Commit | Line | Data |
---|---|---|
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); |
983f938a | 61 | # define is_graph(tr) ((tr)->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 | } | |
983f938a | 67 | # define is_graph(tr) 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); |
cb86e053 SRRH |
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()) | |
5e6d2b9c | 118 | return 0; |
81d68a96 | 119 | |
12883efb | 120 | *data = per_cpu_ptr(tr->trace_buffer.data, cpu); |
5e6d2b9c | 121 | disabled = atomic_inc_return(&(*data)->disabled); |
81d68a96 SR |
122 | |
123 | if (likely(disabled == 1)) | |
5e6d2b9c SR |
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 | */ | |
134 | static void | |
2f5f6ad9 | 135 | irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 136 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
5e6d2b9c SR |
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()); | |
81d68a96 SR |
146 | |
147 | atomic_dec(&data->disabled); | |
148 | } | |
606576ce | 149 | #endif /* CONFIG_FUNCTION_TRACER */ |
81d68a96 | 150 | |
62b915f1 | 151 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
03905582 | 152 | static int irqsoff_display_graph(struct trace_array *tr, int set) |
62b915f1 JO |
153 | { |
154 | int cpu; | |
155 | ||
983f938a | 156 | if (!(is_graph(tr) ^ set)) |
62b915f1 JO |
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 | ||
6d9b3fa5 | 164 | tr->max_latency = 0; |
12883efb | 165 | tracing_reset_online_cpus(&irqsoff_trace->trace_buffer); |
62b915f1 JO |
166 | |
167 | return start_irqsoff_tracer(irqsoff_trace, set); | |
168 | } | |
169 | ||
170 | static 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; | |
62b915f1 | 175 | int ret; |
62b915f1 JO |
176 | int pc; |
177 | ||
1a414428 SRRH |
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 | ||
5e6d2b9c | 190 | if (!func_prolog_dec(tr, &data, &flags)) |
62b915f1 JO |
191 | return 0; |
192 | ||
5e6d2b9c SR |
193 | pc = preempt_count(); |
194 | ret = __trace_graph_entry(tr, trace, flags, pc); | |
62b915f1 | 195 | atomic_dec(&data->disabled); |
5e6d2b9c | 196 | |
62b915f1 JO |
197 | return ret; |
198 | } | |
199 | ||
200 | static 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; | |
62b915f1 JO |
205 | int pc; |
206 | ||
5e6d2b9c | 207 | if (!func_prolog_dec(tr, &data, &flags)) |
62b915f1 JO |
208 | return; |
209 | ||
5e6d2b9c SR |
210 | pc = preempt_count(); |
211 | __trace_graph_return(tr, trace, flags, pc); | |
62b915f1 JO |
212 | atomic_dec(&data->disabled); |
213 | } | |
214 | ||
215 | static void irqsoff_trace_open(struct trace_iterator *iter) | |
216 | { | |
983f938a | 217 | if (is_graph(iter->tr)) |
62b915f1 JO |
218 | graph_trace_open(iter); |
219 | ||
220 | } | |
221 | ||
222 | static 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 | \ | |
321e68b0 JO |
229 | TRACE_GRAPH_PRINT_PROC | \ |
230 | TRACE_GRAPH_PRINT_ABS_TIME | \ | |
231 | TRACE_GRAPH_PRINT_DURATION) | |
62b915f1 JO |
232 | |
233 | static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) | |
234 | { | |
62b915f1 JO |
235 | /* |
236 | * In graph mode call the graph tracer output function, | |
237 | * otherwise go with the TRACE_FN event handler | |
238 | */ | |
983f938a | 239 | if (is_graph(iter->tr)) |
