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 break; 188 189 case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS: 190 pr_emerg("Loss of system critical functions detected. Check" 191 " RTAS error log for details\n"); 192 orderly_poweroff(true); 193 break; 194 195 case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH: 196 pr_emerg("High ambient temperature detected. Check RTAS" 197 " error log for details\n"); 198 orderly_poweroff(true); 199 break; 200 201 default: 202 pr_err("Unknown power/cooling shutdown event (modifier = %d)\n", 203 event_modifier); 204 } 205 } 206 207 struct epow_errorlog { 208 unsigned char sensor_value; 209 unsigned char event_modifier; 210 unsigned char extended_modifier; 211 unsigned char reserved; 212 unsigned char platform_reason; 213 }; 214 215 #define EPOW_RESET 0 216 #define EPOW_WARN_COOLING 1 217 #define EPOW_WARN_POWER 2 218 #define EPOW_SYSTEM_SHUTDOWN 3 219 #define EPOW_SYSTEM_HALT 4 220 #define EPOW_MAIN_ENCLOSURE 5 221 #define EPOW_POWER_OFF 7 222 223 static void rtas_parse_epow_errlog(struct rtas_error_log *log) 224 { 225 struct pseries_errorlog *pseries_log; 226 struct epow_errorlog *epow_log; 227 char action_code; 228 char modifier; 229 230 pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW); 231 if (pseries_log == NULL) 232 return; 233 234 epow_log = (struct epow_errorlog *)pseries_log->data; 235 action_code = epow_log->sensor_value & 0xF; /* bottom 4 bits */ 236 modifier = epow_log->event_modifier & 0xF; /* bottom 4 bits */ 237 238 switch (action_code) { 239 case EPOW_RESET: 240 if (num_epow_events) { 241 pr_info("Non critical power/cooling issue cleared\n"); 242 num_epow_events--; 243 } 244 break; 245 246 case EPOW_WARN_COOLING: 247 pr_info("Non-critical cooling issue detected. Check RTAS error" 248 " log for details\n"); 249 break; 250 251 case EPOW_WARN_POWER: 252 pr_info("Non-critical power issue detected. Check RTAS error" 253 " log for details\n"); 254 break; 255 256 case EPOW_SYSTEM_SHUTDOWN: 257 handle_system_shutdown(modifier); 258 break; 259 260 case EPOW_SYSTEM_HALT: 261 pr_emerg("Critical power/cooling issue detected. Check RTAS" 262 " error log for details. Powering off.\n"); 263 orderly_poweroff(true); 264 break; 265 266 case EPOW_MAIN_ENCLOSURE: 267 case EPOW_POWER_OFF: 268 pr_emerg("System about to lose power. Check RTAS error log " 269 " for details. Powering off immediately.\n"); 270 emergency_sync(); 271 kernel_power_off(); 272 break; 273 274 default: 275 pr_err("Unknown power/cooling event (action code = %d)\n", 276 action_code); 277 } 278 279 /* Increment epow events counter variable */ 280 if (action_code != EPOW_RESET) 281 num_epow_events++; 282 } 283 284 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id) 285 { 286 struct pseries_errorlog *pseries_log; 287 struct pseries_hp_errorlog *hp_elog; 288 289 spin_lock(&ras_log_buf_lock); 290 291 rtas_call(ras_check_exception_token, 6, 1, NULL, 292 RTAS_VECTOR_EXTERNAL_INTERRUPT, virq_to_hw(irq), 293 RTAS_HOTPLUG_EVENTS, 0, __pa(&ras_log_buf), 294 rtas_get_error_log_max()); 295 296 pseries_log = get_pseries_errorlog((struct rtas_error_log *)ras_log_buf, 297 PSERIES_ELOG_SECT_ID_HOTPLUG); 298 hp_elog = (struct pseries_hp_errorlog *)pseries_log->data; 299 300 /* 301 * Since PCI hotplug is not currently supported on pseries, put PCI 302 * hotplug events on the ras_log_buf to be handled by rtas_errd. 303 */ 304 if (hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_MEM || 305 hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_CPU || 306 hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_PMEM) 307 queue_hotplug_event(hp_elog); 308 else 309 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); 310 311 spin_unlock(&ras_log_buf_lock); 312 return IRQ_HANDLED; 313 } 314 315 /* Handle environmental and power warning (EPOW) interrupts. */ 316 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id) 317 { 318 int status; 319 int state; 320 int critical; 321 322 status = rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX, 323 &state); 324 325 if (state > 3) 326 critical = 1; /* Time Critical */ 327 else 328 critical = 0; 329 330 spin_lock(&ras_log_buf_lock); 331 332 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 333 RTAS_VECTOR_EXTERNAL_INTERRUPT, 334 virq_to_hw(irq), 335 RTAS_EPOW_WARNING, 336 critical, __pa(&ras_log_buf), 337 rtas_get_error_log_max()); 338 339 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); 340 341 rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf); 342 343 spin_unlock(&ras_log_buf_lock); 344 return IRQ_HANDLED; 345 } 346 347 /* 348 * Handle hardware error interrupts. 349 * 350 * RTAS check-exception is called to collect data on the exception. If 351 * the error is deemed recoverable, we log a warning and return. 352 * For nonrecoverable errors, an error is logged and we stop all processing 353 * as quickly as possible in order to prevent propagation of the failure. 354 */ 355 static irqreturn_t ras_error_interrupt(int irq, void *dev_id) 356 { 357 struct rtas_error_log *rtas_elog; 358 int status; 359 int fatal; 360 361 spin_lock(&ras_log_buf_lock); 362 363 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 364 RTAS_VECTOR_EXTERNAL_INTERRUPT, 365 virq_to_hw(irq), 366 RTAS_INTERNAL_ERROR, 1 /* Time Critical */, 367 __pa(&ras_log_buf), 368 rtas_get_error_log_max()); 369 370 rtas_elog = (struct rtas_error_log *)ras_log_buf; 371 372 if (status == 0 && 373 rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC) 374 fatal = 1; 375 else 376 fatal = 0; 377 378 /* format and print the extended information */ 379 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal); 380 381 if (fatal) { 382 pr_emerg("Fatal hardware error detected. Check RTAS error" 383 " log for details. Powering off immediately\n"); 384 emergency_sync(); 385 kernel_power_off(); 386 } else { 387 pr_err("Recoverable hardware error detected\n"); 388 } 389 390 spin_unlock(&ras_log_buf_lock); 391 return IRQ_HANDLED; 392 } 393 394 /* 395 * Some versions of FWNMI place the buffer inside the 4kB page starting at 396 * 0x7000. Other versions place it inside the rtas buffer. We check both. 397 * Minimum size of the buffer is 16 bytes. 398 */ 399 #define VALID_FWNMI_BUFFER(A) \ 400 ((((A) >= 0x7000) && ((A) <= 0x8000 - 16)) || \ 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 static __be64 *fwnmi_get_savep(struct pt_regs *regs) 409 { 410 unsigned long savep_ra; 411 412 /* Mask top two bits */ 413 savep_ra = regs->gpr[3] & ~(0x3UL << 62); 414 if (!VALID_FWNMI_BUFFER(savep_ra)) { 415 printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]); 416 return NULL; 417 } 418 419 return __va(savep_ra); 420 } 421 422 /* 423 * Get the error information for errors coming through the 424 * FWNMI vectors. The pt_regs' r3 will be updated to reflect 425 * the actual r3 if possible, and a ptr to the error log entry 426 * will be returned if found. 