1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * intel_pt_decoder.c: Intel Processor Trace support
4  * Copyright (c) 2013-2014, Intel Corporation.
5  */
6 
7 #ifndef _GNU_SOURCE
8 #define _GNU_SOURCE
9 #endif
10 #include <stdlib.h>
11 #include <stdbool.h>
12 #include <string.h>
13 #include <errno.h>
14 #include <stdint.h>
15 #include <inttypes.h>
16 #include <linux/compiler.h>
17 #include <linux/string.h>
18 #include <linux/zalloc.h>
19 
20 #include "../auxtrace.h"
21 
22 #include "intel-pt-insn-decoder.h"
23 #include "intel-pt-pkt-decoder.h"
24 #include "intel-pt-decoder.h"
25 #include "intel-pt-log.h"
26 
27 #define BITULL(x) (1ULL << (x))
28 
29 /* IA32_RTIT_CTL MSR bits */
30 #define INTEL_PT_CYC_ENABLE		BITULL(1)
31 #define INTEL_PT_CYC_THRESHOLD		(BITULL(22) | BITULL(21) | BITULL(20) | BITULL(19))
32 #define INTEL_PT_CYC_THRESHOLD_SHIFT	19
33 
34 #define INTEL_PT_BLK_SIZE 1024
35 
36 #define BIT63 (((uint64_t)1 << 63))
37 
38 #define SEVEN_BYTES 0xffffffffffffffULL
39 
40 #define NO_VMCS 0xffffffffffULL
41 
42 #define INTEL_PT_RETURN 1
43 
44 /*
45  * Default maximum number of loops with no packets consumed i.e. stuck in a
46  * loop.
47  */
48 #define INTEL_PT_MAX_LOOPS 100000
49 
50 struct intel_pt_blk {
51 	struct intel_pt_blk *prev;
52 	uint64_t ip[INTEL_PT_BLK_SIZE];
53 };
54 
55 struct intel_pt_stack {
56 	struct intel_pt_blk *blk;
57 	struct intel_pt_blk *spare;
58 	int pos;
59 };
60 
61 enum intel_pt_p_once {
62 	INTEL_PT_PRT_ONCE_UNK_VMCS,
63 	INTEL_PT_PRT_ONCE_ERANGE,
64 };
65 
66 enum intel_pt_pkt_state {
67 	INTEL_PT_STATE_NO_PSB,
68 	INTEL_PT_STATE_NO_IP,
69 	INTEL_PT_STATE_ERR_RESYNC,
70 	INTEL_PT_STATE_IN_SYNC,
71 	INTEL_PT_STATE_TNT_CONT,
72 	INTEL_PT_STATE_TNT,
73 	INTEL_PT_STATE_TIP,
74 	INTEL_PT_STATE_TIP_PGD,
75 	INTEL_PT_STATE_FUP,
76 	INTEL_PT_STATE_FUP_NO_TIP,
77 	INTEL_PT_STATE_FUP_IN_PSB,
78 	INTEL_PT_STATE_RESAMPLE,
79 	INTEL_PT_STATE_VM_TIME_CORRELATION,
80 };
81 
82 static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state)
83 {
84 	switch (pkt_state) {
85 	case INTEL_PT_STATE_NO_PSB:
86 	case INTEL_PT_STATE_NO_IP:
87 	case INTEL_PT_STATE_ERR_RESYNC:
88 	case INTEL_PT_STATE_IN_SYNC:
89 	case INTEL_PT_STATE_TNT_CONT:
90 	case INTEL_PT_STATE_RESAMPLE:
91 	case INTEL_PT_STATE_VM_TIME_CORRELATION:
92 		return true;
93 	case INTEL_PT_STATE_TNT:
94 	case INTEL_PT_STATE_TIP:
95 	case INTEL_PT_STATE_TIP_PGD:
96 	case INTEL_PT_STATE_FUP:
97 	case INTEL_PT_STATE_FUP_NO_TIP:
98 	case INTEL_PT_STATE_FUP_IN_PSB:
99 		return false;
100 	default:
101 		return true;
102 	};
103 }
104 
105 #ifdef INTEL_PT_STRICT
106 #define INTEL_PT_STATE_ERR1	INTEL_PT_STATE_NO_PSB
107 #define INTEL_PT_STATE_ERR2	INTEL_PT_STATE_NO_PSB
108 #define INTEL_PT_STATE_ERR3	INTEL_PT_STATE_NO_PSB
109 #define INTEL_PT_STATE_ERR4	INTEL_PT_STATE_NO_PSB
110 #else
111 #define INTEL_PT_STATE_ERR1	(decoder->pkt_state)
112 #define INTEL_PT_STATE_ERR2	INTEL_PT_STATE_NO_IP
113 #define INTEL_PT_STATE_ERR3	INTEL_PT_STATE_ERR_RESYNC
114 #define INTEL_PT_STATE_ERR4	INTEL_PT_STATE_IN_SYNC
115 #endif
116 
117 struct intel_pt_decoder {
118 	int (*get_trace)(struct intel_pt_buffer *buffer, void *data);
119 	int (*walk_insn)(struct intel_pt_insn *intel_pt_insn,
120 			 uint64_t *insn_cnt_ptr, uint64_t *ip, uint64_t to_ip,
121 			 uint64_t max_insn_cnt, void *data);
122 	bool (*pgd_ip)(uint64_t ip, void *data);
123 	int (*lookahead)(void *data, intel_pt_lookahead_cb_t cb, void *cb_data);
124 	struct intel_pt_vmcs_info *(*findnew_vmcs_info)(void *data, uint64_t vmcs);
125 	void *data;
126 	struct intel_pt_state state;
127 	const unsigned char *buf;
128 	size_t len;
129 	bool return_compression;
130 	bool branch_enable;
131 	bool mtc_insn;
132 	bool pge;
133 	bool have_tma;
134 	bool have_cyc;
135 	bool fixup_last_mtc;
136 	bool have_last_ip;
137 	bool in_psb;
138 	bool hop;
139 	bool leap;
140 	bool emulated_ptwrite;
141 	bool vm_time_correlation;
142 	bool vm_tm_corr_dry_run;
143 	bool vm_tm_corr_reliable;
144 	bool vm_tm_corr_same_buf;
145 	bool vm_tm_corr_continuous;
146 	bool nr;
147 	bool next_nr;
148 	bool iflag;
149 	bool next_iflag;
150 	enum intel_pt_param_flags flags;
151 	uint64_t pos;
152 	uint64_t last_ip;
153 	uint64_t ip;
154 	uint64_t pip_payload;
155 	uint64_t timestamp;
156 	uint64_t tsc_timestamp;
157 	uint64_t ref_timestamp;
158 	uint64_t buf_timestamp;
159 	uint64_t sample_timestamp;
160 	uint64_t ret_addr;
161 	uint64_t ctc_timestamp;
162 	uint64_t ctc_delta;
163 	uint64_t cycle_cnt;
164 	uint64_t cyc_ref_timestamp;
165 	uint64_t first_timestamp;
166 	uint64_t last_reliable_timestamp;
167 	uint64_t vmcs;
168 	uint64_t print_once;
169 	uint64_t last_ctc;
170 	uint32_t last_mtc;
171 	uint32_t tsc_ctc_ratio_n;
172 	uint32_t tsc_ctc_ratio_d;
173 	uint32_t tsc_ctc_mult;
174 	uint32_t tsc_slip;
175 	uint32_t ctc_rem_mask;
176 	int mtc_shift;
177 	struct intel_pt_stack stack;
178 	enum intel_pt_pkt_state pkt_state;
179 	enum intel_pt_pkt_ctx pkt_ctx;
180 	enum intel_pt_pkt_ctx prev_pkt_ctx;
181 	enum intel_pt_blk_type blk_type;
182 	int blk_type_pos;
183 	struct intel_pt_pkt packet;
184 	struct intel_pt_pkt tnt;
185 	int pkt_step;
186 	int pkt_len;
187 	int last_packet_type;
188 	unsigned int cbr;
189 	unsigned int cbr_seen;
190 	unsigned int max_non_turbo_ratio;
191 	double max_non_turbo_ratio_fp;
192 	double cbr_cyc_to_tsc;
193 	double calc_cyc_to_tsc;
194 	bool have_calc_cyc_to_tsc;
195 	int exec_mode;
196 	unsigned int insn_bytes;
197 	uint64_t period;
198 	enum intel_pt_period_type period_type;
199 	uint64_t tot_insn_cnt;
200 	uint64_t period_insn_cnt;
201 	uint64_t period_mask;
202 	uint64_t period_ticks;
203 	uint64_t last_masked_timestamp;
204 	uint64_t tot_cyc_cnt;
205 	uint64_t sample_tot_cyc_cnt;
206 	uint64_t base_cyc_cnt;
207 	uint64_t cyc_cnt_timestamp;
208 	uint64_t ctl;
209 	uint64_t cyc_threshold;
210 	double tsc_to_cyc;
211 	bool continuous_period;
212 	bool overflow;
213 	bool set_fup_tx_flags;
214 	bool set_fup_ptw;
215 	bool set_fup_mwait;
216 	bool set_fup_pwre;
217 	bool set_fup_exstop;
218 	bool set_fup_bep;
219 	bool set_fup_cfe_ip;
220 	bool set_fup_cfe;
221 	bool set_fup_mode_exec;
222 	bool sample_cyc;
223 	unsigned int fup_tx_flags;
224 	unsigned int tx_flags;
225 	uint64_t fup_ptw_payload;
226 	uint64_t fup_mwait_payload;
227 	uint64_t fup_pwre_payload;
228 	uint64_t cbr_payload;
229 	uint64_t timestamp_insn_cnt;
230 	uint64_t sample_insn_cnt;
231 	uint64_t stuck_ip;
232 	struct intel_pt_pkt fup_cfe_pkt;
233 	int max_loops;
234 	int no_progress;
235 	int stuck_ip_prd;
236 	int stuck_ip_cnt;
237 	uint64_t psb_ip;
238 	const unsigned char *next_buf;
239 	size_t next_len;
240 	unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ];
241 	int evd_cnt;
242 	struct intel_pt_evd evd[INTEL_PT_MAX_EVDS];
243 };
244 
245 static uint64_t intel_pt_lower_power_of_2(uint64_t x)
246 {
247 	int i;
248 
249 	for (i = 0; x != 1; i++)
250 		x >>= 1;
251 
252 	return x << i;
253 }
254 
255 __printf(1, 2)
256 static void p_log(const char *fmt, ...)
257 {
258 	char buf[512];
259 	va_list args;
260 
261 	va_start(args, fmt);
262 	vsnprintf(buf, sizeof(buf), fmt, args);
263 	va_end(args);
264 
265 	fprintf(stderr, "%s\n", buf);
266 	intel_pt_log("%s\n", buf);
267 }
268 
269 static bool intel_pt_print_once(struct intel_pt_decoder *decoder,
270 				enum intel_pt_p_once id)
271 {
272 	uint64_t bit = 1ULL << id;
273 
274 	if (decoder->print_once & bit)
275 		return false;
276 	decoder->print_once |= bit;
277 	return true;
278 }
279 
280 static uint64_t intel_pt_cyc_threshold(uint64_t ctl)
281 {
282 	if (!(ctl & INTEL_PT_CYC_ENABLE))
283 		return 0;
284 
285 	return (ctl & INTEL_PT_CYC_THRESHOLD) >> INTEL_PT_CYC_THRESHOLD_SHIFT;
286 }
287 
288 static void intel_pt_setup_period(struct intel_pt_decoder *decoder)
289 {
290 	if (decoder->period_type == INTEL_PT_PERIOD_TICKS) {
291 		uint64_t period;
292 
293 		period = intel_pt_lower_power_of_2(decoder->period);
294 		decoder->period_mask  = ~(period - 1);
295 		decoder->period_ticks = period;
296 	}
297 }
298 
299 static uint64_t multdiv(uint64_t t, uint32_t n, uint32_t d)
300 {
301 	if (!d)
302 		return 0;
303 	return (t / d) * n + ((t % d) * n) / d;
304 }
305 
306 struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)
307 {
308 	struct intel_pt_decoder *decoder;
309 
310 	if (!params->get_trace || !params->walk_insn)
311 		return NULL;
312 
313 	decoder = zalloc(sizeof(struct intel_pt_decoder));
314 	if (!decoder)
315 		return NULL;
316 
317 	decoder->get_trace          = params->get_trace;
318 	decoder->walk_insn          = params->walk_insn;
319 	decoder->pgd_ip             = params->pgd_ip;
320 	decoder->lookahead          = params->lookahead;
321 	decoder->findnew_vmcs_info  = params->findnew_vmcs_info;
322 	decoder->data               = params->data;
323 	decoder->return_compression = params->return_compression;
324 	decoder->branch_enable      = params->branch_enable;
325 	decoder->hop                = params->quick >= 1;
326 	decoder->leap               = params->quick >= 2;
327 	decoder->vm_time_correlation = params->vm_time_correlation;
328 	decoder->vm_tm_corr_dry_run = params->vm_tm_corr_dry_run;
329 	decoder->first_timestamp    = params->first_timestamp;
330 	decoder->last_reliable_timestamp = params->first_timestamp;
331 	decoder->max_loops          = params->max_loops ? params->max_loops : INTEL_PT_MAX_LOOPS;
332 
333 	decoder->flags              = params->flags;
334 
335 	decoder->ctl                = params->ctl;
336 	decoder->period             = params->period;
337 	decoder->period_type        = params->period_type;
338 
339 	decoder->max_non_turbo_ratio    = params->max_non_turbo_ratio;
340 	decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio;
341 
342 	decoder->cyc_threshold = intel_pt_cyc_threshold(decoder->ctl);
343 
344 	intel_pt_setup_period(decoder);
345 
346 	decoder->mtc_shift = params->mtc_period;
347 	decoder->ctc_rem_mask = (1 << decoder->mtc_shift) - 1;
348 
349 	decoder->tsc_ctc_ratio_n = params->tsc_ctc_ratio_n;
350 	decoder->tsc_ctc_ratio_d = params->tsc_ctc_ratio_d;
351 
352 	if (!decoder->tsc_ctc_ratio_n)
353 		decoder->tsc_ctc_ratio_d = 0;
354 
355 	if (decoder->tsc_ctc_ratio_d) {
356 		if (!(decoder->tsc_ctc_ratio_n % decoder->tsc_ctc_ratio_d))
357 			decoder->tsc_ctc_mult = decoder->tsc_ctc_ratio_n /
358 						decoder->tsc_ctc_ratio_d;
359 	}
360 
361 	/*
362 	 * A TSC packet can slip past MTC packets so that the timestamp appears
363 	 * to go backwards. One estimate is that can be up to about 40 CPU
364 	 * cycles, which is certainly less than 0x1000 TSC ticks, but accept
365 	 * slippage an order of magnitude more to be on the safe side.
366 	 */
367 	decoder->tsc_slip = 0x10000;
368 
369 	intel_pt_log("timestamp: mtc_shift %u\n", decoder->mtc_shift);
370 	intel_pt_log("timestamp: tsc_ctc_ratio_n %u\n", decoder->tsc_ctc_ratio_n);
371 	intel_pt_log("timestamp: tsc_ctc_ratio_d %u\n", decoder->tsc_ctc_ratio_d);
372 	intel_pt_log("timestamp: tsc_ctc_mult %u\n", decoder->tsc_ctc_mult);
373 	intel_pt_log("timestamp: tsc_slip %#x\n", decoder->tsc_slip);
374 
375 	if (decoder->hop)
376 		intel_pt_log("Hop mode: decoding FUP and TIPs, but not TNT\n");
377 
378 	return decoder;
379 }
380 
381 void intel_pt_set_first_timestamp(struct intel_pt_decoder *decoder,
382 				  uint64_t first_timestamp)
383 {
384 	decoder->first_timestamp = first_timestamp;
385 }
386 
387 static void intel_pt_pop_blk(struct intel_pt_stack *stack)
388 {
389 	struct intel_pt_blk *blk = stack->blk;
390 
391 	stack->blk = blk->prev;
392 	if (!stack->spare)
393 		stack->spare = blk;
394 	else
395 		free(blk);
396 }
397 
398 static uint64_t intel_pt_pop(struct intel_pt_stack *stack)
399 {
400 	if (!stack->pos) {
401 		if (!stack->blk)
402 			return 0;
403 		intel_pt_pop_blk(stack);
404 		if (!stack->blk)
405 			return 0;
406 		stack->pos = INTEL_PT_BLK_SIZE;
407 	}
408 	return stack->blk->ip[--stack->pos];
409 }
410 
411 static int intel_pt_alloc_blk(struct intel_pt_stack *stack)
412 {
413 	struct intel_pt_blk *blk;
414 
415 	if (stack->spare) {
416 		blk = stack->spare;
417 		stack->spare = NULL;
418 	} else {
419 		blk = malloc(sizeof(struct intel_pt_blk));
420 		if (!blk)
421 			return -ENOMEM;
422 	}
423 
424 	blk->prev = stack->blk;
425 	stack->blk = blk;
426 	stack->pos = 0;
427 	return 0;
428 }
429 
430 static int intel_pt_push(struct intel_pt_stack *stack, uint64_t ip)
431 {
432 	int err;
433 
434 	if (!stack->blk || stack->pos == INTEL_PT_BLK_SIZE) {
435 		err = intel_pt_alloc_blk(stack);
436 		if (err)
437 			return err;
438 	}
439 
440 	stack->blk->ip[stack->pos++] = ip;
441 	return 0;
442 }
443 
444 static void intel_pt_clear_stack(struct intel_pt_stack *stack)
445 {
446 	while (stack->blk)
447 		intel_pt_pop_blk(stack);
448 	stack->pos = 0;
449 }
450 
451 static void intel_pt_free_stack(struct intel_pt_stack *stack)
452 {
453 	intel_pt_clear_stack(stack);
454 	zfree(&stack->blk);
455 	zfree(&stack->spare);
456 }
457 
458 void intel_pt_decoder_free(struct intel_pt_decoder *decoder)
459 {
460 	intel_pt_free_stack(&decoder->stack);
461 	free(decoder);
462 }
463 
464 static int intel_pt_ext_err(int code)
465 {
466 	switch (code) {
467 	case -ENOMEM:
468 		return INTEL_PT_ERR_NOMEM;
469 	case -ENOSYS:
470 		return INTEL_PT_ERR_INTERN;
471 	case -EBADMSG:
472 		return INTEL_PT_ERR_BADPKT;
473 	case -ENODATA:
474 		return INTEL_PT_ERR_NODATA;
475 	case -EILSEQ:
476 		return INTEL_PT_ERR_NOINSN;
477 	case -ENOENT:
478 		return INTEL_PT_ERR_MISMAT;
479 	case -EOVERFLOW:
480 		return INTEL_PT_ERR_OVR;
481 	case -ENOSPC:
482 		return INTEL_PT_ERR_LOST;
483 	case -ELOOP:
484 		return INTEL_PT_ERR_NELOOP;
485 	case -ECONNRESET:
486 		return INTEL_PT_ERR_EPTW;
487 	default:
488 		return INTEL_PT_ERR_UNK;
489 	}
490 }
491 
492 static const char *intel_pt_err_msgs[] = {
493 	[INTEL_PT_ERR_NOMEM]  = "Memory allocation failed",
494 	[INTEL_PT_ERR_INTERN] = "Internal error",
495 	[INTEL_PT_ERR_BADPKT] = "Bad packet",
496 	[INTEL_PT_ERR_NODATA] = "No more data",
497 	[INTEL_PT_ERR_NOINSN] = "Failed to get instruction",
498 	[INTEL_PT_ERR_MISMAT] = "Trace doesn't match instruction",
499 	[INTEL_PT_ERR_OVR]    = "Overflow packet",
500 	[INTEL_PT_ERR_LOST]   = "Lost trace data",
501 	[INTEL_PT_ERR_UNK]    = "Unknown error!",
502 	[INTEL_PT_ERR_NELOOP] = "Never-ending loop (refer perf config intel-pt.max-loops)",
503 	[INTEL_PT_ERR_EPTW]   = "Broken emulated ptwrite",
504 };
505 
506 int intel_pt__strerror(int code, char *buf, size_t buflen)
507 {
508 	if (code < 1 || code >= INTEL_PT_ERR_MAX)
509 		code = INTEL_PT_ERR_UNK;
510 	strlcpy(buf, intel_pt_err_msgs[code], buflen);
511 	return 0;
512 }
513 
514 static uint64_t intel_pt_calc_ip(const struct intel_pt_pkt *packet,
515 				 uint64_t last_ip)
516 {
517 	uint64_t ip;
518 
519 	switch (packet->count) {
520 	case 1:
521 		ip = (last_ip & (uint64_t)0xffffffffffff0000ULL) |
522 		     packet->payload;
523 		break;
524 	case 2:
525 		ip = (last_ip & (uint64_t)0xffffffff00000000ULL) |
526 		     packet->payload;
527 		break;
528 	case 3:
529 		ip = packet->payload;
530 		/* Sign-extend 6-byte ip */
531 		if (ip & (uint64_t)0x800000000000ULL)
532 			ip |= (uint64_t)0xffff000000000000ULL;
533 		break;
534 	case 4:
535 		ip = (last_ip & (uint64_t)0xffff000000000000ULL) |
536 		     packet->payload;
537 		break;
538 	case 6:
539 		ip = packet->payload;
540 		break;
541 	default:
542 		return 0;
543 	}
544 
545 	return ip;
546 }
547 
548 static inline void intel_pt_set_last_ip(struct intel_pt_decoder *decoder)
549 {
550 	decoder->last_ip = intel_pt_calc_ip(&decoder->packet, decoder->last_ip);
551 	decoder->have_last_ip = true;
552 }
553 
554 static inline void intel_pt_set_ip(struct intel_pt_decoder *decoder)
555 {
556 	intel_pt_set_last_ip(decoder);
557 	decoder->ip = decoder->last_ip;
558 }
559 
560 static void intel_pt_decoder_log_packet(struct intel_pt_decoder *decoder)
561 {
562 	intel_pt_log_packet(&decoder->packet, decoder->pkt_len, decoder->pos,
563 			    decoder->buf);
564 }
565 
566 static int intel_pt_bug(struct intel_pt_decoder *decoder)
567 {
568 	intel_pt_log("ERROR: Internal error\n");
569 	decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
570 	return -ENOSYS;
571 }
572 
573 static inline void intel_pt_clear_tx_flags(struct intel_pt_decoder *decoder)
574 {
