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(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 * Minimum size of the buffer is 16 bytes. 399 */ 400 #define VALID_FWNMI_BUFFER(A) \ 401 ((((A) >= 0x7000) && ((A) <= 0x8000 - 16)) || \ 402 (((A) >= rtas.base) && ((A) <= (rtas.base + rtas.size - 16)))) 403 404 static inline struct rtas_error_log *fwnmi_get_errlog(void) 405 { 406 return (struct rtas_error_log *)local_paca->mce_data_buf; 407 } 408 409 static __be64 *fwnmi_get_savep(struct pt_regs *regs) 410 { 411 unsigned long savep_ra; 412 413 /* Mask top two bits */ 414 savep_ra = regs->gpr[3] & ~(0x3UL << 62); 415 if (!VALID_FWNMI_BUFFER(savep_ra)) { 416 printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]); 417 return NULL; 418 } 419 420 return __va(savep_ra); 421 } 422 423 /* 424 * Get the error information for errors coming through the 425 * FWNMI vectors. The pt_regs' r3 will be updated to reflect 426 * the actual r3 if possible, and a ptr to the error log entry 427 * will be returned if found. 428 * 429 * Use one buffer mce_data_buf per cpu to store RTAS error. 430 * 431 * The mce_data_buf does not have any locks or protection around it, 432 * if a second machine check comes in, or a system reset is done 433 * before we have logged the error, then we will get corruption in the 434 * error log. This is preferable over holding off on calling 435 * ibm,nmi-interlock which would result in us checkstopping if a 436 * second machine check did come in. 437 */ 438 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) 439 { 440 struct rtas_error_log *h; 441 __be64 *savep; 442 443 savep = fwnmi_get_savep(regs); 444 if (!savep) 445 return NULL; 446 447 regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */ 448 449 h = (struct rtas_error_log *)&savep[1]; 450 /* Use the per cpu buffer from paca to store rtas error log */ 451 memset(local_paca->mce_data_buf, 0, RTAS_ERROR_LOG_MAX); 452 if (!rtas_error_extended(h)) { 453 memcpy(local_paca->mce_data_buf, h, sizeof(__u64)); 454 } else { 455 int len, error_log_length; 456 457 error_log_length = 8 + rtas_error_extended_log_length(h); 458 len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX); 459 memcpy(local_paca->mce_data_buf, h, len); 460 } 461 462 return (struct rtas_error_log *)local_paca->mce_data_buf; 463 } 464 465 /* Call this when done with the data returned by FWNMI_get_errinfo. 466 * It will release the saved data area for other CPUs in the 467 * partition to receive FWNMI errors. 468 */ 469 static void fwnmi_release_errinfo(void) 470 { 471 struct rtas_args rtas_args; 472 int ret; 473 474 /* 475 * On pseries, the machine check stack is limited to under 4GB, so 476 * args can be on-stack. 477 */ 478 rtas_call_unlocked(&rtas_args, ibm_nmi_interlock_token, 0, 1, NULL); 479 ret = be32_to_cpu(rtas_args.rets[0]); 480 if (ret != 0) 481 printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret); 482 } 483 484 int pSeries_system_reset_exception(struct pt_regs *regs) 485 { 486 #ifdef __LITTLE_ENDIAN__ 487 /* 488 * Some firmware byteswaps SRR registers and gives incorrect SRR1. Try 489 * to detect the bad SRR1 pattern here. Flip the NIP back to correct 490 * endian for reporting purposes. Unfortunately the MSR can't be fixed, 491 * so clear it. It will be missing MSR_RI so we won't try to recover. 492 */ 493 if ((be64_to_cpu(regs->msr) & 494 (MSR_LE|MSR_RI|MSR_DR|MSR_IR|MSR_ME|MSR_PR| 495 MSR_ILE|MSR_HV|MSR_SF)) == (MSR_DR|MSR_SF)) { 496 regs->nip = be64_to_cpu((__be64)regs->nip); 497 regs->msr = 0; 498 } 499 #endif 500 501 if (fwnmi_active) { 502 __be64 *savep; 503 504 /* 505 * Firmware (PowerVM and KVM) saves r3 to a save area like 506 * machine check, which is not exactly what PAPR (2.9) 507 * suggests but there is no way to detect otherwise, so this 508 * is the interface now. 509 * 510 * System resets do not save any error log or require an 511 * "ibm,nmi-interlock" rtas call to release. 