427 * 428 * Use one buffer mce_data_buf per cpu to store RTAS error. 429 * 430 * The mce_data_buf does not have any locks or protection around it, 431 * if a second machine check comes in, or a system reset is done 432 * before we have logged the error, then we will get corruption in the 433 * error log. This is preferable over holding off on calling 434 * ibm,nmi-interlock which would result in us checkstopping if a 435 * second machine check did come in. 436 */ 437 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) 438 { 439 struct rtas_error_log *h; 440 __be64 *savep; 441 442 savep = fwnmi_get_savep(regs); 443 if (!savep) 444 return NULL; 445 446 regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */ 447 448 h = (struct rtas_error_log *)&savep[1]; 449 /* Use the per cpu buffer from paca to store rtas error log */ 450 memset(local_paca->mce_data_buf, 0, RTAS_ERROR_LOG_MAX); 451 if (!rtas_error_extended(h)) { 452 memcpy(local_paca->mce_data_buf, h, sizeof(__u64)); 453 } else { 454 int len, error_log_length; 455 456 error_log_length = 8 + rtas_error_extended_log_length(h); 457 len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX); 458 memcpy(local_paca->mce_data_buf, h, len); 459 } 460 461 return (struct rtas_error_log *)local_paca->mce_data_buf; 462 } 463 464 /* Call this when done with the data returned by FWNMI_get_errinfo. 465 * It will release the saved data area for other CPUs in the 466 * partition to receive FWNMI errors. 467 */ 468 static void fwnmi_release_errinfo(void) 469 { 470 struct rtas_args rtas_args; 471 int ret; 472 473 /* 474 * On pseries, the machine check stack is limited to under 4GB, so 475 * args can be on-stack. 476 */ 477 rtas_call_unlocked(&rtas_args, ibm_nmi_interlock_token, 0, 1, NULL); 478 ret = be32_to_cpu(rtas_args.rets[0]); 479 if (ret != 0) 480 printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret); 481 } 482 483 int pSeries_system_reset_exception(struct pt_regs *regs) 484 { 485 #ifdef __LITTLE_ENDIAN__ 486 /* 487 * Some firmware byteswaps SRR registers and gives incorrect SRR1. Try 488 * to detect the bad SRR1 pattern here. Flip the NIP back to correct 489 * endian for reporting purposes. Unfortunately the MSR can't be fixed, 490 * so clear it. It will be missing MSR_RI so we won't try to recover. 491 */ 492 if ((be64_to_cpu(regs->msr) & 493 (MSR_LE|MSR_RI|MSR_DR|MSR_IR|MSR_ME|MSR_PR| 494 MSR_ILE|MSR_HV|MSR_SF)) == (MSR_DR|MSR_SF)) { 495 regs->nip = be64_to_cpu((__be64)regs->nip); 496 regs->msr = 0; 497 } 498 #endif 499 500 if (fwnmi_active) { 501 __be64 *savep; 502 503 /* 504 * Firmware (PowerVM and KVM) saves r3 to a save area like 505 * machine check, which is not exactly what PAPR (2.9) 506 * suggests but there is no way to detect otherwise, so this 507 * is the interface now. 508 * 509 * System resets do not save any error log or require an 510 * "ibm,nmi-interlock" rtas call to release. 