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> |
aab03e05 | 49 | #include <linux/sched/deadline.h> |
eea08f32 | 50 | #include <linux/timer.h> |
b0f8c44f | 51 | #include <linux/freezer.h> |
c0a31329 TG |
52 | |
53 | #include <asm/uaccess.h> | |
54 | ||
c6a2a177 XG |
55 | #include <trace/events/timer.h> |
56 | ||
c1797baf | 57 | #include "tick-internal.h" |
8b094cd0 | 58 | |
c0a31329 TG |
59 | /* |
60 | * The timer bases: | |
7978672c | 61 | * |
571af55a | 62 | * There are more clockids than hrtimer bases. Thus, we index |
e06383db JS |
63 | * into the timer bases by the hrtimer_base_type enum. When trying |
64 | * to reach a base using a clockid, hrtimer_clockid_to_base() | |
65 | * is used to convert from clockid to the proper hrtimer_base_type. | |
c0a31329 | 66 | */ |
54cdfdb4 | 67 | DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = |
c0a31329 | 68 | { |
84cc8fd2 | 69 | .lock = __RAW_SPIN_LOCK_UNLOCKED(hrtimer_bases.lock), |
887d9dc9 | 70 | .seq = SEQCNT_ZERO(hrtimer_bases.seq), |
3c8aa39d | 71 | .clock_base = |
c0a31329 | 72 | { |
3c8aa39d | 73 | { |
ab8177bc TG |
74 | .index = HRTIMER_BASE_MONOTONIC, |
75 | .clockid = CLOCK_MONOTONIC, | |
3c8aa39d | 76 | .get_time = &ktime_get, |
3c8aa39d | 77 | }, |
68fa61c0 TG |
78 | { |
79 | .index = HRTIMER_BASE_REALTIME, | |
80 | .clockid = CLOCK_REALTIME, | |
81 | .get_time = &ktime_get_real, | |
68fa61c0 | 82 | }, |
70a08cca | 83 | { |
ab8177bc TG |
84 | .index = HRTIMER_BASE_BOOTTIME, |
85 | .clockid = CLOCK_BOOTTIME, | |
70a08cca | 86 | .get_time = &ktime_get_boottime, |
70a08cca | 87 | }, |
90adda98 JS |
88 | { |
89 | .index = HRTIMER_BASE_TAI, | |
90 | .clockid = CLOCK_TAI, | |
91 | .get_time = &ktime_get_clocktai, | |
90adda98 | 92 | }, |
3c8aa39d | 93 | } |
c0a31329 TG |
94 | }; |
95 | ||
942c3c5c | 96 | static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = { |
ce31332d TG |
97 | [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME, |
98 | [CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC, | |
99 | [CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME, | |
90adda98 | 100 | [CLOCK_TAI] = HRTIMER_BASE_TAI, |
ce31332d | 101 | }; |
e06383db JS |
102 | |
103 | static inline int hrtimer_clockid_to_base(clockid_t clock_id) | |
104 | { | |
105 | return hrtimer_clock_to_base_table[clock_id]; | |
106 | } | |
107 | ||
c0a31329 TG |
108 | /* |
109 | * Functions and macros which are different for UP/SMP systems are kept in a | |
110 | * single place | |
111 | */ | |
112 | #ifdef CONFIG_SMP | |
113 | ||
887d9dc9 PZ |
114 | /* |
115 | * We require the migration_base for lock_hrtimer_base()/switch_hrtimer_base() | |
116 | * such that hrtimer_callback_running() can unconditionally dereference | |
117 | * timer->base->cpu_base | |
118 | */ | |
119 | static struct hrtimer_cpu_base migration_cpu_base = { | |
120 | .seq = SEQCNT_ZERO(migration_cpu_base), | |
121 | .clock_base = { { .cpu_base = &migration_cpu_base, }, }, | |
122 | }; | |
123 | ||
124 | #define migration_base migration_cpu_base.clock_base[0] | |
125 | ||
c0a31329 TG |
126 | /* |
127 | * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock | |
128 | * means that all timers which are tied to this base via timer->base are | |
129 | * locked, and the base itself is locked too. | |
130 | * | |
131 | * So __run_timers/migrate_timers can safely modify all timers which could | |
132 | * be found on the lists/queues. | |
133 | * | |
134 | * When the timer's base is locked, and the timer removed from list, it is | |
887d9dc9 PZ |
135 | * possible to set timer->base = &migration_base and drop the lock: the timer |
136 | * remains locked. | |
c0a31329 | 137 | */ |
3c8aa39d TG |
138 | static |
139 | struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer, | |
140 | unsigned long *flags) | |
c0a31329 | 141 | { |
3c8aa39d | 142 | struct hrtimer_clock_base *base; |
c0a31329 TG |
143 | |
144 | for (;;) { | |
145 | base = timer->base; | |
887d9dc9 | 146 | if (likely(base != &migration_base)) { |
ecb49d1a | 147 | raw_spin_lock_irqsave(&base->cpu_base->lock, *flags); |
c0a31329 TG |
148 | if (likely(base == timer->base)) |
149 | return base; | |
150 | /* The timer has migrated to another CPU: */ | |
ecb49d1a | 151 | raw_spin_unlock_irqrestore(&base->cpu_base->lock, *flags); |
c0a31329 TG |
152 | } |
153 | cpu_relax(); | |
154 | } | |
155 | } | |
156 | ||
6ff7041d TG |
157 | /* |
158 | * With HIGHRES=y we do not migrate the timer when it is expiring | |
159 | * before the next event on the target cpu because we cannot reprogram | |
160 | * the target cpu hardware and we would cause it to fire late. | |
161 | * | |
162 | * Called with cpu_base->lock of target cpu held. | |
163 | */ | |
164 | static int | |
165 | hrtimer_check_target(struct hrtimer *timer, struct hrtimer_clock_base *new_base) | |
166 | { | |
167 | #ifdef CONFIG_HIGH_RES_TIMERS | |
168 | ktime_t expires; | |
169 | ||
170 | if (!new_base->cpu_base->hres_active) | |
171 | return 0; | |
172 | ||
173 | expires = ktime_sub(hrtimer_get_expires(timer), new_base->offset); | |
174 | return expires.tv64 <= new_base->cpu_base->expires_next.tv64; | |
175 | #else | |
176 | return 0; | |
177 | #endif | |
178 | } | |
179 | ||
bc7a34b8 TG |
180 | #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON) |
181 | static inline | |
182 | struct hrtimer_cpu_base *get_target_base(struct hrtimer_cpu_base *base, | |
183 | int pinned) | |
184 | { | |
185 | if (pinned || !base->migration_enabled) | |
662b3e19 | 186 | return base; |
bc7a34b8 TG |
187 | return &per_cpu(hrtimer_bases, get_nohz_timer_target()); |
188 | } | |
189 | #else | |
190 | static inline | |
191 | struct hrtimer_cpu_base *get_target_base(struct hrtimer_cpu_base *base, | |
192 | int pinned) | |
193 | { | |
662b3e19 | 194 | return base; |
bc7a34b8 TG |
195 | } |
196 | #endif | |
197 | ||
c0a31329 | 198 | /* |
b48362d8 FW |
199 | * We switch the timer base to a power-optimized selected CPU target, |
200 | * if: | |
201 | * - NO_HZ_COMMON is enabled | |
202 | * - timer migration is enabled | |
203 | * - the timer callback is not running | |
204 | * - the timer is not the first expiring timer on the new target | |
205 | * | |
206 | * If one of the above requirements is not fulfilled we move the timer | |
207 | * to the current CPU or leave it on the previously assigned CPU if | |
208 | * the timer callback is currently running. | |
c0a31329 | 209 | */ |
3c8aa39d | 210 | static inline struct hrtimer_clock_base * |
597d0275 AB |
211 | switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base, |
212 | int pinned) | |
c0a31329 | 213 | { |
b48362d8 | 214 | struct hrtimer_cpu_base *new_cpu_base, *this_cpu_base; |
3c8aa39d | 215 | struct hrtimer_clock_base *new_base; |
ab8177bc | 216 | int basenum = base->index; |
c0a31329 | 217 | |
b48362d8 FW |
218 | this_cpu_base = this_cpu_ptr(&hrtimer_bases); |
219 | new_cpu_base = get_target_base(this_cpu_base, pinned); | |
eea08f32 | 220 | again: |
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 | ||
887d9dc9 PZ |
236 | /* See the comment in lock_hrtimer_base() */ |
237 | timer->base = &migration_base; | |
ecb49d1a TG |
238 | raw_spin_unlock(&base->cpu_base->lock); |
239 | raw_spin_lock(&new_base->cpu_base->lock); | |
eea08f32 | 240 | |
b48362d8 | 241 | if (new_cpu_base != this_cpu_base && |
bc7a34b8 | 242 | hrtimer_check_target(timer, new_base)) { |
ecb49d1a TG |
243 | raw_spin_unlock(&new_base->cpu_base->lock); |
244 | raw_spin_lock(&base->cpu_base->lock); | |
b48362d8 | 245 | new_cpu_base = this_cpu_base; |
6ff7041d TG |
246 | timer->base = base; |
247 | goto again; | |
eea08f32 | 248 | } |
c0a31329 | 249 | timer->base = new_base; |
012a45e3 | 250 | } else { |
b48362d8 | 251 | if (new_cpu_base != this_cpu_base && |
bc7a34b8 | 252 | hrtimer_check_target(timer, new_base)) { |
b48362d8 | 253 | new_cpu_base = this_cpu_base; |
012a45e3 LM |
254 | goto again; |
255 | } | |
c0a31329 TG |
256 | } |
257 | return new_base; | |
258 | } | |
259 | ||
260 | #else /* CONFIG_SMP */ | |
261 | ||
3c8aa39d | 262 | static inline struct hrtimer_clock_base * |
c0a31329 TG |
263 | lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) |
264 | { | |
3c8aa39d | 265 | struct hrtimer_clock_base *base = timer->base; |
c0a31329 | 266 | |
ecb49d1a | 267 | raw_spin_lock_irqsave(&base->cpu_base->lock, *flags); |
c0a31329 TG |
268 | |
269 | return base; | |
270 | } | |
271 | ||
eea08f32 | 272 | # define switch_hrtimer_base(t, b, p) (b) |
c0a31329 TG |
273 | |
274 | #endif /* !CONFIG_SMP */ | |
275 | ||
276 | /* | |
277 | * Functions for the union type storage format of ktime_t which are | |
278 | * too large for inlining: | |
279 | */ | |
