xref: /dpdk/lib/eal/include/rte_trace_point.h (revision 5dc68f2be8adea7aad24dc56dad57ec9a3bfe413)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(C) 2020 Marvell International Ltd.
3  */
4 
5 #ifndef _RTE_TRACE_POINT_H_
6 #define _RTE_TRACE_POINT_H_
7 
8 /**
9  * @file
10  *
11  * RTE Tracepoint API
12  *
13  * This file provides the tracepoint API to RTE applications.
14  *
15  * @warning
16  * @b EXPERIMENTAL: this API may change without prior notice
17  */
18 
19 #include <stdbool.h>
20 #include <stdio.h>
21 
22 #include <rte_branch_prediction.h>
23 #include <rte_common.h>
24 #include <rte_compat.h>
25 #include <rte_cycles.h>
26 #include <rte_per_lcore.h>
27 #include <rte_stdatomic.h>
28 #include <rte_string_fns.h>
29 #include <rte_trace.h>
30 #include <rte_uuid.h>
31 
32 #ifdef __cplusplus
33 extern "C" {
34 #endif
35 
36 /** The tracepoint object. */
37 typedef RTE_ATOMIC(uint64_t) rte_trace_point_t;
38 
39 /**
40  * Macro to define the tracepoint arguments in RTE_TRACE_POINT macro.
41 
42  * @see RTE_TRACE_POINT, RTE_TRACE_POINT_FP
43  */
44 #define RTE_TRACE_POINT_ARGS
45 
46 /** @internal Helper macro to support RTE_TRACE_POINT and RTE_TRACE_POINT_FP */
47 #define __RTE_TRACE_POINT(_mode, _tp, _args, ...) \
48 extern rte_trace_point_t __##_tp; \
49 static __rte_always_inline void \
50 _tp _args \
51 { \
52 	__rte_trace_point_emit_header_##_mode(&__##_tp); \
53 	__VA_ARGS__ \
54 }
55 
56 /**
57  * Create a tracepoint.
58  *
59  * A tracepoint is defined by specifying:
60  * - its input arguments: they are the C function style parameters to define
61  *   the arguments of tracepoint function. These input arguments are embedded
62  *   using the RTE_TRACE_POINT_ARGS macro.
63  * - its output event fields: they are the sources of event fields that form
64  *   the payload of any event that the execution of the tracepoint macro emits
65  *   for this particular tracepoint. The application uses
66  *   rte_trace_point_emit_* macros to emit the output event fields.
67  *
68  * @param tp
69  *   Tracepoint object. Before using the tracepoint, an application needs to
70  *   define the tracepoint using RTE_TRACE_POINT_REGISTER macro.
71  * @param args
72  *   C function style input arguments to define the arguments to tracepoint
73  *   function.
74  * @param ...
75  *   Define the payload of trace function. The payload will be formed using
76  *   rte_trace_point_emit_* macros. Use ";" delimiter between two payloads.
77  *
78  * @see RTE_TRACE_POINT_ARGS, RTE_TRACE_POINT_REGISTER, rte_trace_point_emit_*
79  */
80 #define RTE_TRACE_POINT(tp, args, ...) \
81 	__RTE_TRACE_POINT(generic, tp, args, __VA_ARGS__)
82 
83 /**
84  * Create a tracepoint for fast path.
85  *
86  * Similar to RTE_TRACE_POINT, except that it is removed at compilation time
87  * unless the RTE_ENABLE_TRACE_FP configuration parameter is set.
88  *
89  * @param tp
90  *   Tracepoint object. Before using the tracepoint, an application needs to
91  *   define the tracepoint using RTE_TRACE_POINT_REGISTER macro.
92  * @param args
93  *   C function style input arguments to define the arguments to tracepoint.
94  *   function.
95  * @param ...
96  *   Define the payload of trace function. The payload will be formed using
97  *   rte_trace_point_emit_* macros, Use ";" delimiter between two payloads.
98  *
99  * @see RTE_TRACE_POINT
100  */
101 #define RTE_TRACE_POINT_FP(tp, args, ...) \
102 	__RTE_TRACE_POINT(fp, tp, args, __VA_ARGS__)
103 
104 #ifdef __DOXYGEN__
105 
106 /**
107  * Register a tracepoint.
108  *
109  * @param trace
110  *   The tracepoint object created using RTE_TRACE_POINT_REGISTER.
111  * @param name
112  *   The name of the tracepoint object.
113  * @return
114  *   - 0: Successfully registered the tracepoint.
115  *   - <0: Failure to register the tracepoint.
