1// SPDX-License-Identifier: GPL-2.0
2/*
3 * List pending timers
4 *
5 * Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
6 */
7
8#include <linux/proc_fs.h>
9#include <linux/module.h>
10#include <linux/spinlock.h>
11#include <linux/sched.h>
12#include <linux/seq_file.h>
13#include <linux/kallsyms.h>
14#include <linux/nmi.h>
15
16#include <linux/uaccess.h>
17
18#include "tick-internal.h"
19
20struct timer_list_iter {
21	int cpu;
22	bool second_pass;
23	u64 now;
24};
25
26/*
27 * This allows printing both to /proc/timer_list and
28 * to the console (on SysRq-Q):
29 */
30__printf(2, 3)
31static void SEQ_printf(struct seq_file *m, const char *fmt, ...)
32{
33	va_list args;
34
35	va_start(args, fmt);
36
37	if (m)
38		seq_vprintf(m, fmt, args);
39	else
40		vprintk(fmt, args);
41
42	va_end(args);
43}
44
45static void
46print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
47	    int idx, u64 now)
48{
49	SEQ_printf(m, " #%d: <%pK>, %ps", idx, taddr, timer->function);
50	SEQ_printf(m, ", S:%02x", timer->state);
51	SEQ_printf(m, "\n");
52	SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
53		(unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
54		(unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
55		(long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
56		(long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
57}
58
59static void
60print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
61		    u64 now)
62{
63	struct hrtimer *timer, tmp;
64	unsigned long next = 0, i;
65	struct timerqueue_node *curr;
66	unsigned long flags;
67
68next_one:
69	i = 0;
70
71	touch_nmi_watchdog();
72
73	raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
74
75	curr = timerqueue_getnext(&base->active);
76	/*
77	 * Crude but we have to do this O(N*N) thing, because
78	 * we have to unlock the base when printing:
79	 */
80	while (curr && i < next) {
81		curr = timerqueue_iterate_next(curr);
82		i++;
83	}
84
85	if (curr) {
86
87		timer = container_of(curr, struct hrtimer, node);
88		tmp = *timer;
89		raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
90
91		print_timer(m, timer, &tmp, i, now);
92		next++;
93		goto next_one;
94	}
95	raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
96}
97
98static void
99print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
100{
101	SEQ_printf(m, "  .base:       %pK\n", base);
102	SEQ_printf(m, "  .index:      %d\n", base->index);
103
104	SEQ_printf(m, "  .resolution: %u nsecs\n", hrtimer_resolution);
105
106	SEQ_printf(m,   "  .get_time:   %ps\n", base->get_time);
107#ifdef CONFIG_HIGH_RES_TIMERS
108	SEQ_printf(m, "  .offset:     %Lu nsecs\n",
109		   (unsigned long long) ktime_to_ns(base->offset));
110#endif
111	SEQ_printf(m,   "active timers:\n");
112	print_active_timers(m, base, now + ktime_to_ns(base->offset));
113}
114
115static void print_cpu(struct seq_file *m, int cpu, u64 now)
116{
117	struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
118	int i;
119
120	SEQ_printf(m, "cpu: %d\n", cpu);
121	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
122		SEQ_printf(m, " clock %d:\n", i);
123		print_base(m, cpu_base->clock_base + i, now);
124	}
125#define P(x) \
126	SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
127		   (unsigned long long)(cpu_base->x))
128#define P_ns(x) \
129	SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
130		   (unsigned long long)(ktime_to_ns(cpu_base->x)))
131
132#ifdef CONFIG_HIGH_RES_TIMERS
133	P_ns(expires_next);
134	P(hres_active);
135	P(nr_events);
136	P(nr_retries);
137	P(nr_hangs);
138	P(max_hang_time);
139#endif
140#undef P
141#undef P_ns
142
143#ifdef CONFIG_TICK_ONESHOT
144# define P(x) \
145	SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
146		   (unsigned long long)(ts->x))
147# define P_ns(x) \
148	SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
149		   (unsigned long long)(ktime_to_ns(ts->x)))
150# define P_flag(x, f)			    \
151	SEQ_printf(m, "  .%-15s: %d\n", #x, !!(ts->flags & (f)))
152
153	{
154		struct tick_sched *ts = tick_get_tick_sched(cpu);
155		P_flag(nohz, TS_FLAG_NOHZ);
156		P_flag(highres, TS_FLAG_HIGHRES);
157		P_ns(last_tick);
158		P_flag(tick_stopped, TS_FLAG_STOPPED);
159		P(idle_jiffies);
160		P(idle_calls);
161		P(idle_sleeps);
162		P_ns(idle_entrytime);
163		P_ns(idle_waketime);
164		P_ns(idle_exittime);
165		P_ns(idle_sleeptime);
166		P_ns(iowait_sleeptime);
167		P(last_jiffies);
168		P(next_timer);
169		P_ns(idle_expires);
170		SEQ_printf(m, "jiffies: %Lu\n",
171			   (unsigned long long)jiffies);
172	}
173#endif
174
175#undef P
176#undef P_ns
177	SEQ_printf(m, "\n");
178}
179
180#ifdef CONFIG_GENERIC_CLOCKEVENTS
181static void
182print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
183{
184	struct clock_event_device *dev = td->evtdev;
185
186	touch_nmi_watchdog();
187
188	SEQ_printf(m, "Tick Device: mode:     %d\n", td->mode);
189	if (cpu < 0)
190		SEQ_printf(m, "Broadcast device\n");
