// 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_top_cpu {
        unsigned long long      irq_count;
        unsigned long long      thread_count;
        unsigned long long      user_count;

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

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

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

struct timerlat_top_data {
        struct timerlat_top_cpu *cpu_data;
        int                     nr_cpus;
};

/*
 * timerlat_free_top - free runtime data
 */
static void timerlat_free_top(struct timerlat_top_data *data)
{
        free(data->cpu_data);
        free(data);
}

static void timerlat_free_top_tool(struct osnoise_tool *tool)
{
        timerlat_free_top(tool->data);
        timerlat_free(tool);
}

/*
 * timerlat_alloc_histogram - alloc runtime data
 */
static struct timerlat_top_data *timerlat_alloc_top(int nr_cpus)
{
        struct timerlat_top_data *data;
        int cpu;

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

        data->nr_cpus = nr_cpus;

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

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

        return data;

cleanup:
        timerlat_free_top(data);
        return NULL;
}

static void
timerlat_top_reset_sum(struct timerlat_top_cpu *summary)
{
        memset(summary, 0, sizeof(*summary));
        summary->min_irq = ~0;
        summary->min_thread = ~0;
        summary->min_user = ~0;
}

static void
timerlat_top_update_sum(struct osnoise_tool *tool, int cpu, struct timerlat_top_cpu *sum)
{
        struct timerlat_top_data *data = tool->data;
        struct timerlat_top_cpu *cpu_data = &data->cpu_data[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);
}

/*
 * timerlat_hist_update - record a new timerlat occurent on cpu, updating data
 */
static void
timerlat_top_update(struct osnoise_tool *tool, int cpu,
                    unsigned long long thread,
                    unsigned long long latency)
{
        struct timerlat_params *params = to_timerlat_params(tool->params);
        struct timerlat_top_data *data = tool->data;
        struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];

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

        if (!thread) {
                cpu_data->irq_count++;
                cpu_data->cur_irq = latency;
                update_min(&cpu_data->min_irq, &latency);
                update_sum(&cpu_data->sum_irq, &latency);
                update_max(&cpu_data->max_irq, &latency);
        } else if (thread == 1) {
                cpu_data->thread_count++;
                cpu_data->cur_thread = latency;
                update_min(&cpu_data->min_thread, &latency);
                update_sum(&cpu_data->sum_thread, &latency);
                update_max(&cpu_data->max_thread, &latency);
        } else {
                cpu_data->user_count++;
                cpu_data->cur_user = latency;
                update_min(&cpu_data->min_user, &latency);
                update_sum(&cpu_data->sum_user, &latency);
                update_max(&cpu_data->max_user, &latency);
        }
}

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

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

        if (!top->params->aa_only) {
                tep_get_field_val(s, event, "context", record, &thread, 1);
                tep_get_field_val(s, event, "timer_latency", record, &latency, 1);

                timerlat_top_update(top, cpu, thread, latency);
        }

        return 0;
}

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

        /* Pull summary */
        err = timerlat_bpf_get_summary_value(SUMMARY_CURRENT,
                                             value_irq, value_thread, value_user,
                                             data->nr_cpus);
        if (err)
                return err;
        for (i = 0; i < data->nr_cpus; i++) {
                data->cpu_data[i].cur_irq = value_irq[i];
                data->cpu_data[i].cur_thread = value_thread[i];
                data->cpu_data[i].cur_user = value_user[i];
        }

        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->cpu_data[i].irq_count = value_irq[i];
                data->cpu_data[i].thread_count = value_thread[i];
                data->cpu_data[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->cpu_data[i].min_irq = value_irq[i];
                data->cpu_data[i].min_thread = value_thread[i];
                data->cpu_data[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->cpu_data[i].max_irq = value_irq[i];
                data->cpu_data[i].max_thread = value_thread[i];
                data->cpu_data[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->cpu_data[i].sum_irq = value_irq[i];
                data->cpu_data[i].sum_thread = value_thread[i];
                data->cpu_data[i].sum_user = value_user[i];
        }

        return 0;
}

/*
 * timerlat_top_header - print the header of the tool output
 */
static void timerlat_top_header(struct timerlat_params *params, struct osnoise_tool *top)
{
        struct trace_seq *s = top->trace.seq;
        bool pretty = params->common.pretty_output;
        char duration[26];

        get_duration(top->start_time, duration, sizeof(duration));

        if (pretty)
                trace_seq_printf(s, "\033[2;37;40m");

        trace_seq_printf(s, "                                     Timer Latency                                              ");
        if (params->common.user_data)
                trace_seq_printf(s, "                                         ");

