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Message-Id: <1386765443-26966-71-git-send-email-alexander.shishkin@linux.intel.com>
Date:	Wed, 11 Dec 2013 14:37:22 +0200
From:	Alexander Shishkin <alexander.shishkin@...ux.intel.com>
To:	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Arnaldo Carvalho de Melo <acme@...stprotocols.net>
Cc:	Ingo Molnar <mingo@...hat.com>, linux-kernel@...r.kernel.org,
	David Ahern <dsahern@...il.com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Jiri Olsa <jolsa@...hat.com>, Mike Galbraith <efault@....de>,
	Namhyung Kim <namhyung@...il.com>,
	Paul Mackerras <paulus@...ba.org>,
	Stephane Eranian <eranian@...gle.com>,
	Andi Kleen <ak@...ux.intel.com>,
	Adrian Hunter <adrian.hunter@...el.com>
Subject: [PATCH v0 70/71] perf tools: Add Intel PT support

From: Adrian Hunter <adrian.hunter@...el.com>

Add support for Intel Processor Trace.

Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
---
 tools/perf/Makefile.perf   |    2 +
 tools/perf/util/intel-pt.c | 2193 ++++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/intel-pt.h |   40 +
 3 files changed, 2235 insertions(+)
 create mode 100644 tools/perf/util/intel-pt.c
 create mode 100644 tools/perf/util/intel-pt.h

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 41f8a97..8ed9434 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -295,6 +295,7 @@ LIB_H += util/unwind.h
 LIB_H += util/vdso.h
 LIB_H += util/tsc.h
 LIB_H += util/itrace.h
+LIB_H += util/intel-pt.h
 LIB_H += util/intel-pt-decoder/intel-pt-pkt-decoder.h
 LIB_H += util/intel-pt-decoder/intel-pt-insn-decoder.h
 LIB_H += util/intel-pt-decoder/intel-pt-log.h
@@ -379,6 +380,7 @@ LIB_OBJS += $(OUTPUT)util/srcline.o
 LIB_OBJS += $(OUTPUT)util/data.o
 LIB_OBJS += $(OUTPUT)util/tsc.o
 LIB_OBJS += $(OUTPUT)util/itrace.o
+LIB_OBJS += $(OUTPUT)util/intel-pt.o
 LIB_OBJS += $(OUTPUT)util/intel-pt-decoder/intel-pt-pkt-decoder.o
 LIB_OBJS += $(OUTPUT)util/intel-pt-decoder/intel-pt-insn-decoder.o
 LIB_OBJS += $(OUTPUT)util/intel-pt-decoder/intel-pt-log.o
diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
new file mode 100644
index 0000000..3223e40
--- /dev/null
+++ b/tools/perf/util/intel-pt.c
@@ -0,0 +1,2193 @@
+/*
+ * intel_pt.c: Intel Processor Trace support
+ * Copyright (c) 2013, 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <linux/kernel.h>
+
+#include "../perf.h"
+#include "session.h"
+#include "machine.h"
+#include "tool.h"
+#include "event.h"
+#include "evlist.h"
+#include "evsel.h"
+#include "map.h"
+#include "cpumap.h"
+#include "types.h"
+#include "color.h"
+#include "util.h"
+#include "thread.h"
+#include "symbol.h"
+#include "parse-options.h"
+#include "parse-events.h"
+#include "pmu.h"
+#include "dso.h"
+#include "debug.h"
+#include "itrace.h"
+#include "tsc.h"
+#include "intel-pt.h"
+
+#include "intel-pt-decoder/intel-pt-log.h"
+#include "intel-pt-decoder/intel-pt-decoder.h"
+#include "intel-pt-decoder/intel-pt-insn-decoder.h"
+#include "intel-pt-decoder/intel-pt-pkt-decoder.h"
+
+#define MAX_TIMESTAMP (~0ULL)
+
+#define KiB(x) ((x) * 1024)
+#define MiB(x) ((x) * 1024 * 1024)
+#define KiB_MASK(x) (KiB(x) - 1)
+#define MiB_MASK(x) (MiB(x) - 1)
+
+#define INTEL_PT_DEFAULT_SAMPLE_SIZE	KiB(4)
+
+#define INTEL_PT_MAX_SAMPLE_SIZE	KiB(60)
+
+#define INTEL_PT_PSB_PERIOD_NEAR	256
+
+struct intel_pt_snapshot_ref {
+	void *ref_buf;
+	size_t ref_offset;
+	bool wrapped;
+};
+
+struct intel_pt_recording {
+	struct itrace_record		itr;
+	struct perf_pmu			*intel_pt_pmu;
+	int				have_sched_switch;
+	struct perf_evlist		*evlist;
+	bool				snapshot_mode;
+	bool				snapshot_init_done;
+	size_t				snapshot_size;
+	size_t				snapshot_ref_buf_size;
+	int				snapshot_ref_cnt;
+	struct intel_pt_snapshot_ref	*snapshot_refs;
+};
+
+struct intel_pt {
+	struct itrace itrace;
+	struct itrace_queues queues;
+	struct itrace_heap heap;
+	u32 itrace_type;
+	struct perf_session *session;
+	struct machine *machine;
+	struct perf_evsel *switch_evsel;
+	bool timeless_decoding;
+	bool sampling_mode;
+	bool snapshot_mode;
+	bool per_cpu_mmaps;
+	bool have_tsc;
+	bool data_queued;
+	int have_sched_switch;
+	u32 pmu_type;
+
+	struct perf_tsc_conversion tc;
+	bool cap_user_time_zero;
+
+	struct itrace_synth_opts synth_opts;
+
+	bool sample_instructions;
+	u64 instructions_sample_type;
+	u64 instructions_sample_period;
+	u64 instructions_id;
+	size_t instructions_event_size;
+
+	bool sample_branches;
+	u64 branches_sample_type;
+	u64 branches_id;
+	size_t branches_event_size;
+
+	bool synth_needs_swap;
+
+	u64 tsc_bit;
+	u64 noretcomp_bit;
+};
+
+struct intel_pt_queue {
+	struct intel_pt *pt;
+	unsigned int queue_nr;
+	struct itrace_buffer *buffer;
+	void *decoder;
+	const struct intel_pt_state *state;
+	bool on_heap;
+	bool stop;
+	bool step_through_buffers;
+	bool use_buffer_pid_tid;
+	pid_t pid, tid;
+	int cpu;
+	bool exclude_kernel;
+	bool have_sample;
+	u64 time;
+};
+
+static void intel_pt_dump(struct intel_pt *pt __maybe_unused,
+			  unsigned char *buf, size_t len)
+{
+	struct intel_pt_pkt packet;
+	size_t pos = 0;
+	int ret, pkt_len, i;
+	char desc[INTEL_PT_PKT_DESC_MAX];
+	const char *color = PERF_COLOR_BLUE;
+
+	color_fprintf(stdout, color,
+		      ". ... Intel Processor Trace data: size %d bytes\n",
+		      len);
+
+	while (len) {
+		ret = intel_pt_get_packet(buf, len, &packet);
+		if (ret > 0)
+			pkt_len = ret;
+		else
+			pkt_len = 1;
+		printf(".");
+		color_fprintf(stdout, color, "  %08x: ", pos);
+		for (i = 0; i < pkt_len; i++)
+			color_fprintf(stdout, color, " %02x", buf[i]);
+		for (; i < 16; i++)
+			color_fprintf(stdout, color, "   ");
+		if (ret > 0) {
+			ret = intel_pt_pkt_desc(&packet, desc,
+						INTEL_PT_PKT_DESC_MAX);
+			if (ret > 0)
+				color_fprintf(stdout, color, " %s\n", desc);
+		} else {
+			color_fprintf(stdout, color, " Bad packet!\n");
+		}
+		pos += pkt_len;
+		buf += pkt_len;
+		len -= pkt_len;
+	}
+}
+
+static void intel_pt_dump_event(struct intel_pt *pt, unsigned char *buf,
+				size_t len)
+{
+	printf(".\n");
+	intel_pt_dump(pt, buf, len);
+}
+
+static void intel_pt_dump_sample(struct perf_session *session,
+				 struct perf_sample *sample)
+{
+	struct intel_pt *pt = container_of(session->itrace, struct intel_pt,
+					   itrace);
+
+	intel_pt_dump(pt, sample->itrace_sample.data,
+		      sample->itrace_sample.size);
+	printf(".\n");
+}
+
+static int intel_pt_fix_overlap(struct intel_pt *pt, unsigned int queue_nr)
+{
+	struct itrace_queue *queue = &pt->queues.queue_array[queue_nr];
+	struct itrace_buffer *a, *b;
+	void *start;
+
+	b = list_entry(queue->head.prev, struct itrace_buffer, list);
+	if (b->list.prev == &queue->head)
+		return 0;
+	a = list_entry(b->list.prev, struct itrace_buffer, list);
+	start = intel_pt_find_overlap(a->data, a->size, b->data,
+				      b->size, pt->have_tsc);
+	if (!start)
+		return -EINVAL;
+	b->size -= start - b->data;
+	b->data = start;
+	return 0;
+}
+
+static void intel_pt_drop_data(struct itrace_buffer *buffer)
+{
+	itrace_buffer__put_data(buffer);
+	if (buffer->data_needs_freeing) {
+		buffer->data_needs_freeing = false;
+		free(buffer->data);
+		buffer->data = NULL;
+		buffer->size = 0;
+	}
+}
+
+/* This function assumes data is processed sequentially only */
+static int intel_pt_get_trace(struct intel_pt_buffer *b, void *data)
+{
+	struct intel_pt_queue *ptq = data;
+	struct itrace_buffer *buffer = ptq->buffer, *old_buffer = buffer;
+	struct itrace_queue *queue;
+
+	if (ptq->stop) {
+		b->len = 0;
+		return 0;
+	}
+
+	queue = &ptq->pt->queues.queue_array[ptq->queue_nr];
+
+	buffer = itrace_buffer__next(queue, buffer);
+	if (!buffer) {
+		if (old_buffer)
