arch/powerpc/platforms/pseries/ras.c

   1 /*
   2  * Copyright (C) 2001 Dave Engebretsen IBM Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  17  */
  18
  19 #include <linux/sched.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irq.h>
  22 #include <linux/of.h>
  23 #include <linux/fs.h>
  24 #include <linux/reboot.h>
  25
  26 #include <asm/machdep.h>
  27 #include <asm/rtas.h>
  28 #include <asm/firmware.h>
  29
  30 #include "pseries.h"
  31
  32 static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX];
  33 static DEFINE_SPINLOCK(ras_log_buf_lock);
  34
  35 static char global_mce_data_buf[RTAS_ERROR_LOG_MAX];
  36 static DEFINE_PER_CPU(__u64, mce_data_buf);
  37
  38 static int ras_check_exception_token;
  39
  40 #define EPOW_SENSOR_TOKEN       9
  41 #define EPOW_SENSOR_INDEX       0
  42
  43 /* EPOW events counter variable */
  44 static int num_epow_events;
  45
  46 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id);
  47 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id);
  48 static irqreturn_t ras_error_interrupt(int irq, void *dev_id);
  49
  50
  51 /*
  52  * Enable the hotplug interrupt late because processing them may touch other
  53  * devices or systems (e.g. hugepages) that have not been initialized at the
  54  * subsys stage.
  55  */
  56 int __init init_ras_hotplug_IRQ(void)
  57 {
  58         struct device_node *np;
  59
  60         /* Hotplug Events */
  61         np = of_find_node_by_path("/event-sources/hot-plug-events");
  62         if (np != NULL) {
  63                 if (dlpar_workqueue_init() == 0)
  64                         request_event_sources_irqs(np, ras_hotplug_interrupt,
  65                                                    "RAS_HOTPLUG");
  66                 of_node_put(np);
  67         }
  68
  69         return 0;
  70 }
  71 machine_late_initcall(pseries, init_ras_hotplug_IRQ);
  72
  73 /*
  74  * Initialize handlers for the set of interrupts caused by hardware errors
  75  * and power system events.
  76  */
  77 static int __init init_ras_IRQ(void)
  78 {
  79         struct device_node *np;
  80
  81         ras_check_exception_token = rtas_token("check-exception");
  82
  83         /* Internal Errors */
  84         np = of_find_node_by_path("/event-sources/internal-errors");
  85         if (np != NULL) {
  86                 request_event_sources_irqs(np, ras_error_interrupt,
  87                                            "RAS_ERROR");
  88                 of_node_put(np);
  89         }
  90
  91         /* EPOW Events */
  92         np = of_find_node_by_path("/event-sources/epow-events");
  93         if (np != NULL) {
  94                 request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW");
  95                 of_node_put(np);
  96         }
  97
  98         return 0;
  99 }
 100 machine_subsys_initcall(pseries, init_ras_IRQ);
 101
 102 #define EPOW_SHUTDOWN_NORMAL                            1
 103 #define EPOW_SHUTDOWN_ON_UPS                            2
 104 #define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS        3
 105 #define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH      4
 106
 107 static void handle_system_shutdown(char event_modifier)
 108 {
 109         switch (event_modifier) {
 110         case EPOW_SHUTDOWN_NORMAL:
 111                 pr_emerg("Power off requested\n");
 112                 orderly_poweroff(true);
 113                 break;
 114
 115         case EPOW_SHUTDOWN_ON_UPS:
 116                 pr_emerg("Loss of system power detected. System is running on"
 117                          " UPS/battery. Check RTAS error log for details\n");
 118                 orderly_poweroff(true);
 119                 break;
 120
 121         case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
 122                 pr_emerg("Loss of system critical functions detected. Check"
 123                          " RTAS error log for details\n");
 124                 orderly_poweroff(true);
 125                 break;
 126
 127         case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH:
 128                 pr_emerg("High ambient temperature detected. Check RTAS"
 129                          " error log for details\n");
 130                 orderly_poweroff(true);
 131                 break;
 132
 133         default:
 134                 pr_err("Unknown power/cooling shutdown event (modifier = %d)\n",
 135                         event_modifier);
 136         }
 137 }
 138
 139 struct epow_errorlog {
 140         unsigned char sensor_value;
 141         unsigned char event_modifier;
 142         unsigned char extended_modifier;
 143         unsigned char reserved;
 144         unsigned char platform_reason;
 145 };
 146
 147 #define EPOW_RESET                      0
 148 #define EPOW_WARN_COOLING               1
 149 #define EPOW_WARN_POWER                 2
 150 #define EPOW_SYSTEM_SHUTDOWN            3
 151 #define EPOW_SYSTEM_HALT                4
