LXR linux/tools/testing/selftests/arm64/signal/testcases/sve

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2021 ARM Limited
   4 *
   5 * Verify that the SVE 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
  16struct fake_sigframe sf;
  17static unsigned int vls[SVE_VQ_MAX];
  18unsigned int nvls = 0;
  19
  20static bool sve_get_vls(struct tdescr *td)
  21{
  22        int vq, vl;
  23
  24        /*
  25         * Enumerate up to SVE_VQ_MAX vector lengths
  26         */
  27        for (vq = SVE_VQ_MAX; vq > 0; --vq) {
  28                vl = prctl(PR_SVE_SET_VL, vq * 16);
  29                if (vl == -1)
  30                        return false;
  31
  32                vl &= PR_SVE_VL_LEN_MASK;
  33
  34                /* Skip missing VLs */
  35                vq = sve_vq_from_vl(vl);
  36
  37                vls[nvls++] = vl;
  38        }
  39
  40        /* We need at least one VL */
  41        if (nvls < 1) {
  42                fprintf(stderr, "Only %d VL supported\n", nvls);
  43                return false;
  44        }
  45
  46        return true;
  47}
  48
  49static void setup_sve_regs(void)
  50{
  51        /* RDVL x16, #1 so we should have SVE regs; real data is TODO */
  52        asm volatile(".inst 0x04bf5030" : : : "x16" );
  53}
  54
  55static int do_one_sve_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
  56                         unsigned int vl)
  57{
  58        size_t resv_sz, offset;
  59        struct _aarch64_ctx *head = GET_SF_RESV_HEAD(sf);
  60        struct sve_context *sve;
  61
  62        fprintf(stderr, "Testing VL %d\n", vl);
  63
  64        if (prctl(PR_SVE_SET_VL, vl) == -1) {
  65                fprintf(stderr, "Failed to set VL\n");
  66                return 1;
  67        }
  68
  69        /*
  70         * Get a signal context which should have a SVE frame and registers
  71         * in it.
  72         */
  73        setup_sve_regs();
  74        if (!get_current_context(td, &sf.uc))
  75                return 1;
  76
  77        resv_sz = GET_SF_RESV_SIZE(sf);
  78        head = get_header(head, SVE_MAGIC, resv_sz, &offset);
  79        if (!head) {
  80                fprintf(stderr, "No SVE context\n");
  81                return 1;
  82        }
  83
  84        sve = (struct sve_context *)head;
  85        if (sve->vl != vl) {
  86                fprintf(stderr, "Got VL %d, expected %d\n", sve->vl, vl);
  87                return 1;
  88        }
  89
  90        /* The actual size validation is done in get_current_context() */
  91        fprintf(stderr, "Got expected size %u and VL %d\n",
  92                head->size, sve->vl);
  93
  94        return 0;
  95}
  96
  97static int sve_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
  98{
  99        int i;
 100
 101        for (i = 0; i < nvls; i++) {
 102                /*
 103                 * TODO: the signal test helpers can't currently cope
 104                 * with signal frames bigger than struct sigcontext,
 105                 * skip VLs that will trigger that.
 106                 */
 107                if (vls[i] > 64)
 108                        continue;
 109
 110                if (do_one_sve_vl(td, si, uc, vls[i]))
 111                        return 1;
 112        }
 113
 114        td->pass = 1;
 115
 116        return 0;
 117}
 118
 119struct tdescr tde = {
 120        .name = "SVE registers",
 121        .descr = "Check that we get the right SVE registers reported",
 122        .feats_required = FEAT_SVE,
 123        .timeout = 3,
 124        .init = sve_get_vls,
 125        .run = sve_regs,
 126};
 127