
692 | * check happens. The timer gets enqueued into the rbtree. The reprogramming | |
693 | * and expiry check is done in the hrtimer_interrupt or in the softirq. | |
694 | */ | |
695 | static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, | |
7f1e2ca9 PZ |
696 | struct hrtimer_clock_base *base, |
697 | int wakeup) | |
54cdfdb4 TG |
698 | { |
699 | if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) { | |
7f1e2ca9 | 700 | if (wakeup) { |
ecb49d1a | 701 | raw_spin_unlock(&base->cpu_base->lock); |
7f1e2ca9 | 702 | raise_softirq_irqoff(HRTIMER_SOFTIRQ); |
ecb49d1a | 703 | raw_spin_lock(&base->cpu_base->lock); |
7f1e2ca9 PZ |
704 | } else |
705 | __raise_softirq_irqoff(HRTIMER_SOFTIRQ); | |
706 | ||
ca109491 | 707 | return 1; |
54cdfdb4 | 708 | } |
7f1e2ca9 | 709 | |
54cdfdb4 TG |
710 | return 0; |
711 | } | |
712 | ||
713 | /* | |
714 | * Switch to high resolution mode | |
715 | */ | |
f8953856 | 716 | static int hrtimer_switch_to_hres(void) |
54cdfdb4 | 717 | { |
820de5c3 IM |
718 | int cpu = smp_processor_id(); |
719 | struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu); | |
54cdfdb4 TG |
720 | unsigned long flags; |
721 | ||
722 | if (base->hres_active) | |
f8953856 | 723 | return 1; |
54cdfdb4 TG |
724 | |
725 | local_irq_save(flags); | |
726 | ||
727 | if (tick_init_highres()) { | |
728 | local_irq_restore(flags); | |
820de5c3 IM |
729 | printk(KERN_WARNING "Could not switch to high resolution " |
730 | "mode on CPU %d\n", cpu); | |
f8953856 | 731 | return 0; |
54cdfdb4 TG |
732 | } |
733 | base->hres_active = 1; | |
e06383db JS |
734 | base->clock_base[HRTIMER_BASE_REALTIME].resolution = KTIME_HIGH_RES; |
735 | base->clock_base[HRTIMER_BASE_MONOTONIC].resolution = KTIME_HIGH_RES; | |
70a08cca | 736 | base->clock_base[HRTIMER_BASE_BOOTTIME].resolution = KTIME_HIGH_RES; |
54cdfdb4 TG |
737 | |
738 | tick_setup_sched_timer(); | |
739 | ||
740 | /* "Retrigger" the interrupt to get things going */ | |
741 | retrigger_next_event(NULL); | |
742 | local_irq_restore(flags); | |
f8953856 | 743 | return 1; |
54cdfdb4 TG |
744 | } |
745 | ||
746 | #else | |
747 | ||
748 | static inline int hrtimer_hres_active(void) { return 0; } | |
749 | static inline int hrtimer_is_hres_enabled(void) { return 0; } | |
f8953856 | 750 | static inline int hrtimer_switch_to_hres(void) { return 0; } |
7403f41f AC |
751 | static inline void |
752 | hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { } | |
54cdfdb4 | 753 | static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, |
7f1e2ca9 PZ |
754 | struct hrtimer_clock_base *base, |
755 | int wakeup) | |
54cdfdb4 TG |
756 | { |
757 | return 0; | |
758 | } | |
54cdfdb4 | 759 | static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { } |
54cdfdb4 TG |
760 | |
761 | #endif /* CONFIG_HIGH_RES_TIMERS */ | |
762 | ||
5f201907 | 763 | static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer) |
82f67cd9 | 764 | { |
5f201907 | 765 | #ifdef CONFIG_TIMER_STATS |
82f67cd9 IM |
766 | if (timer->start_site) |
767 | return; | |
5f201907 | 768 | timer->start_site = __builtin_return_address(0); |
82f67cd9 IM |
769 | memcpy(timer->start_comm, current->comm, TASK_COMM_LEN); |
770 | timer->start_pid = current->pid; | |
5f201907 HC |
771 | #endif |
772 | } | |
773 | ||
774 | static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer) | |
775 | { | |
776 | #ifdef CONFIG_TIMER_STATS | |
777 | timer->start_site = NULL; | |
778 | #endif | |
82f67cd9 | 779 | } |
5f201907 HC |
780 | |
781 | static inline void timer_stats_account_hrtimer(struct hrtimer *timer) | |
782 | { | |
783 | #ifdef CONFIG_TIMER_STATS | |
784 | if (likely(!timer_stats_active)) | |
785 | return; | |
786 | timer_stats_update_stats(timer, timer->start_pid, timer->start_site, | |
787 | timer->function, timer->start_comm, 0); | |
82f67cd9 | 788 | #endif |
5f201907 | 789 | } |
82f67cd9 | 790 | |
c0a31329 | 791 | /* |
6506f2aa | 792 | * Counterpart to lock_hrtimer_base above: |
c0a31329 TG |
793 | */ |
794 | static inline | |
795 | void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) | |
796 | { | |
ecb49d1a | 797 | raw_spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags); |
c0a31329 TG |
798 | } |
799 | ||
800 | /** | |
801 | * hrtimer_forward - forward the timer expiry | |
c0a31329 | 802 | * @timer: hrtimer to forward |
44f21475 | 803 | * @now: forward past this time |
c0a31329 TG |
804 | * @interval: the interval to forward |
805 | * | |
806 | * Forward the timer expiry so it will expire in the future. | |
8dca6f33 | 807 | * Returns the number of overruns. |
c0a31329 | 808 | */ |
4d672e7a | 809 | u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) |
c0a31329 | 810 | { |
4d672e7a | 811 | u64 orun = 1; |
44f21475 | 812 | ktime_t delta; |
c0a31329 | 813 | |
cc584b21 | 814 | delta = ktime_sub(now, hrtimer_get_expires(timer)); |
c0a31329 TG |
815 | |
816 | if (delta.tv64 < 0) | |
817 | return 0; | |
818 | ||
c9db4fa1 TG |
819 | if (interval.tv64 < timer->base->resolution.tv64) |
820 | interval.tv64 = timer->base->resolution.tv64; | |
821 | ||
c0a31329 | 822 | if (unlikely(delta.tv64 >= interval.tv64)) { |
df869b63 | 823 | s64 incr = ktime_to_ns(interval); |
c0a31329 TG |
824 | |
825 | orun = ktime_divns(delta, incr); | |
cc584b21 AV |
826 | hrtimer_add_expires_ns(timer, incr * orun); |
827 | if (hrtimer_get_expires_tv64(timer) > now.tv64) | |
c0a31329 TG |
828 | return orun; |
829 | /* | |
830 | * This (and the ktime_add() below) is the | |
831 | * correction for exact: | |
832 | */ | |
833 | orun++; | |
