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 
16 static union {
17 	ucontext_t uc;
18 	char buf[1024 * 128];
19 } context;
20 static unsigned int vls[SVE_VQ_MAX];
21 unsigned int nvls = 0;
22 
23 static 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 
56 static void setup_za_regs(void)
57 {
58 	/* smstart za; real data is TODO */
59 	asm volatile(".inst 0xd503457f" : : : );
60 }
61 
62 static char zeros[ZA_SIG_REGS_SIZE(SVE_VQ_MAX)];
63 
64 static 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 
117 static 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 
131 struct 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