linux/tools/testing/selftests/powerpc/math/vmx_signal.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2015, Cyril Bur, IBM Corp.
 *
 * This test attempts to see if the VMX registers are correctly reported in a
 * signal context. Each worker just spins checking its VMX registers, at some
 * point a signal will interrupt it and C code will check the signal context
 * ensuring it is also the same.
 */

#include <stdio.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <altivec.h>

#include "utils.h"

/* Number of times each thread should receive the signal */
#define ITERATIONS 10
/*
 * Factor by which to multiply number of online CPUs for total number of
 * worker threads
 */
#define THREAD_FACTOR 8

__thread vector int varray[] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10,11,12},
	{13,14,15,16},{17,18,19,20},{21,22,23,24},
	{25,26,27,28},{29,30,31,32},{33,34,35,36},
	{37,38,39,40},{41,42,43,44},{45,46,47,48}};

bool bad_context;
int running;
int threads_starting;

extern int preempt_vmx(vector int *varray, int *threads_starting, int *sentinal);

void signal_vmx_sig(int sig, siginfo_t *info, void *context)
{
	int i;
	ucontext_t *uc = context;
	mcontext_t *mc = &uc->uc_mcontext;

	/* Only the non volatiles were loaded up */
	for (i = 20; i < 32; i++) {
		if (memcmp(mc->v_regs->vrregs[i], &varray[i - 20], 16)) {
			int j;
			/*
			 * Shouldn't printf() in a signal handler, however, this is a
			 * test and we've detected failure. Understanding what failed
			 * is paramount. All that happens after this is tests exit with
			 * failure.
			 */
			printf("VMX mismatch at reg %d!\n", i);
			printf("Reg | Actual                  | Expected\n");
			for (j = 20; j < 32; j++) {
				printf("%d  | 0x%04x%04x%04x%04x      | 0x%04x%04x%04x%04x\n", j, mc->v_regs->vrregs[j][0],
					   mc->v_regs->vrregs[j][1], mc->v_regs->vrregs[j][2], mc->v_regs->vrregs[j][3],
					   varray[j - 20][0], varray[j - 20][1], varray[j - 20][2], varray[j - 20][3]);
			}
			bad_context = true;
			break;
		}
	}
}

void *signal_vmx_c(void *p)
{
	int i, j;
	long rc;
	struct sigaction act;
	act.sa_sigaction = signal_vmx_sig;
	act.sa_flags = SA_SIGINFO;
	rc = sigaction(SIGUSR1, &act, NULL);
	if (rc)
		return p;

	srand(pthread_self());
	for (i = 0; i < 12; i++)
		for (j = 0; j < 4; j++)
			varray[i][j] = rand();

	rc = preempt_vmx(varray, &threads_starting, &running);

	return (void *) rc;
}

int test_signal_vmx(void)
{
	int i, j, rc, threads;
	void *rc_p;
	pthread_t *tids;

	// vcmpequd used in vmx_asm.S is v2.07
	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07));

	threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR;
	tids = malloc(threads * sizeof(pthread_t));
	FAIL_IF(!tids);

	running = true;
	threads_starting = threads;
	for (i = 0; i < threads; i++) {
		rc = pthread_create(&tids[i], NULL, signal_vmx_c, NULL);
		FAIL_IF(rc);
	}

	setbuf(stdout, NULL);
	printf("\tWaiting for %d workers to start... %d", threads, threads_starting);
	while (threads_starting) {
		asm volatile("": : :"memory");
		usleep(1000);
		printf(", %d", threads_starting);
	}
	printf(" ...done\n");

	printf("\tSending signals to all threads %d times...", ITERATIONS);
	for (i = 0; i < ITERATIONS; i++) {
		for (j = 0; j < threads; j++) {
			pthread_kill(tids[j], SIGUSR1);
		}
		sleep(1);
	}
	printf("done\n");

	printf("\tKilling workers...");
	running = 0;
	for (i = 0; i < threads; i++) {
		pthread_join(tids[i], &rc_p);

		/*
		 * Harness will say the fail was here, look at why signal_vmx
		 * returned
		 */
		if ((long) rc_p || bad_context)
			printf("oops\n");
		if (bad_context)
			fprintf(stderr, "\t!! bad_context is true\n");
		FAIL_IF((long) rc_p || bad_context);
	}
	printf("done\n");

	free(tids);
	return 0;
}

int main(int argc, char *argv[])
{
	return test_harness(test_signal_vmx, "vmx_signal");
}