arch/powerpc/platforms/pseries/ras.c

   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_TLB               0x04
  80 #define MC_ERROR_TYPE_D_CACHE           0x05
  81 #define MC_ERROR_TYPE_I_CACHE           0x07
  82
  83 /* RTAS pseries MCE error sub types */
  84 #define MC_ERROR_UE_INDETERMINATE               0
  85 #define MC_ERROR_UE_IFETCH                      1
  86 #define MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH      2
  87 #define MC_ERROR_UE_LOAD_STORE                  3
  88 #define MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE  4
  89
  90 #define MC_ERROR_SLB_PARITY             0
  91 #define MC_ERROR_SLB_MULTIHIT           1
  92 #define MC_ERROR_SLB_INDETERMINATE      2
  93
  94 #define MC_ERROR_ERAT_PARITY            1
  95 #define MC_ERROR_ERAT_MULTIHIT          2
  96 #define MC_ERROR_ERAT_INDETERMINATE     3
  97
  98 #define MC_ERROR_TLB_PARITY             1
  99 #define MC_ERROR_TLB_MULTIHIT           2
 100 #define MC_ERROR_TLB_INDETERMINATE      3
 101
 102 static inline u8 rtas_mc_error_sub_type(const struct pseries_mc_errorlog *mlog)
 103 {
 104         switch (mlog->error_type) {
 105         case    MC_ERROR_TYPE_UE:
 106                 return (mlog->sub_err_type & 0x07);
 107         case    MC_ERROR_TYPE_SLB:
 108         case    MC_ERROR_TYPE_ERAT:
 109         case    MC_ERROR_TYPE_TLB:
 110                 return (mlog->sub_err_type & 0x03);
 111         default:
 112                 return 0;
 113         }
 114 }
 115
 116 static
 117 inline u64 rtas_mc_get_effective_addr(const struct pseries_mc_errorlog *mlog)
 118 {
 119         __be64 addr = 0;
 120
 121         switch (mlog->error_type) {
 122         case    MC_ERROR_TYPE_UE:
 123                 if (mlog->sub_err_type & 0x40)
 124                         addr = mlog->effective_address;
 125                 break;
 126         case    MC_ERROR_TYPE_SLB:
 127         case    MC_ERROR_TYPE_ERAT:
 128         case    MC_ERROR_TYPE_TLB:
 129                 if (mlog->sub_err_type & 0x80)
 130                         addr = mlog->effective_address;
 131         default:
 132                 break;
 133         }
 134         return be64_to_cpu(addr);
 135 }
 136
 137 /*
 138  * Enable the hotplug interrupt late because processing them may touch other
 139  * devices or systems (e.g. hugepages) that have not been initialized at the
 140  * subsys stage.
 141  */
 142 int __init init_ras_hotplug_IRQ(void)
 143 {
 144         struct device_node *np;
 145
 146         /* Hotplug Events */
 147         np = of_find_node_by_path("/event-sources/hot-plug-events");
 148         if (np != NULL) {
 149                 if (dlpar_workqueue_init() == 0)
 150                         request_event_sources_irqs(np, ras_hotplug_interrupt,
 151                                                    "RAS_HOTPLUG");
 152                 of_node_put(np);
 153         }
 154
 155         return 0;
 156 }
 157 machine_late_initcall(pseries, init_ras_hotplug_IRQ);
 158
 159 /*
 160  * Initialize handlers for the set of interrupts caused by hardware errors
 161  * and power system events.
