1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2001 Dave Engebretsen IBM Corporation 4 */ 5 6 #include <linux/sched.h> 7 #include <linux/interrupt.h> 8 #include <linux/irq.h> 9 #include <linux/of.h> 10 #include <linux/fs.h> 11 #include <linux/reboot.h> 12 #include <linux/irq_work.h> 13 14 #include <asm/machdep.h> 15 #include <asm/rtas.h> 16 #include <asm/firmware.h> 17 #include <asm/mce.h> 18 19 #include "pseries.h" 20 21 static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX]; 22 static DEFINE_SPINLOCK(ras_log_buf_lock); 23 24 static int ras_check_exception_token; 25 26 static void mce_process_errlog_event(struct irq_work *work); 27 static struct irq_work mce_errlog_process_work = { 28 .func = mce_process_errlog_event, 29 }; 30 31 #define EPOW_SENSOR_TOKEN 9 32 #define EPOW_SENSOR_INDEX 0 33 34 /* EPOW events counter variable */ 35 static int num_epow_events; 36 37 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id); 38 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id); 39 static irqreturn_t ras_error_interrupt(int irq, void *dev_id); 40 41 /* RTAS pseries MCE errorlog section. */ 42 struct pseries_mc_errorlog { 43 __be32 fru_id; 44 __be32 proc_id; 45 u8 error_type; 46 /* 47 * sub_err_type (1 byte). Bit fields depends on error_type 48 * 49 * MSB0 50 * | 51 * V 52 * 01234567 53 * XXXXXXXX 54 * 55 * For error_type == MC_ERROR_TYPE_UE 56 * XXXXXXXX 57 * X 1: Permanent or Transient UE. 58 * X 1: Effective address provided. 59 * X 1: Logical address provided. 60 * XX 2: Reserved. 61 * XXX 3: Type of UE error. 62 * 63 * For error_type != MC_ERROR_TYPE_UE 64 * XXXXXXXX 65 * X 1: Effective address provided. 66 * XXXXX 5: Reserved. 67 * XX 2: Type of SLB/ERAT/TLB error. 68 */ 69 u8 sub_err_type; 70 u8 reserved_1[6]; 71 __be64 effective_address; 72 __be64 logical_address; 73 } __packed; 74 75 /* RTAS pseries MCE error types */ 76 #define MC_ERROR_TYPE_UE 0x00 77 #define MC_ERROR_TYPE_SLB 0x01 78 #define MC_ERROR_TYPE_ERAT 0x02 79 #define MC_ERROR_TYPE_UNKNOWN 0x03 80 #define MC_ERROR_TYPE_TLB 0x04 81 #define MC_ERROR_TYPE_D_CACHE 0x05 82 #define MC_ERROR_TYPE_I_CACHE 0x07 83 84 /* RTAS pseries MCE error sub types */ 85 #define MC_ERROR_UE_INDETERMINATE 0 86 #define MC_ERROR_UE_IFETCH 1 87 #define MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH 2 88 #define MC_ERROR_UE_LOAD_STORE 3 89 #define MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE 4 90 91 #define UE_EFFECTIVE_ADDR_PROVIDED 0x40 92 #define UE_LOGICAL_ADDR_PROVIDED 0x20 93 94 #define MC_ERROR_SLB_PARITY 0 95 #define MC_ERROR_SLB_MULTIHIT 1 96 #define MC_ERROR_SLB_INDETERMINATE 2 97 98 #define MC_ERROR_ERAT_PARITY 1 99 #define MC_ERROR_ERAT_MULTIHIT 2 100 #define MC_ERROR_ERAT_INDETERMINATE 3 101 102 #define MC_ERROR_TLB_PARITY 1 103 #define MC_ERROR_TLB_MULTIHIT 2 104 #define MC_ERROR_TLB_INDETERMINATE 3 105 106 static inline u8 rtas_mc_error_sub_type(const struct pseries_mc_errorlog *mlog) 107 { 108 switch (mlog->error_type) { 109 case MC_ERROR_TYPE_UE: 110 return (mlog->sub_err_type & 0x07); 111 case MC_ERROR_TYPE_SLB: 112 case MC_ERROR_TYPE_ERAT: 113 case MC_ERROR_TYPE_TLB: 114 return (mlog->sub_err_type & 0x03); 115 default: 116 return 0; 117 } 118 } 119 120 /* 121 * Enable the hotplug interrupt late because processing them may touch other 122 * devices or systems (e.g. hugepages) that have not been initialized at the 123 * subsys stage. 