/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#include <stdio.h>
#include <stdint.h>
#include <inttypes.h>
#include <string.h>
#include <unistd.h>
#include <sys/queue.h>

#include <rte_common.h>
#include <rte_memory.h>
#include <rte_per_lcore.h>
#include <rte_launch.h>
#include <rte_eal.h>
#include <rte_lcore.h>
#include <rte_cycles.h>
#include <rte_spinlock.h>

#include "test.h"

/*
 * Spinlock test
 * =============
 *
 * - There is a global spinlock and a table of spinlocks (one per lcore).
 *
 * - The test function takes all of these locks and launches the
 *   ``test_spinlock_per_core()`` function on each core (except the main).
 *
 *   - The function takes the global lock, display something, then releases
 *     the global lock.
 *   - The function takes the per-lcore lock, display something, then releases
 *     the per-core lock.
 *
 * - The main function unlocks the per-lcore locks sequentially and
 *   waits between each lock. This triggers the display of a message
 *   for each core, in the correct order. The autotest script checks that
 *   this order is correct.
 *
 * - A load test is carried out, with all cores attempting to lock a single lock
 *   multiple times
 */

static rte_spinlock_t sl, sl_try;
static rte_spinlock_t sl_tab[RTE_MAX_LCORE];
static rte_spinlock_recursive_t slr;
static unsigned count = 0;

static uint32_t synchro;

static int
test_spinlock_per_core(__rte_unused void *arg)
{
        rte_spinlock_lock(&sl);
        printf("Global lock taken on core %u\n", rte_lcore_id());
        rte_spinlock_unlock(&sl);

        rte_spinlock_lock(&sl_tab[rte_lcore_id()]);
        printf("Hello from core %u !\n", rte_lcore_id());
        rte_spinlock_unlock(&sl_tab[rte_lcore_id()]);

        return 0;
}

static int
test_spinlock_recursive_per_core(__rte_unused void *arg)
{
        unsigned id = rte_lcore_id();

        rte_spinlock_recursive_lock(&slr);
        printf("Global recursive lock taken on core %u - count = %d\n",
               id, slr.count);
        rte_spinlock_recursive_lock(&slr);
        printf("Global recursive lock taken on core %u - count = %d\n",
               id, slr.count);
        rte_spinlock_recursive_lock(&slr);
        printf("Global recursive lock taken on core %u - count = %d\n",
               id, slr.count);

        printf("Hello from within recursive locks from core %u !\n", id);

        rte_spinlock_recursive_unlock(&slr);
        printf("Global recursive lock released on core %u - count = %d\n",
               id, slr.count);
        rte_spinlock_recursive_unlock(&slr);
        printf("Global recursive lock released on core %u - count = %d\n",
               id, slr.count);
        rte_spinlock_recursive_unlock(&slr);
        printf("Global recursive lock released on core %u - count = %d\n",
               id, slr.count);

        return 0;
}

static rte_spinlock_t lk = RTE_SPINLOCK_INITIALIZER;
static uint64_t time_count[RTE_MAX_LCORE] = {0};

#define MAX_LOOP 10000

static int
load_loop_fn(void *func_param)
{
        uint64_t time_diff = 0, begin;
        uint64_t hz = rte_get_timer_hz();
        volatile uint64_t lcount = 0;
        const int use_lock = *(int*)func_param;
        const unsigned lcore = rte_lcore_id();

        /* wait synchro for workers */
        if (lcore != rte_get_main_lcore())
                rte_wait_until_equal_32(&synchro, 1, __ATOMIC_RELAXED);

        begin = rte_get_timer_cycles();
        while (lcount < MAX_LOOP) {
                if (use_lock)
                        rte_spinlock_lock(&lk);
                lcount++;
                if (use_lock)
                        rte_spinlock_unlock(&lk);
        }
        time_diff = rte_get_timer_cycles() - begin;
        time_count[lcore] = time_diff * 1000000 / hz;
        return 0;
}

static int
test_spinlock_perf(void)
{
        unsigned int i;
        uint64_t total = 0;
        int lock = 0;
        const unsigned lcore = rte_lcore_id();

        printf("\nTest with no lock on single core...\n");
        load_loop_fn(&lock);
        printf("Core [%u] Cost Time = %"PRIu64" us\n", lcore,
                                                time_count[lcore]);
        memset(time_count, 0, sizeof(time_count));

        printf("\nTest with lock on single core...\n");
        lock = 1;
        load_loop_fn(&lock);
        printf("Core [%u] Cost Time = %"PRIu64" us\n", lcore,
                                                time_count[lcore]);
        memset(time_count, 0, sizeof(time_count));

        printf("\nTest with lock on %u cores...\n", rte_lcore_count());

        /* Clear synchro and start workers */
        __atomic_store_n(&synchro, 0, __ATOMIC_RELAXED);
        rte_eal_mp_remote_launch(load_loop_fn, &lock, SKIP_MAIN);

