tools/testing/selftests/arm64/fp/sve-probe-vls.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2015-2020 ARM Limited.
   4  * Original author: Dave Martin <Dave.Martin@arm.com>
   5  */
   6 #include <assert.h>
   7 #include <errno.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <sys/auxv.h>
  12 #include <sys/prctl.h>
  13 #include <asm/sigcontext.h>
  14
  15 #include "../../kselftest.h"
  16
  17 int main(int argc, char **argv)
  18 {
  19         unsigned int vq;
  20         int vl;
  21         static unsigned int vqs[SVE_VQ_MAX];
  22         unsigned int nvqs = 0;
  23
  24         ksft_print_header();
  25         ksft_set_plan(2);
  26
  27         if (!(getauxval(AT_HWCAP) & HWCAP_SVE))
  28                 ksft_exit_skip("SVE not available");
  29
  30         /*
  31          * Enumerate up to SVE_VQ_MAX vector lengths
  32          */
  33         for (vq = SVE_VQ_MAX; vq > 0; --vq) {
  34                 vl = prctl(PR_SVE_SET_VL, vq * 16);
  35                 if (vl == -1)
  36                         ksft_exit_fail_msg("PR_SVE_SET_VL failed: %s (%d)\n",
  37                                            strerror(errno), errno);
  38
  39                 vl &= PR_SVE_VL_LEN_MASK;
  40
  41                 if (!sve_vl_valid(vl))
  42                         ksft_exit_fail_msg("VL %d invalid\n", vl);
  43                 vq = sve_vq_from_vl(vl);
  44
  45                 if (!(nvqs < SVE_VQ_MAX))
  46                         ksft_exit_fail_msg("Too many VLs %u >= SVE_VQ_MAX\n",
  47                                            nvqs);
  48                 vqs[nvqs++] = vq;
  49         }
  50         ksft_test_result_pass("Enumerated %d vector lengths\n", nvqs);
  51         ksft_test_result_pass("All vector lengths valid\n");
  52
  53         /* Print out the vector lengths in ascending order: */
  54         while (nvqs--)
  55                 ksft_print_msg("%u\n", 16 * vqs[nvqs]);
  56
  57         ksft_exit_pass();
  58 }