0a772620 | 240 | return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); |
62b915f1 JO |
241 | |
242 | return TRACE_TYPE_UNHANDLED; | |
243 | } | |
244 | ||
245 | static void irqsoff_print_header(struct seq_file *s) | |
246 | { | |
983f938a SRRH |
247 | struct trace_array *tr = irqsoff_trace; |
248 | ||
249 | if (is_graph(tr)) | |
0a772620 JO |
250 | print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); |
251 | else | |
62b915f1 JO |
252 | trace_default_header(s); |
253 | } | |
254 | ||
62b915f1 JO |
255 | static void |
256 | __trace_function(struct trace_array *tr, | |
257 | unsigned long ip, unsigned long parent_ip, | |
258 | unsigned long flags, int pc) | |
259 | { | |
983f938a | 260 | if (is_graph(tr)) |
0a772620 JO |
261 | trace_graph_function(tr, ip, parent_ip, flags, pc); |
262 | else | |
62b915f1 | 263 | trace_function(tr, ip, parent_ip, flags, pc); |
62b915f1 JO |
264 | } |
265 | ||
266 | #else | |
267 | #define __trace_function trace_function | |
268 | ||
8179e8a1 | 269 | #ifdef CONFIG_FUNCTION_TRACER |
62b915f1 JO |
270 | static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) |
271 | { | |
272 | return -1; | |
273 | } | |
8179e8a1 | 274 | #endif |
62b915f1 JO |
275 | |
276 | static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) | |
277 | { | |
278 | return TRACE_TYPE_UNHANDLED; | |
279 | } | |
280 | ||
62b915f1 JO |
281 | static void irqsoff_trace_open(struct trace_iterator *iter) { } |
282 | static void irqsoff_trace_close(struct trace_iterator *iter) { } | |
7e9a49ef JO |
283 | |
284 | #ifdef CONFIG_FUNCTION_TRACER | |
8179e8a1 | 285 | static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { } |
7e9a49ef JO |
286 | static void irqsoff_print_header(struct seq_file *s) |
287 | { | |
288 | trace_default_header(s); | |
289 | } | |
290 | #else | |
291 | static void irqsoff_print_header(struct seq_file *s) | |
292 | { | |
293 | trace_latency_header(s); | |
294 | } | |
295 | #endif /* CONFIG_FUNCTION_TRACER */ | |
62b915f1 JO |
296 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
297 | ||
81d68a96 SR |
298 | /* |
299 | * Should this new latency be reported/recorded? | |
300 | */ | |
a5a1d1c2 | 301 | static bool report_latency(struct trace_array *tr, u64 delta) |
81d68a96 SR |
302 | { |
303 | if (tracing_thresh) { | |
304 | if (delta < tracing_thresh) | |
79851821 | 305 | return false; |
81d68a96 | 306 | } else { |
6d9b3fa5 | 307 | if (delta <= tr->max_latency) |
79851821 | 308 | return false; |
81d68a96 | 309 | } |
79851821 | 310 | return true; |
81d68a96 SR |
311 | } |
312 | ||
e309b41d | 313 | static void |
81d68a96 SR |
314 | check_critical_timing(struct trace_array *tr, |
315 | struct trace_array_cpu *data, | |
316 | unsigned long parent_ip, | |
317 | int cpu) | |
318 | { | |
a5a1d1c2 | 319 | u64 T0, T1, delta; |
81d68a96 | 320 | unsigned long flags; |
38697053 | 321 | int pc; |
81d68a96 | 322 | |
81d68a96 | 323 | T0 = data->preempt_timestamp; |
750ed1a4 | 324 | T1 = ftrace_now(cpu); |
81d68a96 SR |
325 | delta = T1-T0; |
326 | ||
327 | local_save_flags(flags); | |
328 | ||
6450c1d3 SR |
329 | pc = preempt_count(); |
330 | ||
6d9b3fa5 | 331 | if (!report_latency(tr, delta)) |
81d68a96 SR |
332 | goto out; |
