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 are correctly reported in a
6  * signal context. Each worker just spins checking its VMX registers, at some
7  * point a signal will interrupt it and C code will check the signal context
8  * ensuring it is also the same.
9  */
10 
11 #include <stdio.h>
12 #include <unistd.h>
13 #include <sys/syscall.h>
14 #include <sys/time.h>
15 #include <sys/types.h>
16 #include <sys/wait.h>
17 #include <stdlib.h>
18 #include <string.h>
19 #include <pthread.h>
20 #include <altivec.h>
21 
22 #include "utils.h"
23 
24 /* Number of times each thread should receive the signal */
25 #define ITERATIONS 10
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 bool bad_context;
38 int running;
39 int threads_starting;
40 
41 extern int preempt_vmx(vector int *varray, int *threads_starting, int *sentinal);
42 
signal_vmx_sig(int sig,siginfo_t * info,void * context)43 void signal_vmx_sig(int sig, siginfo_t *info, void *context)
44 {
45 	int i;
46 	ucontext_t *uc = context;
47 	mcontext_t *mc = &uc->uc_mcontext;
48 
49 	/* Only the non volatiles were loaded up */
50 	for (i = 20; i < 32; i++) {
51 		if (memcmp(mc->v_regs->vrregs[i], &varray[i - 20], 16)) {
52 			int j;
53 			/*
54 			 * Shouldn't printf() in a signal handler, however, this is a
55 			 * test and we've detected failure. Understanding what failed
56 			 * is paramount. All that happens after this is tests exit with
57 			 * failure.
58 			 */
59 			printf("VMX mismatch at reg %d!\n", i);
60 			printf("Reg | Actual                  | Expected\n");
61 			for (j = 20; j < 32; j++) {
62 				printf("%d  | 0x%04x%04x%04x%04x      | 0x%04x%04x%04x%04x\n", j, mc->v_regs->vrregs[j][0],
63 					   mc->v_regs->vrregs[j][1], mc->v_regs->vrregs[j][2], mc->v_regs->vrregs[j][3],
64 					   varray[j - 20][0], varray[j - 20][1], varray[j - 20][2], varray[j - 20][3]);
65 			}
66 			bad_context = true;
67 			break;
68 		}
69 	}
70 }
71 
signal_vmx_c(void * p)72 void *signal_vmx_c(void *p)
73 {
74 	int i, j;
75 	long rc;
76 	struct sigaction act;
77 	act.sa_sigaction = signal_vmx_sig;
78 	act.sa_flags = SA_SIGINFO;
79 	rc = sigaction(SIGUSR1, &act, NULL);
80 	if (rc)
81 		return p;
82 
83 	srand(pthread_self());
84 	for (i = 0; i < 12; i++)
85 		for (j = 0; j < 4; j++)
86 			varray[i][j] = rand();
87 
88 	rc = preempt_vmx(varray, &threads_starting, &running);
89 
90 	return (void *) rc;
91 }
92 
test_signal_vmx(void)93 int test_signal_vmx(void)
94 {
95 	int i, j, rc, threads;
96 	void *rc_p;
97 	pthread_t *tids;
98 
99 	// vcmpequd used in vmx_asm.S is v2.07
100 	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07));
101 
102 	threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR;
103 	tids = malloc(threads * sizeof(pthread_t));
104 	FAIL_IF(!tids);
105 
106 	running = true;
107 	threads_starting = threads;
108 	for (i = 0; i < threads; i++) {
109 		rc = pthread_create(&tids[i], NULL, signal_vmx_c, NULL);
110 		FAIL_IF(rc);
111 	}
112 
113 	setbuf(stdout, NULL);
114 	printf("\tWaiting for %d workers to start... %d", threads, threads_starting);
115 	while (threads_starting) {
116 		asm volatile("": : :"memory");
117 		usleep(1000);
118 		printf(", %d", threads_starting);
119 	}
120 	printf(" ...done\n");
121 
122 	printf("\tSending signals to all threads %d times...", ITERATIONS);
123 	for (i = 0; i < ITERATIONS; i++) {
124 		for (j = 0; j < threads; j++) {
125 			pthread_kill(tids[j], SIGUSR1);
126 		}
127 		sleep(1);
128 	}
129 	printf("done\n");
130 
131 	printf("\tKilling workers...");
132 	running = 0;
133 	for (i = 0; i < threads; i++) {
134 		pthread_join(tids[i], &rc_p);
135 
136 		/*
137 		 * Harness will say the fail was here, look at why signal_vmx
138 		 * returned
139 		 */
140 		if ((long) rc_p || bad_context)
141 			printf("oops\n");
142 		if (bad_context)
143 			fprintf(stderr, "\t!! bad_context is true\n");
144 		FAIL_IF((long) rc_p || bad_context);
145 	}
146 	printf("done\n");
147 
148 	free(tids);
149 	return 0;
150 }
151 
main(int argc,char * argv[])152 int main(int argc, char *argv[])
153 {
154 	return test_harness(test_signal_vmx, "vmx_signal");
155 }
156