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1/*
2 * trace irqs off critical timings
3 *
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
6 *
7 * From code in the latency_tracer, that is:
8 *
9 * Copyright (C) 2004-2006 Ingo Molnar
10 * Copyright (C) 2004 Nadia Yvette Chambers
11 */
12#include <linux/kallsyms.h>
13#include <linux/uaccess.h>
14#include <linux/module.h>
15#include <linux/ftrace.h>
16
17#include "trace.h"
18
19#define CREATE_TRACE_POINTS
20#include <trace/events/preemptirq.h>
21
22#if defined(CONFIG_IRQSOFF_TRACER) || defined(CONFIG_PREEMPT_TRACER)
23static struct trace_array *irqsoff_trace __read_mostly;
24static int tracer_enabled __read_mostly;
25
26static DEFINE_PER_CPU(int, tracing_cpu);
27
28static DEFINE_RAW_SPINLOCK(max_trace_lock);
29
30enum {
31 TRACER_IRQS_OFF = (1 << 1),
32 TRACER_PREEMPT_OFF = (1 << 2),
33};
34
35static int trace_type __read_mostly;
36
37static int save_flags;
38
39static void stop_irqsoff_tracer(struct trace_array *tr, int graph);
40static int start_irqsoff_tracer(struct trace_array *tr, int graph);
41
42#ifdef CONFIG_PREEMPT_TRACER
43static inline int
44preempt_trace(void)
45{
46 return ((trace_type & TRACER_PREEMPT_OFF) && preempt_count());
47}
48#else
49# define preempt_trace() (0)
50#endif
51
52#ifdef CONFIG_IRQSOFF_TRACER
53static inline int
54irq_trace(void)
55{
56 return ((trace_type & TRACER_IRQS_OFF) &&
57 irqs_disabled());
58}
59#else
60# define irq_trace() (0)
61#endif
62
63#ifdef CONFIG_FUNCTION_GRAPH_TRACER
64static int irqsoff_display_graph(struct trace_array *tr, int set);
65# define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH)
66#else
67static inline int irqsoff_display_graph(struct trace_array *tr, int set)
68{
69 return -EINVAL;
70}
71# define is_graph(tr) false
72#endif
73
74/*
75 * Sequence count - we record it when starting a measurement and
76 * skip the latency if the sequence has changed - some other section
77 * did a maximum and could disturb our measurement with serial console
78 * printouts, etc. Truly coinciding maximum latencies should be rare
79 * and what happens together happens separately as well, so this doesn't
80 * decrease the validity of the maximum found:
81 */
82static __cacheline_aligned_in_smp unsigned long max_sequence;
83
84#ifdef CONFIG_FUNCTION_TRACER
85/*
86 * Prologue for the preempt and irqs off function tracers.
87 *
88 * Returns 1 if it is OK to continue, and data->disabled is
89 * incremented.
90 * 0 if the trace is to be ignored, and data->disabled
91 * is kept the same.
92 *
93 * Note, this function is also used outside this ifdef but
94 * inside the #ifdef of the function graph tracer below.
95 * This is OK, since the function graph tracer is
96 * dependent on the function tracer.
97 */
98static int func_prolog_dec(struct trace_array *tr,
99 struct trace_array_cpu **data,
100 unsigned long *flags)
101{
102 long disabled;
103 int cpu;
104
105 /*
106 * Does not matter if we preempt. We test the flags
107 * afterward, to see if irqs are disabled or not.
108 * If we preempt and get a false positive, the flags
109 * test will fail.
110 */
111 cpu = raw_smp_processor_id();
112 if (likely(!per_cpu(tracing_cpu, cpu)))
113 return 0;
114
115 local_save_flags(*flags);
116 /*
117 * Slight chance to get a false positive on tracing_cpu,
118 * although I'm starting to think there isn't a chance.
119 * Leave this for now just to be paranoid.
120 */
121 if (!irqs_disabled_flags(*flags) && !preempt_count())
122 return 0;
123
124 *data = per_cpu_ptr(tr->trace_buffer.data, cpu);
125 disabled = atomic_inc_return(&(*data)->disabled);
126
127 if (likely(disabled == 1))
128 return 1;
129
130 atomic_dec(&(*data)->disabled);
131
132 return 0;
133}
134
135/*
136 * irqsoff uses its own tracer function to keep the overhead down:
137 */
138static void
139irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip,
140 struct ftrace_ops *op, struct pt_regs *pt_regs)
141{
142 struct trace_array *tr = irqsoff_trace;
143 struct trace_array_cpu *data;
144 unsigned long flags;
145
146 if (!func_prolog_dec(tr, &data, &flags))
147 return;
148
149 trace_function(tr, ip, parent_ip, flags, preempt_count());
150
151 atomic_dec(&data->disabled);
152}
153#endif /* CONFIG_FUNCTION_TRACER */
154
155#ifdef CONFIG_FUNCTION_GRAPH_TRACER
156static int irqsoff_display_graph(struct trace_array *tr, int set)
157{
158 int cpu;
159
160 if (!(is_graph(tr) ^ set))
161 return 0;
162
163 stop_irqsoff_tracer(irqsoff_trace, !set);
164
165 for_each_possible_cpu(cpu)
166 per_cpu(tracing_cpu, cpu) = 0;
167
168 tr->max_latency = 0;
169 tracing_reset_online_cpus(&irqsoff_trace->trace_buffer);
170
171 return start_irqsoff_tracer(irqsoff_trace, set);
172}
173
174static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
175{
176 struct trace_array *tr = irqsoff_trace;
177 struct trace_array_cpu *data;
178 unsigned long flags;
179 int ret;
180 int pc;
181
182 if (ftrace_graph_ignore_func(trace))
183 return 0;
184 /*
185 * Do not trace a function if it's filtered by set_graph_notrace.
186 * Make the index of ret stack negative to indicate that it should
187 * ignore further functions. But it needs its own ret stack entry
188 * to recover the original index in order to continue tracing after
189 * returning from the function.
