1 /* -*- mode: C; c-basic-offset: 3; -*- */ 2 3 #include <setjmp.h> 4 #include <signal.h> 5 #include <stdio.h> 6 #include <stdlib.h> 7 #include <string.h> 8 #include <assert.h> 9 #include <ctype.h> // isspace 10 #include <fcntl.h> // open 11 #include <unistd.h> // lseek 12 #include <sys/stat.h> // S_IRUSR 13 14 // This file determines s390x features a processor supports. 15 // 16 // We return: 17 // - 0 if the machine provides the asked-for feature and the cpu 18 // model, if specified, matches the machine 19 // - 1 the machine does not provide the asked-for feature or the 20 // cpu model, if specified, does not match the machine 21 // - 1 for an unknown cpu model in /proc/cpu_info 22 // - 2 if the asked-for feature isn't recognised (this will be the case for 23 // any feature if run on a non-s390x machine). 24 // - 3 if there was a usage error (it also prints an error message). 25 // 26 // USAGE: 27 // 28 // s390x_features <feature> [<machine-model>] 29 // 30 // The machine_model is optional and it can be something like: 31 // 32 // z9 -- Host needs to be a z9 (and nothing else) 33 // z9: -- Host needs to be a z9 or any later model 34 // :z9 -- Host needs to be a model up to and including z9 35 // z900:z9 -- Host needs to be at least a z900 and at most a z9. 36 // Any model in between is OK, too. 37 38 jmp_buf env; 39 40 #if defined(VGA_s390x) 41 42 void handle_sigill(int signum) 43 { 44 longjmp(env, 1); 45 } 46 47 unsigned long long stfle(void) 48 { 49 50 unsigned long long ret; 51 52 signal(SIGILL, handle_sigill); 53 if (setjmp(env)) { 54 /* stfle not available: assume no facilities */ 55 return 0; 56 } else { 57 asm volatile("lghi 0, 0\n" 58 ".insn s,0xb2b00000,%0\n" /* stfle */ 59 : "=Q" (ret)::"0", "cc"); 60 return ret; 61 } 62 } 63 64 65 /* Read /proc/cpuinfo. Look for lines like these 66 67 processor 0: version = FF, identification = 0117C9, machine = 2064 68 69 and return the machine model or NULL on error. 70 Adapted from function VG_(get_machine_model) in coregrind/m_machine.c */ 71 72 typedef struct { 73 const char *cpuinfo_name; 74 const char *real_name; 75 } model_info; 76 77 /* Array needs to be sorted chronologically. Oldest to newest */ 78 model_info models[] = { 79 { "2064", "z900" }, 80 { "2066", "z800" }, 81 { "2084", "z990" }, 82 { "2086", "z890" }, 83 { "2094", "z9-EC" }, 84 { "2096", "z9-BC" }, 85 { "2097", "z10-EC" }, 86 { "2098", "z10-BC" }, 87 { "2817", "z196" }, 88 { "2818", "z114" }, 89 { "2827", "zEC12" }, 90 { "2828", "zBC12" }, 91 }; 92 93 94 /* Locate a machine model by name. Name can be either the cpuinfo 95 name or the external name. */ 96 static model_info *locate_model(const char *name) 97 { 98 model_info *p; 99 100 /* Try cpuinfo name first */ 101 for (p = models; p != models + sizeof models / sizeof models[0]; ++p) { 102 if (strcmp(p->cpuinfo_name, name) == 0) return p; // found it 103 } 104 105 /* Now try external name */ 106 for (p = models; p != models + sizeof models / sizeof models[0]; ++p) { 107 if (strcmp(p->real_name, name) == 0) return p; // found it 108 } 109 110 return NULL; 111 } 112 113 114 static model_info *get_host(void) 115 { 116 int n, fh; 117 size_t num_bytes, file_buf_size; 118 char *p, *m, *model_name, *file_buf; 119 model_info *model; 120 121 /* Slurp contents of /proc/cpuinfo into FILE_BUF */ 122 fh = open("/proc/cpuinfo", O_RDONLY, S_IRUSR); 123 if (fh < 0) return NULL; 124 125 /* Determine the size of /proc/cpuinfo. 126 Work around broken-ness in /proc file system implementation. 127 fstat returns a zero size for /proc/cpuinfo although it is 128 claimed to be a regular file. */ 129 num_bytes = 0; 130 file_buf_size = 1000; 131 file_buf = malloc(file_buf_size + 1); 132 133 while (42) { 134 n = read(fh, file_buf, file_buf_size); 135 if (n < 0) break; 136 137 num_bytes += n; 138 if (n < file_buf_size) break; /* reached EOF */ 139 } 140 141 if (n < 0) num_bytes = 0; /* read error; ignore contents */ 142 143 if (num_bytes > file_buf_size) { 144 free(file_buf); 145 lseek(fh, 0, SEEK_SET); 146 file_buf = malloc(num_bytes + 1); 147 n = read(fh, file_buf, num_bytes); 148 if (n < 0) num_bytes = 0; 149 } 150 151 file_buf[num_bytes] = '\0'; 152 close(fh); 153 154 /* Parse file */ 155 model = models + sizeof models / sizeof models[0]; 156 for (p = file_buf; *p; ++p) { 157 /* Beginning of line */ 158 if (strncmp(p, "processor", sizeof "processor" - 1 ) != 0) continue; 159 160 m = strstr(p, "machine"); 161 if (m == NULL) continue; 162 163 p = m + sizeof "machine" - 1; 164 while (isspace(*p) || *p == '=') { 165 if (*p == '\n') goto next_line; 166 ++p; 167 } 168 169 model_name = p; 170 for (n = 0; n < sizeof models / sizeof models[0]; ++n) { 171 model_info *mm = models + n; 172 size_t len = strlen(mm->cpuinfo_name); 173 if (strncmp(mm->cpuinfo_name, model_name, len) == 0 && 174 isspace(model_name[len])) { 175 /* In case there are different CPUs in this cluster return the 176 one with the dewest capabilities ("oldest" model). */ 177 if (mm < model) model = mm; 178 p = model_name + len; 179 break; 180 } 181 } 182 /* Skip until end-of-line */ 183 while (*p != '\n') 184 ++p; 185 next_line: ; 186 } 187 188 free(file_buf); 189 190 if (model == models + sizeof models / sizeof models[0]) return NULL; 191 192 return model; 193 } 194 195 196 /* Convenience macro that maps the facility bit number as given in the 197 Principles of Ops "facility indications" section to a bit mask */ 198 #define FAC_BIT(x) (1ULL << (63 - (x))) 199 200 static int go(char *feature, char *cpu) 201 { 202 unsigned long long facilities; 203 unsigned long long match; 204 model_info *host, *from, *to, *p; 205 char *colon; 206 207 facilities = stfle(); 208 209 if (strcmp(feature, "s390x-zarch") == 0 ) { 210 match = (facilities & FAC_BIT(1)) && (facilities & FAC_BIT(2)); 211 } else if (strcmp(feature, "s390x-n3") == 0 ) { 212 match = facilities & FAC_BIT(0); 213 } else if (strcmp(feature, "s390x-stfle") == 0 ) { 214 match = facilities & FAC_BIT(7); 215 } else if (strcmp(feature, "s390x-ldisp") == 0 ) { 216 match = (facilities & FAC_BIT(18)) && (facilities & FAC_BIT(19)); 217 } else if (strcmp(feature, "s390x-eimm") == 0 ) { 218 match = facilities & FAC_BIT(21); 219 } else if (strcmp(feature, "s390x-stckf") == 0 ) { 220 match = facilities & FAC_BIT(25); 221 } else if (strcmp(feature, "s390x-genins") == 0 ) { 222 match = facilities & FAC_BIT(34); 223 } else if (strcmp(feature, "s390x-exrl") == 0 ) { 224 match = facilities & FAC_BIT(35); 225 } else if (strcmp(feature, "s390x-etf3") == 0 ) { 226 match = facilities & FAC_BIT(30); 227 } else if (strcmp(feature, "s390x-fpext") == 0 ) { 228 match = facilities & FAC_BIT(37); 229 } else if (strcmp(feature, "s390x-dfp") == 0 ) { 230 match = facilities & FAC_BIT(42); 231 } else if (strcmp(feature, "s390x-pfpo") == 0 ) { 232 match = facilities & FAC_BIT(44); 233 } else { 234 return 2; // Unrecognised feature. 235 } 236 237 if (match == 0) return 1; // facility not provided 238 239 /* Host provides facility. If no CPU was specified, we're done. */ 240 if (cpu == NULL) return 0; 241 242 host = get_host(); 243 if (host == NULL) return 1; // unknown model 244 245 // printf("host = %s (%s)\n", host->cpuinfo_name, host->real_name); 246 247 /* Determine interval of models in which to search for HOST. */ 248 from = to = NULL; 249 colon = strchr(cpu, ':'); 250 251 if (colon == NULL) { 252 // match exact 253 from = to = locate_model(cpu); 254 } else if (colon == cpu) { 255 // :NAME match machines up to and including CPU 256 from = models; 257 to = locate_model(cpu + 1); 258 } else if (colon[1] == '\0') { 259 // NAME: match machines beginning with CPU or later 260 *colon = '\0'; 261 from = locate_model(cpu); 262 to = models + sizeof models / sizeof models[0] - 1; 263 *colon = ':'; 264 } else { 265 // NAME:NAME match machines in interval 266 *colon = '\0'; 267 from = locate_model(cpu); 268 to = locate_model(colon + 1); 269 *colon = ':'; 270 } 271 272 if (from == NULL || to == NULL || from > to) { 273 fprintf(stderr, "invalid cpu specification '%s'\n", cpu); 274 return 3; 275 } 276 277 #if 0 278 printf("from %s (%s) to %s (%s)\n", from->cpuinfo_name, from->real_name, 279 to->cpuinfo_name, to->real_name); 280 #endif 281 282 /* Search for HOST. */ 283 for (p = from; p <= to; ++p) { 284 if (p == host) return 0; 285 } 286 287 return 1; // host does not match CPU specification 288 } 289 290 #else 291 292 static int go(char *feature, char *cpu) 293 { 294 return 2; // Feature not recognised (non-s390x machine!) 295 } 296 297 #endif 298 299 300 //--------------------------------------------------------------------------- 301 // main 302 //--------------------------------------------------------------------------- 303 int main(int argc, char **argv) 304 { 305 int rc, inverted = 0; 306 307 if (argc < 2 || argc > 3) { 308 fprintf( stderr, "usage: s390x_features <feature> [<machine-model>]\n" ); 309 exit(3); // Usage error. 310 } 311 312 if (argv[1][0] == '!') { 313 assert(argv[2] == NULL); // not allowed 314 inverted = 1; 315 ++argv[1]; 316 } 317 318 rc = go(argv[1], argv[2]); 319 320 if (inverted) { 321 switch (rc) { 322 case 0: rc = 1; break; 323 case 1: rc = 0; break; 324 case 2: rc = 2; break; 325 } 326 } 327 328 // printf("rc = %d\n", rc); 329 330 return rc; 331 } 332
