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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Machine check exception handling.
4 *
5 * Copyright 2013 IBM Corporation
6 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
7 */
8
9#undef DEBUG
10#define pr_fmt(fmt) "mce: " fmt
11
12#include <linux/hardirq.h>
13#include <linux/types.h>
14#include <linux/ptrace.h>
15#include <linux/percpu.h>
16#include <linux/export.h>
17#include <linux/irq_work.h>
18#include <linux/extable.h>
19#include <linux/ftrace.h>
20#include <linux/memblock.h>
21#include <linux/of.h>
22
23#include <asm/interrupt.h>
24#include <asm/machdep.h>
25#include <asm/mce.h>
26#include <asm/nmi.h>
27
28#include "setup.h"
29
30static void machine_check_ue_event(struct machine_check_event *evt);
31static void machine_process_ue_event(struct work_struct *work);
32
33static DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
34
35static BLOCKING_NOTIFIER_HEAD(mce_notifier_list);
36
37int mce_register_notifier(struct notifier_block *nb)
38{
39 return blocking_notifier_chain_register(&mce_notifier_list, nb);
40}
41EXPORT_SYMBOL_GPL(mce_register_notifier);
42
43int mce_unregister_notifier(struct notifier_block *nb)
44{
45 return blocking_notifier_chain_unregister(&mce_notifier_list, nb);
46}
47EXPORT_SYMBOL_GPL(mce_unregister_notifier);
48
49static void mce_set_error_info(struct machine_check_event *mce,
50 struct mce_error_info *mce_err)
51{
52 mce->error_type = mce_err->error_type;
53 switch (mce_err->error_type) {
54 case MCE_ERROR_TYPE_UE:
55 mce->u.ue_error.ue_error_type = mce_err->u.ue_error_type;
56 break;
57 case MCE_ERROR_TYPE_SLB:
58 mce->u.slb_error.slb_error_type = mce_err->u.slb_error_type;
59 break;
60 case MCE_ERROR_TYPE_ERAT:
61 mce->u.erat_error.erat_error_type = mce_err->u.erat_error_type;
62 break;
63 case MCE_ERROR_TYPE_TLB:
64 mce->u.tlb_error.tlb_error_type = mce_err->u.tlb_error_type;
65 break;
66 case MCE_ERROR_TYPE_USER:
67 mce->u.user_error.user_error_type = mce_err->u.user_error_type;
68 break;
69 case MCE_ERROR_TYPE_RA:
70 mce->u.ra_error.ra_error_type = mce_err->u.ra_error_type;
71 break;
72 case MCE_ERROR_TYPE_LINK:
73 mce->u.link_error.link_error_type = mce_err->u.link_error_type;
74 break;
75 case MCE_ERROR_TYPE_UNKNOWN:
76 default:
77 break;
78 }
79}
80
81void mce_irq_work_queue(void)
82{
83 /* Raise decrementer interrupt */
84 arch_irq_work_raise();
85 set_mce_pending_irq_work();
86}
87
88/*
89 * Decode and save high level MCE information into per cpu buffer which
90 * is an array of machine_check_event structure.
91 */
92void save_mce_event(struct pt_regs *regs, long handled,
93 struct mce_error_info *mce_err,
94 uint64_t nip, uint64_t addr, uint64_t phys_addr)
95{
96 int index = local_paca->mce_info->mce_nest_count++;
97 struct machine_check_event *mce;
98
99 mce = &local_paca->mce_info->mce_event[index];
100 /*
101 * Return if we don't have enough space to log mce event.
102 * mce_nest_count may go beyond MAX_MC_EVT but that's ok,
103 * the check below will stop buffer overrun.
104 */
105 if (index >= MAX_MC_EVT)
106 return;
107
108 /* Populate generic machine check info */
109 mce->version = MCE_V1;
110 mce->srr0 = nip;
111 mce->srr1 = regs->msr;
112 mce->gpr3 = regs->gpr[3];
113 mce->in_use = 1;
114 mce->cpu = get_paca()->paca_index;
115
116 /* Mark it recovered if we have handled it and MSR(RI=1). */
117 if (handled && (regs->msr & MSR_RI))
118 mce->disposition = MCE_DISPOSITION_RECOVERED;
119 else
120 mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;
121
122 mce->initiator = mce_err->initiator;
123 mce->severity = mce_err->severity;
124 mce->sync_error = mce_err->sync_error;
125 mce->error_class = mce_err->error_class;
126
127 /*
128 * Populate the mce error_type and type-specific error_type.
129 */
130 mce_set_error_info(mce, mce_err);
131 if (mce->error_type == MCE_ERROR_TYPE_UE)
132 mce->u.ue_error.ignore_event = mce_err->ignore_event;
133
134 /*
135 * Raise irq work, So that we don't miss to log the error for
136 * unrecoverable errors.