333 | ||
5389f6fa | 334 | raw_spin_lock_irqsave(&max_trace_lock, flags); |
81d68a96 | 335 | |
89b2f978 | 336 | /* check if we are still the max latency */ |
6d9b3fa5 | 337 | if (!report_latency(tr, delta)) |
89b2f978 SR |
338 | goto out_unlock; |
339 | ||
62b915f1 | 340 | __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); |
cc51a0fc SR |
341 | /* Skip 5 functions to get to the irq/preempt enable function */ |
342 | __trace_stack(tr, flags, 5, pc); | |
81d68a96 | 343 | |
81d68a96 | 344 | if (data->critical_sequence != max_sequence) |
89b2f978 | 345 | goto out_unlock; |
81d68a96 | 346 | |
81d68a96 SR |
347 | data->critical_end = parent_ip; |
348 | ||
b5130b1e | 349 | if (likely(!is_tracing_stopped())) { |
6d9b3fa5 | 350 | tr->max_latency = delta; |
b5130b1e CE |
351 | update_max_tr_single(tr, current, cpu); |
352 | } | |
81d68a96 | 353 | |
81d68a96 SR |
354 | max_sequence++; |
355 | ||
89b2f978 | 356 | out_unlock: |
5389f6fa | 357 | raw_spin_unlock_irqrestore(&max_trace_lock, flags); |
89b2f978 | 358 | |
81d68a96 SR |
359 | out: |
360 | data->critical_sequence = max_sequence; | |
750ed1a4 | 361 | data->preempt_timestamp = ftrace_now(cpu); |
62b915f1 | 362 | __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); |
81d68a96 SR |
363 | } |
364 | ||
e309b41d | 365 | static inline void |
81d68a96 SR |
366 | start_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 | ||
10246fa3 | 373 | if (!tracer_enabled || !tracing_is_enabled()) |
81d68a96 SR |
374 | return; |
375 | ||
c5f888ca SR |
376 | cpu = raw_smp_processor_id(); |
377 | ||
378 | if (per_cpu(tracing_cpu, cpu)) | |
6cd8a4bb SR |
379 | return; |
380 | ||
12883efb | 381 | data = per_cpu_ptr(tr->trace_buffer.data, cpu); |
81d68a96 | 382 | |
c5f888ca | 383 | if (unlikely(!data) || atomic_read(&data->disabled)) |
81d68a96 SR |
384 | return; |
385 | ||
386 | atomic_inc(&data->disabled); | |
387 | ||
388 | data->critical_sequence = max_sequence; | |
750ed1a4 | 389 | data->preempt_timestamp = ftrace_now(cpu); |
6cd8a4bb | 390 | data->critical_start = parent_ip ? : ip; |
81d68a96 SR |
391 | |
392 | local_save_flags(flags); | |
6cd8a4bb | 393 | |
62b915f1 | 394 | __trace_function(tr, ip, parent_ip, flags, preempt_count()); |
81d68a96 | 395 | |
c5f888ca | 396 | per_cpu(tracing_cpu, cpu) = 1; |
6cd8a4bb | 397 | |
81d68a96 SR |
398 | atomic_dec(&data->disabled); |
399 | } | |
400 | ||
e309b41d | 401 | static inline void |
81d68a96 SR |
402 | stop_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 | ||
c5f888ca | 409 | cpu = raw_smp_processor_id(); |
6cd8a4bb | 410 | /* Always clear the tracing cpu on stopping the trace */ |
c5f888ca SR |
411 | if (unlikely(per_cpu(tracing_cpu, cpu))) |
412 | per_cpu(tracing_cpu, cpu) = 0; | |
6cd8a4bb SR |
413 | else |
414 | return; | |
415 | ||
10246fa3 | 416 | if (!tracer_enabled || !tracing_is_enabled()) |
81d68a96 SR |
417 | return; |
418 | ||
12883efb | 419 | data = per_cpu_ptr(tr->trace_buffer.data, cpu); |
81d68a96 | 420 | |
3928a8a2 | 421 | if (unlikely(!data) || |
81d68a96 SR |
422 | !data->critical_start || atomic_read(&data->disabled)) |
423 | return; | |
424 | ||
425 | atomic_inc(&data->disabled); | |
c5f888ca | 426 | |
81d68a96 | 427 | local_save_flags(flags); |
