// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
 */

#define _GNU_SOURCE
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <stdio.h>
#include <time.h>
#include <sched.h>
#include <pthread.h>

#include "timerlat.h"
#include "timerlat_aa.h"
#include "timerlat_bpf.h"

struct timerlat_hist_cpu {
        int                     *irq;
        int                     *thread;
        int                     *user;

        unsigned long long      irq_count;
        unsigned long long      thread_count;
        unsigned long long      user_count;

        unsigned long long      min_irq;
        unsigned long long      sum_irq;
        unsigned long long      max_irq;

        unsigned long long      min_thread;
        unsigned long long      sum_thread;
        unsigned long long      max_thread;

        unsigned long long      min_user;
        unsigned long long      sum_user;
        unsigned long long      max_user;
};

struct timerlat_hist_data {
        struct timerlat_hist_cpu        *hist;
        int                             entries;
        int                             bucket_size;
        int                             nr_cpus;
};

/*
 * timerlat_free_histogram - free runtime data
 */
static void
timerlat_free_histogram(struct timerlat_hist_data *data)
{
        int cpu;

        /* one histogram for IRQ and one for thread, per CPU */
        for (cpu = 0; cpu < data->nr_cpus; cpu++) {
                if (data->hist[cpu].irq)
                        free(data->hist[cpu].irq);

                if (data->hist[cpu].thread)
                        free(data->hist[cpu].thread);

                if (data->hist[cpu].user)
                        free(data->hist[cpu].user);

        }

        /* one set of histograms per CPU */
        if (data->hist)
                free(data->hist);
}

static void timerlat_free_histogram_tool(struct osnoise_tool *tool)
{
        timerlat_free_histogram(tool->data);
        timerlat_free(tool);
}

/*
 * timerlat_alloc_histogram - alloc runtime data
 */
static struct timerlat_hist_data
*timerlat_alloc_histogram(int nr_cpus, int entries, int bucket_size)
{
        struct timerlat_hist_data *data;
        int cpu;

        data = calloc(1, sizeof(*data));
        if (!data)
                return NULL;

        data->entries = entries;
        data->bucket_size = bucket_size;
        data->nr_cpus = nr_cpus;

        /* one set of histograms per CPU */
        data->hist = calloc(1, sizeof(*data->hist) * nr_cpus);
        if (!data->hist)
                goto cleanup;

        /* one histogram for IRQ and one for thread, per cpu */
        for (cpu = 0; cpu < nr_cpus; cpu++) {
                data->hist[cpu].irq = calloc(1, sizeof(*data->hist->irq) * (entries + 1));
                if (!data->hist[cpu].irq)
                        goto cleanup;

                data->hist[cpu].thread = calloc(1, sizeof(*data->hist->thread) * (entries + 1));
                if (!data->hist[cpu].thread)
                        goto cleanup;

                data->hist[cpu].user = calloc(1, sizeof(*data->hist->user) * (entries + 1));
                if (!data->hist[cpu].user)
                        goto cleanup;
        }

        /* set the min to max */
        for (cpu = 0; cpu < nr_cpus; cpu++) {
                data->hist[cpu].min_irq = ~0;
                data->hist[cpu].min_thread = ~0;
                data->hist[cpu].min_user = ~0;
        }

        return data;

cleanup:
        timerlat_free_histogram(data);
        return NULL;
}

/*
 * timerlat_hist_update - record a new timerlat occurent on cpu, updating data
 */
static void
timerlat_hist_update(struct osnoise_tool *tool, int cpu,
                     unsigned long long context,
                     unsigned long long latency)
{
        struct timerlat_params *params = to_timerlat_params(tool->params);
        struct timerlat_hist_data *data = tool->data;
        int entries = data->entries;
        int bucket;
        int *hist;

        if (params->common.output_divisor)
                latency = latency / params->common.output_divisor;

        bucket = latency / data->bucket_size;

        if (!context) {
                hist = data->hist[cpu].irq;
                data->hist[cpu].irq_count++;
                update_min(&data->hist[cpu].min_irq, &latency);
                update_sum(&data->hist[cpu].sum_irq, &latency);
                update_max(&data->hist[cpu].max_irq, &latency);
        } else if (context == 1) {
                hist = data->hist[cpu].thread;
                data->hist[cpu].thread_count++;
                update_min(&data->hist[cpu].min_thread, &latency);
                update_sum(&data->hist[cpu].sum_thread, &latency);
                update_max(&data->hist[cpu].max_thread, &latency);
        } else { /* user */
                hist = data->hist[cpu].user;
                data->hist[cpu].user_count++;
                update_min(&data->hist[cpu].min_user, &latency);
                update_sum(&data->hist[cpu].sum_user, &latency);
                update_max(&data->hist[cpu].max_user, &latency);
        }

        if (bucket < entries)
                hist[bucket]++;
        else
                hist[entries]++;
}

