Merge tag 'v5.8-rc3' into arm/qcom

[linux-2.6-microblaze.git] / tools / perf / util / cs-etm.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright(C) 2015-2018 Linaro Limited.
 *
 * Author: Tor Jeremiassen <tor@ti.com>
 * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
 */

#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include <linux/types.h>
#include <linux/zalloc.h>

#include <opencsd/ocsd_if_types.h>
#include <stdlib.h>

#include "auxtrace.h"
#include "color.h"
#include "cs-etm.h"
#include "cs-etm-decoder/cs-etm-decoder.h"
#include "debug.h"
#include "dso.h"
#include "evlist.h"
#include "intlist.h"
#include "machine.h"
#include "map.h"
#include "perf.h"
#include "session.h"
#include "map_symbol.h"
#include "branch.h"
#include "symbol.h"
#include "tool.h"
#include "thread.h"
#include "thread-stack.h"
#include <tools/libc_compat.h>
#include "util/synthetic-events.h"

#define MAX_TIMESTAMP (~0ULL)

struct cs_etm_auxtrace {
        struct auxtrace auxtrace;
        struct auxtrace_queues queues;
        struct auxtrace_heap heap;
        struct itrace_synth_opts synth_opts;
        struct perf_session *session;
        struct machine *machine;
        struct thread *unknown_thread;

        u8 timeless_decoding;
        u8 snapshot_mode;
        u8 data_queued;
        u8 sample_branches;
        u8 sample_instructions;

        int num_cpu;
        u32 auxtrace_type;
        u64 branches_sample_type;
        u64 branches_id;
        u64 instructions_sample_type;
        u64 instructions_sample_period;
        u64 instructions_id;
        u64 **metadata;
        u64 kernel_start;
        unsigned int pmu_type;
};

struct cs_etm_traceid_queue {
        u8 trace_chan_id;
        pid_t pid, tid;
        u64 period_instructions;
        size_t last_branch_pos;
        union perf_event *event_buf;
        struct thread *thread;
        struct branch_stack *last_branch;
        struct branch_stack *last_branch_rb;
        struct cs_etm_packet *prev_packet;
        struct cs_etm_packet *packet;
        struct cs_etm_packet_queue packet_queue;
};

struct cs_etm_queue {
        struct cs_etm_auxtrace *etm;
        struct cs_etm_decoder *decoder;
        struct auxtrace_buffer *buffer;
        unsigned int queue_nr;
        u8 pending_timestamp;
        u64 offset;
        const unsigned char *buf;
        size_t buf_len, buf_used;
        /* Conversion between traceID and index in traceid_queues array */
        struct intlist *traceid_queues_list;
        struct cs_etm_traceid_queue **traceid_queues;
};

/* RB tree for quick conversion between traceID and metadata pointers */
static struct intlist *traceid_list;

static int cs_etm__update_queues(struct cs_etm_auxtrace *etm);
static int cs_etm__process_queues(struct cs_etm_auxtrace *etm);
static int cs_etm__process_timeless_queues(struct cs_etm_auxtrace *etm,
                                           pid_t tid);
static int cs_etm__get_data_block(struct cs_etm_queue *etmq);
static int cs_etm__decode_data_block(struct cs_etm_queue *etmq);

/* PTMs ETMIDR [11:8] set to b0011 */
#define ETMIDR_PTM_VERSION 0x00000300

/*
 * A struct auxtrace_heap_item only has a queue_nr and a timestamp to
 * work with.  One option is to modify to auxtrace_heap_XYZ() API or simply
 * encode the etm queue number as the upper 16 bit and the channel as
 * the lower 16 bit.
 */
#define TO_CS_QUEUE_NR(queue_nr, trace_chan_id) \
                      (queue_nr << 16 | trace_chan_id)
#define TO_QUEUE_NR(cs_queue_nr) (cs_queue_nr >> 16)
#define TO_TRACE_CHAN_ID(cs_queue_nr) (cs_queue_nr & 0x0000ffff)

static u32 cs_etm__get_v7_protocol_version(u32 etmidr)
{
        etmidr &= ETMIDR_PTM_VERSION;

        if (etmidr == ETMIDR_PTM_VERSION)
                return CS_ETM_PROTO_PTM;

        return CS_ETM_PROTO_ETMV3;
}

static int cs_etm__get_magic(u8 trace_chan_id, u64 *magic)
{
        struct int_node *inode;
        u64 *metadata;

        inode = intlist__find(traceid_list, trace_chan_id);
        if (!inode)
                return -EINVAL;

        metadata = inode->priv;
        *magic = metadata[CS_ETM_MAGIC];
        return 0;
}

int cs_etm__get_cpu(u8 trace_chan_id, int *cpu)
{
        struct int_node *inode;
        u64 *metadata;

        inode = intlist__find(traceid_list, trace_chan_id);
        if (!inode)
                return -EINVAL;

        metadata = inode->priv;
        *cpu = (int)metadata[CS_ETM_CPU];
        return 0;
}

void cs_etm__etmq_set_traceid_queue_timestamp(struct cs_etm_queue *etmq,
                                              u8 trace_chan_id)
{
        /*
         * Wnen a timestamp packet is encountered the backend code
         * is stopped so that the front end has time to process packets
         * that were accumulated in the traceID queue.  Since there can
         * be more than one channel per cs_etm_queue, we need to specify
         * what traceID queue needs servicing.
         */
        etmq->pending_timestamp = trace_chan_id;
}

static u64 cs_etm__etmq_get_timestamp(struct cs_etm_queue *etmq,
                                      u8 *trace_chan_id)
{
        struct cs_etm_packet_queue *packet_queue;

        if (!etmq->pending_timestamp)
                return 0;

        if (trace_chan_id)
                *trace_chan_id = etmq->pending_timestamp;

        packet_queue = cs_etm__etmq_get_packet_queue(etmq,
                                                     etmq->pending_timestamp);
        if (!packet_queue)
                return 0;

        /* Acknowledge pending status */
        etmq->pending_timestamp = 0;

        /* See function cs_etm_decoder__do_{hard|soft}_timestamp() */
        return packet_queue->timestamp;
}

static void cs_etm__clear_packet_queue(struct cs_etm_packet_queue *queue)
{
        int i;

        queue->head = 0;
        queue->tail = 0;
        queue->packet_count = 0;
        for (i = 0; i < CS_ETM_PACKET_MAX_BUFFER; i++) {
                queue->packet_buffer[i].isa = CS_ETM_ISA_UNKNOWN;
                queue->packet_buffer[i].start_addr = CS_ETM_INVAL_ADDR;
                queue->packet_buffer[i].end_addr = CS_ETM_INVAL_ADDR;
                queue->packet_buffer[i].instr_count = 0;
                queue->packet_buffer[i].last_instr_taken_branch = false;
                queue->packet_buffer[i].last_instr_size = 0;
                queue->packet_buffer[i].last_instr_type = 0;
                queue->packet_buffer[i].last_instr_subtype = 0;
                queue->packet_buffer[i].last_instr_cond = 0;
                queue->packet_buffer[i].flags = 0;
                queue->packet_buffer[i].exception_number = UINT32_MAX;
                queue->packet_buffer[i].trace_chan_id = UINT8_MAX;
                queue->packet_buffer[i].cpu = INT_MIN;
        }
}

static void cs_etm__clear_all_packet_queues(struct cs_etm_queue *etmq)
{
        int idx;
        struct int_node *inode;
        struct cs_etm_traceid_queue *tidq;
        struct intlist *traceid_queues_list = etmq->traceid_queues_list;

        intlist__for_each_entry(inode, traceid_queues_list) {
                idx = (int)(intptr_t)inode->priv;
                tidq = etmq->traceid_queues[idx];
                cs_etm__clear_packet_queue(&tidq->packet_queue);
        }
}

static int cs_etm__init_traceid_queue(struct cs_etm_queue *etmq,
                                      struct cs_etm_traceid_queue *tidq,
                                      u8 trace_chan_id)
{
        int rc = -ENOMEM;
        struct auxtrace_queue *queue;
        struct cs_etm_auxtrace *etm = etmq->etm;

        cs_etm__clear_packet_queue(&tidq->packet_queue);

        queue = &etmq->etm->queues.queue_array[etmq->queue_nr];
        tidq->tid = queue->tid;
        tidq->pid = -1;
        tidq->trace_chan_id = trace_chan_id;

        tidq->packet = zalloc(sizeof(struct cs_etm_packet));
        if (!tidq->packet)
                goto out;

        tidq->prev_packet = zalloc(sizeof(struct cs_etm_packet));
        if (!tidq->prev_packet)
                goto out_free;

        if (etm->synth_opts.last_branch) {
                size_t sz = sizeof(struct branch_stack);

                sz += etm->synth_opts.last_branch_sz *
                      sizeof(struct branch_entry);
                tidq->last_branch = zalloc(sz);
                if (!tidq->last_branch)
                        goto out_free;
                tidq->last_branch_rb = zalloc(sz);
                if (!tidq->last_branch_rb)
                        goto out_free;
        }

        tidq->event_buf = malloc(PERF_SAMPLE_MAX_SIZE);
        if (!tidq->event_buf)
                goto out_free;

        return 0;

out_free:
        zfree(&tidq->last_branch_rb);
        zfree(&tidq->last_branch);
        zfree(&tidq->prev_packet);
        zfree(&tidq->packet);
out:
        return rc;
}

static struct cs_etm_traceid_queue
*cs_etm__etmq_get_traceid_queue(struct cs_etm_queue *etmq, u8 trace_chan_id)
{
        int idx;
        struct int_node *inode;
        struct intlist *traceid_queues_list;
        struct cs_etm_traceid_queue *tidq, **traceid_queues;
        struct cs_etm_auxtrace *etm = etmq->etm;

        if (etm->timeless_decoding)
                trace_chan_id = CS_ETM_PER_THREAD_TRACEID;

        traceid_queues_list = etmq->traceid_queues_list;

        /*
         * Check if the traceid_queue exist for this traceID by looking
         * in the queue list.
         */
        inode = intlist__find(traceid_queues_list, trace_chan_id);
        if (inode) {
                idx = (int)(intptr_t)inode->priv;
                return etmq->traceid_queues[idx];
        }

        /* We couldn't find a traceid_queue for this traceID, allocate one */
        tidq = malloc(sizeof(*tidq));
        if (!tidq)
                return NULL;

        memset(tidq, 0, sizeof(*tidq));

        /* Get a valid index for the new traceid_queue */
        idx = intlist__nr_entries(traceid_queues_list);
        /* Memory for the inode is free'ed in cs_etm_free_traceid_queues () */
        inode = intlist__findnew(traceid_queues_list, trace_chan_id);
        if (!inode)
                goto out_free;

        /* Associate this traceID with this index */
        inode->priv = (void *)(intptr_t)idx;

        if (cs_etm__init_traceid_queue(etmq, tidq, trace_chan_id))
                goto out_free;

        /* Grow the traceid_queues array by one unit */
        traceid_queues = etmq->traceid_queues;
        traceid_queues = reallocarray(traceid_queues,
                                      idx + 1,
                                      sizeof(*traceid_queues));

