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 #define EPOW_SENSOR_TOKEN 9
27 #define EPOW_SENSOR_INDEX 0
28
29 /* EPOW events counter variable */
30 static int num_epow_events;
31
32 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id);
33 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id);
34 static irqreturn_t ras_error_interrupt(int irq, void *dev_id);
35
36 /* RTAS pseries MCE errorlog section. */
37 struct pseries_mc_errorlog {
38 __be32 fru_id;
39 __be32 proc_id;
40 u8 error_type;
41 /*
42 * sub_err_type (1 byte). Bit fields depends on error_type
43 *
44 * MSB0
45 * |
46 * V
47 * 01234567
48 * XXXXXXXX
49 *
50 * For error_type == MC_ERROR_TYPE_UE
51 * XXXXXXXX
52 * X 1: Permanent or Transient UE.
53 * X 1: Effective address provided.
54 * X 1: Logical address provided.
55 * XX 2: Reserved.
56 * XXX 3: Type of UE error.
57 *
58 * For error_type == MC_ERROR_TYPE_SLB/ERAT/TLB
59 * XXXXXXXX
60 * X 1: Effective address provided.
61 * XXXXX 5: Reserved.
62 * XX 2: Type of SLB/ERAT/TLB error.
63 *
64 * For error_type == MC_ERROR_TYPE_CTRL_MEM_ACCESS
65 * XXXXXXXX
66 * X 1: Error causing address provided.
67 * XXX 3: Type of error.
68 * XXXX 4: Reserved.
69 */
70 u8 sub_err_type;
71 u8 reserved_1[6];
72 __be64 effective_address;
73 __be64 logical_address;
74 } __packed;
75
76 /* RTAS pseries MCE error types */
77 #define MC_ERROR_TYPE_UE 0x00
78 #define MC_ERROR_TYPE_SLB 0x01
79 #define MC_ERROR_TYPE_ERAT 0x02
80 #define MC_ERROR_TYPE_UNKNOWN 0x03
81 #define MC_ERROR_TYPE_TLB 0x04
82 #define MC_ERROR_TYPE_D_CACHE 0x05
83 #define MC_ERROR_TYPE_I_CACHE 0x07
84 #define MC_ERROR_TYPE_CTRL_MEM_ACCESS 0x08
85
86 /* RTAS pseries MCE error sub types */
87 #define MC_ERROR_UE_INDETERMINATE 0
88 #define MC_ERROR_UE_IFETCH 1
89 #define MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH 2
90 #define MC_ERROR_UE_LOAD_STORE 3
91 #define MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE 4
92
93 #define UE_EFFECTIVE_ADDR_PROVIDED 0x40
94 #define UE_LOGICAL_ADDR_PROVIDED 0x20
95 #define MC_EFFECTIVE_ADDR_PROVIDED 0x80
96
97 #define MC_ERROR_SLB_PARITY 0
98 #define MC_ERROR_SLB_MULTIHIT 1
99 #define MC_ERROR_SLB_INDETERMINATE 2
100
101 #define MC_ERROR_ERAT_PARITY 1
102 #define MC_ERROR_ERAT_MULTIHIT 2
103 #define MC_ERROR_ERAT_INDETERMINATE 3
104
105 #define MC_ERROR_TLB_PARITY 1
106 #define MC_ERROR_TLB_MULTIHIT 2
107 #define MC_ERROR_TLB_INDETERMINATE 3
108
109 #define MC_ERROR_CTRL_MEM_ACCESS_PTABLE_WALK 0
110 #define MC_ERROR_CTRL_MEM_ACCESS_OP_ACCESS 1
111
rtas_mc_error_sub_type(const struct pseries_mc_errorlog * mlog)112 static inline u8 rtas_mc_error_sub_type(const struct pseries_mc_errorlog *mlog)
113 {
114 switch (mlog->error_type) {
115 case MC_ERROR_TYPE_UE:
116 return (mlog->sub_err_type & 0x07);
117 case MC_ERROR_TYPE_SLB:
118 case MC_ERROR_TYPE_ERAT:
119 case MC_ERROR_TYPE_TLB:
120 return (mlog->sub_err_type & 0x03);
121 case MC_ERROR_TYPE_CTRL_MEM_ACCESS:
122 return (mlog->sub_err_type & 0x70) >> 4;
123 default:
124 return 0;
125 }
126 }
127
128 /*
129 * Enable the hotplug interrupt late because processing them may touch other
130 * devices or systems (e.g. hugepages) that have not been initialized at the
131 * subsys stage.