/*
 * timerlat_hist_handler - this is the handler for timerlat tracer events
 */
static int
timerlat_hist_handler(struct trace_seq *s, struct tep_record *record,
                     struct tep_event *event, void *data)
{
        struct trace_instance *trace = data;
        unsigned long long context, latency;
        struct osnoise_tool *tool;
        int cpu = record->cpu;

        tool = container_of(trace, struct osnoise_tool, trace);

        tep_get_field_val(s, event, "context", record, &context, 1);
        tep_get_field_val(s, event, "timer_latency", record, &latency, 1);

        timerlat_hist_update(tool, cpu, context, latency);

        return 0;
}

/*
 * timerlat_hist_bpf_pull_data - copy data from BPF maps into userspace
 */
static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
{
        struct timerlat_hist_data *data = tool->data;
        int i, j, err;
        long long value_irq[data->nr_cpus],
                  value_thread[data->nr_cpus],
                  value_user[data->nr_cpus];

        /* Pull histogram */
        for (i = 0; i < data->entries; i++) {
                err = timerlat_bpf_get_hist_value(i, value_irq, value_thread,
                                                  value_user, data->nr_cpus);
                if (err)
                        return err;
                for (j = 0; j < data->nr_cpus; j++) {
                        data->hist[j].irq[i] = value_irq[j];
                        data->hist[j].thread[i] = value_thread[j];
                        data->hist[j].user[i] = value_user[j];
                }
        }

        /* Pull summary */
        err = timerlat_bpf_get_summary_value(SUMMARY_COUNT,
                                             value_irq, value_thread, value_user,
                                             data->nr_cpus);
        if (err)
                return err;
        for (i = 0; i < data->nr_cpus; i++) {
                data->hist[i].irq_count = value_irq[i];
                data->hist[i].thread_count = value_thread[i];
                data->hist[i].user_count = value_user[i];
        }

        err = timerlat_bpf_get_summary_value(SUMMARY_MIN,
                                             value_irq, value_thread, value_user,
                                             data->nr_cpus);
        if (err)
                return err;
        for (i = 0; i < data->nr_cpus; i++) {
                data->hist[i].min_irq = value_irq[i];
                data->hist[i].min_thread = value_thread[i];
                data->hist[i].min_user = value_user[i];
        }

        err = timerlat_bpf_get_summary_value(SUMMARY_MAX,
                                             value_irq, value_thread, value_user,
                                             data->nr_cpus);
        if (err)
                return err;
        for (i = 0; i < data->nr_cpus; i++) {
                data->hist[i].max_irq = value_irq[i];
                data->hist[i].max_thread = value_thread[i];
                data->hist[i].max_user = value_user[i];
        }

        err = timerlat_bpf_get_summary_value(SUMMARY_SUM,
                                             value_irq, value_thread, value_user,
                                             data->nr_cpus);
        if (err)
                return err;
        for (i = 0; i < data->nr_cpus; i++) {
                data->hist[i].sum_irq = value_irq[i];
                data->hist[i].sum_thread = value_thread[i];
                data->hist[i].sum_user = value_user[i];
        }

        err = timerlat_bpf_get_summary_value(SUMMARY_OVERFLOW,
                                             value_irq, value_thread, value_user,
                                             data->nr_cpus);
        if (err)
                return err;
        for (i = 0; i < data->nr_cpus; i++) {
                data->hist[i].irq[data->entries] = value_irq[i];
                data->hist[i].thread[data->entries] = value_thread[i];
                data->hist[i].user[data->entries] = value_user[i];
        }

        return 0;
}

/*
 * timerlat_hist_header - print the header of the tracer to the output
 */
static void timerlat_hist_header(struct osnoise_tool *tool)
{
        struct timerlat_params *params = to_timerlat_params(tool->params);
        struct timerlat_hist_data *data = tool->data;
        struct trace_seq *s = tool->trace.seq;
        char duration[26];
        int cpu;