124 */ 125 int __init init_ras_hotplug_IRQ(void) 126 { 127 struct device_node *np; 128 129 /* Hotplug Events */ 130 np = of_find_node_by_path("/event-sources/hot-plug-events"); 131 if (np != NULL) { 132 if (dlpar_workqueue_init() == 0) 133 request_event_sources_irqs(np, ras_hotplug_interrupt, 134 "RAS_HOTPLUG"); 135 of_node_put(np); 136 } 137 138 return 0; 139 } 140 machine_late_initcall(pseries, init_ras_hotplug_IRQ); 141 142 /* 143 * Initialize handlers for the set of interrupts caused by hardware errors 144 * and power system events. 145 */ 146 static int __init init_ras_IRQ(void) 147 { 148 struct device_node *np; 149 150 ras_check_exception_token = rtas_token("check-exception"); 151 152 /* Internal Errors */ 153 np = of_find_node_by_path("/event-sources/internal-errors"); 154 if (np != NULL) { 155 request_event_sources_irqs(np, ras_error_interrupt, 156 "RAS_ERROR"); 157 of_node_put(np); 158 } 159 160 /* EPOW Events */ 161 np = of_find_node_by_path("/event-sources/epow-events"); 162 if (np != NULL) { 163 request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW"); 164 of_node_put(np); 165 } 166 167 return 0; 168 } 169 machine_subsys_initcall(pseries, init_ras_IRQ); 170 171 #define EPOW_SHUTDOWN_NORMAL 1 172 #define EPOW_SHUTDOWN_ON_UPS 2 173 #define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS 3 174 #define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH 4 175 176 static void handle_system_shutdown(char event_modifier) 177 { 178 switch (event_modifier) { 179 case EPOW_SHUTDOWN_NORMAL: 180 pr_emerg("Power off requested\n"); 181 orderly_poweroff(true); 182 break; 183 184 case EPOW_SHUTDOWN_ON_UPS: 185 pr_emerg("Loss of system power detected. System is running on" 186 " UPS/battery. Check RTAS error log for details\n"); 187 orderly_poweroff(true); 188 break; 189 190 case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS: 191 pr_emerg("Loss of system critical functions detected. Check" 192 " RTAS error log for details\n"); 193 orderly_poweroff(true); 194 break; 195 196 case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH: 197 pr_emerg("High ambient temperature detected. Check RTAS" 198 " error log for details\n"); 199 orderly_poweroff(true); 200 break; 201 202 default: 203 pr_err("Unknown power/cooling shutdown event (modifier = %d)\n", 204 event_modifier); 205 } 206 } 207 208 struct epow_errorlog { 209 unsigned char sensor_value; 210 unsigned char event_modifier; 211 unsigned char extended_modifier; 212 unsigned char reserved; 213 unsigned char platform_reason; 214 }; 215 216 #define EPOW_RESET 0 217 #define EPOW_WARN_COOLING 1 218 #define EPOW_WARN_POWER 2 219 #define EPOW_SYSTEM_SHUTDOWN 3 220 #define EPOW_SYSTEM_HALT 4 221 #define EPOW_MAIN_ENCLOSURE 5 222 #define EPOW_POWER_OFF 7 223 224 static void rtas_parse_epow_errlog(struct rtas_error_log *log) 225 { 226 struct pseries_errorlog *pseries_log; 227 struct epow_errorlog *epow_log; 228 char action_code; 229 char modifier; 230 231 pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW); 232 if (pseries_log == NULL) 233 return; 234 235 epow_log = (struct epow_errorlog *)pseries_log->data; 236 action_code = epow_log->sensor_value & 0xF; /* bottom 4 bits */ 237 modifier = epow_log->event_modifier & 0xF; /* bottom 4 bits */ 238 239 switch (action_code) { 240 case EPOW_RESET: 241 if (num_epow_events) { 242 pr_info("Non critical power/cooling issue cleared\n"); 243 num_epow_events--; 244 } 245 break; 246 247 case EPOW_WARN_COOLING: 248 pr_info("Non-critical cooling issue detected. Check RTAS error" 249 " log for details\n"); 250 break; 251 252 case EPOW_WARN_POWER: 253 pr_info("Non-critical power issue detected. Check RTAS error" 254 " log for details\n"); 255 break; 256 257 case EPOW_SYSTEM_SHUTDOWN: 258 handle_system_shutdown(epow_log->event_modifier); 259 break; 260 261 case EPOW_SYSTEM_HALT: 262 pr_emerg("Critical power/cooling issue detected. Check RTAS" 263 " error log for details. Powering off.