// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2013, Michael Ellerman, IBM Corp.
 */

#define _GNU_SOURCE
#include <unistd.h>
#include <sys/syscall.h>
#include <string.h>
#include <stdio.h>
#include <stdbool.h>
#include <sys/ioctl.h>

#include "event.h"


int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
                int group_fd, unsigned long flags)
{
        return syscall(__NR_perf_event_open, attr, pid, cpu,
                           group_fd, flags);
}

static void  __event_init_opts(struct event *e, u64 config,
                               int type, char *name, bool sampling)
{
        memset(e, 0, sizeof(*e));

        e->name = name;

        e->attr.type = type;
        e->attr.config = config;
        e->attr.size = sizeof(e->attr);
        /* This has to match the structure layout in the header */
        e->attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | \
                                  PERF_FORMAT_TOTAL_TIME_RUNNING;
        if (sampling) {
                e->attr.sample_period = 1000;
                e->attr.sample_type = PERF_SAMPLE_REGS_INTR;
                e->attr.disabled = 1;
        }
}

void event_init_opts(struct event *e, u64 config, int type, char *name)
{
        __event_init_opts(e, config, type, name, false);
}

void event_init_named(struct event *e, u64 config, char *name)
{
        event_init_opts(e, config, PERF_TYPE_RAW, name);
}

void event_init(struct event *e, u64 config)
{
        event_init_opts(e, config, PERF_TYPE_RAW, "event");
}

void event_init_sampling(struct event *e, u64 config)
{
        __event_init_opts(e, config, PERF_TYPE_RAW, "event", true);
}

#define PERF_CURRENT_PID        0
#define PERF_NO_PID             -1
#define PERF_NO_CPU             -1
#define PERF_NO_GROUP           -1

int event_open_with_options(struct event *e, pid_t pid, int cpu, int group_fd)
{
        e->fd = perf_event_open(&e->attr, pid, cpu, group_fd, 0);
        if (e->fd == -1) {
                perror("perf_event_open");
                return -1;
        }

        return 0;
}

int event_open_with_group(struct event *e, int group_fd)
{
        return event_open_with_options(e, PERF_CURRENT_PID, PERF_NO_CPU, group_fd);
}

int event_open_with_pid(struct event *e, pid_t pid)
{
        return event_open_with_options(e, pid, PERF_NO_CPU, PERF_NO_GROUP);
}

int event_open_with_cpu(struct event *e, int cpu)
{
        return event_open_with_options(e, PERF_NO_PID, cpu, PERF_NO_GROUP);
}

int event_open(struct event *e)
{
        return event_open_with_options(e, PERF_CURRENT_PID, PERF_NO_CPU, PERF_NO_GROUP);
}

void event_close(struct event *e)
{
        close(e->fd);
}

int event_enable(struct event *e)
{
        return ioctl(e->fd, PERF_EVENT_IOC_ENABLE);
}

int event_disable(struct event *e)
{
        return ioctl(e->fd, PERF_EVENT_IOC_DISABLE);
}

int event_reset(struct event *e)
{
        return ioctl(e->fd, PERF_EVENT_IOC_RESET);
}

int event_read(struct event *e)
{
        int rc;

        rc = read(e->fd, &e->result, sizeof(e->result));
        if (rc != sizeof(e->result)) {
                fprintf(stderr, "read error on event %p!\n", e);
                return -1;
        }

        return 0;
}

void event_report_justified(struct event *e, int name_width, int result_width)
{
        printf("%*s: result %*llu ", name_width, e->name, result_width,
               e->result.value);

        if (e->result.running == e->result.enabled)
                printf("running/enabled %llu\n", e->result.running);
        else
                printf("running %llu enabled %llu\n", e->result.running,
                        e->result.enabled);
}

void event_report(struct event *e)
{
        event_report_justified(e, 0, 0);
}