1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright(C) 2015-2018 Linaro Limited.
4  *
5  * Author: Tor Jeremiassen <tor@ti.com>
6  * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
7  */
8 
9 #include <linux/err.h>
10 #include <linux/list.h>
11 #include <stdlib.h>
12 #include <opencsd/c_api/opencsd_c_api.h>
13 #include <opencsd/etmv4/trc_pkt_types_etmv4.h>
14 #include <opencsd/ocsd_if_types.h>
15 
16 #include "cs-etm.h"
17 #include "cs-etm-decoder.h"
18 #include "intlist.h"
19 #include "util.h"
20 
21 #define MAX_BUFFER 1024
22 
23 /* use raw logging */
24 #ifdef CS_DEBUG_RAW
25 #define CS_LOG_RAW_FRAMES
26 #ifdef CS_RAW_PACKED
27 #define CS_RAW_DEBUG_FLAGS (OCSD_DFRMTR_UNPACKED_RAW_OUT | \
28 			    OCSD_DFRMTR_PACKED_RAW_OUT)
29 #else
30 #define CS_RAW_DEBUG_FLAGS (OCSD_DFRMTR_UNPACKED_RAW_OUT)
31 #endif
32 #endif
33 
34 #define CS_ETM_INVAL_ADDR	0xdeadbeefdeadbeefUL
35 
36 struct cs_etm_decoder {
37 	void *data;
38 	void (*packet_printer)(const char *msg);
39 	dcd_tree_handle_t dcd_tree;
40 	cs_etm_mem_cb_type mem_access;
41 	ocsd_datapath_resp_t prev_return;
42 	u32 packet_count;
43 	u32 head;
44 	u32 tail;
45 	struct cs_etm_packet packet_buffer[MAX_BUFFER];
46 };
47 
48 static u32
49 cs_etm_decoder__mem_access(const void *context,
50 			   const ocsd_vaddr_t address,
51 			   const ocsd_mem_space_acc_t mem_space __maybe_unused,
52 			   const u32 req_size,
53 			   u8 *buffer)
54 {
55 	struct cs_etm_decoder *decoder = (struct cs_etm_decoder *) context;
56 
57 	return decoder->mem_access(decoder->data,
58 				   address,
59 				   req_size,
60 				   buffer);
61 }
62 
63 int cs_etm_decoder__add_mem_access_cb(struct cs_etm_decoder *decoder,
64 				      u64 start, u64 end,
65 				      cs_etm_mem_cb_type cb_func)
66 {
67 	decoder->mem_access = cb_func;
68 
69 	if (ocsd_dt_add_callback_mem_acc(decoder->dcd_tree, start, end,
70 					 OCSD_MEM_SPACE_ANY,
71 					 cs_etm_decoder__mem_access, decoder))
72 		return -1;
73 
74 	return 0;
75 }
76 
77 int cs_etm_decoder__reset(struct cs_etm_decoder *decoder)
78 {
79 	ocsd_datapath_resp_t dp_ret;
80 
81 	decoder->prev_return = OCSD_RESP_CONT;
82 
83 	dp_ret = ocsd_dt_process_data(decoder->dcd_tree, OCSD_OP_RESET,
84 				      0, 0, NULL, NULL);
85 	if (OCSD_DATA_RESP_IS_FATAL(dp_ret))
86 		return -1;
87 
88 	return 0;
89 }
90 
91 int cs_etm_decoder__get_packet(struct cs_etm_decoder *decoder,
92 			       struct cs_etm_packet *packet)
93 {
94 	if (!decoder || !packet)
95 		return -EINVAL;
96 
97 	/* Nothing to do, might as well just return */
98 	if (decoder->packet_count == 0)
99 		return 0;
100 	/*
101 	 * The queueing process in function cs_etm_decoder__buffer_packet()
102 	 * increments the tail *before* using it.  This is somewhat counter
103 	 * intuitive but it has the advantage of centralizing tail management
104 	 * at a single location.  Because of that we need to follow the same
105 	 * heuristic with the head, i.e we increment it before using its
106 	 * value.  Otherwise the first element of the packet queue is not
107 	 * used.
