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 		/* Skip missing VLs */
38 		vq = sve_vq_from_vl(vl);
39 
40 		vls[nvls++] = vl;
41 	}
42 
43 	/* We need at least one VL */
44 	if (nvls < 1) {
45 		fprintf(stderr, "Only %d VL supported\n", nvls);
46 		return false;
47 	}
48 
49 	return true;
50 }
51 
52 static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
53 			 unsigned int vl)
54 {
55 	size_t offset;
56 	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
57 	struct za_context *za;
58 
59 	fprintf(stderr, "Testing VL %d\n", vl);
60 
61 	if (prctl(PR_SME_SET_VL, vl) != vl) {
62 		fprintf(stderr, "Failed to set VL\n");
63 		return 1;
64 	}
65 
66 	/*
67 	 * Get a signal context which should have a SVE frame and registers
68 	 * in it.
69 	 */
70 	if (!get_current_context(td, &context.uc, sizeof(context)))
71 		return 1;
72 
73 	head = get_header(head, ZA_MAGIC, GET_BUF_RESV_SIZE(context), &offset);
74 	if (!head) {
75 		fprintf(stderr, "No ZA context\n");
76 		return 1;
77 	}
78 
79 	za = (struct za_context *)head;
80 	if (za->vl != vl) {
81 		fprintf(stderr, "Got VL %d, expected %d\n", za->vl, vl);
82 		return 1;
83 	}
84 
85 	if (head->size != ZA_SIG_REGS_OFFSET) {
86 		fprintf(stderr, "Context size %u, expected %lu\n",
87 			head->size, ZA_SIG_REGS_OFFSET);
88 		return 1;
89 	}
90 
91 	/* The actual size validation is done in get_current_context() */
92 	fprintf(stderr, "Got expected size %u and VL %d\n",
93 		head->size, za->vl);
94 
95 	return 0;
96 }
97 
98 static int sme_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
99 {
100 	int i;
101 
102 	for (i = 0; i < nvls; i++) {
103 		if (do_one_sme_vl(td, si, uc, vls[i]))
104 			return 1;
105 	}
106 
107 	td->pass = 1;
108 
109 	return 0;
110 }
111 
112 struct tdescr tde = {
113 	.name = "ZA registers - ZA disabled",
114 	.descr = "Check ZA context with ZA disabled",
115 	.feats_required = FEAT_SME,
116 	.timeout = 3,
117 	.init = sme_get_vls,
118 	.run = sme_regs,
119 };
120