LXR linux/tools/testing/selftests/arm64/fp/vlset.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2015-2019 ARM Limited.
   4 * Original author: Dave Martin <Dave.Martin@arm.com>
   5 */
   6#define _GNU_SOURCE
   7#include <assert.h>
   8#include <errno.h>
   9#include <limits.h>
  10#include <stddef.h>
  11#include <stdio.h>
  12#include <stdlib.h>
  13#include <string.h>
  14#include <getopt.h>
  15#include <unistd.h>
  16#include <sys/auxv.h>
  17#include <sys/prctl.h>
  18#include <asm/hwcap.h>
  19#include <asm/sigcontext.h>
  20
  21static int inherit = 0;
  22static int no_inherit = 0;
  23static int force = 0;
  24static unsigned long vl;
  25
  26static const struct option options[] = {
  27        { "force",      no_argument, NULL, 'f' },
  28        { "inherit",    no_argument, NULL, 'i' },
  29        { "max",        no_argument, NULL, 'M' },
  30        { "no-inherit", no_argument, &no_inherit, 1 },
  31        { "help",       no_argument, NULL, '?' },
  32        {}
  33};
  34
  35static char const *program_name;
  36
  37static int parse_options(int argc, char **argv)
  38{
  39        int c;
  40        char *rest;
  41
  42        program_name = strrchr(argv[0], '/');
  43        if (program_name)
  44                ++program_name;
  45        else
  46                program_name = argv[0];
  47
  48        while ((c = getopt_long(argc, argv, "Mfhi", options, NULL)) != -1)
  49                switch (c) {
  50                case 'M':       vl = SVE_VL_MAX; break;
  51                case 'f':       force = 1; break;
  52                case 'i':       inherit = 1; break;
  53                case 0:         break;
  54                default:        goto error;
  55                }
  56
  57        if (inherit && no_inherit)
  58                goto error;
  59
  60        if (!vl) {
  61                /* vector length */
  62                if (optind >= argc)
  63                        goto error;
  64
  65                errno = 0;
  66                vl = strtoul(argv[optind], &rest, 0);
  67                if (*rest) {
  68                        vl = ULONG_MAX;
  69                        errno = EINVAL;
  70                }
  71                if (vl == ULONG_MAX && errno) {
  72                        fprintf(stderr, "%s: %s: %s\n",
  73                                program_name, argv[optind], strerror(errno));
  74                        goto error;
  75                }
  76
  77                ++optind;
  78        }
  79
  80        /* command */
  81        if (optind >= argc)
  82                goto error;
  83
  84        return 0;
  85
  86error:
  87        fprintf(stderr,
  88                "Usage: %s [-f | --force] "
  89                "[-i | --inherit | --no-inherit] "
  90                "{-M | --max | <vector length>} "
  91                "<command> [<arguments> ...]\n",
  92                program_name);
  93        return -1;
  94}
  95
  96int main(int argc, char **argv)
  97{
  98        int ret = 126;  /* same as sh(1) command-not-executable error */
  99        long flags;
 100        char *path;
 101        int t, e;
 102
 103        if (parse_options(argc, argv))
 104                return 2;       /* same as sh(1) builtin incorrect-usage */
 105
 106        if (vl & ~(vl & PR_SVE_VL_LEN_MASK)) {
 107                fprintf(stderr, "%s: Invalid vector length %lu\n",
 108                        program_name, vl);
 109                return 2;       /* same as sh(1) builtin incorrect-usage */
 110        }
 111
 112        if (!(getauxval(AT_HWCAP) & HWCAP_SVE)) {
 113                fprintf(stderr, "%s: Scalable Vector Extension not present\n",
 114                        program_name);
 115
 116                if (!force)
 117                        goto error;
 118
 119                fputs("Going ahead anyway (--force):  "
 120                      "This is a debug option.  Don't rely on it.\n",
 121                      stderr);
 122        }
 123
 124        flags = PR_SVE_SET_VL_ONEXEC;
 125        if (inherit)
 126                flags |= PR_SVE_VL_INHERIT;
 127
 128        t = prctl(PR_SVE_SET_VL, vl | flags);
 129        if (t < 0) {
 130                fprintf(stderr, "%s: PR_SVE_SET_VL: %s\n",
 131                        program_name, strerror(errno));
 132                goto error;
 133        }
 134
 135        t = prctl(PR_SVE_GET_VL);
 136        if (t == -1) {
 137                fprintf(stderr, "%s: PR_SVE_GET_VL: %s\n",
 138                        program_name, strerror(errno));
 139                goto error;
 140        }
 141        flags = PR_SVE_VL_LEN_MASK;
 142        flags = t & ~flags;
 143
 144        assert(optind < argc);
 145        path = argv[optind];
 146
 147        execvp(path, &argv[optind]);
 148        e = errno;
 149        if (errno == ENOENT)
 150                ret = 127;      /* same as sh(1) not-found error */
 151        fprintf(stderr, "%s: %s: %s\n", program_name, path, strerror(e));
 152
 153error:
 154        return ret;             /* same as sh(1) not-executable error */
 155}
 156