834 | } | |
cc584b21 | 835 | hrtimer_add_expires(timer, interval); |
c0a31329 TG |
836 | |
837 | return orun; | |
838 | } | |
6bdb6b62 | 839 | EXPORT_SYMBOL_GPL(hrtimer_forward); |
c0a31329 TG |
840 | |
841 | /* | |
842 | * enqueue_hrtimer - internal function to (re)start a timer | |
843 | * | |
844 | * The timer is inserted in expiry order. Insertion into the | |
845 | * red black tree is O(log(n)). Must hold the base lock. | |
a6037b61 PZ |
846 | * |
847 | * Returns 1 when the new timer is the leftmost timer in the tree. | |
c0a31329 | 848 | */ |
a6037b61 PZ |
849 | static int enqueue_hrtimer(struct hrtimer *timer, |
850 | struct hrtimer_clock_base *base) | |
c0a31329 | 851 | { |
c6a2a177 | 852 | debug_activate(timer); |
237fc6e7 | 853 | |
998adc3d | 854 | timerqueue_add(&base->active, &timer->node); |
54cdfdb4 | 855 | |
303e967f TG |
856 | /* |
857 | * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the | |
858 | * state of a possibly running callback. | |
859 | */ | |
860 | timer->state |= HRTIMER_STATE_ENQUEUED; | |
a6037b61 | 861 | |
998adc3d | 862 | return (&timer->node == base->active.next); |
288867ec | 863 | } |
c0a31329 TG |
864 | |
865 | /* | |
866 | * __remove_hrtimer - internal function to remove a timer | |
867 | * | |
868 | * Caller must hold the base lock. | |
54cdfdb4 TG |
869 | * |
870 | * High resolution timer mode reprograms the clock event device when the | |
871 | * timer is the one which expires next. The caller can disable this by setting | |
872 | * reprogram to zero. This is useful, when the context does a reprogramming | |
873 | * anyway (e.g. timer interrupt) | |
c0a31329 | 874 | */ |
3c8aa39d | 875 | static void __remove_hrtimer(struct hrtimer *timer, |
303e967f | 876 | struct hrtimer_clock_base *base, |
54cdfdb4 | 877 | unsigned long newstate, int reprogram) |
c0a31329 | 878 | { |
7403f41f AC |
879 | if (!(timer->state & HRTIMER_STATE_ENQUEUED)) |
880 | goto out; | |
881 | ||
998adc3d | 882 | if (&timer->node == timerqueue_getnext(&base->active)) { |
7403f41f AC |
883 | #ifdef CONFIG_HIGH_RES_TIMERS |
884 | /* Reprogram the clock event device. if enabled */ | |
885 | if (reprogram && hrtimer_hres_active()) { | |
886 | ktime_t expires; | |
887 | ||
888 | expires = ktime_sub(hrtimer_get_expires(timer), | |
889 | base->offset); | |
890 | if (base->cpu_base->expires_next.tv64 == expires.tv64) | |
891 | hrtimer_force_reprogram(base->cpu_base, 1); | |
54cdfdb4 | 892 | } |
7403f41f | 893 | #endif |
54cdfdb4 | 894 | } |
998adc3d | 895 | timerqueue_del(&base->active, &timer->node); |
7403f41f | 896 | out: |
303e967f | 897 | timer->state = newstate; |
c0a31329 TG |
898 | } |
899 | ||
900 | /* | |
901 | * remove hrtimer, called with base lock held | |
902 | */ | |
903 | static inline int | |
3c8aa39d | 904 | remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) |
c0a31329 | 905 | { |
303e967f | 906 | if (hrtimer_is_queued(timer)) { |
f13d4f97 | 907 | unsigned long state; |
54cdfdb4 TG |
908 | int reprogram; |
909 | ||
910 | /* | |
911 | * Remove the timer and force reprogramming when high | |
912 | * resolution mode is active and the timer is on the current | |
913 | * CPU. If we remove a timer on another CPU, reprogramming is | |
914 | * skipped. The interrupt event on this CPU is fired and | |
915 | * reprogramming happens in the interrupt handler. This is a | |
916 | * rare case and less expensive than a smp call. | |
917 | */ | |
c6a2a177 | 918 | debug_deactivate(timer); |
82f67cd9 | 919 | timer_stats_hrtimer_clear_start_info(timer); |
54cdfdb4 | 920 | reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases); |
f13d4f97 SQ |
921 | /* |
922 | * We must preserve the CALLBACK state flag here, | |
923 | * otherwise we could move the timer base in | |
924 | * switch_hrtimer_base. | |
925 | */ | |
926 | state = timer->state & HRTIMER_STATE_CALLBACK; | |
927 | __remove_hrtimer(timer, base, state, reprogram); | |
c0a31329 TG |
928 | return 1; |
929 | } | |
930 | return 0; | |
931 | } | |
932 | ||
7f1e2ca9 PZ |
933 | int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, |
934 | unsigned long delta_ns, const enum hrtimer_mode mode, | |
935 | int wakeup) | |
c0a31329 | 936 | { |
3c8aa39d | 937 | struct hrtimer_clock_base *base, *new_base; |
c0a31329 | 938 | unsigned long flags; |
a6037b61 | 939 | int ret, leftmost; |
c0a31329 TG |
940 | |
941 | base = lock_hrtimer_base(timer, &flags); | |
942 | ||
943 | /* Remove an active timer from the queue: */ | |
944 | ret = remove_hrtimer(timer, base); | |
945 | ||
946 | /* Switch the timer base, if necessary: */ | |
597d0275 | 947 | new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED); |
c0a31329 | 948 | |
597d0275 | 949 | if (mode & HRTIMER_MODE_REL) { |
5a7780e7 | 950 | tim = ktime_add_safe(tim, new_base->get_time()); |
06027bdd IM |
951 | /* |
952 | * CONFIG_TIME_LOW_RES is a temporary way for architectures | |
953 | * to signal that they simply return xtime in | |
954 | * do_gettimeoffset(). In this case we want to round up by | |
955 | * resolution when starting a relative timer, to avoid short | |
956 | * timeouts. This will go away with the GTOD framework. | |
957 | */ | |
958 | #ifdef CONFIG_TIME_LOW_RES | |
5a7780e7 | 959 | tim = ktime_add_safe(tim, base->resolution); |
06027bdd IM |
960 | #endif |
961 | } | |
237fc6e7 | 962 | |
da8f2e17 | 963 | hrtimer_set_expires_range_ns(timer, tim, delta_ns); |
c0a31329 | 964 | |
82f67cd9 IM |
965 | timer_stats_hrtimer_set_start_info(timer); |
966 | ||
a6037b61 PZ |