137 */
138 if (mce->disposition == MCE_DISPOSITION_NOT_RECOVERED)
139 mce_irq_work_queue();
140
141 if (!addr)
142 return;
143
144 if (mce->error_type == MCE_ERROR_TYPE_TLB) {
145 mce->u.tlb_error.effective_address_provided = true;
146 mce->u.tlb_error.effective_address = addr;
147 } else if (mce->error_type == MCE_ERROR_TYPE_SLB) {
148 mce->u.slb_error.effective_address_provided = true;
149 mce->u.slb_error.effective_address = addr;
150 } else if (mce->error_type == MCE_ERROR_TYPE_ERAT) {
151 mce->u.erat_error.effective_address_provided = true;
152 mce->u.erat_error.effective_address = addr;
153 } else if (mce->error_type == MCE_ERROR_TYPE_USER) {
154 mce->u.user_error.effective_address_provided = true;
155 mce->u.user_error.effective_address = addr;
156 } else if (mce->error_type == MCE_ERROR_TYPE_RA) {
157 mce->u.ra_error.effective_address_provided = true;
158 mce->u.ra_error.effective_address = addr;
159 } else if (mce->error_type == MCE_ERROR_TYPE_LINK) {
160 mce->u.link_error.effective_address_provided = true;
161 mce->u.link_error.effective_address = addr;
162 } else if (mce->error_type == MCE_ERROR_TYPE_UE) {
163 mce->u.ue_error.effective_address_provided = true;
164 mce->u.ue_error.effective_address = addr;
165 if (phys_addr != ULONG_MAX) {
166 mce->u.ue_error.physical_address_provided = true;
167 mce->u.ue_error.physical_address = phys_addr;
168 machine_check_ue_event(mce);
169 }
170 }
171 return;
172}
173
174/*
175 * get_mce_event:
176 * mce Pointer to machine_check_event structure to be filled.
177 * release Flag to indicate whether to free the event slot or not.
178 * 0 <= do not release the mce event. Caller will invoke
179 * release_mce_event() once event has been consumed.
180 * 1 <= release the slot.
181 *
182 * return 1 = success
183 * 0 = failure
184 *
185 * get_mce_event() will be called by platform specific machine check
186 * handle routine and in KVM.
187 * When we call get_mce_event(), we are still in interrupt context and
188 * preemption will not be scheduled until ret_from_expect() routine
189 * is called.
190 */
191int get_mce_event(struct machine_check_event *mce, bool release)
192{
193 int index = local_paca->mce_info->mce_nest_count - 1;
194 struct machine_check_event *mc_evt;
195 int ret = 0;
196
197 /* Sanity check */
198 if (index < 0)
199 return ret;
200
201 /* Check if we have MCE info to process. */
202 if (index < MAX_MC_EVT) {
203 mc_evt = &local_paca->mce_info->mce_event[index];
204 /* Copy the event structure and release the original */
205 if (mce)
206 *mce = *mc_evt;
207 if (release)
208 mc_evt->in_use = 0;
209 ret = 1;
210 }
211 /* Decrement the count to free the slot. */
212 if (release)
213 local_paca->mce_info->mce_nest_count--;
214
215 return ret;
216}
217
218void release_mce_event(void)
219{
220 get_mce_event(NULL, true);
221}
222
223static void machine_check_ue_work(void)
224{
225 schedule_work(&mce_ue_event_work);
226}
227
228/*
229 * Queue up the MCE event which then can be handled later.
230 */
231static void machine_check_ue_event(struct machine_check_event *evt)
232{
233 int index;
234
235 index = local_paca->mce_info->mce_ue_count++;
236 /* If queue is full, just return for now. */
237 if (index >= MAX_MC_EVT) {
238 local_paca->mce_info->mce_ue_count--;
239 return;
240 }
241 memcpy(&local_paca->mce_info->mce_ue_event_queue[index],
242 evt, sizeof(*evt));
243}
244
245/*
246 * Queue up the MCE event which then can be handled later.
247 */
248void machine_check_queue_event(void)
249{
250 int index;
251 struct machine_check_event evt;
252
253 if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
254 return;
255
256 index = local_paca->mce_info->mce_queue_count++;
257 /* If queue is full, just return for now. */
258 if (index >= MAX_MC_EVT) {
259 local_paca->mce_info->mce_queue_count--;
260 return;
261 }
262 memcpy(&local_paca->mce_info->mce_event_queue[index],
263 &evt, sizeof(evt));
264
265 mce_irq_work_queue();
266}
267
268void mce_common_process_ue(struct pt_regs *regs,
269 struct mce_error_info *mce_err)
270{
271 const struct exception_table_entry *entry;
272
273 entry = search_kernel_exception_table(regs->nip);
274 if (entry) {
275 mce_err->ignore_event = true;
276 regs_set_return_ip(regs, extable_fixup(entry));
277 }
278}
279
280/*
281 * process pending MCE event from the mce event queue. This function will be
282 * called during syscall exit.
