Merge branch 'linus' into x86/urgent, to be able to merge a dependent fix

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 2345 insertions, 0 deletions

diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
new file mode 100644
index 000000000000..22ba50224319
--- /dev/null
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -0,0 +1,2345 @@
+/*
+ * intel_pt_decoder.c: Intel Processor Trace support
+ * Copyright (c) 2013-2014, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <errno.h>
+#include <stdint.h>
+#include <inttypes.h>
+
+#include "../cache.h"
+#include "../util.h"
+
+#include "intel-pt-insn-decoder.h"
+#include "intel-pt-pkt-decoder.h"
+#include "intel-pt-decoder.h"
+#include "intel-pt-log.h"
+
+#define INTEL_PT_BLK_SIZE 1024
+
+#define BIT63 (((uint64_t)1 << 63))
+
+#define INTEL_PT_RETURN 1
+
+/* Maximum number of loops with no packets consumed i.e. stuck in a loop */
+#define INTEL_PT_MAX_LOOPS 10000
+
+struct intel_pt_blk {
+	struct intel_pt_blk *prev;
+	uint64_t ip[INTEL_PT_BLK_SIZE];
+};
+
+struct intel_pt_stack {
+	struct intel_pt_blk *blk;
+	struct intel_pt_blk *spare;
+	int pos;
+};
+
+enum intel_pt_pkt_state {
+	INTEL_PT_STATE_NO_PSB,
+	INTEL_PT_STATE_NO_IP,
+	INTEL_PT_STATE_ERR_RESYNC,
+	INTEL_PT_STATE_IN_SYNC,
+	INTEL_PT_STATE_TNT,
+	INTEL_PT_STATE_TIP,
+	INTEL_PT_STATE_TIP_PGD,
+	INTEL_PT_STATE_FUP,
+	INTEL_PT_STATE_FUP_NO_TIP,
+};
+
+#ifdef INTEL_PT_STRICT
+#define INTEL_PT_STATE_ERR1	INTEL_PT_STATE_NO_PSB
+#define INTEL_PT_STATE_ERR2	INTEL_PT_STATE_NO_PSB
+#define INTEL_PT_STATE_ERR3	INTEL_PT_STATE_NO_PSB
+#define INTEL_PT_STATE_ERR4	INTEL_PT_STATE_NO_PSB
+#else
+#define INTEL_PT_STATE_ERR1	(decoder->pkt_state)
+#define INTEL_PT_STATE_ERR2	INTEL_PT_STATE_NO_IP
+#define INTEL_PT_STATE_ERR3	INTEL_PT_STATE_ERR_RESYNC
+#define INTEL_PT_STATE_ERR4	INTEL_PT_STATE_IN_SYNC
+#endif
+
+struct intel_pt_decoder {
+	int (*get_trace)(struct intel_pt_buffer *buffer, void *data);
+	int (*walk_insn)(struct intel_pt_insn *intel_pt_insn,
+			 uint64_t *insn_cnt_ptr, uint64_t *ip, uint64_t to_ip,
+			 uint64_t max_insn_cnt, void *data);
+	void *data;
+	struct intel_pt_state state;
+	const unsigned char *buf;
+	size_t len;
+	bool return_compression;
+	bool mtc_insn;
+	bool pge;
+	bool have_tma;
+	bool have_cyc;
+	uint64_t pos;
+	uint64_t last_ip;
+	uint64_t ip;
+	uint64_t cr3;
+	uint64_t timestamp;
+	uint64_t tsc_timestamp;
+	uint64_t ref_timestamp;
+	uint64_t ret_addr;
+	uint64_t ctc_timestamp;
+	uint64_t ctc_delta;
+	uint64_t cycle_cnt;
+	uint64_t cyc_ref_timestamp;
+	uint32_t last_mtc;
+	uint32_t tsc_ctc_ratio_n;
+	uint32_t tsc_ctc_ratio_d;
+	uint32_t tsc_ctc_mult;
+	uint32_t tsc_slip;
+	uint32_t ctc_rem_mask;
+	int mtc_shift;
+	struct intel_pt_stack stack;
+	enum intel_pt_pkt_state pkt_state;
+	struct intel_pt_pkt packet;
+	struct intel_pt_pkt tnt;
+	int pkt_step;
+	int pkt_len;
+	int last_packet_type;
+	unsigned int cbr;
+	unsigned int max_non_turbo_ratio;
+	double max_non_turbo_ratio_fp;
+	double cbr_cyc_to_tsc;
+	double calc_cyc_to_tsc;
+	bool have_calc_cyc_to_tsc;
+	int exec_mode;
+	unsigned int insn_bytes;
+	uint64_t sign_bit;
+	uint64_t sign_bits;
+	uint64_t period;
+	enum intel_pt_period_type period_type;
+	uint64_t tot_insn_cnt;
+	uint64_t period_insn_cnt;
+	uint64_t period_mask;
+	uint64_t period_ticks;
+	uint64_t last_masked_timestamp;
+	bool continuous_period;
+	bool overflow;
+	bool set_fup_tx_flags;
+	unsigned int fup_tx_flags;
+	unsigned int tx_flags;
+	uint64_t timestamp_insn_cnt;
+	uint64_t stuck_ip;
+	int no_progress;
+	int stuck_ip_prd;
+	int stuck_ip_cnt;
+	const unsigned char *next_buf;
+	size_t next_len;
+	unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ];
+};
+
+static uint64_t intel_pt_lower_power_of_2(uint64_t x)
+{
+	int i;
+
+	for (i = 0; x != 1; i++)
+		x >>= 1;
+
+	return x << i;
+}
+
+static void intel_pt_setup_period(struct intel_pt_decoder *decoder)
+{
+	if (decoder->period_type == INTEL_PT_PERIOD_TICKS) {
+		uint64_t period;
+
+		period = intel_pt_lower_power_of_2(decoder->period);
+		decoder->period_mask  = ~(period - 1);
+		decoder->period_ticks = period;
+	}
+}
+
+static uint64_t multdiv(uint64_t t, uint32_t n, uint32_t d)
+{
+	if (!d)
+		return 0;
+	return (t / d) * n + ((t % d) * n) / d;
+}
+
+struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)
+{
+	struct intel_pt_decoder *decoder;
+
+	if (!params->get_trace || !params->walk_insn)
+		return NULL;
+
+	decoder = zalloc(sizeof(struct intel_pt_decoder));
+	if (!decoder)
+		return NULL;
+
+	decoder->get_trace          = params->get_trace;
+	decoder->walk_insn          = params->walk_insn;
+	decoder->data               = params->data;
+	decoder->return_compression = params->return_compression;
+
+	decoder->sign_bit           = (uint64_t)1 << 47;
+	decoder->sign_bits          = ~(((uint64_t)1 << 48) - 1);
+
+	decoder->period             = params->period;
+	decoder->period_type        = params->period_type;
+
+	decoder->max_non_turbo_ratio    = params->max_non_turbo_ratio;
+	decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio;
+
+	intel_pt_setup_period(decoder);
+
+	decoder->mtc_shift = params->mtc_period;
+	decoder->ctc_rem_mask = (1 << decoder->mtc_shift) - 1;
+
+	decoder->tsc_ctc_ratio_n = params->tsc_ctc_ratio_n;
+	decoder->tsc_ctc_ratio_d = params->tsc_ctc_ratio_d;
+
+	if (!decoder->tsc_ctc_ratio_n)
+		decoder->tsc_ctc_ratio_d = 0;
+
+	if (decoder->tsc_ctc_ratio_d) {
+		if (!(decoder->tsc_ctc_ratio_n % decoder->tsc_ctc_ratio_d))
+			decoder->tsc_ctc_mult = decoder->tsc_ctc_ratio_n /
+						decoder->tsc_ctc_ratio_d;
+
+		/*
+		 * Allow for timestamps appearing to backwards because a TSC
+		 * packet has slipped past a MTC packet, so allow 2 MTC ticks
+		 * or ...