132 */
init_ras_hotplug_IRQ(void)133 static int __init init_ras_hotplug_IRQ(void)
134 {
135 struct device_node *np;
136
137 /* Hotplug Events */
138 np = of_find_node_by_path("/event-sources/hot-plug-events");
139 if (np != NULL) {
140 if (dlpar_workqueue_init() == 0)
141 request_event_sources_irqs(np, ras_hotplug_interrupt,
142 "RAS_HOTPLUG");
143 of_node_put(np);
144 }
145
146 return 0;
147 }
148 machine_late_initcall(pseries, init_ras_hotplug_IRQ);
149
150 /*
151 * Initialize handlers for the set of interrupts caused by hardware errors
152 * and power system events.
153 */
init_ras_IRQ(void)154 static int __init init_ras_IRQ(void)
155 {
156 struct device_node *np;
157
158 ras_check_exception_token = rtas_function_token(RTAS_FN_CHECK_EXCEPTION);
159
160 /* Internal Errors */
161 np = of_find_node_by_path("/event-sources/internal-errors");
162 if (np != NULL) {
163 request_event_sources_irqs(np, ras_error_interrupt,
164 "RAS_ERROR");
165 of_node_put(np);
166 }
167
168 /* EPOW Events */
169 np = of_find_node_by_path("/event-sources/epow-events");
170 if (np != NULL) {
171 request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW");
172 of_node_put(np);
173 }
174
175 return 0;
176 }
177 machine_subsys_initcall(pseries, init_ras_IRQ);
178
179 #define EPOW_SHUTDOWN_NORMAL 1
180 #define EPOW_SHUTDOWN_ON_UPS 2
181 #define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS 3
182 #define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH 4
183
handle_system_shutdown(char event_modifier)184 static void handle_system_shutdown(char event_modifier)
185 {
186 switch (event_modifier) {
187 case EPOW_SHUTDOWN_NORMAL:
188 pr_emerg("Power off requested\n");
189 orderly_poweroff(true);
190 break;
191
192 case EPOW_SHUTDOWN_ON_UPS:
193 pr_emerg("Loss of system power detected. System is running on"
194 " UPS/battery. Check RTAS error log for details\n");
195 break;
196
197 case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
198 pr_emerg("Loss of system critical functions detected. Check"
199 " RTAS error log for details\n");
200 orderly_poweroff(true);
201 break;
202
203 case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH:
204 pr_emerg("High ambient temperature detected. Check RTAS"
205 " error log for details\n");
206 orderly_poweroff(true);
207 break;
208
209 default:
210 pr_err("Unknown power/cooling shutdown event (modifier = %d)\n",
211 event_modifier);
212 }
213 }
214
215 struct epow_errorlog {
216 unsigned char sensor_value;
217 unsigned char event_modifier;
218 unsigned char extended_modifier;
219 unsigned char reserved;
220 unsigned char platform_reason;
221 };
222
223 #define EPOW_RESET 0
224 #define EPOW_WARN_COOLING 1
225 #define EPOW_WARN_POWER 2
226 #define EPOW_SYSTEM_SHUTDOWN 3
227 #define EPOW_SYSTEM_HALT 4
228 #define EPOW_MAIN_ENCLOSURE 5
229 #define EPOW_POWER_OFF 7
230
rtas_parse_epow_errlog(struct rtas_error_log * log)231 static void rtas_parse_epow_errlog(struct rtas_error_log *log)
232 {
233 struct pseries_errorlog *pseries_log;
234 struct epow_errorlog *epow_log;
235 char action_code;
236 char modifier;
237
238 pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW);
239 if (pseries_log == NULL)
240 return;
241
242 epow_log = (struct epow_errorlog *)pseries_log->data;
