Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/kernel/timer.c | |
3 | * | |
4a22f166 | 4 | * Kernel internal timers |
1da177e4 LT |
5 | * |
6 | * Copyright (C) 1991, 1992 Linus Torvalds | |
7 | * | |
8 | * 1997-01-28 Modified by Finn Arne Gangstad to make timers scale better. | |
9 | * | |
10 | * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 | |
11 | * "A Kernel Model for Precision Timekeeping" by Dave Mills | |
12 | * 1998-12-24 Fixed a xtime SMP race (we need the xtime_lock rw spinlock to | |
13 | * serialize accesses to xtime/lost_ticks). | |
14 | * Copyright (C) 1998 Andrea Arcangeli | |
15 | * 1999-03-10 Improved NTP compatibility by Ulrich Windl | |
16 | * 2002-05-31 Move sys_sysinfo here and make its locking sane, Robert Love | |
17 | * 2000-10-05 Implemented scalable SMP per-CPU timer handling. | |
18 | * Copyright (C) 2000, 2001, 2002 Ingo Molnar | |
19 | * Designed by David S. Miller, Alexey Kuznetsov and Ingo Molnar | |
20 | */ | |
21 | ||
22 | #include <linux/kernel_stat.h> | |
9984de1a | 23 | #include <linux/export.h> |
1da177e4 LT |
24 | #include <linux/interrupt.h> |
25 | #include <linux/percpu.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/mm.h> | |
28 | #include <linux/swap.h> | |
b488893a | 29 | #include <linux/pid_namespace.h> |
1da177e4 LT |
30 | #include <linux/notifier.h> |
31 | #include <linux/thread_info.h> | |
32 | #include <linux/time.h> | |
33 | #include <linux/jiffies.h> | |
34 | #include <linux/posix-timers.h> | |
35 | #include <linux/cpu.h> | |
36 | #include <linux/syscalls.h> | |
97a41e26 | 37 | #include <linux/delay.h> |
79bf2bb3 | 38 | #include <linux/tick.h> |
82f67cd9 | 39 | #include <linux/kallsyms.h> |
e360adbe | 40 | #include <linux/irq_work.h> |
eea08f32 | 41 | #include <linux/sched.h> |
cf4aebc2 | 42 | #include <linux/sched/sysctl.h> |
5a0e3ad6 | 43 | #include <linux/slab.h> |
1a0df594 | 44 | #include <linux/compat.h> |
1da177e4 LT |
45 | |
46 | #include <asm/uaccess.h> | |
47 | #include <asm/unistd.h> | |
48 | #include <asm/div64.h> | |
49 | #include <asm/timex.h> | |
50 | #include <asm/io.h> | |
51 | ||
2b022e3d XG |
52 | #define CREATE_TRACE_POINTS |
53 | #include <trace/events/timer.h> | |
54 | ||
ecea8d19 TG |
55 | u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES; |
56 | ||
57 | EXPORT_SYMBOL(jiffies_64); | |
58 | ||
1da177e4 LT |
59 | /* |
60 | * per-CPU timer vector definitions: | |
61 | */ | |
1da177e4 LT |
62 | #define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6) |
63 | #define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8) | |
64 | #define TVN_SIZE (1 << TVN_BITS) | |
65 | #define TVR_SIZE (1 << TVR_BITS) | |
66 | #define TVN_MASK (TVN_SIZE - 1) | |
67 | #define TVR_MASK (TVR_SIZE - 1) | |
26cff4e2 | 68 | #define MAX_TVAL ((unsigned long)((1ULL << (TVR_BITS + 4*TVN_BITS)) - 1)) |
1da177e4 | 69 | |
a6fa8e5a | 70 | struct tvec { |
1da177e4 | 71 | struct list_head vec[TVN_SIZE]; |
a6fa8e5a | 72 | }; |
1da177e4 | 73 | |
a6fa8e5a | 74 | struct tvec_root { |
1da177e4 | 75 | struct list_head vec[TVR_SIZE]; |
a6fa8e5a | 76 | }; |
1da177e4 | 77 | |
a6fa8e5a | 78 | struct tvec_base { |
3691c519 ON |
79 | spinlock_t lock; |
80 | struct timer_list *running_timer; | |
1da177e4 | 81 | unsigned long timer_jiffies; |
97fd9ed4 | 82 | unsigned long next_timer; |
99d5f3aa | 83 | unsigned long active_timers; |
a6fa8e5a PM |
84 | struct tvec_root tv1; |
85 | struct tvec tv2; | |
86 | struct tvec tv3; | |
87 | struct tvec tv4; | |
88 | struct tvec tv5; | |
6e453a67 | 89 | } ____cacheline_aligned; |
1da177e4 | 90 | |
a6fa8e5a | 91 | struct tvec_base boot_tvec_bases; |
3691c519 | 92 | EXPORT_SYMBOL(boot_tvec_bases); |
a6fa8e5a | 93 | static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases; |
1da177e4 | 94 | |
6e453a67 | 95 | /* Functions below help us manage 'deferrable' flag */ |
a6fa8e5a | 96 | static inline unsigned int tbase_get_deferrable(struct tvec_base *base) |
6e453a67 | 97 | { |
e52b1db3 | 98 | return ((unsigned int)(unsigned long)base & TIMER_DEFERRABLE); |
6e453a67 VP |
99 | } |
100 | ||
c5f66e99 TH |
101 | static inline unsigned int tbase_get_irqsafe(struct tvec_base *base) |
102 | { | |
103 | return ((unsigned int)(unsigned long)base & TIMER_IRQSAFE); | |
104 | } | |
105 | ||
a6fa8e5a | 106 | static inline struct tvec_base *tbase_get_base(struct tvec_base *base) |
6e453a67 | 107 | { |
e52b1db3 | 108 | return ((struct tvec_base *)((unsigned long)base & ~TIMER_FLAG_MASK)); |
6e453a67 VP |
109 | } |
110 | ||
6e453a67 | 111 | static inline void |
a6fa8e5a | 112 | timer_set_base(struct timer_list *timer, struct tvec_base *new_base) |
6e453a67 | 113 | { |
e52b1db3 TH |
114 | unsigned long flags = (unsigned long)timer->base & TIMER_FLAG_MASK; |
115 | ||
116 | timer->base = (struct tvec_base *)((unsigned long)(new_base) | flags); | |
6e453a67 VP |
117 | } |
118 | ||
9c133c46 AS |
119 | static unsigned long round_jiffies_common(unsigned long j, int cpu, |
120 | bool force_up) | |
4c36a5de AV |
121 | { |
122 | int rem; | |
123 | unsigned long original = j; | |
124 | ||
125 | /* | |
126 | * We don't want all cpus firing their timers at once hitting the | |
127 | * same lock or cachelines, so we skew each extra cpu with an extra | |
128 | * 3 jiffies. This 3 jiffies came originally from the mm/ code which | |
129 | * already did this. | |
130 | * The skew is done by adding 3*cpunr, then round, then subtract this | |
131 | * extra offset again. | |
132 | */ | |
133 | j += cpu * 3; | |
134 | ||
135 | rem = j % HZ; | |
136 | ||
137 | /* | |
138 | * If the target jiffie is just after a whole second (which can happen | |
139 | * due to delays of the timer irq, long irq off times etc etc) then | |
140 | * we should round down to the whole second, not up. Use 1/4th second | |
141 | * as cutoff for this rounding as an extreme upper bound for this. | |
9c133c46 | 142 | * But never round down if @force_up is set. |
4c36a5de | 143 | */ |
9c133c46 | 144 | if (rem < HZ/4 && !force_up) /* round down */ |
4c36a5de AV |
145 | j = j - rem; |
146 | else /* round up */ | |
147 | j = j - rem + HZ; | |
148 | ||
149 | /* now that we have rounded, subtract the extra skew again */ | |
150 | j -= cpu * 3; | |
151 | ||
9e04d380 BVA |
152 | /* |
153 | * Make sure j is still in the future. Otherwise return the | |
154 | * unmodified value. | |
155 | */ | |
156 | return time_is_after_jiffies(j) ? j : original; | |
4c36a5de | 157 | } |
9c133c46 AS |
158 | |
159 | /** | |
160 | * __round_jiffies - function to round jiffies to a full second | |
161 | * @j: the time in (absolute) jiffies that should be rounded | |
162 | * @cpu: the processor number on which the timeout will happen | |
163 | * | |
164 | * __round_jiffies() rounds an absolute time in the future (in jiffies) | |
165 | * up or down to (approximately) full seconds. This is useful for timers | |
166 | * for which the exact time they fire does not matter too much, as long as | |
167 | * they fire approximately every X seconds. | |
168 | * | |
169 | * By rounding these timers to whole seconds, all such timers will fire | |
170 | * at the same time, rather than at various times spread out. The goal | |
171 | * of this is to have the CPU wake up less, which saves power. | |
172 | * | |
173 | * The exact rounding is skewed for each processor to avoid all | |
174 | * processors firing at the exact same time, which could lead | |
175 | * to lock contention or spurious cache line bouncing. | |
176 | * | |
177 | * The return value is the rounded version of the @j parameter. | |
178 | */ | |
179 | unsigned long __round_jiffies(unsigned long j, int cpu) | |
180 | { | |
181 | return round_jiffies_common(j, cpu, false); | |
182 | } | |
4c36a5de AV |
183 | EXPORT_SYMBOL_GPL(__round_jiffies); |
184 | ||
185 | /** | |
186 | * __round_jiffies_relative - function to round jiffies to a full second | |
187 | * @j: the time in (relative) jiffies that should be rounded | |
188 | * @cpu: the processor number on which the timeout will happen | |
189 | * | |
72fd4a35 | 190 | * __round_jiffies_relative() rounds a time delta in the future (in jiffies) |
4c36a5de AV |
191 | * up or down to (approximately) full seconds. This is useful for timers |
192 | * for which the exact time they fire does not matter too much, as long as | |
193 | * they fire approximately every X seconds. | |
194 | * | |
195 | * By rounding these timers to whole seconds, all such timers will fire | |
196 | * at the same time, rather than at various times spread out. The goal | |
197 | * of this is to have the CPU wake up less, which saves power. | |