        /*
         * On failure reallocarray() returns NULL and the original block of
         * memory is left untouched.
         */
        if (!traceid_queues)
                goto out_free;

        traceid_queues[idx] = tidq;
        etmq->traceid_queues = traceid_queues;

        return etmq->traceid_queues[idx];

out_free:
        /*
         * Function intlist__remove() removes the inode from the list
         * and delete the memory associated to it.
         */
        intlist__remove(traceid_queues_list, inode);
        free(tidq);

        return NULL;
}

struct cs_etm_packet_queue
*cs_etm__etmq_get_packet_queue(struct cs_etm_queue *etmq, u8 trace_chan_id)
{
        struct cs_etm_traceid_queue *tidq;

        tidq = cs_etm__etmq_get_traceid_queue(etmq, trace_chan_id);
        if (tidq)
                return &tidq->packet_queue;

        return NULL;
}

static void cs_etm__packet_swap(struct cs_etm_auxtrace *etm,
                                struct cs_etm_traceid_queue *tidq)
{
        struct cs_etm_packet *tmp;

        if (etm->sample_branches || etm->synth_opts.last_branch ||
            etm->sample_instructions) {
                /*
                 * Swap PACKET with PREV_PACKET: PACKET becomes PREV_PACKET for
                 * the next incoming packet.
                 */
                tmp = tidq->packet;
                tidq->packet = tidq->prev_packet;
                tidq->prev_packet = tmp;
        }
}

static void cs_etm__packet_dump(const char *pkt_string)
{
        const char *color = PERF_COLOR_BLUE;
        int len = strlen(pkt_string);

        if (len && (pkt_string[len-1] == '\n'))
                color_fprintf(stdout, color, "  %s", pkt_string);
        else
                color_fprintf(stdout, color, "  %s\n", pkt_string);

        fflush(stdout);
}

static void cs_etm__set_trace_param_etmv3(struct cs_etm_trace_params *t_params,
                                          struct cs_etm_auxtrace *etm, int idx,
                                          u32 etmidr)
{
        u64 **metadata = etm->metadata;

        t_params[idx].protocol = cs_etm__get_v7_protocol_version(etmidr);
        t_params[idx].etmv3.reg_ctrl = metadata[idx][CS_ETM_ETMCR];
        t_params[idx].etmv3.reg_trc_id = metadata[idx][CS_ETM_ETMTRACEIDR];
}

static void cs_etm__set_trace_param_etmv4(struct cs_etm_trace_params *t_params,
                                          struct cs_etm_auxtrace *etm, int idx)
{
        u64 **metadata = etm->metadata;

        t_params[idx].protocol = CS_ETM_PROTO_ETMV4i;
        t_params[idx].etmv4.reg_idr0 = metadata[idx][CS_ETMV4_TRCIDR0];
        t_params[idx].etmv4.reg_idr1 = metadata[idx][CS_ETMV4_TRCIDR1];
        t_params[idx].etmv4.reg_idr2 = metadata[idx][CS_ETMV4_TRCIDR2];
        t_params[idx].etmv4.reg_idr8 = metadata[idx][CS_ETMV4_TRCIDR8];
        t_params[idx].etmv4.reg_configr = metadata[idx][CS_ETMV4_TRCCONFIGR];
        t_params[idx].etmv4.reg_traceidr = metadata[idx][CS_ETMV4_TRCTRACEIDR];
}

static int cs_etm__init_trace_params(struct cs_etm_trace_params *t_params,
                                     struct cs_etm_auxtrace *etm)
{
        int i;
        u32 etmidr;
        u64 architecture;

        for (i = 0; i < etm->num_cpu; i++) {
                architecture = etm->metadata[i][CS_ETM_MAGIC];

                switch (architecture) {
                case __perf_cs_etmv3_magic:
                        etmidr = etm->metadata[i][CS_ETM_ETMIDR];
                        cs_etm__set_trace_param_etmv3(t_params, etm, i, etmidr);
                        break;
                case __perf_cs_etmv4_magic:
                        cs_etm__set_trace_param_etmv4(t_params, etm, i);
                        break;
                default:
                        return -EINVAL;
                }
        }

        return 0;
}

static int cs_etm__init_decoder_params(struct cs_etm_decoder_params *d_params,
                                       struct cs_etm_queue *etmq,
                                       enum cs_etm_decoder_operation mode)
{
        int ret = -EINVAL;

        if (!(mode < CS_ETM_OPERATION_MAX))
                goto out;

        d_params->packet_printer = cs_etm__packet_dump;
        d_params->operation = mode;
        d_params->data = etmq;
        d_params->formatted = true;
        d_params->fsyncs = false;
        d_params->hsyncs = false;
        d_params->frame_aligned = true;

        ret = 0;
out:
        return ret;
}

static void cs_etm__dump_event(struct cs_etm_auxtrace *etm,
                               struct auxtrace_buffer *buffer)
{
        int ret;
        const char *color = PERF_COLOR_BLUE;
        struct cs_etm_decoder_params d_params;
        struct cs_etm_trace_params *t_params;
        struct cs_etm_decoder *decoder;
        size_t buffer_used = 0;

        fprintf(stdout, "\n");
        color_fprintf(stdout, color,
                     ". ... CoreSight ETM Trace data: size %zu bytes\n",
                     buffer->size);

        /* Use metadata to fill in trace parameters for trace decoder */
        t_params = zalloc(sizeof(*t_params) * etm->num_cpu);

        if (!t_params)
                return;

        if (cs_etm__init_trace_params(t_params, etm))
                goto out_free;

        /* Set decoder parameters to simply print the trace packets */
        if (cs_etm__init_decoder_params(&d_params, NULL,
                                        CS_ETM_OPERATION_PRINT))
                goto out_free;

        decoder = cs_etm_decoder__new(etm->num_cpu, &d_params, t_params);

        if (!decoder)
                goto out_free;
        do {
                size_t consumed;

                ret = cs_etm_decoder__process_data_block(
                                decoder, buffer->offset,
                                &((u8 *)buffer->data)[buffer_used],
                                buffer->size - buffer_used, &consumed);
                if (ret)
                        break;

                buffer_used += consumed;
        } while (buffer_used < buffer->size);

        cs_etm_decoder__free(decoder);

out_free:
        zfree(&t_params);
}

static int cs_etm__flush_events(struct perf_session *session,
                                struct perf_tool *tool)
{
        int ret;
        struct cs_etm_auxtrace *etm = container_of(session->auxtrace,
                                                   struct cs_etm_auxtrace,
                                                   auxtrace);
        if (dump_trace)
                return 0;

        if (!tool->ordered_events)
                return -EINVAL;

        ret = cs_etm__update_queues(etm);

        if (ret < 0)
                return ret;

        if (etm->timeless_decoding)
                return cs_etm__process_timeless_queues(etm, -1);

        return cs_etm__process_queues(etm);
}

static void cs_etm__free_traceid_queues(struct cs_etm_queue *etmq)
{
        int idx;
        uintptr_t priv;
        struct int_node *inode, *tmp;
        struct cs_etm_traceid_queue *tidq;
        struct intlist *traceid_queues_list = etmq->traceid_queues_list;

        intlist__for_each_entry_safe(inode, tmp, traceid_queues_list) {
                priv = (uintptr_t)inode->priv;
                idx = priv;

                /* Free this traceid_queue from the array */
                tidq = etmq->traceid_queues[idx];
                thread__zput(tidq->thread);
                zfree(&tidq->event_buf);
                zfree(&tidq->last_branch);
                zfree(&tidq->last_branch_rb);
                zfree(&tidq->prev_packet);
                zfree(&tidq->packet);
                zfree(&tidq);

                /*
                 * Function intlist__remove() removes the inode from the list
                 * and delete the memory associated to it.
                 */
                intlist__remove(traceid_queues_list, inode);
        }

        /* Then the RB tree itself */
        intlist__delete(traceid_queues_list);
        etmq->traceid_queues_list = NULL;

        /* finally free the traceid_queues array */
        zfree(&etmq->traceid_queues);
}

static void cs_etm__free_queue(void *priv)
{
        struct cs_etm_queue *etmq = priv;

        if (!etmq)
                return;

        cs_etm_decoder__free(etmq->decoder);
        cs_etm__free_traceid_queues(etmq);
        free(etmq);
}

static void cs_etm__free_events(struct perf_session *session)
{
        unsigned int i;
        struct cs_etm_auxtrace *aux = container_of(session->auxtrace,
                                                   struct cs_etm_auxtrace,
                                                   auxtrace);
        struct auxtrace_queues *queues = &aux->queues;

        for (i = 0; i < queues->nr_queues; i++) {
                cs_etm__free_queue(queues->queue_array[i].priv);
                queues->queue_array[i].priv = NULL;
        }

        auxtrace_queues__free(queues);
}

static void cs_etm__free(struct perf_session *session)
{
        int i;
        struct int_node *inode, *tmp;
        struct cs_etm_auxtrace *aux = container_of(session->auxtrace,
                                                   struct cs_etm_auxtrace,
                                                   auxtrace);
        cs_etm__free_events(session);
        session->auxtrace = NULL;

        /* First remove all traceID/metadata nodes for the RB tree */
        intlist__for_each_entry_safe(inode, tmp, traceid_list)
                intlist__remove(traceid_list, inode);
        /* Then the RB tree itself */
        intlist__delete(traceid_list);

        for (i = 0; i < aux->num_cpu; i++)
                zfree(&aux->metadata[i]);

        thread__zput(aux->unknown_thread);
        zfree(&aux->metadata);
        zfree(&aux);
}

static bool cs_etm__evsel_is_auxtrace(struct perf_session *session,
                                      struct evsel *evsel)
{
        struct cs_etm_auxtrace *aux = container_of(session->auxtrace,
                                                   struct cs_etm_auxtrace,
                                                   auxtrace);

        return evsel->core.attr.type == aux->pmu_type;
}

static u8 cs_etm__cpu_mode(struct cs_etm_queue *etmq, u64 address)
{
        struct machine *machine;

        machine = etmq->etm->machine;

        if (address >= etmq->etm->kernel_start) {
                if (machine__is_host(machine))
                        return PERF_RECORD_MISC_KERNEL;
                else
                        return PERF_RECORD_MISC_GUEST_KERNEL;
        } else {
                if (machine__is_host(machine))
                        return PERF_RECORD_MISC_USER;
                else if (perf_guest)
                        return PERF_RECORD_MISC_GUEST_USER;
                else
                        return PERF_RECORD_MISC_HYPERVISOR;
        }
}

static u32 cs_etm__mem_access(struct cs_etm_queue *etmq, u8 trace_chan_id,
                              u64 address, size_t size, u8 *buffer)
{
        u8  cpumode;
        u64 offset;
        int len;
        struct thread *thread;
        struct machine *machine;
        struct addr_location al;
        struct cs_etm_traceid_queue *tidq;

        if (!etmq)
                return 0;

        machine = etmq->etm->machine;
        cpumode = cs_etm__cpu_mode(etmq, address);
        tidq = cs_etm__etmq_get_traceid_queue(etmq, trace_chan_id);
        if (!tidq)
                return 0;

        thread = tidq->thread;
        if (!thread) {
                if (cpumode != PERF_RECORD_MISC_KERNEL)
                        return 0;
                thread = etmq->etm->unknown_thread;
        }

        if (!thread__find_map(thread, cpumode, address, &al) || !al.map->dso)
                return 0;

        if (al.map->dso->data.status == DSO_DATA_STATUS_ERROR &&
            dso__data_status_seen(al.map->dso, DSO_DATA_STATUS_SEEN_ITRACE))
                return 0;

        offset = al.map->map_ip(al.map, address);

        map__load(al.map);

        len = dso__data_read_offset(al.map->dso, machine, offset, buffer, size);

        if (len <= 0)
                return 0;

        return len;
}

static struct cs_etm_queue *cs_etm__alloc_queue(struct cs_etm_auxtrace *etm)
{
        struct cs_etm_decoder_params d_params;
        struct cs_etm_trace_params  *t_params = NULL;
        struct cs_etm_queue *etmq;

        etmq = zalloc(sizeof(*etmq));
        if (!etmq)
                return NULL;

        etmq->traceid_queues_list = intlist__new(NULL);
        if (!etmq->traceid_queues_list)
                goto out_free;