        if (pretty)
                trace_seq_printf(s, "\033[0;0;0m");
        trace_seq_printf(s, "\n");

        trace_seq_printf(s, "%-6s   |          IRQ Timer Latency (%s)        |         Thread Timer Latency (%s)", duration,
                        params->common.output_divisor == 1 ? "ns" : "us",
                        params->common.output_divisor == 1 ? "ns" : "us");

        if (params->common.user_data) {
                trace_seq_printf(s, "      |    Ret user Timer Latency (%s)",
                                params->common.output_divisor == 1 ? "ns" : "us");
        }

        trace_seq_printf(s, "\n");
        if (pretty)
                trace_seq_printf(s, "\033[2;30;47m");

        trace_seq_printf(s, "CPU COUNT      |      cur       min       avg       max |      cur       min       avg       max");
        if (params->common.user_data)
                trace_seq_printf(s, " |      cur       min       avg       max");

        if (pretty)
                trace_seq_printf(s, "\033[0;0;0m");
        trace_seq_printf(s, "\n");
}

static const char *no_value = "        -";

/*
 * timerlat_top_print - prints the output of a given CPU
 */
static void timerlat_top_print(struct osnoise_tool *top, int cpu)
{
        struct timerlat_params *params = to_timerlat_params(top->params);
        struct timerlat_top_data *data = top->data;
        struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];
        struct trace_seq *s = top->trace.seq;

        /*
         * Skip if no data is available: is this cpu offline?
         */
        if (!cpu_data->irq_count && !cpu_data->thread_count)
                return;

        /*
         * Unless trace is being lost, IRQ counter is always the max.
         */
        trace_seq_printf(s, "%3d #%-9llu |", cpu, cpu_data->irq_count);

        if (!cpu_data->irq_count) {
                trace_seq_printf(s, "%s %s %s %s |", no_value, no_value, no_value, no_value);
        } else {
                trace_seq_printf(s, "%9llu ", cpu_data->cur_irq);
                trace_seq_printf(s, "%9llu ", cpu_data->min_irq);
                trace_seq_printf(s, "%9llu ", cpu_data->sum_irq / cpu_data->irq_count);
                trace_seq_printf(s, "%9llu |", cpu_data->max_irq);
        }

        if (!cpu_data->thread_count) {
                trace_seq_printf(s, "%s %s %s %s", no_value, no_value, no_value, no_value);
        } else {
                trace_seq_printf(s, "%9llu ", cpu_data->cur_thread);
                trace_seq_printf(s, "%9llu ", cpu_data->min_thread);
                trace_seq_printf(s, "%9llu ",
                                cpu_data->sum_thread / cpu_data->thread_count);
                trace_seq_printf(s, "%9llu", cpu_data->max_thread);
        }

        if (!params->common.user_data) {
                trace_seq_printf(s, "\n");
                return;
        }

        trace_seq_printf(s, " |");

        if (!cpu_data->user_count) {
                trace_seq_printf(s, "%s %s %s %s\n", no_value, no_value, no_value, no_value);
        } else {
                trace_seq_printf(s, "%9llu ", cpu_data->cur_user);
                trace_seq_printf(s, "%9llu ", cpu_data->min_user);
                trace_seq_printf(s, "%9llu ",
                                cpu_data->sum_user / cpu_data->user_count);
                trace_seq_printf(s, "%9llu\n", cpu_data->max_user);
        }
}

/*
 * timerlat_top_print_sum - prints the summary output
 */
static void
timerlat_top_print_sum(struct osnoise_tool *top, struct timerlat_top_cpu *summary)
{
        const char *split = "----------------------------------------";
        struct timerlat_params *params = to_timerlat_params(top->params);
        unsigned long long count = summary->irq_count;
        struct trace_seq *s = top->trace.seq;
        int e = 0;

        /*
         * Skip if no data is available: is this cpu offline?
         */
        if (!summary->irq_count && !summary->thread_count)
                return;

        while (count > 999999) {
                e++;
                count /= 10;
        }

        trace_seq_printf(s, "%.*s|%.*s|%.*s", 15, split, 40, split, 39, split);
        if (params->common.user_data)
                trace_seq_printf(s, "-|%.*s", 39, split);
        trace_seq_printf(s, "\n");

        trace_seq_printf(s, "ALL #%-6llu e%d |", count, e);

