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_UNKNOWN 0x03
80 #define MC_ERROR_TYPE_TLB 0x04
81 #define MC_ERROR_TYPE_D_CACHE 0x05
82 #define MC_ERROR_TYPE_I_CACHE 0x07
83
84 /* RTAS pseries MCE error sub types */
85 #define MC_ERROR_UE_INDETERMINATE 0
86 #define MC_ERROR_UE_IFETCH 1
87 #define MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH 2
88 #define MC_ERROR_UE_LOAD_STORE 3
89 #define MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE 4
90
91 #define UE_EFFECTIVE_ADDR_PROVIDED 0x40
92 #define UE_LOGICAL_ADDR_PROVIDED 0x20
93
94 #define MC_ERROR_SLB_PARITY 0
95 #define MC_ERROR_SLB_MULTIHIT 1
96 #define MC_ERROR_SLB_INDETERMINATE 2
97
98 #define MC_ERROR_ERAT_PARITY 1
99 #define MC_ERROR_ERAT_MULTIHIT 2
100 #define MC_ERROR_ERAT_INDETERMINATE 3
101
102 #define MC_ERROR_TLB_PARITY 1
103 #define MC_ERROR_TLB_MULTIHIT 2
104 #define MC_ERROR_TLB_INDETERMINATE 3
105
rtas_mc_error_sub_type(const struct pseries_mc_errorlog * mlog)106 static inline u8 rtas_mc_error_sub_type(const struct pseries_mc_errorlog *mlog)
107 {
108 switch (mlog->error_type) {
109 case MC_ERROR_TYPE_UE:
110 return (mlog->sub_err_type & 0x07);
111 case MC_ERROR_TYPE_SLB:
112 case MC_ERROR_TYPE_ERAT:
113 case MC_ERROR_TYPE_TLB:
114 return (mlog->sub_err_type & 0x03);
115 default:
116 return 0;
117 }
118 }
119
120 /*
121 * Enable the hotplug interrupt late because processing them may touch other
122 * devices or systems (e.g. hugepages) that have not been initialized at the
123 * subsys stage.
124 */
init_ras_hotplug_IRQ(void)125 int __init init_ras_hotplug_IRQ(void)
126 {
127 struct device_node *np;
128
129 /* Hotplug Events */
130 np = of_find_node_by_path("/event-sources/hot-plug-events");
131 if (np != NULL) {
132 if (dlpar_workqueue_init() == 0)
133 request_event_sources_irqs(np, ras_hotplug_interrupt,
134 "RAS_HOTPLUG");
135 of_node_put(np);
136 }
137
138 return 0;
139 }
140 machine_late_initcall(pseries, init_ras_hotplug_IRQ);
141
142 /*
143 * Initialize handlers for the set of interrupts caused by hardware errors
144 * and power system events.
