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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright 2015, Cyril Bur, IBM Corp.4 *5 * This test attempts to see if the VSX registers change across preemption.6 * There is no way to be sure preemption happened so this test just7 * uses many threads and a long wait. As such, a successful test8 * doesn't mean much but a failure is bad.9 */10 11#include <stdio.h>12#include <string.h>13#include <unistd.h>14#include <sys/syscall.h>15#include <sys/time.h>16#include <sys/types.h>17#include <sys/wait.h>18#include <stdlib.h>19#include <pthread.h>20 21#include "utils.h"22 23/* Time to wait for workers to get preempted (seconds) */24#define PREEMPT_TIME 2025/*26 * Factor by which to multiply number of online CPUs for total number of27 * worker threads28 */29#define THREAD_FACTOR 830 31/*32 * Ensure there is twice the number of non-volatile VMX regs!33 * check_vmx() is going to use the other half as space to put the live34 * registers before calling vsx_memcmp()35 */36__thread vector int varray[24] = {37 {1, 2, 3, 4 }, {5, 6, 7, 8 }, {9, 10,11,12},38 {13,14,15,16}, {17,18,19,20}, {21,22,23,24},39 {25,26,27,28}, {29,30,31,32}, {33,34,35,36},40 {37,38,39,40}, {41,42,43,44}, {45,46,47,48}41};42 43int threads_starting;44int running;45 46extern long preempt_vsx(vector int *varray, int *threads_starting, int *running);47 48long vsx_memcmp(vector int *a) {49 vector int zero = {0, 0, 0, 0};50 int i;51 52 FAIL_IF(a != varray);53 54 for(i = 0; i < 12; i++) {55 if (memcmp(&a[i + 12], &zero, sizeof(vector int)) == 0) {56 fprintf(stderr, "Detected zero from the VSX reg %d\n", i + 12);57 return 2;58 }59 }60 61 if (memcmp(a, &a[12], 12 * sizeof(vector int))) {62 long *p = (long *)a;63 fprintf(stderr, "VSX mismatch\n");64 for (i = 0; i < 24; i=i+2)65 fprintf(stderr, "%d: 0x%08lx%08lx | 0x%08lx%08lx\n",66 i/2 + i%2 + 20, p[i], p[i + 1], p[i + 24], p[i + 25]);67 return 1;68 }69 return 0;70}71 72void *preempt_vsx_c(void *p)73{74 int i, j;75 long rc;76 srand(pthread_self());77 for (i = 0; i < 12; i++)78 for (j = 0; j < 4; j++) {79 varray[i][j] = rand();80 /* Don't want zero because it hides kernel problems */81 if (varray[i][j] == 0)82 j--;83 }84 rc = preempt_vsx(varray, &threads_starting, &running);85 if (rc == 2)86 fprintf(stderr, "Caught zeros in VSX compares\n");87 return (void *)rc;88}89 90int test_preempt_vsx(void)91{92 int i, rc, threads;93 pthread_t *tids;94 95 SKIP_IF(!have_hwcap(PPC_FEATURE_HAS_VSX));96 97 threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR;98 tids = malloc(threads * sizeof(pthread_t));99 FAIL_IF(!tids);100 101 running = true;102 threads_starting = threads;103 for (i = 0; i < threads; i++) {104 rc = pthread_create(&tids[i], NULL, preempt_vsx_c, NULL);105 FAIL_IF(rc);106 }107 108 setbuf(stdout, NULL);109 /* Not really nessesary but nice to wait for every thread to start */110 printf("\tWaiting for %d workers to start...", threads_starting);111 while(threads_starting)112 asm volatile("": : :"memory");113 printf("done\n");114 115 printf("\tWaiting for %d seconds to let some workers get preempted...", PREEMPT_TIME);116 sleep(PREEMPT_TIME);117 printf("done\n");118 119 printf("\tStopping workers...");120 /*121 * Working are checking this value every loop. In preempt_vsx 'cmpwi r5,0; bne 2b'.122 * r5 will have loaded the value of running.123 */124 running = 0;125 for (i = 0; i < threads; i++) {126 void *rc_p;127 pthread_join(tids[i], &rc_p);128 129 /*130 * Harness will say the fail was here, look at why preempt_vsx131 * returned132 */133 if ((long) rc_p)134 printf("oops\n");135 FAIL_IF((long) rc_p);136 }137 printf("done\n");138 139 return 0;140}141 142int main(int argc, char *argv[])143{144 return test_harness(test_preempt_vsx, "vsx_preempt");145}146