        if (params->common.hist.no_header)
                return;

        get_duration(tool->start_time, duration, sizeof(duration));
        trace_seq_printf(s, "# RTLA timerlat histogram\n");
        trace_seq_printf(s, "# Time unit is %s (%s)\n",
                        params->common.output_divisor == 1 ? "nanoseconds" : "microseconds",
                        params->common.output_divisor == 1 ? "ns" : "us");

        trace_seq_printf(s, "# Duration: %s\n", duration);

        if (!params->common.hist.no_index)
                trace_seq_printf(s, "Index");

        for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {

                if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
                        continue;

                if (!params->common.hist.no_irq)
                        trace_seq_printf(s, "   IRQ-%03d", cpu);

                if (!params->common.hist.no_thread)
                        trace_seq_printf(s, "   Thr-%03d", cpu);

                if (params->common.user_data)
                        trace_seq_printf(s, "   Usr-%03d", cpu);
        }
        trace_seq_printf(s, "\n");


        trace_seq_do_printf(s);
        trace_seq_reset(s);
}

/*
 * format_summary_value - format a line of summary value (min, max or avg)
 * of hist data
 */
static void format_summary_value(struct trace_seq *seq,
                                 int count,
                                 unsigned long long val,
                                 bool avg)
{
        if (count)
                trace_seq_printf(seq, "%9llu ", avg ? val / count : val);
        else
                trace_seq_printf(seq, "%9c ", '-');
}

/*
 * timerlat_print_summary - print the summary of the hist data to the output
 */
static void
timerlat_print_summary(struct timerlat_params *params,
                       struct trace_instance *trace,
                       struct timerlat_hist_data *data)
{
        int cpu;

        if (params->common.hist.no_summary)
                return;

        if (!params->common.hist.no_index)
                trace_seq_printf(trace->seq, "count:");

        for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {

                if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
                        continue;

                if (!params->common.hist.no_irq)
                        trace_seq_printf(trace->seq, "%9llu ",
                                        data->hist[cpu].irq_count);

                if (!params->common.hist.no_thread)
                        trace_seq_printf(trace->seq, "%9llu ",
                                        data->hist[cpu].thread_count);

                if (params->common.user_data)
                        trace_seq_printf(trace->seq, "%9llu ",
                                         data->hist[cpu].user_count);
        }
        trace_seq_printf(trace->seq, "\n");

        if (!params->common.hist.no_index)
                trace_seq_printf(trace->seq, "min:  ");

        for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {

                if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
                        continue;

                if (!params->common.hist.no_irq)
                        format_summary_value(trace->seq,
                                             data->hist[cpu].irq_count,
                                             data->hist[cpu].min_irq,
                                             false);

                if (!params->common.hist.no_thread)
                        format_summary_value(trace->seq,
                                             data->hist[cpu].thread_count,
                                             data->hist[cpu].min_thread,
                                             false);

                if (params->common.user_data)
                        format_summary_value(trace->seq,
                                             data->hist[cpu].user_count,
                                             data->hist[cpu].min_user,
                                             false);
        }
        trace_seq_printf(trace->seq, "\n");

        if (!params->common.hist.no_index)
                trace_seq_printf(trace->seq, "avg:  ");

        for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {

                if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
                        continue;

                if (!params->common.hist.no_irq)
                        format_summary_value(trace->seq,
                                             data->hist[cpu].irq_count,
                                             data->hist[cpu].sum_irq,
                                             true);

                if (!params->common.hist.no_thread)
                        format_summary_value(trace->seq,
                                             data->hist[cpu].thread_count,
                                             data->hist[cpu].sum_thread,
                                             true);

                if (params->common.user_data)
                        format_summary_value(trace->seq,
                                             data->hist[cpu].user_count,
                                             data->hist[cpu].sum_user,
                                             true);
        }
        trace_seq_printf(trace->seq, "\n");

        if (!params->common.hist.no_index)
                trace_seq_printf(trace->seq, "max:  ");

        for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {

                if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
                        continue;

                if (!params->common.hist.no_irq)
                        format_summary_value(trace->seq,
                                             data->hist[cpu].irq_count,
                                             data->hist[cpu].max_irq,
                                             false);

                if (!params->common.hist.no_thread)
                        format_summary_value(trace->seq,
                                             data->hist[cpu].thread_count,
                                             data->hist[cpu].max_thread,
                                             false);