283 */
284static void machine_process_ue_event(struct work_struct *work)
285{
286 int index;
287 struct machine_check_event *evt;
288
289 while (local_paca->mce_info->mce_ue_count > 0) {
290 index = local_paca->mce_info->mce_ue_count - 1;
291 evt = &local_paca->mce_info->mce_ue_event_queue[index];
292 blocking_notifier_call_chain(&mce_notifier_list, 0, evt);
293#ifdef CONFIG_MEMORY_FAILURE
294 /*
295 * This should probably queued elsewhere, but
296 * oh! well
297 *
298 * Don't report this machine check because the caller has a
299 * asked us to ignore the event, it has a fixup handler which
300 * will do the appropriate error handling and reporting.
301 */
302 if (evt->error_type == MCE_ERROR_TYPE_UE) {
303 if (evt->u.ue_error.ignore_event) {
304 local_paca->mce_info->mce_ue_count--;
305 continue;
306 }
307
308 if (evt->u.ue_error.physical_address_provided) {
309 unsigned long pfn;
310
311 pfn = evt->u.ue_error.physical_address >>
312 PAGE_SHIFT;
313 memory_failure(pfn, 0);
314 } else
315 pr_warn("Failed to identify bad address from "
316 "where the uncorrectable error (UE) "
317 "was generated\n");
318 }
319#endif
320 local_paca->mce_info->mce_ue_count--;
321 }
322}
323/*
324 * process pending MCE event from the mce event queue. This function will be
325 * called during syscall exit.
326 */
327static void machine_check_process_queued_event(void)
328{
329 int index;
330 struct machine_check_event *evt;
331
332 add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
333
334 /*
335 * For now just print it to console.
336 * TODO: log this error event to FSP or nvram.
337 */
338 while (local_paca->mce_info->mce_queue_count > 0) {
339 index = local_paca->mce_info->mce_queue_count - 1;
340 evt = &local_paca->mce_info->mce_event_queue[index];
341
342 if (evt->error_type == MCE_ERROR_TYPE_UE &&
343 evt->u.ue_error.ignore_event) {
344 local_paca->mce_info->mce_queue_count--;
345 continue;
346 }
347 machine_check_print_event_info(evt, false, false);
348 local_paca->mce_info->mce_queue_count--;
349 }
350}
351
352void set_mce_pending_irq_work(void)
353{
354 local_paca->mce_pending_irq_work = 1;
355}
356
357void clear_mce_pending_irq_work(void)
358{
359 local_paca->mce_pending_irq_work = 0;
360}
361
362void mce_run_irq_context_handlers(void)
363{
364 if (unlikely(local_paca->mce_pending_irq_work)) {
365 if (ppc_md.machine_check_log_err)
366 ppc_md.machine_check_log_err();
367 machine_check_process_queued_event();
368 machine_check_ue_work();
369 clear_mce_pending_irq_work();
370 }
371}
372
373void machine_check_print_event_info(struct machine_check_event *evt,
374 bool user_mode, bool in_guest)
375{
376 const char *level, *sevstr, *subtype, *err_type, *initiator;
377 uint64_t ea = 0, pa = 0;
378 int n = 0;
379 char dar_str[50];
380 char pa_str[50];
381 static const char *mc_ue_types[] = {
382 "Indeterminate",
383 "Instruction fetch",
384 "Page table walk ifetch",
385 "Load/Store",
386 "Page table walk Load/Store",
387 };
388 static const char *mc_slb_types[] = {
389 "Indeterminate",
390 "Parity",
391 "Multihit",
392 };
393 static const char *mc_erat_types[] = {
394 "Indeterminate",
395 "Parity",
396 "Multihit",
397 };
398 static const char *mc_tlb_types[] = {
399 "Indeterminate",
400 "Parity",
401 "Multihit",
402 };
403 static const char *mc_user_types[] = {
404 "Indeterminate",
405 "tlbie(l) invalid",
406 "scv invalid",
407 };
408 static const char *mc_ra_types[] = {
409 "Indeterminate",
410 "Instruction fetch (bad)",
411 "Instruction fetch (foreign/control memory)",
412 "Page table walk ifetch (bad)",
413 "Page table walk ifetch (foreign/control memory)",
414 "Load (bad)",
415 "Store (bad)",