116  */
117 #define RTE_TRACE_POINT_REGISTER(trace, name)
118 
119 /** Tracepoint function payload for uint64_t datatype */
120 #define rte_trace_point_emit_u64(val)
121 /** Tracepoint function payload for int64_t datatype */
122 #define rte_trace_point_emit_i64(val)
123 /** Tracepoint function payload for uint32_t datatype */
124 #define rte_trace_point_emit_u32(val)
125 /** Tracepoint function payload for int32_t datatype */
126 #define rte_trace_point_emit_i32(val)
127 /** Tracepoint function payload for uint16_t datatype */
128 #define rte_trace_point_emit_u16(val)
129 /** Tracepoint function payload for int16_t datatype */
130 #define rte_trace_point_emit_i16(val)
131 /** Tracepoint function payload for uint8_t datatype */
132 #define rte_trace_point_emit_u8(val)
133 /** Tracepoint function payload for int8_t datatype */
134 #define rte_trace_point_emit_i8(val)
135 /** Tracepoint function payload for int datatype */
136 #define rte_trace_point_emit_int(val)
137 /** Tracepoint function payload for long datatype */
138 #define rte_trace_point_emit_long(val)
139 /** Tracepoint function payload for size_t datatype */
140 #define rte_trace_point_emit_size_t(val)
141 /** Tracepoint function payload for float datatype */
142 #define rte_trace_point_emit_float(val)
143 /** Tracepoint function payload for double datatype */
144 #define rte_trace_point_emit_double(val)
145 /** Tracepoint function payload for pointer datatype */
146 #define rte_trace_point_emit_ptr(val)
147 /** Tracepoint function payload for string datatype */
148 #define rte_trace_point_emit_string(val)
149 /**
150  * Tracepoint function to capture a blob.
151  *
152  * @param val
153  *   Pointer to the array to be captured.
154  * @param len
155  *   Length to be captured. The maximum supported length is
156  *   RTE_TRACE_BLOB_LEN_MAX bytes.
157  */
158 #define rte_trace_point_emit_blob(val, len)
159 
160 #endif /* __DOXYGEN__ */
161 
162 /** @internal Macro to define maximum emit length of string datatype. */
163 #define __RTE_TRACE_EMIT_STRING_LEN_MAX 32
164 /** @internal Macro to define event header size. */
165 #define __RTE_TRACE_EVENT_HEADER_SZ sizeof(uint64_t)
166 
167 /** Macro to define maximum emit length of blob. */
168 #define RTE_TRACE_BLOB_LEN_MAX 64
169 
170 /**
171  * Enable recording events of the given tracepoint in the trace buffer.
172  *
173  * @param tp
174  *   The tracepoint object to enable.
175  * @return
176  *   - 0: Success.
177  *   - (-ERANGE): Trace object is not registered.
178  */
179 __rte_experimental
180 int rte_trace_point_enable(rte_trace_point_t *tp);
181 
182 /**
183  * Disable recording events of the given tracepoint in the trace buffer.
184  *
185  * @param tp
186  *   The tracepoint object to disable.
187  * @return
188  *   - 0: Success.
189  *   - (-ERANGE): Trace object is not registered.
190  */
191 __rte_experimental
192 int rte_trace_point_disable(rte_trace_point_t *tp);
193 
194 /**
195  * Test if recording events from the given tracepoint is enabled.
196  *
197  * @param tp
198  *    The tracepoint object.
199  * @return
200  *    true if tracepoint is enabled, false otherwise.
201  */
202 __rte_experimental
203 bool rte_trace_point_is_enabled(rte_trace_point_t *tp);
204 
205 /**
206  * Lookup a tracepoint object from its name.
207  *
208  * @param name
209  *   The name of the tracepoint.
210  * @return
211  *   The tracepoint object or NULL if not found.
212  */
213 __rte_experimental
214 rte_trace_point_t *rte_trace_point_lookup(const char *name);
215 
216 /**
217  * @internal
218  *
219  * Test if the tracepoint fast path compile-time option is enabled.
220  *
221  * @return
222  *   true if tracepoint fast path enabled, false otherwise.
223  */
224 __rte_experimental
225 static __rte_always_inline bool
226 __rte_trace_point_fp_is_enabled(void)
227 {
228 #ifdef RTE_ENABLE_TRACE_FP
229 	return true;
230 #else
231 	return false;
232 #endif
233 }
234 
235 /**
236  * @internal
237  *
238  * Allocate trace memory buffer per thread.
239  */
240 __rte_experimental
241 void __rte_trace_mem_per_thread_alloc(void);
242 
243 /**
244  * @internal
245  *
246  * Helper function to emit field.
247  *
248  * @param sz
249  *   The tracepoint size.