280 | #if BITS_PER_LONG < 64 | |
c0a31329 TG |
281 | /* |
282 | * Divide a ktime value by a nanosecond value | |
283 | */ | |
f7bcb70e | 284 | s64 __ktime_divns(const ktime_t kt, s64 div) |
c0a31329 | 285 | { |
c0a31329 | 286 | int sft = 0; |
f7bcb70e JS |
287 | s64 dclc; |
288 | u64 tmp; | |
c0a31329 | 289 | |
900cfa46 | 290 | dclc = ktime_to_ns(kt); |
f7bcb70e JS |
291 | tmp = dclc < 0 ? -dclc : dclc; |
292 | ||
c0a31329 TG |
293 | /* Make sure the divisor is less than 2^32: */ |
294 | while (div >> 32) { | |
295 | sft++; | |
296 | div >>= 1; | |
297 | } | |
f7bcb70e JS |
298 | tmp >>= sft; |
299 | do_div(tmp, (unsigned long) div); | |
300 | return dclc < 0 ? -tmp : tmp; | |
c0a31329 | 301 | } |
8b618628 | 302 | EXPORT_SYMBOL_GPL(__ktime_divns); |
c0a31329 TG |
303 | #endif /* BITS_PER_LONG >= 64 */ |
304 | ||
5a7780e7 TG |
305 | /* |
306 | * Add two ktime values and do a safety check for overflow: | |
307 | */ | |
308 | ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs) | |
309 | { | |
310 | ktime_t res = ktime_add(lhs, rhs); | |
311 | ||
312 | /* | |
313 | * We use KTIME_SEC_MAX here, the maximum timeout which we can | |
314 | * return to user space in a timespec: | |
315 | */ | |
316 | if (res.tv64 < 0 || res.tv64 < lhs.tv64 || res.tv64 < rhs.tv64) | |
317 | res = ktime_set(KTIME_SEC_MAX, 0); | |
318 | ||
319 | return res; | |
320 | } | |
321 | ||
8daa21e6 AB |
322 | EXPORT_SYMBOL_GPL(ktime_add_safe); |
323 | ||
237fc6e7 TG |
324 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS |
325 | ||
326 | static struct debug_obj_descr hrtimer_debug_descr; | |
327 | ||
99777288 SG |
328 | static void *hrtimer_debug_hint(void *addr) |
329 | { | |
330 | return ((struct hrtimer *) addr)->function; | |
331 | } | |
332 | ||
237fc6e7 TG |
333 | /* |
334 | * fixup_init is called when: | |
335 | * - an active object is initialized | |
336 | */ | |
337 | static int hrtimer_fixup_init(void *addr, enum debug_obj_state state) | |
338 | { | |
339 | struct hrtimer *timer = addr; | |
340 | ||
341 | switch (state) { | |
342 | case ODEBUG_STATE_ACTIVE: | |
343 | hrtimer_cancel(timer); | |
344 | debug_object_init(timer, &hrtimer_debug_descr); | |
345 | return 1; | |
346 | default: | |
347 | return 0; | |
348 | } | |
349 | } | |
350 | ||
351 | /* | |
352 | * fixup_activate is called when: | |
353 | * - an active object is activated | |
354 | * - an unknown object is activated (might be a statically initialized object) | |
355 | */ | |
356 | static int hrtimer_fixup_activate(void *addr, enum debug_obj_state state) | |
357 | { | |
358 | switch (state) { | |
359 | ||
360 | case ODEBUG_STATE_NOTAVAILABLE: | |
361 | WARN_ON_ONCE(1); | |
362 | return 0; | |
363 | ||
364 | case ODEBUG_STATE_ACTIVE: | |
365 | WARN_ON(1); | |
366 | ||
367 | default: | |
368 | return 0; | |
369 | } | |
370 | } | |
371 | ||
372 | /* | |
373 | * fixup_free is called when: | |
374 | * - an active object is freed | |
375 | */ | |
376 | static int hrtimer_fixup_free(void *addr, enum debug_obj_state state) | |
377 | { | |
378 | struct hrtimer *timer = addr; | |
379 | ||
380 | switch (state) { | |
381 | case ODEBUG_STATE_ACTIVE: | |
382 | hrtimer_cancel(timer); | |
383 | debug_object_free(timer, &hrtimer_debug_descr); | |
384 | return 1; | |
385 | default: | |
386 | return 0; | |
387 | } | |
388 | } | |
389 | ||
390 | static struct debug_obj_descr hrtimer_debug_descr = { | |
391 | .name = "hrtimer", | |
99777288 | 392 | .debug_hint = hrtimer_debug_hint, |
237fc6e7 TG |
393 | .fixup_init = hrtimer_fixup_init, |
394 | .fixup_activate = hrtimer_fixup_activate, | |
395 | .fixup_free = hrtimer_fixup_free, | |
396 | }; | |
397 | ||
398 | static inline void debug_hrtimer_init(struct hrtimer *timer) | |
399 | { | |
400 | debug_object_init(timer, &hrtimer_debug_descr); | |
401 | } | |
402 | ||
403 | static inline void debug_hrtimer_activate(struct hrtimer *timer) | |
404 | { | |
405 | debug_object_activate(timer, &hrtimer_debug_descr); | |
406 | } | |
407 | ||
408 | static inline void debug_hrtimer_deactivate(struct hrtimer *timer) | |
409 | { | |
410 | debug_object_deactivate(timer, &hrtimer_debug_descr); | |
411 | } | |
412 | ||
413 | static inline void debug_hrtimer_free(struct hrtimer *timer) | |
414 | { | |
415 | debug_object_free(timer, &hrtimer_debug_descr); | |
416 | } | |
417 | ||
418 | static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, | |
419 | enum hrtimer_mode mode); | |
420 | ||
421 | void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id, | |
422 | enum hrtimer_mode mode) | |
423 | { | |
424 | debug_object_init_on_stack(timer, &hrtimer_debug_descr); | |
425 | __hrtimer_init(timer, clock_id, mode); | |
426 | } | |
2bc481cf | 427 | EXPORT_SYMBOL_GPL(hrtimer_init_on_stack); |
237fc6e7 TG |
428 | |
429 | void destroy_hrtimer_on_stack(struct hrtimer *timer) | |
430 | { | |
431 | debug_object_free(timer, &hrtimer_debug_descr); | |
432 | } | |
433 | ||
434 | #else | |
435 | static inline void debug_hrtimer_init(struct hrtimer *timer) { } | |
436 | static inline void debug_hrtimer_activate(struct hrtimer *timer) { } | |
437 | static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { } | |
438 | #endif | |
439 | ||
c6a2a177 XG |
440 | static inline void |
441 | debug_init(struct hrtimer *timer, clockid_t clockid, | |
442 | enum hrtimer_mode mode) | |
443 | { | |
444 | debug_hrtimer_init(timer); | |
445 | trace_hrtimer_init(timer, clockid, mode); | |
446 | } | |
447 | ||
448 | static inline void debug_activate(struct hrtimer *timer) | |
449 | { | |
450 | debug_hrtimer_activate(timer); | |
451 | trace_hrtimer_start(timer); | |
452 | } | |
453 | ||
454 | static inline void debug_deactivate(struct hrtimer *timer) | |
455 | { | |
456 | debug_hrtimer_deactivate(timer); | |
457 | trace_hrtimer_cancel(timer); | |
458 | } | |
459 | ||
9bc74919 | 460 | #if defined(CONFIG_NO_HZ_COMMON) || defined(CONFIG_HIGH_RES_TIMERS) |
895bdfa7 TG |
461 | static inline void hrtimer_update_next_timer(struct hrtimer_cpu_base *cpu_base, |
462 | struct hrtimer *timer) | |
463 | { | |
464 | #ifdef CONFIG_HIGH_RES_TIMERS | |
465 | cpu_base->next_timer = timer; | |
466 | #endif | |
467 | } | |
468 | ||
4ebbda52 | 469 | static ktime_t __hrtimer_get_next_event(struct hrtimer_cpu_base *cpu_base) |
9bc74919 TG |
470 | { |
471 | struct hrtimer_clock_base *base = cpu_base->clock_base; | |
472 | ktime_t expires, expires_next = { .tv64 = KTIME_MAX }; | |
34aee88a | 473 | unsigned int active = cpu_base->active_bases; |
9bc74919 | 474 | |
895bdfa7 | 475 | hrtimer_update_next_timer(cpu_base, NULL); |
34aee88a | 476 | for (; active; base++, active >>= 1) { |
9bc74919 TG |
477 | struct timerqueue_node *next; |
478 | struct hrtimer *timer; | |
479 | ||
34aee88a | 480 | if (!(active & 0x01)) |
9bc74919 TG |
481 | continue; |
482 | ||
34aee88a | 483 | next = timerqueue_getnext(&base->active); |
9bc74919 TG |
484 | timer = container_of(next, struct hrtimer, node); |
485 | expires = ktime_sub(hrtimer_get_expires(timer), base->offset); | |
895bdfa7 | 486 | if (expires.tv64 < expires_next.tv64) { |
9bc74919 | 487 | expires_next = expires; |
895bdfa7 TG |
488 | hrtimer_update_next_timer(cpu_base, timer); |
489 | } | |
9bc74919 TG |
490 | } |
491 | /* | |
492 | * clock_was_set() might have changed base->offset of any of | |
493 | * the clock bases so the result might be negative. Fix it up | |
494 | * to prevent a false positive in clockevents_program_event(). | |
495 | */ | |
496 | if (expires_next.tv64 < 0) | |
497 | expires_next.tv64 = 0; | |
498 | return expires_next; | |
499 | } | |
500 | #endif | |
501 | ||
21d6d52a TG |
502 | static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base) |
503 | { | |
504 | ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset; | |
505 | ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset; | |
506 | ktime_t *offs_tai = &base->clock_base[HRTIMER_BASE_TAI].offset; | |
507 | ||
868a3e91 TG |
508 | return ktime_get_update_offsets_now(&base->clock_was_set_seq, |
509 | offs_real, offs_boot, offs_tai); | |
21d6d52a TG |
510 | } |
511 | ||
54cdfdb4 TG |
512 | /* High resolution timer related functions */ |
513 | #ifdef CONFIG_HIGH_RES_TIMERS | |
514 | ||
515 | /* | |
516 | * High resolution timer enabled ? | |
517 | */ | |
4cc7ecb7 | 518 | static bool hrtimer_hres_enabled __read_mostly = true; |
398ca17f TG |
519 | unsigned int hrtimer_resolution __read_mostly = LOW_RES_NSEC; |
520 | EXPORT_SYMBOL_GPL(hrtimer_resolution); | |
54cdfdb4 TG |
521 | |
522 | /* | |
523 | * Enable / Disable high resolution mode | |
524 | */ | |
525 | static int __init setup_hrtimer_hres(char *str) | |
526 | { | |