512 */ 513 514 savep = fwnmi_get_savep(regs); 515 if (savep) 516 regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */ 517 } 518 519 if (smp_handle_nmi_ipi(regs)) 520 return 1; 521 522 return 0; /* need to perform reset */ 523 } 524 525 526 static int mce_handle_error(struct pt_regs *regs, struct rtas_error_log *errp) 527 { 528 struct mce_error_info mce_err = { 0 }; 529 unsigned long eaddr = 0, paddr = 0; 530 struct pseries_errorlog *pseries_log; 531 struct pseries_mc_errorlog *mce_log; 532 int disposition = rtas_error_disposition(errp); 533 int initiator = rtas_error_initiator(errp); 534 int severity = rtas_error_severity(errp); 535 u8 error_type, err_sub_type; 536 537 if (initiator == RTAS_INITIATOR_UNKNOWN) 538 mce_err.initiator = MCE_INITIATOR_UNKNOWN; 539 else if (initiator == RTAS_INITIATOR_CPU) 540 mce_err.initiator = MCE_INITIATOR_CPU; 541 else if (initiator == RTAS_INITIATOR_PCI) 542 mce_err.initiator = MCE_INITIATOR_PCI; 543 else if (initiator == RTAS_INITIATOR_ISA) 544 mce_err.initiator = MCE_INITIATOR_ISA; 545 else if (initiator == RTAS_INITIATOR_MEMORY) 546 mce_err.initiator = MCE_INITIATOR_MEMORY; 547 else if (initiator == RTAS_INITIATOR_POWERMGM) 548 mce_err.initiator = MCE_INITIATOR_POWERMGM; 549 else 550 mce_err.initiator = MCE_INITIATOR_UNKNOWN; 551 552 if (severity == RTAS_SEVERITY_NO_ERROR) 553 mce_err.severity = MCE_SEV_NO_ERROR; 554 else if (severity == RTAS_SEVERITY_EVENT) 555 mce_err.severity = MCE_SEV_WARNING; 556 else if (severity == RTAS_SEVERITY_WARNING) 557 mce_err.severity = MCE_SEV_WARNING; 558 else if (severity == RTAS_SEVERITY_ERROR_SYNC) 559 mce_err.severity = MCE_SEV_SEVERE; 560 else if (severity == RTAS_SEVERITY_ERROR) 561 mce_err.severity = MCE_SEV_SEVERE; 562 else if (severity == RTAS_SEVERITY_FATAL) 563 mce_err.severity = MCE_SEV_FATAL; 564 else 565 mce_err.severity = MCE_SEV_FATAL; 566 567 if (severity <= RTAS_SEVERITY_ERROR_SYNC) 568 mce_err.sync_error = true; 569 else 570 mce_err.sync_error = false; 571 572 mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN; 573 mce_err.error_class = MCE_ECLASS_UNKNOWN; 574 575 if (!rtas_error_extended(errp)) 576 goto out; 577 578 pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE); 579 if (pseries_log == NULL) 580 goto out; 581 582 mce_log = (struct pseries_mc_errorlog *)pseries_log->data; 583 error_type = mce_log->error_type; 584 err_sub_type = rtas_mc_error_sub_type(mce_log); 585 586 switch (mce_log->error_type) { 587 case MC_ERROR_TYPE_UE: 588 mce_err.error_type = MCE_ERROR_TYPE_UE; 589 mce_common_process_ue(regs, &mce_err); 590 if (mce_err.ignore_event) 591 disposition = RTAS_DISP_FULLY_RECOVERED; 592 switch (err_sub_type) { 593 case MC_ERROR_UE_IFETCH: 594 mce_err.u.ue_error_type = MCE_UE_ERROR_IFETCH; 595 break; 596 case MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH: 597 mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH; 598 break; 599 case MC_ERROR_UE_LOAD_STORE: 600 mce_err.u.ue_error_type = MCE_UE_ERROR_LOAD_STORE; 601 break; 602 case MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE: 603 mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE; 604 break; 605 case MC_ERROR_UE_INDETERMINATE: 606 default: 607 mce_err.u.ue_error_type = MCE_UE_ERROR_INDETERMINATE; 608 break; 609 } 610 if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) 611 eaddr = be64_to_cpu(mce_log->effective_address); 612 613 if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) { 