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 static int set_ctl = PR_SVE_SET_VL;
  26 static int get_ctl = PR_SVE_GET_VL;
  27
  28 static const struct option options[] = {
  29         { "force",      no_argument, NULL, 'f' },
  30         { "inherit",    no_argument, NULL, 'i' },
  31         { "max",        no_argument, NULL, 'M' },
  32         { "no-inherit", no_argument, &no_inherit, 1 },
  33         { "sme",        no_argument, NULL, 's' },
  34         { "help",       no_argument, NULL, '?' },
  35         {}
  36 };
  37
  38 static char const *program_name;
  39
  40 static int parse_options(int argc, char **argv)
  41 {
  42         int c;
  43         char *rest;
  44
  45         program_name = strrchr(argv[0], '/');
  46         if (program_name)
  47                 ++program_name;
  48         else
  49                 program_name = argv[0];
  50
  51         while ((c = getopt_long(argc, argv, "Mfhi", options, NULL)) != -1)
  52                 switch (c) {
  53                 case 'M':       vl = SVE_VL_MAX; break;
  54                 case 'f':       force = 1; break;
  55                 case 'i':       inherit = 1; break;
  56                 case 's':       set_ctl = PR_SME_SET_VL;
  57                                 get_ctl = PR_SME_GET_VL;
  58                                 break;
  59                 case 0:         break;
  60                 default:        goto error;
  61                 }
  62
  63         if (inherit && no_inherit)
  64                 goto error;
  65
  66         if (!vl) {
  67                 /* vector length */
  68                 if (optind >= argc)
  69                         goto error;
  70
  71                 errno = 0;
  72                 vl = strtoul(argv[optind], &rest, 0);
  73                 if (*rest) {
  74                         vl = ULONG_MAX;
  75                         errno = EINVAL;
  76                 }
  77                 if (vl == ULONG_MAX && errno) {
  78                         fprintf(stderr, "%s: %s: %s\n",
  79                                 program_name, argv[optind], strerror(errno));
  80                         goto error;
  81                 }
  82
  83                 ++optind;
  84         }
  85
  86         /* command */
  87         if (optind >= argc)
  88                 goto error;
  89
  90         return 0;
  91
  92 error:
  93         fprintf(stderr,
  94                 "Usage: %s [-f | --force] "
  95                 "[-i | --inherit | --no-inherit] "
  96                 "{-M | --max | <vector length>} "
  97                 "<command> [<arguments> ...]\n",
  98                 program_name);
  99         return -1;
 100 }
 101
 102 int main(int argc, char **argv)
 103 {
 104         int ret = 126;  /* same as sh(1) command-not-executable error */
 105         long flags;
 106         char *path;
 107         int t, e;
 108
 109         if (parse_options(argc, argv))
 110                 return 2;       /* same as sh(1) builtin incorrect-usage */
 111
 112         if (vl & ~(vl & PR_SVE_VL_LEN_MASK)) {
 113                 fprintf(stderr, "%s: Invalid vector length %lu\n",
 114                         program_name, vl);
 115                 return 2;       /* same as sh(1) builtin incorrect-usage */
 116         }
 117
 118         if (!(getauxval(AT_HWCAP) & HWCAP_SVE)) {
 119                 fprintf(stderr, "%s: Scalable Vector Extension not present\n",
 120                         program_name);
 121
 122                 if (!force)
 123                         goto error;
 124
 125                 fputs("Going ahead anyway (--force):  "
 126                       "This is a debug option.  Don't rely on it.\n",
 127                       stderr);
 128         }
 129
 130         flags = PR_SVE_SET_VL_ONEXEC;
 131         if (inherit)
 132                 flags |= PR_SVE_VL_INHERIT;
 133
 134         t = prctl(set_ctl, vl | flags);
 135         if (t < 0) {
 136                 fprintf(stderr, "%s: PR_SVE_SET_VL: %s\n",
 137                         program_name, strerror(errno));
 138                 goto error;
 139         }
 140
 141         t = prctl(get_ctl);
 142         if (t == -1) {
 143                 fprintf(stderr, "%s: PR_SVE_GET_VL: %s\n",
 144                         program_name, strerror(errno));
 145                 goto error;
 146         }
 147         flags = PR_SVE_VL_LEN_MASK;
 148         flags = t & ~flags;
 149
 150         assert(optind < argc);
 151         path = argv[optind];
 152
 153         execvp(path, &argv[optind]);
 154         e = errno;
 155         if (errno == ENOENT)
 156                 ret = 127;      /* same as sh(1) not-found error */
 157         fprintf(stderr, "%s: %s: %s\n", program_name, path, strerror(e));
 158
 159 error:
 160         return ret;             /* same as sh(1) not-executable error */
 161 }