1 /* 2 * Copyright (C) 2001 Dave Engebretsen IBM Corporation 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 */ 18 19 #include <linux/sched.h> 20 #include <linux/interrupt.h> 21 #include <linux/irq.h> 22 #include <linux/of.h> 23 #include <linux/fs.h> 24 #include <linux/reboot.h> 25 26 #include <asm/machdep.h> 27 #include <asm/rtas.h> 28 #include <asm/firmware.h> 29 30 #include "pseries.h" 31 32 static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX]; 33 static DEFINE_SPINLOCK(ras_log_buf_lock); 34 35 static char global_mce_data_buf[RTAS_ERROR_LOG_MAX]; 36 static DEFINE_PER_CPU(__u64, mce_data_buf); 37 38 static int ras_check_exception_token; 39 40 #define EPOW_SENSOR_TOKEN 9 41 #define EPOW_SENSOR_INDEX 0 42 43 /* EPOW events counter variable */ 44 static int num_epow_events; 45 46 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id); 47 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id); 48 static irqreturn_t ras_error_interrupt(int irq, void *dev_id); 49 50 51 /* 52 * Initialize handlers for the set of interrupts caused by hardware errors 53 * and power system events. 54 */ 55 static int __init init_ras_IRQ(void) 56 { 57 struct device_node *np; 58 59 ras_check_exception_token = rtas_token("check-exception"); 60 61 /* Internal Errors */ 62 np = of_find_node_by_path("/event-sources/internal-errors"); 63 if (np != NULL) { 64 request_event_sources_irqs(np, ras_error_interrupt, 65 "RAS_ERROR"); 66 of_node_put(np); 67 } 68 69 /* Hotplug Events */ 70 np = of_find_node_by_path("/event-sources/hot-plug-events"); 71 if (np != NULL) { 72 request_event_sources_irqs(np, ras_hotplug_interrupt, 73 "RAS_HOTPLUG"); 74 of_node_put(np); 75 } 76 77 /* EPOW Events */ 78 np = of_find_node_by_path("/event-sources/epow-events"); 79 if (np != NULL) { 80 request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW"); 81 of_node_put(np); 82 } 83 84 return 0; 85 } 86 machine_subsys_initcall(pseries, init_ras_IRQ); 87 88 #define EPOW_SHUTDOWN_NORMAL 1 89 #define EPOW_SHUTDOWN_ON_UPS 2 90 #define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS 3 91 #define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH 4 92 93 static void handle_system_shutdown(char event_modifier) 94 { 95 switch (event_modifier) { 96 case EPOW_SHUTDOWN_NORMAL: 97 pr_emerg("Power off requested\n"); 98 orderly_poweroff(true); 99 break; 100 101 case EPOW_SHUTDOWN_ON_UPS: 102 pr_emerg("Loss of system power detected. System is running on" 103 " UPS/battery. Check RTAS error log for details\n"); 104 orderly_poweroff(true); 105 break; 106 107 case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS: 108 pr_emerg("Loss of system critical functions detected. Check" 109 " RTAS error log for details\n"); 110 orderly_poweroff(true); 111 break; 112 113 case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH: 114 pr_emerg("High ambient temperature detected. Check RTAS" 115 " error log for details\n"); 116 orderly_poweroff(true); 117 break; 118 119 default: 120 pr_err("Unknown power/cooling shutdown event (modifier = %d)\n", 121 event_modifier); 122 } 123 } 124 125 struct epow_errorlog { 126 unsigned char sensor_value; 127 unsigned char event_modifier; 128 unsigned char extended_modifier; 129 unsigned char reserved; 130 unsigned char platform_reason; 131 }; 132 133 #define EPOW_RESET 0 134 #define EPOW_WARN_COOLING 1 135 #define EPOW_WARN_POWER 2 136 #define EPOW_SYSTEM_SHUTDOWN 3 137 #define EPOW_SYSTEM_HALT 4 138 #define EPOW_MAIN_ENCLOSURE 5 139 #define EPOW_POWER_OFF 7 140 141 static void rtas_parse_epow_errlog(struct rtas_error_log *log) 142 { 143 struct pseries_errorlog *pseries_log; 144 struct epow_errorlog *epow_log; 145 char action_code; 146 char modifier; 147 148 pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW); 149 if (pseries_log == NULL) 150 return; 151 152 epow_log = (struct epow_errorlog *)pseries_log->data; 153 action_code = epow_log->sensor_value & 0xF; /* bottom 4 bits */ 154 modifier = epow_log->event_modifier & 0xF; /* bottom 4 bits */ 155 156 switch (action_code) { 157 case EPOW_RESET: 158 if (num_epow_events) { 159 pr_info("Non critical power/cooling issue cleared\n"); 160 num_epow_events--; 161 } 162 break; 163 164 case EPOW_WARN_COOLING: 165 pr_info("Non-critical cooling issue detected. Check RTAS error" 166 " log for details\n"); 167 break; 168 169 case EPOW_WARN_POWER: 170 pr_info("Non-critical power issue detected. Check RTAS error" 171 " log for details\n"); 172 break; 173 174 case EPOW_SYSTEM_SHUTDOWN: 175 handle_system_shutdown(epow_log->event_modifier); 176 break; 177 178 case EPOW_SYSTEM_HALT: 179 pr_emerg("Critical power/cooling issue detected. Check RTAS" 180 " error log for details. Powering off.