 152 #define EPOW_MAIN_ENCLOSURE             5
 153 #define EPOW_POWER_OFF                  7
 154
 155 static void rtas_parse_epow_errlog(struct rtas_error_log *log)
 156 {
 157         struct pseries_errorlog *pseries_log;
 158         struct epow_errorlog *epow_log;
 159         char action_code;
 160         char modifier;
 161
 162         pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW);
 163         if (pseries_log == NULL)
 164                 return;
 165
 166         epow_log = (struct epow_errorlog *)pseries_log->data;
 167         action_code = epow_log->sensor_value & 0xF;     /* bottom 4 bits */
 168         modifier = epow_log->event_modifier & 0xF;      /* bottom 4 bits */
 169
 170         switch (action_code) {
 171         case EPOW_RESET:
 172                 if (num_epow_events) {
 173                         pr_info("Non critical power/cooling issue cleared\n");
 174                         num_epow_events--;
 175                 }
 176                 break;
 177
 178         case EPOW_WARN_COOLING:
 179                 pr_info("Non-critical cooling issue detected. Check RTAS error"
 180                         " log for details\n");
 181                 break;
 182
 183         case EPOW_WARN_POWER:
 184                 pr_info("Non-critical power issue detected. Check RTAS error"
 185                         " log for details\n");
 186                 break;
 187
 188         case EPOW_SYSTEM_SHUTDOWN:
 189                 handle_system_shutdown(epow_log->event_modifier);
 190                 break;
 191
 192         case EPOW_SYSTEM_HALT:
 193                 pr_emerg("Critical power/cooling issue detected. Check RTAS"
 194                          " error log for details. Powering off.\n");
 195                 orderly_poweroff(true);
 196                 break;
 197
 198         case EPOW_MAIN_ENCLOSURE:
 199         case EPOW_POWER_OFF:
 200                 pr_emerg("System about to lose power. Check RTAS error log "
 201                          " for details. Powering off immediately.\n");
 202                 emergency_sync();
 203                 kernel_power_off();
 204                 break;
 205
 206         default:
 207                 pr_err("Unknown power/cooling event (action code  = %d)\n",
 208                         action_code);
 209         }
 210
 211         /* Increment epow events counter variable */
 212         if (action_code != EPOW_RESET)
 213                 num_epow_events++;
 214 }
 215
 216 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id)
 217 {
 218         struct pseries_errorlog *pseries_log;
 219         struct pseries_hp_errorlog *hp_elog;
 220
 221         spin_lock(&ras_log_buf_lock);
 222
 223         rtas_call(ras_check_exception_token, 6, 1, NULL,
 224                   RTAS_VECTOR_EXTERNAL_INTERRUPT, virq_to_hw(irq),
 225                   RTAS_HOTPLUG_EVENTS, 0, __pa(&ras_log_buf),
 226                   rtas_get_error_log_max());
 227
 228         pseries_log = get_pseries_errorlog((struct rtas_error_log *)ras_log_buf,
 229                                            PSERIES_ELOG_SECT_ID_HOTPLUG);
 230         hp_elog = (struct pseries_hp_errorlog *)pseries_log->data;
 231
 232         /*
 233          * Since PCI hotplug is not currently supported on pseries, put PCI
 234          * hotplug events on the ras_log_buf to be handled by rtas_errd.
 235          */
 236         if (hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_MEM ||
 237             hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_CPU)
 238                 queue_hotplug_event(hp_elog, NULL, NULL);
 239         else
 240                 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
 241
 242         spin_unlock(&ras_log_buf_lock);
 243         return IRQ_HANDLED;
 244 }
 245
 246 /* Handle environmental and power warning (EPOW) interrupts. */
 247 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id)
 248 {
 249         int status;
 250         int state;
 251         int critical;
 252
 253         status = rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX,
 254                                       &state);
 255
 256         if (state > 3)
 257                 critical = 1;           /* Time Critical */
 258         else
 259                 critical = 0;
 260
 261         spin_lock(&ras_log_buf_lock);
 262
 263         status = rtas_call(ras_check_exception_token, 6, 1, NULL,
 264                            RTAS_VECTOR_EXTERNAL_INTERRUPT,
 265                            virq_to_hw(irq),
 266                            RTAS_EPOW_WARNING,
 267                            critical, __pa(&ras_log_buf),
 268                                 rtas_get_error_log_max());
 269
 270         log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
 271
 272         rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf);
 273
 274         spin_unlock(&ras_log_buf_lock);
 275         return IRQ_HANDLED;
 276 }
 277
 278 /*
 279  * Handle hardware error interrupts.
