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81d68a96 1/*
73d8b8bc 2 * trace irqs off critical timings
81d68a96
SR
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
6d49e352 10 * Copyright (C) 2004 Nadia Yvette Chambers
81d68a96
SR
11 */
12#include <linux/kallsyms.h>
81d68a96
SR
13#include <linux/uaccess.h>
14#include <linux/module.h>
15#include <linux/ftrace.h>
81d68a96
SR
16
17#include "trace.h"
18
d5915816
JF
19#define CREATE_TRACE_POINTS
20#include <trace/events/preemptirq.h>
21
aaecaa0b 22#if defined(CONFIG_IRQSOFF_TRACER) || defined(CONFIG_PREEMPT_TRACER)
81d68a96
SR
23static struct trace_array *irqsoff_trace __read_mostly;
24static int tracer_enabled __read_mostly;
25
6cd8a4bb
SR
26static DEFINE_PER_CPU(int, tracing_cpu);
27
5389f6fa 28static DEFINE_RAW_SPINLOCK(max_trace_lock);
89b2f978 29
6cd8a4bb
SR
30enum {
31 TRACER_IRQS_OFF = (1 << 1),
32 TRACER_PREEMPT_OFF = (1 << 2),
33};
34
35static int trace_type __read_mostly;
36
613f04a0 37static int save_flags;
e9d25fe6 38
62b915f1
JO
39static void stop_irqsoff_tracer(struct trace_array *tr, int graph);
40static int start_irqsoff_tracer(struct trace_array *tr, int graph);
41
6cd8a4bb 42#ifdef CONFIG_PREEMPT_TRACER
e309b41d 43static inline int
6cd8a4bb
SR
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
e309b41d 53static inline int
6cd8a4bb
SR
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
62b915f1 63#ifdef CONFIG_FUNCTION_GRAPH_TRACER
03905582 64static int irqsoff_display_graph(struct trace_array *tr, int set);
983f938a 65# define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH)
03905582
SRRH
66#else
67static inline int irqsoff_display_graph(struct trace_array *tr, int set)
68{
69 return -EINVAL;
70}
983f938a 71# define is_graph(tr) false
62b915f1 72#endif
62b915f1 73
81d68a96
SR
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
25985edc 79 * and what happens together happens separately as well, so this doesn't
81d68a96
SR
80 * decrease the validity of the maximum found:
81 */
82static __cacheline_aligned_in_smp unsigned long max_sequence;
83
606576ce 84#ifdef CONFIG_FUNCTION_TRACER
81d68a96 85/*
5e6d2b9c
SR
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.
81d68a96 97 */
5e6d2b9c
SR
98static int func_prolog_dec(struct trace_array *tr,
99 struct trace_array_cpu **data,
100 unsigned long *flags)
81d68a96 101{
81d68a96
SR
102 long disabled;
103 int cpu;
104
361943ad
SR
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)))
5e6d2b9c 113 return 0;
81d68a96 114
5e6d2b9c 115 local_save_flags(*flags);
cb86e053
SRRH
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())
5e6d2b9c 122 return 0;
81d68a96 123
12883efb 124 *data = per_cpu_ptr(tr->trace_buffer.data, cpu);
5e6d2b9c 125 disabled = atomic_inc_return(&(*data)->disabled);
81d68a96
SR
126
127 if (likely(disabled == 1))
5e6d2b9c
SR
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
2f5f6ad9 139irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip,
a1e2e31d 140 struct ftrace_ops *op, struct pt_regs *pt_regs)
5e6d2b9c
SR
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());
81d68a96
SR
150
151 atomic_dec(&data->disabled);
152}
606576ce 153#endif /* CONFIG_FUNCTION_TRACER */
81d68a96 154
62b915f1 155#ifdef CONFIG_FUNCTION_GRAPH_TRACER
03905582 156static int irqsoff_display_graph(struct trace_array *tr, int set)
62b915f1
JO
157{
158 int cpu;
159
983f938a 160 if (!(is_graph(tr) ^ set))
62b915f1
JO
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
6d9b3fa5 168 tr->max_latency = 0;
12883efb 169 tracing_reset_online_cpus(&irqsoff_trace->trace_buffer);
62b915f1
JO
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;
62b915f1 179 int ret;
62b915f1