511 */ 512 513 savep = fwnmi_get_savep(regs); 514 if (savep) 515 regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */ 516 } 517 518 if (smp_handle_nmi_ipi(regs)) 519 return 1; 520 521 return 0; /* need to perform reset */ 522 } 523 524 525 static int mce_handle_error(struct pt_regs *regs, struct rtas_error_log *errp) 526 { 527 struct mce_error_info mce_err = { 0 }; 528 unsigned long eaddr = 0, paddr = 0; 529 struct pseries_errorlog *pseries_log; 530 struct pseries_mc_errorlog *mce_log; 531 int disposition = rtas_error_disposition(errp); 532 int initiator = rtas_error_initiator(errp); 533 int severity = rtas_error_severity(errp); 534 u8 error_type, err_sub_type; 535 536 if (initiator == RTAS_INITIATOR_UNKNOWN) 537 mce_err.initiator = MCE_INITIATOR_UNKNOWN; 538 else if (initiator == RTAS_INITIATOR_CPU) 539 mce_err.initiator = MCE_INITIATOR_CPU; 540 else if (initiator == RTAS_INITIATOR_PCI) 541 mce_err.initiator = MCE_INITIATOR_PCI; 542 else if (initiator == RTAS_INITIATOR_ISA) 543 mce_err.initiator = MCE_INITIATOR_ISA; 544 else if (initiator == RTAS_INITIATOR_MEMORY) 545 mce_err.initiator = MCE_INITIATOR_MEMORY; 546 else if (initiator == RTAS_INITIATOR_POWERMGM) 547 mce_err.initiator = MCE_INITIATOR_POWERMGM; 548 else 549 mce_err.initiator = MCE_INITIATOR_UNKNOWN; 550 551 if (severity == RTAS_SEVERITY_NO_ERROR) 552 mce_err.severity = MCE_SEV_NO_ERROR; 553 else if (severity == RTAS_SEVERITY_EVENT) 554 mce_err.severity = MCE_SEV_WARNING; 555 else if (severity == RTAS_SEVERITY_WARNING) 556 mce_err.severity = MCE_SEV_WARNING; 557 else if (severity == RTAS_SEVERITY_ERROR_SYNC) 558 mce_err.severity = MCE_SEV_SEVERE; 559 else if (severity == RTAS_SEVERITY_ERROR) 560 mce_err.severity = MCE_SEV_SEVERE; 561 else if (severity == RTAS_SEVERITY_FATAL) 562 mce_err.severity = MCE_SEV_FATAL; 563 else 564 mce_err.severity = MCE_SEV_FATAL; 565 566 if (severity <= RTAS_SEVERITY_ERROR_SYNC) 567 mce_err.sync_error = true; 568 else 569 mce_err.sync_error = false; 570 571 mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN; 572 mce_err.error_class = MCE_ECLASS_UNKNOWN; 573 574 if (!rtas_error_extended(errp)) 575 goto out; 576 577 pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE); 578 if (pseries_log == NULL) 579 goto out; 580 581 mce_log = (struct pseries_mc_errorlog *)pseries_log->data; 582 error_type = mce_log->error_type; 583 err_sub_type = rtas_mc_error_sub_type(mce_log); 584 585 switch (mce_log->error_type) { 586 case MC_ERROR_TYPE_UE: 587 mce_err.error_type = MCE_ERROR_TYPE_UE; 588 mce_common_process_ue(regs, &mce_err); 589 if (mce_err.ignore_event) 590 disposition = RTAS_DISP_FULLY_RECOVERED; 591 switch (err_sub_type) { 592 case MC_ERROR_UE_IFETCH: 593 mce_err.u.ue_error_type = MCE_UE_ERROR_IFETCH; 594 break; 595 case MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH: 596 mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH; 597 break; 598 case MC_ERROR_UE_LOAD_STORE: 599 mce_err.u.ue_error_type = MCE_UE_ERROR_LOAD_STORE; 600 break; 601 case MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE: 602 mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE; 603 break; 604 case MC_ERROR_UE_INDETERMINATE: 605 default: 606 mce_err.u.ue_error_type = MCE_UE_ERROR_INDETERMINATE; 607 break; 608 } 609 if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) 610 eaddr = be64_to_cpu(mce_log->effective_address); 611 612 if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) { 613 paddr = be64_to_cpu(mce_log->logical_address); 614 } else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) { 615 unsigned long pfn; 616 617 pfn = addr_to_pfn(regs, eaddr); 618 if (pfn != ULONG_MAX) 619 paddr = pfn << PAGE_SHIFT; 620 } 621 622 break; 623 case MC_ERROR_TYPE_SLB: 624 mce_err.error_type = MCE_ERROR_TYPE_SLB; 625 switch (err_sub_type) { 626 case MC_ERROR_SLB_PARITY: 627 mce_err.u.slb_error_type = MCE_SLB_ERROR_PARITY; 628 break; 629 case