145 */
init_ras_IRQ(void)146 static int __init init_ras_IRQ(void)
147 {
148 struct device_node *np;
149
150 ras_check_exception_token = rtas_token("check-exception");
151
152 /* Internal Errors */
153 np = of_find_node_by_path("/event-sources/internal-errors");
154 if (np != NULL) {
155 request_event_sources_irqs(np, ras_error_interrupt,
156 "RAS_ERROR");
157 of_node_put(np);
158 }
159
160 /* EPOW Events */
161 np = of_find_node_by_path("/event-sources/epow-events");
162 if (np != NULL) {
163 request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW");
164 of_node_put(np);
165 }
166
167 return 0;
168 }
169 machine_subsys_initcall(pseries, init_ras_IRQ);
170
171 #define EPOW_SHUTDOWN_NORMAL 1
172 #define EPOW_SHUTDOWN_ON_UPS 2
173 #define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS 3
174 #define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH 4
175
handle_system_shutdown(char event_modifier)176 static void handle_system_shutdown(char event_modifier)
177 {
178 switch (event_modifier) {
179 case EPOW_SHUTDOWN_NORMAL:
180 pr_emerg("Power off requested\n");
181 orderly_poweroff(true);
182 break;
183
184 case EPOW_SHUTDOWN_ON_UPS:
185 pr_emerg("Loss of system power detected. System is running on"
186 " UPS/battery. Check RTAS error log for details\n");
187 orderly_poweroff(true);
188 break;
189
190 case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
191 pr_emerg("Loss of system critical functions detected. Check"
192 " RTAS error log for details\n");
193 orderly_poweroff(true);
194 break;
195
196 case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH:
197 pr_emerg("High ambient temperature detected. Check RTAS"
198 " error log for details\n");
199 orderly_poweroff(true);
200 break;
201
202 default:
203 pr_err("Unknown power/cooling shutdown event (modifier = %d)\n",
204 event_modifier);
205 }
206 }
207
208 struct epow_errorlog {
209 unsigned char sensor_value;
210 unsigned char event_modifier;
211 unsigned char extended_modifier;
212 unsigned char reserved;
213 unsigned char platform_reason;
214 };
215
216 #define EPOW_RESET 0
217 #define EPOW_WARN_COOLING 1
218 #define EPOW_WARN_POWER 2
219 #define EPOW_SYSTEM_SHUTDOWN 3
220 #define EPOW_SYSTEM_HALT 4
221 #define EPOW_MAIN_ENCLOSURE 5
222 #define EPOW_POWER_OFF 7
223
rtas_parse_epow_errlog(struct rtas_error_log * log)224 static void rtas_parse_epow_errlog(struct rtas_error_log *log)
225 {
226 struct pseries_errorlog *pseries_log;
227 struct epow_errorlog *epow_log;
228 char action_code;
229 char modifier;
230
231 pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW);
232 if (pseries_log == NULL)
233 return;
234
235 epow_log = (struct epow_errorlog *)pseries_log->data;
236 action_code = epow_log->sensor_value & 0xF; /* bottom 4 bits */
237 modifier = epow_log->event_modifier & 0xF; /* bottom 4 bits */
238
239 switch (action_code) {
240 case EPOW_RESET:
241 if (num_epow_events) {
242 pr_info("Non critical power/cooling issue cleared\n");
243 num_epow_events--;
244 }
245 break;
246
247 case EPOW_WARN_COOLING:
248 pr_info("Non-critical cooling issue detected. Check RTAS error"
249 " log for details\n");
250 break;
251
252 case EPOW_WARN_POWER:
253 pr_info("Non-critical power issue detected. Check RTAS error"
254 " log for details\n");
255 break;
256
257 case EPOW_SYSTEM_SHUTDOWN:
258 handle_system_shutdown(epow_log->event_modifier);
259 break;
260
261 case EPOW_SYSTEM_HALT:
262 pr_emerg("Critical power/cooling issue detected. Check RTAS"
263 " error log for details. Powering off.\n");
264 orderly_poweroff(true);
265 break;
266
267 case EPOW_MAIN_ENCLOSURE:
268 case EPOW_POWER_OFF:
269 pr_emerg("System about to lose power. Check RTAS error log "
270 " for details. Powering off immediately.\n");
271 emergency_sync();
272 kernel_power_off();
273 break;
274
275 default:
276 pr_err("Unknown power/cooling event (action code = %d)\n",
277 action_code);
278 }
279
280 /* Increment epow events counter variable */
281 if (action_code != EPOW_RESET)
282 num_epow_events++;
283 }
284
ras_hotplug_interrupt(int irq,void * dev_id)285 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id)
286 {
287 struct pseries_errorlog *pseries_log;
288 struct pseries_hp_errorlog *hp_elog;
289
290 spin_lock(&ras_log_buf_lock);
291
292 rtas_call(ras_check_exception_token, 6, 1, NULL,
293 RTAS_VECTOR_EXTERNAL_INTERRUPT, virq_to_hw(irq),
294 RTAS_HOTPLUG_EVENTS, 0, __pa(&ras_log_buf),
295 rtas_get_error_log_max());
296
297 pseries_log = get_pseries_errorlog((struct rtas_error_log *)ras_log_buf,
298 PSERIES_ELOG_SECT_ID_HOTPLUG);
299 hp_elog = (struct pseries_hp_errorlog *)pseries_log->data;
300
301 /*
302 * Since PCI hotplug is not currently supported on pseries, put PCI
303 * hotplug events on the ras_log_buf to be handled by rtas_errd.