250  * @param field
251  *   The name of the trace event.
252  * @param type
253  *   The datatype of the trace event as string.
254  * @return
255  *   - 0: Success.
256  *   - <0: Failure.
257  */
258 __rte_experimental
259 void __rte_trace_point_emit_field(size_t sz, const char *field,
260 	const char *type);
261 
262 /**
263  * @internal
264  *
265  * Helper function to register a dynamic tracepoint.
266  * Use RTE_TRACE_POINT_REGISTER macro for tracepoint registration.
267  *
268  * @param trace
269  *   The tracepoint object created using RTE_TRACE_POINT_REGISTER.
270  * @param name
271  *   The name of the tracepoint object.
272  * @param register_fn
273  *   Trace registration function.
274  * @return
275  *   - 0: Successfully registered the tracepoint.
276  *   - <0: Failure to register the tracepoint.
277  */
278 __rte_experimental
279 int __rte_trace_point_register(rte_trace_point_t *trace, const char *name,
280 	void (*register_fn)(void));
281 
282 #ifndef __DOXYGEN__
283 
284 #ifndef _RTE_TRACE_POINT_REGISTER_H_
285 #ifdef ALLOW_EXPERIMENTAL_API
286 
287 #define __RTE_TRACE_EVENT_HEADER_ID_SHIFT (48)
288 
289 #define __RTE_TRACE_FIELD_SIZE_SHIFT 0
290 #define __RTE_TRACE_FIELD_SIZE_MASK (0xffffULL << __RTE_TRACE_FIELD_SIZE_SHIFT)
291 #define __RTE_TRACE_FIELD_ID_SHIFT (16)
292 #define __RTE_TRACE_FIELD_ID_MASK (0xffffULL << __RTE_TRACE_FIELD_ID_SHIFT)
293 #define __RTE_TRACE_FIELD_ENABLE_MASK (1ULL << 63)
294 #define __RTE_TRACE_FIELD_ENABLE_DISCARD (1ULL << 62)
295 
296 struct __rte_trace_stream_header {
297 	uint32_t magic;
298 	rte_uuid_t uuid;
299 	uint32_t lcore_id;
300 	char thread_name[__RTE_TRACE_EMIT_STRING_LEN_MAX];
301 };
302 
303 struct __rte_trace_header {
304 	uint32_t offset;
305 	uint32_t len;
306 	struct __rte_trace_stream_header stream_header;
307 	uint8_t mem[];
308 };
309 
310 RTE_DECLARE_PER_LCORE(void *, trace_mem);
311 
312 static __rte_always_inline void *
313 __rte_trace_mem_get(uint64_t in)
314 {
315 	struct __rte_trace_header *trace =
316 		(struct __rte_trace_header *)(RTE_PER_LCORE(trace_mem));
317 	const uint16_t sz = in & __RTE_TRACE_FIELD_SIZE_MASK;
318 
319 	/* Trace memory is not initialized for this thread */
320 	if (unlikely(trace == NULL)) {
321 		__rte_trace_mem_per_thread_alloc();
322 		trace = (struct __rte_trace_header *)(RTE_PER_LCORE(trace_mem));
323 		if (unlikely(trace == NULL))
324 			return NULL;
325 	}
326 	/* Check the wrap around case */
327 	uint32_t offset = trace->offset;
328 	if (unlikely((offset + sz) >= trace->len)) {
329 		/* Disable the trace event if it in DISCARD mode */
330 		if (unlikely(in & __RTE_TRACE_FIELD_ENABLE_DISCARD))
331 			return NULL;
332 
333 		offset = 0;
334 	}
335 	/* Align to event header size */
336 	offset = RTE_ALIGN_CEIL(offset, __RTE_TRACE_EVENT_HEADER_SZ);
337 	void *mem = RTE_PTR_ADD(&trace->mem[0], offset);
338 	offset += sz;
339 	trace->offset = offset;
340 
341 	return mem;
342 }
343 
344 static __rte_always_inline void *
345 __rte_trace_point_emit_ev_header(void *mem, uint64_t in)
346 {
347 	uint64_t val;
348 
349 	/* Event header [63:0] = id [63:48] | timestamp [47:0] */
350 	val = rte_get_tsc_cycles() &
351 		~(0xffffULL << __RTE_TRACE_EVENT_HEADER_ID_SHIFT);
352 	val |= ((in & __RTE_TRACE_FIELD_ID_MASK) <<
353 		(__RTE_TRACE_EVENT_HEADER_ID_SHIFT -