243 action_code = epow_log->sensor_value & 0xF; /* bottom 4 bits */
244 modifier = epow_log->event_modifier & 0xF; /* bottom 4 bits */
245
246 switch (action_code) {
247 case EPOW_RESET:
248 if (num_epow_events) {
249 pr_info("Non critical power/cooling issue cleared\n");
250 num_epow_events--;
251 }
252 break;
253
254 case EPOW_WARN_COOLING:
255 pr_info("Non-critical cooling issue detected. Check RTAS error"
256 " log for details\n");
257 break;
258
259 case EPOW_WARN_POWER:
260 pr_info("Non-critical power issue detected. Check RTAS error"
261 " log for details\n");
262 break;
263
264 case EPOW_SYSTEM_SHUTDOWN:
265 handle_system_shutdown(modifier);
266 break;
267
268 case EPOW_SYSTEM_HALT:
269 pr_emerg("Critical power/cooling issue detected. Check RTAS"
270 " error log for details. Powering off.\n");
271 orderly_poweroff(true);
272 break;
273
274 case EPOW_MAIN_ENCLOSURE:
275 case EPOW_POWER_OFF:
276 pr_emerg("System about to lose power. Check RTAS error log "
277 " for details. Powering off immediately.\n");
278 emergency_sync();
279 kernel_power_off();
280 break;
281
282 default:
283 pr_err("Unknown power/cooling event (action code = %d)\n",
284 action_code);
285 }
286
287 /* Increment epow events counter variable */
288 if (action_code != EPOW_RESET)
289 num_epow_events++;
290 }
291
ras_hotplug_interrupt(int irq,void * dev_id)292 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id)
293 {
294 struct pseries_errorlog *pseries_log;
295 struct pseries_hp_errorlog *hp_elog;
296
297 spin_lock(&ras_log_buf_lock);
298
299 rtas_call(ras_check_exception_token, 6, 1, NULL,
300 RTAS_VECTOR_EXTERNAL_INTERRUPT, virq_to_hw(irq),
301 RTAS_HOTPLUG_EVENTS, 0, __pa(&ras_log_buf),
302 rtas_get_error_log_max());
303
304 pseries_log = get_pseries_errorlog((struct rtas_error_log *)ras_log_buf,
305 PSERIES_ELOG_SECT_ID_HOTPLUG);
306 hp_elog = (struct pseries_hp_errorlog *)pseries_log->data;
307
308 /*
309 * Since PCI hotplug is not currently supported on pseries, put PCI
310 * hotplug events on the ras_log_buf to be handled by rtas_errd.
311 */
312 if (hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_MEM ||
313 hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_CPU ||
314 hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_PMEM)
315 queue_hotplug_event(hp_elog);
316 else
317 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
318
319 spin_unlock(&ras_log_buf_lock);
320 return IRQ_HANDLED;
321 }
322
323 /* Handle environmental and power warning (EPOW) interrupts. */
ras_epow_interrupt(int irq,void * dev_id)324 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id)
325 {
326 int state;
327 int critical;
328
329 rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX, &state);
330
331 if (state > 3)
332 critical = 1; /* Time Critical */
333 else
334 critical = 0;
335
336 spin_lock(&ras_log_buf_lock);
337
338 rtas_call(ras_check_exception_token, 6, 1, NULL, RTAS_VECTOR_EXTERNAL_INTERRUPT,
339 virq_to_hw(irq), RTAS_EPOW_WARNING, critical, __pa(&ras_log_buf),
340 rtas_get_error_log_max());
341
342 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
343
344 rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf);
345
346 spin_unlock(&ras_log_buf_lock);
347 return IRQ_HANDLED;
348 }
349
350 /*
351 * Handle hardware error interrupts.