198 | * | |
199 | * The exact rounding is skewed for each processor to avoid all | |
200 | * processors firing at the exact same time, which could lead | |
201 | * to lock contention or spurious cache line bouncing. | |
202 | * | |
72fd4a35 | 203 | * The return value is the rounded version of the @j parameter. |
4c36a5de AV |
204 | */ |
205 | unsigned long __round_jiffies_relative(unsigned long j, int cpu) | |
206 | { | |
9c133c46 AS |
207 | unsigned long j0 = jiffies; |
208 | ||
209 | /* Use j0 because jiffies might change while we run */ | |
210 | return round_jiffies_common(j + j0, cpu, false) - j0; | |
4c36a5de AV |
211 | } |
212 | EXPORT_SYMBOL_GPL(__round_jiffies_relative); | |
213 | ||
214 | /** | |
215 | * round_jiffies - function to round jiffies to a full second | |
216 | * @j: the time in (absolute) jiffies that should be rounded | |
217 | * | |
72fd4a35 | 218 | * round_jiffies() rounds an absolute time in the future (in jiffies) |
4c36a5de AV |
219 | * up or down to (approximately) full seconds. This is useful for timers |
220 | * for which the exact time they fire does not matter too much, as long as | |
221 | * they fire approximately every X seconds. | |
222 | * | |
223 | * By rounding these timers to whole seconds, all such timers will fire | |
224 | * at the same time, rather than at various times spread out. The goal | |
225 | * of this is to have the CPU wake up less, which saves power. | |
226 | * | |
72fd4a35 | 227 | * The return value is the rounded version of the @j parameter. |
4c36a5de AV |
228 | */ |
229 | unsigned long round_jiffies(unsigned long j) | |
230 | { | |
9c133c46 | 231 | return round_jiffies_common(j, raw_smp_processor_id(), false); |
4c36a5de AV |
232 | } |
233 | EXPORT_SYMBOL_GPL(round_jiffies); | |
234 | ||
235 | /** | |
236 | * round_jiffies_relative - function to round jiffies to a full second | |
237 | * @j: the time in (relative) jiffies that should be rounded | |
238 | * | |
72fd4a35 | 239 | * round_jiffies_relative() rounds a time delta in the future (in jiffies) |
4c36a5de AV |
240 | * up or down to (approximately) full seconds. This is useful for timers |
241 | * for which the exact time they fire does not matter too much, as long as | |
242 | * they fire approximately every X seconds. | |
243 | * | |
244 | * By rounding these timers to whole seconds, all such timers will fire | |
245 | * at the same time, rather than at various times spread out. The goal | |
246 | * of this is to have the CPU wake up less, which saves power. | |
247 | * | |
72fd4a35 | 248 | * The return value is the rounded version of the @j parameter. |
4c36a5de AV |
249 | */ |
250 | unsigned long round_jiffies_relative(unsigned long j) | |
251 | { | |
252 | return __round_jiffies_relative(j, raw_smp_processor_id()); | |
253 | } | |
254 | EXPORT_SYMBOL_GPL(round_jiffies_relative); | |
255 | ||
9c133c46 AS |
256 | /** |
257 | * __round_jiffies_up - function to round jiffies up to a full second | |
258 | * @j: the time in (absolute) jiffies that should be rounded | |
259 | * @cpu: the processor number on which the timeout will happen | |
260 | * | |
261 | * This is the same as __round_jiffies() except that it will never | |
262 | * round down. This is useful for timeouts for which the exact time | |
263 | * of firing does not matter too much, as long as they don't fire too | |
264 | * early. | |
265 | */ | |
266 | unsigned long __round_jiffies_up(unsigned long j, int cpu) | |
267 | { | |
268 | return round_jiffies_common(j, cpu, true); | |
269 | } | |
270 | EXPORT_SYMBOL_GPL(__round_jiffies_up); | |
271 | ||
272 | /** | |
273 | * __round_jiffies_up_relative - function to round jiffies up to a full second | |
274 | * @j: the time in (relative) jiffies that should be rounded | |
275 | * @cpu: the processor number on which the timeout will happen | |
276 | * | |
277 | * This is the same as __round_jiffies_relative() except that it will never | |
278 | * round down. This is useful for timeouts for which the exact time | |
279 | * of firing does not matter too much, as long as they don't fire too | |
280 | * early. | |
281 | */ | |
282 | unsigned long __round_jiffies_up_relative(unsigned long j, int cpu) | |
283 | { | |
284 | unsigned long j0 = jiffies; | |
285 | ||
286 | /* Use j0 because jiffies might change while we run */ | |
287 | return round_jiffies_common(j + j0, cpu, true) - j0; | |
288 | } | |
289 | EXPORT_SYMBOL_GPL(__round_jiffies_up_relative); | |
290 | ||
291 | /** | |
292 | * round_jiffies_up - function to round jiffies up to a full second | |
293 | * @j: the time in (absolute) jiffies that should be rounded | |
294 | * | |
295 | * This is the same as round_jiffies() except that it will never | |
296 | * round down. This is useful for timeouts for which the exact time | |
297 | * of firing does not matter too much, as long as they don't fire too | |
298 | * early. | |
299 | */ | |
300 | unsigned long round_jiffies_up(unsigned long j) | |
301 | { | |
302 | return round_jiffies_common(j, raw_smp_processor_id(), true); | |
303 | } | |
304 | EXPORT_SYMBOL_GPL(round_jiffies_up); | |
305 | ||
306 | /** | |
307 | * round_jiffies_up_relative - function to round jiffies up to a full second | |
308 | * @j: the time in (relative) jiffies that should be rounded | |
309 | * | |
310 | * This is the same as round_jiffies_relative() except that it will never | |
311 | * round down. This is useful for timeouts for which the exact time | |
312 | * of firing does not matter too much, as long as they don't fire too | |
313 | * early. | |
314 | */ | |
315 | unsigned long round_jiffies_up_relative(unsigned long j) | |
316 | { | |
317 | return __round_jiffies_up_relative(j, raw_smp_processor_id()); | |
318 | } | |
319 | EXPORT_SYMBOL_GPL(round_jiffies_up_relative); | |
320 | ||
3bbb9ec9 AV |
321 | /** |
322 | * set_timer_slack - set the allowed slack for a timer | |
0caa6210 | 323 | * @timer: the timer to be modified |
3bbb9ec9 AV |
324 | * @slack_hz: the amount of time (in jiffies) allowed for rounding |
325 | * | |
326 | * Set the amount of time, in jiffies, that a certain timer has | |
327 | * in terms of slack. By setting this value, the timer subsystem | |
328 | * will schedule the actual timer somewhere between | |
329 | * the time mod_timer() asks for, and that time plus the slack. | |
330 | * | |
331 | * By setting the slack to -1, a percentage of the delay is used | |
332 | * instead. | |
333 | */ | |
334 | void set_timer_slack(struct timer_list *timer, int slack_hz) | |
335 | { | |
336 | timer->slack = slack_hz; | |
337 | } | |
338 | EXPORT_SYMBOL_GPL(set_timer_slack); | |
339 | ||
facbb4a7 TG |
340 | static void |
341 | __internal_add_timer(struct tvec_base *base, struct timer_list *timer) | |
1da177e4 LT |
342 | { |
343 | unsigned long expires = timer->expires; | |
344 | unsigned long idx = expires - base->timer_jiffies; | |
345 | struct list_head *vec; | |
346 | ||
347 | if (idx < TVR_SIZE) { | |
348 | int i = expires & TVR_MASK; | |
349 | vec = base->tv1.vec + i; | |
350 | } else if (idx < 1 << (TVR_BITS + TVN_BITS)) { | |
351 | int i = (expires >> TVR_BITS) & TVN_MASK; | |
352 | vec = base->tv2.vec + i; | |
353 | } else if (idx < 1 << (TVR_BITS + 2 * TVN_BITS)) { | |
354 | int i = (expires >> (TVR_BITS + TVN_BITS)) & TVN_MASK; | |
355 | vec = base->tv3.vec + i; | |
356 | } else if (idx < 1 << (TVR_BITS + 3 * TVN_BITS)) { | |
357 | int i = (expires >> (TVR_BITS + 2 * TVN_BITS)) & TVN_MASK; | |
358 | vec = base->tv4.vec + i; | |
359 | } else if ((signed long) idx < 0) { | |
360 | /* | |
361 | * Can happen if you add a timer with expires == jiffies, | |
362 | * or you set a timer to go off in the past | |
363 | */ | |
364 | vec = base->tv1.vec + (base->timer_jiffies & TVR_MASK); | |
365 | } else { | |
366 | int i; | |
26cff4e2 HC |
367 | /* If the timeout is larger than MAX_TVAL (on 64-bit |
368 | * architectures or with CONFIG_BASE_SMALL=1) then we | |
369 | * use the maximum timeout. | |
1da177e4 | 370 | */ |
26cff4e2 HC |
371 | if (idx > MAX_TVAL) { |
372 | idx = MAX_TVAL; | |
1da177e4 LT |
373 | expires = idx + base->timer_jiffies; |
374 | } | |
375 | i = (expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK; | |
376 | vec = base->tv5.vec + i; | |
377 | } | |
378 | /* | |
379 | * Timers are FIFO: | |
380 | */ | |
381 | list_add_tail(&timer->entry, vec); | |
382 | } | |
383 | ||
facbb4a7 TG |
384 | static void internal_add_timer(struct tvec_base *base, struct timer_list *timer) |
385 | { | |
386 | __internal_add_timer(base, timer); | |
387 | /* | |