575 	decoder->tx_flags = 0;
576 }
577 
578 static inline void intel_pt_update_in_tx(struct intel_pt_decoder *decoder)
579 {
580 	decoder->tx_flags = decoder->packet.payload & INTEL_PT_IN_TX;
581 }
582 
583 static inline void intel_pt_update_pip(struct intel_pt_decoder *decoder)
584 {
585 	decoder->pip_payload = decoder->packet.payload;
586 }
587 
588 static inline void intel_pt_update_nr(struct intel_pt_decoder *decoder)
589 {
590 	decoder->next_nr = decoder->pip_payload & 1;
591 }
592 
593 static inline void intel_pt_set_nr(struct intel_pt_decoder *decoder)
594 {
595 	decoder->nr = decoder->pip_payload & 1;
596 	decoder->next_nr = decoder->nr;
597 }
598 
599 static inline void intel_pt_set_pip(struct intel_pt_decoder *decoder)
600 {
601 	intel_pt_update_pip(decoder);
602 	intel_pt_set_nr(decoder);
603 }
604 
605 static int intel_pt_bad_packet(struct intel_pt_decoder *decoder)
606 {
607 	intel_pt_clear_tx_flags(decoder);
608 	decoder->have_tma = false;
609 	decoder->pkt_len = 1;
610 	decoder->pkt_step = 1;
611 	intel_pt_decoder_log_packet(decoder);
612 	if (decoder->pkt_state != INTEL_PT_STATE_NO_PSB) {
613 		intel_pt_log("ERROR: Bad packet\n");
614 		decoder->pkt_state = INTEL_PT_STATE_ERR1;
615 	}
616 	return -EBADMSG;
617 }
618 
619 static inline void intel_pt_update_sample_time(struct intel_pt_decoder *decoder)
620 {
621 	decoder->sample_timestamp = decoder->timestamp;
622 	decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
623 	decoder->state.cycles = decoder->tot_cyc_cnt;
624 }
625 
626 static void intel_pt_reposition(struct intel_pt_decoder *decoder)
627 {
628 	decoder->ip = 0;
629 	decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
630 	decoder->timestamp = 0;
631 	decoder->have_tma = false;
632 }
633 
634 static int intel_pt_get_data(struct intel_pt_decoder *decoder, bool reposition)
635 {
636 	struct intel_pt_buffer buffer = { .buf = 0, };
637 	int ret;
638 
639 	decoder->pkt_step = 0;
640 
641 	intel_pt_log("Getting more data\n");
642 	ret = decoder->get_trace(&buffer, decoder->data);
643 	if (ret)
644 		return ret;
645 	decoder->buf = buffer.buf;
646 	decoder->len = buffer.len;
647 	if (!decoder->len) {
648 		intel_pt_log("No more data\n");
649 		return -ENODATA;
650 	}
651 	decoder->buf_timestamp = buffer.ref_timestamp;
652 	if (!buffer.consecutive || reposition) {
653 		intel_pt_reposition(decoder);
654 		decoder->ref_timestamp = buffer.ref_timestamp;
655 		decoder->state.trace_nr = buffer.trace_nr;
656 		decoder->vm_tm_corr_same_buf = false;
657 		intel_pt_log("Reference timestamp 0x%" PRIx64 "\n",
658 			     decoder->ref_timestamp);
659 		return -ENOLINK;
660 	}
661 
662 	return 0;
663 }
664 
665 static int intel_pt_get_next_data(struct intel_pt_decoder *decoder,
666 				  bool reposition)
667 {
668 	if (!decoder->next_buf)
669 		return intel_pt_get_data(decoder, reposition);
670 
671 	decoder->buf = decoder->next_buf;
672 	decoder->len = decoder->next_len;
673 	decoder->next_buf = 0;
674 	decoder->next_len = 0;
675 	return 0;
676 }
677 
678 static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder)
679 {
680 	unsigned char *buf = decoder->temp_buf;
681 	size_t old_len, len, n;
682 	int ret;
683 
684 	old_len = decoder->len;
685 	len = decoder->len;
686 	memcpy(buf, decoder->buf, len);
687 
688 	ret = intel_pt_get_data(decoder, false);
689 	if (ret) {
690 		decoder->pos += old_len;
691 		return ret < 0 ? ret : -EINVAL;
692 	}
693 
694 	n = INTEL_PT_PKT_MAX_SZ - len;
695 	if (n > decoder->len)
696 		n = decoder->len;
697 	memcpy(buf + len, decoder->buf, n);
698 	len += n;
699 
700 	decoder->prev_pkt_ctx = decoder->pkt_ctx;
701 	ret = intel_pt_get_packet(buf, len, &decoder->packet, &decoder->pkt_ctx);
702 	if (ret < (int)old_len) {
703 		decoder->next_buf = decoder->buf;
704 		decoder->next_len = decoder->len;
705 		decoder->buf = buf;
706 		decoder->len = old_len;
707 		return intel_pt_bad_packet(decoder);
708 	}
709 
710 	decoder->next_buf = decoder->buf + (ret - old_len);
711 	decoder->next_len = decoder->len - (ret - old_len);
712 
713 	decoder->buf = buf;
714 	decoder->len = ret;
715 
716 	return ret;
717 }
718 
719 struct intel_pt_pkt_info {
720 	struct intel_pt_decoder	  *decoder;
721 	struct intel_pt_pkt       packet;
722 	uint64_t                  pos;
723 	int                       pkt_len;
724 	int                       last_packet_type;
725 	void                      *data;
726 };
727 
728 typedef int (*intel_pt_pkt_cb_t)(struct intel_pt_pkt_info *pkt_info);
729 
730 /* Lookahead packets in current buffer */
731 static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder,
732 				  intel_pt_pkt_cb_t cb, void *data)
733 {
734 	struct intel_pt_pkt_info pkt_info;
735 	const unsigned char *buf = decoder->buf;
736 	enum intel_pt_pkt_ctx pkt_ctx = decoder->pkt_ctx;
737 	size_t len = decoder->len;
738 	int ret;
739 
740 	pkt_info.decoder          = decoder;
741 	pkt_info.pos              = decoder->pos;
742 	pkt_info.pkt_len          = decoder->pkt_step;
743 	pkt_info.last_packet_type = decoder->last_packet_type;
744 	pkt_info.data             = data;
745 
746 	while (1) {
747 		do {
748 			pkt_info.pos += pkt_info.pkt_len;
749 			buf          += pkt_info.pkt_len;
750 			len          -= pkt_info.pkt_len;
751 
752 			if (!len)
753 				return INTEL_PT_NEED_MORE_BYTES;
754 
755 			ret = intel_pt_get_packet(buf, len, &pkt_info.packet,
756 						  &pkt_ctx);
757 			if (!ret)
758 				return INTEL_PT_NEED_MORE_BYTES;
759 			if (ret < 0)
760 				return ret;
761 
762 			pkt_info.pkt_len = ret;
763 		} while (pkt_info.packet.type == INTEL_PT_PAD);
764 
765 		ret = cb(&pkt_info);
766 		if (ret)
767 			return 0;
768 
769 		pkt_info.last_packet_type = pkt_info.packet.type;
770 	}
771 }
772 
773 struct intel_pt_calc_cyc_to_tsc_info {
774 	uint64_t        cycle_cnt;
775 	unsigned int    cbr;
776 	uint32_t        last_mtc;
777 	uint64_t        ctc_timestamp;
778 	uint64_t        ctc_delta;
779 	uint64_t        tsc_timestamp;
780 	uint64_t        timestamp;
781 	bool            have_tma;
782 	bool            fixup_last_mtc;
783 	bool            from_mtc;
784 	double          cbr_cyc_to_tsc;
785 };
786 
787 /*
788  * MTC provides a 8-bit slice of CTC but the TMA packet only provides the lower
789  * 16 bits of CTC. If mtc_shift > 8 then some of the MTC bits are not in the CTC
790  * provided by the TMA packet. Fix-up the last_mtc calculated from the TMA
791  * packet by copying the missing bits from the current MTC assuming the least
792  * difference between the two, and that the current MTC comes after last_mtc.
793  */
794 static void intel_pt_fixup_last_mtc(uint32_t mtc, int mtc_shift,
795 				    uint32_t *last_mtc)
796 {
797 	uint32_t first_missing_bit = 1U << (16 - mtc_shift);
798 	uint32_t mask = ~(first_missing_bit - 1);
799 
800 	*last_mtc |= mtc & mask;
801 	if (*last_mtc >= mtc) {
802 		*last_mtc -= first_missing_bit;
803 		*last_mtc &= 0xff;
804 	}
805 }
806 
807 static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
808 {
809 	struct intel_pt_decoder *decoder = pkt_info->decoder;
810 	struct intel_pt_calc_cyc_to_tsc_info *data = pkt_info->data;
811 	uint64_t timestamp;
812 	double cyc_to_tsc;
813 	unsigned int cbr;
814 	uint32_t mtc, mtc_delta, ctc, fc, ctc_rem;
815 
816 	switch (pkt_info->packet.type) {
817 	case INTEL_PT_TNT:
818 	case INTEL_PT_TIP_PGE:
819 	case INTEL_PT_TIP:
820 	case INTEL_PT_FUP:
821 	case INTEL_PT_PSB:
822 	case INTEL_PT_PIP:
823 	case INTEL_PT_MODE_EXEC:
824 	case INTEL_PT_MODE_TSX:
825 	case INTEL_PT_PSBEND:
826 	case INTEL_PT_PAD:
827 	case INTEL_PT_VMCS:
828 	case INTEL_PT_MNT:
829 	case INTEL_PT_PTWRITE:
830 	case INTEL_PT_PTWRITE_IP:
831 	case INTEL_PT_BBP:
832 	case INTEL_PT_BIP:
833 	case INTEL_PT_BEP:
834 	case INTEL_PT_BEP_IP:
835 	case INTEL_PT_CFE:
836 	case INTEL_PT_CFE_IP:
837 	case INTEL_PT_EVD:
838 		return 0;
839 
840 	case INTEL_PT_MTC:
841 		if (!data->have_tma)
842 			return 0;
843 
844 		mtc = pkt_info->packet.payload;
845 		if (decoder->mtc_shift > 8 && data->fixup_last_mtc) {
846 			data->fixup_last_mtc = false;
847 			intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
848 						&data->last_mtc);
849 		}
850 		if (mtc > data->last_mtc)
851 			mtc_delta = mtc - data->last_mtc;
852 		else
853 			mtc_delta = mtc + 256 - data->last_mtc;
854 		data->ctc_delta += mtc_delta << decoder->mtc_shift;
855 		data->last_mtc = mtc;
856 
857 		if (decoder->tsc_ctc_mult) {
858 			timestamp = data->ctc_timestamp +
859 				data->ctc_delta * decoder->tsc_ctc_mult;
860 		} else {
861 			timestamp = data->ctc_timestamp +
862 				multdiv(data->ctc_delta,
863 					decoder->tsc_ctc_ratio_n,
864 					decoder->tsc_ctc_ratio_d);
865 		}
866 
867 		if (timestamp < data->timestamp)
868 			return 1;
869 
870 		if (pkt_info->last_packet_type != INTEL_PT_CYC) {
871 			data->timestamp = timestamp;
872 			return 0;
873 		}
874 
875 		break;
876 
877 	case INTEL_PT_TSC:
878 		/*
879 		 * For now, do not support using TSC packets - refer
880 		 * intel_pt_calc_cyc_to_tsc().
881 		 */
882 		if (data->from_mtc)
883 			return 1;
884 		timestamp = pkt_info->packet.payload |
885 			    (data->timestamp & (0xffULL << 56));
886 		if (data->from_mtc && timestamp < data->timestamp &&
887 		    data->timestamp - timestamp < decoder->tsc_slip)
888 			return 1;
889 		if (timestamp < data->timestamp)
890 			timestamp += (1ULL << 56);
891 		if (pkt_info->last_packet_type != INTEL_PT_CYC) {
892 			if (data->from_mtc)
893 				return 1;
894 			data->tsc_timestamp = timestamp;
895 			data->timestamp = timestamp;
896 			return 0;
897 		}
898 		break;
899 
900 	case INTEL_PT_TMA:
901 		if (data->from_mtc)
902 			return 1;
903 
904 		if (!decoder->tsc_ctc_ratio_d)
905 			return 0;
906 
907 		ctc = pkt_info->packet.payload;
908 		fc = pkt_info->packet.count;
909 		ctc_rem = ctc & decoder->ctc_rem_mask;
910 
911 		data->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
912 
913 		data->ctc_timestamp = data->tsc_timestamp - fc;
914 		if (decoder->tsc_ctc_mult) {
915 			data->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
916 		} else {
917 			data->ctc_timestamp -=
918 				multdiv(ctc_rem, decoder->tsc_ctc_ratio_n,
919 					decoder->tsc_ctc_ratio_d);
920 		}
921 
922 		data->ctc_delta = 0;
923 		data->have_tma = true;
924 		data->fixup_last_mtc = true;
925 
926 		return 0;
927 
928 	case INTEL_PT_CYC:
929 		data->cycle_cnt += pkt_info->packet.payload;
930 		return 0;
931 
932 	case INTEL_PT_CBR:
933 		cbr = pkt_info->packet.payload;
934 		if (data->cbr && data->cbr != cbr)
935 			return 1;
936 		data->cbr = cbr;
937 		data->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
938 		return 0;
939 
940 	case INTEL_PT_TIP_PGD:
941 	case INTEL_PT_TRACESTOP:
942 	case INTEL_PT_EXSTOP:
943 	case INTEL_PT_EXSTOP_IP:
944 	case INTEL_PT_MWAIT:
945 	case INTEL_PT_PWRE:
946 	case INTEL_PT_PWRX:
947 	case INTEL_PT_OVF:
948 	case INTEL_PT_BAD: /* Does not happen */
949 	default:
950 		return 1;
951 	}
952 
953 	if (!data->cbr && decoder->cbr) {
954 		data->cbr = decoder->cbr;
955 		data->cbr_cyc_to_tsc = decoder->cbr_cyc_to_tsc;
956 	}
957 
958 	if (!data->cycle_cnt)
959 		return 1;
960 
961 	cyc_to_tsc = (double)(timestamp - decoder->timestamp) / data->cycle_cnt;
962 
963 	if (data->cbr && cyc_to_tsc > data->cbr_cyc_to_tsc &&
964 	    cyc_to_tsc / data->cbr_cyc_to_tsc > 1.25) {
965 		intel_pt_log("Timestamp: calculated %g TSC ticks per cycle too big (c.f. CBR-based value %g), pos " x64_fmt "\n",
966 			     cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
967 		return 1;
968 	}
969 
970 	decoder->calc_cyc_to_tsc = cyc_to_tsc;
971 	decoder->have_calc_cyc_to_tsc = true;
972 
973 	if (data->cbr) {
974 		intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. CBR-based value %g, pos " x64_fmt "\n",
975 			     cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
976 	} else {
977 		intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. unknown CBR-based value, pos " x64_fmt "\n",
978 			     cyc_to_tsc, pkt_info->pos);
979 	}
980 
981 	return 1;
982 }
983 
984 static void intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder *decoder,
985 				     bool from_mtc)
986 {
987 	struct intel_pt_calc_cyc_to_tsc_info data = {
988 		.cycle_cnt      = 0,
989 		.cbr            = 0,
990 		.last_mtc       = decoder->last_mtc,
991 		.ctc_timestamp  = decoder->ctc_timestamp,
992 		.ctc_delta      = decoder->ctc_delta,
993 		.tsc_timestamp  = decoder->tsc_timestamp,
994 		.timestamp      = decoder->timestamp,
995 		.have_tma       = decoder->have_tma,
996 		.fixup_last_mtc = decoder->fixup_last_mtc,
997 		.from_mtc       = from_mtc,
998 		.cbr_cyc_to_tsc = 0,
999 	};
1000 
1001 	/*
1002 	 * For now, do not support using TSC packets for at least the reasons:
1003 	 * 1) timing might have stopped
1004 	 * 2) TSC packets within PSB+ can slip against CYC packets
1005 	 */
1006 	if (!from_mtc)
1007 		return;
1008 
1009 	intel_pt_pkt_lookahead(decoder, intel_pt_calc_cyc_cb, &data);
1010 }
1011 
1012 static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder)
1013 {
1014 	int ret;
1015 
1016 	decoder->last_packet_type = decoder->packet.type;
1017 
1018 	do {
1019 		decoder->pos += decoder->pkt_step;
1020 		decoder->buf += decoder->pkt_step;
1021 		decoder->len -= decoder->pkt_step;
1022 
1023 		if (!decoder->len) {
1024 			ret = intel_pt_get_next_data(decoder, false);
1025 			if (ret)
1026 				return ret;
1027 		}
1028 
1029 		decoder->prev_pkt_ctx = decoder->pkt_ctx;
1030 		ret = intel_pt_get_packet(decoder->buf, decoder->len,
1031 					  &decoder->packet, &decoder->pkt_ctx);
1032 		if (ret == INTEL_PT_NEED_MORE_BYTES && BITS_PER_LONG == 32 &&
1033 		    decoder->len < INTEL_PT_PKT_MAX_SZ && !decoder->next_buf) {
1034 			ret = intel_pt_get_split_packet(decoder);
1035 			if (ret < 0)
1036 				return ret;
1037 		}
1038 		if (ret <= 0)
1039 			return intel_pt_bad_packet(decoder);
1040 
1041 		decoder->pkt_len = ret;
1042 		decoder->pkt_step = ret;
1043 		intel_pt_decoder_log_packet(decoder);
1044 	} while (decoder->packet.type == INTEL_PT_PAD);
1045 
1046 	return 0;
1047 }
1048 
1049 static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder)
1050 {
1051 	uint64_t timestamp, masked_timestamp;
1052 
1053 	timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
1054 	masked_timestamp = timestamp & decoder->period_mask;
1055 	if (decoder->continuous_period) {
1056 		if (masked_timestamp > decoder->last_masked_timestamp)
1057 			return 1;
1058 	} else {
1059 		timestamp += 1;
1060 		masked_timestamp = timestamp & decoder->period_mask;
1061 		if (masked_timestamp > decoder->last_masked_timestamp) {
1062 			decoder->last_masked_timestamp = masked_timestamp;
1063 			decoder->continuous_period = true;
1064 		}
1065 	}
1066 
1067 	if (masked_timestamp < decoder->last_masked_timestamp)
1068 		return decoder->period_ticks;
1069 
1070 	return decoder->period_ticks - (timestamp - masked_timestamp);
1071 }
1072 
1073 static uint64_t intel_pt_next_sample(struct intel_pt_decoder *decoder)
1074 {
1075 	switch (decoder->period_type) {
1076 	case INTEL_PT_PERIOD_INSTRUCTIONS:
1077 		return decoder->period - decoder->period_insn_cnt;
1078 	case INTEL_PT_PERIOD_TICKS:
1079 		return intel_pt_next_period(decoder);
1080 	case INTEL_PT_PERIOD_NONE:
1081 	case INTEL_PT_PERIOD_MTC:
1082 	default:
1083 		return 0;
1084 	}
1085 }
1086 
1087 static void intel_pt_sample_insn(struct intel_pt_decoder *decoder)
1088 {
1089 	uint64_t timestamp, masked_timestamp;
1090 
1091 	switch (decoder->period_type) {
1092 	case INTEL_PT_PERIOD_INSTRUCTIONS:
1093 		decoder->period_insn_cnt = 0;
1094 		break;
1095 	case INTEL_PT_PERIOD_TICKS:
1096 		timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
1097 		masked_timestamp = timestamp & decoder->period_mask;
1098 		if (masked_timestamp > decoder->last_masked_timestamp)
1099 			decoder->last_masked_timestamp = masked_timestamp;
1100 		else
1101 			decoder->last_masked_timestamp += decoder->period_ticks;
1102 		break;
1103 	case INTEL_PT_PERIOD_NONE:
1104 	case INTEL_PT_PERIOD_MTC:
1105 	default:
1106 		break;
1107 	}
1108 
1109 	decoder->state.type |= INTEL_PT_INSTRUCTION;
1110 }
1111 
1112 /*
1113  * Sample FUP instruction at the same time as reporting the FUP event, so the
1114  * instruction sample gets the same flags as the FUP event.
