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
  21 static int inherit = 0;
  22 static int no_inherit = 0;
  23 static int force = 0;
  24 static unsigned long vl;
  25
  26 static 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
  35 static char const *program_name;
  36
  37 static 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
  86 error:
  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
  96 int 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
 153 error:
 154         return ret;             /* same as sh(1) not-executable error */
 155 }