304 */
305 if (hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_MEM ||
306 hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_CPU ||
307 hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_PMEM)
308 queue_hotplug_event(hp_elog);
309 else
310 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
311
312 spin_unlock(&ras_log_buf_lock);
313 return IRQ_HANDLED;
314 }
315
316 /* Handle environmental and power warning (EPOW) interrupts. */
ras_epow_interrupt(int irq,void * dev_id)317 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id)
318 {
319 int status;
320 int state;
321 int critical;
322
323 status = rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX,
324 &state);
325
326 if (state > 3)
327 critical = 1; /* Time Critical */
328 else
329 critical = 0;
330
331 spin_lock(&ras_log_buf_lock);
332
333 status = rtas_call(ras_check_exception_token, 6, 1, NULL,
334 RTAS_VECTOR_EXTERNAL_INTERRUPT,
335 virq_to_hw(irq),
336 RTAS_EPOW_WARNING,
337 critical, __pa(&ras_log_buf),
338 rtas_get_error_log_max());
339
340 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
341
342 rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf);
343
344 spin_unlock(&ras_log_buf_lock);
345 return IRQ_HANDLED;
346 }
347
348 /*
349 * Handle hardware error interrupts.
350 *
351 * RTAS check-exception is called to collect data on the exception. If
352 * the error is deemed recoverable, we log a warning and return.
353 * For nonrecoverable errors, an error is logged and we stop all processing
354 * as quickly as possible in order to prevent propagation of the failure.
355 */
ras_error_interrupt(int irq,void * dev_id)356 static irqreturn_t ras_error_interrupt(int irq, void *dev_id)
357 {
358 struct rtas_error_log *rtas_elog;
359 int status;
360 int fatal;
361
362 spin_lock(&ras_log_buf_lock);
363
364 status = rtas_call(ras_check_exception_token, 6, 1, NULL,
365 RTAS_VECTOR_EXTERNAL_INTERRUPT,
366 virq_to_hw(irq),
367 RTAS_INTERNAL_ERROR, 1 /* Time Critical */,
368 __pa(&ras_log_buf),
369 rtas_get_error_log_max());
370
371 rtas_elog = (struct rtas_error_log *)ras_log_buf;
372
373 if (status == 0 &&
374 rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC)
375 fatal = 1;
376 else
377 fatal = 0;
378
379 /* format and print the extended information */
380 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal);
381
382 if (fatal) {
383 pr_emerg("Fatal hardware error detected. Check RTAS error"
384 " log for details. Powering off immediately\n");
385 emergency_sync();
386 kernel_power_off();
387 } else {
388 pr_err("Recoverable hardware error detected\n");
389 }
390
391 spin_unlock(&ras_log_buf_lock);
392 return IRQ_HANDLED;
393 }
394
395 /*
396 * Some versions of FWNMI place the buffer inside the 4kB page starting at
397 * 0x7000. Other versions place it inside the rtas buffer. We check both.
398 */
399 #define VALID_FWNMI_BUFFER(A) \
400 ((((A) >= 0x7000) && ((A) < 0x7ff0)) || \
401 (((A) >= rtas.base) && ((A) < (rtas.base + rtas.size - 16))))
402
fwnmi_get_errlog(void)403 static inline struct rtas_error_log *fwnmi_get_errlog(void)
404 {
405 return (struct rtas_error_log *)local_paca->mce_data_buf;
406 }
407
408 /*
409 * Get the error information for errors coming through the
410 * FWNMI vectors. The pt_regs' r3 will be updated to reflect
411 * the actual r3 if possible, and a ptr to the error log entry
412 * will be returned if found.