+			intel_pt_drop_data(old_buffer);
+		b->len = 0;
+		return 0;
+	}
+
+	ptq->buffer = buffer;
+
+	if (!buffer->data) {
+		int fd = perf_data_file__fd(ptq->pt->session->file);
+
+		buffer->data = itrace_buffer__get_data(buffer, fd);
+		if (!buffer->data)
+			return -ENOMEM;
+	}
+
+	if (ptq->pt->snapshot_mode && !buffer->consecutive &&
+	    intel_pt_fix_overlap(ptq->pt, ptq->queue_nr))
+		return -ENOMEM;
+
+	if (old_buffer)
+		intel_pt_drop_data(old_buffer);
+
+	b->len = buffer->size;
+	b->buf = buffer->data;
+	b->ref_timestamp = buffer->reference;
+
+	if (!old_buffer || ptq->pt->sampling_mode || (ptq->pt->snapshot_mode &&
+						      !buffer->consecutive))
+		b->consecutive = false;
+	else
+		b->consecutive = true;
+
+	if (ptq->use_buffer_pid_tid && (ptq->pid != buffer->pid ||
+					ptq->tid != buffer->tid)) {
+		if (queue->cpu == -1 && buffer->cpu != -1)
+			ptq->cpu = buffer->cpu;
+		ptq->pid = buffer->pid;
+		ptq->tid = buffer->tid;
+		intel_pt_log("queue %u cpu %d pid %d tid %d\n",
+			     ptq->queue_nr, ptq->cpu, ptq->pid, ptq->tid);
+	}
+
+	if (ptq->step_through_buffers)
+		ptq->stop = true;
+
+	if (!b->len)
+		return intel_pt_get_trace(b, data);
+
+	return 0;
+}
+
+static int intel_pt_get_next_insn(struct intel_pt_insn *intel_pt_insn,
+				  uint64_t ip, uint64_t cr3 __maybe_unused,
+				  void *data)
+{
+	struct intel_pt_queue *ptq = data;
+	struct machine *machine = ptq->pt->machine;
+	struct thread *thread;
+	struct addr_location al;
+	unsigned char buf[1024];
+	size_t bufsz;
+	ssize_t len;
+	int x86_64;
+	pid_t pid = ptq->pid;
+	uint8_t cpumode;
+
+	bufsz = intel_pt_insn_max_size();
+
+	/* Assume kernel addresses can be identified by "ip < 0" */
+	if ((int64_t)ip < 0)
+		cpumode = PERF_RECORD_MISC_KERNEL;
+	else
+		cpumode = PERF_RECORD_MISC_USER;
+
+	thread = machine__findnew_thread(machine, pid, pid);
+	if (!thread)
+		return -1;
+
+	thread__find_addr_map(thread, machine, cpumode, MAP__FUNCTION, ip, &al);
+	if (!al.map || !al.map->dso)
+		return -1;
+
+	len = dso__data_read_addr(al.map->dso, al.map, machine, ip, buf, bufsz);
+	if (len <= 0)
+		return -1;
+
+	x86_64 = al.map->dso->is_64_bit;
+
+	if (intel_pt_get_insn(buf, len, x86_64, intel_pt_insn))
+		return -1;
+
+	return 0;
+}
+
+static bool intel_pt_exclude_kernel(struct intel_pt *pt)
+{
+	struct perf_session *session = pt->session;
+	struct perf_evlist *evlist = session->evlist;
+	struct perf_evsel *evsel;
+
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		if ((evsel->attr.type == pt->pmu_type ||
+		     (evsel->attr.sample_type & PERF_SAMPLE_ITRACE)) &&
+		    !evsel->attr.exclude_kernel)
+			return false;
+	}
+	return true;
+}
+
+static bool intel_pt_return_compression(struct intel_pt *pt)
+{
+	struct perf_session *session = pt->session;
+	struct perf_evlist *evlist = session->evlist;
+	struct perf_evsel *evsel;
+
+	if (!pt->noretcomp_bit)
+		return true;
+
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		if (evsel->attr.itrace_config & pt->noretcomp_bit)
+				return false;
+	}
+	return true;
+}
+
+static bool intel_pt_timeless_decoding(struct intel_pt *pt)
+{
+	struct perf_session *session = pt->session;
+	struct perf_evlist *evlist = session->evlist;
+	struct perf_evsel *evsel;
+	bool timeless_decoding = true;
+
+	if (!pt->tsc_bit || !pt->cap_user_time_zero)
+		return true;
+
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		if (!(evsel->attr.sample_type & PERF_SAMPLE_TIME))
+			return true;
+		if (evsel->attr.type == pt->pmu_type ||
+		    (evsel->attr.sample_type & PERF_SAMPLE_ITRACE)) {
+			if (evsel->attr.itrace_config & pt->tsc_bit)
+				timeless_decoding = false;
+			else
+				return true;
+		}
+	}
+	return timeless_decoding;
+}
+
+static bool intel_pt_have_tsc(struct intel_pt *pt)
+{
+	struct perf_session *session = pt->session;
+	struct perf_evlist *evlist = session->evlist;
+	struct perf_evsel *evsel;
+	bool have_tsc = false;
+
+	if (!pt->tsc_bit)
+		return false;
+
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		if (evsel->attr.type == pt->pmu_type ||
+		    (evsel->attr.sample_type & PERF_SAMPLE_ITRACE)) {
+			if (evsel->attr.itrace_config & pt->tsc_bit)
+				have_tsc = true;
+			else
+				return false;
+		}
+	}
+	return have_tsc;
+}
+
+static bool intel_pt_sampling_mode(struct intel_pt *pt)
+{
+	struct perf_session *session = pt->session;
+	struct perf_evlist *evlist = session->evlist;
+	struct perf_evsel *evsel;
+
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		if (evsel->attr.type == pt->pmu_type)
+			return false;
+		if (evsel->attr.sample_type & PERF_SAMPLE_ITRACE)
+			return true;
+	}
+	return false;
+}
+
+static u64 intel_pt_ns_to_ticks(const struct intel_pt *pt, u64 ns)
+{
+	u64 quot, rem;
+
+	quot = ns / pt->tc.time_mult;
+	rem  = ns % pt->tc.time_mult;
+	return (quot << pt->tc.time_shift) + (rem << pt->tc.time_shift) /
+		pt->tc.time_mult;
+}
+
+static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt,
+						   unsigned int queue_nr)
+{
+	struct intel_pt_params params = {0};
+	struct intel_pt_queue *ptq;
+
+	ptq = zalloc(sizeof(struct intel_pt_queue));
+	if (!ptq)
+		return NULL;
+
+	ptq->pt = pt;
+	ptq->queue_nr = queue_nr;
+	ptq->exclude_kernel = intel_pt_exclude_kernel(pt);
+	ptq->pid = -1;
+	ptq->tid = -1;
+	ptq->cpu = -1;
+
+	params.get_trace = intel_pt_get_trace;
+	params.get_insn = intel_pt_get_next_insn;
+	params.data = ptq;
+	params.return_compression = intel_pt_return_compression(pt);
+
+	if (pt->synth_opts.instructions) {
+		if (pt->synth_opts.period) {
+			switch (pt->synth_opts.period_type) {
+			case PERF_ITRACE_PERIOD_INSTRUCTIONS:
+				params.period_type =
+						INTEL_PT_PERIOD_INSTRUCTIONS;
+				params.period = pt->synth_opts.period;
+				break;
+			case PERF_ITRACE_PERIOD_TICKS:
+				params.period_type = INTEL_PT_PERIOD_TICKS;
+				params.period = pt->synth_opts.period;
+				break;
+			case PERF_ITRACE_PERIOD_NANOSECS:
+				params.period_type = INTEL_PT_PERIOD_TICKS;
+				params.period = intel_pt_ns_to_ticks(pt,
+							pt->synth_opts.period);
+				break;
+			default:
+				break;
+			}
+		}
+
+		if (!params.period) {
+			params.period_type = INTEL_PT_PERIOD_INSTRUCTIONS;
+			params.period = 1000;
+		}
+	}
+
+	ptq->decoder = intel_pt_decoder_new(&params);
+	if (!ptq->decoder) {
+		free(ptq);
+		return NULL;
+	}
+
+	return ptq;
+}
+
+static void intel_pt_free_queue(void *priv)
+{
+	struct intel_pt_queue *ptq = priv;
+
+	if (!ptq)
+		return;
+	intel_pt_decoder_free(ptq->decoder);
+	free(ptq);
+}
+
+static void intel_pt_set_pid_tid_cpu(struct intel_pt *pt,
+				     struct itrace_queue *queue)
+{
+	struct intel_pt_queue *ptq = queue->priv;
+
+	if (queue->cpu == -1) {
+		/* queue per-thread */
+		ptq->cpu = machine__get_thread_cpu(pt->machine, ptq->tid,
+						   &ptq->pid);
+	} else if (queue->tid != -1 && !pt->have_sched_switch) {
+		/* queue per-cpu workload only */
+		if (ptq->pid == -1)
+			ptq->pid = machine__get_thread_pid(pt->machine,
+							   ptq->tid);
+	} else {
+		/* queue per-cpu */
+		ptq->tid = machine__get_current_tid(pt->machine, ptq->cpu);
+		ptq->pid = machine__get_thread_pid(pt->machine, ptq->tid);
+	}
+}
+
+static int intel_pt_setup_queue(struct intel_pt *pt, struct itrace_queue *queue,
+				unsigned int queue_nr)
+{
+	struct intel_pt_queue *ptq = queue->priv;
+
+	if (list_empty(&queue->head))
+		return 0;
+
+	if (!ptq) {
+		ptq = intel_pt_alloc_queue(pt, queue_nr);
+		if (!ptq)
+			return -ENOMEM;
+		queue->priv = ptq;
+
+		if (queue->cpu != -1)
+			ptq->cpu = queue->cpu;
+		ptq->tid = queue->tid;
+
+		if (pt->sampling_mode) {
+			if (pt->timeless_decoding)
+				ptq->step_through_buffers = true;