4cc7ecb7 | 527 | return (kstrtobool(str, &hrtimer_hres_enabled) == 0); |
54cdfdb4 TG |
528 | } |
529 | ||
530 | __setup("highres=", setup_hrtimer_hres); | |
531 | ||
532 | /* | |
533 | * hrtimer_high_res_enabled - query, if the highres mode is enabled | |
534 | */ | |
535 | static inline int hrtimer_is_hres_enabled(void) | |
536 | { | |
537 | return hrtimer_hres_enabled; | |
538 | } | |
539 | ||
540 | /* | |
541 | * Is the high resolution mode active ? | |
542 | */ | |
e19ffe8b TG |
543 | static inline int __hrtimer_hres_active(struct hrtimer_cpu_base *cpu_base) |
544 | { | |
545 | return cpu_base->hres_active; | |
546 | } | |
547 | ||
54cdfdb4 TG |
548 | static inline int hrtimer_hres_active(void) |
549 | { | |
e19ffe8b | 550 | return __hrtimer_hres_active(this_cpu_ptr(&hrtimer_bases)); |
54cdfdb4 TG |
551 | } |
552 | ||
553 | /* | |
554 | * Reprogram the event source with checking both queues for the | |
555 | * next event | |
556 | * Called with interrupts disabled and base->lock held | |
557 | */ | |
7403f41f AC |
558 | static void |
559 | hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal) | |
54cdfdb4 | 560 | { |
21d6d52a TG |
561 | ktime_t expires_next; |
562 | ||
563 | if (!cpu_base->hres_active) | |
564 | return; | |
565 | ||
566 | expires_next = __hrtimer_get_next_event(cpu_base); | |
54cdfdb4 | 567 | |
7403f41f AC |
568 | if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64) |
569 | return; | |
570 | ||
571 | cpu_base->expires_next.tv64 = expires_next.tv64; | |
572 | ||
6c6c0d5a SH |
573 | /* |
574 | * If a hang was detected in the last timer interrupt then we | |
575 | * leave the hang delay active in the hardware. We want the | |
576 | * system to make progress. That also prevents the following | |
577 | * scenario: | |
578 | * T1 expires 50ms from now | |
579 | * T2 expires 5s from now | |
580 | * | |
581 | * T1 is removed, so this code is called and would reprogram | |
582 | * the hardware to 5s from now. Any hrtimer_start after that | |
583 | * will not reprogram the hardware due to hang_detected being | |
584 | * set. So we'd effectivly block all timers until the T2 event | |
585 | * fires. | |
586 | */ | |
587 | if (cpu_base->hang_detected) | |
588 | return; | |
589 | ||
d2540875 | 590 | tick_program_event(cpu_base->expires_next, 1); |
54cdfdb4 TG |
591 | } |
592 | ||
593 | /* | |
54cdfdb4 TG |
594 | * When a timer is enqueued and expires earlier than the already enqueued |
595 | * timers, we have to check, whether it expires earlier than the timer for | |
596 | * which the clock event device was armed. | |
597 | * | |
598 | * Called with interrupts disabled and base->cpu_base.lock held | |
599 | */ | |
c6eb3f70 TG |
600 | static void hrtimer_reprogram(struct hrtimer *timer, |
601 | struct hrtimer_clock_base *base) | |
54cdfdb4 | 602 | { |
dc5df73b | 603 | struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); |
cc584b21 | 604 | ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset); |
54cdfdb4 | 605 | |
cc584b21 | 606 | WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0); |
63070a79 | 607 | |
54cdfdb4 | 608 | /* |
c6eb3f70 TG |
609 | * If the timer is not on the current cpu, we cannot reprogram |
610 | * the other cpus clock event device. | |
54cdfdb4 | 611 | */ |
c6eb3f70 TG |
612 | if (base->cpu_base != cpu_base) |
613 | return; | |
614 | ||
615 | /* | |
616 | * If the hrtimer interrupt is running, then it will | |
617 | * reevaluate the clock bases and reprogram the clock event | |
618 | * device. The callbacks are always executed in hard interrupt | |
619 | * context so we don't need an extra check for a running | |
620 | * callback. | |
621 | */ | |
622 | if (cpu_base->in_hrtirq) | |
623 | return; | |
54cdfdb4 | 624 | |
63070a79 TG |
625 | /* |
626 | * CLOCK_REALTIME timer might be requested with an absolute | |
c6eb3f70 | 627 | * expiry time which is less than base->offset. Set it to 0. |
63070a79 TG |
628 | */ |
629 | if (expires.tv64 < 0) | |
c6eb3f70 | 630 | expires.tv64 = 0; |
63070a79 | 631 | |
41d2e494 | 632 | if (expires.tv64 >= cpu_base->expires_next.tv64) |
c6eb3f70 | 633 | return; |
41d2e494 | 634 | |
c6eb3f70 | 635 | /* Update the pointer to the next expiring timer */ |
895bdfa7 | 636 | cpu_base->next_timer = timer; |
9bc74919 | 637 | |
41d2e494 TG |
638 | /* |
639 | * If a hang was detected in the last timer interrupt then we | |
640 | * do not schedule a timer which is earlier than the expiry | |
641 | * which we enforced in the hang detection. We want the system | |
642 | * to make progress. | |
643 | */ | |
644 | if (cpu_base->hang_detected) | |
c6eb3f70 | 645 | return; |
54cdfdb4 TG |
646 | |
647 | /* | |
c6eb3f70 TG |
648 | * Program the timer hardware. We enforce the expiry for |
649 | * events which are already in the past. | |
54cdfdb4 | 650 | */ |
c6eb3f70 TG |
651 | cpu_base->expires_next = expires; |
652 | tick_program_event(expires, 1); | |
54cdfdb4 TG |
653 | } |
654 | ||
54cdfdb4 TG |
655 | /* |
656 | * Initialize the high resolution related parts of cpu_base | |
657 | */ | |
658 | static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) | |
659 | { | |
660 | base->expires_next.tv64 = KTIME_MAX; | |
661 | base->hres_active = 0; | |
54cdfdb4 TG |
662 | } |
663 | ||
9ec26907 TG |
664 | /* |
665 | * Retrigger next event is called after clock was set | |
666 | * | |
667 | * Called with interrupts disabled via on_each_cpu() | |
668 | */ | |
669 | static void retrigger_next_event(void *arg) | |
670 | { | |
dc5df73b | 671 | struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases); |
9ec26907 | 672 | |
e19ffe8b | 673 | if (!base->hres_active) |
9ec26907 TG |
674 | return; |
675 | ||
9ec26907 | 676 | raw_spin_lock(&base->lock); |
5baefd6d | 677 | hrtimer_update_base(base); |
9ec26907 TG |
678 | hrtimer_force_reprogram(base, 0); |
679 | raw_spin_unlock(&base->lock); | |
680 | } | |
b12a03ce | 681 | |
54cdfdb4 TG |
682 | /* |
683 | * Switch to high resolution mode | |
684 | */ | |
75e3b37d | 685 | static void hrtimer_switch_to_hres(void) |
54cdfdb4 | 686 | { |
c6eb3f70 | 687 | struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases); |
54cdfdb4 TG |
688 | |
689 | if (tick_init_highres()) { | |
820de5c3 | 690 | printk(KERN_WARNING "Could not switch to high resolution " |
c6eb3f70 | 691 | "mode on CPU %d\n", base->cpu); |
85e1cd6e | 692 | return; |
54cdfdb4 TG |
693 | } |
694 | base->hres_active = 1; | |
398ca17f | 695 | hrtimer_resolution = HIGH_RES_NSEC; |
54cdfdb4 TG |
696 | |
697 | tick_setup_sched_timer(); | |
54cdfdb4 TG |
698 | /* "Retrigger" the interrupt to get things going */ |
699 | retrigger_next_event(NULL); | |
54cdfdb4 TG |
700 | } |
701 | ||
5ec2481b TG |
702 | static void clock_was_set_work(struct work_struct *work) |
703 | { | |
704 | clock_was_set(); | |
705 | } | |
706 | ||
707 | static DECLARE_WORK(hrtimer_work, clock_was_set_work); | |
708 | ||
f55a6faa | 709 | /* |
5ec2481b TG |
710 | * Called from timekeeping and resume code to reprogramm the hrtimer |
711 | * interrupt device on all cpus. | |
f55a6faa JS |
712 | */ |
713 | void clock_was_set_delayed(void) | |
714 | { | |
5ec2481b | 715 | schedule_work(&hrtimer_work); |
f55a6faa JS |
716 | } |
717 | ||
54cdfdb4 TG |
718 | #else |
719 | ||
e19ffe8b | 720 | static inline int __hrtimer_hres_active(struct hrtimer_cpu_base *b) { return 0; } |
54cdfdb4 TG |
721 | static inline int hrtimer_hres_active(void) { return 0; } |
722 | static inline int hrtimer_is_hres_enabled(void) { return 0; } | |
75e3b37d | 723 | static inline void hrtimer_switch_to_hres(void) { } |
7403f41f AC |
724 | static inline void |
725 | hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { } | |
9e1e01dd VK |
726 | static inline int hrtimer_reprogram(struct hrtimer *timer, |
727 | struct hrtimer_clock_base *base) | |
54cdfdb4 TG |
728 | { |
729 | return 0; | |
730 | } | |
54cdfdb4 | 731 | static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { } |
9ec26907 | 732 | static inline void retrigger_next_event(void *arg) { } |
54cdfdb4 TG |
733 | |
734 | #endif /* CONFIG_HIGH_RES_TIMERS */ | |
735 | ||
b12a03ce TG |
736 | /* |
737 | * Clock realtime was set | |
738 | * | |
739 | * Change the offset of the realtime clock vs. the monotonic | |
740 | * clock. | |
741 | * | |
742 | * We might have to reprogram the high resolution timer interrupt. On | |
743 | * SMP we call the architecture specific code to retrigger _all_ high | |
744 | * resolution timer interrupts. On UP we just disable interrupts and | |
745 | * call the high resolution interrupt code. | |
746 | */ | |
747 | void clock_was_set(void) | |
748 | { | |
90ff1f30 | 749 | #ifdef CONFIG_HIGH_RES_TIMERS |
b12a03ce TG |