413 *
414 * Use one buffer mce_data_buf per cpu to store RTAS error.
415 *
416 * The mce_data_buf does not have any locks or protection around it,
417 * if a second machine check comes in, or a system reset is done
418 * before we have logged the error, then we will get corruption in the
419 * error log. This is preferable over holding off on calling
420 * ibm,nmi-interlock which would result in us checkstopping if a
421 * second machine check did come in.
422 */
fwnmi_get_errinfo(struct pt_regs * regs)423 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
424 {
425 unsigned long *savep;
426 struct rtas_error_log *h;
427
428 /* Mask top two bits */
429 regs->gpr[3] &= ~(0x3UL << 62);
430
431 if (!VALID_FWNMI_BUFFER(regs->gpr[3])) {
432 printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]);
433 return NULL;
434 }
435
436 savep = __va(regs->gpr[3]);
437 regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */
438
439 h = (struct rtas_error_log *)&savep[1];
440 /* Use the per cpu buffer from paca to store rtas error log */
441 memset(local_paca->mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
442 if (!rtas_error_extended(h)) {
443 memcpy(local_paca->mce_data_buf, h, sizeof(__u64));
444 } else {
445 int len, error_log_length;
446
447 error_log_length = 8 + rtas_error_extended_log_length(h);
448 len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX);
449 memcpy(local_paca->mce_data_buf, h, len);
450 }
451
452 return (struct rtas_error_log *)local_paca->mce_data_buf;
453 }
454
455 /* Call this when done with the data returned by FWNMI_get_errinfo.
456 * It will release the saved data area for other CPUs in the
457 * partition to receive FWNMI errors.
458 */
fwnmi_release_errinfo(void)459 static void fwnmi_release_errinfo(void)
460 {
461 int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL);
462 if (ret != 0)
463 printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret);
464 }
465
pSeries_system_reset_exception(struct pt_regs * regs)466 int pSeries_system_reset_exception(struct pt_regs *regs)
467 {
468 #ifdef __LITTLE_ENDIAN__
469 /*
470 * Some firmware byteswaps SRR registers and gives incorrect SRR1. Try
471 * to detect the bad SRR1 pattern here. Flip the NIP back to correct
472 * endian for reporting purposes. Unfortunately the MSR can't be fixed,
473 * so clear it. It will be missing MSR_RI so we won't try to recover.
474 */
475 if ((be64_to_cpu(regs->msr) &
476 (MSR_LE|MSR_RI|MSR_DR|MSR_IR|MSR_ME|MSR_PR|
477 MSR_ILE|MSR_HV|MSR_SF)) == (MSR_DR|MSR_SF)) {
478 regs->nip = be64_to_cpu((__be64)regs->nip);
479 regs->msr = 0;
480 }
481 #endif
482
483 if (fwnmi_active) {
484 struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs);
485 if (errhdr) {
486 /* XXX Should look at FWNMI information */
487 }
488 fwnmi_release_errinfo();
489 }
490
491 if (smp_handle_nmi_ipi(regs))
492 return 1;
493
494 return 0; /* need to perform reset */
495 }
496
497
mce_handle_error(struct pt_regs * regs,struct rtas_error_log * errp)498 static int mce_handle_error(struct pt_regs *regs, struct rtas_error_log *errp)
499 {
500 struct mce_error_info mce_err = { 0 };