967 | leftmost = enqueue_hrtimer(timer, new_base); |
968 | ||
935c631d IM |
969 | /* |
970 | * Only allow reprogramming if the new base is on this CPU. | |
971 | * (it might still be on another CPU if the timer was pending) | |
a6037b61 PZ |
972 | * |
973 | * XXX send_remote_softirq() ? | |
935c631d | 974 | */ |
a6037b61 | 975 | if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases)) |
7f1e2ca9 | 976 | hrtimer_enqueue_reprogram(timer, new_base, wakeup); |
c0a31329 TG |
977 | |
978 | unlock_hrtimer_base(timer, &flags); | |
979 | ||
980 | return ret; | |
981 | } | |
7f1e2ca9 PZ |
982 | |
983 | /** | |
984 | * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU | |
985 | * @timer: the timer to be added | |
986 | * @tim: expiry time | |
987 | * @delta_ns: "slack" range for the timer | |
988 | * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL) | |
989 | * | |
990 | * Returns: | |
991 | * 0 on success | |
992 | * 1 when the timer was active | |
993 | */ | |
994 | int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, | |
995 | unsigned long delta_ns, const enum hrtimer_mode mode) | |
996 | { | |
997 | return __hrtimer_start_range_ns(timer, tim, delta_ns, mode, 1); | |
998 | } | |
da8f2e17 AV |
999 | EXPORT_SYMBOL_GPL(hrtimer_start_range_ns); |
1000 | ||
1001 | /** | |
e1dd7bc5 | 1002 | * hrtimer_start - (re)start an hrtimer on the current CPU |
da8f2e17 AV |
1003 | * @timer: the timer to be added |
1004 | * @tim: expiry time | |
1005 | * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL) | |
1006 | * | |
1007 | * Returns: | |
1008 | * 0 on success | |
1009 | * 1 when the timer was active | |
1010 | */ | |
1011 | int | |
1012 | hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) | |
1013 | { | |
7f1e2ca9 | 1014 | return __hrtimer_start_range_ns(timer, tim, 0, mode, 1); |
da8f2e17 | 1015 | } |
8d16b764 | 1016 | EXPORT_SYMBOL_GPL(hrtimer_start); |
c0a31329 | 1017 | |
da8f2e17 | 1018 | |
c0a31329 TG |
1019 | /** |
1020 | * hrtimer_try_to_cancel - try to deactivate a timer | |
c0a31329 TG |
1021 | * @timer: hrtimer to stop |
1022 | * | |
1023 | * Returns: | |
1024 | * 0 when the timer was not active | |
1025 | * 1 when the timer was active | |
1026 | * -1 when the timer is currently excuting the callback function and | |
fa9799e3 | 1027 | * cannot be stopped |
c0a31329 TG |
1028 | */ |
1029 | int hrtimer_try_to_cancel(struct hrtimer *timer) | |
1030 | { | |
3c8aa39d | 1031 | struct hrtimer_clock_base *base; |
c0a31329 TG |
1032 | unsigned long flags; |
1033 | int ret = -1; | |
1034 | ||
1035 | base = lock_hrtimer_base(timer, &flags); | |
1036 | ||
303e967f | 1037 | if (!hrtimer_callback_running(timer)) |
c0a31329 TG |
1038 | ret = remove_hrtimer(timer, base); |
1039 | ||
1040 | unlock_hrtimer_base(timer, &flags); | |
1041 | ||
1042 | return ret; | |
1043 | ||
1044 | } | |
8d16b764 | 1045 | EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel); |
c0a31329 TG |
1046 | |
1047 | /** | |
1048 | * hrtimer_cancel - cancel a timer and wait for the handler to finish. | |
c0a31329 TG |
1049 | * @timer: the timer to be cancelled |
1050 | * | |
1051 | * Returns: | |
1052 | * 0 when the timer was not active | |
1053 | * 1 when the timer was active | |
1054 | */ | |
1055 | int hrtimer_cancel(struct hrtimer *timer) | |
1056 | { | |
1057 | for (;;) { | |
1058 | int ret = hrtimer_try_to_cancel(timer); | |
1059 | ||
1060 | if (ret >= 0) | |
1061 | return ret; | |
5ef37b19 | 1062 | cpu_relax(); |
c0a31329 TG |
1063 | } |
1064 | } | |
8d16b764 | 1065 | EXPORT_SYMBOL_GPL(hrtimer_cancel); |
c0a31329 TG |
1066 | |
1067 | /** | |
1068 | * hrtimer_get_remaining - get remaining time for the timer | |
c0a31329 TG |
1069 | * @timer: the timer to read |
1070 | */ | |
1071 | ktime_t hrtimer_get_remaining(const struct hrtimer *timer) | |
1072 | { | |
c0a31329 TG |
1073 | unsigned long flags; |
1074 | ktime_t rem; | |
1075 | ||
b3bd3de6 | 1076 | lock_hrtimer_base(timer, &flags); |
cc584b21 | 1077 | rem = hrtimer_expires_remaining(timer); |
c0a31329 TG |
1078 | unlock_hrtimer_base(timer, &flags); |
1079 | ||
1080 | return rem; | |
1081 | } | |
8d16b764 | 1082 | EXPORT_SYMBOL_GPL(hrtimer_get_remaining); |
c0a31329 | 1083 | |
ee9c5785 | 1084 | #ifdef CONFIG_NO_HZ |
69239749 TL |
1085 | /** |
1086 | * hrtimer_get_next_event - get the time until next expiry event | |
1087 | * | |
1088 | * Returns the delta to the next expiry event or KTIME_MAX if no timer | |
1089 | * is pending. | |
1090 | */ | |
1091 | ktime_t hrtimer_get_next_event(void) | |
1092 | { | |
3c8aa39d TG |
1093 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); |
1094 | struct hrtimer_clock_base *base = cpu_base->clock_base; | |
69239749 TL |
1095 | ktime_t delta, mindelta = { .tv64 = KTIME_MAX }; |
1096 | unsigned long flags; | |
1097 | int i; | |
1098 | ||
ecb49d1a | 1099 | raw_spin_lock_irqsave(&cpu_base->lock, flags); |
3c8aa39d | 1100 | |
54cdfdb4 TG |
1101 | if (!hrtimer_hres_active()) { |
1102 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { | |
1103 | struct hrtimer *timer; | |
998adc3d | 1104 | struct timerqueue_node *next; |
69239749 | 1105 | |
998adc3d JS |
1106 | next = timerqueue_getnext(&base->active); |
1107 | if (!next) | |
54cdfdb4 | 1108 | continue; |
3c8aa39d | 1109 | |
998adc3d | 1110 | timer = container_of(next, struct hrtimer, node); |
cc584b21 | 1111 | delta.tv64 = hrtimer_get_expires_tv64(timer); |
54cdfdb4 TG |
1112 | delta = ktime_sub(delta, base->get_time()); |
1113 | if (delta.tv64 < mindelta.tv64) | |
1114 | mindelta.tv64 = delta.tv64; | |
1115 | } | |