        if (!summary->irq_count) {
                trace_seq_printf(s, "          %s %s %s |", no_value, no_value, no_value);
        } else {
                trace_seq_printf(s, "          ");
                trace_seq_printf(s, "%9llu ", summary->min_irq);
                trace_seq_printf(s, "%9llu ", summary->sum_irq / summary->irq_count);
                trace_seq_printf(s, "%9llu |", summary->max_irq);
        }

        if (!summary->thread_count) {
                trace_seq_printf(s, "%s %s %s %s", no_value, no_value, no_value, no_value);
        } else {
                trace_seq_printf(s, "          ");
                trace_seq_printf(s, "%9llu ", summary->min_thread);
                trace_seq_printf(s, "%9llu ",
                                summary->sum_thread / summary->thread_count);
                trace_seq_printf(s, "%9llu", summary->max_thread);
        }

        if (!params->common.user_data) {
                trace_seq_printf(s, "\n");
                return;
        }

        trace_seq_printf(s, " |");

        if (!summary->user_count) {
                trace_seq_printf(s, "          %s %s %s |", no_value, no_value, no_value);
        } else {
                trace_seq_printf(s, "          ");
                trace_seq_printf(s, "%9llu ", summary->min_user);
                trace_seq_printf(s, "%9llu ",
                                summary->sum_user / summary->user_count);
                trace_seq_printf(s, "%9llu\n", summary->max_user);
        }
}

/*
 * clear_terminal - clears the output terminal
 */
static void clear_terminal(struct trace_seq *seq)
{
        if (!config_debug)
                trace_seq_printf(seq, "\033c");
}

/*
 * timerlat_print_stats - print data for all cpus
 */
static void
timerlat_print_stats(struct osnoise_tool *top)
{
        struct timerlat_params *params = to_timerlat_params(top->params);
        struct trace_instance *trace = &top->trace;
        struct timerlat_top_cpu summary;
        static int nr_cpus = -1;
        int i;

        if (params->common.aa_only)
                return;

        if (nr_cpus == -1)
                nr_cpus = sysconf(_SC_NPROCESSORS_CONF);

        if (!params->common.quiet)
                clear_terminal(trace->seq);

        timerlat_top_reset_sum(&summary);

        timerlat_top_header(params, top);

        for_each_monitored_cpu(i, nr_cpus, &params->common) {
                timerlat_top_print(top, i);
                timerlat_top_update_sum(top, i, &summary);
        }

        timerlat_top_print_sum(top, &summary);

        trace_seq_do_printf(trace->seq);
        trace_seq_reset(trace->seq);
        osnoise_report_missed_events(top);
}

/*
 * timerlat_top_usage - prints timerlat top usage message
 */
static void timerlat_top_usage(void)
{
        static const char *const msg_start[] = {
                "[-q] [-a us] [-d s] [-D] [-n] [-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] [--dma-latency us] [--aa-only us] [-C [cgroup_name]] [-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",
                "            --aa-only us: stop if <us> latency is hit, only printing the auto analysis (reduces CPU usage)",
                "         -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[s|m|h|d]: duration of the session",
                "         -D/--debug: print debug info",
                "            --dump-tasks: prints the task running on all CPUs if stop conditions are met (depends on !--no-aa)",
                "         -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 <command>: enable a trace event filter to the previous -e event",
                "            --trigger <command>: 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",
                "         -q/--quiet print only a summary at the end",
                "            --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: 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", "top", "a per-cpu summary of the timer latency",
                     msg_start, msg_opts);
}

/*
 * timerlat_top_parse_args - allocs, parse and fill the cmd line parameters
 */
static struct common_params
*timerlat_top_parse_args(int argc, char **argv)
{
        struct timerlat_params *params;
        long long 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;

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

        while (1) {
                static struct option long_options[] = {
                        {"auto",                required_argument,      0, 'a'},
                        {"help",                no_argument,            0, 'h'},
                        {"irq",                 required_argument,      0, 'i'},
                        {"nano",                no_argument,            0, 'n'},
                        {"period",              required_argument,      0, 'p'},
                        {"quiet",               no_argument,            0, 'q'},
                        {"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'},
                        {"trigger",             required_argument,      0, '0'},
                        {"filter",              required_argument,      0, '1'},
                        {"dma-latency",         required_argument,      0, '2'},
                        {"no-aa",               no_argument,            0, '3'},
                        {"dump-tasks",          no_argument,            0, '4'},
                        {"aa-only",             required_argument,      0, '5'},
                        {"warm-up",             required_argument,      0, '6'},
                        {"trace-buffer-size",   required_argument,      0, '7'},
                        {"deepest-idle-state",  required_argument,      0, '8'},
                        {"on-threshold",        required_argument,      0, '9'},
                        {"on-end",              required_argument,      0, '\1'},
                        {"bpf-action",          required_argument,      0, '\2'},
                        {0, 0, 0, 0}
                };

