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