99d5f3aa | 388 | * Update base->active_timers and base->next_timer |
facbb4a7 | 389 | */ |
99d5f3aa TG |
390 | if (!tbase_get_deferrable(timer->base)) { |
391 | if (time_before(timer->expires, base->next_timer)) | |
392 | base->next_timer = timer->expires; | |
393 | base->active_timers++; | |
394 | } | |
facbb4a7 TG |
395 | } |
396 | ||
82f67cd9 IM |
397 | #ifdef CONFIG_TIMER_STATS |
398 | void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr) | |
399 | { | |
400 | if (timer->start_site) | |
401 | return; | |
402 | ||
403 | timer->start_site = addr; | |
404 | memcpy(timer->start_comm, current->comm, TASK_COMM_LEN); | |
405 | timer->start_pid = current->pid; | |
406 | } | |
c5c061b8 VP |
407 | |
408 | static void timer_stats_account_timer(struct timer_list *timer) | |
409 | { | |
410 | unsigned int flag = 0; | |
411 | ||
507e1231 HC |
412 | if (likely(!timer->start_site)) |
413 | return; | |
c5c061b8 VP |
414 | if (unlikely(tbase_get_deferrable(timer->base))) |
415 | flag |= TIMER_STATS_FLAG_DEFERRABLE; | |
416 | ||
417 | timer_stats_update_stats(timer, timer->start_pid, timer->start_site, | |
418 | timer->function, timer->start_comm, flag); | |
419 | } | |
420 | ||
421 | #else | |
422 | static void timer_stats_account_timer(struct timer_list *timer) {} | |
82f67cd9 IM |
423 | #endif |
424 | ||
c6f3a97f TG |
425 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS |
426 | ||
427 | static struct debug_obj_descr timer_debug_descr; | |
428 | ||
99777288 SG |
429 | static void *timer_debug_hint(void *addr) |
430 | { | |
431 | return ((struct timer_list *) addr)->function; | |
432 | } | |
433 | ||
c6f3a97f TG |
434 | /* |
435 | * fixup_init is called when: | |
436 | * - an active object is initialized | |
55c888d6 | 437 | */ |
c6f3a97f TG |
438 | static int timer_fixup_init(void *addr, enum debug_obj_state state) |
439 | { | |
440 | struct timer_list *timer = addr; | |
441 | ||
442 | switch (state) { | |
443 | case ODEBUG_STATE_ACTIVE: | |
444 | del_timer_sync(timer); | |
445 | debug_object_init(timer, &timer_debug_descr); | |
446 | return 1; | |
447 | default: | |
448 | return 0; | |
449 | } | |
450 | } | |
451 | ||
fb16b8cf SB |
452 | /* Stub timer callback for improperly used timers. */ |
453 | static void stub_timer(unsigned long data) | |
454 | { | |
455 | WARN_ON(1); | |
456 | } | |
457 | ||
c6f3a97f TG |
458 | /* |
459 | * fixup_activate is called when: | |
460 | * - an active object is activated | |
461 | * - an unknown object is activated (might be a statically initialized object) | |
462 | */ | |
463 | static int timer_fixup_activate(void *addr, enum debug_obj_state state) | |
464 | { | |
465 | struct timer_list *timer = addr; | |
466 | ||
467 | switch (state) { | |
468 | ||
469 | case ODEBUG_STATE_NOTAVAILABLE: | |
470 | /* | |
471 | * This is not really a fixup. The timer was | |
472 | * statically initialized. We just make sure that it | |
473 | * is tracked in the object tracker. | |
474 | */ | |
475 | if (timer->entry.next == NULL && | |
476 | timer->entry.prev == TIMER_ENTRY_STATIC) { | |
477 | debug_object_init(timer, &timer_debug_descr); | |
478 | debug_object_activate(timer, &timer_debug_descr); | |
479 | return 0; | |
480 | } else { | |
fb16b8cf SB |
481 | setup_timer(timer, stub_timer, 0); |
482 | return 1; | |
c6f3a97f TG |
483 | } |
484 | return 0; | |
485 | ||
486 | case ODEBUG_STATE_ACTIVE: | |
487 | WARN_ON(1); | |
488 | ||
489 | default: | |
490 | return 0; | |
491 | } | |
492 | } | |
493 | ||
494 | /* | |
495 | * fixup_free is called when: | |
496 | * - an active object is freed | |
497 | */ | |
498 | static int timer_fixup_free(void *addr, enum debug_obj_state state) | |
499 | { | |
500 | struct timer_list *timer = addr; | |
501 | ||
502 | switch (state) { | |
503 | case ODEBUG_STATE_ACTIVE: | |
504 | del_timer_sync(timer); | |
505 | debug_object_free(timer, &timer_debug_descr); | |
506 | return 1; | |
507 | default: | |
508 | return 0; | |
509 | } | |
510 | } | |
511 | ||
dc4218bd CC |
512 | /* |
513 | * fixup_assert_init is called when: | |
514 | * - an untracked/uninit-ed object is found | |
515 | */ | |
516 | static int timer_fixup_assert_init(void *addr, enum debug_obj_state state) | |
517 | { | |
518 | struct timer_list *timer = addr; | |
519 | ||
520 | switch (state) { | |
521 | case ODEBUG_STATE_NOTAVAILABLE: | |
522 | if (timer->entry.prev == TIMER_ENTRY_STATIC) { | |
523 | /* | |
524 | * This is not really a fixup. The timer was | |
525 | * statically initialized. We just make sure that it | |
526 | * is tracked in the object tracker. | |
527 | */ | |
528 | debug_object_init(timer, &timer_debug_descr); | |
529 | return 0; | |
530 | } else { | |
531 | setup_timer(timer, stub_timer, 0); | |
532 | return 1; | |
533 | } | |
534 | default: | |
535 | return 0; | |
536 | } | |
537 | } | |
538 | ||
c6f3a97f | 539 | static struct debug_obj_descr timer_debug_descr = { |
dc4218bd CC |
540 | .name = "timer_list", |
541 | .debug_hint = timer_debug_hint, | |
542 | .fixup_init = timer_fixup_init, | |
543 | .fixup_activate = timer_fixup_activate, | |
544 | .fixup_free = timer_fixup_free, | |
545 | .fixup_assert_init = timer_fixup_assert_init, | |
c6f3a97f TG |
546 | }; |
547 | ||
548 | static inline void debug_timer_init(struct timer_list *timer) | |
549 | { | |
550 | debug_object_init(timer, &timer_debug_descr); | |
551 | } | |
552 | ||
553 | static inline void debug_timer_activate(struct timer_list *timer) | |
554 | { | |
555 | debug_object_activate(timer, &timer_debug_descr); | |
556 | } | |
557 | ||
558 | static inline void debug_timer_deactivate(struct timer_list *timer) | |
559 | { | |
560 | debug_object_deactivate(timer, &timer_debug_descr); | |
561 | } | |
562 | ||
563 | static inline void debug_timer_free(struct timer_list *timer) | |
564 | { | |
565 | debug_object_free(timer, &timer_debug_descr); | |
566 | } | |
567 | ||
dc4218bd CC |
568 | static inline void debug_timer_assert_init(struct timer_list *timer) |
569 | { | |
570 | debug_object_assert_init(timer, &timer_debug_descr); | |
571 | } | |
572 | ||
fc683995 TH |
573 | static void do_init_timer(struct timer_list *timer, unsigned int flags, |
574 | const char *name, struct lock_class_key *key); | |
c6f3a97f | 575 | |
fc683995 TH |
576 | void init_timer_on_stack_key(struct timer_list *timer, unsigned int flags, |
577 | const char *name, struct lock_class_key *key) | |
c6f3a97f TG |
578 | { |
579 | debug_object_init_on_stack(timer, &timer_debug_descr); | |
fc683995 | 580 | do_init_timer(timer, flags, name, key); |
c6f3a97f | 581 | } |
6f2b9b9a | 582 | EXPORT_SYMBOL_GPL(init_timer_on_stack_key); |
c6f3a97f TG |
583 | |
584 | void destroy_timer_on_stack(struct timer_list *timer) | |
585 | { | |
586 | debug_object_free(timer, &timer_debug_descr); | |
587 | } | |
588 | EXPORT_SYMBOL_GPL(destroy_timer_on_stack); | |
589 | ||
590 | #else | |
591 | static inline void debug_timer_init(struct timer_list *timer) { } | |
592 | static inline void debug_timer_activate(struct timer_list *timer) { } | |
593 | static inline void debug_timer_deactivate(struct timer_list *timer) { } | |
dc4218bd | 594 | static inline void debug_timer_assert_init(struct timer_list *timer) { } |
c6f3a97f TG |
595 | #endif |
596 | ||
2b022e3d XG |
597 | static inline void debug_init(struct timer_list *timer) |
598 | { | |
599 | debug_timer_init(timer); | |
600 | trace_timer_init(timer); | |
601 | } | |
602 | ||
603 | static inline void | |
604 | debug_activate(struct timer_list *timer, unsigned long expires) | |
605 | { | |
606 | debug_timer_activate(timer); | |
607 | trace_timer_start(timer, expires); | |
608 | } | |
609 | ||
610 | static inline void debug_deactivate(struct timer_list *timer) | |
611 | { | |
612 | debug_timer_deactivate(timer); | |
613 | trace_timer_cancel(timer); | |
614 | } | |
615 | ||
dc4218bd CC |
616 | static inline void debug_assert_init(struct timer_list *timer) |
617 | { | |
618 | debug_timer_assert_init(timer); | |
619 | } | |
620 | ||
fc683995 TH |
621 | static void do_init_timer(struct timer_list *timer, unsigned int flags, |
622 | const char *name, struct lock_class_key *key) | |
55c888d6 | 623 | { |
fc683995 TH |
624 | struct tvec_base *base = __raw_get_cpu_var(tvec_bases); |
625 | ||
55c888d6 | 626 | timer->entry.next = NULL; |
fc683995 | 627 | timer->base = (void *)((unsigned long)base | flags); |
3bbb9ec9 | 628 | timer->slack = -1; |
82f67cd9 IM |
629 | #ifdef CONFIG_TIMER_STATS |
630 | timer->start_site = NULL; | |
631 | timer->start_pid = -1; | |
632 | memset(timer->start_comm, 0, TASK_COMM_LEN); | |
633 | #endif | |
