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Steven Rostedt81d68a92008-05-12 21:20:42 +02001/*
Wenji Huang73d8b8b2009-02-17 01:10:02 -05002 * trace irqs off critical timings
Steven Rostedt81d68a92008-05-12 21:20:42 +02003 *
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
Nadia Yvette Chambers6d49e352012-12-06 10:39:54 +010010 * Copyright (C) 2004 Nadia Yvette Chambers
Steven Rostedt81d68a92008-05-12 21:20:42 +020011 */
12#include <linux/kallsyms.h>
13#include <linux/debugfs.h>
14#include <linux/uaccess.h>
15#include <linux/module.h>
16#include <linux/ftrace.h>
17#include <linux/fs.h>
18
19#include "trace.h"
20
21static struct trace_array *irqsoff_trace __read_mostly;
22static int tracer_enabled __read_mostly;
23
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +020024static DEFINE_PER_CPU(int, tracing_cpu);
25
Thomas Gleixner5389f6f2009-07-25 17:13:33 +020026static DEFINE_RAW_SPINLOCK(max_trace_lock);
Steven Rostedt89b2f972008-05-12 21:20:44 +020027
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +020028enum {
29 TRACER_IRQS_OFF = (1 << 1),
30 TRACER_PREEMPT_OFF = (1 << 2),
31};
32
33static int trace_type __read_mostly;
34
Steven Rostedt (Red Hat)613f04a2013-03-14 15:03:53 -040035static int save_flags;
Steven Rostedt (Red Hat)328df472013-03-14 12:10:40 -040036static bool function_enabled;
Steven Rostedte9d25fe2009-03-04 22:15:30 -050037
Jiri Olsa62b915f2010-04-02 19:01:22 +020038static void stop_irqsoff_tracer(struct trace_array *tr, int graph);
39static int start_irqsoff_tracer(struct trace_array *tr, int graph);
40
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +020041#ifdef CONFIG_PREEMPT_TRACER
Ingo Molnare309b412008-05-12 21:20:51 +020042static inline int
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +020043preempt_trace(void)
44{
45 return ((trace_type & TRACER_PREEMPT_OFF) && preempt_count());
46}
47#else
48# define preempt_trace() (0)
49#endif
50
51#ifdef CONFIG_IRQSOFF_TRACER
Ingo Molnare309b412008-05-12 21:20:51 +020052static inline int
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +020053irq_trace(void)
54{
55 return ((trace_type & TRACER_IRQS_OFF) &&
56 irqs_disabled());
57}
58#else
59# define irq_trace() (0)
60#endif
61
Jiri Olsa62b915f2010-04-02 19:01:22 +020062#define TRACE_DISPLAY_GRAPH 1
63
64static struct tracer_opt trace_opts[] = {
65#ifdef CONFIG_FUNCTION_GRAPH_TRACER
66 /* display latency trace as call graph */
67 { TRACER_OPT(display-graph, TRACE_DISPLAY_GRAPH) },
68#endif
69 { } /* Empty entry */
70};
71
72static struct tracer_flags tracer_flags = {
73 .val = 0,
74 .opts = trace_opts,
75};
76
77#define is_graph() (tracer_flags.val & TRACE_DISPLAY_GRAPH)
78
Steven Rostedt81d68a92008-05-12 21:20:42 +020079/*
80 * Sequence count - we record it when starting a measurement and
81 * skip the latency if the sequence has changed - some other section
82 * did a maximum and could disturb our measurement with serial console
83 * printouts, etc. Truly coinciding maximum latencies should be rare
Lucas De Marchi25985ed2011-03-30 22:57:33 -030084 * and what happens together happens separately as well, so this doesn't
Steven Rostedt81d68a92008-05-12 21:20:42 +020085 * decrease the validity of the maximum found:
86 */
87static __cacheline_aligned_in_smp unsigned long max_sequence;
88
Steven Rostedt606576c2008-10-06 19:06:12 -040089#ifdef CONFIG_FUNCTION_TRACER
Steven Rostedt81d68a92008-05-12 21:20:42 +020090/*
Steven Rostedt5e6d2b92010-10-05 19:41:43 -040091 * Prologue for the preempt and irqs off function tracers.
92 *
93 * Returns 1 if it is OK to continue, and data->disabled is
94 * incremented.
95 * 0 if the trace is to be ignored, and data->disabled
96 * is kept the same.
97 *
98 * Note, this function is also used outside this ifdef but
99 * inside the #ifdef of the function graph tracer below.
100 * This is OK, since the function graph tracer is
101 * dependent on the function tracer.
