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> | |
9984de1a | 35 | #include <linux/export.h> |
c0a31329 TG |
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 | 46 | #include <linux/sched.h> |
cf4aebc2 | 47 | #include <linux/sched/sysctl.h> |
8bd75c77 | 48 | #include <linux/sched/rt.h> |
eea08f32 | 49 | #include <linux/timer.h> |
b0f8c44f | 50 | #include <linux/freezer.h> |
c0a31329 TG |
51 | |
52 | #include <asm/uaccess.h> | |
53 | ||
c6a2a177 XG |
54 | #include <trace/events/timer.h> |
55 | ||
c0a31329 TG |
56 | /* |
57 | * The timer bases: | |
7978672c | 58 | * |
e06383db JS |
59 | * There are more clockids then hrtimer bases. Thus, we index |
60 | * into the timer bases by the hrtimer_base_type enum. When trying | |
61 | * to reach a base using a clockid, hrtimer_clockid_to_base() | |
62 | * is used to convert from clockid to the proper hrtimer_base_type. | |
c0a31329 | 63 | */ |
54cdfdb4 | 64 | DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = |
c0a31329 | 65 | { |
3c8aa39d | 66 | |
84cc8fd2 | 67 | .lock = __RAW_SPIN_LOCK_UNLOCKED(hrtimer_bases.lock), |
3c8aa39d | 68 | .clock_base = |
c0a31329 | 69 | { |
3c8aa39d | 70 | { |
ab8177bc TG |
71 | .index = HRTIMER_BASE_MONOTONIC, |
72 | .clockid = CLOCK_MONOTONIC, | |
3c8aa39d | 73 | .get_time = &ktime_get, |
54cdfdb4 | 74 | .resolution = KTIME_LOW_RES, |
3c8aa39d | 75 | }, |
68fa61c0 TG |
76 | { |
77 | .index = HRTIMER_BASE_REALTIME, | |
78 | .clockid = CLOCK_REALTIME, | |
79 | .get_time = &ktime_get_real, | |
80 | .resolution = KTIME_LOW_RES, | |
81 | }, | |
70a08cca | 82 | { |
ab8177bc TG |
83 | .index = HRTIMER_BASE_BOOTTIME, |
84 | .clockid = CLOCK_BOOTTIME, | |
70a08cca JS |
85 | .get_time = &ktime_get_boottime, |
86 | .resolution = KTIME_LOW_RES, | |
87 | }, | |
90adda98 JS |
88 | { |
89 | .index = HRTIMER_BASE_TAI, | |
90 | .clockid = CLOCK_TAI, | |
91 | .get_time = &ktime_get_clocktai, | |
92 | .resolution = KTIME_LOW_RES, | |
93 | }, | |
3c8aa39d | 94 | } |
c0a31329 TG |
95 | }; |
96 | ||
942c3c5c | 97 | static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = { |
ce31332d TG |
98 | [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME, |
99 | [CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC, | |
100 | [CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME, | |
90adda98 | 101 | [CLOCK_TAI] = HRTIMER_BASE_TAI, |
ce31332d | 102 | }; |
e06383db JS |
103 | |
104 | static inline int hrtimer_clockid_to_base(clockid_t clock_id) | |
105 | { | |
106 | return hrtimer_clock_to_base_table[clock_id]; | |
107 | } | |
108 | ||
109 | ||
92127c7a TG |
110 | /* |
111 | * Get the coarse grained time at the softirq based on xtime and | |
112 | * wall_to_monotonic. | |
113 | */ | |
3c8aa39d | 114 | static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) |
92127c7a | 115 | { |
70a08cca | 116 | ktime_t xtim, mono, boot; |
314ac371 | 117 | struct timespec xts, tom, slp; |
90adda98 | 118 | s32 tai_offset; |
92127c7a | 119 | |
314ac371 | 120 | get_xtime_and_monotonic_and_sleep_offset(&xts, &tom, &slp); |
90adda98 | 121 | tai_offset = timekeeping_get_tai_offset(); |
92127c7a | 122 | |
f4304ab2 | 123 | xtim = timespec_to_ktime(xts); |
70a08cca JS |
124 | mono = ktime_add(xtim, timespec_to_ktime(tom)); |
125 | boot = ktime_add(mono, timespec_to_ktime(slp)); | |
e06383db | 126 | base->clock_base[HRTIMER_BASE_REALTIME].softirq_time = xtim; |
70a08cca JS |
127 | base->clock_base[HRTIMER_BASE_MONOTONIC].softirq_time = mono; |
128 | base->clock_base[HRTIMER_BASE_BOOTTIME].softirq_time = boot; | |
90adda98 JS |
129 | base->clock_base[HRTIMER_BASE_TAI].softirq_time = |
130 | ktime_add(xtim, ktime_set(tai_offset, 0)); | |
92127c7a TG |
131 | } |
132 | ||
c0a31329 TG |
133 | /* |
134 | * Functions and macros which are different for UP/SMP systems are kept in a | |
135 | * single place | |
136 | */ | |
137 | #ifdef CONFIG_SMP | |
138 | ||
c0a31329 TG |
139 | /* |
140 | * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock | |
141 | * means that all timers which are tied to this base via timer->base are | |
142 | * locked, and the base itself is locked too. | |
143 | * | |
144 | * So __run_timers/migrate_timers can safely modify all timers which could | |
145 | * be found on the lists/queues. | |
146 | * | |
147 | * When the timer's base is locked, and the timer removed from list, it is | |
148 | * possible to set timer->base = NULL and drop the lock: the timer remains | |
149 | * locked. | |
150 | */ | |
3c8aa39d TG |
151 | static |
152 | struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer, | |
153 | unsigned long *flags) | |
c0a31329 | 154 | { |
3c8aa39d | 155 | struct hrtimer_clock_base *base; |
c0a31329 TG |
156 | |
157 | for (;;) { | |
158 | base = timer->base; | |
159 | if (likely(base != NULL)) { | |
ecb49d1a | 160 | raw_spin_lock_irqsave(&base->cpu_base->lock, *flags); |
c0a31329 TG |
161 | if (likely(base == timer->base)) |
162 | return base; | |
163 | /* The timer has migrated to another CPU: */ | |
ecb49d1a | 164 | raw_spin_unlock_irqrestore(&base->cpu_base->lock, *flags); |
c0a31329 TG |
165 | } |
166 | cpu_relax(); | |
167 | } | |
168 | } | |
169 | ||
6ff7041d TG |
170 | |
171 | /* | |
172 | * Get the preferred target CPU for NOHZ | |
173 | */ | |
174 | static int hrtimer_get_target(int this_cpu, int pinned) | |
175 | { | |
3451d024 | 176 | #ifdef CONFIG_NO_HZ_COMMON |
83cd4fe2 VP |
177 | if (!pinned && get_sysctl_timer_migration() && idle_cpu(this_cpu)) |
178 | return get_nohz_timer_target(); | |
6ff7041d TG |
179 | #endif |
180 | return this_cpu; | |
181 | } | |
182 | ||
183 | /* | |
184 | * With HIGHRES=y we do not migrate the timer when it is expiring | |
185 | * before the next event on the target cpu because we cannot reprogram | |
186 | * the target cpu hardware and we would cause it to fire late. | |
187 | * | |
188 | * Called with cpu_base->lock of target cpu held. | |
189 | */ | |
190 | static int | |
191 | hrtimer_check_target(struct hrtimer *timer, struct hrtimer_clock_base *new_base) | |
192 | { | |
193 | #ifdef CONFIG_HIGH_RES_TIMERS | |
194 | ktime_t expires; | |
195 | ||
196 | if (!new_base->cpu_base->hres_active) | |
197 | return 0; | |
198 | ||
199 | expires = ktime_sub(hrtimer_get_expires(timer), new_base->offset); | |
200 | return expires.tv64 <= new_base->cpu_base->expires_next.tv64; | |
201 | #else | |
202 | return 0; | |
203 | #endif | |
204 | } | |
205 | ||
c0a31329 TG |
206 | /* |
207 | * Switch the timer base to the current CPU when possible. | |
208 | */ | |
3c8aa39d | 209 | static inline struct hrtimer_clock_base * |
597d0275 AB |
210 | switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base, |
211 | int pinned) | |
c0a31329 | 212 | { |
3c8aa39d TG |
213 | struct hrtimer_clock_base *new_base; |
214 | struct hrtimer_cpu_base *new_cpu_base; | |
6ff7041d TG |
215 | int this_cpu = smp_processor_id(); |
216 | int cpu = hrtimer_get_target(this_cpu, pinned); | |
ab8177bc | 217 | int basenum = base->index; |
c0a31329 | 218 | |
eea08f32 AB |
219 | again: |
220 | new_cpu_base = &per_cpu(hrtimer_bases, cpu); | |
e06383db | 221 | new_base = &new_cpu_base->clock_base[basenum]; |
c0a31329 TG |
222 | |
223 | if (base != new_base) { | |
224 | /* | |
6ff7041d | 225 | * We are trying to move timer to new_base. |
c0a31329 TG |
226 | * However we can't change timer's base while it is running, |
227 | * so we keep it on the same CPU. No hassle vs. reprogramming | |
228 | * the event source in the high resolution case. The softirq | |
229 | * code will take care of this when the timer function has | |
230 | * completed. There is no conflict as we hold the lock until | |
231 | * the timer is enqueued. | |
232 | */ | |
54cdfdb4 | 233 | if (unlikely(hrtimer_callback_running(timer))) |
c0a31329 TG |
234 | return base; |
235 | ||
236 | /* See the comment in lock_timer_base() */ | |
237 | timer->base = NULL; | |
ecb49d1a TG |
238 | raw_spin_unlock(&base->cpu_base->lock); |
239 | raw_spin_lock(&new_base->cpu_base->lock); | |
eea08f32 | 240 | |
6ff7041d TG |
241 | if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) { |
242 | cpu = this_cpu; | |
ecb49d1a TG |
243 | raw_spin_unlock(&new_base->cpu_base->lock); |
244 | raw_spin_lock(&base->cpu_base->lock); | |
6ff7041d TG |
245 | timer->base = base; |
246 | goto again; | |
eea08f32 | 247 | } |
c0a31329 TG |
248 | timer->base = new_base; |
249 | } | |
250 | return new_base; | |
251 | } | |
252 | ||
253 | #else /* CONFIG_SMP */ | |
254 | ||
3c8aa39d | 255 | static inline struct hrtimer_clock_base * |
c0a31329 TG |
256 | lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) |
257 | { | |
3c8aa39d | 258 | struct hrtimer_clock_base *base = timer->base; |
c0a31329 | 259 | |
ecb49d1a | 260 | raw_spin_lock_irqsave(&base->cpu_base->lock, *flags); |
c0a31329 TG |
261 | |
262 | return base; | |
263 | } | |
264 | ||
eea08f32 | 265 | # define switch_hrtimer_base(t, b, p) (b) |