\n"); 264 orderly_poweroff(true); 265 break; 266 267 case EPOW_MAIN_ENCLOSURE: 268 case EPOW_POWER_OFF: 269 pr_emerg("System about to lose power. Check RTAS error log " 270 " for details. Powering off immediately.\n"); 271 emergency_sync(); 272 kernel_power_off(); 273 break; 274 275 default: 276 pr_err("Unknown power/cooling event (action code = %d)\n", 277 action_code); 278 } 279 280 /* Increment epow events counter variable */ 281 if (action_code != EPOW_RESET) 282 num_epow_events++; 283 } 284 285 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id) 286 { 287 struct pseries_errorlog *pseries_log; 288 struct pseries_hp_errorlog *hp_elog; 289 290 spin_lock(&ras_log_buf_lock); 291 292 rtas_call(ras_check_exception_token, 6, 1, NULL, 293 RTAS_VECTOR_EXTERNAL_INTERRUPT, virq_to_hw(irq), 294 RTAS_HOTPLUG_EVENTS, 0, __pa(&ras_log_buf), 295 rtas_get_error_log_max()); 296 297 pseries_log = get_pseries_errorlog((struct rtas_error_log *)ras_log_buf, 298 PSERIES_ELOG_SECT_ID_HOTPLUG); 299 hp_elog = (struct pseries_hp_errorlog *)pseries_log->data; 300 301 /* 302 * Since PCI hotplug is not currently supported on pseries, put PCI 303 * hotplug events on the ras_log_buf to be handled by rtas_errd. 304 */ 305 if (hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_MEM || 306 hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_CPU || 307 hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_PMEM) 308 queue_hotplug_event(hp_elog); 309 else 310 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); 311 312 spin_unlock(&ras_log_buf_lock); 313 return IRQ_HANDLED; 314 } 315 316 /* Handle environmental and power warning (EPOW) interrupts. */ 317 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id) 318 { 319 int status; 320 int state; 321 int critical; 322 323 status = rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX, 324 &state); 325 326 if (state > 3) 327 critical = 1; /* Time Critical */ 328 else 329 critical = 0; 330 331 spin_lock(&ras_log_buf_lock); 332 333 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 334 RTAS_VECTOR_EXTERNAL_INTERRUPT, 335 virq_to_hw(irq), 336 RTAS_EPOW_WARNING, 337 critical, __pa(&ras_log_buf), 338 rtas_get_error_log_max()); 339 340 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); 341 342 rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf); 343 344 spin_unlock(&ras_log_buf_lock); 345 return IRQ_HANDLED; 346 } 347 348 /* 349 * Handle hardware error interrupts. 350 * 351 * RTAS check-exception is called to collect data on the exception. If 352 * the error is deemed recoverable, we log a warning and return. 353 * For nonrecoverable errors, an error is logged and we stop all processing 354 * as quickly as possible in order to prevent propagation of the failure. 