Steven Rostedt81d68a92008-05-12 21:20:42 +0200102 */
Steven Rostedt5e6d2b92010-10-05 19:41:43 -0400103static int func_prolog_dec(struct trace_array *tr,
104 struct trace_array_cpu **data,
105 unsigned long *flags)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200106{
Steven Rostedt81d68a92008-05-12 21:20:42 +0200107 long disabled;
108 int cpu;
109
Steven Rostedt361943a2008-05-12 21:20:44 +0200110 /*
111 * Does not matter if we preempt. We test the flags
112 * afterward, to see if irqs are disabled or not.
113 * If we preempt and get a false positive, the flags
114 * test will fail.
115 */
116 cpu = raw_smp_processor_id();
117 if (likely(!per_cpu(tracing_cpu, cpu)))
Steven Rostedt5e6d2b92010-10-05 19:41:43 -0400118 return 0;
Steven Rostedt81d68a92008-05-12 21:20:42 +0200119
Steven Rostedt5e6d2b92010-10-05 19:41:43 -0400120 local_save_flags(*flags);
Steven Rostedt361943a2008-05-12 21:20:44 +0200121 /* slight chance to get a false positive on tracing_cpu */
Steven Rostedt5e6d2b92010-10-05 19:41:43 -0400122 if (!irqs_disabled_flags(*flags))
123 return 0;
Steven Rostedt81d68a92008-05-12 21:20:42 +0200124
Steven Rostedt (Red Hat)12883ef2013-03-05 09:24:35 -0500125 *data = per_cpu_ptr(tr->trace_buffer.data, cpu);
Steven Rostedt5e6d2b92010-10-05 19:41:43 -0400126 disabled = atomic_inc_return(&(*data)->disabled);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200127
128 if (likely(disabled == 1))
Steven Rostedt5e6d2b92010-10-05 19:41:43 -0400129 return 1;
130
131 atomic_dec(&(*data)->disabled);
132
133 return 0;
134}
135
136/*
137 * irqsoff uses its own tracer function to keep the overhead down:
138 */
139static void
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400140irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -0400141 struct ftrace_ops *op, struct pt_regs *pt_regs)
Steven Rostedt5e6d2b92010-10-05 19:41:43 -0400142{
143 struct trace_array *tr = irqsoff_trace;
144 struct trace_array_cpu *data;
145 unsigned long flags;
146
147 if (!func_prolog_dec(tr, &data, &flags))
148 return;
149
150 trace_function(tr, ip, parent_ip, flags, preempt_count());
Steven Rostedt81d68a92008-05-12 21:20:42 +0200151
152 atomic_dec(&data->disabled);
153}
154
155static struct ftrace_ops trace_ops __read_mostly =
156{
157 .func = irqsoff_tracer_call,
Steven Rostedt47409742012-07-20 11:04:44 -0400158 .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
Steven Rostedt81d68a92008-05-12 21:20:42 +0200159};
Steven Rostedt606576c2008-10-06 19:06:12 -0400160#endif /* CONFIG_FUNCTION_TRACER */
Steven Rostedt81d68a92008-05-12 21:20:42 +0200161
Jiri Olsa62b915f2010-04-02 19:01:22 +0200162#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Steven Rostedt (Red Hat)8c1a49a2014-01-10 11:13:54 -0500163static int
164irqsoff_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
Jiri Olsa62b915f2010-04-02 19:01:22 +0200165{
166 int cpu;
167
168 if (!(bit & TRACE_DISPLAY_GRAPH))
169 return -EINVAL;
170
171 if (!(is_graph() ^ set))
172 return 0;
173
174 stop_irqsoff_tracer(irqsoff_trace, !set);
175
176 for_each_possible_cpu(cpu)
177 per_cpu(tracing_cpu, cpu) = 0;
178
179 tracing_max_latency = 0;
Steven Rostedt (Red Hat)12883ef2013-03-05 09:24:35 -0500180 tracing_reset_online_cpus(&irqsoff_trace->trace_buffer);
Jiri Olsa62b915f2010-04-02 19:01:22 +0200181
182 return start_irqsoff_tracer(irqsoff_trace, set);
183}
184
185static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
186{
187 struct trace_array *tr = irqsoff_trace;
188 struct trace_array_cpu *data;
189 unsigned long flags;
Jiri Olsa62b915f2010-04-02 19:01:22 +0200190 int ret;
Jiri Olsa62b915f2010-04-02 19:01:22 +0200191 int pc;
192
Steven Rostedt5e6d2b92010-10-05 19:41:43 -0400193 if (!func_prolog_dec(tr, &data, &flags))
Jiri Olsa62b915f2010-04-02 19:01:22 +0200194 return 0;
195