c0a31329 TG |
266 | |
267 | #endif /* !CONFIG_SMP */ | |
268 | ||
269 | /* | |
270 | * Functions for the union type storage format of ktime_t which are | |
271 | * too large for inlining: | |
272 | */ | |
273 | #if BITS_PER_LONG < 64 | |
274 | # ifndef CONFIG_KTIME_SCALAR | |
275 | /** | |
276 | * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable | |
c0a31329 TG |
277 | * @kt: addend |
278 | * @nsec: the scalar nsec value to add | |
279 | * | |
280 | * Returns the sum of kt and nsec in ktime_t format | |
281 | */ | |
282 | ktime_t ktime_add_ns(const ktime_t kt, u64 nsec) | |
283 | { | |
284 | ktime_t tmp; | |
285 | ||
286 | if (likely(nsec < NSEC_PER_SEC)) { | |
287 | tmp.tv64 = nsec; | |
288 | } else { | |
289 | unsigned long rem = do_div(nsec, NSEC_PER_SEC); | |
290 | ||
51fd36f3 DE |
291 | /* Make sure nsec fits into long */ |
292 | if (unlikely(nsec > KTIME_SEC_MAX)) | |
293 | return (ktime_t){ .tv64 = KTIME_MAX }; | |
294 | ||
c0a31329 TG |
295 | tmp = ktime_set((long)nsec, rem); |
296 | } | |
297 | ||
298 | return ktime_add(kt, tmp); | |
299 | } | |
b8b8fd2d DH |
300 | |
301 | EXPORT_SYMBOL_GPL(ktime_add_ns); | |
a272378d ACM |
302 | |
303 | /** | |
304 | * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable | |
305 | * @kt: minuend | |
306 | * @nsec: the scalar nsec value to subtract | |
307 | * | |
308 | * Returns the subtraction of @nsec from @kt in ktime_t format | |
309 | */ | |
310 | ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec) | |
311 | { | |
312 | ktime_t tmp; | |
313 | ||
314 | if (likely(nsec < NSEC_PER_SEC)) { | |
315 | tmp.tv64 = nsec; | |
316 | } else { | |
317 | unsigned long rem = do_div(nsec, NSEC_PER_SEC); | |
318 | ||
319 | tmp = ktime_set((long)nsec, rem); | |
320 | } | |
321 | ||
322 | return ktime_sub(kt, tmp); | |
323 | } | |
324 | ||
325 | EXPORT_SYMBOL_GPL(ktime_sub_ns); | |
c0a31329 TG |
326 | # endif /* !CONFIG_KTIME_SCALAR */ |
327 | ||
328 | /* | |
329 | * Divide a ktime value by a nanosecond value | |
330 | */ | |
4d672e7a | 331 | u64 ktime_divns(const ktime_t kt, s64 div) |
c0a31329 | 332 | { |
900cfa46 | 333 | u64 dclc; |
c0a31329 TG |
334 | int sft = 0; |
335 | ||
900cfa46 | 336 | dclc = ktime_to_ns(kt); |
c0a31329 TG |
337 | /* Make sure the divisor is less than 2^32: */ |
338 | while (div >> 32) { | |
339 | sft++; | |
340 | div >>= 1; | |
341 | } | |
342 | dclc >>= sft; | |
343 | do_div(dclc, (unsigned long) div); | |
344 | ||
4d672e7a | 345 | return dclc; |
c0a31329 | 346 | } |
c0a31329 TG |
347 | #endif /* BITS_PER_LONG >= 64 */ |
348 | ||
5a7780e7 TG |
349 | /* |
350 | * Add two ktime values and do a safety check for overflow: | |
351 | */ | |
352 | ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs) | |
353 | { | |
354 | ktime_t res = ktime_add(lhs, rhs); | |
355 | ||
356 | /* | |
357 | * We use KTIME_SEC_MAX here, the maximum timeout which we can | |
358 | * return to user space in a timespec: | |
359 | */ | |
360 | if (res.tv64 < 0 || res.tv64 < lhs.tv64 || res.tv64 < rhs.tv64) | |
361 | res = ktime_set(KTIME_SEC_MAX, 0); | |
362 | ||
363 | return res; | |
364 | } | |
365 | ||
8daa21e6 AB |
366 | EXPORT_SYMBOL_GPL(ktime_add_safe); |
367 | ||
237fc6e7 TG |
368 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS |
369 | ||
370 | static struct debug_obj_descr hrtimer_debug_descr; | |
371 | ||
99777288 SG |
372 | static void *hrtimer_debug_hint(void *addr) |
373 | { | |
374 | return ((struct hrtimer *) addr)->function; | |
375 | } | |
376 | ||
237fc6e7 TG |
377 | /* |
378 | * fixup_init is called when: | |
379 | * - an active object is initialized | |
380 | */ | |
381 | static int hrtimer_fixup_init(void *addr, enum debug_obj_state state) | |
382 | { | |
383 | struct hrtimer *timer = addr; | |
384 | ||
385 | switch (state) { | |
386 | case ODEBUG_STATE_ACTIVE: | |
387 | hrtimer_cancel(timer); | |
388 | debug_object_init(timer, &hrtimer_debug_descr); | |
389 | return 1; | |
390 | default: | |
391 | return 0; | |
392 | } | |
393 | } | |
394 | ||
395 | /* | |
396 | * fixup_activate is called when: | |
397 | * - an active object is activated | |
398 | * - an unknown object is activated (might be a statically initialized object) | |
399 | */ | |
400 | static int hrtimer_fixup_activate(void *addr, enum debug_obj_state state) | |
401 | { | |
402 | switch (state) { | |
403 | ||
404 | case ODEBUG_STATE_NOTAVAILABLE: | |
405 | WARN_ON_ONCE(1); | |
406 | return 0; | |
407 | ||
408 | case ODEBUG_STATE_ACTIVE: | |
409 | WARN_ON(1); | |
410 | ||
411 | default: | |
412 | return 0; | |
413 | } | |
414 | } | |
415 | ||
416 | /* | |
417 | * fixup_free is called when: | |
418 | * - an active object is freed | |
419 | */ | |
420 | static int hrtimer_fixup_free(void *addr, enum debug_obj_state state) | |
421 | { | |
422 | struct hrtimer *timer = addr; | |
423 | ||
424 | switch (state) { | |
425 | case ODEBUG_STATE_ACTIVE: | |
426 | hrtimer_cancel(timer); | |
427 | debug_object_free(timer, &hrtimer_debug_descr); | |
428 | return 1; | |
429 | default: | |
430 | return 0; | |
431 | } | |
432 | } | |
433 | ||
434 | static struct debug_obj_descr hrtimer_debug_descr = { | |
435 | .name = "hrtimer", | |
99777288 | 436 | .debug_hint = hrtimer_debug_hint, |
237fc6e7 TG |
437 | .fixup_init = hrtimer_fixup_init, |
438 | .fixup_activate = hrtimer_fixup_activate, | |
439 | .fixup_free = hrtimer_fixup_free, | |
440 | }; | |
441 | ||
442 | static inline void debug_hrtimer_init(struct hrtimer *timer) | |
443 | { | |
444 | debug_object_init(timer, &hrtimer_debug_descr); | |
445 | } | |
446 | ||
447 | static inline void debug_hrtimer_activate(struct hrtimer *timer) | |
448 | { | |
449 | debug_object_activate(timer, &hrtimer_debug_descr); | |
450 | } | |
451 | ||
452 | static inline void debug_hrtimer_deactivate(struct hrtimer *timer) | |
453 | { | |
454 | debug_object_deactivate(timer, &hrtimer_debug_descr); | |
455 | } | |
456 | ||
457 | static inline void debug_hrtimer_free(struct hrtimer *timer) | |
458 | { | |
459 | debug_object_free(timer, &hrtimer_debug_descr); | |
460 | } | |
461 | ||
462 | static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, | |
463 | enum hrtimer_mode mode); | |
464 | ||
465 | void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id, | |
466 | enum hrtimer_mode mode) | |
467 | { | |
468 | debug_object_init_on_stack(timer, &hrtimer_debug_descr); | |
469 | __hrtimer_init(timer, clock_id, mode); | |
470 | } | |
2bc481cf | 471 | EXPORT_SYMBOL_GPL(hrtimer_init_on_stack); |
237fc6e7 TG |
472 | |
473 | void destroy_hrtimer_on_stack(struct hrtimer *timer) | |
474 | { | |
475 | debug_object_free(timer, &hrtimer_debug_descr); | |
476 | } | |
477 | ||
478 | #else | |
479 | static inline void debug_hrtimer_init(struct hrtimer *timer) { } | |
480 | static inline void debug_hrtimer_activate(struct hrtimer *timer) { } | |
481 | static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { } | |
482 | #endif | |
483 | ||
c6a2a177 XG |
484 | static inline void |
485 | debug_init(struct hrtimer *timer, clockid_t clockid, | |
486 | enum hrtimer_mode mode) | |
487 | { | |
488 | debug_hrtimer_init(timer); | |
489 | trace_hrtimer_init(timer, clockid, mode); | |
490 | } | |
491 | ||
492 | static inline void debug_activate(struct hrtimer *timer) | |
493 | { | |
494 | debug_hrtimer_activate(timer); | |
495 | trace_hrtimer_start(timer); | |
496 | } | |
497 | ||
498 | static inline void debug_deactivate(struct hrtimer *timer) | |
499 | { | |
500 | debug_hrtimer_deactivate(timer); | |
501 | trace_hrtimer_cancel(timer); | |
502 | } | |
503 | ||
54cdfdb4 TG |
504 | /* High resolution timer related functions */ |
505 | #ifdef CONFIG_HIGH_RES_TIMERS | |
506 | ||
507 | /* | |
508 | * High resolution timer enabled ? | |
509 | */ | |
510 | static int hrtimer_hres_enabled __read_mostly = 1; | |
511 | ||
512 | /* | |
513 | * Enable / Disable high resolution mode | |
514 | */ | |
515 | static int __init setup_hrtimer_hres(char *str) | |
516 | { | |
517 | if (!strcmp(str, "off")) | |
518 | hrtimer_hres_enabled = 0; | |
519 | else if (!strcmp(str, "on")) | |
520 | hrtimer_hres_enabled = 1; | |
521 | else | |
522 | return 0; | |
523 | return 1; | |
524 | } | |
525 | ||
526 | __setup("highres=", setup_hrtimer_hres); | |
527 | ||
528 | /* | |
529 | * hrtimer_high_res_enabled - query, if the highres mode is enabled | |
530 | */ | |
531 | static inline int hrtimer_is_hres_enabled(void) | |
532 | { | |
533 | return hrtimer_hres_enabled; | |
534 | } | |
535 | ||
536 | /* | |
537 | * Is the high resolution mode active ? | |
538 | */ | |
539 | static inline int hrtimer_hres_active(void) | |
540 | { | |
909ea964 | 541 | return __this_cpu_read(hrtimer_bases.hres_active); |
54cdfdb4 TG |
542 | } |
543 | ||
544 | /* | |
545 | * Reprogram the event source with checking both queues for the | |
546 | * next event | |