JO
180 int pc;
181
1a414428
SRRH
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
5e6d2b9c 194 if (!func_prolog_dec(tr, &data, &flags))
62b915f1
JO
195 return 0;
196
5e6d2b9c
SR
197 pc = preempt_count();
198 ret = __trace_graph_entry(tr, trace, flags, pc);
62b915f1 199 atomic_dec(&data->disabled);
5e6d2b9c 200
62b915f1
JO
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;
62b915f1
JO
209 int pc;
210
5e6d2b9c 211 if (!func_prolog_dec(tr, &data, &flags))
62b915f1
JO
212 return;
213
5e6d2b9c
SR
214 pc = preempt_count();
215 __trace_graph_return(tr, trace, flags, pc);
62b915f1
JO
216 atomic_dec(&data->disabled);
217}
218
219static void irqsoff_trace_open(struct trace_iterator *iter)
220{
983f938a 221 if (is_graph(iter->tr))
62b915f1
JO
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 | \
321e68b0
JO
233 TRACE_GRAPH_PRINT_PROC | \
234 TRACE_GRAPH_PRINT_ABS_TIME | \
235 TRACE_GRAPH_PRINT_DURATION)
62b915f1
JO
236
237static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
238{
62b915f1
JO
239 /*
240 * In graph mode call the graph tracer output function,
241 * otherwise go with the TRACE_FN event handler
242 */
983f938a 243 if (is_graph(iter->tr))
0a772620 244 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS);
62b915f1
JO
245
246 return TRACE_TYPE_UNHANDLED;
247}
248
249static void irqsoff_print_header(struct seq_file *s)
250{
983f938a
SRRH
251 struct trace_array *tr = irqsoff_trace;
252
253 if (is_graph(tr))
0a772620
JO
254 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS);
255 else
62b915f1
JO
256 trace_default_header(s);
257}
258
62b915f1
JO
259static void
260__trace_function(struct trace_array *tr,
261 unsigned long ip, unsigned long parent_ip,
262 unsigned long flags, int pc)
263{
983f938a 264 if (is_graph(tr))
0a772620
JO
265 trace_graph_function(tr, ip, parent_ip, flags, pc);
266 else
62b915f1 267 trace_function(tr, ip, parent_ip, flags, pc);
62b915f1
JO
268}
269
270#else
271#define __trace_function trace_function
272
8179e8a1 273#ifdef CONFIG_FUNCTION_TRACER
62b915f1
JO
274static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
275{
276 return -1;
277}
8179e8a1 278#endif
62b915f1
JO
279
280static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
281{
282 return TRACE_TYPE_UNHANDLED;
283}
284
62b915f1
JO
285static void irqsoff_trace_open(struct trace_iterator *iter) { }
286static void irqsoff_trace_close(struct trace_iterator *iter) { }
7e9a49ef
JO
287
288#ifdef CONFIG_FUNCTION_TRACER
8179e8a1 289static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { }
7e9a49ef
JO
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 */
62b915f1
JO
300#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
301
81d68a96
SR
302/*
303 * Should this new latency be reported/recorded?
304 */
a5a1d1c2 305static bool report_latency(struct trace_array *tr, u64 delta)
81d68a96
SR
306{
307 if (tracing_thresh) {
308 if (delta < tracing_thresh)
79851821 309 return false;
81d68a96 310 } else {
6d9b3fa5 311 if (delta <= tr->max_latency)
79851821 312 return false;
81d68a96 313 }
79851821 314 return true;
81d68a96
SR
315}
316
e309b41d 317static void
81d68a96
SR
318check_critical_timing(struct trace_array *tr,
319 struct trace_array_cpu *data,
320 unsigned long parent_ip,
321 int cpu)
322{
a5a1d1c2 323 u64 T0, T1, delta;
81d68a96 324 unsigned long flags;
38697053 325 int pc;
81d68a96 326
81d68a96 327 T0 = data->preempt_timestamp;
750ed1a4 328 T1 = ftrace_now(cpu);
81d68a96
SR
329 delta = T1-T0;
330
331 local_save_flags(flags);
332
6450c1d3
SR
333 pc = preempt_count();
334
6d9b3fa5 335 if (!report_latency(tr, delta))
81d68a96
SR
336 goto out;
337
5389f6fa 338 raw_spin_lock_irqsave(&max_trace_lock, flags);