Steven Rostedt5e6d2b92010-10-05 19:41:43 -0400196 pc = preempt_count();
197 ret = __trace_graph_entry(tr, trace, flags, pc);
Jiri Olsa62b915f2010-04-02 19:01:22 +0200198 atomic_dec(&data->disabled);
Steven Rostedt5e6d2b92010-10-05 19:41:43 -0400199
Jiri Olsa62b915f2010-04-02 19:01:22 +0200200 return ret;
201}
202
203static void irqsoff_graph_return(struct ftrace_graph_ret *trace)
204{
205 struct trace_array *tr = irqsoff_trace;
206 struct trace_array_cpu *data;
207 unsigned long flags;
Jiri Olsa62b915f2010-04-02 19:01:22 +0200208 int pc;
209
Steven Rostedt5e6d2b92010-10-05 19:41:43 -0400210 if (!func_prolog_dec(tr, &data, &flags))
Jiri Olsa62b915f2010-04-02 19:01:22 +0200211 return;
212
Steven Rostedt5e6d2b92010-10-05 19:41:43 -0400213 pc = preempt_count();
214 __trace_graph_return(tr, trace, flags, pc);
Jiri Olsa62b915f2010-04-02 19:01:22 +0200215 atomic_dec(&data->disabled);
216}
217
218static void irqsoff_trace_open(struct trace_iterator *iter)
219{
220 if (is_graph())
221 graph_trace_open(iter);
222
223}
224
225static void irqsoff_trace_close(struct trace_iterator *iter)
226{
227 if (iter->private)
228 graph_trace_close(iter);
229}
230
231#define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
Jiri Olsa321e68b2011-06-03 16:58:47 +0200232 TRACE_GRAPH_PRINT_PROC | \
233 TRACE_GRAPH_PRINT_ABS_TIME | \
234 TRACE_GRAPH_PRINT_DURATION)
Jiri Olsa62b915f2010-04-02 19:01:22 +0200235
236static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
237{
Jiri Olsa62b915f2010-04-02 19:01:22 +0200238 /*
239 * In graph mode call the graph tracer output function,
240 * otherwise go with the TRACE_FN event handler
241 */
242 if (is_graph())
Jiri Olsa0a772622010-09-23 14:00:52 +0200243 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS);
Jiri Olsa62b915f2010-04-02 19:01:22 +0200244
245 return TRACE_TYPE_UNHANDLED;
246}
247
248static void irqsoff_print_header(struct seq_file *s)
249{
Jiri Olsa0a772622010-09-23 14:00:52 +0200250 if (is_graph())
251 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS);
252 else
Jiri Olsa62b915f2010-04-02 19:01:22 +0200253 trace_default_header(s);
254}
255
256static void
Jiri Olsa62b915f2010-04-02 19:01:22 +0200257__trace_function(struct trace_array *tr,
258 unsigned long ip, unsigned long parent_ip,
259 unsigned long flags, int pc)
260{
Jiri Olsa0a772622010-09-23 14:00:52 +0200261 if (is_graph())
262 trace_graph_function(tr, ip, parent_ip, flags, pc);
263 else
Jiri Olsa62b915f2010-04-02 19:01:22 +0200264 trace_function(tr, ip, parent_ip, flags, pc);
Jiri Olsa62b915f2010-04-02 19:01:22 +0200265}
266
267#else
268#define __trace_function trace_function
269
Steven Rostedt (Red Hat)8c1a49a2014-01-10 11:13:54 -0500270static int
271irqsoff_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
Jiri Olsa62b915f2010-04-02 19:01:22 +0200272{
273 return -EINVAL;
274}
275
276static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
277{
278 return -1;
279}
280
281static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
282{
283 return TRACE_TYPE_UNHANDLED;
284}
285
286static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { }
Jiri Olsa62b915f2010-04-02 19:01:22 +0200287static void irqsoff_trace_open(struct trace_iterator *iter) { }
288static void irqsoff_trace_close(struct trace_iterator *iter) { }
Jiri Olsa7e9a49e2011-11-07 16:08:49 +0100289
290#ifdef CONFIG_FUNCTION_TRACER
291static void irqsoff_print_header(struct seq_file *s)
292{
293 trace_default_header(s);
294}
295#else
296static void irqsoff_print_header(struct seq_file *s)
297{
298 trace_latency_header(s);
299}
300#endif /* CONFIG_FUNCTION_TRACER */
Jiri Olsa62b915f2010-04-02 19:01:22 +0200301#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
302
Steven Rostedt81d68a92008-05-12 21:20:42 +0200303/*
304 * Should this new latency be reported/recorded?