+			if (pt->timeless_decoding || !pt->have_sched_switch)
+				ptq->use_buffer_pid_tid = true;
+		}
+	}
+
+	if (!ptq->on_heap) {
+		const struct intel_pt_state *state;
+		int ret;
+
+		if (pt->timeless_decoding)
+			return 0;
+
+		intel_pt_set_pid_tid_cpu(pt, queue);
+
+		intel_pt_log("queue %u getting timestamp\n", queue_nr);
+		intel_pt_log("queue %u decoding cpu %d pid %d tid %d\n",
+			     queue_nr, ptq->cpu, ptq->pid, ptq->tid);
+		while (1) {
+			state = intel_pt_decode(ptq->decoder);
+			if (state->err) {
+				if (state->err == -ENODATA) {
+					intel_pt_log("queue %u has no timestamp\n",
+						     queue_nr);
+					return 0;
+				}
+				continue;
+			}
+			if (state->timestamp)
+				break;
+		}
+
+		intel_pt_log("queue %u timestamp 0x%" PRIx64 "\n",
+			     queue_nr, state->timestamp);
+		ptq->state = state;
+		ptq->have_sample = true;
+		ret = itrace_heap__add(&pt->heap, queue_nr, state->timestamp);
+		if (ret)
+			return ret;
+		ptq->on_heap = true;
+	}
+
+	return 0;
+}
+
+static int intel_pt_setup_queues(struct intel_pt *pt)
+{
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < pt->queues.nr_queues; i++) {
+		ret = intel_pt_setup_queue(pt, &pt->queues.queue_array[i], i);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
+static int intel_pt_synth_branch_sample(struct intel_pt_queue *ptq,
+					struct perf_tool *tool)
+{
+	int ret;
+	struct intel_pt *pt = ptq->pt;
+	union perf_event event;
+	struct perf_sample sample = {0};
+
+	event.sample.header.type = PERF_RECORD_SAMPLE;
+	event.sample.header.misc = PERF_RECORD_MISC_USER;
+	event.sample.header.size = sizeof(struct perf_event_header);
+
+	if (!pt->timeless_decoding)
+		sample.time = tsc_to_perf_time(ptq->state->timestamp, &pt->tc);
+
+	sample.ip = ptq->state->from_ip;
+	sample.pid = ptq->pid;
+	sample.tid = ptq->tid;
+	sample.addr = ptq->state->to_ip;
+	sample.id = ptq->pt->branches_id;
+	sample.stream_id = ptq->pt->branches_id;
+	sample.period = 1;
+	sample.cpu = ptq->cpu;
+
+	if (pt->synth_opts.inject) {
+		event.sample.header.size = pt->branches_event_size;
+		ret = perf_event__synthesize_sample(&event,
+						    pt->branches_sample_type, 0,
+						    0, &sample,
+						    pt->synth_needs_swap);
+		if (ret)
+			return ret;
+	}
+
+	ret = perf_session__deliver_synth_event(pt->session, &event, &sample,
+						tool);
+	if (ret)
+		pr_err("Intel Processor Trace: failed to deliver branch event, error %d\n",
+		       ret);
+
+	return ret;
+}
+
+static int intel_pt_synth_instruction_sample(struct intel_pt_queue *ptq,
+					     struct perf_tool *tool)
+{
+	int ret;
+	struct intel_pt *pt = ptq->pt;
+	union perf_event event;
+	struct perf_sample sample = {0};
+
+	event.sample.header.type = PERF_RECORD_SAMPLE;
+	event.sample.header.misc = PERF_RECORD_MISC_USER;
+	event.sample.header.size = sizeof(struct perf_event_header);
+
+	if (!pt->timeless_decoding)
+		sample.time = tsc_to_perf_time(ptq->state->timestamp, &pt->tc);
+
+	sample.ip = ptq->state->from_ip;
+	sample.pid = ptq->pid;
+	sample.tid = ptq->tid;
+	sample.addr = ptq->state->to_ip;
+	sample.id = ptq->pt->instructions_id;
+	sample.stream_id = ptq->pt->instructions_id;
+	sample.period = ptq->pt->instructions_sample_period;
+	sample.cpu = ptq->cpu;
+
+	if (pt->synth_opts.inject) {
+		event.sample.header.size = pt->instructions_event_size;
+		ret = perf_event__synthesize_sample(&event,
+						pt->instructions_sample_type, 0,
+						0, &sample,
+						pt->synth_needs_swap);
+		if (ret)
+			return ret;
+	}
+
+	ret = perf_session__deliver_synth_event(pt->session, &event, &sample,
+						tool);
+	if (ret)
+		pr_err("Intel Processor Trace: failed to deliver instruction event, error %d\n",
+		       ret);
+
+	return ret;
+}
+
+static int intel_pt_synth_error(struct intel_pt *pt, struct perf_tool *tool,
+				int code, int cpu, pid_t pid, pid_t tid, u64 ip)
+{
+	union perf_event event;
+	const char *msg;
+	int err;
+
+	msg = intel_pt_error_message(code);
+
+	itrace_synth_error(&event.itrace_error, PERF_ITRACE_DECODER_ERROR, code,
+			   cpu, pid, tid, ip, msg);
+
+	err = perf_session__deliver_synth_event(pt->session, &event, NULL,
+						tool);
+	if (err)
+		pr_err("Intel Processor Trace: failed to deliver error event, error %d\n",
+		       err);
+
+	return err;
+}
+
+static int intel_pt_run_decoder(struct intel_pt_queue *ptq, u64 *timestamp,
+				struct perf_tool *tool)
+{
+	const struct intel_pt_state *state = ptq->state;
+	struct intel_pt *pt = ptq->pt;
+	int err;
+
+	intel_pt_log("queue %u decoding cpu %d pid %d tid %d\n",
+		     ptq->queue_nr, ptq->cpu, ptq->pid, ptq->tid);
+	while (1) {
+		if (ptq->have_sample) {
+			ptq->have_sample = false;
+
+			if (pt->sample_instructions &&
+			    (state->type & INTEL_PT_INSTRUCTION)) {
+				err = intel_pt_synth_instruction_sample(ptq,
+									tool);
+				if (err)
+					return err;
+			}
+
+			if (pt->sample_branches &&
+			    (state->type & INTEL_PT_BRANCH)) {
+				err = intel_pt_synth_branch_sample(ptq, tool);
+				if (err)
+					return err;
+			}
+		}
+
+		state = intel_pt_decode(ptq->decoder);
+		if (state->err) {
+			if (state->err == -ENODATA)
+				return 1;
+			if (pt->synth_opts.errors) {
+				err = intel_pt_synth_error(pt, tool,
+						-state->err, ptq->cpu, ptq->pid,
+						ptq->tid, state->from_ip);
+				if (err)
+					return err;
+			}
+			continue;
+		}
+
+		ptq->state = state;
+		ptq->have_sample = true;
+
+		if (!pt->timeless_decoding && state->timestamp >= *timestamp) {
+			*timestamp = state->timestamp;
+			return 0;
+		}
+	}
+	return 0;
+}
+
+static inline int intel_pt_update_queues(struct intel_pt *pt)
+{
+	if (pt->queues.new_data) {
+		pt->queues.new_data = false;
+		return intel_pt_setup_queues(pt);
+	}
+	return 0;
+}
+
+static int intel_pt_process_queues(struct intel_pt *pt, u64 timestamp,
+				   struct perf_tool *tool)
+{
+	unsigned int queue_nr;
+	u64 ts;
+	int ret;
+
+	while (1) {
+		struct itrace_queue *queue;
+		struct intel_pt_queue *ptq;
+
+		if (!pt->heap.heap_cnt)
+			return 0;
+
+		if (pt->heap.heap_array[0].ordinal >= timestamp)
+			return 0;
+
+		queue_nr = pt->heap.heap_array[0].queue_nr;
+		queue = &pt->queues.queue_array[queue_nr];
+		ptq = queue->priv;
+
+		intel_pt_log("queue %u processing 0x%" PRIx64 " < 0x%" PRIx64 "\n",
+			     queue_nr, pt->heap.heap_array[0].ordinal,
+			     timestamp);
+
+		itrace_heap__pop(&pt->heap);
+
+		if (pt->heap.heap_cnt) {
+			ts = pt->heap.heap_array[0].ordinal + 1;
+			if (ts > timestamp)
+				ts = timestamp;
+		} else {
+			ts = timestamp;
+		}
+
+		intel_pt_set_pid_tid_cpu(pt, queue);
+
+		ret = intel_pt_run_decoder(ptq, &ts, tool);
+
+		if (ret < 0) {
+			itrace_heap__add(&pt->heap, queue_nr, ts);
+			return ret;
+		}
+
+		if (!ret) {
+			ret = itrace_heap__add(&pt->heap, queue_nr, ts);
+			if (ret < 0)
+				return ret;
+		} else {
+			ptq->on_heap = false;
+		}
+	}
+
+	return 0;
+}
+
+static int intel_pt_process_sample_queues(struct intel_pt *pt, u64 timestamp,
+				union perf_event *event __maybe_unused,
+				struct perf_sample *sample __maybe_unused,
+				struct perf_tool *tool)
+{
+	unsigned int queue_nr;
+	u64 ts;
+	int ret;
+
+	while (1) {
+		struct itrace_queue *queue;
+		struct intel_pt_queue *ptq;
+
+		if (!pt->heap.heap_cnt)
+			return 0;
+
+		if (pt->heap.heap_array[0].ordinal >= timestamp)
+			return 0;
+
+		queue_nr = pt->heap.heap_array[0].queue_nr;
+		queue = &pt->queues.queue_array[queue_nr];
+		ptq = queue->priv;
+
+		intel_pt_log("queue %u processing 0x%" PRIx64 " < 0x%" PRIx64 "\n",
+			     queue_nr, pt->heap.heap_array[0].ordinal,
+			     timestamp);
+
+		itrace_heap__pop(&pt->heap);
+
+		if (pt->heap.heap_cnt) {
+			ts = pt->heap.heap_array[0].ordinal + 1;