190 */
191 if (ftrace_graph_notrace_addr(trace->func))
192 return 1;
193
194 if (!func_prolog_dec(tr, &data, &flags))
195 return 0;
196
197 pc = preempt_count();
198 ret = __trace_graph_entry(tr, trace, flags, pc);
199 atomic_dec(&data->disabled);
200
201 return ret;
202}
203
204static void irqsoff_graph_return(struct ftrace_graph_ret *trace)
205{
206 struct trace_array *tr = irqsoff_trace;
207 struct trace_array_cpu *data;
208 unsigned long flags;
209 int pc;
210
211 if (!func_prolog_dec(tr, &data, &flags))
212 return;
213
214 pc = preempt_count();
215 __trace_graph_return(tr, trace, flags, pc);
216 atomic_dec(&data->disabled);
217}
218
219static void irqsoff_trace_open(struct trace_iterator *iter)
220{
221 if (is_graph(iter->tr))
222 graph_trace_open(iter);
223
224}
225
226static void irqsoff_trace_close(struct trace_iterator *iter)
227{
228 if (iter->private)
229 graph_trace_close(iter);
230}
231
232#define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
233 TRACE_GRAPH_PRINT_PROC | \
234 TRACE_GRAPH_PRINT_ABS_TIME | \
235 TRACE_GRAPH_PRINT_DURATION)
236
237static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
238{
239 /*
240 * In graph mode call the graph tracer output function,
241 * otherwise go with the TRACE_FN event handler
242 */
243 if (is_graph(iter->tr))
244 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS);
245
246 return TRACE_TYPE_UNHANDLED;
247}
248
249static void irqsoff_print_header(struct seq_file *s)
250{
251 struct trace_array *tr = irqsoff_trace;
252
253 if (is_graph(tr))
254 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS);
255 else
256 trace_default_header(s);
257}
258
259static void
260__trace_function(struct trace_array *tr,
261 unsigned long ip, unsigned long parent_ip,
262 unsigned long flags, int pc)
263{
264 if (is_graph(tr))
265 trace_graph_function(tr, ip, parent_ip, flags, pc);
266 else
267 trace_function(tr, ip, parent_ip, flags, pc);
268}
269
270#else
271#define __trace_function trace_function
272
273#ifdef CONFIG_FUNCTION_TRACER
274static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
275{
276 return -1;
277}
278#endif
279
280static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
281{
282 return TRACE_TYPE_UNHANDLED;
283}
284
285static void irqsoff_trace_open(struct trace_iterator *iter) { }
286static void irqsoff_trace_close(struct trace_iterator *iter) { }
287
288#ifdef CONFIG_FUNCTION_TRACER
289static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { }
290static void irqsoff_print_header(struct seq_file *s)
291{
292 trace_default_header(s);
293}
294#else
295static void irqsoff_print_header(struct seq_file *s)
296{
297 trace_latency_header(s);
298}
299#endif /* CONFIG_FUNCTION_TRACER */
300#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
301
302/*
303 * Should this new latency be reported/recorded?
304 */
305static bool report_latency(struct trace_array *tr, u64 delta)
306{
307 if (tracing_thresh) {
308 if (delta < tracing_thresh)
309 return false;
310 } else {
311 if (delta <= tr->max_latency)
312 return false;
313 }
314 return true;
315}
316
317static void
318check_critical_timing(struct trace_array *tr,
319 struct trace_array_cpu *data,
320 unsigned long parent_ip,
321 int cpu)
322{
323 u64 T0, T1, delta;
324 unsigned long flags;
325 int pc;
326
327 T0 = data->preempt_timestamp;
328 T1 = ftrace_now(cpu);
329 delta = T1-T0;
330
331 local_save_flags(flags);
332
333 pc = preempt_count();
334
335 if (!report_latency(tr, delta))
336 goto out;
337
338 raw_spin_lock_irqsave(&max_trace_lock, flags);
339
340 /* check if we are still the max latency */
341 if (!report_latency(tr, delta))
342 goto out_unlock;
343
344 __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
345 /* Skip 5 functions to get to the irq/preempt enable function */
346 __trace_stack(tr, flags, 5, pc);
347
348 if (data->critical_sequence != max_sequence)
349 goto out_unlock;
350
351 data->critical_end = parent_ip;
352
353 if (likely(!is_tracing_stopped())) {
354 tr->max_latency = delta;
355 update_max_tr_single(tr, current, cpu);
356 }
357
358 max_sequence++;
359
360out_unlock:
361 raw_spin_unlock_irqrestore(&max_trace_lock, flags);
362
363out:
364 data->critical_sequence = max_sequence;
365 data->preempt_timestamp = ftrace_now(cpu);
366 __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
367}
368
369static inline void
370start_critical_timing(unsigned long ip, unsigned long parent_ip)
371{
372 int cpu;
373 struct trace_array *tr = irqsoff_trace;
374 struct trace_array_cpu *data;
375 unsigned long flags;
376
377 if (!tracer_enabled || !tracing_is_enabled())
378 return;
379
380 cpu = raw_smp_processor_id();
381
382 if (per_cpu(tracing_cpu, cpu))
383 return;
384
385 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
386
387 if (unlikely(!data) || atomic_read(&data->disabled))
388 return;
389
390 atomic_inc(&data->disabled);
391
392 data->critical_sequence = max_sequence;
393 data->preempt_timestamp = ftrace_now(cpu);
394 data->critical_start = parent_ip ? : ip;
395
396 local_save_flags(flags);
397
398 __trace_function(tr, ip, parent_ip, flags, preempt_count());
399
400 per_cpu(tracing_cpu, cpu) = 1;
401
402 atomic_dec(&data->disabled);
403}
404
405static inline void
406stop_critical_timing(unsigned long ip, unsigned long parent_ip)
407{
408 int cpu;
409 struct trace_array *tr = irqsoff_trace;
410 struct trace_array_cpu *data;
411 unsigned long flags;
412
413 cpu = raw_smp_processor_id();
414 /* Always clear the tracing cpu on stopping the trace */
415 if (unlikely(per_cpu(tracing_cpu, cpu)))
416 per_cpu(tracing_cpu, cpu) = 0;