        /* Use metadata to fill in trace parameters for trace decoder */
        t_params = zalloc(sizeof(*t_params) * etm->num_cpu);

        if (!t_params)
                goto out_free;

        if (cs_etm__init_trace_params(t_params, etm))
                goto out_free;

        /* Set decoder parameters to decode trace packets */
        if (cs_etm__init_decoder_params(&d_params, etmq,
                                        CS_ETM_OPERATION_DECODE))
                goto out_free;

        etmq->decoder = cs_etm_decoder__new(etm->num_cpu, &d_params, t_params);

        if (!etmq->decoder)
                goto out_free;

        /*
         * Register a function to handle all memory accesses required by
         * the trace decoder library.
         */
        if (cs_etm_decoder__add_mem_access_cb(etmq->decoder,
                                              0x0L, ((u64) -1L),
                                              cs_etm__mem_access))
                goto out_free_decoder;

        zfree(&t_params);
        return etmq;

out_free_decoder:
        cs_etm_decoder__free(etmq->decoder);
out_free:
        intlist__delete(etmq->traceid_queues_list);
        free(etmq);

        return NULL;
}

static int cs_etm__setup_queue(struct cs_etm_auxtrace *etm,
                               struct auxtrace_queue *queue,
                               unsigned int queue_nr)
{
        int ret = 0;
        unsigned int cs_queue_nr;
        u8 trace_chan_id;
        u64 timestamp;
        struct cs_etm_queue *etmq = queue->priv;

        if (list_empty(&queue->head) || etmq)
                goto out;

        etmq = cs_etm__alloc_queue(etm);

        if (!etmq) {
                ret = -ENOMEM;
                goto out;
        }

        queue->priv = etmq;
        etmq->etm = etm;
        etmq->queue_nr = queue_nr;
        etmq->offset = 0;

        if (etm->timeless_decoding)
                goto out;

        /*
         * We are under a CPU-wide trace scenario.  As such we need to know
         * when the code that generated the traces started to execute so that
         * it can be correlated with execution on other CPUs.  So we get a
         * handle on the beginning of traces and decode until we find a
         * timestamp.  The timestamp is then added to the auxtrace min heap
         * in order to know what nibble (of all the etmqs) to decode first.
         */
        while (1) {
                /*
                 * Fetch an aux_buffer from this etmq.  Bail if no more
                 * blocks or an error has been encountered.
                 */
                ret = cs_etm__get_data_block(etmq);
                if (ret <= 0)
                        goto out;

                /*
                 * Run decoder on the trace block.  The decoder will stop when
                 * encountering a timestamp, a full packet queue or the end of
                 * trace for that block.
                 */
                ret = cs_etm__decode_data_block(etmq);
                if (ret)
                        goto out;

                /*
                 * Function cs_etm_decoder__do_{hard|soft}_timestamp() does all
                 * the timestamp calculation for us.
                 */
                timestamp = cs_etm__etmq_get_timestamp(etmq, &trace_chan_id);

                /* We found a timestamp, no need to continue. */
                if (timestamp)
                        break;

                /*
                 * We didn't find a timestamp so empty all the traceid packet
                 * queues before looking for another timestamp packet, either
                 * in the current data block or a new one.  Packets that were
                 * just decoded are useless since no timestamp has been
                 * associated with them.  As such simply discard them.
                 */
                cs_etm__clear_all_packet_queues(etmq);
        }

        /*
         * We have a timestamp.  Add it to the min heap to reflect when
         * instructions conveyed by the range packets of this traceID queue
         * started to execute.  Once the same has been done for all the traceID
         * queues of each etmq, redenring and decoding can start in
         * chronological order.
         *
         * Note that packets decoded above are still in the traceID's packet
         * queue and will be processed in cs_etm__process_queues().
         */
        cs_queue_nr = TO_CS_QUEUE_NR(queue_nr, trace_chan_id);
        ret = auxtrace_heap__add(&etm->heap, cs_queue_nr, timestamp);
out:
        return ret;
}

static int cs_etm__setup_queues(struct cs_etm_auxtrace *etm)
{
        unsigned int i;
        int ret;

        if (!etm->kernel_start)
                etm->kernel_start = machine__kernel_start(etm->machine);

        for (i = 0; i < etm->queues.nr_queues; i++) {
                ret = cs_etm__setup_queue(etm, &etm->queues.queue_array[i], i);
                if (ret)
                        return ret;
        }

        return 0;
}

static int cs_etm__update_queues(struct cs_etm_auxtrace *etm)
{
        if (etm->queues.new_data) {
                etm->queues.new_data = false;
                return cs_etm__setup_queues(etm);
        }

        return 0;
}

static inline
void cs_etm__copy_last_branch_rb(struct cs_etm_queue *etmq,
                                 struct cs_etm_traceid_queue *tidq)
{
        struct branch_stack *bs_src = tidq->last_branch_rb;
        struct branch_stack *bs_dst = tidq->last_branch;
        size_t nr = 0;

        /*
         * Set the number of records before early exit: ->nr is used to
         * determine how many branches to copy from ->entries.
         */
        bs_dst->nr = bs_src->nr;

        /*
         * Early exit when there is nothing to copy.
         */
        if (!bs_src->nr)
                return;

        /*
         * As bs_src->entries is a circular buffer, we need to copy from it in
         * two steps.  First, copy the branches from the most recently inserted
         * branch ->last_branch_pos until the end of bs_src->entries buffer.
         */
        nr = etmq->etm->synth_opts.last_branch_sz - tidq->last_branch_pos;
        memcpy(&bs_dst->entries[0],
               &bs_src->entries[tidq->last_branch_pos],
               sizeof(struct branch_entry) * nr);

        /*
         * If we wrapped around at least once, the branches from the beginning
         * of the bs_src->entries buffer and until the ->last_branch_pos element
         * are older valid branches: copy them over.  The total number of
         * branches copied over will be equal to the number of branches asked by
         * the user in last_branch_sz.
         */
        if (bs_src->nr >= etmq->etm->synth_opts.last_branch_sz) {
                memcpy(&bs_dst->entries[nr],
                       &bs_src->entries[0],
                       sizeof(struct branch_entry) * tidq->last_branch_pos);
        }
}

static inline
void cs_etm__reset_last_branch_rb(struct cs_etm_traceid_queue *tidq)
{
        tidq->last_branch_pos = 0;
        tidq->last_branch_rb->nr = 0;
}

static inline int cs_etm__t32_instr_size(struct cs_etm_queue *etmq,
                                         u8 trace_chan_id, u64 addr)
{
        u8 instrBytes[2];

        cs_etm__mem_access(etmq, trace_chan_id, addr,
                           ARRAY_SIZE(instrBytes), instrBytes);
        /*
         * T32 instruction size is indicated by bits[15:11] of the first
         * 16-bit word of the instruction: 0b11101, 0b11110 and 0b11111
         * denote a 32-bit instruction.
         */
        return ((instrBytes[1] & 0xF8) >= 0xE8) ? 4 : 2;
}

static inline u64 cs_etm__first_executed_instr(struct cs_etm_packet *packet)
{
        /* Returns 0 for the CS_ETM_DISCONTINUITY packet */
        if (packet->sample_type == CS_ETM_DISCONTINUITY)
                return 0;

        return packet->start_addr;
}

static inline
u64 cs_etm__last_executed_instr(const struct cs_etm_packet *packet)
{
        /* Returns 0 for the CS_ETM_DISCONTINUITY packet */
        if (packet->sample_type == CS_ETM_DISCONTINUITY)
                return 0;

        return packet->end_addr - packet->last_instr_size;
}

static inline u64 cs_etm__instr_addr(struct cs_etm_queue *etmq,
                                     u64 trace_chan_id,
                                     const struct cs_etm_packet *packet,
                                     u64 offset)
{
        if (packet->isa == CS_ETM_ISA_T32) {
                u64 addr = packet->start_addr;

                while (offset) {
                        addr += cs_etm__t32_instr_size(etmq,
                                                       trace_chan_id, addr);
                        offset--;
                }
                return addr;
        }

        /* Assume a 4 byte instruction size (A32/A64) */
        return packet->start_addr + offset * 4;
}

static void cs_etm__update_last_branch_rb(struct cs_etm_queue *etmq,
                                          struct cs_etm_traceid_queue *tidq)
{
        struct branch_stack *bs = tidq->last_branch_rb;
        struct branch_entry *be;

        /*
         * The branches are recorded in a circular buffer in reverse
         * chronological order: we start recording from the last element of the
         * buffer down.  After writing the first element of the stack, move the
         * insert position back to the end of the buffer.
         */
        if (!tidq->last_branch_pos)
                tidq->last_branch_pos = etmq->etm->synth_opts.last_branch_sz;

        tidq->last_branch_pos -= 1;

        be       = &bs->entries[tidq->last_branch_pos];
        be->from = cs_etm__last_executed_instr(tidq->prev_packet);
        be->to   = cs_etm__first_executed_instr(tidq->packet);
        /* No support for mispredict */
        be->flags.mispred = 0;
        be->flags.predicted = 1;

        /*
         * Increment bs->nr until reaching the number of last branches asked by
         * the user on the command line.
         */
        if (bs->nr < etmq->etm->synth_opts.last_branch_sz)
                bs->nr += 1;
}

static int cs_etm__inject_event(union perf_event *event,
                               struct perf_sample *sample, u64 type)
{
        event->header.size = perf_event__sample_event_size(sample, type, 0);
        return perf_event__synthesize_sample(event, type, 0, sample);
}


static int
cs_etm__get_trace(struct cs_etm_queue *etmq)
{
        struct auxtrace_buffer *aux_buffer = etmq->buffer;
        struct auxtrace_buffer *old_buffer = aux_buffer;
        struct auxtrace_queue *queue;

        queue = &etmq->etm->queues.queue_array[etmq->queue_nr];

        aux_buffer = auxtrace_buffer__next(queue, aux_buffer);

        /* If no more data, drop the previous auxtrace_buffer and return */
        if (!aux_buffer) {
                if (old_buffer)
                        auxtrace_buffer__drop_data(old_buffer);
                etmq->buf_len = 0;
                return 0;
        }

        etmq->buffer = aux_buffer;