+			if (ts > timestamp)
+				ts = timestamp;
+		} else {
+			ts = timestamp;
+		}
+
+		if (!ptq->use_buffer_pid_tid)
+			intel_pt_set_pid_tid_cpu(pt, queue);
+
+		ret = intel_pt_run_decoder(ptq, &ts, tool);
+		if (ret < 0) {
+			itrace_heap__add(&pt->heap, queue_nr, ts);
+			return ret;
+		}
+
+		if (ret) {
+			ptq->on_heap = false;
+		} else {
+			ret = itrace_heap__add(&pt->heap, queue_nr, ts);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int intel_pt_process_timeless_queues(struct intel_pt *pt, pid_t tid,
+					    u64 time, struct perf_tool *tool)
+{
+	struct itrace_queues *queues = &pt->queues;
+	unsigned int i;
+	u64 ts = 0;
+
+	for (i = 0; i < queues->nr_queues; i++) {
+		struct itrace_queue *queue = &pt->queues.queue_array[i];
+		struct intel_pt_queue *ptq = queue->priv;
+
+		if (ptq && (tid == -1 || ptq->tid == tid)) {
+			ptq->time = time;
+
+			if (ptq->pid == -1 && ptq->tid != -1)
+				ptq->pid = machine__get_thread_pid(pt->machine,
+								   ptq->tid);
+
+			intel_pt_run_decoder(ptq, &ts, tool);
+		}
+	}
+	return 0;
+}
+
+static int intel_pt_process_timeless_sample(struct intel_pt *pt,
+					    struct perf_sample *sample,
+					    struct perf_tool *tool)
+{
+	struct itrace_queue *queue = itrace_queues__sample_queue(&pt->queues,
+								 sample,
+								 pt->session);
+	struct intel_pt_queue *ptq = queue->priv;
+	u64 ts = 0;
+
+	ptq->stop = false;
+	ptq->time = sample->time;
+	intel_pt_run_decoder(ptq, &ts, tool);
+	return 0;
+}
+
+static int intel_pt_lost(struct intel_pt *pt, struct perf_sample *sample,
+			 struct perf_tool *tool)
+{
+	union perf_event event;
+	int err;
+
+	itrace_synth_error(&event.itrace_error, PERF_ITRACE_DECODER_ERROR,
+			   ENOSPC, sample->cpu, sample->pid, sample->tid, 0,
+			   "Lost trace data");
+
+	err = perf_session__deliver_synth_event(pt->session, &event, NULL,
+						tool);
+	if (err)
+		pr_err("Intel Processor Trace: failed to deliver error event, error %d\n",
+		       err);
+
+	return err;
+}
+
+static int intel_pt_process_switch(struct intel_pt *pt,
+				   struct perf_sample *sample)
+{
+	struct perf_evsel *evsel;
+	pid_t tid;
+	int cpu;
+
+	evsel = perf_evlist__id2evsel(pt->session->evlist, sample->id);
+	if (evsel != pt->switch_evsel)
+		return 0;
+
+	tid = perf_evsel__intval(evsel, sample, "next_pid");
+	cpu = sample->cpu;
+
+	return machine__set_current_tid(pt->machine, cpu, 0, tid);
+}
+
+static int intel_pt_process_event(struct perf_session *session,
+				  union perf_event *event,
+				  struct perf_sample *sample,
+				  struct perf_tool *tool)
+{
+	struct intel_pt *pt = container_of(session->itrace, struct intel_pt,
+					   itrace);
+	u64 timestamp;
+	int err = 0;
+
+	if (dump_trace)
+		return 0;
+
+	if (!tool->ordered_samples) {
+		pr_err("Intel Processor Trace requires ordered samples\n");
+		return -EINVAL;
+	}
+
+	if (sample->time)
+		timestamp = perf_time_to_tsc(sample->time, &pt->tc);
+	else
+		timestamp = 0;
+
+	if (timestamp || pt->timeless_decoding) {
+		err = intel_pt_update_queues(pt);
+		if (err)
+			return err;
+	}
+
+	if (pt->timeless_decoding) {
+		if (pt->sampling_mode) {
+			if (sample->itrace_sample.size)
+				err = intel_pt_process_timeless_sample(pt,
+								sample, tool);
+		} else if (event->header.type == PERF_RECORD_EXIT) {
+			err = intel_pt_process_timeless_queues(pt,
+					event->comm.tid, sample->time, tool);
+		}
+	} else if (timestamp) {
+		if (pt->sampling_mode)
+			err = intel_pt_process_sample_queues(pt, timestamp,
+							event, sample, tool);
+		else
+			err = intel_pt_process_queues(pt, timestamp, tool);
+	}
+	if (err)
+		return err;
+
+	if (event->header.type == PERF_RECORD_ITRACE_LOST &&
+	    pt->synth_opts.errors)
+		err = intel_pt_lost(pt, sample, tool);
+
+	if (pt->switch_evsel && event->header.type == PERF_RECORD_SAMPLE)
+		err = intel_pt_process_switch(pt, sample);
+
+	return err;
+}
+
+static int intel_pt_flush(struct perf_session *session, struct perf_tool *tool)
+{
+	struct intel_pt *pt = container_of(session->itrace, struct intel_pt,
+					   itrace);
+	int ret;
+
+	if (dump_trace)
+		return 0;
+
+	if (!tool->ordered_samples)
+		return -EINVAL;
+
+	ret = intel_pt_update_queues(pt);
+	if (ret < 0)
+		return ret;
+
+	if (pt->timeless_decoding)
+		return intel_pt_process_timeless_queues(pt, -1,
+						MAX_TIMESTAMP - 1, tool);
+
+	return intel_pt_process_queues(pt, MAX_TIMESTAMP, tool);
+}
+
+static void intel_pt_free_events(struct perf_session *session)
+{
+	struct intel_pt *pt = container_of(session->itrace, struct intel_pt,
+					   itrace);
+	struct itrace_queues *queues = &pt->queues;
+	unsigned int i;
+
+	for (i = 0; i < queues->nr_queues; i++) {
+		intel_pt_free_queue(queues->queue_array[i].priv);
+		queues->queue_array[i].priv = NULL;
+	}
+	itrace_queues__free(queues);
+}
+
+static void intel_pt_free(struct perf_session *session)
+{
+	struct intel_pt *pt = container_of(session->itrace, struct intel_pt,
+					   itrace);
+
+	itrace_heap__free(&pt->heap);
+	intel_pt_free_events(session);
+	session->itrace = NULL;
+	free(pt);
+}
+
+static int intel_pt_process_itrace_event(struct perf_session *session,
+					 union perf_event *event,
+					 struct perf_tool *tool __maybe_unused)
+{
+	struct intel_pt *pt = container_of(session->itrace, struct intel_pt,
+					   itrace);
+
+	if (pt->sampling_mode)
+		return 0;
+
+	if (!pt->data_queued) {
+		struct itrace_buffer *buffer;
+		off_t data_offset;
+		int fd = perf_data_file__fd(session->file);
+		int err;
+
+		if (perf_data_file__is_pipe(session->file)) {
+			data_offset = 0;
+		} else {
+			data_offset = lseek(fd, 0, SEEK_CUR);
+			if (data_offset == -1)
+				return -errno;
+		}
+
+		err = itrace_queues__add_event(&pt->queues, session, event,
+					       data_offset, &buffer);
+		if (err)
+			return err;
+
+		/* Dump here now we have copied a piped trace out of the pipe */
+		if (dump_trace) {
+			if (itrace_buffer__get_data(buffer, fd)) {
+				intel_pt_dump_event(pt, buffer->data,
+						    buffer->size);
+				itrace_buffer__put_data(buffer);
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int intel_pt_queue_event(struct perf_session *session,
+				union perf_event *event __maybe_unused,
+				struct perf_sample *sample)
+{
+	struct intel_pt *pt = container_of(session->itrace, struct intel_pt,
+					   itrace);
+	unsigned int queue_nr;
+	u64 timestamp;
+	int err;
+
+	if (!sample->itrace_sample.size)
+		return 0;
+
+	if (!pt->sampling_mode)
+		return 0;
+
+	if (sample->time)
+		timestamp = perf_time_to_tsc(sample->time, &pt->tc);
+	else
+		timestamp = 0;
+
+	err = itrace_queues__add_sample(&pt->queues, sample, session, &queue_nr,
+					timestamp);
+	if (err)
+		return err;
+
+	return intel_pt_fix_overlap(pt, queue_nr);
+}
+
+struct intel_pt_synth {
+	struct perf_tool dummy_tool;
+	struct perf_tool *tool;
+	struct perf_session *session;
+};
+
+static int intel_pt_event_synth(struct perf_tool *tool,
+				union perf_event *event,
+				struct perf_sample *sample __maybe_unused,
+				struct machine *machine __maybe_unused)
+{
+	struct intel_pt_synth *intel_pt_synth =
+			container_of(tool, struct intel_pt_synth, dummy_tool);
+
+	return perf_session__deliver_synth_event(intel_pt_synth->session, event,
+						 NULL, intel_pt_synth->tool);
+}
+
+static int intel_pt_synth_event(struct perf_session *session,
+				struct perf_tool *tool,
+				struct perf_event_attr *attr, u64 id)
+{
+	struct intel_pt_synth intel_pt_synth;
+
+	memset(&intel_pt_synth, 0, sizeof(struct intel_pt_synth));
+	intel_pt_synth.tool = tool;
+	intel_pt_synth.session = session;
+
+	return perf_event__synthesize_attr(&intel_pt_synth.dummy_tool, attr, 1,
