1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright 2015, Cyril Bur, IBM Corp. 4 * 5 * This test attempts to see if the VMX registers change across preemption. 6 * Two things should be noted here a) The check_vmx function in asm only checks 7 * the non volatile registers as it is reused from the syscall test b) There is 8 * no way to be sure preemption happened so this test just uses many threads 9 * and a long wait. As such, a successful test doesn't mean much but a failure 10 * is bad. 11 */ 12 13 #include <stdio.h> 14 #include <unistd.h> 15 #include <sys/syscall.h> 16 #include <sys/time.h> 17 #include <sys/types.h> 18 #include <sys/wait.h> 19 #include <stdlib.h> 20 #include <pthread.h> 21 22 #include "utils.h" 23 24 /* Time to wait for workers to get preempted (seconds) */ 25 #define PREEMPT_TIME 20 26 /* 27 * Factor by which to multiply number of online CPUs for total number of 28 * worker threads 29 */ 30 #define THREAD_FACTOR 8 31 32 __thread vector int varray[] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10,11,12}, 33 {13,14,15,16},{17,18,19,20},{21,22,23,24}, 34 {25,26,27,28},{29,30,31,32},{33,34,35,36}, 35 {37,38,39,40},{41,42,43,44},{45,46,47,48}}; 36 37 int threads_starting; 38 int running; 39 40 extern int preempt_vmx(vector int *varray, int *threads_starting, int *running); 41 42 void *preempt_vmx_c(void *p) 43 { 44 int i, j; 45 long rc; 46 47 srand(pthread_self()); 48 for (i = 0; i < 12; i++) 49 for (j = 0; j < 4; j++) 50 varray[i][j] = rand(); 51 52 rc = preempt_vmx(varray, &threads_starting, &running); 53 54 return (void *)rc; 55 } 56 57 int test_preempt_vmx(void) 58 { 59 int i, rc, threads; 60 pthread_t *tids; 61 62 // vcmpequd used in vmx_asm.S is v2.07 63 SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07)); 64 65 threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR; 66 tids = malloc(threads * sizeof(pthread_t)); 67 FAIL_IF(!tids); 68 69 running = true; 70 threads_starting = threads; 71 for (i = 0; i < threads; i++) { 72 rc = pthread_create(&tids[i], NULL, preempt_vmx_c, NULL); 73 FAIL_IF(rc); 74 } 75 76 setbuf(stdout, NULL); 77 /* Not really nessesary but nice to wait for every thread to start */ 78 printf("\tWaiting for all workers to start..."); 79 while(threads_starting) 80 asm volatile("": : :"memory"); 81 printf("done\n"); 82 83 printf("\tWaiting for %d seconds to let some workers get preempted...", PREEMPT_TIME); 84 sleep(PREEMPT_TIME); 85 printf("done\n"); 86 87 printf("\tStopping workers..."); 88 /* 89 * Working are checking this value every loop. In preempt_vmx 'cmpwi r5,0; bne 2b'. 90 * r5 will have loaded the value of running. 91 */ 92 running = 0; 93 for (i = 0; i < threads; i++) { 94 void *rc_p; 95 pthread_join(tids[i], &rc_p); 96 97 /* 98 * Harness will say the fail was here, look at why preempt_vmx 99 * returned 100 */ 101 if ((long) rc_p) 102 printf("oops\n"); 103 FAIL_IF((long) rc_p); 104 } 105 printf("done\n"); 106 107 return 0; 108 } 109 110 int main(int argc, char *argv[]) 111 { 112 return test_harness(test_preempt_vmx, "vmx_preempt"); 113 } 114