        /* start synchro and launch test on main */
        __atomic_store_n(&synchro, 1, __ATOMIC_RELAXED);
        load_loop_fn(&lock);

        rte_eal_mp_wait_lcore();

        RTE_LCORE_FOREACH(i) {
                printf("Core [%u] Cost Time = %"PRIu64" us\n", i,
                                                time_count[i]);
                total += time_count[i];
        }

        printf("Total Cost Time = %"PRIu64" us\n", total);

        return 0;
}

/*
 * Use rte_spinlock_trylock() to trylock a spinlock object,
 * If it could not lock the object successfully, it would
 * return immediately and the variable of "count" would be
 * increased by one per times. the value of "count" could be
 * checked as the result later.
 */
static int
test_spinlock_try(__rte_unused void *arg)
{
        if (rte_spinlock_trylock(&sl_try) == 0) {
                rte_spinlock_lock(&sl);
                count ++;
                rte_spinlock_unlock(&sl);
        }

        return 0;
}


/*
 * Test rte_eal_get_lcore_state() in addition to spinlocks
 * as we have "waiting" then "running" lcores.
 */
static int
test_spinlock(void)
{
        int ret = 0;
        int i;

        /* worker cores should be waiting: print it */
        RTE_LCORE_FOREACH_WORKER(i) {
                printf("lcore %d state: %d\n", i,
                       (int) rte_eal_get_lcore_state(i));
        }

        rte_spinlock_init(&sl);
        rte_spinlock_init(&sl_try);
        rte_spinlock_recursive_init(&slr);
        for (i=0; i<RTE_MAX_LCORE; i++)
                rte_spinlock_init(&sl_tab[i]);

        rte_spinlock_lock(&sl);

        RTE_LCORE_FOREACH_WORKER(i) {
                rte_spinlock_lock(&sl_tab[i]);
                rte_eal_remote_launch(test_spinlock_per_core, NULL, i);
        }

        /* worker cores should be busy: print it */
        RTE_LCORE_FOREACH_WORKER(i) {
                printf("lcore %d state: %d\n", i,
                       (int) rte_eal_get_lcore_state(i));
        }
        rte_spinlock_unlock(&sl);

        RTE_LCORE_FOREACH_WORKER(i) {
                rte_spinlock_unlock(&sl_tab[i]);
                rte_delay_ms(10);
        }

        rte_eal_mp_wait_lcore();

        rte_spinlock_recursive_lock(&slr);

        /*
         * Try to acquire a lock that we already own
         */
        if(!rte_spinlock_recursive_trylock(&slr)) {
                printf("rte_spinlock_recursive_trylock failed on a lock that "
                       "we already own\n");
                ret = -1;
        } else
                rte_spinlock_recursive_unlock(&slr);

        RTE_LCORE_FOREACH_WORKER(i) {
                rte_eal_remote_launch(test_spinlock_recursive_per_core, NULL, i);
        }
        rte_spinlock_recursive_unlock(&slr);
        rte_eal_mp_wait_lcore();

        /*
         * Test if it could return immediately from try-locking a locked object.
         * Here it will lock the spinlock object first, then launch all the worker
         * lcores to trylock the same spinlock object.
         * All the worker lcores should give up try-locking a locked object and
         * return immediately, and then increase the "count" initialized with zero
         * by one per times.
         * We can check if the "count" is finally equal to the number of all worker
         * lcores to see if the behavior of try-locking a locked spinlock object
         * is correct.
         */
        if (rte_spinlock_trylock(&sl_try) == 0) {
                return -1;
        }
        count = 0;
        RTE_LCORE_FOREACH_WORKER(i) {
                rte_eal_remote_launch(test_spinlock_try, NULL, i);
        }
        rte_eal_mp_wait_lcore();
        rte_spinlock_unlock(&sl_try);
        if (rte_spinlock_is_locked(&sl)) {
                printf("spinlock is locked but it should not be\n");
                return -1;
        }
        rte_spinlock_lock(&sl);
        if (count != ( rte_lcore_count() - 1)) {
                ret = -1;
        }
        rte_spinlock_unlock(&sl);

        /*
         * Test if it can trylock recursively.
         * Use rte_spinlock_recursive_trylock() to check if it can lock a spinlock
         * object recursively. Here it will try to lock a spinlock object twice.
         */
        if (rte_spinlock_recursive_trylock(&slr) == 0) {
                printf("It failed to do the first spinlock_recursive_trylock but it should able to do\n");
                return -1;
        }
        if (rte_spinlock_recursive_trylock(&slr) == 0) {
                printf("It failed to do the second spinlock_recursive_trylock but it should able to do\n");
                return -1;
        }
        rte_spinlock_recursive_unlock(&slr);
        rte_spinlock_recursive_unlock(&slr);

        if (test_spinlock_perf() < 0)
                return -1;

        return ret;
}

REGISTER_TEST_COMMAND(spinlock_autotest, test_spinlock);