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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#include <asm/asm-prototypes.h>
 28
 29#include "setup.h"
 30
 31static void machine_check_process_queued_event(struct irq_work *work);
 32static void machine_check_ue_irq_work(struct irq_work *work);
 33static void machine_check_ue_event(struct machine_check_event *evt);
 34static void machine_process_ue_event(struct work_struct *work);
 35
 36static struct irq_work mce_event_process_work = {
 37        .func = machine_check_process_queued_event,
 38};
 39
 40static struct irq_work mce_ue_event_irq_work = {
 41	.func = machine_check_ue_irq_work,
 42};
 43
 44static DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
 45
 46static BLOCKING_NOTIFIER_HEAD(mce_notifier_list);
 47
 48int mce_register_notifier(struct notifier_block *nb)
 49{
 50	return blocking_notifier_chain_register(&mce_notifier_list, nb);
 51}
 52EXPORT_SYMBOL_GPL(mce_register_notifier);
 53
 54int mce_unregister_notifier(struct notifier_block *nb)
 55{
 56	return blocking_notifier_chain_unregister(&mce_notifier_list, nb);
 57}
 58EXPORT_SYMBOL_GPL(mce_unregister_notifier);
 59
 60static void mce_set_error_info(struct machine_check_event *mce,
 61			       struct mce_error_info *mce_err)
 62{
 63	mce->error_type = mce_err->error_type;
 64	switch (mce_err->error_type) {
 65	case MCE_ERROR_TYPE_UE:
 66		mce->u.ue_error.ue_error_type = mce_err->u.ue_error_type;
 67		break;
 68	case MCE_ERROR_TYPE_SLB:
 69		mce->u.slb_error.slb_error_type = mce_err->u.slb_error_type;
 70		break;
 71	case MCE_ERROR_TYPE_ERAT:
 72		mce->u.erat_error.erat_error_type = mce_err->u.erat_error_type;
 73		break;
 74	case MCE_ERROR_TYPE_TLB:
 75		mce->u.tlb_error.tlb_error_type = mce_err->u.tlb_error_type;
 76		break;
 77	case MCE_ERROR_TYPE_USER:
 78		mce->u.user_error.user_error_type = mce_err->u.user_error_type;
 79		break;
 80	case MCE_ERROR_TYPE_RA:
 81		mce->u.ra_error.ra_error_type = mce_err->u.ra_error_type;
 82		break;
 83	case MCE_ERROR_TYPE_LINK:
 84		mce->u.link_error.link_error_type = mce_err->u.link_error_type;
 85		break;
 86	case MCE_ERROR_TYPE_UNKNOWN:
 87	default:
 88		break;
 89	}
 90}
 91
 92/*
 93 * Decode and save high level MCE information into per cpu buffer which
 94 * is an array of machine_check_event structure.
 95 */
 96void save_mce_event(struct pt_regs *regs, long handled,
 97		    struct mce_error_info *mce_err,
 98		    uint64_t nip, uint64_t addr, uint64_t phys_addr)
 99{
100	int index = local_paca->mce_info->mce_nest_count++;
101	struct machine_check_event *mce;
102
103	mce = &local_paca->mce_info->mce_event[index];
104	/*
105	 * Return if we don't have enough space to log mce event.
106	 * mce_nest_count may go beyond MAX_MC_EVT but that's ok,
107	 * the check below will stop buffer overrun.
108	 */
109	if (index >= MAX_MC_EVT)
110		return;
111
112	/* Populate generic machine check info */
113	mce->version = MCE_V1;
114	mce->srr0 = nip;
115	mce->srr1 = regs->msr;
116	mce->gpr3 = regs->gpr[3];
117	mce->in_use = 1;
118	mce->cpu = get_paca()->paca_index;
119
120	/* Mark it recovered if we have handled it and MSR(RI=1). */
121	if (handled && (regs->msr & MSR_RI))
122		mce->disposition = MCE_DISPOSITION_RECOVERED;
123	else
124		mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;
125
126	mce->initiator = mce_err->initiator;
127	mce->severity = mce_err->severity;
128	mce->sync_error = mce_err->sync_error;
129	mce->error_class = mce_err->error_class;
130
131	/*
132	 * Populate the mce error_type and type-specific error_type.
