Commit | Line | Data |
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bcea3f96 | 1 | // SPDX-License-Identifier: GPL-2.0 |
81d68a96 | 2 | /* |
73d8b8bc | 3 | * trace irqs off critical timings |
81d68a96 SR |
4 | * |
5 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
6 | * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> | |
7 | * | |
8 | * From code in the latency_tracer, that is: | |
9 | * | |
10 | * Copyright (C) 2004-2006 Ingo Molnar | |
6d49e352 | 11 | * Copyright (C) 2004 Nadia Yvette Chambers |
81d68a96 SR |
12 | */ |
13 | #include <linux/kallsyms.h> | |
81d68a96 SR |
14 | #include <linux/uaccess.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/ftrace.h> | |
81d68a96 SR |
17 | |
18 | #include "trace.h" | |
19 | ||
d5915816 JF |
20 | #include <trace/events/preemptirq.h> |
21 | ||
aaecaa0b | 22 | #if defined(CONFIG_IRQSOFF_TRACER) || defined(CONFIG_PREEMPT_TRACER) |
81d68a96 SR |
23 | static struct trace_array *irqsoff_trace __read_mostly; |
24 | static int tracer_enabled __read_mostly; | |
25 | ||
6cd8a4bb SR |
26 | static DEFINE_PER_CPU(int, tracing_cpu); |
27 | ||
5389f6fa | 28 | static DEFINE_RAW_SPINLOCK(max_trace_lock); |
89b2f978 | 29 | |
6cd8a4bb SR |
30 | enum { |
31 | TRACER_IRQS_OFF = (1 << 1), | |
32 | TRACER_PREEMPT_OFF = (1 << 2), | |
33 | }; | |
34 | ||
35 | static int trace_type __read_mostly; | |
36 | ||
613f04a0 | 37 | static int save_flags; |
e9d25fe6 | 38 | |
62b915f1 JO |
39 | static void stop_irqsoff_tracer(struct trace_array *tr, int graph); |
40 | static int start_irqsoff_tracer(struct trace_array *tr, int graph); | |
41 | ||
6cd8a4bb | 42 | #ifdef CONFIG_PREEMPT_TRACER |
e309b41d | 43 | static inline int |
f27107fa | 44 | preempt_trace(int pc) |
6cd8a4bb | 45 | { |
f27107fa | 46 | return ((trace_type & TRACER_PREEMPT_OFF) && pc); |
6cd8a4bb SR |
47 | } |
48 | #else | |
f27107fa | 49 | # define preempt_trace(pc) (0) |
6cd8a4bb SR |
50 | #endif |
51 | ||
52 | #ifdef CONFIG_IRQSOFF_TRACER | |
e309b41d | 53 | static inline int |
6cd8a4bb SR |
54 | irq_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 | 64 | static 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 |
67 | static 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 | */ | |
82 | static __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 |
98 | static 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 | */ | |
138 | static void | |
2f5f6ad9 | 139 | irqsoff_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 | 156 | static 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 | ||
174 | static 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 | ||
204 | static 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 | ||
219 | static 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 | ||
226 | static 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 | |
237 | static 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 | ||
249 | static 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 |
259 | static 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 |
274 | static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) |
275 | { | |
276 | return -1; | |
277 | } | |
8179e8a1 | 278 | #endif |
62b915f1 JO |
279 | |
280 | static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) | |
281 | { | |
282 | return TRACE_TYPE_UNHANDLED; | |
283 | } | |
284 | ||
62b915f1 JO |
285 | static void irqsoff_trace_open(struct trace_iterator *iter) { } |