 162  */
 163 static int __init init_ras_IRQ(void)
 164 {
 165         struct device_node *np;
 166
 167         ras_check_exception_token = rtas_token("check-exception");
 168
 169         /* Internal Errors */
 170         np = of_find_node_by_path("/event-sources/internal-errors");
 171         if (np != NULL) {
 172                 request_event_sources_irqs(np, ras_error_interrupt,
 173                                            "RAS_ERROR");
 174                 of_node_put(np);
 175         }
 176
 177         /* EPOW Events */
 178         np = of_find_node_by_path("/event-sources/epow-events");
 179         if (np != NULL) {
 180                 request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW");
 181                 of_node_put(np);
 182         }
 183
 184         return 0;
 185 }
 186 machine_subsys_initcall(pseries, init_ras_IRQ);
 187
 188 #define EPOW_SHUTDOWN_NORMAL                            1
 189 #define EPOW_SHUTDOWN_ON_UPS                            2
 190 #define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS        3
 191 #define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH      4
 192
 193 static void handle_system_shutdown(char event_modifier)
 194 {
 195         switch (event_modifier) {
 196         case EPOW_SHUTDOWN_NORMAL:
 197                 pr_emerg("Power off requested\n");
 198                 orderly_poweroff(true);
 199                 break;
 200
 201         case EPOW_SHUTDOWN_ON_UPS:
 202                 pr_emerg("Loss of system power detected. System is running on"
 203                          " UPS/battery. Check RTAS error log for details\n");
 204                 orderly_poweroff(true);
 205                 break;
 206
 207         case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
 208                 pr_emerg("Loss of system critical functions detected. Check"
 209                          " RTAS error log for details\n");
 210                 orderly_poweroff(true);
 211                 break;
 212
 213         case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH:
 214                 pr_emerg("High ambient temperature detected. Check RTAS"
 215                          " error log for details\n");
 216                 orderly_poweroff(true);
 217                 break;
 218
 219         default:
 220                 pr_err("Unknown power/cooling shutdown event (modifier = %d)\n",
 221                         event_modifier);
 222         }
 223 }
 224
 225 struct epow_errorlog {
 226         unsigned char sensor_value;
 227         unsigned char event_modifier;
 228         unsigned char extended_modifier;
 229         unsigned char reserved;
 230         unsigned char platform_reason;
 231 };
 232
 233 #define EPOW_RESET                      0
 234 #define EPOW_WARN_COOLING               1
 235 #define EPOW_WARN_POWER                 2
 236 #define EPOW_SYSTEM_SHUTDOWN            3
 237 #define EPOW_SYSTEM_HALT                4
 238 #define EPOW_MAIN_ENCLOSURE             5
 239 #define EPOW_POWER_OFF                  7
 240
 241 static void rtas_parse_epow_errlog(struct rtas_error_log *log)
 242 {
 243         struct pseries_errorlog *pseries_log;
 244         struct epow_errorlog *epow_log;
 245         char action_code;
 246         char modifier;
 247
 248         pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW);
 249         if (pseries_log == NULL)
 250                 return;
 251
 252         epow_log = (struct epow_errorlog *)pseries_log->data;
 253         action_code = epow_log->sensor_value & 0xF;     /* bottom 4 bits */
 254         modifier = epow_log->event_modifier & 0xF;      /* bottom 4 bits */
 255
 256         switch (action_code) {
 257         case EPOW_RESET:
 258                 if (num_epow_events) {
 259                         pr_info("Non critical power/cooling issue cleared\n");
 260                         num_epow_events--;
 261                 }
 262                 break;
 263
 264         case EPOW_WARN_COOLING:
 265                 pr_info("Non-critical cooling issue detected. Check RTAS error"
 266                         " log for details\n");
 267                 break;
 268
 269         case EPOW_WARN_POWER:
 270                 pr_info("Non-critical power issue detected. Check RTAS error"
 271                         " log for details\n");
 272                 break;
 273
 274         case EPOW_SYSTEM_SHUTDOWN:
 275                 handle_system_shutdown(epow_log->event_modifier);
 276                 break;
 277
 278         case EPOW_SYSTEM_HALT:
 279                 pr_emerg("Critical power/cooling issue detected. Check RTAS"
 280                          " error log for details. Powering off.\n");
 281                 orderly_poweroff(true);
 282                 break;
 283
 284         case EPOW_MAIN_ENCLOSURE:
 285         case EPOW_POWER_OFF:
 286                 pr_emerg("System about to lose power. Check RTAS error log "
 287                          " for details. Powering off immediately.\n");
 288                 emergency_sync();
 289                 kernel_power_off();
 290                 break;
 291
 292         default:
 293                 pr_err("Unknown power/cooling event (action code  = %d)\n",
 294                         action_code);
 295         }
 296
 297         /* Increment epow events counter variable */
 298         if (action_code != EPOW_RESET)
 299                 num_epow_events++;
 300 }
 301
 302 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id)
 303 {
 304         struct pseries_errorlog *pseries_log;
 305         struct pseries_hp_errorlog *hp_elog;
 306
 307         spin_lock(&ras_log_buf_lock);
 308
 309         rtas_call(ras_check_exception_token, 6, 1, NULL,
 310                   RTAS_VECTOR_EXTERNAL_INTERRUPT, virq_to_hw(irq),
 311                   RTAS_HOTPLUG_EVENTS, 0, __pa(&ras_log_buf),
 312                   rtas_get_error_log_max());
 313
 314         pseries_log = get_pseries_errorlog((struct rtas_error_log *)ras_log_buf,
 315                                            PSERIES_ELOG_SECT_ID_HOTPLUG);
 316         hp_elog = (struct pseries_hp_errorlog *)pseries_log->data;
 317
 318         /*
 319          * Since PCI hotplug is not currently supported on pseries, put PCI
 320          * hotplug events on the ras_log_buf to be handled by rtas_errd.