416 "Page table walk Load/Store (bad)",
417 "Page table walk Load/Store (foreign/control memory)",
418 "Load/Store (foreign/control memory)",
419 };
420 static const char *mc_link_types[] = {
421 "Indeterminate",
422 "Instruction fetch (timeout)",
423 "Page table walk ifetch (timeout)",
424 "Load (timeout)",
425 "Store (timeout)",
426 "Page table walk Load/Store (timeout)",
427 };
428 static const char *mc_error_class[] = {
429 "Unknown",
430 "Hardware error",
431 "Probable Hardware error (some chance of software cause)",
432 "Software error",
433 "Probable Software error (some chance of hardware cause)",
434 };
435
436 /* Print things out */
437 if (evt->version != MCE_V1) {
438 pr_err("Machine Check Exception, Unknown event version %d !\n",
439 evt->version);
440 return;
441 }
442 switch (evt->severity) {
443 case MCE_SEV_NO_ERROR:
444 level = KERN_INFO;
445 sevstr = "Harmless";
446 break;
447 case MCE_SEV_WARNING:
448 level = KERN_WARNING;
449 sevstr = "Warning";
450 break;
451 case MCE_SEV_SEVERE:
452 level = KERN_ERR;
453 sevstr = "Severe";
454 break;
455 case MCE_SEV_FATAL:
456 default:
457 level = KERN_ERR;
458 sevstr = "Fatal";
459 break;
460 }
461
462 switch(evt->initiator) {
463 case MCE_INITIATOR_CPU:
464 initiator = "CPU";
465 break;
466 case MCE_INITIATOR_PCI:
467 initiator = "PCI";
468 break;
469 case MCE_INITIATOR_ISA:
470 initiator = "ISA";
471 break;
472 case MCE_INITIATOR_MEMORY:
473 initiator = "Memory";
474 break;
475 case MCE_INITIATOR_POWERMGM:
476 initiator = "Power Management";
477 break;
478 case MCE_INITIATOR_UNKNOWN:
479 default:
480 initiator = "Unknown";
481 break;
482 }
483
484 switch (evt->error_type) {
485 case MCE_ERROR_TYPE_UE:
486 err_type = "UE";
487 subtype = evt->u.ue_error.ue_error_type <
488 ARRAY_SIZE(mc_ue_types) ?
489 mc_ue_types[evt->u.ue_error.ue_error_type]
490 : "Unknown";
491 if (evt->u.ue_error.effective_address_provided)
492 ea = evt->u.ue_error.effective_address;
493 if (evt->u.ue_error.physical_address_provided)
494 pa = evt->u.ue_error.physical_address;
495 break;
496 case MCE_ERROR_TYPE_SLB:
497 err_type = "SLB";
498 subtype = evt->u.slb_error.slb_error_type <
499 ARRAY_SIZE(mc_slb_types) ?
500 mc_slb_types[evt->u.slb_error.slb_error_type]
501 : "Unknown";
502 if (evt->u.slb_error.effective_address_provided)
503 ea = evt->u.slb_error.effective_address;
504 break;
505 case MCE_ERROR_TYPE_ERAT:
506 err_type = "ERAT";
507 subtype = evt->u.erat_error.erat_error_type <
508 ARRAY_SIZE(mc_erat_types) ?
509 mc_erat_types[evt->u.erat_error.erat_error_type]
510 : "Unknown";
511 if (evt->u.erat_error.effective_address_provided)
512 ea = evt->u.erat_error.effective_address;
513 break;
514 case MCE_ERROR_TYPE_TLB:
515 err_type = "TLB";
516 subtype = evt->u.tlb_error.tlb_error_type <
517 ARRAY_SIZE(mc_tlb_types) ?
518 mc_tlb_types[evt->u.tlb_error.tlb_error_type]
519 : "Unknown";
520 if (evt->u.tlb_error.effective_address_provided)
521 ea = evt->u.tlb_error.effective_address;
522 break;
523 case MCE_ERROR_TYPE_USER:
524 err_type = "User";
525 subtype = evt->u.user_error.user_error_type <
526 ARRAY_SIZE(mc_user_types) ?
527 mc_user_types[evt->u.user_error.user_error_type]
528 : "Unknown";
529 if (evt->u.user_error.effective_address_provided)
530 ea = evt->u.user_error.effective_address;
531 break;
532 case MCE_ERROR_TYPE_RA:
533 err_type = "Real address";
534 subtype = evt->u.ra_error.ra_error_type <
535 ARRAY_SIZE(mc_ra_types) ?
536 mc_ra_types[evt->u.ra_error.ra_error_type]
537 : "Unknown";
538 if (evt->u.ra_error.effective_address_provided)
539 ea = evt->u.ra_error.effective_address;
540 break;
541 case MCE_ERROR_TYPE_LINK:
542 err_type = "Link";