        /* If the aux_buffer doesn't have data associated, try to load it */
        if (!aux_buffer->data) {
                /* get the file desc associated with the perf data file */
                int fd = perf_data__fd(etmq->etm->session->data);

                aux_buffer->data = auxtrace_buffer__get_data(aux_buffer, fd);
                if (!aux_buffer->data)
                        return -ENOMEM;
        }

        /* If valid, drop the previous buffer */
        if (old_buffer)
                auxtrace_buffer__drop_data(old_buffer);

        etmq->buf_used = 0;
        etmq->buf_len = aux_buffer->size;
        etmq->buf = aux_buffer->data;

        return etmq->buf_len;
}

static void cs_etm__set_pid_tid_cpu(struct cs_etm_auxtrace *etm,
                                    struct cs_etm_traceid_queue *tidq)
{
        if ((!tidq->thread) && (tidq->tid != -1))
                tidq->thread = machine__find_thread(etm->machine, -1,
                                                    tidq->tid);

        if (tidq->thread)
                tidq->pid = tidq->thread->pid_;
}

int cs_etm__etmq_set_tid(struct cs_etm_queue *etmq,
                         pid_t tid, u8 trace_chan_id)
{
        int cpu, err = -EINVAL;
        struct cs_etm_auxtrace *etm = etmq->etm;
        struct cs_etm_traceid_queue *tidq;

        tidq = cs_etm__etmq_get_traceid_queue(etmq, trace_chan_id);
        if (!tidq)
                return err;

        if (cs_etm__get_cpu(trace_chan_id, &cpu) < 0)
                return err;

        err = machine__set_current_tid(etm->machine, cpu, tid, tid);
        if (err)
                return err;

        tidq->tid = tid;
        thread__zput(tidq->thread);

        cs_etm__set_pid_tid_cpu(etm, tidq);
        return 0;
}

bool cs_etm__etmq_is_timeless(struct cs_etm_queue *etmq)
{
        return !!etmq->etm->timeless_decoding;
}

static void cs_etm__copy_insn(struct cs_etm_queue *etmq,
                              u64 trace_chan_id,
                              const struct cs_etm_packet *packet,
                              struct perf_sample *sample)
{
        /*
         * It's pointless to read instructions for the CS_ETM_DISCONTINUITY
         * packet, so directly bail out with 'insn_len' = 0.
         */
        if (packet->sample_type == CS_ETM_DISCONTINUITY) {
                sample->insn_len = 0;
                return;
        }

        /*
         * T32 instruction size might be 32-bit or 16-bit, decide by calling
         * cs_etm__t32_instr_size().
         */
        if (packet->isa == CS_ETM_ISA_T32)
                sample->insn_len = cs_etm__t32_instr_size(etmq, trace_chan_id,
                                                          sample->ip);
        /* Otherwise, A64 and A32 instruction size are always 32-bit. */
        else
                sample->insn_len = 4;

        cs_etm__mem_access(etmq, trace_chan_id, sample->ip,
                           sample->insn_len, (void *)sample->insn);
}

static int cs_etm__synth_instruction_sample(struct cs_etm_queue *etmq,
                                            struct cs_etm_traceid_queue *tidq,
                                            u64 addr, u64 period)
{
        int ret = 0;
        struct cs_etm_auxtrace *etm = etmq->etm;
        union perf_event *event = tidq->event_buf;
        struct perf_sample sample = {.ip = 0,};

        event->sample.header.type = PERF_RECORD_SAMPLE;
        event->sample.header.misc = cs_etm__cpu_mode(etmq, addr);
        event->sample.header.size = sizeof(struct perf_event_header);

        sample.ip = addr;
        sample.pid = tidq->pid;
        sample.tid = tidq->tid;
        sample.id = etmq->etm->instructions_id;
        sample.stream_id = etmq->etm->instructions_id;
        sample.period = period;
        sample.cpu = tidq->packet->cpu;
        sample.flags = tidq->prev_packet->flags;
        sample.cpumode = event->sample.header.misc;

        cs_etm__copy_insn(etmq, tidq->trace_chan_id, tidq->packet, &sample);

        if (etm->synth_opts.last_branch)
                sample.branch_stack = tidq->last_branch;

        if (etm->synth_opts.inject) {
                ret = cs_etm__inject_event(event, &sample,
                                           etm->instructions_sample_type);
                if (ret)
                        return ret;
        }

        ret = perf_session__deliver_synth_event(etm->session, event, &sample);

        if (ret)
                pr_err(
                        "CS ETM Trace: failed to deliver instruction event, error %d\n",
                        ret);

        return ret;
}

/*
 * The cs etm packet encodes an instruction range between a branch target
 * and the next taken branch. Generate sample accordingly.
 */
static int cs_etm__synth_branch_sample(struct cs_etm_queue *etmq,
                                       struct cs_etm_traceid_queue *tidq)
{
        int ret = 0;
        struct cs_etm_auxtrace *etm = etmq->etm;
        struct perf_sample sample = {.ip = 0,};
        union perf_event *event = tidq->event_buf;
        struct dummy_branch_stack {
                u64                     nr;
                u64                     hw_idx;
                struct branch_entry     entries;
        } dummy_bs;
        u64 ip;

        ip = cs_etm__last_executed_instr(tidq->prev_packet);

        event->sample.header.type = PERF_RECORD_SAMPLE;
        event->sample.header.misc = cs_etm__cpu_mode(etmq, ip);
        event->sample.header.size = sizeof(struct perf_event_header);

        sample.ip = ip;
        sample.pid = tidq->pid;
        sample.tid = tidq->tid;
        sample.addr = cs_etm__first_executed_instr(tidq->packet);
        sample.id = etmq->etm->branches_id;
        sample.stream_id = etmq->etm->branches_id;
        sample.period = 1;
        sample.cpu = tidq->packet->cpu;
        sample.flags = tidq->prev_packet->flags;
        sample.cpumode = event->sample.header.misc;

        cs_etm__copy_insn(etmq, tidq->trace_chan_id, tidq->prev_packet,
                          &sample);

        /*
         * perf report cannot handle events without a branch stack
         */
        if (etm->synth_opts.last_branch) {
                dummy_bs = (struct dummy_branch_stack){
                        .nr = 1,
                        .hw_idx = -1ULL,
                        .entries = {
                                .from = sample.ip,
                                .to = sample.addr,
                        },
                };
                sample.branch_stack = (struct branch_stack *)&dummy_bs;
        }

        if (etm->synth_opts.inject) {
                ret = cs_etm__inject_event(event, &sample,
                                           etm->branches_sample_type);
                if (ret)
                        return ret;
        }

        ret = perf_session__deliver_synth_event(etm->session, event, &sample);

        if (ret)
                pr_err(
                "CS ETM Trace: failed to deliver instruction event, error %d\n",
                ret);

        return ret;
}

struct cs_etm_synth {
        struct perf_tool dummy_tool;
        struct perf_session *session;
};

static int cs_etm__event_synth(struct perf_tool *tool,
                               union perf_event *event,
                               struct perf_sample *sample __maybe_unused,
                               struct machine *machine __maybe_unused)
{
        struct cs_etm_synth *cs_etm_synth =
                      container_of(tool, struct cs_etm_synth, dummy_tool);

        return perf_session__deliver_synth_event(cs_etm_synth->session,
                                                 event, NULL);
}

static int cs_etm__synth_event(struct perf_session *session,
                               struct perf_event_attr *attr, u64 id)
{
        struct cs_etm_synth cs_etm_synth;

        memset(&cs_etm_synth, 0, sizeof(struct cs_etm_synth));
        cs_etm_synth.session = session;

        return perf_event__synthesize_attr(&cs_etm_synth.dummy_tool, attr, 1,
                                           &id, cs_etm__event_synth);
}

static int cs_etm__synth_events(struct cs_etm_auxtrace *etm,
                                struct perf_session *session)
{
        struct evlist *evlist = session->evlist;
        struct evsel *evsel;
        struct perf_event_attr attr;
        bool found = false;
        u64 id;
        int err;

        evlist__for_each_entry(evlist, evsel) {
                if (evsel->core.attr.type == etm->pmu_type) {
                        found = true;
                        break;
                }
        }

        if (!found) {
                pr_debug("No selected events with CoreSight Trace data\n");
                return 0;
        }

        memset(&attr, 0, sizeof(struct perf_event_attr));
        attr.size = sizeof(struct perf_event_attr);
        attr.type = PERF_TYPE_HARDWARE;
        attr.sample_type = evsel->core.attr.sample_type & PERF_SAMPLE_MASK;
        attr.sample_type |= PERF_SAMPLE_IP | PERF_SAMPLE_TID |
                            PERF_SAMPLE_PERIOD;
        if (etm->timeless_decoding)
                attr.sample_type &= ~(u64)PERF_SAMPLE_TIME;
        else
                attr.sample_type |= PERF_SAMPLE_TIME;

        attr.exclude_user = evsel->core.attr.exclude_user;
        attr.exclude_kernel = evsel->core.attr.exclude_kernel;
        attr.exclude_hv = evsel->core.attr.exclude_hv;
        attr.exclude_host = evsel->core.attr.exclude_host;
        attr.exclude_guest = evsel->core.attr.exclude_guest;
        attr.sample_id_all = evsel->core.attr.sample_id_all;
        attr.read_format = evsel->core.attr.read_format;

        /* create new id val to be a fixed offset from evsel id */
        id = evsel->core.id[0] + 1000000000;

        if (!id)
                id = 1;

        if (etm->synth_opts.branches) {
                attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS;
                attr.sample_period = 1;
                attr.sample_type |= PERF_SAMPLE_ADDR;
                err = cs_etm__synth_event(session, &attr, id);
                if (err)
                        return err;
                etm->sample_branches = true;
                etm->branches_sample_type = attr.sample_type;
                etm->branches_id = id;
                id += 1;
                attr.sample_type &= ~(u64)PERF_SAMPLE_ADDR;
        }

        if (etm->synth_opts.last_branch)
                attr.sample_type |= PERF_SAMPLE_BRANCH_STACK;

        if (etm->synth_opts.instructions) {
                attr.config = PERF_COUNT_HW_INSTRUCTIONS;
                attr.sample_period = etm->synth_opts.period;
                etm->instructions_sample_period = attr.sample_period;
                err = cs_etm__synth_event(session, &attr, id);
                if (err)
                        return err;
                etm->sample_instructions = true;
                etm->instructions_sample_type = attr.sample_type;
                etm->instructions_id = id;
                id += 1;
        }

        return 0;
}

static int cs_etm__sample(struct cs_etm_queue *etmq,
                          struct cs_etm_traceid_queue *tidq)
{
        struct cs_etm_auxtrace *etm = etmq->etm;
        int ret;
        u8 trace_chan_id = tidq->trace_chan_id;
        u64 instrs_prev;

        /* Get instructions remainder from previous packet */
        instrs_prev = tidq->period_instructions;

        tidq->period_instructions += tidq->packet->instr_count;

        /*
         * Record a branch when the last instruction in
         * PREV_PACKET is a branch.
         */
        if (etm->synth_opts.last_branch &&
            tidq->prev_packet->sample_type == CS_ETM_RANGE &&
            tidq->prev_packet->last_instr_taken_branch)
                cs_etm__update_last_branch_rb(etmq, tidq);

        if (etm->sample_instructions &&
            tidq->period_instructions >= etm->instructions_sample_period) {
                /*
                 * Emit instruction sample periodically
                 * TODO: allow period to be defined in cycles and clock time
                 */