286 | static void irqsoff_trace_close(struct trace_iterator *iter) { } | |
7e9a49ef JO |
287 | |
288 | #ifdef CONFIG_FUNCTION_TRACER | |
8179e8a1 | 289 | static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { } |
7e9a49ef JO |
290 | static void irqsoff_print_header(struct seq_file *s) |
291 | { | |
292 | trace_default_header(s); | |
293 | } | |
294 | #else | |
295 | static 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 | 305 | static 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 | 317 | static void |
81d68a96 SR |
318 | check_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 | 360 | out_unlock: |
5389f6fa | 361 | raw_spin_unlock_irqrestore(&max_trace_lock, flags); |
89b2f978 | 362 | |
81d68a96 SR |
363 | out: |
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 | 369 | static inline void |
f27107fa | 370 | start_critical_timing(unsigned long ip, unsigned long parent_ip, int pc) |
81d68a96 SR |
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 | |
f27107fa | 398 | __trace_function(tr, ip, parent_ip, flags, pc); |
81d68a96 | 399 | |
c5f888ca | 400 | per_cpu(tracing_cpu, cpu) = 1; |
6cd8a4bb | 401 | |
81d68a96 SR |
402 | atomic_dec(&data->disabled); |
403 | } | |
404 | ||
e309b41d | 405 | static inline void |
f27107fa | 406 | stop_critical_timing(unsigned long ip, unsigned long parent_ip, int pc) |
81d68a96 SR |
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); |
f27107fa | 432 | __trace_function(tr, ip, parent_ip, flags, pc); |
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 | 439 | void start_critical_timings(void) |
81d68a96 | 440 | { |
f27107fa SRV |
441 | int pc = preempt_count(); |
442 | ||
443 | if (preempt_trace(pc) || irq_trace()) | |
444 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1, pc); | |
81d68a96 | 445 | } |
1fe37104 | 446 | EXPORT_SYMBOL_GPL(start_critical_timings); |
81d68a96 | 447 | |
e309b41d | 448 | void stop_critical_timings(void) |
81d68a96 | 449 | { |
f27107fa SRV |
450 | int pc = preempt_count(); |
451 | ||
452 | if (preempt_trace(pc) || irq_trace()) | |
453 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1, pc); | |
81d68a96 | 454 | } |
1fe37104 | 455 | EXPORT_SYMBOL_GPL(stop_critical_timings); |
81d68a96 | 456 | |
8179e8a1 SRRH |
457 | #ifdef CONFIG_FUNCTION_TRACER |
458 | static bool function_enabled; | |
459 | ||
4104d326 | 460 | static int register_irqsoff_function(struct trace_array *tr, int graph, int set) |
81d68a96 | 461 | { |
328df475 | 462 | int ret; |
62b915f1 | 463 | |
328df475 | 464 | /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ |
983f938a | 465 | if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION))) |
328df475 SRRH |
466 | return 0; |
467 | ||
468 | if (graph) | |
62b915f1 JO |
469 | ret = register_ftrace_graph(&irqsoff_graph_return, |
470 | &irqsoff_graph_entry); | |
328df475 | 471 | else |
4104d326 | 472 | ret = register_ftrace_function(tr->ops); |
328df475 SRRH |
473 | |
474 | if (!ret) | |
475 | function_enabled = true; | |
476 | ||
477 | return ret; | |
478 | } | |
479 | ||
4104d326 | 480 | static void unregister_irqsoff_function(struct trace_array *tr, int graph) |
328df475 SRRH |
481 | { |
482 | if (!function_enabled) | |
483 | return; | |
484 | ||
485 | if (graph) | |
486 | unregister_ftrace_graph(); | |
487 | else | |
4104d326 | 488 | unregister_ftrace_function(tr->ops); |
328df475 SRRH |
489 | |