547 | * Called with interrupts disabled and base->lock held | |
548 | */ | |
7403f41f AC |
549 | static void |
550 | hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal) | |
54cdfdb4 TG |
551 | { |
552 | int i; | |
553 | struct hrtimer_clock_base *base = cpu_base->clock_base; | |
7403f41f | 554 | ktime_t expires, expires_next; |
54cdfdb4 | 555 | |
7403f41f | 556 | expires_next.tv64 = KTIME_MAX; |
54cdfdb4 TG |
557 | |
558 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { | |
559 | struct hrtimer *timer; | |
998adc3d | 560 | struct timerqueue_node *next; |
54cdfdb4 | 561 | |
998adc3d JS |
562 | next = timerqueue_getnext(&base->active); |
563 | if (!next) | |
54cdfdb4 | 564 | continue; |
998adc3d JS |
565 | timer = container_of(next, struct hrtimer, node); |
566 | ||
cc584b21 | 567 | expires = ktime_sub(hrtimer_get_expires(timer), base->offset); |
b0a9b511 TG |
568 | /* |
569 | * clock_was_set() has changed base->offset so the | |
570 | * result might be negative. Fix it up to prevent a | |
571 | * false positive in clockevents_program_event() | |
572 | */ | |
573 | if (expires.tv64 < 0) | |
574 | expires.tv64 = 0; | |
7403f41f AC |
575 | if (expires.tv64 < expires_next.tv64) |
576 | expires_next = expires; | |
54cdfdb4 TG |
577 | } |
578 | ||
7403f41f AC |
579 | if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64) |
580 | return; | |
581 | ||
582 | cpu_base->expires_next.tv64 = expires_next.tv64; | |
583 | ||
54cdfdb4 TG |
584 | if (cpu_base->expires_next.tv64 != KTIME_MAX) |
585 | tick_program_event(cpu_base->expires_next, 1); | |
586 | } | |
587 | ||
588 | /* | |
589 | * Shared reprogramming for clock_realtime and clock_monotonic | |
590 | * | |
591 | * When a timer is enqueued and expires earlier than the already enqueued | |
592 | * timers, we have to check, whether it expires earlier than the timer for | |
593 | * which the clock event device was armed. | |
594 | * | |
595 | * Called with interrupts disabled and base->cpu_base.lock held | |
596 | */ | |
597 | static int hrtimer_reprogram(struct hrtimer *timer, | |
598 | struct hrtimer_clock_base *base) | |
599 | { | |
41d2e494 | 600 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); |
cc584b21 | 601 | ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset); |
54cdfdb4 TG |
602 | int res; |
603 | ||
cc584b21 | 604 | WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0); |
63070a79 | 605 | |
54cdfdb4 TG |
606 | /* |
607 | * When the callback is running, we do not reprogram the clock event | |
608 | * device. The timer callback is either running on a different CPU or | |
3a4fa0a2 | 609 | * the callback is executed in the hrtimer_interrupt context. The |
54cdfdb4 TG |
610 | * reprogramming is handled either by the softirq, which called the |
611 | * callback or at the end of the hrtimer_interrupt. | |
612 | */ | |
613 | if (hrtimer_callback_running(timer)) | |
614 | return 0; | |
615 | ||
63070a79 TG |
616 | /* |
617 | * CLOCK_REALTIME timer might be requested with an absolute | |
618 | * expiry time which is less than base->offset. Nothing wrong | |
619 | * about that, just avoid to call into the tick code, which | |
620 | * has now objections against negative expiry values. | |
621 | */ | |
622 | if (expires.tv64 < 0) | |
623 | return -ETIME; | |
624 | ||
41d2e494 TG |
625 | if (expires.tv64 >= cpu_base->expires_next.tv64) |
626 | return 0; | |
627 | ||
628 | /* | |
629 | * If a hang was detected in the last timer interrupt then we | |
630 | * do not schedule a timer which is earlier than the expiry | |
631 | * which we enforced in the hang detection. We want the system | |
632 | * to make progress. | |
633 | */ | |
634 | if (cpu_base->hang_detected) | |
54cdfdb4 TG |
635 | return 0; |
636 | ||
637 | /* | |
638 | * Clockevents returns -ETIME, when the event was in the past. | |
639 | */ | |
640 | res = tick_program_event(expires, 0); | |
641 | if (!IS_ERR_VALUE(res)) | |
41d2e494 | 642 | cpu_base->expires_next = expires; |
54cdfdb4 TG |
643 | return res; |
644 | } | |
645 | ||
54cdfdb4 TG |
646 | /* |
647 | * Initialize the high resolution related parts of cpu_base | |
648 | */ | |
649 | static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) | |
650 | { | |
651 | base->expires_next.tv64 = KTIME_MAX; | |
652 | base->hres_active = 0; | |
54cdfdb4 TG |
653 | } |
654 | ||
54cdfdb4 TG |
655 | /* |
656 | * When High resolution timers are active, try to reprogram. Note, that in case | |
657 | * the state has HRTIMER_STATE_CALLBACK set, no reprogramming and no expiry | |
658 | * check happens. The timer gets enqueued into the rbtree. The reprogramming | |
659 | * and expiry check is done in the hrtimer_interrupt or in the softirq. | |
660 | */ | |
661 | static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, | |
b22affe0 | 662 | struct hrtimer_clock_base *base) |
54cdfdb4 | 663 | { |
b22affe0 | 664 | return base->cpu_base->hres_active && hrtimer_reprogram(timer, base); |
54cdfdb4 TG |
665 | } |
666 | ||
5baefd6d JS |
667 | static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base) |
668 | { | |
669 | ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset; | |
670 | ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset; | |
90adda98 | 671 | ktime_t *offs_tai = &base->clock_base[HRTIMER_BASE_TAI].offset; |
5baefd6d | 672 | |
90adda98 | 673 | return ktime_get_update_offsets(offs_real, offs_boot, offs_tai); |
5baefd6d JS |
674 | } |
675 | ||
9ec26907 TG |
676 | /* |
677 | * Retrigger next event is called after clock was set | |
678 | * | |
679 | * Called with interrupts disabled via on_each_cpu() | |
680 | */ | |
681 | static void retrigger_next_event(void *arg) | |
682 | { | |
683 | struct hrtimer_cpu_base *base = &__get_cpu_var(hrtimer_bases); | |
9ec26907 TG |
684 | |
685 | if (!hrtimer_hres_active()) | |
686 | return; | |
687 | ||
9ec26907 | 688 | raw_spin_lock(&base->lock); |
5baefd6d | 689 | hrtimer_update_base(base); |
9ec26907 TG |
690 | hrtimer_force_reprogram(base, 0); |
691 | raw_spin_unlock(&base->lock); | |
692 | } | |
b12a03ce | 693 | |
54cdfdb4 TG |
694 | /* |
695 | * Switch to high resolution mode | |
696 | */ | |
f8953856 | 697 | static int hrtimer_switch_to_hres(void) |
54cdfdb4 | 698 | { |
b12a03ce | 699 | int i, cpu = smp_processor_id(); |
820de5c3 | 700 | struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu); |
54cdfdb4 TG |
701 | unsigned long flags; |
702 | ||
703 | if (base->hres_active) | |
f8953856 | 704 | return 1; |
54cdfdb4 TG |
705 | |
706 | local_irq_save(flags); | |
707 | ||
708 | if (tick_init_highres()) { | |
709 | local_irq_restore(flags); | |
820de5c3 IM |
710 | printk(KERN_WARNING "Could not switch to high resolution " |
711 | "mode on CPU %d\n", cpu); | |
f8953856 | 712 | return 0; |
54cdfdb4 TG |
713 | } |
714 | base->hres_active = 1; | |
b12a03ce TG |
715 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) |
716 | base->clock_base[i].resolution = KTIME_HIGH_RES; | |
54cdfdb4 TG |
717 | |
718 | tick_setup_sched_timer(); | |
54cdfdb4 TG |
719 | /* "Retrigger" the interrupt to get things going */ |
720 | retrigger_next_event(NULL); | |
721 | local_irq_restore(flags); | |
f8953856 | 722 | return 1; |
54cdfdb4 TG |
723 | } |
724 | ||
5ec2481b TG |
725 | static void clock_was_set_work(struct work_struct *work) |
726 | { | |
727 | clock_was_set(); | |
728 | } | |
729 | ||
730 | static DECLARE_WORK(hrtimer_work, clock_was_set_work); | |
731 | ||
f55a6faa | 732 | /* |
5ec2481b TG |
733 | * Called from timekeeping and resume code to reprogramm the hrtimer |
734 | * interrupt device on all cpus. | |
f55a6faa JS |
735 | */ |
736 | void clock_was_set_delayed(void) | |
737 | { | |
5ec2481b | 738 | schedule_work(&hrtimer_work); |
f55a6faa JS |
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; } |
7403f41f AC |
746 | static inline void |
747 | hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { } | |
54cdfdb4 | 748 | static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, |
b22affe0 | 749 | struct hrtimer_clock_base *base) |
54cdfdb4 TG |
750 | { |
751 | return 0; | |
752 | } | |
54cdfdb4 | 753 | static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { } |
9ec26907 | 754 | static inline void retrigger_next_event(void *arg) { } |
54cdfdb4 TG |
755 | |
756 | #endif /* CONFIG_HIGH_RES_TIMERS */ | |
757 | ||
b12a03ce TG |
758 | /* |
759 | * Clock realtime was set | |
760 | * | |
761 | * Change the offset of the realtime clock vs. the monotonic | |
762 | * clock. | |
763 | * | |
764 | * We might have to reprogram the high resolution timer interrupt. On | |
765 | * SMP we call the architecture specific code to retrigger _all_ high | |
766 | * resolution timer interrupts. On UP we just disable interrupts and | |
767 | * call the high resolution interrupt code. | |
768 | */ | |
769 | void clock_was_set(void) | |
770 | { | |
90ff1f30 | 771 | #ifdef CONFIG_HIGH_RES_TIMERS |
b12a03ce TG |
