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 	decoder->state.insn_op = INTEL_PT_OP_OTHER;
1323 	decoder->state.insn_len = 0;
1324 
1325 	if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
1326 		bool ip = decoder->set_fup_cfe_ip;
1327 
1328 		decoder->set_fup_cfe_ip = false;
1329 		decoder->set_fup_cfe = false;
1330 		decoder->state.type |= INTEL_PT_EVT;
1331 		if (!ip && decoder->pge)
1332 			decoder->state.type |= INTEL_PT_BRANCH;
1333 		decoder->state.cfe_type = decoder->fup_cfe_pkt.count;
1334 		decoder->state.cfe_vector = decoder->fup_cfe_pkt.payload;
1335 		decoder->state.evd_cnt = decoder->evd_cnt;
1336 		decoder->state.evd = decoder->evd;
1337 		decoder->evd_cnt = 0;
1338 		if (ip || decoder->pge)
1339 			decoder->state.flags |= INTEL_PT_FUP_IP;
1340 		ret = true;
1341 	}
1342 	if (decoder->set_fup_mode_exec) {
1343 		decoder->set_fup_mode_exec = false;
1344 		intel_pt_sample_iflag(decoder);
1345 		sample_fup_insn = no_tip;
1346 		ret = true;
1347 	}
1348 	if (decoder->set_fup_tx_flags) {
1349 		decoder->set_fup_tx_flags = false;
1350 		decoder->tx_flags = decoder->fup_tx_flags;
1351 		decoder->state.type |= INTEL_PT_TRANSACTION;
1352 		if (decoder->fup_tx_flags & INTEL_PT_ABORT_TX)
1353 			decoder->state.type |= INTEL_PT_BRANCH;
1354 		decoder->state.flags = decoder->fup_tx_flags;
1355 		ret = true;
1356 	}
1357 	if (decoder->set_fup_ptw) {
1358 		decoder->set_fup_ptw = false;
1359 		decoder->state.type |= INTEL_PT_PTW;
1360 		decoder->state.flags |= INTEL_PT_FUP_IP;
1361 		decoder->state.ptw_payload = decoder->fup_ptw_payload;
1362 		ret = true;
1363 	}
1364 	if (decoder->set_fup_mwait) {
1365 		decoder->set_fup_mwait = false;
1366 		decoder->state.type |= INTEL_PT_MWAIT_OP;
1367 		decoder->state.mwait_payload = decoder->fup_mwait_payload;
1368 		ret = true;
1369 	}
1370 	if (decoder->set_fup_pwre) {
1371 		decoder->set_fup_pwre = false;
1372 		decoder->state.type |= INTEL_PT_PWR_ENTRY;
1373 		decoder->state.pwre_payload = decoder->fup_pwre_payload;
1374 		ret = true;
1375 	}
1376 	if (decoder->set_fup_exstop) {
1377 		decoder->set_fup_exstop = false;
1378 		decoder->state.type |= INTEL_PT_EX_STOP;
1379 		decoder->state.flags |= INTEL_PT_FUP_IP;
1380 		ret = true;
1381 	}
1382 	if (decoder->set_fup_bep) {
1383 		decoder->set_fup_bep = false;
1384 		decoder->state.type |= INTEL_PT_BLK_ITEMS;
1385 		ret = true;
1386 	}
1387 	if (decoder->overflow) {
1388 		decoder->overflow = false;
1389 		if (!ret && !decoder->pge) {
1390 			if (decoder->hop) {
1391 				decoder->state.type = 0;
1392 				decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
1393 			}
1394 			decoder->pge = true;
1395 			decoder->state.type |= INTEL_PT_BRANCH | INTEL_PT_TRACE_BEGIN;
1396 			decoder->state.from_ip = 0;
1397 			decoder->state.to_ip = decoder->ip;
1398 			return true;
1399 		}
1400 	}
1401 	if (ret) {
1402 		decoder->state.from_ip = decoder->ip;
1403 		decoder->state.to_ip = 0;
1404 		if (sample_fup_insn)
1405 			intel_pt_sample_fup_insn(decoder);
1406 	} else {
1407 		decoder->state.type = type;
1408 	}
1409 	return ret;
1410 }
1411 
1412 static inline bool intel_pt_fup_with_nlip(struct intel_pt_decoder *decoder,
1413 					  struct intel_pt_insn *intel_pt_insn,
1414 					  uint64_t ip, int err)
1415 {
1416 	return decoder->flags & INTEL_PT_FUP_WITH_NLIP && !err &&
1417 	       intel_pt_insn->branch == INTEL_PT_BR_INDIRECT &&
1418 	       ip == decoder->ip + intel_pt_insn->length;
1419 }
1420 
1421 static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
1422 {
1423 	struct intel_pt_insn intel_pt_insn;
1424 	uint64_t ip;
1425 	int err;
1426 
1427 	ip = decoder->last_ip;
1428 
1429 	while (1) {
1430 		err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
1431 		if (err == INTEL_PT_RETURN)
1432 			return 0;
1433 		if (err == -EAGAIN ||
1434 		    intel_pt_fup_with_nlip(decoder, &intel_pt_insn, ip, err)) {
1435 			bool no_tip = decoder->pkt_state != INTEL_PT_STATE_FUP;
1436 
1437 			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1438 			if (intel_pt_fup_event(decoder, no_tip) && no_tip)
1439 				return 0;
1440 			return -EAGAIN;
1441 		}
1442 		decoder->set_fup_tx_flags = false;
1443 		if (err)
1444 			return err;
1445 
1446 		if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1447 			intel_pt_log_at("ERROR: Unexpected indirect branch",
1448 					decoder->ip);
1449 			decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1450 			return -ENOENT;
1451 		}
1452 
1453 		if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1454 			intel_pt_log_at("ERROR: Unexpected conditional branch",
1455 					decoder->ip);
1456 			decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1457 			return -ENOENT;
1458 		}
1459 
1460 		intel_pt_bug(decoder);
1461 	}
1462 }
1463 
1464 static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
1465 {
1466 	struct intel_pt_insn intel_pt_insn;
1467 	int err;
1468 
1469 	err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1470 	if (err == INTEL_PT_RETURN &&
1471 	    decoder->pgd_ip &&
1472 	    decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1473 	    (decoder->state.type & INTEL_PT_BRANCH) &&
1474 	    decoder->pgd_ip(decoder->state.to_ip, decoder->data)) {
1475 		/* Unconditional branch leaving filter region */
1476 		decoder->no_progress = 0;
1477 		decoder->pge = false;
1478 		decoder->continuous_period = false;
1479 		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1480 		decoder->state.type |= INTEL_PT_TRACE_END;
1481 		intel_pt_update_nr(decoder);
1482 		return 0;
1483 	}
1484 	if (err == INTEL_PT_RETURN)
1485 		return 0;
1486 	if (err)
1487 		return err;
1488 
1489 	intel_pt_update_nr(decoder);
1490 	intel_pt_sample_iflag_chg(decoder);
1491 
1492 	if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1493 		if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
1494 			decoder->pge = false;
1495 			decoder->continuous_period = false;
1496 			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1497 			decoder->state.from_ip = decoder->ip;
1498 			if (decoder->packet.count == 0) {
1499 				decoder->state.to_ip = 0;
1500 			} else {
1501 				decoder->state.to_ip = decoder->last_ip;
1502 				decoder->ip = decoder->last_ip;
1503 			}
1504 			decoder->state.type |= INTEL_PT_TRACE_END;
1505 		} else {
1506 			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1507 			decoder->state.from_ip = decoder->ip;
1508 			if (decoder->packet.count == 0) {
1509 				decoder->state.to_ip = 0;
1510 			} else {
1511 				decoder->state.to_ip = decoder->last_ip;
1512 				decoder->ip = decoder->last_ip;
1513 			}
1514 		}
1515 		return 0;
1516 	}
1517 
1518 	if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1519 		uint64_t to_ip = decoder->ip + intel_pt_insn.length +
1520 				 intel_pt_insn.rel;
1521 
1522 		if (decoder->pgd_ip &&
1523 		    decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1524 		    decoder->pgd_ip(to_ip, decoder->data)) {
1525 			/* Conditional branch leaving filter region */
1526 			decoder->pge = false;
1527 			decoder->continuous_period = false;
1528 			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1529 			decoder->ip = to_ip;
1530 			decoder->state.from_ip = decoder->ip;
1531 			decoder->state.to_ip = to_ip;
1532 			decoder->state.type |= INTEL_PT_TRACE_END;
1533 			return 0;
1534 		}
1535 		intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
1536 				decoder->ip);
1537 		decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1538 		return -ENOENT;
1539 	}
1540 
1541 	return intel_pt_bug(decoder);
1542 }
1543 
1544 struct eptw_data {
1545 	int bit_countdown;
1546 	uint64_t payload;
1547 };
1548 
1549 static int intel_pt_eptw_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
1550 {
1551 	struct eptw_data *data = pkt_info->data;
1552 	int nr_bits;
1553 
1554 	switch (pkt_info->packet.type) {
1555 	case INTEL_PT_PAD:
1556 	case INTEL_PT_MNT:
1557 	case INTEL_PT_MODE_EXEC:
1558 	case INTEL_PT_MODE_TSX:
1559 	case INTEL_PT_MTC:
1560 	case INTEL_PT_FUP:
1561 	case INTEL_PT_CYC:
1562 	case INTEL_PT_CBR:
1563 	case INTEL_PT_TSC:
1564 	case INTEL_PT_TMA:
1565 	case INTEL_PT_PIP:
1566 	case INTEL_PT_VMCS:
1567 	case INTEL_PT_PSB:
1568 	case INTEL_PT_PSBEND:
1569 	case INTEL_PT_PTWRITE:
1570 	case INTEL_PT_PTWRITE_IP:
1571 	case INTEL_PT_EXSTOP:
1572 	case INTEL_PT_EXSTOP_IP:
1573 	case INTEL_PT_MWAIT:
1574 	case INTEL_PT_PWRE:
1575 	case INTEL_PT_PWRX:
1576 	case INTEL_PT_BBP:
1577 	case INTEL_PT_BIP:
1578 	case INTEL_PT_BEP:
1579 	case INTEL_PT_BEP_IP:
1580 	case INTEL_PT_CFE:
1581 	case INTEL_PT_CFE_IP:
1582 	case INTEL_PT_EVD:
1583 		break;
1584 
1585 	case INTEL_PT_TNT:
1586 		nr_bits = data->bit_countdown;
1587 		if (nr_bits > pkt_info->packet.count)
1588 			nr_bits = pkt_info->packet.count;
1589 		data->payload <<= nr_bits;
1590 		data->payload |= pkt_info->packet.payload >> (64 - nr_bits);
1591 		data->bit_countdown -= nr_bits;
1592 		return !data->bit_countdown;
1593 
1594 	case INTEL_PT_TIP_PGE:
1595 	case INTEL_PT_TIP_PGD:
1596 	case INTEL_PT_TIP:
1597 	case INTEL_PT_BAD:
1598 	case INTEL_PT_OVF:
1599 	case INTEL_PT_TRACESTOP:
1600 	default:
1601 		return 1;
1602 	}
1603 
1604 	return 0;
1605 }
1606 
1607 static int intel_pt_emulated_ptwrite(struct intel_pt_decoder *decoder)
1608 {
1609 	int n = 64 - decoder->tnt.count;
1610 	struct eptw_data data = {
1611 		.bit_countdown = n,
1612 		.payload = decoder->tnt.payload >> n,
1613 	};
1614 
1615 	decoder->emulated_ptwrite = false;
1616 	intel_pt_log("Emulated ptwrite detected\n");
1617 
1618 	intel_pt_pkt_lookahead(decoder, intel_pt_eptw_lookahead_cb, &data);
1619 	if (data.bit_countdown)
1620 		return -ECONNRESET;
1621 
1622 	decoder->state.type = INTEL_PT_PTW;
1623 	decoder->state.from_ip = decoder->ip;
1624 	decoder->state.to_ip = 0;
1625 	decoder->state.ptw_payload = data.payload;
1626 	return 0;
1627 }
1628 
1629 static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
1630 {
1631 	struct intel_pt_insn intel_pt_insn;
1632 	int err;
1633 
1634 	while (1) {
1635 		if (decoder->emulated_ptwrite)
1636 			return intel_pt_emulated_ptwrite(decoder);
1637 		err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1638 		if (err == INTEL_PT_RETURN) {
1639 			decoder->emulated_ptwrite = intel_pt_insn.emulated_ptwrite;
1640 			return 0;
1641 		}
1642 		if (err) {
1643 			decoder->emulated_ptwrite = false;
1644 			return err;
1645 		}
1646 
1647 		if (intel_pt_insn.op == INTEL_PT_OP_RET) {
1648 			if (!decoder->return_compression) {
1649 				intel_pt_log_at("ERROR: RET when expecting conditional branch",
1650 						decoder->ip);
1651 				decoder->pkt_state = INTEL_PT_STATE_ERR3;
1652 				return -ENOENT;
1653 			}
1654 			if (!decoder->ret_addr) {
1655 				intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
1656 						decoder->ip);
1657 				decoder->pkt_state = INTEL_PT_STATE_ERR3;
1658 				return -ENOENT;
1659 			}
1660 			if (!(decoder->tnt.payload & BIT63)) {
1661 				intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
1662 						decoder->ip);
1663 				decoder->pkt_state = INTEL_PT_STATE_ERR3;
1664 				return -ENOENT;
1665 			}
1666 			decoder->tnt.count -= 1;
1667 			if (decoder->tnt.count)
1668 				decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
1669 			else
1670 				decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1671 			decoder->tnt.payload <<= 1;
1672 			decoder->state.from_ip = decoder->ip;
1673 			decoder->ip = decoder->ret_addr;
1674 			decoder->state.to_ip = decoder->ip;
1675 			return 0;
1676 		}
1677 
1678 		if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1679 			/* Handle deferred TIPs */
1680 			err = intel_pt_get_next_packet(decoder);
1681 			if (err)
1682 				return err;
1683 			if (decoder->packet.type != INTEL_PT_TIP ||
1684 			    decoder->packet.count == 0) {
1685 				intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