 321          */
 322         if (hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_MEM ||
 323             hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_CPU ||
 324             hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_PMEM)
 325                 queue_hotplug_event(hp_elog);
 326         else
 327                 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
 328
 329         spin_unlock(&ras_log_buf_lock);
 330         return IRQ_HANDLED;
 331 }
 332
 333 /* Handle environmental and power warning (EPOW) interrupts. */
 334 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id)
 335 {
 336         int status;
 337         int state;
 338         int critical;
 339
 340         status = rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX,
 341                                       &state);
 342
 343         if (state > 3)
 344                 critical = 1;           /* Time Critical */
 345         else
 346                 critical = 0;
 347
 348         spin_lock(&ras_log_buf_lock);
 349
 350         status = rtas_call(ras_check_exception_token, 6, 1, NULL,
 351                            RTAS_VECTOR_EXTERNAL_INTERRUPT,
 352                            virq_to_hw(irq),
 353                            RTAS_EPOW_WARNING,
 354                            critical, __pa(&ras_log_buf),
 355                                 rtas_get_error_log_max());
 356
 357         log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
 358
 359         rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf);
 360
 361         spin_unlock(&ras_log_buf_lock);
 362         return IRQ_HANDLED;
 363 }
 364
 365 /*
 366  * Handle hardware error interrupts.
 367  *
 368  * RTAS check-exception is called to collect data on the exception.  If
 369  * the error is deemed recoverable, we log a warning and return.
 370  * For nonrecoverable errors, an error is logged and we stop all processing
 371  * as quickly as possible in order to prevent propagation of the failure.
 372  */
 373 static irqreturn_t ras_error_interrupt(int irq, void *dev_id)
 374 {
 375         struct rtas_error_log *rtas_elog;
 376         int status;
 377         int fatal;
 378
 379         spin_lock(&ras_log_buf_lock);
 380
 381         status = rtas_call(ras_check_exception_token, 6, 1, NULL,
 382                            RTAS_VECTOR_EXTERNAL_INTERRUPT,
 383                            virq_to_hw(irq),
 384                            RTAS_INTERNAL_ERROR, 1 /* Time Critical */,
 385                            __pa(&ras_log_buf),
 386                                 rtas_get_error_log_max());
 387
 388         rtas_elog = (struct rtas_error_log *)ras_log_buf;
 389
 390         if (status == 0 &&
 391             rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC)
 392                 fatal = 1;
 393         else
 394                 fatal = 0;
 395
 396         /* format and print the extended information */
 397         log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal);
 398
 399         if (fatal) {
 400                 pr_emerg("Fatal hardware error detected. Check RTAS error"
 401                          " log for details. Powering off immediately\n");
 402                 emergency_sync();
 403                 kernel_power_off();
 404         } else {
 405                 pr_err("Recoverable hardware error detected\n");
 406         }
 407
 408         spin_unlock(&ras_log_buf_lock);
 409         return IRQ_HANDLED;
 410 }
 411
 412 /*
 413  * Some versions of FWNMI place the buffer inside the 4kB page starting at
 414  * 0x7000. Other versions place it inside the rtas buffer. We check both.