108 	 */
109 	decoder->head = (decoder->head + 1) & (MAX_BUFFER - 1);
110 
111 	*packet = decoder->packet_buffer[decoder->head];
112 
113 	decoder->packet_count--;
114 
115 	return 1;
116 }
117 
118 static int cs_etm_decoder__gen_etmv3_config(struct cs_etm_trace_params *params,
119 					    ocsd_etmv3_cfg *config)
120 {
121 	config->reg_idr = params->etmv3.reg_idr;
122 	config->reg_ctrl = params->etmv3.reg_ctrl;
123 	config->reg_ccer = params->etmv3.reg_ccer;
124 	config->reg_trc_id = params->etmv3.reg_trc_id;
125 	config->arch_ver = ARCH_V7;
126 	config->core_prof = profile_CortexA;
127 
128 	return 0;
129 }
130 
131 static void cs_etm_decoder__gen_etmv4_config(struct cs_etm_trace_params *params,
132 					     ocsd_etmv4_cfg *config)
133 {
134 	config->reg_configr = params->etmv4.reg_configr;
135 	config->reg_traceidr = params->etmv4.reg_traceidr;
136 	config->reg_idr0 = params->etmv4.reg_idr0;
137 	config->reg_idr1 = params->etmv4.reg_idr1;
138 	config->reg_idr2 = params->etmv4.reg_idr2;
139 	config->reg_idr8 = params->etmv4.reg_idr8;
140 	config->reg_idr9 = 0;
141 	config->reg_idr10 = 0;
142 	config->reg_idr11 = 0;
143 	config->reg_idr12 = 0;
144 	config->reg_idr13 = 0;
145 	config->arch_ver = ARCH_V8;
146 	config->core_prof = profile_CortexA;
147 }
148 
149 static void cs_etm_decoder__print_str_cb(const void *p_context,
150 					 const char *msg,
151 					 const int str_len)
152 {
153 	if (p_context && str_len)
154 		((struct cs_etm_decoder *)p_context)->packet_printer(msg);
155 }
156 
157 static int
158 cs_etm_decoder__init_def_logger_printing(struct cs_etm_decoder_params *d_params,
159 					 struct cs_etm_decoder *decoder)
160 {
161 	int ret = 0;
162 
163 	if (d_params->packet_printer == NULL)
164 		return -1;
165 
166 	decoder->packet_printer = d_params->packet_printer;
167 
168 	/*
169 	 * Set up a library default logger to process any printers
170 	 * (packet/raw frame) we add later.
171 	 */
172 	ret = ocsd_def_errlog_init(OCSD_ERR_SEV_ERROR, 1);
173 	if (ret != 0)
174 		return -1;
175 
176 	/* no stdout / err / file output */
177 	ret = ocsd_def_errlog_config_output(C_API_MSGLOGOUT_FLG_NONE, NULL);
178 	if (ret != 0)
179 		return -1;
180 
181 	/*
182 	 * Set the string CB for the default logger, passes strings to
183 	 * perf print logger.
184 	 */
185 	ret = ocsd_def_errlog_set_strprint_cb(decoder->dcd_tree,
186 					      (void *)decoder,
187 					      cs_etm_decoder__print_str_cb);
188 	if (ret != 0)
189 		ret = -1;
190 
191 	return 0;
192 }
193 
194 #ifdef CS_LOG_RAW_FRAMES
195 static void
196 cs_etm_decoder__init_raw_frame_logging(struct cs_etm_decoder_params *d_params,
197 				       struct cs_etm_decoder *decoder)
198 {
199 	/* Only log these during a --dump operation */
200 	if (d_params->operation == CS_ETM_OPERATION_PRINT) {
201 		/* set up a library default logger to process the
202 		 *  raw frame printer we add later
203 		 */
204 		ocsd_def_errlog_init(OCSD_ERR_SEV_ERROR, 1);
205 
206 		/* no stdout / err / file output */
207 		ocsd_def_errlog_config_output(C_API_MSGLOGOUT_FLG_NONE, NULL);
208 
209 		/* set the string CB for the default logger,
210 		 * passes strings to perf print logger.