MC_ERROR_SLB_MULTIHIT: 630 mce_err.u.slb_error_type = MCE_SLB_ERROR_MULTIHIT; 631 break; 632 case MC_ERROR_SLB_INDETERMINATE: 633 default: 634 mce_err.u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE; 635 break; 636 } 637 if (mce_log->sub_err_type & 0x80) 638 eaddr = be64_to_cpu(mce_log->effective_address); 639 break; 640 case MC_ERROR_TYPE_ERAT: 641 mce_err.error_type = MCE_ERROR_TYPE_ERAT; 642 switch (err_sub_type) { 643 case MC_ERROR_ERAT_PARITY: 644 mce_err.u.erat_error_type = MCE_ERAT_ERROR_PARITY; 645 break; 646 case MC_ERROR_ERAT_MULTIHIT: 647 mce_err.u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT; 648 break; 649 case MC_ERROR_ERAT_INDETERMINATE: 650 default: 651 mce_err.u.erat_error_type = MCE_ERAT_ERROR_INDETERMINATE; 652 break; 653 } 654 if (mce_log->sub_err_type & 0x80) 655 eaddr = be64_to_cpu(mce_log->effective_address); 656 break; 657 case MC_ERROR_TYPE_TLB: 658 mce_err.error_type = MCE_ERROR_TYPE_TLB; 659 switch (err_sub_type) { 660 case MC_ERROR_TLB_PARITY: 661 mce_err.u.tlb_error_type = MCE_TLB_ERROR_PARITY; 662 break; 663 case MC_ERROR_TLB_MULTIHIT: 664 mce_err.u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT; 665 break; 666 case MC_ERROR_TLB_INDETERMINATE: 667 default: 668 mce_err.u.tlb_error_type = MCE_TLB_ERROR_INDETERMINATE; 669 break; 670 } 671 if (mce_log->sub_err_type & 0x80) 672 eaddr = be64_to_cpu(mce_log->effective_address); 673 break; 674 case MC_ERROR_TYPE_D_CACHE: 675 mce_err.error_type = MCE_ERROR_TYPE_DCACHE; 676 break; 677 case MC_ERROR_TYPE_I_CACHE: 678 mce_err.error_type = MCE_ERROR_TYPE_DCACHE; 679 break; 680 case MC_ERROR_TYPE_UNKNOWN: 681 default: 682 mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN; 683 break; 684 } 685 686 #ifdef CONFIG_PPC_BOOK3S_64 687 if (disposition == RTAS_DISP_NOT_RECOVERED) { 688 switch (error_type) { 689 case MC_ERROR_TYPE_SLB: 690 case MC_ERROR_TYPE_ERAT: 691 /* 692 * Store the old slb content in paca before flushing. 693 * Print this when we go to virtual mode. 694 * There are chances that we may hit MCE again if there 695 * is a parity error on the SLB entry we trying to read 696 * for saving. Hence limit the slb saving to single 697 * level of recursion. 698 */ 699 if (local_paca->in_mce == 1) 700 slb_save_contents(local_paca->mce_faulty_slbs); 701 flush_and_reload_slb(); 702 disposition = RTAS_DISP_FULLY_RECOVERED; 703 break; 704 default: 705 break; 706 } 707 } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) { 708 /* Platform corrected itself but could be degraded */ 709 printk(KERN_ERR "MCE: limited recovery, system may " 710 "be degraded\n"); 711 disposition = RTAS_DISP_FULLY_RECOVERED; 712 } 713 #endif 714 715 out: 716 /* 717 * Enable translation as we will be accessing per-cpu variables 718 * in save_mce_event() which may fall outside RMO region, also 719 * leave it enabled because subsequently we will be queuing work 720 * to workqueues where again per-cpu variables accessed, besides 721 * fwnmi_release_errinfo() crashes when called in realmode on 722 * pseries. 723 * Note: All the realmode handling like flushing SLB entries for 724 * SLB multihit is done by now. 725 */ 726 mtmsr(mfmsr() | MSR_IR | MSR_DR); 727 save_mce_event(regs, disposition == RTAS_DISP_FULLY_RECOVERED, 728 &mce_err, regs->nip, eaddr, paddr); 729 730 return disposition; 731 } 732 733 /* 734 * Process MCE rtas errlog event. 