+					   &id, intel_pt_event_synth);
+}
+
+static int intel_pt_synth_events(struct intel_pt *pt,
+				 struct perf_session *session,
+				 struct perf_tool *tool)
+{
+	struct perf_evlist *evlist = session->evlist;
+	struct perf_evsel *evsel;
+	struct perf_event_attr attr;
+	bool found = false;
+	u64 id;
+	int err;
+
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		if ((evsel->attr.type == pt->pmu_type ||
+		     (evsel->attr.sample_type & PERF_SAMPLE_ITRACE)) &&
+		    evsel->ids) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		pr_err("%s: failed\n", __func__);
+		return -EINVAL;
+	}
+
+	memset(&attr, 0, sizeof(struct perf_event_attr));
+	attr.size = sizeof(struct perf_event_attr);
+	attr.type = PERF_TYPE_HARDWARE;
+	attr.sample_type = evsel->attr.sample_type & PERF_SAMPLE_MASK;
+	attr.sample_type |= PERF_SAMPLE_IP | PERF_SAMPLE_TID |
+			    PERF_SAMPLE_PERIOD;
+	if (pt->timeless_decoding)
+		attr.sample_type &= ~(u64)PERF_SAMPLE_TIME;
+	else
+		attr.sample_type |= PERF_SAMPLE_TIME;
+	if (!pt->per_cpu_mmaps)
+		attr.sample_type &= ~(u64)PERF_SAMPLE_CPU;
+	attr.exclude_user = evsel->attr.exclude_user;
+	attr.exclude_kernel = evsel->attr.exclude_kernel;
+	attr.exclude_hv = evsel->attr.exclude_hv;
+	attr.exclude_host = evsel->attr.exclude_host;
+	attr.exclude_guest = evsel->attr.exclude_guest;
+	attr.sample_id_all = evsel->attr.sample_id_all;
+	attr.read_format = evsel->attr.read_format;
+
+	id = evsel->id[0] + 1000000000;
+	if (!id)
+		id = 1;
+
+	if (pt->synth_opts.instructions) {
+		attr.config = PERF_COUNT_HW_INSTRUCTIONS;
+		if (pt->synth_opts.period_type == PERF_ITRACE_PERIOD_NANOSECS)
+			attr.sample_period =
+				intel_pt_ns_to_ticks(pt, pt->synth_opts.period);
+		else
+			attr.sample_period = pt->synth_opts.period;
+		pt->instructions_sample_period = attr.sample_period;
+		pr_debug("Synthesizing 'instructions' event with id %" PRIu64 " sample type %#" PRIx64 "\n",
+			 id, (u64)attr.sample_type);
+		err = intel_pt_synth_event(session, tool, &attr, id);
+		if (err) {
+			pr_err("%s: failed to synthesize 'instructions' event type\n",
+			       __func__);
+			return err;
+		}
+		pt->sample_instructions = true;
+		pt->instructions_sample_type = attr.sample_type;
+		pt->instructions_id = id;
+		/*
+		 * We only use sample types from PERF_SAMPLE_MASK so we can use
+		 * __perf_evsel__sample_size() here.
+		 */
+		pt->instructions_event_size = sizeof(struct sample_event) +
+				__perf_evsel__sample_size(attr.sample_type);
+		id += 1;
+	}
+
+	if (pt->synth_opts.branches) {
+		attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS;
+		attr.sample_period = 1;
+		attr.sample_type |= PERF_SAMPLE_ADDR;
+		pr_debug("Synthesizing 'branches' event with id %" PRIu64 " sample type %#" PRIx64 "\n",
+			 id, (u64)attr.sample_type);
+		err = intel_pt_synth_event(session, tool, &attr, id);
+		if (err) {
+			pr_err("%s: failed to synthesize 'branches' event type\n",
+			       __func__);
+			return err;
+		}
+		pt->sample_branches = true;
+		pt->branches_sample_type = attr.sample_type;
+		pt->branches_id = id;
+		/*
+		 * We only use sample types from PERF_SAMPLE_MASK so we can use
+		 * __perf_evsel__sample_size() here.
+		 */
+		pt->branches_event_size = sizeof(struct sample_event) +
+				__perf_evsel__sample_size(attr.sample_type);
+	}
+
+	pt->synth_needs_swap = evsel->needs_swap;
+
+	return 0;
+}
+
+static struct perf_evsel *intel_pt_find_sched_switch(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel;
+
+	list_for_each_entry_reverse(evsel, &evlist->entries, node) {
+		const char *name = perf_evsel__name(evsel);
+
+		if (!strcmp(name, "sched:sched_switch"))
+			return evsel;
+	}
+
+	return NULL;
+}
+
+enum {
+	INTEL_PT_PMU_TYPE,
+	INTEL_PT_TIME_SHIFT,
+	INTEL_PT_TIME_MULT,
+	INTEL_PT_TIME_ZERO,
+	INTEL_PT_CAP_USER_TIME_ZERO,
+	INTEL_PT_TSC_BIT,
+	INTEL_PT_NORETCOMP_BIT,
+	INTEL_PT_HAVE_SCHED_SWITCH,
+	INTEL_PT_SNAPSHOT_MODE,
+	INTEL_PT_PER_CPU_MMAPS,
+	INTEL_PT_ITRACE_PRIV_SIZE,
+};
+
+u64 intel_pt_itrace_info_priv[INTEL_PT_ITRACE_PRIV_SIZE];
+
+int intel_pt_process_itrace_info(struct perf_tool *tool,
+				 union perf_event *event,
+				 struct perf_session *session)
+{
+	struct itrace_info_event *itrace_info = &event->itrace_info;
+	size_t min_sz = sizeof(u64) * INTEL_PT_PER_CPU_MMAPS;
+	struct intel_pt *pt;
+	int err;
+
+	if (itrace_info->header.size < sizeof(struct itrace_info_event) +
+					min_sz)
+		return -EINVAL;
+
+	pt = zalloc(sizeof(struct intel_pt));
+	if (!pt)
+		return -ENOMEM;
+
+	err = itrace_queues__init(&pt->queues);
+	if (err)
+		goto err_free;
+
+	intel_pt_log_set_name(INTEL_PT_PMU_NAME);
+
+	pt->session = session;
+	pt->machine = &session->machines.host; /* No kvm support */
+	pt->itrace_type = itrace_info->type;
+	pt->pmu_type = itrace_info->priv[INTEL_PT_PMU_TYPE];
+	pt->tc.time_shift = itrace_info->priv[INTEL_PT_TIME_SHIFT];
+	pt->tc.time_mult = itrace_info->priv[INTEL_PT_TIME_MULT];
+	pt->tc.time_zero = itrace_info->priv[INTEL_PT_TIME_ZERO];
+	pt->cap_user_time_zero = itrace_info->priv[INTEL_PT_CAP_USER_TIME_ZERO];
+	pt->tsc_bit = itrace_info->priv[INTEL_PT_TSC_BIT];
+	pt->noretcomp_bit = itrace_info->priv[INTEL_PT_NORETCOMP_BIT];
+	pt->have_sched_switch = itrace_info->priv[INTEL_PT_HAVE_SCHED_SWITCH];
+	pt->snapshot_mode = itrace_info->priv[INTEL_PT_SNAPSHOT_MODE];
+	pt->per_cpu_mmaps = itrace_info->priv[INTEL_PT_PER_CPU_MMAPS];
+
+	pt->timeless_decoding = intel_pt_timeless_decoding(pt);
+	pt->have_tsc = intel_pt_have_tsc(pt);
+	pt->sampling_mode = intel_pt_sampling_mode(pt);
+
+	pt->itrace.process_event = intel_pt_process_event;
+	pt->itrace.queue_event = intel_pt_queue_event;
+	pt->itrace.process_itrace_event = intel_pt_process_itrace_event;
+	pt->itrace.dump_itrace_sample = intel_pt_dump_sample;
+	pt->itrace.flush_events = intel_pt_flush;
+	pt->itrace.free_events = intel_pt_free_events;
+	pt->itrace.free = intel_pt_free;
+	session->itrace = &pt->itrace;
+
+	if (dump_trace)
+		return 0;
+
+	if (pt->have_sched_switch == 1) {
+		pt->switch_evsel = intel_pt_find_sched_switch(session->evlist);
+		if (!pt->switch_evsel) {
+			pr_err("%s: missing sched_switch event\n", __func__);
+			goto err_free_queues;
+		}
+	}
+
+	if (session->itrace_synth_opts && session->itrace_synth_opts->set)
+		pt->synth_opts = *session->itrace_synth_opts;
+	else
+		itrace_synth_opts__set_default(&pt->synth_opts);
+
+	err = intel_pt_synth_events(pt, session, tool);
+	if (err)
+		goto err_free_queues;
+
+	err = itrace_queues__process_index(&pt->queues, session);
+	if (err)
+		goto err_free_queues;
+
+	if (pt->queues.populated)
+		pt->data_queued = true;
+
+	if (pt->timeless_decoding)
+		pr_debug2("Intel PT decoding without timestamps\n");
+
+	return 0;
+
+err_free_queues:
+	itrace_queues__free(&pt->queues);
+	session->itrace = NULL;
+err_free:
+	free(pt);
+	return err;
+}
+
+static bool intel_pt_has_topa_multiple_entries(struct perf_pmu *intel_pt_pmu)
+{
+	unsigned int topa_multiple_entries;
+
+	if (perf_pmu__scan_file(intel_pt_pmu,
+				"caps/topa_multiple_entries", "%u",
+				&topa_multiple_entries) == 1 &&
+	    topa_multiple_entries)
+		return true;
+
+	return false;
+}
+
+static int intel_pt_parse_terms_with_default(struct list_head *formats,
+					     const char *str,
+					     u64 *itrace_config)
+{
+	struct list_head *terms;
+	struct perf_event_attr attr = {0};
+	int err;
+
+	terms = malloc(sizeof(struct list_head));
+	if (!terms)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(terms);
+
+	err = parse_events_terms(terms, str);
+	if (err)
+		goto out_free;
+
+	attr.itrace_config = *itrace_config;
+	err = perf_pmu__config_terms(formats, &attr, terms, true);