352 *
353 * RTAS check-exception is called to collect data on the exception. If
354 * the error is deemed recoverable, we log a warning and return.
355 * For nonrecoverable errors, an error is logged and we stop all processing
356 * as quickly as possible in order to prevent propagation of the failure.
357 */
ras_error_interrupt(int irq,void * dev_id)358 static irqreturn_t ras_error_interrupt(int irq, void *dev_id)
359 {
360 struct rtas_error_log *rtas_elog;
361 int status;
362 int fatal;
363
364 spin_lock(&ras_log_buf_lock);
365
366 status = rtas_call(ras_check_exception_token, 6, 1, NULL,
367 RTAS_VECTOR_EXTERNAL_INTERRUPT,
368 virq_to_hw(irq),
369 RTAS_INTERNAL_ERROR, 1 /* Time Critical */,
370 __pa(&ras_log_buf),
371 rtas_get_error_log_max());
372
373 rtas_elog = (struct rtas_error_log *)ras_log_buf;
374
375 if (status == 0 &&
376 rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC)
377 fatal = 1;
378 else
379 fatal = 0;
380
381 /* format and print the extended information */
382 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal);
383
384 if (fatal) {
385 pr_emerg("Fatal hardware error detected. Check RTAS error"
386 " log for details. Powering off immediately\n");
387 emergency_sync();
388 kernel_power_off();
389 } else {
390 pr_err("Recoverable hardware error detected\n");
391 }
392
393 spin_unlock(&ras_log_buf_lock);
394 return IRQ_HANDLED;
395 }
396
397 /*
398 * Some versions of FWNMI place the buffer inside the 4kB page starting at
399 * 0x7000. Other versions place it inside the rtas buffer. We check both.
400 * Minimum size of the buffer is 16 bytes.
401 */
402 #define VALID_FWNMI_BUFFER(A) \
403 ((((A) >= 0x7000) && ((A) <= 0x8000 - 16)) || \
404 (((A) >= rtas.base) && ((A) <= (rtas.base + rtas.size - 16))))
405
fwnmi_get_errlog(void)406 static inline struct rtas_error_log *fwnmi_get_errlog(void)
407 {
408 return (struct rtas_error_log *)local_paca->mce_data_buf;
409 }
410
fwnmi_get_savep(struct pt_regs * regs)411 static __be64 *fwnmi_get_savep(struct pt_regs *regs)
412 {
413 unsigned long savep_ra;
414
415 /* Mask top two bits */
416 savep_ra = regs->gpr[3] & ~(0x3UL << 62);
417 if (!VALID_FWNMI_BUFFER(savep_ra)) {
418 printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]);
419 return NULL;
420 }
421
422 return __va(savep_ra);
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 */
fwnmi_get_errinfo(struct pt_regs * regs)440 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
441 {
442 struct rtas_error_log *h;
443 __be64 *savep;
444
445 savep = fwnmi_get_savep(regs);
446 if (!savep)
447 return NULL;
448
449 regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */
450
451 h = (struct rtas_error_log *)&savep[1];
452 /* Use the per cpu buffer from paca to store rtas error log */
453 memset(local_paca->mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
454 if (!rtas_error_extended(h)) {
455 memcpy(local_paca->mce_data_buf, h, sizeof(__u64));
456 } else {
457 int len, error_log_length;
458
459 error_log_length = 8 + rtas_error_extended_log_length(h);
460 len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX);
461 memcpy(local_paca->mce_data_buf, h, len);
462 }
463
464 return (struct rtas_error_log *)local_paca->mce_data_buf;
465 }
466
467 /* Call this when done with the data returned by FWNMI_get_errinfo.
468 * It will release the saved data area for other CPUs in the
469 * partition to receive FWNMI errors.
470 */
fwnmi_release_errinfo(void)471 static void fwnmi_release_errinfo(void)
472 {
473 struct rtas_args rtas_args;
474 int ret;
475
476 /*
477 * On pseries, the machine check stack is limited to under 4GB, so
478 * args can be on-stack.
