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Commit | Line | Data |
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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 | ||
19 | static struct trace_array *irqsoff_trace __read_mostly; | |
20 | static int tracer_enabled __read_mostly; | |
21 | ||
6cd8a4bb SR |
22 | static DEFINE_PER_CPU(int, tracing_cpu); |
23 | ||
5389f6fa | 24 | static DEFINE_RAW_SPINLOCK(max_trace_lock); |
89b2f978 | 25 | |
6cd8a4bb SR |
26 | enum { |
27 | TRACER_IRQS_OFF = (1 << 1), | |
28 | TRACER_PREEMPT_OFF = (1 << 2), | |
29 | }; | |
30 | ||
31 | static int trace_type __read_mostly; | |
32 | ||
613f04a0 | 33 | static int save_flags; |
e9d25fe6 | 34 | |
62b915f1 JO |
35 | static void stop_irqsoff_tracer(struct trace_array *tr, int graph); |
36 | static int start_irqsoff_tracer(struct trace_array *tr, int graph); | |
37 | ||
6cd8a4bb | 38 | #ifdef CONFIG_PREEMPT_TRACER |
e309b41d | 39 | static inline int |
6cd8a4bb SR |
40 | preempt_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 | |
e309b41d | 49 | static inline int |
6cd8a4bb SR |
50 | irq_trace(void) |
51 | { | |
52 | return ((trace_type & TRACER_IRQS_OFF) && | |
53 | irqs_disabled()); | |
54 | } | |
55 | #else | |
56 | # define irq_trace() (0) | |
57 | #endif | |
58 | ||
62b915f1 | 59 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
03905582 | 60 | static int irqsoff_display_graph(struct trace_array *tr, int set); |
729358da | 61 | # define is_graph() (trace_flags & TRACE_ITER_DISPLAY_GRAPH) |
03905582 SRRH |
62 | #else |
63 | static inline int irqsoff_display_graph(struct trace_array *tr, int set) | |
64 | { | |
65 | return -EINVAL; | |
66 | } | |
729358da | 67 | # define is_graph() false |
62b915f1 | 68 | #endif |
62b915f1 | 69 | |
81d68a96 SR |
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 | |
25985edc | 75 | * and what happens together happens separately as well, so this doesn't |
81d68a96 SR |
76 | * decrease the validity of the maximum found: |
77 | */ | |
78 | static __cacheline_aligned_in_smp unsigned long max_sequence; | |
79 | ||
606576ce | 80 | #ifdef CONFIG_FUNCTION_TRACER |
81d68a96 | 81 | /* |
5e6d2b9c SR |
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. | |
81d68a96 | 93 | */ |
5e6d2b9c SR |
94 | static int func_prolog_dec(struct trace_array *tr, |
95 | struct trace_array_cpu **data, | |
96 | unsigned long *flags) | |
81d68a96 | 97 | { |
81d68a96 SR |
98 | long disabled; |
99 | int cpu; | |
100 | ||
361943ad SR |
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))) | |
5e6d2b9c | 109 | return 0; |
81d68a96 | 110 | |
5e6d2b9c | 111 | local_save_flags(*flags); |
361943ad | 112 | /* slight chance to get a false positive on tracing_cpu */ |
5e6d2b9c SR |
113 | if (!irqs_disabled_flags(*flags)) |
114 | return 0; | |
81d68a96 | 115 | |
12883efb | 116 | *data = per_cpu_ptr(tr->trace_buffer.data, cpu); |
5e6d2b9c | 117 | disabled = atomic_inc_return(&(*data)->disabled); |
81d68a96 SR |
118 | |
119 | if (likely(disabled == 1)) | |
5e6d2b9c SR |
120 | return 1; |
121 | ||
122 | atomic_dec(&(*data)->disabled); | |
123 | ||
124 | return 0; | |
125 | } | |
126 | ||
127 | /* | |
128 | * irqsoff uses its own tracer function to keep the overhead down: | |
129 | */ | |
130 | static void | |