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

                c = getopt_long(argc, argv, "a:hi:knp:qs:t::T:uU0:1:2:345:6:7:",
                                 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 '5':
                        /* it is here because it is similar to -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 aa_only to avoid parsing the trace */
                        params->common.aa_only = 1;
                        break;
                case 'h':
                case '?':
                        timerlat_top_usage();
                        break;
                case 'i':
                        params->common.stop_us = get_llong_from_str(optarg);
                        break;
                case 'k':
                        params->common.kernel_workload = true;
                        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 'q':
                        params->common.quiet = 1;
                        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 = true;
                        /* fallback: -u implies -U */
                case 'U':
                        params->common.user_data = true;
                        break;
                case '0': /* 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 '1': /* 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 '2': /* dma-latency */
                        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 '3': /* no-aa */
                        params->no_aa = 1;
                        break;
                case '4':
                        params->dump_tasks = 1;
                        break;
                case '6':
                        params->common.warmup = get_llong_from_str(optarg);
                        break;
                case '7':
                        params->common.buffer_size = get_llong_from_str(optarg);
                        break;
                case '8':
                        params->deepest_idle_state = get_llong_from_str(optarg);
                        break;
                case '9':
                        retval = actions_parse(&params->common.threshold_actions, optarg,
                                               "timerlat_trace.txt");
                        if (retval)
                                fatal("Invalid action %s", optarg);
                        break;
                case '\1':
                        retval = actions_parse(&params->common.end_actions, optarg,
                                               "timerlat_trace.txt");
                        if (retval)
                                fatal("Invalid action %s", optarg);
                        break;
                case '\2':
                        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");

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

        if (params->no_aa && params->common.aa_only)
                fatal("--no-aa and --aa-only are mutually exclusive!");

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

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

        if (isatty(STDOUT_FILENO) && !params->common.quiet)
                params->common.pretty_output = 1;

        return 0;

out_err:
        return -1;
}

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

        nr_cpus = sysconf(_SC_NPROCESSORS_CONF);

        top = osnoise_init_tool("timerlat_top");
        if (!top)
                return NULL;

        top->data = timerlat_alloc_top(nr_cpus);
        if (!top->data)
                goto out_err;

        tep_register_event_handler(top->trace.tep, -1, "ftrace", "timerlat",
                                   timerlat_top_handler, top);

        return top;

out_err:
        osnoise_destroy_tool(top);
        return NULL;
}

/*
 * timerlat_top_bpf_main_loop - main loop to process events (BPF variant)
 */
static int
timerlat_top_bpf_main_loop(struct osnoise_tool *tool)
{
        struct timerlat_params *params = to_timerlat_params(tool->params);
        int retval, wait_retval;

        if (params->common.aa_only) {
                /* Auto-analysis only, just wait for stop tracing */
                timerlat_bpf_wait(-1);
                return 0;
        }

        /* Pull and display data in a loop */
        while (!stop_tracing) {
                wait_retval = timerlat_bpf_wait(params->common.quiet ? -1 :
                                                params->common.sleep_time);

                retval = timerlat_top_bpf_pull_data(tool);
                if (retval) {
                        err_msg("Error pulling BPF data\n");
                        return retval;
                }

                if (!params->common.quiet)
                        timerlat_print_stats(tool);

                if (wait_retval != 0) {
                        /* Stopping requested by tracer */
                        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();
                }

                /* is there still any user-threads ? */
                if (params->common.user_workload) {
                        if (params->common.user.stopped_running) {
                                debug_msg("timerlat user space threads stopped!\n");
                                break;
                        }
                }
        }

        return 0;
}

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

        if (params->mode == TRACING_MODE_TRACEFS) {
                retval = top_main_loop(tool);
        } else {
                retval = timerlat_top_bpf_main_loop(tool);
                timerlat_bpf_detach();
        }

        return retval;
}

struct tool_ops timerlat_top_ops = {
        .tracer = "timerlat",
        .comm_prefix = "timerlat/",
        .parse_args = timerlat_top_parse_args,
        .init_tool = timerlat_init_top,
        .apply_config = timerlat_top_apply_config,
        .enable = timerlat_enable,
        .main = timerlat_top_main_loop,
        .print_stats = timerlat_print_stats,
        .analyze = timerlat_analyze,
        .free = timerlat_free_top_tool,
};