355 */ 356 static irqreturn_t ras_error_interrupt(int irq, void *dev_id) 357 { 358 struct rtas_error_log *rtas_elog; 359 int status; 360 int fatal; 361 362 spin_lock(&ras_log_buf_lock); 363 364 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 365 RTAS_VECTOR_EXTERNAL_INTERRUPT, 366 virq_to_hw(irq), 367 RTAS_INTERNAL_ERROR, 1 /* Time Critical */, 368 __pa(&ras_log_buf), 369 rtas_get_error_log_max()); 370 371 rtas_elog = (struct rtas_error_log *)ras_log_buf; 372 373 if (status == 0 && 374 rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC) 375 fatal = 1; 376 else 377 fatal = 0; 378 379 /* format and print the extended information */ 380 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal); 381 382 if (fatal) { 383 pr_emerg("Fatal hardware error detected. Check RTAS error" 384 " log for details. Powering off immediately\n"); 385 emergency_sync(); 386 kernel_power_off(); 387 } else { 388 pr_err("Recoverable hardware error detected\n"); 389 } 390 391 spin_unlock(&ras_log_buf_lock); 392 return IRQ_HANDLED; 393 } 394 395 /* 396 * Some versions of FWNMI place the buffer inside the 4kB page starting at 397 * 0x7000. Other versions place it inside the rtas buffer. We check both. 398 */ 399 #define VALID_FWNMI_BUFFER(A) \ 400 ((((A) >= 0x7000) && ((A) < 0x7ff0)) || \ 401 (((A) >= rtas.base) && ((A) < (rtas.base + rtas.size - 16)))) 402 403 static inline struct rtas_error_log *fwnmi_get_errlog(void) 404 { 405 return (struct rtas_error_log *)local_paca->mce_data_buf; 406 } 407 408 /* 409 * Get the error information for errors coming through the 410 * FWNMI vectors. The pt_regs' r3 will be updated to reflect 411 * the actual r3 if possible, and a ptr to the error log entry 412 * will be returned if found. 413 * 414 * Use one buffer mce_data_buf per cpu to store RTAS error. 415 * 416 * The mce_data_buf does not have any locks or protection around it, 417 * if a second machine check comes in, or a system reset is done 418 * before we have logged the error, then we will get corruption in the 419 * error log. This is preferable over holding off on calling 420 * ibm,nmi-interlock which would result in us checkstopping if a 421 * second machine check did come in. 422 */ 423 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) 424 { 425 unsigned long *savep; 426 struct rtas_error_log *h; 427 428 /* Mask top two bits */ 429 regs->gpr[3] &= ~(0x3UL << 62); 430 431 if (!VALID_FWNMI_BUFFER(regs->gpr[3])) { 432 printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]); 433 return NULL; 434 } 435 436 savep = __va(regs->gpr[3]); 437 regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */ 438 439 h = (struct rtas_error_log *)&savep[1]; 440 /* Use the per cpu buffer from paca to store rtas error log */ 441 memset(local_paca->mce_data_buf, 0, RTAS_ERROR_LOG_MAX); 442 if (!rtas_error_extended(h)) { 443 memcpy(local_paca->mce_data_buf, h, sizeof(__u64)); 444 } else { 445 int len, error_log_length; 446 447 error_log_length = 8 + rtas_error_extended_log_length(h); 448 len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX); 449 memcpy(local_paca->mce_data_buf, h, len); 450 } 451 452 return (struct rtas_error_log *)local_paca->mce_data_buf; 453 } 454 455 /* Call this when done with the data returned by FWNMI_get_errinfo. 456 * It will release the saved data area for other CPUs in the 457 * partition to receive FWNMI errors. 458 */ 459 static void fwnmi_release_errinfo(void) 460 { 461 int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL); 462 if (ret != 0) 463 printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret); 464 } 465 466 int pSeries_system_reset_exception(struct pt_regs *regs) 467 { 468 #ifdef __LITTLE_ENDIAN__ 469 /* 470 * Some firmware byteswaps SRR registers and gives incorrect SRR1. Try 471 * to detect the bad SRR1 pattern here. Flip the NIP back to correct 472 * endian for reporting purposes. Unfortunately the MSR can't be fixed, 473 * so clear it. It will be missing MSR_RI so we won't try to recover. 