133	 */
134	mce_set_error_info(mce, mce_err);
135	if (mce->error_type == MCE_ERROR_TYPE_UE)
136		mce->u.ue_error.ignore_event = mce_err->ignore_event;
137
138	if (!addr)
139		return;
140
141	if (mce->error_type == MCE_ERROR_TYPE_TLB) {
142		mce->u.tlb_error.effective_address_provided = true;
143		mce->u.tlb_error.effective_address = addr;
144	} else if (mce->error_type == MCE_ERROR_TYPE_SLB) {
145		mce->u.slb_error.effective_address_provided = true;
146		mce->u.slb_error.effective_address = addr;
147	} else if (mce->error_type == MCE_ERROR_TYPE_ERAT) {
148		mce->u.erat_error.effective_address_provided = true;
149		mce->u.erat_error.effective_address = addr;
150	} else if (mce->error_type == MCE_ERROR_TYPE_USER) {
151		mce->u.user_error.effective_address_provided = true;
152		mce->u.user_error.effective_address = addr;
153	} else if (mce->error_type == MCE_ERROR_TYPE_RA) {
154		mce->u.ra_error.effective_address_provided = true;
155		mce->u.ra_error.effective_address = addr;
156	} else if (mce->error_type == MCE_ERROR_TYPE_LINK) {
157		mce->u.link_error.effective_address_provided = true;
158		mce->u.link_error.effective_address = addr;
159	} else if (mce->error_type == MCE_ERROR_TYPE_UE) {
160		mce->u.ue_error.effective_address_provided = true;
161		mce->u.ue_error.effective_address = addr;
162		if (phys_addr != ULONG_MAX) {
163			mce->u.ue_error.physical_address_provided = true;
164			mce->u.ue_error.physical_address = phys_addr;
165			machine_check_ue_event(mce);
166		}
167	}
168	return;
169}
170
171/*
172 * get_mce_event:
173 *	mce	Pointer to machine_check_event structure to be filled.
174 *	release Flag to indicate whether to free the event slot or not.
175 *		0 <= do not release the mce event. Caller will invoke
176 *		     release_mce_event() once event has been consumed.
177 *		1 <= release the slot.
178 *
179 *	return	1 = success
180 *		0 = failure
181 *
182 * get_mce_event() will be called by platform specific machine check
183 * handle routine and in KVM.
184 * When we call get_mce_event(), we are still in interrupt context and
185 * preemption will not be scheduled until ret_from_expect() routine
186 * is called.
187 */
188int get_mce_event(struct machine_check_event *mce, bool release)
189{
190	int index = local_paca->mce_info->mce_nest_count - 1;
191	struct machine_check_event *mc_evt;
192	int ret = 0;
193
194	/* Sanity check */
195	if (index < 0)
196		return ret;
197
198	/* Check if we have MCE info to process. */
199	if (index < MAX_MC_EVT) {
200		mc_evt = &local_paca->mce_info->mce_event[index];
201		/* Copy the event structure and release the original */
202		if (mce)
203			*mce = *mc_evt;
204		if (release)
205			mc_evt->in_use = 0;
206		ret = 1;
207	}
208	/* Decrement the count to free the slot. */
209	if (release)
210		local_paca->mce_info->mce_nest_count--;
211
212	return ret;
213}
214
215void release_mce_event(void)
216{
217	get_mce_event(NULL, true);
218}
219
220static void machine_check_ue_irq_work(struct irq_work *work)
221{
222	schedule_work(&mce_ue_event_work);
223}
224
225/*
226 * Queue up the MCE event which then can be handled later.
227 */
228static void machine_check_ue_event(struct machine_check_event *evt)
229{
230	int index;
231
232	index = local_paca->mce_info->mce_ue_count++;
233	/* If queue is full, just return for now. */
234	if (index >= MAX_MC_EVT) {
235		local_paca->mce_info->mce_ue_count--;
236		return;
237	}
238	memcpy(&local_paca->mce_info->mce_ue_event_queue[index],
239	       evt, sizeof(*evt));
240
241	/* Queue work to process this event later. */
242	irq_work_queue(&mce_ue_event_irq_work);
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	unsigned long msr;
253
254	if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
255		return;
256
257	index = local_paca->mce_info->mce_queue_count++;
258	/* If queue is full, just return for now. */
259	if (index >= MAX_MC_EVT) {
260		local_paca->mce_info->mce_queue_count--;
261		return;
262	}
263	memcpy(&local_paca->mce_info->mce_event_queue[index],
264	       &evt, sizeof(evt));
265
266	/*
267	 * Queue irq work to process this event later. Before
268	 * queuing the work enable translation for non radix LPAR,
269	 * as irq_work_queue may try to access memory outside RMO
270	 * region.