490 | function_enabled = false; | |
491 | } | |
492 | ||
8179e8a1 | 493 | static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set) |
328df475 | 494 | { |
8179e8a1 SRRH |
495 | if (!(mask & TRACE_ITER_FUNCTION)) |
496 | return 0; | |
497 | ||
328df475 | 498 | if (set) |
983f938a | 499 | register_irqsoff_function(tr, is_graph(tr), 1); |
328df475 | 500 | else |
983f938a | 501 | unregister_irqsoff_function(tr, is_graph(tr)); |
8179e8a1 SRRH |
502 | return 1; |
503 | } | |
504 | #else | |
505 | static int register_irqsoff_function(struct trace_array *tr, int graph, int set) | |
506 | { | |
03905582 | 507 | return 0; |
328df475 | 508 | } |
8179e8a1 SRRH |
509 | static void unregister_irqsoff_function(struct trace_array *tr, int graph) { } |
510 | static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set) | |
511 | { | |
512 | return 0; | |
513 | } | |
514 | #endif /* CONFIG_FUNCTION_TRACER */ | |
328df475 | 515 | |
bf6065b5 | 516 | static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set) |
328df475 | 517 | { |
bf6065b5 SRRH |
518 | struct tracer *tracer = tr->current_trace; |
519 | ||
8179e8a1 SRRH |
520 | if (irqsoff_function_set(tr, mask, set)) |
521 | return 0; | |
03905582 | 522 | |
729358da | 523 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
03905582 SRRH |
524 | if (mask & TRACE_ITER_DISPLAY_GRAPH) |
525 | return irqsoff_display_graph(tr, set); | |
729358da | 526 | #endif |
328df475 SRRH |
527 | |
528 | return trace_keep_overwrite(tracer, mask, set); | |
529 | } | |
530 | ||
531 | static int start_irqsoff_tracer(struct trace_array *tr, int graph) | |
532 | { | |
533 | int ret; | |
534 | ||
4104d326 | 535 | ret = register_irqsoff_function(tr, graph, 0); |
62b915f1 JO |
536 | |
537 | if (!ret && tracing_is_enabled()) | |
9036990d | 538 | tracer_enabled = 1; |
94523e81 | 539 | else |
9036990d | 540 | tracer_enabled = 0; |
62b915f1 JO |
541 | |
542 | return ret; | |
81d68a96 SR |
543 | } |
544 | ||
62b915f1 | 545 | static void stop_irqsoff_tracer(struct trace_array *tr, int graph) |
81d68a96 | 546 | { |
81d68a96 | 547 | tracer_enabled = 0; |
62b915f1 | 548 | |
4104d326 | 549 | unregister_irqsoff_function(tr, graph); |
81d68a96 SR |
550 | } |
551 | ||
02f2f764 SRRH |
552 | static bool irqsoff_busy; |
553 | ||
554 | static int __irqsoff_tracer_init(struct trace_array *tr) | |
81d68a96 | 555 | { |
02f2f764 SRRH |
556 | if (irqsoff_busy) |
557 | return -EBUSY; | |
558 | ||
983f938a | 559 | save_flags = tr->trace_flags; |
613f04a0 SRRH |
560 | |
561 | /* non overwrite screws up the latency tracers */ | |
2b6080f2 SR |
562 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); |
563 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); | |
e9d25fe6 | 564 | |
6d9b3fa5 | 565 | tr->max_latency = 0; |
81d68a96 | 566 | irqsoff_trace = tr; |
c5f888ca | 567 | /* make sure that the tracer is visible */ |
81d68a96 | 568 | smp_wmb(); |
62b915f1 | 569 | |
4104d326 SRRH |
570 | ftrace_init_array_ops(tr, irqsoff_tracer_call); |
571 | ||
572 | /* Only toplevel instance supports graph tracing */ | |
573 | if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL && | |
983f938a | 574 | is_graph(tr)))) |
62b915f1 | 575 | printk(KERN_ERR "failed to start irqsoff tracer\n"); |
02f2f764 SRRH |
576 | |
577 | irqsoff_busy = true; | |
578 | return 0; | |
81d68a96 SR |
579 | } |
580 | ||
2b27ece6 | 581 | static void __irqsoff_tracer_reset(struct trace_array *tr) |