69239749 | 1116 | } |
3c8aa39d | 1117 | |
ecb49d1a | 1118 | raw_spin_unlock_irqrestore(&cpu_base->lock, flags); |
3c8aa39d | 1119 | |
69239749 TL |
1120 | if (mindelta.tv64 < 0) |
1121 | mindelta.tv64 = 0; | |
1122 | return mindelta; | |
1123 | } | |
1124 | #endif | |
1125 | ||
237fc6e7 TG |
1126 | static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, |
1127 | enum hrtimer_mode mode) | |
c0a31329 | 1128 | { |
3c8aa39d | 1129 | struct hrtimer_cpu_base *cpu_base; |
e06383db | 1130 | int 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 | ||
e06383db JS |
1139 | base = hrtimer_clockid_to_base(clock_id); |
1140 | timer->base = &cpu_base->clock_base[base]; | |
998adc3d | 1141 | timerqueue_init(&timer->node); |
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 | { | |
c6a2a177 | 1159 | debug_init(timer, clock_id, mode); |
237fc6e7 TG |
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; |
e06383db | 1175 | int base = hrtimer_clockid_to_base(which_clock); |
c0a31329 | 1176 | |
3c8aa39d | 1177 | cpu_base = &__raw_get_cpu_var(hrtimer_bases); |
e06383db | 1178 | *tp = ktime_to_timespec(cpu_base->clock_base[base].resolution); |
c0a31329 TG |
1179 | |
1180 | return 0; | |
1181 | } | |
8d16b764 | 1182 | EXPORT_SYMBOL_GPL(hrtimer_get_res); |
c0a31329 | 1183 | |
c6a2a177 | 1184 | static void __run_hrtimer(struct hrtimer *timer, ktime_t *now) |
d3d74453 PZ |
1185 | { |
1186 | struct hrtimer_clock_base *base = timer->base; | |
1187 | struct hrtimer_cpu_base *cpu_base = base->cpu_base; | |
1188 | enum hrtimer_restart (*fn)(struct hrtimer *); | |
1189 | int restart; | |
1190 | ||
ca109491 PZ |
1191 | WARN_ON(!irqs_disabled()); |
1192 | ||
c6a2a177 | 1193 | debug_deactivate(timer); |
d3d74453 PZ |
1194 | __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0); |
1195 | timer_stats_account_hrtimer(timer); | |
d3d74453 | 1196 | fn = timer->function; |
ca109491 PZ |
1197 | |
1198 | /* | |
1199 | * Because we run timers from hardirq context, there is no chance | |
1200 | * they get migrated to another cpu, therefore its safe to unlock | |
1201 | * the timer base. | |
1202 | */ | |
ecb49d1a | 1203 | raw_spin_unlock(&cpu_base->lock); |
c6a2a177 | 1204 | trace_hrtimer_expire_entry(timer, now); |
ca109491 | 1205 | restart = fn(timer); |
c6a2a177 | 1206 | trace_hrtimer_expire_exit(timer); |
ecb49d1a | 1207 | raw_spin_lock(&cpu_base->lock); |
d3d74453 PZ |
1208 | |
1209 | /* | |
e3f1d883 TG |
1210 | * Note: We clear the CALLBACK bit after enqueue_hrtimer and |
1211 | * we do not reprogramm the event hardware. Happens either in | |
1212 | * hrtimer_start_range_ns() or in hrtimer_interrupt() | |
d3d74453 PZ |
1213 | */ |
1214 | if (restart != HRTIMER_NORESTART) { | |
1215 | BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); | |
a6037b61 | 1216 | enqueue_hrtimer(timer, base); |
d3d74453 | 1217 | } |
f13d4f97 SQ |
1218 | |
1219 | WARN_ON_ONCE(!(timer->state & HRTIMER_STATE_CALLBACK)); | |
1220 | ||
d3d74453 PZ |
1221 | timer->state &= ~HRTIMER_STATE_CALLBACK; |
1222 | } | |
1223 | ||
54cdfdb4 TG |
1224 | #ifdef CONFIG_HIGH_RES_TIMERS |
1225 | ||
1226 | /* | |
1227 | * High resolution timer interrupt | |
1228 | * Called with interrupts disabled | |
1229 | */ | |
1230 | void hrtimer_interrupt(struct clock_event_device *dev) | |
1231 | { | |
1232 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); | |
1233 | struct hrtimer_clock_base *base; | |
41d2e494 TG |
1234 | ktime_t expires_next, now, entry_time, delta; |
1235 | int i, retries = 0; | |
54cdfdb4 TG |
1236 | |
1237 | BUG_ON(!cpu_base->hres_active); | |
1238 | cpu_base->nr_events++; | |
1239 | dev->next_event.tv64 = KTIME_MAX; | |
1240 | ||
41d2e494 TG |
1241 | entry_time = now = ktime_get(); |
1242 | retry: | |
54cdfdb4 TG |
1243 | expires_next.tv64 = KTIME_MAX; |
1244 | ||
ecb49d1a | 1245 | raw_spin_lock(&cpu_base->lock); |
6ff7041d TG |
1246 | /* |
1247 | * We set expires_next to KTIME_MAX here with cpu_base->lock | |
1248 | * held to prevent that a timer is enqueued in our queue via | |
1249 | * the migration code. This does not affect enqueueing of | |
1250 | * timers which run their callback and need to be requeued on | |
1251 | * this CPU. | |
1252 | */ | |
1253 | cpu_base->expires_next.tv64 = KTIME_MAX; | |
1254 | ||
54cdfdb4 TG |
1255 | base = cpu_base->clock_base; |
1256 | ||
1257 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { | |
1258 | ktime_t basenow; | |
998adc3d | 1259 | struct timerqueue_node *node; |
54cdfdb4 | 1260 | |
54cdfdb4 TG |
1261 | basenow = ktime_add(now, base->offset); |
1262 | ||
998adc3d | 1263 | while ((node = timerqueue_getnext(&base->active))) { |
54cdfdb4 TG |
1264 | struct hrtimer *timer; |
1265 | ||
998adc3d | 1266 | timer = container_of(node, struct hrtimer, node); |
54cdfdb4 | 1267 | |
654c8e0b AV |
1268 | /* |
1269 | * The immediate goal for using the softexpires is | |
1270 | * minimizing wakeups, not running timers at the | |
1271 | * earliest interrupt after their soft expiration. | |
1272 | * This allows us to avoid using a Priority Search | |
1273 | * Tree, which can answer a stabbing querry for | |
1274 | * overlapping intervals and instead use the simple | |
1275 | * BST we already have. | |
1276 | * We don't add extra wakeups by delaying timers that | |
1277 | * are right-of a not yet expired timer, because that | |
1278 | * timer will have to trigger a wakeup anyway. | |
1279 | */ | |
1280 | ||
1281 | if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) { | |
54cdfdb4 TG |
1282 | ktime_t expires; |
1283 | ||