                /*
                 * Below diagram demonstrates the instruction samples
                 * generation flows:
                 *
                 *    Instrs     Instrs       Instrs       Instrs
                 *   Sample(n)  Sample(n+1)  Sample(n+2)  Sample(n+3)
                 *    |            |            |            |
                 *    V            V            V            V
                 *   --------------------------------------------------
                 *            ^                                  ^
                 *            |                                  |
                 *         Period                             Period
                 *    instructions(Pi)                   instructions(Pi')
                 *
                 *            |                                  |
                 *            \---------------- -----------------/
                 *                             V
                 *                 tidq->packet->instr_count
                 *
                 * Instrs Sample(n...) are the synthesised samples occurring
                 * every etm->instructions_sample_period instructions - as
                 * defined on the perf command line.  Sample(n) is being the
                 * last sample before the current etm packet, n+1 to n+3
                 * samples are generated from the current etm packet.
                 *
                 * tidq->packet->instr_count represents the number of
                 * instructions in the current etm packet.
                 *
                 * Period instructions (Pi) contains the the number of
                 * instructions executed after the sample point(n) from the
                 * previous etm packet.  This will always be less than
                 * etm->instructions_sample_period.
                 *
                 * When generate new samples, it combines with two parts
                 * instructions, one is the tail of the old packet and another
                 * is the head of the new coming packet, to generate
                 * sample(n+1); sample(n+2) and sample(n+3) consume the
                 * instructions with sample period.  After sample(n+3), the rest
                 * instructions will be used by later packet and it is assigned
                 * to tidq->period_instructions for next round calculation.
                 */

                /*
                 * Get the initial offset into the current packet instructions;
                 * entry conditions ensure that instrs_prev is less than
                 * etm->instructions_sample_period.
                 */
                u64 offset = etm->instructions_sample_period - instrs_prev;
                u64 addr;

                /* Prepare last branches for instruction sample */
                if (etm->synth_opts.last_branch)
                        cs_etm__copy_last_branch_rb(etmq, tidq);

                while (tidq->period_instructions >=
                                etm->instructions_sample_period) {
                        /*
                         * Calculate the address of the sampled instruction (-1
                         * as sample is reported as though instruction has just
                         * been executed, but PC has not advanced to next
                         * instruction)
                         */
                        addr = cs_etm__instr_addr(etmq, trace_chan_id,
                                                  tidq->packet, offset - 1);
                        ret = cs_etm__synth_instruction_sample(
                                etmq, tidq, addr,
                                etm->instructions_sample_period);
                        if (ret)
                                return ret;

                        offset += etm->instructions_sample_period;
                        tidq->period_instructions -=
                                etm->instructions_sample_period;
                }
        }

        if (etm->sample_branches) {
                bool generate_sample = false;

                /* Generate sample for tracing on packet */
                if (tidq->prev_packet->sample_type == CS_ETM_DISCONTINUITY)
                        generate_sample = true;

                /* Generate sample for branch taken packet */
                if (tidq->prev_packet->sample_type == CS_ETM_RANGE &&
                    tidq->prev_packet->last_instr_taken_branch)
                        generate_sample = true;

                if (generate_sample) {
                        ret = cs_etm__synth_branch_sample(etmq, tidq);
                        if (ret)
                                return ret;
                }
        }

        cs_etm__packet_swap(etm, tidq);

        return 0;
}

static int cs_etm__exception(struct cs_etm_traceid_queue *tidq)
{
        /*
         * When the exception packet is inserted, whether the last instruction
         * in previous range packet is taken branch or not, we need to force
         * to set 'prev_packet->last_instr_taken_branch' to true.  This ensures
         * to generate branch sample for the instruction range before the
         * exception is trapped to kernel or before the exception returning.
         *
         * The exception packet includes the dummy address values, so don't
         * swap PACKET with PREV_PACKET.  This keeps PREV_PACKET to be useful
         * for generating instruction and branch samples.
         */
        if (tidq->prev_packet->sample_type == CS_ETM_RANGE)
                tidq->prev_packet->last_instr_taken_branch = true;

        return 0;
}

static int cs_etm__flush(struct cs_etm_queue *etmq,
                         struct cs_etm_traceid_queue *tidq)
{
        int err = 0;
        struct cs_etm_auxtrace *etm = etmq->etm;

        /* Handle start tracing packet */
        if (tidq->prev_packet->sample_type == CS_ETM_EMPTY)
                goto swap_packet;

        if (etmq->etm->synth_opts.last_branch &&
            tidq->prev_packet->sample_type == CS_ETM_RANGE) {
                u64 addr;

                /* Prepare last branches for instruction sample */
                cs_etm__copy_last_branch_rb(etmq, tidq);

                /*
                 * Generate a last branch event for the branches left in the
                 * circular buffer at the end of the trace.
                 *
                 * Use the address of the end of the last reported execution
                 * range
                 */
                addr = cs_etm__last_executed_instr(tidq->prev_packet);

                err = cs_etm__synth_instruction_sample(
                        etmq, tidq, addr,
                        tidq->period_instructions);
                if (err)
                        return err;

                tidq->period_instructions = 0;

        }

        if (etm->sample_branches &&
            tidq->prev_packet->sample_type == CS_ETM_RANGE) {
                err = cs_etm__synth_branch_sample(etmq, tidq);
                if (err)
                        return err;
        }

swap_packet:
        cs_etm__packet_swap(etm, tidq);

        /* Reset last branches after flush the trace */
        if (etm->synth_opts.last_branch)
                cs_etm__reset_last_branch_rb(tidq);

        return err;
}

static int cs_etm__end_block(struct cs_etm_queue *etmq,
                             struct cs_etm_traceid_queue *tidq)
{
        int err;

        /*
         * It has no new packet coming and 'etmq->packet' contains the stale
         * packet which was set at the previous time with packets swapping;
         * so skip to generate branch sample to avoid stale packet.
         *
         * For this case only flush branch stack and generate a last branch
         * event for the branches left in the circular buffer at the end of
         * the trace.
         */
        if (etmq->etm->synth_opts.last_branch &&
            tidq->prev_packet->sample_type == CS_ETM_RANGE) {
                u64 addr;

                /* Prepare last branches for instruction sample */
                cs_etm__copy_last_branch_rb(etmq, tidq);

                /*
                 * Use the address of the end of the last reported execution
                 * range.
                 */
                addr = cs_etm__last_executed_instr(tidq->prev_packet);

                err = cs_etm__synth_instruction_sample(
                        etmq, tidq, addr,
                        tidq->period_instructions);
                if (err)
                        return err;

                tidq->period_instructions = 0;
        }

        return 0;
}
/*
 * cs_etm__get_data_block: Fetch a block from the auxtrace_buffer queue
 *                         if need be.
 * Returns:     < 0     if error
 *              = 0     if no more auxtrace_buffer to read
 *              > 0     if the current buffer isn't empty yet
 */
static int cs_etm__get_data_block(struct cs_etm_queue *etmq)
{
        int ret;

        if (!etmq->buf_len) {
                ret = cs_etm__get_trace(etmq);
                if (ret <= 0)
                        return ret;
                /*
                 * We cannot assume consecutive blocks in the data file
                 * are contiguous, reset the decoder to force re-sync.
                 */
                ret = cs_etm_decoder__reset(etmq->decoder);
                if (ret)
                        return ret;
        }

        return etmq->buf_len;
}

static bool cs_etm__is_svc_instr(struct cs_etm_queue *etmq, u8 trace_chan_id,
                                 struct cs_etm_packet *packet,
                                 u64 end_addr)
{
        /* Initialise to keep compiler happy */
        u16 instr16 = 0;
        u32 instr32 = 0;
        u64 addr;

        switch (packet->isa) {
        case CS_ETM_ISA_T32:
                /*
                 * The SVC of T32 is defined in ARM DDI 0487D.a, F5.1.247:
                 *
                 *  b'15         b'8
                 * +-----------------+--------+
                 * | 1 1 0 1 1 1 1 1 |  imm8  |
                 * +-----------------+--------+
                 *
                 * According to the specifiction, it only defines SVC for T32
                 * with 16 bits instruction and has no definition for 32bits;
                 * so below only read 2 bytes as instruction size for T32.
                 */
                addr = end_addr - 2;
                cs_etm__mem_access(etmq, trace_chan_id, addr,
                                   sizeof(instr16), (u8 *)&instr16);
                if ((instr16 & 0xFF00) == 0xDF00)
                        return true;

                break;
        case CS_ETM_ISA_A32:
                /*
                 * The SVC of A32 is defined in ARM DDI 0487D.a, F5.1.247:
                 *
                 *  b'31 b'28 b'27 b'24
                 * +---------+---------+-------------------------+
                 * |  !1111  | 1 1 1 1 |        imm24            |
                 * +---------+---------+-------------------------+
                 */
                addr = end_addr - 4;
                cs_etm__mem_access(etmq, trace_chan_id, addr,
                                   sizeof(instr32), (u8 *)&instr32);
                if ((instr32 & 0x0F000000) == 0x0F000000 &&
                    (instr32 & 0xF0000000) != 0xF0000000)
                        return true;

                break;
        case CS_ETM_ISA_A64:
                /*
                 * The SVC of A64 is defined in ARM DDI 0487D.a, C6.2.294:
                 *
                 *  b'31               b'21           b'4     b'0
                 * +-----------------------+---------+-----------+
                 * | 1 1 0 1 0 1 0 0 0 0 0 |  imm16  | 0 0 0 0 1 |
                 * +-----------------------+---------+-----------+
                 */
                addr = end_addr - 4;
                cs_etm__mem_access(etmq, trace_chan_id, addr,
                                   sizeof(instr32), (u8 *)&instr32);
                if ((instr32 & 0xFFE0001F) == 0xd4000001)
                        return true;

                break;
        case CS_ETM_ISA_UNKNOWN:
        default:
                break;
        }

        return false;
}

static bool cs_etm__is_syscall(struct cs_etm_queue *etmq,
                               struct cs_etm_traceid_queue *tidq, u64 magic)
{
        u8 trace_chan_id = tidq->trace_chan_id;
        struct cs_etm_packet *packet = tidq->packet;
        struct cs_etm_packet *prev_packet = tidq->prev_packet;

        if (magic == __perf_cs_etmv3_magic)
                if (packet->exception_number == CS_ETMV3_EXC_SVC)
                        return true;