1115  */
1116 static void intel_pt_sample_fup_insn(struct intel_pt_decoder *decoder)
1117 {
1118 	struct intel_pt_insn intel_pt_insn;
1119 	uint64_t max_insn_cnt, insn_cnt = 0;
1120 	int err;
1121 
1122 	decoder->state.insn_op = INTEL_PT_OP_OTHER;
1123 	decoder->state.insn_len = 0;
1124 
1125 	if (!decoder->branch_enable || !decoder->pge || decoder->hop ||
1126 	    decoder->ip != decoder->last_ip)
1127 		return;
1128 
1129 	if (!decoder->mtc_insn)
1130 		decoder->mtc_insn = true;
1131 
1132 	max_insn_cnt = intel_pt_next_sample(decoder);
1133 	if (max_insn_cnt != 1)
1134 		return;
1135 
1136 	err = decoder->walk_insn(&intel_pt_insn, &insn_cnt, &decoder->ip,
1137 				 0, max_insn_cnt, decoder->data);
1138 	/* Ignore error, it will be reported next walk anyway */
1139 	if (err)
1140 		return;
1141 
1142 	if (intel_pt_insn.branch != INTEL_PT_BR_NO_BRANCH) {
1143 		intel_pt_log_at("ERROR: Unexpected branch at FUP instruction", decoder->ip);
1144 		return;
1145 	}
1146 
1147 	decoder->tot_insn_cnt += insn_cnt;
1148 	decoder->timestamp_insn_cnt += insn_cnt;
1149 	decoder->sample_insn_cnt += insn_cnt;
1150 	decoder->period_insn_cnt += insn_cnt;
1151 
1152 	intel_pt_sample_insn(decoder);
1153 
1154 	decoder->state.type |= INTEL_PT_INSTRUCTION;
1155 	decoder->ip += intel_pt_insn.length;
1156 }
1157 
1158 static int intel_pt_walk_insn(struct intel_pt_decoder *decoder,
1159 			      struct intel_pt_insn *intel_pt_insn, uint64_t ip)
1160 {
1161 	uint64_t max_insn_cnt, insn_cnt = 0;
1162 	int err;
1163 
1164 	if (!decoder->mtc_insn)
1165 		decoder->mtc_insn = true;
1166 
1167 	max_insn_cnt = intel_pt_next_sample(decoder);
1168 
1169 	err = decoder->walk_insn(intel_pt_insn, &insn_cnt, &decoder->ip, ip,
1170 				 max_insn_cnt, decoder->data);
1171 
1172 	decoder->tot_insn_cnt += insn_cnt;
1173 	decoder->timestamp_insn_cnt += insn_cnt;
1174 	decoder->sample_insn_cnt += insn_cnt;
1175 	decoder->period_insn_cnt += insn_cnt;
1176 
1177 	if (err) {
1178 		decoder->no_progress = 0;
1179 		decoder->pkt_state = INTEL_PT_STATE_ERR2;
1180 		intel_pt_log_at("ERROR: Failed to get instruction",
1181 				decoder->ip);
1182 		if (err == -ENOENT)
1183 			return -ENOLINK;
1184 		return -EILSEQ;
1185 	}
1186 
1187 	if (ip && decoder->ip == ip) {
1188 		err = -EAGAIN;
1189 		goto out;
1190 	}
1191 
1192 	if (max_insn_cnt && insn_cnt >= max_insn_cnt)
1193 		intel_pt_sample_insn(decoder);
1194 
1195 	if (intel_pt_insn->branch == INTEL_PT_BR_NO_BRANCH) {
1196 		decoder->state.type = INTEL_PT_INSTRUCTION;
1197 		decoder->state.from_ip = decoder->ip;
1198 		decoder->state.to_ip = 0;
1199 		decoder->ip += intel_pt_insn->length;
1200 		err = INTEL_PT_RETURN;
1201 		goto out;
1202 	}
1203 
1204 	if (intel_pt_insn->op == INTEL_PT_OP_CALL) {
1205 		/* Zero-length calls are excluded */
1206 		if (intel_pt_insn->branch != INTEL_PT_BR_UNCONDITIONAL ||
1207 		    intel_pt_insn->rel) {
1208 			err = intel_pt_push(&decoder->stack, decoder->ip +
1209 					    intel_pt_insn->length);
1210 			if (err)
1211 				goto out;
1212 		}
1213 	} else if (intel_pt_insn->op == INTEL_PT_OP_RET) {
1214 		decoder->ret_addr = intel_pt_pop(&decoder->stack);
1215 	}
1216 
1217 	if (intel_pt_insn->branch == INTEL_PT_BR_UNCONDITIONAL) {
1218 		int cnt = decoder->no_progress++;
1219 
1220 		decoder->state.from_ip = decoder->ip;
1221 		decoder->ip += intel_pt_insn->length +
1222 				intel_pt_insn->rel;
1223 		decoder->state.to_ip = decoder->ip;
1224 		err = INTEL_PT_RETURN;
1225 
1226 		/*
1227 		 * Check for being stuck in a loop.  This can happen if a
1228 		 * decoder error results in the decoder erroneously setting the
1229 		 * ip to an address that is itself in an infinite loop that
1230 		 * consumes no packets.  When that happens, there must be an
1231 		 * unconditional branch.
1232 		 */
1233 		if (cnt) {
1234 			if (cnt == 1) {
1235 				decoder->stuck_ip = decoder->state.to_ip;
1236 				decoder->stuck_ip_prd = 1;
1237 				decoder->stuck_ip_cnt = 1;
1238 			} else if (cnt > decoder->max_loops ||
1239 				   decoder->state.to_ip == decoder->stuck_ip) {
1240 				intel_pt_log_at("ERROR: Never-ending loop",
1241 						decoder->state.to_ip);
1242 				decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1243 				err = -ELOOP;
1244 				goto out;
1245 			} else if (!--decoder->stuck_ip_cnt) {
1246 				decoder->stuck_ip_prd += 1;
1247 				decoder->stuck_ip_cnt = decoder->stuck_ip_prd;
1248 				decoder->stuck_ip = decoder->state.to_ip;
1249 			}
1250 		}
1251 		goto out_no_progress;
1252 	}
1253 out:
1254 	decoder->no_progress = 0;
1255 out_no_progress:
1256 	decoder->state.insn_op = intel_pt_insn->op;
1257 	decoder->state.insn_len = intel_pt_insn->length;
1258 	memcpy(decoder->state.insn, intel_pt_insn->buf,
1259 	       INTEL_PT_INSN_BUF_SZ);
1260 
1261 	if (decoder->tx_flags & INTEL_PT_IN_TX)
1262 		decoder->state.flags |= INTEL_PT_IN_TX;
1263 
1264 	return err;
1265 }
1266 
1267 static void intel_pt_mode_exec_status(struct intel_pt_decoder *decoder)
1268 {
1269 	bool iflag = decoder->packet.count & INTEL_PT_IFLAG;
1270 
1271 	decoder->exec_mode = decoder->packet.payload;
1272 	decoder->iflag = iflag;
1273 	decoder->next_iflag = iflag;
1274 	decoder->state.from_iflag = iflag;
1275 	decoder->state.to_iflag = iflag;
1276 }
1277 
1278 static void intel_pt_mode_exec(struct intel_pt_decoder *decoder)
1279 {
1280 	bool iflag = decoder->packet.count & INTEL_PT_IFLAG;
1281 
1282 	decoder->exec_mode = decoder->packet.payload;
1283 	decoder->next_iflag = iflag;
1284 }
1285 
1286 static void intel_pt_sample_iflag(struct intel_pt_decoder *decoder)
1287 {
1288 	decoder->state.type |= INTEL_PT_IFLAG_CHG;
1289 	decoder->state.from_iflag = decoder->iflag;
1290 	decoder->state.to_iflag = decoder->next_iflag;
1291 	decoder->iflag = decoder->next_iflag;
1292 }
1293 
1294 static void intel_pt_sample_iflag_chg(struct intel_pt_decoder *decoder)
1295 {
1296 	if (decoder->iflag != decoder->next_iflag)
1297 		intel_pt_sample_iflag(decoder);
1298 }
1299 
1300 static void intel_pt_clear_fup_event(struct intel_pt_decoder *decoder)
1301 {
1302 	decoder->set_fup_tx_flags = false;
1303 	decoder->set_fup_ptw = false;
1304 	decoder->set_fup_mwait = false;
1305 	decoder->set_fup_pwre = false;
1306 	decoder->set_fup_exstop = false;
1307 	decoder->set_fup_bep = false;
1308 	decoder->set_fup_cfe_ip = false;
1309 	decoder->set_fup_cfe = false;
1310 	decoder->evd_cnt = 0;
1311 	decoder->set_fup_mode_exec = false;
1312 	decoder->iflag = decoder->next_iflag;
1313 }
1314 
1315 static bool intel_pt_fup_event(struct intel_pt_decoder *decoder, bool no_tip)
1316 {
1317 	enum intel_pt_sample_type type = decoder->state.type;
1318 	bool sample_fup_insn = false;
1319 	bool ret = false;
1320 
1321 	decoder->state.type &= ~INTEL_PT_BRANCH;
1322 
1323 	if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
1324 		bool ip = decoder->set_fup_cfe_ip;
1325 
1326 		decoder->set_fup_cfe_ip = false;
1327 		decoder->set_fup_cfe = false;
1328 		decoder->state.type |= INTEL_PT_EVT;
1329 		if (!ip && decoder->pge)
1330 			decoder->state.type |= INTEL_PT_BRANCH;
1331 		decoder->state.cfe_type = decoder->fup_cfe_pkt.count;
1332 		decoder->state.cfe_vector = decoder->fup_cfe_pkt.payload;
1333 		decoder->state.evd_cnt = decoder->evd_cnt;
1334 		decoder->state.evd = decoder->evd;
1335 		decoder->evd_cnt = 0;
1336 		if (ip || decoder->pge)
1337 			decoder->state.flags |= INTEL_PT_FUP_IP;
1338 		ret = true;
1339 	}
1340 	if (decoder->set_fup_mode_exec) {
1341 		decoder->set_fup_mode_exec = false;
1342 		intel_pt_sample_iflag(decoder);
1343 		sample_fup_insn = no_tip;
1344 		ret = true;
1345 	}
1346 	if (decoder->set_fup_tx_flags) {
1347 		decoder->set_fup_tx_flags = false;
1348 		decoder->tx_flags = decoder->fup_tx_flags;
1349 		decoder->state.type |= INTEL_PT_TRANSACTION;
1350 		if (decoder->fup_tx_flags & INTEL_PT_ABORT_TX)
1351 			decoder->state.type |= INTEL_PT_BRANCH;
1352 		decoder->state.flags = decoder->fup_tx_flags;
1353 		ret = true;
1354 	}
1355 	if (decoder->set_fup_ptw) {
1356 		decoder->set_fup_ptw = false;
1357 		decoder->state.type |= INTEL_PT_PTW;
1358 		decoder->state.flags |= INTEL_PT_FUP_IP;
1359 		decoder->state.ptw_payload = decoder->fup_ptw_payload;
1360 		ret = true;
1361 	}
1362 	if (decoder->set_fup_mwait) {
1363 		decoder->set_fup_mwait = false;
1364 		decoder->state.type |= INTEL_PT_MWAIT_OP;
1365 		decoder->state.mwait_payload = decoder->fup_mwait_payload;
1366 		ret = true;
1367 	}
1368 	if (decoder->set_fup_pwre) {
1369 		decoder->set_fup_pwre = false;
1370 		decoder->state.type |= INTEL_PT_PWR_ENTRY;
1371 		decoder->state.pwre_payload = decoder->fup_pwre_payload;
1372 		ret = true;
1373 	}
1374 	if (decoder->set_fup_exstop) {
1375 		decoder->set_fup_exstop = false;
1376 		decoder->state.type |= INTEL_PT_EX_STOP;
1377 		decoder->state.flags |= INTEL_PT_FUP_IP;
1378 		ret = true;
1379 	}
1380 	if (decoder->set_fup_bep) {
1381 		decoder->set_fup_bep = false;
1382 		decoder->state.type |= INTEL_PT_BLK_ITEMS;
1383 		ret = true;
1384 	}
1385 	if (decoder->overflow) {
1386 		decoder->overflow = false;
1387 		if (!ret && !decoder->pge) {
1388 			if (decoder->hop) {
1389 				decoder->state.type = 0;
1390 				decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
1391 			}
1392 			decoder->pge = true;
1393 			decoder->state.type |= INTEL_PT_BRANCH | INTEL_PT_TRACE_BEGIN;
1394 			decoder->state.from_ip = 0;
1395 			decoder->state.to_ip = decoder->ip;
1396 			return true;
1397 		}
1398 	}
1399 	if (ret) {
1400 		decoder->state.from_ip = decoder->ip;
1401 		decoder->state.to_ip = 0;
1402 		if (sample_fup_insn)
1403 			intel_pt_sample_fup_insn(decoder);
1404 	} else {
1405 		decoder->state.type = type;
1406 	}
1407 	return ret;
1408 }
1409 
1410 static inline bool intel_pt_fup_with_nlip(struct intel_pt_decoder *decoder,
1411 					  struct intel_pt_insn *intel_pt_insn,
1412 					  uint64_t ip, int err)
1413 {
1414 	return decoder->flags & INTEL_PT_FUP_WITH_NLIP && !err &&
1415 	       intel_pt_insn->branch == INTEL_PT_BR_INDIRECT &&
1416 	       ip == decoder->ip + intel_pt_insn->length;
1417 }
1418 
1419 static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
1420 {
1421 	struct intel_pt_insn intel_pt_insn;
1422 	uint64_t ip;
1423 	int err;
1424 
1425 	ip = decoder->last_ip;
1426 
1427 	while (1) {
1428 		err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
1429 		if (err == INTEL_PT_RETURN)
1430 			return 0;
1431 		if (err == -EAGAIN ||
1432 		    intel_pt_fup_with_nlip(decoder, &intel_pt_insn, ip, err)) {
1433 			bool no_tip = decoder->pkt_state != INTEL_PT_STATE_FUP;
1434 
1435 			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1436 			if (intel_pt_fup_event(decoder, no_tip) && no_tip)
1437 				return 0;
1438 			return -EAGAIN;
1439 		}
1440 		decoder->set_fup_tx_flags = false;
1441 		if (err)
1442 			return err;
1443 
1444 		if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1445 			intel_pt_log_at("ERROR: Unexpected indirect branch",
1446 					decoder->ip);
1447 			decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1448 			return -ENOENT;
1449 		}
1450 
1451 		if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1452 			intel_pt_log_at("ERROR: Unexpected conditional branch",
1453 					decoder->ip);
1454 			decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1455 			return -ENOENT;
1456 		}
1457 
1458 		intel_pt_bug(decoder);
1459 	}
1460 }
1461 
1462 static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
1463 {
1464 	struct intel_pt_insn intel_pt_insn;
1465 	int err;
1466 
1467 	err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1468 	if (err == INTEL_PT_RETURN &&
1469 	    decoder->pgd_ip &&
1470 	    decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1471 	    (decoder->state.type & INTEL_PT_BRANCH) &&
1472 	    decoder->pgd_ip(decoder->state.to_ip, decoder->data)) {
1473 		/* Unconditional branch leaving filter region */
1474 		decoder->no_progress = 0;
1475 		decoder->pge = false;
1476 		decoder->continuous_period = false;
1477 		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1478 		decoder->state.type |= INTEL_PT_TRACE_END;
1479 		intel_pt_update_nr(decoder);
1480 		return 0;
1481 	}
1482 	if (err == INTEL_PT_RETURN)
1483 		return 0;
1484 	if (err)
1485 		return err;
1486 
1487 	intel_pt_update_nr(decoder);
1488 	intel_pt_sample_iflag_chg(decoder);
1489 
1490 	if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1491 		if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
1492 			decoder->pge = false;
1493 			decoder->continuous_period = false;
1494 			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1495 			decoder->state.from_ip = decoder->ip;
1496 			if (decoder->packet.count == 0) {
1497 				decoder->state.to_ip = 0;
1498 			} else {
1499 				decoder->state.to_ip = decoder->last_ip;
1500 				decoder->ip = decoder->last_ip;
1501 			}
1502 			decoder->state.type |= INTEL_PT_TRACE_END;
1503 		} else {
1504 			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1505 			decoder->state.from_ip = decoder->ip;
1506 			if (decoder->packet.count == 0) {
1507 				decoder->state.to_ip = 0;
1508 			} else {
1509 				decoder->state.to_ip = decoder->last_ip;
1510 				decoder->ip = decoder->last_ip;
1511 			}
1512 		}
1513 		return 0;
1514 	}
1515 
1516 	if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1517 		uint64_t to_ip = decoder->ip + intel_pt_insn.length +
1518 				 intel_pt_insn.rel;
1519 
1520 		if (decoder->pgd_ip &&
1521 		    decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1522 		    decoder->pgd_ip(to_ip, decoder->data)) {
1523 			/* Conditional branch leaving filter region */
1524 			decoder->pge = false;
1525 			decoder->continuous_period = false;
1526 			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1527 			decoder->ip = to_ip;
1528 			decoder->state.from_ip = decoder->ip;
1529 			decoder->state.to_ip = to_ip;
1530 			decoder->state.type |= INTEL_PT_TRACE_END;
1531 			return 0;
1532 		}
1533 		intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
1534 				decoder->ip);
1535 		decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1536 		return -ENOENT;
1537 	}
1538 
1539 	return intel_pt_bug(decoder);
1540 }
1541 
1542 struct eptw_data {
1543 	int bit_countdown;
1544 	uint64_t payload;
1545 };
1546 
1547 static int intel_pt_eptw_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
1548 {
1549 	struct eptw_data *data = pkt_info->data;
1550 	int nr_bits;
1551 
1552 	switch (pkt_info->packet.type) {
1553 	case INTEL_PT_PAD:
1554 	case INTEL_PT_MNT:
1555 	case INTEL_PT_MODE_EXEC:
1556 	case INTEL_PT_MODE_TSX:
1557 	case INTEL_PT_MTC:
1558 	case INTEL_PT_FUP:
1559 	case INTEL_PT_CYC:
1560 	case INTEL_PT_CBR:
1561 	case INTEL_PT_TSC:
1562 	case INTEL_PT_TMA:
1563 	case INTEL_PT_PIP:
1564 	case INTEL_PT_VMCS:
1565 	case INTEL_PT_PSB:
1566 	case INTEL_PT_PSBEND:
1567 	case INTEL_PT_PTWRITE:
1568 	case INTEL_PT_PTWRITE_IP:
1569 	case INTEL_PT_EXSTOP:
1570 	case INTEL_PT_EXSTOP_IP:
1571 	case INTEL_PT_MWAIT:
1572 	case INTEL_PT_PWRE:
1573 	case INTEL_PT_PWRX:
1574 	case INTEL_PT_BBP:
1575 	case INTEL_PT_BIP:
1576 	case INTEL_PT_BEP:
1577 	case INTEL_PT_BEP_IP:
1578 	case INTEL_PT_CFE:
1579 	case INTEL_PT_CFE_IP:
1580 	case INTEL_PT_EVD:
1581 		break;
1582 
1583 	case INTEL_PT_TNT:
1584 		nr_bits = data->bit_countdown;
1585 		if (nr_bits > pkt_info->packet.count)
1586 			nr_bits = pkt_info->packet.count;
1587 		data->payload <<= nr_bits;
1588 		data->payload |= pkt_info->packet.payload >> (64 - nr_bits);
1589 		data->bit_countdown -= nr_bits;
1590 		return !data->bit_countdown;
1591 
1592 	case INTEL_PT_TIP_PGE:
1593 	case INTEL_PT_TIP_PGD:
1594 	case INTEL_PT_TIP:
1595 	case INTEL_PT_BAD:
1596 	case INTEL_PT_OVF:
1597 	case INTEL_PT_TRACESTOP:
1598 	default:
1599 		return 1;
1600 	}
1601 
1602 	return 0;
1603 }
1604 
1605 static int intel_pt_emulated_ptwrite(struct intel_pt_decoder *decoder)
1606 {
1607 	int n = 64 - decoder->tnt.count;
1608 	struct eptw_data data = {
1609 		.bit_countdown = n,
1610 		.payload = decoder->tnt.payload >> n,
1611 	};
1612 
1613 	decoder->emulated_ptwrite = false;
1614 	intel_pt_log("Emulated ptwrite detected\n");
1615 
1616 	intel_pt_pkt_lookahead(decoder, intel_pt_eptw_lookahead_cb, &data);
1617 	if (data.bit_countdown)
1618 		return -ECONNRESET;
1619 
1620 	decoder->state.type = INTEL_PT_PTW;
1621 	decoder->state.from_ip = decoder->ip;
1622 	decoder->state.to_ip = 0;
1623 	decoder->state.ptw_payload = data.payload;
1624 	return 0;
1625 }
1626 
1627 static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
1628 {
1629 	struct intel_pt_insn intel_pt_insn;
1630 	int err;
1631 
1632 	while (1) {
1633 		if (decoder->emulated_ptwrite)
1634 			return intel_pt_emulated_ptwrite(decoder);
1635 		err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1636 		if (err == INTEL_PT_RETURN) {