2f5f6ad9 | 131 | irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 132 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
5e6d2b9c SR |
133 | { |
134 | struct trace_array *tr = irqsoff_trace; | |
135 | struct trace_array_cpu *data; | |
136 | unsigned long flags; | |
137 | ||
138 | if (!func_prolog_dec(tr, &data, &flags)) | |
139 | return; | |
140 | ||
141 | trace_function(tr, ip, parent_ip, flags, preempt_count()); | |
81d68a96 SR |
142 | |
143 | atomic_dec(&data->disabled); | |
144 | } | |
606576ce | 145 | #endif /* CONFIG_FUNCTION_TRACER */ |
81d68a96 | 146 | |
62b915f1 | 147 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
03905582 | 148 | static int irqsoff_display_graph(struct trace_array *tr, int set) |
62b915f1 JO |
149 | { |
150 | int cpu; | |
151 | ||
62b915f1 JO |
152 | if (!(is_graph() ^ set)) |
153 | return 0; | |
154 | ||
155 | stop_irqsoff_tracer(irqsoff_trace, !set); | |
156 | ||
157 | for_each_possible_cpu(cpu) | |
158 | per_cpu(tracing_cpu, cpu) = 0; | |
159 | ||
6d9b3fa5 | 160 | tr->max_latency = 0; |
12883efb | 161 | tracing_reset_online_cpus(&irqsoff_trace->trace_buffer); |
62b915f1 JO |
162 | |
163 | return start_irqsoff_tracer(irqsoff_trace, set); | |
164 | } | |
165 | ||
166 | static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) | |
167 | { | |
168 | struct trace_array *tr = irqsoff_trace; | |
169 | struct trace_array_cpu *data; | |
170 | unsigned long flags; | |
62b915f1 | 171 | int ret; |
62b915f1 JO |
172 | int pc; |
173 | ||
5e6d2b9c | 174 | if (!func_prolog_dec(tr, &data, &flags)) |
62b915f1 JO |
175 | return 0; |
176 | ||
5e6d2b9c SR |
177 | pc = preempt_count(); |
178 | ret = __trace_graph_entry(tr, trace, flags, pc); | |
62b915f1 | 179 | atomic_dec(&data->disabled); |
5e6d2b9c | 180 | |
62b915f1 JO |
181 | return ret; |
182 | } | |
183 | ||
184 | static void irqsoff_graph_return(struct ftrace_graph_ret *trace) | |
185 | { | |
186 | struct trace_array *tr = irqsoff_trace; | |
187 | struct trace_array_cpu *data; | |
188 | unsigned long flags; | |
62b915f1 JO |
189 | int pc; |
190 | ||
5e6d2b9c | 191 | if (!func_prolog_dec(tr, &data, &flags)) |
62b915f1 JO |
192 | return; |
193 | ||
5e6d2b9c SR |
194 | pc = preempt_count(); |
195 | __trace_graph_return(tr, trace, flags, pc); | |
62b915f1 JO |
196 | atomic_dec(&data->disabled); |
197 | } | |
198 | ||
199 | static void irqsoff_trace_open(struct trace_iterator *iter) | |
200 | { | |
201 | if (is_graph()) | |
202 | graph_trace_open(iter); | |
203 | ||
204 | } | |
205 | ||
206 | static void irqsoff_trace_close(struct trace_iterator *iter) | |
207 | { | |
208 | if (iter->private) | |
209 | graph_trace_close(iter); | |
210 | } | |
211 | ||
212 | #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \ | |
321e68b0 JO |
213 | TRACE_GRAPH_PRINT_PROC | \ |
214 | TRACE_GRAPH_PRINT_ABS_TIME | \ | |
215 | TRACE_GRAPH_PRINT_DURATION) | |
62b915f1 JO |
216 | |
217 | static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) | |
218 | { | |
62b915f1 JO |
219 | /* |
220 | * In graph mode call the graph tracer output function, | |
221 | * otherwise go with the TRACE_FN event handler | |
222 | */ | |
223 | if (is_graph()) | |
0a772620 | 224 | return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); |
62b915f1 JO |
225 | |
226 | return TRACE_TYPE_UNHANDLED; | |
227 | } | |
228 | ||
229 | static void irqsoff_print_header(struct seq_file *s) | |