772 | /* Retrigger the CPU local events everywhere */ |
773 | on_each_cpu(retrigger_next_event, NULL, 1); | |
9ec26907 TG |
774 | #endif |
775 | timerfd_clock_was_set(); | |
b12a03ce TG |
776 | } |
777 | ||
778 | /* | |
779 | * During resume we might have to reprogram the high resolution timer | |
7c4c3a0f DV |
780 | * interrupt on all online CPUs. However, all other CPUs will be |
781 | * stopped with IRQs interrupts disabled so the clock_was_set() call | |
5ec2481b | 782 | * must be deferred. |
b12a03ce TG |
783 | */ |
784 | void hrtimers_resume(void) | |
785 | { | |
786 | WARN_ONCE(!irqs_disabled(), | |
787 | KERN_INFO "hrtimers_resume() called with IRQs enabled!"); | |
788 | ||
5ec2481b | 789 | /* Retrigger on the local CPU */ |
b12a03ce | 790 | retrigger_next_event(NULL); |
5ec2481b TG |
791 | /* And schedule a retrigger for all others */ |
792 | clock_was_set_delayed(); | |
b12a03ce TG |
793 | } |
794 | ||
5f201907 | 795 | static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer) |
82f67cd9 | 796 | { |
5f201907 | 797 | #ifdef CONFIG_TIMER_STATS |
82f67cd9 IM |
798 | if (timer->start_site) |
799 | return; | |
5f201907 | 800 | timer->start_site = __builtin_return_address(0); |
82f67cd9 IM |
801 | memcpy(timer->start_comm, current->comm, TASK_COMM_LEN); |
802 | timer->start_pid = current->pid; | |
5f201907 HC |
803 | #endif |
804 | } | |
805 | ||
806 | static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer) | |
807 | { | |
808 | #ifdef CONFIG_TIMER_STATS | |
809 | timer->start_site = NULL; | |
810 | #endif | |
82f67cd9 | 811 | } |
5f201907 HC |
812 | |
813 | static inline void timer_stats_account_hrtimer(struct hrtimer *timer) | |
814 | { | |
815 | #ifdef CONFIG_TIMER_STATS | |
816 | if (likely(!timer_stats_active)) | |
817 | return; | |
818 | timer_stats_update_stats(timer, timer->start_pid, timer->start_site, | |
819 | timer->function, timer->start_comm, 0); | |
82f67cd9 | 820 | #endif |
5f201907 | 821 | } |
82f67cd9 | 822 | |
c0a31329 | 823 | /* |
6506f2aa | 824 | * Counterpart to lock_hrtimer_base above: |
c0a31329 TG |
825 | */ |
826 | static inline | |
827 | void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) | |
828 | { | |
ecb49d1a | 829 | raw_spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags); |
c0a31329 TG |
830 | } |
831 | ||
832 | /** | |
833 | * hrtimer_forward - forward the timer expiry | |
c0a31329 | 834 | * @timer: hrtimer to forward |
44f21475 | 835 | * @now: forward past this time |
c0a31329 TG |
836 | * @interval: the interval to forward |
837 | * | |
838 | * Forward the timer expiry so it will expire in the future. | |
8dca6f33 | 839 | * Returns the number of overruns. |
c0a31329 | 840 | */ |
4d672e7a | 841 | u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) |
c0a31329 | 842 | { |
4d672e7a | 843 | u64 orun = 1; |
44f21475 | 844 | ktime_t delta; |
c0a31329 | 845 | |
cc584b21 | 846 | delta = ktime_sub(now, hrtimer_get_expires(timer)); |
c0a31329 TG |
847 | |
848 | if (delta.tv64 < 0) | |
849 | return 0; | |
850 | ||
c9db4fa1 TG |
851 | if (interval.tv64 < timer->base->resolution.tv64) |
852 | interval.tv64 = timer->base->resolution.tv64; | |
853 | ||
c0a31329 | 854 | if (unlikely(delta.tv64 >= interval.tv64)) { |
df869b63 | 855 | s64 incr = ktime_to_ns(interval); |
c0a31329 TG |
856 | |
857 | orun = ktime_divns(delta, incr); | |
cc584b21 AV |
858 | hrtimer_add_expires_ns(timer, incr * orun); |
859 | if (hrtimer_get_expires_tv64(timer) > now.tv64) | |
c0a31329 TG |
860 | return orun; |
861 | /* | |
862 | * This (and the ktime_add() below) is the | |
863 | * correction for exact: | |
864 | */ | |
865 | orun++; | |
866 | } | |
cc584b21 | 867 | hrtimer_add_expires(timer, interval); |
c0a31329 TG |
868 | |
869 | return orun; | |
870 | } | |
6bdb6b62 | 871 | EXPORT_SYMBOL_GPL(hrtimer_forward); |
c0a31329 TG |
872 | |
873 | /* | |
874 | * enqueue_hrtimer - internal function to (re)start a timer | |
875 | * | |
876 | * The timer is inserted in expiry order. Insertion into the | |
877 | * red black tree is O(log(n)). Must hold the base lock. | |
a6037b61 PZ |
878 | * |
879 | * Returns 1 when the new timer is the leftmost timer in the tree. | |
c0a31329 | 880 | */ |
a6037b61 PZ |
881 | static int enqueue_hrtimer(struct hrtimer *timer, |
882 | struct hrtimer_clock_base *base) | |
c0a31329 | 883 | { |
c6a2a177 | 884 | debug_activate(timer); |
237fc6e7 | 885 | |
998adc3d | 886 | timerqueue_add(&base->active, &timer->node); |
ab8177bc | 887 | base->cpu_base->active_bases |= 1 << base->index; |
54cdfdb4 | 888 | |
303e967f TG |
889 | /* |
890 | * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the | |
891 | * state of a possibly running callback. | |
892 | */ | |
893 | timer->state |= HRTIMER_STATE_ENQUEUED; | |
a6037b61 | 894 | |
998adc3d | 895 | return (&timer->node == base->active.next); |
288867ec | 896 | } |
c0a31329 TG |
897 | |
898 | /* | |
899 | * __remove_hrtimer - internal function to remove a timer | |
900 | * | |
901 | * Caller must hold the base lock. | |
54cdfdb4 TG |
902 | * |
903 | * High resolution timer mode reprograms the clock event device when the | |
904 | * timer is the one which expires next. The caller can disable this by setting | |
905 | * reprogram to zero. This is useful, when the context does a reprogramming | |
906 | * anyway (e.g. timer interrupt) | |
c0a31329 | 907 | */ |
3c8aa39d | 908 | static void __remove_hrtimer(struct hrtimer *timer, |
303e967f | 909 | struct hrtimer_clock_base *base, |
54cdfdb4 | 910 | unsigned long newstate, int reprogram) |
c0a31329 | 911 | { |
27c9cd7e | 912 | struct timerqueue_node *next_timer; |
7403f41f AC |
913 | if (!(timer->state & HRTIMER_STATE_ENQUEUED)) |
914 | goto out; | |
915 | ||
27c9cd7e JO |
916 | next_timer = timerqueue_getnext(&base->active); |
917 | timerqueue_del(&base->active, &timer->node); | |
918 | if (&timer->node == next_timer) { | |
7403f41f AC |
919 | #ifdef CONFIG_HIGH_RES_TIMERS |
920 | /* Reprogram the clock event device. if enabled */ | |
921 | if (reprogram && hrtimer_hres_active()) { | |
922 | ktime_t expires; | |
923 | ||
924 | expires = ktime_sub(hrtimer_get_expires(timer), | |
925 | base->offset); | |
926 | if (base->cpu_base->expires_next.tv64 == expires.tv64) | |
927 | hrtimer_force_reprogram(base->cpu_base, 1); | |
54cdfdb4 | 928 | } |
7403f41f | 929 | #endif |
54cdfdb4 | 930 | } |
ab8177bc TG |
931 | if (!timerqueue_getnext(&base->active)) |
932 | base->cpu_base->active_bases &= ~(1 << base->index); | |
7403f41f | 933 | out: |
303e967f | 934 | timer->state = newstate; |
c0a31329 TG |
935 | } |
936 | ||
937 | /* | |
938 | * remove hrtimer, called with base lock held | |
939 | */ | |
940 | static inline int | |
3c8aa39d | 941 | remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) |
c0a31329 | 942 | { |
303e967f | 943 | if (hrtimer_is_queued(timer)) { |
f13d4f97 | 944 | unsigned long state; |
54cdfdb4 TG |
945 | int reprogram; |
946 | ||
947 | /* | |
948 | * Remove the timer and force reprogramming when high | |
949 | * resolution mode is active and the timer is on the current | |
950 | * CPU. If we remove a timer on another CPU, reprogramming is | |
951 | * skipped. The interrupt event on this CPU is fired and | |
952 | * reprogramming happens in the interrupt handler. This is a | |
953 | * rare case and less expensive than a smp call. | |
954 | */ | |
c6a2a177 | 955 | debug_deactivate(timer); |
82f67cd9 | 956 | timer_stats_hrtimer_clear_start_info(timer); |
54cdfdb4 | 957 | reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases); |
f13d4f97 SQ |
958 | /* |
959 | * We must preserve the CALLBACK state flag here, | |
960 | * otherwise we could move the timer base in | |
961 | * switch_hrtimer_base. | |
962 | */ | |
963 | state = timer->state & HRTIMER_STATE_CALLBACK; | |
964 | __remove_hrtimer(timer, base, state, reprogram); | |
c0a31329 TG |
965 | return 1; |
966 | } | |
967 | return 0; | |
968 | } | |
969 | ||
7f1e2ca9 PZ |
970 | int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, |
971 | unsigned long delta_ns, const enum hrtimer_mode mode, | |
972 | int wakeup) | |
c0a31329 | 973 | { |
3c8aa39d | 974 | struct hrtimer_clock_base *base, *new_base; |
c0a31329 | 975 | unsigned long flags; |
a6037b61 | 976 | int ret, leftmost; |
c0a31329 TG |
977 | |
978 | base = lock_hrtimer_base(timer, &flags); | |
979 | ||
980 | /* Remove an active timer from the queue: */ | |
981 | ret = remove_hrtimer(timer, base); | |
982 | ||
983 | /* Switch the timer base, if necessary: */ | |
597d0275 | 984 | new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED); |
c0a31329 | 985 | |
597d0275 | 986 | if (mode & HRTIMER_MODE_REL) { |
5a7780e7 | 987 | tim = ktime_add_safe(tim, new_base->get_time()); |
06027bdd IM |
988 | /* |
989 | * CONFIG_TIME_LOW_RES is a temporary way for architectures | |
990 | * to signal that they simply return xtime in | |