1686 						decoder->ip);
1687 				decoder->pkt_state = INTEL_PT_STATE_ERR3;
1688 				decoder->pkt_step = 0;
1689 				return -ENOENT;
1690 			}
1691 			intel_pt_set_last_ip(decoder);
1692 			decoder->state.from_ip = decoder->ip;
1693 			decoder->state.to_ip = decoder->last_ip;
1694 			decoder->ip = decoder->last_ip;
1695 			intel_pt_update_nr(decoder);
1696 			intel_pt_sample_iflag_chg(decoder);
1697 			return 0;
1698 		}
1699 
1700 		if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1701 			decoder->tnt.count -= 1;
1702 			if (decoder->tnt.count)
1703 				decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
1704 			else
1705 				decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1706 			if (decoder->tnt.payload & BIT63) {
1707 				decoder->tnt.payload <<= 1;
1708 				decoder->state.from_ip = decoder->ip;
1709 				decoder->ip += intel_pt_insn.length +
1710 					       intel_pt_insn.rel;
1711 				decoder->state.to_ip = decoder->ip;
1712 				return 0;
1713 			}
1714 			/* Instruction sample for a non-taken branch */
1715 			if (decoder->state.type & INTEL_PT_INSTRUCTION) {
1716 				decoder->tnt.payload <<= 1;
1717 				decoder->state.type = INTEL_PT_INSTRUCTION;
1718 				decoder->state.from_ip = decoder->ip;
1719 				decoder->state.to_ip = 0;
1720 				decoder->ip += intel_pt_insn.length;
1721 				return 0;
1722 			}
1723 			decoder->sample_cyc = false;
1724 			decoder->ip += intel_pt_insn.length;
1725 			if (!decoder->tnt.count) {
1726 				intel_pt_update_sample_time(decoder);
1727 				return -EAGAIN;
1728 			}
1729 			decoder->tnt.payload <<= 1;
1730 			continue;
1731 		}
1732 
1733 		return intel_pt_bug(decoder);
1734 	}
1735 }
1736 
1737 static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
1738 {
1739 	unsigned int fup_tx_flags;
1740 	int err;
1741 
1742 	fup_tx_flags = decoder->packet.payload &
1743 		       (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
1744 	err = intel_pt_get_next_packet(decoder);
1745 	if (err)
1746 		return err;
1747 	if (decoder->packet.type == INTEL_PT_FUP) {
1748 		decoder->fup_tx_flags = fup_tx_flags;
1749 		decoder->set_fup_tx_flags = true;
1750 		if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
1751 			*no_tip = true;
1752 	} else {
1753 		intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
1754 				decoder->pos);
1755 		intel_pt_update_in_tx(decoder);
1756 	}
1757 	return 0;
1758 }
1759 
1760 static int intel_pt_evd(struct intel_pt_decoder *decoder)
1761 {
1762 	if (decoder->evd_cnt >= INTEL_PT_MAX_EVDS) {
1763 		intel_pt_log_at("ERROR: Too many EVD packets", decoder->pos);
1764 		return -ENOSYS;
1765 	}
1766 	decoder->evd[decoder->evd_cnt++] = (struct intel_pt_evd){
1767 		.type = decoder->packet.count,
1768 		.payload = decoder->packet.payload,
1769 	};
1770 	return 0;
1771 }
1772 
1773 static uint64_t intel_pt_8b_tsc(uint64_t timestamp, uint64_t ref_timestamp)
1774 {
1775 	timestamp |= (ref_timestamp & (0xffULL << 56));
1776 
1777 	if (timestamp < ref_timestamp) {
1778 		if (ref_timestamp - timestamp > (1ULL << 55))
1779 			timestamp += (1ULL << 56);
1780 	} else {
1781 		if (timestamp - ref_timestamp > (1ULL << 55))
1782 			timestamp -= (1ULL << 56);
1783 	}
1784 
1785 	return timestamp;
1786 }
1787 
1788 /* For use only when decoder->vm_time_correlation is true */
1789 static bool intel_pt_time_in_range(struct intel_pt_decoder *decoder,
1790 				   uint64_t timestamp)
1791 {
1792 	uint64_t max_timestamp = decoder->buf_timestamp;
1793 
1794 	if (!max_timestamp) {
1795 		max_timestamp = decoder->last_reliable_timestamp +
1796 				0x400000000ULL;
1797 	}
1798 	return timestamp >= decoder->last_reliable_timestamp &&
1799 	       timestamp < decoder->buf_timestamp;
1800 }
1801 
1802 static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
1803 {
1804 	uint64_t timestamp;
1805 	bool bad = false;
1806 
1807 	decoder->have_tma = false;
1808 
1809 	if (decoder->ref_timestamp) {
1810 		timestamp = intel_pt_8b_tsc(decoder->packet.payload,
1811 					    decoder->ref_timestamp);
1812 		decoder->tsc_timestamp = timestamp;
1813 		decoder->timestamp = timestamp;
1814 		decoder->ref_timestamp = 0;
1815 		decoder->timestamp_insn_cnt = 0;
1816 	} else if (decoder->timestamp) {
1817 		timestamp = decoder->packet.payload |
1818 			    (decoder->timestamp & (0xffULL << 56));
1819 		decoder->tsc_timestamp = timestamp;
1820 		if (timestamp < decoder->timestamp &&
1821 		    decoder->timestamp - timestamp < decoder->tsc_slip) {
1822 			intel_pt_log_to("Suppressing backwards timestamp",
1823 					timestamp);
1824 			timestamp = decoder->timestamp;
1825 		}
1826 		if (timestamp < decoder->timestamp) {
1827 			if (!decoder->buf_timestamp ||
1828 			    (timestamp + (1ULL << 56) < decoder->buf_timestamp)) {
1829 				intel_pt_log_to("Wraparound timestamp", timestamp);
1830 				timestamp += (1ULL << 56);
1831 				decoder->tsc_timestamp = timestamp;
1832 			} else {
1833 				intel_pt_log_to("Suppressing bad timestamp", timestamp);
1834 				timestamp = decoder->timestamp;
1835 				bad = true;
1836 			}
1837 		}
1838 		if (decoder->vm_time_correlation &&
1839 		    (bad || !intel_pt_time_in_range(decoder, timestamp)) &&
1840 		    intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
1841 			p_log("Timestamp out of range");
1842 		decoder->timestamp = timestamp;
1843 		decoder->timestamp_insn_cnt = 0;
1844 	}
1845 
1846 	if (decoder->last_packet_type == INTEL_PT_CYC) {
1847 		decoder->cyc_ref_timestamp = decoder->timestamp;
1848 		decoder->cycle_cnt = 0;
1849 		decoder->have_calc_cyc_to_tsc = false;
1850 		intel_pt_calc_cyc_to_tsc(decoder, false);
1851 	}
1852 
1853 	intel_pt_log_to("Setting timestamp", decoder->timestamp);
1854 }
1855 
1856 static int intel_pt_overflow(struct intel_pt_decoder *decoder)
1857 {
1858 	intel_pt_log("ERROR: Buffer overflow\n");
1859 	intel_pt_clear_tx_flags(decoder);
1860 	intel_pt_set_nr(decoder);
1861 	decoder->timestamp_insn_cnt = 0;
1862 	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1863 	decoder->state.from_ip = decoder->ip;
1864 	decoder->ip = 0;
1865 	decoder->pge = false;
1866 	intel_pt_clear_fup_event(decoder);
1867 	decoder->overflow = true;
1868 	return -EOVERFLOW;
1869 }
1870 
1871 static inline void intel_pt_mtc_cyc_cnt_pge(struct intel_pt_decoder *decoder)
1872 {
1873 	if (decoder->have_cyc)
1874 		return;
1875 
1876 	decoder->cyc_cnt_timestamp = decoder->timestamp;
1877 	decoder->base_cyc_cnt = decoder->tot_cyc_cnt;
1878 }
1879 
1880 static inline void intel_pt_mtc_cyc_cnt_cbr(struct intel_pt_decoder *decoder)
1881 {
1882 	decoder->tsc_to_cyc = decoder->cbr / decoder->max_non_turbo_ratio_fp;
1883 
1884 	if (decoder->pge)
1885 		intel_pt_mtc_cyc_cnt_pge(decoder);
1886 }
1887 
1888 static inline void intel_pt_mtc_cyc_cnt_upd(struct intel_pt_decoder *decoder)
1889 {
1890 	uint64_t tot_cyc_cnt, tsc_delta;
1891 
1892 	if (decoder->have_cyc)
1893 		return;
1894 
1895 	decoder->sample_cyc = true;
1896 
1897 	if (!decoder->pge || decoder->timestamp <= decoder->cyc_cnt_timestamp)
1898 		return;
1899 
1900 	tsc_delta = decoder->timestamp - decoder->cyc_cnt_timestamp;
1901 	tot_cyc_cnt = tsc_delta * decoder->tsc_to_cyc + decoder->base_cyc_cnt;
1902 
1903 	if (tot_cyc_cnt > decoder->tot_cyc_cnt)
1904 		decoder->tot_cyc_cnt = tot_cyc_cnt;
1905 }
1906 
1907 static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
1908 {
1909 	uint32_t ctc = decoder->packet.payload;
1910 	uint32_t fc = decoder->packet.count;
1911 	uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;
1912 
1913 	if (!decoder->tsc_ctc_ratio_d)
1914 		return;
1915 
1916 	if (decoder->pge && !decoder->in_psb)
1917 		intel_pt_mtc_cyc_cnt_pge(decoder);
1918 	else
1919 		intel_pt_mtc_cyc_cnt_upd(decoder);
1920 
1921 	decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
1922 	decoder->last_ctc = ctc - ctc_rem;
1923 	decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
1924 	if (decoder->tsc_ctc_mult) {
1925 		decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
1926 	} else {
1927 		decoder->ctc_timestamp -= multdiv(ctc_rem,
1928 						  decoder->tsc_ctc_ratio_n,
1929 						  decoder->tsc_ctc_ratio_d);
1930 	}
1931 	decoder->ctc_delta = 0;
1932 	decoder->have_tma = true;
1933 	decoder->fixup_last_mtc = true;
1934 	intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x  CTC rem %#x\n",
1935 		     decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
1936 }
1937 
1938 static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
1939 {
1940 	uint64_t timestamp;
1941 	uint32_t mtc, mtc_delta;
1942 
1943 	if (!decoder->have_tma)
1944 		return;
1945 
1946 	mtc = decoder->packet.payload;
1947 
1948 	if (decoder->mtc_shift > 8 && decoder->fixup_last_mtc) {
1949 		decoder->fixup_last_mtc = false;
1950 		intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
1951 					&decoder->last_mtc);
1952 	}
1953 
1954 	if (mtc > decoder->last_mtc)
1955 		mtc_delta = mtc - decoder->last_mtc;
1956 	else
1957 		mtc_delta = mtc + 256 - decoder->last_mtc;
1958 
1959 	decoder->ctc_delta += mtc_delta << decoder->mtc_shift;
1960 
1961 	if (decoder->tsc_ctc_mult) {
1962 		timestamp = decoder->ctc_timestamp +
1963 			    decoder->ctc_delta * decoder->tsc_ctc_mult;
1964 	} else {
1965 		timestamp = decoder->ctc_timestamp +
1966 			    multdiv(decoder->ctc_delta,
1967 				    decoder->tsc_ctc_ratio_n,
1968 				    decoder->tsc_ctc_ratio_d);
1969 	}
1970 
1971 	if (timestamp < decoder->timestamp)
1972 		intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1973 			     timestamp, decoder->timestamp);
1974 	else
1975 		decoder->timestamp = timestamp;
1976 
1977 	intel_pt_mtc_cyc_cnt_upd(decoder);
1978 
1979 	decoder->timestamp_insn_cnt = 0;
1980 	decoder->last_mtc = mtc;
1981 
1982 	if (decoder->last_packet_type == INTEL_PT_CYC) {
1983 		decoder->cyc_ref_timestamp = decoder->timestamp;
1984 		decoder->cycle_cnt = 0;
1985 		decoder->have_calc_cyc_to_tsc = false;
1986 		intel_pt_calc_cyc_to_tsc(decoder, true);
1987 	}
1988 
1989 	intel_pt_log_to("Setting timestamp", decoder->timestamp);
1990 }
1991 
1992 static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
1993 {
1994 	unsigned int cbr = decoder->packet.payload & 0xff;
1995 
1996 	decoder->cbr_payload = decoder->packet.payload;
1997 
1998 	if (decoder->cbr == cbr)
1999 		return;
2000 
2001 	decoder->cbr = cbr;
2002 	decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
2003 	decoder->cyc_ref_timestamp = decoder->timestamp;
2004 	decoder->cycle_cnt = 0;
2005 
2006 	intel_pt_mtc_cyc_cnt_cbr(decoder);
2007 }
2008 
2009 static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
2010 {
2011 	uint64_t timestamp = decoder->cyc_ref_timestamp;
2012 
2013 	decoder->have_cyc = true;
2014 
2015 	decoder->cycle_cnt += decoder->packet.payload;
2016 	if (decoder->pge)
2017 		decoder->tot_cyc_cnt += decoder->packet.payload;
2018 	decoder->sample_cyc = true;
2019 
2020 	if (!decoder->cyc_ref_timestamp)
2021 		return;
2022 
2023 	if (decoder->have_calc_cyc_to_tsc)
2024 		timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
2025 	else if (decoder->cbr)
2026 		timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
2027 	else
2028 		return;
2029 
2030 	if (timestamp < decoder->timestamp)
2031 		intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
2032 			     timestamp, decoder->timestamp);
2033 	else
2034 		decoder->timestamp = timestamp;
2035 
2036 	decoder->timestamp_insn_cnt = 0;
2037 
2038 	intel_pt_log_to("Setting timestamp", decoder->timestamp);
2039 }
2040 
2041 static void intel_pt_bbp(struct intel_pt_decoder *decoder)
2042 {
2043 	if (decoder->prev_pkt_ctx == INTEL_PT_NO_CTX) {
2044 		memset(decoder->state.items.mask, 0, sizeof(decoder->state.items.mask));
2045 		decoder->state.items.is_32_bit = false;
2046 	}
2047 	decoder->blk_type = decoder->packet.payload;
2048 	decoder->blk_type_pos = intel_pt_blk_type_pos(decoder->blk_type);
