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 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id);
  44 static irqreturn_t ras_error_interrupt(int irq, void *dev_id);
  45
  46
  47 /*
  48  * Initialize handlers for the set of interrupts caused by hardware errors
  49  * and power system events.
  50  */
  51 static int __init init_ras_IRQ(void)
  52 {
  53         struct device_node *np;
  54
  55         ras_check_exception_token = rtas_token("check-exception");
  56
  57         /* Internal Errors */
  58         np = of_find_node_by_path("/event-sources/internal-errors");
  59         if (np != NULL) {
  60                 request_event_sources_irqs(np, ras_error_interrupt,
  61                                            "RAS_ERROR");
  62                 of_node_put(np);
  63         }
  64
  65         /* EPOW Events */
  66         np = of_find_node_by_path("/event-sources/epow-events");
  67         if (np != NULL) {
  68                 request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW");
  69                 of_node_put(np);
  70         }
  71
  72         return 0;
  73 }
  74 machine_subsys_initcall(pseries, init_ras_IRQ);
  75
  76 #define EPOW_SHUTDOWN_NORMAL                            1
  77 #define EPOW_SHUTDOWN_ON_UPS                            2
  78 #define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS        3
  79 #define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH      4
  80
  81 static void handle_system_shutdown(char event_modifier)
  82 {
  83         switch (event_modifier) {
  84         case EPOW_SHUTDOWN_NORMAL:
  85                 pr_emerg("Firmware initiated power off");
  86                 orderly_poweroff(true);
  87                 break;
  88
  89         case EPOW_SHUTDOWN_ON_UPS:
  90                 pr_emerg("Loss of power reported by firmware, system is "
  91                         "running on UPS/battery");
  92                 pr_emerg("Check RTAS error log for details");
  93                 orderly_poweroff(true);
  94                 break;
  95
  96         case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
  97                 pr_emerg("Loss of system critical functions reported by "
  98                         "firmware");
  99                 pr_emerg("Check RTAS error log for details");
 100                 orderly_poweroff(true);
 101                 break;
 102
 103         case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH:
 104                 pr_emerg("Ambient temperature too high reported by firmware");
 105                 pr_emerg("Check RTAS error log for details");
 106                 orderly_poweroff(true);
 107                 break;
 108
 109         default:
 110                 pr_err("Unknown power/cooling shutdown event (modifier %d)",
 111                         event_modifier);
 112         }
 113 }
 114
 115 struct epow_errorlog {
 116         unsigned char sensor_value;
 117         unsigned char event_modifier;
 118         unsigned char extended_modifier;
 119         unsigned char reserved;
 120         unsigned char platform_reason;
 121 };
 122
 123 #define EPOW_RESET                      0
 124 #define EPOW_WARN_COOLING               1
 125 #define EPOW_WARN_POWER                 2
 126 #define EPOW_SYSTEM_SHUTDOWN            3
 127 #define EPOW_SYSTEM_HALT                4
 128 #define EPOW_MAIN_ENCLOSURE             5
 129 #define EPOW_POWER_OFF                  7
 130
 131 static void rtas_parse_epow_errlog(struct rtas_error_log *log)
 132 {
 133         struct pseries_errorlog *pseries_log;
 134         struct epow_errorlog *epow_log;
 135         char action_code;
 136         char modifier;
 137
 138         pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW);
 139         if (pseries_log == NULL)
 140                 return;
 141
 142         epow_log = (struct epow_errorlog *)pseries_log->data;
 143         action_code = epow_log->sensor_value & 0xF;     /* bottom 4 bits */
 144         modifier = epow_log->event_modifier & 0xF;      /* bottom 4 bits */
 145
 146         switch (action_code) {
 147         case EPOW_RESET:
 148                 pr_err("Non critical power or cooling issue cleared");
 149                 break;
 150
 151         case EPOW_WARN_COOLING:
 152                 pr_err("Non critical cooling issue reported by firmware");
 153                 pr_err("Check RTAS error log for details");
 154                 break;
 155
 156         case EPOW_WARN_POWER:
 157                 pr_err("Non critical power issue reported by firmware");
 158                 pr_err("Check RTAS error log for details");
 159                 break;
 160
 161         case EPOW_SYSTEM_SHUTDOWN:
 162                 handle_system_shutdown(epow_log->event_modifier);
 163                 break;
 164
 165         case EPOW_SYSTEM_HALT:
 166                 pr_emerg("Firmware initiated power off");
 167                 orderly_poweroff(true);
 168                 break;
 169
 170         case EPOW_MAIN_ENCLOSURE:
 171         case EPOW_POWER_OFF:
 172                 pr_emerg("Critical power/cooling issue reported by firmware");
 173                 pr_emerg("Check RTAS error log for details");
 174                 pr_emerg("Immediate power off");
 175                 emergency_sync();
 176                 kernel_power_off();
 177                 break;
 178
 179         default:
 180                 pr_err("Unknown power/cooling event (action code %d)",
 181                         action_code);
 182         }
 183 }
 184
 185 /* Handle environmental and power warning (EPOW) interrupts. */
 186 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id)
 187 {
 188         int status;
 189         int state;
 190         int critical;
 191
 192         status = rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX,
 193                                       &state);
 194
 195         if (state > 3)
 196                 critical = 1;           /* Time Critical */
 197         else
 198                 critical = 0;
 199
 200         spin_lock(&ras_log_buf_lock);
 201
 202         status = rtas_call(ras_check_exception_token, 6, 1, NULL,
 203                            RTAS_VECTOR_EXTERNAL_INTERRUPT,
 204                            virq_to_hw(irq),
 205                            RTAS_EPOW_WARNING,
 206                            critical, __pa(&ras_log_buf),
 207                                 rtas_get_error_log_max());
 208
 209         log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
 210
 211         rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf);
 212
 213         spin_unlock(&ras_log_buf_lock);
 214         return IRQ_HANDLED;
 215 }
 216
 217 /*
 218  * Handle hardware error interrupts.
 219  *
 220  * RTAS check-exception is called to collect data on the exception.  If
 221  * the error is deemed recoverable, we log a warning and return.
 222  * For nonrecoverable errors, an error is logged and we stop all processing
 223  * as quickly as possible in order to prevent propagation of the failure.
 224  */
 225 static irqreturn_t ras_error_interrupt(int irq, void *dev_id)
 226 {
 227         struct rtas_error_log *rtas_elog;
 228         int status;
 229         int fatal;
 230
 231         spin_lock(&ras_log_buf_lock);
 232
 233         status = rtas_call(ras_check_exception_token, 6, 1, NULL,
 234                            RTAS_VECTOR_EXTERNAL_INTERRUPT,
 235                            virq_to_hw(irq),
 236                            RTAS_INTERNAL_ERROR, 1 /* Time Critical */,
 237                            __pa(&ras_log_buf),
 238                                 rtas_get_error_log_max());
 239
 240         rtas_elog = (struct rtas_error_log *)ras_log_buf;
 241
 242         if (status == 0 &&
 243             rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC)
 244                 fatal = 1;
 245         else
 246                 fatal = 0;
 247
 248         /* format and print the extended information */
 249         log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal);
 250
 251         if (fatal) {
 252                 pr_emerg("Fatal hardware error reported by firmware");
 253                 pr_emerg("Check RTAS error log for details");
 254                 pr_emerg("Immediate power off");
 255                 emergency_sync();
 256                 kernel_power_off();
 257         } else {
 258                 pr_err("Recoverable hardware error reported by firmware");
 259         }
 260
 261         spin_unlock(&ras_log_buf_lock);
 262         return IRQ_HANDLED;
 263 }
 264
 265 /*
 266  * Some versions of FWNMI place the buffer inside the 4kB page starting at
 267  * 0x7000. Other versions place it inside the rtas buffer. We check both.
 268  */
 269 #define VALID_FWNMI_BUFFER(A) \
 270         ((((A) >= 0x7000) && ((A) < 0x7ff0)) || \
 271         (((A) >= rtas.base) && ((A) < (rtas.base + rtas.size - 16))))
 272
 273 /*
 274  * Get the error information for errors coming through the
 275  * FWNMI vectors.  The pt_regs' r3 will be updated to reflect
 276  * the actual r3 if possible, and a ptr to the error log entry
 277  * will be returned if found.
 278  *
 279  * If the RTAS error is not of the extended type, then we put it in a per
 280  * cpu 64bit buffer. If it is the extended type we use global_mce_data_buf.
 281  *
 282  * The global_mce_data_buf does not have any locks or protection around it,
 283  * if a second machine check comes in, or a system reset is done
 284  * before we have logged the error, then we will get corruption in the
 285  * error log.  This is preferable over holding off on calling
 286  * ibm,nmi-interlock which would result in us checkstopping if a
 287  * second machine check did come in.
