/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2017 Intel Corporation
 */

#include "test.h"

#include <unistd.h>
#include <string.h>
#include <rte_mempool.h>
#include <rte_cycles.h>
#include <rte_common.h>
#include <rte_mbuf.h>
#include <rte_distributor.h>
#include <rte_pause.h>

#define ITER_POWER_CL 25 /* log 2 of how many iterations  for Cache Line test */
#define ITER_POWER 21 /* log 2 of how many iterations we do when timing. */
#define BURST 64
#define BIG_BATCH 1024

/* static vars - zero initialized by default */
static volatile int quit;
static volatile unsigned worker_idx;

struct worker_stats {
        volatile unsigned handled_packets;
} __rte_cache_aligned;
static struct worker_stats worker_stats[RTE_MAX_LCORE];

/*
 * worker thread used for testing the time to do a round-trip of a cache
 * line between two cores and back again
 */
static int
flip_bit(volatile uint64_t *arg)
{
        uint64_t old_val = 0;
        while (old_val != 2) {
                while (!*arg)
                        rte_pause();
                old_val = *arg;
                *arg = 0;
        }
        return 0;
}

/*
 * test case to time the number of cycles to round-trip a cache line between
 * two cores and back again.
 */
static void
time_cache_line_switch(void)
{
        /* allocate a full cache line for data, we use only first byte of it */
        uint64_t data[RTE_CACHE_LINE_SIZE*3 / sizeof(uint64_t)];

        unsigned int i, workerid = rte_get_next_lcore(rte_lcore_id(), 0, 0);
        volatile uint64_t *pdata = &data[0];
        *pdata = 1;
        rte_eal_remote_launch((lcore_function_t *)flip_bit, &data[0], workerid);
        while (*pdata)
                rte_pause();

        const uint64_t start_time = rte_rdtsc();
        for (i = 0; i < (1 << ITER_POWER_CL); i++) {
                while (*pdata)
                        rte_pause();
                *pdata = 1;
        }
        const uint64_t end_time = rte_rdtsc();

        while (*pdata)
                rte_pause();
        *pdata = 2;
        rte_eal_wait_lcore(workerid);
        printf("==== Cache line switch test ===\n");
        printf("Time for %u iterations = %"PRIu64" ticks\n", (1<<ITER_POWER_CL),
                        end_time-start_time);
        printf("Ticks per iteration = %"PRIu64"\n\n",
                        (end_time-start_time) >> ITER_POWER_CL);
}

/*
 * returns the total count of the number of packets handled by the worker
 * functions given below.
 */
static unsigned
total_packet_count(void)
{
        unsigned i, count = 0;
        for (i = 0; i < worker_idx; i++)
                count += worker_stats[i].handled_packets;
        return count;
}

/* resets the packet counts for a new test */
static void
clear_packet_count(void)
{
        memset(&worker_stats, 0, sizeof(worker_stats));
}

/*
 * This is the basic worker function for performance tests.
 * it does nothing but return packets and count them.
 */
static int
handle_work(void *arg)
{
        struct rte_distributor *d = arg;
        unsigned int num = 0;
        int i;
        unsigned int id = __atomic_fetch_add(&worker_idx, 1, __ATOMIC_RELAXED);
        struct rte_mbuf *buf[8] __rte_cache_aligned;

        for (i = 0; i < 8; i++)
                buf[i] = NULL;

        num = rte_distributor_get_pkt(d, id, buf, buf, num);
        while (!quit) {
                worker_stats[id].handled_packets += num;
                num = rte_distributor_get_pkt(d, id, buf, buf, num);
        }
        worker_stats[id].handled_packets += num;
        rte_distributor_return_pkt(d, id, buf, num);
        return 0;
}