305 */
Ingo Molnare309b412008-05-12 21:20:51 +0200306static int report_latency(cycle_t delta)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200307{
308 if (tracing_thresh) {
309 if (delta < tracing_thresh)
310 return 0;
311 } else {
312 if (delta <= tracing_max_latency)
313 return 0;
314 }
315 return 1;
316}
317
Ingo Molnare309b412008-05-12 21:20:51 +0200318static void
Steven Rostedt81d68a92008-05-12 21:20:42 +0200319check_critical_timing(struct trace_array *tr,
320 struct trace_array_cpu *data,
321 unsigned long parent_ip,
322 int cpu)
323{
Steven Rostedt89b2f972008-05-12 21:20:44 +0200324 cycle_t T0, T1, delta;
Steven Rostedt81d68a92008-05-12 21:20:42 +0200325 unsigned long flags;
Steven Rostedt38697052008-10-01 13:14:09 -0400326 int pc;
Steven Rostedt81d68a92008-05-12 21:20:42 +0200327
Steven Rostedt81d68a92008-05-12 21:20:42 +0200328 T0 = data->preempt_timestamp;
Ingo Molnar750ed1a2008-05-12 21:20:46 +0200329 T1 = ftrace_now(cpu);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200330 delta = T1-T0;
331
332 local_save_flags(flags);
333
Steven Rostedt6450c1d2008-10-02 19:23:04 -0400334 pc = preempt_count();
335
Steven Rostedt81d68a92008-05-12 21:20:42 +0200336 if (!report_latency(delta))
337 goto out;
338
Thomas Gleixner5389f6f2009-07-25 17:13:33 +0200339 raw_spin_lock_irqsave(&max_trace_lock, flags);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200340
Steven Rostedt89b2f972008-05-12 21:20:44 +0200341 /* check if we are still the max latency */
342 if (!report_latency(delta))
343 goto out_unlock;
344
Jiri Olsa62b915f2010-04-02 19:01:22 +0200345 __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
Steven Rostedtcc51a0f2009-12-11 11:54:51 -0500346 /* Skip 5 functions to get to the irq/preempt enable function */
347 __trace_stack(tr, flags, 5, pc);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200348
Steven Rostedt81d68a92008-05-12 21:20:42 +0200349 if (data->critical_sequence != max_sequence)
Steven Rostedt89b2f972008-05-12 21:20:44 +0200350 goto out_unlock;
Steven Rostedt81d68a92008-05-12 21:20:42 +0200351
Steven Rostedt81d68a92008-05-12 21:20:42 +0200352 data->critical_end = parent_ip;
353
Carsten Emdeb5130b12009-09-13 01:43:07 +0200354 if (likely(!is_tracing_stopped())) {
355 tracing_max_latency = delta;
356 update_max_tr_single(tr, current, cpu);
357 }
Steven Rostedt81d68a92008-05-12 21:20:42 +0200358
Steven Rostedt81d68a92008-05-12 21:20:42 +0200359 max_sequence++;
360
Steven Rostedt89b2f972008-05-12 21:20:44 +0200361out_unlock:
Thomas Gleixner5389f6f2009-07-25 17:13:33 +0200362 raw_spin_unlock_irqrestore(&max_trace_lock, flags);
Steven Rostedt89b2f972008-05-12 21:20:44 +0200363
Steven Rostedt81d68a92008-05-12 21:20:42 +0200364out:
365 data->critical_sequence = max_sequence;
Ingo Molnar750ed1a2008-05-12 21:20:46 +0200366 data->preempt_timestamp = ftrace_now(cpu);
Jiri Olsa62b915f2010-04-02 19:01:22 +0200367 __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200368}
369
Ingo Molnare309b412008-05-12 21:20:51 +0200370static inline void
Steven Rostedt81d68a92008-05-12 21:20:42 +0200371start_critical_timing(unsigned long ip, unsigned long parent_ip)
372{
373 int cpu;
374 struct trace_array *tr = irqsoff_trace;
375 struct trace_array_cpu *data;
376 unsigned long flags;
377
Steven Rostedt (Red Hat)10246fa2013-07-01 15:58:24 -0400378 if (!tracer_enabled || !tracing_is_enabled())
Steven Rostedt81d68a92008-05-12 21:20:42 +0200379 return;
380
Steven Rostedtc5f888c2008-05-12 21:20:55 +0200381 cpu = raw_smp_processor_id();
382
383 if (per_cpu(tracing_cpu, cpu))
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200384 return;
385
Steven Rostedt (Red Hat)12883ef2013-03-05 09:24:35 -0500386 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200387
Steven Rostedtc5f888c2008-05-12 21:20:55 +0200388 if (unlikely(!data) || atomic_read(&data->disabled))
Steven Rostedt81d68a92008-05-12 21:20:42 +0200389 return;
390
391 atomic_inc(&data->disabled);
392
393 data->critical_sequence = max_sequence;
Ingo Molnar750ed1a2008-05-12 21:20:46 +0200394 data->preempt_timestamp = ftrace_now(cpu);
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200395 data->critical_start = parent_ip ? : ip;
Steven Rostedt81d68a92008-05-12 21:20:42 +0200396
397 local_save_flags(flags);
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200398