1637 			decoder->emulated_ptwrite = intel_pt_insn.emulated_ptwrite;
1638 			return 0;
1639 		}
1640 		if (err) {
1641 			decoder->emulated_ptwrite = false;
1642 			return err;
1643 		}
1644 
1645 		if (intel_pt_insn.op == INTEL_PT_OP_RET) {
1646 			if (!decoder->return_compression) {
1647 				intel_pt_log_at("ERROR: RET when expecting conditional branch",
1648 						decoder->ip);
1649 				decoder->pkt_state = INTEL_PT_STATE_ERR3;
1650 				return -ENOENT;
1651 			}
1652 			if (!decoder->ret_addr) {
1653 				intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
1654 						decoder->ip);
1655 				decoder->pkt_state = INTEL_PT_STATE_ERR3;
1656 				return -ENOENT;
1657 			}
1658 			if (!(decoder->tnt.payload & BIT63)) {
1659 				intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
1660 						decoder->ip);
1661 				decoder->pkt_state = INTEL_PT_STATE_ERR3;
1662 				return -ENOENT;
1663 			}
1664 			decoder->tnt.count -= 1;
1665 			if (decoder->tnt.count)
1666 				decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
1667 			else
1668 				decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1669 			decoder->tnt.payload <<= 1;
1670 			decoder->state.from_ip = decoder->ip;
1671 			decoder->ip = decoder->ret_addr;
1672 			decoder->state.to_ip = decoder->ip;
1673 			return 0;
1674 		}
1675 
1676 		if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1677 			/* Handle deferred TIPs */
1678 			err = intel_pt_get_next_packet(decoder);
1679 			if (err)
1680 				return err;
1681 			if (decoder->packet.type != INTEL_PT_TIP ||
1682 			    decoder->packet.count == 0) {
1683 				intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
1684 						decoder->ip);
1685 				decoder->pkt_state = INTEL_PT_STATE_ERR3;
1686 				decoder->pkt_step = 0;
1687 				return -ENOENT;
1688 			}
1689 			intel_pt_set_last_ip(decoder);
1690 			decoder->state.from_ip = decoder->ip;
1691 			decoder->state.to_ip = decoder->last_ip;
1692 			decoder->ip = decoder->last_ip;
1693 			intel_pt_update_nr(decoder);
1694 			intel_pt_sample_iflag_chg(decoder);
1695 			return 0;
1696 		}
1697 
1698 		if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1699 			decoder->tnt.count -= 1;
1700 			if (decoder->tnt.count)
1701 				decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
1702 			else
1703 				decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1704 			if (decoder->tnt.payload & BIT63) {
1705 				decoder->tnt.payload <<= 1;
1706 				decoder->state.from_ip = decoder->ip;
1707 				decoder->ip += intel_pt_insn.length +
1708 					       intel_pt_insn.rel;
1709 				decoder->state.to_ip = decoder->ip;
1710 				return 0;
1711 			}
1712 			/* Instruction sample for a non-taken branch */
1713 			if (decoder->state.type & INTEL_PT_INSTRUCTION) {
1714 				decoder->tnt.payload <<= 1;
1715 				decoder->state.type = INTEL_PT_INSTRUCTION;
1716 				decoder->state.from_ip = decoder->ip;
1717 				decoder->state.to_ip = 0;
1718 				decoder->ip += intel_pt_insn.length;
1719 				return 0;
1720 			}
1721 			decoder->sample_cyc = false;
1722 			decoder->ip += intel_pt_insn.length;
1723 			if (!decoder->tnt.count) {
1724 				intel_pt_update_sample_time(decoder);
1725 				return -EAGAIN;
1726 			}
1727 			decoder->tnt.payload <<= 1;
1728 			continue;
1729 		}
1730 
1731 		return intel_pt_bug(decoder);
1732 	}
1733 }
1734 
1735 static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
1736 {
1737 	unsigned int fup_tx_flags;
1738 	int err;
1739 
1740 	fup_tx_flags = decoder->packet.payload &
1741 		       (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
1742 	err = intel_pt_get_next_packet(decoder);
1743 	if (err)
1744 		return err;
1745 	if (decoder->packet.type == INTEL_PT_FUP) {
1746 		decoder->fup_tx_flags = fup_tx_flags;
1747 		decoder->set_fup_tx_flags = true;
1748 		if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
1749 			*no_tip = true;
1750 	} else {
1751 		intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
1752 				decoder->pos);
1753 		intel_pt_update_in_tx(decoder);
1754 	}
1755 	return 0;
1756 }
1757 
1758 static int intel_pt_evd(struct intel_pt_decoder *decoder)
1759 {
1760 	if (decoder->evd_cnt >= INTEL_PT_MAX_EVDS) {
1761 		intel_pt_log_at("ERROR: Too many EVD packets", decoder->pos);
1762 		return -ENOSYS;
1763 	}
1764 	decoder->evd[decoder->evd_cnt++] = (struct intel_pt_evd){
1765 		.type = decoder->packet.count,
1766 		.payload = decoder->packet.payload,
1767 	};
1768 	return 0;
1769 }
1770 
1771 static uint64_t intel_pt_8b_tsc(uint64_t timestamp, uint64_t ref_timestamp)
1772 {
1773 	timestamp |= (ref_timestamp & (0xffULL << 56));
1774 
1775 	if (timestamp < ref_timestamp) {
1776 		if (ref_timestamp - timestamp > (1ULL << 55))
1777 			timestamp += (1ULL << 56);
1778 	} else {
1779 		if (timestamp - ref_timestamp > (1ULL << 55))
1780 			timestamp -= (1ULL << 56);
1781 	}
1782 
1783 	return timestamp;
1784 }
1785 
1786 /* For use only when decoder->vm_time_correlation is true */
1787 static bool intel_pt_time_in_range(struct intel_pt_decoder *decoder,
1788 				   uint64_t timestamp)
1789 {
1790 	uint64_t max_timestamp = decoder->buf_timestamp;
1791 
1792 	if (!max_timestamp) {
1793 		max_timestamp = decoder->last_reliable_timestamp +
1794 				0x400000000ULL;
1795 	}
1796 	return timestamp >= decoder->last_reliable_timestamp &&
1797 	       timestamp < decoder->buf_timestamp;
1798 }
1799 
1800 static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
1801 {
1802 	uint64_t timestamp;
1803 	bool bad = false;
1804 
1805 	decoder->have_tma = false;
1806 
1807 	if (decoder->ref_timestamp) {
1808 		timestamp = intel_pt_8b_tsc(decoder->packet.payload,
1809 					    decoder->ref_timestamp);
1810 		decoder->tsc_timestamp = timestamp;
1811 		decoder->timestamp = timestamp;
1812 		decoder->ref_timestamp = 0;
1813 		decoder->timestamp_insn_cnt = 0;
1814 	} else if (decoder->timestamp) {
1815 		timestamp = decoder->packet.payload |
1816 			    (decoder->timestamp & (0xffULL << 56));
1817 		decoder->tsc_timestamp = timestamp;
1818 		if (timestamp < decoder->timestamp &&
1819 		    decoder->timestamp - timestamp < decoder->tsc_slip) {
1820 			intel_pt_log_to("Suppressing backwards timestamp",
1821 					timestamp);
1822 			timestamp = decoder->timestamp;
1823 		}
1824 		if (timestamp < decoder->timestamp) {
1825 			if (!decoder->buf_timestamp ||
1826 			    (timestamp + (1ULL << 56) < decoder->buf_timestamp)) {
1827 				intel_pt_log_to("Wraparound timestamp", timestamp);
1828 				timestamp += (1ULL << 56);
1829 				decoder->tsc_timestamp = timestamp;
1830 			} else {
1831 				intel_pt_log_to("Suppressing bad timestamp", timestamp);
1832 				timestamp = decoder->timestamp;
1833 				bad = true;
1834 			}
1835 		}
1836 		if (decoder->vm_time_correlation &&
1837 		    (bad || !intel_pt_time_in_range(decoder, timestamp)) &&
1838 		    intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
1839 			p_log("Timestamp out of range");
1840 		decoder->timestamp = timestamp;
1841 		decoder->timestamp_insn_cnt = 0;
1842 	}
1843 
1844 	if (decoder->last_packet_type == INTEL_PT_CYC) {
1845 		decoder->cyc_ref_timestamp = decoder->timestamp;
1846 		decoder->cycle_cnt = 0;
1847 		decoder->have_calc_cyc_to_tsc = false;
1848 		intel_pt_calc_cyc_to_tsc(decoder, false);
1849 	}
1850 
1851 	intel_pt_log_to("Setting timestamp", decoder->timestamp);
1852 }
1853 
1854 static int intel_pt_overflow(struct intel_pt_decoder *decoder)
1855 {
1856 	intel_pt_log("ERROR: Buffer overflow\n");
1857 	intel_pt_clear_tx_flags(decoder);
1858 	intel_pt_set_nr(decoder);
1859 	decoder->timestamp_insn_cnt = 0;
1860 	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1861 	decoder->state.from_ip = decoder->ip;
1862 	decoder->ip = 0;
1863 	decoder->pge = false;
1864 	intel_pt_clear_fup_event(decoder);
1865 	decoder->overflow = true;
1866 	return -EOVERFLOW;
1867 }
1868 
1869 static inline void intel_pt_mtc_cyc_cnt_pge(struct intel_pt_decoder *decoder)
1870 {
1871 	if (decoder->have_cyc)
1872 		return;
1873 
1874 	decoder->cyc_cnt_timestamp = decoder->timestamp;
1875 	decoder->base_cyc_cnt = decoder->tot_cyc_cnt;
1876 }
1877 
1878 static inline void intel_pt_mtc_cyc_cnt_cbr(struct intel_pt_decoder *decoder)
1879 {
1880 	decoder->tsc_to_cyc = decoder->cbr / decoder->max_non_turbo_ratio_fp;
1881 
1882 	if (decoder->pge)
1883 		intel_pt_mtc_cyc_cnt_pge(decoder);
1884 }
1885 
1886 static inline void intel_pt_mtc_cyc_cnt_upd(struct intel_pt_decoder *decoder)
1887 {
1888 	uint64_t tot_cyc_cnt, tsc_delta;
1889 
1890 	if (decoder->have_cyc)
1891 		return;
1892 
1893 	decoder->sample_cyc = true;
1894 
1895 	if (!decoder->pge || decoder->timestamp <= decoder->cyc_cnt_timestamp)
1896 		return;
1897 
1898 	tsc_delta = decoder->timestamp - decoder->cyc_cnt_timestamp;
1899 	tot_cyc_cnt = tsc_delta * decoder->tsc_to_cyc + decoder->base_cyc_cnt;
1900 
1901 	if (tot_cyc_cnt > decoder->tot_cyc_cnt)
1902 		decoder->tot_cyc_cnt = tot_cyc_cnt;
1903 }
1904 
1905 static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
1906 {
1907 	uint32_t ctc = decoder->packet.payload;
1908 	uint32_t fc = decoder->packet.count;
1909 	uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;
1910 
1911 	if (!decoder->tsc_ctc_ratio_d)
1912 		return;
1913 
1914 	if (decoder->pge && !decoder->in_psb)
1915 		intel_pt_mtc_cyc_cnt_pge(decoder);
1916 	else
1917 		intel_pt_mtc_cyc_cnt_upd(decoder);
1918 
1919 	decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
1920 	decoder->last_ctc = ctc - ctc_rem;
1921 	decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
1922 	if (decoder->tsc_ctc_mult) {
1923 		decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
1924 	} else {
1925 		decoder->ctc_timestamp -= multdiv(ctc_rem,
1926 						  decoder->tsc_ctc_ratio_n,
1927 						  decoder->tsc_ctc_ratio_d);
1928 	}
1929 	decoder->ctc_delta = 0;
1930 	decoder->have_tma = true;
1931 	decoder->fixup_last_mtc = true;
1932 	intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x  CTC rem %#x\n",
1933 		     decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
1934 }
1935 
1936 static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
1937 {
1938 	uint64_t timestamp;
1939 	uint32_t mtc, mtc_delta;
1940 
1941 	if (!decoder->have_tma)
1942 		return;
1943 
1944 	mtc = decoder->packet.payload;
1945 
1946 	if (decoder->mtc_shift > 8 && decoder->fixup_last_mtc) {
1947 		decoder->fixup_last_mtc = false;
1948 		intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
1949 					&decoder->last_mtc);
1950 	}
1951 
1952 	if (mtc > decoder->last_mtc)
1953 		mtc_delta = mtc - decoder->last_mtc;
1954 	else
1955 		mtc_delta = mtc + 256 - decoder->last_mtc;
1956 
1957 	decoder->ctc_delta += mtc_delta << decoder->mtc_shift;
1958 
1959 	if (decoder->tsc_ctc_mult) {
1960 		timestamp = decoder->ctc_timestamp +
1961 			    decoder->ctc_delta * decoder->tsc_ctc_mult;
1962 	} else {
1963 		timestamp = decoder->ctc_timestamp +
1964 			    multdiv(decoder->ctc_delta,
1965 				    decoder->tsc_ctc_ratio_n,
1966 				    decoder->tsc_ctc_ratio_d);
1967 	}
1968 
1969 	if (timestamp < decoder->timestamp)
1970 		intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1971 			     timestamp, decoder->timestamp);
1972 	else
1973 		decoder->timestamp = timestamp;
1974 
1975 	intel_pt_mtc_cyc_cnt_upd(decoder);
1976 
1977 	decoder->timestamp_insn_cnt = 0;
1978 	decoder->last_mtc = mtc;
1979 
1980 	if (decoder->last_packet_type == INTEL_PT_CYC) {
1981 		decoder->cyc_ref_timestamp = decoder->timestamp;
1982 		decoder->cycle_cnt = 0;
1983 		decoder->have_calc_cyc_to_tsc = false;
1984 		intel_pt_calc_cyc_to_tsc(decoder, true);
1985 	}
1986 
1987 	intel_pt_log_to("Setting timestamp", decoder->timestamp);
1988 }
1989 
1990 static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
1991 {
1992 	unsigned int cbr = decoder->packet.payload & 0xff;
1993 
1994 	decoder->cbr_payload = decoder->packet.payload;
1995 
1996 	if (decoder->cbr == cbr)
1997 		return;
1998 
1999 	decoder->cbr = cbr;
2000 	decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
2001 	decoder->cyc_ref_timestamp = decoder->timestamp;
2002 	decoder->cycle_cnt = 0;
2003 
2004 	intel_pt_mtc_cyc_cnt_cbr(decoder);
2005 }
2006 
2007 static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
2008 {
2009 	uint64_t timestamp = decoder->cyc_ref_timestamp;
2010 
2011 	decoder->have_cyc = true;
2012 
2013 	decoder->cycle_cnt += decoder->packet.payload;
2014 	if (decoder->pge)
2015 		decoder->tot_cyc_cnt += decoder->packet.payload;
2016 	decoder->sample_cyc = true;
2017 
2018 	if (!decoder->cyc_ref_timestamp)
2019 		return;
2020 
2021 	if (decoder->have_calc_cyc_to_tsc)
2022 		timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
2023 	else if (decoder->cbr)
2024 		timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
2025 	else
2026 		return;
2027 
2028 	if (timestamp < decoder->timestamp)
2029 		intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
2030 			     timestamp, decoder->timestamp);
2031 	else
2032 		decoder->timestamp = timestamp;
2033 
2034 	decoder->timestamp_insn_cnt = 0;
2035 
2036 	intel_pt_log_to("Setting timestamp", decoder->timestamp);
2037 }
2038 
2039 static void intel_pt_bbp(struct intel_pt_decoder *decoder)
2040 {
2041 	if (decoder->prev_pkt_ctx == INTEL_PT_NO_CTX) {
2042 		memset(decoder->state.items.mask, 0, sizeof(decoder->state.items.mask));
2043 		decoder->state.items.is_32_bit = false;
2044 	}
2045 	decoder->blk_type = decoder->packet.payload;
2046 	decoder->blk_type_pos = intel_pt_blk_type_pos(decoder->blk_type);
2047 	if (decoder->blk_type == INTEL_PT_GP_REGS)
2048 		decoder->state.items.is_32_bit = decoder->packet.count;
2049 	if (decoder->blk_type_pos < 0) {
2050 		intel_pt_log("WARNING: Unknown block type %u\n",
2051 			     decoder->blk_type);
2052 	} else if (decoder->state.items.mask[decoder->blk_type_pos]) {
2053 		intel_pt_log("WARNING: Duplicate block type %u\n",
2054 			     decoder->blk_type);
2055 	}
2056 }
2057 
2058 static void intel_pt_bip(struct intel_pt_decoder *decoder)
2059 {
2060 	uint32_t id = decoder->packet.count;
2061 	uint32_t bit = 1 << id;
2062 	int pos = decoder->blk_type_pos;
2063 
2064 	if (pos < 0 || id >= INTEL_PT_BLK_ITEM_ID_CNT) {
2065 		intel_pt_log("WARNING: Unknown block item %u type %d\n",
2066 			     id, decoder->blk_type);
2067 		return;
2068 	}
2069 
2070 	if (decoder->state.items.mask[pos] & bit) {
2071 		intel_pt_log("WARNING: Duplicate block item %u type %d\n",
2072 			     id, decoder->blk_type);
2073 	}
2074 
2075 	decoder->state.items.mask[pos] |= bit;
2076 	decoder->state.items.val[pos][id] = decoder->packet.payload;
2077 }
2078 
2079 /* Walk PSB+ packets when already in sync. */
2080 static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
2081 {
2082 	int err;
2083 
2084 	decoder->in_psb = true;
2085 
2086 	while (1) {
2087 		err = intel_pt_get_next_packet(decoder);
2088 		if (err)
2089 			goto out;
2090 
2091 		switch (decoder->packet.type) {
2092 		case INTEL_PT_PSBEND:
2093 			err = 0;
2094 			goto out;
2095 
2096 		case INTEL_PT_TIP_PGD:
2097 		case INTEL_PT_TIP_PGE:
2098 		case INTEL_PT_TIP:
2099 		case INTEL_PT_TNT:
2100 		case INTEL_PT_TRACESTOP:
2101 		case INTEL_PT_BAD:
2102 		case INTEL_PT_PSB:
2103 		case INTEL_PT_PTWRITE:
2104 		case INTEL_PT_PTWRITE_IP:
2105 		case INTEL_PT_EXSTOP:
2106 		case INTEL_PT_EXSTOP_IP:
2107 		case INTEL_PT_MWAIT:
2108 		case INTEL_PT_PWRE:
2109 		case INTEL_PT_PWRX:
2110 		case INTEL_PT_BBP:
2111 		case INTEL_PT_BIP:
2112 		case INTEL_PT_BEP:
2113 		case INTEL_PT_BEP_IP:
2114 		case INTEL_PT_CFE:
2115 		case INTEL_PT_CFE_IP:
2116 		case INTEL_PT_EVD:
2117 			decoder->have_tma = false;
2118 			intel_pt_log("ERROR: Unexpected packet\n");
2119 			err = -EAGAIN;
2120 			goto out;
2121 
2122 		case INTEL_PT_OVF:
2123 			err = intel_pt_overflow(decoder);
2124 			goto out;
2125 
2126 		case INTEL_PT_TSC:
2127 			intel_pt_calc_tsc_timestamp(decoder);
2128 			break;
2129 
2130 		case INTEL_PT_TMA:
2131 			intel_pt_calc_tma(decoder);
2132 			break;
2133 
2134 		case INTEL_PT_CBR:
2135 			intel_pt_calc_cbr(decoder);
2136 			break;
2137 
2138 		case INTEL_PT_MODE_EXEC:
2139 			intel_pt_mode_exec_status(decoder);
2140 			break;
2141 
2142 		case INTEL_PT_PIP:
2143 			intel_pt_set_pip(decoder);
2144 			break;
2145 
2146 		case INTEL_PT_FUP:
2147 			decoder->pge = true;
2148 			if (decoder->packet.count) {
2149 				intel_pt_set_last_ip(decoder);
2150 				decoder->psb_ip = decoder->last_ip;
2151 			}
2152 			break;
2153 
2154 		case INTEL_PT_MODE_TSX:
2155 			intel_pt_update_in_tx(decoder);
2156 			break;
2157 
2158 		case INTEL_PT_MTC:
2159 			intel_pt_calc_mtc_timestamp(decoder);
2160 			if (decoder->period_type == INTEL_PT_PERIOD_MTC)
2161 				decoder->state.type |= INTEL_PT_INSTRUCTION;
2162 			break;
2163 
2164 		case INTEL_PT_CYC:
2165 			intel_pt_calc_cyc_timestamp(decoder);
2166 			break;