417 else
418 return;
419
420 if (!tracer_enabled || !tracing_is_enabled())
421 return;
422
423 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
424
425 if (unlikely(!data) ||
426 !data->critical_start || atomic_read(&data->disabled))
427 return;
428
429 atomic_inc(&data->disabled);
430
431 local_save_flags(flags);
432 __trace_function(tr, ip, parent_ip, flags, preempt_count());
433 check_critical_timing(tr, data, parent_ip ? : ip, cpu);
434 data->critical_start = 0;
435 atomic_dec(&data->disabled);
436}
437
438/* start and stop critical timings used to for stoppage (in idle) */
439void start_critical_timings(void)
440{
441 if (preempt_trace() || irq_trace())
442 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
443}
444EXPORT_SYMBOL_GPL(start_critical_timings);
445
446void stop_critical_timings(void)
447{
448 if (preempt_trace() || irq_trace())
449 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
450}
451EXPORT_SYMBOL_GPL(stop_critical_timings);
452
453#ifdef CONFIG_IRQSOFF_TRACER
454#ifdef CONFIG_PROVE_LOCKING
455void time_hardirqs_on(unsigned long a0, unsigned long a1)
456{
457 if (!preempt_trace() && irq_trace())
458 stop_critical_timing(a0, a1);
459}
460
461void time_hardirqs_off(unsigned long a0, unsigned long a1)
462{
463 if (!preempt_trace() && irq_trace())
464 start_critical_timing(a0, a1);
465}
466
467#else /* !CONFIG_PROVE_LOCKING */
468
469/*
470 * We are only interested in hardirq on/off events:
471 */
472static inline void tracer_hardirqs_on(void)
473{
474 if (!preempt_trace() && irq_trace())
475 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
476}
477
478static inline void tracer_hardirqs_off(void)
479{
480 if (!preempt_trace() && irq_trace())
481 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
482}
483
484static inline void tracer_hardirqs_on_caller(unsigned long caller_addr)
485{
486 if (!preempt_trace() && irq_trace())
487 stop_critical_timing(CALLER_ADDR0, caller_addr);
488}
489
490static inline void tracer_hardirqs_off_caller(unsigned long caller_addr)
491{
492 if (!preempt_trace() && irq_trace())
493 start_critical_timing(CALLER_ADDR0, caller_addr);
494}
495
496#endif /* CONFIG_PROVE_LOCKING */
497#endif /* CONFIG_IRQSOFF_TRACER */
498
499#ifdef CONFIG_PREEMPT_TRACER
500static inline void tracer_preempt_on(unsigned long a0, unsigned long a1)
501{
502 if (preempt_trace() && !irq_trace())
503 stop_critical_timing(a0, a1);
504}
505
506static inline void tracer_preempt_off(unsigned long a0, unsigned long a1)
507{
508 if (preempt_trace() && !irq_trace())
509 start_critical_timing(a0, a1);
510}
511#endif /* CONFIG_PREEMPT_TRACER */
512
513#ifdef CONFIG_FUNCTION_TRACER
514static bool function_enabled;
515
516static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
517{
518 int ret;
519
520 /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
521 if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))
522 return 0;
523
524 if (graph)
525 ret = register_ftrace_graph(&irqsoff_graph_return,
526 &irqsoff_graph_entry);
527 else
528 ret = register_ftrace_function(tr->ops);
529
530 if (!ret)
531 function_enabled = true;
532
533 return ret;
534}
535
536static void unregister_irqsoff_function(struct trace_array *tr, int graph)
537{
538 if (!function_enabled)
539 return;
540
541 if (graph)
542 unregister_ftrace_graph();
543 else
544 unregister_ftrace_function(tr->ops);
545
546 function_enabled = false;
547}
548
549static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
550{
551 if (!(mask & TRACE_ITER_FUNCTION))
552 return 0;
553
554 if (set)
555 register_irqsoff_function(tr, is_graph(tr), 1);
556 else
557 unregister_irqsoff_function(tr, is_graph(tr));
558 return 1;
559}
560#else
561static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
562{
563 return 0;
564}
565static void unregister_irqsoff_function(struct trace_array *tr, int graph) { }
566static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
567{
568 return 0;
569}
570#endif /* CONFIG_FUNCTION_TRACER */
571
572static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set)
573{
574 struct tracer *tracer = tr->current_trace;
575
576 if (irqsoff_function_set(tr, mask, set))
577 return 0;
578
579#ifdef CONFIG_FUNCTION_GRAPH_TRACER
580 if (mask & TRACE_ITER_DISPLAY_GRAPH)
581 return irqsoff_display_graph(tr, set);
582#endif
583
584 return trace_keep_overwrite(tracer, mask, set);
585}
586
587static int start_irqsoff_tracer(struct trace_array *tr, int graph)
588{
589 int ret;
590
591 ret = register_irqsoff_function(tr, graph, 0);
592
593 if (!ret && tracing_is_enabled())
594 tracer_enabled = 1;
595 else
596 tracer_enabled = 0;
597
598 return ret;
599}
600
601static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
602{
603 tracer_enabled = 0;
604
605 unregister_irqsoff_function(tr, graph);
606}
607
608static bool irqsoff_busy;
609
610static int __irqsoff_tracer_init(struct trace_array *tr)
611{
612 if (irqsoff_busy)
613 return -EBUSY;
614
615 save_flags = tr->trace_flags;
616
617 /* non overwrite screws up the latency tracers */
618 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
619 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
620
621 tr->max_latency = 0;
622 irqsoff_trace = tr;
623 /* make sure that the tracer is visible */
624 smp_wmb();
625
626 ftrace_init_array_ops(tr, irqsoff_tracer_call);
627
628 /* Only toplevel instance supports graph tracing */
629 if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
630 is_graph(tr))))
631 printk(KERN_ERR "failed to start irqsoff tracer\n");
632
633 irqsoff_busy = true;
634 return 0;
635}
636