2049 	if (decoder->blk_type == INTEL_PT_GP_REGS)
2050 		decoder->state.items.is_32_bit = decoder->packet.count;
2051 	if (decoder->blk_type_pos < 0) {
2052 		intel_pt_log("WARNING: Unknown block type %u\n",
2053 			     decoder->blk_type);
2054 	} else if (decoder->state.items.mask[decoder->blk_type_pos]) {
2055 		intel_pt_log("WARNING: Duplicate block type %u\n",
2056 			     decoder->blk_type);
2057 	}
2058 }
2059 
2060 static void intel_pt_bip(struct intel_pt_decoder *decoder)
2061 {
2062 	uint32_t id = decoder->packet.count;
2063 	uint32_t bit = 1 << id;
2064 	int pos = decoder->blk_type_pos;
2065 
2066 	if (pos < 0 || id >= INTEL_PT_BLK_ITEM_ID_CNT) {
2067 		intel_pt_log("WARNING: Unknown block item %u type %d\n",
2068 			     id, decoder->blk_type);
2069 		return;
2070 	}
2071 
2072 	if (decoder->state.items.mask[pos] & bit) {
2073 		intel_pt_log("WARNING: Duplicate block item %u type %d\n",
2074 			     id, decoder->blk_type);
2075 	}
2076 
2077 	decoder->state.items.mask[pos] |= bit;
2078 	decoder->state.items.val[pos][id] = decoder->packet.payload;
2079 }
2080 
2081 /* Walk PSB+ packets when already in sync. */
2082 static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
2083 {
2084 	int err;
2085 
2086 	decoder->in_psb = true;
2087 
2088 	while (1) {
2089 		err = intel_pt_get_next_packet(decoder);
2090 		if (err)
2091 			goto out;
2092 
2093 		switch (decoder->packet.type) {
2094 		case INTEL_PT_PSBEND:
2095 			err = 0;
2096 			goto out;
2097 
2098 		case INTEL_PT_TIP_PGD:
2099 		case INTEL_PT_TIP_PGE:
2100 		case INTEL_PT_TIP:
2101 		case INTEL_PT_TNT:
2102 		case INTEL_PT_TRACESTOP:
2103 		case INTEL_PT_BAD:
2104 		case INTEL_PT_PSB:
2105 		case INTEL_PT_PTWRITE:
2106 		case INTEL_PT_PTWRITE_IP:
2107 		case INTEL_PT_EXSTOP:
2108 		case INTEL_PT_EXSTOP_IP:
2109 		case INTEL_PT_MWAIT:
2110 		case INTEL_PT_PWRE:
2111 		case INTEL_PT_PWRX:
2112 		case INTEL_PT_BBP:
2113 		case INTEL_PT_BIP:
2114 		case INTEL_PT_BEP:
2115 		case INTEL_PT_BEP_IP:
2116 		case INTEL_PT_CFE:
2117 		case INTEL_PT_CFE_IP:
2118 		case INTEL_PT_EVD:
2119 			decoder->have_tma = false;
2120 			intel_pt_log("ERROR: Unexpected packet\n");
2121 			err = -EAGAIN;
2122 			goto out;
2123 
2124 		case INTEL_PT_OVF:
2125 			err = intel_pt_overflow(decoder);
2126 			goto out;
2127 
2128 		case INTEL_PT_TSC:
2129 			intel_pt_calc_tsc_timestamp(decoder);
2130 			break;
2131 
2132 		case INTEL_PT_TMA:
2133 			intel_pt_calc_tma(decoder);
2134 			break;
2135 
2136 		case INTEL_PT_CBR:
2137 			intel_pt_calc_cbr(decoder);
2138 			break;
2139 
2140 		case INTEL_PT_MODE_EXEC:
2141 			intel_pt_mode_exec_status(decoder);
2142 			break;
2143 
2144 		case INTEL_PT_PIP:
2145 			intel_pt_set_pip(decoder);
2146 			break;
2147 
2148 		case INTEL_PT_FUP:
2149 			decoder->pge = true;
2150 			if (decoder->packet.count) {
2151 				intel_pt_set_last_ip(decoder);
2152 				decoder->psb_ip = decoder->last_ip;
2153 			}
2154 			break;
2155 
2156 		case INTEL_PT_MODE_TSX:
2157 			intel_pt_update_in_tx(decoder);
2158 			break;
2159 
2160 		case INTEL_PT_MTC:
2161 			intel_pt_calc_mtc_timestamp(decoder);
2162 			if (decoder->period_type == INTEL_PT_PERIOD_MTC)
2163 				decoder->state.type |= INTEL_PT_INSTRUCTION;
2164 			break;
2165 
2166 		case INTEL_PT_CYC:
2167 			intel_pt_calc_cyc_timestamp(decoder);
2168 			break;
2169 
2170 		case INTEL_PT_VMCS:
2171 		case INTEL_PT_MNT:
2172 		case INTEL_PT_PAD:
2173 		default:
2174 			break;
2175 		}
2176 	}
2177 out:
2178 	decoder->in_psb = false;
2179 
2180 	return err;
2181 }
2182 
2183 static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
2184 {
2185 	int err;
2186 
2187 	if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
2188 		decoder->tx_flags = 0;
2189 		decoder->state.flags &= ~INTEL_PT_IN_TX;
2190 		decoder->state.flags |= INTEL_PT_ABORT_TX;
2191 	} else {
2192 		decoder->state.flags |= INTEL_PT_ASYNC;
2193 	}
2194 
2195 	while (1) {
2196 		err = intel_pt_get_next_packet(decoder);
2197 		if (err)
2198 			return err;
2199 
2200 		switch (decoder->packet.type) {
2201 		case INTEL_PT_TNT:
2202 		case INTEL_PT_FUP:
2203 		case INTEL_PT_TRACESTOP:
2204 		case INTEL_PT_PSB:
2205 		case INTEL_PT_TSC:
2206 		case INTEL_PT_TMA:
2207 		case INTEL_PT_MODE_TSX:
2208 		case INTEL_PT_BAD:
2209 		case INTEL_PT_PSBEND:
2210 		case INTEL_PT_PTWRITE:
2211 		case INTEL_PT_PTWRITE_IP:
2212 		case INTEL_PT_EXSTOP:
2213 		case INTEL_PT_EXSTOP_IP:
2214 		case INTEL_PT_MWAIT:
2215 		case INTEL_PT_PWRE:
2216 		case INTEL_PT_PWRX:
2217 		case INTEL_PT_BBP:
2218 		case INTEL_PT_BIP:
2219 		case INTEL_PT_BEP:
2220 		case INTEL_PT_BEP_IP:
2221 		case INTEL_PT_CFE:
2222 		case INTEL_PT_CFE_IP:
2223 		case INTEL_PT_EVD:
2224 			intel_pt_log("ERROR: Missing TIP after FUP\n");
2225 			decoder->pkt_state = INTEL_PT_STATE_ERR3;
2226 			decoder->pkt_step = 0;
2227 			return -ENOENT;
2228 
2229 		case INTEL_PT_CBR:
2230 			intel_pt_calc_cbr(decoder);
2231 			break;
2232 
2233 		case INTEL_PT_OVF:
2234 			return intel_pt_overflow(decoder);
2235 
2236 		case INTEL_PT_TIP_PGD:
2237 			decoder->state.from_ip = decoder->ip;
2238 			if (decoder->packet.count == 0) {
2239 				decoder->state.to_ip = 0;
2240 			} else {
2241 				intel_pt_set_ip(decoder);
2242 				decoder->state.to_ip = decoder->ip;
2243 			}
2244 			decoder->pge = false;
2245 			decoder->continuous_period = false;
2246 			decoder->state.type |= INTEL_PT_TRACE_END;
2247 			intel_pt_update_nr(decoder);
2248 			return 0;
2249 
2250 		case INTEL_PT_TIP_PGE:
2251 			decoder->pge = true;
2252 			intel_pt_log("Omitting PGE ip " x64_fmt "\n",
2253 				     decoder->ip);
2254 			decoder->state.from_ip = 0;
2255 			if (decoder->packet.count == 0) {
2256 				decoder->state.to_ip = 0;
2257 			} else {
2258 				intel_pt_set_ip(decoder);
2259 				decoder->state.to_ip = decoder->ip;
2260 			}
2261 			decoder->state.type |= INTEL_PT_TRACE_BEGIN;
2262 			intel_pt_mtc_cyc_cnt_pge(decoder);
2263 			intel_pt_set_nr(decoder);
2264 			return 0;
2265 
2266 		case INTEL_PT_TIP:
2267 			decoder->state.from_ip = decoder->ip;
2268 			if (decoder->packet.count == 0) {
2269 				decoder->state.to_ip = 0;
2270 			} else {
2271 				intel_pt_set_ip(decoder);
2272 				decoder->state.to_ip = decoder->ip;
2273 			}
2274 			intel_pt_update_nr(decoder);
2275 			intel_pt_sample_iflag_chg(decoder);
2276 			return 0;
2277 
2278 		case INTEL_PT_PIP:
2279 			intel_pt_update_pip(decoder);
2280 			break;
2281 
2282 		case INTEL_PT_MTC:
2283 			intel_pt_calc_mtc_timestamp(decoder);
2284 			if (decoder->period_type == INTEL_PT_PERIOD_MTC)
2285 				decoder->state.type |= INTEL_PT_INSTRUCTION;
2286 			break;
2287 
2288 		case INTEL_PT_CYC:
2289 			intel_pt_calc_cyc_timestamp(decoder);
2290 			break;
2291 
2292 		case INTEL_PT_MODE_EXEC:
2293 			intel_pt_mode_exec(decoder);
2294 			break;
2295 
2296 		case INTEL_PT_VMCS:
2297 		case INTEL_PT_MNT:
2298 		case INTEL_PT_PAD:
2299 			break;
2300 
2301 		default:
2302 			return intel_pt_bug(decoder);
2303 		}
2304 	}
2305 }
2306 
2307 static int intel_pt_resample(struct intel_pt_decoder *decoder)
2308 {
2309 	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2310 	decoder->state.type = INTEL_PT_INSTRUCTION;
2311 	decoder->state.from_ip = decoder->ip;
2312 	decoder->state.to_ip = 0;
2313 	return 0;
2314 }
2315 
2316 struct intel_pt_vm_tsc_info {
2317 	struct intel_pt_pkt pip_packet;
2318 	struct intel_pt_pkt vmcs_packet;
2319 	struct intel_pt_pkt tma_packet;
2320 	bool tsc, pip, vmcs, tma, psbend;
2321 	uint64_t ctc_delta;
2322 	uint64_t last_ctc;
2323 	int max_lookahead;
2324 };
2325 
2326 /* Lookahead and get the PIP, VMCS and TMA packets from PSB+ */
2327 static int intel_pt_vm_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2328 {
2329 	struct intel_pt_vm_tsc_info *data = pkt_info->data;
2330 
2331 	switch (pkt_info->packet.type) {
2332 	case INTEL_PT_PAD:
2333 	case INTEL_PT_MNT:
2334 	case INTEL_PT_MODE_EXEC:
2335 	case INTEL_PT_MODE_TSX:
2336 	case INTEL_PT_MTC:
2337 	case INTEL_PT_FUP:
2338 	case INTEL_PT_CYC:
2339 	case INTEL_PT_CBR:
2340 		break;
2341 
2342 	case INTEL_PT_TSC:
2343 		data->tsc = true;
2344 		break;
2345 
2346 	case INTEL_PT_TMA:
2347 		data->tma_packet = pkt_info->packet;
2348 		data->tma = true;
2349 		break;
2350 
2351 	case INTEL_PT_PIP:
2352 		data->pip_packet = pkt_info->packet;
2353 		data->pip = true;
2354 		break;
2355 
2356 	case INTEL_PT_VMCS:
2357 		data->vmcs_packet = pkt_info->packet;
2358 		data->vmcs = true;
2359 		break;
2360 
2361 	case INTEL_PT_PSBEND:
2362 		data->psbend = true;
2363 		return 1;
2364 
2365 	case INTEL_PT_TIP_PGE:
2366 	case INTEL_PT_PTWRITE:
2367 	case INTEL_PT_PTWRITE_IP:
2368 	case INTEL_PT_EXSTOP:
2369 	case INTEL_PT_EXSTOP_IP:
2370 	case INTEL_PT_MWAIT:
2371 	case INTEL_PT_PWRE:
2372 	case INTEL_PT_PWRX:
2373 	case INTEL_PT_BBP:
2374 	case INTEL_PT_BIP:
2375 	case INTEL_PT_BEP:
2376 	case INTEL_PT_BEP_IP:
2377 	case INTEL_PT_OVF:
2378 	case INTEL_PT_BAD:
2379 	case INTEL_PT_TNT:
2380 	case INTEL_PT_TIP_PGD:
2381 	case INTEL_PT_TIP:
2382 	case INTEL_PT_PSB:
2383 	case INTEL_PT_TRACESTOP:
2384 	case INTEL_PT_CFE:
2385 	case INTEL_PT_CFE_IP:
2386 	case INTEL_PT_EVD:
2387 	default:
2388 		return 1;
2389 	}
2390 
2391 	return 0;
2392 }
2393 
2394 struct intel_pt_ovf_fup_info {
2395 	int max_lookahead;
2396 	bool found;
2397 };
2398 
2399 /* Lookahead to detect a FUP packet after OVF */
2400 static int intel_pt_ovf_fup_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2401 {
2402 	struct intel_pt_ovf_fup_info *data = pkt_info->data;
2403 
2404 	if (pkt_info->packet.type == INTEL_PT_CYC ||
2405 	    pkt_info->packet.type == INTEL_PT_MTC ||
2406 	    pkt_info->packet.type == INTEL_PT_TSC)
2407 		return !--(data->max_lookahead);
2408 	data->found = pkt_info->packet.type == INTEL_PT_FUP;
2409 	return 1;
2410 }
2411 
2412 static bool intel_pt_ovf_fup_lookahead(struct intel_pt_decoder *decoder)
2413 {
2414 	struct intel_pt_ovf_fup_info data = {
2415 		.max_lookahead = 16,
2416 		.found = false,
2417 	};
2418 
2419 	intel_pt_pkt_lookahead(decoder, intel_pt_ovf_fup_lookahead_cb, &data);
2420 	return data.found;
2421 }
2422 
2423 /* Lookahead and get the TMA packet after TSC */
2424 static int intel_pt_tma_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2425 {
2426 	struct intel_pt_vm_tsc_info *data = pkt_info->data;
2427 
2428 	if (pkt_info->packet.type == INTEL_PT_CYC ||
2429 	    pkt_info->packet.type == INTEL_PT_MTC)
2430 		return !--(data->max_lookahead);
2431 
2432 	if (pkt_info->packet.type == INTEL_PT_TMA) {
2433 		data->tma_packet = pkt_info->packet;
2434 		data->tma = true;
2435 	}
2436 	return 1;
2437 }
2438 
2439 static uint64_t intel_pt_ctc_to_tsc(struct intel_pt_decoder *decoder, uint64_t ctc)
2440 {
2441 	if (decoder->tsc_ctc_mult)
2442 		return ctc * decoder->tsc_ctc_mult;
2443 	else
2444 		return multdiv(ctc, decoder->tsc_ctc_ratio_n, decoder->tsc_ctc_ratio_d);
2445 }
2446 
2447 static uint64_t intel_pt_calc_expected_tsc(struct intel_pt_decoder *decoder,
2448 					   uint32_t ctc,
2449 					   uint32_t fc,
2450 					   uint64_t last_ctc_timestamp,
2451 					   uint64_t ctc_delta,
2452 					   uint32_t last_ctc)
2453 {
2454 	/* Number of CTC ticks from last_ctc_timestamp to last_mtc */
2455 	uint64_t last_mtc_ctc = last_ctc + ctc_delta;
2456 	/*
2457 	 * Number of CTC ticks from there until current TMA packet. We would
2458 	 * expect last_mtc_ctc to be before ctc, but the TSC packet can slip
2459 	 * past an MTC, so a sign-extended value is used.
2460 	 */
2461 	uint64_t delta = (int16_t)((uint16_t)ctc - (uint16_t)last_mtc_ctc);
2462 	/* Total CTC ticks from last_ctc_timestamp to current TMA packet */
2463 	uint64_t new_ctc_delta = ctc_delta + delta;
2464 	uint64_t expected_tsc;
2465 
2466 	/*
2467 	 * Convert CTC ticks to TSC ticks, add the starting point
2468 	 * (last_ctc_timestamp) and the fast counter from the TMA packet.