81d68a96 | 582 | { |
613f04a0 SRRH |
583 | int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; |
584 | int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; | |
585 | ||
983f938a | 586 | stop_irqsoff_tracer(tr, is_graph(tr)); |
e9d25fe6 | 587 | |
2b6080f2 SR |
588 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); |
589 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); | |
4104d326 | 590 | ftrace_reset_array_ops(tr); |
02f2f764 SRRH |
591 | |
592 | irqsoff_busy = false; | |
81d68a96 SR |
593 | } |
594 | ||
9036990d SR |
595 | static void irqsoff_tracer_start(struct trace_array *tr) |
596 | { | |
9036990d | 597 | tracer_enabled = 1; |
9036990d SR |
598 | } |
599 | ||
600 | static void irqsoff_tracer_stop(struct trace_array *tr) | |
601 | { | |
602 | tracer_enabled = 0; | |
81d68a96 SR |
603 | } |
604 | ||
6cd8a4bb | 605 | #ifdef CONFIG_IRQSOFF_TRACER |
c3bc8fd6 JFG |
606 | /* |
607 | * We are only interested in hardirq on/off events: | |
608 | */ | |
3f1756dc | 609 | void tracer_hardirqs_on(unsigned long a0, unsigned long a1) |
c3bc8fd6 | 610 | { |
f27107fa SRV |
611 | unsigned int pc = preempt_count(); |
612 | ||
f27107fa SRV |
613 | if (!preempt_trace(pc) && irq_trace()) |
614 | stop_critical_timing(a0, a1, pc); | |
c3bc8fd6 JFG |
615 | } |
616 | ||
3f1756dc | 617 | void tracer_hardirqs_off(unsigned long a0, unsigned long a1) |
c3bc8fd6 | 618 | { |
f27107fa SRV |
619 | unsigned int pc = preempt_count(); |
620 | ||
f27107fa SRV |
621 | if (!preempt_trace(pc) && irq_trace()) |
622 | start_critical_timing(a0, a1, pc); | |
c3bc8fd6 JFG |
623 | } |
624 | ||
1c80025a | 625 | static int irqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
626 | { |
627 | trace_type = TRACER_IRQS_OFF; | |
628 | ||
02f2f764 | 629 | return __irqsoff_tracer_init(tr); |
6cd8a4bb | 630 | } |
2b27ece6 JFG |
631 | |
632 | static void irqsoff_tracer_reset(struct trace_array *tr) | |
633 | { | |
634 | __irqsoff_tracer_reset(tr); | |
635 | } | |
636 | ||
81d68a96 SR |
637 | static struct tracer irqsoff_tracer __read_mostly = |
638 | { | |
639 | .name = "irqsoff", | |
640 | .init = irqsoff_tracer_init, | |
641 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
642 | .start = irqsoff_tracer_start, |
643 | .stop = irqsoff_tracer_stop, | |
f43c738b | 644 | .print_max = true, |
62b915f1 JO |
645 | .print_header = irqsoff_print_header, |
646 | .print_line = irqsoff_print_line, | |
328df475 | 647 | .flag_changed = irqsoff_flag_changed, |
60a11774 SR |
648 | #ifdef CONFIG_FTRACE_SELFTEST |
649 | .selftest = trace_selftest_startup_irqsoff, | |
650 | #endif | |
62b915f1 JO |
651 | .open = irqsoff_trace_open, |
652 | .close = irqsoff_trace_close, | |
02f2f764 | 653 | .allow_instances = true, |
f43c738b | 654 | .use_max_tr = true, |
81d68a96 | 655 | }; |
c3bc8fd6 | 656 | #endif /* CONFIG_IRQSOFF_TRACER */ |
6cd8a4bb SR |
657 | |
658 | #ifdef CONFIG_PREEMPT_TRACER | |
3f1756dc | 659 | void tracer_preempt_on(unsigned long a0, unsigned long a1) |
c3bc8fd6 | 660 | { |
f27107fa SRV |
661 | int pc = preempt_count(); |
662 | ||
663 | if (preempt_trace(pc) && !irq_trace()) | |
664 | stop_critical_timing(a0, a1, pc); | |
c3bc8fd6 JFG |
665 | } |
666 | ||
3f1756dc | 667 | void tracer_preempt_off(unsigned long a0, unsigned long a1) |
c3bc8fd6 | 668 | { |
f27107fa SRV |
669 | int pc = preempt_count(); |
670 | ||
671 | if (preempt_trace(pc) && !irq_trace()) | |