                if (params->common.user_data)
                        format_summary_value(trace->seq,
                                             data->hist[cpu].user_count,
                                             data->hist[cpu].max_user,
                                             false);
        }
        trace_seq_printf(trace->seq, "\n");
        trace_seq_do_printf(trace->seq);
        trace_seq_reset(trace->seq);
}

static void
timerlat_print_stats_all(struct timerlat_params *params,
                         struct trace_instance *trace,
                         struct timerlat_hist_data *data)
{
        struct timerlat_hist_cpu *cpu_data;
        struct timerlat_hist_cpu sum;
        int cpu;

        if (params->common.hist.no_summary)
                return;

        memset(&sum, 0, sizeof(sum));
        sum.min_irq = ~0;
        sum.min_thread = ~0;
        sum.min_user = ~0;

        for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {

                if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
                        continue;

                cpu_data = &data->hist[cpu];

                sum.irq_count += cpu_data->irq_count;
                update_min(&sum.min_irq, &cpu_data->min_irq);
                update_sum(&sum.sum_irq, &cpu_data->sum_irq);
                update_max(&sum.max_irq, &cpu_data->max_irq);

                sum.thread_count += cpu_data->thread_count;
                update_min(&sum.min_thread, &cpu_data->min_thread);
                update_sum(&sum.sum_thread, &cpu_data->sum_thread);
                update_max(&sum.max_thread, &cpu_data->max_thread);

                sum.user_count += cpu_data->user_count;
                update_min(&sum.min_user, &cpu_data->min_user);
                update_sum(&sum.sum_user, &cpu_data->sum_user);
                update_max(&sum.max_user, &cpu_data->max_user);
        }

        if (!params->common.hist.no_index)
                trace_seq_printf(trace->seq, "ALL:  ");

        if (!params->common.hist.no_irq)
                trace_seq_printf(trace->seq, "      IRQ");

        if (!params->common.hist.no_thread)
                trace_seq_printf(trace->seq, "       Thr");

        if (params->common.user_data)
                trace_seq_printf(trace->seq, "       Usr");

        trace_seq_printf(trace->seq, "\n");

        if (!params->common.hist.no_index)
                trace_seq_printf(trace->seq, "count:");

        if (!params->common.hist.no_irq)
                trace_seq_printf(trace->seq, "%9llu ",
                                 sum.irq_count);

        if (!params->common.hist.no_thread)
                trace_seq_printf(trace->seq, "%9llu ",
                                 sum.thread_count);

        if (params->common.user_data)
                trace_seq_printf(trace->seq, "%9llu ",
                                 sum.user_count);

        trace_seq_printf(trace->seq, "\n");

        if (!params->common.hist.no_index)
                trace_seq_printf(trace->seq, "min:  ");

        if (!params->common.hist.no_irq)
                format_summary_value(trace->seq,
                                     sum.irq_count,
                                     sum.min_irq,
                                     false);

        if (!params->common.hist.no_thread)
                format_summary_value(trace->seq,
                                     sum.thread_count,
                                     sum.min_thread,
                                     false);

        if (params->common.user_data)
                format_summary_value(trace->seq,
                                     sum.user_count,
                                     sum.min_user,
                                     false);

        trace_seq_printf(trace->seq, "\n");

        if (!params->common.hist.no_index)
                trace_seq_printf(trace->seq, "avg:  ");

        if (!params->common.hist.no_irq)
                format_summary_value(trace->seq,
                                     sum.irq_count,
                                     sum.sum_irq,
                                     true);

        if (!params->common.hist.no_thread)
                format_summary_value(trace->seq,
                                     sum.thread_count,
                                     sum.sum_thread,
                                     true);

        if (params->common.user_data)
                format_summary_value(trace->seq,
                                     sum.user_count,
                                     sum.sum_user,
                                     true);

        trace_seq_printf(trace->seq, "\n");

        if (!params->common.hist.no_index)
                trace_seq_printf(trace->seq, "max:  ");

        if (!params->common.hist.no_irq)
                format_summary_value(trace->seq,
                                     sum.irq_count,
                                     sum.max_irq,
                                     false);

        if (!params->common.hist.no_thread)
                format_summary_value(trace->seq,
                                     sum.thread_count,
                                     sum.max_thread,
                                     false);

        if (params->common.user_data)
                format_summary_value(trace->seq,
                                     sum.user_count,
                                     sum.max_user,
                                     false);

        trace_seq_printf(trace->seq, "\n");
        trace_seq_do_printf(trace->seq);
        trace_seq_reset(trace->seq);
}