991 | * do_gettimeoffset(). In this case we want to round up by | |
992 | * resolution when starting a relative timer, to avoid short | |
993 | * timeouts. This will go away with the GTOD framework. | |
994 | */ | |
995 | #ifdef CONFIG_TIME_LOW_RES | |
5a7780e7 | 996 | tim = ktime_add_safe(tim, base->resolution); |
06027bdd IM |
997 | #endif |
998 | } | |
237fc6e7 | 999 | |
da8f2e17 | 1000 | hrtimer_set_expires_range_ns(timer, tim, delta_ns); |
c0a31329 | 1001 | |
82f67cd9 IM |
1002 | timer_stats_hrtimer_set_start_info(timer); |
1003 | ||
a6037b61 PZ |
1004 | leftmost = enqueue_hrtimer(timer, new_base); |
1005 | ||
935c631d IM |
1006 | /* |
1007 | * Only allow reprogramming if the new base is on this CPU. | |
1008 | * (it might still be on another CPU if the timer was pending) | |
a6037b61 PZ |
1009 | * |
1010 | * XXX send_remote_softirq() ? | |
935c631d | 1011 | */ |
b22affe0 LS |
1012 | if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases) |
1013 | && hrtimer_enqueue_reprogram(timer, new_base)) { | |
1014 | if (wakeup) { | |
1015 | /* | |
1016 | * We need to drop cpu_base->lock to avoid a | |
1017 | * lock ordering issue vs. rq->lock. | |
1018 | */ | |
1019 | raw_spin_unlock(&new_base->cpu_base->lock); | |
1020 | raise_softirq_irqoff(HRTIMER_SOFTIRQ); | |
1021 | local_irq_restore(flags); | |
1022 | return ret; | |
1023 | } else { | |
1024 | __raise_softirq_irqoff(HRTIMER_SOFTIRQ); | |
1025 | } | |
1026 | } | |
c0a31329 TG |
1027 | |
1028 | unlock_hrtimer_base(timer, &flags); | |
1029 | ||
1030 | return ret; | |
1031 | } | |
7f1e2ca9 PZ |
1032 | |
1033 | /** | |
1034 | * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU | |
1035 | * @timer: the timer to be added | |
1036 | * @tim: expiry time | |
1037 | * @delta_ns: "slack" range for the timer | |
8ffbc7d9 DD |
1038 | * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or |
1039 | * relative (HRTIMER_MODE_REL) | |
7f1e2ca9 PZ |
1040 | * |
1041 | * Returns: | |
1042 | * 0 on success | |
1043 | * 1 when the timer was active | |
1044 | */ | |
1045 | int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, | |
1046 | unsigned long delta_ns, const enum hrtimer_mode mode) | |
1047 | { | |
1048 | return __hrtimer_start_range_ns(timer, tim, delta_ns, mode, 1); | |
1049 | } | |
da8f2e17 AV |
1050 | EXPORT_SYMBOL_GPL(hrtimer_start_range_ns); |
1051 | ||
1052 | /** | |
e1dd7bc5 | 1053 | * hrtimer_start - (re)start an hrtimer on the current CPU |
da8f2e17 AV |
1054 | * @timer: the timer to be added |
1055 | * @tim: expiry time | |
8ffbc7d9 DD |
1056 | * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or |
1057 | * relative (HRTIMER_MODE_REL) | |
da8f2e17 AV |
1058 | * |
1059 | * Returns: | |
1060 | * 0 on success | |
1061 | * 1 when the timer was active | |
1062 | */ | |
1063 | int | |
1064 | hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) | |
1065 | { | |
7f1e2ca9 | 1066 | return __hrtimer_start_range_ns(timer, tim, 0, mode, 1); |
da8f2e17 | 1067 | } |
8d16b764 | 1068 | EXPORT_SYMBOL_GPL(hrtimer_start); |
c0a31329 | 1069 | |
da8f2e17 | 1070 | |
c0a31329 TG |
1071 | /** |
1072 | * hrtimer_try_to_cancel - try to deactivate a timer | |
c0a31329 TG |
1073 | * @timer: hrtimer to stop |
1074 | * | |
1075 | * Returns: | |
1076 | * 0 when the timer was not active | |
1077 | * 1 when the timer was active | |
1078 | * -1 when the timer is currently excuting the callback function and | |
fa9799e3 | 1079 | * cannot be stopped |
c0a31329 TG |
1080 | */ |
1081 | int hrtimer_try_to_cancel(struct hrtimer *timer) | |
1082 | { | |
3c8aa39d | 1083 | struct hrtimer_clock_base *base; |
c0a31329 TG |
1084 | unsigned long flags; |
1085 | int ret = -1; | |
1086 | ||
1087 | base = lock_hrtimer_base(timer, &flags); | |
1088 | ||
303e967f | 1089 | if (!hrtimer_callback_running(timer)) |
c0a31329 TG |
1090 | ret = remove_hrtimer(timer, base); |
1091 | ||
1092 | unlock_hrtimer_base(timer, &flags); | |
1093 | ||
1094 | return ret; | |
1095 | ||
1096 | } | |
8d16b764 | 1097 | EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel); |
c0a31329 TG |
1098 | |
1099 | /** | |
1100 | * hrtimer_cancel - cancel a timer and wait for the handler to finish. | |
c0a31329 TG |
1101 | * @timer: the timer to be cancelled |
1102 | * | |
1103 | * Returns: | |
1104 | * 0 when the timer was not active | |
1105 | * 1 when the timer was active | |
1106 | */ | |
1107 | int hrtimer_cancel(struct hrtimer *timer) | |
1108 | { | |
1109 | for (;;) { | |
1110 | int ret = hrtimer_try_to_cancel(timer); | |
1111 | ||
1112 | if (ret >= 0) | |
1113 | return ret; | |
5ef37b19 | 1114 | cpu_relax(); |
c0a31329 TG |
1115 | } |
1116 | } | |
8d16b764 | 1117 | EXPORT_SYMBOL_GPL(hrtimer_cancel); |
c0a31329 TG |
1118 | |
1119 | /** | |
1120 | * hrtimer_get_remaining - get remaining time for the timer | |
c0a31329 TG |
1121 | * @timer: the timer to read |
1122 | */ | |
1123 | ktime_t hrtimer_get_remaining(const struct hrtimer *timer) | |
1124 | { | |
c0a31329 TG |
1125 | unsigned long flags; |
1126 | ktime_t rem; | |
1127 | ||
b3bd3de6 | 1128 | lock_hrtimer_base(timer, &flags); |
cc584b21 | 1129 | rem = hrtimer_expires_remaining(timer); |
c0a31329 TG |
1130 | unlock_hrtimer_base(timer, &flags); |
1131 | ||
1132 | return rem; | |
1133 | } | |
8d16b764 | 1134 | EXPORT_SYMBOL_GPL(hrtimer_get_remaining); |
c0a31329 | 1135 | |
3451d024 | 1136 | #ifdef CONFIG_NO_HZ_COMMON |
69239749 TL |
1137 | /** |
1138 | * hrtimer_get_next_event - get the time until next expiry event | |
1139 | * | |
1140 | * Returns the delta to the next expiry event or KTIME_MAX if no timer | |
1141 | * is pending. | |
1142 | */ | |
1143 | ktime_t hrtimer_get_next_event(void) | |
1144 | { | |
3c8aa39d TG |
1145 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); |
1146 | struct hrtimer_clock_base *base = cpu_base->clock_base; | |
69239749 TL |
1147 | ktime_t delta, mindelta = { .tv64 = KTIME_MAX }; |
1148 | unsigned long flags; | |
1149 | int i; | |
1150 | ||
ecb49d1a | 1151 | raw_spin_lock_irqsave(&cpu_base->lock, flags); |
3c8aa39d | 1152 | |
54cdfdb4 TG |
1153 | if (!hrtimer_hres_active()) { |
1154 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { | |
1155 | struct hrtimer *timer; | |
998adc3d | 1156 | struct timerqueue_node *next; |
69239749 | 1157 | |
998adc3d JS |
1158 | next = timerqueue_getnext(&base->active); |
1159 | if (!next) | |
54cdfdb4 | 1160 | continue; |
3c8aa39d | 1161 | |
998adc3d | 1162 | timer = container_of(next, struct hrtimer, node); |
cc584b21 | 1163 | delta.tv64 = hrtimer_get_expires_tv64(timer); |
54cdfdb4 TG |
1164 | delta = ktime_sub(delta, base->get_time()); |
1165 | if (delta.tv64 < mindelta.tv64) | |
1166 | mindelta.tv64 = delta.tv64; | |
1167 | } | |
69239749 | 1168 | } |
3c8aa39d | 1169 | |
ecb49d1a | 1170 | raw_spin_unlock_irqrestore(&cpu_base->lock, flags); |
3c8aa39d | 1171 | |
69239749 TL |
1172 | if (mindelta.tv64 < 0) |
1173 | mindelta.tv64 = 0; | |
1174 | return mindelta; | |
1175 | } | |
1176 | #endif | |
1177 | ||
237fc6e7 TG |
1178 | static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, |
1179 | enum hrtimer_mode mode) | |
c0a31329 | 1180 | { |
3c8aa39d | 1181 | struct hrtimer_cpu_base *cpu_base; |
e06383db | 1182 | int base; |
c0a31329 | 1183 | |
7978672c GA |
1184 | memset(timer, 0, sizeof(struct hrtimer)); |
1185 | ||
3c8aa39d | 1186 | cpu_base = &__raw_get_cpu_var(hrtimer_bases); |
c0a31329 | 1187 | |
c9cb2e3d | 1188 | if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS) |
7978672c GA |
1189 | clock_id = CLOCK_MONOTONIC; |
1190 | ||
e06383db JS |
1191 | base = hrtimer_clockid_to_base(clock_id); |
1192 | timer->base = &cpu_base->clock_base[base]; | |
998adc3d | 1193 | timerqueue_init(&timer->node); |
82f67cd9 IM |
1194 | |
1195 | #ifdef CONFIG_TIMER_STATS | |
1196 | timer->start_site = NULL; | |
1197 | timer->start_pid = -1; | |
1198 | memset(timer->start_comm, 0, TASK_COMM_LEN); | |
1199 | #endif | |
c0a31329 | 1200 | } |
237fc6e7 TG |
1201 | |
1202 | /** | |
1203 | * hrtimer_init - initialize a timer to the given clock | |
1204 | * @timer: the timer to be initialized | |
1205 | * @clock_id: the clock to be used | |
1206 | * @mode: timer mode abs/rel | |
1207 | */ | |
1208 | void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, | |
1209 | enum hrtimer_mode mode) | |
1210 | { | |
c6a2a177 | 1211 | debug_init(timer, clock_id, mode); |
237fc6e7 TG |
1212 | __hrtimer_init(timer, clock_id, mode); |
1213 | } | |
8d16b764 | 1214 | EXPORT_SYMBOL_GPL(hrtimer_init); |
c0a31329 TG |
1215 | |
1216 | /** | |
1217 | * hrtimer_get_res - get the timer resolution for a clock | |
c0a31329 TG |
1218 | * @which_clock: which clock to query |
1219 | * @tp: pointer to timespec variable to store the resolution | |
1220 | * | |
72fd4a35 RD |
1221 | * Store the resolution of the clock selected by @which_clock in the |
1222 | * variable pointed to by @tp. | |
c0a31329 TG |
1223 | */ |
