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
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