/*
 * timerlat_print_stats - print data for each CPUs
 */
static void
timerlat_print_stats(struct osnoise_tool *tool)
{
        struct timerlat_params *params = to_timerlat_params(tool->params);
        struct timerlat_hist_data *data = tool->data;
        struct trace_instance *trace = &tool->trace;
        int bucket, cpu;
        int total;

        timerlat_hist_header(tool);

        for (bucket = 0; bucket < data->entries; bucket++) {
                total = 0;

                if (!params->common.hist.no_index)
                        trace_seq_printf(trace->seq, "%-6d",
                                         bucket * data->bucket_size);

                for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {

                        if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
                                continue;

                        if (!params->common.hist.no_irq) {
                                total += data->hist[cpu].irq[bucket];
                                trace_seq_printf(trace->seq, "%9d ",
                                                data->hist[cpu].irq[bucket]);
                        }

                        if (!params->common.hist.no_thread) {
                                total += data->hist[cpu].thread[bucket];
                                trace_seq_printf(trace->seq, "%9d ",
                                                data->hist[cpu].thread[bucket]);
                        }

                        if (params->common.user_data) {
                                total += data->hist[cpu].user[bucket];
                                trace_seq_printf(trace->seq, "%9d ",
                                                data->hist[cpu].user[bucket]);
                        }

                }

                if (total == 0 && !params->common.hist.with_zeros) {
                        trace_seq_reset(trace->seq);
                        continue;
                }

                trace_seq_printf(trace->seq, "\n");
                trace_seq_do_printf(trace->seq);
                trace_seq_reset(trace->seq);
        }

        if (!params->common.hist.no_index)
                trace_seq_printf(trace->seq, "over: ");

        for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {

                if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
                        continue;

                if (!params->common.hist.no_irq)
                        trace_seq_printf(trace->seq, "%9d ",
                                         data->hist[cpu].irq[data->entries]);

                if (!params->common.hist.no_thread)
                        trace_seq_printf(trace->seq, "%9d ",
                                         data->hist[cpu].thread[data->entries]);

                if (params->common.user_data)
                        trace_seq_printf(trace->seq, "%9d ",
                                         data->hist[cpu].user[data->entries]);
        }
        trace_seq_printf(trace->seq, "\n");
        trace_seq_do_printf(trace->seq);
        trace_seq_reset(trace->seq);

        timerlat_print_summary(params, trace, data);
        timerlat_print_stats_all(params, trace, data);
        osnoise_report_missed_events(tool);
}

/*
 * timerlat_hist_usage - prints timerlat top usage message
 */
static void timerlat_hist_usage(void)
{
        static const char * const msg_start[] = {
                "[-d s] [-D] [-n] [-a us] [-p us] [-i us] [-T us] [-s us] \\",
                "         [-t [file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\",
                "         [-P priority] [-E N] [-b N] [--no-irq] [--no-thread] [--no-header] [--no-summary] \\",
                "         [--no-index] [--with-zeros] [--dma-latency us] [-C [cgroup_name]] [--no-aa] [--dump-task] [-u|-k]",
                "         [--warm-up s] [--deepest-idle-state n]",
                NULL,
        };

