1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright 2015, Cyril Bur, IBM Corp.
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
15 #include <sys/syscall.h>
17 #include <sys/types.h>
24 /* Time to wait for workers to get preempted (seconds) */
25 #define PREEMPT_TIME 20
27 * Factor by which to multiply number of online CPUs for total number of
30 #define THREAD_FACTOR 8
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}};
40 extern void preempt_vmx(vector int *varray, int *threads_starting, int *running);
42 void *preempt_vmx_c(void *p)
45 srand(pthread_self());
46 for (i = 0; i < 12; i++)
47 for (j = 0; j < 4; j++)
48 varray[i][j] = rand();
50 /* Test fails if it ever returns */
51 preempt_vmx(varray, &threads_starting, &running);
55 int test_preempt_vmx(void)
60 // vcmpequd used in vmx_asm.S is v2.07
61 SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07));
63 threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR;
64 tids = malloc(threads * sizeof(pthread_t));
68 threads_starting = threads;
69 for (i = 0; i < threads; i++) {
70 rc = pthread_create(&tids[i], NULL, preempt_vmx_c, NULL);
75 /* Not really nessesary but nice to wait for every thread to start */
76 printf("\tWaiting for all workers to start...");
77 while(threads_starting)
78 asm volatile("": : :"memory");
81 printf("\tWaiting for %d seconds to let some workers get preempted...", PREEMPT_TIME);
85 printf("\tStopping workers...");
87 * Working are checking this value every loop. In preempt_vmx 'cmpwi r5,0; bne 2b'.
88 * r5 will have loaded the value of running.
91 for (i = 0; i < threads; i++) {
93 pthread_join(tids[i], &rc_p);
96 * Harness will say the fail was here, look at why preempt_vmx
101 FAIL_IF((long) rc_p);
108 int main(int argc, char *argv[])
110 return test_harness(test_preempt_vmx, "vmx_preempt");