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(nh: &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(nh: &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(evt: 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, release: true);
221}
222
223static void machine_check_ue_work(void)
224{
225 schedule_work(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(mce: &evt, release: 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(addr: 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(nh: &mce_notifier_list, val: 0, v: 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, flags: 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(buf: dar_str, fmt: "DAR: %016llx ", ea);
569 if (pa)
570 sprintf(buf: dar_str + n, fmt: "paddr: %016llx ", pa);
571 } else if (pa) {
572 sprintf(buf: pa_str, fmt: " 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(node: 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(fmt: "Failed to allocate memory for MCE event data\n");
771}
772

source code of linux/arch/powerpc/kernel/mce.c