474 */ 475 if ((be64_to_cpu(regs->msr) & 476 (MSR_LE|MSR_RI|MSR_DR|MSR_IR|MSR_ME|MSR_PR| 477 MSR_ILE|MSR_HV|MSR_SF)) == (MSR_DR|MSR_SF)) { 478 regs->nip = be64_to_cpu((__be64)regs->nip); 479 regs->msr = 0; 480 } 481 #endif 482 483 if (fwnmi_active) { 484 struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs); 485 if (errhdr) { 486 /* XXX Should look at FWNMI information */ 487 } 488 fwnmi_release_errinfo(); 489 } 490 491 if (smp_handle_nmi_ipi(regs)) 492 return 1; 493 494 return 0; /* need to perform reset */ 495 } 496 497 498 static int mce_handle_error(struct pt_regs *regs, struct rtas_error_log *errp) 499 { 500 struct mce_error_info mce_err = { 0 }; 501 unsigned long eaddr = 0, paddr = 0; 502 struct pseries_errorlog *pseries_log; 503 struct pseries_mc_errorlog *mce_log; 504 int disposition = rtas_error_disposition(errp); 505 int initiator = rtas_error_initiator(errp); 506 int severity = rtas_error_severity(errp); 507 u8 error_type, err_sub_type; 508 509 if (initiator == RTAS_INITIATOR_UNKNOWN) 510 mce_err.initiator = MCE_INITIATOR_UNKNOWN; 511 else if (initiator == RTAS_INITIATOR_CPU) 512 mce_err.initiator = MCE_INITIATOR_CPU; 513 else if (initiator == RTAS_INITIATOR_PCI) 514 mce_err.initiator = MCE_INITIATOR_PCI; 515 else if (initiator == RTAS_INITIATOR_ISA) 516 mce_err.initiator = MCE_INITIATOR_ISA; 517 else if (initiator == RTAS_INITIATOR_MEMORY) 518 mce_err.initiator = MCE_INITIATOR_MEMORY; 519 else if (initiator == RTAS_INITIATOR_POWERMGM) 520 mce_err.initiator = MCE_INITIATOR_POWERMGM; 521 else 522 mce_err.initiator = MCE_INITIATOR_UNKNOWN; 523 524 if (severity == RTAS_SEVERITY_NO_ERROR) 525 mce_err.severity = MCE_SEV_NO_ERROR; 526 else if (severity == RTAS_SEVERITY_EVENT) 527 mce_err.severity = MCE_SEV_WARNING; 528 else if (severity == RTAS_SEVERITY_WARNING) 529 mce_err.severity = MCE_SEV_WARNING; 530 else if (severity == RTAS_SEVERITY_ERROR_SYNC) 531 mce_err.severity = MCE_SEV_SEVERE; 532 else if (severity == RTAS_SEVERITY_ERROR) 533 mce_err.severity = MCE_SEV_SEVERE; 534 else if (severity == RTAS_SEVERITY_FATAL) 535 mce_err.severity = MCE_SEV_FATAL; 536 else 537 mce_err.severity = MCE_SEV_FATAL; 538 539 if (severity <= RTAS_SEVERITY_ERROR_SYNC) 540 mce_err.sync_error = true; 541 else 542 mce_err.sync_error = false; 543 544 mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN; 545 mce_err.error_class = MCE_ECLASS_UNKNOWN; 546 547 if (!rtas_error_extended(errp)) 548 goto out; 549 550 pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE); 551 if (pseries_log == NULL) 552 goto out; 553 554 mce_log = (struct pseries_mc_errorlog *)pseries_log->data; 555 error_type = mce_log->error_type; 556 err_sub_type = rtas_mc_error_sub_type(mce_log); 557 558 switch (mce_log->error_type) { 559 case MC_ERROR_TYPE_UE: 560 mce_err.error_type = MCE_ERROR_TYPE_UE; 561 switch (err_sub_type) { 562 case MC_ERROR_UE_IFETCH: 563 mce_err.u.ue_error_type = MCE_UE_ERROR_IFETCH; 564 break; 565 case MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH: 566 mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH; 567 break; 568 case MC_ERROR_UE_LOAD_STORE: 569 mce_err.u.ue_error_type = MCE_UE_ERROR_LOAD_STORE; 570 break; 571 case MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE: 572 mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE; 573 break; 574 case MC_ERROR_UE_INDETERMINATE: 575 default: 576 mce_err.u.ue_error_type = MCE_UE_ERROR_INDETERMINATE; 577 break; 