211 		 */
212 		ocsd_def_errlog_set_strprint_cb(decoder->dcd_tree,
213 						(void *)decoder,
214 						cs_etm_decoder__print_str_cb);
215 
216 		/* use the built in library printer for the raw frames */
217 		ocsd_dt_set_raw_frame_printer(decoder->dcd_tree,
218 					      CS_RAW_DEBUG_FLAGS);
219 	}
220 }
221 #else
222 static void
223 cs_etm_decoder__init_raw_frame_logging(
224 		struct cs_etm_decoder_params *d_params __maybe_unused,
225 		struct cs_etm_decoder *decoder __maybe_unused)
226 {
227 }
228 #endif
229 
230 static int cs_etm_decoder__create_packet_printer(struct cs_etm_decoder *decoder,
231 						 const char *decoder_name,
232 						 void *trace_config)
233 {
234 	u8 csid;
235 
236 	if (ocsd_dt_create_decoder(decoder->dcd_tree, decoder_name,
237 				   OCSD_CREATE_FLG_PACKET_PROC,
238 				   trace_config, &csid))
239 		return -1;
240 
241 	if (ocsd_dt_set_pkt_protocol_printer(decoder->dcd_tree, csid, 0))
242 		return -1;
243 
244 	return 0;
245 }
246 
247 static int
248 cs_etm_decoder__create_etm_packet_printer(struct cs_etm_trace_params *t_params,
249 					  struct cs_etm_decoder *decoder)
250 {
251 	const char *decoder_name;
252 	ocsd_etmv3_cfg config_etmv3;
253 	ocsd_etmv4_cfg trace_config_etmv4;
254 	void *trace_config;
255 
256 	switch (t_params->protocol) {
257 	case CS_ETM_PROTO_ETMV3:
258 	case CS_ETM_PROTO_PTM:
259 		cs_etm_decoder__gen_etmv3_config(t_params, &config_etmv3);
260 		decoder_name = (t_params->protocol == CS_ETM_PROTO_ETMV3) ?
261 							OCSD_BUILTIN_DCD_ETMV3 :
262 							OCSD_BUILTIN_DCD_PTM;
263 		trace_config = &config_etmv3;
264 		break;
265 	case CS_ETM_PROTO_ETMV4i:
266 		cs_etm_decoder__gen_etmv4_config(t_params, &trace_config_etmv4);
267 		decoder_name = OCSD_BUILTIN_DCD_ETMV4I;
268 		trace_config = &trace_config_etmv4;
269 		break;
270 	default:
271 		return -1;
272 	}
273 
274 	return cs_etm_decoder__create_packet_printer(decoder,
275 						     decoder_name,
276 						     trace_config);
277 }
278 
279 static void cs_etm_decoder__clear_buffer(struct cs_etm_decoder *decoder)
280 {
281 	int i;
282 
283 	decoder->head = 0;
284 	decoder->tail = 0;
285 	decoder->packet_count = 0;
286 	for (i = 0; i < MAX_BUFFER; i++) {
287 		decoder->packet_buffer[i].isa = CS_ETM_ISA_UNKNOWN;
288 		decoder->packet_buffer[i].start_addr = CS_ETM_INVAL_ADDR;
289 		decoder->packet_buffer[i].end_addr = CS_ETM_INVAL_ADDR;
290 		decoder->packet_buffer[i].instr_count = 0;
291 		decoder->packet_buffer[i].last_instr_taken_branch = false;
292 		decoder->packet_buffer[i].last_instr_size = 0;
293 		decoder->packet_buffer[i].last_instr_type = 0;
294 		decoder->packet_buffer[i].last_instr_subtype = 0;
295 		decoder->packet_buffer[i].last_instr_cond = 0;
296 		decoder->packet_buffer[i].flags = 0;
297 		decoder->packet_buffer[i].exception_number = UINT32_MAX;
298 		decoder->packet_buffer[i].trace_chan_id = UINT8_MAX;