        static const char * const msg_opts[] = {
                "         -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
                "         -p/--period us: timerlat period in us",
                "         -i/--irq us: stop trace if the irq latency is higher than the argument in us",
                "         -T/--thread us: stop trace if the thread latency is higher than the argument in us",
                "         -s/--stack us: save the stack trace at the IRQ if a thread latency is higher than the argument in us",
                "         -c/--cpus cpus: run the tracer only on the given cpus",
                "         -H/--house-keeping cpus: run rtla control threads only on the given cpus",
                "         -C/--cgroup [cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
                "         -d/--duration time[m|h|d]: duration of the session in seconds",
                "            --dump-tasks: prints the task running on all CPUs if stop conditions are met (depends on !--no-aa)",
                "         -D/--debug: print debug info",
                "         -t/--trace [file]: save the stopped trace to [file|timerlat_trace.txt]",
                "         -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",
                "            --filter <filter>: enable a trace event filter to the previous -e event",
                "            --trigger <trigger>: enable a trace event trigger to the previous -e event",
                "         -n/--nano: display data in nanoseconds",
                "            --no-aa: disable auto-analysis, reducing rtla timerlat cpu usage",
                "         -b/--bucket-size N: set the histogram bucket size (default 1)",
                "         -E/--entries N: set the number of entries of the histogram (default 256)",
                "            --no-irq: ignore IRQ latencies",
                "            --no-thread: ignore thread latencies",
                "            --no-header: do not print header",
                "            --no-summary: do not print summary",
                "            --no-index: do not print index",
                "            --with-zeros: print zero only entries",
                "            --dma-latency us: set /dev/cpu_dma_latency latency <us> to reduce exit from idle latency",
                "         -P/--priority o:prio|r:prio|f:prio|d:runtime:period : set scheduling parameters",
                "               o:prio - use SCHED_OTHER with prio",
                "               r:prio - use SCHED_RR with prio",
                "               f:prio - use SCHED_FIFO with prio",
                "               d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
                "                                                      in nanoseconds",
                "         -u/--user-threads: use rtla user-space threads instead of kernel-space timerlat threads",
                "         -k/--kernel-threads: use timerlat kernel-space threads instead of rtla user-space threads",
                "         -U/--user-load: enable timerlat for user-defined user-space workload",
                "            --warm-up s: let the workload run for s seconds before collecting data",
                "            --trace-buffer-size kB: set the per-cpu trace buffer size in kB",
                "            --deepest-idle-state n: only go down to idle state n on cpus used by timerlat to reduce exit from idle latency",
                "            --on-threshold <action>: define action to be executed at latency threshold, multiple are allowed",
                "            --on-end <action>: define action to be executed at measurement end, multiple are allowed",
                "            --bpf-action <program>: load and execute BPF program when latency threshold is exceeded",
                NULL,
        };

        common_usage("timerlat", "hist", "a per-cpu histogram of the timer latency",
                     msg_start, msg_opts);
}

/*
 * timerlat_hist_parse_args - allocs, parse and fill the cmd line parameters
 */
static struct common_params
*timerlat_hist_parse_args(int argc, char *argv[])
{
        struct timerlat_params *params;
        int auto_thresh;
        int retval;
        int c;
        char *trace_output = NULL;

        params = calloc(1, sizeof(*params));
        if (!params)
                exit(1);

        actions_init(&params->common.threshold_actions);
        actions_init(&params->common.end_actions);

        /* disabled by default */
        params->dma_latency = -1;

        /* disabled by default */
        params->deepest_idle_state = -2;

        /* display data in microseconds */
        params->common.output_divisor = 1000;
        params->common.hist.bucket_size = 1;
        params->common.hist.entries = 256;

        /* default to BPF mode */
        params->mode = TRACING_MODE_BPF;

        while (1) {
                static struct option long_options[] = {
                        {"auto",                required_argument,      0, 'a'},
                        {"bucket-size",         required_argument,      0, 'b'},
                        {"entries",             required_argument,      0, 'E'},
                        {"help",                no_argument,            0, 'h'},
                        {"irq",                 required_argument,      0, 'i'},
                        {"nano",                no_argument,            0, 'n'},
                        {"period",              required_argument,      0, 'p'},
                        {"stack",               required_argument,      0, 's'},
                        {"thread",              required_argument,      0, 'T'},
                        {"trace",               optional_argument,      0, 't'},
                        {"user-threads",        no_argument,            0, 'u'},
                        {"kernel-threads",      no_argument,            0, 'k'},
                        {"user-load",           no_argument,            0, 'U'},
                        {"no-irq",              no_argument,            0, '0'},
                        {"no-thread",           no_argument,            0, '1'},
                        {"no-header",           no_argument,            0, '2'},
                        {"no-summary",          no_argument,            0, '3'},
                        {"no-index",            no_argument,            0, '4'},
                        {"with-zeros",          no_argument,            0, '5'},
                        {"trigger",             required_argument,      0, '6'},
                        {"filter",              required_argument,      0, '7'},
                        {"dma-latency",         required_argument,      0, '8'},
                        {"no-aa",               no_argument,            0, '9'},
                        {"dump-task",           no_argument,            0, '\1'},
                        {"warm-up",             required_argument,      0, '\2'},
                        {"trace-buffer-size",   required_argument,      0, '\3'},
                        {"deepest-idle-state",  required_argument,      0, '\4'},
                        {"on-threshold",        required_argument,      0, '\5'},
                        {"on-end",              required_argument,      0, '\6'},
                        {"bpf-action",          required_argument,      0, '\7'},
                        {0, 0, 0, 0}
                };

                if (common_parse_options(argc, argv, &params->common))
                        continue;

                c = getopt_long(argc, argv, "a:b:E:hi:knp:s:t::T:uU0123456:7:8:9\1\2:\3:",
                                 long_options, NULL);