6f2b9b9a | 634 | lockdep_init_map(&timer->lockdep_map, name, key, 0); |
55c888d6 | 635 | } |
c6f3a97f TG |
636 | |
637 | /** | |
633fe795 | 638 | * init_timer_key - initialize a timer |
c6f3a97f | 639 | * @timer: the timer to be initialized |
fc683995 | 640 | * @flags: timer flags |
633fe795 RD |
641 | * @name: name of the timer |
642 | * @key: lockdep class key of the fake lock used for tracking timer | |
643 | * sync lock dependencies | |
c6f3a97f | 644 | * |
633fe795 | 645 | * init_timer_key() must be done to a timer prior calling *any* of the |
c6f3a97f TG |
646 | * other timer functions. |
647 | */ | |
fc683995 TH |
648 | void init_timer_key(struct timer_list *timer, unsigned int flags, |
649 | const char *name, struct lock_class_key *key) | |
c6f3a97f | 650 | { |
2b022e3d | 651 | debug_init(timer); |
fc683995 | 652 | do_init_timer(timer, flags, name, key); |
c6f3a97f | 653 | } |
6f2b9b9a | 654 | EXPORT_SYMBOL(init_timer_key); |
55c888d6 | 655 | |
ec44bc7a | 656 | static inline void detach_timer(struct timer_list *timer, bool clear_pending) |
55c888d6 ON |
657 | { |
658 | struct list_head *entry = &timer->entry; | |
659 | ||
2b022e3d | 660 | debug_deactivate(timer); |
c6f3a97f | 661 | |
55c888d6 ON |
662 | __list_del(entry->prev, entry->next); |
663 | if (clear_pending) | |
664 | entry->next = NULL; | |
665 | entry->prev = LIST_POISON2; | |
666 | } | |
667 | ||
99d5f3aa TG |
668 | static inline void |
669 | detach_expired_timer(struct timer_list *timer, struct tvec_base *base) | |
670 | { | |
671 | detach_timer(timer, true); | |
672 | if (!tbase_get_deferrable(timer->base)) | |
e52b1db3 | 673 | base->active_timers--; |
99d5f3aa TG |
674 | } |
675 | ||
ec44bc7a TG |
676 | static int detach_if_pending(struct timer_list *timer, struct tvec_base *base, |
677 | bool clear_pending) | |
678 | { | |
679 | if (!timer_pending(timer)) | |
680 | return 0; | |
681 | ||
682 | detach_timer(timer, clear_pending); | |
99d5f3aa | 683 | if (!tbase_get_deferrable(timer->base)) { |
e52b1db3 | 684 | base->active_timers--; |
99d5f3aa TG |
685 | if (timer->expires == base->next_timer) |
686 | base->next_timer = base->timer_jiffies; | |
687 | } | |
ec44bc7a TG |
688 | return 1; |
689 | } | |
690 | ||
55c888d6 | 691 | /* |
3691c519 | 692 | * We are using hashed locking: holding per_cpu(tvec_bases).lock |
55c888d6 ON |
693 | * means that all timers which are tied to this base via timer->base are |
694 | * locked, and the base itself is locked too. | |
695 | * | |
696 | * So __run_timers/migrate_timers can safely modify all timers which could | |
697 | * be found on ->tvX lists. | |
698 | * | |
699 | * When the timer's base is locked, and the timer removed from list, it is | |
700 | * possible to set timer->base = NULL and drop the lock: the timer remains | |
701 | * locked. | |
702 | */ | |
a6fa8e5a | 703 | static struct tvec_base *lock_timer_base(struct timer_list *timer, |
55c888d6 | 704 | unsigned long *flags) |
89e7e374 | 705 | __acquires(timer->base->lock) |
55c888d6 | 706 | { |
a6fa8e5a | 707 | struct tvec_base *base; |
55c888d6 ON |
708 | |
709 | for (;;) { | |
a6fa8e5a | 710 | struct tvec_base *prelock_base = timer->base; |
6e453a67 | 711 | base = tbase_get_base(prelock_base); |
55c888d6 ON |
712 | if (likely(base != NULL)) { |
713 | spin_lock_irqsave(&base->lock, *flags); | |
6e453a67 | 714 | if (likely(prelock_base == timer->base)) |
55c888d6 ON |
715 | return base; |
716 | /* The timer has migrated to another CPU */ | |
717 | spin_unlock_irqrestore(&base->lock, *flags); | |
718 | } | |
719 | cpu_relax(); | |
720 | } | |
721 | } | |
722 | ||
74019224 | 723 | static inline int |
597d0275 AB |
724 | __mod_timer(struct timer_list *timer, unsigned long expires, |
725 | bool pending_only, int pinned) | |
1da177e4 | 726 | { |
a6fa8e5a | 727 | struct tvec_base *base, *new_base; |
1da177e4 | 728 | unsigned long flags; |
eea08f32 | 729 | int ret = 0 , cpu; |
1da177e4 | 730 | |
82f67cd9 | 731 | timer_stats_timer_set_start_info(timer); |
1da177e4 | 732 | BUG_ON(!timer->function); |
1da177e4 | 733 | |
55c888d6 ON |
734 | base = lock_timer_base(timer, &flags); |
735 | ||
ec44bc7a TG |
736 | ret = detach_if_pending(timer, base, false); |
737 | if (!ret && pending_only) | |
738 | goto out_unlock; | |
55c888d6 | 739 | |
2b022e3d | 740 | debug_activate(timer, expires); |
c6f3a97f | 741 | |
eea08f32 AB |
742 | cpu = smp_processor_id(); |
743 | ||
3451d024 | 744 | #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP) |
83cd4fe2 VP |
745 | if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu)) |
746 | cpu = get_nohz_timer_target(); | |
eea08f32 AB |
747 | #endif |
748 | new_base = per_cpu(tvec_bases, cpu); | |
749 | ||
3691c519 | 750 | if (base != new_base) { |
1da177e4 | 751 | /* |
55c888d6 ON |
752 | * We are trying to schedule the timer on the local CPU. |
753 | * However we can't change timer's base while it is running, | |
754 | * otherwise del_timer_sync() can't detect that the timer's | |
755 | * handler yet has not finished. This also guarantees that | |
756 | * the timer is serialized wrt itself. | |
1da177e4 | 757 | */ |
a2c348fe | 758 | if (likely(base->running_timer != timer)) { |
55c888d6 | 759 | /* See the comment in lock_timer_base() */ |
6e453a67 | 760 | timer_set_base(timer, NULL); |
55c888d6 | 761 | spin_unlock(&base->lock); |
a2c348fe ON |
762 | base = new_base; |
763 | spin_lock(&base->lock); | |
6e453a67 | 764 | timer_set_base(timer, base); |
1da177e4 LT |
765 | } |
766 | } | |
767 | ||
1da177e4 | 768 | timer->expires = expires; |
a2c348fe | 769 | internal_add_timer(base, timer); |
74019224 IM |
770 | |
771 | out_unlock: | |
a2c348fe | 772 | spin_unlock_irqrestore(&base->lock, flags); |
1da177e4 LT |
773 | |
774 | return ret; | |
775 | } | |
776 | ||
2aae4a10 | 777 | /** |
74019224 IM |
778 | * mod_timer_pending - modify a pending timer's timeout |
779 | * @timer: the pending timer to be modified | |
780 | * @expires: new timeout in jiffies | |
1da177e4 | 781 | * |
74019224 IM |
782 | * mod_timer_pending() is the same for pending timers as mod_timer(), |
783 | * but will not re-activate and modify already deleted timers. | |
784 | * | |
785 | * It is useful for unserialized use of timers. | |
1da177e4 | 786 | */ |
74019224 | 787 | int mod_timer_pending(struct timer_list *timer, unsigned long expires) |
1da177e4 | 788 | { |
597d0275 | 789 | return __mod_timer(timer, expires, true, TIMER_NOT_PINNED); |
1da177e4 | 790 | } |
74019224 | 791 | EXPORT_SYMBOL(mod_timer_pending); |
1da177e4 | 792 | |
3bbb9ec9 AV |
793 | /* |
794 | * Decide where to put the timer while taking the slack into account | |
795 | * | |
796 | * Algorithm: | |
797 | * 1) calculate the maximum (absolute) time | |
798 | * 2) calculate the highest bit where the expires and new max are different | |
799 | * 3) use this bit to make a mask | |
800 | * 4) use the bitmask to round down the maximum time, so that all last | |
801 | * bits are zeros | |
802 | */ | |
803 | static inline | |
804 | unsigned long apply_slack(struct timer_list *timer, unsigned long expires) | |
805 | { | |
806 | unsigned long expires_limit, mask; | |
807 | int bit; | |
808 | ||
8e63d779 | 809 | if (timer->slack >= 0) { |
f00e047e | 810 | expires_limit = expires + timer->slack; |
8e63d779 | 811 | } else { |
1c3cc116 SAS |
812 | long delta = expires - jiffies; |
813 | ||
814 | if (delta < 256) | |
815 | return expires; | |
3bbb9ec9 | 816 | |
1c3cc116 | 817 | expires_limit = expires + delta / 256; |
8e63d779 | 818 | } |
3bbb9ec9 | 819 | mask = expires ^ expires_limit; |
3bbb9ec9 AV |
820 | if (mask == 0) |
821 | return expires; | |
822 | ||
823 | bit = find_last_bit(&mask, BITS_PER_LONG); | |
824 | ||
825 | mask = (1 << bit) - 1; | |
826 | ||
827 | expires_limit = expires_limit & ~(mask); | |
828 | ||
829 | return expires_limit; | |
830 | } | |
831 | ||
2aae4a10 | 832 | /** |
1da177e4 LT |
833 | * mod_timer - modify a timer's timeout |
834 | * @timer: the timer to be modified | |
2aae4a10 | 835 | * @expires: new timeout in jiffies |
1da177e4 | 836 | * |
72fd4a35 | 837 | * mod_timer() is a more efficient way to update the expire field of an |
1da177e4 LT |
838 | * active timer (if the timer is inactive it will be activated) |
839 | * | |
840 | * mod_timer(timer, expires) is equivalent to: | |
841 | * | |
842 | * del_timer(timer); timer->expires = expires; add_timer(timer); | |
843 | * | |
844 | * Note that if there are multiple unserialized concurrent users of the | |
845 | * same timer, then mod_timer() is the only safe way to modify the timeout, | |