81d68a96 339
89b2f978 340 /* check if we are still the max latency */
6d9b3fa5 341 if (!report_latency(tr, delta))
89b2f978
SR
342 goto out_unlock;
343
62b915f1 344 __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
cc51a0fc
SR
345 /* Skip 5 functions to get to the irq/preempt enable function */
346 __trace_stack(tr, flags, 5, pc);
81d68a96 347
81d68a96 348 if (data->critical_sequence != max_sequence)
89b2f978 349 goto out_unlock;
81d68a96 350
81d68a96
SR
351 data->critical_end = parent_ip;
352
b5130b1e 353 if (likely(!is_tracing_stopped())) {
6d9b3fa5 354 tr->max_latency = delta;
b5130b1e
CE
355 update_max_tr_single(tr, current, cpu);
356 }
81d68a96 357
81d68a96
SR
358 max_sequence++;
359
89b2f978 360out_unlock:
5389f6fa 361 raw_spin_unlock_irqrestore(&max_trace_lock, flags);
89b2f978 362
81d68a96
SR
363out:
364 data->critical_sequence = max_sequence;
750ed1a4 365 data->preempt_timestamp = ftrace_now(cpu);
62b915f1 366 __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
81d68a96
SR
367}
368
e309b41d 369static inline void
81d68a96
SR
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
10246fa3 377 if (!tracer_enabled || !tracing_is_enabled())
81d68a96
SR
378 return;
379
c5f888ca
SR
380 cpu = raw_smp_processor_id();
381
382 if (per_cpu(tracing_cpu, cpu))
6cd8a4bb
SR
383 return;
384
12883efb 385 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
81d68a96 386
c5f888ca 387 if (unlikely(!data) || atomic_read(&data->disabled))
81d68a96
SR
388 return;
389
390 atomic_inc(&data->disabled);
391
392 data->critical_sequence = max_sequence;
750ed1a4 393 data->preempt_timestamp = ftrace_now(cpu);
6cd8a4bb 394 data->critical_start = parent_ip ? : ip;
81d68a96
SR
395
396 local_save_flags(flags);
6cd8a4bb 397
62b915f1 398 __trace_function(tr, ip, parent_ip, flags, preempt_count());
81d68a96 399
c5f888ca 400 per_cpu(tracing_cpu, cpu) = 1;
6cd8a4bb 401
81d68a96
SR
402 atomic_dec(&data->disabled);
403}
404
e309b41d 405static inline void
81d68a96
SR
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
c5f888ca 413 cpu = raw_smp_processor_id();
6cd8a4bb 414 /* Always clear the tracing cpu on stopping the trace */
c5f888ca
SR
415 if (unlikely(per_cpu(tracing_cpu, cpu)))
416 per_cpu(tracing_cpu, cpu) = 0;
6cd8a4bb
SR
417 else
418 return;
419
10246fa3 420 if (!tracer_enabled || !tracing_is_enabled())
81d68a96
SR
421 return;
422
12883efb 423 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
81d68a96 424
3928a8a2 425 if (unlikely(!data) ||
81d68a96
SR
426 !data->critical_start || atomic_read(&data->disabled))
427 return;
428
429 atomic_inc(&data->disabled);
c5f888ca 430
81d68a96 431 local_save_flags(flags);
62b915f1 432 __trace_function(tr, ip, parent_ip, flags, preempt_count());
6cd8a4bb 433 check_critical_timing(tr, data, parent_ip ? : ip, cpu);
81d68a96
SR
434 data->critical_start = 0;
435 atomic_dec(&data->disabled);
436}
437
6cd8a4bb 438/* start and stop critical timings used to for stoppage (in idle) */
e309b41d 439void start_critical_timings(void)
81d68a96 440{
6cd8a4bb 441 if (preempt_trace() || irq_trace())
81d68a96
SR
442 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
443}
1fe37104 444EXPORT_SYMBOL_GPL(start_critical_timings);
81d68a96 445
e309b41d 446void stop_critical_timings(void)
81d68a96 447{
6cd8a4bb 448 if (preempt_trace() || irq_trace())
81d68a96
SR
449 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
450}
1fe37104 451EXPORT_SYMBOL_GPL(stop_critical_timings);
81d68a96 452
6cd8a4bb 453#ifdef CONFIG_IRQSOFF_TRACER
81d68a96 454#ifdef CONFIG_PROVE_LOCKING
e309b41d 455void time_hardirqs_on(unsigned long a0, unsigned long a1)
81d68a96 456{
6cd8a4bb 457 if (!preempt_trace() && irq_trace())