                /* detect the end of the options. */
                if (c == -1)
                        break;

                switch (c) {
                case 'a':
                        auto_thresh = get_llong_from_str(optarg);

                        /* set thread stop to auto_thresh */
                        params->common.stop_total_us = auto_thresh;
                        params->common.stop_us = auto_thresh;

                        /* get stack trace */
                        params->print_stack = auto_thresh;

                        /* set trace */
                        if (!trace_output)
                                trace_output = "timerlat_trace.txt";

                        break;
                case 'b':
                        params->common.hist.bucket_size = get_llong_from_str(optarg);
                        if (params->common.hist.bucket_size == 0 ||
                            params->common.hist.bucket_size >= 1000000)
                                fatal("Bucket size needs to be > 0 and <= 1000000");
                        break;
                case 'E':
                        params->common.hist.entries = get_llong_from_str(optarg);
                        if (params->common.hist.entries < 10 ||
                            params->common.hist.entries > 9999999)
                                fatal("Entries must be > 10 and < 9999999");
                        break;
                case 'h':
                case '?':
                        timerlat_hist_usage();
                        break;
                case 'i':
                        params->common.stop_us = get_llong_from_str(optarg);
                        break;
                case 'k':
                        params->common.kernel_workload = 1;
                        break;
                case 'n':
                        params->common.output_divisor = 1;
                        break;
                case 'p':
                        params->timerlat_period_us = get_llong_from_str(optarg);
                        if (params->timerlat_period_us > 1000000)
                                fatal("Period longer than 1 s");
                        break;
                case 's':
                        params->print_stack = get_llong_from_str(optarg);
                        break;
                case 'T':
                        params->common.stop_total_us = get_llong_from_str(optarg);
                        break;
                case 't':
                        trace_output = parse_optional_arg(argc, argv);
                        if (!trace_output)
                                trace_output = "timerlat_trace.txt";
                        break;
                case 'u':
                        params->common.user_workload = 1;
                        /* fallback: -u implies in -U */
                case 'U':
                        params->common.user_data = 1;
                        break;
                case '0': /* no irq */
                        params->common.hist.no_irq = 1;
                        break;
                case '1': /* no thread */
                        params->common.hist.no_thread = 1;
                        break;
                case '2': /* no header */
                        params->common.hist.no_header = 1;
                        break;
                case '3': /* no summary */
                        params->common.hist.no_summary = 1;
                        break;
                case '4': /* no index */
                        params->common.hist.no_index = 1;
                        break;
                case '5': /* with zeros */
                        params->common.hist.with_zeros = 1;
                        break;
                case '6': /* trigger */
                        if (params->common.events) {
                                retval = trace_event_add_trigger(params->common.events, optarg);
                                if (retval)
                                        fatal("Error adding trigger %s", optarg);
                        } else {
                                fatal("--trigger requires a previous -e");
                        }
                        break;
                case '7': /* filter */
                        if (params->common.events) {
                                retval = trace_event_add_filter(params->common.events, optarg);
                                if (retval)
                                        fatal("Error adding filter %s", optarg);
                        } else {
                                fatal("--filter requires a previous -e");
                        }
                        break;
                case '8':
                        params->dma_latency = get_llong_from_str(optarg);
                        if (params->dma_latency < 0 || params->dma_latency > 10000)
                                fatal("--dma-latency needs to be >= 0 and < 10000");
                        break;
                case '9':
                        params->no_aa = 1;
                        break;
                case '\1':
                        params->dump_tasks = 1;
                        break;
                case '\2':
                        params->common.warmup = get_llong_from_str(optarg);
                        break;
                case '\3':
                        params->common.buffer_size = get_llong_from_str(optarg);
                        break;
                case '\4':
                        params->deepest_idle_state = get_llong_from_str(optarg);
                        break;
                case '\5':
                        retval = actions_parse(&params->common.threshold_actions, optarg,
                                               "timerlat_trace.txt");
                        if (retval)
                                fatal("Invalid action %s", optarg);
                        break;
                case '\6':
                        retval = actions_parse(&params->common.end_actions, optarg,
                                               "timerlat_trace.txt");
                        if (retval)
                                fatal("Invalid action %s", optarg);
                        break;
                case '\7':
                        params->bpf_action_program = optarg;
                        break;
                default:
                        fatal("Invalid option");
                }
        }