230 | { | |
0a772620 JO |
231 | if (is_graph()) |
232 | print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); | |
233 | else | |
62b915f1 JO |
234 | trace_default_header(s); |
235 | } | |
236 | ||
62b915f1 JO |
237 | static void |
238 | __trace_function(struct trace_array *tr, | |
239 | unsigned long ip, unsigned long parent_ip, | |
240 | unsigned long flags, int pc) | |
241 | { | |
0a772620 JO |
242 | if (is_graph()) |
243 | trace_graph_function(tr, ip, parent_ip, flags, pc); | |
244 | else | |
62b915f1 | 245 | trace_function(tr, ip, parent_ip, flags, pc); |
62b915f1 JO |
246 | } |
247 | ||
248 | #else | |
249 | #define __trace_function trace_function | |
250 | ||
8179e8a1 | 251 | #ifdef CONFIG_FUNCTION_TRACER |
62b915f1 JO |
252 | static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) |
253 | { | |
254 | return -1; | |
255 | } | |
8179e8a1 | 256 | #endif |
62b915f1 JO |
257 | |
258 | static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) | |
259 | { | |
260 | return TRACE_TYPE_UNHANDLED; | |
261 | } | |
262 | ||
62b915f1 JO |
263 | static void irqsoff_trace_open(struct trace_iterator *iter) { } |
264 | static void irqsoff_trace_close(struct trace_iterator *iter) { } | |
7e9a49ef JO |
265 | |
266 | #ifdef CONFIG_FUNCTION_TRACER | |
8179e8a1 | 267 | static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { } |
7e9a49ef JO |
268 | static void irqsoff_print_header(struct seq_file *s) |
269 | { | |
270 | trace_default_header(s); | |
271 | } | |
272 | #else | |
273 | static void irqsoff_print_header(struct seq_file *s) | |
274 | { | |
275 | trace_latency_header(s); | |
276 | } | |
277 | #endif /* CONFIG_FUNCTION_TRACER */ | |
62b915f1 JO |
278 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
279 | ||
81d68a96 SR |
280 | /* |
281 | * Should this new latency be reported/recorded? | |
282 | */ | |
6d9b3fa5 | 283 | static int report_latency(struct trace_array *tr, cycle_t delta) |
81d68a96 SR |
284 | { |
285 | if (tracing_thresh) { | |
286 | if (delta < tracing_thresh) | |
287 | return 0; | |
288 | } else { | |
6d9b3fa5 | 289 | if (delta <= tr->max_latency) |
81d68a96 SR |
290 | return 0; |
291 | } | |
292 | return 1; | |
293 | } | |
294 | ||
e309b41d | 295 | static void |
81d68a96 SR |
296 | check_critical_timing(struct trace_array *tr, |
297 | struct trace_array_cpu *data, | |
298 | unsigned long parent_ip, | |
299 | int cpu) | |
300 | { | |
89b2f978 | 301 | cycle_t T0, T1, delta; |
81d68a96 | 302 | unsigned long flags; |
38697053 | 303 | int pc; |
81d68a96 | 304 | |
81d68a96 | 305 | T0 = data->preempt_timestamp; |
750ed1a4 | 306 | T1 = ftrace_now(cpu); |
81d68a96 SR |
307 | delta = T1-T0; |
308 | ||
309 | local_save_flags(flags); | |
310 | ||
6450c1d3 SR |
311 | pc = preempt_count(); |
312 | ||
6d9b3fa5 | 313 | if (!report_latency(tr, delta)) |
81d68a96 SR |
314 | goto out; |
315 | ||
5389f6fa | 316 | raw_spin_lock_irqsave(&max_trace_lock, flags); |
81d68a96 | 317 | |
89b2f978 | 318 | /* check if we are still the max latency */ |
6d9b3fa5 | 319 | if (!report_latency(tr, delta)) |
89b2f978 SR |
320 | goto out_unlock; |
321 | ||
62b915f1 | 322 | __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); |
cc51a0fc SR |
323 | /* Skip 5 functions to get to the irq/preempt enable function */ |