\n"); 181 orderly_poweroff(true); 182 break; 183 184 case EPOW_MAIN_ENCLOSURE: 185 case EPOW_POWER_OFF: 186 pr_emerg("System about to lose power. Check RTAS error log " 187 " for details. Powering off immediately.\n"); 188 emergency_sync(); 189 kernel_power_off(); 190 break; 191 192 default: 193 pr_err("Unknown power/cooling event (action code = %d)\n", 194 action_code); 195 } 196 197 /* Increment epow events counter variable */ 198 if (action_code != EPOW_RESET) 199 num_epow_events++; 200 } 201 202 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id) 203 { 204 struct pseries_errorlog *pseries_log; 205 struct pseries_hp_errorlog *hp_elog; 206 207 spin_lock(&ras_log_buf_lock); 208 209 rtas_call(ras_check_exception_token, 6, 1, NULL, 210 RTAS_VECTOR_EXTERNAL_INTERRUPT, virq_to_hw(irq), 211 RTAS_HOTPLUG_EVENTS, 0, __pa(&ras_log_buf), 212 rtas_get_error_log_max()); 213 214 pseries_log = get_pseries_errorlog((struct rtas_error_log *)ras_log_buf, 215 PSERIES_ELOG_SECT_ID_HOTPLUG); 216 hp_elog = (struct pseries_hp_errorlog *)pseries_log->data; 217 218 /* 219 * Since PCI hotplug is not currently supported on pseries, put PCI 220 * hotplug events on the ras_log_buf to be handled by rtas_errd. 221 */ 222 if (hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_MEM || 223 hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_CPU) 224 queue_hotplug_event(hp_elog, NULL, NULL); 225 else 226 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); 227 228 spin_unlock(&ras_log_buf_lock); 229 return IRQ_HANDLED; 230 } 231 232 /* Handle environmental and power warning (EPOW) interrupts. */ 233 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id) 234 { 235 int status; 236 int state; 237 int critical; 238 239 status = rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX, 240 &state); 241 242 if (state > 3) 243 critical = 1; /* Time Critical */ 244 else 245 critical = 0; 246 247 spin_lock(&ras_log_buf_lock); 248 249 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 250 RTAS_VECTOR_EXTERNAL_INTERRUPT, 251 virq_to_hw(irq), 252 RTAS_EPOW_WARNING, 253 critical, __pa(&ras_log_buf), 254 rtas_get_error_log_max()); 255 256 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); 257 258 rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf); 259 260 spin_unlock(&ras_log_buf_lock); 261 return IRQ_HANDLED; 262 } 263 264 /* 265 * Handle hardware error interrupts. 266 * 267 * RTAS check-exception is called to collect data on the exception. If 268 * the error is deemed recoverable, we log a warning and return. 269 * For nonrecoverable errors, an error is logged and we stop all processing 270 * as quickly as possible in order to prevent propagation of the failure. 271 */ 272 static irqreturn_t ras_error_interrupt(int irq, void *dev_id) 273 { 274 struct rtas_error_log *rtas_elog; 275 int status; 276 int fatal; 277 278 spin_lock(&ras_log_buf_lock); 279 280 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 281 RTAS_VECTOR_EXTERNAL_INTERRUPT, 282 virq_to_hw(irq), 283 RTAS_INTERNAL_ERROR, 1 /* Time Critical */, 284 __pa(&ras_log_buf), 285 rtas_get_error_log_max()); 286 287 rtas_elog = (struct rtas_error_log *)ras_log_buf; 288 289 if (status == 0 && 290 rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC) 291 fatal = 1; 292 else 293 fatal = 0; 294 295 /* format and print the extended information */ 296 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal); 297 298 if (fatal) { 299 pr_emerg("Fatal hardware error detected. Check RTAS error" 300 " log for details. Powering off immediately\n"); 301 emergency_sync(); 302 kernel_power_off(); 303 } else { 304 pr_err("Recoverable hardware error detected\n"); 305 } 306 307 spin_unlock(&ras_log_buf_lock); 308 return IRQ_HANDLED; 309 } 310 311 /* 312 * Some versions of FWNMI place the buffer inside the 4kB page starting at 313 * 0x7000. Other versions place it inside the rtas buffer. We check both. 314 */ 315 #define VALID_FWNMI_BUFFER(A) \ 316 ((((A) >= 0x7000) && ((A) < 0x7ff0)) || \ 317 (((A) >= rtas.base) && ((A) < (rtas.base + rtas.size - 16)))) 318 319 /* 320 * Get the error information for errors coming through the 321 * FWNMI vectors. The pt_regs' r3 will be updated to reflect 322 * the actual r3 if possible, and a ptr to the error log entry 323 * will be returned if found. 