 280  *
 281  * RTAS check-exception is called to collect data on the exception.  If
 282  * the error is deemed recoverable, we log a warning and return.
 283  * For nonrecoverable errors, an error is logged and we stop all processing
 284  * as quickly as possible in order to prevent propagation of the failure.
 285  */
 286 static irqreturn_t ras_error_interrupt(int irq, void *dev_id)
 287 {
 288         struct rtas_error_log *rtas_elog;
 289         int status;
 290         int fatal;
 291
 292         spin_lock(&ras_log_buf_lock);
 293
 294         status = rtas_call(ras_check_exception_token, 6, 1, NULL,
 295                            RTAS_VECTOR_EXTERNAL_INTERRUPT,
 296                            virq_to_hw(irq),
 297                            RTAS_INTERNAL_ERROR, 1 /* Time Critical */,
 298                            __pa(&ras_log_buf),
 299                                 rtas_get_error_log_max());
 300
 301         rtas_elog = (struct rtas_error_log *)ras_log_buf;
 302
 303         if (status == 0 &&
 304             rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC)
 305                 fatal = 1;
 306         else
 307                 fatal = 0;
 308
 309         /* format and print the extended information */
 310         log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal);
 311
 312         if (fatal) {
 313                 pr_emerg("Fatal hardware error detected. Check RTAS error"
 314                          " log for details. Powering off immediately\n");
 315                 emergency_sync();
 316                 kernel_power_off();
 317         } else {
 318                 pr_err("Recoverable hardware error detected\n");
 319         }
 320
 321         spin_unlock(&ras_log_buf_lock);
 322         return IRQ_HANDLED;
 323 }
 324
 325 /*
 326  * Some versions of FWNMI place the buffer inside the 4kB page starting at
 327  * 0x7000. Other versions place it inside the rtas buffer. We check both.
 328  */
 329 #define VALID_FWNMI_BUFFER(A) \
 330         ((((A) >= 0x7000) && ((A) < 0x7ff0)) || \
 331         (((A) >= rtas.base) && ((A) < (rtas.base + rtas.size - 16))))
 332
 333 /*
 334  * Get the error information for errors coming through the
 335  * FWNMI vectors.  The pt_regs' r3 will be updated to reflect
 336  * the actual r3 if possible, and a ptr to the error log entry
 337  * will be returned if found.
 338  *
 339  * If the RTAS error is not of the extended type, then we put it in a per
 340  * cpu 64bit buffer. If it is the extended type we use global_mce_data_buf.
 341  *
 342  * The global_mce_data_buf does not have any locks or protection around it,
 343  * if a second machine check comes in, or a system reset is done
 344  * before we have logged the error, then we will get corruption in the
 345  * error log.  This is preferable over holding off on calling
 346  * ibm,nmi-interlock which would result in us checkstopping if a
 347  * second machine check did come in.
 348  */
 349 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
 350 {
 351         unsigned long *savep;
 352         struct rtas_error_log *h, *errhdr = NULL;
 353
 354         /* Mask top two bits */
 355         regs->gpr[3] &= ~(0x3UL << 62);
 356
 357         if (!VALID_FWNMI_BUFFER(regs->gpr[3])) {
 358                 printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]);
 359                 return NULL;
 360         }
 361
 362         savep = __va(regs->gpr[3]);
 363         regs->gpr[3] = savep[0];        /* restore original r3 */
 364
 365         /* If it isn't an extended log we can use the per cpu 64bit buffer */
 366         h = (struct rtas_error_log *)&savep[1];
 367         if (!rtas_error_extended(h)) {
 368                 memcpy(this_cpu_ptr(&mce_data_buf), h, sizeof(__u64));
 369                 errhdr = (struct rtas_error_log *)this_cpu_ptr(&mce_data_buf);
 370         } else {
 371                 int len, error_log_length;
 372
 373                 error_log_length = 8 + rtas_error_extended_log_length(h);
 374                 len = max_t(int, error_log_length, RTAS_ERROR_LOG_MAX);
 375                 memset(global_mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
 376                 memcpy(global_mce_data_buf, h, len);
 377                 errhdr = (struct rtas_error_log *)global_mce_data_buf;
 378         }
 379
 380         return errhdr;
 381 }
 382
 383 /* Call this when done with the data returned by FWNMI_get_errinfo.