 415  */
 416 #define VALID_FWNMI_BUFFER(A) \
 417         ((((A) >= 0x7000) && ((A) < 0x7ff0)) || \
 418         (((A) >= rtas.base) && ((A) < (rtas.base + rtas.size - 16))))
 419
 420 static inline struct rtas_error_log *fwnmi_get_errlog(void)
 421 {
 422         return (struct rtas_error_log *)local_paca->mce_data_buf;
 423 }
 424
 425 /*
 426  * Get the error information for errors coming through the
 427  * FWNMI vectors.  The pt_regs' r3 will be updated to reflect
 428  * the actual r3 if possible, and a ptr to the error log entry
 429  * will be returned if found.
 430  *
 431  * Use one buffer mce_data_buf per cpu to store RTAS error.
 432  *
 433  * The mce_data_buf does not have any locks or protection around it,
 434  * if a second machine check comes in, or a system reset is done
 435  * before we have logged the error, then we will get corruption in the
 436  * error log.  This is preferable over holding off on calling
 437  * ibm,nmi-interlock which would result in us checkstopping if a
 438  * second machine check did come in.
 439  */
 440 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
 441 {
 442         unsigned long *savep;
 443         struct rtas_error_log *h;
 444
 445         /* Mask top two bits */
 446         regs->gpr[3] &= ~(0x3UL << 62);
 447
 448         if (!VALID_FWNMI_BUFFER(regs->gpr[3])) {
 449                 printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]);
 450                 return NULL;
 451         }
 452
 453         savep = __va(regs->gpr[3]);
 454         regs->gpr[3] = be64_to_cpu(savep[0]);   /* restore original r3 */
 455
 456         h = (struct rtas_error_log *)&savep[1];
 457         /* Use the per cpu buffer from paca to store rtas error log */
 458         memset(local_paca->mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
 459         if (!rtas_error_extended(h)) {
 460                 memcpy(local_paca->mce_data_buf, h, sizeof(__u64));
 461         } else {
 462                 int len, error_log_length;
 463
 464                 error_log_length = 8 + rtas_error_extended_log_length(h);
 465                 len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX);
 466                 memcpy(local_paca->mce_data_buf, h, len);
 467         }
 468
 469         return (struct rtas_error_log *)local_paca->mce_data_buf;
 470 }
 471
 472 /* Call this when done with the data returned by FWNMI_get_errinfo.
 473  * It will release the saved data area for other CPUs in the
 474  * partition to receive FWNMI errors.
 475  */
 476 static void fwnmi_release_errinfo(void)
 477 {
 478         int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL);
 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                 struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs);
 502                 if (errhdr) {
 503                         /* XXX Should look at FWNMI information */
 504                 }
 505                 fwnmi_release_errinfo();
 506         }
 507
 508         if (smp_handle_nmi_ipi(regs))
 509                 return 1;
 510
 511         return 0; /* need to perform reset */
 512 }
 513
 514 #define VAL_TO_STRING(ar, val)  \
 515         (((val) < ARRAY_SIZE(ar)) ? ar[(val)] : "Unknown")
 516
 517 static void pseries_print_mce_info(struct pt_regs *regs,
 518                                    struct rtas_error_log *errp)
 519 {
 520         const char *level, *sevstr;
 521         struct pseries_errorlog *pseries_log;
 522         struct pseries_mc_errorlog *mce_log;
 523         u8 error_type, err_sub_type;
 524         u64 addr;
 525         u8 initiator = rtas_error_initiator(errp);
 526         int disposition = rtas_error_disposition(errp);
 527
 528         static const char * const initiators[] = {
 529                 [0] = "Unknown",
 530                 [1] = "CPU",
 531                 [2] = "PCI",
 532                 [3] = "ISA",
 533                 [4] = "Memory",
 534                 [5] = "Power Mgmt",
 535         };
 536         static const char * const mc_err_types[] = {
 537                 [0] = "UE",
 538                 [1] = "SLB",
 539                 [2] = "ERAT",
 540                 [3] = "Unknown",
 541                 [4] = "TLB",
 542                 [5] = "D-Cache",
 543                 [6] = "Unknown",
 544                 [7] = "I-Cache",
 545         };
 546         static const char * const mc_ue_types[] = {
 547                 [0] = "Indeterminate",
 548                 [1] = "Instruction fetch",
 549                 [2] = "Page table walk ifetch",
 550                 [3] = "Load/Store",
 551                 [4] = "Page table walk Load/Store",
 552         };
 553
 554         /* SLB sub errors valid values are 0x0, 0x1, 0x2 */
 555         static const char * const mc_slb_types[] = {