846 | * since add_timer() cannot modify an already running timer. | |
847 | * | |
848 | * The function returns whether it has modified a pending timer or not. | |
849 | * (ie. mod_timer() of an inactive timer returns 0, mod_timer() of an | |
850 | * active timer returns 1.) | |
851 | */ | |
852 | int mod_timer(struct timer_list *timer, unsigned long expires) | |
853 | { | |
1c3cc116 SAS |
854 | expires = apply_slack(timer, expires); |
855 | ||
1da177e4 LT |
856 | /* |
857 | * This is a common optimization triggered by the | |
858 | * networking code - if the timer is re-modified | |
859 | * to be the same thing then just return: | |
860 | */ | |
4841158b | 861 | if (timer_pending(timer) && timer->expires == expires) |
1da177e4 LT |
862 | return 1; |
863 | ||
597d0275 | 864 | return __mod_timer(timer, expires, false, TIMER_NOT_PINNED); |
1da177e4 | 865 | } |
1da177e4 LT |
866 | EXPORT_SYMBOL(mod_timer); |
867 | ||
597d0275 AB |
868 | /** |
869 | * mod_timer_pinned - modify a timer's timeout | |
870 | * @timer: the timer to be modified | |
871 | * @expires: new timeout in jiffies | |
872 | * | |
873 | * mod_timer_pinned() is a way to update the expire field of an | |
874 | * active timer (if the timer is inactive it will be activated) | |
048a0e8f PM |
875 | * and to ensure that the timer is scheduled on the current CPU. |
876 | * | |
877 | * Note that this does not prevent the timer from being migrated | |
878 | * when the current CPU goes offline. If this is a problem for | |
879 | * you, use CPU-hotplug notifiers to handle it correctly, for | |
880 | * example, cancelling the timer when the corresponding CPU goes | |
881 | * offline. | |
597d0275 AB |
882 | * |
883 | * mod_timer_pinned(timer, expires) is equivalent to: | |
884 | * | |
885 | * del_timer(timer); timer->expires = expires; add_timer(timer); | |
886 | */ | |
887 | int mod_timer_pinned(struct timer_list *timer, unsigned long expires) | |
888 | { | |
889 | if (timer->expires == expires && timer_pending(timer)) | |
890 | return 1; | |
891 | ||
892 | return __mod_timer(timer, expires, false, TIMER_PINNED); | |
893 | } | |
894 | EXPORT_SYMBOL(mod_timer_pinned); | |
895 | ||
74019224 IM |
896 | /** |
897 | * add_timer - start a timer | |
898 | * @timer: the timer to be added | |
899 | * | |
900 | * The kernel will do a ->function(->data) callback from the | |
901 | * timer interrupt at the ->expires point in the future. The | |
902 | * current time is 'jiffies'. | |
903 | * | |
904 | * The timer's ->expires, ->function (and if the handler uses it, ->data) | |
905 | * fields must be set prior calling this function. | |
906 | * | |
907 | * Timers with an ->expires field in the past will be executed in the next | |
908 | * timer tick. | |
909 | */ | |
910 | void add_timer(struct timer_list *timer) | |
911 | { | |
912 | BUG_ON(timer_pending(timer)); | |
913 | mod_timer(timer, timer->expires); | |
914 | } | |
915 | EXPORT_SYMBOL(add_timer); | |
916 | ||
917 | /** | |
918 | * add_timer_on - start a timer on a particular CPU | |
919 | * @timer: the timer to be added | |
920 | * @cpu: the CPU to start it on | |
921 | * | |
922 | * This is not very scalable on SMP. Double adds are not possible. | |
923 | */ | |
924 | void add_timer_on(struct timer_list *timer, int cpu) | |
925 | { | |
926 | struct tvec_base *base = per_cpu(tvec_bases, cpu); | |
927 | unsigned long flags; | |
928 | ||
929 | timer_stats_timer_set_start_info(timer); | |
930 | BUG_ON(timer_pending(timer) || !timer->function); | |
931 | spin_lock_irqsave(&base->lock, flags); | |
932 | timer_set_base(timer, base); | |
2b022e3d | 933 | debug_activate(timer, timer->expires); |
74019224 IM |
934 | internal_add_timer(base, timer); |
935 | /* | |
1c20091e FW |
936 | * Check whether the other CPU is in dynticks mode and needs |
937 | * to be triggered to reevaluate the timer wheel. | |
938 | * We are protected against the other CPU fiddling | |
74019224 | 939 | * with the timer by holding the timer base lock. This also |
1c20091e FW |
940 | * makes sure that a CPU on the way to stop its tick can not |
941 | * evaluate the timer wheel. | |
74019224 | 942 | */ |
1c20091e | 943 | wake_up_nohz_cpu(cpu); |
74019224 IM |
944 | spin_unlock_irqrestore(&base->lock, flags); |
945 | } | |
a9862e05 | 946 | EXPORT_SYMBOL_GPL(add_timer_on); |
74019224 | 947 | |
2aae4a10 | 948 | /** |
1da177e4 LT |
949 | * del_timer - deactive a timer. |
950 | * @timer: the timer to be deactivated | |
951 | * | |
952 | * del_timer() deactivates a timer - this works on both active and inactive | |
953 | * timers. | |
954 | * | |
955 | * The function returns whether it has deactivated a pending timer or not. | |
956 | * (ie. del_timer() of an inactive timer returns 0, del_timer() of an | |
957 | * active timer returns 1.) | |
958 | */ | |
959 | int del_timer(struct timer_list *timer) | |
960 | { | |
a6fa8e5a | 961 | struct tvec_base *base; |
1da177e4 | 962 | unsigned long flags; |
55c888d6 | 963 | int ret = 0; |
1da177e4 | 964 | |
dc4218bd CC |
965 | debug_assert_init(timer); |
966 | ||
82f67cd9 | 967 | timer_stats_timer_clear_start_info(timer); |
55c888d6 ON |
968 | if (timer_pending(timer)) { |
969 | base = lock_timer_base(timer, &flags); | |
ec44bc7a | 970 | ret = detach_if_pending(timer, base, true); |
1da177e4 | 971 | spin_unlock_irqrestore(&base->lock, flags); |
1da177e4 | 972 | } |
1da177e4 | 973 | |
55c888d6 | 974 | return ret; |
1da177e4 | 975 | } |
1da177e4 LT |
976 | EXPORT_SYMBOL(del_timer); |
977 | ||
2aae4a10 REB |
978 | /** |
979 | * try_to_del_timer_sync - Try to deactivate a timer | |
980 | * @timer: timer do del | |
981 | * | |
fd450b73 ON |
982 | * This function tries to deactivate a timer. Upon successful (ret >= 0) |
983 | * exit the timer is not queued and the handler is not running on any CPU. | |
fd450b73 ON |
984 | */ |
985 | int try_to_del_timer_sync(struct timer_list *timer) | |
986 | { | |
a6fa8e5a | 987 | struct tvec_base *base; |
fd450b73 ON |
988 | unsigned long flags; |
989 | int ret = -1; | |
990 | ||
dc4218bd CC |
991 | debug_assert_init(timer); |
992 | ||
fd450b73 ON |
993 | base = lock_timer_base(timer, &flags); |
994 | ||
ec44bc7a TG |
995 | if (base->running_timer != timer) { |
996 | timer_stats_timer_clear_start_info(timer); | |
997 | ret = detach_if_pending(timer, base, true); | |
fd450b73 | 998 | } |
fd450b73 ON |
999 | spin_unlock_irqrestore(&base->lock, flags); |
1000 | ||
1001 | return ret; | |
1002 | } | |
e19dff1f DH |
1003 | EXPORT_SYMBOL(try_to_del_timer_sync); |
1004 | ||
6f1bc451 | 1005 | #ifdef CONFIG_SMP |
2aae4a10 | 1006 | /** |
1da177e4 LT |
1007 | * del_timer_sync - deactivate a timer and wait for the handler to finish. |
1008 | * @timer: the timer to be deactivated | |
1009 | * | |
1010 | * This function only differs from del_timer() on SMP: besides deactivating | |
1011 | * the timer it also makes sure the handler has finished executing on other | |
1012 | * CPUs. | |
1013 | * | |
72fd4a35 | 1014 | * Synchronization rules: Callers must prevent restarting of the timer, |
1da177e4 | 1015 | * otherwise this function is meaningless. It must not be called from |
c5f66e99 TH |
1016 | * interrupt contexts unless the timer is an irqsafe one. The caller must |
1017 | * not hold locks which would prevent completion of the timer's | |
1018 | * handler. The timer's handler must not call add_timer_on(). Upon exit the | |
1019 | * timer is not queued and the handler is not running on any CPU. | |
1da177e4 | 1020 | * |
c5f66e99 TH |
1021 | * Note: For !irqsafe timers, you must not hold locks that are held in |
1022 | * interrupt context while calling this function. Even if the lock has | |
1023 | * nothing to do with the timer in question. Here's why: | |
48228f7b SR |
1024 | * |
1025 | * CPU0 CPU1 | |
1026 | * ---- ---- | |
1027 | * <SOFTIRQ> | |
1028 | * call_timer_fn(); | |
1029 | * base->running_timer = mytimer; | |
1030 | * spin_lock_irq(somelock); | |
1031 | * <IRQ> | |
1032 | * spin_lock(somelock); | |
1033 | * del_timer_sync(mytimer); | |
1034 | * while (base->running_timer == mytimer); | |
1035 | * | |
1036 | * Now del_timer_sync() will never return and never release somelock. | |
1037 | * The interrupt on the other CPU is waiting to grab somelock but | |
1038 | * it has interrupted the softirq that CPU0 is waiting to finish. | |
1039 | * | |
1da177e4 | 1040 | * The function returns whether it has deactivated a pending timer or not. |
1da177e4 LT |
1041 | */ |
1042 | int del_timer_sync(struct timer_list *timer) | |
1043 | { | |
6f2b9b9a | 1044 | #ifdef CONFIG_LOCKDEP |
f266a511 PZ |