750 | /* Retrigger the CPU local events everywhere */ |
751 | on_each_cpu(retrigger_next_event, NULL, 1); | |
9ec26907 TG |
752 | #endif |
753 | timerfd_clock_was_set(); | |
b12a03ce TG |
754 | } |
755 | ||
756 | /* | |
757 | * During resume we might have to reprogram the high resolution timer | |
7c4c3a0f DV |
758 | * interrupt on all online CPUs. However, all other CPUs will be |
759 | * stopped with IRQs interrupts disabled so the clock_was_set() call | |
5ec2481b | 760 | * must be deferred. |
b12a03ce TG |
761 | */ |
762 | void hrtimers_resume(void) | |
763 | { | |
764 | WARN_ONCE(!irqs_disabled(), | |
765 | KERN_INFO "hrtimers_resume() called with IRQs enabled!"); | |
766 | ||
5ec2481b | 767 | /* Retrigger on the local CPU */ |
b12a03ce | 768 | retrigger_next_event(NULL); |
5ec2481b TG |
769 | /* And schedule a retrigger for all others */ |
770 | clock_was_set_delayed(); | |
b12a03ce TG |
771 | } |
772 | ||
5f201907 | 773 | static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer) |
82f67cd9 | 774 | { |
5f201907 | 775 | #ifdef CONFIG_TIMER_STATS |
82f67cd9 IM |
776 | if (timer->start_site) |
777 | return; | |
5f201907 | 778 | timer->start_site = __builtin_return_address(0); |
82f67cd9 IM |
779 | memcpy(timer->start_comm, current->comm, TASK_COMM_LEN); |
780 | timer->start_pid = current->pid; | |
5f201907 HC |
781 | #endif |
782 | } | |
783 | ||
784 | static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer) | |
785 | { | |
786 | #ifdef CONFIG_TIMER_STATS | |
787 | timer->start_site = NULL; | |
788 | #endif | |
82f67cd9 | 789 | } |
5f201907 HC |
790 | |
791 | static inline void timer_stats_account_hrtimer(struct hrtimer *timer) | |
792 | { | |
793 | #ifdef CONFIG_TIMER_STATS | |
794 | if (likely(!timer_stats_active)) | |
795 | return; | |
796 | timer_stats_update_stats(timer, timer->start_pid, timer->start_site, | |
797 | timer->function, timer->start_comm, 0); | |
82f67cd9 | 798 | #endif |
5f201907 | 799 | } |
82f67cd9 | 800 | |
c0a31329 | 801 | /* |
6506f2aa | 802 | * Counterpart to lock_hrtimer_base above: |
c0a31329 TG |
803 | */ |
804 | static inline | |
805 | void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) | |
806 | { | |
ecb49d1a | 807 | raw_spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags); |
c0a31329 TG |
808 | } |
809 | ||
810 | /** | |
811 | * hrtimer_forward - forward the timer expiry | |
c0a31329 | 812 | * @timer: hrtimer to forward |
44f21475 | 813 | * @now: forward past this time |
c0a31329 TG |
814 | * @interval: the interval to forward |
815 | * | |
816 | * Forward the timer expiry so it will expire in the future. | |
8dca6f33 | 817 | * Returns the number of overruns. |
91e5a217 TG |
818 | * |
819 | * Can be safely called from the callback function of @timer. If | |
820 | * called from other contexts @timer must neither be enqueued nor | |
821 | * running the callback and the caller needs to take care of | |
822 | * serialization. | |
823 | * | |
824 | * Note: This only updates the timer expiry value and does not requeue | |
825 | * the timer. | |
c0a31329 | 826 | */ |
4d672e7a | 827 | u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) |
c0a31329 | 828 | { |
4d672e7a | 829 | u64 orun = 1; |
44f21475 | 830 | ktime_t delta; |
c0a31329 | 831 | |
cc584b21 | 832 | delta = ktime_sub(now, hrtimer_get_expires(timer)); |
c0a31329 TG |
833 | |
834 | if (delta.tv64 < 0) | |
835 | return 0; | |
836 | ||
5de2755c PZ |
837 | if (WARN_ON(timer->state & HRTIMER_STATE_ENQUEUED)) |
838 | return 0; | |
839 | ||
398ca17f TG |
840 | if (interval.tv64 < hrtimer_resolution) |
841 | interval.tv64 = hrtimer_resolution; | |
c9db4fa1 | 842 | |
c0a31329 | 843 | if (unlikely(delta.tv64 >= interval.tv64)) { |
df869b63 | 844 | s64 incr = ktime_to_ns(interval); |
c0a31329 TG |
845 | |
846 | orun = ktime_divns(delta, incr); | |
cc584b21 AV |
847 | hrtimer_add_expires_ns(timer, incr * orun); |
848 | if (hrtimer_get_expires_tv64(timer) > now.tv64) | |
c0a31329 TG |
849 | return orun; |
850 | /* | |
851 | * This (and the ktime_add() below) is the | |
852 | * correction for exact: | |
853 | */ | |
854 | orun++; | |
855 | } | |
cc584b21 | 856 | hrtimer_add_expires(timer, interval); |
c0a31329 TG |
857 | |
858 | return orun; | |
859 | } | |
6bdb6b62 | 860 | EXPORT_SYMBOL_GPL(hrtimer_forward); |
c0a31329 TG |
861 | |
862 | /* | |
863 | * enqueue_hrtimer - internal function to (re)start a timer | |
864 | * | |
865 | * The timer is inserted in expiry order. Insertion into the | |
866 | * red black tree is O(log(n)). Must hold the base lock. | |
a6037b61 PZ |
867 | * |
868 | * Returns 1 when the new timer is the leftmost timer in the tree. | |
c0a31329 | 869 | */ |
a6037b61 PZ |
870 | static int enqueue_hrtimer(struct hrtimer *timer, |
871 | struct hrtimer_clock_base *base) | |
c0a31329 | 872 | { |
c6a2a177 | 873 | debug_activate(timer); |
237fc6e7 | 874 | |
ab8177bc | 875 | base->cpu_base->active_bases |= 1 << base->index; |
54cdfdb4 | 876 | |
887d9dc9 | 877 | timer->state = HRTIMER_STATE_ENQUEUED; |
a6037b61 | 878 | |
b97f44c9 | 879 | return timerqueue_add(&base->active, &timer->node); |
288867ec | 880 | } |
c0a31329 TG |
881 | |
882 | /* | |
883 | * __remove_hrtimer - internal function to remove a timer | |
884 | * | |
885 | * Caller must hold the base lock. | |
54cdfdb4 TG |
886 | * |
887 | * High resolution timer mode reprograms the clock event device when the | |
888 | * timer is the one which expires next. The caller can disable this by setting | |
889 | * reprogram to zero. This is useful, when the context does a reprogramming | |
890 | * anyway (e.g. timer interrupt) | |
c0a31329 | 891 | */ |
3c8aa39d | 892 | static void __remove_hrtimer(struct hrtimer *timer, |
303e967f | 893 | struct hrtimer_clock_base *base, |
203cbf77 | 894 | u8 newstate, int reprogram) |
c0a31329 | 895 | { |
e19ffe8b | 896 | struct hrtimer_cpu_base *cpu_base = base->cpu_base; |
203cbf77 | 897 | u8 state = timer->state; |
e19ffe8b | 898 | |
895bdfa7 TG |
899 | timer->state = newstate; |
900 | if (!(state & HRTIMER_STATE_ENQUEUED)) | |
901 | return; | |
7403f41f | 902 | |
b97f44c9 | 903 | if (!timerqueue_del(&base->active, &timer->node)) |
e19ffe8b | 904 | cpu_base->active_bases &= ~(1 << base->index); |
7403f41f | 905 | |
7403f41f | 906 | #ifdef CONFIG_HIGH_RES_TIMERS |
895bdfa7 TG |
907 | /* |
908 | * Note: If reprogram is false we do not update | |
909 | * cpu_base->next_timer. This happens when we remove the first | |
910 | * timer on a remote cpu. No harm as we never dereference | |
911 | * cpu_base->next_timer. So the worst thing what can happen is | |
912 | * an superflous call to hrtimer_force_reprogram() on the | |
913 | * remote cpu later on if the same timer gets enqueued again. | |
914 | */ | |
915 | if (reprogram && timer == cpu_base->next_timer) | |
916 | hrtimer_force_reprogram(cpu_base, 1); | |
7403f41f | 917 | #endif |
c0a31329 TG |
918 | } |
919 | ||
920 | /* | |
921 | * remove hrtimer, called with base lock held | |
922 | */ | |
923 | static inline int | |
8edfb036 | 924 | remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base, bool restart) |
c0a31329 | 925 | { |
303e967f | 926 | if (hrtimer_is_queued(timer)) { |
203cbf77 | 927 | u8 state = timer->state; |
54cdfdb4 TG |
928 | int reprogram; |
929 | ||
930 | /* | |
931 | * Remove the timer and force reprogramming when high | |
932 | * resolution mode is active and the timer is on the current | |
933 | * CPU. If we remove a timer on another CPU, reprogramming is | |
934 | * skipped. The interrupt event on this CPU is fired and | |
935 | * reprogramming happens in the interrupt handler. This is a | |
936 | * rare case and less expensive than a smp call. | |
937 | */ | |
c6a2a177 | 938 | debug_deactivate(timer); |
82f67cd9 | 939 | timer_stats_hrtimer_clear_start_info(timer); |
dc5df73b | 940 | reprogram = base->cpu_base == this_cpu_ptr(&hrtimer_bases); |
8edfb036 | 941 | |
887d9dc9 PZ |
942 | if (!restart) |
943 | state = HRTIMER_STATE_INACTIVE; | |
944 | ||
f13d4f97 | 945 | __remove_hrtimer(timer, base, state, reprogram); |
c0a31329 TG |
946 | return 1; |
947 | } | |
948 | return 0; | |
949 | } | |
950 | ||
203cbf77 TG |
951 | static inline ktime_t hrtimer_update_lowres(struct hrtimer *timer, ktime_t tim, |
952 | const enum hrtimer_mode mode) | |
953 | { | |
954 | #ifdef CONFIG_TIME_LOW_RES | |
955 | /* | |
956 | * CONFIG_TIME_LOW_RES indicates that the system has no way to return | |
957 | * granular time values. For relative timers we add hrtimer_resolution | |
958 | * (i.e. one jiffie) to prevent short timeouts. | |
959 | */ | |
960 | timer->is_rel = mode & HRTIMER_MODE_REL; | |
961 | if (timer->is_rel) | |