+	if (err)
+		goto out_free;
+
+	*itrace_config = attr.itrace_config;
+out_free:
+	parse_events__free_terms(terms);
+	return err;
+}
+
+static int intel_pt_parse_terms(struct list_head *formats, const char *str,
+				u64 *itrace_config)
+{
+	*itrace_config = 0;
+	return intel_pt_parse_terms_with_default(formats, str, itrace_config);
+}
+
+static size_t intel_pt_psb_period(struct perf_pmu *intel_pt_pmu __maybe_unused,
+				  struct perf_evlist *evlist __maybe_unused)
+{
+	return 256;
+}
+
+static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu)
+{
+	u64 itrace_config;
+
+	intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &itrace_config);
+	return itrace_config;
+}
+
+static size_t intel_pt_sample_size(const char **str)
+{
+	char *endptr;
+	unsigned long sample_size;
+
+	sample_size = strtoul(*str, &endptr, 0);
+	if (sample_size)
+		*str = endptr;
+	return sample_size;
+}
+
+static int intel_pt_parse_sample_options(struct itrace_record *itr,
+					 struct perf_record_opts *opts,
+					 const char *str)
+{
+	struct intel_pt_recording *ptr =
+			container_of(itr, struct intel_pt_recording, itr);
+	struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
+	u64 *itrace_config = &opts->itrace_sample_config;
+	int err;
+
+	opts->itrace_sample_size = str ? intel_pt_sample_size(&str) : 0;
+	if (opts->itrace_sample_size > INTEL_PT_MAX_SAMPLE_SIZE) {
+		pr_err("Intel Processor Trace: sample size too big\n");
+		return -1;
+	}
+
+	*itrace_config = intel_pt_default_config(intel_pt_pmu);
+	opts->itrace_sample_type = intel_pt_pmu->type;
+	opts->sample_itrace = true;
+
+	if (!str || !*str)
+		return 0;
+
+	err = intel_pt_parse_terms_with_default(&intel_pt_pmu->format, str,
+						itrace_config);
+	if (err)
+		goto bad_options;
+
+	return 0;
+
+bad_options:
+	pr_err("Intel Processor Trace: bad sampling options \"%s\"\n", str);
+	return -1;
+}
+
+static int intel_pt_parse_snapshot_options(struct itrace_record *itr,
+					   struct perf_record_opts *opts,
+					   const char *str)
+{
+	struct intel_pt_recording *ptr =
+			container_of(itr, struct intel_pt_recording, itr);
+	unsigned long long snapshot_size = 0;
+	char *endptr;
+
+	if (str) {
+		snapshot_size = strtoull(str, &endptr, 0);
+		if (*endptr || snapshot_size > SIZE_MAX)
+			return -1;
+	}
+
+	opts->itrace_snapshot_mode = true;
+	opts->itrace_snapshot_size = snapshot_size;
+
+	ptr->snapshot_size = snapshot_size;
+
+	return 0;
+}
+
+struct perf_event_attr *
+intel_pt_pmu_default_config(struct perf_pmu *intel_pt_pmu)
+{
+	struct perf_event_attr *attr;
+
+	attr = zalloc(sizeof(struct perf_event_attr));
+	if (!attr)
+		return NULL;
+
+	attr->itrace_config = intel_pt_default_config(intel_pt_pmu);
+
+	intel_pt_pmu->selectable = true;
+
+	return attr;
+}
+
+static size_t intel_pt_info_priv_size(struct itrace_record *itr __maybe_unused)
+{
+	return sizeof(intel_pt_itrace_info_priv);
+}
+
+static int intel_pt_info_fill(struct itrace_record *itr,
+			      struct perf_session *session,
+			      struct itrace_info_event *itrace_info,
+			      size_t priv_size)
+{
+	struct intel_pt_recording *ptr =
+			container_of(itr, struct intel_pt_recording, itr);
+	struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
+	struct perf_event_mmap_page *pc;
+	struct perf_tsc_conversion tc;
+	bool cap_user_time_zero, per_cpu_mmaps;
+	u64 tsc_bit, noretcomp_bit;
+	int err;
+
+	if (priv_size != sizeof(intel_pt_itrace_info_priv))
+		return -EINVAL;
+
+	intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &tsc_bit);
+	intel_pt_parse_terms(&intel_pt_pmu->format, "noretcomp",
+			     &noretcomp_bit);
+
+	if (!session->evlist->nr_mmaps)
+		return -EINVAL;
+
+	pc = session->evlist->mmap[0].base;
+	err = perf_read_tsc_conversion(pc, &tc);
+	if (err) {
+		if (err != -EOPNOTSUPP)
+			return err;
+		cap_user_time_zero = false;
+	} else {
+		cap_user_time_zero = tc.time_mult != 0;
+	}
+
+	if (!cap_user_time_zero)
+		ui__warning("Intel Processor Trace: TSC not available\n");
+
+	per_cpu_mmaps = !cpu_map__empty(session->evlist->cpus);
+
+	itrace_info->type = PERF_ITRACE_INTEL_PT;
+	itrace_info->priv[INTEL_PT_PMU_TYPE] = intel_pt_pmu->type;
+	itrace_info->priv[INTEL_PT_TIME_SHIFT] = tc.time_shift;
+	itrace_info->priv[INTEL_PT_TIME_MULT] = tc.time_mult;
+	itrace_info->priv[INTEL_PT_TIME_ZERO] = tc.time_zero;
+	itrace_info->priv[INTEL_PT_CAP_USER_TIME_ZERO] = cap_user_time_zero;
+	itrace_info->priv[INTEL_PT_TSC_BIT] = tsc_bit;
+	itrace_info->priv[INTEL_PT_NORETCOMP_BIT] = noretcomp_bit;
+	itrace_info->priv[INTEL_PT_HAVE_SCHED_SWITCH] = ptr->have_sched_switch;
+	itrace_info->priv[INTEL_PT_SNAPSHOT_MODE] = ptr->snapshot_mode;
+	itrace_info->priv[INTEL_PT_PER_CPU_MMAPS] = per_cpu_mmaps;
+
+	return 0;
+}
+
+static size_t intel_pt_to_power_of_2(size_t x, size_t min)
+{
+	size_t y = x;
+	int i;
+
+	if (!x)
+		return min;
+	for (i = 0; y != 1; i++)
+		y >>= 1;
+	y <<= i;
+	if (x & (y - 1))
+		y <<= 1;
+	if (y < min)
+		return min;
+	return y;
+}
+
+static int intel_pt_track_switches(struct perf_evlist *evlist)
+{
+	const char *sched_switch = "sched:sched_switch";
+	struct perf_evsel *evsel;
+	int err;
+
+	if (!perf_evlist__can_select_event(evlist, sched_switch))
+		return -EPERM;
+
+	err = parse_events(evlist, sched_switch);
+	if (err) {
+		pr_debug2("%s: failed to parse %s, error %d\n",
+			  __func__, sched_switch, err);
+		return err;
+	}
+
+	evsel = perf_evlist__last(evlist);
+
+	perf_evsel__set_sample_bit(evsel, CPU);
+
+	evsel->system_wide = true;
+	evsel->no_aux_samples = true;
+	evsel->immediate = true;
+
+	return 0;
+}
+
+static int intel_pt_recording_options(struct itrace_record *itr,
+				      struct perf_evlist *evlist,
+				      struct perf_record_opts *opts)
+{
+	struct intel_pt_recording *ptr =
+			container_of(itr, struct intel_pt_recording, itr);
+	struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
+	bool have_timing_info, topa_multiple_entries;
+	struct perf_evsel *evsel, *intel_pt_evsel = NULL;
+	const struct cpu_map *cpus = evlist->cpus;
+	bool privileged = geteuid() == 0 || perf_event_paranoid() < 0;
+	u64 tsc_bit;
+
+	ptr->evlist = evlist;
+	ptr->snapshot_mode = opts->itrace_snapshot_mode;
+
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		if (evsel->attr.type == intel_pt_pmu->type) {
+			if (intel_pt_evsel) {
+				pr_err("There may be only one " INTEL_PT_PMU_NAME " event\n");
+				return -EINVAL;
+			}
+			evsel->attr.freq = 0;
+			evsel->attr.sample_period = 1;
+			intel_pt_evsel = evsel;
+			opts->full_itrace = true;
+		}
+	}
+
+	if (opts->itrace_snapshot_mode && !opts->full_itrace) {
+		pr_err("Snapshot mode (-S option) requires " INTEL_PT_PMU_NAME " PMU event (-e " INTEL_PT_PMU_NAME ")\n");
+		return -EINVAL;
+	}
+
+	if (!opts->full_itrace && !opts->sample_itrace)
+		return 0;
+
+	if (opts->full_itrace && opts->sample_itrace) {
+		pr_err("Full trace (" INTEL_PT_PMU_NAME " PMU) and sample trace (-I option) cannot be used together\n");
+		return -EINVAL;
+	}
+
+	/* Set default size for sample mode */
+	if (opts->sample_itrace) {
+		size_t psb_period = intel_pt_psb_period(intel_pt_pmu, evlist);
+
+		if (!opts->itrace_sample_size)
+			opts->itrace_sample_size = INTEL_PT_DEFAULT_SAMPLE_SIZE;
+		pr_debug2("Intel PT sample size: %zu\n",
+			  opts->itrace_sample_size);
+		if (psb_period &&
+		    opts->itrace_sample_size <= psb_period +
+						INTEL_PT_PSB_PERIOD_NEAR)
+			ui__warning("Intel PT sample size (%zu) may be too small for PSB period (%zu)\n",
+				    opts->itrace_sample_size, psb_period);
+	}
+
+	topa_multiple_entries =
+			intel_pt_has_topa_multiple_entries(intel_pt_pmu);
+
+	/* Set default sizes for snapshot mode */