        if (trace_output)
                actions_add_trace_output(&params->common.threshold_actions, trace_output);

        if (geteuid())
                fatal("rtla needs root permission");

        if (params->common.hist.no_irq && params->common.hist.no_thread)
                fatal("no-irq and no-thread set, there is nothing to do here");

        if (params->common.hist.no_index && !params->common.hist.with_zeros)
                fatal("no-index set with with-zeros is not set - it does not make sense");

        /*
         * Auto analysis only happens if stop tracing, thus:
         */
        if (!params->common.stop_us && !params->common.stop_total_us)
                params->no_aa = 1;

        if (params->common.kernel_workload && params->common.user_workload)
                fatal("--kernel-threads and --user-threads are mutually exclusive!");

        /*
         * If auto-analysis or trace output is enabled, switch from BPF mode to
         * mixed mode
         */
        if (params->mode == TRACING_MODE_BPF &&
            (params->common.threshold_actions.present[ACTION_TRACE_OUTPUT] ||
             params->common.end_actions.present[ACTION_TRACE_OUTPUT] ||
             !params->no_aa))
                params->mode = TRACING_MODE_MIXED;

        return &params->common;
}

/*
 * timerlat_hist_apply_config - apply the hist configs to the initialized tool
 */
static int
timerlat_hist_apply_config(struct osnoise_tool *tool)
{
        struct timerlat_params *params = to_timerlat_params(tool->params);
        int retval;

        retval = timerlat_apply_config(tool, params);
        if (retval)
                goto out_err;

        return 0;

out_err:
        return -1;
}

/*
 * timerlat_init_hist - initialize a timerlat hist tool with parameters
 */
static struct osnoise_tool
*timerlat_init_hist(struct common_params *params)
{
        struct osnoise_tool *tool;
        int nr_cpus;

        nr_cpus = sysconf(_SC_NPROCESSORS_CONF);

        tool = osnoise_init_tool("timerlat_hist");
        if (!tool)
                return NULL;

        tool->data = timerlat_alloc_histogram(nr_cpus, params->hist.entries,
                                              params->hist.bucket_size);
        if (!tool->data)
                goto out_err;

        tep_register_event_handler(tool->trace.tep, -1, "ftrace", "timerlat",
                                   timerlat_hist_handler, tool);

        return tool;

out_err:
        osnoise_destroy_tool(tool);
        return NULL;
}

static int timerlat_hist_bpf_main_loop(struct osnoise_tool *tool)
{
        struct timerlat_params *params = to_timerlat_params(tool->params);
        int retval;

        while (!stop_tracing) {
                timerlat_bpf_wait(-1);

                if (!stop_tracing) {
                        /* Threshold overflow, perform actions on threshold */
                        actions_perform(&params->common.threshold_actions);

                        if (!params->common.threshold_actions.continue_flag)
                                /* continue flag not set, break */
                                break;

                        /* continue action reached, re-enable tracing */
                        if (tool->record)
                                trace_instance_start(&tool->record->trace);
                        if (tool->aa)
                                trace_instance_start(&tool->aa->trace);
                        timerlat_bpf_restart_tracing();
                }
        }
        timerlat_bpf_detach();

        retval = timerlat_hist_bpf_pull_data(tool);
        if (retval)
                err_msg("Error pulling BPF data\n");

        return retval;
}

static int timerlat_hist_main(struct osnoise_tool *tool)
{
        struct timerlat_params *params = to_timerlat_params(tool->params);
        int retval;

        if (params->mode == TRACING_MODE_TRACEFS)
                retval = hist_main_loop(tool);
        else
                retval = timerlat_hist_bpf_main_loop(tool);

        return retval;
}

struct tool_ops timerlat_hist_ops = {
        .tracer = "timerlat",
        .comm_prefix = "timerlat/",
        .parse_args = timerlat_hist_parse_args,
        .init_tool = timerlat_init_hist,
        .apply_config = timerlat_hist_apply_config,
        .enable = timerlat_enable,
        .main = timerlat_hist_main,
        .print_stats = timerlat_print_stats,
        .analyze = timerlat_analyze,
        .free = timerlat_free_histogram_tool,
};