cc584b21 | 1284 | expires = ktime_sub(hrtimer_get_expires(timer), |
54cdfdb4 TG |
1285 | base->offset); |
1286 | if (expires.tv64 < expires_next.tv64) | |
1287 | expires_next = expires; | |
1288 | break; | |
1289 | } | |
1290 | ||
c6a2a177 | 1291 | __run_hrtimer(timer, &basenow); |
54cdfdb4 | 1292 | } |
54cdfdb4 TG |
1293 | base++; |
1294 | } | |
1295 | ||
6ff7041d TG |
1296 | /* |
1297 | * Store the new expiry value so the migration code can verify | |
1298 | * against it. | |
1299 | */ | |
54cdfdb4 | 1300 | cpu_base->expires_next = expires_next; |
ecb49d1a | 1301 | raw_spin_unlock(&cpu_base->lock); |
54cdfdb4 TG |
1302 | |
1303 | /* Reprogramming necessary ? */ | |
41d2e494 TG |
1304 | if (expires_next.tv64 == KTIME_MAX || |
1305 | !tick_program_event(expires_next, 0)) { | |
1306 | cpu_base->hang_detected = 0; | |
1307 | return; | |
54cdfdb4 | 1308 | } |
41d2e494 TG |
1309 | |
1310 | /* | |
1311 | * The next timer was already expired due to: | |
1312 | * - tracing | |
1313 | * - long lasting callbacks | |
1314 | * - being scheduled away when running in a VM | |
1315 | * | |
1316 | * We need to prevent that we loop forever in the hrtimer | |
1317 | * interrupt routine. We give it 3 attempts to avoid | |
1318 | * overreacting on some spurious event. | |
1319 | */ | |
1320 | now = ktime_get(); | |
1321 | cpu_base->nr_retries++; | |
1322 | if (++retries < 3) | |
1323 | goto retry; | |
1324 | /* | |
1325 | * Give the system a chance to do something else than looping | |
1326 | * here. We stored the entry time, so we know exactly how long | |
1327 | * we spent here. We schedule the next event this amount of | |
1328 | * time away. | |
1329 | */ | |
1330 | cpu_base->nr_hangs++; | |
1331 | cpu_base->hang_detected = 1; | |
1332 | delta = ktime_sub(now, entry_time); | |
1333 | if (delta.tv64 > cpu_base->max_hang_time.tv64) | |
1334 | cpu_base->max_hang_time = delta; | |
1335 | /* | |
1336 | * Limit it to a sensible value as we enforce a longer | |
1337 | * delay. Give the CPU at least 100ms to catch up. | |
1338 | */ | |
1339 | if (delta.tv64 > 100 * NSEC_PER_MSEC) | |
1340 | expires_next = ktime_add_ns(now, 100 * NSEC_PER_MSEC); | |
1341 | else | |
1342 | expires_next = ktime_add(now, delta); | |
1343 | tick_program_event(expires_next, 1); | |
1344 | printk_once(KERN_WARNING "hrtimer: interrupt took %llu ns\n", | |
1345 | ktime_to_ns(delta)); | |
54cdfdb4 TG |
1346 | } |
1347 | ||
8bdec955 TG |
1348 | /* |
1349 | * local version of hrtimer_peek_ahead_timers() called with interrupts | |
1350 | * disabled. | |
1351 | */ | |
1352 | static void __hrtimer_peek_ahead_timers(void) | |
1353 | { | |
1354 | struct tick_device *td; | |
1355 | ||
1356 | if (!hrtimer_hres_active()) | |
1357 | return; | |
1358 | ||
1359 | td = &__get_cpu_var(tick_cpu_device); | |
1360 | if (td && td->evtdev) | |
1361 | hrtimer_interrupt(td->evtdev); | |
1362 | } | |
1363 | ||
2e94d1f7 AV |
1364 | /** |
1365 | * hrtimer_peek_ahead_timers -- run soft-expired timers now | |
1366 | * | |
1367 | * hrtimer_peek_ahead_timers will peek at the timer queue of | |
1368 | * the current cpu and check if there are any timers for which | |
1369 | * the soft expires time has passed. If any such timers exist, | |
1370 | * they are run immediately and then removed from the timer queue. | |
1371 | * | |
1372 | */ | |
1373 | void hrtimer_peek_ahead_timers(void) | |
1374 | { | |
643bdf68 | 1375 | unsigned long flags; |
dc4304f7 | 1376 | |
2e94d1f7 | 1377 | local_irq_save(flags); |
8bdec955 | 1378 | __hrtimer_peek_ahead_timers(); |
2e94d1f7 AV |
1379 | local_irq_restore(flags); |
1380 | } | |
1381 | ||
a6037b61 PZ |
1382 | static void run_hrtimer_softirq(struct softirq_action *h) |
1383 | { | |
1384 | hrtimer_peek_ahead_timers(); | |
1385 | } | |
1386 | ||
82c5b7b5 IM |
1387 | #else /* CONFIG_HIGH_RES_TIMERS */ |
1388 | ||
1389 | static inline void __hrtimer_peek_ahead_timers(void) { } | |
1390 | ||
1391 | #endif /* !CONFIG_HIGH_RES_TIMERS */ | |
82f67cd9 | 1392 | |
d3d74453 PZ |
1393 | /* |
1394 | * Called from timer softirq every jiffy, expire hrtimers: | |
1395 | * | |
1396 | * For HRT its the fall back code to run the softirq in the timer | |
1397 | * softirq context in case the hrtimer initialization failed or has | |
1398 | * not been done yet. | |
1399 | */ | |
1400 | void hrtimer_run_pending(void) | |
1401 | { | |
d3d74453 PZ |
1402 | if (hrtimer_hres_active()) |
1403 | return; | |
54cdfdb4 | 1404 | |
d3d74453 PZ |
1405 | /* |
1406 | * This _is_ ugly: We have to check in the softirq context, | |
1407 | * whether we can switch to highres and / or nohz mode. The | |
1408 | * clocksource switch happens in the timer interrupt with | |
1409 | * xtime_lock held. Notification from there only sets the | |
1410 | * check bit in the tick_oneshot code, otherwise we might | |
1411 | * deadlock vs. xtime_lock. | |
1412 | */ | |
1413 | if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())) | |
1414 | hrtimer_switch_to_hres(); | |
54cdfdb4 TG |
1415 | } |
1416 | ||
c0a31329 | 1417 | /* |
d3d74453 | 1418 | * Called from hardirq context every jiffy |
c0a31329 | 1419 | */ |
833883d9 | 1420 | void hrtimer_run_queues(void) |
c0a31329 | 1421 | { |
998adc3d | 1422 | struct timerqueue_node *node; |
833883d9 DS |
1423 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); |
1424 | struct hrtimer_clock_base *base; | |
1425 | int index, gettime = 1; | |
c0a31329 | 1426 | |
833883d9 | 1427 | if (hrtimer_hres_active()) |
3055adda DS |
1428 | return; |
1429 | ||
833883d9 DS |