543 subtype = evt->u.link_error.link_error_type <
544 ARRAY_SIZE(mc_link_types) ?
545 mc_link_types[evt->u.link_error.link_error_type]
546 : "Unknown";
547 if (evt->u.link_error.effective_address_provided)
548 ea = evt->u.link_error.effective_address;
549 break;
550 case MCE_ERROR_TYPE_DCACHE:
551 err_type = "D-Cache";
552 subtype = "Unknown";
553 break;
554 case MCE_ERROR_TYPE_ICACHE:
555 err_type = "I-Cache";
556 subtype = "Unknown";
557 break;
558 default:
559 case MCE_ERROR_TYPE_UNKNOWN:
560 err_type = "Unknown";
561 subtype = "";
562 break;
563 }
564
565 dar_str[0] = pa_str[0] = '\0';
566 if (ea && evt->srr0 != ea) {
567 /* Load/Store address */
568 n = sprintf(dar_str, "DAR: %016llx ", ea);
569 if (pa)
570 sprintf(dar_str + n, "paddr: %016llx ", pa);
571 } else if (pa) {
572 sprintf(pa_str, " paddr: %016llx", pa);
573 }
574
575 printk("%sMCE: CPU%d: machine check (%s) %s %s %s %s[%s]\n",
576 level, evt->cpu, sevstr, in_guest ? "Guest" : "",
577 err_type, subtype, dar_str,
578 evt->disposition == MCE_DISPOSITION_RECOVERED ?
579 "Recovered" : "Not recovered");
580
581 if (in_guest || user_mode) {
582 printk("%sMCE: CPU%d: PID: %d Comm: %s %sNIP: [%016llx]%s\n",
583 level, evt->cpu, current->pid, current->comm,
584 in_guest ? "Guest " : "", evt->srr0, pa_str);
585 } else {
586 printk("%sMCE: CPU%d: NIP: [%016llx] %pS%s\n",
587 level, evt->cpu, evt->srr0, (void *)evt->srr0, pa_str);
588 }
589
590 printk("%sMCE: CPU%d: Initiator %s\n", level, evt->cpu, initiator);
591
592 subtype = evt->error_class < ARRAY_SIZE(mc_error_class) ?
593 mc_error_class[evt->error_class] : "Unknown";
594 printk("%sMCE: CPU%d: %s\n", level, evt->cpu, subtype);
595
596#ifdef CONFIG_PPC_64S_HASH_MMU
597 /* Display faulty slb contents for SLB errors. */
598 if (evt->error_type == MCE_ERROR_TYPE_SLB && !in_guest)
599 slb_dump_contents(local_paca->mce_faulty_slbs);
600#endif
601}
602EXPORT_SYMBOL_GPL(machine_check_print_event_info);
603
604/*
605 * This function is called in real mode. Strictly no printk's please.
606 *
607 * regs->nip and regs->msr contains srr0 and ssr1.
608 */
609DEFINE_INTERRUPT_HANDLER_NMI(machine_check_early)
610{
611 long handled = 0;
612
613 hv_nmi_check_nonrecoverable(regs);
614
615 /*
616 * See if platform is capable of handling machine check.
617 */
618 if (ppc_md.machine_check_early)
619 handled = ppc_md.machine_check_early(regs);
620
621 return handled;
622}
623
624/* Possible meanings for HMER_DEBUG_TRIG bit being set on POWER9 */
625static enum {
626 DTRIG_UNKNOWN,
627 DTRIG_VECTOR_CI, /* need to emulate vector CI load instr */
628 DTRIG_SUSPEND_ESCAPE, /* need to escape from TM suspend mode */
629} hmer_debug_trig_function;
630
631static int init_debug_trig_function(void)
632{
633 int pvr;
634 struct device_node *cpun;
635 struct property *prop = NULL;
636 const char *str;
637
638 /* First look in the device tree */
639 preempt_disable();
640 cpun = of_get_cpu_node(smp_processor_id(), NULL);
641 if (cpun) {
642 of_property_for_each_string(cpun, "ibm,hmi-special-triggers",
643 prop, str) {
644 if (strcmp(str, "bit17-vector-ci-load") == 0)
645 hmer_debug_trig_function = DTRIG_VECTOR_CI;
646 else if (strcmp(str, "bit17-tm-suspend-escape") == 0)
647 hmer_debug_trig_function = DTRIG_SUSPEND_ESCAPE;
648 }
649 of_node_put(cpun);
650 }
651 preempt_enable();
652
653 /* If we found the property, don't look at PVR */
654 if (prop)
655 goto out;
656
657 pvr = mfspr(SPRN_PVR);
658 /* Check for POWER9 Nimbus (scale-out) */
659 if ((PVR_VER(pvr) == PVR_POWER9) && (pvr & 0xe000) == 0) {
660 /* DD2.2 and later */
661 if ((pvr & 0xfff) >= 0x202)
662 hmer_debug_trig_function = DTRIG_SUSPEND_ESCAPE;
663 /* DD2.0 and DD2.1 - used for vector CI load emulation */
664 else if ((pvr & 0xfff) >= 0x200)
665 hmer_debug_trig_function = DTRIG_VECTOR_CI;
666 }
667
668 out:
669 switch (hmer_debug_trig_function) {
670 case DTRIG_VECTOR_CI:
671 pr_debug("HMI debug trigger used for vector CI load\n");
672 break;
673 case DTRIG_SUSPEND_ESCAPE:
674 pr_debug("HMI debug trigger used for TM suspend escape\n");
675 break;
676 default:
677 break;
678 }
679 return 0;
680}
681__initcall(init_debug_trig_function);
682
683/*
684 * Handle HMIs that occur as a result of a debug trigger.