501 unsigned long eaddr = 0, paddr = 0;
502 struct pseries_errorlog *pseries_log;
503 struct pseries_mc_errorlog *mce_log;
504 int disposition = rtas_error_disposition(errp);
505 int initiator = rtas_error_initiator(errp);
506 int severity = rtas_error_severity(errp);
507 u8 error_type, err_sub_type;
508
509 if (initiator == RTAS_INITIATOR_UNKNOWN)
510 mce_err.initiator = MCE_INITIATOR_UNKNOWN;
511 else if (initiator == RTAS_INITIATOR_CPU)
512 mce_err.initiator = MCE_INITIATOR_CPU;
513 else if (initiator == RTAS_INITIATOR_PCI)
514 mce_err.initiator = MCE_INITIATOR_PCI;
515 else if (initiator == RTAS_INITIATOR_ISA)
516 mce_err.initiator = MCE_INITIATOR_ISA;
517 else if (initiator == RTAS_INITIATOR_MEMORY)
518 mce_err.initiator = MCE_INITIATOR_MEMORY;
519 else if (initiator == RTAS_INITIATOR_POWERMGM)
520 mce_err.initiator = MCE_INITIATOR_POWERMGM;
521 else
522 mce_err.initiator = MCE_INITIATOR_UNKNOWN;
523
524 if (severity == RTAS_SEVERITY_NO_ERROR)
525 mce_err.severity = MCE_SEV_NO_ERROR;
526 else if (severity == RTAS_SEVERITY_EVENT)
527 mce_err.severity = MCE_SEV_WARNING;
528 else if (severity == RTAS_SEVERITY_WARNING)
529 mce_err.severity = MCE_SEV_WARNING;
530 else if (severity == RTAS_SEVERITY_ERROR_SYNC)
531 mce_err.severity = MCE_SEV_SEVERE;
532 else if (severity == RTAS_SEVERITY_ERROR)
533 mce_err.severity = MCE_SEV_SEVERE;
534 else if (severity == RTAS_SEVERITY_FATAL)
535 mce_err.severity = MCE_SEV_FATAL;
536 else
537 mce_err.severity = MCE_SEV_FATAL;
538
539 if (severity <= RTAS_SEVERITY_ERROR_SYNC)
540 mce_err.sync_error = true;
541 else
542 mce_err.sync_error = false;
543
544 mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN;
545 mce_err.error_class = MCE_ECLASS_UNKNOWN;
546
547 if (!rtas_error_extended(errp))
548 goto out;
549
550 pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);
551 if (pseries_log == NULL)
552 goto out;
553
554 mce_log = (struct pseries_mc_errorlog *)pseries_log->data;
555 error_type = mce_log->error_type;
556 err_sub_type = rtas_mc_error_sub_type(mce_log);
557
558 switch (mce_log->error_type) {
559 case MC_ERROR_TYPE_UE:
560 mce_err.error_type = MCE_ERROR_TYPE_UE;
561 switch (err_sub_type) {
562 case MC_ERROR_UE_IFETCH:
563 mce_err.u.ue_error_type = MCE_UE_ERROR_IFETCH;
564 break;
565 case MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH:
566 mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH;
567 break;
568 case MC_ERROR_UE_LOAD_STORE:
569 mce_err.u.ue_error_type = MCE_UE_ERROR_LOAD_STORE;
570 break;
571 case MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE:
572 mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE;
573 break;
574 case MC_ERROR_UE_INDETERMINATE:
575 default:
576 mce_err.u.ue_error_type = MCE_UE_ERROR_INDETERMINATE;
577 break;
578 }
579 if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED)
580 eaddr = be64_to_cpu(mce_log->effective_address);
581
582 if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) {
583 paddr = be64_to_cpu(mce_log->logical_address);
584 } else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) {
585 unsigned long pfn;
586
587 pfn = addr_to_pfn(regs, eaddr);