1224 | int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) | |
1225 | { | |
3c8aa39d | 1226 | struct hrtimer_cpu_base *cpu_base; |
e06383db | 1227 | int base = hrtimer_clockid_to_base(which_clock); |
c0a31329 | 1228 | |
3c8aa39d | 1229 | cpu_base = &__raw_get_cpu_var(hrtimer_bases); |
e06383db | 1230 | *tp = ktime_to_timespec(cpu_base->clock_base[base].resolution); |
c0a31329 TG |
1231 | |
1232 | return 0; | |
1233 | } | |
8d16b764 | 1234 | EXPORT_SYMBOL_GPL(hrtimer_get_res); |
c0a31329 | 1235 | |
c6a2a177 | 1236 | static void __run_hrtimer(struct hrtimer *timer, ktime_t *now) |
d3d74453 PZ |
1237 | { |
1238 | struct hrtimer_clock_base *base = timer->base; | |
1239 | struct hrtimer_cpu_base *cpu_base = base->cpu_base; | |
1240 | enum hrtimer_restart (*fn)(struct hrtimer *); | |
1241 | int restart; | |
1242 | ||
ca109491 PZ |
1243 | WARN_ON(!irqs_disabled()); |
1244 | ||
c6a2a177 | 1245 | debug_deactivate(timer); |
d3d74453 PZ |
1246 | __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0); |
1247 | timer_stats_account_hrtimer(timer); | |
d3d74453 | 1248 | fn = timer->function; |
ca109491 PZ |
1249 | |
1250 | /* | |
1251 | * Because we run timers from hardirq context, there is no chance | |
1252 | * they get migrated to another cpu, therefore its safe to unlock | |
1253 | * the timer base. | |
1254 | */ | |
ecb49d1a | 1255 | raw_spin_unlock(&cpu_base->lock); |
c6a2a177 | 1256 | trace_hrtimer_expire_entry(timer, now); |
ca109491 | 1257 | restart = fn(timer); |
c6a2a177 | 1258 | trace_hrtimer_expire_exit(timer); |
ecb49d1a | 1259 | raw_spin_lock(&cpu_base->lock); |
d3d74453 PZ |
1260 | |
1261 | /* | |
e3f1d883 TG |
1262 | * Note: We clear the CALLBACK bit after enqueue_hrtimer and |
1263 | * we do not reprogramm the event hardware. Happens either in | |
1264 | * hrtimer_start_range_ns() or in hrtimer_interrupt() | |
d3d74453 PZ |
1265 | */ |
1266 | if (restart != HRTIMER_NORESTART) { | |
1267 | BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); | |
a6037b61 | 1268 | enqueue_hrtimer(timer, base); |
d3d74453 | 1269 | } |
f13d4f97 SQ |
1270 | |
1271 | WARN_ON_ONCE(!(timer->state & HRTIMER_STATE_CALLBACK)); | |
1272 | ||
d3d74453 PZ |
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); | |
41d2e494 TG |
1285 | ktime_t expires_next, now, entry_time, delta; |
1286 | int i, retries = 0; | |
54cdfdb4 TG |
1287 | |
1288 | BUG_ON(!cpu_base->hres_active); | |
1289 | cpu_base->nr_events++; | |
1290 | dev->next_event.tv64 = KTIME_MAX; | |
1291 | ||
196951e9 | 1292 | raw_spin_lock(&cpu_base->lock); |
5baefd6d | 1293 | entry_time = now = hrtimer_update_base(cpu_base); |
41d2e494 | 1294 | retry: |
54cdfdb4 | 1295 | expires_next.tv64 = KTIME_MAX; |
6ff7041d TG |
1296 | /* |
1297 | * We set expires_next to KTIME_MAX here with cpu_base->lock | |
1298 | * held to prevent that a timer is enqueued in our queue via | |
1299 | * the migration code. This does not affect enqueueing of | |
1300 | * timers which run their callback and need to be requeued on | |
1301 | * this CPU. | |
1302 | */ | |
1303 | cpu_base->expires_next.tv64 = KTIME_MAX; | |
1304 | ||
54cdfdb4 | 1305 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { |
ab8177bc | 1306 | struct hrtimer_clock_base *base; |
998adc3d | 1307 | struct timerqueue_node *node; |
ab8177bc TG |
1308 | ktime_t basenow; |
1309 | ||
1310 | if (!(cpu_base->active_bases & (1 << i))) | |
1311 | continue; | |
54cdfdb4 | 1312 | |
ab8177bc | 1313 | base = cpu_base->clock_base + i; |
54cdfdb4 TG |
1314 | basenow = ktime_add(now, base->offset); |
1315 | ||
998adc3d | 1316 | while ((node = timerqueue_getnext(&base->active))) { |
54cdfdb4 TG |
1317 | struct hrtimer *timer; |
1318 | ||
998adc3d | 1319 | timer = container_of(node, struct hrtimer, node); |
54cdfdb4 | 1320 | |
654c8e0b AV |
1321 | /* |
1322 | * The immediate goal for using the softexpires is | |
1323 | * minimizing wakeups, not running timers at the | |
1324 | * earliest interrupt after their soft expiration. | |
1325 | * This allows us to avoid using a Priority Search | |
1326 | * Tree, which can answer a stabbing querry for | |
1327 | * overlapping intervals and instead use the simple | |
1328 | * BST we already have. | |
1329 | * We don't add extra wakeups by delaying timers that | |
1330 | * are right-of a not yet expired timer, because that | |
1331 | * timer will have to trigger a wakeup anyway. | |
1332 | */ | |
1333 | ||
1334 | if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) { | |
54cdfdb4 TG |
1335 | ktime_t expires; |
1336 | ||
cc584b21 | 1337 | expires = ktime_sub(hrtimer_get_expires(timer), |
54cdfdb4 | 1338 | base->offset); |
8f294b5a PB |
1339 | if (expires.tv64 < 0) |
1340 | expires.tv64 = KTIME_MAX; | |
54cdfdb4 TG |
1341 | if (expires.tv64 < expires_next.tv64) |
1342 | expires_next = expires; | |
1343 | break; | |
1344 | } | |
1345 | ||
c6a2a177 | 1346 | __run_hrtimer(timer, &basenow); |
54cdfdb4 | 1347 | } |
54cdfdb4 TG |
1348 | } |
1349 | ||
6ff7041d TG |
1350 | /* |
1351 | * Store the new expiry value so the migration code can verify | |
1352 | * against it. | |
1353 | */ | |
54cdfdb4 | 1354 | cpu_base->expires_next = expires_next; |
ecb49d1a | 1355 | raw_spin_unlock(&cpu_base->lock); |
54cdfdb4 TG |
1356 | |
1357 | /* Reprogramming necessary ? */ | |
41d2e494 TG |
1358 | if (expires_next.tv64 == KTIME_MAX || |
1359 | !tick_program_event(expires_next, 0)) { | |
1360 | cpu_base->hang_detected = 0; | |
1361 | return; | |
54cdfdb4 | 1362 | } |
41d2e494 TG |
1363 | |
1364 | /* | |
1365 | * The next timer was already expired due to: | |
1366 | * - tracing | |
1367 | * - long lasting callbacks | |
1368 | * - being scheduled away when running in a VM | |
1369 | * | |
1370 | * We need to prevent that we loop forever in the hrtimer | |
1371 | * interrupt routine. We give it 3 attempts to avoid | |
1372 | * overreacting on some spurious event. | |
5baefd6d JS |
1373 | * |
1374 | * Acquire base lock for updating the offsets and retrieving | |
1375 | * the current time. | |
41d2e494 | 1376 | */ |
196951e9 | 1377 | raw_spin_lock(&cpu_base->lock); |
5baefd6d | 1378 | now = hrtimer_update_base(cpu_base); |
41d2e494 TG |
1379 | cpu_base->nr_retries++; |
1380 | if (++retries < 3) | |
1381 | goto retry; | |
1382 | /* | |
1383 | * Give the system a chance to do something else than looping | |
1384 | * here. We stored the entry time, so we know exactly how long | |
1385 | * we spent here. We schedule the next event this amount of | |
1386 | * time away. | |
1387 | */ | |
1388 | cpu_base->nr_hangs++; | |
1389 | cpu_base->hang_detected = 1; | |
196951e9 | 1390 | raw_spin_unlock(&cpu_base->lock); |
41d2e494 TG |
1391 | delta = ktime_sub(now, entry_time); |
1392 | if (delta.tv64 > cpu_base->max_hang_time.tv64) | |
1393 | cpu_base->max_hang_time = delta; | |
1394 | /* | |
1395 | * Limit it to a sensible value as we enforce a longer | |
1396 | * delay. Give the CPU at least 100ms to catch up. | |
1397 | */ | |
1398 | if (delta.tv64 > 100 * NSEC_PER_MSEC) | |
1399 | expires_next = ktime_add_ns(now, 100 * NSEC_PER_MSEC); | |
1400 | else | |
1401 | expires_next = ktime_add(now, delta); | |
1402 | tick_program_event(expires_next, 1); | |
1403 | printk_once(KERN_WARNING "hrtimer: interrupt took %llu ns\n", | |
1404 | ktime_to_ns(delta)); | |
54cdfdb4 TG |
1405 | } |
1406 | ||
8bdec955 TG |
1407 | /* |
1408 | * local version of hrtimer_peek_ahead_timers() called with interrupts | |
1409 | * disabled. | |
1410 | */ | |
1411 | static void __hrtimer_peek_ahead_timers(void) | |
1412 | { | |
1413 | struct tick_device *td; | |
1414 | ||
1415 | if (!hrtimer_hres_active()) | |
1416 | return; | |
1417 | ||
1418 | td = &__get_cpu_var(tick_cpu_device); | |
1419 | if (td && td->evtdev) | |
1420 | hrtimer_interrupt(td->evtdev); | |
1421 | } | |
1422 | ||
2e94d1f7 AV |
1423 | /** |
1424 | * hrtimer_peek_ahead_timers -- run soft-expired timers now | |
1425 | * | |
1426 | * hrtimer_peek_ahead_timers will peek at the timer queue of | |
1427 | * the current cpu and check if there are any timers for which | |
1428 | * the soft expires time has passed. If any such timers exist, | |
1429 | * they are run immediately and then removed from the timer queue. | |
1430 | * | |
1431 | */ | |
1432 | void hrtimer_peek_ahead_timers(void) | |
1433 | { | |
643bdf68 | 1434 | unsigned long flags; |
dc4304f7 | 1435 | |
2e94d1f7 | 1436 | local_irq_save(flags); |
8bdec955 | 1437 | __hrtimer_peek_ahead_timers(); |
2e94d1f7 AV |
1438 | local_irq_restore(flags); |
1439 | } | |
1440 | ||
a6037b61 PZ |
1441 | static void run_hrtimer_softirq(struct softirq_action *h) |
1442 | { | |
1443 | hrtimer_peek_ahead_timers(); | |
1444 | } | |
1445 | ||
82c5b7b5 IM |
1446 | #else /* CONFIG_HIGH_RES_TIMERS */ |
1447 | ||
1448 | static inline void __hrtimer_peek_ahead_timers(void) { } | |
1449 | ||
1450 | #endif /* !CONFIG_HIGH_RES_TIMERS */ | |