Jiri Olsa62b915f2010-04-02 19:01:22 +0200399 __trace_function(tr, ip, parent_ip, flags, preempt_count());
Steven Rostedt81d68a92008-05-12 21:20:42 +0200400
Steven Rostedtc5f888c2008-05-12 21:20:55 +0200401 per_cpu(tracing_cpu, cpu) = 1;
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200402
Steven Rostedt81d68a92008-05-12 21:20:42 +0200403 atomic_dec(&data->disabled);
404}
405
Ingo Molnare309b412008-05-12 21:20:51 +0200406static inline void
Steven Rostedt81d68a92008-05-12 21:20:42 +0200407stop_critical_timing(unsigned long ip, unsigned long parent_ip)
408{
409 int cpu;
410 struct trace_array *tr = irqsoff_trace;
411 struct trace_array_cpu *data;
412 unsigned long flags;
413
Steven Rostedtc5f888c2008-05-12 21:20:55 +0200414 cpu = raw_smp_processor_id();
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200415 /* Always clear the tracing cpu on stopping the trace */
Steven Rostedtc5f888c2008-05-12 21:20:55 +0200416 if (unlikely(per_cpu(tracing_cpu, cpu)))
417 per_cpu(tracing_cpu, cpu) = 0;
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200418 else
419 return;
420
Steven Rostedt (Red Hat)10246fa2013-07-01 15:58:24 -0400421 if (!tracer_enabled || !tracing_is_enabled())
Steven Rostedt81d68a92008-05-12 21:20:42 +0200422 return;
423
Steven Rostedt (Red Hat)12883ef2013-03-05 09:24:35 -0500424 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200425
Steven Rostedt3928a8a2008-09-29 23:02:41 -0400426 if (unlikely(!data) ||
Steven Rostedt81d68a92008-05-12 21:20:42 +0200427 !data->critical_start || atomic_read(&data->disabled))
428 return;
429
430 atomic_inc(&data->disabled);
Steven Rostedtc5f888c2008-05-12 21:20:55 +0200431
Steven Rostedt81d68a92008-05-12 21:20:42 +0200432 local_save_flags(flags);
Jiri Olsa62b915f2010-04-02 19:01:22 +0200433 __trace_function(tr, ip, parent_ip, flags, preempt_count());
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200434 check_critical_timing(tr, data, parent_ip ? : ip, cpu);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200435 data->critical_start = 0;
436 atomic_dec(&data->disabled);
437}
438
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200439/* start and stop critical timings used to for stoppage (in idle) */
Ingo Molnare309b412008-05-12 21:20:51 +0200440void start_critical_timings(void)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200441{
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200442 if (preempt_trace() || irq_trace())
Steven Rostedt81d68a92008-05-12 21:20:42 +0200443 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
444}
Ingo Molnar1fe37102008-07-26 15:09:47 +0200445EXPORT_SYMBOL_GPL(start_critical_timings);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200446
Ingo Molnare309b412008-05-12 21:20:51 +0200447void stop_critical_timings(void)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200448{
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200449 if (preempt_trace() || irq_trace())
Steven Rostedt81d68a92008-05-12 21:20:42 +0200450 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
451}
Ingo Molnar1fe37102008-07-26 15:09:47 +0200452EXPORT_SYMBOL_GPL(stop_critical_timings);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200453
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200454#ifdef CONFIG_IRQSOFF_TRACER
Steven Rostedt81d68a92008-05-12 21:20:42 +0200455#ifdef CONFIG_PROVE_LOCKING
Ingo Molnare309b412008-05-12 21:20:51 +0200456void time_hardirqs_on(unsigned long a0, unsigned long a1)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200457{
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200458 if (!preempt_trace() && irq_trace())
Steven Rostedt81d68a92008-05-12 21:20:42 +0200459 stop_critical_timing(a0, a1);
460}
461
Ingo Molnare309b412008-05-12 21:20:51 +0200462void time_hardirqs_off(unsigned long a0, unsigned long a1)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200463{
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200464 if (!preempt_trace() && irq_trace())
Steven Rostedt81d68a92008-05-12 21:20:42 +0200465 start_critical_timing(a0, a1);
466}
467
468#else /* !CONFIG_PROVE_LOCKING */
469
470/*
471 * Stubs:
472 */
473
Steven Rostedt81d68a92008-05-12 21:20:42 +0200474void trace_softirqs_on(unsigned long ip)
475{
476}
477
478void trace_softirqs_off(unsigned long ip)
479{
480}
481