/*
 * This basic performance test just repeatedly sends in 32 packets at a time
 * to the distributor and verifies at the end that we got them all in the worker
 * threads and finally how long per packet the processing took.
 */
static inline int
perf_test(struct rte_distributor *d, struct rte_mempool *p)
{
        unsigned int i;
        uint64_t start, end;
        struct rte_mbuf *bufs[BURST];

        clear_packet_count();
        if (rte_mempool_get_bulk(p, (void *)bufs, BURST) != 0) {
                printf("Error getting mbufs from pool\n");
                return -1;
        }
        /* ensure we have different hash value for each pkt */
        for (i = 0; i < BURST; i++)
                bufs[i]->hash.usr = i;

        start = rte_rdtsc();
        for (i = 0; i < (1<<ITER_POWER); i++)
                rte_distributor_process(d, bufs, BURST);
        end = rte_rdtsc();

        do {
                usleep(100);
                rte_distributor_process(d, NULL, 0);
        } while (total_packet_count() < (BURST << ITER_POWER));

        rte_distributor_clear_returns(d);

        printf("Time per burst:  %"PRIu64"\n", (end - start) >> ITER_POWER);
        printf("Time per packet: %"PRIu64"\n\n",
                        ((end - start) >> ITER_POWER)/BURST);
        rte_mempool_put_bulk(p, (void *)bufs, BURST);

        for (i = 0; i < rte_lcore_count() - 1; i++)
                printf("Worker %u handled %u packets\n", i,
                                worker_stats[i].handled_packets);
        printf("Total packets: %u (%x)\n", total_packet_count(),
                        total_packet_count());
        printf("=== Perf test done ===\n\n");

        return 0;
}

/* Useful function which ensures that all worker functions terminate */
static void
quit_workers(struct rte_distributor *d, struct rte_mempool *p)
{
        const unsigned int num_workers = rte_lcore_count() - 1;
        unsigned int i;
        struct rte_mbuf *bufs[RTE_MAX_LCORE];

        rte_mempool_get_bulk(p, (void *)bufs, num_workers);

        quit = 1;
        for (i = 0; i < num_workers; i++) {
                bufs[i]->hash.usr = i << 1;
                rte_distributor_process(d, &bufs[i], 1);
        }

        rte_mempool_put_bulk(p, (void *)bufs, num_workers);

        rte_distributor_process(d, NULL, 0);
        rte_distributor_flush(d);
        rte_eal_mp_wait_lcore();
        quit = 0;
        worker_idx = 0;
}

static int
test_distributor_perf(void)
{
        static struct rte_distributor *ds;
        static struct rte_distributor *db;
        static struct rte_mempool *p;

        if (rte_lcore_count() < 2) {
                printf("Not enough cores for distributor_perf_autotest, expecting at least 2\n");
                return TEST_SKIPPED;
        }

        /* first time how long it takes to round-trip a cache line */
        time_cache_line_switch();

        if (ds == NULL) {
                ds = rte_distributor_create("Test_perf", rte_socket_id(),
                                rte_lcore_count() - 1,
                                RTE_DIST_ALG_SINGLE);
                if (ds == NULL) {
                        printf("Error creating distributor\n");
                        return -1;
                }
        } else {
                rte_distributor_clear_returns(ds);
        }

        if (db == NULL) {
                db = rte_distributor_create("Test_burst", rte_socket_id(),
                                rte_lcore_count() - 1,
                                RTE_DIST_ALG_BURST);
                if (db == NULL) {
                        printf("Error creating burst distributor\n");
                        return -1;
                }
        } else {
                rte_distributor_clear_returns(db);
        }

        const unsigned nb_bufs = (511 * rte_lcore_count()) < BIG_BATCH ?
                        (BIG_BATCH * 2) - 1 : (511 * rte_lcore_count());
        if (p == NULL) {
                p = rte_pktmbuf_pool_create("DPT_MBUF_POOL", nb_bufs, BURST,
                        0, RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id());
                if (p == NULL) {
                        printf("Error creating mempool\n");
                        return -1;
                }
        }

        printf("=== Performance test of distributor (single mode) ===\n");
        rte_eal_mp_remote_launch(handle_work, ds, SKIP_MAIN);
        if (perf_test(ds, p) < 0)
                return -1;
        quit_workers(ds, p);

        printf("=== Performance test of distributor (burst mode) ===\n");
        rte_eal_mp_remote_launch(handle_work, db, SKIP_MAIN);
        if (perf_test(db, p) < 0)
                return -1;
        quit_workers(db, p);

        return 0;
}

REGISTER_TEST_COMMAND(distributor_perf_autotest, test_distributor_perf);