637static void irqsoff_tracer_reset(struct trace_array *tr)
638{
639 int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
640 int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
641
642 stop_irqsoff_tracer(tr, is_graph(tr));
643
644 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
645 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
646 ftrace_reset_array_ops(tr);
647
648 irqsoff_busy = false;
649}
650
651static void irqsoff_tracer_start(struct trace_array *tr)
652{
653 tracer_enabled = 1;
654}
655
656static void irqsoff_tracer_stop(struct trace_array *tr)
657{
658 tracer_enabled = 0;
659}
660
661#ifdef CONFIG_IRQSOFF_TRACER
662static int irqsoff_tracer_init(struct trace_array *tr)
663{
664 trace_type = TRACER_IRQS_OFF;
665
666 return __irqsoff_tracer_init(tr);
667}
668static struct tracer irqsoff_tracer __read_mostly =
669{
670 .name = "irqsoff",
671 .init = irqsoff_tracer_init,
672 .reset = irqsoff_tracer_reset,
673 .start = irqsoff_tracer_start,
674 .stop = irqsoff_tracer_stop,
675 .print_max = true,
676 .print_header = irqsoff_print_header,
677 .print_line = irqsoff_print_line,
678 .flag_changed = irqsoff_flag_changed,
679#ifdef CONFIG_FTRACE_SELFTEST
680 .selftest = trace_selftest_startup_irqsoff,
681#endif
682 .open = irqsoff_trace_open,
683 .close = irqsoff_trace_close,
684 .allow_instances = true,
685 .use_max_tr = true,
686};
687# define register_irqsoff(trace) register_tracer(&trace)
688#else
689# define register_irqsoff(trace) do { } while (0)
690#endif
691
692#ifdef CONFIG_PREEMPT_TRACER
693static int preemptoff_tracer_init(struct trace_array *tr)
694{
695 trace_type = TRACER_PREEMPT_OFF;
696
697 return __irqsoff_tracer_init(tr);
698}
699
700static struct tracer preemptoff_tracer __read_mostly =
701{
702 .name = "preemptoff",
703 .init = preemptoff_tracer_init,
704 .reset = irqsoff_tracer_reset,
705 .start = irqsoff_tracer_start,
706 .stop = irqsoff_tracer_stop,
707 .print_max = true,
708 .print_header = irqsoff_print_header,
709 .print_line = irqsoff_print_line,
710 .flag_changed = irqsoff_flag_changed,
711#ifdef CONFIG_FTRACE_SELFTEST
712 .selftest = trace_selftest_startup_preemptoff,
713#endif
714 .open = irqsoff_trace_open,
715 .close = irqsoff_trace_close,
716 .allow_instances = true,
717 .use_max_tr = true,
718};
719# define register_preemptoff(trace) register_tracer(&trace)
720#else
721# define register_preemptoff(trace) do { } while (0)
722#endif
723
724#if defined(CONFIG_IRQSOFF_TRACER) && \
725 defined(CONFIG_PREEMPT_TRACER)
726
727static int preemptirqsoff_tracer_init(struct trace_array *tr)
728{
729 trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
730
731 return __irqsoff_tracer_init(tr);
732}
733
734static struct tracer preemptirqsoff_tracer __read_mostly =
735{
736 .name = "preemptirqsoff",
737 .init = preemptirqsoff_tracer_init,
738 .reset = irqsoff_tracer_reset,
739 .start = irqsoff_tracer_start,
740 .stop = irqsoff_tracer_stop,
741 .print_max = true,
742 .print_header = irqsoff_print_header,
743 .print_line = irqsoff_print_line,
744 .flag_changed = irqsoff_flag_changed,
745#ifdef CONFIG_FTRACE_SELFTEST
746 .selftest = trace_selftest_startup_preemptirqsoff,
747#endif
748 .open = irqsoff_trace_open,
749 .close = irqsoff_trace_close,
750 .allow_instances = true,
751 .use_max_tr = true,
752};
753
754# define register_preemptirqsoff(trace) register_tracer(&trace)
755#else
756# define register_preemptirqsoff(trace) do { } while (0)
757#endif
758
759__init static int init_irqsoff_tracer(void)
760{
761 register_irqsoff(irqsoff_tracer);
762 register_preemptoff(preemptoff_tracer);
763 register_preemptirqsoff(preemptirqsoff_tracer);
764
765 return 0;
766}
767core_initcall(init_irqsoff_tracer);
768#endif /* IRQSOFF_TRACER || PREEMPTOFF_TRACER */
769
770#ifndef CONFIG_IRQSOFF_TRACER
771static inline void tracer_hardirqs_on(void) { }
772static inline void tracer_hardirqs_off(void) { }
773static inline void tracer_hardirqs_on_caller(unsigned long caller_addr) { }
774static inline void tracer_hardirqs_off_caller(unsigned long caller_addr) { }
775#endif
776
777#ifndef CONFIG_PREEMPT_TRACER
778static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
779static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
780#endif
781
782#if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PROVE_LOCKING)
783/* Per-cpu variable to prevent redundant calls when IRQs already off */
784static DEFINE_PER_CPU(int, tracing_irq_cpu);
785
786void trace_hardirqs_on(void)
787{
788 if (!this_cpu_read(tracing_irq_cpu))
789 return;
790
791 trace_irq_enable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
792 tracer_hardirqs_on();
793
794 this_cpu_write(tracing_irq_cpu, 0);
795}
796EXPORT_SYMBOL(trace_hardirqs_on);
797
798void trace_hardirqs_off(void)
799{
800 if (this_cpu_read(tracing_irq_cpu))
801 return;
802
803 this_cpu_write(tracing_irq_cpu, 1);
804
805 trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
806 tracer_hardirqs_off();
807}
808EXPORT_SYMBOL(trace_hardirqs_off);
809
810__visible void trace_hardirqs_on_caller(unsigned long caller_addr)
811{
812 if (!this_cpu_read(tracing_irq_cpu))
813 return;
814
815 trace_irq_enable_rcuidle(CALLER_ADDR0, caller_addr);
816 tracer_hardirqs_on_caller(caller_addr);
817
818 this_cpu_write(tracing_irq_cpu, 0);
819}
820EXPORT_SYMBOL(trace_hardirqs_on_caller);
821
822__visible void trace_hardirqs_off_caller(unsigned long caller_addr)
823{
824 if (this_cpu_read(tracing_irq_cpu))
825 return;
826
827 this_cpu_write(tracing_irq_cpu, 1);
828
829 trace_irq_disable_rcuidle(CALLER_ADDR0, caller_addr);