2167 
2168 		case INTEL_PT_VMCS:
2169 		case INTEL_PT_MNT:
2170 		case INTEL_PT_PAD:
2171 		default:
2172 			break;
2173 		}
2174 	}
2175 out:
2176 	decoder->in_psb = false;
2177 
2178 	return err;
2179 }
2180 
2181 static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
2182 {
2183 	int err;
2184 
2185 	if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
2186 		decoder->tx_flags = 0;
2187 		decoder->state.flags &= ~INTEL_PT_IN_TX;
2188 		decoder->state.flags |= INTEL_PT_ABORT_TX;
2189 	} else {
2190 		decoder->state.flags |= INTEL_PT_ASYNC;
2191 	}
2192 
2193 	while (1) {
2194 		err = intel_pt_get_next_packet(decoder);
2195 		if (err)
2196 			return err;
2197 
2198 		switch (decoder->packet.type) {
2199 		case INTEL_PT_TNT:
2200 		case INTEL_PT_FUP:
2201 		case INTEL_PT_TRACESTOP:
2202 		case INTEL_PT_PSB:
2203 		case INTEL_PT_TSC:
2204 		case INTEL_PT_TMA:
2205 		case INTEL_PT_MODE_TSX:
2206 		case INTEL_PT_BAD:
2207 		case INTEL_PT_PSBEND:
2208 		case INTEL_PT_PTWRITE:
2209 		case INTEL_PT_PTWRITE_IP:
2210 		case INTEL_PT_EXSTOP:
2211 		case INTEL_PT_EXSTOP_IP:
2212 		case INTEL_PT_MWAIT:
2213 		case INTEL_PT_PWRE:
2214 		case INTEL_PT_PWRX:
2215 		case INTEL_PT_BBP:
2216 		case INTEL_PT_BIP:
2217 		case INTEL_PT_BEP:
2218 		case INTEL_PT_BEP_IP:
2219 		case INTEL_PT_CFE:
2220 		case INTEL_PT_CFE_IP:
2221 		case INTEL_PT_EVD:
2222 			intel_pt_log("ERROR: Missing TIP after FUP\n");
2223 			decoder->pkt_state = INTEL_PT_STATE_ERR3;
2224 			decoder->pkt_step = 0;
2225 			return -ENOENT;
2226 
2227 		case INTEL_PT_CBR:
2228 			intel_pt_calc_cbr(decoder);
2229 			break;
2230 
2231 		case INTEL_PT_OVF:
2232 			return intel_pt_overflow(decoder);
2233 
2234 		case INTEL_PT_TIP_PGD:
2235 			decoder->state.from_ip = decoder->ip;
2236 			if (decoder->packet.count == 0) {
2237 				decoder->state.to_ip = 0;
2238 			} else {
2239 				intel_pt_set_ip(decoder);
2240 				decoder->state.to_ip = decoder->ip;
2241 			}
2242 			decoder->pge = false;
2243 			decoder->continuous_period = false;
2244 			decoder->state.type |= INTEL_PT_TRACE_END;
2245 			intel_pt_update_nr(decoder);
2246 			return 0;
2247 
2248 		case INTEL_PT_TIP_PGE:
2249 			decoder->pge = true;
2250 			intel_pt_log("Omitting PGE ip " x64_fmt "\n",
2251 				     decoder->ip);
2252 			decoder->state.from_ip = 0;
2253 			if (decoder->packet.count == 0) {
2254 				decoder->state.to_ip = 0;
2255 			} else {
2256 				intel_pt_set_ip(decoder);
2257 				decoder->state.to_ip = decoder->ip;
2258 			}
2259 			decoder->state.type |= INTEL_PT_TRACE_BEGIN;
2260 			intel_pt_mtc_cyc_cnt_pge(decoder);
2261 			intel_pt_set_nr(decoder);
2262 			return 0;
2263 
2264 		case INTEL_PT_TIP:
2265 			decoder->state.from_ip = decoder->ip;
2266 			if (decoder->packet.count == 0) {
2267 				decoder->state.to_ip = 0;
2268 			} else {
2269 				intel_pt_set_ip(decoder);
2270 				decoder->state.to_ip = decoder->ip;
2271 			}
2272 			intel_pt_update_nr(decoder);
2273 			intel_pt_sample_iflag_chg(decoder);
2274 			return 0;
2275 
2276 		case INTEL_PT_PIP:
2277 			intel_pt_update_pip(decoder);
2278 			break;
2279 
2280 		case INTEL_PT_MTC:
2281 			intel_pt_calc_mtc_timestamp(decoder);
2282 			if (decoder->period_type == INTEL_PT_PERIOD_MTC)
2283 				decoder->state.type |= INTEL_PT_INSTRUCTION;
2284 			break;
2285 
2286 		case INTEL_PT_CYC:
2287 			intel_pt_calc_cyc_timestamp(decoder);
2288 			break;
2289 
2290 		case INTEL_PT_MODE_EXEC:
2291 			intel_pt_mode_exec(decoder);
2292 			break;
2293 
2294 		case INTEL_PT_VMCS:
2295 		case INTEL_PT_MNT:
2296 		case INTEL_PT_PAD:
2297 			break;
2298 
2299 		default:
2300 			return intel_pt_bug(decoder);
2301 		}
2302 	}
2303 }
2304 
2305 static int intel_pt_resample(struct intel_pt_decoder *decoder)
2306 {
2307 	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2308 	decoder->state.type = INTEL_PT_INSTRUCTION;
2309 	decoder->state.from_ip = decoder->ip;
2310 	decoder->state.to_ip = 0;
2311 	return 0;
2312 }
2313 
2314 struct intel_pt_vm_tsc_info {
2315 	struct intel_pt_pkt pip_packet;
2316 	struct intel_pt_pkt vmcs_packet;
2317 	struct intel_pt_pkt tma_packet;
2318 	bool tsc, pip, vmcs, tma, psbend;
2319 	uint64_t ctc_delta;
2320 	uint64_t last_ctc;
2321 	int max_lookahead;
2322 };
2323 
2324 /* Lookahead and get the PIP, VMCS and TMA packets from PSB+ */
2325 static int intel_pt_vm_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2326 {
2327 	struct intel_pt_vm_tsc_info *data = pkt_info->data;
2328 
2329 	switch (pkt_info->packet.type) {
2330 	case INTEL_PT_PAD:
2331 	case INTEL_PT_MNT:
2332 	case INTEL_PT_MODE_EXEC:
2333 	case INTEL_PT_MODE_TSX:
2334 	case INTEL_PT_MTC:
2335 	case INTEL_PT_FUP:
2336 	case INTEL_PT_CYC:
2337 	case INTEL_PT_CBR:
2338 		break;
2339 
2340 	case INTEL_PT_TSC:
2341 		data->tsc = true;
2342 		break;
2343 
2344 	case INTEL_PT_TMA:
2345 		data->tma_packet = pkt_info->packet;
2346 		data->tma = true;
2347 		break;
2348 
2349 	case INTEL_PT_PIP:
2350 		data->pip_packet = pkt_info->packet;
2351 		data->pip = true;
2352 		break;
2353 
2354 	case INTEL_PT_VMCS:
2355 		data->vmcs_packet = pkt_info->packet;
2356 		data->vmcs = true;
2357 		break;
2358 
2359 	case INTEL_PT_PSBEND:
2360 		data->psbend = true;
2361 		return 1;
2362 
2363 	case INTEL_PT_TIP_PGE:
2364 	case INTEL_PT_PTWRITE:
2365 	case INTEL_PT_PTWRITE_IP:
2366 	case INTEL_PT_EXSTOP:
2367 	case INTEL_PT_EXSTOP_IP:
2368 	case INTEL_PT_MWAIT:
2369 	case INTEL_PT_PWRE:
2370 	case INTEL_PT_PWRX:
2371 	case INTEL_PT_BBP:
2372 	case INTEL_PT_BIP:
2373 	case INTEL_PT_BEP:
2374 	case INTEL_PT_BEP_IP:
2375 	case INTEL_PT_OVF:
2376 	case INTEL_PT_BAD:
2377 	case INTEL_PT_TNT:
2378 	case INTEL_PT_TIP_PGD:
2379 	case INTEL_PT_TIP:
2380 	case INTEL_PT_PSB:
2381 	case INTEL_PT_TRACESTOP:
2382 	case INTEL_PT_CFE:
2383 	case INTEL_PT_CFE_IP:
2384 	case INTEL_PT_EVD:
2385 	default:
2386 		return 1;
2387 	}
2388 
2389 	return 0;
2390 }
2391 
2392 struct intel_pt_ovf_fup_info {
2393 	int max_lookahead;
2394 	bool found;
2395 };
2396 
2397 /* Lookahead to detect a FUP packet after OVF */
2398 static int intel_pt_ovf_fup_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2399 {
2400 	struct intel_pt_ovf_fup_info *data = pkt_info->data;
2401 
2402 	if (pkt_info->packet.type == INTEL_PT_CYC ||
2403 	    pkt_info->packet.type == INTEL_PT_MTC ||
2404 	    pkt_info->packet.type == INTEL_PT_TSC)
2405 		return !--(data->max_lookahead);
2406 	data->found = pkt_info->packet.type == INTEL_PT_FUP;
2407 	return 1;
2408 }
2409 
2410 static bool intel_pt_ovf_fup_lookahead(struct intel_pt_decoder *decoder)
2411 {
2412 	struct intel_pt_ovf_fup_info data = {
2413 		.max_lookahead = 16,
2414 		.found = false,
2415 	};
2416 
2417 	intel_pt_pkt_lookahead(decoder, intel_pt_ovf_fup_lookahead_cb, &data);
2418 	return data.found;
2419 }
2420 
2421 /* Lookahead and get the TMA packet after TSC */
2422 static int intel_pt_tma_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2423 {
2424 	struct intel_pt_vm_tsc_info *data = pkt_info->data;
2425 
2426 	if (pkt_info->packet.type == INTEL_PT_CYC ||
2427 	    pkt_info->packet.type == INTEL_PT_MTC)
2428 		return !--(data->max_lookahead);
2429 
2430 	if (pkt_info->packet.type == INTEL_PT_TMA) {
2431 		data->tma_packet = pkt_info->packet;
2432 		data->tma = true;
2433 	}
2434 	return 1;
2435 }
2436 
2437 static uint64_t intel_pt_ctc_to_tsc(struct intel_pt_decoder *decoder, uint64_t ctc)
2438 {
2439 	if (decoder->tsc_ctc_mult)
2440 		return ctc * decoder->tsc_ctc_mult;
2441 	else
2442 		return multdiv(ctc, decoder->tsc_ctc_ratio_n, decoder->tsc_ctc_ratio_d);
2443 }
2444 
2445 static uint64_t intel_pt_calc_expected_tsc(struct intel_pt_decoder *decoder,
2446 					   uint32_t ctc,
2447 					   uint32_t fc,
2448 					   uint64_t last_ctc_timestamp,
2449 					   uint64_t ctc_delta,
2450 					   uint32_t last_ctc)
2451 {
2452 	/* Number of CTC ticks from last_ctc_timestamp to last_mtc */
2453 	uint64_t last_mtc_ctc = last_ctc + ctc_delta;
2454 	/*
2455 	 * Number of CTC ticks from there until current TMA packet. We would
2456 	 * expect last_mtc_ctc to be before ctc, but the TSC packet can slip
2457 	 * past an MTC, so a sign-extended value is used.
2458 	 */
2459 	uint64_t delta = (int16_t)((uint16_t)ctc - (uint16_t)last_mtc_ctc);
2460 	/* Total CTC ticks from last_ctc_timestamp to current TMA packet */
2461 	uint64_t new_ctc_delta = ctc_delta + delta;
2462 	uint64_t expected_tsc;
2463 
2464 	/*
2465 	 * Convert CTC ticks to TSC ticks, add the starting point
2466 	 * (last_ctc_timestamp) and the fast counter from the TMA packet.
2467 	 */
2468 	expected_tsc = last_ctc_timestamp + intel_pt_ctc_to_tsc(decoder, new_ctc_delta) + fc;
2469 
2470 	if (intel_pt_enable_logging) {
2471 		intel_pt_log_x64(last_mtc_ctc);
2472 		intel_pt_log_x32(last_ctc);
2473 		intel_pt_log_x64(ctc_delta);
2474 		intel_pt_log_x64(delta);
2475 		intel_pt_log_x32(ctc);
2476 		intel_pt_log_x64(new_ctc_delta);
2477 		intel_pt_log_x64(last_ctc_timestamp);
2478 		intel_pt_log_x32(fc);
2479 		intel_pt_log_x64(intel_pt_ctc_to_tsc(decoder, new_ctc_delta));
2480 		intel_pt_log_x64(expected_tsc);
2481 	}
2482 
2483 	return expected_tsc;
2484 }
2485 
2486 static uint64_t intel_pt_expected_tsc(struct intel_pt_decoder *decoder,
2487 				      struct intel_pt_vm_tsc_info *data)
2488 {
2489 	uint32_t ctc = data->tma_packet.payload;
2490 	uint32_t fc = data->tma_packet.count;
2491 
2492 	return intel_pt_calc_expected_tsc(decoder, ctc, fc,
2493 					  decoder->ctc_timestamp,
2494 					  data->ctc_delta, data->last_ctc);
2495 }
2496 
2497 static void intel_pt_translate_vm_tsc(struct intel_pt_decoder *decoder,
2498 				      struct intel_pt_vmcs_info *vmcs_info)
2499 {
2500 	uint64_t payload = decoder->packet.payload;
2501 
2502 	/* VMX adds the TSC Offset, so subtract to get host TSC */
2503 	decoder->packet.payload -= vmcs_info->tsc_offset;
2504 	/* TSC packet has only 7 bytes */
2505 	decoder->packet.payload &= SEVEN_BYTES;
2506 
2507 	/*
2508 	 * The buffer is mmapped from the data file, so this also updates the
2509 	 * data file.
2510 	 */
2511 	if (!decoder->vm_tm_corr_dry_run)
2512 		memcpy((void *)decoder->buf + 1, &decoder->packet.payload, 7);
2513 
2514 	intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
2515 		     "    VMCS %#" PRIx64 "    TSC Offset %#" PRIx64 "\n",
2516 		     payload, decoder->packet.payload, vmcs_info->vmcs,
2517 		     vmcs_info->tsc_offset);
2518 }
2519 
2520 static void intel_pt_translate_vm_tsc_offset(struct intel_pt_decoder *decoder,
2521 					     uint64_t tsc_offset)
2522 {
2523 	struct intel_pt_vmcs_info vmcs_info = {
2524 		.vmcs = NO_VMCS,
2525 		.tsc_offset = tsc_offset
2526 	};
2527 
2528 	intel_pt_translate_vm_tsc(decoder, &vmcs_info);
2529 }
2530 
2531 static inline bool in_vm(uint64_t pip_payload)
2532 {
2533 	return pip_payload & 1;
2534 }
2535 
2536 static inline bool pip_in_vm(struct intel_pt_pkt *pip_packet)
2537 {
2538 	return pip_packet->payload & 1;
2539 }
2540 
2541 static void intel_pt_print_vmcs_info(struct intel_pt_vmcs_info *vmcs_info)
2542 {
2543 	p_log("VMCS: %#" PRIx64 "  TSC Offset %#" PRIx64,
2544 	      vmcs_info->vmcs, vmcs_info->tsc_offset);
2545 }
2546 
2547 static void intel_pt_vm_tm_corr_psb(struct intel_pt_decoder *decoder,
2548 				    struct intel_pt_vm_tsc_info *data)
2549 {
2550 	memset(data, 0, sizeof(*data));
2551 	data->ctc_delta = decoder->ctc_delta;
2552 	data->last_ctc = decoder->last_ctc;
2553 	intel_pt_pkt_lookahead(decoder, intel_pt_vm_psb_lookahead_cb, data);
2554 	if (data->tsc && !data->psbend)
2555 		p_log("ERROR: PSB without PSBEND");
2556 	decoder->in_psb = data->psbend;
2557 }
2558 
2559 static void intel_pt_vm_tm_corr_first_tsc(struct intel_pt_decoder *decoder,
2560 					  struct intel_pt_vm_tsc_info *data,
2561 					  struct intel_pt_vmcs_info *vmcs_info,
2562 					  uint64_t host_tsc)
2563 {
2564 	if (!decoder->in_psb) {
2565 		/* Can't happen */
2566 		p_log("ERROR: First TSC is not in PSB+");
2567 	}
2568 
2569 	if (data->pip) {
2570 		if (pip_in_vm(&data->pip_packet)) { /* Guest */
2571 			if (vmcs_info && vmcs_info->tsc_offset) {
2572 				intel_pt_translate_vm_tsc(decoder, vmcs_info);
2573 				decoder->vm_tm_corr_reliable = true;
2574 			} else {
2575 				p_log("ERROR: First TSC, unknown TSC Offset");
2576 			}
2577 		} else { /* Host */
2578 			decoder->vm_tm_corr_reliable = true;
2579 		}
2580 	} else { /* Host or Guest */
2581 		decoder->vm_tm_corr_reliable = false;
2582 		if (intel_pt_time_in_range(decoder, host_tsc)) {
2583 			/* Assume Host */
2584 		} else {
2585 			/* Assume Guest */
2586 			if (vmcs_info && vmcs_info->tsc_offset)
2587 				intel_pt_translate_vm_tsc(decoder, vmcs_info);
2588 			else
2589 				p_log("ERROR: First TSC, no PIP, unknown TSC Offset");
2590 		}
2591 	}
2592 }
2593 
2594 static void intel_pt_vm_tm_corr_tsc(struct intel_pt_decoder *decoder,
2595 				    struct intel_pt_vm_tsc_info *data)
2596 {
2597 	struct intel_pt_vmcs_info *vmcs_info;
2598 	uint64_t tsc_offset = 0;
2599 	uint64_t vmcs;
2600 	bool reliable = true;
2601 	uint64_t expected_tsc;
2602 	uint64_t host_tsc;
2603 	uint64_t ref_timestamp;
2604 
2605 	bool assign = false;
2606 	bool assign_reliable = false;
2607 
2608 	/* Already have 'data' for the in_psb case */
2609 	if (!decoder->in_psb) {
2610 		memset(data, 0, sizeof(*data));
2611 		data->ctc_delta = decoder->ctc_delta;
2612 		data->last_ctc = decoder->last_ctc;
2613 		data->max_lookahead = 16;
2614 		intel_pt_pkt_lookahead(decoder, intel_pt_tma_lookahead_cb, data);
2615 		if (decoder->pge) {
2616 			data->pip = true;
2617 			data->pip_packet.payload = decoder->pip_payload;
2618 		}
2619 	}
2620 
2621 	/* Calculations depend on having TMA packets */
2622 	if (!data->tma) {
2623 		p_log("ERROR: TSC without TMA");
2624 		return;
2625 	}
2626 
2627 	vmcs = data->vmcs ? data->vmcs_packet.payload : decoder->vmcs;
2628 	if (vmcs == NO_VMCS)
2629 		vmcs = 0;
2630 
2631 	vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);
2632 
2633 	ref_timestamp = decoder->timestamp ? decoder->timestamp : decoder->buf_timestamp;
2634 	host_tsc = intel_pt_8b_tsc(decoder->packet.payload, ref_timestamp);
2635 
2636 	if (!decoder->ctc_timestamp) {
2637 		intel_pt_vm_tm_corr_first_tsc(decoder, data, vmcs_info, host_tsc);
2638 		return;
2639 	}
2640 
2641 	expected_tsc = intel_pt_expected_tsc(decoder, data);
2642 
2643 	tsc_offset = host_tsc - expected_tsc;
2644 
2645 	/* Determine if TSC is from Host or Guest */
2646 	if (data->pip) {
2647 		if (pip_in_vm(&data->pip_packet)) { /* Guest */
2648 			if (!vmcs_info) {
2649 				/* PIP NR=1 without VMCS cannot happen */
2650 				p_log("ERROR: Missing VMCS");
2651 				intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
2652 				decoder->vm_tm_corr_reliable = false;
2653 				return;
2654 			}
2655 		} else { /* Host */
2656 			decoder->last_reliable_timestamp = host_tsc;
2657 			decoder->vm_tm_corr_reliable = true;
2658 			return;
2659 		}
2660 	} else { /* Host or Guest */
2661 		reliable = false; /* Host/Guest is a guess, so not reliable */
2662 		if (decoder->in_psb) {
2663 			if (!tsc_offset)
2664 				return; /* Zero TSC Offset, assume Host */
2665 			/*
2666 			 * TSC packet has only 7 bytes of TSC. We have no
2667 			 * information about the Guest's 8th byte, but it
2668 			 * doesn't matter because we only need 7 bytes.
2669 			 * Here, since the 8th byte is unreliable and
2670 			 * irrelevant, compare only 7 byes.
2671 			 */
2672 			if (vmcs_info &&
2673 			    (tsc_offset & SEVEN_BYTES) ==
2674 			    (vmcs_info->tsc_offset & SEVEN_BYTES)) {
2675 				/* Same TSC Offset as last VMCS, assume Guest */
2676 				goto guest;
2677 			}
2678 		}
2679 		/*
2680 		 * Check if the host_tsc is within the expected range.
2681 		 * Note, we could narrow the range more by looking ahead for
2682 		 * the next host TSC in the same buffer, but we don't bother to
2683 		 * do that because this is probably good enough.
2684 		 */
2685 		if (host_tsc >= expected_tsc && intel_pt_time_in_range(decoder, host_tsc)) {
2686 			/* Within expected range for Host TSC, assume Host */
2687 			decoder->vm_tm_corr_reliable = false;
2688 			return;
2689 		}
2690 	}
2691 
2692 guest: /* Assuming Guest */
2693 
2694 	/* Determine whether to assign TSC Offset */
2695 	if (vmcs_info && vmcs_info->vmcs) {
2696 		if (vmcs_info->tsc_offset && vmcs_info->reliable) {
2697 			assign = false;
2698 		} else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_reliable &&
2699 			   decoder->vm_tm_corr_continuous && decoder->vm_tm_corr_same_buf) {
2700 			/* Continuous tracing, TSC in a PSB is not a time loss */
2701 			assign = true;
2702 			assign_reliable = true;
2703 		} else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_same_buf) {
2704 			/*
2705 			 * Unlikely to be a time loss TSC in a PSB which is not
2706 			 * at the start of a buffer.