 556                 [0] = "Parity",
 557                 [1] = "Multihit",
 558                 [2] = "Indeterminate",
 559         };
 560
 561         /* TLB and ERAT sub errors valid values are 0x1, 0x2, 0x3 */
 562         static const char * const mc_soft_types[] = {
 563                 [0] = "Unknown",
 564                 [1] = "Parity",
 565                 [2] = "Multihit",
 566                 [3] = "Indeterminate",
 567         };
 568
 569         if (!rtas_error_extended(errp)) {
 570                 pr_err("Machine check interrupt: Missing extended error log\n");
 571                 return;
 572         }
 573
 574         pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);
 575         if (pseries_log == NULL)
 576                 return;
 577
 578         mce_log = (struct pseries_mc_errorlog *)pseries_log->data;
 579
 580         error_type = mce_log->error_type;
 581         err_sub_type = rtas_mc_error_sub_type(mce_log);
 582
 583         switch (rtas_error_severity(errp)) {
 584         case RTAS_SEVERITY_NO_ERROR:
 585                 level = KERN_INFO;
 586                 sevstr = "Harmless";
 587                 break;
 588         case RTAS_SEVERITY_WARNING:
 589                 level = KERN_WARNING;
 590                 sevstr = "";
 591                 break;
 592         case RTAS_SEVERITY_ERROR:
 593         case RTAS_SEVERITY_ERROR_SYNC:
 594                 level = KERN_ERR;
 595                 sevstr = "Severe";
 596                 break;
 597         case RTAS_SEVERITY_FATAL:
 598         default:
 599                 level = KERN_ERR;
 600                 sevstr = "Fatal";
 601                 break;
 602         }
 603
 604 #ifdef CONFIG_PPC_BOOK3S_64
 605         /* Display faulty slb contents for SLB errors. */
 606         if (error_type == MC_ERROR_TYPE_SLB)
 607                 slb_dump_contents(local_paca->mce_faulty_slbs);
 608 #endif
 609
 610         printk("%s%s Machine check interrupt [%s]\n", level, sevstr,
 611                disposition == RTAS_DISP_FULLY_RECOVERED ?
 612                "Recovered" : "Not recovered");
 613         if (user_mode(regs)) {
 614                 printk("%s  NIP: [%016lx] PID: %d Comm: %s\n", level,
 615                        regs->nip, current->pid, current->comm);
 616         } else {
 617                 printk("%s  NIP [%016lx]: %pS\n", level, regs->nip,
 618                        (void *)regs->nip);
 619         }
 620         printk("%s  Initiator: %s\n", level,
 621                VAL_TO_STRING(initiators, initiator));
 622
 623         switch (error_type) {
 624         case MC_ERROR_TYPE_UE:
 625                 printk("%s  Error type: %s [%s]\n", level,
 626                        VAL_TO_STRING(mc_err_types, error_type),
 627                        VAL_TO_STRING(mc_ue_types, err_sub_type));
 628                 break;
 629         case MC_ERROR_TYPE_SLB:
 630                 printk("%s  Error type: %s [%s]\n", level,
 631                        VAL_TO_STRING(mc_err_types, error_type),
 632                        VAL_TO_STRING(mc_slb_types, err_sub_type));
 633                 break;
 634         case MC_ERROR_TYPE_ERAT:
 635         case MC_ERROR_TYPE_TLB:
 636                 printk("%s  Error type: %s [%s]\n", level,
 637                        VAL_TO_STRING(mc_err_types, error_type),
 638                        VAL_TO_STRING(mc_soft_types, err_sub_type));
 639                 break;
 640         default:
 641                 printk("%s  Error type: %s\n", level,
 642                        VAL_TO_STRING(mc_err_types, error_type));
 643                 break;
 644         }
 645
 646         addr = rtas_mc_get_effective_addr(mce_log);
 647         if (addr)
 648                 printk("%s    Effective address: %016llx\n", level, addr);
 649 }
 650
 651 static int mce_handle_error(struct rtas_error_log *errp)
 652 {
 653         struct pseries_errorlog *pseries_log;
 654         struct pseries_mc_errorlog *mce_log;
 655         int disposition = rtas_error_disposition(errp);
 656         u8 error_type;
 657
 658         if (!rtas_error_extended(errp))
 659                 goto out;
 660
 661         pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);
 662         if (pseries_log == NULL)
 663                 goto out;
 664
 665         mce_log = (struct pseries_mc_errorlog *)pseries_log->data;
 666         error_type = mce_log->error_type;
 667
 668 #ifdef CONFIG_PPC_BOOK3S_64
 669         if (disposition == RTAS_DISP_NOT_RECOVERED) {
 670                 switch (error_type) {
 671                 case    MC_ERROR_TYPE_SLB:
 672                 case    MC_ERROR_TYPE_ERAT:
 673                         /*
 674                          * Store the old slb content in paca before flushing.