354 		 __RTE_TRACE_FIELD_ID_SHIFT));
355 
356 	*(uint64_t *)mem = val;
357 	return RTE_PTR_ADD(mem, __RTE_TRACE_EVENT_HEADER_SZ);
358 }
359 
360 #define __rte_trace_point_emit_header_generic(t) \
361 void *mem; \
362 do { \
363 	if (!rte_trace_feature_is_enabled()) \
364 		return; \
365 	const uint64_t val = rte_atomic_load_explicit(t, rte_memory_order_acquire); \
366 	if (likely(!(val & __RTE_TRACE_FIELD_ENABLE_MASK))) \
367 		return; \
368 	mem = __rte_trace_mem_get(val); \
369 	if (unlikely(mem == NULL)) \
370 		return; \
371 	mem = __rte_trace_point_emit_ev_header(mem, val); \
372 } while (0)
373 
374 #define __rte_trace_point_emit_header_fp(t) \
375 	if (!__rte_trace_point_fp_is_enabled()) \
376 		return; \
377 	__rte_trace_point_emit_header_generic(t)
378 
379 #define __rte_trace_point_emit(in, type) \
380 do { \
381 	memcpy(mem, &(in), sizeof(in)); \
382 	mem = RTE_PTR_ADD(mem, sizeof(in)); \
383 } while (0)
384 
385 #define rte_trace_point_emit_string(in) \
386 do { \
387 	if (unlikely(in == NULL)) \
388 		return; \
389 	rte_strscpy((char *)mem, in, __RTE_TRACE_EMIT_STRING_LEN_MAX); \
390 	mem = RTE_PTR_ADD(mem, __RTE_TRACE_EMIT_STRING_LEN_MAX); \
391 } while (0)
392 
393 #define rte_trace_point_emit_blob(in, len) \
394 do { \
395 	if (unlikely(in == NULL)) \
396 		return; \
397 	if (len > RTE_TRACE_BLOB_LEN_MAX) \
398 		len = RTE_TRACE_BLOB_LEN_MAX; \
399 	__rte_trace_point_emit(len, uint8_t); \
400 	memcpy(mem, in, len); \
401 	memset(RTE_PTR_ADD(mem, len), 0, RTE_TRACE_BLOB_LEN_MAX - len); \
402 	mem = RTE_PTR_ADD(mem, RTE_TRACE_BLOB_LEN_MAX); \
403 } while (0)
404 
405 #else
406 
407 #define __rte_trace_point_emit_header_generic(t) RTE_SET_USED(t)
408 #define __rte_trace_point_emit_header_fp(t) RTE_SET_USED(t)
409 #define __rte_trace_point_emit(in, type) RTE_SET_USED(in)
410 #define rte_trace_point_emit_string(in) RTE_SET_USED(in)
411 #define rte_trace_point_emit_blob(in, len) \
412 do { \
413 	RTE_SET_USED(in); \
414 	RTE_SET_USED(len); \
415 } while (0)
416 
417 
418 #endif /* ALLOW_EXPERIMENTAL_API */
419 #endif /* _RTE_TRACE_POINT_REGISTER_H_ */
420 
421 #define rte_trace_point_emit_u64(in) __rte_trace_point_emit(in, uint64_t)
422 #define rte_trace_point_emit_i64(in) __rte_trace_point_emit(in, int64_t)
423 #define rte_trace_point_emit_u32(in) __rte_trace_point_emit(in, uint32_t)
424 #define rte_trace_point_emit_i32(in) __rte_trace_point_emit(in, int32_t)
425 #define rte_trace_point_emit_u16(in) __rte_trace_point_emit(in, uint16_t)
426 #define rte_trace_point_emit_i16(in) __rte_trace_point_emit(in, int16_t)
427 #define rte_trace_point_emit_u8(in) __rte_trace_point_emit(in, uint8_t)
428 #define rte_trace_point_emit_i8(in) __rte_trace_point_emit(in, int8_t)
429 #define rte_trace_point_emit_int(in) __rte_trace_point_emit(in, int32_t)
430 #define rte_trace_point_emit_long(in) __rte_trace_point_emit(in, long)
431 #define rte_trace_point_emit_size_t(in) __rte_trace_point_emit(in, size_t)
432 #define rte_trace_point_emit_float(in) __rte_trace_point_emit(in, float)
433 #define rte_trace_point_emit_double(in) __rte_trace_point_emit(in, double)
434 #define rte_trace_point_emit_ptr(in) __rte_trace_point_emit(in, uintptr_t)
435 
436 #endif /* __DOXYGEN__ */
437 
438 #ifdef __cplusplus
439 }
440 #endif
441 
442 #endif /* _RTE_TRACE_POINT_H_ */
443