2707 			 */
2708 			assign = true;
2709 			assign_reliable = false;
2710 		}
2711 	}
2712 
2713 	/* Record VMCS TSC Offset */
2714 	if (assign && (vmcs_info->tsc_offset != tsc_offset ||
2715 		       vmcs_info->reliable != assign_reliable)) {
2716 		bool print = vmcs_info->tsc_offset != tsc_offset;
2717 
2718 		vmcs_info->tsc_offset = tsc_offset;
2719 		vmcs_info->reliable = assign_reliable;
2720 		if (print)
2721 			intel_pt_print_vmcs_info(vmcs_info);
2722 	}
2723 
2724 	/* Determine what TSC Offset to use */
2725 	if (vmcs_info && vmcs_info->tsc_offset) {
2726 		if (!vmcs_info->reliable)
2727 			reliable = false;
2728 		intel_pt_translate_vm_tsc(decoder, vmcs_info);
2729 	} else {
2730 		reliable = false;
2731 		if (vmcs_info) {
2732 			if (!vmcs_info->error_printed) {
2733 				p_log("ERROR: Unknown TSC Offset for VMCS %#" PRIx64,
2734 				      vmcs_info->vmcs);
2735 				vmcs_info->error_printed = true;
2736 			}
2737 		} else {
2738 			if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
2739 				p_log("ERROR: Unknown VMCS");
2740 		}
2741 		intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
2742 	}
2743 
2744 	decoder->vm_tm_corr_reliable = reliable;
2745 }
2746 
2747 static void intel_pt_vm_tm_corr_pebs_tsc(struct intel_pt_decoder *decoder)
2748 {
2749 	uint64_t host_tsc = decoder->packet.payload;
2750 	uint64_t guest_tsc = decoder->packet.payload;
2751 	struct intel_pt_vmcs_info *vmcs_info;
2752 	uint64_t vmcs;
2753 
2754 	vmcs = decoder->vmcs;
2755 	if (vmcs == NO_VMCS)
2756 		vmcs = 0;
2757 
2758 	vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);
2759 
2760 	if (decoder->pge) {
2761 		if (in_vm(decoder->pip_payload)) { /* Guest */
2762 			if (!vmcs_info) {
2763 				/* PIP NR=1 without VMCS cannot happen */
2764 				p_log("ERROR: Missing VMCS");
2765 			}
2766 		} else { /* Host */
2767 			return;
2768 		}
2769 	} else { /* Host or Guest */
2770 		if (intel_pt_time_in_range(decoder, host_tsc)) {
2771 			/* Within expected range for Host TSC, assume Host */
2772 			return;
2773 		}
2774 	}
2775 
2776 	if (vmcs_info) {
2777 		/* Translate Guest TSC to Host TSC */
2778 		host_tsc = ((guest_tsc & SEVEN_BYTES) - vmcs_info->tsc_offset) & SEVEN_BYTES;
2779 		host_tsc = intel_pt_8b_tsc(host_tsc, decoder->timestamp);
2780 		intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
2781 			     "    VMCS %#" PRIx64 "    TSC Offset %#" PRIx64 "\n",
2782 			     guest_tsc, host_tsc, vmcs_info->vmcs,
2783 			     vmcs_info->tsc_offset);
2784 		if (!intel_pt_time_in_range(decoder, host_tsc) &&
2785 		    intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
2786 			p_log("Timestamp out of range");
2787 	} else {
2788 		if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
2789 			p_log("ERROR: Unknown VMCS");
2790 		host_tsc = decoder->timestamp;
2791 	}
2792 
2793 	decoder->packet.payload = host_tsc;
2794 
2795 	if (!decoder->vm_tm_corr_dry_run)
2796 		memcpy((void *)decoder->buf + 1, &host_tsc, 8);
2797 }
2798 
2799 static int intel_pt_vm_time_correlation(struct intel_pt_decoder *decoder)
2800 {
2801 	struct intel_pt_vm_tsc_info data = { .psbend = false };
2802 	bool pge;
2803 	int err;
2804 
2805 	if (decoder->in_psb)
2806 		intel_pt_vm_tm_corr_psb(decoder, &data);
2807 
2808 	while (1) {
2809 		err = intel_pt_get_next_packet(decoder);
2810 		if (err == -ENOLINK)
2811 			continue;
2812 		if (err)
2813 			break;
2814 
2815 		switch (decoder->packet.type) {
2816 		case INTEL_PT_TIP_PGD:
2817 			decoder->pge = false;
2818 			decoder->vm_tm_corr_continuous = false;
2819 			break;
2820 
2821 		case INTEL_PT_TNT:
2822 		case INTEL_PT_TIP:
2823 		case INTEL_PT_TIP_PGE:
2824 			decoder->pge = true;
2825 			break;
2826 
2827 		case INTEL_PT_OVF:
2828 			decoder->in_psb = false;
2829 			pge = decoder->pge;
2830 			decoder->pge = intel_pt_ovf_fup_lookahead(decoder);
2831 			if (pge != decoder->pge)
2832 				intel_pt_log("Surprising PGE change in OVF!");
2833 			if (!decoder->pge)
2834 				decoder->vm_tm_corr_continuous = false;
2835 			break;
2836 
2837 		case INTEL_PT_FUP:
2838 			if (decoder->in_psb)
2839 				decoder->pge = true;
2840 			break;
2841 
2842 		case INTEL_PT_TRACESTOP:
2843 			decoder->pge = false;
2844 			decoder->vm_tm_corr_continuous = false;
2845 			decoder->have_tma = false;
2846 			break;
2847 
2848 		case INTEL_PT_PSB:
2849 			intel_pt_vm_tm_corr_psb(decoder, &data);
2850 			break;
2851 
2852 		case INTEL_PT_PIP:
2853 			decoder->pip_payload = decoder->packet.payload;
2854 			break;
2855 
2856 		case INTEL_PT_MTC:
2857 			intel_pt_calc_mtc_timestamp(decoder);
2858 			break;
2859 
2860 		case INTEL_PT_TSC:
2861 			intel_pt_vm_tm_corr_tsc(decoder, &data);
2862 			intel_pt_calc_tsc_timestamp(decoder);
2863 			decoder->vm_tm_corr_same_buf = true;
2864 			decoder->vm_tm_corr_continuous = decoder->pge;
2865 			break;
2866 
2867 		case INTEL_PT_TMA:
2868 			intel_pt_calc_tma(decoder);
2869 			break;
2870 
2871 		case INTEL_PT_CYC:
2872 			intel_pt_calc_cyc_timestamp(decoder);
2873 			break;
2874 
2875 		case INTEL_PT_CBR:
2876 			intel_pt_calc_cbr(decoder);
2877 			break;
2878 
2879 		case INTEL_PT_PSBEND:
2880 			decoder->in_psb = false;
2881 			data.psbend = false;
2882 			break;
2883 
2884 		case INTEL_PT_VMCS:
2885 			if (decoder->packet.payload != NO_VMCS)
2886 				decoder->vmcs = decoder->packet.payload;
2887 			break;
2888 
2889 		case INTEL_PT_BBP:
2890 			decoder->blk_type = decoder->packet.payload;
2891 			break;
2892 
2893 		case INTEL_PT_BIP:
2894 			if (decoder->blk_type == INTEL_PT_PEBS_BASIC &&
2895 			    decoder->packet.count == 2)
2896 				intel_pt_vm_tm_corr_pebs_tsc(decoder);
2897 			break;
2898 
2899 		case INTEL_PT_BEP:
2900 		case INTEL_PT_BEP_IP:
2901 			decoder->blk_type = 0;
2902 			break;
2903 
2904 		case INTEL_PT_CFE:
2905 		case INTEL_PT_CFE_IP:
2906 		case INTEL_PT_EVD:
2907 		case INTEL_PT_MODE_EXEC:
2908 		case INTEL_PT_MODE_TSX:
2909 		case INTEL_PT_MNT:
2910 		case INTEL_PT_PAD:
2911 		case INTEL_PT_PTWRITE_IP:
2912 		case INTEL_PT_PTWRITE:
2913 		case INTEL_PT_MWAIT:
2914 		case INTEL_PT_PWRE:
2915 		case INTEL_PT_EXSTOP_IP:
2916 		case INTEL_PT_EXSTOP:
2917 		case INTEL_PT_PWRX:
2918 		case INTEL_PT_BAD: /* Does not happen */
2919 		default:
2920 			break;
2921 		}
2922 	}
2923 
2924 	return err;
2925 }
2926 
2927 #define HOP_PROCESS	0
2928 #define HOP_IGNORE	1
2929 #define HOP_RETURN	2
2930 #define HOP_AGAIN	3
2931 
2932 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder);
2933 
2934 /* Hop mode: Ignore TNT, do not walk code, but get ip from FUPs and TIPs */
2935 static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, int *err)
2936 {
2937 	*err = 0;
2938 
2939 	/* Leap from PSB to PSB, getting ip from FUP within PSB+ */
2940 	if (decoder->leap && !decoder->in_psb && decoder->packet.type != INTEL_PT_PSB) {
2941 		*err = intel_pt_scan_for_psb(decoder);
2942 		if (*err)
2943 			return HOP_RETURN;
2944 	}
2945 
2946 	switch (decoder->packet.type) {
2947 	case INTEL_PT_TNT:
2948 		return HOP_IGNORE;
2949 
2950 	case INTEL_PT_TIP_PGD:
2951 		decoder->pge = false;
2952 		if (!decoder->packet.count) {
2953 			intel_pt_set_nr(decoder);
2954 			return HOP_IGNORE;
2955 		}
2956 		intel_pt_set_ip(decoder);
2957 		decoder->state.type |= INTEL_PT_TRACE_END;
2958 		decoder->state.from_ip = 0;
2959 		decoder->state.to_ip = decoder->ip;
2960 		intel_pt_update_nr(decoder);
2961 		return HOP_RETURN;
2962 
2963 	case INTEL_PT_TIP:
2964 		if (!decoder->packet.count) {
2965 			intel_pt_set_nr(decoder);
2966 			return HOP_IGNORE;
2967 		}
2968 		intel_pt_set_ip(decoder);
2969 		decoder->state.type = INTEL_PT_INSTRUCTION;
2970 		decoder->state.from_ip = decoder->ip;
2971 		decoder->state.to_ip = 0;
2972 		intel_pt_update_nr(decoder);
2973 		intel_pt_sample_iflag_chg(decoder);
2974 		return HOP_RETURN;
2975 
2976 	case INTEL_PT_FUP:
2977 		if (!decoder->packet.count)
2978 			return HOP_IGNORE;
2979 		intel_pt_set_ip(decoder);
2980 		if (decoder->set_fup_mwait || decoder->set_fup_pwre)
2981 			*no_tip = true;
2982 		if (!decoder->branch_enable || !decoder->pge)
2983 			*no_tip = true;
2984 		if (*no_tip) {
2985 			decoder->state.type = INTEL_PT_INSTRUCTION;
2986 			decoder->state.from_ip = decoder->ip;
2987 			decoder->state.to_ip = 0;
2988 			intel_pt_fup_event(decoder, *no_tip);
2989 			return HOP_RETURN;
2990 		}
2991 		intel_pt_fup_event(decoder, *no_tip);
2992 		decoder->state.type |= INTEL_PT_INSTRUCTION | INTEL_PT_BRANCH;
2993 		*err = intel_pt_walk_fup_tip(decoder);
2994 		if (!*err && decoder->state.to_ip)
2995 			decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
2996 		return HOP_RETURN;
2997 
2998 	case INTEL_PT_PSB:
2999 		decoder->state.psb_offset = decoder->pos;
3000 		decoder->psb_ip = 0;
3001 		decoder->last_ip = 0;
3002 		decoder->have_last_ip = true;
3003 		*err = intel_pt_walk_psbend(decoder);
3004 		if (*err == -EAGAIN)
3005 			return HOP_AGAIN;
3006 		if (*err)
3007 			return HOP_RETURN;
3008 		decoder->state.type = INTEL_PT_PSB_EVT;
3009 		if (decoder->psb_ip) {
3010 			decoder->state.type |= INTEL_PT_INSTRUCTION;
3011 			decoder->ip = decoder->psb_ip;
3012 		}
3013 		decoder->state.from_ip = decoder->psb_ip;
3014 		decoder->state.to_ip = 0;
3015 		return HOP_RETURN;
3016 
3017 	case INTEL_PT_BAD:
3018 	case INTEL_PT_PAD:
3019 	case INTEL_PT_TIP_PGE:
3020 	case INTEL_PT_TSC:
3021 	case INTEL_PT_TMA:
3022 	case INTEL_PT_MODE_EXEC:
3023 	case INTEL_PT_MODE_TSX:
3024 	case INTEL_PT_MTC:
3025 	case INTEL_PT_CYC:
3026 	case INTEL_PT_VMCS:
3027 	case INTEL_PT_PSBEND:
3028 	case INTEL_PT_CBR:
3029 	case INTEL_PT_TRACESTOP:
3030 	case INTEL_PT_PIP:
3031 	case INTEL_PT_OVF:
3032 	case INTEL_PT_MNT:
3033 	case INTEL_PT_PTWRITE:
3034 	case INTEL_PT_PTWRITE_IP:
3035 	case INTEL_PT_EXSTOP:
3036 	case INTEL_PT_EXSTOP_IP:
3037 	case INTEL_PT_MWAIT:
3038 	case INTEL_PT_PWRE:
3039 	case INTEL_PT_PWRX:
3040 	case INTEL_PT_BBP:
3041 	case INTEL_PT_BIP:
3042 	case INTEL_PT_BEP:
3043 	case INTEL_PT_BEP_IP:
3044 	case INTEL_PT_CFE:
3045 	case INTEL_PT_CFE_IP:
3046 	case INTEL_PT_EVD:
3047 	default:
3048 		return HOP_PROCESS;
3049 	}
3050 }
3051 
3052 struct intel_pt_psb_info {
3053 	struct intel_pt_pkt fup_packet;
3054 	bool fup;
3055 	int after_psbend;
3056 };
3057 
3058 /* Lookahead and get the FUP packet from PSB+ */
3059 static int intel_pt_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
3060 {
3061 	struct intel_pt_psb_info *data = pkt_info->data;
3062 
3063 	switch (pkt_info->packet.type) {
3064 	case INTEL_PT_PAD:
3065 	case INTEL_PT_MNT:
3066 	case INTEL_PT_TSC:
3067 	case INTEL_PT_TMA:
3068 	case INTEL_PT_MODE_EXEC:
3069 	case INTEL_PT_MODE_TSX:
3070 	case INTEL_PT_MTC:
3071 	case INTEL_PT_CYC:
3072 	case INTEL_PT_VMCS:
3073 	case INTEL_PT_CBR:
3074 	case INTEL_PT_PIP:
3075 		if (data->after_psbend) {
3076 			data->after_psbend -= 1;
3077 			if (!data->after_psbend)
3078 				return 1;
3079 		}
3080 		break;
3081 
3082 	case INTEL_PT_FUP:
3083 		if (data->after_psbend)
3084 			return 1;
3085 		if (data->fup || pkt_info->packet.count == 0)
3086 			return 1;
3087 		data->fup_packet = pkt_info->packet;
3088 		data->fup = true;
3089 		break;
3090 
3091 	case INTEL_PT_PSBEND:
3092 		if (!data->fup)
3093 			return 1;
3094 		/* Keep going to check for a TIP.PGE */
3095 		data->after_psbend = 6;
3096 		break;
3097 
3098 	case INTEL_PT_TIP_PGE:
3099 		/* Ignore FUP in PSB+ if followed by TIP.PGE */
3100 		if (data->after_psbend)
3101 			data->fup = false;
3102 		return 1;
3103 
3104 	case INTEL_PT_PTWRITE:
3105 	case INTEL_PT_PTWRITE_IP:
3106 	case INTEL_PT_EXSTOP:
3107 	case INTEL_PT_EXSTOP_IP:
3108 	case INTEL_PT_MWAIT:
3109 	case INTEL_PT_PWRE:
3110 	case INTEL_PT_PWRX:
3111 	case INTEL_PT_BBP:
3112 	case INTEL_PT_BIP:
3113 	case INTEL_PT_BEP:
3114 	case INTEL_PT_BEP_IP:
3115 	case INTEL_PT_CFE:
3116 	case INTEL_PT_CFE_IP:
3117 	case INTEL_PT_EVD:
3118 		if (data->after_psbend) {
3119 			data->after_psbend -= 1;
3120 			if (!data->after_psbend)
3121 				return 1;
3122 			break;
3123 		}
3124 		return 1;
3125 
3126 	case INTEL_PT_OVF:
3127 	case INTEL_PT_BAD:
3128 	case INTEL_PT_TNT:
3129 	case INTEL_PT_TIP_PGD:
3130 	case INTEL_PT_TIP:
3131 	case INTEL_PT_PSB:
3132 	case INTEL_PT_TRACESTOP:
3133 	default:
3134 		return 1;
3135 	}
3136 
3137 	return 0;
3138 }
3139 
3140 static int intel_pt_psb(struct intel_pt_decoder *decoder)
3141 {
3142 	int err;
3143 
3144 	decoder->last_ip = 0;
3145 	decoder->psb_ip = 0;
3146 	decoder->have_last_ip = true;
3147 	intel_pt_clear_stack(&decoder->stack);
3148 	err = intel_pt_walk_psbend(decoder);
3149 	if (err)
3150 		return err;
3151 	decoder->state.type = INTEL_PT_PSB_EVT;
3152 	decoder->state.from_ip = decoder->psb_ip;
3153 	decoder->state.to_ip = 0;
3154 	return 0;
3155 }
3156 
3157 static int intel_pt_fup_in_psb(struct intel_pt_decoder *decoder)
3158 {
3159 	int err;
3160 
3161 	if (decoder->ip != decoder->last_ip) {
3162 		err = intel_pt_walk_fup(decoder);
3163 		if (!err || err != -EAGAIN)
3164 			return err;
3165 	}
3166 
3167 	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3168 	err = intel_pt_psb(decoder);
3169 	if (err) {
3170 		decoder->pkt_state = INTEL_PT_STATE_ERR3;
3171 		return -ENOENT;
3172 	}
3173 
3174 	return 0;
3175 }
3176 
3177 static bool intel_pt_psb_with_fup(struct intel_pt_decoder *decoder, int *err)
3178 {
3179 	struct intel_pt_psb_info data = { .fup = false };
3180 
3181 	if (!decoder->branch_enable)
3182 		return false;
3183 
3184 	intel_pt_pkt_lookahead(decoder, intel_pt_psb_lookahead_cb, &data);
3185 	if (!data.fup)
3186 		return false;
3187 
3188 	decoder->packet = data.fup_packet;
3189 	intel_pt_set_last_ip(decoder);
3190 	decoder->pkt_state = INTEL_PT_STATE_FUP_IN_PSB;
3191 
3192 	*err = intel_pt_fup_in_psb(decoder);
3193 
3194 	return true;
3195 }
3196 
3197 static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
3198 {
3199 	int last_packet_type = INTEL_PT_PAD;
3200 	bool no_tip = false;
3201 	int err;
3202 
3203 	while (1) {
3204 		err = intel_pt_get_next_packet(decoder);
3205 		if (err)
3206 			return err;
3207 next:
3208 		err = 0;
3209 		if (decoder->cyc_threshold) {
3210 			if (decoder->sample_cyc && last_packet_type != INTEL_PT_CYC)
3211 				decoder->sample_cyc = false;
3212 			last_packet_type = decoder->packet.type;
3213 		}
3214 
3215 		if (decoder->hop) {
3216 			switch (intel_pt_hop_trace(decoder, &no_tip, &err)) {
3217 			case HOP_IGNORE:
3218 				continue;
3219 			case HOP_RETURN:
3220 				return err;
3221 			case HOP_AGAIN:
3222 				goto next;
3223 			default:
3224 				break;
3225 			}
3226 		}
3227 
3228 		switch (decoder->packet.type) {
3229 		case INTEL_PT_TNT:
3230 			if (!decoder->packet.count)
3231 				break;
3232 			decoder->tnt = decoder->packet;
3233 			decoder->pkt_state = INTEL_PT_STATE_TNT;
3234 			err = intel_pt_walk_tnt(decoder);
3235 			if (err == -EAGAIN)
3236 				break;
3237 			return err;
3238 
3239 		case INTEL_PT_TIP_PGD:
3240 			if (decoder->packet.count != 0)
3241 				intel_pt_set_last_ip(decoder);
3242 			decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
3243 			return intel_pt_walk_tip(decoder);
3244 
3245 		case INTEL_PT_TIP_PGE: {
3246 			decoder->pge = true;
3247 			decoder->overflow = false;
3248 			intel_pt_mtc_cyc_cnt_pge(decoder);
3249 			intel_pt_set_nr(decoder);
3250 			if (decoder->packet.count == 0) {
3251 				intel_pt_log_at("Skipping zero TIP.PGE",
3252 						decoder->pos);
3253 				break;
3254 			}
3255 			intel_pt_sample_iflag_chg(decoder);
3256 			intel_pt_set_ip(decoder);
3257 			decoder->state.from_ip = 0;
3258 			decoder->state.to_ip = decoder->ip;
3259 			decoder->state.type |= INTEL_PT_TRACE_BEGIN;
3260 			/*
3261 			 * In hop mode, resample to get the to_ip as an
3262 			 * "instruction" sample.