1045 | unsigned long flags; |
1046 | ||
48228f7b SR |
1047 | /* |
1048 | * If lockdep gives a backtrace here, please reference | |
1049 | * the synchronization rules above. | |
1050 | */ | |
7ff20792 | 1051 | local_irq_save(flags); |
6f2b9b9a JB |
1052 | lock_map_acquire(&timer->lockdep_map); |
1053 | lock_map_release(&timer->lockdep_map); | |
7ff20792 | 1054 | local_irq_restore(flags); |
6f2b9b9a | 1055 | #endif |
466bd303 YZ |
1056 | /* |
1057 | * don't use it in hardirq context, because it | |
1058 | * could lead to deadlock. | |
1059 | */ | |
c5f66e99 | 1060 | WARN_ON(in_irq() && !tbase_get_irqsafe(timer->base)); |
fd450b73 ON |
1061 | for (;;) { |
1062 | int ret = try_to_del_timer_sync(timer); | |
1063 | if (ret >= 0) | |
1064 | return ret; | |
a0009652 | 1065 | cpu_relax(); |
fd450b73 | 1066 | } |
1da177e4 | 1067 | } |
55c888d6 | 1068 | EXPORT_SYMBOL(del_timer_sync); |
1da177e4 LT |
1069 | #endif |
1070 | ||
a6fa8e5a | 1071 | static int cascade(struct tvec_base *base, struct tvec *tv, int index) |
1da177e4 LT |
1072 | { |
1073 | /* cascade all the timers from tv up one level */ | |
3439dd86 P |
1074 | struct timer_list *timer, *tmp; |
1075 | struct list_head tv_list; | |
1076 | ||
1077 | list_replace_init(tv->vec + index, &tv_list); | |
1da177e4 | 1078 | |
1da177e4 | 1079 | /* |
3439dd86 P |
1080 | * We are removing _all_ timers from the list, so we |
1081 | * don't have to detach them individually. | |
1da177e4 | 1082 | */ |
3439dd86 | 1083 | list_for_each_entry_safe(timer, tmp, &tv_list, entry) { |
6e453a67 | 1084 | BUG_ON(tbase_get_base(timer->base) != base); |
facbb4a7 TG |
1085 | /* No accounting, while moving them */ |
1086 | __internal_add_timer(base, timer); | |
1da177e4 | 1087 | } |
1da177e4 LT |
1088 | |
1089 | return index; | |
1090 | } | |
1091 | ||
576da126 TG |
1092 | static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long), |
1093 | unsigned long data) | |
1094 | { | |
1095 | int preempt_count = preempt_count(); | |
1096 | ||
1097 | #ifdef CONFIG_LOCKDEP | |
1098 | /* | |
1099 | * It is permissible to free the timer from inside the | |
1100 | * function that is called from it, this we need to take into | |
1101 | * account for lockdep too. To avoid bogus "held lock freed" | |
1102 | * warnings as well as problems when looking into | |
1103 | * timer->lockdep_map, make a copy and use that here. | |
1104 | */ | |
4d82a1de PZ |
1105 | struct lockdep_map lockdep_map; |
1106 | ||
1107 | lockdep_copy_map(&lockdep_map, &timer->lockdep_map); | |
576da126 TG |
1108 | #endif |
1109 | /* | |
1110 | * Couple the lock chain with the lock chain at | |
1111 | * del_timer_sync() by acquiring the lock_map around the fn() | |
1112 | * call here and in del_timer_sync(). | |
1113 | */ | |
1114 | lock_map_acquire(&lockdep_map); | |
1115 | ||
1116 | trace_timer_expire_entry(timer); | |
1117 | fn(data); | |
1118 | trace_timer_expire_exit(timer); | |
1119 | ||
1120 | lock_map_release(&lockdep_map); | |
1121 | ||
1122 | if (preempt_count != preempt_count()) { | |
802702e0 TG |
1123 | WARN_ONCE(1, "timer: %pF preempt leak: %08x -> %08x\n", |
1124 | fn, preempt_count, preempt_count()); | |
1125 | /* | |
1126 | * Restore the preempt count. That gives us a decent | |
1127 | * chance to survive and extract information. If the | |
1128 | * callback kept a lock held, bad luck, but not worse | |
1129 | * than the BUG() we had. | |
1130 | */ | |
1131 | preempt_count() = preempt_count; | |
576da126 TG |
1132 | } |
1133 | } | |
1134 | ||
2aae4a10 REB |
1135 | #define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK) |
1136 | ||
1137 | /** | |
1da177e4 LT |
1138 | * __run_timers - run all expired timers (if any) on this CPU. |
1139 | * @base: the timer vector to be processed. | |
1140 | * | |
1141 | * This function cascades all vectors and executes all expired timer | |
1142 | * vectors. | |
1143 | */ | |
a6fa8e5a | 1144 | static inline void __run_timers(struct tvec_base *base) |
1da177e4 LT |
1145 | { |
1146 | struct timer_list *timer; | |
1147 | ||
3691c519 | 1148 | spin_lock_irq(&base->lock); |
1da177e4 | 1149 | while (time_after_eq(jiffies, base->timer_jiffies)) { |
626ab0e6 | 1150 | struct list_head work_list; |
1da177e4 | 1151 | struct list_head *head = &work_list; |
6819457d | 1152 | int index = base->timer_jiffies & TVR_MASK; |
626ab0e6 | 1153 | |
1da177e4 LT |
1154 | /* |
1155 | * Cascade timers: | |
1156 | */ | |
1157 | if (!index && | |
1158 | (!cascade(base, &base->tv2, INDEX(0))) && | |
1159 | (!cascade(base, &base->tv3, INDEX(1))) && | |
1160 | !cascade(base, &base->tv4, INDEX(2))) | |
1161 | cascade(base, &base->tv5, INDEX(3)); | |
626ab0e6 ON |
1162 | ++base->timer_jiffies; |
1163 | list_replace_init(base->tv1.vec + index, &work_list); | |
55c888d6 | 1164 | while (!list_empty(head)) { |
1da177e4 LT |
1165 | void (*fn)(unsigned long); |
1166 | unsigned long data; | |
c5f66e99 | 1167 | bool irqsafe; |
1da177e4 | 1168 | |
b5e61818 | 1169 | timer = list_first_entry(head, struct timer_list,entry); |
6819457d TG |
1170 | fn = timer->function; |
1171 | data = timer->data; | |
c5f66e99 | 1172 | irqsafe = tbase_get_irqsafe(timer->base); |
1da177e4 | 1173 | |
82f67cd9 IM |
1174 | timer_stats_account_timer(timer); |
1175 | ||
6f1bc451 | 1176 | base->running_timer = timer; |
99d5f3aa | 1177 | detach_expired_timer(timer, base); |
6f2b9b9a | 1178 | |
c5f66e99 TH |
1179 | if (irqsafe) { |
1180 | spin_unlock(&base->lock); | |
1181 | call_timer_fn(timer, fn, data); | |
1182 | spin_lock(&base->lock); | |
1183 | } else { | |
1184 | spin_unlock_irq(&base->lock); | |
1185 | call_timer_fn(timer, fn, data); | |
1186 | spin_lock_irq(&base->lock); | |
1187 | } | |
1da177e4 LT |
1188 | } |
1189 | } | |
6f1bc451 | 1190 | base->running_timer = NULL; |
3691c519 | 1191 | spin_unlock_irq(&base->lock); |
1da177e4 LT |
1192 | } |
1193 | ||
3451d024 | 1194 | #ifdef CONFIG_NO_HZ_COMMON |
1da177e4 LT |
1195 | /* |
1196 | * Find out when the next timer event is due to happen. This | |
90cba64a RD |
1197 | * is used on S/390 to stop all activity when a CPU is idle. |
1198 | * This function needs to be called with interrupts disabled. | |
1da177e4 | 1199 | */ |
a6fa8e5a | 1200 | static unsigned long __next_timer_interrupt(struct tvec_base *base) |
1da177e4 | 1201 | { |
1cfd6849 | 1202 | unsigned long timer_jiffies = base->timer_jiffies; |
eaad084b | 1203 | unsigned long expires = timer_jiffies + NEXT_TIMER_MAX_DELTA; |
1cfd6849 | 1204 | int index, slot, array, found = 0; |
1da177e4 | 1205 | struct timer_list *nte; |
a6fa8e5a | 1206 | struct tvec *varray[4]; |
1da177e4 LT |
1207 | |
1208 | /* Look for timer events in tv1. */ | |
1cfd6849 | 1209 | index = slot = timer_jiffies & TVR_MASK; |
1da177e4 | 1210 | do { |
1cfd6849 | 1211 | list_for_each_entry(nte, base->tv1.vec + slot, entry) { |
6819457d TG |
1212 | if (tbase_get_deferrable(nte->base)) |
1213 | continue; | |
6e453a67 | 1214 | |
1cfd6849 | 1215 | found = 1; |
1da177e4 | 1216 | expires = nte->expires; |
1cfd6849 TG |
1217 | /* Look at the cascade bucket(s)? */ |
1218 | if (!index || slot < index) | |
1219 | goto cascade; | |
1220 | return expires; | |
1da177e4 | 1221 | } |
1cfd6849 TG |
1222 | slot = (slot + 1) & TVR_MASK; |
1223 | } while (slot != index); | |
1224 | ||
1225 | cascade: | |
1226 | /* Calculate the next cascade event */ | |
1227 | if (index) | |
1228 | timer_jiffies += TVR_SIZE - index; | |
1229 | timer_jiffies >>= TVR_BITS; | |
1da177e4 LT |
1230 | |
1231 | /* Check tv2-tv5. */ | |
1232 | varray[0] = &base->tv2; | |
1233 | varray[1] = &base->tv3; | |
1234 | varray[2] = &base->tv4; | |
1235 | varray[3] = &base->tv5; | |
1cfd6849 TG |
1236 | |
1237 | for (array = 0; array < 4; array++) { | |
a6fa8e5a | 1238 | struct tvec *varp = varray[array]; |
1cfd6849 TG |
1239 | |
1240 | index = slot = timer_jiffies & TVN_MASK; | |
1da177e4 | 1241 | do { |
1cfd6849 | 1242 | list_for_each_entry(nte, varp->vec + slot, entry) { |
a0419888 JH |
1243 | if (tbase_get_deferrable(nte->base)) |
1244 | continue; | |
1245 | ||
1cfd6849 | 1246 | found = 1; |
1da177e4 LT |
1247 | if (time_before(nte->expires, expires)) |
1248 | expires = nte->expires; | |
1cfd6849 TG |
1249 | } |
1250 | /* | |
1251 | * Do we still search for the first timer or are | |
1252 | * we looking up the cascade buckets ? | |
1253 | */ | |
1254 | if (found) { | |
1255 | /* Look at the cascade bucket(s)? */ | |
1256 | if (!index || slot < index) | |
1257 | break; | |
1258 | return expires; | |
1259 | } | |
1260 | slot = (slot + 1) & TVN_MASK; | |
1261 | } while (slot != index); | |
1262 | ||