324 * 325 * If the RTAS error is not of the extended type, then we put it in a per 326 * cpu 64bit buffer. If it is the extended type we use global_mce_data_buf. 327 * 328 * The global_mce_data_buf does not have any locks or protection around it, 329 * if a second machine check comes in, or a system reset is done 330 * before we have logged the error, then we will get corruption in the 331 * error log. This is preferable over holding off on calling 332 * ibm,nmi-interlock which would result in us checkstopping if a 333 * second machine check did come in. 334 */ 335 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) 336 { 337 unsigned long *savep; 338 struct rtas_error_log *h, *errhdr = NULL; 339 340 /* Mask top two bits */ 341 regs->gpr[3] &= ~(0x3UL << 62); 342 343 if (!VALID_FWNMI_BUFFER(regs->gpr[3])) { 344 printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]); 345 return NULL; 346 } 347 348 savep = __va(regs->gpr[3]); 349 regs->gpr[3] = savep[0]; /* restore original r3 */ 350 351 /* If it isn't an extended log we can use the per cpu 64bit buffer */ 352 h = (struct rtas_error_log *)&savep[1]; 353 if (!rtas_error_extended(h)) { 354 memcpy(this_cpu_ptr(&mce_data_buf), h, sizeof(__u64)); 355 errhdr = (struct rtas_error_log *)this_cpu_ptr(&mce_data_buf); 356 } else { 357 int len, error_log_length; 358 359 error_log_length = 8 + rtas_error_extended_log_length(h); 360 len = max_t(int, error_log_length, RTAS_ERROR_LOG_MAX); 361 memset(global_mce_data_buf, 0, RTAS_ERROR_LOG_MAX); 362 memcpy(global_mce_data_buf, h, len); 363 errhdr = (struct rtas_error_log *)global_mce_data_buf; 364 } 365 366 return errhdr; 367 } 368 369 /* Call this when done with the data returned by FWNMI_get_errinfo. 370 * It will release the saved data area for other CPUs in the 371 * partition to receive FWNMI errors. 372 */ 373 static void fwnmi_release_errinfo(void) 374 { 375 int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL); 376 if (ret != 0) 377 printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret); 378 } 379 380 int pSeries_system_reset_exception(struct pt_regs *regs) 381 { 382 if (fwnmi_active) { 383 struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs); 384 if (errhdr) { 385 /* XXX Should look at FWNMI information */ 386 } 387 fwnmi_release_errinfo(); 388 } 389 return 0; /* need to perform reset */ 390 } 391 392 /* 393 * See if we can recover from a machine check exception. 394 * This is only called on power4 (or above) and only via 395 * the Firmware Non-Maskable Interrupts (fwnmi) handler 396 * which provides the error analysis for us. 397 * 398 * Return 1 if corrected (or delivered a signal). 399 * Return 0 if there is nothing we can do. 400 */ 401 static int recover_mce(struct pt_regs *regs, struct rtas_error_log *err) 402 { 403 int recovered = 0; 404 int disposition = rtas_error_disposition(err); 405 406 if (!(regs->msr & MSR_RI)) { 407 /* If MSR_RI isn't set, we cannot recover */ 408 recovered = 0; 409 410 } else if (disposition == RTAS_DISP_FULLY_RECOVERED) { 411 /* Platform corrected itself */ 412 recovered = 1; 413 414 } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) { 415 /* Platform corrected itself but could be degraded */ 416 printk(KERN_ERR "MCE: limited recovery, system may " 417 "be degraded\n"); 418 recovered = 1; 419 420 } else if (user_mode(regs) && !is_global_init(current) && 421 rtas_error_severity(err) == RTAS_SEVERITY_ERROR_SYNC) { 422 423 /* 424 * If we received a synchronous error when in userspace 425 * kill the task. Firmware may report details of the fail 426 * asynchronously, so we can't rely on the target and type 427 * fields being valid here. 428 */ 429 printk(KERN_ERR "MCE: uncorrectable error, killing task " 430 "%s:%d\n", current->comm, current->pid); 431 432 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip); 433 recovered = 1; 434 } 435 436 log_error((char *)err, ERR_TYPE_RTAS_LOG, 0); 437 438 return recovered; 439 } 440 441 /* 442 * Handle a machine check. 443 * 444 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi) 445 * should be present. If so the handler which called us tells us if the 446 * error was recovered (never true if RI=0). 447 * 448 * On hardware prior to Power 4 these exceptions were asynchronous which 449 * means we can't tell exactly where it occurred and so we can't recover. 450 */ 451 int pSeries_machine_check_exception(struct pt_regs *regs) 452 { 453 struct rtas_error_log *errp; 454 455 if (fwnmi_active) { 456 errp = fwnmi_get_errinfo(regs); 457 fwnmi_release_errinfo(); 458 if (errp && recover_mce(regs, errp)) 459 return 1; 460 } 461 462 return 0; 463 } 464