 675                          * Print this when we go to virtual mode.
 676                          * There are chances that we may hit MCE again if there
 677                          * is a parity error on the SLB entry we trying to read
 678                          * for saving. Hence limit the slb saving to single
 679                          * level of recursion.
 680                          */
 681                         if (local_paca->in_mce == 1)
 682                                 slb_save_contents(local_paca->mce_faulty_slbs);
 683                         flush_and_reload_slb();
 684                         disposition = RTAS_DISP_FULLY_RECOVERED;
 685                         rtas_set_disposition_recovered(errp);
 686                         break;
 687                 default:
 688                         break;
 689                 }
 690         }
 691 #endif
 692
 693 out:
 694         return disposition;
 695 }
 696
 697 #ifdef CONFIG_MEMORY_FAILURE
 698
 699 static DEFINE_PER_CPU(int, rtas_ue_count);
 700 static DEFINE_PER_CPU(unsigned long, rtas_ue_paddr[MAX_MC_EVT]);
 701
 702 #define UE_EFFECTIVE_ADDR_PROVIDED      0x40
 703 #define UE_LOGICAL_ADDR_PROVIDED        0x20
 704
 705
 706 static void pseries_hwpoison_work_fn(struct work_struct *work)
 707 {
 708         unsigned long paddr;
 709         int index;
 710
 711         while (__this_cpu_read(rtas_ue_count) > 0) {
 712                 index = __this_cpu_read(rtas_ue_count) - 1;
 713                 paddr = __this_cpu_read(rtas_ue_paddr[index]);
 714                 memory_failure(paddr >> PAGE_SHIFT, 0);
 715                 __this_cpu_dec(rtas_ue_count);
 716         }
 717 }
 718
 719 static DECLARE_WORK(hwpoison_work, pseries_hwpoison_work_fn);
 720
 721 static void queue_ue_paddr(unsigned long paddr)
 722 {
 723         int index;
 724
 725         index = __this_cpu_inc_return(rtas_ue_count) - 1;
 726         if (index >= MAX_MC_EVT) {
 727                 __this_cpu_dec(rtas_ue_count);
 728                 return;
 729         }
 730         this_cpu_write(rtas_ue_paddr[index], paddr);
 731         schedule_work(&hwpoison_work);
 732 }
 733
 734 static void pseries_do_memory_failure(struct pt_regs *regs,
 735                                       struct pseries_mc_errorlog *mce_log)
 736 {
 737         unsigned long paddr;
 738
 739         if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) {
 740                 paddr = be64_to_cpu(mce_log->logical_address);
 741         } else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) {
 742                 unsigned long pfn;
 743
 744                 pfn = addr_to_pfn(regs,
 745                                   be64_to_cpu(mce_log->effective_address));
 746                 if (pfn == ULONG_MAX)
 747                         return;
 748                 paddr = pfn << PAGE_SHIFT;
 749         } else {
 750                 return;
 751         }
 752         queue_ue_paddr(paddr);
 753 }
 754
 755 static void pseries_process_ue(struct pt_regs *regs,
 756                                struct rtas_error_log *errp)
 757 {
 758         struct pseries_errorlog *pseries_log;
 759         struct pseries_mc_errorlog *mce_log;
 760
 761         if (!rtas_error_extended(errp))
 762                 return;
 763
 764         pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);
 765         if (!pseries_log)
 766                 return;
 767
 768         mce_log = (struct pseries_mc_errorlog *)pseries_log->data;
 769
 770         if (mce_log->error_type == MC_ERROR_TYPE_UE)
 771                 pseries_do_memory_failure(regs, mce_log);
 772 }
 773 #else
 774 static inline void pseries_process_ue(struct pt_regs *regs,
 775                                       struct rtas_error_log *errp) { }
 776 #endif /*CONFIG_MEMORY_FAILURE */
 777
 778 /*
 779  * Process MCE rtas errlog event.