324 | __trace_stack(tr, flags, 5, pc); | |
81d68a96 | 325 | |
81d68a96 | 326 | if (data->critical_sequence != max_sequence) |
89b2f978 | 327 | goto out_unlock; |
81d68a96 | 328 | |
81d68a96 SR |
329 | data->critical_end = parent_ip; |
330 | ||
b5130b1e | 331 | if (likely(!is_tracing_stopped())) { |
6d9b3fa5 | 332 | tr->max_latency = delta; |
b5130b1e CE |
333 | update_max_tr_single(tr, current, cpu); |
334 | } | |
81d68a96 | 335 | |
81d68a96 SR |
336 | max_sequence++; |
337 | ||
89b2f978 | 338 | out_unlock: |
5389f6fa | 339 | raw_spin_unlock_irqrestore(&max_trace_lock, flags); |
89b2f978 | 340 | |
81d68a96 SR |
341 | out: |
342 | data->critical_sequence = max_sequence; | |
750ed1a4 | 343 | data->preempt_timestamp = ftrace_now(cpu); |
62b915f1 | 344 | __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); |
81d68a96 SR |
345 | } |
346 | ||
e309b41d | 347 | static inline void |
81d68a96 SR |
348 | start_critical_timing(unsigned long ip, unsigned long parent_ip) |
349 | { | |
350 | int cpu; | |
351 | struct trace_array *tr = irqsoff_trace; | |
352 | struct trace_array_cpu *data; | |
353 | unsigned long flags; | |
354 | ||
10246fa3 | 355 | if (!tracer_enabled || !tracing_is_enabled()) |
81d68a96 SR |
356 | return; |
357 | ||
c5f888ca SR |
358 | cpu = raw_smp_processor_id(); |
359 | ||
360 | if (per_cpu(tracing_cpu, cpu)) | |
6cd8a4bb SR |
361 | return; |
362 | ||
12883efb | 363 | data = per_cpu_ptr(tr->trace_buffer.data, cpu); |
81d68a96 | 364 | |
c5f888ca | 365 | if (unlikely(!data) || atomic_read(&data->disabled)) |
81d68a96 SR |
366 | return; |
367 | ||
368 | atomic_inc(&data->disabled); | |
369 | ||
370 | data->critical_sequence = max_sequence; | |
750ed1a4 | 371 | data->preempt_timestamp = ftrace_now(cpu); |
6cd8a4bb | 372 | data->critical_start = parent_ip ? : ip; |
81d68a96 SR |
373 | |
374 | local_save_flags(flags); | |
6cd8a4bb | 375 | |
62b915f1 | 376 | __trace_function(tr, ip, parent_ip, flags, preempt_count()); |
81d68a96 | 377 | |
c5f888ca | 378 | per_cpu(tracing_cpu, cpu) = 1; |
6cd8a4bb | 379 | |
81d68a96 SR |
380 | atomic_dec(&data->disabled); |
381 | } | |
382 | ||
e309b41d | 383 | static inline void |
81d68a96 SR |
384 | stop_critical_timing(unsigned long ip, unsigned long parent_ip) |
385 | { | |
386 | int cpu; | |
387 | struct trace_array *tr = irqsoff_trace; | |
388 | struct trace_array_cpu *data; | |
389 | unsigned long flags; | |
390 | ||
c5f888ca | 391 | cpu = raw_smp_processor_id(); |
6cd8a4bb | 392 | /* Always clear the tracing cpu on stopping the trace */ |
c5f888ca SR |
393 | if (unlikely(per_cpu(tracing_cpu, cpu))) |
394 | per_cpu(tracing_cpu, cpu) = 0; | |
6cd8a4bb SR |
395 | else |
396 | return; | |
397 | ||
10246fa3 | 398 | if (!tracer_enabled || !tracing_is_enabled()) |
81d68a96 SR |
399 | return; |
400 | ||
12883efb | 401 | data = per_cpu_ptr(tr->trace_buffer.data, cpu); |
81d68a96 | 402 | |
3928a8a2 | 403 | if (unlikely(!data) || |
81d68a96 SR |
404 | !data->critical_start || atomic_read(&data->disabled)) |
405 | return; | |
406 | ||
407 | atomic_inc(&data->disabled); | |
c5f888ca | 408 | |
81d68a96 | 409 | local_save_flags(flags); |
62b915f1 | 410 | __trace_function(tr, ip, parent_ip, flags, preempt_count()); |
6cd8a4bb | 411 | check_critical_timing(tr, data, parent_ip ? : ip, cpu); |
81d68a96 SR |
412 | data->critical_start = 0; |