479 */
480 rtas_call_unlocked(&rtas_args, ibm_nmi_interlock_token, 0, 1, NULL);
481 ret = be32_to_cpu(rtas_args.rets[0]);
482 if (ret != 0)
483 printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret);
484 }
485
pSeries_system_reset_exception(struct pt_regs * regs)486 int pSeries_system_reset_exception(struct pt_regs *regs)
487 {
488 #ifdef __LITTLE_ENDIAN__
489 /*
490 * Some firmware byteswaps SRR registers and gives incorrect SRR1. Try
491 * to detect the bad SRR1 pattern here. Flip the NIP back to correct
492 * endian for reporting purposes. Unfortunately the MSR can't be fixed,
493 * so clear it. It will be missing MSR_RI so we won't try to recover.
494 */
495 if ((be64_to_cpu(regs->msr) &
496 (MSR_LE|MSR_RI|MSR_DR|MSR_IR|MSR_ME|MSR_PR|
497 MSR_ILE|MSR_HV|MSR_SF)) == (MSR_DR|MSR_SF)) {
498 regs_set_return_ip(regs, be64_to_cpu((__be64)regs->nip));
499 regs_set_return_msr(regs, 0);
500 }
501 #endif
502
503 if (fwnmi_active) {
504 __be64 *savep;
505
506 /*
507 * Firmware (PowerVM and KVM) saves r3 to a save area like
508 * machine check, which is not exactly what PAPR (2.9)
509 * suggests but there is no way to detect otherwise, so this
510 * is the interface now.
511 *
512 * System resets do not save any error log or require an
513 * "ibm,nmi-interlock" rtas call to release.
514 */
515
516 savep = fwnmi_get_savep(regs);
517 if (savep)
518 regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */
519 }
520
521 if (smp_handle_nmi_ipi(regs))
522 return 1;
523
524 return 0; /* need to perform reset */
525 }
526
mce_handle_err_realmode(int disposition,u8 error_type)527 static int mce_handle_err_realmode(int disposition, u8 error_type)
528 {
529 #ifdef CONFIG_PPC_BOOK3S_64
530 if (disposition == RTAS_DISP_NOT_RECOVERED) {
531 switch (error_type) {
532 case MC_ERROR_TYPE_ERAT:
533 flush_erat();
534 disposition = RTAS_DISP_FULLY_RECOVERED;
535 break;
536 case MC_ERROR_TYPE_SLB:
537 #ifdef CONFIG_PPC_64S_HASH_MMU
538 /*
539 * Store the old slb content in paca before flushing.
540 * Print this when we go to virtual mode.
541 * There are chances that we may hit MCE again if there
542 * is a parity error on the SLB entry we trying to read
543 * for saving. Hence limit the slb saving to single
544 * level of recursion.
545 */
546 if (local_paca->in_mce == 1)
547 slb_save_contents(local_paca->mce_faulty_slbs);
548 flush_and_reload_slb();
549 disposition = RTAS_DISP_FULLY_RECOVERED;
550 #endif
551 break;
552 default:
553 break;
554 }
555 } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
556 /* Platform corrected itself but could be degraded */
557 pr_err("MCE: limited recovery, system may be degraded\n");
558 disposition = RTAS_DISP_FULLY_RECOVERED;
559 }
560 #endif
561 return disposition;
562 }
563
mce_handle_err_virtmode(struct pt_regs * regs,struct rtas_error_log * errp,struct pseries_mc_errorlog * mce_log,int disposition)564 static int mce_handle_err_virtmode(struct pt_regs *regs,
565 struct rtas_error_log *errp,
566 struct pseries_mc_errorlog *mce_log,
567 int disposition)
568 {
569 struct mce_error_info mce_err = { 0 };
570 int initiator = rtas_error_initiator(errp);