+		 */
+		decoder->tsc_slip = multdiv(2 << decoder->mtc_shift,
+					decoder->tsc_ctc_ratio_n,
+					decoder->tsc_ctc_ratio_d);
+	}
+	/* ... or 0x100 paranoia */
+	if (decoder->tsc_slip < 0x100)
+		decoder->tsc_slip = 0x100;
+
+	intel_pt_log("timestamp: mtc_shift %u\n", decoder->mtc_shift);
+	intel_pt_log("timestamp: tsc_ctc_ratio_n %u\n", decoder->tsc_ctc_ratio_n);
+	intel_pt_log("timestamp: tsc_ctc_ratio_d %u\n", decoder->tsc_ctc_ratio_d);
+	intel_pt_log("timestamp: tsc_ctc_mult %u\n", decoder->tsc_ctc_mult);
+	intel_pt_log("timestamp: tsc_slip %#x\n", decoder->tsc_slip);
+
+	return decoder;
+}
+
+static void intel_pt_pop_blk(struct intel_pt_stack *stack)
+{
+	struct intel_pt_blk *blk = stack->blk;
+
+	stack->blk = blk->prev;
+	if (!stack->spare)
+		stack->spare = blk;
+	else
+		free(blk);
+}
+
+static uint64_t intel_pt_pop(struct intel_pt_stack *stack)
+{
+	if (!stack->pos) {
+		if (!stack->blk)
+			return 0;
+		intel_pt_pop_blk(stack);
+		if (!stack->blk)
+			return 0;
+		stack->pos = INTEL_PT_BLK_SIZE;
+	}
+	return stack->blk->ip[--stack->pos];
+}
+
+static int intel_pt_alloc_blk(struct intel_pt_stack *stack)
+{
+	struct intel_pt_blk *blk;
+
+	if (stack->spare) {
+		blk = stack->spare;
+		stack->spare = NULL;
+	} else {
+		blk = malloc(sizeof(struct intel_pt_blk));
+		if (!blk)
+			return -ENOMEM;
+	}
+
+	blk->prev = stack->blk;
+	stack->blk = blk;
+	stack->pos = 0;
+	return 0;
+}
+
+static int intel_pt_push(struct intel_pt_stack *stack, uint64_t ip)
+{
+	int err;
+
+	if (!stack->blk || stack->pos == INTEL_PT_BLK_SIZE) {
+		err = intel_pt_alloc_blk(stack);
+		if (err)
+			return err;
+	}
+
+	stack->blk->ip[stack->pos++] = ip;
+	return 0;
+}
+
+static void intel_pt_clear_stack(struct intel_pt_stack *stack)
+{
+	while (stack->blk)
+		intel_pt_pop_blk(stack);
+	stack->pos = 0;
+}
+
+static void intel_pt_free_stack(struct intel_pt_stack *stack)
+{
+	intel_pt_clear_stack(stack);
+	zfree(&stack->blk);
+	zfree(&stack->spare);
+}
+
+void intel_pt_decoder_free(struct intel_pt_decoder *decoder)
+{
+	intel_pt_free_stack(&decoder->stack);
+	free(decoder);
+}
+
+static int intel_pt_ext_err(int code)
+{
+	switch (code) {
+	case -ENOMEM:
+		return INTEL_PT_ERR_NOMEM;
+	case -ENOSYS:
+		return INTEL_PT_ERR_INTERN;
+	case -EBADMSG:
+		return INTEL_PT_ERR_BADPKT;
+	case -ENODATA:
+		return INTEL_PT_ERR_NODATA;
+	case -EILSEQ:
+		return INTEL_PT_ERR_NOINSN;
+	case -ENOENT:
+		return INTEL_PT_ERR_MISMAT;
+	case -EOVERFLOW:
+		return INTEL_PT_ERR_OVR;
+	case -ENOSPC:
+		return INTEL_PT_ERR_LOST;
+	case -ELOOP:
+		return INTEL_PT_ERR_NELOOP;
+	default:
+		return INTEL_PT_ERR_UNK;
+	}
+}
+
+static const char *intel_pt_err_msgs[] = {
+	[INTEL_PT_ERR_NOMEM]  = "Memory allocation failed",
+	[INTEL_PT_ERR_INTERN] = "Internal error",
+	[INTEL_PT_ERR_BADPKT] = "Bad packet",
+	[INTEL_PT_ERR_NODATA] = "No more data",
+	[INTEL_PT_ERR_NOINSN] = "Failed to get instruction",
+	[INTEL_PT_ERR_MISMAT] = "Trace doesn't match instruction",
+	[INTEL_PT_ERR_OVR]    = "Overflow packet",
+	[INTEL_PT_ERR_LOST]   = "Lost trace data",
+	[INTEL_PT_ERR_UNK]    = "Unknown error!",
+	[INTEL_PT_ERR_NELOOP] = "Never-ending loop",
+};
+
+int intel_pt__strerror(int code, char *buf, size_t buflen)
+{
+	if (code < 1 || code > INTEL_PT_ERR_MAX)
+		code = INTEL_PT_ERR_UNK;
+	strlcpy(buf, intel_pt_err_msgs[code], buflen);
+	return 0;
+}
+
+static uint64_t intel_pt_calc_ip(struct intel_pt_decoder *decoder,
+				 const struct intel_pt_pkt *packet,
+				 uint64_t last_ip)
+{
+	uint64_t ip;
+
+	switch (packet->count) {
+	case 2:
+		ip = (last_ip & (uint64_t)0xffffffffffff0000ULL) |
+		     packet->payload;
+		break;
+	case 4:
+		ip = (last_ip & (uint64_t)0xffffffff00000000ULL) |
+		     packet->payload;
+		break;
+	case 6:
+		ip = packet->payload;
+		break;
+	default:
+		return 0;
+	}
+
+	if (ip & decoder->sign_bit)
+		return ip | decoder->sign_bits;
+
+	return ip;
+}
+
+static inline void intel_pt_set_last_ip(struct intel_pt_decoder *decoder)
+{
+	decoder->last_ip = intel_pt_calc_ip(decoder, &decoder->packet,
+					    decoder->last_ip);
+}
+
+static inline void intel_pt_set_ip(struct intel_pt_decoder *decoder)
+{
+	intel_pt_set_last_ip(decoder);
+	decoder->ip = decoder->last_ip;
+}
+
+static void intel_pt_decoder_log_packet(struct intel_pt_decoder *decoder)
+{
+	intel_pt_log_packet(&decoder->packet, decoder->pkt_len, decoder->pos,
+			    decoder->buf);
+}
+
+static int intel_pt_bug(struct intel_pt_decoder *decoder)
+{
+	intel_pt_log("ERROR: Internal error\n");
+	decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
+	return -ENOSYS;
+}
+
+static inline void intel_pt_clear_tx_flags(struct intel_pt_decoder *decoder)
+{
+	decoder->tx_flags = 0;
+}
+
+static inline void intel_pt_update_in_tx(struct intel_pt_decoder *decoder)
+{
+	decoder->tx_flags = decoder->packet.payload & INTEL_PT_IN_TX;
+}
+
+static int intel_pt_bad_packet(struct intel_pt_decoder *decoder)
+{
+	intel_pt_clear_tx_flags(decoder);
+	decoder->have_tma = false;
+	decoder->pkt_len = 1;
+	decoder->pkt_step = 1;
+	intel_pt_decoder_log_packet(decoder);
+	if (decoder->pkt_state != INTEL_PT_STATE_NO_PSB) {
+		intel_pt_log("ERROR: Bad packet\n");
+		decoder->pkt_state = INTEL_PT_STATE_ERR1;
+	}
+	return -EBADMSG;
+}
+
+static int intel_pt_get_data(struct intel_pt_decoder *decoder)
+{
+	struct intel_pt_buffer buffer = { .buf = 0, };
+	int ret;
+
+	decoder->pkt_step = 0;
+
+	intel_pt_log("Getting more data\n");
+	ret = decoder->get_trace(&buffer, decoder->data);
+	if (ret)
+		return ret;
+	decoder->buf = buffer.buf;
+	decoder->len = buffer.len;
+	if (!decoder->len) {
+		intel_pt_log("No more data\n");
+		return -ENODATA;
+	}
+	if (!buffer.consecutive) {
+		decoder->ip = 0;
+		decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
+		decoder->ref_timestamp = buffer.ref_timestamp;
+		decoder->timestamp = 0;
+		decoder->have_tma = false;
+		decoder->state.trace_nr = buffer.trace_nr;
+		intel_pt_log("Reference timestamp 0x%" PRIx64 "\n",
+			     decoder->ref_timestamp);
+		return -ENOLINK;
+	}
+
+	return 0;
+}
+
+static int intel_pt_get_next_data(struct intel_pt_decoder *decoder)
+{
+	if (!decoder->next_buf)
+		return intel_pt_get_data(decoder);
+
+	decoder->buf = decoder->next_buf;
+	decoder->len = decoder->next_len;
+	decoder->next_buf = 0;
+	decoder->next_len = 0;
+	return 0;
+}
+
+static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder)
+{
+	unsigned char *buf = decoder->temp_buf;
+	size_t old_len, len, n;
+	int ret;
+
+	old_len = decoder->len;
+	len = decoder->len;
+	memcpy(buf, decoder->buf, len);
+
+	ret = intel_pt_get_data(decoder);
+	if (ret) {
+		decoder->pos += old_len;
+		return ret < 0 ? ret : -EINVAL;
+	}
+
+	n = INTEL_PT_PKT_MAX_SZ - len;
+	if (n > decoder->len)
+		n = decoder->len;
+	memcpy(buf + len, decoder->buf, n);
+	len += n;
+
+	ret = intel_pt_get_packet(buf, len, &decoder->packet);
+	if (ret < (int)old_len) {
+		decoder->next_buf = decoder->buf;
+		decoder->next_len = decoder->len;
+		decoder->buf = buf;
+		decoder->len = old_len;
+		return intel_pt_bad_packet(decoder);
+	}
+
+	decoder->next_buf = decoder->buf + (ret - old_len);
+	decoder->next_len = decoder->len - (ret - old_len);
+
+	decoder->buf = buf;
+	decoder->len = ret;
+
+	return ret;
+}
+
+struct intel_pt_pkt_info {
+	struct intel_pt_decoder	  *decoder;
+	struct intel_pt_pkt       packet;
+	uint64_t                  pos;
+	int                       pkt_len;
+	int                       last_packet_type;
+	void                      *data;
+};
+
+typedef int (*intel_pt_pkt_cb_t)(struct intel_pt_pkt_info *pkt_info);
+
+/* Lookahead packets in current buffer */
+static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder,
+				  intel_pt_pkt_cb_t cb, void *data)
+{
+	struct intel_pt_pkt_info pkt_info;