299 		decoder->packet_buffer[i].cpu = INT_MIN;
300 	}
301 }
302 
303 static ocsd_datapath_resp_t
304 cs_etm_decoder__buffer_packet(struct cs_etm_decoder *decoder,
305 			      const u8 trace_chan_id,
306 			      enum cs_etm_sample_type sample_type)
307 {
308 	u32 et = 0;
309 	int cpu;
310 
311 	if (decoder->packet_count >= MAX_BUFFER - 1)
312 		return OCSD_RESP_FATAL_SYS_ERR;
313 
314 	if (cs_etm__get_cpu(trace_chan_id, &cpu) < 0)
315 		return OCSD_RESP_FATAL_SYS_ERR;
316 
317 	et = decoder->tail;
318 	et = (et + 1) & (MAX_BUFFER - 1);
319 	decoder->tail = et;
320 	decoder->packet_count++;
321 
322 	decoder->packet_buffer[et].sample_type = sample_type;
323 	decoder->packet_buffer[et].isa = CS_ETM_ISA_UNKNOWN;
324 	decoder->packet_buffer[et].cpu = cpu;
325 	decoder->packet_buffer[et].start_addr = CS_ETM_INVAL_ADDR;
326 	decoder->packet_buffer[et].end_addr = CS_ETM_INVAL_ADDR;
327 	decoder->packet_buffer[et].instr_count = 0;
328 	decoder->packet_buffer[et].last_instr_taken_branch = false;
329 	decoder->packet_buffer[et].last_instr_size = 0;
330 	decoder->packet_buffer[et].last_instr_type = 0;
331 	decoder->packet_buffer[et].last_instr_subtype = 0;
332 	decoder->packet_buffer[et].last_instr_cond = 0;
333 	decoder->packet_buffer[et].flags = 0;
334 	decoder->packet_buffer[et].exception_number = UINT32_MAX;
335 	decoder->packet_buffer[et].trace_chan_id = trace_chan_id;
336 
337 	if (decoder->packet_count == MAX_BUFFER - 1)
338 		return OCSD_RESP_WAIT;
339 
340 	return OCSD_RESP_CONT;
341 }
342 
343 static ocsd_datapath_resp_t
344 cs_etm_decoder__buffer_range(struct cs_etm_decoder *decoder,
345 			     const ocsd_generic_trace_elem *elem,
346 			     const uint8_t trace_chan_id)
347 {
348 	int ret = 0;
349 	struct cs_etm_packet *packet;
350 
351 	ret = cs_etm_decoder__buffer_packet(decoder, trace_chan_id,
352 					    CS_ETM_RANGE);
353 	if (ret != OCSD_RESP_CONT && ret != OCSD_RESP_WAIT)
354 		return ret;
355 
356 	packet = &decoder->packet_buffer[decoder->tail];
357 
358 	switch (elem->isa) {
359 	case ocsd_isa_aarch64:
360 		packet->isa = CS_ETM_ISA_A64;
361 		break;
362 	case ocsd_isa_arm:
363 		packet->isa = CS_ETM_ISA_A32;
364 		break;
365 	case ocsd_isa_thumb2:
366 		packet->isa = CS_ETM_ISA_T32;
367 		break;
368 	case ocsd_isa_tee:
369 	case ocsd_isa_jazelle:
370 	case ocsd_isa_custom:
371 	case ocsd_isa_unknown:
372 	default:
373 		packet->isa = CS_ETM_ISA_UNKNOWN;
374 	}
375 
376 	packet->start_addr = elem->st_addr;
377 	packet->end_addr = elem->en_addr;
378 	packet->instr_count = elem->num_instr_range;
379 	packet->last_instr_type = elem->last_i_type;
380 	packet->last_instr_subtype = elem->last_i_subtype;
381 	packet->last_instr_cond = elem->last_instr_cond;
382 
383 	switch (elem->last_i_type) {
384 	case OCSD_INSTR_BR:
385 	case OCSD_INSTR_BR_INDIRECT:
386 		packet->last_instr_taken_branch = elem->last_instr_exec;
387 		break;
388 	case OCSD_INSTR_ISB:
389 	case OCSD_INSTR_DSB_DMB:
390 	case OCSD_INSTR_WFI_WFE:
391 	case OCSD_INSTR_OTHER:
392 	default:
393 		packet->last_instr_taken_branch = false;
394 		break;
395 	}
396 
397 	packet->last_instr_size = elem->last_instr_sz;
398 
399 	return ret;
400 }
401 
402 static ocsd_datapath_resp_t
403 cs_etm_decoder__buffer_discontinuity(struct cs_etm_decoder *decoder,
404 					   const uint8_t trace_chan_id)
405 {
406 	return cs_etm_decoder__buffer_packet(decoder, trace_chan_id,
407 					     CS_ETM_DISCONTINUITY);
408 }
409 
410 static ocsd_datapath_resp_t
411 cs_etm_decoder__buffer_exception(struct cs_etm_decoder *decoder,
412 				 const ocsd_generic_trace_elem *elem,
413 				 const uint8_t trace_chan_id)
414 {	int ret = 0;
415 	struct cs_etm_packet *packet;
416 
417 	ret = cs_etm_decoder__buffer_packet(decoder, trace_chan_id,
418 					    CS_ETM_EXCEPTION);
419 	if (ret != OCSD_RESP_CONT && ret != OCSD_RESP_WAIT)
420 		return ret;
421 
422 	packet = &decoder->packet_buffer[decoder->tail];
423 	packet->exception_number = elem->exception_number;
424 
425 	return ret;
426 }
427 
428 static ocsd_datapath_resp_t
429 cs_etm_decoder__buffer_exception_ret(struct cs_etm_decoder *decoder,
430 				     const uint8_t trace_chan_id)
431 {
432 	return cs_etm_decoder__buffer_packet(decoder, trace_chan_id,
433 					     CS_ETM_EXCEPTION_RET);
434 }
435 
436 static ocsd_datapath_resp_t cs_etm_decoder__gen_trace_elem_printer(
437 				const void *context,
438 				const ocsd_trc_index_t indx __maybe_unused,
439 				const u8 trace_chan_id __maybe_unused,
440 				const ocsd_generic_trace_elem *elem)
441 {
442 	ocsd_datapath_resp_t resp = OCSD_RESP_CONT;
443 	struct cs_etm_decoder *decoder = (struct cs_etm_decoder *) context;
444 
445 	switch (elem->elem_type) {
446 	case OCSD_GEN_TRC_ELEM_UNKNOWN:
447 		break;
448 	case OCSD_GEN_TRC_ELEM_EO_TRACE:
449 	case OCSD_GEN_TRC_ELEM_NO_SYNC:
450 	case OCSD_GEN_TRC_ELEM_TRACE_ON:
451 		resp = cs_etm_decoder__buffer_discontinuity(decoder,
452 							    trace_chan_id);
453 		break;
454 	case OCSD_GEN_TRC_ELEM_INSTR_RANGE:
455 		resp = cs_etm_decoder__buffer_range(decoder, elem,
456 						    trace_chan_id);
457 		break;
458 	case OCSD_GEN_TRC_ELEM_EXCEPTION:
459 		resp = cs_etm_decoder__buffer_exception(decoder, elem,
460 							trace_chan_id);
461 		break;
462 	case OCSD_GEN_TRC_ELEM_EXCEPTION_RET:
463 		resp = cs_etm_decoder__buffer_exception_ret(decoder,
464 							    trace_chan_id);
465 		break;
466 	case OCSD_GEN_TRC_ELEM_PE_CONTEXT:
467 	case OCSD_GEN_TRC_ELEM_ADDR_NACC:
468 	case OCSD_GEN_TRC_ELEM_TIMESTAMP:
469 	case OCSD_GEN_TRC_ELEM_CYCLE_COUNT:
470 	case OCSD_GEN_TRC_ELEM_ADDR_UNKNOWN:
471 	case OCSD_GEN_TRC_ELEM_EVENT:
472 	case OCSD_GEN_TRC_ELEM_SWTRACE:
473 	case OCSD_GEN_TRC_ELEM_CUSTOM:
474 	default:
475 		break;
476 	}
477 
478 	return resp;
479 }
480 
481 static int cs_etm_decoder__create_etm_packet_decoder(
482 					struct cs_etm_trace_params *t_params,
483 					struct cs_etm_decoder *decoder)
484 {
485 	const char *decoder_name;
486 	ocsd_etmv3_cfg config_etmv3;
487 	ocsd_etmv4_cfg trace_config_etmv4;
488 	void *trace_config;
489 	u8 csid;
490 
491 	switch (t_params->protocol) {
492 	case CS_ETM_PROTO_ETMV3:
493 	case CS_ETM_PROTO_PTM:
494 		cs_etm_decoder__gen_etmv3_config(t_params, &config_etmv3);
495 		decoder_name = (t_params->protocol == CS_ETM_PROTO_ETMV3) ?
496 							OCSD_BUILTIN_DCD_ETMV3 :
497 							OCSD_BUILTIN_DCD_PTM;
498 		trace_config = &config_etmv3;
499 		break;
500 	case CS_ETM_PROTO_ETMV4i:
501 		cs_etm_decoder__gen_etmv4_config(t_params, &trace_config_etmv4);
502 		decoder_name = OCSD_BUILTIN_DCD_ETMV4I;
503 		trace_config = &trace_config_etmv4;
504 		break;
505 	default:
506 		return -1;
507 	}
508 
509 	if (ocsd_dt_create_decoder(decoder->dcd_tree,
510 				     decoder_name,
511 				     OCSD_CREATE_FLG_FULL_DECODER,
512 				     trace_config, &csid))
513 		return -1;
514 
515 	if (ocsd_dt_set_gen_elem_outfn(decoder->dcd_tree,
516 				       cs_etm_decoder__gen_trace_elem_printer,
517 				       decoder))
518 		return -1;
519 
520 	return 0;
521 }
522 
523 static int
524 cs_etm_decoder__create_etm_decoder(struct cs_etm_decoder_params *d_params,
525 				   struct cs_etm_trace_params *t_params,
526 				   struct cs_etm_decoder *decoder)
527 {
528 	if (d_params->operation == CS_ETM_OPERATION_PRINT)
529 		return cs_etm_decoder__create_etm_packet_printer(t_params,
530 								 decoder);
531 	else if (d_params->operation == CS_ETM_OPERATION_DECODE)
532 		return cs_etm_decoder__create_etm_packet_decoder(t_params,
533 								 decoder);
534 
535 	return -1;
536 }
537 
538 struct cs_etm_decoder *
539 cs_etm_decoder__new(int num_cpu, struct cs_etm_decoder_params *d_params,
540 		    struct cs_etm_trace_params t_params[])
541 {
542 	struct cs_etm_decoder *decoder;
543 	ocsd_dcd_tree_src_t format;
544 	u32 flags;
545 	int i, ret;
546 
547 	if ((!t_params) || (!d_params))
548 		return NULL;
549 
550 	decoder = zalloc(sizeof(*decoder));
551 
552 	if (!decoder)
553 		return NULL;
554 
555 	decoder->data = d_params->data;
556 	decoder->prev_return = OCSD_RESP_CONT;
557 	cs_etm_decoder__clear_buffer(decoder);
558 	format = (d_params->formatted ? OCSD_TRC_SRC_FRAME_FORMATTED :
559 					 OCSD_TRC_SRC_SINGLE);
560 	flags = 0;
561 	flags |= (d_params->fsyncs ? OCSD_DFRMTR_HAS_FSYNCS : 0);
562 	flags |= (d_params->hsyncs ? OCSD_DFRMTR_HAS_HSYNCS : 0);
563 	flags |= (d_params->frame_aligned ? OCSD_DFRMTR_FRAME_MEM_ALIGN : 0);
564 
565 	/*
566 	 * Drivers may add barrier frames when used with perf, set up to
567 	 * handle this. Barriers const of FSYNC packet repeated 4 times.