Ingo Molnare309b412008-05-12 21:20:51 +0200482inline void print_irqtrace_events(struct task_struct *curr)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200483{
484}
485
486/*
487 * We are only interested in hardirq on/off events:
488 */
Ingo Molnare309b412008-05-12 21:20:51 +0200489void trace_hardirqs_on(void)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200490{
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200491 if (!preempt_trace() && irq_trace())
Steven Rostedt81d68a92008-05-12 21:20:42 +0200492 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
493}
494EXPORT_SYMBOL(trace_hardirqs_on);
495
Ingo Molnare309b412008-05-12 21:20:51 +0200496void trace_hardirqs_off(void)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200497{
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200498 if (!preempt_trace() && irq_trace())
Steven Rostedt81d68a92008-05-12 21:20:42 +0200499 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
500}
501EXPORT_SYMBOL(trace_hardirqs_off);
502
Andi Kleen285c00a2014-02-08 08:52:08 +0100503__visible void trace_hardirqs_on_caller(unsigned long caller_addr)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200504{
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200505 if (!preempt_trace() && irq_trace())
Steven Rostedt81d68a92008-05-12 21:20:42 +0200506 stop_critical_timing(CALLER_ADDR0, caller_addr);
507}
508EXPORT_SYMBOL(trace_hardirqs_on_caller);
509
Andi Kleen285c00a2014-02-08 08:52:08 +0100510__visible void trace_hardirqs_off_caller(unsigned long caller_addr)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200511{
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200512 if (!preempt_trace() && irq_trace())
Steven Rostedt81d68a92008-05-12 21:20:42 +0200513 start_critical_timing(CALLER_ADDR0, caller_addr);
514}
515EXPORT_SYMBOL(trace_hardirqs_off_caller);
516
517#endif /* CONFIG_PROVE_LOCKING */
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200518#endif /* CONFIG_IRQSOFF_TRACER */
519
520#ifdef CONFIG_PREEMPT_TRACER
Ingo Molnare309b412008-05-12 21:20:51 +0200521void trace_preempt_on(unsigned long a0, unsigned long a1)
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200522{
Steven Rostedte36de1d2011-09-22 11:11:51 -0400523 if (preempt_trace() && !irq_trace())
Steven Rostedt1e01cb02008-07-15 09:53:37 -0400524 stop_critical_timing(a0, a1);
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200525}
526
Ingo Molnare309b412008-05-12 21:20:51 +0200527void trace_preempt_off(unsigned long a0, unsigned long a1)
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200528{
Steven Rostedte36de1d2011-09-22 11:11:51 -0400529 if (preempt_trace() && !irq_trace())
Steven Rostedt1e01cb02008-07-15 09:53:37 -0400530 start_critical_timing(a0, a1);
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200531}
532#endif /* CONFIG_PREEMPT_TRACER */
Steven Rostedt81d68a92008-05-12 21:20:42 +0200533
Steven Rostedt (Red Hat)328df472013-03-14 12:10:40 -0400534static int register_irqsoff_function(int graph, int set)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200535{
Steven Rostedt (Red Hat)328df472013-03-14 12:10:40 -0400536 int ret;
Jiri Olsa62b915f2010-04-02 19:01:22 +0200537
Steven Rostedt (Red Hat)328df472013-03-14 12:10:40 -0400538 /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
539 if (function_enabled || (!set && !(trace_flags & TRACE_ITER_FUNCTION)))
540 return 0;
541
542 if (graph)
Jiri Olsa62b915f2010-04-02 19:01:22 +0200543 ret = register_ftrace_graph(&irqsoff_graph_return,
544 &irqsoff_graph_entry);
Steven Rostedt (Red Hat)328df472013-03-14 12:10:40 -0400545 else
546 ret = register_ftrace_function(&trace_ops);
547
548 if (!ret)
549 function_enabled = true;
550
551 return ret;
552}
553
554static void unregister_irqsoff_function(int graph)
555{
556 if (!function_enabled)
557 return;
558
559 if (graph)
560 unregister_ftrace_graph();
561 else
562 unregister_ftrace_function(&trace_ops);
563
564 function_enabled = false;
565}
566
567static void irqsoff_function_set(int set)
568{
569 if (set)
570 register_irqsoff_function(is_graph(), 1);
571 else
572 unregister_irqsoff_function(is_graph());
573}
574
Steven Rostedt (Red Hat)bf6065b2014-01-10 17:51:01 -0500575static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set)
Steven Rostedt (Red Hat)328df472013-03-14 12:10:40 -0400576{