62b915f1 | 428 | __trace_function(tr, ip, parent_ip, flags, preempt_count()); |
6cd8a4bb | 429 | check_critical_timing(tr, data, parent_ip ? : ip, cpu); |
81d68a96 SR |
430 | data->critical_start = 0; |
431 | atomic_dec(&data->disabled); | |
432 | } | |
433 | ||
6cd8a4bb | 434 | /* start and stop critical timings used to for stoppage (in idle) */ |
e309b41d | 435 | void start_critical_timings(void) |
81d68a96 | 436 | { |
6cd8a4bb | 437 | if (preempt_trace() || irq_trace()) |
81d68a96 SR |
438 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
439 | } | |
1fe37104 | 440 | EXPORT_SYMBOL_GPL(start_critical_timings); |
81d68a96 | 441 | |
e309b41d | 442 | void stop_critical_timings(void) |
81d68a96 | 443 | { |
6cd8a4bb | 444 | if (preempt_trace() || irq_trace()) |
81d68a96 SR |
445 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
446 | } | |
1fe37104 | 447 | EXPORT_SYMBOL_GPL(stop_critical_timings); |
81d68a96 | 448 | |
6cd8a4bb | 449 | #ifdef CONFIG_IRQSOFF_TRACER |
81d68a96 | 450 | #ifdef CONFIG_PROVE_LOCKING |
e309b41d | 451 | void time_hardirqs_on(unsigned long a0, unsigned long a1) |
81d68a96 | 452 | { |
6cd8a4bb | 453 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
454 | stop_critical_timing(a0, a1); |
455 | } | |
456 | ||
e309b41d | 457 | void time_hardirqs_off(unsigned long a0, unsigned long a1) |
81d68a96 | 458 | { |
6cd8a4bb | 459 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
460 | start_critical_timing(a0, a1); |
461 | } | |
462 | ||
463 | #else /* !CONFIG_PROVE_LOCKING */ | |
464 | ||
465 | /* | |
466 | * Stubs: | |
467 | */ | |
468 | ||
81d68a96 SR |
469 | void trace_softirqs_on(unsigned long ip) |
470 | { | |
471 | } | |
472 | ||
473 | void trace_softirqs_off(unsigned long ip) | |
474 | { | |
475 | } | |
476 | ||
e309b41d | 477 | inline void print_irqtrace_events(struct task_struct *curr) |
81d68a96 SR |
478 | { |
479 | } | |
480 | ||
481 | /* | |
482 | * We are only interested in hardirq on/off events: | |
483 | */ | |
e309b41d | 484 | void trace_hardirqs_on(void) |
81d68a96 | 485 | { |
6cd8a4bb | 486 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
487 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
488 | } | |
489 | EXPORT_SYMBOL(trace_hardirqs_on); | |
490 | ||
e309b41d | 491 | void trace_hardirqs_off(void) |
81d68a96 | 492 | { |
6cd8a4bb | 493 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
494 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
495 | } | |
496 | EXPORT_SYMBOL(trace_hardirqs_off); | |
497 | ||
285c00ad | 498 | __visible void trace_hardirqs_on_caller(unsigned long caller_addr) |
81d68a96 | 499 | { |
6cd8a4bb | 500 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
501 | stop_critical_timing(CALLER_ADDR0, caller_addr); |
502 | } | |
503 | EXPORT_SYMBOL(trace_hardirqs_on_caller); | |
504 | ||
285c00ad | 505 | __visible void trace_hardirqs_off_caller(unsigned long caller_addr) |
81d68a96 | 506 | { |
6cd8a4bb | 507 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
508 | start_critical_timing(CALLER_ADDR0, caller_addr); |
509 | } | |
510 | EXPORT_SYMBOL(trace_hardirqs_off_caller); | |
511 | ||
512 | #endif /* CONFIG_PROVE_LOCKING */ | |
6cd8a4bb SR |
513 | #endif /* CONFIG_IRQSOFF_TRACER */ |
514 | ||