614 paddr = be64_to_cpu(mce_log->logical_address); 615 } else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) { 616 unsigned long pfn; 617 618 pfn = addr_to_pfn(regs, eaddr); 619 if (pfn != ULONG_MAX) 620 paddr = pfn << PAGE_SHIFT; 621 } 622 623 break; 624 case MC_ERROR_TYPE_SLB: 625 mce_err.error_type = MCE_ERROR_TYPE_SLB; 626 switch (err_sub_type) { 627 case MC_ERROR_SLB_PARITY: 628 mce_err.u.slb_error_type = MCE_SLB_ERROR_PARITY; 629 break; 630 case MC_ERROR_SLB_MULTIHIT: 631 mce_err.u.slb_error_type = MCE_SLB_ERROR_MULTIHIT; 632 break; 633 case MC_ERROR_SLB_INDETERMINATE: 634 default: 635 mce_err.u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE; 636 break; 637 } 638 if (mce_log->sub_err_type & 0x80) 639 eaddr = be64_to_cpu(mce_log->effective_address); 640 break; 641 case MC_ERROR_TYPE_ERAT: 642 mce_err.error_type = MCE_ERROR_TYPE_ERAT; 643 switch (err_sub_type) { 644 case MC_ERROR_ERAT_PARITY: 645 mce_err.u.erat_error_type = MCE_ERAT_ERROR_PARITY; 646 break; 647 case MC_ERROR_ERAT_MULTIHIT: 648 mce_err.u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT; 649 break; 650 case MC_ERROR_ERAT_INDETERMINATE: 651 default: 652 mce_err.u.erat_error_type = MCE_ERAT_ERROR_INDETERMINATE; 653 break; 654 } 655 if (mce_log->sub_err_type & 0x80) 656 eaddr = be64_to_cpu(mce_log->effective_address); 657 break; 658 case MC_ERROR_TYPE_TLB: 659 mce_err.error_type = MCE_ERROR_TYPE_TLB; 660 switch (err_sub_type) { 661 case MC_ERROR_TLB_PARITY: 662 mce_err.u.tlb_error_type = MCE_TLB_ERROR_PARITY; 663 break; 664 case MC_ERROR_TLB_MULTIHIT: 665 mce_err.u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT; 666 break; 667 case MC_ERROR_TLB_INDETERMINATE: 668 default: 669 mce_err.u.tlb_error_type = MCE_TLB_ERROR_INDETERMINATE; 670 break; 671 } 672 if (mce_log->sub_err_type & 0x80) 673 eaddr = be64_to_cpu(mce_log->effective_address); 674 break; 675 case MC_ERROR_TYPE_D_CACHE: 676 mce_err.error_type = MCE_ERROR_TYPE_DCACHE; 677 break; 678 case MC_ERROR_TYPE_I_CACHE: 679 mce_err.error_type = MCE_ERROR_TYPE_DCACHE; 680 break; 681 case MC_ERROR_TYPE_UNKNOWN: 682 default: 683 mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN; 684 break; 685 } 686 687 #ifdef CONFIG_PPC_BOOK3S_64 688 if (disposition == RTAS_DISP_NOT_RECOVERED) { 689 switch (error_type) { 690 case MC_ERROR_TYPE_SLB: 691 case MC_ERROR_TYPE_ERAT: 692 /* 693 * Store the old slb content in paca before flushing. 694 * Print this when we go to virtual mode. 695 * There are chances that we may hit MCE again if there 696 * is a parity error on the SLB entry we trying to read 697 * for saving. Hence limit the slb saving to single 698 * level of recursion. 699 */ 700 if (local_paca->in_mce == 1) 701 slb_save_contents(local_paca->mce_faulty_slbs); 702 flush_and_reload_slb(); 703 disposition = RTAS_DISP_FULLY_RECOVERED; 704 break; 705 default: 706 break; 707 } 708 } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) { 709 /* Platform corrected itself but could be degraded */ 710 printk(KERN_ERR "MCE: limited recovery, system may " 711 "be degraded\n"); 712 disposition = RTAS_DISP_FULLY_RECOVERED; 713 } 714 #endif 715 716 out: 717 /* 718 * Enable translation as we will be accessing per-cpu variables 719 * in save_mce_event() which may fall outside RMO region, also 720 * leave it enabled because subsequently we will be queuing work 721 * to workqueues where again per-cpu variables accessed, besides 722 * fwnmi_release_errinfo() crashes when called in realmode on 723 * pseries. 