571 int severity = rtas_error_severity(errp);
572 unsigned long eaddr = 0, paddr = 0;
573 u8 error_type, err_sub_type;
574
575 if (!mce_log)
576 goto out;
577
578 error_type = mce_log->error_type;
579 err_sub_type = rtas_mc_error_sub_type(mce_log);
580
581 if (initiator == RTAS_INITIATOR_UNKNOWN)
582 mce_err.initiator = MCE_INITIATOR_UNKNOWN;
583 else if (initiator == RTAS_INITIATOR_CPU)
584 mce_err.initiator = MCE_INITIATOR_CPU;
585 else if (initiator == RTAS_INITIATOR_PCI)
586 mce_err.initiator = MCE_INITIATOR_PCI;
587 else if (initiator == RTAS_INITIATOR_ISA)
588 mce_err.initiator = MCE_INITIATOR_ISA;
589 else if (initiator == RTAS_INITIATOR_MEMORY)
590 mce_err.initiator = MCE_INITIATOR_MEMORY;
591 else if (initiator == RTAS_INITIATOR_POWERMGM)
592 mce_err.initiator = MCE_INITIATOR_POWERMGM;
593 else
594 mce_err.initiator = MCE_INITIATOR_UNKNOWN;
595
596 if (severity == RTAS_SEVERITY_NO_ERROR)
597 mce_err.severity = MCE_SEV_NO_ERROR;
598 else if (severity == RTAS_SEVERITY_EVENT)
599 mce_err.severity = MCE_SEV_WARNING;
600 else if (severity == RTAS_SEVERITY_WARNING)
601 mce_err.severity = MCE_SEV_WARNING;
602 else if (severity == RTAS_SEVERITY_ERROR_SYNC)
603 mce_err.severity = MCE_SEV_SEVERE;
604 else if (severity == RTAS_SEVERITY_ERROR)
605 mce_err.severity = MCE_SEV_SEVERE;
606 else
607 mce_err.severity = MCE_SEV_FATAL;
608
609 if (severity <= RTAS_SEVERITY_ERROR_SYNC)
610 mce_err.sync_error = true;
611 else
612 mce_err.sync_error = false;
613
614 mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN;
615 mce_err.error_class = MCE_ECLASS_UNKNOWN;
616
617 switch (error_type) {
618 case MC_ERROR_TYPE_UE:
619 mce_err.error_type = MCE_ERROR_TYPE_UE;
620 mce_common_process_ue(regs, &mce_err);
621 if (mce_err.ignore_event)
622 disposition = RTAS_DISP_FULLY_RECOVERED;
623 switch (err_sub_type) {
624 case MC_ERROR_UE_IFETCH:
625 mce_err.u.ue_error_type = MCE_UE_ERROR_IFETCH;
626 break;
627 case MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH:
628 mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH;
629 break;
630 case MC_ERROR_UE_LOAD_STORE:
631 mce_err.u.ue_error_type = MCE_UE_ERROR_LOAD_STORE;
632 break;
633 case MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE:
634 mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE;
635 break;
636 case MC_ERROR_UE_INDETERMINATE:
637 default:
638 mce_err.u.ue_error_type = MCE_UE_ERROR_INDETERMINATE;
639 break;
640 }
641 if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED)
642 eaddr = be64_to_cpu(mce_log->effective_address);
643
644 if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) {
645 paddr = be64_to_cpu(mce_log->logical_address);
646 } else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) {
647 unsigned long pfn;
648
649 pfn = addr_to_pfn(regs, eaddr);
650 if (pfn != ULONG_MAX)
651 paddr = pfn << PAGE_SHIFT;
652 }
653
654 break;
655 case MC_ERROR_TYPE_SLB:
656 mce_err.error_type = MCE_ERROR_TYPE_SLB;
657 switch (err_sub_type) {
658 case MC_ERROR_SLB_PARITY:
659 mce_err.u.slb_error_type = MCE_SLB_ERROR_PARITY;
660 break;
661 case MC_ERROR_SLB_MULTIHIT:
662 mce_err.u.slb_error_type = MCE_SLB_ERROR_MULTIHIT;
663 break;