830 tracer_hardirqs_off_caller(caller_addr);
831}
832EXPORT_SYMBOL(trace_hardirqs_off_caller);
833
834/*
835 * Stubs:
836 */
837
838void trace_softirqs_on(unsigned long ip)
839{
840}
841
842void trace_softirqs_off(unsigned long ip)
843{
844}
845
846inline void print_irqtrace_events(struct task_struct *curr)
847{
848}
849#endif
850
851#if defined(CONFIG_PREEMPT_TRACER) || \
852 (defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_PREEMPTIRQ_EVENTS))
853void trace_preempt_on(unsigned long a0, unsigned long a1)
854{
855 trace_preempt_enable_rcuidle(a0, a1);
856 tracer_preempt_on(a0, a1);
857}
858
859void trace_preempt_off(unsigned long a0, unsigned long a1)
860{
861 trace_preempt_disable_rcuidle(a0, a1);
862 tracer_preempt_off(a0, a1);
863}
864#endif
1/*
2 * trace irqs off critical timings
3 *
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
6 *
7 * From code in the latency_tracer, that is:
8 *
9 * Copyright (C) 2004-2006 Ingo Molnar
10 * Copyright (C) 2004 Nadia Yvette Chambers
11 */
12#include <linux/kallsyms.h>
13#include <linux/uaccess.h>
14#include <linux/module.h>
15#include <linux/ftrace.h>
16
17#include "trace.h"
18
19static struct trace_array *irqsoff_trace __read_mostly;
20static int tracer_enabled __read_mostly;
21
22static DEFINE_PER_CPU(int, tracing_cpu);
23
24static DEFINE_RAW_SPINLOCK(max_trace_lock);
25
26enum {
27 TRACER_IRQS_OFF = (1 << 1),
28 TRACER_PREEMPT_OFF = (1 << 2),
29};
30
31static int trace_type __read_mostly;
32
33static int save_flags;
34
35static void stop_irqsoff_tracer(struct trace_array *tr, int graph);
36static int start_irqsoff_tracer(struct trace_array *tr, int graph);
37
38#ifdef CONFIG_PREEMPT_TRACER
39static inline int
40preempt_trace(void)
41{
42 return ((trace_type & TRACER_PREEMPT_OFF) && preempt_count());
43}
44#else
45# define preempt_trace() (0)
46#endif
47
48#ifdef CONFIG_IRQSOFF_TRACER
49static inline int
50irq_trace(void)
51{
52 return ((trace_type & TRACER_IRQS_OFF) &&
53 irqs_disabled());
54}
55#else
56# define irq_trace() (0)
57#endif
58
59#ifdef CONFIG_FUNCTION_GRAPH_TRACER
60static int irqsoff_display_graph(struct trace_array *tr, int set);
61# define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH)
62#else
63static inline int irqsoff_display_graph(struct trace_array *tr, int set)
64{
65 return -EINVAL;
66}
67# define is_graph(tr) false
68#endif
69
70/*
71 * Sequence count - we record it when starting a measurement and
72 * skip the latency if the sequence has changed - some other section
73 * did a maximum and could disturb our measurement with serial console
74 * printouts, etc. Truly coinciding maximum latencies should be rare
75 * and what happens together happens separately as well, so this doesn't
76 * decrease the validity of the maximum found:
77 */
78static __cacheline_aligned_in_smp unsigned long max_sequence;
79
80#ifdef CONFIG_FUNCTION_TRACER
81/*
82 * Prologue for the preempt and irqs off function tracers.
83 *
84 * Returns 1 if it is OK to continue, and data->disabled is
85 * incremented.
86 * 0 if the trace is to be ignored, and data->disabled
87 * is kept the same.
88 *
89 * Note, this function is also used outside this ifdef but
90 * inside the #ifdef of the function graph tracer below.
91 * This is OK, since the function graph tracer is
92 * dependent on the function tracer.
93 */
94static int func_prolog_dec(struct trace_array *tr,
95 struct trace_array_cpu **data,
96 unsigned long *flags)
97{
98 long disabled;
99 int cpu;
100
101 /*
102 * Does not matter if we preempt. We test the flags
103 * afterward, to see if irqs are disabled or not.
104 * If we preempt and get a false positive, the flags
105 * test will fail.
106 */
107 cpu = raw_smp_processor_id();
108 if (likely(!per_cpu(tracing_cpu, cpu)))
109 return 0;
110
111 local_save_flags(*flags);
112 /*
113 * Slight chance to get a false positive on tracing_cpu,
114 * although I'm starting to think there isn't a chance.
115 * Leave this for now just to be paranoid.
116 */
117 if (!irqs_disabled_flags(*flags) && !preempt_count())
118 return 0;
119
120 *data = per_cpu_ptr(tr->trace_buffer.data, cpu);
121 disabled = atomic_inc_return(&(*data)->disabled);
122
123 if (likely(disabled == 1))
124 return 1;
125
126 atomic_dec(&(*data)->disabled);
127
128 return 0;
129}
130
131/*
132 * irqsoff uses its own tracer function to keep the overhead down:
133 */
134static void
135irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip,
136 struct ftrace_ops *op, struct pt_regs *pt_regs)
137{
138 struct trace_array *tr = irqsoff_trace;
139 struct trace_array_cpu *data;
140 unsigned long flags;
141
142 if (!func_prolog_dec(tr, &data, &flags))
143 return;
144
145 trace_function(tr, ip, parent_ip, flags, preempt_count());
146
147 atomic_dec(&data->disabled);
148}
149#endif /* CONFIG_FUNCTION_TRACER */
150
151#ifdef CONFIG_FUNCTION_GRAPH_TRACER
152static int irqsoff_display_graph(struct trace_array *tr, int set)
153{
154 int cpu;
155
156 if (!(is_graph(tr) ^ set))
157 return 0;
158
159 stop_irqsoff_tracer(irqsoff_trace, !set);
160
161 for_each_possible_cpu(cpu)
162 per_cpu(tracing_cpu, cpu) = 0;
163
164 tr->max_latency = 0;
165 tracing_reset_online_cpus(&irqsoff_trace->trace_buffer);
166
167 return start_irqsoff_tracer(irqsoff_trace, set);
168}
169
170static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
171{
172 struct trace_array *tr = irqsoff_trace;
173 struct trace_array_cpu *data;
174 unsigned long flags;
175 int ret;
176 int pc;
177
178 if (ftrace_graph_ignore_func(trace))
179 return 0;
180 /*
181 * Do not trace a function if it's filtered by set_graph_notrace.