+	if (opts->itrace_snapshot_mode) {
+		size_t psb_period = intel_pt_psb_period(intel_pt_pmu, evlist);
+
+		if (!opts->itrace_snapshot_size && !opts->itrace_mmap_pages) {
+			if (privileged) {
+				opts->itrace_mmap_pages = MiB(4) / page_size;
+			} else {
+				opts->itrace_mmap_pages = KiB(128) / page_size;
+				if (opts->mmap_pages == UINT_MAX)
+					opts->mmap_pages = KiB(256) / page_size;
+			}
+		} else if (!opts->itrace_mmap_pages && !privileged &&
+			   opts->mmap_pages == UINT_MAX) {
+			opts->mmap_pages = KiB(256) / page_size;
+		}
+		if (!opts->itrace_snapshot_size)
+			opts->itrace_snapshot_size =
+					opts->itrace_mmap_pages * page_size;
+		if (!opts->itrace_mmap_pages) {
+			size_t sz = opts->itrace_snapshot_size;
+
+			if (topa_multiple_entries)
+				sz += page_size - 1;
+			else if (sz <= MiB(128))
+				sz = intel_pt_to_power_of_2(sz, 4096);
+			else
+				sz = roundup(sz, MiB(128));
+			opts->itrace_mmap_pages = sz / page_size;
+		}
+		if (opts->itrace_snapshot_size >
+					opts->itrace_mmap_pages * page_size) {
+			pr_err("Snapshot size %zu must not be greater than instruction tracing mmap size %zu\n",
+			       opts->itrace_snapshot_size,
+			       opts->itrace_mmap_pages * (size_t)page_size);
+			return -EINVAL;
+		}
+		if (!opts->itrace_snapshot_size || !opts->itrace_mmap_pages) {
+			pr_err("Failed to calculate default snapshot size and/or instruction tracing mmap pages\n");
+			return -EINVAL;
+		}
+		pr_debug2("Intel PT snapshot size: %zu\n",
+			  opts->itrace_snapshot_size);
+		if (psb_period &&
+		    opts->itrace_snapshot_size <= psb_period +
+						  INTEL_PT_PSB_PERIOD_NEAR)
+			ui__warning("Intel PT snapshot size (%zu) may be too small for PSB period (%zu)\n",
+				    opts->itrace_sample_size, psb_period);
+	}
+
+	/* Set default sizes for full trace mode */
+	if (opts->full_itrace && !opts->itrace_mmap_pages) {
+		if (privileged) {
+			opts->itrace_mmap_pages = MiB(4) / page_size;
+		} else {
+			opts->itrace_mmap_pages = KiB(128) / page_size;
+			if (opts->mmap_pages == UINT_MAX)
+				opts->mmap_pages = KiB(256) / page_size;
+		}
+	}
+
+	/* Validate itrace_mmap_pages */
+	if (opts->itrace_mmap_pages && !topa_multiple_entries) {
+		size_t sz = opts->itrace_mmap_pages * page_size;
+		size_t min_sz;
+
+		if (opts->itrace_snapshot_mode)
+			min_sz = KiB(4);
+		else
+			min_sz = KiB(8);
+
+		if (sz < min_sz ||
+		    (!is_power_of_2(sz) && (sz & MiB_MASK(128)))) {
+			pr_err("Invalid mmap size for Intel Processor Trace: must be at least %zuKiB and a power of 2 or a multiple of 128MiB\n",
+			       min_sz / 1024);
+			return -EINVAL;
+		}
+	}
+
+	intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &tsc_bit);
+
+	if ((opts->sample_itrace && (opts->itrace_sample_config & tsc_bit)) ||
+	    (opts->full_itrace &&
+		    (intel_pt_evsel->attr.itrace_config & tsc_bit)))
+		have_timing_info = true;
+	else
+		have_timing_info = false;
+
+	/*
+	 * Per-cpu recording needs sched_switch events to distinguish different
+	 * threads.
+	 */
+	if (have_timing_info && !cpu_map__empty(cpus)) {
+		int err;
+
+		err = intel_pt_track_switches(evlist);
+		if (err == -EPERM)
+			pr_debug2("Unable to select sched:sched_switch\n");
+		else if (err)
+			return err;
+		else
+			ptr->have_sched_switch = 1;
+	}
+
+	if (intel_pt_evsel) {
+		/*
+		 * To mmap the magic offset, the Intel PT event must come first.
+		 */
+		perf_evlist__to_front(evlist, intel_pt_evsel);
+		/*
+		 * In the case of per-cpu mmaps, we need the CPU on the
+		 * ITRACE_LOST event.
+		 */
+		if (!cpu_map__empty(cpus))
+			perf_evsel__set_sample_bit(intel_pt_evsel, CPU);
+	}
+
+	/* Add dummy event to keep tracking */
+	if (opts->full_itrace) {
+		struct perf_evsel *tracking_evsel;
+		int err;
+
+		err = parse_events(evlist, "dummy:u");
+		if (err)
+			return err;
+
+		tracking_evsel = perf_evlist__last(evlist);
+
+		err = perf_evlist__set_tracking_event(evlist, tracking_evsel);
+		if (err)
+			return err;
+
+		tracking_evsel->attr.freq = 0;
+		tracking_evsel->attr.sample_period = 1;
+
+		/* In per-cpu case, always need the time of mmap events etc */
+		if (!cpu_map__empty(cpus))
+			perf_evsel__set_sample_bit(tracking_evsel, TIME);
+	}
+
+	/*
+	 * Warn the user when we do not have enough information to decode i.e.
+	 * per-cpu with no sched_switch (except workload-only).
+	 */
+	if (!ptr->have_sched_switch && !opts->sample_itrace &&
+	    !cpu_map__empty(cpus) && !target__none(&opts->target))
+		ui__warning("Intel Processor Trace decoding will not be possible except for kernel tracing!\n");
+
+	return 0;
+}
+
+static int intel_pt_snapshot_start(struct itrace_record *itr)
+{
+	struct intel_pt_recording *ptr =
+			container_of(itr, struct intel_pt_recording, itr);
+	struct perf_evsel *evsel;
+
+	list_for_each_entry(evsel, &ptr->evlist->entries, node) {
+		if (evsel->attr.type == ptr->intel_pt_pmu->type)
+			return perf_evlist__disable_event(ptr->evlist, evsel);
+	}
+	return -EINVAL;
+}
+
+static int intel_pt_snapshot_finish(struct itrace_record *itr)
+{
+	struct intel_pt_recording *ptr =
+			container_of(itr, struct intel_pt_recording, itr);
+	struct perf_evsel *evsel;
+
+	list_for_each_entry(evsel, &ptr->evlist->entries, node) {
+		if (evsel->attr.type == ptr->intel_pt_pmu->type)
+			return perf_evlist__enable_event(ptr->evlist, evsel);
+	}
+	return -EINVAL;
+}
+
+static int intel_pt_alloc_snapshot_refs(struct intel_pt_recording *ptr, int idx)
+{
+	const size_t sz = sizeof(struct intel_pt_snapshot_ref);
+	int cnt = ptr->snapshot_ref_cnt, new_cnt = cnt * 2;
+	struct intel_pt_snapshot_ref *refs;
+
+	if (!new_cnt)
+		new_cnt = 16;
+
+	while (new_cnt <= idx)
+		new_cnt *= 2;
+
+	refs = calloc(new_cnt, sz);
+	if (!refs)
+		return -ENOMEM;
+
+	memcpy(refs, ptr->snapshot_refs, cnt * sz);
+
+	ptr->snapshot_refs = refs;
+	ptr->snapshot_ref_cnt = new_cnt;
+
+	return 0;
+}
+
+static void intel_pt_free_snapshot_refs(struct intel_pt_recording *ptr)
+{
+	int i;
+
+	for (i = 0; i < ptr->snapshot_ref_cnt; i++)
+		free(ptr->snapshot_refs[i].ref_buf);
+	free(ptr->snapshot_refs);
+}
+
+static void intel_pt_recording_free(struct itrace_record *itr)
+{
+	struct intel_pt_recording *ptr =
+			container_of(itr, struct intel_pt_recording, itr);
+
+	intel_pt_free_snapshot_refs(ptr);
+	free(ptr);
+}
+
+static int intel_pt_alloc_snapshot_ref(struct intel_pt_recording *ptr, int idx,
+				       size_t snapshot_buf_size)
+{
+	size_t ref_buf_size = ptr->snapshot_ref_buf_size;
+	void *ref_buf;
+
+	ref_buf = zalloc(ref_buf_size);
+	if (!ref_buf)
+		return -ENOMEM;
+
+	ptr->snapshot_refs[idx].ref_buf = ref_buf;
+	ptr->snapshot_refs[idx].ref_offset = snapshot_buf_size - ref_buf_size;
+
+	return 0;
+}
+
+static size_t intel_pt_snapshot_ref_buf_size(struct intel_pt_recording *ptr,
+					     size_t snapshot_buf_size)
+{
+	const size_t max_size = 256 * 1024;
+	size_t buf_size = 0, psb_period;
+
+	if (ptr->snapshot_size <= 64 * 1024)
+		return 0;
+
+	psb_period = intel_pt_psb_period(ptr->intel_pt_pmu, ptr->evlist);
+	if (psb_period)
+		buf_size = psb_period * 2;
+
+	if (!buf_size || buf_size > max_size)
+		buf_size = max_size;
+
+	if (buf_size >= snapshot_buf_size)
+		return 0;
+
+	if (buf_size >= ptr->snapshot_size / 2)
+		return 0;
+
+	return buf_size;
+}
+
+static int intel_pt_snapshot_init(struct intel_pt_recording *ptr,
+				  size_t snapshot_buf_size)
+{
+	if (ptr->snapshot_init_done)
+		return 0;
+
+	ptr->snapshot_init_done = true;
+
+	ptr->snapshot_ref_buf_size = intel_pt_snapshot_ref_buf_size(ptr,
+							snapshot_buf_size);
+
+	return 0;
+}
+
+/**
+ * intel_pt_compare_buffers - compare bytes in a buffer to a circular buffer.