Steven Rostedt (Red Hat)bf6065b2014-01-10 17:51:01 -0500577 struct tracer *tracer = tr->current_trace;
578
Steven Rostedt (Red Hat)328df472013-03-14 12:10:40 -0400579 if (mask & TRACE_ITER_FUNCTION)
580 irqsoff_function_set(set);
581
582 return trace_keep_overwrite(tracer, mask, set);
583}
584
585static int start_irqsoff_tracer(struct trace_array *tr, int graph)
586{
587 int ret;
588
589 ret = register_irqsoff_function(graph, 0);
Jiri Olsa62b915f2010-04-02 19:01:22 +0200590
591 if (!ret && tracing_is_enabled())
Steven Rostedt90369902008-11-05 16:05:44 -0500592 tracer_enabled = 1;
Steven Rostedt94523e82009-01-22 11:18:06 -0500593 else
Steven Rostedt90369902008-11-05 16:05:44 -0500594 tracer_enabled = 0;
Jiri Olsa62b915f2010-04-02 19:01:22 +0200595
596 return ret;
Steven Rostedt81d68a92008-05-12 21:20:42 +0200597}
598
Jiri Olsa62b915f2010-04-02 19:01:22 +0200599static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200600{
Steven Rostedt81d68a92008-05-12 21:20:42 +0200601 tracer_enabled = 0;
Jiri Olsa62b915f2010-04-02 19:01:22 +0200602
Steven Rostedt (Red Hat)328df472013-03-14 12:10:40 -0400603 unregister_irqsoff_function(graph);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200604}
605
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200606static void __irqsoff_tracer_init(struct trace_array *tr)
Steven Rostedt81d68a92008-05-12 21:20:42 +0200607{
Steven Rostedt (Red Hat)613f04a2013-03-14 15:03:53 -0400608 save_flags = trace_flags;
609
610 /* non overwrite screws up the latency tracers */
Steven Rostedt2b6080f2012-05-11 13:29:49 -0400611 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
612 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
Steven Rostedte9d25fe2009-03-04 22:15:30 -0500613
Steven Rostedt745b1622009-01-15 23:40:11 -0500614 tracing_max_latency = 0;
Steven Rostedt81d68a92008-05-12 21:20:42 +0200615 irqsoff_trace = tr;
Steven Rostedtc5f888c2008-05-12 21:20:55 +0200616 /* make sure that the tracer is visible */
Steven Rostedt81d68a92008-05-12 21:20:42 +0200617 smp_wmb();
Steven Rostedt (Red Hat)12883ef2013-03-05 09:24:35 -0500618 tracing_reset_online_cpus(&tr->trace_buffer);
Jiri Olsa62b915f2010-04-02 19:01:22 +0200619
620 if (start_irqsoff_tracer(tr, is_graph()))
621 printk(KERN_ERR "failed to start irqsoff tracer\n");
Steven Rostedt81d68a92008-05-12 21:20:42 +0200622}
623
624static void irqsoff_tracer_reset(struct trace_array *tr)
625{
Steven Rostedt (Red Hat)613f04a2013-03-14 15:03:53 -0400626 int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
627 int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
628
Jiri Olsa62b915f2010-04-02 19:01:22 +0200629 stop_irqsoff_tracer(tr, is_graph());
Steven Rostedte9d25fe2009-03-04 22:15:30 -0500630
Steven Rostedt2b6080f2012-05-11 13:29:49 -0400631 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
632 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200633}
634
Steven Rostedt90369902008-11-05 16:05:44 -0500635static void irqsoff_tracer_start(struct trace_array *tr)
636{
Steven Rostedt90369902008-11-05 16:05:44 -0500637 tracer_enabled = 1;
Steven Rostedt90369902008-11-05 16:05:44 -0500638}
639
640static void irqsoff_tracer_stop(struct trace_array *tr)
641{
642 tracer_enabled = 0;
Steven Rostedt81d68a92008-05-12 21:20:42 +0200643}
644
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200645#ifdef CONFIG_IRQSOFF_TRACER
Frederic Weisbecker1c800252008-11-16 05:57:26 +0100646static int irqsoff_tracer_init(struct trace_array *tr)
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200647{
648 trace_type = TRACER_IRQS_OFF;
649
650 __irqsoff_tracer_init(tr);
Frederic Weisbecker1c800252008-11-16 05:57:26 +0100651 return 0;
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200652}
Steven Rostedt81d68a92008-05-12 21:20:42 +0200653static struct tracer irqsoff_tracer __read_mostly =
654{
655 .name = "irqsoff",
656 .init = irqsoff_tracer_init,
657 .reset = irqsoff_tracer_reset,
Steven Rostedt90369902008-11-05 16:05:44 -0500658 .start = irqsoff_tracer_start,
659 .stop = irqsoff_tracer_stop,
Hiraku Toyookaf43c7382012-10-02 17:27:10 +0900660 .print_max = true,
Jiri Olsa62b915f2010-04-02 19:01:22 +0200661 .print_header = irqsoff_print_header,
662 .print_line = irqsoff_print_line,
663 .flags = &tracer_flags,
664 .set_flag = irqsoff_set_flag,