+	const unsigned char *buf = decoder->buf;
+	size_t len = decoder->len;
+	int ret;
+
+	pkt_info.decoder          = decoder;
+	pkt_info.pos              = decoder->pos;
+	pkt_info.pkt_len          = decoder->pkt_step;
+	pkt_info.last_packet_type = decoder->last_packet_type;
+	pkt_info.data             = data;
+
+	while (1) {
+		do {
+			pkt_info.pos += pkt_info.pkt_len;
+			buf          += pkt_info.pkt_len;
+			len          -= pkt_info.pkt_len;
+
+			if (!len)
+				return INTEL_PT_NEED_MORE_BYTES;
+
+			ret = intel_pt_get_packet(buf, len, &pkt_info.packet);
+			if (!ret)
+				return INTEL_PT_NEED_MORE_BYTES;
+			if (ret < 0)
+				return ret;
+
+			pkt_info.pkt_len = ret;
+		} while (pkt_info.packet.type == INTEL_PT_PAD);
+
+		ret = cb(&pkt_info);
+		if (ret)
+			return 0;
+
+		pkt_info.last_packet_type = pkt_info.packet.type;
+	}
+}
+
+struct intel_pt_calc_cyc_to_tsc_info {
+	uint64_t        cycle_cnt;
+	unsigned int    cbr;
+	uint32_t        last_mtc;
+	uint64_t        ctc_timestamp;
+	uint64_t        ctc_delta;
+	uint64_t        tsc_timestamp;
+	uint64_t        timestamp;
+	bool            have_tma;
+	bool            from_mtc;
+	double          cbr_cyc_to_tsc;
+};
+
+static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
+{
+	struct intel_pt_decoder *decoder = pkt_info->decoder;
+	struct intel_pt_calc_cyc_to_tsc_info *data = pkt_info->data;
+	uint64_t timestamp;
+	double cyc_to_tsc;
+	unsigned int cbr;
+	uint32_t mtc, mtc_delta, ctc, fc, ctc_rem;
+
+	switch (pkt_info->packet.type) {
+	case INTEL_PT_TNT:
+	case INTEL_PT_TIP_PGE:
+	case INTEL_PT_TIP:
+	case INTEL_PT_FUP:
+	case INTEL_PT_PSB:
+	case INTEL_PT_PIP:
+	case INTEL_PT_MODE_EXEC:
+	case INTEL_PT_MODE_TSX:
+	case INTEL_PT_PSBEND:
+	case INTEL_PT_PAD:
+	case INTEL_PT_VMCS:
+	case INTEL_PT_MNT:
+		return 0;
+
+	case INTEL_PT_MTC:
+		if (!data->have_tma)
+			return 0;
+
+		mtc = pkt_info->packet.payload;
+		if (mtc > data->last_mtc)
+			mtc_delta = mtc - data->last_mtc;
+		else
+			mtc_delta = mtc + 256 - data->last_mtc;
+		data->ctc_delta += mtc_delta << decoder->mtc_shift;
+		data->last_mtc = mtc;
+
+		if (decoder->tsc_ctc_mult) {
+			timestamp = data->ctc_timestamp +
+				data->ctc_delta * decoder->tsc_ctc_mult;
+		} else {
+			timestamp = data->ctc_timestamp +
+				multdiv(data->ctc_delta,
+					decoder->tsc_ctc_ratio_n,
+					decoder->tsc_ctc_ratio_d);
+		}
+
+		if (timestamp < data->timestamp)
+			return 1;
+
+		if (pkt_info->last_packet_type != INTEL_PT_CYC) {
+			data->timestamp = timestamp;
+			return 0;
+		}
+
+		break;
+
+	case INTEL_PT_TSC:
+		timestamp = pkt_info->packet.payload |
+			    (data->timestamp & (0xffULL << 56));
+		if (data->from_mtc && timestamp < data->timestamp &&
+		    data->timestamp - timestamp < decoder->tsc_slip)
+			return 1;
+		while (timestamp < data->timestamp)
+			timestamp += (1ULL << 56);
+		if (pkt_info->last_packet_type != INTEL_PT_CYC) {
+			if (data->from_mtc)
+				return 1;
+			data->tsc_timestamp = timestamp;
+			data->timestamp = timestamp;
+			return 0;
+		}
+		break;
+
+	case INTEL_PT_TMA:
+		if (data->from_mtc)
+			return 1;
+
+		if (!decoder->tsc_ctc_ratio_d)
+			return 0;
+
+		ctc = pkt_info->packet.payload;
+		fc = pkt_info->packet.count;
+		ctc_rem = ctc & decoder->ctc_rem_mask;
+
+		data->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
+
+		data->ctc_timestamp = data->tsc_timestamp - fc;
+		if (decoder->tsc_ctc_mult) {
+			data->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
+		} else {
+			data->ctc_timestamp -=
+				multdiv(ctc_rem, decoder->tsc_ctc_ratio_n,
+					decoder->tsc_ctc_ratio_d);
+		}
+
+		data->ctc_delta = 0;
+		data->have_tma = true;
+
+		return 0;
+
+	case INTEL_PT_CYC:
+		data->cycle_cnt += pkt_info->packet.payload;
+		return 0;
+
+	case INTEL_PT_CBR:
+		cbr = pkt_info->packet.payload;
+		if (data->cbr && data->cbr != cbr)
+			return 1;
+		data->cbr = cbr;
+		data->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
+		return 0;
+
+	case INTEL_PT_TIP_PGD:
+	case INTEL_PT_TRACESTOP:
+	case INTEL_PT_OVF:
+	case INTEL_PT_BAD: /* Does not happen */
+	default:
+		return 1;
+	}
+
+	if (!data->cbr && decoder->cbr) {
+		data->cbr = decoder->cbr;
+		data->cbr_cyc_to_tsc = decoder->cbr_cyc_to_tsc;
+	}
+
+	if (!data->cycle_cnt)
+		return 1;
+
+	cyc_to_tsc = (double)(timestamp - decoder->timestamp) / data->cycle_cnt;
+
+	if (data->cbr && cyc_to_tsc > data->cbr_cyc_to_tsc &&
+	    cyc_to_tsc / data->cbr_cyc_to_tsc > 1.25) {
+		intel_pt_log("Timestamp: calculated %g TSC ticks per cycle too big (c.f. CBR-based value %g), pos " x64_fmt "\n",
+			     cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
+		return 1;
+	}
+
+	decoder->calc_cyc_to_tsc = cyc_to_tsc;
+	decoder->have_calc_cyc_to_tsc = true;
+
+	if (data->cbr) {
+		intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. CBR-based value %g, pos " x64_fmt "\n",
+			     cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
+	} else {
+		intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. unknown CBR-based value, pos " x64_fmt "\n",
+			     cyc_to_tsc, pkt_info->pos);
+	}
+
+	return 1;
+}
+
+static void intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder *decoder,
+				     bool from_mtc)
+{
+	struct intel_pt_calc_cyc_to_tsc_info data = {
+		.cycle_cnt      = 0,
+		.cbr            = 0,
+		.last_mtc       = decoder->last_mtc,
+		.ctc_timestamp  = decoder->ctc_timestamp,
+		.ctc_delta      = decoder->ctc_delta,
+		.tsc_timestamp  = decoder->tsc_timestamp,
+		.timestamp      = decoder->timestamp,
+		.have_tma       = decoder->have_tma,
+		.from_mtc       = from_mtc,
+		.cbr_cyc_to_tsc = 0,
+	};
+
+	intel_pt_pkt_lookahead(decoder, intel_pt_calc_cyc_cb, &data);
+}
+
+static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder)
+{
+	int ret;
+
+	decoder->last_packet_type = decoder->packet.type;
+
+	do {
+		decoder->pos += decoder->pkt_step;
+		decoder->buf += decoder->pkt_step;
+		decoder->len -= decoder->pkt_step;
+
+		if (!decoder->len) {
+			ret = intel_pt_get_next_data(decoder);
+			if (ret)
+				return ret;
+		}
+
+		ret = intel_pt_get_packet(decoder->buf, decoder->len,
+					  &decoder->packet);
+		if (ret == INTEL_PT_NEED_MORE_BYTES &&
+		    decoder->len < INTEL_PT_PKT_MAX_SZ && !decoder->next_buf) {
+			ret = intel_pt_get_split_packet(decoder);
+			if (ret < 0)
+				return ret;
+		}
+		if (ret <= 0)
+			return intel_pt_bad_packet(decoder);
+
+		decoder->pkt_len = ret;
+		decoder->pkt_step = ret;
+		intel_pt_decoder_log_packet(decoder);
+	} while (decoder->packet.type == INTEL_PT_PAD);
+
+	return 0;
+}
+
+static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder)
+{
+	uint64_t timestamp, masked_timestamp;
+
+	timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
+	masked_timestamp = timestamp & decoder->period_mask;
+	if (decoder->continuous_period) {
+		if (masked_timestamp != decoder->last_masked_timestamp)
+			return 1;
+	} else {
+		timestamp += 1;
+		masked_timestamp = timestamp & decoder->period_mask;
+		if (masked_timestamp != decoder->last_masked_timestamp) {
+			decoder->last_masked_timestamp = masked_timestamp;
+			decoder->continuous_period = true;
+		}
+	}
+	return decoder->period_ticks - (timestamp - masked_timestamp);
+}
+
+static uint64_t intel_pt_next_sample(struct intel_pt_decoder *decoder)
+{
+	switch (decoder->period_type) {
+	case INTEL_PT_PERIOD_INSTRUCTIONS:
+		return decoder->period - decoder->period_insn_cnt;
+	case INTEL_PT_PERIOD_TICKS:
+		return intel_pt_next_period(decoder);
+	case INTEL_PT_PERIOD_NONE:
+	case INTEL_PT_PERIOD_MTC:
+	default:
+		return 0;
+	}
+}
+
+static void intel_pt_sample_insn(struct intel_pt_decoder *decoder)
+{
+	uint64_t timestamp, masked_timestamp;
+
+	switch (decoder->period_type) {
+	case INTEL_PT_PERIOD_INSTRUCTIONS:
+		decoder->period_insn_cnt = 0;
+		break;
+	case INTEL_PT_PERIOD_TICKS:
+		timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
+		masked_timestamp = timestamp & decoder->period_mask;
+		decoder->last_masked_timestamp = masked_timestamp;
+		break;
+	case INTEL_PT_PERIOD_NONE:
+	case INTEL_PT_PERIOD_MTC:
+	default:
+		break;
+	}
+
+	decoder->state.type |= INTEL_PT_INSTRUCTION;
+}
+
+static int intel_pt_walk_insn(struct intel_pt_decoder *decoder,
+			      struct intel_pt_insn *intel_pt_insn, uint64_t ip)
+{
+	uint64_t max_insn_cnt, insn_cnt = 0;
+	int err;
+
+	if (!decoder->mtc_insn)
+		decoder->mtc_insn = true;
+
+	max_insn_cnt = intel_pt_next_sample(decoder);
+
+	err = decoder->walk_insn(intel_pt_insn, &insn_cnt, &decoder->ip, ip,
+				 max_insn_cnt, decoder->data);
+
+	decoder->tot_insn_cnt += insn_cnt;
+	decoder->timestamp_insn_cnt += insn_cnt;
+	decoder->period_insn_cnt += insn_cnt;
+
+	if (err) {
+		decoder->no_progress = 0;
+		decoder->pkt_state = INTEL_PT_STATE_ERR2;
+		intel_pt_log_at("ERROR: Failed to get instruction",
+				decoder->ip);
+		if (err == -ENOENT)
+			return -ENOLINK;
+		return -EILSEQ;
+	}
+
+	if (ip && decoder->ip == ip) {
+		err = -EAGAIN;
+		goto out;
+	}
+
+	if (max_insn_cnt && insn_cnt >= max_insn_cnt)
+		intel_pt_sample_insn(decoder);
+
+	if (intel_pt_insn->branch == INTEL_PT_BR_NO_BRANCH) {
+		decoder->state.type = INTEL_PT_INSTRUCTION;
+		decoder->state.from_ip = decoder->ip;
+		decoder->state.to_ip = 0;
+		decoder->ip += intel_pt_insn->length;
+		err = INTEL_PT_RETURN;
+		goto out;
+	}
+
+	if (intel_pt_insn->op == INTEL_PT_OP_CALL) {
+		/* Zero-length calls are excluded */
+		if (intel_pt_insn->branch != INTEL_PT_BR_UNCONDITIONAL ||
+		    intel_pt_insn->rel) {
+			err = intel_pt_push(&decoder->stack, decoder->ip +
+					    intel_pt_insn->length);
+			if (err)
+				goto out;
+		}
+	} else if (intel_pt_insn->op == INTEL_PT_OP_RET) {
+		decoder->ret_addr = intel_pt_pop(&decoder->stack);
+	}
+
+	if (intel_pt_insn->branch == INTEL_PT_BR_UNCONDITIONAL) {
+		int cnt = decoder->no_progress++;
+
+		decoder->state.from_ip = decoder->ip;
+		decoder->ip += intel_pt_insn->length +
+				intel_pt_insn->rel;
+		decoder->state.to_ip = decoder->ip;
+		err = INTEL_PT_RETURN;
+
+		/*
+		 * Check for being stuck in a loop.  This can happen if a
+		 * decoder error results in the decoder erroneously setting the
+		 * ip to an address that is itself in an infinite loop that
+		 * consumes no packets.  When that happens, there must be an
+		 * unconditional branch.
+		 */
+		if (cnt) {
+			if (cnt == 1) {
+				decoder->stuck_ip = decoder->state.to_ip;
+				decoder->stuck_ip_prd = 1;
+				decoder->stuck_ip_cnt = 1;
+			} else if (cnt > INTEL_PT_MAX_LOOPS ||
+				   decoder->state.to_ip == decoder->stuck_ip) {
+				intel_pt_log_at("ERROR: Never-ending loop",
+						decoder->state.to_ip);
+				decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
+				err = -ELOOP;
+				goto out;
+			} else if (!--decoder->stuck_ip_cnt) {
+				decoder->stuck_ip_prd += 1;
+				decoder->stuck_ip_cnt = decoder->stuck_ip_prd;
+				decoder->stuck_ip = decoder->state.to_ip;
+			}
+		}
+		goto out_no_progress;
+	}
+out:
+	decoder->no_progress = 0;
+out_no_progress:
+	decoder->state.insn_op = intel_pt_insn->op;
+	decoder->state.insn_len = intel_pt_insn->length;
+
+	if (decoder->tx_flags & INTEL_PT_IN_TX)
+		decoder->state.flags |= INTEL_PT_IN_TX;
+
+	return err;
+}
+
+static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
+{
+	struct intel_pt_insn intel_pt_insn;
+	uint64_t ip;
+	int err;
+
+	ip = decoder->last_ip;
+
+	while (1) {
+		err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
+		if (err == INTEL_PT_RETURN)
+			return 0;
+		if (err == -EAGAIN) {
+			if (decoder->set_fup_tx_flags) {
+				decoder->set_fup_tx_flags = false;
+				decoder->tx_flags = decoder->fup_tx_flags;
+				decoder->state.type = INTEL_PT_TRANSACTION;
+				decoder->state.from_ip = decoder->ip;
+				decoder->state.to_ip = 0;
+				decoder->state.flags = decoder->fup_tx_flags;
+				return 0;
+			}
+			return err;
+		}
+		decoder->set_fup_tx_flags = false;
+		if (err)
+			return err;
+
+		if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
+			intel_pt_log_at("ERROR: Unexpected indirect branch",
+					decoder->ip);
+			decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
+			return -ENOENT;
+		}
+
+		if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
+			intel_pt_log_at("ERROR: Unexpected conditional branch",
+					decoder->ip);
+			decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
+			return -ENOENT;
+		}
+
+		intel_pt_bug(decoder);
+	}
+}
+
+static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
+{
+	struct intel_pt_insn intel_pt_insn;
+	int err;
+
+	err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
+	if (err == INTEL_PT_RETURN)
+		return 0;
+	if (err)
+		return err;
+
+	if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
+		if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
+			decoder->pge = false;
+			decoder->continuous_period = false;
+			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
+			decoder->state.from_ip = decoder->ip;
+			decoder->state.to_ip = 0;
+			if (decoder->packet.count != 0)
+				decoder->ip = decoder->last_ip;
+		} else {
+			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
+			decoder->state.from_ip = decoder->ip;
+			if (decoder->packet.count == 0) {
+				decoder->state.to_ip = 0;
+			} else {
+				decoder->state.to_ip = decoder->last_ip;
+				decoder->ip = decoder->last_ip;
+			}
+		}
+		return 0;
+	}
+
+	if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
+		intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
+				decoder->ip);
+		decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
+		return -ENOENT;
+	}
+
+	return intel_pt_bug(decoder);
+}
+
+static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
+{
+	struct intel_pt_insn intel_pt_insn;
+	int err;
+
+	while (1) {
+		err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
+		if (err == INTEL_PT_RETURN)
+			return 0;
+		if (err)
+			return err;
+
+		if (intel_pt_insn.op == INTEL_PT_OP_RET) {
+			if (!decoder->return_compression) {
+				intel_pt_log_at("ERROR: RET when expecting conditional branch",
+						decoder->ip);
+				decoder->pkt_state = INTEL_PT_STATE_ERR3;
+				return -ENOENT;
+			}
+			if (!decoder->ret_addr) {
+				intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
+						decoder->ip);
+				decoder->pkt_state = INTEL_PT_STATE_ERR3;
+				return -ENOENT;
+			}
+			if (!(decoder->tnt.payload & BIT63)) {
+				intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
+						decoder->ip);
+				decoder->pkt_state = INTEL_PT_STATE_ERR3;
+				return -ENOENT;
+			}
+			decoder->tnt.count -= 1;
+			if (!decoder->tnt.count)
+				decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
+			decoder->tnt.payload <<= 1;
+			decoder->state.from_ip = decoder->ip;
+			decoder->ip = decoder->ret_addr;
+			decoder->state.to_ip = decoder->ip;
+			return 0;
+		}
+
+		if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
+			/* Handle deferred TIPs */
+			err = intel_pt_get_next_packet(decoder);
+			if (err)
+				return err;
+			if (decoder->packet.type != INTEL_PT_TIP ||
+			    decoder->packet.count == 0) {
+				intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
+						decoder->ip);
+				decoder->pkt_state = INTEL_PT_STATE_ERR3;
+				decoder->pkt_step = 0;
+				return -ENOENT;
+			}
+			intel_pt_set_last_ip(decoder);
+			decoder->state.from_ip = decoder->ip;
+			decoder->state.to_ip = decoder->last_ip;
+			decoder->ip = decoder->last_ip;
+			return 0;
+		}
+
+		if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
+			decoder->tnt.count -= 1;
+			if (!decoder->tnt.count)