735 */ 736 static void mce_process_errlog_event(struct irq_work *work) 737 { 738 struct rtas_error_log *err; 739 740 err = fwnmi_get_errlog(); 741 log_error((char *)err, ERR_TYPE_RTAS_LOG, 0); 742 } 743 744 /* 745 * See if we can recover from a machine check exception. 746 * This is only called on power4 (or above) and only via 747 * the Firmware Non-Maskable Interrupts (fwnmi) handler 748 * which provides the error analysis for us. 749 * 750 * Return 1 if corrected (or delivered a signal). 751 * Return 0 if there is nothing we can do. 752 */ 753 static int recover_mce(struct pt_regs *regs, struct machine_check_event *evt) 754 { 755 int recovered = 0; 756 757 if (!(regs->msr & MSR_RI)) { 758 /* If MSR_RI isn't set, we cannot recover */ 759 pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n"); 760 recovered = 0; 761 } else if (evt->disposition == MCE_DISPOSITION_RECOVERED) { 762 /* Platform corrected itself */ 763 recovered = 1; 764 } else if (evt->severity == MCE_SEV_FATAL) { 765 /* Fatal machine check */ 766 pr_err("Machine check interrupt is fatal\n"); 767 recovered = 0; 768 } 769 770 if (!recovered && evt->sync_error) { 771 /* 772 * Try to kill processes if we get a synchronous machine check 773 * (e.g., one caused by execution of this instruction). This 774 * will devolve into a panic if we try to kill init or are in 775 * an interrupt etc. 776 * 777 * TODO: Queue up this address for hwpoisioning later. 778 * TODO: This is not quite right for d-side machine 779 * checks ->nip is not necessarily the important 780 * address. 781 */ 782 if ((user_mode(regs))) { 783 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip); 784 recovered = 1; 785 } else if (die_will_crash()) { 786 /* 787 * die() would kill the kernel, so better to go via 788 * the platform reboot code that will log the 789 * machine check. 790 */ 791 recovered = 0; 792 } else { 793 die("Machine check", regs, SIGBUS); 794 recovered = 1; 795 } 796 } 797 798 return recovered; 799 } 800 801 /* 802 * Handle a machine check. 803 * 804 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi) 805 * should be present. If so the handler which called us tells us if the 806 * error was recovered (never true if RI=0). 807 * 808 * On hardware prior to Power 4 these exceptions were asynchronous which 809 * means we can't tell exactly where it occurred and so we can't recover. 810 */ 811 int pSeries_machine_check_exception(struct pt_regs *regs) 812 { 813 struct machine_check_event evt; 814 815 if (!get_mce_event(&evt, MCE_EVENT_RELEASE)) 816 return 0; 817 818 /* Print things out */ 819 if (evt.version != MCE_V1) { 820 pr_err("Machine Check Exception, Unknown event version %d !\n", 821 evt.version); 822 return 0; 823 } 824 machine_check_print_event_info(&evt, user_mode(regs), false); 825 826 if (recover_mce(regs, &evt)) 827 return 1; 828 829 return 0; 830 } 831 832 long pseries_machine_check_realmode(struct pt_regs *regs) 833 { 834 struct rtas_error_log *errp; 835 int disposition; 836 837 if (fwnmi_active) { 838 errp = fwnmi_get_errinfo(regs); 839 /* 840 * Call to fwnmi_release_errinfo() in real mode causes kernel 841 * to panic. Hence we will call it as soon as we go into 842 * virtual mode. 843 */ 844 disposition = mce_handle_error(regs, errp); 845 fwnmi_release_errinfo(); 846 847 /* Queue irq work to log this rtas event later. */ 848 irq_work_queue(&mce_errlog_process_work); 849 850 if (disposition == RTAS_DISP_FULLY_RECOVERED) 851 return 1; 852 } 853 854 return 0; 855 } 856