685 * Return values:
686 * -1 means this is not a HMI cause that we know about
687 * 0 means no further handling is required
688 * 1 means further handling is required
689 */
690long hmi_handle_debugtrig(struct pt_regs *regs)
691{
692 unsigned long hmer = mfspr(SPRN_HMER);
693 long ret = 0;
694
695 /* HMER_DEBUG_TRIG bit is used for various workarounds on P9 */
696 if (!((hmer & HMER_DEBUG_TRIG)
697 && hmer_debug_trig_function != DTRIG_UNKNOWN))
698 return -1;
699
700 hmer &= ~HMER_DEBUG_TRIG;
701 /* HMER is a write-AND register */
702 mtspr(SPRN_HMER, ~HMER_DEBUG_TRIG);
703
704 switch (hmer_debug_trig_function) {
705 case DTRIG_VECTOR_CI:
706 /*
707 * Now to avoid problems with soft-disable we
708 * only do the emulation if we are coming from
709 * host user space
710 */
711 if (regs && user_mode(regs))
712 ret = local_paca->hmi_p9_special_emu = 1;
713
714 break;
715
716 default:
717 break;
718 }
719
720 /*
721 * See if any other HMI causes remain to be handled
722 */
723 if (hmer & mfspr(SPRN_HMEER))
724 return -1;
725
726 return ret;
727}
728
729/*
730 * Return values:
731 */
732DEFINE_INTERRUPT_HANDLER_NMI(hmi_exception_realmode)
733{
734 int ret;
735
736 local_paca->hmi_irqs++;
737
738 ret = hmi_handle_debugtrig(regs);
739 if (ret >= 0)
740 return ret;
741
742 wait_for_subcore_guest_exit();
743
744 if (ppc_md.hmi_exception_early)
745 ppc_md.hmi_exception_early(regs);
746
747 wait_for_tb_resync();
748
749 return 1;
750}
751
752void __init mce_init(void)
753{
754 struct mce_info *mce_info;
755 u64 limit;
756 int i;
757
758 limit = min(ppc64_bolted_size(), ppc64_rma_size);
759 for_each_possible_cpu(i) {
760 mce_info = memblock_alloc_try_nid(sizeof(*mce_info),
761 __alignof__(*mce_info),
762 MEMBLOCK_LOW_LIMIT,
763 limit, early_cpu_to_node(i));
764 if (!mce_info)
765 goto err;
766 paca_ptrs[i]->mce_info = mce_info;
767 }
768 return;
769err:
770 panic("Failed to allocate memory for MCE event data\n");
771}
1/*
2 * Machine check exception handling.
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 * Copyright 2013 IBM Corporation
19 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
20 */
21
22#undef DEBUG
23#define pr_fmt(fmt) "mce: " fmt
24
25#include <linux/types.h>
26#include <linux/ptrace.h>
27#include <linux/percpu.h>
28#include <linux/export.h>
29#include <linux/irq_work.h>
30#include <asm/mce.h>
31
32static DEFINE_PER_CPU(int, mce_nest_count);
33static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event);
34
35/* Queue for delayed MCE events. */
36static DEFINE_PER_CPU(int, mce_queue_count);
37static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event_queue);
38
39static void machine_check_process_queued_event(struct irq_work *work);
40static struct irq_work mce_event_process_work = {
41 .func = machine_check_process_queued_event,
42};
43
44static void mce_set_error_info(struct machine_check_event *mce,
45 struct mce_error_info *mce_err)
46{
47 mce->error_type = mce_err->error_type;
48 switch (mce_err->error_type) {
49 case MCE_ERROR_TYPE_UE:
50 mce->u.ue_error.ue_error_type = mce_err->u.ue_error_type;
51 break;
52 case MCE_ERROR_TYPE_SLB:
53 mce->u.slb_error.slb_error_type = mce_err->u.slb_error_type;
54 break;
55 case MCE_ERROR_TYPE_ERAT:
56 mce->u.erat_error.erat_error_type = mce_err->u.erat_error_type;
57 break;
58 case MCE_ERROR_TYPE_TLB:
59 mce->u.tlb_error.tlb_error_type = mce_err->u.tlb_error_type;
60 break;
61 case MCE_ERROR_TYPE_UNKNOWN:
62 default:
63 break;
64 }
65}
66
67/*
68 * Decode and save high level MCE information into per cpu buffer which
69 * is an array of machine_check_event structure.
70 */
71void save_mce_event(struct pt_regs *regs, long handled,
72 struct mce_error_info *mce_err,
73 uint64_t nip, uint64_t addr)
74{
75 int index = __this_cpu_inc_return(mce_nest_count) - 1;
76 struct machine_check_event *mce = this_cpu_ptr(&mce_event[index]);
77
78 /*
79 * Return if we don't have enough space to log mce event.