182 * Make the index of ret stack negative to indicate that it should
183 * ignore further functions. But it needs its own ret stack entry
184 * to recover the original index in order to continue tracing after
185 * returning from the function.
186 */
187 if (ftrace_graph_notrace_addr(trace->func))
188 return 1;
189
190 if (!func_prolog_dec(tr, &data, &flags))
191 return 0;
192
193 pc = preempt_count();
194 ret = __trace_graph_entry(tr, trace, flags, pc);
195 atomic_dec(&data->disabled);
196
197 return ret;
198}
199
200static void irqsoff_graph_return(struct ftrace_graph_ret *trace)
201{
202 struct trace_array *tr = irqsoff_trace;
203 struct trace_array_cpu *data;
204 unsigned long flags;
205 int pc;
206
207 if (!func_prolog_dec(tr, &data, &flags))
208 return;
209
210 pc = preempt_count();
211 __trace_graph_return(tr, trace, flags, pc);
212 atomic_dec(&data->disabled);
213}
214
215static void irqsoff_trace_open(struct trace_iterator *iter)
216{
217 if (is_graph(iter->tr))
218 graph_trace_open(iter);
219
220}
221
222static void irqsoff_trace_close(struct trace_iterator *iter)
223{
224 if (iter->private)
225 graph_trace_close(iter);
226}
227
228#define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
229 TRACE_GRAPH_PRINT_PROC | \
230 TRACE_GRAPH_PRINT_ABS_TIME | \
231 TRACE_GRAPH_PRINT_DURATION)
232
233static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
234{
235 /*
236 * In graph mode call the graph tracer output function,
237 * otherwise go with the TRACE_FN event handler
238 */
239 if (is_graph(iter->tr))
240 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS);
241
242 return TRACE_TYPE_UNHANDLED;
243}
244
245static void irqsoff_print_header(struct seq_file *s)
246{
247 struct trace_array *tr = irqsoff_trace;
248
249 if (is_graph(tr))
250 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS);
251 else
252 trace_default_header(s);
253}
254
255static void
256__trace_function(struct trace_array *tr,
257 unsigned long ip, unsigned long parent_ip,
258 unsigned long flags, int pc)
259{
260 if (is_graph(tr))
261 trace_graph_function(tr, ip, parent_ip, flags, pc);
262 else
263 trace_function(tr, ip, parent_ip, flags, pc);
264}
265
266#else
267#define __trace_function trace_function
268
269#ifdef CONFIG_FUNCTION_TRACER
270static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
271{
272 return -1;
273}
274#endif
275
276static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
277{
278 return TRACE_TYPE_UNHANDLED;
279}
280
281static void irqsoff_trace_open(struct trace_iterator *iter) { }
282static void irqsoff_trace_close(struct trace_iterator *iter) { }
283
284#ifdef CONFIG_FUNCTION_TRACER
285static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { }
286static void irqsoff_print_header(struct seq_file *s)
287{
288 trace_default_header(s);
289}
290#else
291static void irqsoff_print_header(struct seq_file *s)
292{
293 trace_latency_header(s);
294}
295#endif /* CONFIG_FUNCTION_TRACER */
296#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
297
298/*
299 * Should this new latency be reported/recorded?
300 */
301static bool report_latency(struct trace_array *tr, u64 delta)
302{
303 if (tracing_thresh) {
304 if (delta < tracing_thresh)
305 return false;
306 } else {
307 if (delta <= tr->max_latency)
308 return false;
309 }
310 return true;
311}
312
313static void
314check_critical_timing(struct trace_array *tr,
315 struct trace_array_cpu *data,
316 unsigned long parent_ip,
317 int cpu)
318{
319 u64 T0, T1, delta;
320 unsigned long flags;
321 int pc;
322
323 T0 = data->preempt_timestamp;
324 T1 = ftrace_now(cpu);
325 delta = T1-T0;
326
327 local_save_flags(flags);
328
329 pc = preempt_count();
330
331 if (!report_latency(tr, delta))
332 goto out;
333
334 raw_spin_lock_irqsave(&max_trace_lock, flags);
335
336 /* check if we are still the max latency */
337 if (!report_latency(tr, delta))
338 goto out_unlock;
339
340 __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
341 /* Skip 5 functions to get to the irq/preempt enable function */
342 __trace_stack(tr, flags, 5, pc);
343
344 if (data->critical_sequence != max_sequence)
345 goto out_unlock;
346
347 data->critical_end = parent_ip;
348
349 if (likely(!is_tracing_stopped())) {
350 tr->max_latency = delta;
351 update_max_tr_single(tr, current, cpu);
352 }
353
354 max_sequence++;
355
356out_unlock:
357 raw_spin_unlock_irqrestore(&max_trace_lock, flags);
358
359out:
360 data->critical_sequence = max_sequence;
361 data->preempt_timestamp = ftrace_now(cpu);
362 __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
363}
364
365static inline void
366start_critical_timing(unsigned long ip, unsigned long parent_ip)
367{
368 int cpu;
369 struct trace_array *tr = irqsoff_trace;
370 struct trace_array_cpu *data;
371 unsigned long flags;
372
373 if (!tracer_enabled || !tracing_is_enabled())
374 return;
375
376 cpu = raw_smp_processor_id();
377
378 if (per_cpu(tracing_cpu, cpu))
379 return;
380
381 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
382
383 if (unlikely(!data) || atomic_read(&data->disabled))
384 return;
385
386 atomic_inc(&data->disabled);
387