578 } 579 if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) 580 eaddr = be64_to_cpu(mce_log->effective_address); 581 582 if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) { 583 paddr = be64_to_cpu(mce_log->logical_address); 584 } else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) { 585 unsigned long pfn; 586 587 pfn = addr_to_pfn(regs, eaddr); 588 if (pfn != ULONG_MAX) 589 paddr = pfn << PAGE_SHIFT; 590 } 591 592 break; 593 case MC_ERROR_TYPE_SLB: 594 mce_err.error_type = MCE_ERROR_TYPE_SLB; 595 switch (err_sub_type) { 596 case MC_ERROR_SLB_PARITY: 597 mce_err.u.slb_error_type = MCE_SLB_ERROR_PARITY; 598 break; 599 case MC_ERROR_SLB_MULTIHIT: 600 mce_err.u.slb_error_type = MCE_SLB_ERROR_MULTIHIT; 601 break; 602 case MC_ERROR_SLB_INDETERMINATE: 603 default: 604 mce_err.u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE; 605 break; 606 } 607 if (mce_log->sub_err_type & 0x80) 608 eaddr = be64_to_cpu(mce_log->effective_address); 609 break; 610 case MC_ERROR_TYPE_ERAT: 611 mce_err.error_type = MCE_ERROR_TYPE_ERAT; 612 switch (err_sub_type) { 613 case MC_ERROR_ERAT_PARITY: 614 mce_err.u.erat_error_type = MCE_ERAT_ERROR_PARITY; 615 break; 616 case MC_ERROR_ERAT_MULTIHIT: 617 mce_err.u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT; 618 break; 619 case MC_ERROR_ERAT_INDETERMINATE: 620 default: 621 mce_err.u.erat_error_type = MCE_ERAT_ERROR_INDETERMINATE; 622 break; 623 } 624 if (mce_log->sub_err_type & 0x80) 625 eaddr = be64_to_cpu(mce_log->effective_address); 626 break; 627 case MC_ERROR_TYPE_TLB: 628 mce_err.error_type = MCE_ERROR_TYPE_TLB; 629 switch (err_sub_type) { 630 case MC_ERROR_TLB_PARITY: 631 mce_err.u.tlb_error_type = MCE_TLB_ERROR_PARITY; 632 break; 633 case MC_ERROR_TLB_MULTIHIT: 634 mce_err.u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT; 635 break; 636 case MC_ERROR_TLB_INDETERMINATE: 637 default: 638 mce_err.u.tlb_error_type = MCE_TLB_ERROR_INDETERMINATE; 639 break; 640 } 641 if (mce_log->sub_err_type & 0x80) 642 eaddr = be64_to_cpu(mce_log->effective_address); 643 break; 644 case MC_ERROR_TYPE_D_CACHE: 645 mce_err.error_type = MCE_ERROR_TYPE_DCACHE; 646 break; 647 case MC_ERROR_TYPE_I_CACHE: 648 mce_err.error_type = MCE_ERROR_TYPE_DCACHE; 649 break; 650 case MC_ERROR_TYPE_UNKNOWN: 651 default: 652 mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN; 653 break; 654 } 655 656 #ifdef CONFIG_PPC_BOOK3S_64 657 if (disposition == RTAS_DISP_NOT_RECOVERED) { 658 switch (error_type) { 659 case MC_ERROR_TYPE_SLB: 660 case MC_ERROR_TYPE_ERAT: 661 /* 662 * Store the old slb content in paca before flushing. 663 * Print this when we go to virtual mode. 664 * There are chances that we may hit MCE again if there 665 * is a parity error on the SLB entry we trying to read 666 * for saving. Hence limit the slb saving to single 667 * level of recursion. 668 */ 669 if (local_paca->in_mce == 1) 670 slb_save_contents(local_paca->mce_faulty_slbs); 671 flush_and_reload_slb(); 672 disposition = RTAS_DISP_FULLY_RECOVERED; 673 break; 674 default: 675 break; 676 } 677 } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) { 678 /* Platform corrected itself but could be degraded */ 679 printk(KERN_ERR "MCE: limited recovery, system may " 680 "be degraded\n"); 681 disposition = RTAS_DISP_FULLY_RECOVERED; 682 } 683 #endif 684 685 out: 686 save_mce_event(regs, disposition == RTAS_DISP_FULLY_RECOVERED, 687 &mce_err, regs->nip, eaddr, paddr); 688 689 return disposition; 690 } 691 692 /* 693 * Process MCE rtas errlog event. 