724 * Note: All the realmode handling like flushing SLB entries for 725 * SLB multihit is done by now. 726 */ 727 mtmsr(mfmsr() | MSR_IR | MSR_DR); 728 save_mce_event(regs, disposition == RTAS_DISP_FULLY_RECOVERED, 729 &mce_err, regs->nip, eaddr, paddr); 730 731 return disposition; 732 } 733 734 /* 735 * Process MCE rtas errlog event. 736 */ 737 static void mce_process_errlog_event(struct irq_work *work) 738 { 739 struct rtas_error_log *err; 740 741 err = fwnmi_get_errlog(); 742 log_error((char *)err, ERR_TYPE_RTAS_LOG, 0); 743 } 744 745 /* 746 * See if we can recover from a machine check exception. 747 * This is only called on power4 (or above) and only via 748 * the Firmware Non-Maskable Interrupts (fwnmi) handler 749 * which provides the error analysis for us. 750 * 751 * Return 1 if corrected (or delivered a signal). 752 * Return 0 if there is nothing we can do. 753 */ 754 static int recover_mce(struct pt_regs *regs, struct machine_check_event *evt) 755 { 756 int recovered = 0; 757 758 if (!(regs->msr & MSR_RI)) { 759 /* If MSR_RI isn't set, we cannot recover */ 760 pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n"); 761 recovered = 0; 762 } else if (evt->disposition == MCE_DISPOSITION_RECOVERED) { 763 /* Platform corrected itself */ 764 recovered = 1; 765 } else if (evt->severity == MCE_SEV_FATAL) { 766 /* Fatal machine check */ 767 pr_err("Machine check interrupt is fatal\n"); 768 recovered = 0; 769 } 770 771 if (!recovered && evt->sync_error) { 772 /* 773 * Try to kill processes if we get a synchronous machine check 774 * (e.g., one caused by execution of this instruction). This 775 * will devolve into a panic if we try to kill init or are in 776 * an interrupt etc. 777 * 778 * TODO: Queue up this address for hwpoisioning later. 779 * TODO: This is not quite right for d-side machine 780 * checks ->nip is not necessarily the important 781 * address. 782 */ 783 if ((user_mode(regs))) { 784 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip); 785 recovered = 1; 786 } else if (die_will_crash()) { 787 /* 788 * die() would kill the kernel, so better to go via 789 * the platform reboot code that will log the 790 * machine check. 791 */ 792 recovered = 0; 793 } else { 794 die("Machine check", regs, SIGBUS); 795 recovered = 1; 796 } 797 } 798 799 return recovered; 800 } 801 802 /* 803 * Handle a machine check. 804 * 805 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi) 806 * should be present. If so the handler which called us tells us if the 807 * error was recovered (never true if RI=0). 808 * 809 * On hardware prior to Power 4 these exceptions were asynchronous which 810 * means we can't tell exactly where it occurred and so we can't recover. 811 */ 812 int pSeries_machine_check_exception(struct pt_regs *regs) 813 { 814 struct machine_check_event evt; 815 816 if (!get_mce_event(&evt, MCE_EVENT_RELEASE)) 817 return 0; 818 819 /* Print things out */ 820 if (evt.version != MCE_V1) { 821 pr_err("Machine Check Exception, Unknown event version %d !\n", 822 evt.version); 823 return 0; 824 } 825 machine_check_print_event_info(&evt, user_mode(regs), false); 826 827 if (recover_mce(regs, &evt)) 828 return 1; 829 830 return 0; 831 } 832 833 long pseries_machine_check_realmode(struct pt_regs *regs) 834 { 835 struct rtas_error_log *errp; 836 int disposition; 837 838 if (fwnmi_active) { 839 errp = fwnmi_get_errinfo(regs); 840 /* 841 * Call to fwnmi_release_errinfo() in real mode causes kernel 842 * to panic. Hence we will call it as soon as we go into 843 * virtual mode. 844 */ 845 disposition = mce_handle_error(regs, errp); 846 fwnmi_release_errinfo(); 847 848 /* Queue irq work to log this rtas event later. */ 849 irq_work_queue(&mce_errlog_process_work); 850 851 if (disposition == RTAS_DISP_FULLY_RECOVERED) 852 return 1; 853 } 854 855 return 0; 856 } 857