1263 | if (index) | |
1264 | timer_jiffies += TVN_SIZE - index; | |
1265 | timer_jiffies >>= TVN_BITS; | |
1da177e4 | 1266 | } |
1cfd6849 TG |
1267 | return expires; |
1268 | } | |
69239749 | 1269 | |
1cfd6849 TG |
1270 | /* |
1271 | * Check, if the next hrtimer event is before the next timer wheel | |
1272 | * event: | |
1273 | */ | |
1274 | static unsigned long cmp_next_hrtimer_event(unsigned long now, | |
1275 | unsigned long expires) | |
1276 | { | |
1277 | ktime_t hr_delta = hrtimer_get_next_event(); | |
1278 | struct timespec tsdelta; | |
9501b6cf | 1279 | unsigned long delta; |
1cfd6849 TG |
1280 | |
1281 | if (hr_delta.tv64 == KTIME_MAX) | |
1282 | return expires; | |
0662b713 | 1283 | |
9501b6cf TG |
1284 | /* |
1285 | * Expired timer available, let it expire in the next tick | |
1286 | */ | |
1287 | if (hr_delta.tv64 <= 0) | |
1288 | return now + 1; | |
69239749 | 1289 | |
1cfd6849 | 1290 | tsdelta = ktime_to_timespec(hr_delta); |
9501b6cf | 1291 | delta = timespec_to_jiffies(&tsdelta); |
eaad084b TG |
1292 | |
1293 | /* | |
1294 | * Limit the delta to the max value, which is checked in | |
1295 | * tick_nohz_stop_sched_tick(): | |
1296 | */ | |
1297 | if (delta > NEXT_TIMER_MAX_DELTA) | |
1298 | delta = NEXT_TIMER_MAX_DELTA; | |
1299 | ||
9501b6cf TG |
1300 | /* |
1301 | * Take rounding errors in to account and make sure, that it | |
1302 | * expires in the next tick. Otherwise we go into an endless | |
1303 | * ping pong due to tick_nohz_stop_sched_tick() retriggering | |
1304 | * the timer softirq | |
1305 | */ | |
1306 | if (delta < 1) | |
1307 | delta = 1; | |
1308 | now += delta; | |
1cfd6849 TG |
1309 | if (time_before(now, expires)) |
1310 | return now; | |
1da177e4 LT |
1311 | return expires; |
1312 | } | |
1cfd6849 TG |
1313 | |
1314 | /** | |
8dce39c2 | 1315 | * get_next_timer_interrupt - return the jiffy of the next pending timer |
05fb6bf0 | 1316 | * @now: current time (in jiffies) |
1cfd6849 | 1317 | */ |
fd064b9b | 1318 | unsigned long get_next_timer_interrupt(unsigned long now) |
1cfd6849 | 1319 | { |
7496351a | 1320 | struct tvec_base *base = __this_cpu_read(tvec_bases); |
e40468a5 | 1321 | unsigned long expires = now + NEXT_TIMER_MAX_DELTA; |
1cfd6849 | 1322 | |
dbd87b5a HC |
1323 | /* |
1324 | * Pretend that there is no timer pending if the cpu is offline. | |
1325 | * Possible pending timers will be migrated later to an active cpu. | |
1326 | */ | |
1327 | if (cpu_is_offline(smp_processor_id())) | |
e40468a5 TG |
1328 | return expires; |
1329 | ||
1cfd6849 | 1330 | spin_lock(&base->lock); |
e40468a5 TG |
1331 | if (base->active_timers) { |
1332 | if (time_before_eq(base->next_timer, base->timer_jiffies)) | |
1333 | base->next_timer = __next_timer_interrupt(base); | |
1334 | expires = base->next_timer; | |
1335 | } | |
1cfd6849 TG |
1336 | spin_unlock(&base->lock); |
1337 | ||
1338 | if (time_before_eq(expires, now)) | |
1339 | return now; | |
1340 | ||
1341 | return cmp_next_hrtimer_event(now, expires); | |
1342 | } | |
1da177e4 LT |
1343 | #endif |
1344 | ||
1da177e4 | 1345 | /* |
5b4db0c2 | 1346 | * Called from the timer interrupt handler to charge one tick to the current |
1da177e4 LT |
1347 | * process. user_tick is 1 if the tick is user time, 0 for system. |
1348 | */ | |
1349 | void update_process_times(int user_tick) | |
1350 | { | |
1351 | struct task_struct *p = current; | |
1352 | int cpu = smp_processor_id(); | |
1353 | ||
1354 | /* Note: this timer irq context must be accounted for as well. */ | |
fa13a5a1 | 1355 | account_process_tick(p, user_tick); |
1da177e4 | 1356 | run_local_timers(); |
a157229c | 1357 | rcu_check_callbacks(cpu, user_tick); |
e360adbe PZ |
1358 | #ifdef CONFIG_IRQ_WORK |
1359 | if (in_irq()) | |
1360 | irq_work_run(); | |
1361 | #endif | |
1da177e4 | 1362 | scheduler_tick(); |
6819457d | 1363 | run_posix_cpu_timers(p); |
1da177e4 LT |
1364 | } |
1365 | ||
1da177e4 LT |
1366 | /* |
1367 | * This function runs timers and the timer-tq in bottom half context. | |
1368 | */ | |
1369 | static void run_timer_softirq(struct softirq_action *h) | |
1370 | { | |
7496351a | 1371 | struct tvec_base *base = __this_cpu_read(tvec_bases); |
1da177e4 | 1372 | |
d3d74453 | 1373 | hrtimer_run_pending(); |
82f67cd9 | 1374 | |
1da177e4 LT |
1375 | if (time_after_eq(jiffies, base->timer_jiffies)) |
1376 | __run_timers(base); | |
1377 | } | |
1378 | ||
1379 | /* | |
1380 | * Called by the local, per-CPU timer interrupt on SMP. | |
1381 | */ | |
1382 | void run_local_timers(void) | |
1383 | { | |
d3d74453 | 1384 | hrtimer_run_queues(); |
1da177e4 LT |
1385 | raise_softirq(TIMER_SOFTIRQ); |
1386 | } | |
1387 | ||
1da177e4 LT |
1388 | #ifdef __ARCH_WANT_SYS_ALARM |
1389 | ||
1390 | /* | |
1391 | * For backwards compatibility? This can be done in libc so Alpha | |
1392 | * and all newer ports shouldn't need it. | |
1393 | */ | |
58fd3aa2 | 1394 | SYSCALL_DEFINE1(alarm, unsigned int, seconds) |
1da177e4 | 1395 | { |
c08b8a49 | 1396 | return alarm_setitimer(seconds); |
1da177e4 LT |
1397 | } |
1398 | ||
1399 | #endif | |
1400 | ||
1da177e4 LT |
1401 | static void process_timeout(unsigned long __data) |
1402 | { | |
36c8b586 | 1403 | wake_up_process((struct task_struct *)__data); |
1da177e4 LT |
1404 | } |
1405 | ||
1406 | /** | |
1407 | * schedule_timeout - sleep until timeout | |
1408 | * @timeout: timeout value in jiffies | |
1409 | * | |
1410 | * Make the current task sleep until @timeout jiffies have | |
1411 | * elapsed. The routine will return immediately unless | |
1412 | * the current task state has been set (see set_current_state()). | |
1413 | * | |
1414 | * You can set the task state as follows - | |
1415 | * | |
1416 | * %TASK_UNINTERRUPTIBLE - at least @timeout jiffies are guaranteed to | |
1417 | * pass before the routine returns. The routine will return 0 | |
1418 | * | |
1419 | * %TASK_INTERRUPTIBLE - the routine may return early if a signal is | |
1420 | * delivered to the current task. In this case the remaining time | |
1421 | * in jiffies will be returned, or 0 if the timer expired in time | |
1422 | * | |
1423 | * The current task state is guaranteed to be TASK_RUNNING when this | |
1424 | * routine returns. | |
1425 | * | |
1426 | * Specifying a @timeout value of %MAX_SCHEDULE_TIMEOUT will schedule | |
1427 | * the CPU away without a bound on the timeout. In this case the return | |
1428 | * value will be %MAX_SCHEDULE_TIMEOUT. | |
1429 | * | |
1430 | * In all cases the return value is guaranteed to be non-negative. | |
1431 | */ | |
7ad5b3a5 | 1432 | signed long __sched schedule_timeout(signed long timeout) |
1da177e4 LT |
1433 | { |
1434 | struct timer_list timer; | |
1435 | unsigned long expire; | |
1436 | ||
1437 | switch (timeout) | |
1438 | { | |
1439 | case MAX_SCHEDULE_TIMEOUT: | |
1440 | /* | |
1441 | * These two special cases are useful to be comfortable | |
1442 | * in the caller. Nothing more. We could take | |
1443 | * MAX_SCHEDULE_TIMEOUT from one of the negative value | |
1444 | * but I' d like to return a valid offset (>=0) to allow | |
1445 | * the caller to do everything it want with the retval. | |
1446 | */ | |
1447 | schedule(); | |
1448 | goto out; | |
1449 | default: | |
1450 | /* | |
1451 | * Another bit of PARANOID. Note that the retval will be | |
1452 | * 0 since no piece of kernel is supposed to do a check | |
1453 | * for a negative retval of schedule_timeout() (since it | |
1454 | * should never happens anyway). You just have the printk() | |
1455 | * that will tell you if something is gone wrong and where. | |
1456 | */ | |
5b149bcc | 1457 | if (timeout < 0) { |
1da177e4 | 1458 | printk(KERN_ERR "schedule_timeout: wrong timeout " |
5b149bcc AM |
1459 | "value %lx\n", timeout); |
1460 | dump_stack(); | |
1da177e4 LT |
1461 | current->state = TASK_RUNNING; |
1462 | goto out; | |
1463 | } | |
1464 | } | |
1465 | ||
1466 | expire = timeout + jiffies; | |
1467 | ||
c6f3a97f | 1468 | setup_timer_on_stack(&timer, process_timeout, (unsigned long)current); |
597d0275 | 1469 | __mod_timer(&timer, expire, false, TIMER_NOT_PINNED); |
1da177e4 LT |
1470 | schedule(); |
1471 | del_singleshot_timer_sync(&timer); | |
1472 | ||
c6f3a97f TG |
1473 | /* Remove the timer from the object tracker */ |
1474 | destroy_timer_on_stack(&timer); | |
1475 | ||
1da177e4 LT |
1476 | timeout = expire - jiffies; |
1477 | ||
1478 | out: | |
1479 | return timeout < 0 ? 0 : timeout; | |
1480 | } | |
1da177e4 LT |
1481 | EXPORT_SYMBOL(schedule_timeout); |
1482 | ||
8a1c1757 AM |
1483 | /* |
1484 | * We can use __set_current_state() here because schedule_timeout() calls | |