191	else
192		SEQ_printf(m, "Per CPU device: %d\n", cpu);
193
194	SEQ_printf(m, "Clock Event Device: ");
195	if (!dev) {
196		SEQ_printf(m, "<NULL>\n");
197		return;
198	}
199	SEQ_printf(m, "%s\n", dev->name);
200	SEQ_printf(m, " max_delta_ns:   %llu\n",
201		   (unsigned long long) dev->max_delta_ns);
202	SEQ_printf(m, " min_delta_ns:   %llu\n",
203		   (unsigned long long) dev->min_delta_ns);
204	SEQ_printf(m, " mult:           %u\n", dev->mult);
205	SEQ_printf(m, " shift:          %u\n", dev->shift);
206	SEQ_printf(m, " mode:           %d\n", clockevent_get_state(dev));
207	SEQ_printf(m, " next_event:     %Ld nsecs\n",
208		   (unsigned long long) ktime_to_ns(dev->next_event));
209
210	SEQ_printf(m, " set_next_event: %ps\n", dev->set_next_event);
211
212	if (dev->set_state_shutdown)
213		SEQ_printf(m, " shutdown:       %ps\n",
214			dev->set_state_shutdown);
215
216	if (dev->set_state_periodic)
217		SEQ_printf(m, " periodic:       %ps\n",
218			dev->set_state_periodic);
219
220	if (dev->set_state_oneshot)
221		SEQ_printf(m, " oneshot:        %ps\n",
222			dev->set_state_oneshot);
223
224	if (dev->set_state_oneshot_stopped)
225		SEQ_printf(m, " oneshot stopped: %ps\n",
226			dev->set_state_oneshot_stopped);
227
228	if (dev->tick_resume)
229		SEQ_printf(m, " resume:         %ps\n",
230			dev->tick_resume);
231
232	SEQ_printf(m, " event_handler:  %ps\n", dev->event_handler);
233	SEQ_printf(m, "\n");
234	SEQ_printf(m, " retries:        %lu\n", dev->retries);
235
236#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
237	if (cpu >= 0) {
238		const struct clock_event_device *wd = tick_get_wakeup_device(cpu);
239
240		SEQ_printf(m, "Wakeup Device: %s\n", wd ? wd->name : "<NULL>");
241	}
242#endif
243	SEQ_printf(m, "\n");
244}
245
246static void timer_list_show_tickdevices_header(struct seq_file *m)
247{
248#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
249	print_tickdevice(m, tick_get_broadcast_device(), -1);
250	SEQ_printf(m, "tick_broadcast_mask: %*pb\n",
251		   cpumask_pr_args(tick_get_broadcast_mask()));
252#ifdef CONFIG_TICK_ONESHOT
253	SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n",
254		   cpumask_pr_args(tick_get_broadcast_oneshot_mask()));
255#endif
256	SEQ_printf(m, "\n");
257#endif
258}
259#endif
260
261static inline void timer_list_header(struct seq_file *m, u64 now)
262{
263	SEQ_printf(m, "Timer List Version: v0.10\n");
264	SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
265	SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
266	SEQ_printf(m, "\n");
267}
268
269void sysrq_timer_list_show(void)
270{
271	u64 now = ktime_to_ns(ktime_get());
272	int cpu;
273
274	timer_list_header(NULL, now);
275
276	for_each_online_cpu(cpu)
277		print_cpu(NULL, cpu, now);
278
279#ifdef CONFIG_GENERIC_CLOCKEVENTS
280	timer_list_show_tickdevices_header(NULL);
281	for_each_online_cpu(cpu)
282		print_tickdevice(NULL, tick_get_device(cpu), cpu);
283#endif
284	return;
285}
286
287#ifdef CONFIG_PROC_FS
288static int timer_list_show(struct seq_file *m, void *v)
289{
290	struct timer_list_iter *iter = v;
291
292	if (iter->cpu == -1 && !iter->second_pass)
293		timer_list_header(m, iter->now);
294	else if (!iter->second_pass)
295		print_cpu(m, iter->cpu, iter->now);
296#ifdef CONFIG_GENERIC_CLOCKEVENTS
297	else if (iter->cpu == -1 && iter->second_pass)
298		timer_list_show_tickdevices_header(m);
299	else
300		print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu);
301#endif
302	return 0;
303}
304
305static void *move_iter(struct timer_list_iter *iter, loff_t offset)
306{
307	for (; offset; offset--) {
308		iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
309		if (iter->cpu >= nr_cpu_ids) {
310#ifdef CONFIG_GENERIC_CLOCKEVENTS
311			if (!iter->second_pass) {
312				iter->cpu = -1;
313				iter->second_pass = true;
314			} else
315				return NULL;
316#else
317			return NULL;
318#endif
319		}
320	}
321	return iter;
322}
323
324static void *timer_list_start(struct seq_file *file, loff_t *offset)
325{
326	struct timer_list_iter *iter = file->private;
327
328	if (!*offset)
329		iter->now = ktime_to_ns(ktime_get());
330	iter->cpu = -1;
331	iter->second_pass = false;
332	return move_iter(iter, *offset);
333}
334
335static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
336{
337	struct timer_list_iter *iter = file->private;
338	++*offset;
339	return move_iter(iter, 1);
340}
341
342static void timer_list_stop(struct seq_file *seq, void *v)
343{
344}
345
346static const struct seq_operations timer_list_sops = {
347	.start = timer_list_start,
348	.next = timer_list_next,
349	.stop = timer_list_stop,
350	.show = timer_list_show,
351};
352
353static int __init init_timer_list_procfs(void)
354{
355	struct proc_dir_entry *pe;
356
357	pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops,
358			sizeof(struct timer_list_iter), NULL);
359	if (!pe)
360		return -ENOMEM;
361	return 0;
362}
363__initcall(init_timer_list_procfs);
364#endif
365