388 data->critical_sequence = max_sequence;
389 data->preempt_timestamp = ftrace_now(cpu);
390 data->critical_start = parent_ip ? : ip;
391
392 local_save_flags(flags);
393
394 __trace_function(tr, ip, parent_ip, flags, preempt_count());
395
396 per_cpu(tracing_cpu, cpu) = 1;
397
398 atomic_dec(&data->disabled);
399}
400
401static inline void
402stop_critical_timing(unsigned long ip, unsigned long parent_ip)
403{
404 int cpu;
405 struct trace_array *tr = irqsoff_trace;
406 struct trace_array_cpu *data;
407 unsigned long flags;
408
409 cpu = raw_smp_processor_id();
410 /* Always clear the tracing cpu on stopping the trace */
411 if (unlikely(per_cpu(tracing_cpu, cpu)))
412 per_cpu(tracing_cpu, cpu) = 0;
413 else
414 return;
415
416 if (!tracer_enabled || !tracing_is_enabled())
417 return;
418
419 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
420
421 if (unlikely(!data) ||
422 !data->critical_start || atomic_read(&data->disabled))
423 return;
424
425 atomic_inc(&data->disabled);
426
427 local_save_flags(flags);
428 __trace_function(tr, ip, parent_ip, flags, preempt_count());
429 check_critical_timing(tr, data, parent_ip ? : ip, cpu);
430 data->critical_start = 0;
431 atomic_dec(&data->disabled);
432}
433
434/* start and stop critical timings used to for stoppage (in idle) */
435void start_critical_timings(void)
436{
437 if (preempt_trace() || irq_trace())
438 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
439}
440EXPORT_SYMBOL_GPL(start_critical_timings);
441
442void stop_critical_timings(void)
443{
444 if (preempt_trace() || irq_trace())
445 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
446}
447EXPORT_SYMBOL_GPL(stop_critical_timings);
448
449#ifdef CONFIG_IRQSOFF_TRACER
450#ifdef CONFIG_PROVE_LOCKING
451void time_hardirqs_on(unsigned long a0, unsigned long a1)
452{
453 if (!preempt_trace() && irq_trace())
454 stop_critical_timing(a0, a1);
455}
456
457void time_hardirqs_off(unsigned long a0, unsigned long a1)
458{
459 if (!preempt_trace() && irq_trace())
460 start_critical_timing(a0, a1);
461}
462
463#else /* !CONFIG_PROVE_LOCKING */
464
465/*
466 * Stubs:
467 */
468
469void trace_softirqs_on(unsigned long ip)
470{
471}
472
473void trace_softirqs_off(unsigned long ip)
474{
475}
476
477inline void print_irqtrace_events(struct task_struct *curr)
478{
479}
480
481/*
482 * We are only interested in hardirq on/off events:
483 */
484void trace_hardirqs_on(void)
485{
486 if (!preempt_trace() && irq_trace())
487 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
488}
489EXPORT_SYMBOL(trace_hardirqs_on);
490
491void trace_hardirqs_off(void)
492{
493 if (!preempt_trace() && irq_trace())
494 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
495}
496EXPORT_SYMBOL(trace_hardirqs_off);
497
498__visible void trace_hardirqs_on_caller(unsigned long caller_addr)
499{
500 if (!preempt_trace() && irq_trace())
501 stop_critical_timing(CALLER_ADDR0, caller_addr);
502}
503EXPORT_SYMBOL(trace_hardirqs_on_caller);
504
505__visible void trace_hardirqs_off_caller(unsigned long caller_addr)
506{
507 if (!preempt_trace() && irq_trace())
508 start_critical_timing(CALLER_ADDR0, caller_addr);
509}
510EXPORT_SYMBOL(trace_hardirqs_off_caller);
511
512#endif /* CONFIG_PROVE_LOCKING */
513#endif /* CONFIG_IRQSOFF_TRACER */
514
515#ifdef CONFIG_PREEMPT_TRACER
516void trace_preempt_on(unsigned long a0, unsigned long a1)
517{
518 if (preempt_trace() && !irq_trace())
519 stop_critical_timing(a0, a1);
520}
521
522void trace_preempt_off(unsigned long a0, unsigned long a1)
523{
524 if (preempt_trace() && !irq_trace())
525 start_critical_timing(a0, a1);
526}
527#endif /* CONFIG_PREEMPT_TRACER */
528
529#ifdef CONFIG_FUNCTION_TRACER
530static bool function_enabled;
531
532static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
533{
534 int ret;
535
536 /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
537 if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))
538 return 0;
539
540 if (graph)
541 ret = register_ftrace_graph(&irqsoff_graph_return,
542 &irqsoff_graph_entry);
543 else
544 ret = register_ftrace_function(tr->ops);
545
546 if (!ret)
547 function_enabled = true;
548
549 return ret;
550}
551
552static void unregister_irqsoff_function(struct trace_array *tr, int graph)
553{
554 if (!function_enabled)
555 return;
556
557 if (graph)
558 unregister_ftrace_graph();
559 else
560 unregister_ftrace_function(tr->ops);
561
562 function_enabled = false;
563}
564
565static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
566{
567 if (!(mask & TRACE_ITER_FUNCTION))
568 return 0;
569
570 if (set)
571 register_irqsoff_function(tr, is_graph(tr), 1);
572 else
573 unregister_irqsoff_function(tr, is_graph(tr));
574 return 1;
575}
576#else
577static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
578{
579 return 0;
580}
581static void unregister_irqsoff_function(struct trace_array *tr, int graph) { }
582static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
583{
584 return 0;
585}
586#endif /* CONFIG_FUNCTION_TRACER */
587
588static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set)
589{
590 struct tracer *tracer = tr->current_trace;
591