80 * mce_nest_count may go beyond MAX_MC_EVT but that's ok,
81 * the check below will stop buffer overrun.
82 */
83 if (index >= MAX_MC_EVT)
84 return;
85
86 /* Populate generic machine check info */
87 mce->version = MCE_V1;
88 mce->srr0 = nip;
89 mce->srr1 = regs->msr;
90 mce->gpr3 = regs->gpr[3];
91 mce->in_use = 1;
92
93 mce->initiator = MCE_INITIATOR_CPU;
94 /* Mark it recovered if we have handled it and MSR(RI=1). */
95 if (handled && (regs->msr & MSR_RI))
96 mce->disposition = MCE_DISPOSITION_RECOVERED;
97 else
98 mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;
99 mce->severity = MCE_SEV_ERROR_SYNC;
100
101 /*
102 * Populate the mce error_type and type-specific error_type.
103 */
104 mce_set_error_info(mce, mce_err);
105
106 if (!addr)
107 return;
108
109 if (mce->error_type == MCE_ERROR_TYPE_TLB) {
110 mce->u.tlb_error.effective_address_provided = true;
111 mce->u.tlb_error.effective_address = addr;
112 } else if (mce->error_type == MCE_ERROR_TYPE_SLB) {
113 mce->u.slb_error.effective_address_provided = true;
114 mce->u.slb_error.effective_address = addr;
115 } else if (mce->error_type == MCE_ERROR_TYPE_ERAT) {
116 mce->u.erat_error.effective_address_provided = true;
117 mce->u.erat_error.effective_address = addr;
118 } else if (mce->error_type == MCE_ERROR_TYPE_UE) {
119 mce->u.ue_error.effective_address_provided = true;
120 mce->u.ue_error.effective_address = addr;
121 }
122 return;
123}
124
125/*
126 * get_mce_event:
127 * mce Pointer to machine_check_event structure to be filled.
128 * release Flag to indicate whether to free the event slot or not.
129 * 0 <= do not release the mce event. Caller will invoke
130 * release_mce_event() once event has been consumed.
131 * 1 <= release the slot.
132 *
133 * return 1 = success
134 * 0 = failure
135 *
136 * get_mce_event() will be called by platform specific machine check
137 * handle routine and in KVM.
138 * When we call get_mce_event(), we are still in interrupt context and
139 * preemption will not be scheduled until ret_from_expect() routine
140 * is called.
141 */
142int get_mce_event(struct machine_check_event *mce, bool release)
143{
144 int index = __this_cpu_read(mce_nest_count) - 1;
145 struct machine_check_event *mc_evt;
146 int ret = 0;
147
148 /* Sanity check */
149 if (index < 0)
150 return ret;
151
152 /* Check if we have MCE info to process. */
153 if (index < MAX_MC_EVT) {
154 mc_evt = this_cpu_ptr(&mce_event[index]);
155 /* Copy the event structure and release the original */
156 if (mce)
157 *mce = *mc_evt;
158 if (release)
159 mc_evt->in_use = 0;
160 ret = 1;
161 }
162 /* Decrement the count to free the slot. */
163 if (release)
164 __this_cpu_dec(mce_nest_count);
165
166 return ret;
167}
168
169void release_mce_event(void)
170{
171 get_mce_event(NULL, true);
172}
173
174/*
175 * Queue up the MCE event which then can be handled later.
176 */
177void machine_check_queue_event(void)
178{
179 int index;
180 struct machine_check_event evt;
181
182 if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
183 return;
184
185 index = __this_cpu_inc_return(mce_queue_count) - 1;
186 /* If queue is full, just return for now. */
187 if (index >= MAX_MC_EVT) {
188 __this_cpu_dec(mce_queue_count);
189 return;
190 }
191 memcpy(this_cpu_ptr(&mce_event_queue[index]), &evt, sizeof(evt));
192
193 /* Queue irq work to process this event later. */
194 irq_work_queue(&mce_event_process_work);
195}
196
197/*
198 * process pending MCE event from the mce event queue. This function will be
199 * called during syscall exit.
200 */
201static void machine_check_process_queued_event(struct irq_work *work)
202{
203 int index;
204
205 /*
206 * For now just print it to console.
207 * TODO: log this error event to FSP or nvram.