515 | #ifdef CONFIG_PREEMPT_TRACER | |
e309b41d | 516 | void trace_preempt_on(unsigned long a0, unsigned long a1) |
6cd8a4bb | 517 | { |
e36de1de | 518 | if (preempt_trace() && !irq_trace()) |
1e01cb0c | 519 | stop_critical_timing(a0, a1); |
6cd8a4bb SR |
520 | } |
521 | ||
e309b41d | 522 | void trace_preempt_off(unsigned long a0, unsigned long a1) |
6cd8a4bb | 523 | { |
e36de1de | 524 | if (preempt_trace() && !irq_trace()) |
1e01cb0c | 525 | start_critical_timing(a0, a1); |
6cd8a4bb SR |
526 | } |
527 | #endif /* CONFIG_PREEMPT_TRACER */ | |
81d68a96 | 528 | |
8179e8a1 SRRH |
529 | #ifdef CONFIG_FUNCTION_TRACER |
530 | static bool function_enabled; | |
531 | ||
4104d326 | 532 | static int register_irqsoff_function(struct trace_array *tr, int graph, int set) |
81d68a96 | 533 | { |
328df475 | 534 | int ret; |
62b915f1 | 535 | |
328df475 | 536 | /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ |
983f938a | 537 | if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION))) |
328df475 SRRH |
538 | return 0; |
539 | ||
540 | if (graph) | |
62b915f1 JO |
541 | ret = register_ftrace_graph(&irqsoff_graph_return, |
542 | &irqsoff_graph_entry); | |
328df475 | 543 | else |
4104d326 | 544 | ret = register_ftrace_function(tr->ops); |
328df475 SRRH |
545 | |
546 | if (!ret) | |
547 | function_enabled = true; | |
548 | ||
549 | return ret; | |
550 | } | |
551 | ||
4104d326 | 552 | static void unregister_irqsoff_function(struct trace_array *tr, int graph) |
328df475 SRRH |
553 | { |
554 | if (!function_enabled) | |
555 | return; | |
556 | ||
557 | if (graph) | |
558 | unregister_ftrace_graph(); | |
559 | else | |
4104d326 | 560 | unregister_ftrace_function(tr->ops); |
328df475 SRRH |
561 | |
562 | function_enabled = false; | |
563 | } | |
564 | ||
8179e8a1 | 565 | static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set) |
328df475 | 566 | { |
8179e8a1 SRRH |
567 | if (!(mask & TRACE_ITER_FUNCTION)) |
568 | return 0; | |
569 | ||
328df475 | 570 | if (set) |
983f938a | 571 | register_irqsoff_function(tr, is_graph(tr), 1); |
328df475 | 572 | else |
983f938a | 573 | unregister_irqsoff_function(tr, is_graph(tr)); |
8179e8a1 SRRH |
574 | return 1; |
575 | } | |
576 | #else | |
577 | static int register_irqsoff_function(struct trace_array *tr, int graph, int set) | |
578 | { | |
03905582 | 579 | return 0; |
328df475 | 580 | } |
8179e8a1 SRRH |
581 | static void unregister_irqsoff_function(struct trace_array *tr, int graph) { } |
582 | static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set) | |
583 | { | |
584 | return 0; | |
585 | } | |
586 | #endif /* CONFIG_FUNCTION_TRACER */ | |
328df475 | 587 | |
bf6065b5 | 588 | static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set) |
328df475 | 589 | { |
bf6065b5 SRRH |
590 | struct tracer *tracer = tr->current_trace; |
591 | ||
8179e8a1 SRRH |
592 | if (irqsoff_function_set(tr, mask, set)) |
593 | return 0; | |
03905582 | 594 | |
729358da | 595 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
03905582 SRRH |
596 | if (mask & TRACE_ITER_DISPLAY_GRAPH) |
597 | return irqsoff_display_graph(tr, set); | |
729358da | 598 | #endif |
328df475 SRRH |
599 | |
600 | return trace_keep_overwrite(tracer, mask, set); | |
601 | } | |