1430 | for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) { |
1431 | base = &cpu_base->clock_base[index]; | |
b007c389 | 1432 | if (!timerqueue_getnext(&base->active)) |
d3d74453 | 1433 | continue; |
833883d9 | 1434 | |
d7cfb60c | 1435 | if (gettime) { |
833883d9 DS |
1436 | hrtimer_get_softirq_time(cpu_base); |
1437 | gettime = 0; | |
b75f7a51 | 1438 | } |
d3d74453 | 1439 | |
ecb49d1a | 1440 | raw_spin_lock(&cpu_base->lock); |
c0a31329 | 1441 | |
b007c389 | 1442 | while ((node = timerqueue_getnext(&base->active))) { |
833883d9 | 1443 | struct hrtimer *timer; |
54cdfdb4 | 1444 | |
998adc3d | 1445 | timer = container_of(node, struct hrtimer, node); |
cc584b21 AV |
1446 | if (base->softirq_time.tv64 <= |
1447 | hrtimer_get_expires_tv64(timer)) | |
833883d9 DS |
1448 | break; |
1449 | ||
c6a2a177 | 1450 | __run_hrtimer(timer, &base->softirq_time); |
833883d9 | 1451 | } |
ecb49d1a | 1452 | raw_spin_unlock(&cpu_base->lock); |
833883d9 | 1453 | } |
c0a31329 TG |
1454 | } |
1455 | ||
10c94ec1 TG |
1456 | /* |
1457 | * Sleep related functions: | |
1458 | */ | |
c9cb2e3d | 1459 | static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer) |
00362e33 TG |
1460 | { |
1461 | struct hrtimer_sleeper *t = | |
1462 | container_of(timer, struct hrtimer_sleeper, timer); | |
1463 | struct task_struct *task = t->task; | |
1464 | ||
1465 | t->task = NULL; | |
1466 | if (task) | |
1467 | wake_up_process(task); | |
1468 | ||
1469 | return HRTIMER_NORESTART; | |
1470 | } | |
1471 | ||
36c8b586 | 1472 | void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) |
00362e33 TG |
1473 | { |
1474 | sl->timer.function = hrtimer_wakeup; | |
1475 | sl->task = task; | |
1476 | } | |
2bc481cf | 1477 | EXPORT_SYMBOL_GPL(hrtimer_init_sleeper); |
00362e33 | 1478 | |
669d7868 | 1479 | static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode) |
432569bb | 1480 | { |
669d7868 | 1481 | hrtimer_init_sleeper(t, current); |
10c94ec1 | 1482 | |
432569bb RZ |
1483 | do { |
1484 | set_current_state(TASK_INTERRUPTIBLE); | |
cc584b21 | 1485 | hrtimer_start_expires(&t->timer, mode); |
37bb6cb4 PZ |
1486 | if (!hrtimer_active(&t->timer)) |
1487 | t->task = NULL; | |
432569bb | 1488 | |
54cdfdb4 TG |
1489 | if (likely(t->task)) |
1490 | schedule(); | |
432569bb | 1491 | |
669d7868 | 1492 | hrtimer_cancel(&t->timer); |
c9cb2e3d | 1493 | mode = HRTIMER_MODE_ABS; |
669d7868 TG |
1494 | |
1495 | } while (t->task && !signal_pending(current)); | |
432569bb | 1496 | |
3588a085 PZ |
1497 | __set_current_state(TASK_RUNNING); |
1498 | ||
669d7868 | 1499 | return t->task == NULL; |
10c94ec1 TG |
1500 | } |
1501 | ||
080344b9 ON |
1502 | static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp) |
1503 | { | |
1504 | struct timespec rmt; | |
1505 | ktime_t rem; | |
1506 | ||
cc584b21 | 1507 | rem = hrtimer_expires_remaining(timer); |
080344b9 ON |
1508 | if (rem.tv64 <= 0) |
1509 | return 0; | |
1510 | rmt = ktime_to_timespec(rem); | |
1511 | ||
1512 | if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) | |
1513 | return -EFAULT; | |
1514 | ||
1515 | return 1; | |
1516 | } | |
1517 | ||
1711ef38 | 1518 | long __sched hrtimer_nanosleep_restart(struct restart_block *restart) |
10c94ec1 | 1519 | { |
669d7868 | 1520 | struct hrtimer_sleeper t; |
080344b9 | 1521 | struct timespec __user *rmtp; |
237fc6e7 | 1522 | int ret = 0; |
10c94ec1 | 1523 | |
237fc6e7 TG |
1524 | hrtimer_init_on_stack(&t.timer, restart->nanosleep.index, |
1525 | HRTIMER_MODE_ABS); | |
cc584b21 | 1526 | hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires); |
10c94ec1 | 1527 | |
c9cb2e3d | 1528 | if (do_nanosleep(&t, HRTIMER_MODE_ABS)) |
237fc6e7 | 1529 | goto out; |
10c94ec1 | 1530 | |
029a07e0 | 1531 | rmtp = restart->nanosleep.rmtp; |
432569bb | 1532 | if (rmtp) { |
237fc6e7 | 1533 | ret = update_rmtp(&t.timer, rmtp); |
080344b9 | 1534 | if (ret <= 0) |
237fc6e7 | 1535 | goto out; |
432569bb | 1536 | } |
10c94ec1 | 1537 | |
10c94ec1 | 1538 | /* The other values in restart are already filled in */ |
237fc6e7 TG |
1539 | ret = -ERESTART_RESTARTBLOCK; |
1540 | out: | |
1541 | destroy_hrtimer_on_stack(&t.timer); | |
1542 | return ret; | |
10c94ec1 TG |
1543 | } |
1544 | ||
080344b9 | 1545 | long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, |
10c94ec1 TG |
1546 | const enum hrtimer_mode mode, const clockid_t clockid) |
1547 | { | |
1548 | struct restart_block *restart; | |
669d7868 | 1549 | struct hrtimer_sleeper t; |
237fc6e7 | 1550 | int ret = 0; |
3bd01206 AV |
1551 | unsigned long slack; |
1552 | ||
1553 | slack = current->timer_slack_ns; | |
1554 | if (rt_task(current)) | |
1555 | slack = 0; | |
10c94ec1 | 1556 | |
237fc6e7 | 1557 | hrtimer_init_on_stack(&t.timer, clockid, mode); |
3bd01206 | 1558 | hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack); |
432569bb | 1559 | if (do_nanosleep(&t, mode)) |
237fc6e7 | 1560 | goto out; |
10c94ec1 | 1561 | |
7978672c | 1562 | /* Absolute timers do not update the rmtp value and restart: */ |
237fc6e7 TG |
1563 | if (mode == HRTIMER_MODE_ABS) { |
1564 | ret = -ERESTARTNOHAND; | |
1565 | goto out; | |
1566 | } | |
10c94ec1 | 1567 | |
432569bb | 1568 | if (rmtp) { |
237fc6e7 | 1569 | ret = update_rmtp(&t.timer, rmtp); |
080344b9 | 1570 | if (ret <= 0) |
237fc6e7 | 1571 | goto out; |
432569bb | 1572 | } |
10c94ec1 TG |
1573 | |
1574 | restart = ¤t_thread_info()->restart_block; | |
1711ef38 | 1575 | restart->fn = hrtimer_nanosleep_restart; |
029a07e0 TG |
1576 | restart->nanosleep.index = t.timer.base->index; |
1577 | restart->nanosleep.rmtp = rmtp; | |