413 | atomic_dec(&data->disabled); | |
414 | } | |
415 | ||
6cd8a4bb | 416 | /* start and stop critical timings used to for stoppage (in idle) */ |
e309b41d | 417 | void start_critical_timings(void) |
81d68a96 | 418 | { |
6cd8a4bb | 419 | if (preempt_trace() || irq_trace()) |
81d68a96 SR |
420 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
421 | } | |
1fe37104 | 422 | EXPORT_SYMBOL_GPL(start_critical_timings); |
81d68a96 | 423 | |
e309b41d | 424 | void stop_critical_timings(void) |
81d68a96 | 425 | { |
6cd8a4bb | 426 | if (preempt_trace() || irq_trace()) |
81d68a96 SR |
427 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
428 | } | |
1fe37104 | 429 | EXPORT_SYMBOL_GPL(stop_critical_timings); |
81d68a96 | 430 | |
6cd8a4bb | 431 | #ifdef CONFIG_IRQSOFF_TRACER |
81d68a96 | 432 | #ifdef CONFIG_PROVE_LOCKING |
e309b41d | 433 | void time_hardirqs_on(unsigned long a0, unsigned long a1) |
81d68a96 | 434 | { |
6cd8a4bb | 435 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
436 | stop_critical_timing(a0, a1); |
437 | } | |
438 | ||
e309b41d | 439 | void time_hardirqs_off(unsigned long a0, unsigned long a1) |
81d68a96 | 440 | { |
6cd8a4bb | 441 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
442 | start_critical_timing(a0, a1); |
443 | } | |
444 | ||
445 | #else /* !CONFIG_PROVE_LOCKING */ | |
446 | ||
447 | /* | |
448 | * Stubs: | |
449 | */ | |
450 | ||
81d68a96 SR |
451 | void trace_softirqs_on(unsigned long ip) |
452 | { | |
453 | } | |
454 | ||
455 | void trace_softirqs_off(unsigned long ip) | |
456 | { | |
457 | } | |
458 | ||
e309b41d | 459 | inline void print_irqtrace_events(struct task_struct *curr) |
81d68a96 SR |
460 | { |
461 | } | |
462 | ||
463 | /* | |
464 | * We are only interested in hardirq on/off events: | |
465 | */ | |
e309b41d | 466 | void trace_hardirqs_on(void) |
81d68a96 | 467 | { |
6cd8a4bb | 468 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
469 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
470 | } | |
471 | EXPORT_SYMBOL(trace_hardirqs_on); | |
472 | ||
e309b41d | 473 | void trace_hardirqs_off(void) |
81d68a96 | 474 | { |
6cd8a4bb | 475 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
476 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
477 | } | |
478 | EXPORT_SYMBOL(trace_hardirqs_off); | |
479 | ||
285c00ad | 480 | __visible void trace_hardirqs_on_caller(unsigned long caller_addr) |
81d68a96 | 481 | { |
6cd8a4bb | 482 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
483 | stop_critical_timing(CALLER_ADDR0, caller_addr); |
484 | } | |
485 | EXPORT_SYMBOL(trace_hardirqs_on_caller); | |
486 | ||
285c00ad | 487 | __visible void trace_hardirqs_off_caller(unsigned long caller_addr) |
81d68a96 | 488 | { |
6cd8a4bb | 489 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
490 | start_critical_timing(CALLER_ADDR0, caller_addr); |
491 | } | |
492 | EXPORT_SYMBOL(trace_hardirqs_off_caller); | |
493 | ||
494 | #endif /* CONFIG_PROVE_LOCKING */ | |
6cd8a4bb SR |
495 | #endif /* CONFIG_IRQSOFF_TRACER */ |
496 | ||
497 | #ifdef CONFIG_PREEMPT_TRACER | |
e309b41d | 498 | void trace_preempt_on(unsigned long a0, unsigned long a1) |
6cd8a4bb | 499 | { |
e36de1de | 500 | if (preempt_trace() && !irq_trace()) |
1e01cb0c | 501 | stop_critical_timing(a0, a1); |
6cd8a4bb SR |
502 | } |
503 | ||