592 if (irqsoff_function_set(tr, mask, set))
593 return 0;
594
595#ifdef CONFIG_FUNCTION_GRAPH_TRACER
596 if (mask & TRACE_ITER_DISPLAY_GRAPH)
597 return irqsoff_display_graph(tr, set);
598#endif
599
600 return trace_keep_overwrite(tracer, mask, set);
601}
602
603static int start_irqsoff_tracer(struct trace_array *tr, int graph)
604{
605 int ret;
606
607 ret = register_irqsoff_function(tr, graph, 0);
608
609 if (!ret && tracing_is_enabled())
610 tracer_enabled = 1;
611 else
612 tracer_enabled = 0;
613
614 return ret;
615}
616
617static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
618{
619 tracer_enabled = 0;
620
621 unregister_irqsoff_function(tr, graph);
622}
623
624static bool irqsoff_busy;
625
626static int __irqsoff_tracer_init(struct trace_array *tr)
627{
628 if (irqsoff_busy)
629 return -EBUSY;
630
631 save_flags = tr->trace_flags;
632
633 /* non overwrite screws up the latency tracers */
634 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
635 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
636
637 tr->max_latency = 0;
638 irqsoff_trace = tr;
639 /* make sure that the tracer is visible */
640 smp_wmb();
641
642 ftrace_init_array_ops(tr, irqsoff_tracer_call);
643
644 /* Only toplevel instance supports graph tracing */
645 if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
646 is_graph(tr))))
647 printk(KERN_ERR "failed to start irqsoff tracer\n");
648
649 irqsoff_busy = true;
650 return 0;
651}
652
653static void irqsoff_tracer_reset(struct trace_array *tr)
654{
655 int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
656 int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
657
658 stop_irqsoff_tracer(tr, is_graph(tr));
659
660 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
661 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
662 ftrace_reset_array_ops(tr);
663
664 irqsoff_busy = false;
665}
666
667static void irqsoff_tracer_start(struct trace_array *tr)
668{
669 tracer_enabled = 1;
670}
671
672static void irqsoff_tracer_stop(struct trace_array *tr)
673{
674 tracer_enabled = 0;
675}
676
677#ifdef CONFIG_IRQSOFF_TRACER
678static int irqsoff_tracer_init(struct trace_array *tr)
679{
680 trace_type = TRACER_IRQS_OFF;
681
682 return __irqsoff_tracer_init(tr);
683}
684static struct tracer irqsoff_tracer __read_mostly =
685{
686 .name = "irqsoff",
687 .init = irqsoff_tracer_init,
688 .reset = irqsoff_tracer_reset,
689 .start = irqsoff_tracer_start,
690 .stop = irqsoff_tracer_stop,
691 .print_max = true,
692 .print_header = irqsoff_print_header,
693 .print_line = irqsoff_print_line,
694 .flag_changed = irqsoff_flag_changed,
695#ifdef CONFIG_FTRACE_SELFTEST
696 .selftest = trace_selftest_startup_irqsoff,
697#endif
698 .open = irqsoff_trace_open,
699 .close = irqsoff_trace_close,
700 .allow_instances = true,
701 .use_max_tr = true,
702};
703# define register_irqsoff(trace) register_tracer(&trace)
704#else
705# define register_irqsoff(trace) do { } while (0)
706#endif
707
708#ifdef CONFIG_PREEMPT_TRACER
709static int preemptoff_tracer_init(struct trace_array *tr)
710{
711 trace_type = TRACER_PREEMPT_OFF;
712
713 return __irqsoff_tracer_init(tr);
714}
715
716static struct tracer preemptoff_tracer __read_mostly =
717{
718 .name = "preemptoff",
719 .init = preemptoff_tracer_init,
720 .reset = irqsoff_tracer_reset,
721 .start = irqsoff_tracer_start,
722 .stop = irqsoff_tracer_stop,
723 .print_max = true,
724 .print_header = irqsoff_print_header,
725 .print_line = irqsoff_print_line,
726 .flag_changed = irqsoff_flag_changed,
727#ifdef CONFIG_FTRACE_SELFTEST
728 .selftest = trace_selftest_startup_preemptoff,
729#endif
730 .open = irqsoff_trace_open,
731 .close = irqsoff_trace_close,
732 .allow_instances = true,
733 .use_max_tr = true,
734};
735# define register_preemptoff(trace) register_tracer(&trace)
736#else
737# define register_preemptoff(trace) do { } while (0)
738#endif
739
740#if defined(CONFIG_IRQSOFF_TRACER) && \
741 defined(CONFIG_PREEMPT_TRACER)
742
743static int preemptirqsoff_tracer_init(struct trace_array *tr)
744{
745 trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
746
747 return __irqsoff_tracer_init(tr);
748}
749
750static struct tracer preemptirqsoff_tracer __read_mostly =
751{
752 .name = "preemptirqsoff",
753 .init = preemptirqsoff_tracer_init,
754 .reset = irqsoff_tracer_reset,
755 .start = irqsoff_tracer_start,
756 .stop = irqsoff_tracer_stop,
757 .print_max = true,
758 .print_header = irqsoff_print_header,
759 .print_line = irqsoff_print_line,
760 .flag_changed = irqsoff_flag_changed,
761#ifdef CONFIG_FTRACE_SELFTEST
762 .selftest = trace_selftest_startup_preemptirqsoff,
763#endif
764 .open = irqsoff_trace_open,
765 .close = irqsoff_trace_close,
766 .allow_instances = true,
767 .use_max_tr = true,
768};
769
770# define register_preemptirqsoff(trace) register_tracer(&trace)
771#else
772# define register_preemptirqsoff(trace) do { } while (0)
773#endif
774
775__init static int init_irqsoff_tracer(void)
776{
777 register_irqsoff(irqsoff_tracer);
778 register_preemptoff(preemptoff_tracer);
779 register_preemptirqsoff(preemptirqsoff_tracer);
780
781 return 0;
782}
783core_initcall(init_irqsoff_tracer);