602 | ||
603 | static int start_irqsoff_tracer(struct trace_array *tr, int graph) | |
604 | { | |
605 | int ret; | |
606 | ||
4104d326 | 607 | ret = register_irqsoff_function(tr, graph, 0); |
62b915f1 JO |
608 | |
609 | if (!ret && tracing_is_enabled()) | |
9036990d | 610 | tracer_enabled = 1; |
94523e81 | 611 | else |
9036990d | 612 | tracer_enabled = 0; |
62b915f1 JO |
613 | |
614 | return ret; | |
81d68a96 SR |
615 | } |
616 | ||
62b915f1 | 617 | static void stop_irqsoff_tracer(struct trace_array *tr, int graph) |
81d68a96 | 618 | { |
81d68a96 | 619 | tracer_enabled = 0; |
62b915f1 | 620 | |
4104d326 | 621 | unregister_irqsoff_function(tr, graph); |
81d68a96 SR |
622 | } |
623 | ||
02f2f764 SRRH |
624 | static bool irqsoff_busy; |
625 | ||
626 | static int __irqsoff_tracer_init(struct trace_array *tr) | |
81d68a96 | 627 | { |
02f2f764 SRRH |
628 | if (irqsoff_busy) |
629 | return -EBUSY; | |
630 | ||
983f938a | 631 | save_flags = tr->trace_flags; |
613f04a0 SRRH |
632 | |
633 | /* non overwrite screws up the latency tracers */ | |
2b6080f2 SR |
634 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); |
635 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); | |
e9d25fe6 | 636 | |
6d9b3fa5 | 637 | tr->max_latency = 0; |
81d68a96 | 638 | irqsoff_trace = tr; |
c5f888ca | 639 | /* make sure that the tracer is visible */ |
81d68a96 | 640 | smp_wmb(); |
62b915f1 | 641 | |
4104d326 SRRH |
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 && | |
983f938a | 646 | is_graph(tr)))) |
62b915f1 | 647 | printk(KERN_ERR "failed to start irqsoff tracer\n"); |
02f2f764 SRRH |
648 | |
649 | irqsoff_busy = true; | |
650 | return 0; | |
81d68a96 SR |
651 | } |
652 | ||
653 | static void irqsoff_tracer_reset(struct trace_array *tr) | |
654 | { | |
613f04a0 SRRH |
655 | int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; |
656 | int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; | |
657 | ||
983f938a | 658 | stop_irqsoff_tracer(tr, is_graph(tr)); |
e9d25fe6 | 659 | |
2b6080f2 SR |
660 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); |
661 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); | |
4104d326 | 662 | ftrace_reset_array_ops(tr); |
02f2f764 SRRH |
663 | |
664 | irqsoff_busy = false; | |
81d68a96 SR |
665 | } |
666 | ||
9036990d SR |
667 | static void irqsoff_tracer_start(struct trace_array *tr) |
668 | { | |
9036990d | 669 | tracer_enabled = 1; |
9036990d SR |
670 | } |
671 | ||
672 | static void irqsoff_tracer_stop(struct trace_array *tr) | |
673 | { | |
674 | tracer_enabled = 0; | |
81d68a96 SR |
675 | } |
676 | ||
6cd8a4bb | 677 | #ifdef CONFIG_IRQSOFF_TRACER |
1c80025a | 678 | static int irqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
679 | { |
680 | trace_type = TRACER_IRQS_OFF; | |
681 | ||
02f2f764 | 682 | return __irqsoff_tracer_init(tr); |
6cd8a4bb | 683 | } |
81d68a96 SR |
684 | static struct tracer irqsoff_tracer __read_mostly = |
685 | { | |
686 | .name = "irqsoff", | |
687 | .init = irqsoff_tracer_init, | |
688 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
689 | .start = irqsoff_tracer_start, |
690 | .stop = irqsoff_tracer_stop, | |
f43c738b | 691 | .print_max = true, |
62b915f1 JO |
692 | .print_header = irqsoff_print_header, |
