// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2015, Cyril Bur, IBM Corp.
 *
 * This test attempts to see if the VMX registers change across preemption.
 * Two things should be noted here a) The check_vmx function in asm only checks
 * the non volatile registers as it is reused from the syscall test b) There is
 * no way to be sure preemption happened so this test just uses many threads
 * and a long wait. As such, a successful test doesn't mean much but a failure
 * is bad.
 */

#include <stdio.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <pthread.h>

#include "utils.h"

/* Time to wait for workers to get preempted (seconds) */
#define PREEMPT_TIME 20
/*
 * Factor by which to multiply number of online CPUs for total number of
 * worker threads
 */
#define THREAD_FACTOR 8

__thread vector int varray[] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10,11,12},
        {13,14,15,16},{17,18,19,20},{21,22,23,24},
        {25,26,27,28},{29,30,31,32},{33,34,35,36},
        {37,38,39,40},{41,42,43,44},{45,46,47,48}};

int threads_starting;
int running;

extern int preempt_vmx(vector int *varray, int *threads_starting, int *running);

void *preempt_vmx_c(void *p)
{
        int i, j;
        long rc;

        srand(pthread_self());
        for (i = 0; i < 12; i++)
                for (j = 0; j < 4; j++)
                        varray[i][j] = rand();

        rc = preempt_vmx(varray, &threads_starting, &running);

        return (void *)rc;
}

int test_preempt_vmx(void)
{
        int i, rc, threads;
        pthread_t *tids;

        // vcmpequd used in vmx_asm.S is v2.07
        SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07));

        threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR;
        tids = malloc(threads * sizeof(pthread_t));
        FAIL_IF(!tids);

        running = true;
        threads_starting = threads;
        for (i = 0; i < threads; i++) {
                rc = pthread_create(&tids[i], NULL, preempt_vmx_c, NULL);
                FAIL_IF(rc);
        }

        setbuf(stdout, NULL);
        /* Not really nessesary but nice to wait for every thread to start */
        printf("\tWaiting for all workers to start...");
        while(threads_starting)
                asm volatile("": : :"memory");
        printf("done\n");

        printf("\tWaiting for %d seconds to let some workers get preempted...", PREEMPT_TIME);
        sleep(PREEMPT_TIME);
        printf("done\n");

        printf("\tStopping workers...");
        /*
         * Working are checking this value every loop. In preempt_vmx 'cmpwi r5,0; bne 2b'.
         * r5 will have loaded the value of running.
         */
        running = 0;
        for (i = 0; i < threads; i++) {
                void *rc_p;
                pthread_join(tids[i], &rc_p);

                /*
                 * Harness will say the fail was here, look at why preempt_vmx
                 * returned
                 */
                if ((long) rc_p)
                        printf("oops\n");
                FAIL_IF((long) rc_p);
        }
        printf("done\n");

        return 0;
}

int main(int argc, char *argv[])
{
        return test_harness(test_preempt_vmx, "vmx_preempt");
}