82f67cd9 | 1451 | |
d3d74453 PZ |
1452 | /* |
1453 | * Called from timer softirq every jiffy, expire hrtimers: | |
1454 | * | |
1455 | * For HRT its the fall back code to run the softirq in the timer | |
1456 | * softirq context in case the hrtimer initialization failed or has | |
1457 | * not been done yet. | |
1458 | */ | |
1459 | void hrtimer_run_pending(void) | |
1460 | { | |
d3d74453 PZ |
1461 | if (hrtimer_hres_active()) |
1462 | return; | |
54cdfdb4 | 1463 | |
d3d74453 PZ |
1464 | /* |
1465 | * This _is_ ugly: We have to check in the softirq context, | |
1466 | * whether we can switch to highres and / or nohz mode. The | |
1467 | * clocksource switch happens in the timer interrupt with | |
1468 | * xtime_lock held. Notification from there only sets the | |
1469 | * check bit in the tick_oneshot code, otherwise we might | |
1470 | * deadlock vs. xtime_lock. | |
1471 | */ | |
1472 | if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())) | |
1473 | hrtimer_switch_to_hres(); | |
54cdfdb4 TG |
1474 | } |
1475 | ||
c0a31329 | 1476 | /* |
d3d74453 | 1477 | * Called from hardirq context every jiffy |
c0a31329 | 1478 | */ |
833883d9 | 1479 | void hrtimer_run_queues(void) |
c0a31329 | 1480 | { |
998adc3d | 1481 | struct timerqueue_node *node; |
833883d9 DS |
1482 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); |
1483 | struct hrtimer_clock_base *base; | |
1484 | int index, gettime = 1; | |
c0a31329 | 1485 | |
833883d9 | 1486 | if (hrtimer_hres_active()) |
3055adda DS |
1487 | return; |
1488 | ||
833883d9 DS |
1489 | for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) { |
1490 | base = &cpu_base->clock_base[index]; | |
b007c389 | 1491 | if (!timerqueue_getnext(&base->active)) |
d3d74453 | 1492 | continue; |
833883d9 | 1493 | |
d7cfb60c | 1494 | if (gettime) { |
833883d9 DS |
1495 | hrtimer_get_softirq_time(cpu_base); |
1496 | gettime = 0; | |
b75f7a51 | 1497 | } |
d3d74453 | 1498 | |
ecb49d1a | 1499 | raw_spin_lock(&cpu_base->lock); |
c0a31329 | 1500 | |
b007c389 | 1501 | while ((node = timerqueue_getnext(&base->active))) { |
833883d9 | 1502 | struct hrtimer *timer; |
54cdfdb4 | 1503 | |
998adc3d | 1504 | timer = container_of(node, struct hrtimer, node); |
cc584b21 AV |
1505 | if (base->softirq_time.tv64 <= |
1506 | hrtimer_get_expires_tv64(timer)) | |
833883d9 DS |
1507 | break; |
1508 | ||
c6a2a177 | 1509 | __run_hrtimer(timer, &base->softirq_time); |
833883d9 | 1510 | } |
ecb49d1a | 1511 | raw_spin_unlock(&cpu_base->lock); |
833883d9 | 1512 | } |
c0a31329 TG |
1513 | } |
1514 | ||
10c94ec1 TG |
1515 | /* |
1516 | * Sleep related functions: | |
1517 | */ | |
c9cb2e3d | 1518 | static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer) |
00362e33 TG |
1519 | { |
1520 | struct hrtimer_sleeper *t = | |
1521 | container_of(timer, struct hrtimer_sleeper, timer); | |
1522 | struct task_struct *task = t->task; | |
1523 | ||
1524 | t->task = NULL; | |
1525 | if (task) | |
1526 | wake_up_process(task); | |
1527 | ||
1528 | return HRTIMER_NORESTART; | |
1529 | } | |
1530 | ||
36c8b586 | 1531 | void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) |
00362e33 TG |
1532 | { |
1533 | sl->timer.function = hrtimer_wakeup; | |
1534 | sl->task = task; | |
1535 | } | |
2bc481cf | 1536 | EXPORT_SYMBOL_GPL(hrtimer_init_sleeper); |
00362e33 | 1537 | |
669d7868 | 1538 | static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode) |
432569bb | 1539 | { |
669d7868 | 1540 | hrtimer_init_sleeper(t, current); |
10c94ec1 | 1541 | |
432569bb RZ |
1542 | do { |
1543 | set_current_state(TASK_INTERRUPTIBLE); | |
cc584b21 | 1544 | hrtimer_start_expires(&t->timer, mode); |
37bb6cb4 PZ |
1545 | if (!hrtimer_active(&t->timer)) |
1546 | t->task = NULL; | |
432569bb | 1547 | |
54cdfdb4 | 1548 | if (likely(t->task)) |
b0f8c44f | 1549 | freezable_schedule(); |
432569bb | 1550 | |
669d7868 | 1551 | hrtimer_cancel(&t->timer); |
c9cb2e3d | 1552 | mode = HRTIMER_MODE_ABS; |
669d7868 TG |
1553 | |
1554 | } while (t->task && !signal_pending(current)); | |
432569bb | 1555 | |
3588a085 PZ |
1556 | __set_current_state(TASK_RUNNING); |
1557 | ||
669d7868 | 1558 | return t->task == NULL; |
10c94ec1 TG |
1559 | } |
1560 | ||
080344b9 ON |
1561 | static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp) |
1562 | { | |
1563 | struct timespec rmt; | |
1564 | ktime_t rem; | |
1565 | ||
cc584b21 | 1566 | rem = hrtimer_expires_remaining(timer); |
080344b9 ON |
1567 | if (rem.tv64 <= 0) |
1568 | return 0; | |
1569 | rmt = ktime_to_timespec(rem); | |
1570 | ||
1571 | if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) | |
1572 | return -EFAULT; | |
1573 | ||
1574 | return 1; | |
1575 | } | |
1576 | ||
1711ef38 | 1577 | long __sched hrtimer_nanosleep_restart(struct restart_block *restart) |
10c94ec1 | 1578 | { |
669d7868 | 1579 | struct hrtimer_sleeper t; |
080344b9 | 1580 | struct timespec __user *rmtp; |
237fc6e7 | 1581 | int ret = 0; |
10c94ec1 | 1582 | |
ab8177bc | 1583 | hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid, |
237fc6e7 | 1584 | HRTIMER_MODE_ABS); |
cc584b21 | 1585 | hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires); |
10c94ec1 | 1586 | |
c9cb2e3d | 1587 | if (do_nanosleep(&t, HRTIMER_MODE_ABS)) |
237fc6e7 | 1588 | goto out; |
10c94ec1 | 1589 | |
029a07e0 | 1590 | rmtp = restart->nanosleep.rmtp; |
432569bb | 1591 | if (rmtp) { |
237fc6e7 | 1592 | ret = update_rmtp(&t.timer, rmtp); |
080344b9 | 1593 | if (ret <= 0) |
237fc6e7 | 1594 | goto out; |
432569bb | 1595 | } |
10c94ec1 | 1596 | |
10c94ec1 | 1597 | /* The other values in restart are already filled in */ |
237fc6e7 TG |
1598 | ret = -ERESTART_RESTARTBLOCK; |
1599 | out: | |
1600 | destroy_hrtimer_on_stack(&t.timer); | |
1601 | return ret; | |
10c94ec1 TG |
1602 | } |
1603 | ||
080344b9 | 1604 | long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, |
10c94ec1 TG |
1605 | const enum hrtimer_mode mode, const clockid_t clockid) |
1606 | { | |
1607 | struct restart_block *restart; | |
669d7868 | 1608 | struct hrtimer_sleeper t; |
237fc6e7 | 1609 | int ret = 0; |
3bd01206 AV |
1610 | unsigned long slack; |
1611 | ||
1612 | slack = current->timer_slack_ns; | |
1613 | if (rt_task(current)) | |
1614 | slack = 0; | |
10c94ec1 | 1615 | |
237fc6e7 | 1616 | hrtimer_init_on_stack(&t.timer, clockid, mode); |
3bd01206 | 1617 | hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack); |
432569bb | 1618 | if (do_nanosleep(&t, mode)) |
237fc6e7 | 1619 | goto out; |
10c94ec1 | 1620 | |
7978672c | 1621 | /* Absolute timers do not update the rmtp value and restart: */ |
237fc6e7 TG |
1622 | if (mode == HRTIMER_MODE_ABS) { |
1623 | ret = -ERESTARTNOHAND; | |
1624 | goto out; | |
1625 | } | |
10c94ec1 | 1626 | |
432569bb | 1627 | if (rmtp) { |
237fc6e7 | 1628 | ret = update_rmtp(&t.timer, rmtp); |
080344b9 | 1629 | if (ret <= 0) |
237fc6e7 | 1630 | goto out; |
432569bb | 1631 | } |
10c94ec1 TG |
1632 | |
1633 | restart = ¤t_thread_info()->restart_block; | |
1711ef38 | 1634 | restart->fn = hrtimer_nanosleep_restart; |
ab8177bc | 1635 | restart->nanosleep.clockid = t.timer.base->clockid; |
029a07e0 | 1636 | restart->nanosleep.rmtp = rmtp; |
cc584b21 | 1637 | restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer); |
10c94ec1 | 1638 | |
237fc6e7 TG |
1639 | ret = -ERESTART_RESTARTBLOCK; |
1640 | out: | |
1641 | destroy_hrtimer_on_stack(&t.timer); | |
1642 | return ret; | |
10c94ec1 TG |
1643 | } |
1644 | ||
58fd3aa2 HC |
1645 | SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp, |
1646 | struct timespec __user *, rmtp) | |
6ba1b912 | 1647 | { |
080344b9 | 1648 | struct timespec tu; |
6ba1b912 TG |
1649 | |
1650 | if (copy_from_user(&tu, rqtp, sizeof(tu))) | |
1651 | return -EFAULT; | |
1652 | ||
1653 | if (!timespec_valid(&tu)) | |
1654 | return -EINVAL; | |
1655 | ||
080344b9 | 1656 | return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC); |
6ba1b912 TG |
1657 | } |
1658 | ||
c0a31329 TG |
1659 | /* |
1660 | * Functions related to boot-time initialization: | |
1661 | */ | |
0db0628d | 1662 | static void init_hrtimers_cpu(int cpu) |
c0a31329 | 1663 | { |
3c8aa39d | 1664 | struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); |
c0a31329 TG |
1665 | int i; |
1666 | ||
998adc3d | 1667 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { |
3c8aa39d | 1668 | cpu_base->clock_base[i].cpu_base = cpu_base; |
998adc3d JS |
1669 | timerqueue_init_head(&cpu_base->clock_base[i].active); |
1670 | } | |
3c8aa39d | 1671 | |
54cdfdb4 | 1672 | hrtimer_init_hres(cpu_base); |
c0a31329 TG |
1673 | } |
1674 | ||
1675 | #ifdef CONFIG_HOTPLUG_CPU | |
1676 | ||
ca109491 | 1677 | static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, |
37810659 | 1678 | struct hrtimer_clock_base *new_base) |
c0a31329 TG |
1679 | { |
1680 | struct hrtimer *timer; | |
998adc3d | 1681 | struct timerqueue_node *node; |
c0a31329 | 1682 | |
998adc3d JS |