1485 | * schedule() unconditionally. | |
1486 | */ | |
64ed93a2 NA |
1487 | signed long __sched schedule_timeout_interruptible(signed long timeout) |
1488 | { | |
a5a0d52c AM |
1489 | __set_current_state(TASK_INTERRUPTIBLE); |
1490 | return schedule_timeout(timeout); | |
64ed93a2 NA |
1491 | } |
1492 | EXPORT_SYMBOL(schedule_timeout_interruptible); | |
1493 | ||
294d5cc2 MW |
1494 | signed long __sched schedule_timeout_killable(signed long timeout) |
1495 | { | |
1496 | __set_current_state(TASK_KILLABLE); | |
1497 | return schedule_timeout(timeout); | |
1498 | } | |
1499 | EXPORT_SYMBOL(schedule_timeout_killable); | |
1500 | ||
64ed93a2 NA |
1501 | signed long __sched schedule_timeout_uninterruptible(signed long timeout) |
1502 | { | |
a5a0d52c AM |
1503 | __set_current_state(TASK_UNINTERRUPTIBLE); |
1504 | return schedule_timeout(timeout); | |
64ed93a2 NA |
1505 | } |
1506 | EXPORT_SYMBOL(schedule_timeout_uninterruptible); | |
1507 | ||
0db0628d | 1508 | static int init_timers_cpu(int cpu) |
1da177e4 LT |
1509 | { |
1510 | int j; | |
a6fa8e5a | 1511 | struct tvec_base *base; |
0db0628d | 1512 | static char tvec_base_done[NR_CPUS]; |
55c888d6 | 1513 | |
ba6edfcd | 1514 | if (!tvec_base_done[cpu]) { |
a4a6198b JB |
1515 | static char boot_done; |
1516 | ||
a4a6198b | 1517 | if (boot_done) { |
ba6edfcd AM |
1518 | /* |
1519 | * The APs use this path later in boot | |
1520 | */ | |
94f6030c CL |
1521 | base = kmalloc_node(sizeof(*base), |
1522 | GFP_KERNEL | __GFP_ZERO, | |
a4a6198b JB |
1523 | cpu_to_node(cpu)); |
1524 | if (!base) | |
1525 | return -ENOMEM; | |
6e453a67 VP |
1526 | |
1527 | /* Make sure that tvec_base is 2 byte aligned */ | |
1528 | if (tbase_get_deferrable(base)) { | |
1529 | WARN_ON(1); | |
1530 | kfree(base); | |
1531 | return -ENOMEM; | |
1532 | } | |
ba6edfcd | 1533 | per_cpu(tvec_bases, cpu) = base; |
a4a6198b | 1534 | } else { |
ba6edfcd AM |
1535 | /* |
1536 | * This is for the boot CPU - we use compile-time | |
1537 | * static initialisation because per-cpu memory isn't | |
1538 | * ready yet and because the memory allocators are not | |
1539 | * initialised either. | |
1540 | */ | |
a4a6198b | 1541 | boot_done = 1; |
ba6edfcd | 1542 | base = &boot_tvec_bases; |
a4a6198b | 1543 | } |
42a5cf46 | 1544 | spin_lock_init(&base->lock); |
ba6edfcd AM |
1545 | tvec_base_done[cpu] = 1; |
1546 | } else { | |
1547 | base = per_cpu(tvec_bases, cpu); | |
a4a6198b | 1548 | } |
ba6edfcd | 1549 | |
d730e882 | 1550 | |
1da177e4 LT |
1551 | for (j = 0; j < TVN_SIZE; j++) { |
1552 | INIT_LIST_HEAD(base->tv5.vec + j); | |
1553 | INIT_LIST_HEAD(base->tv4.vec + j); | |
1554 | INIT_LIST_HEAD(base->tv3.vec + j); | |
1555 | INIT_LIST_HEAD(base->tv2.vec + j); | |
1556 | } | |
1557 | for (j = 0; j < TVR_SIZE; j++) | |
1558 | INIT_LIST_HEAD(base->tv1.vec + j); | |
1559 | ||
1560 | base->timer_jiffies = jiffies; | |
97fd9ed4 | 1561 | base->next_timer = base->timer_jiffies; |
99d5f3aa | 1562 | base->active_timers = 0; |
a4a6198b | 1563 | return 0; |
1da177e4 LT |
1564 | } |
1565 | ||
1566 | #ifdef CONFIG_HOTPLUG_CPU | |
a6fa8e5a | 1567 | static void migrate_timer_list(struct tvec_base *new_base, struct list_head *head) |
1da177e4 LT |
1568 | { |
1569 | struct timer_list *timer; | |
1570 | ||
1571 | while (!list_empty(head)) { | |
b5e61818 | 1572 | timer = list_first_entry(head, struct timer_list, entry); |
99d5f3aa | 1573 | /* We ignore the accounting on the dying cpu */ |
ec44bc7a | 1574 | detach_timer(timer, false); |
6e453a67 | 1575 | timer_set_base(timer, new_base); |
1da177e4 | 1576 | internal_add_timer(new_base, timer); |
1da177e4 | 1577 | } |
1da177e4 LT |
1578 | } |
1579 | ||
0db0628d | 1580 | static void migrate_timers(int cpu) |
1da177e4 | 1581 | { |
a6fa8e5a PM |
1582 | struct tvec_base *old_base; |
1583 | struct tvec_base *new_base; | |
1da177e4 LT |
1584 | int i; |
1585 | ||
1586 | BUG_ON(cpu_online(cpu)); | |
a4a6198b JB |
1587 | old_base = per_cpu(tvec_bases, cpu); |
1588 | new_base = get_cpu_var(tvec_bases); | |
d82f0b0f ON |
1589 | /* |
1590 | * The caller is globally serialized and nobody else | |
1591 | * takes two locks at once, deadlock is not possible. | |
1592 | */ | |
1593 | spin_lock_irq(&new_base->lock); | |
0d180406 | 1594 | spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); |
3691c519 ON |
1595 | |
1596 | BUG_ON(old_base->running_timer); | |
1da177e4 | 1597 | |
1da177e4 | 1598 | for (i = 0; i < TVR_SIZE; i++) |
55c888d6 ON |
1599 | migrate_timer_list(new_base, old_base->tv1.vec + i); |
1600 | for (i = 0; i < TVN_SIZE; i++) { | |
1601 | migrate_timer_list(new_base, old_base->tv2.vec + i); | |
1602 | migrate_timer_list(new_base, old_base->tv3.vec + i); | |
1603 | migrate_timer_list(new_base, old_base->tv4.vec + i); | |
1604 | migrate_timer_list(new_base, old_base->tv5.vec + i); | |
1605 | } | |
1606 | ||
0d180406 | 1607 | spin_unlock(&old_base->lock); |
d82f0b0f | 1608 | spin_unlock_irq(&new_base->lock); |
1da177e4 | 1609 | put_cpu_var(tvec_bases); |
1da177e4 LT |
1610 | } |
1611 | #endif /* CONFIG_HOTPLUG_CPU */ | |
1612 | ||
0db0628d | 1613 | static int timer_cpu_notify(struct notifier_block *self, |
1da177e4 LT |
1614 | unsigned long action, void *hcpu) |
1615 | { | |
1616 | long cpu = (long)hcpu; | |
80b5184c AM |
1617 | int err; |
1618 | ||
1da177e4 LT |
1619 | switch(action) { |
1620 | case CPU_UP_PREPARE: | |
8bb78442 | 1621 | case CPU_UP_PREPARE_FROZEN: |
80b5184c AM |
1622 | err = init_timers_cpu(cpu); |
1623 | if (err < 0) | |
1624 | return notifier_from_errno(err); | |
1da177e4 LT |
1625 | break; |
1626 | #ifdef CONFIG_HOTPLUG_CPU | |
1627 | case CPU_DEAD: | |
8bb78442 | 1628 | case CPU_DEAD_FROZEN: |
1da177e4 LT |
1629 | migrate_timers(cpu); |
1630 | break; | |
1631 | #endif | |
1632 | default: | |
1633 | break; | |
1634 | } | |
1635 | return NOTIFY_OK; | |
1636 | } | |
1637 | ||
0db0628d | 1638 | static struct notifier_block timers_nb = { |
1da177e4 LT |
1639 | .notifier_call = timer_cpu_notify, |
1640 | }; | |
1641 | ||
1642 | ||
1643 | void __init init_timers(void) | |
1644 | { | |
e52b1db3 TH |
1645 | int err; |
1646 | ||
1647 | /* ensure there are enough low bits for flags in timer->base pointer */ | |
1648 | BUILD_BUG_ON(__alignof__(struct tvec_base) & TIMER_FLAG_MASK); | |
07dccf33 | 1649 | |
e52b1db3 TH |
1650 | err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE, |
1651 | (void *)(long)smp_processor_id()); | |
82f67cd9 IM |
1652 | init_timer_stats(); |
1653 | ||
9e506f7a | 1654 | BUG_ON(err != NOTIFY_OK); |
1da177e4 | 1655 | register_cpu_notifier(&timers_nb); |
962cf36c | 1656 | open_softirq(TIMER_SOFTIRQ, run_timer_softirq); |
1da177e4 LT |
1657 | } |
1658 | ||
1da177e4 LT |
1659 | /** |
1660 | * msleep - sleep safely even with waitqueue interruptions | |
1661 | * @msecs: Time in milliseconds to sleep for | |
1662 | */ | |
1663 | void msleep(unsigned int msecs) | |
1664 | { | |
1665 | unsigned long timeout = msecs_to_jiffies(msecs) + 1; | |
1666 | ||
75bcc8c5 NA |
1667 | while (timeout) |
1668 | timeout = schedule_timeout_uninterruptible(timeout); | |
1da177e4 LT |
1669 | } |
1670 | ||
1671 | EXPORT_SYMBOL(msleep); | |
1672 | ||
1673 | /** | |
96ec3efd | 1674 | * msleep_interruptible - sleep waiting for signals |
1da177e4 LT |
1675 | * @msecs: Time in milliseconds to sleep for |
1676 | */ | |
1677 | unsigned long msleep_interruptible(unsigned int msecs) | |
1678 | { | |
1679 | unsigned long timeout = msecs_to_jiffies(msecs) + 1; | |
1680 | ||
75bcc8c5 NA |
1681 | while (timeout && !signal_pending(current)) |
1682 | timeout = schedule_timeout_interruptible(timeout); | |
1da177e4 LT |
1683 | return jiffies_to_msecs(timeout); |
1684 | } | |
1685 | ||
1686 | EXPORT_SYMBOL(msleep_interruptible); | |
5e7f5a17 PP |
1687 | |
1688 | static int __sched do_usleep_range(unsigned long min, unsigned long max) | |
1689 | { | |
1690 | ktime_t kmin; | |
1691 | unsigned long delta; | |
1692 | ||
1693 | kmin = ktime_set(0, min * NSEC_PER_USEC); | |
1694 | delta = (max - min) * NSEC_PER_USEC; | |
1695 | return schedule_hrtimeout_range(&kmin, delta, HRTIMER_MODE_REL); | |
1696 | } | |
1697 | ||
1698 | /** | |
1699 | * usleep_range - Drop in replacement for udelay where wakeup is flexible | |
1700 | * @min: Minimum time in usecs to sleep | |
1701 | * @max: Maximum time in usecs to sleep | |
1702 | */ | |
1703 | void usleep_range(unsigned long min, unsigned long max) | |
1704 | { | |
1705 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
1706 | do_usleep_range(min, max); | |
1707 | } | |
1708 | EXPORT_SYMBOL(usleep_range); |