672 | start_critical_timing(a0, a1, pc); | |
c3bc8fd6 JFG |
673 | } |
674 | ||
1c80025a | 675 | static int preemptoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
676 | { |
677 | trace_type = TRACER_PREEMPT_OFF; | |
678 | ||
02f2f764 | 679 | return __irqsoff_tracer_init(tr); |
6cd8a4bb SR |
680 | } |
681 | ||
2b27ece6 JFG |
682 | static void preemptoff_tracer_reset(struct trace_array *tr) |
683 | { | |
684 | __irqsoff_tracer_reset(tr); | |
685 | } | |
686 | ||
6cd8a4bb SR |
687 | static struct tracer preemptoff_tracer __read_mostly = |
688 | { | |
689 | .name = "preemptoff", | |
690 | .init = preemptoff_tracer_init, | |
2b27ece6 | 691 | .reset = preemptoff_tracer_reset, |
9036990d SR |
692 | .start = irqsoff_tracer_start, |
693 | .stop = irqsoff_tracer_stop, | |
f43c738b | 694 | .print_max = true, |
62b915f1 JO |
695 | .print_header = irqsoff_print_header, |
696 | .print_line = irqsoff_print_line, | |
328df475 | 697 | .flag_changed = irqsoff_flag_changed, |
60a11774 SR |
698 | #ifdef CONFIG_FTRACE_SELFTEST |
699 | .selftest = trace_selftest_startup_preemptoff, | |
700 | #endif | |
62b915f1 JO |
701 | .open = irqsoff_trace_open, |
702 | .close = irqsoff_trace_close, | |
02f2f764 | 703 | .allow_instances = true, |
f43c738b | 704 | .use_max_tr = true, |
6cd8a4bb | 705 | }; |
c3bc8fd6 | 706 | #endif /* CONFIG_PREEMPT_TRACER */ |
6cd8a4bb | 707 | |
c3bc8fd6 | 708 | #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER) |
6cd8a4bb | 709 | |
1c80025a | 710 | static int preemptirqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
711 | { |
712 | trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; | |
713 | ||
02f2f764 | 714 | return __irqsoff_tracer_init(tr); |
6cd8a4bb SR |
715 | } |
716 | ||
2b27ece6 JFG |
717 | static void preemptirqsoff_tracer_reset(struct trace_array *tr) |
718 | { | |
719 | __irqsoff_tracer_reset(tr); | |
720 | } | |
721 | ||
6cd8a4bb SR |
722 | static struct tracer preemptirqsoff_tracer __read_mostly = |
723 | { | |
724 | .name = "preemptirqsoff", | |
725 | .init = preemptirqsoff_tracer_init, | |
2b27ece6 | 726 | .reset = preemptirqsoff_tracer_reset, |
9036990d SR |
727 | .start = irqsoff_tracer_start, |
728 | .stop = irqsoff_tracer_stop, | |
f43c738b | 729 | .print_max = true, |
62b915f1 JO |
730 | .print_header = irqsoff_print_header, |
731 | .print_line = irqsoff_print_line, | |
328df475 | 732 | .flag_changed = irqsoff_flag_changed, |
60a11774 SR |
733 | #ifdef CONFIG_FTRACE_SELFTEST |
734 | .selftest = trace_selftest_startup_preemptirqsoff, | |
735 | #endif | |
62b915f1 JO |
736 | .open = irqsoff_trace_open, |
737 | .close = irqsoff_trace_close, | |
02f2f764 | 738 | .allow_instances = true, |
f43c738b | 739 | .use_max_tr = true, |
6cd8a4bb | 740 | }; |
6cd8a4bb | 741 | #endif |
81d68a96 SR |
742 | |
743 | __init static int init_irqsoff_tracer(void) | |
744 | { | |
c3bc8fd6 JFG |
745 | #ifdef CONFIG_IRQSOFF_TRACER |
746 | register_tracer(&irqsoff_tracer); | |
aaecaa0b | 747 | #endif |
c3bc8fd6 JFG |
748 | #ifdef CONFIG_PREEMPT_TRACER |
749 | register_tracer(&preemptoff_tracer); | |
aaecaa0b | 750 | #endif |
c3bc8fd6 JFG |
751 | #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER) |
752 | register_tracer(&preemptirqsoff_tracer); | |
aaecaa0b JF |
753 | #endif |
754 | ||
c3bc8fd6 | 755 | return 0; |
aaecaa0b | 756 | } |
c3bc8fd6 JFG |
757 | core_initcall(init_irqsoff_tracer); |
758 | #endif /* IRQSOFF_TRACER || PREEMPTOFF_TRACER */ |