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

#define _GNU_SOURCE
#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"
#include "cli.h"
#include "common.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;
};

/*
 * 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(void)
{
        struct timerlat_top_data *data;
        int cpu;

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

        /* 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[nr_cpus],
                  value_thread[nr_cpus],
                  value_user[nr_cpus];

        /* Pull summary */
        err = timerlat_bpf_get_summary_value(SUMMARY_CURRENT,
                                             value_irq, value_thread, value_user);
        if (err)
                return err;
        for (i = 0; i < 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);
        if (err)
                return err;
        for (i = 0; i < 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);
        if (err)
                return err;
        for (i = 0; i < 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);
        if (err)
                return err;
        for (i = 0; i < 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);
        if (err)
                return err;
        for (i = 0; i < 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;
        int i;

        if (params->common.aa_only)
                return;

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

        timerlat_top_reset_sum(&summary);

        timerlat_top_header(params, top);

        for_each_monitored_cpu(i, &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_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;

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

        top->data = timerlat_alloc_top();
        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)
{
        const struct common_params *params = tool->params;
        int retval, wait_retval;

        if (params->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->quiet ? -1 :
                                                params->sleep_time);

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

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

                if (wait_retval != 0) {
                        /* Stopping requested by tracer */
                        retval = common_threshold_handler(tool);
                        if (retval)
                                return retval;

                        if (!should_continue_tracing(tool->params))
                                break;

                        if (timerlat_bpf_restart_tracing()) {
                                err_msg("Error restarting BPF trace\n");
                                return -1;
                        }
                }

                /* is there still any user-threads ? */
                if (params->user_workload) {
                        if (params->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,
};