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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
65ca668f CB |
2 | /* |
3 | * Copyright 2015, Cyril Bur, IBM Corp. | |
4 | * | |
65ca668f CB |
5 | * This test attempts to see if the VSX registers change across preemption. |
6 | * There is no way to be sure preemption happened so this test just | |
7 | * uses many threads and a long wait. As such, a successful test | |
8 | * doesn't mean much but a failure is bad. | |
9 | */ | |
10 | ||
11 | #include <stdio.h> | |
12 | #include <string.h> | |
13 | #include <unistd.h> | |
14 | #include <sys/syscall.h> | |
15 | #include <sys/time.h> | |
16 | #include <sys/types.h> | |
17 | #include <sys/wait.h> | |
18 | #include <stdlib.h> | |
19 | #include <pthread.h> | |
20 | ||
21 | #include "utils.h" | |
22 | ||
23 | /* Time to wait for workers to get preempted (seconds) */ | |
24 | #define PREEMPT_TIME 20 | |
25 | /* | |
26 | * Factor by which to multiply number of online CPUs for total number of | |
27 | * worker threads | |
28 | */ | |
29 | #define THREAD_FACTOR 8 | |
30 | ||
31 | /* | |
32 | * Ensure there is twice the number of non-volatile VMX regs! | |
33 | * check_vmx() is going to use the other half as space to put the live | |
34 | * registers before calling vsx_memcmp() | |
35 | */ | |
36 | __thread vector int varray[24] = { | |
37 | {1, 2, 3, 4 }, {5, 6, 7, 8 }, {9, 10,11,12}, | |
38 | {13,14,15,16}, {17,18,19,20}, {21,22,23,24}, | |
39 | {25,26,27,28}, {29,30,31,32}, {33,34,35,36}, | |
40 | {37,38,39,40}, {41,42,43,44}, {45,46,47,48} | |
41 | }; | |
42 | ||
43 | int threads_starting; | |
44 | int running; | |
45 | ||
46 | extern long preempt_vsx(vector int *varray, int *threads_starting, int *running); | |
47 | ||
48 | long vsx_memcmp(vector int *a) { | |
49 | vector int zero = {0, 0, 0, 0}; | |
50 | int i; | |
51 | ||
52 | FAIL_IF(a != varray); | |
53 | ||
54 | for(i = 0; i < 12; i++) { | |
55 | if (memcmp(&a[i + 12], &zero, sizeof(vector int)) == 0) { | |
56 | fprintf(stderr, "Detected zero from the VSX reg %d\n", i + 12); | |
57 | return 2; | |
58 | } | |
59 | } | |
60 | ||
61 | if (memcmp(a, &a[12], 12 * sizeof(vector int))) { | |
62 | long *p = (long *)a; | |
63 | fprintf(stderr, "VSX mismatch\n"); | |
64 | for (i = 0; i < 24; i=i+2) | |
65 | fprintf(stderr, "%d: 0x%08lx%08lx | 0x%08lx%08lx\n", | |
66 | i/2 + i%2 + 20, p[i], p[i + 1], p[i + 24], p[i + 25]); | |
67 | return 1; | |
68 | } | |
69 | return 0; | |
70 | } | |
71 | ||
72 | void *preempt_vsx_c(void *p) | |
73 | { | |
74 | int i, j; | |
75 | long rc; | |
76 | srand(pthread_self()); | |
77 | for (i = 0; i < 12; i++) | |
78 | for (j = 0; j < 4; j++) { | |
79 | varray[i][j] = rand(); | |
80 | /* Don't want zero because it hides kernel problems */ | |
81 | if (varray[i][j] == 0) | |
82 | j--; | |
83 | } | |
84 | rc = preempt_vsx(varray, &threads_starting, &running); | |
85 | if (rc == 2) | |
86 | fprintf(stderr, "Caught zeros in VSX compares\n"); | |
87 | return (void *)rc; | |
88 | } | |
89 | ||
90 | int test_preempt_vsx(void) | |
91 | { | |
92 | int i, rc, threads; | |
93 | pthread_t *tids; | |
94 | ||
95 | threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR; | |
96 | tids = malloc(threads * sizeof(pthread_t)); | |
97 | FAIL_IF(!tids); | |
98 | ||
99 | running = true; | |
100 | threads_starting = threads; | |
101 | for (i = 0; i < threads; i++) { | |
102 | rc = pthread_create(&tids[i], NULL, preempt_vsx_c, NULL); | |
103 | FAIL_IF(rc); | |
104 | } | |
105 | ||
106 | setbuf(stdout, NULL); | |
107 | /* Not really nessesary but nice to wait for every thread to start */ | |
108 | printf("\tWaiting for %d workers to start...", threads_starting); | |
109 | while(threads_starting) | |
110 | asm volatile("": : :"memory"); | |
111 | printf("done\n"); | |
112 | ||
113 | printf("\tWaiting for %d seconds to let some workers get preempted...", PREEMPT_TIME); | |
114 | sleep(PREEMPT_TIME); | |
115 | printf("done\n"); | |
116 | ||
117 | printf("\tStopping workers..."); | |
118 | /* | |
119 | * Working are checking this value every loop. In preempt_vsx 'cmpwi r5,0; bne 2b'. | |
120 | * r5 will have loaded the value of running. | |
121 | */ | |
122 | running = 0; | |
123 | for (i = 0; i < threads; i++) { | |
124 | void *rc_p; | |
125 | pthread_join(tids[i], &rc_p); | |
126 | ||
127 | /* | |
128 | * Harness will say the fail was here, look at why preempt_vsx | |
129 | * returned | |
130 | */ | |
131 | if ((long) rc_p) | |
132 | printf("oops\n"); | |
133 | FAIL_IF((long) rc_p); | |
134 | } | |
135 | printf("done\n"); | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
140 | int main(int argc, char *argv[]) | |
141 | { | |
142 | return test_harness(test_preempt_vsx, "vsx_preempt"); | |
143 | } |