selftests: arm64: Test case for enumeration of SVE vector lengths

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

/*

 * Copyright (C) 2015-2020 ARM Limited.

 * Original author: Dave Martin <Dave.Martin@arm.com>

 */

#include <assert.h>

#include <errno.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sys/auxv.h>

#include <sys/prctl.h>

#include <asm/sigcontext.h>

#include "../../kselftest.h"

int main(int argc, char **argv)

{

	unsigned int vq;

	int vl;

	static unsigned int vqs[SVE_VQ_MAX];

	unsigned int nvqs = 0;

	ksft_print_header();

	ksft_set_plan(2);

	if (!(getauxval(AT_HWCAP) & HWCAP_SVE))

		ksft_exit_skip("SVE not available");

	/*

	 * Enumerate up to SVE_VQ_MAX vector lengths

	 */

	for (vq = SVE_VQ_MAX; vq > 0; --vq) {

		vl = prctl(PR_SVE_SET_VL, vq * 16);

		if (vl == -1)

			ksft_exit_fail_msg("PR_SVE_SET_VL failed: %s (%d)\n",

					   strerror(errno), errno);

		vl &= PR_SVE_VL_LEN_MASK;

		if (!sve_vl_valid(vl))

			ksft_exit_fail_msg("VL %d invalid\n", vl);

		vq = sve_vq_from_vl(vl);

		if (!(nvqs < SVE_VQ_MAX))

			ksft_exit_fail_msg("Too many VLs %u >= SVE_VQ_MAX\n",

					   nvqs);

		vqs[nvqs++] = vq;

	}

	ksft_test_result_pass("Enumerated %d vector lengths\n", nvqs);

	ksft_test_result_pass("All vector lengths valid\n");

	/* Print out the vector lengths in ascending order: */

	while (nvqs--)

		ksft_print_msg("%u\n", 16 * vqs[nvqs]);

	ksft_exit_pass();

}