3263 			 */
3264 			if (decoder->hop)
3265 				decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3266 			return 0;
3267 		}
3268 
3269 		case INTEL_PT_OVF:
3270 			return intel_pt_overflow(decoder);
3271 
3272 		case INTEL_PT_TIP:
3273 			if (decoder->packet.count != 0)
3274 				intel_pt_set_last_ip(decoder);
3275 			decoder->pkt_state = INTEL_PT_STATE_TIP;
3276 			return intel_pt_walk_tip(decoder);
3277 
3278 		case INTEL_PT_FUP:
3279 			if (decoder->packet.count == 0) {
3280 				intel_pt_log_at("Skipping zero FUP",
3281 						decoder->pos);
3282 				no_tip = false;
3283 				break;
3284 			}
3285 			intel_pt_set_last_ip(decoder);
3286 			if (!decoder->branch_enable || !decoder->pge) {
3287 				decoder->ip = decoder->last_ip;
3288 				if (intel_pt_fup_event(decoder, no_tip))
3289 					return 0;
3290 				no_tip = false;
3291 				break;
3292 			}
3293 			if (decoder->set_fup_mwait)
3294 				no_tip = true;
3295 			if (no_tip)
3296 				decoder->pkt_state = INTEL_PT_STATE_FUP_NO_TIP;
3297 			else
3298 				decoder->pkt_state = INTEL_PT_STATE_FUP;
3299 			err = intel_pt_walk_fup(decoder);
3300 			if (err != -EAGAIN)
3301 				return err;
3302 			if (no_tip) {
3303 				no_tip = false;
3304 				break;
3305 			}
3306 			return intel_pt_walk_fup_tip(decoder);
3307 
3308 		case INTEL_PT_TRACESTOP:
3309 			decoder->pge = false;
3310 			decoder->continuous_period = false;
3311 			intel_pt_clear_tx_flags(decoder);
3312 			decoder->have_tma = false;
3313 			break;
3314 
3315 		case INTEL_PT_PSB:
3316 			decoder->state.psb_offset = decoder->pos;
3317 			decoder->psb_ip = 0;
3318 			if (intel_pt_psb_with_fup(decoder, &err))
3319 				return err;
3320 			err = intel_pt_psb(decoder);
3321 			if (err == -EAGAIN)
3322 				goto next;
3323 			return err;
3324 
3325 		case INTEL_PT_PIP:
3326 			intel_pt_update_pip(decoder);
3327 			break;
3328 
3329 		case INTEL_PT_MTC:
3330 			intel_pt_calc_mtc_timestamp(decoder);
3331 			if (decoder->period_type != INTEL_PT_PERIOD_MTC)
3332 				break;
3333 			/*
3334 			 * Ensure that there has been an instruction since the
3335 			 * last MTC.
3336 			 */
3337 			if (!decoder->mtc_insn)
3338 				break;
3339 			decoder->mtc_insn = false;
3340 			/* Ensure that there is a timestamp */
3341 			if (!decoder->timestamp)
3342 				break;
3343 			decoder->state.type = INTEL_PT_INSTRUCTION;
3344 			decoder->state.from_ip = decoder->ip;
3345 			decoder->state.to_ip = 0;
3346 			decoder->mtc_insn = false;
3347 			return 0;
3348 
3349 		case INTEL_PT_TSC:
3350 			intel_pt_calc_tsc_timestamp(decoder);
3351 			break;
3352 
3353 		case INTEL_PT_TMA:
3354 			intel_pt_calc_tma(decoder);
3355 			break;
3356 
3357 		case INTEL_PT_CYC:
3358 			intel_pt_calc_cyc_timestamp(decoder);
3359 			break;
3360 
3361 		case INTEL_PT_CBR:
3362 			intel_pt_calc_cbr(decoder);
3363 			if (decoder->cbr != decoder->cbr_seen) {
3364 				decoder->state.type = 0;
3365 				return 0;
3366 			}
3367 			break;
3368 
3369 		case INTEL_PT_MODE_EXEC:
3370 			intel_pt_mode_exec(decoder);
3371 			err = intel_pt_get_next_packet(decoder);
3372 			if (err)
3373 				return err;
3374 			if (decoder->packet.type == INTEL_PT_FUP) {
3375 				decoder->set_fup_mode_exec = true;
3376 				no_tip = true;
3377 			}
3378 			goto next;
3379 
3380 		case INTEL_PT_MODE_TSX:
3381 			/* MODE_TSX need not be followed by FUP */
3382 			if (!decoder->pge || decoder->in_psb) {
3383 				intel_pt_update_in_tx(decoder);
3384 				break;
3385 			}
3386 			err = intel_pt_mode_tsx(decoder, &no_tip);
3387 			if (err)
3388 				return err;
3389 			goto next;
3390 
3391 		case INTEL_PT_BAD: /* Does not happen */
3392 			return intel_pt_bug(decoder);
3393 
3394 		case INTEL_PT_PSBEND:
3395 		case INTEL_PT_VMCS:
3396 		case INTEL_PT_MNT:
3397 		case INTEL_PT_PAD:
3398 			break;
3399 
3400 		case INTEL_PT_PTWRITE_IP:
3401 			decoder->fup_ptw_payload = decoder->packet.payload;
3402 			err = intel_pt_get_next_packet(decoder);
3403 			if (err)
3404 				return err;
3405 			if (decoder->packet.type == INTEL_PT_FUP) {
3406 				decoder->set_fup_ptw = true;
3407 				no_tip = true;
3408 			} else {
3409 				intel_pt_log_at("ERROR: Missing FUP after PTWRITE",
3410 						decoder->pos);
3411 			}
3412 			goto next;
3413 
3414 		case INTEL_PT_PTWRITE:
3415 			decoder->state.type = INTEL_PT_PTW;
3416 			decoder->state.from_ip = decoder->ip;
3417 			decoder->state.to_ip = 0;
3418 			decoder->state.ptw_payload = decoder->packet.payload;
3419 			return 0;
3420 
3421 		case INTEL_PT_MWAIT:
3422 			decoder->fup_mwait_payload = decoder->packet.payload;
3423 			decoder->set_fup_mwait = true;
3424 			break;
3425 
3426 		case INTEL_PT_PWRE:
3427 			if (decoder->set_fup_mwait) {
3428 				decoder->fup_pwre_payload =
3429 							decoder->packet.payload;
3430 				decoder->set_fup_pwre = true;
3431 				break;
3432 			}
3433 			decoder->state.type = INTEL_PT_PWR_ENTRY;
3434 			decoder->state.from_ip = decoder->ip;
3435 			decoder->state.to_ip = 0;
3436 			decoder->state.pwrx_payload = decoder->packet.payload;
3437 			return 0;
3438 
3439 		case INTEL_PT_EXSTOP_IP:
3440 			err = intel_pt_get_next_packet(decoder);
3441 			if (err)
3442 				return err;
3443 			if (decoder->packet.type == INTEL_PT_FUP) {
3444 				decoder->set_fup_exstop = true;
3445 				no_tip = true;
3446 			} else {
3447 				intel_pt_log_at("ERROR: Missing FUP after EXSTOP",
3448 						decoder->pos);
3449 			}
3450 			goto next;
3451 
3452 		case INTEL_PT_EXSTOP:
3453 			decoder->state.type = INTEL_PT_EX_STOP;
3454 			decoder->state.from_ip = decoder->ip;
3455 			decoder->state.to_ip = 0;
3456 			return 0;
3457 
3458 		case INTEL_PT_PWRX:
3459 			decoder->state.type = INTEL_PT_PWR_EXIT;
3460 			decoder->state.from_ip = decoder->ip;
3461 			decoder->state.to_ip = 0;
3462 			decoder->state.pwrx_payload = decoder->packet.payload;
3463 			return 0;
3464 
3465 		case INTEL_PT_BBP:
3466 			intel_pt_bbp(decoder);
3467 			break;
3468 
3469 		case INTEL_PT_BIP:
3470 			intel_pt_bip(decoder);
3471 			break;
3472 
3473 		case INTEL_PT_BEP:
3474 			decoder->state.type = INTEL_PT_BLK_ITEMS;
3475 			decoder->state.from_ip = decoder->ip;
3476 			decoder->state.to_ip = 0;
3477 			return 0;
3478 
3479 		case INTEL_PT_BEP_IP:
3480 			err = intel_pt_get_next_packet(decoder);
3481 			if (err)
3482 				return err;
3483 			if (decoder->packet.type == INTEL_PT_FUP) {
3484 				decoder->set_fup_bep = true;
3485 				no_tip = true;
3486 			} else {
3487 				intel_pt_log_at("ERROR: Missing FUP after BEP",
3488 						decoder->pos);
3489 			}
3490 			goto next;
3491 
3492 		case INTEL_PT_CFE:
3493 			decoder->fup_cfe_pkt = decoder->packet;
3494 			decoder->set_fup_cfe = true;
3495 			if (!decoder->pge) {
3496 				intel_pt_fup_event(decoder, true);
3497 				return 0;
3498 			}
3499 			break;
3500 
3501 		case INTEL_PT_CFE_IP:
3502 			decoder->fup_cfe_pkt = decoder->packet;
3503 			err = intel_pt_get_next_packet(decoder);
3504 			if (err)
3505 				return err;
3506 			if (decoder->packet.type == INTEL_PT_FUP) {
3507 				decoder->set_fup_cfe_ip = true;
3508 				no_tip = true;
3509 			} else {
3510 				intel_pt_log_at("ERROR: Missing FUP after CFE",
3511 						decoder->pos);
3512 			}
3513 			goto next;
3514 
3515 		case INTEL_PT_EVD:
3516 			err = intel_pt_evd(decoder);
3517 			if (err)
3518 				return err;
3519 			break;
3520 
3521 		default:
3522 			return intel_pt_bug(decoder);
3523 		}
3524 	}
3525 }
3526 
3527 static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
3528 {
3529 	return decoder->packet.count &&
3530 	       (decoder->have_last_ip || decoder->packet.count == 3 ||
3531 		decoder->packet.count == 6);
3532 }
3533 
3534 /* Walk PSB+ packets to get in sync. */
3535 static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
3536 {
3537 	int err;
3538 
3539 	decoder->in_psb = true;
3540 
3541 	while (1) {
3542 		err = intel_pt_get_next_packet(decoder);
3543 		if (err)
3544 			goto out;
3545 
3546 		switch (decoder->packet.type) {
3547 		case INTEL_PT_TIP_PGD:
3548 			decoder->continuous_period = false;
3549 			fallthrough;
3550 		case INTEL_PT_TIP_PGE:
3551 		case INTEL_PT_TIP:
3552 		case INTEL_PT_PTWRITE:
3553 		case INTEL_PT_PTWRITE_IP:
3554 		case INTEL_PT_EXSTOP:
3555 		case INTEL_PT_EXSTOP_IP:
3556 		case INTEL_PT_MWAIT:
3557 		case INTEL_PT_PWRE:
3558 		case INTEL_PT_PWRX:
3559 		case INTEL_PT_BBP:
3560 		case INTEL_PT_BIP:
3561 		case INTEL_PT_BEP:
3562 		case INTEL_PT_BEP_IP:
3563 		case INTEL_PT_CFE:
3564 		case INTEL_PT_CFE_IP:
3565 		case INTEL_PT_EVD:
3566 			intel_pt_log("ERROR: Unexpected packet\n");
3567 			err = -ENOENT;
3568 			goto out;
3569 
3570 		case INTEL_PT_FUP:
3571 			decoder->pge = true;
3572 			if (intel_pt_have_ip(decoder)) {
3573 				uint64_t current_ip = decoder->ip;
3574 
3575 				intel_pt_set_ip(decoder);
3576 				decoder->psb_ip = decoder->ip;
3577 				if (current_ip)
3578 					intel_pt_log_to("Setting IP",
3579 							decoder->ip);
3580 			}
3581 			break;
3582 
3583 		case INTEL_PT_MTC:
3584 			intel_pt_calc_mtc_timestamp(decoder);
3585 			break;
3586 
3587 		case INTEL_PT_TSC:
3588 			intel_pt_calc_tsc_timestamp(decoder);
3589 			break;
3590 
3591 		case INTEL_PT_TMA:
3592 			intel_pt_calc_tma(decoder);
3593 			break;
3594 
3595 		case INTEL_PT_CYC:
3596 			intel_pt_calc_cyc_timestamp(decoder);
3597 			break;
3598 
3599 		case INTEL_PT_CBR:
3600 			intel_pt_calc_cbr(decoder);
3601 			break;
3602 
3603 		case INTEL_PT_PIP:
3604 			intel_pt_set_pip(decoder);
3605 			break;
3606 
3607 		case INTEL_PT_MODE_EXEC:
3608 			intel_pt_mode_exec_status(decoder);
3609 			break;
3610 
3611 		case INTEL_PT_MODE_TSX:
3612 			intel_pt_update_in_tx(decoder);
3613 			break;
3614 
3615 		case INTEL_PT_TRACESTOP:
3616 			decoder->pge = false;
3617 			decoder->continuous_period = false;
3618 			intel_pt_clear_tx_flags(decoder);
3619 			fallthrough;
3620 
3621 		case INTEL_PT_TNT:
3622 			decoder->have_tma = false;
3623 			intel_pt_log("ERROR: Unexpected packet\n");
3624 			if (decoder->ip)
3625 				decoder->pkt_state = INTEL_PT_STATE_ERR4;
3626 			else
3627 				decoder->pkt_state = INTEL_PT_STATE_ERR3;
3628 			err = -ENOENT;
3629 			goto out;
3630 
3631 		case INTEL_PT_BAD: /* Does not happen */
3632 			err = intel_pt_bug(decoder);
3633 			goto out;
3634 
3635 		case INTEL_PT_OVF:
3636 			err = intel_pt_overflow(decoder);
3637 			goto out;
3638 
3639 		case INTEL_PT_PSBEND:
3640 			err = 0;
3641 			goto out;
3642 
3643 		case INTEL_PT_PSB:
3644 		case INTEL_PT_VMCS:
3645 		case INTEL_PT_MNT:
3646 		case INTEL_PT_PAD:
3647 		default:
3648 			break;
3649 		}
3650 	}
3651 out:
3652 	decoder->in_psb = false;
3653 
3654 	return err;
3655 }
3656 
3657 static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
3658 {
3659 	int err;
3660 
3661 	while (1) {
3662 		err = intel_pt_get_next_packet(decoder);
3663 		if (err)
3664 			return err;
3665 
3666 		switch (decoder->packet.type) {
3667 		case INTEL_PT_TIP_PGD:
3668 			decoder->continuous_period = false;
3669 			decoder->pge = false;
3670 			if (intel_pt_have_ip(decoder))
3671 				intel_pt_set_ip(decoder);
3672 			if (!decoder->ip)
3673 				break;
3674 			decoder->state.type |= INTEL_PT_TRACE_END;
3675 			return 0;
3676 
3677 		case INTEL_PT_TIP_PGE:
3678 			decoder->pge = true;
3679 			intel_pt_mtc_cyc_cnt_pge(decoder);
3680 			if (intel_pt_have_ip(decoder))
3681 				intel_pt_set_ip(decoder);
3682 			if (!decoder->ip)
3683 				break;
3684 			decoder->state.type |= INTEL_PT_TRACE_BEGIN;
3685 			return 0;
3686 
3687 		case INTEL_PT_TIP:
3688 			decoder->pge = true;
3689 			if (intel_pt_have_ip(decoder))
3690 				intel_pt_set_ip(decoder);
3691 			if (!decoder->ip)
3692 				break;
3693 			return 0;
3694 
3695 		case INTEL_PT_FUP:
3696 			if (intel_pt_have_ip(decoder))
3697 				intel_pt_set_ip(decoder);
3698 			if (decoder->ip)
3699 				return 0;
3700 			break;
3701 
3702 		case INTEL_PT_MTC:
3703 			intel_pt_calc_mtc_timestamp(decoder);
3704 			break;
3705 
3706 		case INTEL_PT_TSC:
3707 			intel_pt_calc_tsc_timestamp(decoder);
3708 			break;
3709 
3710 		case INTEL_PT_TMA:
3711 			intel_pt_calc_tma(decoder);
3712 			break;
3713 
3714 		case INTEL_PT_CYC:
3715 			intel_pt_calc_cyc_timestamp(decoder);
3716 			break;
3717 
3718 		case INTEL_PT_CBR:
3719 			intel_pt_calc_cbr(decoder);
3720 			break;
3721 
3722 		case INTEL_PT_PIP:
3723 			intel_pt_set_pip(decoder);
3724 			break;
3725 
3726 		case INTEL_PT_MODE_EXEC:
3727 			intel_pt_mode_exec_status(decoder);
3728 			break;
3729 
3730 		case INTEL_PT_MODE_TSX:
3731 			intel_pt_update_in_tx(decoder);
3732 			break;
3733 
3734 		case INTEL_PT_OVF:
3735 			return intel_pt_overflow(decoder);
3736 
3737 		case INTEL_PT_BAD: /* Does not happen */
3738 			return intel_pt_bug(decoder);
3739 
3740 		case INTEL_PT_TRACESTOP:
3741 			decoder->pge = false;
3742 			decoder->continuous_period = false;
3743 			intel_pt_clear_tx_flags(decoder);
3744 			decoder->have_tma = false;
3745 			break;
3746 
3747 		case INTEL_PT_PSB:
3748 			decoder->state.psb_offset = decoder->pos;
3749 			decoder->psb_ip = 0;
3750 			decoder->last_ip = 0;
3751 			decoder->have_last_ip = true;
3752 			intel_pt_clear_stack(&decoder->stack);
3753 			err = intel_pt_walk_psb(decoder);
3754 			if (err)
3755 				return err;
3756 			decoder->state.type = INTEL_PT_PSB_EVT;
3757 			decoder->state.from_ip = decoder->psb_ip;
3758 			decoder->state.to_ip = 0;
3759 			return 0;
3760 
3761 		case INTEL_PT_TNT:
3762 		case INTEL_PT_PSBEND:
3763 		case INTEL_PT_VMCS:
3764 		case INTEL_PT_MNT:
3765 		case INTEL_PT_PAD:
3766 		case INTEL_PT_PTWRITE:
3767 		case INTEL_PT_PTWRITE_IP:
3768 		case INTEL_PT_EXSTOP:
3769 		case INTEL_PT_EXSTOP_IP:
3770 		case INTEL_PT_MWAIT:
3771 		case INTEL_PT_PWRE:
3772 		case INTEL_PT_PWRX:
3773 		case INTEL_PT_BBP:
3774 		case INTEL_PT_BIP:
3775 		case INTEL_PT_BEP:
3776 		case INTEL_PT_BEP_IP:
3777 		case INTEL_PT_CFE:
3778 		case INTEL_PT_CFE_IP:
3779 		case INTEL_PT_EVD:
3780 		default:
3781 			break;
3782 		}
3783 	}
3784 }
3785 
3786 static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
3787 {
3788 	int err;
3789 
3790 	intel_pt_clear_fup_event(decoder);
3791 	decoder->overflow = false;
3792 
3793 	if (!decoder->branch_enable) {
3794 		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3795 		decoder->state.type = 0; /* Do not have a sample */
3796 		return 0;
3797 	}
3798 
3799 	intel_pt_log("Scanning for full IP\n");
3800 	err = intel_pt_walk_to_ip(decoder);
3801 	if (err || ((decoder->state.type & INTEL_PT_PSB_EVT) && !decoder->ip))
3802 		return err;
3803 
3804 	/* In hop mode, resample to get the to_ip as an "instruction" sample */
3805 	if (decoder->hop)
3806 		decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3807 	else
3808 		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3809 
3810 	decoder->state.from_ip = 0;
3811 	decoder->state.to_ip = decoder->ip;
3812 	intel_pt_log_to("Setting IP", decoder->ip);
3813 
3814 	return 0;
3815 }
3816 
3817 static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
3818 {
3819 	const unsigned char *end = decoder->buf + decoder->len;
3820 	size_t i;
3821 
3822 	for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
3823 		if (i > decoder->len)
3824 			continue;
3825 		if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
3826 			return i;
3827 	}
3828 	return 0;
3829 }
3830 
3831 static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
3832 {
3833 	size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
3834 	const char *psb = INTEL_PT_PSB_STR;
3835 
3836 	if (rest_psb > decoder->len ||
3837 	    memcmp(decoder->buf, psb + part_psb, rest_psb))
3838 		return 0;
3839 
3840 	return rest_psb;
3841 }
3842 
3843 static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
3844 				  int part_psb)
3845 {
3846 	int rest_psb, ret;
3847 
3848 	decoder->pos += decoder->len;
3849 	decoder->len = 0;
3850 
3851 	ret = intel_pt_get_next_data(decoder, false);
3852 	if (ret)
3853 		return ret;
3854 
3855 	rest_psb = intel_pt_rest_psb(decoder, part_psb);
3856 	if (!rest_psb)
3857 		return 0;
3858 
3859 	decoder->pos -= part_psb;
3860 	decoder->next_buf = decoder->buf + rest_psb;
3861 	decoder->next_len = decoder->len - rest_psb;
3862 	memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
3863 	decoder->buf = decoder->temp_buf;
3864 	decoder->len = INTEL_PT_PSB_LEN;
3865 
3866 	return 0;
3867 }
3868 
3869 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
3870 {
3871 	unsigned char *next;
3872 	int ret;
3873 
3874 	intel_pt_log("Scanning for PSB\n");
3875 	while (1) {
3876 		if (!decoder->len) {
3877 			ret = intel_pt_get_next_data(decoder, false);
3878 			if (ret)
3879 				return ret;
3880 		}
3881 
3882 		next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
3883 			      INTEL_PT_PSB_LEN);
3884 		if (!next) {
3885 			int part_psb;
3886 
3887 			part_psb = intel_pt_part_psb(decoder);
3888 			if (part_psb) {
3889 				ret = intel_pt_get_split_psb(decoder, part_psb);
3890 				if (ret)
3891 					return ret;
3892 			} else {
3893 				decoder->pos += decoder->len;
3894 				decoder->len = 0;
3895 			}
3896 			continue;
3897 		}
3898 
3899 		decoder->pkt_step = next - decoder->buf;
3900 		return intel_pt_get_next_packet(decoder);
3901 	}
3902 }
3903 
3904 static int intel_pt_sync(struct intel_pt_decoder *decoder)
3905 {
3906 	int err;
3907 
3908 	decoder->pge = false;
3909 	decoder->continuous_period = false;
3910 	decoder->have_last_ip = false;
3911 	decoder->last_ip = 0;
3912 	decoder->psb_ip = 0;
3913 	decoder->ip = 0;
3914 	intel_pt_clear_stack(&decoder->stack);
3915 
3916 	err = intel_pt_scan_for_psb(decoder);
3917 	if (err)
3918 		return err;
3919 
3920 	if (decoder->vm_time_correlation) {
3921 		decoder->in_psb = true;
3922 		if (!decoder->timestamp)
3923 			decoder->timestamp = 1;
3924 		decoder->state.type = 0;
3925 		decoder->pkt_state = INTEL_PT_STATE_VM_TIME_CORRELATION;
3926 		return 0;
3927 	}
3928 
3929 	decoder->have_last_ip = true;
3930 	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3931 
3932 	err = intel_pt_walk_psb(decoder);
3933 	if (err)
3934 		return err;
3935 
3936 	decoder->state.type = INTEL_PT_PSB_EVT; /* Only PSB sample */
3937 	decoder->state.from_ip = decoder->psb_ip;
3938 	decoder->state.to_ip = 0;
3939 
3940 	if (decoder->ip) {
3941 		/*
3942 		 * In hop mode, resample to get the PSB FUP ip as an
3943 		 * "instruction" sample.