e309b41d | 504 | void trace_preempt_off(unsigned long a0, unsigned long a1) |
6cd8a4bb | 505 | { |
e36de1de | 506 | if (preempt_trace() && !irq_trace()) |
1e01cb0c | 507 | start_critical_timing(a0, a1); |
6cd8a4bb SR |
508 | } |
509 | #endif /* CONFIG_PREEMPT_TRACER */ | |
81d68a96 | 510 | |
8179e8a1 SRRH |
511 | #ifdef CONFIG_FUNCTION_TRACER |
512 | static bool function_enabled; | |
513 | ||
4104d326 | 514 | static int register_irqsoff_function(struct trace_array *tr, int graph, int set) |
81d68a96 | 515 | { |
328df475 | 516 | int ret; |
62b915f1 | 517 | |
328df475 SRRH |
518 | /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ |
519 | if (function_enabled || (!set && !(trace_flags & TRACE_ITER_FUNCTION))) | |
520 | return 0; | |
521 | ||
522 | if (graph) | |
62b915f1 JO |
523 | ret = register_ftrace_graph(&irqsoff_graph_return, |
524 | &irqsoff_graph_entry); | |
328df475 | 525 | else |
4104d326 | 526 | ret = register_ftrace_function(tr->ops); |
328df475 SRRH |
527 | |
528 | if (!ret) | |
529 | function_enabled = true; | |
530 | ||
531 | return ret; | |
532 | } | |
533 | ||
4104d326 | 534 | static void unregister_irqsoff_function(struct trace_array *tr, int graph) |
328df475 SRRH |
535 | { |
536 | if (!function_enabled) | |
537 | return; | |
538 | ||
539 | if (graph) | |
540 | unregister_ftrace_graph(); | |
541 | else | |
4104d326 | 542 | unregister_ftrace_function(tr->ops); |
328df475 SRRH |
543 | |
544 | function_enabled = false; | |
545 | } | |
546 | ||
8179e8a1 | 547 | static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set) |
328df475 | 548 | { |
8179e8a1 SRRH |
549 | if (!(mask & TRACE_ITER_FUNCTION)) |
550 | return 0; | |
551 | ||
328df475 | 552 | if (set) |
4104d326 | 553 | register_irqsoff_function(tr, is_graph(), 1); |
328df475 | 554 | else |
4104d326 | 555 | unregister_irqsoff_function(tr, is_graph()); |
8179e8a1 SRRH |
556 | return 1; |
557 | } | |
558 | #else | |
559 | static int register_irqsoff_function(struct trace_array *tr, int graph, int set) | |
560 | { | |
03905582 | 561 | return 0; |
328df475 | 562 | } |
8179e8a1 SRRH |
563 | static void unregister_irqsoff_function(struct trace_array *tr, int graph) { } |
564 | static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set) | |
565 | { | |
566 | return 0; | |
567 | } | |
568 | #endif /* CONFIG_FUNCTION_TRACER */ | |
328df475 | 569 | |
bf6065b5 | 570 | static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set) |
328df475 | 571 | { |
bf6065b5 SRRH |
572 | struct tracer *tracer = tr->current_trace; |
573 | ||
8179e8a1 SRRH |
574 | if (irqsoff_function_set(tr, mask, set)) |
575 | return 0; | |
03905582 | 576 | |
729358da | 577 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
03905582 SRRH |
578 | if (mask & TRACE_ITER_DISPLAY_GRAPH) |
579 | return irqsoff_display_graph(tr, set); | |
729358da | 580 | #endif |
328df475 SRRH |
581 | |
582 | return trace_keep_overwrite(tracer, mask, set); | |
583 | } | |
584 | ||
585 | static int start_irqsoff_tracer(struct trace_array *tr, int graph) | |
586 | { | |
587 | int ret; | |
588 | ||
4104d326 | 589 | ret = register_irqsoff_function(tr, graph, 0); |
62b915f1 JO |
590 | |
591 | if (!ret && tracing_is_enabled()) | |
9036990d | 592 | tracer_enabled = 1; |
94523e81 | 593 | else |
9036990d | 594 | tracer_enabled = 0; |
62b915f1 JO |
595 | |
