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 <signal.h>
10#include <ucontext.h>
11#include <sys/prctl.h>
12
13#include "test_signals_utils.h"
14#include "testcases.h"
15
16static union {
17	ucontext_t uc;
18	char buf[1024 * 128];
19} context;
20static unsigned int vls[SVE_VQ_MAX];
21unsigned int nvls = 0;
22
23static bool sme_get_vls(struct tdescr *td)
24{
25	int vq, vl;
26
27	/*
28	 * Enumerate up to SME_VQ_MAX vector lengths
29	 */
30	for (vq = SVE_VQ_MAX; vq > 0; --vq) {
31		vl = prctl(PR_SME_SET_VL, vq * 16);
32		if (vl == -1)
33			return false;
34
35		vl &= PR_SME_VL_LEN_MASK;
36
37		/* Did we find the lowest supported VL? */
38		if (vq < sve_vq_from_vl(vl))
39			break;
40
41		/* Skip missing VLs */
42		vq = sve_vq_from_vl(vl);
43
44		vls[nvls++] = vl;
45	}
46
47	/* We need at least one VL */
48	if (nvls < 1) {
49		fprintf(stderr, "Only %d VL supported\n", nvls);
50		return false;
51	}
52
53	return true;
54}
55
56static void setup_za_regs(void)
57{
58	/* smstart za; real data is TODO */
59	asm volatile(".inst 0xd503457f" : : : );
60}
61
62static char zeros[ZA_SIG_REGS_SIZE(SVE_VQ_MAX)];
63
64static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
65			 unsigned int vl)
66{
67	size_t offset;
68	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
69	struct za_context *za;
70
71	fprintf(stderr, "Testing VL %d\n", vl);
72
73	if (prctl(PR_SME_SET_VL, vl) != vl) {
74		fprintf(stderr, "Failed to set VL\n");
75		return 1;
76	}
77
78	/*
79	 * Get a signal context which should have a SVE frame and registers
80	 * in it.
81	 */
82	setup_za_regs();
83	if (!get_current_context(td, &context.uc, sizeof(context)))
84		return 1;
85
86	head = get_header(head, ZA_MAGIC, GET_BUF_RESV_SIZE(context), &offset);
87	if (!head) {
88		fprintf(stderr, "No ZA context\n");
89		return 1;
90	}
91
92	za = (struct za_context *)head;
93	if (za->vl != vl) {
94		fprintf(stderr, "Got VL %d, expected %d\n", za->vl, vl);
95		return 1;
96	}
97
98	if (head->size != ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(vl))) {
99		fprintf(stderr, "ZA context size %u, expected %lu\n",
100			head->size, ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(vl)));
101		return 1;
102	}
103
104	fprintf(stderr, "Got expected size %u and VL %d\n",
105		head->size, za->vl);
106
107	/* We didn't load any data into ZA so it should be all zeros */
108	if (memcmp(zeros, (char *)za + ZA_SIG_REGS_OFFSET,
109		   ZA_SIG_REGS_SIZE(sve_vq_from_vl(za->vl))) != 0) {
110		fprintf(stderr, "ZA data invalid\n");
111		return 1;
112	}
113
114	return 0;
115}
116
117static int sme_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
118{
119	int i;
120
121	for (i = 0; i < nvls; i++) {
122		if (do_one_sme_vl(td, si, uc, vls[i]))
123			return 1;
124	}
125
126	td->pass = 1;
127
128	return 0;
129}
130
131struct tdescr tde = {
132	.name = "ZA register",
133	.descr = "Check that we get the right ZA registers reported",
134	.feats_required = FEAT_SME,
135	.timeout = 3,
136	.init = sme_get_vls,
137	.run = sme_regs,
138};
139