81d68a96
SR
458 stop_critical_timing(a0, a1);
459}
460
e309b41d 461void time_hardirqs_off(unsigned long a0, unsigned long a1)
81d68a96 462{
6cd8a4bb 463 if (!preempt_trace() && irq_trace())
81d68a96
SR
464 start_critical_timing(a0, a1);
465}
466
467#else /* !CONFIG_PROVE_LOCKING */
468
81d68a96
SR
469/*
470 * We are only interested in hardirq on/off events:
471 */
aaecaa0b 472static inline void tracer_hardirqs_on(void)
81d68a96 473{
6cd8a4bb 474 if (!preempt_trace() && irq_trace())
81d68a96
SR
475 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
476}
81d68a96 477
aaecaa0b 478static inline void tracer_hardirqs_off(void)
81d68a96 479{
6cd8a4bb 480 if (!preempt_trace() && irq_trace())
81d68a96
SR
481 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
482}
81d68a96 483
aaecaa0b 484static inline void tracer_hardirqs_on_caller(unsigned long caller_addr)
81d68a96 485{
6cd8a4bb 486 if (!preempt_trace() && irq_trace())
81d68a96
SR
487 stop_critical_timing(CALLER_ADDR0, caller_addr);
488}
81d68a96 489
aaecaa0b 490static inline void tracer_hardirqs_off_caller(unsigned long caller_addr)
81d68a96 491{
6cd8a4bb 492 if (!preempt_trace() && irq_trace())
81d68a96
SR
493 start_critical_timing(CALLER_ADDR0, caller_addr);
494}
81d68a96
SR
495
496#endif /* CONFIG_PROVE_LOCKING */
6cd8a4bb
SR
497#endif /* CONFIG_IRQSOFF_TRACER */
498
499#ifdef CONFIG_PREEMPT_TRACER
aaecaa0b 500static inline void tracer_preempt_on(unsigned long a0, unsigned long a1)
6cd8a4bb 501{
e36de1de 502 if (preempt_trace() && !irq_trace())
1e01cb0c 503 stop_critical_timing(a0, a1);
6cd8a4bb
SR
504}
505
aaecaa0b 506static inline void tracer_preempt_off(unsigned long a0, unsigned long a1)
6cd8a4bb 507{
e36de1de 508 if (preempt_trace() && !irq_trace())
1e01cb0c 509 start_critical_timing(a0, a1);
6cd8a4bb
SR
510}
511#endif /* CONFIG_PREEMPT_TRACER */
81d68a96 512
8179e8a1
SRRH
513#ifdef CONFIG_FUNCTION_TRACER
514static bool function_enabled;
515
4104d326 516static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
81d68a96 517{
328df475 518 int ret;
62b915f1 519
328df475 520 /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
983f938a 521 if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))
328df475
SRRH
522 return 0;
523
524 if (graph)
62b915f1
JO
525 ret = register_ftrace_graph(&irqsoff_graph_return,
526 &irqsoff_graph_entry);
328df475 527 else
4104d326 528 ret = register_ftrace_function(tr->ops);
328df475
SRRH
529
530 if (!ret)
531 function_enabled = true;
532
533 return ret;
534}
535
4104d326 536static void unregister_irqsoff_function(struct trace_array *tr, int graph)
328df475
SRRH
537{
538 if (!function_enabled)
539 return;
540
541 if (graph)
542 unregister_ftrace_graph();
543 else
4104d326 544 unregister_ftrace_function(tr->ops);
328df475
SRRH
545
546 function_enabled = false;
547}
548
8179e8a1 549static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
328df475 550{
8179e8a1
SRRH
551 if (!(mask & TRACE_ITER_FUNCTION))
552 return 0;
553
328df475 554 if (set)
983f938a 555 register_irqsoff_function(tr, is_graph(tr), 1);
328df475 556 else
983f938a 557 unregister_irqsoff_function(tr, is_graph(tr));
8179e8a1
SRRH
558 return 1;
559}
560#else
561static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
562{
03905582 563 return 0;
328df475 564}
8179e8a1
SRRH
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 */
328df475 571
bf6065b5 572static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set)
328df475 573{
bf6065b5
SRRH
574 struct tracer *tracer = tr->current_trace;
575
8179e8a1
SRRH
576 if (irqsoff_function_set(tr, mask, set))
577 return 0;
03905582 578
729358da 579#ifdef CONFIG_FUNCTION_GRAPH_TRACER