208 */
209 while (__this_cpu_read(mce_queue_count) > 0) {
210 index = __this_cpu_read(mce_queue_count) - 1;
211 machine_check_print_event_info(
212 this_cpu_ptr(&mce_event_queue[index]));
213 __this_cpu_dec(mce_queue_count);
214 }
215}
216
217void machine_check_print_event_info(struct machine_check_event *evt)
218{
219 const char *level, *sevstr, *subtype;
220 static const char *mc_ue_types[] = {
221 "Indeterminate",
222 "Instruction fetch",
223 "Page table walk ifetch",
224 "Load/Store",
225 "Page table walk Load/Store",
226 };
227 static const char *mc_slb_types[] = {
228 "Indeterminate",
229 "Parity",
230 "Multihit",
231 };
232 static const char *mc_erat_types[] = {
233 "Indeterminate",
234 "Parity",
235 "Multihit",
236 };
237 static const char *mc_tlb_types[] = {
238 "Indeterminate",
239 "Parity",
240 "Multihit",
241 };
242
243 /* Print things out */
244 if (evt->version != MCE_V1) {
245 pr_err("Machine Check Exception, Unknown event version %d !\n",
246 evt->version);
247 return;
248 }
249 switch (evt->severity) {
250 case MCE_SEV_NO_ERROR:
251 level = KERN_INFO;
252 sevstr = "Harmless";
253 break;
254 case MCE_SEV_WARNING:
255 level = KERN_WARNING;
256 sevstr = "";
257 break;
258 case MCE_SEV_ERROR_SYNC:
259 level = KERN_ERR;
260 sevstr = "Severe";
261 break;
262 case MCE_SEV_FATAL:
263 default:
264 level = KERN_ERR;
265 sevstr = "Fatal";
266 break;
267 }
268
269 printk("%s%s Machine check interrupt [%s]\n", level, sevstr,
270 evt->disposition == MCE_DISPOSITION_RECOVERED ?
271 "Recovered" : "[Not recovered");
272 printk("%s Initiator: %s\n", level,
273 evt->initiator == MCE_INITIATOR_CPU ? "CPU" : "Unknown");
274 switch (evt->error_type) {
275 case MCE_ERROR_TYPE_UE:
276 subtype = evt->u.ue_error.ue_error_type <
277 ARRAY_SIZE(mc_ue_types) ?
278 mc_ue_types[evt->u.ue_error.ue_error_type]
279 : "Unknown";
280 printk("%s Error type: UE [%s]\n", level, subtype);
281 if (evt->u.ue_error.effective_address_provided)
282 printk("%s Effective address: %016llx\n",
283 level, evt->u.ue_error.effective_address);
284 if (evt->u.ue_error.physical_address_provided)
285 printk("%s Physical address: %016llx\n",
286 level, evt->u.ue_error.physical_address);
287 break;
288 case MCE_ERROR_TYPE_SLB:
289 subtype = evt->u.slb_error.slb_error_type <
290 ARRAY_SIZE(mc_slb_types) ?
291 mc_slb_types[evt->u.slb_error.slb_error_type]
292 : "Unknown";
293 printk("%s Error type: SLB [%s]\n", level, subtype);
294 if (evt->u.slb_error.effective_address_provided)
295 printk("%s Effective address: %016llx\n",
296 level, evt->u.slb_error.effective_address);
297 break;
298 case MCE_ERROR_TYPE_ERAT:
299 subtype = evt->u.erat_error.erat_error_type <
300 ARRAY_SIZE(mc_erat_types) ?
301 mc_erat_types[evt->u.erat_error.erat_error_type]
302 : "Unknown";
303 printk("%s Error type: ERAT [%s]\n", level, subtype);
304 if (evt->u.erat_error.effective_address_provided)
305 printk("%s Effective address: %016llx\n",
306 level, evt->u.erat_error.effective_address);
307 break;
308 case MCE_ERROR_TYPE_TLB:
309 subtype = evt->u.tlb_error.tlb_error_type <
310 ARRAY_SIZE(mc_tlb_types) ?
311 mc_tlb_types[evt->u.tlb_error.tlb_error_type]
312 : "Unknown";
313 printk("%s Error type: TLB [%s]\n", level, subtype);
314 if (evt->u.tlb_error.effective_address_provided)
315 printk("%s Effective address: %016llx\n",
316 level, evt->u.tlb_error.effective_address);
317 break;
318 default:
319 case MCE_ERROR_TYPE_UNKNOWN:
320 printk("%s Error type: Unknown\n", level);
321 break;
322 }
323}
324
325uint64_t get_mce_fault_addr(struct machine_check_event *evt)
326{
327 switch (evt->error_type) {
328 case MCE_ERROR_TYPE_UE:
329 if (evt->u.ue_error.effective_address_provided)
330 return evt->u.ue_error.effective_address;
331 break;
332 case MCE_ERROR_TYPE_SLB:
333 if (evt->u.slb_error.effective_address_provided)
334 return evt->u.slb_error.effective_address;
335 break;
336 case MCE_ERROR_TYPE_ERAT:
337 if (evt->u.erat_error.effective_address_provided)
338 return evt->u.erat_error.effective_address;
339 break;
340 case MCE_ERROR_TYPE_TLB:
341 if (evt->u.tlb_error.effective_address_provided)
342 return evt->u.tlb_error.effective_address;
343 break;
344 default:
345 case MCE_ERROR_TYPE_UNKNOWN:
346 break;
347 }
348 return 0;
349}
350EXPORT_SYMBOL(get_mce_fault_addr);