+				decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
+			if (decoder->tnt.payload & BIT63) {
+				decoder->tnt.payload <<= 1;
+				decoder->state.from_ip = decoder->ip;
+				decoder->ip += intel_pt_insn.length +
+					       intel_pt_insn.rel;
+				decoder->state.to_ip = decoder->ip;
+				return 0;
+			}
+			/* Instruction sample for a non-taken branch */
+			if (decoder->state.type & INTEL_PT_INSTRUCTION) {
+				decoder->tnt.payload <<= 1;
+				decoder->state.type = INTEL_PT_INSTRUCTION;
+				decoder->state.from_ip = decoder->ip;
+				decoder->state.to_ip = 0;
+				decoder->ip += intel_pt_insn.length;
+				return 0;
+			}
+			decoder->ip += intel_pt_insn.length;
+			if (!decoder->tnt.count)
+				return -EAGAIN;
+			decoder->tnt.payload <<= 1;
+			continue;
+		}
+
+		return intel_pt_bug(decoder);
+	}
+}
+
+static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
+{
+	unsigned int fup_tx_flags;
+	int err;
+
+	fup_tx_flags = decoder->packet.payload &
+		       (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
+	err = intel_pt_get_next_packet(decoder);
+	if (err)
+		return err;
+	if (decoder->packet.type == INTEL_PT_FUP) {
+		decoder->fup_tx_flags = fup_tx_flags;
+		decoder->set_fup_tx_flags = true;
+		if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
+			*no_tip = true;
+	} else {
+		intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
+				decoder->pos);
+		intel_pt_update_in_tx(decoder);
+	}
+	return 0;
+}
+
+static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
+{
+	uint64_t timestamp;
+
+	decoder->have_tma = false;
+
+	if (decoder->ref_timestamp) {
+		timestamp = decoder->packet.payload |
+			    (decoder->ref_timestamp & (0xffULL << 56));
+		if (timestamp < decoder->ref_timestamp) {
+			if (decoder->ref_timestamp - timestamp > (1ULL << 55))
+				timestamp += (1ULL << 56);
+		} else {
+			if (timestamp - decoder->ref_timestamp > (1ULL << 55))
+				timestamp -= (1ULL << 56);
+		}
+		decoder->tsc_timestamp = timestamp;
+		decoder->timestamp = timestamp;
+		decoder->ref_timestamp = 0;
+		decoder->timestamp_insn_cnt = 0;
+	} else if (decoder->timestamp) {
+		timestamp = decoder->packet.payload |
+			    (decoder->timestamp & (0xffULL << 56));
+		decoder->tsc_timestamp = timestamp;
+		if (timestamp < decoder->timestamp &&
+		    decoder->timestamp - timestamp < decoder->tsc_slip) {
+			intel_pt_log_to("Suppressing backwards timestamp",
+					timestamp);
+			timestamp = decoder->timestamp;
+		}
+		while (timestamp < decoder->timestamp) {
+			intel_pt_log_to("Wraparound timestamp", timestamp);
+			timestamp += (1ULL << 56);
+			decoder->tsc_timestamp = timestamp;
+		}
+		decoder->timestamp = timestamp;
+		decoder->timestamp_insn_cnt = 0;
+	}
+
+	if (decoder->last_packet_type == INTEL_PT_CYC) {
+		decoder->cyc_ref_timestamp = decoder->timestamp;
+		decoder->cycle_cnt = 0;
+		decoder->have_calc_cyc_to_tsc = false;
+		intel_pt_calc_cyc_to_tsc(decoder, false);
+	}
+
+	intel_pt_log_to("Setting timestamp", decoder->timestamp);
+}
+
+static int intel_pt_overflow(struct intel_pt_decoder *decoder)
+{
+	intel_pt_log("ERROR: Buffer overflow\n");
+	intel_pt_clear_tx_flags(decoder);
+	decoder->have_tma = false;
+	decoder->cbr = 0;
+	decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
+	decoder->overflow = true;
+	return -EOVERFLOW;
+}
+
+static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
+{
+	uint32_t ctc = decoder->packet.payload;
+	uint32_t fc = decoder->packet.count;
+	uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;
+
+	if (!decoder->tsc_ctc_ratio_d)
+		return;
+
+	decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
+	decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
+	if (decoder->tsc_ctc_mult) {
+		decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
+	} else {
+		decoder->ctc_timestamp -= multdiv(ctc_rem,
+						  decoder->tsc_ctc_ratio_n,
+						  decoder->tsc_ctc_ratio_d);
+	}
+	decoder->ctc_delta = 0;
+	decoder->have_tma = true;
+	intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x  CTC rem %#x\n",
+		     decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
+}
+
+static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
+{
+	uint64_t timestamp;
+	uint32_t mtc, mtc_delta;
+
+	if (!decoder->have_tma)
+		return;
+
+	mtc = decoder->packet.payload;
+
+	if (mtc > decoder->last_mtc)
+		mtc_delta = mtc - decoder->last_mtc;
+	else
+		mtc_delta = mtc + 256 - decoder->last_mtc;
+
+	decoder->ctc_delta += mtc_delta << decoder->mtc_shift;
+
+	if (decoder->tsc_ctc_mult) {
+		timestamp = decoder->ctc_timestamp +
+			    decoder->ctc_delta * decoder->tsc_ctc_mult;
+	} else {
+		timestamp = decoder->ctc_timestamp +
+			    multdiv(decoder->ctc_delta,
+				    decoder->tsc_ctc_ratio_n,
+				    decoder->tsc_ctc_ratio_d);
+	}
+
+	if (timestamp < decoder->timestamp)
+		intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
+			     timestamp, decoder->timestamp);
+	else
+		decoder->timestamp = timestamp;
+
+	decoder->timestamp_insn_cnt = 0;
+	decoder->last_mtc = mtc;
+
+	if (decoder->last_packet_type == INTEL_PT_CYC) {
+		decoder->cyc_ref_timestamp = decoder->timestamp;
+		decoder->cycle_cnt = 0;
+		decoder->have_calc_cyc_to_tsc = false;
+		intel_pt_calc_cyc_to_tsc(decoder, true);
+	}
+}
+
+static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
+{
+	unsigned int cbr = decoder->packet.payload;
+
+	if (decoder->cbr == cbr)
+		return;
+
+	decoder->cbr = cbr;
+	decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
+}
+
+static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
+{
+	uint64_t timestamp = decoder->cyc_ref_timestamp;
+
+	decoder->have_cyc = true;
+
+	decoder->cycle_cnt += decoder->packet.payload;
+
+	if (!decoder->cyc_ref_timestamp)
+		return;
+
+	if (decoder->have_calc_cyc_to_tsc)
+		timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
+	else if (decoder->cbr)
+		timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
+	else
+		return;
+
+	if (timestamp < decoder->timestamp)
+		intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
+			     timestamp, decoder->timestamp);
+	else
+		decoder->timestamp = timestamp;
+}
+
+/* Walk PSB+ packets when already in sync. */
+static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
+{
+	int err;
+
+	while (1) {
+		err = intel_pt_get_next_packet(decoder);
+		if (err)
+			return err;
+
+		switch (decoder->packet.type) {
+		case INTEL_PT_PSBEND:
+			return 0;
+
+		case INTEL_PT_TIP_PGD:
+		case INTEL_PT_TIP_PGE:
+		case INTEL_PT_TIP:
+		case INTEL_PT_TNT:
+		case INTEL_PT_TRACESTOP:
+		case INTEL_PT_BAD:
+		case INTEL_PT_PSB:
+			decoder->have_tma = false;
+			intel_pt_log("ERROR: Unexpected packet\n");
+			return -EAGAIN;
+
+		case INTEL_PT_OVF:
+			return intel_pt_overflow(decoder);
+
+		case INTEL_PT_TSC:
+			intel_pt_calc_tsc_timestamp(decoder);
+			break;
+
+		case INTEL_PT_TMA:
+			intel_pt_calc_tma(decoder);
+			break;
+
+		case INTEL_PT_CBR:
+			intel_pt_calc_cbr(decoder);
+			break;
+
+		case INTEL_PT_MODE_EXEC:
+			decoder->exec_mode = decoder->packet.payload;
+			break;
+
+		case INTEL_PT_PIP:
+			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
+			break;
+
+		case INTEL_PT_FUP:
+			decoder->pge = true;
+			intel_pt_set_last_ip(decoder);
+			break;
+
+		case INTEL_PT_MODE_TSX:
+			intel_pt_update_in_tx(decoder);
+			break;
+
+		case INTEL_PT_MTC:
+			intel_pt_calc_mtc_timestamp(decoder);
+			if (decoder->period_type == INTEL_PT_PERIOD_MTC)
+				decoder->state.type |= INTEL_PT_INSTRUCTION;
+			break;
+
+		case INTEL_PT_CYC:
+		case INTEL_PT_VMCS:
+		case INTEL_PT_MNT:
+		case INTEL_PT_PAD:
+		default:
+			break;
+		}
+	}
+}
+
+static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
+{
+	int err;
+
+	if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