        /*
         * ETMv4 exception type CS_ETMV4_EXC_CALL covers SVC, SMC and
         * HVC cases; need to check if it's SVC instruction based on
         * packet address.
         */
        if (magic == __perf_cs_etmv4_magic) {
                if (packet->exception_number == CS_ETMV4_EXC_CALL &&
                    cs_etm__is_svc_instr(etmq, trace_chan_id, prev_packet,
                                         prev_packet->end_addr))
                        return true;
        }

        return false;
}

static bool cs_etm__is_async_exception(struct cs_etm_traceid_queue *tidq,
                                       u64 magic)
{
        struct cs_etm_packet *packet = tidq->packet;

        if (magic == __perf_cs_etmv3_magic)
                if (packet->exception_number == CS_ETMV3_EXC_DEBUG_HALT ||
                    packet->exception_number == CS_ETMV3_EXC_ASYNC_DATA_ABORT ||
                    packet->exception_number == CS_ETMV3_EXC_PE_RESET ||
                    packet->exception_number == CS_ETMV3_EXC_IRQ ||
                    packet->exception_number == CS_ETMV3_EXC_FIQ)
                        return true;

        if (magic == __perf_cs_etmv4_magic)
                if (packet->exception_number == CS_ETMV4_EXC_RESET ||
                    packet->exception_number == CS_ETMV4_EXC_DEBUG_HALT ||
                    packet->exception_number == CS_ETMV4_EXC_SYSTEM_ERROR ||
                    packet->exception_number == CS_ETMV4_EXC_INST_DEBUG ||
                    packet->exception_number == CS_ETMV4_EXC_DATA_DEBUG ||
                    packet->exception_number == CS_ETMV4_EXC_IRQ ||
                    packet->exception_number == CS_ETMV4_EXC_FIQ)
                        return true;

        return false;
}

static bool cs_etm__is_sync_exception(struct cs_etm_queue *etmq,
                                      struct cs_etm_traceid_queue *tidq,
                                      u64 magic)
{
        u8 trace_chan_id = tidq->trace_chan_id;
        struct cs_etm_packet *packet = tidq->packet;
        struct cs_etm_packet *prev_packet = tidq->prev_packet;

        if (magic == __perf_cs_etmv3_magic)
                if (packet->exception_number == CS_ETMV3_EXC_SMC ||
                    packet->exception_number == CS_ETMV3_EXC_HYP ||
                    packet->exception_number == CS_ETMV3_EXC_JAZELLE_THUMBEE ||
                    packet->exception_number == CS_ETMV3_EXC_UNDEFINED_INSTR ||
                    packet->exception_number == CS_ETMV3_EXC_PREFETCH_ABORT ||
                    packet->exception_number == CS_ETMV3_EXC_DATA_FAULT ||
                    packet->exception_number == CS_ETMV3_EXC_GENERIC)
                        return true;

        if (magic == __perf_cs_etmv4_magic) {
                if (packet->exception_number == CS_ETMV4_EXC_TRAP ||
                    packet->exception_number == CS_ETMV4_EXC_ALIGNMENT ||
                    packet->exception_number == CS_ETMV4_EXC_INST_FAULT ||
                    packet->exception_number == CS_ETMV4_EXC_DATA_FAULT)
                        return true;

                /*
                 * For CS_ETMV4_EXC_CALL, except SVC other instructions
                 * (SMC, HVC) are taken as sync exceptions.
                 */
                if (packet->exception_number == CS_ETMV4_EXC_CALL &&
                    !cs_etm__is_svc_instr(etmq, trace_chan_id, prev_packet,
                                          prev_packet->end_addr))
                        return true;

                /*
                 * ETMv4 has 5 bits for exception number; if the numbers
                 * are in the range ( CS_ETMV4_EXC_FIQ, CS_ETMV4_EXC_END ]
                 * they are implementation defined exceptions.
                 *
                 * For this case, simply take it as sync exception.
                 */
                if (packet->exception_number > CS_ETMV4_EXC_FIQ &&
                    packet->exception_number <= CS_ETMV4_EXC_END)
                        return true;
        }

        return false;
}

static int cs_etm__set_sample_flags(struct cs_etm_queue *etmq,
                                    struct cs_etm_traceid_queue *tidq)
{
        struct cs_etm_packet *packet = tidq->packet;
        struct cs_etm_packet *prev_packet = tidq->prev_packet;
        u8 trace_chan_id = tidq->trace_chan_id;
        u64 magic;
        int ret;

        switch (packet->sample_type) {
        case CS_ETM_RANGE:
                /*
                 * Immediate branch instruction without neither link nor
                 * return flag, it's normal branch instruction within
                 * the function.
                 */
                if (packet->last_instr_type == OCSD_INSTR_BR &&
                    packet->last_instr_subtype == OCSD_S_INSTR_NONE) {
                        packet->flags = PERF_IP_FLAG_BRANCH;

                        if (packet->last_instr_cond)
                                packet->flags |= PERF_IP_FLAG_CONDITIONAL;
                }

                /*
                 * Immediate branch instruction with link (e.g. BL), this is
                 * branch instruction for function call.
                 */
                if (packet->last_instr_type == OCSD_INSTR_BR &&
                    packet->last_instr_subtype == OCSD_S_INSTR_BR_LINK)
                        packet->flags = PERF_IP_FLAG_BRANCH |
                                        PERF_IP_FLAG_CALL;

                /*
                 * Indirect branch instruction with link (e.g. BLR), this is
                 * branch instruction for function call.
                 */
                if (packet->last_instr_type == OCSD_INSTR_BR_INDIRECT &&
                    packet->last_instr_subtype == OCSD_S_INSTR_BR_LINK)
                        packet->flags = PERF_IP_FLAG_BRANCH |
                                        PERF_IP_FLAG_CALL;

                /*
                 * Indirect branch instruction with subtype of
                 * OCSD_S_INSTR_V7_IMPLIED_RET, this is explicit hint for
                 * function return for A32/T32.
                 */
                if (packet->last_instr_type == OCSD_INSTR_BR_INDIRECT &&
                    packet->last_instr_subtype == OCSD_S_INSTR_V7_IMPLIED_RET)
                        packet->flags = PERF_IP_FLAG_BRANCH |
                                        PERF_IP_FLAG_RETURN;

                /*
                 * Indirect branch instruction without link (e.g. BR), usually
                 * this is used for function return, especially for functions
                 * within dynamic link lib.
                 */
                if (packet->last_instr_type == OCSD_INSTR_BR_INDIRECT &&
                    packet->last_instr_subtype == OCSD_S_INSTR_NONE)
                        packet->flags = PERF_IP_FLAG_BRANCH |
                                        PERF_IP_FLAG_RETURN;

                /* Return instruction for function return. */
                if (packet->last_instr_type == OCSD_INSTR_BR_INDIRECT &&
                    packet->last_instr_subtype == OCSD_S_INSTR_V8_RET)
                        packet->flags = PERF_IP_FLAG_BRANCH |
                                        PERF_IP_FLAG_RETURN;

                /*
                 * Decoder might insert a discontinuity in the middle of
                 * instruction packets, fixup prev_packet with flag
                 * PERF_IP_FLAG_TRACE_BEGIN to indicate restarting trace.
                 */
                if (prev_packet->sample_type == CS_ETM_DISCONTINUITY)
                        prev_packet->flags |= PERF_IP_FLAG_BRANCH |
                                              PERF_IP_FLAG_TRACE_BEGIN;

                /*
                 * If the previous packet is an exception return packet
                 * and the return address just follows SVC instuction,
                 * it needs to calibrate the previous packet sample flags
                 * as PERF_IP_FLAG_SYSCALLRET.
                 */
                if (prev_packet->flags == (PERF_IP_FLAG_BRANCH |
                                           PERF_IP_FLAG_RETURN |
                                           PERF_IP_FLAG_INTERRUPT) &&
                    cs_etm__is_svc_instr(etmq, trace_chan_id,
                                         packet, packet->start_addr))
                        prev_packet->flags = PERF_IP_FLAG_BRANCH |
                                             PERF_IP_FLAG_RETURN |
                                             PERF_IP_FLAG_SYSCALLRET;
                break;
        case CS_ETM_DISCONTINUITY:
                /*
                 * The trace is discontinuous, if the previous packet is
                 * instruction packet, set flag PERF_IP_FLAG_TRACE_END
                 * for previous packet.
                 */
                if (prev_packet->sample_type == CS_ETM_RANGE)
                        prev_packet->flags |= PERF_IP_FLAG_BRANCH |
                                              PERF_IP_FLAG_TRACE_END;
                break;
        case CS_ETM_EXCEPTION:
                ret = cs_etm__get_magic(packet->trace_chan_id, &magic);
                if (ret)
                        return ret;

                /* The exception is for system call. */
                if (cs_etm__is_syscall(etmq, tidq, magic))
                        packet->flags = PERF_IP_FLAG_BRANCH |
                                        PERF_IP_FLAG_CALL |
                                        PERF_IP_FLAG_SYSCALLRET;
                /*
                 * The exceptions are triggered by external signals from bus,
                 * interrupt controller, debug module, PE reset or halt.
                 */
                else if (cs_etm__is_async_exception(tidq, magic))
                        packet->flags = PERF_IP_FLAG_BRANCH |
                                        PERF_IP_FLAG_CALL |
                                        PERF_IP_FLAG_ASYNC |
                                        PERF_IP_FLAG_INTERRUPT;
                /*
                 * Otherwise, exception is caused by trap, instruction &
                 * data fault, or alignment errors.
                 */
                else if (cs_etm__is_sync_exception(etmq, tidq, magic))
                        packet->flags = PERF_IP_FLAG_BRANCH |
                                        PERF_IP_FLAG_CALL |
                                        PERF_IP_FLAG_INTERRUPT;

                /*
                 * When the exception packet is inserted, since exception
                 * packet is not used standalone for generating samples
                 * and it's affiliation to the previous instruction range
                 * packet; so set previous range packet flags to tell perf
                 * it is an exception taken branch.
                 */
                if (prev_packet->sample_type == CS_ETM_RANGE)
                        prev_packet->flags = packet->flags;
                break;
        case CS_ETM_EXCEPTION_RET:
                /*
                 * When the exception return packet is inserted, since
                 * exception return packet is not used standalone for
                 * generating samples and it's affiliation to the previous
                 * instruction range packet; so set previous range packet
                 * flags to tell perf it is an exception return branch.
                 *
                 * The exception return can be for either system call or
                 * other exception types; unfortunately the packet doesn't
                 * contain exception type related info so we cannot decide
                 * the exception type purely based on exception return packet.
                 * If we record the exception number from exception packet and
                 * reuse it for excpetion return packet, this is not reliable
                 * due the trace can be discontinuity or the interrupt can
                 * be nested, thus the recorded exception number cannot be
                 * used for exception return packet for these two cases.
                 *
                 * For exception return packet, we only need to distinguish the
                 * packet is for system call or for other types.  Thus the
                 * decision can be deferred when receive the next packet which
                 * contains the return address, based on the return address we
                 * can read out the previous instruction and check if it's a
                 * system call instruction and then calibrate the sample flag
                 * as needed.
                 */
                if (prev_packet->sample_type == CS_ETM_RANGE)
                        prev_packet->flags = PERF_IP_FLAG_BRANCH |
                                             PERF_IP_FLAG_RETURN |
                                             PERF_IP_FLAG_INTERRUPT;
                break;
        case CS_ETM_EMPTY:
        default:
                break;
        }

        return 0;
}

static int cs_etm__decode_data_block(struct cs_etm_queue *etmq)
{
        int ret = 0;
        size_t processed = 0;