962 | tim = ktime_add_safe(tim, ktime_set(0, hrtimer_resolution)); | |
963 | #endif | |
964 | return tim; | |
965 | } | |
966 | ||
58f1f803 TG |
967 | /** |
968 | * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU | |
969 | * @timer: the timer to be added | |
970 | * @tim: expiry time | |
971 | * @delta_ns: "slack" range for the timer | |
972 | * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or | |
973 | * relative (HRTIMER_MODE_REL) | |
58f1f803 | 974 | */ |
61699e13 | 975 | void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, |
da8b44d5 | 976 | u64 delta_ns, const enum hrtimer_mode mode) |
c0a31329 | 977 | { |
3c8aa39d | 978 | struct hrtimer_clock_base *base, *new_base; |
c0a31329 | 979 | unsigned long flags; |
61699e13 | 980 | int leftmost; |
c0a31329 TG |
981 | |
982 | base = lock_hrtimer_base(timer, &flags); | |
983 | ||
984 | /* Remove an active timer from the queue: */ | |
8edfb036 | 985 | remove_hrtimer(timer, base, true); |
c0a31329 | 986 | |
203cbf77 | 987 | if (mode & HRTIMER_MODE_REL) |
84ea7fe3 | 988 | tim = ktime_add_safe(tim, base->get_time()); |
203cbf77 TG |
989 | |
990 | tim = hrtimer_update_lowres(timer, tim, mode); | |
237fc6e7 | 991 | |
da8f2e17 | 992 | hrtimer_set_expires_range_ns(timer, tim, delta_ns); |
c0a31329 | 993 | |
84ea7fe3 VK |
994 | /* Switch the timer base, if necessary: */ |
995 | new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED); | |
996 | ||
82f67cd9 IM |
997 | timer_stats_hrtimer_set_start_info(timer); |
998 | ||
a6037b61 | 999 | leftmost = enqueue_hrtimer(timer, new_base); |
61699e13 TG |
1000 | if (!leftmost) |
1001 | goto unlock; | |
49a2a075 VK |
1002 | |
1003 | if (!hrtimer_is_hres_active(timer)) { | |
1004 | /* | |
1005 | * Kick to reschedule the next tick to handle the new timer | |
1006 | * on dynticks target. | |
1007 | */ | |
683be13a TG |
1008 | if (new_base->cpu_base->nohz_active) |
1009 | wake_up_nohz_cpu(new_base->cpu_base->cpu); | |
c6eb3f70 TG |
1010 | } else { |
1011 | hrtimer_reprogram(timer, new_base); | |
b22affe0 | 1012 | } |
61699e13 | 1013 | unlock: |
c0a31329 | 1014 | unlock_hrtimer_base(timer, &flags); |
7f1e2ca9 | 1015 | } |
da8f2e17 AV |
1016 | EXPORT_SYMBOL_GPL(hrtimer_start_range_ns); |
1017 | ||
c0a31329 TG |
1018 | /** |
1019 | * hrtimer_try_to_cancel - try to deactivate a timer | |
c0a31329 TG |
1020 | * @timer: hrtimer to stop |
1021 | * | |
1022 | * Returns: | |
1023 | * 0 when the timer was not active | |
1024 | * 1 when the timer was active | |
1025 | * -1 when the timer is currently excuting the callback function and | |
fa9799e3 | 1026 | * cannot be stopped |
c0a31329 TG |
1027 | */ |
1028 | int hrtimer_try_to_cancel(struct hrtimer *timer) | |
1029 | { | |
3c8aa39d | 1030 | struct hrtimer_clock_base *base; |
c0a31329 TG |
1031 | unsigned long flags; |
1032 | int ret = -1; | |
1033 | ||
19d9f422 TG |
1034 | /* |
1035 | * Check lockless first. If the timer is not active (neither | |
1036 | * enqueued nor running the callback, nothing to do here. The | |
1037 | * base lock does not serialize against a concurrent enqueue, | |
1038 | * so we can avoid taking it. | |
1039 | */ | |
1040 | if (!hrtimer_active(timer)) | |
1041 | return 0; | |
1042 | ||
c0a31329 TG |
1043 | base = lock_hrtimer_base(timer, &flags); |
1044 | ||
303e967f | 1045 | if (!hrtimer_callback_running(timer)) |
8edfb036 | 1046 | ret = remove_hrtimer(timer, base, false); |
c0a31329 TG |
1047 | |
1048 | unlock_hrtimer_base(timer, &flags); | |
1049 | ||
1050 | return ret; | |
1051 | ||
1052 | } | |
8d16b764 | 1053 | EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel); |
c0a31329 TG |
1054 | |
1055 | /** | |
1056 | * hrtimer_cancel - cancel a timer and wait for the handler to finish. | |
c0a31329 TG |
1057 | * @timer: the timer to be cancelled |
1058 | * | |
1059 | * Returns: | |
1060 | * 0 when the timer was not active | |
1061 | * 1 when the timer was active | |
1062 | */ | |
1063 | int hrtimer_cancel(struct hrtimer *timer) | |
1064 | { | |
1065 | for (;;) { | |
1066 | int ret = hrtimer_try_to_cancel(timer); | |
1067 | ||
1068 | if (ret >= 0) | |
1069 | return ret; | |
5ef37b19 | 1070 | cpu_relax(); |
c0a31329 TG |
1071 | } |
1072 | } | |
8d16b764 | 1073 | EXPORT_SYMBOL_GPL(hrtimer_cancel); |
c0a31329 TG |
1074 | |
1075 | /** | |
1076 | * hrtimer_get_remaining - get remaining time for the timer | |
c0a31329 | 1077 | * @timer: the timer to read |
203cbf77 | 1078 | * @adjust: adjust relative timers when CONFIG_TIME_LOW_RES=y |
c0a31329 | 1079 | */ |
203cbf77 | 1080 | ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust) |
c0a31329 | 1081 | { |
c0a31329 TG |
1082 | unsigned long flags; |
1083 | ktime_t rem; | |
1084 | ||
b3bd3de6 | 1085 | lock_hrtimer_base(timer, &flags); |
203cbf77 TG |
1086 | if (IS_ENABLED(CONFIG_TIME_LOW_RES) && adjust) |
1087 | rem = hrtimer_expires_remaining_adjusted(timer); | |
1088 | else | |
1089 | rem = hrtimer_expires_remaining(timer); | |
c0a31329 TG |
1090 | unlock_hrtimer_base(timer, &flags); |
1091 | ||
1092 | return rem; | |
1093 | } | |
203cbf77 | 1094 | EXPORT_SYMBOL_GPL(__hrtimer_get_remaining); |
c0a31329 | 1095 | |
3451d024 | 1096 | #ifdef CONFIG_NO_HZ_COMMON |
69239749 TL |
1097 | /** |
1098 | * hrtimer_get_next_event - get the time until next expiry event | |
1099 | * | |
c1ad348b | 1100 | * Returns the next expiry time or KTIME_MAX if no timer is pending. |
69239749 | 1101 | */ |
c1ad348b | 1102 | u64 hrtimer_get_next_event(void) |
69239749 | 1103 | { |
dc5df73b | 1104 | struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); |
c1ad348b | 1105 | u64 expires = KTIME_MAX; |
69239749 | 1106 | unsigned long flags; |
69239749 | 1107 | |
ecb49d1a | 1108 | raw_spin_lock_irqsave(&cpu_base->lock, flags); |
3c8aa39d | 1109 | |
e19ffe8b | 1110 | if (!__hrtimer_hres_active(cpu_base)) |
c1ad348b | 1111 | expires = __hrtimer_get_next_event(cpu_base).tv64; |
3c8aa39d | 1112 | |
ecb49d1a | 1113 | raw_spin_unlock_irqrestore(&cpu_base->lock, flags); |
3c8aa39d | 1114 | |
c1ad348b | 1115 | return expires; |
69239749 TL |
1116 | } |
1117 | #endif | |
1118 | ||
237fc6e7 TG |
1119 | static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, |
1120 | enum hrtimer_mode mode) | |
c0a31329 | 1121 | { |
3c8aa39d | 1122 | struct hrtimer_cpu_base *cpu_base; |
e06383db | 1123 | int base; |
c0a31329 | 1124 | |
7978672c GA |
1125 | memset(timer, 0, sizeof(struct hrtimer)); |
1126 | ||
22127e93 | 1127 | cpu_base = raw_cpu_ptr(&hrtimer_bases); |
c0a31329 | 1128 | |
c9cb2e3d | 1129 | if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS) |
7978672c GA |
1130 | clock_id = CLOCK_MONOTONIC; |
1131 | ||
e06383db JS |
1132 | base = hrtimer_clockid_to_base(clock_id); |
1133 | timer->base = &cpu_base->clock_base[base]; | |
998adc3d | 1134 | timerqueue_init(&timer->node); |
82f67cd9 IM |
1135 | |
1136 | #ifdef CONFIG_TIMER_STATS | |
1137 | timer->start_site = NULL; | |
1138 | timer->start_pid = -1; | |
1139 | memset(timer->start_comm, 0, TASK_COMM_LEN); | |
1140 | #endif | |
c0a31329 | 1141 | } |
237fc6e7 TG |
1142 | |
1143 | /** | |
1144 | * hrtimer_init - initialize a timer to the given clock | |
1145 | * @timer: the timer to be initialized | |
1146 | * @clock_id: the clock to be used | |
1147 | * @mode: timer mode abs/rel | |
1148 | */ | |
1149 | void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, | |
1150 | enum hrtimer_mode mode) | |
1151 | { | |
c6a2a177 | 1152 | debug_init(timer, clock_id, mode); |
237fc6e7 TG |
1153 | __hrtimer_init(timer, clock_id, mode); |
1154 | } | |
8d16b764 | 1155 | EXPORT_SYMBOL_GPL(hrtimer_init); |
c0a31329 | 1156 | |
887d9dc9 PZ |
1157 | /* |
1158 | * A timer is active, when it is enqueued into the rbtree or the | |
1159 | * callback function is running or it's in the state of being migrated | |
1160 | * to another cpu. | |
c0a31329 | 1161 | * |
887d9dc9 | 1162 | * It is important for this function to not return a false negative. |
c0a31329 | 1163 | */ |
887d9dc9 | 1164 | bool hrtimer_active(const struct hrtimer *timer) |
c0a31329 | 1165 | { |
3c8aa39d | 1166 | struct hrtimer_cpu_base *cpu_base; |
887d9dc9 | 1167 | unsigned int seq; |
c0a31329 | 1168 | |
887d9dc9 PZ |
1169 | do { |
1170 | cpu_base = READ_ONCE(timer->base->cpu_base); | |
1171 | seq = raw_read_seqcount_begin(&cpu_base->seq); | |
c0a31329 | 1172 | |
887d9dc9 PZ |
1173 | if (timer->state != HRTIMER_STATE_INACTIVE || |
1174 | cpu_base->running == timer) | |
1175 | return true; | |
1176 | ||
1177 | } while (read_seqcount_retry(&cpu_base->seq, seq) || | |
1178 | cpu_base != READ_ONCE(timer->base->cpu_base)); | |
1179 | ||
1180 | return false; | |
c0a31329 | 1181 | } |
887d9dc9 | 1182 | EXPORT_SYMBOL_GPL(hrtimer_active); |
