/*
 * Copyright (c) 2014 Remy Noel.
 * Copyright (c) 2014 Richard Braun.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 * Here, we test the perfmon module for cross CPU performances monitoring.
 */

#include <stdbool.h>
#include <stddef.h>

#include <kern/error.h>
#include <kern/perfmon_i.h>
#include <kern/printf.h>
#include <kern/thread.h>
#include <test/test.h>

#define WAIT_DELAY_USEC 1000000

static volatile bool stop;

static void
test_do_nothing(void* arg)
{
    (void)arg;

    while (!stop);
}

static void
test_report_event(const struct perfmon_event *event, const char *name)
{
    unsigned long long count;

    count = perfmon_event_read(event);
    printf("test: %s: %llu\n", name, count);
}

static uint64_t
test_get_pre_overflow_value(uint64_t value)
{
    uint64_t pmc_max;
    unsigned int pmc_width;

    pmc_width = perfmon_get_pmc_width();
    pmc_max = (1ULL << pmc_width) - 1;
    pmc_max &= 0xffffffff80000000;

    /* XXX: workaround most processor not allowing full width writes */
    return ((~value + 1) & 0x7fffffff) | pmc_max;
}

static void
test_run(void *arg)
{
    struct perfmon_event *ev_cycle, *ev_instruction;
    struct perfmon_group *group;
    int error;
    uint64_t value;

    (void)arg;

    error = perfmon_group_create(&group);
    error_check(error, "perfmon_group_create");

    error = perfmon_event_create(&ev_cycle, PERFMON_ET_GENERIC,
                                 PERFMON_EV_CYCLE, PERFMON_EF_KERN);
    error_check(error, "perfmon_event_create");
    perfmon_group_add(group, ev_cycle);

    error = perfmon_event_create(&ev_instruction, PERFMON_ET_GENERIC,
                                 PERFMON_EV_INSTRUCTION, PERFMON_EF_KERN);
    error_check(error, "perfmon_event_create");
    perfmon_group_add(group, ev_instruction);

    error = perfmon_group_attach_cpu(group, 1);
    error_check(error, "perfmon_group_attach_cpu 1");

    error = perfmon_group_start(group);
    error_check(error, "perfmon_group_start");

    cpu_delay(WAIT_DELAY_USEC);
    error = perfmon_group_stop(group);
    error_check(error, "perfmon_group_stop");
    test_report_event(ev_cycle, "cycle");
    test_report_event(ev_instruction, "instruction");

    printf("checking with overflow ...\n");
    value = test_get_pre_overflow_value( perfmon_event_read(ev_cycle) / 2);
    error = perfmon_event_write(ev_cycle, value);
    error_check(error, "perfmon_event_write");

    value = test_get_pre_overflow_value(perfmon_event_read(ev_instruction) / 3);
    error = perfmon_event_write(ev_instruction, value);
    error_check(error, "perfmon_event_write");

    perfmon_event_reset(ev_cycle);
    perfmon_event_reset(ev_instruction);

    error = perfmon_group_start(group);
    error_check(error, "perfmon_group_start");

    cpu_delay(WAIT_DELAY_USEC);
    error = perfmon_group_stop(group);
    error_check(error, "perfmon_group_stop");
    test_report_event(ev_cycle, "cycle");
    test_report_event(ev_instruction, "instruction");

    error = perfmon_group_detach(group);
    error_check(error, "perfmon_group_detach");

    error = perfmon_group_destroy(group);
    error_check(error, "perfmon_group_destroy");

    stop = true;
}

void
test_setup(void)
{
    struct thread_attr attr;
    struct thread *thread0, *thread1;
    struct cpumap *cpumap;
    int error;

    error = cpumap_create(&cpumap);
    error_check(error, "cpumap_create 0");
    cpumap_zero(cpumap);
    cpumap_set(cpumap, 0);

    thread_attr_init(&attr, "x15_test_run");
    thread_attr_set_detached(&attr);
    thread_attr_set_cpumap(&attr, cpumap);
    error = thread_create(&thread0, &attr, test_run, NULL);
    error_check(error, "thread_create 0");

    cpumap_zero(cpumap);
    cpumap_set(cpumap, 1);

    thread_attr_init(&attr, "x15_test_do_nothing");
    thread_attr_set_detached(&attr);
    thread_attr_set_cpumap(&attr, cpumap);
    error = thread_create(&thread1, &attr, test_do_nothing, NULL);
    error_check(error, "thread_create 1");
}