        /*
         * Packets are decoded and added to the decoder's packet queue
         * until the decoder packet processing callback has requested that
         * processing stops or there is nothing left in the buffer.  Normal
         * operations that stop processing are a timestamp packet or a full
         * decoder buffer queue.
         */
        ret = cs_etm_decoder__process_data_block(etmq->decoder,
                                                 etmq->offset,
                                                 &etmq->buf[etmq->buf_used],
                                                 etmq->buf_len,
                                                 &processed);
        if (ret)
                goto out;

        etmq->offset += processed;
        etmq->buf_used += processed;
        etmq->buf_len -= processed;

out:
        return ret;
}

static int cs_etm__process_traceid_queue(struct cs_etm_queue *etmq,
                                         struct cs_etm_traceid_queue *tidq)
{
        int ret;
        struct cs_etm_packet_queue *packet_queue;

        packet_queue = &tidq->packet_queue;

        /* Process each packet in this chunk */
        while (1) {
                ret = cs_etm_decoder__get_packet(packet_queue,
                                                 tidq->packet);
                if (ret <= 0)
                        /*
                         * Stop processing this chunk on
                         * end of data or error
                         */
                        break;

                /*
                 * Since packet addresses are swapped in packet
                 * handling within below switch() statements,
                 * thus setting sample flags must be called
                 * prior to switch() statement to use address
                 * information before packets swapping.
                 */
                ret = cs_etm__set_sample_flags(etmq, tidq);
                if (ret < 0)
                        break;

                switch (tidq->packet->sample_type) {
                case CS_ETM_RANGE:
                        /*
                         * If the packet contains an instruction
                         * range, generate instruction sequence
                         * events.
                         */
                        cs_etm__sample(etmq, tidq);
                        break;
                case CS_ETM_EXCEPTION:
                case CS_ETM_EXCEPTION_RET:
                        /*
                         * If the exception packet is coming,
                         * make sure the previous instruction
                         * range packet to be handled properly.
                         */
                        cs_etm__exception(tidq);
                        break;
                case CS_ETM_DISCONTINUITY:
                        /*
                         * Discontinuity in trace, flush
                         * previous branch stack
                         */
                        cs_etm__flush(etmq, tidq);
                        break;
                case CS_ETM_EMPTY:
                        /*
                         * Should not receive empty packet,
                         * report error.
                         */
                        pr_err("CS ETM Trace: empty packet\n");
                        return -EINVAL;
                default:
                        break;
                }
        }

        return ret;
}

static void cs_etm__clear_all_traceid_queues(struct cs_etm_queue *etmq)
{
        int idx;
        struct int_node *inode;
        struct cs_etm_traceid_queue *tidq;
        struct intlist *traceid_queues_list = etmq->traceid_queues_list;

        intlist__for_each_entry(inode, traceid_queues_list) {
                idx = (int)(intptr_t)inode->priv;
                tidq = etmq->traceid_queues[idx];

                /* Ignore return value */
                cs_etm__process_traceid_queue(etmq, tidq);

                /*
                 * Generate an instruction sample with the remaining
                 * branchstack entries.
                 */
                cs_etm__flush(etmq, tidq);
        }
}

static int cs_etm__run_decoder(struct cs_etm_queue *etmq)
{
        int err = 0;
        struct cs_etm_traceid_queue *tidq;

        tidq = cs_etm__etmq_get_traceid_queue(etmq, CS_ETM_PER_THREAD_TRACEID);
        if (!tidq)
                return -EINVAL;

        /* Go through each buffer in the queue and decode them one by one */
        while (1) {
                err = cs_etm__get_data_block(etmq);
                if (err <= 0)
                        return err;

                /* Run trace decoder until buffer consumed or end of trace */
                do {
                        err = cs_etm__decode_data_block(etmq);
                        if (err)
                                return err;

                        /*
                         * Process each packet in this chunk, nothing to do if
                         * an error occurs other than hoping the next one will
                         * be better.
                         */
                        err = cs_etm__process_traceid_queue(etmq, tidq);

                } while (etmq->buf_len);

                if (err == 0)
                        /* Flush any remaining branch stack entries */
                        err = cs_etm__end_block(etmq, tidq);
        }

        return err;
}

static int cs_etm__process_timeless_queues(struct cs_etm_auxtrace *etm,
                                           pid_t tid)
{
        unsigned int i;
        struct auxtrace_queues *queues = &etm->queues;

        for (i = 0; i < queues->nr_queues; i++) {
                struct auxtrace_queue *queue = &etm->queues.queue_array[i];
                struct cs_etm_queue *etmq = queue->priv;
                struct cs_etm_traceid_queue *tidq;

                if (!etmq)
                        continue;

                tidq = cs_etm__etmq_get_traceid_queue(etmq,
                                                CS_ETM_PER_THREAD_TRACEID);

                if (!tidq)
                        continue;

                if ((tid == -1) || (tidq->tid == tid)) {
                        cs_etm__set_pid_tid_cpu(etm, tidq);
                        cs_etm__run_decoder(etmq);
                }
        }

        return 0;
}

static int cs_etm__process_queues(struct cs_etm_auxtrace *etm)
{
        int ret = 0;
        unsigned int cs_queue_nr, queue_nr;
        u8 trace_chan_id;
        u64 timestamp;
        struct auxtrace_queue *queue;
        struct cs_etm_queue *etmq;
        struct cs_etm_traceid_queue *tidq;

        while (1) {
                if (!etm->heap.heap_cnt)
                        goto out;

                /* Take the entry at the top of the min heap */
                cs_queue_nr = etm->heap.heap_array[0].queue_nr;
                queue_nr = TO_QUEUE_NR(cs_queue_nr);
                trace_chan_id = TO_TRACE_CHAN_ID(cs_queue_nr);
                queue = &etm->queues.queue_array[queue_nr];
                etmq = queue->priv;

                /*
                 * Remove the top entry from the heap since we are about
                 * to process it.
                 */
                auxtrace_heap__pop(&etm->heap);

                tidq  = cs_etm__etmq_get_traceid_queue(etmq, trace_chan_id);
                if (!tidq) {
                        /*
                         * No traceID queue has been allocated for this traceID,
                         * which means something somewhere went very wrong.  No
                         * other choice than simply exit.
                         */
                        ret = -EINVAL;
                        goto out;
                }

                /*
                 * Packets associated with this timestamp are already in
                 * the etmq's traceID queue, so process them.
                 */
                ret = cs_etm__process_traceid_queue(etmq, tidq);
                if (ret < 0)
                        goto out;

                /*
                 * Packets for this timestamp have been processed, time to
                 * move on to the next timestamp, fetching a new auxtrace_buffer
                 * if need be.
                 */
refetch:
                ret = cs_etm__get_data_block(etmq);
                if (ret < 0)
                        goto out;

                /*
                 * No more auxtrace_buffers to process in this etmq, simply
                 * move on to another entry in the auxtrace_heap.
                 */
                if (!ret)
                        continue;

                ret = cs_etm__decode_data_block(etmq);
                if (ret)
                        goto out;

                timestamp = cs_etm__etmq_get_timestamp(etmq, &trace_chan_id);

                if (!timestamp) {
                        /*
                         * Function cs_etm__decode_data_block() returns when
                         * there is no more traces to decode in the current
                         * auxtrace_buffer OR when a timestamp has been
                         * encountered on any of the traceID queues.  Since we
                         * did not get a timestamp, there is no more traces to
                         * process in this auxtrace_buffer.  As such empty and
                         * flush all traceID queues.
                         */
                        cs_etm__clear_all_traceid_queues(etmq);

                        /* Fetch another auxtrace_buffer for this etmq */
                        goto refetch;
                }

                /*
                 * Add to the min heap the timestamp for packets that have
                 * just been decoded.  They will be processed and synthesized
                 * during the next call to cs_etm__process_traceid_queue() for
                 * this queue/traceID.
                 */
                cs_queue_nr = TO_CS_QUEUE_NR(queue_nr, trace_chan_id);
                ret = auxtrace_heap__add(&etm->heap, cs_queue_nr, timestamp);
        }

out:
        return ret;
}

static int cs_etm__process_itrace_start(struct cs_etm_auxtrace *etm,
                                        union perf_event *event)
{
        struct thread *th;

        if (etm->timeless_decoding)
                return 0;

        /*
         * Add the tid/pid to the log so that we can get a match when
         * we get a contextID from the decoder.
         */
        th = machine__findnew_thread(etm->machine,
                                     event->itrace_start.pid,
                                     event->itrace_start.tid);
        if (!th)
                return -ENOMEM;

        thread__put(th);

        return 0;
}

static int cs_etm__process_switch_cpu_wide(struct cs_etm_auxtrace *etm,
                                           union perf_event *event)
{
        struct thread *th;
        bool out = event->header.misc & PERF_RECORD_MISC_SWITCH_OUT;

        /*
         * Context switch in per-thread mode are irrelevant since perf
         * will start/stop tracing as the process is scheduled.
         */
        if (etm->timeless_decoding)
                return 0;

        /*
         * SWITCH_IN events carry the next process to be switched out while
         * SWITCH_OUT events carry the process to be switched in.  As such
         * we don't care about IN events.
         */
        if (!out)
                return 0;

        /*
         * Add the tid/pid to the log so that we can get a match when
         * we get a contextID from the decoder.
         */
        th = machine__findnew_thread(etm->machine,
                                     event->context_switch.next_prev_pid,
                                     event->context_switch.next_prev_tid);
        if (!th)
                return -ENOMEM;

        thread__put(th);

        return 0;
}

static int cs_etm__process_event(struct perf_session *session,
                                 union perf_event *event,
                                 struct perf_sample *sample,
                                 struct perf_tool *tool)
{
        int err = 0;
        u64 timestamp;
        struct cs_etm_auxtrace *etm = container_of(session->auxtrace,
                                                   struct cs_etm_auxtrace,
                                                   auxtrace);

        if (dump_trace)
                return 0;

        if (!tool->ordered_events) {
                pr_err("CoreSight ETM Trace requires ordered events\n");
                return -EINVAL;
        }

        if (sample->time && (sample->time != (u64) -1))
                timestamp = sample->time;
        else
                timestamp = 0;

        if (timestamp || etm->timeless_decoding) {
                err = cs_etm__update_queues(etm);
                if (err)
                        return err;
        }

        if (etm->timeless_decoding &&
            event->header.type == PERF_RECORD_EXIT)
                return cs_etm__process_timeless_queues(etm,
                                                       event->fork.tid);

        if (event->header.type == PERF_RECORD_ITRACE_START)
                return cs_etm__process_itrace_start(etm, event);
        else if (event->header.type == PERF_RECORD_SWITCH_CPU_WIDE)
                return cs_etm__process_switch_cpu_wide(etm, event);

        if (!etm->timeless_decoding &&
            event->header.type == PERF_RECORD_AUX)
                return cs_etm__process_queues(etm);

        return 0;
}

static int cs_etm__process_auxtrace_event(struct perf_session *session,
                                          union perf_event *event,
                                          struct perf_tool *tool __maybe_unused)
{
        struct cs_etm_auxtrace *etm = container_of(session->auxtrace,
                                                   struct cs_etm_auxtrace,
                                                   auxtrace);
        if (!etm->data_queued) {
                struct auxtrace_buffer *buffer;
                off_t  data_offset;
                int fd = perf_data__fd(session->data);
                bool is_pipe = perf_data__is_pipe(session->data);
                int err;

                if (is_pipe)
                        data_offset = 0;
                else {
                        data_offset = lseek(fd, 0, SEEK_CUR);
                        if (data_offset == -1)
                                return -errno;
                }

                err = auxtrace_queues__add_event(&etm->queues, session,
                                                 event, data_offset, &buffer);
                if (err)
                        return err;

                if (dump_trace)
                        if (auxtrace_buffer__get_data(buffer, fd)) {
                                cs_etm__dump_event(etm, buffer);
                                auxtrace_buffer__put_data(buffer);
                        }
        }

        return 0;
}

static bool cs_etm__is_timeless_decoding(struct cs_etm_auxtrace *etm)
{
        struct evsel *evsel;
        struct evlist *evlist = etm->session->evlist;
        bool timeless_decoding = true;

