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
37int threads_starting;
38int running;
39
40extern int preempt_vmx(vector int *varray, int *threads_starting, int *running);
41
42void *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
57int 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
110int main(int argc, char *argv[])
111{
112	return test_harness(test_preempt_vmx, "vmx_preempt");
113}
114