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