+ * @buf1: first buffer
+ * @compare_size: number of bytes to compare
+ * @buf2: second buffer (a circular buffer)
+ * @offs2: offset in second buffer
+ * @buf2_size: size of second buffer
+ *
+ * The comparison allows for the possibility that the bytes to compare in the
+ * circular buffer are not contiguous.  It is assumed that @compare_size <=
+ * @buf2_size.  This function returns %false if the bytes are identical, %true
+ * otherwise.
+ */
+static bool intel_pt_compare_buffers(void *buf1, size_t compare_size,
+				     void *buf2, size_t offs2, size_t buf2_size)
+{
+	size_t end2 = offs2 + compare_size, part_size;
+
+	if (end2 <= buf2_size)
+		return memcmp(buf1, buf2 + offs2, compare_size);
+
+	part_size = end2 - buf2_size;
+	if (memcmp(buf1, buf2 + offs2, part_size))
+		return true;
+
+	compare_size -= part_size;
+
+	return memcmp(buf1 + part_size, buf2, compare_size);
+}
+
+static bool intel_pt_compare_ref(void *ref_buf, size_t ref_offset,
+				 size_t ref_size, size_t buf_size,
+				 void *data, size_t head)
+{
+	size_t ref_end = ref_offset + ref_size;
+
+	if (ref_end > buf_size) {
+		if (head > ref_offset || head < ref_end - buf_size)
+			return true;
+	} else if (head > ref_offset && head < ref_end) {
+		return true;
+	}
+
+	return intel_pt_compare_buffers(ref_buf, ref_size, data, ref_offset,
+					buf_size);
+}
+
+static void intel_pt_copy_ref(void *ref_buf, size_t ref_size, size_t buf_size,
+			      void *data, size_t head)
+{
+	if (head >= ref_size) {
+		memcpy(ref_buf, data + head - ref_size, ref_size);
+	} else {
+		memcpy(ref_buf, data, head);
+		ref_size -= head;
+		memcpy(ref_buf + head, data + buf_size - ref_size, ref_size);
+	}
+}
+
+static bool intel_pt_wrapped(struct intel_pt_recording *ptr, int idx,
+			     struct itrace_mmap *mm, unsigned char *data,
+			     u64 head)
+{
+	struct intel_pt_snapshot_ref *ref = &ptr->snapshot_refs[idx];
+	bool wrapped;
+
+	wrapped = intel_pt_compare_ref(ref->ref_buf, ref->ref_offset,
+				       ptr->snapshot_ref_buf_size, mm->len,
+				       data, head);
+
+	intel_pt_copy_ref(ref->ref_buf, ptr->snapshot_ref_buf_size, mm->len,
+			  data, head);
+
+	return wrapped;
+}
+
+static bool intel_pt_first_wrap(u64 *data, size_t buf_size)
+{
+	int i, a, b;
+
+	b = buf_size >> 3;
+	a = b - 512;
+	if (a < 0)
+		a = 0;
+
+	for (i = a; i < b; i++) {
+		if (data[i])
+			return true;
+	}
+
+	return false;
+}
+
+static int intel_pt_find_snapshot(struct itrace_record *itr, int idx,
+				  struct itrace_mmap *mm, unsigned char *data,
+				  u64 *head, u64 *old)
+{
+	struct intel_pt_recording *ptr =
+			container_of(itr, struct intel_pt_recording, itr);
+	bool wrapped;
+	int err;
+
+	pr_debug3("%s: mmap index %d old head %zu new head %zu\n",
+		  __func__, idx, (size_t)*old, (size_t)*head);
+
+	err = intel_pt_snapshot_init(ptr, mm->len);
+	if (err)
+		goto out_err;
+
+	if (idx >= ptr->snapshot_ref_cnt) {
+		err = intel_pt_alloc_snapshot_refs(ptr, idx);
+		if (err)
+			goto out_err;
+	}
+
+	if (ptr->snapshot_ref_buf_size) {
+		if (!ptr->snapshot_refs[idx].ref_buf) {
+			err = intel_pt_alloc_snapshot_ref(ptr, idx, mm->len);
+			if (err)
+				goto out_err;
+		}
+		wrapped = intel_pt_wrapped(ptr, idx, mm, data, *head);
+	} else {
+		wrapped = ptr->snapshot_refs[idx].wrapped;
+		if (!wrapped && intel_pt_first_wrap((u64 *)data, mm->len)) {
+			ptr->snapshot_refs[idx].wrapped = true;
+			wrapped = true;
+		}
+	}
+
+	/*
+	 * In full trace mode 'head' continually increases.  However in snapshot
+	 * mode 'head' is an offset within the buffer.  Here 'old' and 'head'
+	 * are adjusted to match the full trace case which expects that 'old' is
+	 * always less than 'head'.
+	 */
+	if (wrapped) {
+		*old = *head;
+		*head += mm->len;
+	} else {
+		if (mm->mask)
+			*old &= mm->mask;
+		else
+			*old %= mm->len;
+		if (*old > *head)
+			*head += mm->len;
+	}
+
+	pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n",
+		  __func__, wrapped ? "" : "not ", (size_t)*old, (size_t)*head);
+
+	return 0;
+
+out_err:
+	pr_err("%s: failed, error %d\n", __func__, err);
+	return err;
+}
+
+static u64 intel_pt_reference(struct itrace_record *itr __maybe_unused)
+{
+	return rdtsc();
+}
+
+static int intel_pt_read_finish(struct itrace_record *itr, int idx)
+{
+	struct intel_pt_recording *ptr =
+			container_of(itr, struct intel_pt_recording, itr);
+	struct perf_evsel *evsel;
+
+	list_for_each_entry(evsel, &ptr->evlist->entries, node) {
+		if (evsel->attr.type == ptr->intel_pt_pmu->type)
+			return perf_evlist__enable_event_idx(ptr->evlist, evsel,
+							     idx);
+	}
+	return -EINVAL;
+}
+
+struct itrace_record *intel_pt_recording_init(int *err)
+{
+	struct perf_pmu *intel_pt_pmu = perf_pmu__find(INTEL_PT_PMU_NAME);
+	struct intel_pt_recording *ptr;
+
+	if (!intel_pt_pmu)
+		return NULL;
+
+	ptr = zalloc(sizeof(struct intel_pt_recording));
+	if (!ptr) {
+		*err = -ENOMEM;
+		return NULL;
+	}
+
+	ptr->intel_pt_pmu = intel_pt_pmu;
+	ptr->itr.parse_sample_options = intel_pt_parse_sample_options;
+	ptr->itr.recording_options = intel_pt_recording_options;
+	ptr->itr.info_priv_size = intel_pt_info_priv_size;
+	ptr->itr.info_fill = intel_pt_info_fill;
+	ptr->itr.free = intel_pt_recording_free;
+	ptr->itr.snapshot_start = intel_pt_snapshot_start;
+	ptr->itr.snapshot_finish = intel_pt_snapshot_finish;
+	ptr->itr.find_snapshot = intel_pt_find_snapshot;
+	ptr->itr.parse_snapshot_options = intel_pt_parse_snapshot_options;
+	ptr->itr.reference = intel_pt_reference;
+	ptr->itr.read_finish = intel_pt_read_finish;
+	return &ptr->itr;
+}
diff --git a/tools/perf/util/intel-pt.h b/tools/perf/util/intel-pt.h
new file mode 100644
index 0000000..99898ca
--- /dev/null
+++ b/tools/perf/util/intel-pt.h
@@ -0,0 +1,40 @@
+/*
+ * intel_pt.h: Intel Processor Trace support
+ * Copyright (c) 2013, 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef INCLUDE__PERF_INTEL_PT_H__
+#define INCLUDE__PERF_INTEL_PT_H__
+
+#define INTEL_PT_PMU_NAME "intel_pt"
+
+struct itrace_record;
+struct perf_tool;
+union perf_event;
+struct perf_session;
+struct perf_event_attr;
+struct perf_pmu;
+
+struct itrace_record *intel_pt_recording_init(int *err);
+
+int intel_pt_process_itrace_info(struct perf_tool *tool,
+				 union perf_event *event,
+				 struct perf_session *session);
+
+struct perf_event_attr *intel_pt_pmu_default_config(struct perf_pmu *pmu);
+
+#endif
-- 
1.8.5.1

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