c0a31329 | 1183 | |
887d9dc9 PZ |
1184 | /* |
1185 | * The write_seqcount_barrier()s in __run_hrtimer() split the thing into 3 | |
1186 | * distinct sections: | |
1187 | * | |
1188 | * - queued: the timer is queued | |
1189 | * - callback: the timer is being ran | |
1190 | * - post: the timer is inactive or (re)queued | |
1191 | * | |
1192 | * On the read side we ensure we observe timer->state and cpu_base->running | |
1193 | * from the same section, if anything changed while we looked at it, we retry. | |
1194 | * This includes timer->base changing because sequence numbers alone are | |
1195 | * insufficient for that. | |
1196 | * | |
1197 | * The sequence numbers are required because otherwise we could still observe | |
1198 | * a false negative if the read side got smeared over multiple consequtive | |
1199 | * __run_hrtimer() invocations. | |
1200 | */ | |
1201 | ||
21d6d52a TG |
1202 | static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base, |
1203 | struct hrtimer_clock_base *base, | |
1204 | struct hrtimer *timer, ktime_t *now) | |
d3d74453 | 1205 | { |
d3d74453 PZ |
1206 | enum hrtimer_restart (*fn)(struct hrtimer *); |
1207 | int restart; | |
1208 | ||
887d9dc9 | 1209 | lockdep_assert_held(&cpu_base->lock); |
ca109491 | 1210 | |
c6a2a177 | 1211 | debug_deactivate(timer); |
887d9dc9 PZ |
1212 | cpu_base->running = timer; |
1213 | ||
1214 | /* | |
1215 | * Separate the ->running assignment from the ->state assignment. | |
1216 | * | |
1217 | * As with a regular write barrier, this ensures the read side in | |
1218 | * hrtimer_active() cannot observe cpu_base->running == NULL && | |
1219 | * timer->state == INACTIVE. | |
1220 | */ | |
1221 | raw_write_seqcount_barrier(&cpu_base->seq); | |
1222 | ||
1223 | __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE, 0); | |
d3d74453 | 1224 | timer_stats_account_hrtimer(timer); |
d3d74453 | 1225 | fn = timer->function; |
ca109491 | 1226 | |
203cbf77 TG |
1227 | /* |
1228 | * Clear the 'is relative' flag for the TIME_LOW_RES case. If the | |
1229 | * timer is restarted with a period then it becomes an absolute | |
1230 | * timer. If its not restarted it does not matter. | |
1231 | */ | |
1232 | if (IS_ENABLED(CONFIG_TIME_LOW_RES)) | |
1233 | timer->is_rel = false; | |
1234 | ||
ca109491 PZ |
1235 | /* |
1236 | * Because we run timers from hardirq context, there is no chance | |
1237 | * they get migrated to another cpu, therefore its safe to unlock | |
1238 | * the timer base. | |
1239 | */ | |
ecb49d1a | 1240 | raw_spin_unlock(&cpu_base->lock); |
c6a2a177 | 1241 | trace_hrtimer_expire_entry(timer, now); |
ca109491 | 1242 | restart = fn(timer); |
c6a2a177 | 1243 | trace_hrtimer_expire_exit(timer); |
ecb49d1a | 1244 | raw_spin_lock(&cpu_base->lock); |
d3d74453 PZ |
1245 | |
1246 | /* | |
887d9dc9 | 1247 | * Note: We clear the running state after enqueue_hrtimer and |
e3f1d883 TG |
1248 | * we do not reprogramm the event hardware. Happens either in |
1249 | * hrtimer_start_range_ns() or in hrtimer_interrupt() | |
5de2755c PZ |
1250 | * |
1251 | * Note: Because we dropped the cpu_base->lock above, | |
1252 | * hrtimer_start_range_ns() can have popped in and enqueued the timer | |
1253 | * for us already. | |
d3d74453 | 1254 | */ |
5de2755c PZ |
1255 | if (restart != HRTIMER_NORESTART && |
1256 | !(timer->state & HRTIMER_STATE_ENQUEUED)) | |
a6037b61 | 1257 | enqueue_hrtimer(timer, base); |
f13d4f97 | 1258 | |
887d9dc9 PZ |
1259 | /* |
1260 | * Separate the ->running assignment from the ->state assignment. | |
1261 | * | |
1262 | * As with a regular write barrier, this ensures the read side in | |
1263 | * hrtimer_active() cannot observe cpu_base->running == NULL && | |
1264 | * timer->state == INACTIVE. | |
1265 | */ | |
1266 | raw_write_seqcount_barrier(&cpu_base->seq); | |
f13d4f97 | 1267 | |
887d9dc9 PZ |
1268 | WARN_ON_ONCE(cpu_base->running != timer); |
1269 | cpu_base->running = NULL; | |
d3d74453 PZ |
1270 | } |
1271 | ||
21d6d52a | 1272 | static void __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base, ktime_t now) |
54cdfdb4 | 1273 | { |
34aee88a TG |
1274 | struct hrtimer_clock_base *base = cpu_base->clock_base; |
1275 | unsigned int active = cpu_base->active_bases; | |
6ff7041d | 1276 | |
34aee88a | 1277 | for (; active; base++, active >>= 1) { |
998adc3d | 1278 | struct timerqueue_node *node; |
ab8177bc TG |
1279 | ktime_t basenow; |
1280 | ||
34aee88a | 1281 | if (!(active & 0x01)) |
ab8177bc | 1282 | continue; |
54cdfdb4 | 1283 | |
54cdfdb4 TG |
1284 | basenow = ktime_add(now, base->offset); |
1285 | ||
998adc3d | 1286 | while ((node = timerqueue_getnext(&base->active))) { |
54cdfdb4 TG |
1287 | struct hrtimer *timer; |
1288 | ||
998adc3d | 1289 | timer = container_of(node, struct hrtimer, node); |
54cdfdb4 | 1290 | |
654c8e0b AV |
1291 | /* |
1292 | * The immediate goal for using the softexpires is | |
1293 | * minimizing wakeups, not running timers at the | |
1294 | * earliest interrupt after their soft expiration. | |
1295 | * This allows us to avoid using a Priority Search | |
1296 | * Tree, which can answer a stabbing querry for | |
1297 | * overlapping intervals and instead use the simple | |
1298 | * BST we already have. | |
1299 | * We don't add extra wakeups by delaying timers that | |
1300 | * are right-of a not yet expired timer, because that | |
1301 | * timer will have to trigger a wakeup anyway. | |
1302 | */ | |
9bc74919 | 1303 | if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) |
54cdfdb4 | 1304 | break; |
54cdfdb4 | 1305 | |
21d6d52a | 1306 | __run_hrtimer(cpu_base, base, timer, &basenow); |
54cdfdb4 | 1307 | } |
54cdfdb4 | 1308 | } |
21d6d52a TG |
1309 | } |
1310 | ||
1311 | #ifdef CONFIG_HIGH_RES_TIMERS | |
1312 | ||
1313 | /* | |
1314 | * High resolution timer interrupt | |
1315 | * Called with interrupts disabled | |
1316 | */ | |
1317 | void hrtimer_interrupt(struct clock_event_device *dev) | |
1318 | { | |
1319 | struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); | |
1320 | ktime_t expires_next, now, entry_time, delta; | |
1321 | int retries = 0; | |
1322 | ||
1323 | BUG_ON(!cpu_base->hres_active); | |
1324 | cpu_base->nr_events++; | |
1325 | dev->next_event.tv64 = KTIME_MAX; | |
1326 | ||
1327 | raw_spin_lock(&cpu_base->lock); | |
1328 | entry_time = now = hrtimer_update_base(cpu_base); | |
1329 | retry: | |
1330 | cpu_base->in_hrtirq = 1; | |
1331 | /* | |
1332 | * We set expires_next to KTIME_MAX here with cpu_base->lock | |
1333 | * held to prevent that a timer is enqueued in our queue via | |
1334 | * the migration code. This does not affect enqueueing of | |
1335 | * timers which run their callback and need to be requeued on | |
1336 | * this CPU. | |
1337 | */ | |
1338 | cpu_base->expires_next.tv64 = KTIME_MAX; | |
1339 | ||
1340 | __hrtimer_run_queues(cpu_base, now); | |
1341 | ||
9bc74919 TG |
1342 | /* Reevaluate the clock bases for the next expiry */ |
1343 | expires_next = __hrtimer_get_next_event(cpu_base); | |
6ff7041d TG |
1344 | /* |
1345 | * Store the new expiry value so the migration code can verify | |
1346 | * against it. | |
1347 | */ | |
54cdfdb4 | 1348 | cpu_base->expires_next = expires_next; |
9bc74919 | 1349 | cpu_base->in_hrtirq = 0; |
ecb49d1a | 1350 | raw_spin_unlock(&cpu_base->lock); |
54cdfdb4 TG |
1351 | |
1352 | /* Reprogramming necessary ? */ | |
d2540875 | 1353 | if (!tick_program_event(expires_next, 0)) { |
41d2e494 TG |
1354 | cpu_base->hang_detected = 0; |
1355 | return; | |
54cdfdb4 | 1356 | } |
41d2e494 TG |
1357 | |
1358 | /* | |
1359 | * The next timer was already expired due to: | |
1360 | * - tracing | |
1361 | * - long lasting callbacks | |
1362 | * - being scheduled away when running in a VM | |
1363 | * | |
1364 | * We need to prevent that we loop forever in the hrtimer | |
1365 | * interrupt routine. We give it 3 attempts to avoid | |
1366 | * overreacting on some spurious event. | |
5baefd6d JS |
1367 | * |
1368 | * Acquire base lock for updating the offsets and retrieving | |
1369 | * the current time. | |
41d2e494 | 1370 | */ |
196951e9 | 1371 | raw_spin_lock(&cpu_base->lock); |
5baefd6d | 1372 | now = hrtimer_update_base(cpu_base); |
41d2e494 TG |
1373 | cpu_base->nr_retries++; |
1374 | if (++retries < 3) | |
1375 | goto retry; | |
1376 | /* | |
1377 | * Give the system a chance to do something else than looping | |
1378 | * here. We stored the entry time, so we know exactly how long | |
1379 | * we spent here. We schedule the next event this amount of | |
1380 | * time away. | |
1381 | */ | |
1382 | cpu_base->nr_hangs++; | |
1383 | cpu_base->hang_detected = 1; | |
196951e9 | 1384 | raw_spin_unlock(&cpu_base->lock); |