cc584b21 | 1578 | restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer); |
10c94ec1 | 1579 | |
237fc6e7 TG |
1580 | ret = -ERESTART_RESTARTBLOCK; |
1581 | out: | |
1582 | destroy_hrtimer_on_stack(&t.timer); | |
1583 | return ret; | |
10c94ec1 TG |
1584 | } |
1585 | ||
58fd3aa2 HC |
1586 | SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp, |
1587 | struct timespec __user *, rmtp) | |
6ba1b912 | 1588 | { |
080344b9 | 1589 | struct timespec tu; |
6ba1b912 TG |
1590 | |
1591 | if (copy_from_user(&tu, rqtp, sizeof(tu))) | |
1592 | return -EFAULT; | |
1593 | ||
1594 | if (!timespec_valid(&tu)) | |
1595 | return -EINVAL; | |
1596 | ||
080344b9 | 1597 | return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC); |
6ba1b912 TG |
1598 | } |
1599 | ||
c0a31329 TG |
1600 | /* |
1601 | * Functions related to boot-time initialization: | |
1602 | */ | |
0ec160dd | 1603 | static void __cpuinit init_hrtimers_cpu(int cpu) |
c0a31329 | 1604 | { |
3c8aa39d | 1605 | struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); |
c0a31329 TG |
1606 | int i; |
1607 | ||
ecb49d1a | 1608 | raw_spin_lock_init(&cpu_base->lock); |
3c8aa39d | 1609 | |
998adc3d | 1610 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { |
3c8aa39d | 1611 | cpu_base->clock_base[i].cpu_base = cpu_base; |
998adc3d JS |
1612 | timerqueue_init_head(&cpu_base->clock_base[i].active); |
1613 | } | |
3c8aa39d | 1614 | |
54cdfdb4 | 1615 | hrtimer_init_hres(cpu_base); |
c0a31329 TG |
1616 | } |
1617 | ||
1618 | #ifdef CONFIG_HOTPLUG_CPU | |
1619 | ||
ca109491 | 1620 | static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, |
37810659 | 1621 | struct hrtimer_clock_base *new_base) |
c0a31329 TG |
1622 | { |
1623 | struct hrtimer *timer; | |
998adc3d | 1624 | struct timerqueue_node *node; |
c0a31329 | 1625 | |
998adc3d JS |
1626 | while ((node = timerqueue_getnext(&old_base->active))) { |
1627 | timer = container_of(node, struct hrtimer, node); | |
54cdfdb4 | 1628 | BUG_ON(hrtimer_callback_running(timer)); |
c6a2a177 | 1629 | debug_deactivate(timer); |
b00c1a99 TG |
1630 | |
1631 | /* | |
1632 | * Mark it as STATE_MIGRATE not INACTIVE otherwise the | |
1633 | * timer could be seen as !active and just vanish away | |
1634 | * under us on another CPU | |
1635 | */ | |
1636 | __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0); | |
c0a31329 | 1637 | timer->base = new_base; |
54cdfdb4 | 1638 | /* |
e3f1d883 TG |
1639 | * Enqueue the timers on the new cpu. This does not |
1640 | * reprogram the event device in case the timer | |
1641 | * expires before the earliest on this CPU, but we run | |
1642 | * hrtimer_interrupt after we migrated everything to | |
1643 | * sort out already expired timers and reprogram the | |
1644 | * event device. | |
54cdfdb4 | 1645 | */ |
a6037b61 | 1646 | enqueue_hrtimer(timer, new_base); |
41e1022e | 1647 | |
b00c1a99 TG |
1648 | /* Clear the migration state bit */ |
1649 | timer->state &= ~HRTIMER_STATE_MIGRATE; | |
c0a31329 TG |
1650 | } |
1651 | } | |
1652 | ||
d5fd43c4 | 1653 | static void migrate_hrtimers(int scpu) |
c0a31329 | 1654 | { |
3c8aa39d | 1655 | struct hrtimer_cpu_base *old_base, *new_base; |
731a55ba | 1656 | int i; |
c0a31329 | 1657 | |
37810659 | 1658 | BUG_ON(cpu_online(scpu)); |
37810659 | 1659 | tick_cancel_sched_timer(scpu); |
731a55ba TG |
1660 | |
1661 | local_irq_disable(); | |
1662 | old_base = &per_cpu(hrtimer_bases, scpu); | |
1663 | new_base = &__get_cpu_var(hrtimer_bases); | |
d82f0b0f ON |
1664 | /* |
1665 | * The caller is globally serialized and nobody else | |
1666 | * takes two locks at once, deadlock is not possible. | |
1667 | */ | |
ecb49d1a TG |
1668 | raw_spin_lock(&new_base->lock); |
1669 | raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); | |
c0a31329 | 1670 | |
3c8aa39d | 1671 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { |
ca109491 | 1672 | migrate_hrtimer_list(&old_base->clock_base[i], |
37810659 | 1673 | &new_base->clock_base[i]); |
c0a31329 TG |
1674 | } |
1675 | ||
ecb49d1a TG |
1676 | raw_spin_unlock(&old_base->lock); |
1677 | raw_spin_unlock(&new_base->lock); | |
37810659 | 1678 | |
731a55ba TG |
1679 | /* Check, if we got expired work to do */ |
1680 | __hrtimer_peek_ahead_timers(); | |
1681 | local_irq_enable(); | |
c0a31329 | 1682 | } |
37810659 | 1683 | |
c0a31329 TG |
1684 | #endif /* CONFIG_HOTPLUG_CPU */ |
1685 | ||
8c78f307 | 1686 | static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self, |
c0a31329 TG |
1687 | unsigned long action, void *hcpu) |
1688 | { | |
b2e3c0ad | 1689 | int scpu = (long)hcpu; |
c0a31329 TG |
1690 | |
1691 | switch (action) { | |
1692 | ||
1693 | case CPU_UP_PREPARE: | |
8bb78442 | 1694 | case CPU_UP_PREPARE_FROZEN: |
37810659 | 1695 | init_hrtimers_cpu(scpu); |
c0a31329 TG |
1696 | break; |
1697 | ||
1698 | #ifdef CONFIG_HOTPLUG_CPU | |
94df7de0 SD |
1699 | case CPU_DYING: |
1700 | case CPU_DYING_FROZEN: | |
1701 | clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DYING, &scpu); | |
1702 | break; | |
c0a31329 | 1703 | case CPU_DEAD: |
8bb78442 | 1704 | case CPU_DEAD_FROZEN: |
b2e3c0ad | 1705 | { |
37810659 | 1706 | clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &scpu); |
d5fd43c4 | 1707 | migrate_hrtimers(scpu); |
c0a31329 | 1708 | break; |
b2e3c0ad | 1709 | } |
c0a31329 TG |
1710 | #endif |
1711 | ||
1712 | default: | |
1713 | break; | |
1714 | } | |
1715 | ||
1716 | return NOTIFY_OK; | |
1717 | } | |
1718 | ||
8c78f307 | 1719 | static struct notifier_block __cpuinitdata hrtimers_nb = { |
