linux/tools/testing/selftests/riscv/vector/v_helpers.c

// SPDX-License-Identifier: GPL-2.0-only

#include "../hwprobe/hwprobe.h"
#include <asm/vendor/thead.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>

bool is_xtheadvector_supported(void)
{
	struct riscv_hwprobe pair;

	pair.key = RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0;
	riscv_hwprobe(&pair, 1, 0, NULL, 0);
	return pair.value & RISCV_HWPROBE_VENDOR_EXT_XTHEADVECTOR;
}

bool is_vector_supported(void)
{
	struct riscv_hwprobe pair;

	pair.key = RISCV_HWPROBE_KEY_IMA_EXT_0;
	riscv_hwprobe(&pair, 1, 0, NULL, 0);
	return pair.value & RISCV_HWPROBE_EXT_ZVE32X;
}

unsigned long get_vr_len(void)
{
	unsigned long vlenb;

	if (is_vector_supported()) {
		asm volatile("csrr %[vlenb], vlenb" : [vlenb] "=r"(vlenb));
		return vlenb;
	}

	if (is_xtheadvector_supported()) {
		asm volatile (
			// 0 | zimm[10:0] | rs1 | 1 1 1 | rd | 1010111 | vsetvli
			// vsetvli	t4, x0, e8, m1, d1
			".4byte		0b00000000000000000111111011010111\n\t"
			"mv		%[vlenb], t4\n\t"
			: [vlenb] "=r"(vlenb) : : "memory", "t4");
		return vlenb;
	}

	printf("WARNING: vector not supported\n");
	return 0;
}

int launch_test(char *next_program, int test_inherit, int xtheadvector)
{
	char *exec_argv[4], *exec_envp[1];
	int rc, pid, status;

	pid = fork();
	if (pid < 0) {
		printf("fork failed %d", pid);
		return -1;
	}

	if (!pid) {
		exec_argv[0] = next_program;
		exec_argv[1] = test_inherit != 0 ? "x" : NULL;
		exec_argv[2] = xtheadvector != 0 ? "x" : NULL;
		exec_argv[3] = NULL;
		exec_envp[0] = NULL;
		/* launch the program again to check inherit */
		rc = execve(next_program, exec_argv, exec_envp);
		if (rc) {
			perror("execve");
			printf("child execve failed %d\n", rc);
			exit(-1);
		}
	}

	rc = waitpid(-1, &status, 0);
	if (rc < 0) {
		printf("waitpid failed\n");
		return -3;
	}

	if ((WIFEXITED(status) && WEXITSTATUS(status) == -1) ||
	    WIFSIGNALED(status)) {
		printf("child exited abnormally\n");
		return -4;
	}

	return WEXITSTATUS(status);
}