 780  */
 781 static void mce_process_errlog_event(struct irq_work *work)
 782 {
 783         struct rtas_error_log *err;
 784
 785         err = fwnmi_get_errlog();
 786         log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);
 787 }
 788
 789 /*
 790  * See if we can recover from a machine check exception.
 791  * This is only called on power4 (or above) and only via
 792  * the Firmware Non-Maskable Interrupts (fwnmi) handler
 793  * which provides the error analysis for us.
 794  *
 795  * Return 1 if corrected (or delivered a signal).
 796  * Return 0 if there is nothing we can do.
 797  */
 798 static int recover_mce(struct pt_regs *regs, struct rtas_error_log *err)
 799 {
 800         int recovered = 0;
 801         int disposition = rtas_error_disposition(err);
 802
 803         pseries_print_mce_info(regs, err);
 804
 805         if (!(regs->msr & MSR_RI)) {
 806                 /* If MSR_RI isn't set, we cannot recover */
 807                 pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n");
 808                 recovered = 0;
 809
 810         } else if (disposition == RTAS_DISP_FULLY_RECOVERED) {
 811                 /* Platform corrected itself */
 812                 recovered = 1;
 813
 814         } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
 815                 /* Platform corrected itself but could be degraded */
 816                 printk(KERN_ERR "MCE: limited recovery, system may "
 817                        "be degraded\n");
 818                 recovered = 1;
 819
 820         } else if (user_mode(regs) && !is_global_init(current) &&
 821                    rtas_error_severity(err) == RTAS_SEVERITY_ERROR_SYNC) {
 822
 823                 /*
 824                  * If we received a synchronous error when in userspace
 825                  * kill the task. Firmware may report details of the fail
 826                  * asynchronously, so we can't rely on the target and type
 827                  * fields being valid here.
 828                  */
 829                 printk(KERN_ERR "MCE: uncorrectable error, killing task "
 830                        "%s:%d\n", current->comm, current->pid);
 831
 832                 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
 833                 recovered = 1;
 834         }
 835
 836         pseries_process_ue(regs, err);
 837
 838         /* Queue irq work to log this rtas event later. */
 839         irq_work_queue(&mce_errlog_process_work);
 840
 841         return recovered;
 842 }
 843
 844 /*
 845  * Handle a machine check.
 846  *
 847  * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi)
 848  * should be present.  If so the handler which called us tells us if the
 849  * error was recovered (never true if RI=0).
 850  *
 851  * On hardware prior to Power 4 these exceptions were asynchronous which
 852  * means we can't tell exactly where it occurred and so we can't recover.
 853  */
 854 int pSeries_machine_check_exception(struct pt_regs *regs)
 855 {
 856         struct rtas_error_log *errp;
 857
 858         if (fwnmi_active) {
 859                 fwnmi_release_errinfo();
 860                 errp = fwnmi_get_errlog();
 861                 if (errp && recover_mce(regs, errp))
 862                         return 1;
 863         }
 864
 865         return 0;
 866 }
 867
 868 long pseries_machine_check_realmode(struct pt_regs *regs)
 869 {
 870         struct rtas_error_log *errp;
 871         int disposition;
 872
 873         if (fwnmi_active) {
 874                 errp = fwnmi_get_errinfo(regs);
 875                 /*
 876                  * Call to fwnmi_release_errinfo() in real mode causes kernel
 877                  * to panic. Hence we will call it as soon as we go into
 878                  * virtual mode.
 879                  */
 880                 disposition = mce_handle_error(errp);
 881                 if (disposition == RTAS_DISP_FULLY_RECOVERED)
 882                         return 1;
 883         }
 884
 885         return 0;
 886 }