        /*
         * Circle through the list of event and complain if we find one
         * with the time bit set.
         */
        evlist__for_each_entry(evlist, evsel) {
                if ((evsel->core.attr.sample_type & PERF_SAMPLE_TIME))
                        timeless_decoding = false;
        }

        return timeless_decoding;
}

static const char * const cs_etm_global_header_fmts[] = {
        [CS_HEADER_VERSION_0]   = "     Header version                 %llx\n",
        [CS_PMU_TYPE_CPUS]      = "     PMU type/num cpus              %llx\n",
        [CS_ETM_SNAPSHOT]       = "     Snapshot                       %llx\n",
};

static const char * const cs_etm_priv_fmts[] = {
        [CS_ETM_MAGIC]          = "     Magic number                   %llx\n",
        [CS_ETM_CPU]            = "     CPU                            %lld\n",
        [CS_ETM_ETMCR]          = "     ETMCR                          %llx\n",
        [CS_ETM_ETMTRACEIDR]    = "     ETMTRACEIDR                    %llx\n",
        [CS_ETM_ETMCCER]        = "     ETMCCER                        %llx\n",
        [CS_ETM_ETMIDR]         = "     ETMIDR                         %llx\n",
};

static const char * const cs_etmv4_priv_fmts[] = {
        [CS_ETM_MAGIC]          = "     Magic number                   %llx\n",
        [CS_ETM_CPU]            = "     CPU                            %lld\n",
        [CS_ETMV4_TRCCONFIGR]   = "     TRCCONFIGR                     %llx\n",
        [CS_ETMV4_TRCTRACEIDR]  = "     TRCTRACEIDR                    %llx\n",
        [CS_ETMV4_TRCIDR0]      = "     TRCIDR0                        %llx\n",
        [CS_ETMV4_TRCIDR1]      = "     TRCIDR1                        %llx\n",
        [CS_ETMV4_TRCIDR2]      = "     TRCIDR2                        %llx\n",
        [CS_ETMV4_TRCIDR8]      = "     TRCIDR8                        %llx\n",
        [CS_ETMV4_TRCAUTHSTATUS] = "    TRCAUTHSTATUS                  %llx\n",
};

static void cs_etm__print_auxtrace_info(__u64 *val, int num)
{
        int i, j, cpu = 0;

        for (i = 0; i < CS_HEADER_VERSION_0_MAX; i++)
                fprintf(stdout, cs_etm_global_header_fmts[i], val[i]);

        for (i = CS_HEADER_VERSION_0_MAX; cpu < num; cpu++) {
                if (val[i] == __perf_cs_etmv3_magic)
                        for (j = 0; j < CS_ETM_PRIV_MAX; j++, i++)
                                fprintf(stdout, cs_etm_priv_fmts[j], val[i]);
                else if (val[i] == __perf_cs_etmv4_magic)
                        for (j = 0; j < CS_ETMV4_PRIV_MAX; j++, i++)
                                fprintf(stdout, cs_etmv4_priv_fmts[j], val[i]);
                else
                        /* failure.. return */
                        return;
        }
}

int cs_etm__process_auxtrace_info(union perf_event *event,
                                  struct perf_session *session)
{
        struct perf_record_auxtrace_info *auxtrace_info = &event->auxtrace_info;
        struct cs_etm_auxtrace *etm = NULL;
        struct int_node *inode;
        unsigned int pmu_type;
        int event_header_size = sizeof(struct perf_event_header);
        int info_header_size;
        int total_size = auxtrace_info->header.size;
        int priv_size = 0;
        int num_cpu;
        int err = 0, idx = -1;
        int i, j, k;
        u64 *ptr, *hdr = NULL;
        u64 **metadata = NULL;

        /*
         * sizeof(auxtrace_info_event::type) +
         * sizeof(auxtrace_info_event::reserved) == 8
         */
        info_header_size = 8;

        if (total_size < (event_header_size + info_header_size))
                return -EINVAL;

        priv_size = total_size - event_header_size - info_header_size;

        /* First the global part */
        ptr = (u64 *) auxtrace_info->priv;

        /* Look for version '0' of the header */
        if (ptr[0] != 0)
                return -EINVAL;

        hdr = zalloc(sizeof(*hdr) * CS_HEADER_VERSION_0_MAX);
        if (!hdr)
                return -ENOMEM;

        /* Extract header information - see cs-etm.h for format */
        for (i = 0; i < CS_HEADER_VERSION_0_MAX; i++)
                hdr[i] = ptr[i];
        num_cpu = hdr[CS_PMU_TYPE_CPUS] & 0xffffffff;
        pmu_type = (unsigned int) ((hdr[CS_PMU_TYPE_CPUS] >> 32) &
                                    0xffffffff);

        /*
         * Create an RB tree for traceID-metadata tuple.  Since the conversion
         * has to be made for each packet that gets decoded, optimizing access
         * in anything other than a sequential array is worth doing.
         */
        traceid_list = intlist__new(NULL);
        if (!traceid_list) {
                err = -ENOMEM;
                goto err_free_hdr;
        }

        metadata = zalloc(sizeof(*metadata) * num_cpu);
        if (!metadata) {
                err = -ENOMEM;
                goto err_free_traceid_list;
        }

        /*
         * The metadata is stored in the auxtrace_info section and encodes
         * the configuration of the ARM embedded trace macrocell which is
         * required by the trace decoder to properly decode the trace due
         * to its highly compressed nature.
         */
        for (j = 0; j < num_cpu; j++) {
                if (ptr[i] == __perf_cs_etmv3_magic) {
                        metadata[j] = zalloc(sizeof(*metadata[j]) *
                                             CS_ETM_PRIV_MAX);
                        if (!metadata[j]) {
                                err = -ENOMEM;
                                goto err_free_metadata;
                        }
                        for (k = 0; k < CS_ETM_PRIV_MAX; k++)
                                metadata[j][k] = ptr[i + k];

                        /* The traceID is our handle */
                        idx = metadata[j][CS_ETM_ETMTRACEIDR];
                        i += CS_ETM_PRIV_MAX;
                } else if (ptr[i] == __perf_cs_etmv4_magic) {
                        metadata[j] = zalloc(sizeof(*metadata[j]) *
                                             CS_ETMV4_PRIV_MAX);
                        if (!metadata[j]) {
                                err = -ENOMEM;
                                goto err_free_metadata;
                        }
                        for (k = 0; k < CS_ETMV4_PRIV_MAX; k++)
                                metadata[j][k] = ptr[i + k];

                        /* The traceID is our handle */
                        idx = metadata[j][CS_ETMV4_TRCTRACEIDR];
                        i += CS_ETMV4_PRIV_MAX;
                }

                /* Get an RB node for this CPU */
                inode = intlist__findnew(traceid_list, idx);

                /* Something went wrong, no need to continue */
                if (!inode) {
                        err = -ENOMEM;
                        goto err_free_metadata;
                }

                /*
                 * The node for that CPU should not be taken.
                 * Back out if that's the case.
                 */
                if (inode->priv) {
                        err = -EINVAL;
                        goto err_free_metadata;
                }
                /* All good, associate the traceID with the metadata pointer */
                inode->priv = metadata[j];
        }

        /*
         * Each of CS_HEADER_VERSION_0_MAX, CS_ETM_PRIV_MAX and
         * CS_ETMV4_PRIV_MAX mark how many double words are in the
         * global metadata, and each cpu's metadata respectively.
         * The following tests if the correct number of double words was
         * present in the auxtrace info section.
         */
        if (i * 8 != priv_size) {
                err = -EINVAL;
                goto err_free_metadata;
        }

        etm = zalloc(sizeof(*etm));

        if (!etm) {
                err = -ENOMEM;
                goto err_free_metadata;
        }

        err = auxtrace_queues__init(&etm->queues);
        if (err)
                goto err_free_etm;

        etm->session = session;
        etm->machine = &session->machines.host;

        etm->num_cpu = num_cpu;
        etm->pmu_type = pmu_type;
        etm->snapshot_mode = (hdr[CS_ETM_SNAPSHOT] != 0);
        etm->metadata = metadata;
        etm->auxtrace_type = auxtrace_info->type;
        etm->timeless_decoding = cs_etm__is_timeless_decoding(etm);

        etm->auxtrace.process_event = cs_etm__process_event;
        etm->auxtrace.process_auxtrace_event = cs_etm__process_auxtrace_event;
        etm->auxtrace.flush_events = cs_etm__flush_events;
        etm->auxtrace.free_events = cs_etm__free_events;
        etm->auxtrace.free = cs_etm__free;
        etm->auxtrace.evsel_is_auxtrace = cs_etm__evsel_is_auxtrace;
        session->auxtrace = &etm->auxtrace;

        etm->unknown_thread = thread__new(999999999, 999999999);
        if (!etm->unknown_thread) {
                err = -ENOMEM;
                goto err_free_queues;
        }

        /*
         * Initialize list node so that at thread__zput() we can avoid
         * segmentation fault at list_del_init().
         */
        INIT_LIST_HEAD(&etm->unknown_thread->node);

        err = thread__set_comm(etm->unknown_thread, "unknown", 0);
        if (err)
                goto err_delete_thread;

        if (thread__init_maps(etm->unknown_thread, etm->machine)) {
                err = -ENOMEM;
                goto err_delete_thread;
        }

        if (dump_trace) {
                cs_etm__print_auxtrace_info(auxtrace_info->priv, num_cpu);
                return 0;
        }

        if (session->itrace_synth_opts->set) {
                etm->synth_opts = *session->itrace_synth_opts;
        } else {
                itrace_synth_opts__set_default(&etm->synth_opts,
                                session->itrace_synth_opts->default_no_sample);
                etm->synth_opts.callchain = false;
        }

        err = cs_etm__synth_events(etm, session);
        if (err)
                goto err_delete_thread;

        err = auxtrace_queues__process_index(&etm->queues, session);
        if (err)
                goto err_delete_thread;

        etm->data_queued = etm->queues.populated;

        return 0;

err_delete_thread:
        thread__zput(etm->unknown_thread);
err_free_queues:
        auxtrace_queues__free(&etm->queues);
        session->auxtrace = NULL;
err_free_etm:
        zfree(&etm);
err_free_metadata:
        /* No need to check @metadata[j], free(NULL) is supported */
        for (j = 0; j < num_cpu; j++)
                zfree(&metadata[j]);
        zfree(&metadata);
err_free_traceid_list:
        intlist__delete(traceid_list);
err_free_hdr:
        zfree(&hdr);

        return err;
}