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