41d2e494 | 1385 | delta = ktime_sub(now, entry_time); |
a6ffebce TG |
1386 | if ((unsigned int)delta.tv64 > cpu_base->max_hang_time) |
1387 | cpu_base->max_hang_time = (unsigned int) delta.tv64; | |
41d2e494 TG |
1388 | /* |
1389 | * Limit it to a sensible value as we enforce a longer | |
1390 | * delay. Give the CPU at least 100ms to catch up. | |
1391 | */ | |
1392 | if (delta.tv64 > 100 * NSEC_PER_MSEC) | |
1393 | expires_next = ktime_add_ns(now, 100 * NSEC_PER_MSEC); | |
1394 | else | |
1395 | expires_next = ktime_add(now, delta); | |
1396 | tick_program_event(expires_next, 1); | |
1397 | printk_once(KERN_WARNING "hrtimer: interrupt took %llu ns\n", | |
1398 | ktime_to_ns(delta)); | |
54cdfdb4 TG |
1399 | } |
1400 | ||
8bdec955 TG |
1401 | /* |
1402 | * local version of hrtimer_peek_ahead_timers() called with interrupts | |
1403 | * disabled. | |
1404 | */ | |
c6eb3f70 | 1405 | static inline void __hrtimer_peek_ahead_timers(void) |
8bdec955 TG |
1406 | { |
1407 | struct tick_device *td; | |
1408 | ||
1409 | if (!hrtimer_hres_active()) | |
1410 | return; | |
1411 | ||
22127e93 | 1412 | td = this_cpu_ptr(&tick_cpu_device); |
8bdec955 TG |
1413 | if (td && td->evtdev) |
1414 | hrtimer_interrupt(td->evtdev); | |
1415 | } | |
1416 | ||
82c5b7b5 IM |
1417 | #else /* CONFIG_HIGH_RES_TIMERS */ |
1418 | ||
1419 | static inline void __hrtimer_peek_ahead_timers(void) { } | |
1420 | ||
1421 | #endif /* !CONFIG_HIGH_RES_TIMERS */ | |
82f67cd9 | 1422 | |
d3d74453 | 1423 | /* |
c6eb3f70 | 1424 | * Called from run_local_timers in hardirq context every jiffy |
d3d74453 | 1425 | */ |
833883d9 | 1426 | void hrtimer_run_queues(void) |
d3d74453 | 1427 | { |
dc5df73b | 1428 | struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); |
21d6d52a | 1429 | ktime_t now; |
c0a31329 | 1430 | |
e19ffe8b | 1431 | if (__hrtimer_hres_active(cpu_base)) |
d3d74453 | 1432 | return; |
54cdfdb4 | 1433 | |
d3d74453 | 1434 | /* |
c6eb3f70 TG |
1435 | * This _is_ ugly: We have to check periodically, whether we |
1436 | * can switch to highres and / or nohz mode. The clocksource | |
1437 | * switch happens with xtime_lock held. Notification from | |
1438 | * there only sets the check bit in the tick_oneshot code, | |
1439 | * otherwise we might deadlock vs. xtime_lock. | |
d3d74453 | 1440 | */ |
c6eb3f70 | 1441 | if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())) { |
d3d74453 | 1442 | hrtimer_switch_to_hres(); |
3055adda | 1443 | return; |
833883d9 | 1444 | } |
c6eb3f70 | 1445 | |
21d6d52a TG |
1446 | raw_spin_lock(&cpu_base->lock); |
1447 | now = hrtimer_update_base(cpu_base); | |
1448 | __hrtimer_run_queues(cpu_base, now); | |
1449 | raw_spin_unlock(&cpu_base->lock); | |
c0a31329 TG |
1450 | } |
1451 | ||
10c94ec1 TG |
1452 | /* |
1453 | * Sleep related functions: | |
1454 | */ | |
c9cb2e3d | 1455 | static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer) |
00362e33 TG |
1456 | { |
1457 | struct hrtimer_sleeper *t = | |
1458 | container_of(timer, struct hrtimer_sleeper, timer); | |
1459 | struct task_struct *task = t->task; | |
1460 | ||
1461 | t->task = NULL; | |
1462 | if (task) | |
1463 | wake_up_process(task); | |
1464 | ||
1465 | return HRTIMER_NORESTART; | |
1466 | } | |
1467 | ||
36c8b586 | 1468 | void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) |
00362e33 TG |
1469 | { |
1470 | sl->timer.function = hrtimer_wakeup; | |
1471 | sl->task = task; | |
1472 | } | |
2bc481cf | 1473 | EXPORT_SYMBOL_GPL(hrtimer_init_sleeper); |
00362e33 | 1474 | |
669d7868 | 1475 | static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode) |
432569bb | 1476 | { |
669d7868 | 1477 | hrtimer_init_sleeper(t, current); |
10c94ec1 | 1478 | |
432569bb RZ |
1479 | do { |
1480 | set_current_state(TASK_INTERRUPTIBLE); | |
cc584b21 | 1481 | hrtimer_start_expires(&t->timer, mode); |
432569bb | 1482 | |
54cdfdb4 | 1483 | if (likely(t->task)) |
b0f8c44f | 1484 | freezable_schedule(); |
432569bb | 1485 | |
669d7868 | 1486 | hrtimer_cancel(&t->timer); |
c9cb2e3d | 1487 | mode = HRTIMER_MODE_ABS; |
669d7868 TG |
1488 | |
1489 | } while (t->task && !signal_pending(current)); | |
432569bb | 1490 | |
3588a085 PZ |
1491 | __set_current_state(TASK_RUNNING); |
1492 | ||
669d7868 | 1493 | return t->task == NULL; |
10c94ec1 TG |
1494 | } |
1495 | ||
080344b9 ON |
1496 | static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp) |
1497 | { | |
1498 | struct timespec rmt; | |
1499 | ktime_t rem; | |
1500 | ||
cc584b21 | 1501 | rem = hrtimer_expires_remaining(timer); |
080344b9 ON |
1502 | if (rem.tv64 <= 0) |
1503 | return 0; | |
1504 | rmt = ktime_to_timespec(rem); | |
1505 | ||
1506 | if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) | |
1507 | return -EFAULT; | |
1508 | ||
1509 | return 1; | |
1510 | } | |
1511 | ||
1711ef38 | 1512 | long __sched hrtimer_nanosleep_restart(struct restart_block *restart) |
10c94ec1 | 1513 | { |
669d7868 | 1514 | struct hrtimer_sleeper t; |
080344b9 | 1515 | struct timespec __user *rmtp; |
237fc6e7 | 1516 | int ret = 0; |
10c94ec1 | 1517 | |
ab8177bc | 1518 | hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid, |
237fc6e7 | 1519 | HRTIMER_MODE_ABS); |
cc584b21 | 1520 | hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires); |
10c94ec1 | 1521 | |
c9cb2e3d | 1522 | if (do_nanosleep(&t, HRTIMER_MODE_ABS)) |
237fc6e7 | 1523 | goto out; |
10c94ec1 | 1524 | |
029a07e0 | 1525 | rmtp = restart->nanosleep.rmtp; |
432569bb | 1526 | if (rmtp) { |
237fc6e7 | 1527 | ret = update_rmtp(&t.timer, rmtp); |
080344b9 | 1528 | if (ret <= 0) |
237fc6e7 | 1529 | goto out; |
432569bb | 1530 | } |
10c94ec1 | 1531 | |
10c94ec1 | 1532 | /* The other values in restart are already filled in */ |
237fc6e7 TG |
1533 | ret = -ERESTART_RESTARTBLOCK; |
1534 | out: | |
1535 | destroy_hrtimer_on_stack(&t.timer); | |
1536 | return ret; | |
10c94ec1 TG |
1537 | } |
1538 | ||
080344b9 | 1539 | long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, |
10c94ec1 TG |
1540 | const enum hrtimer_mode mode, const clockid_t clockid) |
1541 | { | |
1542 | struct restart_block *restart; | |
669d7868 | 1543 | struct hrtimer_sleeper t; |
237fc6e7 | 1544 | int ret = 0; |
da8b44d5 | 1545 | u64 slack; |
3bd01206 AV |
1546 | |
1547 | slack = current->timer_slack_ns; | |
aab03e05 | 1548 | if (dl_task(current) || rt_task(current)) |
3bd01206 | 1549 | slack = 0; |
10c94ec1 | 1550 | |
237fc6e7 | 1551 | hrtimer_init_on_stack(&t.timer, clockid, mode); |
3bd01206 | 1552 | hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack); |
432569bb | 1553 | if (do_nanosleep(&t, mode)) |
237fc6e7 | 1554 | goto out; |
10c94ec1 | 1555 | |
7978672c | 1556 | /* Absolute timers do not update the rmtp value and restart: */ |
237fc6e7 TG |
1557 | if (mode == HRTIMER_MODE_ABS) { |
1558 | ret = -ERESTARTNOHAND; | |
1559 | goto out; | |
1560 | } | |
10c94ec1 | 1561 | |
432569bb | 1562 | if (rmtp) { |
237fc6e7 | 1563 | ret = update_rmtp(&t.timer, rmtp); |
080344b9 | 1564 | if (ret <= 0) |
237fc6e7 | 1565 | goto out; |
432569bb | 1566 | } |
10c94ec1 | 1567 | |
f56141e3 | 1568 | restart = ¤t->restart_block; |
1711ef38 | 1569 | restart->fn = hrtimer_nanosleep_restart; |
ab8177bc | 1570 | restart->nanosleep.clockid = t.timer.base->clockid; |
029a07e0 | 1571 | restart->nanosleep.rmtp = rmtp; |
cc584b21 | 1572 | restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer); |
10c94ec1 | 1573 | |
237fc6e7 TG |
1574 | ret = -ERESTART_RESTARTBLOCK; |
1575 | out: | |
1576 | destroy_hrtimer_on_stack(&t.timer); | |
1577 | return ret; | |
10c94ec1 TG |
1578 | } |
1579 | ||
58fd3aa2 HC |
1580 | SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp, |
1581 | struct timespec __user *, rmtp) | |
6ba1b912 | 1582 | { |
080344b9 | 1583 | struct timespec tu; |
6ba1b912 TG |
1584 | |
1585 | if (copy_from_user(&tu, rqtp, sizeof(tu))) | |
1586 | return -EFAULT; | |
1587 | ||
1588 | if (!timespec_valid(&tu)) | |
1589 | return -EINVAL; | |
1590 | ||
080344b9 | 1591 | return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC); |
6ba1b912 TG |
1592 | } |
1593 | ||
c0a31329 TG |
1594 | /* |
1595 | * Functions related to boot-time initialization: | |
1596 | */ | |
0db0628d | 1597 | static void init_hrtimers_cpu(int cpu) |
c0a31329 | 1598 | { |
3c8aa39d | 1599 | struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); |
c0a31329 TG |
1600 | int i; |
1601 | ||
998adc3d | 1602 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { |
3c8aa39d | 1603 | cpu_base->clock_base[i].cpu_base = cpu_base; |
998adc3d JS |
1604 | timerqueue_init_head(&cpu_base->clock_base[i].active); |
1605 | } | |
3c8aa39d | 1606 | |
cddd0248 | 1607 | cpu_base->cpu = cpu; |