3944 		 */
3945 		if (decoder->hop)
3946 			decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3947 		else
3948 			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3949 	}
3950 
3951 	return 0;
3952 }
3953 
3954 static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
3955 {
3956 	uint64_t est = decoder->sample_insn_cnt << 1;
3957 
3958 	if (!decoder->cbr || !decoder->max_non_turbo_ratio)
3959 		goto out;
3960 
3961 	est *= decoder->max_non_turbo_ratio;
3962 	est /= decoder->cbr;
3963 out:
3964 	return decoder->sample_timestamp + est;
3965 }
3966 
3967 const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
3968 {
3969 	int err;
3970 
3971 	do {
3972 		decoder->state.type = INTEL_PT_BRANCH;
3973 		decoder->state.flags = 0;
3974 
3975 		switch (decoder->pkt_state) {
3976 		case INTEL_PT_STATE_NO_PSB:
3977 			err = intel_pt_sync(decoder);
3978 			break;
3979 		case INTEL_PT_STATE_NO_IP:
3980 			decoder->have_last_ip = false;
3981 			decoder->last_ip = 0;
3982 			decoder->ip = 0;
3983 			fallthrough;
3984 		case INTEL_PT_STATE_ERR_RESYNC:
3985 			err = intel_pt_sync_ip(decoder);
3986 			break;
3987 		case INTEL_PT_STATE_IN_SYNC:
3988 			err = intel_pt_walk_trace(decoder);
3989 			break;
3990 		case INTEL_PT_STATE_TNT:
3991 		case INTEL_PT_STATE_TNT_CONT:
3992 			err = intel_pt_walk_tnt(decoder);
3993 			if (err == -EAGAIN)
3994 				err = intel_pt_walk_trace(decoder);
3995 			break;
3996 		case INTEL_PT_STATE_TIP:
3997 		case INTEL_PT_STATE_TIP_PGD:
3998 			err = intel_pt_walk_tip(decoder);
3999 			break;
4000 		case INTEL_PT_STATE_FUP:
4001 			err = intel_pt_walk_fup(decoder);
4002 			if (err == -EAGAIN)
4003 				err = intel_pt_walk_fup_tip(decoder);
4004 			break;
4005 		case INTEL_PT_STATE_FUP_NO_TIP:
4006 			err = intel_pt_walk_fup(decoder);
4007 			if (err == -EAGAIN)
4008 				err = intel_pt_walk_trace(decoder);
4009 			break;
4010 		case INTEL_PT_STATE_FUP_IN_PSB:
4011 			err = intel_pt_fup_in_psb(decoder);
4012 			break;
4013 		case INTEL_PT_STATE_RESAMPLE:
4014 			err = intel_pt_resample(decoder);
4015 			break;
4016 		case INTEL_PT_STATE_VM_TIME_CORRELATION:
4017 			err = intel_pt_vm_time_correlation(decoder);
4018 			break;
4019 		default:
4020 			err = intel_pt_bug(decoder);
4021 			break;
4022 		}
4023 	} while (err == -ENOLINK);
4024 
4025 	if (err) {
4026 		decoder->state.err = intel_pt_ext_err(err);
4027 		if (err != -EOVERFLOW)
4028 			decoder->state.from_ip = decoder->ip;
4029 		intel_pt_update_sample_time(decoder);
4030 		decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
4031 		intel_pt_set_nr(decoder);
4032 	} else {
4033 		decoder->state.err = 0;
4034 		if (decoder->cbr != decoder->cbr_seen) {
4035 			decoder->cbr_seen = decoder->cbr;
4036 			if (!decoder->state.type) {
4037 				decoder->state.from_ip = decoder->ip;
4038 				decoder->state.to_ip = 0;
4039 			}
4040 			decoder->state.type |= INTEL_PT_CBR_CHG;
4041 			decoder->state.cbr_payload = decoder->cbr_payload;
4042 			decoder->state.cbr = decoder->cbr;
4043 		}
4044 		if (intel_pt_sample_time(decoder->pkt_state)) {
4045 			intel_pt_update_sample_time(decoder);
4046 			if (decoder->sample_cyc) {
4047 				decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
4048 				decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
4049 				decoder->sample_cyc = false;
4050 			}
4051 		}
4052 		/*
4053 		 * When using only TSC/MTC to compute cycles, IPC can be
4054 		 * sampled as soon as the cycle count changes.
4055 		 */
4056 		if (!decoder->have_cyc)
4057 			decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
4058 	}
4059 
4060 	 /* Let PSB event always have TSC timestamp */
4061 	if ((decoder->state.type & INTEL_PT_PSB_EVT) && decoder->tsc_timestamp)
4062 		decoder->sample_timestamp = decoder->tsc_timestamp;
4063 
4064 	decoder->state.from_nr = decoder->nr;
4065 	decoder->state.to_nr = decoder->next_nr;
4066 	decoder->nr = decoder->next_nr;
4067 
4068 	decoder->state.timestamp = decoder->sample_timestamp;
4069 	decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
4070 	decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
4071 	decoder->state.tot_cyc_cnt = decoder->sample_tot_cyc_cnt;
4072 
4073 	return &decoder->state;
4074 }
4075 
4076 /**
4077  * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
4078  * @buf: pointer to buffer pointer
4079  * @len: size of buffer
4080  *
4081  * Updates the buffer pointer to point to the start of the next PSB packet if
4082  * there is one, otherwise the buffer pointer is unchanged.  If @buf is updated,
4083  * @len is adjusted accordingly.
4084  *
4085  * Return: %true if a PSB packet is found, %false otherwise.
4086  */
4087 static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
4088 {
4089 	unsigned char *next;
4090 
4091 	next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
4092 	if (next) {
4093 		*len -= next - *buf;
4094 		*buf = next;
4095 		return true;
4096 	}
4097 	return false;
4098 }
4099 
4100 /**
4101  * intel_pt_step_psb - move buffer pointer to the start of the following PSB
4102  *                     packet.
4103  * @buf: pointer to buffer pointer
4104  * @len: size of buffer
4105  *
4106  * Updates the buffer pointer to point to the start of the following PSB packet
4107  * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
4108  * pointer is unchanged.  If @buf is updated, @len is adjusted accordingly.
4109  *
4110  * Return: %true if a PSB packet is found, %false otherwise.
4111  */
4112 static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
4113 {
4114 	unsigned char *next;
4115 
4116 	if (!*len)
4117 		return false;
4118 
4119 	next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
4120 	if (next) {
4121 		*len -= next - *buf;
4122 		*buf = next;
4123 		return true;
4124 	}
4125 	return false;
4126 }
4127 
4128 /**
4129  * intel_pt_last_psb - find the last PSB packet in a buffer.
4130  * @buf: buffer
4131  * @len: size of buffer
4132  *
4133  * This function finds the last PSB in a buffer.
4134  *
4135  * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
4136  */
4137 static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
4138 {
4139 	const char *n = INTEL_PT_PSB_STR;
4140 	unsigned char *p;
4141 	size_t k;
4142 
4143 	if (len < INTEL_PT_PSB_LEN)
4144 		return NULL;
4145 
4146 	k = len - INTEL_PT_PSB_LEN + 1;
4147 	while (1) {
4148 		p = memrchr(buf, n[0], k);
4149 		if (!p)
4150 			return NULL;
4151 		if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
4152 			return p;
4153 		k = p - buf;
4154 		if (!k)
4155 			return NULL;
4156 	}
4157 }
4158 
4159 /**
4160  * intel_pt_next_tsc - find and return next TSC.
4161  * @buf: buffer
4162  * @len: size of buffer
4163  * @tsc: TSC value returned
4164  * @rem: returns remaining size when TSC is found
4165  *
4166  * Find a TSC packet in @buf and return the TSC value.  This function assumes
4167  * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
4168  * PSBEND packet is found.
4169  *
4170  * Return: %true if TSC is found, false otherwise.
4171  */
4172 static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc,
4173 			      size_t *rem)
4174 {
4175 	enum intel_pt_pkt_ctx ctx = INTEL_PT_NO_CTX;
4176 	struct intel_pt_pkt packet;
4177 	int ret;
4178 
4179 	while (len) {
4180 		ret = intel_pt_get_packet(buf, len, &packet, &ctx);
4181 		if (ret <= 0)
4182 			return false;
4183 		if (packet.type == INTEL_PT_TSC) {
4184 			*tsc = packet.payload;
4185 			*rem = len;
4186 			return true;
4187 		}
4188 		if (packet.type == INTEL_PT_PSBEND)
4189 			return false;
4190 		buf += ret;
4191 		len -= ret;
4192 	}
4193 	return false;
4194 }
4195 
4196 /**
4197  * intel_pt_tsc_cmp - compare 7-byte TSCs.
4198  * @tsc1: first TSC to compare
4199  * @tsc2: second TSC to compare
4200  *
4201  * This function compares 7-byte TSC values allowing for the possibility that
4202  * TSC wrapped around.  Generally it is not possible to know if TSC has wrapped
4203  * around so for that purpose this function assumes the absolute difference is
4204  * less than half the maximum difference.
4205  *
4206  * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
4207  * after @tsc2.
4208  */
4209 static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
4210 {
4211 	const uint64_t halfway = (1ULL << 55);
4212 
4213 	if (tsc1 == tsc2)
4214 		return 0;
4215 
4216 	if (tsc1 < tsc2) {
4217 		if (tsc2 - tsc1 < halfway)
4218 			return -1;
4219 		else
4220 			return 1;
4221 	} else {
4222 		if (tsc1 - tsc2 < halfway)
4223 			return 1;
4224 		else
4225 			return -1;
4226 	}
4227 }
4228 
4229 #define MAX_PADDING (PERF_AUXTRACE_RECORD_ALIGNMENT - 1)
4230 
4231 /**
4232  * adj_for_padding - adjust overlap to account for padding.
4233  * @buf_b: second buffer
4234  * @buf_a: first buffer
4235  * @len_a: size of first buffer
4236  *
4237  * @buf_a might have up to 7 bytes of padding appended. Adjust the overlap
4238  * accordingly.
4239  *
4240  * Return: A pointer into @buf_b from where non-overlapped data starts
4241  */
4242 static unsigned char *adj_for_padding(unsigned char *buf_b,
4243 				      unsigned char *buf_a, size_t len_a)
4244 {
4245 	unsigned char *p = buf_b - MAX_PADDING;
4246 	unsigned char *q = buf_a + len_a - MAX_PADDING;
4247 	int i;
4248 
4249 	for (i = MAX_PADDING; i; i--, p++, q++) {
4250 		if (*p != *q)
4251 			break;
4252 	}
4253 
4254 	return p;
4255 }
4256 
4257 /**
4258  * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
4259  *                             using TSC.
4260  * @buf_a: first buffer
4261  * @len_a: size of first buffer
4262  * @buf_b: second buffer
4263  * @len_b: size of second buffer
4264  * @consecutive: returns true if there is data in buf_b that is consecutive
4265  *               to buf_a
4266  * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
4267  *
4268  * If the trace contains TSC we can look at the last TSC of @buf_a and the
4269  * first TSC of @buf_b in order to determine if the buffers overlap, and then
4270  * walk forward in @buf_b until a later TSC is found.  A precondition is that
4271  * @buf_a and @buf_b are positioned at a PSB.
4272  *
4273  * Return: A pointer into @buf_b from where non-overlapped data starts, or
4274  * @buf_b + @len_b if there is no non-overlapped data.
4275  */
4276 static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
4277 						size_t len_a,
4278 						unsigned char *buf_b,
4279 						size_t len_b, bool *consecutive,
4280 						bool ooo_tsc)
4281 {
4282 	uint64_t tsc_a, tsc_b;
4283 	unsigned char *p;
4284 	size_t len, rem_a, rem_b;
4285 
4286 	p = intel_pt_last_psb(buf_a, len_a);
4287 	if (!p)
4288 		return buf_b; /* No PSB in buf_a => no overlap */
4289 
4290 	len = len_a - (p - buf_a);
4291 	if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a)) {
4292 		/* The last PSB+ in buf_a is incomplete, so go back one more */
4293 		len_a -= len;
4294 		p = intel_pt_last_psb(buf_a, len_a);
4295 		if (!p)
4296 			return buf_b; /* No full PSB+ => assume no overlap */
4297 		len = len_a - (p - buf_a);
4298 		if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a))
4299 			return buf_b; /* No TSC in buf_a => assume no overlap */
4300 	}
4301 
4302 	while (1) {
4303 		/* Ignore PSB+ with no TSC */
4304 		if (intel_pt_next_tsc(buf_b, len_b, &tsc_b, &rem_b)) {
4305 			int cmp = intel_pt_tsc_cmp(tsc_a, tsc_b);
4306 
4307 			/* Same TSC, so buffers are consecutive */
4308 			if (!cmp && rem_b >= rem_a) {
4309 				unsigned char *start;
4310 
4311 				*consecutive = true;
4312 				start = buf_b + len_b - (rem_b - rem_a);
4313 				return adj_for_padding(start, buf_a, len_a);
4314 			}
4315 			if (cmp < 0 && !ooo_tsc)
4316 				return buf_b; /* tsc_a < tsc_b => no overlap */
4317 		}
4318 
4319 		if (!intel_pt_step_psb(&buf_b, &len_b))
4320 			return buf_b + len_b; /* No PSB in buf_b => no data */
4321 	}
4322 }
4323 
4324 /**
4325  * intel_pt_find_overlap - determine start of non-overlapped trace data.
4326  * @buf_a: first buffer
4327  * @len_a: size of first buffer
4328  * @buf_b: second buffer
4329  * @len_b: size of second buffer
4330  * @have_tsc: can use TSC packets to detect overlap
4331  * @consecutive: returns true if there is data in buf_b that is consecutive
4332  *               to buf_a
4333  * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
4334  *
4335  * When trace samples or snapshots are recorded there is the possibility that
4336  * the data overlaps.  Note that, for the purposes of decoding, data is only
4337  * useful if it begins with a PSB packet.
4338  *
4339  * Return: A pointer into @buf_b from where non-overlapped data starts, or
4340  * @buf_b + @len_b if there is no non-overlapped data.
4341  */
4342 unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
4343 				     unsigned char *buf_b, size_t len_b,
4344 				     bool have_tsc, bool *consecutive,
4345 				     bool ooo_tsc)
4346 {
4347 	unsigned char *found;
4348 
4349 	/* Buffer 'b' must start at PSB so throw away everything before that */
4350 	if (!intel_pt_next_psb(&buf_b, &len_b))
4351 		return buf_b + len_b; /* No PSB */
4352 
4353 	if (!intel_pt_next_psb(&buf_a, &len_a))
4354 		return buf_b; /* No overlap */
4355 
4356 	if (have_tsc) {
4357 		found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b,
4358 						  consecutive, ooo_tsc);
4359 		if (found)
4360 			return found;
4361 	}
4362 
4363 	/*
4364 	 * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
4365 	 * we can ignore the first part of buffer 'a'.
4366 	 */
4367 	while (len_b < len_a) {
4368 		if (!intel_pt_step_psb(&buf_a, &len_a))
4369 			return buf_b; /* No overlap */
4370 	}
4371 
4372 	/* Now len_b >= len_a */
4373 	while (1) {
4374 		/* Potential overlap so check the bytes */
4375 		found = memmem(buf_a, len_a, buf_b, len_a);
4376 		if (found) {
4377 			*consecutive = true;
4378 			return adj_for_padding(buf_b + len_a, buf_a, len_a);
4379 		}
4380 
4381 		/* Try again at next PSB in buffer 'a' */
4382 		if (!intel_pt_step_psb(&buf_a, &len_a))
4383 			return buf_b; /* No overlap */
4384 	}
4385 }
4386 
4387 /**
4388  * struct fast_forward_data - data used by intel_pt_ff_cb().
4389  * @timestamp: timestamp to fast forward towards
4390  * @buf_timestamp: buffer timestamp of last buffer with trace data earlier than
4391  *                 the fast forward timestamp.
4392  */
4393 struct fast_forward_data {
4394 	uint64_t timestamp;
4395 	uint64_t buf_timestamp;
4396 };
4397 
4398 /**
4399  * intel_pt_ff_cb - fast forward lookahead callback.
4400  * @buffer: Intel PT trace buffer
4401  * @data: opaque pointer to fast forward data (struct fast_forward_data)
4402  *
4403  * Determine if @buffer trace is past the fast forward timestamp.
4404  *
4405  * Return: 1 (stop lookahead) if @buffer trace is past the fast forward
4406  *         timestamp, and 0 otherwise.
4407  */
4408 static int intel_pt_ff_cb(struct intel_pt_buffer *buffer, void *data)
4409 {
4410 	struct fast_forward_data *d = data;
4411 	unsigned char *buf;
4412 	uint64_t tsc;
4413 	size_t rem;
4414 	size_t len;
4415 
4416 	buf = (unsigned char *)buffer->buf;
4417 	len = buffer->len;
4418 
4419 	if (!intel_pt_next_psb(&buf, &len) ||
4420 	    !intel_pt_next_tsc(buf, len, &tsc, &rem))
4421 		return 0;
4422 
4423 	tsc = intel_pt_8b_tsc(tsc, buffer->ref_timestamp);
4424 
4425 	intel_pt_log("Buffer 1st timestamp " x64_fmt " ref timestamp " x64_fmt "\n",
4426 		     tsc, buffer->ref_timestamp);
4427 
4428 	/*
4429 	 * If the buffer contains a timestamp earlier that the fast forward
4430 	 * timestamp, then record it, else stop.
4431 	 */
4432 	if (tsc < d->timestamp)
4433 		d->buf_timestamp = buffer->ref_timestamp;
4434 	else
4435 		return 1;
4436 
4437 	return 0;
4438 }
4439 
4440 /**
4441  * intel_pt_fast_forward - reposition decoder forwards.
4442  * @decoder: Intel PT decoder
4443  * @timestamp: timestamp to fast forward towards
4444  *
4445  * Reposition decoder at the last PSB with a timestamp earlier than @timestamp.
4446  *
4447  * Return: 0 on success or negative error code on failure.
4448  */
4449 int intel_pt_fast_forward(struct intel_pt_decoder *decoder, uint64_t timestamp)
4450 {
4451 	struct fast_forward_data d = { .timestamp = timestamp };
4452 	unsigned char *buf;
4453 	size_t len;
4454 	int err;
4455 
4456 	intel_pt_log("Fast forward towards timestamp " x64_fmt "\n", timestamp);
4457 
4458 	/* Find buffer timestamp of buffer to fast forward to */
4459 	err = decoder->lookahead(decoder->data, intel_pt_ff_cb, &d);
4460 	if (err < 0)
4461 		return err;
4462 
4463 	/* Walk to buffer with same buffer timestamp */
4464 	if (d.buf_timestamp) {
4465 		do {
4466 			decoder->pos += decoder->len;
4467 			decoder->len = 0;
4468 			err = intel_pt_get_next_data(decoder, true);
4469 			/* -ENOLINK means non-consecutive trace */
4470 			if (err && err != -ENOLINK)
4471 				return err;
4472 		} while (decoder->buf_timestamp != d.buf_timestamp);
4473 	}
4474 
4475 	if (!decoder->buf)
4476 		return 0;
4477 
4478 	buf = (unsigned char *)decoder->buf;
4479 	len = decoder->len;
4480 
4481 	if (!intel_pt_next_psb(&buf, &len))
4482 		return 0;
4483 
4484 	/*
4485 	 * Walk PSBs while the PSB timestamp is less than the fast forward
4486 	 * timestamp.
4487 	 */
4488 	do {
4489 		uint64_t tsc;
4490 		size_t rem;
4491 
4492 		if (!intel_pt_next_tsc(buf, len, &tsc, &rem))
4493 			break;
4494 		tsc = intel_pt_8b_tsc(tsc, decoder->buf_timestamp);
4495 		/*
4496 		 * A TSC packet can slip past MTC packets but, after fast
4497 		 * forward, decoding starts at the TSC timestamp. That means
4498 		 * the timestamps may not be exactly the same as the timestamps
4499 		 * that would have been decoded without fast forward.
4500 		 */
4501 		if (tsc < timestamp) {
4502 			intel_pt_log("Fast forward to next PSB timestamp " x64_fmt "\n", tsc);
4503 			decoder->pos += decoder->len - len;
4504 			decoder->buf = buf;
4505 			decoder->len = len;
4506 			intel_pt_reposition(decoder);
4507 		} else {
4508 			break;
4509 		}
4510 	} while (intel_pt_step_psb(&buf, &len));
4511 
4512 	return 0;
4513 }
4514