03905582
SRRH
580 if (mask & TRACE_ITER_DISPLAY_GRAPH)
581 return irqsoff_display_graph(tr, set);
729358da 582#endif
328df475
SRRH
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
4104d326 591 ret = register_irqsoff_function(tr, graph, 0);
62b915f1
JO
592
593 if (!ret && tracing_is_enabled())
9036990d 594 tracer_enabled = 1;
94523e81 595 else
9036990d 596 tracer_enabled = 0;
62b915f1
JO
597
598 return ret;
81d68a96
SR
599}
600
62b915f1 601static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
81d68a96 602{
81d68a96 603 tracer_enabled = 0;
62b915f1 604
4104d326 605 unregister_irqsoff_function(tr, graph);
81d68a96
SR
606}
607
02f2f764
SRRH
608static bool irqsoff_busy;
609
610static int __irqsoff_tracer_init(struct trace_array *tr)
81d68a96 611{
02f2f764
SRRH
612 if (irqsoff_busy)
613 return -EBUSY;
614
983f938a 615 save_flags = tr->trace_flags;
613f04a0
SRRH
616
617 /* non overwrite screws up the latency tracers */
2b6080f2
SR
618 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
619 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
e9d25fe6 620
6d9b3fa5 621 tr->max_latency = 0;
81d68a96 622 irqsoff_trace = tr;
c5f888ca 623 /* make sure that the tracer is visible */
81d68a96 624 smp_wmb();
62b915f1 625
4104d326
SRRH
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 &&
983f938a 630 is_graph(tr))))
62b915f1 631 printk(KERN_ERR "failed to start irqsoff tracer\n");
02f2f764
SRRH
632
633 irqsoff_busy = true;
634 return 0;
81d68a96
SR
635}
636
637static void irqsoff_tracer_reset(struct trace_array *tr)
638{
613f04a0
SRRH
639 int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
640 int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
641
983f938a 642 stop_irqsoff_tracer(tr, is_graph(tr));
e9d25fe6 643
2b6080f2
SR
644 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
645 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
4104d326 646 ftrace_reset_array_ops(tr);
02f2f764
SRRH
647
648 irqsoff_busy = false;
81d68a96
SR
649}
650
9036990d
SR
651static void irqsoff_tracer_start(struct trace_array *tr)
652{
9036990d 653 tracer_enabled = 1;
9036990d
SR
654}
655
656static void irqsoff_tracer_stop(struct trace_array *tr)
657{
658 tracer_enabled = 0;
81d68a96
SR
659}
660
6cd8a4bb 661#ifdef CONFIG_IRQSOFF_TRACER
1c80025a 662static int irqsoff_tracer_init(struct trace_array *tr)
6cd8a4bb
SR
663{
664 trace_type = TRACER_IRQS_OFF;
665
02f2f764 666 return __irqsoff_tracer_init(tr);
6cd8a4bb 667}
81d68a96
SR
668static struct tracer irqsoff_tracer __read_mostly =
669{
670 .name = "irqsoff",
671 .init = irqsoff_tracer_init,
672 .reset = irqsoff_tracer_reset,
9036990d
SR
673 .start = irqsoff_tracer_start,
674 .stop = irqsoff_tracer_stop,
f43c738b 675 .print_max = true,
62b915f1
JO
676 .print_header = irqsoff_print_header,
677 .print_line = irqsoff_print_line,
328df475 678 .flag_changed = irqsoff_flag_changed,
60a11774
SR
679#ifdef CONFIG_FTRACE_SELFTEST
680 .selftest = trace_selftest_startup_irqsoff,
681#endif
62b915f1
JO
682 .open = irqsoff_trace_open,
683 .close = irqsoff_trace_close,
02f2f764 684 .allow_instances = true,
f43c738b 685 .use_max_tr = true,
81d68a96 686};
6cd8a4bb
SR
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
1c80025a 693static int preemptoff_tracer_init(struct trace_array *tr)
6cd8a4bb
SR
694{
695 trace_type = TRACER_PREEMPT_OFF;
696
02f2f764 697 return __irqsoff_tracer_init(tr);
6cd8a4bb
SR
698}
699
700static struct tracer preemptoff_tracer __read_mostly =
701{
702 .name = "preemptoff",
703 .init = preemptoff_tracer_init,
704 .reset = irqsoff_tracer_reset,
9036990d
SR
705 .start = irqsoff_tracer_start,
706 .stop = irqsoff_tracer_stop,
f43c738b 707 .print_max = true,
