xref: /openbmc/u-boot/lib/trace.c (revision 64d16706)
1 /*
2  * Copyright (c) 2012 The Chromium OS Authors.
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <mapmem.h>
9 #include <trace.h>
10 #include <asm/io.h>
11 #include <asm/sections.h>
12 
13 DECLARE_GLOBAL_DATA_PTR;
14 
15 static char trace_enabled __attribute__((section(".data")));
16 static char trace_inited __attribute__((section(".data")));
17 
18 /* The header block at the start of the trace memory area */
19 struct trace_hdr {
20 	int func_count;		/* Total number of function call sites */
21 	u64 call_count;		/* Total number of tracked function calls */
22 	u64 untracked_count;	/* Total number of untracked function calls */
23 	int funcs_used;		/* Total number of functions used */
24 
25 	/*
26 	 * Call count for each function. This is indexed by the word offset
27 	 * of the function from gd->relocaddr
28 	 */
29 	uintptr_t *call_accum;
30 
31 	/* Function trace list */
32 	struct trace_call *ftrace;	/* The function call records */
33 	ulong ftrace_size;	/* Num. of ftrace records we have space for */
34 	ulong ftrace_count;	/* Num. of ftrace records written */
35 	ulong ftrace_too_deep_count;	/* Functions that were too deep */
36 
37 	int depth;
38 	int depth_limit;
39 	int max_depth;
40 };
41 
42 static struct trace_hdr *hdr;	/* Pointer to start of trace buffer */
43 
44 static inline uintptr_t __attribute__((no_instrument_function))
45 		func_ptr_to_num(void *func_ptr)
46 {
47 	uintptr_t offset = (uintptr_t)func_ptr;
48 
49 #ifdef CONFIG_SANDBOX
50 	offset -= (uintptr_t)&_init;
51 #else
52 	if (gd->flags & GD_FLG_RELOC)
53 		offset -= gd->relocaddr;
54 	else
55 		offset -= CONFIG_SYS_TEXT_BASE;
56 #endif
57 	return offset / FUNC_SITE_SIZE;
58 }
59 
60 static void __attribute__((no_instrument_function)) add_ftrace(void *func_ptr,
61 				void *caller, ulong flags)
62 {
63 	if (hdr->depth > hdr->depth_limit) {
64 		hdr->ftrace_too_deep_count++;
65 		return;
66 	}
67 	if (hdr->ftrace_count < hdr->ftrace_size) {
68 		struct trace_call *rec = &hdr->ftrace[hdr->ftrace_count];
69 
70 		rec->func = func_ptr_to_num(func_ptr);
71 		rec->caller = func_ptr_to_num(caller);
72 		rec->flags = flags | (timer_get_us() & FUNCF_TIMESTAMP_MASK);
73 	}
74 	hdr->ftrace_count++;
75 }
76 
77 static void __attribute__((no_instrument_function)) add_textbase(void)
78 {
79 	if (hdr->ftrace_count < hdr->ftrace_size) {
80 		struct trace_call *rec = &hdr->ftrace[hdr->ftrace_count];
81 
82 		rec->func = CONFIG_SYS_TEXT_BASE;
83 		rec->caller = 0;
84 		rec->flags = FUNCF_TEXTBASE;
85 	}
86 	hdr->ftrace_count++;
87 }
88 
89 /**
90  * This is called on every function entry
91  *
92  * We add to our tally for this function and add to the list of called
93  * functions.
94  *
95  * @param func_ptr	Pointer to function being entered
96  * @param caller	Pointer to function which called this function
97  */
98 void __attribute__((no_instrument_function)) __cyg_profile_func_enter(
99 		void *func_ptr, void *caller)
100 {
101 	if (trace_enabled) {
102 		int func;
103 
104 		add_ftrace(func_ptr, caller, FUNCF_ENTRY);
105 		func = func_ptr_to_num(func_ptr);
106 		if (func < hdr->func_count) {
107 			hdr->call_accum[func]++;
108 			hdr->call_count++;
109 		} else {
110 			hdr->untracked_count++;
111 		}
112 		hdr->depth++;
113 		if (hdr->depth > hdr->depth_limit)
114 			hdr->max_depth = hdr->depth;
115 	}
116 }
117 
118 /**
119  * This is called on every function exit
120  *
121  * We do nothing here.