2469 	 */
2470 	expected_tsc = last_ctc_timestamp + intel_pt_ctc_to_tsc(decoder, new_ctc_delta) + fc;
2471 
2472 	if (intel_pt_enable_logging) {
2473 		intel_pt_log_x64(last_mtc_ctc);
2474 		intel_pt_log_x32(last_ctc);
2475 		intel_pt_log_x64(ctc_delta);
2476 		intel_pt_log_x64(delta);
2477 		intel_pt_log_x32(ctc);
2478 		intel_pt_log_x64(new_ctc_delta);
2479 		intel_pt_log_x64(last_ctc_timestamp);
2480 		intel_pt_log_x32(fc);
2481 		intel_pt_log_x64(intel_pt_ctc_to_tsc(decoder, new_ctc_delta));
2482 		intel_pt_log_x64(expected_tsc);
2483 	}
2484 
2485 	return expected_tsc;
2486 }
2487 
2488 static uint64_t intel_pt_expected_tsc(struct intel_pt_decoder *decoder,
2489 				      struct intel_pt_vm_tsc_info *data)
2490 {
2491 	uint32_t ctc = data->tma_packet.payload;
2492 	uint32_t fc = data->tma_packet.count;
2493 
2494 	return intel_pt_calc_expected_tsc(decoder, ctc, fc,
2495 					  decoder->ctc_timestamp,
2496 					  data->ctc_delta, data->last_ctc);
2497 }
2498 
2499 static void intel_pt_translate_vm_tsc(struct intel_pt_decoder *decoder,
2500 				      struct intel_pt_vmcs_info *vmcs_info)
2501 {
2502 	uint64_t payload = decoder->packet.payload;
2503 
2504 	/* VMX adds the TSC Offset, so subtract to get host TSC */
2505 	decoder->packet.payload -= vmcs_info->tsc_offset;
2506 	/* TSC packet has only 7 bytes */
2507 	decoder->packet.payload &= SEVEN_BYTES;
2508 
2509 	/*
2510 	 * The buffer is mmapped from the data file, so this also updates the
2511 	 * data file.
2512 	 */
2513 	if (!decoder->vm_tm_corr_dry_run)
2514 		memcpy((void *)decoder->buf + 1, &decoder->packet.payload, 7);
2515 
2516 	intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
2517 		     "    VMCS %#" PRIx64 "    TSC Offset %#" PRIx64 "\n",
2518 		     payload, decoder->packet.payload, vmcs_info->vmcs,
2519 		     vmcs_info->tsc_offset);
2520 }
2521 
2522 static void intel_pt_translate_vm_tsc_offset(struct intel_pt_decoder *decoder,
2523 					     uint64_t tsc_offset)
2524 {
2525 	struct intel_pt_vmcs_info vmcs_info = {
2526 		.vmcs = NO_VMCS,
2527 		.tsc_offset = tsc_offset
2528 	};
2529 
2530 	intel_pt_translate_vm_tsc(decoder, &vmcs_info);
2531 }
2532 
2533 static inline bool in_vm(uint64_t pip_payload)
2534 {
2535 	return pip_payload & 1;
2536 }
2537 
2538 static inline bool pip_in_vm(struct intel_pt_pkt *pip_packet)
2539 {
2540 	return pip_packet->payload & 1;
2541 }
2542 
2543 static void intel_pt_print_vmcs_info(struct intel_pt_vmcs_info *vmcs_info)
2544 {
2545 	p_log("VMCS: %#" PRIx64 "  TSC Offset %#" PRIx64,
2546 	      vmcs_info->vmcs, vmcs_info->tsc_offset);
2547 }
2548 
2549 static void intel_pt_vm_tm_corr_psb(struct intel_pt_decoder *decoder,
2550 				    struct intel_pt_vm_tsc_info *data)
2551 {
2552 	memset(data, 0, sizeof(*data));
2553 	data->ctc_delta = decoder->ctc_delta;
2554 	data->last_ctc = decoder->last_ctc;
2555 	intel_pt_pkt_lookahead(decoder, intel_pt_vm_psb_lookahead_cb, data);
2556 	if (data->tsc && !data->psbend)
2557 		p_log("ERROR: PSB without PSBEND");
2558 	decoder->in_psb = data->psbend;
2559 }
2560 
2561 static void intel_pt_vm_tm_corr_first_tsc(struct intel_pt_decoder *decoder,
2562 					  struct intel_pt_vm_tsc_info *data,
2563 					  struct intel_pt_vmcs_info *vmcs_info,
2564 					  uint64_t host_tsc)
2565 {
2566 	if (!decoder->in_psb) {
2567 		/* Can't happen */
2568 		p_log("ERROR: First TSC is not in PSB+");
2569 	}
2570 
2571 	if (data->pip) {
2572 		if (pip_in_vm(&data->pip_packet)) { /* Guest */
2573 			if (vmcs_info && vmcs_info->tsc_offset) {
2574 				intel_pt_translate_vm_tsc(decoder, vmcs_info);
2575 				decoder->vm_tm_corr_reliable = true;
2576 			} else {
2577 				p_log("ERROR: First TSC, unknown TSC Offset");
2578 			}
2579 		} else { /* Host */
2580 			decoder->vm_tm_corr_reliable = true;
2581 		}
2582 	} else { /* Host or Guest */
2583 		decoder->vm_tm_corr_reliable = false;
2584 		if (intel_pt_time_in_range(decoder, host_tsc)) {
2585 			/* Assume Host */
2586 		} else {
2587 			/* Assume Guest */
2588 			if (vmcs_info && vmcs_info->tsc_offset)
2589 				intel_pt_translate_vm_tsc(decoder, vmcs_info);
2590 			else
2591 				p_log("ERROR: First TSC, no PIP, unknown TSC Offset");
2592 		}
2593 	}
2594 }
2595 
2596 static void intel_pt_vm_tm_corr_tsc(struct intel_pt_decoder *decoder,
2597 				    struct intel_pt_vm_tsc_info *data)
2598 {
2599 	struct intel_pt_vmcs_info *vmcs_info;
2600 	uint64_t tsc_offset = 0;
2601 	uint64_t vmcs;
2602 	bool reliable = true;
2603 	uint64_t expected_tsc;
2604 	uint64_t host_tsc;
2605 	uint64_t ref_timestamp;
2606 
2607 	bool assign = false;
2608 	bool assign_reliable = false;
2609 
2610 	/* Already have 'data' for the in_psb case */
2611 	if (!decoder->in_psb) {
2612 		memset(data, 0, sizeof(*data));
2613 		data->ctc_delta = decoder->ctc_delta;
2614 		data->last_ctc = decoder->last_ctc;
2615 		data->max_lookahead = 16;
2616 		intel_pt_pkt_lookahead(decoder, intel_pt_tma_lookahead_cb, data);
2617 		if (decoder->pge) {
2618 			data->pip = true;
2619 			data->pip_packet.payload = decoder->pip_payload;
2620 		}
2621 	}
2622 
2623 	/* Calculations depend on having TMA packets */
2624 	if (!data->tma) {
2625 		p_log("ERROR: TSC without TMA");
2626 		return;
2627 	}
2628 
2629 	vmcs = data->vmcs ? data->vmcs_packet.payload : decoder->vmcs;
2630 	if (vmcs == NO_VMCS)
2631 		vmcs = 0;
2632 
2633 	vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);
2634 
2635 	ref_timestamp = decoder->timestamp ? decoder->timestamp : decoder->buf_timestamp;
2636 	host_tsc = intel_pt_8b_tsc(decoder->packet.payload, ref_timestamp);
2637 
2638 	if (!decoder->ctc_timestamp) {
2639 		intel_pt_vm_tm_corr_first_tsc(decoder, data, vmcs_info, host_tsc);
2640 		return;
2641 	}
2642 
2643 	expected_tsc = intel_pt_expected_tsc(decoder, data);
2644 
2645 	tsc_offset = host_tsc - expected_tsc;
2646 
2647 	/* Determine if TSC is from Host or Guest */
2648 	if (data->pip) {
2649 		if (pip_in_vm(&data->pip_packet)) { /* Guest */
2650 			if (!vmcs_info) {
2651 				/* PIP NR=1 without VMCS cannot happen */
2652 				p_log("ERROR: Missing VMCS");
2653 				intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
2654 				decoder->vm_tm_corr_reliable = false;
2655 				return;
2656 			}
2657 		} else { /* Host */
2658 			decoder->last_reliable_timestamp = host_tsc;
2659 			decoder->vm_tm_corr_reliable = true;
2660 			return;
2661 		}
2662 	} else { /* Host or Guest */
2663 		reliable = false; /* Host/Guest is a guess, so not reliable */
2664 		if (decoder->in_psb) {
2665 			if (!tsc_offset)
2666 				return; /* Zero TSC Offset, assume Host */
2667 			/*
2668 			 * TSC packet has only 7 bytes of TSC. We have no
2669 			 * information about the Guest's 8th byte, but it
2670 			 * doesn't matter because we only need 7 bytes.
2671 			 * Here, since the 8th byte is unreliable and
2672 			 * irrelevant, compare only 7 byes.
2673 			 */
2674 			if (vmcs_info &&
2675 			    (tsc_offset & SEVEN_BYTES) ==
2676 			    (vmcs_info->tsc_offset & SEVEN_BYTES)) {
2677 				/* Same TSC Offset as last VMCS, assume Guest */
2678 				goto guest;
2679 			}
2680 		}
2681 		/*
2682 		 * Check if the host_tsc is within the expected range.
2683 		 * Note, we could narrow the range more by looking ahead for
2684 		 * the next host TSC in the same buffer, but we don't bother to
2685 		 * do that because this is probably good enough.
2686 		 */
2687 		if (host_tsc >= expected_tsc && intel_pt_time_in_range(decoder, host_tsc)) {
2688 			/* Within expected range for Host TSC, assume Host */
2689 			decoder->vm_tm_corr_reliable = false;
2690 			return;
2691 		}
2692 	}
2693 
2694 guest: /* Assuming Guest */
2695 
2696 	/* Determine whether to assign TSC Offset */
2697 	if (vmcs_info && vmcs_info->vmcs) {
2698 		if (vmcs_info->tsc_offset && vmcs_info->reliable) {
2699 			assign = false;
2700 		} else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_reliable &&
2701 			   decoder->vm_tm_corr_continuous && decoder->vm_tm_corr_same_buf) {
2702 			/* Continuous tracing, TSC in a PSB is not a time loss */
2703 			assign = true;
2704 			assign_reliable = true;
2705 		} else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_same_buf) {
2706 			/*
2707 			 * Unlikely to be a time loss TSC in a PSB which is not
2708 			 * at the start of a buffer.
2709 			 */
2710 			assign = true;
2711 			assign_reliable = false;
2712 		}
2713 	}
2714 
2715 	/* Record VMCS TSC Offset */
2716 	if (assign && (vmcs_info->tsc_offset != tsc_offset ||
2717 		       vmcs_info->reliable != assign_reliable)) {
2718 		bool print = vmcs_info->tsc_offset != tsc_offset;
2719 
2720 		vmcs_info->tsc_offset = tsc_offset;
2721 		vmcs_info->reliable = assign_reliable;
2722 		if (print)
2723 			intel_pt_print_vmcs_info(vmcs_info);
2724 	}
2725 
2726 	/* Determine what TSC Offset to use */
2727 	if (vmcs_info && vmcs_info->tsc_offset) {
2728 		if (!vmcs_info->reliable)
2729 			reliable = false;
2730 		intel_pt_translate_vm_tsc(decoder, vmcs_info);
2731 	} else {
2732 		reliable = false;
2733 		if (vmcs_info) {
2734 			if (!vmcs_info->error_printed) {
2735 				p_log("ERROR: Unknown TSC Offset for VMCS %#" PRIx64,
2736 				      vmcs_info->vmcs);
2737 				vmcs_info->error_printed = true;
2738 			}
2739 		} else {
2740 			if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
2741 				p_log("ERROR: Unknown VMCS");
2742 		}
2743 		intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
2744 	}
2745 
2746 	decoder->vm_tm_corr_reliable = reliable;
2747 }
2748 
2749 static void intel_pt_vm_tm_corr_pebs_tsc(struct intel_pt_decoder *decoder)
2750 {
2751 	uint64_t host_tsc = decoder->packet.payload;
2752 	uint64_t guest_tsc = decoder->packet.payload;
2753 	struct intel_pt_vmcs_info *vmcs_info;
2754 	uint64_t vmcs;
2755 
2756 	vmcs = decoder->vmcs;
2757 	if (vmcs == NO_VMCS)
2758 		vmcs = 0;
2759 
2760 	vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);
2761 
2762 	if (decoder->pge) {
2763 		if (in_vm(decoder->pip_payload)) { /* Guest */
2764 			if (!vmcs_info) {
2765 				/* PIP NR=1 without VMCS cannot happen */
2766 				p_log("ERROR: Missing VMCS");
2767 			}
2768 		} else { /* Host */
2769 			return;
2770 		}
2771 	} else { /* Host or Guest */
2772 		if (intel_pt_time_in_range(decoder, host_tsc)) {
2773 			/* Within expected range for Host TSC, assume Host */
2774 			return;
2775 		}
2776 	}
2777 
2778 	if (vmcs_info) {
2779 		/* Translate Guest TSC to Host TSC */
2780 		host_tsc = ((guest_tsc & SEVEN_BYTES) - vmcs_info->tsc_offset) & SEVEN_BYTES;
2781 		host_tsc = intel_pt_8b_tsc(host_tsc, decoder->timestamp);
2782 		intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
2783 			     "    VMCS %#" PRIx64 "    TSC Offset %#" PRIx64 "\n",
2784 			     guest_tsc, host_tsc, vmcs_info->vmcs,
2785 			     vmcs_info->tsc_offset);
2786 		if (!intel_pt_time_in_range(decoder, host_tsc) &&
2787 		    intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
2788 			p_log("Timestamp out of range");
2789 	} else {
2790 		if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
2791 			p_log("ERROR: Unknown VMCS");
2792 		host_tsc = decoder->timestamp;
2793 	}
2794 
2795 	decoder->packet.payload = host_tsc;
2796 
2797 	if (!decoder->vm_tm_corr_dry_run)
2798 		memcpy((void *)decoder->buf + 1, &host_tsc, 8);
2799 }
2800 
2801 static int intel_pt_vm_time_correlation(struct intel_pt_decoder *decoder)
2802 {
2803 	struct intel_pt_vm_tsc_info data = { .psbend = false };
2804 	bool pge;
2805 	int err;
2806 
2807 	if (decoder->in_psb)
2808 		intel_pt_vm_tm_corr_psb(decoder, &data);
2809 
2810 	while (1) {
2811 		err = intel_pt_get_next_packet(decoder);
2812 		if (err == -ENOLINK)
2813 			continue;
2814 		if (err)
2815 			break;
2816 
2817 		switch (decoder->packet.type) {
2818 		case INTEL_PT_TIP_PGD:
2819 			decoder->pge = false;
2820 			decoder->vm_tm_corr_continuous = false;
2821 			break;
2822 
2823 		case INTEL_PT_TNT:
2824 		case INTEL_PT_TIP:
2825 		case INTEL_PT_TIP_PGE:
2826 			decoder->pge = true;
2827 			break;
2828 
2829 		case INTEL_PT_OVF:
2830 			decoder->in_psb = false;
2831 			pge = decoder->pge;
2832 			decoder->pge = intel_pt_ovf_fup_lookahead(decoder);
2833 			if (pge != decoder->pge)
2834 				intel_pt_log("Surprising PGE change in OVF!");
2835 			if (!decoder->pge)
2836 				decoder->vm_tm_corr_continuous = false;
2837 			break;
2838 
2839 		case INTEL_PT_FUP:
2840 			if (decoder->in_psb)
2841 				decoder->pge = true;
2842 			break;
2843 
2844 		case INTEL_PT_TRACESTOP:
2845 			decoder->pge = false;
2846 			decoder->vm_tm_corr_continuous = false;
2847 			decoder->have_tma = false;
2848 			break;
2849 
2850 		case INTEL_PT_PSB:
2851 			intel_pt_vm_tm_corr_psb(decoder, &data);
2852 			break;
2853 
2854 		case INTEL_PT_PIP:
2855 			decoder->pip_payload = decoder->packet.payload;
2856 			break;
2857 
2858 		case INTEL_PT_MTC:
2859 			intel_pt_calc_mtc_timestamp(decoder);
2860 			break;
2861 
2862 		case INTEL_PT_TSC:
2863 			intel_pt_vm_tm_corr_tsc(decoder, &data);
2864 			intel_pt_calc_tsc_timestamp(decoder);
2865 			decoder->vm_tm_corr_same_buf = true;
2866 			decoder->vm_tm_corr_continuous = decoder->pge;
2867 			break;
2868 
2869 		case INTEL_PT_TMA:
2870 			intel_pt_calc_tma(decoder);
2871 			break;
2872 
2873 		case INTEL_PT_CYC:
2874 			intel_pt_calc_cyc_timestamp(decoder);
2875 			break;
2876 
2877 		case INTEL_PT_CBR:
2878 			intel_pt_calc_cbr(decoder);
2879 			break;
2880 
2881 		case INTEL_PT_PSBEND:
2882 			decoder->in_psb = false;
2883 			data.psbend = false;
2884 			break;
2885 
2886 		case INTEL_PT_VMCS:
2887 			if (decoder->packet.payload != NO_VMCS)
2888 				decoder->vmcs = decoder->packet.payload;
2889 			break;
2890 
2891 		case INTEL_PT_BBP:
2892 			decoder->blk_type = decoder->packet.payload;
2893 			break;
2894 
2895 		case INTEL_PT_BIP:
2896 			if (decoder->blk_type == INTEL_PT_PEBS_BASIC &&
2897 			    decoder->packet.count == 2)
2898 				intel_pt_vm_tm_corr_pebs_tsc(decoder);
2899 			break;
2900 
2901 		case INTEL_PT_BEP:
2902 		case INTEL_PT_BEP_IP:
2903 			decoder->blk_type = 0;
2904 			break;
2905 
2906 		case INTEL_PT_CFE:
2907 		case INTEL_PT_CFE_IP:
2908 		case INTEL_PT_EVD:
2909 		case INTEL_PT_MODE_EXEC:
2910 		case INTEL_PT_MODE_TSX:
2911 		case INTEL_PT_MNT:
2912 		case INTEL_PT_PAD:
2913 		case INTEL_PT_PTWRITE_IP:
2914 		case INTEL_PT_PTWRITE:
2915 		case INTEL_PT_MWAIT:
2916 		case INTEL_PT_PWRE:
2917 		case INTEL_PT_EXSTOP_IP:
2918 		case INTEL_PT_EXSTOP:
2919 		case INTEL_PT_PWRX:
2920 		case INTEL_PT_BAD: /* Does not happen */
2921 		default:
2922 			break;
2923 		}
2924 	}
2925 
2926 	return err;
2927 }
2928 
2929 #define HOP_PROCESS	0
2930 #define HOP_IGNORE	1
2931 #define HOP_RETURN	2
2932 #define HOP_AGAIN	3
2933 
2934 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder);
2935 
2936 /* Hop mode: Ignore TNT, do not walk code, but get ip from FUPs and TIPs */
2937 static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, int *err)
2938 {
2939 	*err = 0;
2940 
2941 	/* Leap from PSB to PSB, getting ip from FUP within PSB+ */
2942 	if (decoder->leap && !decoder->in_psb && decoder->packet.type != INTEL_PT_PSB) {
2943 		*err = intel_pt_scan_for_psb(decoder);
2944 		if (*err)
2945 			return HOP_RETURN;
2946 	}
2947 
2948 	switch (decoder->packet.type) {
2949 	case INTEL_PT_TNT:
2950 		return HOP_IGNORE;
2951 
2952 	case INTEL_PT_TIP_PGD:
2953 		decoder->pge = false;
2954 		if (!decoder->packet.count) {
2955 			intel_pt_set_nr(decoder);
2956 			return HOP_IGNORE;
2957 		}
2958 		intel_pt_set_ip(decoder);
2959 		decoder->state.type |= INTEL_PT_TRACE_END;
2960 		decoder->state.from_ip = 0;
2961 		decoder->state.to_ip = decoder->ip;
2962 		intel_pt_update_nr(decoder);
2963 		return HOP_RETURN;
2964 
2965 	case INTEL_PT_TIP:
2966 		if (!decoder->packet.count) {
2967 			intel_pt_set_nr(decoder);
2968 			return HOP_IGNORE;
2969 		}
2970 		intel_pt_set_ip(decoder);
2971 		decoder->state.type = INTEL_PT_INSTRUCTION;
2972 		decoder->state.from_ip = decoder->ip;
2973 		decoder->state.to_ip = 0;
2974 		intel_pt_update_nr(decoder);
2975 		intel_pt_sample_iflag_chg(decoder);
2976 		return HOP_RETURN;
2977 
2978 	case INTEL_PT_FUP:
2979 		if (!decoder->packet.count)
2980 			return HOP_IGNORE;
2981 		intel_pt_set_ip(decoder);
2982 		if (decoder->set_fup_mwait || decoder->set_fup_pwre)
2983 			*no_tip = true;
2984 		if (!decoder->branch_enable || !decoder->pge)
2985 			*no_tip = true;
2986 		if (*no_tip) {
2987 			decoder->state.type = INTEL_PT_INSTRUCTION;
2988 			decoder->state.from_ip = decoder->ip;
2989 			decoder->state.to_ip = 0;
2990 			intel_pt_fup_event(decoder, *no_tip);
2991 			return HOP_RETURN;
2992 		}
2993 		intel_pt_fup_event(decoder, *no_tip);
2994 		decoder->state.type |= INTEL_PT_INSTRUCTION | INTEL_PT_BRANCH;
2995 		*err = intel_pt_walk_fup_tip(decoder);
2996 		if (!*err && decoder->state.to_ip)
2997 			decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
2998 		return HOP_RETURN;
2999 
3000 	case INTEL_PT_PSB:
3001 		decoder->state.psb_offset = decoder->pos;
3002 		decoder->psb_ip = 0;
3003 		decoder->last_ip = 0;
3004 		decoder->have_last_ip = true;
3005 		*err = intel_pt_walk_psbend(decoder);
3006 		if (*err == -EAGAIN)
3007 			return HOP_AGAIN;
3008 		if (*err)
3009 			return HOP_RETURN;
3010 		decoder->state.type = INTEL_PT_PSB_EVT;
3011 		if (decoder->psb_ip) {
3012 			decoder->state.type |= INTEL_PT_INSTRUCTION;
3013 			decoder->ip = decoder->psb_ip;
3014 		}
3015 		decoder->state.from_ip = decoder->psb_ip;
3016 		decoder->state.to_ip = 0;
3017 		return HOP_RETURN;
3018 
3019 	case INTEL_PT_BAD:
3020 	case INTEL_PT_PAD:
3021 	case INTEL_PT_TIP_PGE:
3022 	case INTEL_PT_TSC:
3023 	case INTEL_PT_TMA:
3024 	case INTEL_PT_MODE_EXEC:
3025 	case INTEL_PT_MODE_TSX:
3026 	case INTEL_PT_MTC:
3027 	case INTEL_PT_CYC:
3028 	case INTEL_PT_VMCS:
3029 	case INTEL_PT_PSBEND:
3030 	case INTEL_PT_CBR:
3031 	case INTEL_PT_TRACESTOP:
3032 	case INTEL_PT_PIP:
3033 	case INTEL_PT_OVF:
3034 	case INTEL_PT_MNT:
3035 	case INTEL_PT_PTWRITE:
3036 	case INTEL_PT_PTWRITE_IP:
3037 	case INTEL_PT_EXSTOP:
3038 	case INTEL_PT_EXSTOP_IP:
3039 	case INTEL_PT_MWAIT:
3040 	case INTEL_PT_PWRE:
3041 	case INTEL_PT_PWRX:
3042 	case INTEL_PT_BBP:
3043 	case INTEL_PT_BIP:
3044 	case INTEL_PT_BEP:
3045 	case INTEL_PT_BEP_IP:
3046 	case INTEL_PT_CFE:
3047 	case INTEL_PT_CFE_IP:
3048 	case INTEL_PT_EVD:
3049 	default:
3050 		return HOP_PROCESS;
3051 	}
3052 }
3053 
3054 struct intel_pt_psb_info {
3055 	struct intel_pt_pkt fup_packet;
3056 	bool fup;
3057 	int after_psbend;
3058 };
3059 
3060 /* Lookahead and get the FUP packet from PSB+ */
3061 static int intel_pt_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
3062 {
3063 	struct intel_pt_psb_info *data = pkt_info->data;
3064 
3065 	switch (pkt_info->packet.type) {
3066 	case INTEL_PT_PAD:
3067 	case INTEL_PT_MNT:
3068 	case INTEL_PT_TSC:
3069 	case INTEL_PT_TMA:
3070 	case INTEL_PT_MODE_EXEC:
3071 	case INTEL_PT_MODE_TSX:
3072 	case INTEL_PT_MTC:
3073 	case INTEL_PT_CYC:
3074 	case INTEL_PT_VMCS:
3075 	case INTEL_PT_CBR:
3076 	case INTEL_PT_PIP:
3077 		if (data->after_psbend) {
3078 			data->after_psbend -= 1;
3079 			if (!data->after_psbend)
3080 				return 1;
3081 		}
3082 		break;
3083 
3084 	case INTEL_PT_FUP:
3085 		if (data->after_psbend)
3086 			return 1;
3087 		if (data->fup || pkt_info->packet.count == 0)
3088 			return 1;
3089 		data->fup_packet = pkt_info->packet;
3090 		data->fup = true;
3091 		break;
3092 
3093 	case INTEL_PT_PSBEND:
3094 		if (!data->fup)
3095 			return 1;
3096 		/* Keep going to check for a TIP.PGE */
3097 		data->after_psbend = 6;
3098 		break;
3099 
3100 	case INTEL_PT_TIP_PGE:
3101 		/* Ignore FUP in PSB+ if followed by TIP.PGE */
3102 		if (data->after_psbend)
3103 			data->fup = false;
3104 		return 1;
3105 
3106 	case INTEL_PT_PTWRITE:
3107 	case INTEL_PT_PTWRITE_IP:
3108 	case INTEL_PT_EXSTOP:
3109 	case INTEL_PT_EXSTOP_IP:
3110 	case INTEL_PT_MWAIT:
3111 	case INTEL_PT_PWRE:
3112 	case INTEL_PT_PWRX:
3113 	case INTEL_PT_BBP:
3114 	case INTEL_PT_BIP:
3115 	case INTEL_PT_BEP:
3116 	case INTEL_PT_BEP_IP:
3117 	case INTEL_PT_CFE:
3118 	case INTEL_PT_CFE_IP:
3119 	case INTEL_PT_EVD:
3120 		if (data->after_psbend) {
3121 			data->after_psbend -= 1;
3122 			if (!data->after_psbend)
3123 				return 1;
3124 			break;
3125 		}
3126 		return 1;
3127 
3128 	case INTEL_PT_OVF:
3129 	case INTEL_PT_BAD:
3130 	case INTEL_PT_TNT:
3131 	case INTEL_PT_TIP_PGD:
3132 	case INTEL_PT_TIP:
3133 	case INTEL_PT_PSB:
3134 	case INTEL_PT_TRACESTOP:
3135 	default:
3136 		return 1;
3137 	}
3138 
3139 	return 0;
3140 }
3141 
3142 static int intel_pt_psb(struct intel_pt_decoder *decoder)
3143 {
3144 	int err;
3145 
3146 	decoder->last_ip = 0;
3147 	decoder->psb_ip = 0;
3148 	decoder->have_last_ip = true;
3149 	intel_pt_clear_stack(&decoder->stack);
3150 	err = intel_pt_walk_psbend(decoder);
3151 	if (err)
3152 		return err;
3153 	decoder->state.type = INTEL_PT_PSB_EVT;
3154 	decoder->state.from_ip = decoder->psb_ip;
3155 	decoder->state.to_ip = 0;
3156 	return 0;
3157 }
3158 
3159 static int intel_pt_fup_in_psb(struct intel_pt_decoder *decoder)
3160 {
3161 	int err;
3162 
3163 	if (decoder->ip != decoder->last_ip) {
3164 		err = intel_pt_walk_fup(decoder);
3165 		if (!err || err != -EAGAIN)
3166 			return err;
3167 	}
3168 
3169 	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3170 	err = intel_pt_psb(decoder);
3171 	if (err) {
3172 		decoder->pkt_state = INTEL_PT_STATE_ERR3;
3173 		return -ENOENT;
3174 	}
3175 
3176 	return 0;
3177 }
3178 
3179 static bool intel_pt_psb_with_fup(struct intel_pt_decoder *decoder, int *err)
3180 {
3181 	struct intel_pt_psb_info data = { .fup = false };
3182 
3183 	if (!decoder->branch_enable)
3184 		return false;
3185 
3186 	intel_pt_pkt_lookahead(decoder, intel_pt_psb_lookahead_cb, &data);
3187 	if (!data.fup)
3188 		return false;
3189 
3190 	decoder->packet = data.fup_packet;
3191 	intel_pt_set_last_ip(decoder);
3192 	decoder->pkt_state = INTEL_PT_STATE_FUP_IN_PSB;
3193 
3194 	*err = intel_pt_fup_in_psb(decoder);
3195 
3196 	return true;
3197 }
3198 
3199 static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
3200 {
3201 	int last_packet_type = INTEL_PT_PAD;
3202 	bool no_tip = false;
3203 	int err;
3204 
3205 	while (1) {
3206 		err = intel_pt_get_next_packet(decoder);
3207 		if (err)
3208 			return err;
3209 next:
3210 		err = 0;
3211 		if (decoder->cyc_threshold) {
3212 			if (decoder->sample_cyc && last_packet_type != INTEL_PT_CYC)
3213 				decoder->sample_cyc = false;
3214 			last_packet_type = decoder->packet.type;
3215 		}
3216 
3217 		if (decoder->hop) {
3218 			switch (intel_pt_hop_trace(decoder, &no_tip, &err)) {
3219 			case HOP_IGNORE:
3220 				continue;
3221 			case HOP_RETURN:
3222 				return err;
3223 			case HOP_AGAIN:
3224 				goto next;
3225 			default:
3226 				break;
3227 			}
3228 		}
3229 
3230 		switch (decoder->packet.type) {
3231 		case INTEL_PT_TNT:
3232 			if (!decoder->packet.count)
3233 				break;
3234 			decoder->tnt = decoder->packet;
3235 			decoder->pkt_state = INTEL_PT_STATE_TNT;
3236 			err = intel_pt_walk_tnt(decoder);
3237 			if (err == -EAGAIN)
3238 				break;
3239 			return err;
3240 
3241 		case INTEL_PT_TIP_PGD:
3242 			if (decoder->packet.count != 0)
3243 				intel_pt_set_last_ip(decoder);
3244 			decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
3245 			return intel_pt_walk_tip(decoder);
3246 
3247 		case INTEL_PT_TIP_PGE: {
3248 			decoder->pge = true;
3249 			decoder->overflow = false;
3250 			intel_pt_mtc_cyc_cnt_pge(decoder);
3251 			intel_pt_set_nr(decoder);
3252 			if (decoder->packet.count == 0) {
3253 				intel_pt_log_at("Skipping zero TIP.PGE",
3254 						decoder->pos);
3255 				break;
3256 			}
3257 			intel_pt_sample_iflag_chg(decoder);
3258 			intel_pt_set_ip(decoder);
3259 			decoder->state.from_ip = 0;
3260 			decoder->state.to_ip = decoder->ip;
3261 			decoder->state.type |= INTEL_PT_TRACE_BEGIN;
3262 			/*
3263 			 * In hop mode, resample to get the to_ip as an
3264 			 * "instruction" sample.