+		decoder->tx_flags = 0;
+		decoder->state.flags &= ~INTEL_PT_IN_TX;
+		decoder->state.flags |= INTEL_PT_ABORT_TX;
+	} else {
+		decoder->state.flags |= INTEL_PT_ASYNC;
+	}
+
+	while (1) {
+		err = intel_pt_get_next_packet(decoder);
+		if (err)
+			return err;
+
+		switch (decoder->packet.type) {
+		case INTEL_PT_TNT:
+		case INTEL_PT_FUP:
+		case INTEL_PT_TRACESTOP:
+		case INTEL_PT_PSB:
+		case INTEL_PT_TSC:
+		case INTEL_PT_TMA:
+		case INTEL_PT_CBR:
+		case INTEL_PT_MODE_TSX:
+		case INTEL_PT_BAD:
+		case INTEL_PT_PSBEND:
+			intel_pt_log("ERROR: Missing TIP after FUP\n");
+			decoder->pkt_state = INTEL_PT_STATE_ERR3;
+			return -ENOENT;
+
+		case INTEL_PT_OVF:
+			return intel_pt_overflow(decoder);
+
+		case INTEL_PT_TIP_PGD:
+			decoder->state.from_ip = decoder->ip;
+			decoder->state.to_ip = 0;
+			if (decoder->packet.count != 0) {
+				intel_pt_set_ip(decoder);
+				intel_pt_log("Omitting PGD ip " x64_fmt "\n",
+					     decoder->ip);
+			}
+			decoder->pge = false;
+			decoder->continuous_period = false;
+			return 0;
+
+		case INTEL_PT_TIP_PGE:
+			decoder->pge = true;
+			intel_pt_log("Omitting PGE ip " x64_fmt "\n",
+				     decoder->ip);
+			decoder->state.from_ip = 0;
+			if (decoder->packet.count == 0) {
+				decoder->state.to_ip = 0;
+			} else {
+				intel_pt_set_ip(decoder);
+				decoder->state.to_ip = decoder->ip;
+			}
+			return 0;
+
+		case INTEL_PT_TIP:
+			decoder->state.from_ip = decoder->ip;
+			if (decoder->packet.count == 0) {
+				decoder->state.to_ip = 0;
+			} else {
+				intel_pt_set_ip(decoder);
+				decoder->state.to_ip = decoder->ip;
+			}
+			return 0;
+
+		case INTEL_PT_PIP:
+			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
+			break;
+
+		case INTEL_PT_MTC:
+			intel_pt_calc_mtc_timestamp(decoder);
+			if (decoder->period_type == INTEL_PT_PERIOD_MTC)
+				decoder->state.type |= INTEL_PT_INSTRUCTION;
+			break;
+
+		case INTEL_PT_CYC:
+			intel_pt_calc_cyc_timestamp(decoder);
+			break;
+
+		case INTEL_PT_MODE_EXEC:
+			decoder->exec_mode = decoder->packet.payload;
+			break;
+
+		case INTEL_PT_VMCS:
+		case INTEL_PT_MNT:
+		case INTEL_PT_PAD:
+			break;
+
+		default:
+			return intel_pt_bug(decoder);
+		}
+	}
+}
+
+static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
+{
+	bool no_tip = false;
+	int err;
+
+	while (1) {
+		err = intel_pt_get_next_packet(decoder);
+		if (err)
+			return err;
+next:
+		switch (decoder->packet.type) {
+		case INTEL_PT_TNT:
+			if (!decoder->packet.count)
+				break;
+			decoder->tnt = decoder->packet;
+			decoder->pkt_state = INTEL_PT_STATE_TNT;
+			err = intel_pt_walk_tnt(decoder);
+			if (err == -EAGAIN)
+				break;
+			return err;
+
+		case INTEL_PT_TIP_PGD:
+			if (decoder->packet.count != 0)
+				intel_pt_set_last_ip(decoder);
+			decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
+			return intel_pt_walk_tip(decoder);
+
+		case INTEL_PT_TIP_PGE: {
+			decoder->pge = true;
+			if (decoder->packet.count == 0) {
+				intel_pt_log_at("Skipping zero TIP.PGE",
+						decoder->pos);
+				break;
+			}
+			intel_pt_set_ip(decoder);
+			decoder->state.from_ip = 0;
+			decoder->state.to_ip = decoder->ip;
+			return 0;
+		}
+
+		case INTEL_PT_OVF:
+			return intel_pt_overflow(decoder);
+
+		case INTEL_PT_TIP:
+			if (decoder->packet.count != 0)
+				intel_pt_set_last_ip(decoder);
+			decoder->pkt_state = INTEL_PT_STATE_TIP;
+			return intel_pt_walk_tip(decoder);
+
+		case INTEL_PT_FUP:
+			if (decoder->packet.count == 0) {
+				intel_pt_log_at("Skipping zero FUP",
+						decoder->pos);
+				no_tip = false;
+				break;
+			}
+			intel_pt_set_last_ip(decoder);
+			err = intel_pt_walk_fup(decoder);
+			if (err != -EAGAIN) {
+				if (err)
+					return err;
+				if (no_tip)
+					decoder->pkt_state =
+						INTEL_PT_STATE_FUP_NO_TIP;
+				else
+					decoder->pkt_state = INTEL_PT_STATE_FUP;
+				return 0;
+			}
+			if (no_tip) {
+				no_tip = false;
+				break;
+			}
+			return intel_pt_walk_fup_tip(decoder);
+
+		case INTEL_PT_TRACESTOP:
+			decoder->pge = false;
+			decoder->continuous_period = false;
+			intel_pt_clear_tx_flags(decoder);
+			decoder->have_tma = false;
+			break;
+
+		case INTEL_PT_PSB:
+			intel_pt_clear_stack(&decoder->stack);
+			err = intel_pt_walk_psbend(decoder);
+			if (err == -EAGAIN)
+				goto next;
+			if (err)
+				return err;
+			break;
+
+		case INTEL_PT_PIP:
+			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
+			break;
+
+		case INTEL_PT_MTC:
+			intel_pt_calc_mtc_timestamp(decoder);
+			if (decoder->period_type != INTEL_PT_PERIOD_MTC)
+				break;
+			/*
+			 * Ensure that there has been an instruction since the
+			 * last MTC.
+			 */
+			if (!decoder->mtc_insn)
+				break;
+			decoder->mtc_insn = false;
+			/* Ensure that there is a timestamp */
+			if (!decoder->timestamp)
+				break;
+			decoder->state.type = INTEL_PT_INSTRUCTION;
+			decoder->state.from_ip = decoder->ip;
+			decoder->state.to_ip = 0;
+			decoder->mtc_insn = false;
+			return 0;
+
+		case INTEL_PT_TSC:
+			intel_pt_calc_tsc_timestamp(decoder);
+			break;
+
+		case INTEL_PT_TMA:
+			intel_pt_calc_tma(decoder);
+			break;
+
+		case INTEL_PT_CYC:
+			intel_pt_calc_cyc_timestamp(decoder);
+			break;
+
+		case INTEL_PT_CBR:
+			intel_pt_calc_cbr(decoder);
+			break;
+
+		case INTEL_PT_MODE_EXEC:
+			decoder->exec_mode = decoder->packet.payload;
+			break;
+
+		case INTEL_PT_MODE_TSX:
+			/* MODE_TSX need not be followed by FUP */
+			if (!decoder->pge) {
+				intel_pt_update_in_tx(decoder);
+				break;
+			}
+			err = intel_pt_mode_tsx(decoder, &no_tip);
+			if (err)
+				return err;
+			goto next;
+
+		case INTEL_PT_BAD: /* Does not happen */
+			return intel_pt_bug(decoder);
+
+		case INTEL_PT_PSBEND:
+		case INTEL_PT_VMCS:
+		case INTEL_PT_MNT:
+		case INTEL_PT_PAD:
+			break;
+
+		default:
+			return intel_pt_bug(decoder);
+		}
+	}
+}
+
+/* Walk PSB+ packets to get in sync. */
+static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
+{
+	int err;
+
+	while (1) {
+		err = intel_pt_get_next_packet(decoder);
+		if (err)
+			return err;
+
+		switch (decoder->packet.type) {
+		case INTEL_PT_TIP_PGD:
+			decoder->continuous_period = false;
+		case INTEL_PT_TIP_PGE:
+		case INTEL_PT_TIP:
+			intel_pt_log("ERROR: Unexpected packet\n");
+			return -ENOENT;
+
+		case INTEL_PT_FUP:
+			decoder->pge = true;
+			if (decoder->last_ip || decoder->packet.count == 6 ||
+			    decoder->packet.count == 0) {
+				uint64_t current_ip = decoder->ip;
+
+				intel_pt_set_ip(decoder);
+				if (current_ip)
+					intel_pt_log_to("Setting IP",
+							decoder->ip);
+			}
+			break;
+
+		case INTEL_PT_MTC:
+			intel_pt_calc_mtc_timestamp(decoder);
+			break;
+
+		case INTEL_PT_TSC:
+			intel_pt_calc_tsc_timestamp(decoder);
+			break;
+
+		case INTEL_PT_TMA:
+			intel_pt_calc_tma(decoder);
+			break;
+
+		case INTEL_PT_CYC:
+			intel_pt_calc_cyc_timestamp(decoder);
+			break;
+
+		case INTEL_PT_CBR:
+			intel_pt_calc_cbr(decoder);
+			break;
+
+		case INTEL_PT_PIP:
+			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
+			break;
+
+		case INTEL_PT_MODE_EXEC:
+			decoder->exec_mode = decoder->packet.payload;
+			break;
+
+		case INTEL_PT_MODE_TSX:
+			intel_pt_update_in_tx(decoder);
+			break;
+
+		case INTEL_PT_TRACESTOP:
+			decoder->pge = false;
+			decoder->continuous_period = false;
+			intel_pt_clear_tx_flags(decoder);
+		case INTEL_PT_TNT:
+			decoder->have_tma = false;
+			intel_pt_log("ERROR: Unexpected packet\n");
+			if (decoder->ip)
+				decoder->pkt_state = INTEL_PT_STATE_ERR4;
+			else
+				decoder->pkt_state = INTEL_PT_STATE_ERR3;
+			return -ENOENT;
+
+		case INTEL_PT_BAD: /* Does not happen */
+			return intel_pt_bug(decoder);
+
+		case INTEL_PT_OVF:
+			return intel_pt_overflow(decoder);
+
+		case INTEL_PT_PSBEND:
+			return 0;
+
+		case INTEL_PT_PSB:
+		case INTEL_PT_VMCS:
+		case INTEL_PT_MNT:
+		case INTEL_PT_PAD:
+		default:
+			break;
+		}
+	}
+}
+
+static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
+{
+	int err;
+
+	while (1) {
+		err = intel_pt_get_next_packet(decoder);
+		if (err)
+			return err;
+
+		switch (decoder->packet.type) {
+		case INTEL_PT_TIP_PGD:
+			decoder->continuous_period = false;
+		case INTEL_PT_TIP_PGE:
+		case INTEL_PT_TIP:
+			decoder->pge = decoder->packet.type != INTEL_PT_TIP_PGD;
+			if (decoder->last_ip || decoder->packet.count == 6 ||
+			    decoder->packet.count == 0)
+				intel_pt_set_ip(decoder);
+			if (decoder->ip)
+				return 0;
+			break;
+
+		case INTEL_PT_FUP:
+			if (decoder->overflow) {
+				if (decoder->last_ip ||
+				    decoder->packet.count == 6 ||
+				    decoder->packet.count == 0)
+					intel_pt_set_ip(decoder);
+				if (decoder->ip)
+					return 0;
+			}
+			if (decoder->packet.count)
+				intel_pt_set_last_ip(decoder);
+			break;
+
+		case INTEL_PT_MTC:
+			intel_pt_calc_mtc_timestamp(decoder);
+			break;
+
+		case INTEL_PT_TSC:
+			intel_pt_calc_tsc_timestamp(decoder);
+			break;
+
+		case INTEL_PT_TMA:
+			intel_pt_calc_tma(decoder);
+			break;
+
+		case INTEL_PT_CYC:
+			intel_pt_calc_cyc_timestamp(decoder);
+			break;
+
+		case INTEL_PT_CBR:
+			intel_pt_calc_cbr(decoder);
+			break;
+
+		case INTEL_PT_PIP:
+			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
+			break;
+
+		case INTEL_PT_MODE_EXEC:
+			decoder->exec_mode = decoder->packet.payload;
+			break;
+
+		case INTEL_PT_MODE_TSX:
+			intel_pt_update_in_tx(decoder);
+			break;
+
+		case INTEL_PT_OVF:
+			return intel_pt_overflow(decoder);
+
+		case INTEL_PT_BAD: /* Does not happen */
+			return intel_pt_bug(decoder);
+
+		case INTEL_PT_TRACESTOP:
+			decoder->pge = false;
+			decoder->continuous_period = false;
+			intel_pt_clear_tx_flags(decoder);
+			decoder->have_tma = false;
+			break;
+
+		case INTEL_PT_PSB:
+			err = intel_pt_walk_psb(decoder);
+			if (err)
+				return err;
+			if (decoder->ip) {
+				/* Do not have a sample */
+				decoder->state.type = 0;
+				return 0;
+			}
+			break;
+
+		case INTEL_PT_TNT:
+		case INTEL_PT_PSBEND:
+		case INTEL_PT_VMCS:
+		case INTEL_PT_MNT:
+		case INTEL_PT_PAD:
+		default:
+			break;
+		}
+	}
+}
+
+static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
+{
+	int err;
+
+	intel_pt_log("Scanning for full IP\n");
+	err = intel_pt_walk_to_ip(decoder);
+	if (err)
+		return err;
+
+	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
+	decoder->overflow = false;
+
+	decoder->state.from_ip = 0;
+	decoder->state.to_ip = decoder->ip;
+	intel_pt_log_to("Setting IP", decoder->ip);
+
+	return 0;
+}
+
+static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
+{
+	const unsigned char *end = decoder->buf + decoder->len;
+	size_t i;
+
+	for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
+		if (i > decoder->len)
+			continue;
+		if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
+			return i;
+	}
+	return 0;
+}
+
+static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
+{
+	size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
+	const char *psb = INTEL_PT_PSB_STR;
+
+	if (rest_psb > decoder->len ||
+	    memcmp(decoder->buf, psb + part_psb, rest_psb))
+		return 0;
+
+	return rest_psb;
+}
+
+static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
+				  int part_psb)
+{
+	int rest_psb, ret;
+
+	decoder->pos += decoder->len;
+	decoder->len = 0;
+
+	ret = intel_pt_get_next_data(decoder);
+	if (ret)
+		return ret;
+
+	rest_psb = intel_pt_rest_psb(decoder, part_psb);
+	if (!rest_psb)
+		return 0;
+
+	decoder->pos -= part_psb;
+	decoder->next_buf = decoder->buf + rest_psb;
+	decoder->next_len = decoder->len - rest_psb;
+	memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
+	decoder->buf = decoder->temp_buf;
+	decoder->len = INTEL_PT_PSB_LEN;
+
+	return 0;
+}
+
+static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
+{
+	unsigned char *next;
+	int ret;
+
+	intel_pt_log("Scanning for PSB\n");
+	while (1) {
+		if (!decoder->len) {
+			ret = intel_pt_get_next_data(decoder);
+			if (ret)
+				return ret;
+		}
+
+		next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
+			      INTEL_PT_PSB_LEN);
+		if (!next) {
+			int part_psb;
+
+			part_psb = intel_pt_part_psb(decoder);
+			if (part_psb) {
+				ret = intel_pt_get_split_psb(decoder, part_psb);
+				if (ret)
+					return ret;
+			} else {
+				decoder->pos += decoder->len;
+				decoder->len = 0;
+			}
+			continue;
+		}
+
+		decoder->pkt_step = next - decoder->buf;
+		return intel_pt_get_next_packet(decoder);
+	}
+}
+
+static int intel_pt_sync(struct intel_pt_decoder *decoder)
+{
+	int err;
+
+	decoder->pge = false;
+	decoder->continuous_period = false;
+	decoder->last_ip = 0;
+	decoder->ip = 0;
+	intel_pt_clear_stack(&decoder->stack);
+
+	err = intel_pt_scan_for_psb(decoder);
+	if (err)
+		return err;
+
+	decoder->pkt_state = INTEL_PT_STATE_NO_IP;
+
+	err = intel_pt_walk_psb(decoder);
+	if (err)
+		return err;
+
+	if (decoder->ip) {
+		decoder->state.type = 0; /* Do not have a sample */
+		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
+	} else {
+		return intel_pt_sync_ip(decoder);
+	}
+
+	return 0;
+}
+
+static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
+{
+	uint64_t est = decoder->timestamp_insn_cnt << 1;
+
+	if (!decoder->cbr || !decoder->max_non_turbo_ratio)
+		goto out;
+
+	est *= decoder->max_non_turbo_ratio;
+	est /= decoder->cbr;
+out:
+	return decoder->timestamp + est;
+}
+
+const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
+{
+	int err;
+
+	do {
+		decoder->state.type = INTEL_PT_BRANCH;
+		decoder->state.flags = 0;
+
+		switch (decoder->pkt_state) {
+		case INTEL_PT_STATE_NO_PSB:
+			err = intel_pt_sync(decoder);
+			break;
+		case INTEL_PT_STATE_NO_IP:
+			decoder->last_ip = 0;
+			/* Fall through */
+		case INTEL_PT_STATE_ERR_RESYNC:
+			err = intel_pt_sync_ip(decoder);
+			break;
+		case INTEL_PT_STATE_IN_SYNC:
+			err = intel_pt_walk_trace(decoder);
+			break;
+		case INTEL_PT_STATE_TNT:
+			err = intel_pt_walk_tnt(decoder);
+			if (err == -EAGAIN)
+				err = intel_pt_walk_trace(decoder);
+			break;
+		case INTEL_PT_STATE_TIP:
+		case INTEL_PT_STATE_TIP_PGD:
+			err = intel_pt_walk_tip(decoder);
+			break;
+		case INTEL_PT_STATE_FUP:
+			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
+			err = intel_pt_walk_fup(decoder);
+			if (err == -EAGAIN)
+				err = intel_pt_walk_fup_tip(decoder);
+			else if (!err)
+				decoder->pkt_state = INTEL_PT_STATE_FUP;
+			break;
+		case INTEL_PT_STATE_FUP_NO_TIP:
+			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
+			err = intel_pt_walk_fup(decoder);
+			if (err == -EAGAIN)
+				err = intel_pt_walk_trace(decoder);
+			break;
+		default:
+			err = intel_pt_bug(decoder);
+			break;
+		}
+	} while (err == -ENOLINK);
+
+	decoder->state.err = err ? intel_pt_ext_err(err) : 0;
+	decoder->state.timestamp = decoder->timestamp;
+	decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
+	decoder->state.cr3 = decoder->cr3;
+	decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
+
+	if (err)
+		decoder->state.from_ip = decoder->ip;
+
+	return &decoder->state;
+}
+
+static bool intel_pt_at_psb(unsigned char *buf, size_t len)
+{
+	if (len < INTEL_PT_PSB_LEN)
+		return false;
+	return memmem(buf, INTEL_PT_PSB_LEN, INTEL_PT_PSB_STR,
+		      INTEL_PT_PSB_LEN);
+}
+
+/**
+ * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
+ * @buf: pointer to buffer pointer
+ * @len: size of buffer
+ *
+ * Updates the buffer pointer to point to the start of the next PSB packet if
+ * there is one, otherwise the buffer pointer is unchanged.  If @buf is updated,
+ * @len is adjusted accordingly.