693 | .print_line = irqsoff_print_line, | |
328df475 | 694 | .flag_changed = irqsoff_flag_changed, |
60a11774 SR |
695 | #ifdef CONFIG_FTRACE_SELFTEST |
696 | .selftest = trace_selftest_startup_irqsoff, | |
697 | #endif | |
62b915f1 JO |
698 | .open = irqsoff_trace_open, |
699 | .close = irqsoff_trace_close, | |
02f2f764 | 700 | .allow_instances = true, |
f43c738b | 701 | .use_max_tr = true, |
81d68a96 | 702 | }; |
6cd8a4bb SR |
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 | |
1c80025a | 709 | static int preemptoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
710 | { |
711 | trace_type = TRACER_PREEMPT_OFF; | |
712 | ||
02f2f764 | 713 | return __irqsoff_tracer_init(tr); |
6cd8a4bb SR |
714 | } |
715 | ||
716 | static struct tracer preemptoff_tracer __read_mostly = | |
717 | { | |
718 | .name = "preemptoff", | |
719 | .init = preemptoff_tracer_init, | |
720 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
721 | .start = irqsoff_tracer_start, |
722 | .stop = irqsoff_tracer_stop, | |
f43c738b | 723 | .print_max = true, |
62b915f1 JO |
724 | .print_header = irqsoff_print_header, |
725 | .print_line = irqsoff_print_line, | |
328df475 | 726 | .flag_changed = irqsoff_flag_changed, |
60a11774 SR |
727 | #ifdef CONFIG_FTRACE_SELFTEST |
728 | .selftest = trace_selftest_startup_preemptoff, | |
729 | #endif | |
62b915f1 JO |
730 | .open = irqsoff_trace_open, |
731 | .close = irqsoff_trace_close, | |
02f2f764 | 732 | .allow_instances = true, |
f43c738b | 733 | .use_max_tr = true, |
6cd8a4bb SR |
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 | ||
1c80025a | 743 | static int preemptirqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
744 | { |
745 | trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; | |
746 | ||
02f2f764 | 747 | return __irqsoff_tracer_init(tr); |
6cd8a4bb SR |
748 | } |
749 | ||
750 | static struct tracer preemptirqsoff_tracer __read_mostly = | |
751 | { | |
752 | .name = "preemptirqsoff", | |
753 | .init = preemptirqsoff_tracer_init, | |
754 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
755 | .start = irqsoff_tracer_start, |
756 | .stop = irqsoff_tracer_stop, | |
f43c738b | 757 | .print_max = true, |
62b915f1 JO |
758 | .print_header = irqsoff_print_header, |
759 | .print_line = irqsoff_print_line, | |
328df475 | 760 | .flag_changed = irqsoff_flag_changed, |
60a11774 SR |
761 | #ifdef CONFIG_FTRACE_SELFTEST |
762 | .selftest = trace_selftest_startup_preemptirqsoff, | |
763 | #endif | |
62b915f1 JO |
764 | .open = irqsoff_trace_open, |
765 | .close = irqsoff_trace_close, | |
02f2f764 | 766 | .allow_instances = true, |
f43c738b | 767 | .use_max_tr = true, |
6cd8a4bb SR |
768 | }; |
769 | ||
770 | # define register_preemptirqsoff(trace) register_tracer(&trace) | |
771 | #else | |
772 | # define register_preemptirqsoff(trace) do { } while (0) | |
773 | #endif | |
81d68a96 SR |
774 | |
775 | __init static int init_irqsoff_tracer(void) | |
776 | { | |
6cd8a4bb SR |
777 | register_irqsoff(irqsoff_tracer); |
778 | register_preemptoff(preemptoff_tracer); | |
779 | register_preemptirqsoff(preemptirqsoff_tracer); | |
81d68a96 SR |
780 | |
781 | return 0; | |
782 | } | |
6f415672 | 783 | core_initcall(init_irqsoff_tracer); |