596 | return ret; | |
81d68a96 SR |
597 | } |
598 | ||
62b915f1 | 599 | static void stop_irqsoff_tracer(struct trace_array *tr, int graph) |
81d68a96 | 600 | { |
81d68a96 | 601 | tracer_enabled = 0; |
62b915f1 | 602 | |
4104d326 | 603 | unregister_irqsoff_function(tr, graph); |
81d68a96 SR |
604 | } |
605 | ||
02f2f764 SRRH |
606 | static bool irqsoff_busy; |
607 | ||
608 | static int __irqsoff_tracer_init(struct trace_array *tr) | |
81d68a96 | 609 | { |
02f2f764 SRRH |
610 | if (irqsoff_busy) |
611 | return -EBUSY; | |
612 | ||
613f04a0 SRRH |
613 | save_flags = trace_flags; |
614 | ||
615 | /* non overwrite screws up the latency tracers */ | |
2b6080f2 SR |
616 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); |
617 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); | |
e9d25fe6 | 618 | |
6d9b3fa5 | 619 | tr->max_latency = 0; |
81d68a96 | 620 | irqsoff_trace = tr; |
c5f888ca | 621 | /* make sure that the tracer is visible */ |
81d68a96 | 622 | smp_wmb(); |
12883efb | 623 | tracing_reset_online_cpus(&tr->trace_buffer); |
62b915f1 | 624 | |
4104d326 SRRH |
625 | ftrace_init_array_ops(tr, irqsoff_tracer_call); |
626 | ||
627 | /* Only toplevel instance supports graph tracing */ | |
628 | if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL && | |
629 | is_graph()))) | |
62b915f1 | 630 | printk(KERN_ERR "failed to start irqsoff tracer\n"); |
02f2f764 SRRH |
631 | |
632 | irqsoff_busy = true; | |
633 | return 0; | |
81d68a96 SR |
634 | } |
635 | ||
636 | static void irqsoff_tracer_reset(struct trace_array *tr) | |
637 | { | |
613f04a0 SRRH |
638 | int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; |
639 | int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; | |
640 | ||
62b915f1 | 641 | stop_irqsoff_tracer(tr, is_graph()); |
e9d25fe6 | 642 | |
2b6080f2 SR |
643 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); |
644 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); | |
4104d326 | 645 | ftrace_reset_array_ops(tr); |
02f2f764 SRRH |
646 | |
647 | irqsoff_busy = false; | |
81d68a96 SR |
648 | } |
649 | ||
9036990d SR |
650 | static void irqsoff_tracer_start(struct trace_array *tr) |
651 | { | |
9036990d | 652 | tracer_enabled = 1; |
9036990d SR |
653 | } |
654 | ||
655 | static void irqsoff_tracer_stop(struct trace_array *tr) | |
656 | { | |
657 | tracer_enabled = 0; | |
81d68a96 SR |
658 | } |
659 | ||
6cd8a4bb | 660 | #ifdef CONFIG_IRQSOFF_TRACER |
1c80025a | 661 | static int irqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
662 | { |
663 | trace_type = TRACER_IRQS_OFF; | |
664 | ||
02f2f764 | 665 | return __irqsoff_tracer_init(tr); |
6cd8a4bb | 666 | } |
81d68a96 SR |
667 | static struct tracer irqsoff_tracer __read_mostly = |
668 | { | |
669 | .name = "irqsoff", | |
670 | .init = irqsoff_tracer_init, | |
671 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
672 | .start = irqsoff_tracer_start, |
673 | .stop = irqsoff_tracer_stop, | |
f43c738b | 674 | .print_max = true, |
62b915f1 JO |
675 | .print_header = irqsoff_print_header, |
676 | .print_line = irqsoff_print_line, | |
328df475 | 677 | .flag_changed = irqsoff_flag_changed, |
60a11774 SR |
678 | #ifdef CONFIG_FTRACE_SELFTEST |
679 | .selftest = trace_selftest_startup_irqsoff, | |
680 | #endif | |
62b915f1 JO |
681 | .open = irqsoff_trace_open, |