122  *
123  * @param func_ptr	Pointer to function being entered
124  * @param caller	Pointer to function which called this function
125  */
126 void __attribute__((no_instrument_function)) __cyg_profile_func_exit(
127 		void *func_ptr, void *caller)
128 {
129 	if (trace_enabled) {
130 		add_ftrace(func_ptr, caller, FUNCF_EXIT);
131 		hdr->depth--;
132 	}
133 }
134 
135 /**
136  * Produce a list of called functions
137  *
138  * The information is written into the supplied buffer - a header followed
139  * by a list of function records.
140  *
141  * @param buff		Buffer to place list into
142  * @param buff_size	Size of buffer
143  * @param needed	Returns size of buffer needed, which may be
144  *			greater than buff_size if we ran out of space.
145  * @return 0 if ok, -1 if space was exhausted
146  */
147 int trace_list_functions(void *buff, int buff_size, unsigned int *needed)
148 {
149 	struct trace_output_hdr *output_hdr = NULL;
150 	void *end, *ptr = buff;
151 	int func;
152 	int upto;
153 
154 	end = buff ? buff + buff_size : NULL;
155 
156 	/* Place some header information */
157 	if (ptr + sizeof(struct trace_output_hdr) < end)
158 		output_hdr = ptr;
159 	ptr += sizeof(struct trace_output_hdr);
160 
161 	/* Add information about each function */
162 	for (func = upto = 0; func < hdr->func_count; func++) {
163 		int calls = hdr->call_accum[func];
164 
165 		if (!calls)
166 			continue;
167 
168 		if (ptr + sizeof(struct trace_output_func) < end) {
169 			struct trace_output_func *stats = ptr;
170 
171 			stats->offset = func * FUNC_SITE_SIZE;
172 			stats->call_count = calls;
173 			upto++;
174 		}
175 		ptr += sizeof(struct trace_output_func);
176 	}
177 
178 	/* Update the header */
179 	if (output_hdr) {
180 		output_hdr->rec_count = upto;
181 		output_hdr->type = TRACE_CHUNK_FUNCS;
182 	}
183 
184 	/* Work out how must of the buffer we used */
185 	*needed = ptr - buff;
186 	if (ptr > end)
187 		return -1;
188 	return 0;
189 }
190 
191 int trace_list_calls(void *buff, int buff_size, unsigned *needed)
192 {
193 	struct trace_output_hdr *output_hdr = NULL;
194 	void *end, *ptr = buff;
195 	int rec, upto;
196 	int count;
197 
198 	end = buff ? buff + buff_size : NULL;
199 
200 	/* Place some header information */
201 	if (ptr + sizeof(struct trace_output_hdr) < end)
202 		output_hdr = ptr;
203 	ptr += sizeof(struct trace_output_hdr);
204 
205 	/* Add information about each call */
206 	count = hdr->ftrace_count;
207 	if (count > hdr->ftrace_size)
208 		count = hdr->ftrace_size;
209 	for (rec = upto = 0; rec < count; rec++) {
210 		if (ptr + sizeof(struct trace_call) < end) {
211 			struct trace_call *call = &hdr->ftrace[rec];
212 			struct trace_call *out = ptr;
213 
214 			out->func = call->func * FUNC_SITE_SIZE;
215 			out->caller = call->caller * FUNC_SITE_SIZE;
216 			out->flags = call->flags;
217 			upto++;
218 		}
219 		ptr += sizeof(struct trace_call);
220 	}
221 
222 	/* Update the header */
223 	if (output_hdr) {
224 		output_hdr->rec_count = upto;
225 		output_hdr->type = TRACE_CHUNK_CALLS;
226 	}
227 
228 	/* Work out how must of the buffer we used */
229 	*needed = ptr - buff;
230 	if (ptr > end)
231 		return -1;
232 	return 0;
233 }
234 
235 /* Print basic information about tracing */
236 void trace_print_stats(void)
237 {
238 	ulong count;
239 
240 #ifndef FTRACE
241 	puts("Warning: make U-Boot with FTRACE to enable function instrumenting.\n");
242 	puts("You will likely get zeroed data here\n");
243 #endif
244 	if (!trace_inited) {
245 		printf("Trace is disabled\n");
246 		return;
247 	}
248 	print_grouped_ull(hdr->func_count, 10);
249 	puts(" function sites\n");
250 	print_grouped_ull(hdr->call_count, 10);
251 	puts(" function calls\n");
252 	print_grouped_ull(hdr->untracked_count, 10);
253 	puts(" untracked function calls\n");
254 	count = min(hdr->ftrace_count, hdr->ftrace_size);
255 	print_grouped_ull(count, 10);
256 	puts(" traced function calls");
257 	if (hdr->ftrace_count > hdr->ftrace_size) {
258 		printf(" (%lu dropped due to overflow)",
259 		       hdr->ftrace_count - hdr->ftrace_size);
260 	}
261 	puts("\n");
262 	printf("%15d maximum observed call depth\n", hdr->max_depth);
263 	printf("%15d call depth limit\n", hdr->depth_limit);
264 	print_grouped_ull(hdr->ftrace_too_deep_count, 10);
265 	puts(" calls not traced due to depth\n");
266 }
267 
268 void __attribute__((no_instrument_function)) trace_set_enabled(int enabled)
269 {
270 	trace_enabled = enabled != 0;
271 }
272 
273 /**
274  * Init the tracing system ready for used, and enable it
275  *
276  * @param buff		Pointer to trace buffer
277  * @param buff_size	Size of trace buffer
278  */
279 int __attribute__((no_instrument_function)) trace_init(void *buff,
280 		size_t buff_size)
281 {
282 	ulong func_count = gd->mon_len / FUNC_SITE_SIZE;
283 	size_t needed;
284 	int was_disabled = !trace_enabled;
285 
286 	if (!was_disabled) {
287 #ifdef CONFIG_TRACE_EARLY
288 		char *end;
289 		ulong used;
290 
291 		/*
292 		 * Copy over the early trace data if we have it. Disable
293 		 * tracing while we are doing this.