Steven Rostedt (Red Hat)328df472013-03-14 12:10:40 -0400665 .flag_changed = irqsoff_flag_changed,
Steven Rostedt60a11772008-05-12 21:20:44 +0200666#ifdef CONFIG_FTRACE_SELFTEST
667 .selftest = trace_selftest_startup_irqsoff,
668#endif
Jiri Olsa62b915f2010-04-02 19:01:22 +0200669 .open = irqsoff_trace_open,
670 .close = irqsoff_trace_close,
Hiraku Toyookaf43c7382012-10-02 17:27:10 +0900671 .use_max_tr = true,
Steven Rostedt81d68a92008-05-12 21:20:42 +0200672};
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200673# define register_irqsoff(trace) register_tracer(&trace)
674#else
675# define register_irqsoff(trace) do { } while (0)
676#endif
677
678#ifdef CONFIG_PREEMPT_TRACER
Frederic Weisbecker1c800252008-11-16 05:57:26 +0100679static int preemptoff_tracer_init(struct trace_array *tr)
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200680{
681 trace_type = TRACER_PREEMPT_OFF;
682
683 __irqsoff_tracer_init(tr);
Frederic Weisbecker1c800252008-11-16 05:57:26 +0100684 return 0;
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200685}
686
687static struct tracer preemptoff_tracer __read_mostly =
688{
689 .name = "preemptoff",
690 .init = preemptoff_tracer_init,
691 .reset = irqsoff_tracer_reset,
Steven Rostedt90369902008-11-05 16:05:44 -0500692 .start = irqsoff_tracer_start,
693 .stop = irqsoff_tracer_stop,
Hiraku Toyookaf43c7382012-10-02 17:27:10 +0900694 .print_max = true,
Jiri Olsa62b915f2010-04-02 19:01:22 +0200695 .print_header = irqsoff_print_header,
696 .print_line = irqsoff_print_line,
697 .flags = &tracer_flags,
698 .set_flag = irqsoff_set_flag,
Steven Rostedt (Red Hat)328df472013-03-14 12:10:40 -0400699 .flag_changed = irqsoff_flag_changed,
Steven Rostedt60a11772008-05-12 21:20:44 +0200700#ifdef CONFIG_FTRACE_SELFTEST
701 .selftest = trace_selftest_startup_preemptoff,
702#endif
Jiri Olsa62b915f2010-04-02 19:01:22 +0200703 .open = irqsoff_trace_open,
704 .close = irqsoff_trace_close,
Hiraku Toyookaf43c7382012-10-02 17:27:10 +0900705 .use_max_tr = true,
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200706};
707# define register_preemptoff(trace) register_tracer(&trace)
708#else
709# define register_preemptoff(trace) do { } while (0)
710#endif
711
712#if defined(CONFIG_IRQSOFF_TRACER) && \
713 defined(CONFIG_PREEMPT_TRACER)
714
Frederic Weisbecker1c800252008-11-16 05:57:26 +0100715static int preemptirqsoff_tracer_init(struct trace_array *tr)
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200716{
717 trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
718
719 __irqsoff_tracer_init(tr);
Frederic Weisbecker1c800252008-11-16 05:57:26 +0100720 return 0;
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200721}
722
723static struct tracer preemptirqsoff_tracer __read_mostly =
724{
725 .name = "preemptirqsoff",
726 .init = preemptirqsoff_tracer_init,
727 .reset = irqsoff_tracer_reset,
Steven Rostedt90369902008-11-05 16:05:44 -0500728 .start = irqsoff_tracer_start,
729 .stop = irqsoff_tracer_stop,
Hiraku Toyookaf43c7382012-10-02 17:27:10 +0900730 .print_max = true,
Jiri Olsa62b915f2010-04-02 19:01:22 +0200731 .print_header = irqsoff_print_header,
732 .print_line = irqsoff_print_line,
733 .flags = &tracer_flags,
734 .set_flag = irqsoff_set_flag,
Steven Rostedt (Red Hat)328df472013-03-14 12:10:40 -0400735 .flag_changed = irqsoff_flag_changed,
Steven Rostedt60a11772008-05-12 21:20:44 +0200736#ifdef CONFIG_FTRACE_SELFTEST
737 .selftest = trace_selftest_startup_preemptirqsoff,
738#endif
Jiri Olsa62b915f2010-04-02 19:01:22 +0200739 .open = irqsoff_trace_open,
740 .close = irqsoff_trace_close,
Hiraku Toyookaf43c7382012-10-02 17:27:10 +0900741 .use_max_tr = true,
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200742};
743
744# define register_preemptirqsoff(trace) register_tracer(&trace)
745#else
746# define register_preemptirqsoff(trace) do { } while (0)
747#endif
Steven Rostedt81d68a92008-05-12 21:20:42 +0200748
749__init static int init_irqsoff_tracer(void)
750{
Steven Rostedt6cd8a4b2008-05-12 21:20:42 +0200751 register_irqsoff(irqsoff_tracer);
752 register_preemptoff(preemptoff_tracer);
753 register_preemptirqsoff(preemptirqsoff_tracer);
Steven Rostedt81d68a92008-05-12 21:20:42 +0200754
755 return 0;
756}
Steven Rostedt6f415672012-10-05 12:13:07 -0400757core_initcall(init_irqsoff_tracer);