1683 | while ((node = timerqueue_getnext(&old_base->active))) { |
1684 | timer = container_of(node, struct hrtimer, node); | |
54cdfdb4 | 1685 | BUG_ON(hrtimer_callback_running(timer)); |
c6a2a177 | 1686 | debug_deactivate(timer); |
b00c1a99 TG |
1687 | |
1688 | /* | |
1689 | * Mark it as STATE_MIGRATE not INACTIVE otherwise the | |
1690 | * timer could be seen as !active and just vanish away | |
1691 | * under us on another CPU | |
1692 | */ | |
1693 | __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0); | |
c0a31329 | 1694 | timer->base = new_base; |
54cdfdb4 | 1695 | /* |
e3f1d883 TG |
1696 | * Enqueue the timers on the new cpu. This does not |
1697 | * reprogram the event device in case the timer | |
1698 | * expires before the earliest on this CPU, but we run | |
1699 | * hrtimer_interrupt after we migrated everything to | |
1700 | * sort out already expired timers and reprogram the | |
1701 | * event device. | |
54cdfdb4 | 1702 | */ |
a6037b61 | 1703 | enqueue_hrtimer(timer, new_base); |
41e1022e | 1704 | |
b00c1a99 TG |
1705 | /* Clear the migration state bit */ |
1706 | timer->state &= ~HRTIMER_STATE_MIGRATE; | |
c0a31329 TG |
1707 | } |
1708 | } | |
1709 | ||
d5fd43c4 | 1710 | static void migrate_hrtimers(int scpu) |
c0a31329 | 1711 | { |
3c8aa39d | 1712 | struct hrtimer_cpu_base *old_base, *new_base; |
731a55ba | 1713 | int i; |
c0a31329 | 1714 | |
37810659 | 1715 | BUG_ON(cpu_online(scpu)); |
37810659 | 1716 | tick_cancel_sched_timer(scpu); |
731a55ba TG |
1717 | |
1718 | local_irq_disable(); | |
1719 | old_base = &per_cpu(hrtimer_bases, scpu); | |
1720 | new_base = &__get_cpu_var(hrtimer_bases); | |
d82f0b0f ON |
1721 | /* |
1722 | * The caller is globally serialized and nobody else | |
1723 | * takes two locks at once, deadlock is not possible. | |
1724 | */ | |
ecb49d1a TG |
1725 | raw_spin_lock(&new_base->lock); |
1726 | raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); | |
c0a31329 | 1727 | |
3c8aa39d | 1728 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { |
ca109491 | 1729 | migrate_hrtimer_list(&old_base->clock_base[i], |
37810659 | 1730 | &new_base->clock_base[i]); |
c0a31329 TG |
1731 | } |
1732 | ||
ecb49d1a TG |
1733 | raw_spin_unlock(&old_base->lock); |
1734 | raw_spin_unlock(&new_base->lock); | |
37810659 | 1735 | |
731a55ba TG |
1736 | /* Check, if we got expired work to do */ |
1737 | __hrtimer_peek_ahead_timers(); | |
1738 | local_irq_enable(); | |
c0a31329 | 1739 | } |
37810659 | 1740 | |
c0a31329 TG |
1741 | #endif /* CONFIG_HOTPLUG_CPU */ |
1742 | ||
0db0628d | 1743 | static int hrtimer_cpu_notify(struct notifier_block *self, |
c0a31329 TG |
1744 | unsigned long action, void *hcpu) |
1745 | { | |
b2e3c0ad | 1746 | int scpu = (long)hcpu; |
c0a31329 TG |
1747 | |
1748 | switch (action) { | |
1749 | ||
1750 | case CPU_UP_PREPARE: | |
8bb78442 | 1751 | case CPU_UP_PREPARE_FROZEN: |
37810659 | 1752 | init_hrtimers_cpu(scpu); |
c0a31329 TG |
1753 | break; |
1754 | ||
1755 | #ifdef CONFIG_HOTPLUG_CPU | |
94df7de0 SD |
1756 | case CPU_DYING: |
1757 | case CPU_DYING_FROZEN: | |
1758 | clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DYING, &scpu); | |
1759 | break; | |
c0a31329 | 1760 | case CPU_DEAD: |
8bb78442 | 1761 | case CPU_DEAD_FROZEN: |
b2e3c0ad | 1762 | { |
37810659 | 1763 | clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &scpu); |
d5fd43c4 | 1764 | migrate_hrtimers(scpu); |
c0a31329 | 1765 | break; |
b2e3c0ad | 1766 | } |
c0a31329 TG |
1767 | #endif |
1768 | ||
1769 | default: | |
1770 | break; | |
1771 | } | |
1772 | ||
1773 | return NOTIFY_OK; | |
1774 | } | |
1775 | ||
0db0628d | 1776 | static struct notifier_block hrtimers_nb = { |
c0a31329 TG |
1777 | .notifier_call = hrtimer_cpu_notify, |
1778 | }; | |
1779 | ||
1780 | void __init hrtimers_init(void) | |
1781 | { | |
1782 | hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE, | |
1783 | (void *)(long)smp_processor_id()); | |
1784 | register_cpu_notifier(&hrtimers_nb); | |
a6037b61 PZ |
1785 | #ifdef CONFIG_HIGH_RES_TIMERS |
1786 | open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq); | |
1787 | #endif | |
c0a31329 TG |
1788 | } |
1789 | ||
7bb67439 | 1790 | /** |
351b3f7a | 1791 | * schedule_hrtimeout_range_clock - sleep until timeout |
7bb67439 | 1792 | * @expires: timeout value (ktime_t) |
654c8e0b | 1793 | * @delta: slack in expires timeout (ktime_t) |
7bb67439 | 1794 | * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL |
351b3f7a | 1795 | * @clock: timer clock, CLOCK_MONOTONIC or CLOCK_REALTIME |
7bb67439 | 1796 | */ |
351b3f7a CE |
1797 | int __sched |
1798 | schedule_hrtimeout_range_clock(ktime_t *expires, unsigned long delta, | |
1799 | const enum hrtimer_mode mode, int clock) | |
7bb67439 AV |
1800 | { |
1801 | struct hrtimer_sleeper t; | |
1802 | ||
1803 | /* | |
1804 | * Optimize when a zero timeout value is given. It does not | |
1805 | * matter whether this is an absolute or a relative time. | |
1806 | */ | |
1807 | if (expires && !expires->tv64) { | |
1808 | __set_current_state(TASK_RUNNING); | |
1809 | return 0; | |
1810 | } | |
1811 | ||
1812 | /* | |
43b21013 | 1813 | * A NULL parameter means "infinite" |
7bb67439 AV |
1814 | */ |
1815 | if (!expires) { | |
1816 | schedule(); | |
1817 | __set_current_state(TASK_RUNNING); | |
1818 | return -EINTR; | |
1819 | } | |
1820 | ||
351b3f7a | 1821 | hrtimer_init_on_stack(&t.timer, clock, mode); |
654c8e0b | 1822 | hrtimer_set_expires_range_ns(&t.timer, *expires, delta); |
7bb67439 AV |
1823 | |
1824 | hrtimer_init_sleeper(&t, current); | |
1825 | ||
cc584b21 | 1826 | hrtimer_start_expires(&t.timer, mode); |
7bb67439 AV |
1827 | if (!hrtimer_active(&t.timer)) |
1828 | t.task = NULL; | |
1829 | ||
1830 | if (likely(t.task)) | |
1831 | schedule(); | |
1832 | ||
1833 | hrtimer_cancel(&t.timer); | |
1834 | destroy_hrtimer_on_stack(&t.timer); | |
1835 | ||
1836 | __set_current_state(TASK_RUNNING); | |
1837 | ||
1838 | return !t.task ? 0 : -EINTR; | |
1839 | } | |
351b3f7a CE |
1840 | |
1841 | /** | |
1842 | * schedule_hrtimeout_range - sleep until timeout | |
1843 | * @expires: timeout value (ktime_t) | |
1844 | * @delta: slack in expires timeout (ktime_t) | |
1845 | * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL | |
1846 | * | |
1847 | * Make the current task sleep until the given expiry time has | |
1848 | * elapsed. The routine will return immediately unless | |
1849 | * the current task state has been set (see set_current_state()). | |
1850 | * | |
1851 | * The @delta argument gives the kernel the freedom to schedule the | |
1852 | * actual wakeup to a time that is both power and performance friendly. | |
1853 | * The kernel give the normal best effort behavior for "@expires+@delta", | |
1854 | * but may decide to fire the timer earlier, but no earlier than @expires. | |
1855 | * | |
1856 | * You can set the task state as follows - | |
1857 | * | |
1858 | * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to | |
1859 | * pass before the routine returns. | |
1860 | * | |
1861 | * %TASK_INTERRUPTIBLE - the routine may return early if a signal is | |
1862 | * delivered to the current task. | |
1863 | * | |
1864 | * The current task state is guaranteed to be TASK_RUNNING when this | |
1865 | * routine returns. | |
1866 | * | |
1867 | * Returns 0 when the timer has expired otherwise -EINTR | |
1868 | */ | |
1869 | int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta, | |
1870 | const enum hrtimer_mode mode) | |
1871 | { | |
1872 | return schedule_hrtimeout_range_clock(expires, delta, mode, | |
1873 | CLOCK_MONOTONIC); | |
1874 | } | |
654c8e0b AV |
1875 | EXPORT_SYMBOL_GPL(schedule_hrtimeout_range); |
1876 | ||
1877 | /** | |
1878 | * schedule_hrtimeout - sleep until timeout | |
1879 | * @expires: timeout value (ktime_t) | |
1880 | * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL | |
1881 | * | |
1882 | * Make the current task sleep until the given expiry time has | |
1883 | * elapsed. The routine will return immediately unless | |
1884 | * the current task state has been set (see set_current_state()). | |
1885 | * | |
1886 | * You can set the task state as follows - | |
1887 | * | |
1888 | * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to | |
1889 | * pass before the routine returns. | |
1890 | * | |
1891 | * %TASK_INTERRUPTIBLE - the routine may return early if a signal is | |
1892 | * delivered to the current task. | |
1893 | * | |
1894 | * The current task state is guaranteed to be TASK_RUNNING when this | |
1895 | * routine returns. | |
1896 | * | |
1897 | * Returns 0 when the timer has expired otherwise -EINTR | |
1898 | */ | |
1899 | int __sched schedule_hrtimeout(ktime_t *expires, | |
1900 | const enum hrtimer_mode mode) | |
1901 | { | |
1902 | return schedule_hrtimeout_range(expires, 0, mode); | |
1903 | } | |
7bb67439 | 1904 | EXPORT_SYMBOL_GPL(schedule_hrtimeout); |