62b915f1
JO
708 .print_header = irqsoff_print_header,
709 .print_line = irqsoff_print_line,
328df475 710 .flag_changed = irqsoff_flag_changed,
60a11774
SR
711#ifdef CONFIG_FTRACE_SELFTEST
712 .selftest = trace_selftest_startup_preemptoff,
713#endif
62b915f1
JO
714 .open = irqsoff_trace_open,
715 .close = irqsoff_trace_close,
02f2f764 716 .allow_instances = true,
f43c738b 717 .use_max_tr = true,
6cd8a4bb
SR
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
1c80025a 727static int preemptirqsoff_tracer_init(struct trace_array *tr)
6cd8a4bb
SR
728{
729 trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
730
02f2f764 731 return __irqsoff_tracer_init(tr);
6cd8a4bb
SR
732}
733
734static struct tracer preemptirqsoff_tracer __read_mostly =
735{
736 .name = "preemptirqsoff",
737 .init = preemptirqsoff_tracer_init,
738 .reset = irqsoff_tracer_reset,
9036990d
SR
739 .start = irqsoff_tracer_start,
740 .stop = irqsoff_tracer_stop,
f43c738b 741 .print_max = true,
62b915f1
JO
742 .print_header = irqsoff_print_header,
743 .print_line = irqsoff_print_line,
328df475 744 .flag_changed = irqsoff_flag_changed,
60a11774
SR
745#ifdef CONFIG_FTRACE_SELFTEST
746 .selftest = trace_selftest_startup_preemptirqsoff,
747#endif
62b915f1
JO
748 .open = irqsoff_trace_open,
749 .close = irqsoff_trace_close,
02f2f764 750 .allow_instances = true,
f43c738b 751 .use_max_tr = true,
6cd8a4bb
SR
752};
753
754# define register_preemptirqsoff(trace) register_tracer(&trace)
755#else
756# define register_preemptirqsoff(trace) do { } while (0)
757#endif
81d68a96
SR
758
759__init static int init_irqsoff_tracer(void)
760{
6cd8a4bb
SR
761 register_irqsoff(irqsoff_tracer);
762 register_preemptoff(preemptoff_tracer);
763 register_preemptirqsoff(preemptirqsoff_tracer);
81d68a96
SR
764
765 return 0;
766}
6f415672 767core_initcall(init_irqsoff_tracer);
aaecaa0b
JF
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)
d5915816
JF
783/* Per-cpu variable to prevent redundant calls when IRQs already off */
784static DEFINE_PER_CPU(int, tracing_irq_cpu);
785
aaecaa0b
JF
786void trace_hardirqs_on(void)
787{
d5915816
JF
788 if (!this_cpu_read(tracing_irq_cpu))
789 return;
790
791 trace_irq_enable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
aaecaa0b 792 tracer_hardirqs_on();
d5915816
JF
793
794 this_cpu_write(tracing_irq_cpu, 0);
aaecaa0b
JF
795}
796EXPORT_SYMBOL(trace_hardirqs_on);
797
798void trace_hardirqs_off(void)
799{
d5915816
JF
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);
aaecaa0b
JF
806 tracer_hardirqs_off();
807}
808EXPORT_SYMBOL(trace_hardirqs_off);
809
810__visible void trace_hardirqs_on_caller(unsigned long caller_addr)
811{
d5915816
JF
812 if (!this_cpu_read(tracing_irq_cpu))
813 return;
814
815 trace_irq_enable_rcuidle(CALLER_ADDR0, caller_addr);
aaecaa0b 816 tracer_hardirqs_on_caller(caller_addr);
d5915816
JF
817
818 this_cpu_write(tracing_irq_cpu, 0);
aaecaa0b
JF
819}
820EXPORT_SYMBOL(trace_hardirqs_on_caller);
821
822__visible void trace_hardirqs_off_caller(unsigned long caller_addr)
823{
d5915816
JF
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);
aaecaa0b
JF
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
d5915816
JF
851#if defined(CONFIG_PREEMPT_TRACER) || \
852 (defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_PREEMPTIRQ_EVENTS))
aaecaa0b
JF
853void trace_preempt_on(unsigned long a0, unsigned long a1)
854{
d5915816 855 trace_preempt_enable_rcuidle(a0, a1);
aaecaa0b
JF
856 tracer_preempt_on(a0, a1);
857}
858
859void trace_preempt_off(unsigned long a0, unsigned long a1)
860{
d5915816 861 trace_preempt_disable_rcuidle(a0, a1);
aaecaa0b
JF
862 tracer_preempt_off(a0, a1);
863}
864#endif