+ *
+ * Return: %true if a PSB packet is found, %false otherwise.
+ */
+static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
+{
+	unsigned char *next;
+
+	next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
+	if (next) {
+		*len -= next - *buf;
+		*buf = next;
+		return true;
+	}
+	return false;
+}
+
+/**
+ * intel_pt_step_psb - move buffer pointer to the start of the following PSB
+ *                     packet.
+ * @buf: pointer to buffer pointer
+ * @len: size of buffer
+ *
+ * Updates the buffer pointer to point to the start of the following PSB packet
+ * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
+ * pointer is unchanged.  If @buf is updated, @len is adjusted accordingly.
+ *
+ * Return: %true if a PSB packet is found, %false otherwise.
+ */
+static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
+{
+	unsigned char *next;
+
+	if (!*len)
+		return false;
+
+	next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
+	if (next) {
+		*len -= next - *buf;
+		*buf = next;
+		return true;
+	}
+	return false;
+}
+
+/**
+ * intel_pt_last_psb - find the last PSB packet in a buffer.
+ * @buf: buffer
+ * @len: size of buffer
+ *
+ * This function finds the last PSB in a buffer.
+ *
+ * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
+ */
+static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
+{
+	const char *n = INTEL_PT_PSB_STR;
+	unsigned char *p;
+	size_t k;
+
+	if (len < INTEL_PT_PSB_LEN)
+		return NULL;
+
+	k = len - INTEL_PT_PSB_LEN + 1;
+	while (1) {
+		p = memrchr(buf, n[0], k);
+		if (!p)
+			return NULL;
+		if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
+			return p;
+		k = p - buf;
+		if (!k)
+			return NULL;
+	}
+}
+
+/**
+ * intel_pt_next_tsc - find and return next TSC.
+ * @buf: buffer
+ * @len: size of buffer
+ * @tsc: TSC value returned
+ *
+ * Find a TSC packet in @buf and return the TSC value.  This function assumes
+ * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
+ * PSBEND packet is found.
+ *
+ * Return: %true if TSC is found, false otherwise.
+ */
+static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc)
+{
+	struct intel_pt_pkt packet;
+	int ret;
+
+	while (len) {
+		ret = intel_pt_get_packet(buf, len, &packet);
+		if (ret <= 0)
+			return false;
+		if (packet.type == INTEL_PT_TSC) {
+			*tsc = packet.payload;
+			return true;
+		}
+		if (packet.type == INTEL_PT_PSBEND)
+			return false;
+		buf += ret;
+		len -= ret;
+	}
+	return false;
+}
+
+/**
+ * intel_pt_tsc_cmp - compare 7-byte TSCs.
+ * @tsc1: first TSC to compare
+ * @tsc2: second TSC to compare
+ *
+ * This function compares 7-byte TSC values allowing for the possibility that
+ * TSC wrapped around.  Generally it is not possible to know if TSC has wrapped
+ * around so for that purpose this function assumes the absolute difference is
+ * less than half the maximum difference.
+ *
+ * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
+ * after @tsc2.
+ */
+static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
+{
+	const uint64_t halfway = (1ULL << 55);
+
+	if (tsc1 == tsc2)
+		return 0;
+
+	if (tsc1 < tsc2) {
+		if (tsc2 - tsc1 < halfway)
+			return -1;
+		else
+			return 1;
+	} else {
+		if (tsc1 - tsc2 < halfway)
+			return 1;
+		else
+			return -1;
+	}
+}
+
+/**
+ * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
+ *                             using TSC.
+ * @buf_a: first buffer
+ * @len_a: size of first buffer
+ * @buf_b: second buffer
+ * @len_b: size of second buffer
+ *
+ * If the trace contains TSC we can look at the last TSC of @buf_a and the
+ * first TSC of @buf_b in order to determine if the buffers overlap, and then
+ * walk forward in @buf_b until a later TSC is found.  A precondition is that
+ * @buf_a and @buf_b are positioned at a PSB.
+ *
+ * Return: A pointer into @buf_b from where non-overlapped data starts, or
+ * @buf_b + @len_b if there is no non-overlapped data.
+ */
+static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
+						size_t len_a,
+						unsigned char *buf_b,
+						size_t len_b)
+{
+	uint64_t tsc_a, tsc_b;
+	unsigned char *p;
+	size_t len;
+
+	p = intel_pt_last_psb(buf_a, len_a);
+	if (!p)
+		return buf_b; /* No PSB in buf_a => no overlap */
+
+	len = len_a - (p - buf_a);
+	if (!intel_pt_next_tsc(p, len, &tsc_a)) {
+		/* The last PSB+ in buf_a is incomplete, so go back one more */
+		len_a -= len;
+		p = intel_pt_last_psb(buf_a, len_a);
+		if (!p)
+			return buf_b; /* No full PSB+ => assume no overlap */
+		len = len_a - (p - buf_a);
+		if (!intel_pt_next_tsc(p, len, &tsc_a))
+			return buf_b; /* No TSC in buf_a => assume no overlap */
+	}
+
+	while (1) {
+		/* Ignore PSB+ with no TSC */
+		if (intel_pt_next_tsc(buf_b, len_b, &tsc_b) &&
+		    intel_pt_tsc_cmp(tsc_a, tsc_b) < 0)
+			return buf_b; /* tsc_a < tsc_b => no overlap */
+
+		if (!intel_pt_step_psb(&buf_b, &len_b))
+			return buf_b + len_b; /* No PSB in buf_b => no data */
+	}
+}
+
+/**
+ * intel_pt_find_overlap - determine start of non-overlapped trace data.
+ * @buf_a: first buffer
+ * @len_a: size of first buffer
+ * @buf_b: second buffer
+ * @len_b: size of second buffer
+ * @have_tsc: can use TSC packets to detect overlap
+ *
+ * When trace samples or snapshots are recorded there is the possibility that
+ * the data overlaps.  Note that, for the purposes of decoding, data is only
+ * useful if it begins with a PSB packet.
+ *
+ * Return: A pointer into @buf_b from where non-overlapped data starts, or
+ * @buf_b + @len_b if there is no non-overlapped data.
+ */
+unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
+				     unsigned char *buf_b, size_t len_b,
+				     bool have_tsc)
+{
+	unsigned char *found;
+
+	/* Buffer 'b' must start at PSB so throw away everything before that */
+	if (!intel_pt_next_psb(&buf_b, &len_b))
+		return buf_b + len_b; /* No PSB */
+
+	if (!intel_pt_next_psb(&buf_a, &len_a))
+		return buf_b; /* No overlap */
+
+	if (have_tsc) {
+		found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b);
+		if (found)
+			return found;
+	}
+
+	/*
+	 * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
+	 * we can ignore the first part of buffer 'a'.
+	 */
+	while (len_b < len_a) {
+		if (!intel_pt_step_psb(&buf_a, &len_a))
+			return buf_b; /* No overlap */
+	}
+
+	/* Now len_b >= len_a */
+	if (len_b > len_a) {
+		/* The leftover buffer 'b' must start at a PSB */
+		while (!intel_pt_at_psb(buf_b + len_a, len_b - len_a)) {
+			if (!intel_pt_step_psb(&buf_a, &len_a))
+				return buf_b; /* No overlap */
+		}
+	}
+
+	while (1) {
+		/* Potential overlap so check the bytes */
+		found = memmem(buf_a, len_a, buf_b, len_a);
+		if (found)
+			return buf_b + len_a;
+
+		/* Try again at next PSB in buffer 'a' */
+		if (!intel_pt_step_psb(&buf_a, &len_a))
+			return buf_b; /* No overlap */
+
+		/* The leftover buffer 'b' must start at a PSB */
+		while (!intel_pt_at_psb(buf_b + len_a, len_b - len_a)) {
+			if (!intel_pt_step_psb(&buf_a, &len_a))
+				return buf_b; /* No overlap */
+		}
+	}
+}