588 if (pfn != ULONG_MAX)
589 paddr = pfn << PAGE_SHIFT;
590 }
591
592 break;
593 case MC_ERROR_TYPE_SLB:
594 mce_err.error_type = MCE_ERROR_TYPE_SLB;
595 switch (err_sub_type) {
596 case MC_ERROR_SLB_PARITY:
597 mce_err.u.slb_error_type = MCE_SLB_ERROR_PARITY;
598 break;
599 case MC_ERROR_SLB_MULTIHIT:
600 mce_err.u.slb_error_type = MCE_SLB_ERROR_MULTIHIT;
601 break;
602 case MC_ERROR_SLB_INDETERMINATE:
603 default:
604 mce_err.u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE;
605 break;
606 }
607 if (mce_log->sub_err_type & 0x80)
608 eaddr = be64_to_cpu(mce_log->effective_address);
609 break;
610 case MC_ERROR_TYPE_ERAT:
611 mce_err.error_type = MCE_ERROR_TYPE_ERAT;
612 switch (err_sub_type) {
613 case MC_ERROR_ERAT_PARITY:
614 mce_err.u.erat_error_type = MCE_ERAT_ERROR_PARITY;
615 break;
616 case MC_ERROR_ERAT_MULTIHIT:
617 mce_err.u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
618 break;
619 case MC_ERROR_ERAT_INDETERMINATE:
620 default:
621 mce_err.u.erat_error_type = MCE_ERAT_ERROR_INDETERMINATE;
622 break;
623 }
624 if (mce_log->sub_err_type & 0x80)
625 eaddr = be64_to_cpu(mce_log->effective_address);
626 break;
627 case MC_ERROR_TYPE_TLB:
628 mce_err.error_type = MCE_ERROR_TYPE_TLB;
629 switch (err_sub_type) {
630 case MC_ERROR_TLB_PARITY:
631 mce_err.u.tlb_error_type = MCE_TLB_ERROR_PARITY;
632 break;
633 case MC_ERROR_TLB_MULTIHIT:
634 mce_err.u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT;
635 break;
636 case MC_ERROR_TLB_INDETERMINATE:
637 default:
638 mce_err.u.tlb_error_type = MCE_TLB_ERROR_INDETERMINATE;
639 break;
640 }
641 if (mce_log->sub_err_type & 0x80)
642 eaddr = be64_to_cpu(mce_log->effective_address);
643 break;
644 case MC_ERROR_TYPE_D_CACHE:
645 mce_err.error_type = MCE_ERROR_TYPE_DCACHE;
646 break;
647 case MC_ERROR_TYPE_I_CACHE:
648 mce_err.error_type = MCE_ERROR_TYPE_DCACHE;
649 break;
650 case MC_ERROR_TYPE_UNKNOWN:
651 default:
652 mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN;
653 break;
654 }
655
656 #ifdef CONFIG_PPC_BOOK3S_64
657 if (disposition == RTAS_DISP_NOT_RECOVERED) {
658 switch (error_type) {
659 case MC_ERROR_TYPE_SLB:
660 case MC_ERROR_TYPE_ERAT:
661 /*
662 * Store the old slb content in paca before flushing.
663 * Print this when we go to virtual mode.
664 * There are chances that we may hit MCE again if there
665 * is a parity error on the SLB entry we trying to read
666 * for saving. Hence limit the slb saving to single
667 * level of recursion.
668 */
669 if (local_paca->in_mce == 1)
670 slb_save_contents(local_paca->mce_faulty_slbs);
671 flush_and_reload_slb();
672 disposition = RTAS_DISP_FULLY_RECOVERED;
673 break;
674 default:
675 break;
676 }
677 } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
678 /* Platform corrected itself but could be degraded */
679 printk(KERN_ERR "MCE: limited recovery, system may "
680 "be degraded\n");
681 disposition = RTAS_DISP_FULLY_RECOVERED;
682 }
683 #endif
684
685 out:
686 save_mce_event(regs, disposition == RTAS_DISP_FULLY_RECOVERED,
687 &mce_err, regs->nip, eaddr, paddr);
688
689 return disposition;
690 }
691
692 /*
693 * Process MCE rtas errlog event.