c0a31329 TG |
1720 | .notifier_call = hrtimer_cpu_notify, |
1721 | }; | |
1722 | ||
1723 | void __init hrtimers_init(void) | |
1724 | { | |
e06383db JS |
1725 | hrtimer_clock_to_base_table[CLOCK_REALTIME] = HRTIMER_BASE_REALTIME; |
1726 | hrtimer_clock_to_base_table[CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC; | |
70a08cca | 1727 | hrtimer_clock_to_base_table[CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME; |
e06383db | 1728 | |
c0a31329 TG |
1729 | hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE, |
1730 | (void *)(long)smp_processor_id()); | |
1731 | register_cpu_notifier(&hrtimers_nb); | |
a6037b61 PZ |
1732 | #ifdef CONFIG_HIGH_RES_TIMERS |
1733 | open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq); | |
1734 | #endif | |
c0a31329 TG |
1735 | } |
1736 | ||
7bb67439 | 1737 | /** |
351b3f7a | 1738 | * schedule_hrtimeout_range_clock - sleep until timeout |
7bb67439 | 1739 | * @expires: timeout value (ktime_t) |
654c8e0b | 1740 | * @delta: slack in expires timeout (ktime_t) |
7bb67439 | 1741 | * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL |
351b3f7a | 1742 | * @clock: timer clock, CLOCK_MONOTONIC or CLOCK_REALTIME |
7bb67439 | 1743 | */ |
351b3f7a CE |
1744 | int __sched |
1745 | schedule_hrtimeout_range_clock(ktime_t *expires, unsigned long delta, | |
1746 | const enum hrtimer_mode mode, int clock) | |
7bb67439 AV |
1747 | { |
1748 | struct hrtimer_sleeper t; | |
1749 | ||
1750 | /* | |
1751 | * Optimize when a zero timeout value is given. It does not | |
1752 | * matter whether this is an absolute or a relative time. | |
1753 | */ | |
1754 | if (expires && !expires->tv64) { | |
1755 | __set_current_state(TASK_RUNNING); | |
1756 | return 0; | |
1757 | } | |
1758 | ||
1759 | /* | |
43b21013 | 1760 | * A NULL parameter means "infinite" |
7bb67439 AV |
1761 | */ |
1762 | if (!expires) { | |
1763 | schedule(); | |
1764 | __set_current_state(TASK_RUNNING); | |
1765 | return -EINTR; | |
1766 | } | |
1767 | ||
351b3f7a | 1768 | hrtimer_init_on_stack(&t.timer, clock, mode); |
654c8e0b | 1769 | hrtimer_set_expires_range_ns(&t.timer, *expires, delta); |
7bb67439 AV |
1770 | |
1771 | hrtimer_init_sleeper(&t, current); | |
1772 | ||
cc584b21 | 1773 | hrtimer_start_expires(&t.timer, mode); |
7bb67439 AV |
1774 | if (!hrtimer_active(&t.timer)) |
1775 | t.task = NULL; | |
1776 | ||
1777 | if (likely(t.task)) | |
1778 | schedule(); | |
1779 | ||
1780 | hrtimer_cancel(&t.timer); | |
1781 | destroy_hrtimer_on_stack(&t.timer); | |
1782 | ||
1783 | __set_current_state(TASK_RUNNING); | |
1784 | ||
1785 | return !t.task ? 0 : -EINTR; | |
1786 | } | |
351b3f7a CE |
1787 | |
1788 | /** | |
1789 | * schedule_hrtimeout_range - sleep until timeout | |
1790 | * @expires: timeout value (ktime_t) | |
1791 | * @delta: slack in expires timeout (ktime_t) | |
1792 | * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL | |
1793 | * | |
1794 | * Make the current task sleep until the given expiry time has | |
1795 | * elapsed. The routine will return immediately unless | |
1796 | * the current task state has been set (see set_current_state()). | |
1797 | * | |
1798 | * The @delta argument gives the kernel the freedom to schedule the | |
1799 | * actual wakeup to a time that is both power and performance friendly. | |
1800 | * The kernel give the normal best effort behavior for "@expires+@delta", | |
1801 | * but may decide to fire the timer earlier, but no earlier than @expires. | |
1802 | * | |
1803 | * You can set the task state as follows - | |
1804 | * | |
1805 | * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to | |
1806 | * pass before the routine returns. | |
1807 | * | |
1808 | * %TASK_INTERRUPTIBLE - the routine may return early if a signal is | |
1809 | * delivered to the current task. | |
1810 | * | |
1811 | * The current task state is guaranteed to be TASK_RUNNING when this | |
1812 | * routine returns. | |
1813 | * | |
1814 | * Returns 0 when the timer has expired otherwise -EINTR | |
1815 | */ | |
1816 | int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta, | |
1817 | const enum hrtimer_mode mode) | |
1818 | { | |
1819 | return schedule_hrtimeout_range_clock(expires, delta, mode, | |
1820 | CLOCK_MONOTONIC); | |
1821 | } | |
654c8e0b AV |
1822 | EXPORT_SYMBOL_GPL(schedule_hrtimeout_range); |
1823 | ||
1824 | /** | |
1825 | * schedule_hrtimeout - sleep until timeout | |
1826 | * @expires: timeout value (ktime_t) | |
1827 | * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL | |
1828 | * | |
1829 | * Make the current task sleep until the given expiry time has | |
1830 | * elapsed. The routine will return immediately unless | |
1831 | * the current task state has been set (see set_current_state()). | |
1832 | * | |
1833 | * You can set the task state as follows - | |
1834 | * | |
1835 | * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to | |
1836 | * pass before the routine returns. | |
1837 | * | |
1838 | * %TASK_INTERRUPTIBLE - the routine may return early if a signal is | |
1839 | * delivered to the current task. | |
1840 | * | |
1841 | * The current task state is guaranteed to be TASK_RUNNING when this | |
1842 | * routine returns. | |
1843 | * | |
1844 | * Returns 0 when the timer has expired otherwise -EINTR | |
1845 | */ | |
1846 | int __sched schedule_hrtimeout(ktime_t *expires, | |
1847 | const enum hrtimer_mode mode) | |
1848 | { | |
1849 | return schedule_hrtimeout_range(expires, 0, mode); | |
1850 | } | |
7bb67439 | 1851 | EXPORT_SYMBOL_GPL(schedule_hrtimeout); |