568 	 */
569 	flags |= OCSD_DFRMTR_RESET_ON_4X_FSYNC;
570 
571 	/* Create decode tree for the data source */
572 	decoder->dcd_tree = ocsd_create_dcd_tree(format, flags);
573 
574 	if (decoder->dcd_tree == 0)
575 		goto err_free_decoder;
576 
577 	/* init library print logging support */
578 	ret = cs_etm_decoder__init_def_logger_printing(d_params, decoder);
579 	if (ret != 0)
580 		goto err_free_decoder_tree;
581 
582 	/* init raw frame logging if required */
583 	cs_etm_decoder__init_raw_frame_logging(d_params, decoder);
584 
585 	for (i = 0; i < num_cpu; i++) {
586 		ret = cs_etm_decoder__create_etm_decoder(d_params,
587 							 &t_params[i],
588 							 decoder);
589 		if (ret != 0)
590 			goto err_free_decoder_tree;
591 	}
592 
593 	return decoder;
594 
595 err_free_decoder_tree:
596 	ocsd_destroy_dcd_tree(decoder->dcd_tree);
597 err_free_decoder:
598 	free(decoder);
599 	return NULL;
600 }
601 
602 int cs_etm_decoder__process_data_block(struct cs_etm_decoder *decoder,
603 				       u64 indx, const u8 *buf,
604 				       size_t len, size_t *consumed)
605 {
606 	int ret = 0;
607 	ocsd_datapath_resp_t cur = OCSD_RESP_CONT;
608 	ocsd_datapath_resp_t prev_return = decoder->prev_return;
609 	size_t processed = 0;
610 	u32 count;
611 
612 	while (processed < len) {
613 		if (OCSD_DATA_RESP_IS_WAIT(prev_return)) {
614 			cur = ocsd_dt_process_data(decoder->dcd_tree,
615 						   OCSD_OP_FLUSH,
616 						   0,
617 						   0,
618 						   NULL,
619 						   NULL);
620 		} else if (OCSD_DATA_RESP_IS_CONT(prev_return)) {
621 			cur = ocsd_dt_process_data(decoder->dcd_tree,
622 						   OCSD_OP_DATA,
623 						   indx + processed,
624 						   len - processed,
625 						   &buf[processed],
626 						   &count);
627 			processed += count;
628 		} else {
629 			ret = -EINVAL;
630 			break;
631 		}
632 
633 		/*
634 		 * Return to the input code if the packet buffer is full.
635 		 * Flushing will get done once the packet buffer has been
636 		 * processed.
637 		 */
638 		if (OCSD_DATA_RESP_IS_WAIT(cur))
639 			break;
640 
641 		prev_return = cur;
642 	}
643 
644 	decoder->prev_return = cur;
645 	*consumed = processed;
646 
647 	return ret;
648 }
649 
650 void cs_etm_decoder__free(struct cs_etm_decoder *decoder)
651 {
652 	if (!decoder)
653 		return;
654 
655 	ocsd_destroy_dcd_tree(decoder->dcd_tree);
656 	decoder->dcd_tree = NULL;
657 	free(decoder);
658 }
659