1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (c) 2012 The Chromium OS Authors.
4 */
5
6 #include <common.h>
7 #include <mapmem.h>
8 #include <time.h>
9 #include <trace.h>
10 #include <asm/global_data.h>
11 #include <asm/io.h>
12 #include <asm/sections.h>
13
14 DECLARE_GLOBAL_DATA_PTR;
15
16 static char trace_enabled __attribute__((section(".data")));
17 static char trace_inited __attribute__((section(".data")));
18
19 /* The header block at the start of the trace memory area */
20 struct trace_hdr {
21 int func_count; /* Total number of function call sites */
22 u64 call_count; /* Total number of tracked function calls */
23 u64 untracked_count; /* Total number of untracked function calls */
24 int funcs_used; /* Total number of functions used */
25
26 /*
27 * Call count for each function. This is indexed by the word offset
28 * of the function from gd->relocaddr
29 */
30 uintptr_t *call_accum;
31
32 /* Function trace list */
33 struct trace_call *ftrace; /* The function call records */
34 ulong ftrace_size; /* Num. of ftrace records we have space for */
35 ulong ftrace_count; /* Num. of ftrace records written */
36 ulong ftrace_too_deep_count; /* Functions that were too deep */
37
38 int depth;
39 int depth_limit;
40 int max_depth;
41 };
42
43 static struct trace_hdr *hdr; /* Pointer to start of trace buffer */
44
45 static inline uintptr_t __attribute__((no_instrument_function))
func_ptr_to_num(void * func_ptr)46 func_ptr_to_num(void *func_ptr)
47 {
48 uintptr_t offset = (uintptr_t)func_ptr;
49
50 #ifdef CONFIG_SANDBOX
51 offset -= (uintptr_t)&_init;
52 #else
53 if (gd->flags & GD_FLG_RELOC)
54 offset -= gd->relocaddr;
55 else
56 offset -= CONFIG_SYS_TEXT_BASE;
57 #endif
58 return offset / FUNC_SITE_SIZE;
59 }
60
61 #if defined(CONFIG_EFI_LOADER) && (defined(CONFIG_ARM) || defined(CONFIG_RISCV))
62
63 /**
64 * trace_gd - the value of the gd register
65 */
66 static volatile gd_t *trace_gd;
67
68 /**
69 * trace_save_gd() - save the value of the gd register
70 */
trace_save_gd(void)71 static void __attribute__((no_instrument_function)) trace_save_gd(void)
72 {
73 trace_gd = gd;
74 }
75
76 /**
77 * trace_swap_gd() - swap between U-Boot and application gd register value
78 *
79 * An UEFI application may change the value of the register that gd lives in.
80 * But some of our functions like get_ticks() access this register. So we
81 * have to set the gd register to the U-Boot value when entering a trace
82 * point and set it back to the application value when exiting the trace point.
83 */
trace_swap_gd(void)84 static void __attribute__((no_instrument_function)) trace_swap_gd(void)
85 {
86 volatile gd_t *temp_gd = trace_gd;
87
88 trace_gd = gd;
89 set_gd(temp_gd);
90 }
91
92 #else
93
trace_save_gd(void)94 static void __attribute__((no_instrument_function)) trace_save_gd(void)
95 {
96 }
97
trace_swap_gd(void)98 static void __attribute__((no_instrument_function)) trace_swap_gd(void)
99 {
100 }
101
102 #endif
103
add_ftrace(void * func_ptr,void * caller,ulong flags)104 static void __attribute__((no_instrument_function)) add_ftrace(void *func_ptr,
105 void *caller, ulong flags)
106 {
107 if (hdr->depth > hdr->depth_limit) {
108 hdr->ftrace_too_deep_count++;
109 return;
110 }
111 if (hdr->ftrace_count < hdr->ftrace_size) {
112 struct trace_call *rec = &hdr->ftrace[hdr->ftrace_count];
113
114 rec->func = func_ptr_to_num(func_ptr);
115 rec->caller = func_ptr_to_num(caller);
116 rec->flags = flags | (timer_get_us() & FUNCF_TIMESTAMP_MASK);
117 }
118 hdr->ftrace_count++;
119 }
120
add_textbase(void)121 static void __attribute__((no_instrument_function)) add_textbase(void)
122 {
123 if (hdr->ftrace_count < hdr->ftrace_size) {
124 struct trace_call *rec = &hdr->ftrace[hdr->ftrace_count];
125
126 rec->func = CONFIG_SYS_TEXT_BASE;
127 rec->caller = 0;
128 rec->flags = FUNCF_TEXTBASE;
129 }
130 hdr->ftrace_count++;
131 }
132
133 /**
134 * __cyg_profile_func_enter() - record function entry
135 *
136 * We add to our tally for this function and add to the list of called
137 * functions.