664 case MC_ERROR_SLB_INDETERMINATE:
665 default:
666 mce_err.u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE;
667 break;
668 }
669 if (mce_log->sub_err_type & MC_EFFECTIVE_ADDR_PROVIDED)
670 eaddr = be64_to_cpu(mce_log->effective_address);
671 break;
672 case MC_ERROR_TYPE_ERAT:
673 mce_err.error_type = MCE_ERROR_TYPE_ERAT;
674 switch (err_sub_type) {
675 case MC_ERROR_ERAT_PARITY:
676 mce_err.u.erat_error_type = MCE_ERAT_ERROR_PARITY;
677 break;
678 case MC_ERROR_ERAT_MULTIHIT:
679 mce_err.u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
680 break;
681 case MC_ERROR_ERAT_INDETERMINATE:
682 default:
683 mce_err.u.erat_error_type = MCE_ERAT_ERROR_INDETERMINATE;
684 break;
685 }
686 if (mce_log->sub_err_type & MC_EFFECTIVE_ADDR_PROVIDED)
687 eaddr = be64_to_cpu(mce_log->effective_address);
688 break;
689 case MC_ERROR_TYPE_TLB:
690 mce_err.error_type = MCE_ERROR_TYPE_TLB;
691 switch (err_sub_type) {
692 case MC_ERROR_TLB_PARITY:
693 mce_err.u.tlb_error_type = MCE_TLB_ERROR_PARITY;
694 break;
695 case MC_ERROR_TLB_MULTIHIT:
696 mce_err.u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT;
697 break;
698 case MC_ERROR_TLB_INDETERMINATE:
699 default:
700 mce_err.u.tlb_error_type = MCE_TLB_ERROR_INDETERMINATE;
701 break;
702 }
703 if (mce_log->sub_err_type & MC_EFFECTIVE_ADDR_PROVIDED)
704 eaddr = be64_to_cpu(mce_log->effective_address);
705 break;
706 case MC_ERROR_TYPE_D_CACHE:
707 mce_err.error_type = MCE_ERROR_TYPE_DCACHE;
708 break;
709 case MC_ERROR_TYPE_I_CACHE:
710 mce_err.error_type = MCE_ERROR_TYPE_ICACHE;
711 break;
712 case MC_ERROR_TYPE_CTRL_MEM_ACCESS:
713 mce_err.error_type = MCE_ERROR_TYPE_RA;
714 switch (err_sub_type) {
715 case MC_ERROR_CTRL_MEM_ACCESS_PTABLE_WALK:
716 mce_err.u.ra_error_type =
717 MCE_RA_ERROR_PAGE_TABLE_WALK_LOAD_STORE_FOREIGN;
718 break;
719 case MC_ERROR_CTRL_MEM_ACCESS_OP_ACCESS:
720 mce_err.u.ra_error_type =
721 MCE_RA_ERROR_LOAD_STORE_FOREIGN;
722 break;
723 }
724 if (mce_log->sub_err_type & MC_EFFECTIVE_ADDR_PROVIDED)
725 eaddr = be64_to_cpu(mce_log->effective_address);
726 break;
727 case MC_ERROR_TYPE_UNKNOWN:
728 default:
729 mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN;
730 break;
731 }
732 out:
733 save_mce_event(regs, disposition == RTAS_DISP_FULLY_RECOVERED,
734 &mce_err, regs->nip, eaddr, paddr);
735 return disposition;
736 }
737
mce_handle_error(struct pt_regs * regs,struct rtas_error_log * errp)738 static int mce_handle_error(struct pt_regs *regs, struct rtas_error_log *errp)
739 {
740 struct pseries_errorlog *pseries_log;
741 struct pseries_mc_errorlog *mce_log = NULL;
742 int disposition = rtas_error_disposition(errp);
743 u8 error_type;
744
745 if (!rtas_error_extended(errp))
746 goto out;
747
748 pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);
749 if (!pseries_log)
750 goto out;
751
752 mce_log = (struct pseries_mc_errorlog *)pseries_log->data;
753 error_type = mce_log->error_type;
754
755 disposition = mce_handle_err_realmode(disposition, error_type);
756 out:
757 disposition = mce_handle_err_virtmode(regs, errp, mce_log,
758 disposition);
759 return disposition;
760 }
761
762 /*
763 * Process MCE rtas errlog event.