3265 			 */
3266 			if (decoder->hop)
3267 				decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3268 			return 0;
3269 		}
3270 
3271 		case INTEL_PT_OVF:
3272 			return intel_pt_overflow(decoder);
3273 
3274 		case INTEL_PT_TIP:
3275 			if (decoder->packet.count != 0)
3276 				intel_pt_set_last_ip(decoder);
3277 			decoder->pkt_state = INTEL_PT_STATE_TIP;
3278 			return intel_pt_walk_tip(decoder);
3279 
3280 		case INTEL_PT_FUP:
3281 			if (decoder->packet.count == 0) {
3282 				intel_pt_log_at("Skipping zero FUP",
3283 						decoder->pos);
3284 				no_tip = false;
3285 				break;
3286 			}
3287 			intel_pt_set_last_ip(decoder);
3288 			if (!decoder->branch_enable || !decoder->pge) {
3289 				decoder->ip = decoder->last_ip;
3290 				if (intel_pt_fup_event(decoder, no_tip))
3291 					return 0;
3292 				no_tip = false;
3293 				break;
3294 			}
3295 			if (decoder->set_fup_mwait)
3296 				no_tip = true;
3297 			if (no_tip)
3298 				decoder->pkt_state = INTEL_PT_STATE_FUP_NO_TIP;
3299 			else
3300 				decoder->pkt_state = INTEL_PT_STATE_FUP;
3301 			err = intel_pt_walk_fup(decoder);
3302 			if (err != -EAGAIN)
3303 				return err;
3304 			if (no_tip) {
3305 				no_tip = false;
3306 				break;
3307 			}
3308 			return intel_pt_walk_fup_tip(decoder);
3309 
3310 		case INTEL_PT_TRACESTOP:
3311 			decoder->pge = false;
3312 			decoder->continuous_period = false;
3313 			intel_pt_clear_tx_flags(decoder);
3314 			decoder->have_tma = false;
3315 			break;
3316 
3317 		case INTEL_PT_PSB:
3318 			decoder->state.psb_offset = decoder->pos;
3319 			decoder->psb_ip = 0;
3320 			if (intel_pt_psb_with_fup(decoder, &err))
3321 				return err;
3322 			err = intel_pt_psb(decoder);
3323 			if (err == -EAGAIN)
3324 				goto next;
3325 			return err;
3326 
3327 		case INTEL_PT_PIP:
3328 			intel_pt_update_pip(decoder);
3329 			break;
3330 
3331 		case INTEL_PT_MTC:
3332 			intel_pt_calc_mtc_timestamp(decoder);
3333 			if (decoder->period_type != INTEL_PT_PERIOD_MTC)
3334 				break;
3335 			/*
3336 			 * Ensure that there has been an instruction since the
3337 			 * last MTC.
3338 			 */
3339 			if (!decoder->mtc_insn)
3340 				break;
3341 			decoder->mtc_insn = false;
3342 			/* Ensure that there is a timestamp */
3343 			if (!decoder->timestamp)
3344 				break;
3345 			decoder->state.type = INTEL_PT_INSTRUCTION;
3346 			decoder->state.from_ip = decoder->ip;
3347 			decoder->state.to_ip = 0;
3348 			decoder->mtc_insn = false;
3349 			return 0;
3350 
3351 		case INTEL_PT_TSC:
3352 			intel_pt_calc_tsc_timestamp(decoder);
3353 			break;
3354 
3355 		case INTEL_PT_TMA:
3356 			intel_pt_calc_tma(decoder);
3357 			break;
3358 
3359 		case INTEL_PT_CYC:
3360 			intel_pt_calc_cyc_timestamp(decoder);
3361 			break;
3362 
3363 		case INTEL_PT_CBR:
3364 			intel_pt_calc_cbr(decoder);
3365 			if (decoder->cbr != decoder->cbr_seen) {
3366 				decoder->state.type = 0;
3367 				return 0;
3368 			}
3369 			break;
3370 
3371 		case INTEL_PT_MODE_EXEC:
3372 			intel_pt_mode_exec(decoder);
3373 			err = intel_pt_get_next_packet(decoder);
3374 			if (err)
3375 				return err;
3376 			if (decoder->packet.type == INTEL_PT_FUP) {
3377 				decoder->set_fup_mode_exec = true;
3378 				no_tip = true;
3379 			}
3380 			goto next;
3381 
3382 		case INTEL_PT_MODE_TSX:
3383 			/* MODE_TSX need not be followed by FUP */
3384 			if (!decoder->pge || decoder->in_psb) {
3385 				intel_pt_update_in_tx(decoder);
3386 				break;
3387 			}
3388 			err = intel_pt_mode_tsx(decoder, &no_tip);
3389 			if (err)
3390 				return err;
3391 			goto next;
3392 
3393 		case INTEL_PT_BAD: /* Does not happen */
3394 			return intel_pt_bug(decoder);
3395 
3396 		case INTEL_PT_PSBEND:
3397 		case INTEL_PT_VMCS:
3398 		case INTEL_PT_MNT:
3399 		case INTEL_PT_PAD:
3400 			break;
3401 
3402 		case INTEL_PT_PTWRITE_IP:
3403 			decoder->fup_ptw_payload = decoder->packet.payload;
3404 			err = intel_pt_get_next_packet(decoder);
3405 			if (err)
3406 				return err;
3407 			if (decoder->packet.type == INTEL_PT_FUP) {
3408 				decoder->set_fup_ptw = true;
3409 				no_tip = true;
3410 			} else {
3411 				intel_pt_log_at("ERROR: Missing FUP after PTWRITE",
3412 						decoder->pos);
3413 			}
3414 			goto next;
3415 
3416 		case INTEL_PT_PTWRITE:
3417 			decoder->state.type = INTEL_PT_PTW;
3418 			decoder->state.from_ip = decoder->ip;
3419 			decoder->state.to_ip = 0;
3420 			decoder->state.ptw_payload = decoder->packet.payload;
3421 			return 0;
3422 
3423 		case INTEL_PT_MWAIT:
3424 			decoder->fup_mwait_payload = decoder->packet.payload;
3425 			decoder->set_fup_mwait = true;
3426 			break;
3427 
3428 		case INTEL_PT_PWRE:
3429 			if (decoder->set_fup_mwait) {
3430 				decoder->fup_pwre_payload =
3431 							decoder->packet.payload;
3432 				decoder->set_fup_pwre = true;
3433 				break;
3434 			}
3435 			decoder->state.type = INTEL_PT_PWR_ENTRY;
3436 			decoder->state.from_ip = decoder->ip;
3437 			decoder->state.to_ip = 0;
3438 			decoder->state.pwrx_payload = decoder->packet.payload;
3439 			return 0;
3440 
3441 		case INTEL_PT_EXSTOP_IP:
3442 			err = intel_pt_get_next_packet(decoder);
3443 			if (err)
3444 				return err;
3445 			if (decoder->packet.type == INTEL_PT_FUP) {
3446 				decoder->set_fup_exstop = true;
3447 				no_tip = true;
3448 			} else {
3449 				intel_pt_log_at("ERROR: Missing FUP after EXSTOP",
3450 						decoder->pos);
3451 			}
3452 			goto next;
3453 
3454 		case INTEL_PT_EXSTOP:
3455 			decoder->state.type = INTEL_PT_EX_STOP;
3456 			decoder->state.from_ip = decoder->ip;
3457 			decoder->state.to_ip = 0;
3458 			return 0;
3459 
3460 		case INTEL_PT_PWRX:
3461 			decoder->state.type = INTEL_PT_PWR_EXIT;
3462 			decoder->state.from_ip = decoder->ip;
3463 			decoder->state.to_ip = 0;
3464 			decoder->state.pwrx_payload = decoder->packet.payload;
3465 			return 0;
3466 
3467 		case INTEL_PT_BBP:
3468 			intel_pt_bbp(decoder);
3469 			break;
3470 
3471 		case INTEL_PT_BIP:
3472 			intel_pt_bip(decoder);
3473 			break;
3474 
3475 		case INTEL_PT_BEP:
3476 			decoder->state.type = INTEL_PT_BLK_ITEMS;
3477 			decoder->state.from_ip = decoder->ip;
3478 			decoder->state.to_ip = 0;
3479 			return 0;
3480 
3481 		case INTEL_PT_BEP_IP:
3482 			err = intel_pt_get_next_packet(decoder);
3483 			if (err)
3484 				return err;
3485 			if (decoder->packet.type == INTEL_PT_FUP) {
3486 				decoder->set_fup_bep = true;
3487 				no_tip = true;
3488 			} else {
3489 				intel_pt_log_at("ERROR: Missing FUP after BEP",
3490 						decoder->pos);
3491 			}
3492 			goto next;
3493 
3494 		case INTEL_PT_CFE:
3495 			decoder->fup_cfe_pkt = decoder->packet;
3496 			decoder->set_fup_cfe = true;
3497 			if (!decoder->pge) {
3498 				intel_pt_fup_event(decoder, true);
3499 				return 0;
3500 			}
3501 			break;
3502 
3503 		case INTEL_PT_CFE_IP:
3504 			decoder->fup_cfe_pkt = decoder->packet;
3505 			err = intel_pt_get_next_packet(decoder);
3506 			if (err)
3507 				return err;
3508 			if (decoder->packet.type == INTEL_PT_FUP) {
3509 				decoder->set_fup_cfe_ip = true;
3510 				no_tip = true;
3511 			} else {
3512 				intel_pt_log_at("ERROR: Missing FUP after CFE",
3513 						decoder->pos);
3514 			}
3515 			goto next;
3516 
3517 		case INTEL_PT_EVD:
3518 			err = intel_pt_evd(decoder);
3519 			if (err)
3520 				return err;
3521 			break;
3522 
3523 		default:
3524 			return intel_pt_bug(decoder);
3525 		}
3526 	}
3527 }
3528 
3529 static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
3530 {
3531 	return decoder->packet.count &&
3532 	       (decoder->have_last_ip || decoder->packet.count == 3 ||
3533 		decoder->packet.count == 6);
3534 }
3535 
3536 /* Walk PSB+ packets to get in sync. */
3537 static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
3538 {
3539 	int err;
3540 
3541 	decoder->in_psb = true;
3542 
3543 	while (1) {
3544 		err = intel_pt_get_next_packet(decoder);
3545 		if (err)
3546 			goto out;
3547 
3548 		switch (decoder->packet.type) {
3549 		case INTEL_PT_TIP_PGD:
3550 			decoder->continuous_period = false;
3551 			fallthrough;
3552 		case INTEL_PT_TIP_PGE:
3553 		case INTEL_PT_TIP:
3554 		case INTEL_PT_PTWRITE:
3555 		case INTEL_PT_PTWRITE_IP:
3556 		case INTEL_PT_EXSTOP:
3557 		case INTEL_PT_EXSTOP_IP:
3558 		case INTEL_PT_MWAIT:
3559 		case INTEL_PT_PWRE:
3560 		case INTEL_PT_PWRX:
3561 		case INTEL_PT_BBP:
3562 		case INTEL_PT_BIP:
3563 		case INTEL_PT_BEP:
3564 		case INTEL_PT_BEP_IP:
3565 		case INTEL_PT_CFE:
3566 		case INTEL_PT_CFE_IP:
3567 		case INTEL_PT_EVD:
3568 			intel_pt_log("ERROR: Unexpected packet\n");
3569 			err = -ENOENT;
3570 			goto out;
3571 
3572 		case INTEL_PT_FUP:
3573 			decoder->pge = true;
3574 			if (intel_pt_have_ip(decoder)) {
3575 				uint64_t current_ip = decoder->ip;
3576 
3577 				intel_pt_set_ip(decoder);
3578 				decoder->psb_ip = decoder->ip;
3579 				if (current_ip)
3580 					intel_pt_log_to("Setting IP",
3581 							decoder->ip);
3582 			}
3583 			break;
3584 
3585 		case INTEL_PT_MTC:
3586 			intel_pt_calc_mtc_timestamp(decoder);
3587 			break;
3588 
3589 		case INTEL_PT_TSC:
3590 			intel_pt_calc_tsc_timestamp(decoder);
3591 			break;
3592 
3593 		case INTEL_PT_TMA:
3594 			intel_pt_calc_tma(decoder);
3595 			break;
3596 
3597 		case INTEL_PT_CYC:
3598 			intel_pt_calc_cyc_timestamp(decoder);
3599 			break;
3600 
3601 		case INTEL_PT_CBR:
3602 			intel_pt_calc_cbr(decoder);
3603 			break;
3604 
3605 		case INTEL_PT_PIP:
3606 			intel_pt_set_pip(decoder);
3607 			break;
3608 
3609 		case INTEL_PT_MODE_EXEC:
3610 			intel_pt_mode_exec_status(decoder);
3611 			break;
3612 
3613 		case INTEL_PT_MODE_TSX:
3614 			intel_pt_update_in_tx(decoder);
3615 			break;
3616 
3617 		case INTEL_PT_TRACESTOP:
3618 			decoder->pge = false;
3619 			decoder->continuous_period = false;
3620 			intel_pt_clear_tx_flags(decoder);
3621 			fallthrough;
3622 
3623 		case INTEL_PT_TNT:
3624 			decoder->have_tma = false;
3625 			intel_pt_log("ERROR: Unexpected packet\n");
3626 			if (decoder->ip)
3627 				decoder->pkt_state = INTEL_PT_STATE_ERR4;
3628 			else
3629 				decoder->pkt_state = INTEL_PT_STATE_ERR3;
3630 			err = -ENOENT;
3631 			goto out;
3632 
3633 		case INTEL_PT_BAD: /* Does not happen */
3634 			err = intel_pt_bug(decoder);
3635 			goto out;
3636 
3637 		case INTEL_PT_OVF:
3638 			err = intel_pt_overflow(decoder);
3639 			goto out;
3640 
3641 		case INTEL_PT_PSBEND:
3642 			err = 0;
3643 			goto out;
3644 
3645 		case INTEL_PT_PSB:
3646 		case INTEL_PT_VMCS:
3647 		case INTEL_PT_MNT:
3648 		case INTEL_PT_PAD:
3649 		default:
3650 			break;
3651 		}
3652 	}
3653 out:
3654 	decoder->in_psb = false;
3655 
3656 	return err;
3657 }
3658 
3659 static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
3660 {
3661 	int err;
3662 
3663 	while (1) {
3664 		err = intel_pt_get_next_packet(decoder);
3665 		if (err)
3666 			return err;
3667 
3668 		switch (decoder->packet.type) {
3669 		case INTEL_PT_TIP_PGD:
3670 			decoder->continuous_period = false;
3671 			decoder->pge = false;
3672 			if (intel_pt_have_ip(decoder))
3673 				intel_pt_set_ip(decoder);
3674 			if (!decoder->ip)
3675 				break;
3676 			decoder->state.type |= INTEL_PT_TRACE_END;
3677 			return 0;
3678 
3679 		case INTEL_PT_TIP_PGE:
3680 			decoder->pge = true;
3681 			intel_pt_mtc_cyc_cnt_pge(decoder);
3682 			if (intel_pt_have_ip(decoder))
3683 				intel_pt_set_ip(decoder);
3684 			if (!decoder->ip)
3685 				break;
3686 			decoder->state.type |= INTEL_PT_TRACE_BEGIN;
3687 			return 0;
3688 
3689 		case INTEL_PT_TIP:
3690 			decoder->pge = true;
3691 			if (intel_pt_have_ip(decoder))
3692 				intel_pt_set_ip(decoder);
3693 			if (!decoder->ip)
3694 				break;
3695 			return 0;
3696 
3697 		case INTEL_PT_FUP:
3698 			if (intel_pt_have_ip(decoder))
3699 				intel_pt_set_ip(decoder);
3700 			if (decoder->ip)
3701 				return 0;
3702 			break;
3703 
3704 		case INTEL_PT_MTC:
3705 			intel_pt_calc_mtc_timestamp(decoder);
3706 			break;
3707 
3708 		case INTEL_PT_TSC:
3709 			intel_pt_calc_tsc_timestamp(decoder);
3710 			break;
3711 
3712 		case INTEL_PT_TMA:
3713 			intel_pt_calc_tma(decoder);
3714 			break;
3715 
3716 		case INTEL_PT_CYC:
3717 			intel_pt_calc_cyc_timestamp(decoder);
3718 			break;
3719 
3720 		case INTEL_PT_CBR:
3721 			intel_pt_calc_cbr(decoder);
3722 			break;
3723 
3724 		case INTEL_PT_PIP:
3725 			intel_pt_set_pip(decoder);
3726 			break;
3727 
3728 		case INTEL_PT_MODE_EXEC:
3729 			intel_pt_mode_exec_status(decoder);
3730 			break;
3731 
3732 		case INTEL_PT_MODE_TSX:
3733 			intel_pt_update_in_tx(decoder);
3734 			break;
3735 
3736 		case INTEL_PT_OVF:
3737 			return intel_pt_overflow(decoder);
3738 
3739 		case INTEL_PT_BAD: /* Does not happen */
3740 			return intel_pt_bug(decoder);
3741 
3742 		case INTEL_PT_TRACESTOP:
3743 			decoder->pge = false;
3744 			decoder->continuous_period = false;
3745 			intel_pt_clear_tx_flags(decoder);
3746 			decoder->have_tma = false;
3747 			break;
3748 
3749 		case INTEL_PT_PSB:
3750 			decoder->state.psb_offset = decoder->pos;
3751 			decoder->psb_ip = 0;
3752 			decoder->last_ip = 0;
3753 			decoder->have_last_ip = true;
3754 			intel_pt_clear_stack(&decoder->stack);
3755 			err = intel_pt_walk_psb(decoder);
3756 			if (err)
3757 				return err;
3758 			decoder->state.type = INTEL_PT_PSB_EVT;
3759 			decoder->state.from_ip = decoder->psb_ip;
3760 			decoder->state.to_ip = 0;
3761 			return 0;
3762 
3763 		case INTEL_PT_TNT:
3764 		case INTEL_PT_PSBEND:
3765 		case INTEL_PT_VMCS:
3766 		case INTEL_PT_MNT:
3767 		case INTEL_PT_PAD:
3768 		case INTEL_PT_PTWRITE:
3769 		case INTEL_PT_PTWRITE_IP:
3770 		case INTEL_PT_EXSTOP:
3771 		case INTEL_PT_EXSTOP_IP:
3772 		case INTEL_PT_MWAIT:
3773 		case INTEL_PT_PWRE:
3774 		case INTEL_PT_PWRX:
3775 		case INTEL_PT_BBP:
3776 		case INTEL_PT_BIP:
3777 		case INTEL_PT_BEP:
3778 		case INTEL_PT_BEP_IP:
3779 		case INTEL_PT_CFE:
3780 		case INTEL_PT_CFE_IP:
3781 		case INTEL_PT_EVD:
3782 		default:
3783 			break;
3784 		}
3785 	}
3786 }
3787 
3788 static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
3789 {
3790 	int err;
3791 
3792 	intel_pt_clear_fup_event(decoder);
3793 	decoder->overflow = false;
3794 
3795 	if (!decoder->branch_enable) {
3796 		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3797 		decoder->state.type = 0; /* Do not have a sample */
3798 		return 0;
3799 	}
3800 
3801 	intel_pt_log("Scanning for full IP\n");
3802 	err = intel_pt_walk_to_ip(decoder);
3803 	if (err || ((decoder->state.type & INTEL_PT_PSB_EVT) && !decoder->ip))
3804 		return err;
3805 
3806 	/* In hop mode, resample to get the to_ip as an "instruction" sample */
3807 	if (decoder->hop)
3808 		decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3809 	else
3810 		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3811 
3812 	decoder->state.from_ip = 0;
3813 	decoder->state.to_ip = decoder->ip;
3814 	intel_pt_log_to("Setting IP", decoder->ip);
3815 
3816 	return 0;
3817 }
3818 
3819 static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
3820 {
3821 	const unsigned char *end = decoder->buf + decoder->len;
3822 	size_t i;
3823 
3824 	for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
3825 		if (i > decoder->len)
3826 			continue;
3827 		if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
3828 			return i;
3829 	}
3830 	return 0;
3831 }
3832 
3833 static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
3834 {
3835 	size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
3836 	const char *psb = INTEL_PT_PSB_STR;
3837 
3838 	if (rest_psb > decoder->len ||
3839 	    memcmp(decoder->buf, psb + part_psb, rest_psb))
3840 		return 0;
3841 
3842 	return rest_psb;
3843 }
3844 
3845 static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
3846 				  int part_psb)
3847 {
3848 	int rest_psb, ret;
3849 
3850 	decoder->pos += decoder->len;
3851 	decoder->len = 0;
3852 
3853 	ret = intel_pt_get_next_data(decoder, false);
3854 	if (ret)
3855 		return ret;
3856 
3857 	rest_psb = intel_pt_rest_psb(decoder, part_psb);
3858 	if (!rest_psb)
3859 		return 0;
3860 
3861 	decoder->pos -= part_psb;
3862 	decoder->next_buf = decoder->buf + rest_psb;
3863 	decoder->next_len = decoder->len - rest_psb;
3864 	memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
3865 	decoder->buf = decoder->temp_buf;
3866 	decoder->len = INTEL_PT_PSB_LEN;
3867 
3868 	return 0;
3869 }
3870 
3871 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
3872 {
3873 	unsigned char *next;
3874 	int ret;
3875 
3876 	intel_pt_log("Scanning for PSB\n");
3877 	while (1) {
3878 		if (!decoder->len) {
3879 			ret = intel_pt_get_next_data(decoder, false);
3880 			if (ret)
3881 				return ret;
3882 		}
3883 
3884 		next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
3885 			      INTEL_PT_PSB_LEN);
3886 		if (!next) {
3887 			int part_psb;
3888 
3889 			part_psb = intel_pt_part_psb(decoder);
3890 			if (part_psb) {
3891 				ret = intel_pt_get_split_psb(decoder, part_psb);
3892 				if (ret)
3893 					return ret;
3894 			} else {
3895 				decoder->pos += decoder->len;
3896 				decoder->len = 0;
3897 			}
3898 			continue;
3899 		}
3900 
3901 		decoder->pkt_step = next - decoder->buf;
3902 		return intel_pt_get_next_packet(decoder);
3903 	}
3904 }
3905 
3906 static int intel_pt_sync(struct intel_pt_decoder *decoder)
3907 {
3908 	int err;
3909 
3910 	decoder->pge = false;
3911 	decoder->continuous_period = false;
3912 	decoder->have_last_ip = false;
3913 	decoder->last_ip = 0;
3914 	decoder->psb_ip = 0;
3915 	decoder->ip = 0;
3916 	intel_pt_clear_stack(&decoder->stack);
3917 
3918 	err = intel_pt_scan_for_psb(decoder);
3919 	if (err)
3920 		return err;
3921 
3922 	if (decoder->vm_time_correlation) {
3923 		decoder->in_psb = true;
3924 		if (!decoder->timestamp)
3925 			decoder->timestamp = 1;
3926 		decoder->state.type = 0;
3927 		decoder->pkt_state = INTEL_PT_STATE_VM_TIME_CORRELATION;
3928 		return 0;
3929 	}
3930 
3931 	decoder->have_last_ip = true;
3932 	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3933 
3934 	err = intel_pt_walk_psb(decoder);
3935 	if (err)
3936 		return err;
3937 
3938 	decoder->state.type = INTEL_PT_PSB_EVT; /* Only PSB sample */
3939 	decoder->state.from_ip = decoder->psb_ip;
3940 	decoder->state.to_ip = 0;
3941 
3942 	if (decoder->ip) {
3943 		/*
3944 		 * In hop mode, resample to get the PSB FUP ip as an
3945 		 * "instruction" sample.
3946 		 */
3947 		if (decoder->hop)
3948 			decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3949 		else
3950 			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3951 	}
3952 
3953 	return 0;
3954 }
3955 
3956 static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
3957 {
3958 	uint64_t est = decoder->sample_insn_cnt << 1;
3959 
3960 	if (!decoder->cbr || !decoder->max_non_turbo_ratio)
3961 		goto out;
3962 
3963 	est *= decoder->max_non_turbo_ratio;
3964 	est /= decoder->cbr;
3965 out:
3966 	return decoder->sample_timestamp + est;
3967 }
3968 
3969 const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
3970 {
3971 	int err;
3972 
3973 	do {
3974 		decoder->state.type = INTEL_PT_BRANCH;
3975 		decoder->state.flags = 0;
3976 
3977 		switch (decoder->pkt_state) {
3978 		case INTEL_PT_STATE_NO_PSB:
3979 			err = intel_pt_sync(decoder);
3980 			break;
3981 		case INTEL_PT_STATE_NO_IP:
3982 			decoder->have_last_ip = false;
3983 			decoder->last_ip = 0;
3984 			decoder->ip = 0;
3985 			fallthrough;
3986 		case INTEL_PT_STATE_ERR_RESYNC:
3987 			err = intel_pt_sync_ip(decoder);
3988 			break;
3989 		case INTEL_PT_STATE_IN_SYNC:
3990 			err = intel_pt_walk_trace(decoder);
3991 			break;
3992 		case INTEL_PT_STATE_TNT:
3993 		case INTEL_PT_STATE_TNT_CONT:
3994 			err = intel_pt_walk_tnt(decoder);
3995 			if (err == -EAGAIN)
3996 				err = intel_pt_walk_trace(decoder);
3997 			break;
3998 		case INTEL_PT_STATE_TIP:
3999 		case INTEL_PT_STATE_TIP_PGD:
4000 			err = intel_pt_walk_tip(decoder);
4001 			break;
4002 		case INTEL_PT_STATE_FUP:
4003 			err = intel_pt_walk_fup(decoder);
4004 			if (err == -EAGAIN)
4005 				err = intel_pt_walk_fup_tip(decoder);
4006 			break;
4007 		case INTEL_PT_STATE_FUP_NO_TIP:
4008 			err = intel_pt_walk_fup(decoder);
4009 			if (err == -EAGAIN)
4010 				err = intel_pt_walk_trace(decoder);
4011 			break;
4012 		case INTEL_PT_STATE_FUP_IN_PSB:
4013 			err = intel_pt_fup_in_psb(decoder);
4014 			break;
4015 		case INTEL_PT_STATE_RESAMPLE:
4016 			err = intel_pt_resample(decoder);
4017 			break;
4018 		case INTEL_PT_STATE_VM_TIME_CORRELATION:
4019 			err = intel_pt_vm_time_correlation(decoder);
4020 			break;
4021 		default:
4022 			err = intel_pt_bug(decoder);
4023 			break;
4024 		}
4025 	} while (err == -ENOLINK);
4026 
4027 	if (err) {
4028 		decoder->state.err = intel_pt_ext_err(err);
4029 		if (err != -EOVERFLOW)
4030 			decoder->state.from_ip = decoder->ip;
4031 		intel_pt_update_sample_time(decoder);
4032 		decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
4033 		intel_pt_set_nr(decoder);
4034 	} else {
4035 		decoder->state.err = 0;
4036 		if (decoder->cbr != decoder->cbr_seen) {
4037 			decoder->cbr_seen = decoder->cbr;
4038 			if (!decoder->state.type) {
4039 				decoder->state.from_ip = decoder->ip;
4040 				decoder->state.to_ip = 0;
4041 			}
4042 			decoder->state.type |= INTEL_PT_CBR_CHG;
4043 			decoder->state.cbr_payload = decoder->cbr_payload;
4044 			decoder->state.cbr = decoder->cbr;
4045 		}
4046 		if (intel_pt_sample_time(decoder->pkt_state)) {
4047 			intel_pt_update_sample_time(decoder);
4048 			if (decoder->sample_cyc) {
4049 				decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
4050 				decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
4051 				decoder->sample_cyc = false;
4052 			}
4053 		}
4054 		/*
4055 		 * When using only TSC/MTC to compute cycles, IPC can be
4056 		 * sampled as soon as the cycle count changes.
4057 		 */
4058 		if (!decoder->have_cyc)
4059 			decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
4060 	}
4061 
4062 	 /* Let PSB event always have TSC timestamp */
4063 	if ((decoder->state.type & INTEL_PT_PSB_EVT) && decoder->tsc_timestamp)
4064 		decoder->sample_timestamp = decoder->tsc_timestamp;
4065 
4066 	decoder->state.from_nr = decoder->nr;
4067 	decoder->state.to_nr = decoder->next_nr;
4068 	decoder->nr = decoder->next_nr;
4069 
4070 	decoder->state.timestamp = decoder->sample_timestamp;
4071 	decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
4072 	decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
4073 	decoder->state.tot_cyc_cnt = decoder->sample_tot_cyc_cnt;
4074 
4075 	return &decoder->state;
4076 }
4077 
4078 /**
4079  * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
4080  * @buf: pointer to buffer pointer
4081  * @len: size of buffer
4082  *
4083  * Updates the buffer pointer to point to the start of the next PSB packet if
4084  * there is one, otherwise the buffer pointer is unchanged.  If @buf is updated,
4085  * @len is adjusted accordingly.
4086  *
4087  * Return: %true if a PSB packet is found, %false otherwise.