138 *
139 * @func_ptr: pointer to function being entered
140 * @caller: pointer to function which called this function
141 */
__cyg_profile_func_enter(void * func_ptr,void * caller)142 void __attribute__((no_instrument_function)) __cyg_profile_func_enter(
143 void *func_ptr, void *caller)
144 {
145 if (trace_enabled) {
146 int func;
147
148 trace_swap_gd();
149 add_ftrace(func_ptr, caller, FUNCF_ENTRY);
150 func = func_ptr_to_num(func_ptr);
151 if (func < hdr->func_count) {
152 hdr->call_accum[func]++;
153 hdr->call_count++;
154 } else {
155 hdr->untracked_count++;
156 }
157 hdr->depth++;
158 if (hdr->depth > hdr->depth_limit)
159 hdr->max_depth = hdr->depth;
160 trace_swap_gd();
161 }
162 }
163
164 /**
165 * __cyg_profile_func_exit() - record function exit
166 *
167 * @func_ptr: pointer to function being entered
168 * @caller: pointer to function which called this function
169 */
__cyg_profile_func_exit(void * func_ptr,void * caller)170 void __attribute__((no_instrument_function)) __cyg_profile_func_exit(
171 void *func_ptr, void *caller)
172 {
173 if (trace_enabled) {
174 trace_swap_gd();
175 add_ftrace(func_ptr, caller, FUNCF_EXIT);
176 hdr->depth--;
177 trace_swap_gd();
178 }
179 }
180
181 /**
182 * trace_list_functions() - produce a list of called functions
183 *
184 * The information is written into the supplied buffer - a header followed
185 * by a list of function records.
186 *
187 * @buff: buffer to place list into
188 * @buff_size: size of buffer
189 * @needed: returns size of buffer needed, which may be
190 * greater than buff_size if we ran out of space.
191 * Return: 0 if ok, -ENOSPC if space was exhausted
192 */
trace_list_functions(void * buff,size_t buff_size,size_t * needed)193 int trace_list_functions(void *buff, size_t buff_size, size_t *needed)
194 {
195 struct trace_output_hdr *output_hdr = NULL;
196 void *end, *ptr = buff;
197 size_t func;
198 size_t upto;
199
200 end = buff ? buff + buff_size : NULL;
201
202 /* Place some header information */
203 if (ptr + sizeof(struct trace_output_hdr) < end)
204 output_hdr = ptr;
205 ptr += sizeof(struct trace_output_hdr);
206
207 /* Add information about each function */
208 for (func = upto = 0; func < hdr->func_count; func++) {
209 size_t calls = hdr->call_accum[func];
210
211 if (!calls)
212 continue;
213
214 if (ptr + sizeof(struct trace_output_func) < end) {
215 struct trace_output_func *stats = ptr;
216
217 stats->offset = func * FUNC_SITE_SIZE;
218 stats->call_count = calls;
219 upto++;
220 }
221 ptr += sizeof(struct trace_output_func);
222 }
223
224 /* Update the header */
225 if (output_hdr) {
226 output_hdr->rec_count = upto;
227 output_hdr->type = TRACE_CHUNK_FUNCS;
228 }
229
230 /* Work out how must of the buffer we used */
231 *needed = ptr - buff;
232 if (ptr > end)
233 return -ENOSPC;
234
235 return 0;
236 }
237
238 /**
239 * trace_list_functions() - produce a list of function calls
240 *
241 * The information is written into the supplied buffer - a header followed
242 * by a list of function records.