 288  */
 289 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
 290 {
 291         unsigned long *savep;
 292         struct rtas_error_log *h, *errhdr = NULL;
 293
 294         /* Mask top two bits */
 295         regs->gpr[3] &= ~(0x3UL << 62);
 296
 297         if (!VALID_FWNMI_BUFFER(regs->gpr[3])) {
 298                 printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]);
 299                 return NULL;
 300         }
 301
 302         savep = __va(regs->gpr[3]);
 303         regs->gpr[3] = savep[0];        /* restore original r3 */
 304
 305         /* If it isn't an extended log we can use the per cpu 64bit buffer */
 306         h = (struct rtas_error_log *)&savep[1];
 307         if (!rtas_error_extended(h)) {
 308                 memcpy(this_cpu_ptr(&mce_data_buf), h, sizeof(__u64));
 309                 errhdr = (struct rtas_error_log *)this_cpu_ptr(&mce_data_buf);
 310         } else {
 311                 int len, error_log_length;
 312
 313                 error_log_length = 8 + rtas_error_extended_log_length(h);
 314                 len = max_t(int, error_log_length, RTAS_ERROR_LOG_MAX);
 315                 memset(global_mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
 316                 memcpy(global_mce_data_buf, h, len);
 317                 errhdr = (struct rtas_error_log *)global_mce_data_buf;
 318         }
 319
 320         return errhdr;
 321 }
 322
 323 /* Call this when done with the data returned by FWNMI_get_errinfo.
 324  * It will release the saved data area for other CPUs in the
 325  * partition to receive FWNMI errors.
 326  */
 327 static void fwnmi_release_errinfo(void)
 328 {
 329         int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL);
 330         if (ret != 0)
 331                 printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret);
 332 }
 333
 334 int pSeries_system_reset_exception(struct pt_regs *regs)
 335 {
 336         if (fwnmi_active) {
 337                 struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs);
 338                 if (errhdr) {
 339                         /* XXX Should look at FWNMI information */
 340                 }
 341                 fwnmi_release_errinfo();
 342         }
 343         return 0; /* need to perform reset */
 344 }
 345
 346 /*
 347  * See if we can recover from a machine check exception.
 348  * This is only called on power4 (or above) and only via
 349  * the Firmware Non-Maskable Interrupts (fwnmi) handler
 350  * which provides the error analysis for us.
 351  *
 352  * Return 1 if corrected (or delivered a signal).
 353  * Return 0 if there is nothing we can do.
 354  */
 355 static int recover_mce(struct pt_regs *regs, struct rtas_error_log *err)
 356 {
 357         int recovered = 0;
 358         int disposition = rtas_error_disposition(err);
 359
 360         if (!(regs->msr & MSR_RI)) {
 361                 /* If MSR_RI isn't set, we cannot recover */
 362                 recovered = 0;
 363
 364         } else if (disposition == RTAS_DISP_FULLY_RECOVERED) {
 365                 /* Platform corrected itself */
 366                 recovered = 1;
 367
 368         } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
 369                 /* Platform corrected itself but could be degraded */
 370                 printk(KERN_ERR "MCE: limited recovery, system may "
 371                        "be degraded\n");
 372                 recovered = 1;
 373
 374         } else if (user_mode(regs) && !is_global_init(current) &&
 375                    rtas_error_severity(err) == RTAS_SEVERITY_ERROR_SYNC) {
 376
 377                 /*
 378                  * If we received a synchronous error when in userspace
 379                  * kill the task. Firmware may report details of the fail
 380                  * asynchronously, so we can't rely on the target and type
 381                  * fields being valid here.
 382                  */
 383                 printk(KERN_ERR "MCE: uncorrectable error, killing task "
 384                        "%s:%d\n", current->comm, current->pid);
 385
 386                 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
 387                 recovered = 1;
 388         }
 389
 390         log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);
 391
 392         return recovered;
 393 }
 394
 395 /*
 396  * Handle a machine check.
 397  *
 398  * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi)
 399  * should be present.  If so the handler which called us tells us if the
 400  * error was recovered (never true if RI=0).
 401  *
 402  * On hardware prior to Power 4 these exceptions were asynchronous which
 403  * means we can't tell exactly where it occurred and so we can't recover.
 404  */
 405 int pSeries_machine_check_exception(struct pt_regs *regs)
 406 {
 407         struct rtas_error_log *errp;
 408
 409         if (fwnmi_active) {
 410                 errp = fwnmi_get_errinfo(regs);
 411                 fwnmi_release_errinfo();
 412                 if (errp && recover_mce(regs, errp))
 413                         return 1;
 414         }
 415
 416         return 0;
 417 }