694 */
mce_process_errlog_event(struct irq_work * work)695 static void mce_process_errlog_event(struct irq_work *work)
696 {
697 struct rtas_error_log *err;
698
699 err = fwnmi_get_errlog();
700 log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);
701 }
702
703 /*
704 * See if we can recover from a machine check exception.
705 * This is only called on power4 (or above) and only via
706 * the Firmware Non-Maskable Interrupts (fwnmi) handler
707 * which provides the error analysis for us.
708 *
709 * Return 1 if corrected (or delivered a signal).
710 * Return 0 if there is nothing we can do.
711 */
recover_mce(struct pt_regs * regs,struct machine_check_event * evt)712 static int recover_mce(struct pt_regs *regs, struct machine_check_event *evt)
713 {
714 int recovered = 0;
715
716 if (!(regs->msr & MSR_RI)) {
717 /* If MSR_RI isn't set, we cannot recover */
718 pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n");
719 recovered = 0;
720 } else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
721 /* Platform corrected itself */
722 recovered = 1;
723 } else if (evt->severity == MCE_SEV_FATAL) {
724 /* Fatal machine check */
725 pr_err("Machine check interrupt is fatal\n");
726 recovered = 0;
727 }
728
729 if (!recovered && evt->sync_error) {
730 /*
731 * Try to kill processes if we get a synchronous machine check
732 * (e.g., one caused by execution of this instruction). This
733 * will devolve into a panic if we try to kill init or are in
734 * an interrupt etc.
735 *
736 * TODO: Queue up this address for hwpoisioning later.
737 * TODO: This is not quite right for d-side machine
738 * checks ->nip is not necessarily the important
739 * address.
740 */
741 if ((user_mode(regs))) {
742 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
743 recovered = 1;
744 } else if (die_will_crash()) {
745 /*
746 * die() would kill the kernel, so better to go via
747 * the platform reboot code that will log the
748 * machine check.
749 */
750 recovered = 0;
751 } else {
752 die("Machine check", regs, SIGBUS);
753 recovered = 1;
754 }
755 }
756
757 return recovered;
758 }
759
760 /*
761 * Handle a machine check.
762 *
763 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi)
764 * should be present. If so the handler which called us tells us if the
765 * error was recovered (never true if RI=0).
766 *
767 * On hardware prior to Power 4 these exceptions were asynchronous which
768 * means we can't tell exactly where it occurred and so we can't recover.
769 */
pSeries_machine_check_exception(struct pt_regs * regs)770 int pSeries_machine_check_exception(struct pt_regs *regs)
771 {
772 struct machine_check_event evt;
773
774 if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
775 return 0;
776
777 /* Print things out */
778 if (evt.version != MCE_V1) {
779 pr_err("Machine Check Exception, Unknown event version %d !\n",
780 evt.version);
781 return 0;
782 }
783 machine_check_print_event_info(&evt, user_mode(regs), false);
784
785 if (recover_mce(regs, &evt))
786 return 1;
787
788 return 0;
789 }
790
pseries_machine_check_realmode(struct pt_regs * regs)791 long pseries_machine_check_realmode(struct pt_regs *regs)
792 {
793 struct rtas_error_log *errp;
794 int disposition;
795
796 if (fwnmi_active) {
797 errp = fwnmi_get_errinfo(regs);
798 /*
799 * Call to fwnmi_release_errinfo() in real mode causes kernel
800 * to panic. Hence we will call it as soon as we go into
801 * virtual mode.
802 */
803 disposition = mce_handle_error(regs, errp);
804 fwnmi_release_errinfo();
805
806 /* Queue irq work to log this rtas event later. */
807 irq_work_queue(&mce_errlog_process_work);
808
809 if (disposition == RTAS_DISP_FULLY_RECOVERED)
810 return 1;
811 }
812
813 return 0;
814 }
815