294 		 */
295 		trace_enabled = 0;
296 		hdr = map_sysmem(CONFIG_TRACE_EARLY_ADDR,
297 				 CONFIG_TRACE_EARLY_SIZE);
298 		end = (char *)&hdr->ftrace[hdr->ftrace_count];
299 		used = end - (char *)hdr;
300 		printf("trace: copying %08lx bytes of early data from %x to %08lx\n",
301 		       used, CONFIG_TRACE_EARLY_ADDR,
302 		       (ulong)map_to_sysmem(buff));
303 		memcpy(buff, hdr, used);
304 #else
305 		puts("trace: already enabled\n");
306 		return -1;
307 #endif
308 	}
309 	hdr = (struct trace_hdr *)buff;
310 	needed = sizeof(*hdr) + func_count * sizeof(uintptr_t);
311 	if (needed > buff_size) {
312 		printf("trace: buffer size %zd bytes: at least %zd needed\n",
313 		       buff_size, needed);
314 		return -1;
315 	}
316 
317 	if (was_disabled)
318 		memset(hdr, '\0', needed);
319 	hdr->func_count = func_count;
320 	hdr->call_accum = (uintptr_t *)(hdr + 1);
321 
322 	/* Use any remaining space for the timed function trace */
323 	hdr->ftrace = (struct trace_call *)(buff + needed);
324 	hdr->ftrace_size = (buff_size - needed) / sizeof(*hdr->ftrace);
325 	add_textbase();
326 
327 	puts("trace: enabled\n");
328 	hdr->depth_limit = 15;
329 	trace_enabled = 1;
330 	trace_inited = 1;
331 	return 0;
332 }
333 
334 #ifdef CONFIG_TRACE_EARLY
335 int __attribute__((no_instrument_function)) trace_early_init(void)
336 {
337 	ulong func_count = gd->mon_len / FUNC_SITE_SIZE;
338 	size_t buff_size = CONFIG_TRACE_EARLY_SIZE;
339 	size_t needed;
340 
341 	/* We can ignore additional calls to this function */
342 	if (trace_enabled)
343 		return 0;
344 
345 	hdr = map_sysmem(CONFIG_TRACE_EARLY_ADDR, CONFIG_TRACE_EARLY_SIZE);
346 	needed = sizeof(*hdr) + func_count * sizeof(uintptr_t);
347 	if (needed > buff_size) {
348 		printf("trace: buffer size is %zd bytes, at least %zd needed\n",
349 		       buff_size, needed);
350 		return -1;
351 	}
352 
353 	memset(hdr, '\0', needed);
354 	hdr->call_accum = (uintptr_t *)(hdr + 1);
355 	hdr->func_count = func_count;
356 
357 	/* Use any remaining space for the timed function trace */
358 	hdr->ftrace = (struct trace_call *)((char *)hdr + needed);
359 	hdr->ftrace_size = (buff_size - needed) / sizeof(*hdr->ftrace);
360 	add_textbase();
361 	hdr->depth_limit = 200;
362 	printf("trace: early enable at %08x\n", CONFIG_TRACE_EARLY_ADDR);
363 
364 	trace_enabled = 1;
365 	return 0;
366 }
367 #endif
368