4088  */
4089 static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
4090 {
4091 	unsigned char *next;
4092 
4093 	next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
4094 	if (next) {
4095 		*len -= next - *buf;
4096 		*buf = next;
4097 		return true;
4098 	}
4099 	return false;
4100 }
4101 
4102 /**
4103  * intel_pt_step_psb - move buffer pointer to the start of the following PSB
4104  *                     packet.
4105  * @buf: pointer to buffer pointer
4106  * @len: size of buffer
4107  *
4108  * Updates the buffer pointer to point to the start of the following PSB packet
4109  * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
4110  * pointer is unchanged.  If @buf is updated, @len is adjusted accordingly.
4111  *
4112  * Return: %true if a PSB packet is found, %false otherwise.
4113  */
4114 static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
4115 {
4116 	unsigned char *next;
4117 
4118 	if (!*len)
4119 		return false;
4120 
4121 	next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
4122 	if (next) {
4123 		*len -= next - *buf;
4124 		*buf = next;
4125 		return true;
4126 	}
4127 	return false;
4128 }
4129 
4130 /**
4131  * intel_pt_last_psb - find the last PSB packet in a buffer.
4132  * @buf: buffer
4133  * @len: size of buffer
4134  *
4135  * This function finds the last PSB in a buffer.
4136  *
4137  * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
4138  */
4139 static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
4140 {
4141 	const char *n = INTEL_PT_PSB_STR;
4142 	unsigned char *p;
4143 	size_t k;
4144 
4145 	if (len < INTEL_PT_PSB_LEN)
4146 		return NULL;
4147 
4148 	k = len - INTEL_PT_PSB_LEN + 1;
4149 	while (1) {
4150 		p = memrchr(buf, n[0], k);
4151 		if (!p)
4152 			return NULL;
4153 		if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
4154 			return p;
4155 		k = p - buf;
4156 		if (!k)
4157 			return NULL;
4158 	}
4159 }
4160 
4161 /**
4162  * intel_pt_next_tsc - find and return next TSC.
4163  * @buf: buffer
4164  * @len: size of buffer
4165  * @tsc: TSC value returned
4166  * @rem: returns remaining size when TSC is found
4167  *
4168  * Find a TSC packet in @buf and return the TSC value.  This function assumes
4169  * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
4170  * PSBEND packet is found.
4171  *
4172  * Return: %true if TSC is found, false otherwise.
4173  */
4174 static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc,
4175 			      size_t *rem)
4176 {
4177 	enum intel_pt_pkt_ctx ctx = INTEL_PT_NO_CTX;
4178 	struct intel_pt_pkt packet;
4179 	int ret;
4180 
4181 	while (len) {
4182 		ret = intel_pt_get_packet(buf, len, &packet, &ctx);
4183 		if (ret <= 0)
4184 			return false;
4185 		if (packet.type == INTEL_PT_TSC) {
4186 			*tsc = packet.payload;
4187 			*rem = len;
4188 			return true;
4189 		}
4190 		if (packet.type == INTEL_PT_PSBEND)
4191 			return false;
4192 		buf += ret;
4193 		len -= ret;
4194 	}
4195 	return false;
4196 }
4197 
4198 /**
4199  * intel_pt_tsc_cmp - compare 7-byte TSCs.
4200  * @tsc1: first TSC to compare
4201  * @tsc2: second TSC to compare
4202  *
4203  * This function compares 7-byte TSC values allowing for the possibility that
4204  * TSC wrapped around.  Generally it is not possible to know if TSC has wrapped
4205  * around so for that purpose this function assumes the absolute difference is
4206  * less than half the maximum difference.
4207  *
4208  * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
4209  * after @tsc2.
4210  */
4211 static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
4212 {
4213 	const uint64_t halfway = (1ULL << 55);
4214 
4215 	if (tsc1 == tsc2)
4216 		return 0;
4217 
4218 	if (tsc1 < tsc2) {
4219 		if (tsc2 - tsc1 < halfway)
4220 			return -1;
4221 		else
4222 			return 1;
4223 	} else {
4224 		if (tsc1 - tsc2 < halfway)
4225 			return 1;
4226 		else
4227 			return -1;
4228 	}
4229 }
4230 
4231 #define MAX_PADDING (PERF_AUXTRACE_RECORD_ALIGNMENT - 1)
4232 
4233 /**
4234  * adj_for_padding - adjust overlap to account for padding.
4235  * @buf_b: second buffer
4236  * @buf_a: first buffer
4237  * @len_a: size of first buffer
4238  *
4239  * @buf_a might have up to 7 bytes of padding appended. Adjust the overlap
4240  * accordingly.
4241  *
4242  * Return: A pointer into @buf_b from where non-overlapped data starts
4243  */
4244 static unsigned char *adj_for_padding(unsigned char *buf_b,
4245 				      unsigned char *buf_a, size_t len_a)
4246 {
4247 	unsigned char *p = buf_b - MAX_PADDING;
4248 	unsigned char *q = buf_a + len_a - MAX_PADDING;
4249 	int i;
4250 
4251 	for (i = MAX_PADDING; i; i--, p++, q++) {
4252 		if (*p != *q)
4253 			break;
4254 	}
4255 
4256 	return p;
4257 }
4258 
4259 /**
4260  * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
4261  *                             using TSC.
4262  * @buf_a: first buffer
4263  * @len_a: size of first buffer
4264  * @buf_b: second buffer
4265  * @len_b: size of second buffer
4266  * @consecutive: returns true if there is data in buf_b that is consecutive
4267  *               to buf_a
4268  * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
4269  *
4270  * If the trace contains TSC we can look at the last TSC of @buf_a and the
4271  * first TSC of @buf_b in order to determine if the buffers overlap, and then
4272  * walk forward in @buf_b until a later TSC is found.  A precondition is that
4273  * @buf_a and @buf_b are positioned at a PSB.
4274  *
4275  * Return: A pointer into @buf_b from where non-overlapped data starts, or
4276  * @buf_b + @len_b if there is no non-overlapped data.
4277  */
4278 static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
4279 						size_t len_a,
4280 						unsigned char *buf_b,
4281 						size_t len_b, bool *consecutive,
4282 						bool ooo_tsc)
4283 {
4284 	uint64_t tsc_a, tsc_b;
4285 	unsigned char *p;
4286 	size_t len, rem_a, rem_b;
4287 
4288 	p = intel_pt_last_psb(buf_a, len_a);
4289 	if (!p)
4290 		return buf_b; /* No PSB in buf_a => no overlap */
4291 
4292 	len = len_a - (p - buf_a);
4293 	if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a)) {
4294 		/* The last PSB+ in buf_a is incomplete, so go back one more */
4295 		len_a -= len;
4296 		p = intel_pt_last_psb(buf_a, len_a);
4297 		if (!p)
4298 			return buf_b; /* No full PSB+ => assume no overlap */
4299 		len = len_a - (p - buf_a);
4300 		if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a))
4301 			return buf_b; /* No TSC in buf_a => assume no overlap */
4302 	}
4303 
4304 	while (1) {
4305 		/* Ignore PSB+ with no TSC */
4306 		if (intel_pt_next_tsc(buf_b, len_b, &tsc_b, &rem_b)) {
4307 			int cmp = intel_pt_tsc_cmp(tsc_a, tsc_b);
4308 
4309 			/* Same TSC, so buffers are consecutive */
4310 			if (!cmp && rem_b >= rem_a) {
4311 				unsigned char *start;
4312 
4313 				*consecutive = true;
4314 				start = buf_b + len_b - (rem_b - rem_a);
4315 				return adj_for_padding(start, buf_a, len_a);
4316 			}
4317 			if (cmp < 0 && !ooo_tsc)
4318 				return buf_b; /* tsc_a < tsc_b => no overlap */
4319 		}
4320 
4321 		if (!intel_pt_step_psb(&buf_b, &len_b))
4322 			return buf_b + len_b; /* No PSB in buf_b => no data */
4323 	}
4324 }
4325 
4326 /**
4327  * intel_pt_find_overlap - determine start of non-overlapped trace data.
4328  * @buf_a: first buffer
4329  * @len_a: size of first buffer
4330  * @buf_b: second buffer
4331  * @len_b: size of second buffer
4332  * @have_tsc: can use TSC packets to detect overlap
4333  * @consecutive: returns true if there is data in buf_b that is consecutive
4334  *               to buf_a
4335  * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
4336  *
4337  * When trace samples or snapshots are recorded there is the possibility that
4338  * the data overlaps.  Note that, for the purposes of decoding, data is only
4339  * useful if it begins with a PSB packet.
4340  *
4341  * Return: A pointer into @buf_b from where non-overlapped data starts, or
4342  * @buf_b + @len_b if there is no non-overlapped data.
4343  */
4344 unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
4345 				     unsigned char *buf_b, size_t len_b,
4346 				     bool have_tsc, bool *consecutive,
4347 				     bool ooo_tsc)
4348 {
4349 	unsigned char *found;
4350 
4351 	/* Buffer 'b' must start at PSB so throw away everything before that */
4352 	if (!intel_pt_next_psb(&buf_b, &len_b))
4353 		return buf_b + len_b; /* No PSB */
4354 
4355 	if (!intel_pt_next_psb(&buf_a, &len_a))
4356 		return buf_b; /* No overlap */
4357 
4358 	if (have_tsc) {
4359 		found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b,
4360 						  consecutive, ooo_tsc);
4361 		if (found)
4362 			return found;
4363 	}
4364 
4365 	/*
4366 	 * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
4367 	 * we can ignore the first part of buffer 'a'.
4368 	 */
4369 	while (len_b < len_a) {
4370 		if (!intel_pt_step_psb(&buf_a, &len_a))
4371 			return buf_b; /* No overlap */
4372 	}
4373 
4374 	/* Now len_b >= len_a */
4375 	while (1) {
4376 		/* Potential overlap so check the bytes */
4377 		found = memmem(buf_a, len_a, buf_b, len_a);
4378 		if (found) {
4379 			*consecutive = true;
4380 			return adj_for_padding(buf_b + len_a, buf_a, len_a);
4381 		}
4382 
4383 		/* Try again at next PSB in buffer 'a' */
4384 		if (!intel_pt_step_psb(&buf_a, &len_a))
4385 			return buf_b; /* No overlap */
4386 	}
4387 }
4388 
4389 /**
4390  * struct fast_forward_data - data used by intel_pt_ff_cb().
4391  * @timestamp: timestamp to fast forward towards
4392  * @buf_timestamp: buffer timestamp of last buffer with trace data earlier than
4393  *                 the fast forward timestamp.
4394  */
4395 struct fast_forward_data {
4396 	uint64_t timestamp;
4397 	uint64_t buf_timestamp;
4398 };
4399 
4400 /**
4401  * intel_pt_ff_cb - fast forward lookahead callback.
4402  * @buffer: Intel PT trace buffer
4403  * @data: opaque pointer to fast forward data (struct fast_forward_data)
4404  *
4405  * Determine if @buffer trace is past the fast forward timestamp.
4406  *
4407  * Return: 1 (stop lookahead) if @buffer trace is past the fast forward
4408  *         timestamp, and 0 otherwise.
4409  */
4410 static int intel_pt_ff_cb(struct intel_pt_buffer *buffer, void *data)
4411 {
4412 	struct fast_forward_data *d = data;
4413 	unsigned char *buf;
4414 	uint64_t tsc;
4415 	size_t rem;
4416 	size_t len;
4417 
4418 	buf = (unsigned char *)buffer->buf;
4419 	len = buffer->len;
4420 
4421 	if (!intel_pt_next_psb(&buf, &len) ||
4422 	    !intel_pt_next_tsc(buf, len, &tsc, &rem))
4423 		return 0;
4424 
4425 	tsc = intel_pt_8b_tsc(tsc, buffer->ref_timestamp);
4426 
4427 	intel_pt_log("Buffer 1st timestamp " x64_fmt " ref timestamp " x64_fmt "\n",
4428 		     tsc, buffer->ref_timestamp);
4429 
4430 	/*
4431 	 * If the buffer contains a timestamp earlier that the fast forward
4432 	 * timestamp, then record it, else stop.
4433 	 */
4434 	if (tsc < d->timestamp)
4435 		d->buf_timestamp = buffer->ref_timestamp;
4436 	else
4437 		return 1;
4438 
4439 	return 0;
4440 }
4441 
4442 /**
4443  * intel_pt_fast_forward - reposition decoder forwards.
4444  * @decoder: Intel PT decoder
4445  * @timestamp: timestamp to fast forward towards
4446  *
4447  * Reposition decoder at the last PSB with a timestamp earlier than @timestamp.
4448  *
4449  * Return: 0 on success or negative error code on failure.
4450  */
4451 int intel_pt_fast_forward(struct intel_pt_decoder *decoder, uint64_t timestamp)
4452 {
4453 	struct fast_forward_data d = { .timestamp = timestamp };
4454 	unsigned char *buf;
4455 	size_t len;
4456 	int err;
4457 
4458 	intel_pt_log("Fast forward towards timestamp " x64_fmt "\n", timestamp);
4459 
4460 	/* Find buffer timestamp of buffer to fast forward to */
4461 	err = decoder->lookahead(decoder->data, intel_pt_ff_cb, &d);
4462 	if (err < 0)
4463 		return err;
4464 
4465 	/* Walk to buffer with same buffer timestamp */
4466 	if (d.buf_timestamp) {
4467 		do {
4468 			decoder->pos += decoder->len;
4469 			decoder->len = 0;
4470 			err = intel_pt_get_next_data(decoder, true);
4471 			/* -ENOLINK means non-consecutive trace */
4472 			if (err && err != -ENOLINK)
4473 				return err;
4474 		} while (decoder->buf_timestamp != d.buf_timestamp);
4475 	}
4476 
4477 	if (!decoder->buf)
4478 		return 0;
4479 
4480 	buf = (unsigned char *)decoder->buf;
4481 	len = decoder->len;
4482 
4483 	if (!intel_pt_next_psb(&buf, &len))
4484 		return 0;
4485 
4486 	/*
4487 	 * Walk PSBs while the PSB timestamp is less than the fast forward
4488 	 * timestamp.
4489 	 */
4490 	do {
4491 		uint64_t tsc;
4492 		size_t rem;
4493 
4494 		if (!intel_pt_next_tsc(buf, len, &tsc, &rem))
4495 			break;
4496 		tsc = intel_pt_8b_tsc(tsc, decoder->buf_timestamp);
4497 		/*
4498 		 * A TSC packet can slip past MTC packets but, after fast
4499 		 * forward, decoding starts at the TSC timestamp. That means
4500 		 * the timestamps may not be exactly the same as the timestamps
4501 		 * that would have been decoded without fast forward.
4502 		 */
4503 		if (tsc < timestamp) {
4504 			intel_pt_log("Fast forward to next PSB timestamp " x64_fmt "\n", tsc);
4505 			decoder->pos += decoder->len - len;
4506 			decoder->buf = buf;
4507 			decoder->len = len;
4508 			intel_pt_reposition(decoder);
4509 		} else {
4510 			break;
4511 		}
4512 	} while (intel_pt_step_psb(&buf, &len));
4513 
4514 	return 0;
4515 }
4516