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}
772