54cdfdb4 | 1608 | hrtimer_init_hres(cpu_base); |
c0a31329 TG |
1609 | } |
1610 | ||
1611 | #ifdef CONFIG_HOTPLUG_CPU | |
1612 | ||
ca109491 | 1613 | static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, |
37810659 | 1614 | struct hrtimer_clock_base *new_base) |
c0a31329 TG |
1615 | { |
1616 | struct hrtimer *timer; | |
998adc3d | 1617 | struct timerqueue_node *node; |
c0a31329 | 1618 | |
998adc3d JS |
1619 | while ((node = timerqueue_getnext(&old_base->active))) { |
1620 | timer = container_of(node, struct hrtimer, node); | |
54cdfdb4 | 1621 | BUG_ON(hrtimer_callback_running(timer)); |
c6a2a177 | 1622 | debug_deactivate(timer); |
b00c1a99 TG |
1623 | |
1624 | /* | |
c04dca02 | 1625 | * Mark it as ENQUEUED not INACTIVE otherwise the |
b00c1a99 TG |
1626 | * timer could be seen as !active and just vanish away |
1627 | * under us on another CPU | |
1628 | */ | |
c04dca02 | 1629 | __remove_hrtimer(timer, old_base, HRTIMER_STATE_ENQUEUED, 0); |
c0a31329 | 1630 | timer->base = new_base; |
54cdfdb4 | 1631 | /* |
e3f1d883 TG |
1632 | * Enqueue the timers on the new cpu. This does not |
1633 | * reprogram the event device in case the timer | |
1634 | * expires before the earliest on this CPU, but we run | |
1635 | * hrtimer_interrupt after we migrated everything to | |
1636 | * sort out already expired timers and reprogram the | |
1637 | * event device. | |
54cdfdb4 | 1638 | */ |
a6037b61 | 1639 | enqueue_hrtimer(timer, new_base); |
c0a31329 TG |
1640 | } |
1641 | } | |
1642 | ||
d5fd43c4 | 1643 | static void migrate_hrtimers(int scpu) |
c0a31329 | 1644 | { |
3c8aa39d | 1645 | struct hrtimer_cpu_base *old_base, *new_base; |
731a55ba | 1646 | int i; |
c0a31329 | 1647 | |
37810659 | 1648 | BUG_ON(cpu_online(scpu)); |
37810659 | 1649 | tick_cancel_sched_timer(scpu); |
731a55ba TG |
1650 | |
1651 | local_irq_disable(); | |
1652 | old_base = &per_cpu(hrtimer_bases, scpu); | |
dc5df73b | 1653 | new_base = this_cpu_ptr(&hrtimer_bases); |
d82f0b0f ON |
1654 | /* |
1655 | * The caller is globally serialized and nobody else | |
1656 | * takes two locks at once, deadlock is not possible. | |
1657 | */ | |
ecb49d1a TG |
1658 | raw_spin_lock(&new_base->lock); |
1659 | raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); | |
c0a31329 | 1660 | |
3c8aa39d | 1661 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { |
ca109491 | 1662 | migrate_hrtimer_list(&old_base->clock_base[i], |
37810659 | 1663 | &new_base->clock_base[i]); |
c0a31329 TG |
1664 | } |
1665 | ||
ecb49d1a TG |
1666 | raw_spin_unlock(&old_base->lock); |
1667 | raw_spin_unlock(&new_base->lock); | |
37810659 | 1668 | |
731a55ba TG |
1669 | /* Check, if we got expired work to do */ |
1670 | __hrtimer_peek_ahead_timers(); | |
1671 | local_irq_enable(); | |
c0a31329 | 1672 | } |
37810659 | 1673 | |
c0a31329 TG |
1674 | #endif /* CONFIG_HOTPLUG_CPU */ |
1675 | ||
0db0628d | 1676 | static int hrtimer_cpu_notify(struct notifier_block *self, |
c0a31329 TG |
1677 | unsigned long action, void *hcpu) |
1678 | { | |
b2e3c0ad | 1679 | int scpu = (long)hcpu; |
c0a31329 TG |
1680 | |
1681 | switch (action) { | |
1682 | ||
1683 | case CPU_UP_PREPARE: | |
8bb78442 | 1684 | case CPU_UP_PREPARE_FROZEN: |
37810659 | 1685 | init_hrtimers_cpu(scpu); |
c0a31329 TG |
1686 | break; |
1687 | ||
1688 | #ifdef CONFIG_HOTPLUG_CPU | |
1689 | case CPU_DEAD: | |
8bb78442 | 1690 | case CPU_DEAD_FROZEN: |
d5fd43c4 | 1691 | migrate_hrtimers(scpu); |
c0a31329 TG |
1692 | break; |
1693 | #endif | |
1694 | ||
1695 | default: | |
1696 | break; | |
1697 | } | |
1698 | ||
1699 | return NOTIFY_OK; | |
1700 | } | |
1701 | ||
0db0628d | 1702 | static struct notifier_block hrtimers_nb = { |
c0a31329 TG |
1703 | .notifier_call = hrtimer_cpu_notify, |
1704 | }; | |
1705 | ||
1706 | void __init hrtimers_init(void) | |
1707 | { | |
1708 | hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE, | |
1709 | (void *)(long)smp_processor_id()); | |
1710 | register_cpu_notifier(&hrtimers_nb); | |
1711 | } | |
1712 | ||
7bb67439 | 1713 | /** |
351b3f7a | 1714 | * schedule_hrtimeout_range_clock - sleep until timeout |
7bb67439 | 1715 | * @expires: timeout value (ktime_t) |
654c8e0b | 1716 | * @delta: slack in expires timeout (ktime_t) |
7bb67439 | 1717 | * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL |
351b3f7a | 1718 | * @clock: timer clock, CLOCK_MONOTONIC or CLOCK_REALTIME |
7bb67439 | 1719 | */ |
351b3f7a | 1720 | int __sched |
da8b44d5 | 1721 | schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta, |
351b3f7a | 1722 | const enum hrtimer_mode mode, int clock) |
7bb67439 AV |
1723 | { |
1724 | struct hrtimer_sleeper t; | |
1725 | ||
1726 | /* | |
1727 | * Optimize when a zero timeout value is given. It does not | |
1728 | * matter whether this is an absolute or a relative time. | |
1729 | */ | |
1730 | if (expires && !expires->tv64) { | |
1731 | __set_current_state(TASK_RUNNING); | |
1732 | return 0; | |
1733 | } | |
1734 | ||
1735 | /* | |
43b21013 | 1736 | * A NULL parameter means "infinite" |
7bb67439 AV |
1737 | */ |
1738 | if (!expires) { | |
1739 | schedule(); | |
7bb67439 AV |
1740 | return -EINTR; |
1741 | } | |
1742 | ||
351b3f7a | 1743 | hrtimer_init_on_stack(&t.timer, clock, mode); |
654c8e0b | 1744 | hrtimer_set_expires_range_ns(&t.timer, *expires, delta); |
7bb67439 AV |
1745 | |
1746 | hrtimer_init_sleeper(&t, current); | |
1747 | ||
cc584b21 | 1748 | hrtimer_start_expires(&t.timer, mode); |
7bb67439 AV |
1749 | |
1750 | if (likely(t.task)) | |
1751 | schedule(); | |
1752 | ||
1753 | hrtimer_cancel(&t.timer); | |
1754 | destroy_hrtimer_on_stack(&t.timer); | |
1755 | ||
1756 | __set_current_state(TASK_RUNNING); | |
1757 | ||
1758 | return !t.task ? 0 : -EINTR; | |
1759 | } | |
351b3f7a CE |
1760 | |
1761 | /** | |
1762 | * schedule_hrtimeout_range - sleep until timeout | |
1763 | * @expires: timeout value (ktime_t) | |
1764 | * @delta: slack in expires timeout (ktime_t) | |
1765 | * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL | |
1766 | * | |
1767 | * Make the current task sleep until the given expiry time has | |
1768 | * elapsed. The routine will return immediately unless | |
1769 | * the current task state has been set (see set_current_state()). | |
1770 | * | |
1771 | * The @delta argument gives the kernel the freedom to schedule the | |
1772 | * actual wakeup to a time that is both power and performance friendly. | |
1773 | * The kernel give the normal best effort behavior for "@expires+@delta", | |
1774 | * but may decide to fire the timer earlier, but no earlier than @expires. | |
1775 | * | |
1776 | * You can set the task state as follows - | |
1777 | * | |
1778 | * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to | |
1779 | * pass before the routine returns. | |
1780 | * | |
1781 | * %TASK_INTERRUPTIBLE - the routine may return early if a signal is | |
1782 | * delivered to the current task. | |
1783 | * | |
1784 | * The current task state is guaranteed to be TASK_RUNNING when this | |
1785 | * routine returns. | |
1786 | * | |
1787 | * Returns 0 when the timer has expired otherwise -EINTR | |
1788 | */ | |
da8b44d5 | 1789 | int __sched schedule_hrtimeout_range(ktime_t *expires, u64 delta, |
351b3f7a CE |
1790 | const enum hrtimer_mode mode) |
1791 | { | |
1792 | return schedule_hrtimeout_range_clock(expires, delta, mode, | |
1793 | CLOCK_MONOTONIC); | |
1794 | } | |
654c8e0b AV |
1795 | EXPORT_SYMBOL_GPL(schedule_hrtimeout_range); |
1796 | ||
1797 | /** | |
1798 | * schedule_hrtimeout - sleep until timeout | |
1799 | * @expires: timeout value (ktime_t) | |
1800 | * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL | |
1801 | * | |
1802 | * Make the current task sleep until the given expiry time has | |
1803 | * elapsed. The routine will return immediately unless | |
1804 | * the current task state has been set (see set_current_state()). | |
1805 | * | |
1806 | * You can set the task state as follows - | |
1807 | * | |
1808 | * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to | |
1809 | * pass before the routine returns. | |
1810 | * | |
1811 | * %TASK_INTERRUPTIBLE - the routine may return early if a signal is | |
1812 | * delivered to the current task. | |
1813 | * | |
1814 | * The current task state is guaranteed to be TASK_RUNNING when this | |
1815 | * routine returns. | |
1816 | * | |
1817 | * Returns 0 when the timer has expired otherwise -EINTR | |
1818 | */ | |
1819 | int __sched schedule_hrtimeout(ktime_t *expires, | |
1820 | const enum hrtimer_mode mode) | |
1821 | { | |
1822 | return schedule_hrtimeout_range(expires, 0, mode); | |
1823 | } | |
7bb67439 | 1824 | EXPORT_SYMBOL_GPL(schedule_hrtimeout); |