694 */ 695 static void mce_process_errlog_event(struct irq_work *work) 696 { 697 struct rtas_error_log *err; 698 699 err = fwnmi_get_errlog(); 700 log_error((char *)err, ERR_TYPE_RTAS_LOG, 0); 701 } 702 703 /* 704 * See if we can recover from a machine check exception. 705 * This is only called on power4 (or above) and only via 706 * the Firmware Non-Maskable Interrupts (fwnmi) handler 707 * which provides the error analysis for us. 708 * 709 * Return 1 if corrected (or delivered a signal). 710 * Return 0 if there is nothing we can do. 711 */ 712 static int recover_mce(struct pt_regs *regs, struct machine_check_event *evt) 713 { 714 int recovered = 0; 715 716 if (!(regs->msr & MSR_RI)) { 717 /* If MSR_RI isn't set, we cannot recover */ 718 pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n"); 719 recovered = 0; 720 } else if (evt->disposition == MCE_DISPOSITION_RECOVERED) { 721 /* Platform corrected itself */ 722 recovered = 1; 723 } else if (evt->severity == MCE_SEV_FATAL) { 724 /* Fatal machine check */ 725 pr_err("Machine check interrupt is fatal\n"); 726 recovered = 0; 727 } 728 729 if (!recovered && evt->sync_error) { 730 /* 731 * Try to kill processes if we get a synchronous machine check 732 * (e.g., one caused by execution of this instruction). This 733 * will devolve into a panic if we try to kill init or are in 734 * an interrupt etc. 735 * 736 * TODO: Queue up this address for hwpoisioning later. 737 * TODO: This is not quite right for d-side machine 738 * checks ->nip is not necessarily the important 739 * address. 740 */ 741 if ((user_mode(regs))) { 742 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip); 743 recovered = 1; 744 } else if (die_will_crash()) { 745 /* 746 * die() would kill the kernel, so better to go via 747 * the platform reboot code that will log the 748 * machine check. 749 */ 750 recovered = 0; 751 } else { 752 die("Machine check", regs, SIGBUS); 753 recovered = 1; 754 } 755 } 756 757 return recovered; 758 } 759 760 /* 761 * Handle a machine check. 762 * 763 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi) 764 * should be present. If so the handler which called us tells us if the 765 * error was recovered (never true if RI=0). 766 * 767 * On hardware prior to Power 4 these exceptions were asynchronous which 768 * means we can't tell exactly where it occurred and so we can't recover. 769 */ 770 int pSeries_machine_check_exception(struct pt_regs *regs) 771 { 772 struct machine_check_event evt; 773 774 if (!get_mce_event(&evt, MCE_EVENT_RELEASE)) 775 return 0; 776 777 /* Print things out */ 778 if (evt.version != MCE_V1) { 779 pr_err("Machine Check Exception, Unknown event version %d !\n", 780 evt.version); 781 return 0; 782 } 783 machine_check_print_event_info(&evt, user_mode(regs), false); 784 785 if (recover_mce(regs, &evt)) 786 return 1; 787 788 return 0; 789 } 790 791 long pseries_machine_check_realmode(struct pt_regs *regs) 792 { 793 struct rtas_error_log *errp; 794 int disposition; 795 796 if (fwnmi_active) { 797 errp = fwnmi_get_errinfo(regs); 798 /* 799 * Call to fwnmi_release_errinfo() in real mode causes kernel 800 * to panic. Hence we will call it as soon as we go into 801 * virtual mode. 802 */ 803 disposition = mce_handle_error(regs, errp); 804 fwnmi_release_errinfo(); 805 806 /* Queue irq work to log this rtas event later. */ 807 irq_work_queue(&mce_errlog_process_work); 808 809 if (disposition == RTAS_DISP_FULLY_RECOVERED) 810 return 1; 811 } 812 813 return 0; 814 } 815