682 | .close = irqsoff_trace_close, | |
02f2f764 | 683 | .allow_instances = true, |
f43c738b | 684 | .use_max_tr = true, |
81d68a96 | 685 | }; |
6cd8a4bb SR |
686 | # define register_irqsoff(trace) register_tracer(&trace) |
687 | #else | |
688 | # define register_irqsoff(trace) do { } while (0) | |
689 | #endif | |
690 | ||
691 | #ifdef CONFIG_PREEMPT_TRACER | |
1c80025a | 692 | static int preemptoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
693 | { |
694 | trace_type = TRACER_PREEMPT_OFF; | |
695 | ||
02f2f764 | 696 | return __irqsoff_tracer_init(tr); |
6cd8a4bb SR |
697 | } |
698 | ||
699 | static struct tracer preemptoff_tracer __read_mostly = | |
700 | { | |
701 | .name = "preemptoff", | |
702 | .init = preemptoff_tracer_init, | |
703 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
704 | .start = irqsoff_tracer_start, |
705 | .stop = irqsoff_tracer_stop, | |
f43c738b | 706 | .print_max = true, |
62b915f1 JO |
707 | .print_header = irqsoff_print_header, |
708 | .print_line = irqsoff_print_line, | |
328df475 | 709 | .flag_changed = irqsoff_flag_changed, |
60a11774 SR |
710 | #ifdef CONFIG_FTRACE_SELFTEST |
711 | .selftest = trace_selftest_startup_preemptoff, | |
712 | #endif | |
62b915f1 JO |
713 | .open = irqsoff_trace_open, |
714 | .close = irqsoff_trace_close, | |
02f2f764 | 715 | .allow_instances = true, |
f43c738b | 716 | .use_max_tr = true, |
6cd8a4bb SR |
717 | }; |
718 | # define register_preemptoff(trace) register_tracer(&trace) | |
719 | #else | |
720 | # define register_preemptoff(trace) do { } while (0) | |
721 | #endif | |
722 | ||
723 | #if defined(CONFIG_IRQSOFF_TRACER) && \ | |
724 | defined(CONFIG_PREEMPT_TRACER) | |
725 | ||
1c80025a | 726 | static int preemptirqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
727 | { |
728 | trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; | |
729 | ||
02f2f764 | 730 | return __irqsoff_tracer_init(tr); |
6cd8a4bb SR |
731 | } |
732 | ||
733 | static struct tracer preemptirqsoff_tracer __read_mostly = | |
734 | { | |
735 | .name = "preemptirqsoff", | |
736 | .init = preemptirqsoff_tracer_init, | |
737 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
738 | .start = irqsoff_tracer_start, |
739 | .stop = irqsoff_tracer_stop, | |
f43c738b | 740 | .print_max = true, |
62b915f1 JO |
741 | .print_header = irqsoff_print_header, |
742 | .print_line = irqsoff_print_line, | |
328df475 | 743 | .flag_changed = irqsoff_flag_changed, |
60a11774 SR |
744 | #ifdef CONFIG_FTRACE_SELFTEST |
745 | .selftest = trace_selftest_startup_preemptirqsoff, | |
746 | #endif | |
62b915f1 JO |
747 | .open = irqsoff_trace_open, |
748 | .close = irqsoff_trace_close, | |
02f2f764 | 749 | .allow_instances = true, |
f43c738b | 750 | .use_max_tr = true, |
6cd8a4bb SR |
751 | }; |
752 | ||
753 | # define register_preemptirqsoff(trace) register_tracer(&trace) | |
754 | #else | |
755 | # define register_preemptirqsoff(trace) do { } while (0) | |
756 | #endif | |
81d68a96 SR |
757 | |
758 | __init static int init_irqsoff_tracer(void) | |
759 | { | |
6cd8a4bb SR |
760 | register_irqsoff(irqsoff_tracer); |
761 | register_preemptoff(preemptoff_tracer); | |
762 | register_preemptirqsoff(preemptirqsoff_tracer); | |
81d68a96 SR |
763 | |
764 | return 0; | |
765 | } | |
6f415672 | 766 | core_initcall(init_irqsoff_tracer); |