za_regs.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2021 ARM Limited
  4 *
  5 * Verify that the ZA register context in signal frames is set up as
  6 * expected.
  7 */
  8
  9#include <kselftest.h>
 10#include <signal.h>
 11#include <ucontext.h>
 12#include <sys/prctl.h>
 13
 14#include "test_signals_utils.h"
 15#include "sve_helpers.h"
 16#include "testcases.h"
 17
 18static union {
 19	ucontext_t uc;
 20	char buf[1024 * 128];
 21} context;
 22
 23static bool sme_get_vls(struct tdescr *td)
 24{
 25	int res = sve_fill_vls(VLS_USE_SME, 1);
 26
 27	if (!res)
 28		return true;
 29
 30	if (res == KSFT_SKIP)
 31		td->result = KSFT_SKIP;
 32
 33	return false;
 34}
 35
 36static void setup_za_regs(void)
 37{
 38	/* smstart za; real data is TODO */
 39	asm volatile(".inst 0xd503457f" : : : );
 40}
 41
 42static char zeros[ZA_SIG_REGS_SIZE(SVE_VQ_MAX)];
 43
 44static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 45			 unsigned int vl)
 46{
 47	size_t offset;
 48	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
 49	struct za_context *za;
 50
 51	fprintf(stderr, "Testing VL %d\n", vl);
 52
 53	if (prctl(PR_SME_SET_VL, vl) != vl) {
 54		fprintf(stderr, "Failed to set VL\n");
 55		return 1;
 56	}
 57
 58	/*
 59	 * Get a signal context which should have a SVE frame and registers
 60	 * in it.
 61	 */
 62	setup_za_regs();
 63	if (!get_current_context(td, &context.uc, sizeof(context)))
 64		return 1;
 65
 66	head = get_header(head, ZA_MAGIC, GET_BUF_RESV_SIZE(context), &offset);
 67	if (!head) {
 68		fprintf(stderr, "No ZA context\n");
 69		return 1;
 70	}
 71
 72	za = (struct za_context *)head;
 73	if (za->vl != vl) {
 74		fprintf(stderr, "Got VL %d, expected %d\n", za->vl, vl);
 75		return 1;
 76	}
 77
 78	if (head->size != ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(vl))) {
 79		fprintf(stderr, "ZA context size %u, expected %lu\n",
 80			head->size, ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(vl)));
 81		return 1;
 82	}
 83
 84	fprintf(stderr, "Got expected size %u and VL %d\n",
 85		head->size, za->vl);
 86
 87	/* We didn't load any data into ZA so it should be all zeros */
 88	if (memcmp(zeros, (char *)za + ZA_SIG_REGS_OFFSET,
 89		   ZA_SIG_REGS_SIZE(sve_vq_from_vl(za->vl))) != 0) {
 90		fprintf(stderr, "ZA data invalid\n");
 91		return 1;
 92	}
 93
 94	if (get_svcr() != 0) {
 95		fprintf(stderr, "Unexpected SVCR %lx\n", get_svcr());
 96		return 1;
 97	}
 98
 99	return 0;
100}
101
102static int sme_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
103{
104	int i;
105
106	for (i = 0; i < nvls; i++) {
107		if (do_one_sme_vl(td, si, uc, vls[i]))
108			return 1;
109	}
110
111	td->pass = 1;
112
113	return 0;
114}
115
116struct tdescr tde = {
117	.name = "ZA register",
118	.descr = "Check that we get the right ZA registers reported",
119	.feats_required = FEAT_SME,
120	.timeout = 3,
121	.init = sme_get_vls,
122	.run = sme_regs,
123};