 384  * It will release the saved data area for other CPUs in the
 385  * partition to receive FWNMI errors.
 386  */
 387 static void fwnmi_release_errinfo(void)
 388 {
 389         int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL);
 390         if (ret != 0)
 391                 printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret);
 392 }
 393
 394 int pSeries_system_reset_exception(struct pt_regs *regs)
 395 {
 396 #ifdef __LITTLE_ENDIAN__
 397         /*
 398          * Some firmware byteswaps SRR registers and gives incorrect SRR1. Try
 399          * to detect the bad SRR1 pattern here. Flip the NIP back to correct
 400          * endian for reporting purposes. Unfortunately the MSR can't be fixed,
 401          * so clear it. It will be missing MSR_RI so we won't try to recover.
 402          */
 403         if ((be64_to_cpu(regs->msr) &
 404                         (MSR_LE|MSR_RI|MSR_DR|MSR_IR|MSR_ME|MSR_PR|
 405                          MSR_ILE|MSR_HV|MSR_SF)) == (MSR_DR|MSR_SF)) {
 406                 regs->nip = be64_to_cpu((__be64)regs->nip);
 407                 regs->msr = 0;
 408         }
 409 #endif
 410
 411         if (fwnmi_active) {
 412                 struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs);
 413                 if (errhdr) {
 414                         /* XXX Should look at FWNMI information */
 415                 }
 416                 fwnmi_release_errinfo();
 417         }
 418
 419         if (smp_handle_nmi_ipi(regs))
 420                 return 1;
 421
 422         return 0; /* need to perform reset */
 423 }
 424
 425 /*
 426  * See if we can recover from a machine check exception.
 427  * This is only called on power4 (or above) and only via
 428  * the Firmware Non-Maskable Interrupts (fwnmi) handler
 429  * which provides the error analysis for us.
 430  *
 431  * Return 1 if corrected (or delivered a signal).
 432  * Return 0 if there is nothing we can do.
 433  */
 434 static int recover_mce(struct pt_regs *regs, struct rtas_error_log *err)
 435 {
 436         int recovered = 0;
 437         int disposition = rtas_error_disposition(err);
 438
 439         if (!(regs->msr & MSR_RI)) {
 440                 /* If MSR_RI isn't set, we cannot recover */
 441                 recovered = 0;
 442
 443         } else if (disposition == RTAS_DISP_FULLY_RECOVERED) {
 444                 /* Platform corrected itself */
 445                 recovered = 1;
 446
 447         } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
 448                 /* Platform corrected itself but could be degraded */
 449                 printk(KERN_ERR "MCE: limited recovery, system may "
 450                        "be degraded\n");
 451                 recovered = 1;
 452
 453         } else if (user_mode(regs) && !is_global_init(current) &&
 454                    rtas_error_severity(err) == RTAS_SEVERITY_ERROR_SYNC) {
 455
 456                 /*
 457                  * If we received a synchronous error when in userspace
 458                  * kill the task. Firmware may report details of the fail
 459                  * asynchronously, so we can't rely on the target and type
 460                  * fields being valid here.
 461                  */
 462                 printk(KERN_ERR "MCE: uncorrectable error, killing task "
 463                        "%s:%d\n", current->comm, current->pid);
 464
 465                 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
 466                 recovered = 1;
 467         }
 468
 469         log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);
 470
 471         return recovered;
 472 }
 473
 474 /*
 475  * Handle a machine check.
 476  *
 477  * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi)
 478  * should be present.  If so the handler which called us tells us if the
 479  * error was recovered (never true if RI=0).
 480  *
 481  * On hardware prior to Power 4 these exceptions were asynchronous which
 482  * means we can't tell exactly where it occurred and so we can't recover.
 483  */
 484 int pSeries_machine_check_exception(struct pt_regs *regs)
 485 {
 486         struct rtas_error_log *errp;
 487
 488         if (fwnmi_active) {
 489                 errp = fwnmi_get_errinfo(regs);
 490                 fwnmi_release_errinfo();
 491                 if (errp && recover_mce(regs, errp))
 492                         return 1;
 493         }
 494
 495         return 0;
 496 }