243 *
244 * @buff: buffer to place list into
245 * @buff_size: size of buffer
246 * @needed: returns size of buffer needed, which may be
247 * greater than buff_size if we ran out of space.
248 * Return: 0 if ok, -ENOSPC if space was exhausted
249 */
trace_list_calls(void * buff,size_t buff_size,size_t * needed)250 int trace_list_calls(void *buff, size_t buff_size, size_t *needed)
251 {
252 struct trace_output_hdr *output_hdr = NULL;
253 void *end, *ptr = buff;
254 size_t rec, upto;
255 size_t count;
256
257 end = buff ? buff + buff_size : NULL;
258
259 /* Place some header information */
260 if (ptr + sizeof(struct trace_output_hdr) < end)
261 output_hdr = ptr;
262 ptr += sizeof(struct trace_output_hdr);
263
264 /* Add information about each call */
265 count = hdr->ftrace_count;
266 if (count > hdr->ftrace_size)
267 count = hdr->ftrace_size;
268 for (rec = upto = 0; rec < count; rec++) {
269 if (ptr + sizeof(struct trace_call) < end) {
270 struct trace_call *call = &hdr->ftrace[rec];
271 struct trace_call *out = ptr;
272
273 out->func = call->func * FUNC_SITE_SIZE;
274 out->caller = call->caller * FUNC_SITE_SIZE;
275 out->flags = call->flags;
276 upto++;
277 }
278 ptr += sizeof(struct trace_call);
279 }
280
281 /* Update the header */
282 if (output_hdr) {
283 output_hdr->rec_count = upto;
284 output_hdr->type = TRACE_CHUNK_CALLS;
285 }
286
287 /* Work out how must of the buffer we used */
288 *needed = ptr - buff;
289 if (ptr > end)
290 return -ENOSPC;
291
292 return 0;
293 }
294
295 /**
296 * trace_print_stats() - print basic information about tracing
297 */
trace_print_stats(void)298 void trace_print_stats(void)
299 {
300 ulong count;
301
302 #ifndef FTRACE
303 puts("Warning: make U-Boot with FTRACE to enable function instrumenting.\n");
304 puts("You will likely get zeroed data here\n");
305 #endif
306 if (!trace_inited) {
307 printf("Trace is disabled\n");
308 return;
309 }
310 print_grouped_ull(hdr->func_count, 10);
311 puts(" function sites\n");
312 print_grouped_ull(hdr->call_count, 10);
313 puts(" function calls\n");
314 print_grouped_ull(hdr->untracked_count, 10);
315 puts(" untracked function calls\n");
316 count = min(hdr->ftrace_count, hdr->ftrace_size);
317 print_grouped_ull(count, 10);
318 puts(" traced function calls");
319 if (hdr->ftrace_count > hdr->ftrace_size) {
320 printf(" (%lu dropped due to overflow)",
321 hdr->ftrace_count - hdr->ftrace_size);
322 }
323 puts("\n");
324 printf("%15d maximum observed call depth\n", hdr->max_depth);
325 printf("%15d call depth limit\n", hdr->depth_limit);
326 print_grouped_ull(hdr->ftrace_too_deep_count, 10);
327 puts(" calls not traced due to depth\n");
328 }
329
trace_set_enabled(int enabled)330 void __attribute__((no_instrument_function)) trace_set_enabled(int enabled)
331 {
332 trace_enabled = enabled != 0;
333 }
334
335 /**
336 * trace_init() - initialize the tracing system and enable it
337 *
338 * @buff: Pointer to trace buffer
339 * @buff_size: Size of trace buffer
340 * Return: 0 if ok
341 */
trace_init(void * buff,size_t buff_size)342 int __attribute__((no_instrument_function)) trace_init(void *buff,
343 size_t buff_size)
344 {
345 ulong func_count = gd->mon_len / FUNC_SITE_SIZE;
346 size_t needed;
347 int was_disabled = !trace_enabled;
348
349 trace_save_gd();
350
351 if (!was_disabled) {
352 #ifdef CONFIG_TRACE_EARLY
353 char *end;
354 ulong used;
355
356 /*
357 * Copy over the early trace data if we have it. Disable
358 * tracing while we are doing this.