764 */
pSeries_machine_check_log_err(void)765 void pSeries_machine_check_log_err(void)
766 {
767 struct rtas_error_log *err;
768
769 err = fwnmi_get_errlog();
770 log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);
771 }
772
773 /*
774 * See if we can recover from a machine check exception.
775 * This is only called on power4 (or above) and only via
776 * the Firmware Non-Maskable Interrupts (fwnmi) handler
777 * which provides the error analysis for us.
778 *
779 * Return 1 if corrected (or delivered a signal).
780 * Return 0 if there is nothing we can do.
781 */
recover_mce(struct pt_regs * regs,struct machine_check_event * evt)782 static int recover_mce(struct pt_regs *regs, struct machine_check_event *evt)
783 {
784 int recovered = 0;
785
786 if (regs_is_unrecoverable(regs)) {
787 /* If MSR_RI isn't set, we cannot recover */
788 pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n");
789 recovered = 0;
790 } else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
791 /* Platform corrected itself */
792 recovered = 1;
793 } else if (evt->severity == MCE_SEV_FATAL) {
794 /* Fatal machine check */
795 pr_err("Machine check interrupt is fatal\n");
796 recovered = 0;
797 }
798
799 if (!recovered && evt->sync_error) {
800 /*
801 * Try to kill processes if we get a synchronous machine check
802 * (e.g., one caused by execution of this instruction). This
803 * will devolve into a panic if we try to kill init or are in
804 * an interrupt etc.
805 *
806 * TODO: Queue up this address for hwpoisioning later.
807 * TODO: This is not quite right for d-side machine
808 * checks ->nip is not necessarily the important
809 * address.
810 */
811 if ((user_mode(regs))) {
812 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
813 recovered = 1;
814 } else if (die_will_crash()) {
815 /*
816 * die() would kill the kernel, so better to go via
817 * the platform reboot code that will log the
818 * machine check.
819 */
820 recovered = 0;
821 } else {
822 die_mce("Machine check", regs, SIGBUS);
823 recovered = 1;
824 }
825 }
826
827 return recovered;
828 }
829
830 /*
831 * Handle a machine check.
832 *
833 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi)
834 * should be present. If so the handler which called us tells us if the
835 * error was recovered (never true if RI=0).
836 *
837 * On hardware prior to Power 4 these exceptions were asynchronous which
838 * means we can't tell exactly where it occurred and so we can't recover.
839 */
pSeries_machine_check_exception(struct pt_regs * regs)840 int pSeries_machine_check_exception(struct pt_regs *regs)
841 {
842 struct machine_check_event evt;
843
844 if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
845 return 0;
846
847 /* Print things out */
848 if (evt.version != MCE_V1) {
849 pr_err("Machine Check Exception, Unknown event version %d !\n",
850 evt.version);
851 return 0;
852 }
853 machine_check_print_event_info(&evt, user_mode(regs), false);
854
855 if (recover_mce(regs, &evt))
856 return 1;
857
858 return 0;
859 }
860
pseries_machine_check_realmode(struct pt_regs * regs)861 long pseries_machine_check_realmode(struct pt_regs *regs)
862 {
863 struct rtas_error_log *errp;
864 int disposition;
865
866 if (fwnmi_active) {
867 errp = fwnmi_get_errinfo(regs);
868 /*
869 * Call to fwnmi_release_errinfo() in real mode causes kernel
870 * to panic. Hence we will call it as soon as we go into
871 * virtual mode.
872 */
873 disposition = mce_handle_error(regs, errp);
874
875 fwnmi_release_errinfo();
876
877 if (disposition == RTAS_DISP_FULLY_RECOVERED)
878 return 1;
879 }
880
881 return 0;
882 }
883