359 */
360 trace_enabled = 0;
361 hdr = map_sysmem(CONFIG_TRACE_EARLY_ADDR,
362 CONFIG_TRACE_EARLY_SIZE);
363 end = (char *)&hdr->ftrace[min(hdr->ftrace_count,
364 hdr->ftrace_size)];
365 used = end - (char *)hdr;
366 printf("trace: copying %08lx bytes of early data from %x to %08lx\n",
367 used, CONFIG_TRACE_EARLY_ADDR,
368 (ulong)map_to_sysmem(buff));
369 memcpy(buff, hdr, used);
370 #else
371 puts("trace: already enabled\n");
372 return -EALREADY;
373 #endif
374 }
375 hdr = (struct trace_hdr *)buff;
376 needed = sizeof(*hdr) + func_count * sizeof(uintptr_t);
377 if (needed > buff_size) {
378 printf("trace: buffer size %zd bytes: at least %zd needed\n",
379 buff_size, needed);
380 return -ENOSPC;
381 }
382
383 if (was_disabled)
384 memset(hdr, '\0', needed);
385 hdr->func_count = func_count;
386 hdr->call_accum = (uintptr_t *)(hdr + 1);
387
388 /* Use any remaining space for the timed function trace */
389 hdr->ftrace = (struct trace_call *)(buff + needed);
390 hdr->ftrace_size = (buff_size - needed) / sizeof(*hdr->ftrace);
391 add_textbase();
392
393 puts("trace: enabled\n");
394 hdr->depth_limit = CONFIG_TRACE_CALL_DEPTH_LIMIT;
395 trace_enabled = 1;
396 trace_inited = 1;
397
398 return 0;
399 }
400
401 #ifdef CONFIG_TRACE_EARLY
402 /**
403 * trace_early_init() - initialize the tracing system for early tracing
404 *
405 * Return: 0 if ok, -ENOSPC if not enough memory is available
406 */
trace_early_init(void)407 int __attribute__((no_instrument_function)) trace_early_init(void)
408 {
409 ulong func_count = gd->mon_len / FUNC_SITE_SIZE;
410 size_t buff_size = CONFIG_TRACE_EARLY_SIZE;
411 size_t needed;
412
413 /* We can ignore additional calls to this function */
414 if (trace_enabled)
415 return 0;
416
417 hdr = map_sysmem(CONFIG_TRACE_EARLY_ADDR, CONFIG_TRACE_EARLY_SIZE);
418 needed = sizeof(*hdr) + func_count * sizeof(uintptr_t);
419 if (needed > buff_size) {
420 printf("trace: buffer size is %zd bytes, at least %zd needed\n",
421 buff_size, needed);
422 return -ENOSPC;
423 }
424
425 memset(hdr, '\0', needed);
426 hdr->call_accum = (uintptr_t *)(hdr + 1);
427 hdr->func_count = func_count;
428
429 /* Use any remaining space for the timed function trace */
430 hdr->ftrace = (struct trace_call *)((char *)hdr + needed);
431 hdr->ftrace_size = (buff_size - needed) / sizeof(*hdr->ftrace);
432 add_textbase();
433 hdr->depth_limit = CONFIG_TRACE_EARLY_CALL_DEPTH_LIMIT;
434 printf("trace: early enable at %08x\n", CONFIG_TRACE_EARLY_ADDR);
435
436 trace_enabled = 1;
437
438 return 0;
439 }
440 #endif
441