271	 */
272	if (!radix_enabled() && firmware_has_feature(FW_FEATURE_LPAR)) {
273		msr = mfmsr();
274		mtmsr(msr | MSR_IR | MSR_DR);
275		irq_work_queue(&mce_event_process_work);
276		mtmsr(msr);
277	} else {
278		irq_work_queue(&mce_event_process_work);
279	}
280}
281
282void mce_common_process_ue(struct pt_regs *regs,
283			   struct mce_error_info *mce_err)
284{
285	const struct exception_table_entry *entry;
286
287	entry = search_kernel_exception_table(regs->nip);
288	if (entry) {
289		mce_err->ignore_event = true;
290		regs_set_return_ip(regs, extable_fixup(entry));
291	}
292}
293
294/*
295 * process pending MCE event from the mce event queue. This function will be
296 * called during syscall exit.
297 */
298static void machine_process_ue_event(struct work_struct *work)
299{
300	int index;
301	struct machine_check_event *evt;
302
303	while (local_paca->mce_info->mce_ue_count > 0) {
304		index = local_paca->mce_info->mce_ue_count - 1;
305		evt = &local_paca->mce_info->mce_ue_event_queue[index];
306		blocking_notifier_call_chain(&mce_notifier_list, 0, evt);
307#ifdef CONFIG_MEMORY_FAILURE
308		/*
309		 * This should probably queued elsewhere, but
310		 * oh! well
311		 *
312		 * Don't report this machine check because the caller has a
313		 * asked us to ignore the event, it has a fixup handler which
314		 * will do the appropriate error handling and reporting.
315		 */
316		if (evt->error_type == MCE_ERROR_TYPE_UE) {
317			if (evt->u.ue_error.ignore_event) {
318				local_paca->mce_info->mce_ue_count--;
319				continue;
320			}
321
322			if (evt->u.ue_error.physical_address_provided) {
323				unsigned long pfn;
324
325				pfn = evt->u.ue_error.physical_address >>
326					PAGE_SHIFT;
327				memory_failure(pfn, 0);
328			} else
329				pr_warn("Failed to identify bad address from "
330					"where the uncorrectable error (UE) "
331					"was generated\n");
332		}
333#endif
334		local_paca->mce_info->mce_ue_count--;
335	}
336}
337/*
338 * process pending MCE event from the mce event queue. This function will be
339 * called during syscall exit.
340 */
341static void machine_check_process_queued_event(struct irq_work *work)
342{
343	int index;
344	struct machine_check_event *evt;
345
346	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
347
348	/*
349	 * For now just print it to console.
350	 * TODO: log this error event to FSP or nvram.
351	 */
352	while (local_paca->mce_info->mce_queue_count > 0) {
353		index = local_paca->mce_info->mce_queue_count - 1;
354		evt = &local_paca->mce_info->mce_event_queue[index];
355
356		if (evt->error_type == MCE_ERROR_TYPE_UE &&
357		    evt->u.ue_error.ignore_event) {
358			local_paca->mce_info->mce_queue_count--;
359			continue;
360		}
361		machine_check_print_event_info(evt, false, false);
362		local_paca->mce_info->mce_queue_count--;
363	}
364}
365
366void machine_check_print_event_info(struct machine_check_event *evt,
367				    bool user_mode, bool in_guest)
368{
369	const char *level, *sevstr, *subtype, *err_type, *initiator;
370	uint64_t ea = 0, pa = 0;
371	int n = 0;
372	char dar_str[50];
373	char pa_str[50];
374	static const char *mc_ue_types[] = {
375		"Indeterminate",
376		"Instruction fetch",
377		"Page table walk ifetch",
378		"Load/Store",
379		"Page table walk Load/Store",
380	};
381	static const char *mc_slb_types[] = {
382		"Indeterminate",
383		"Parity",
384		"Multihit",
385	};
386	static const char *mc_erat_types[] = {
387		"Indeterminate",
388		"Parity",
389		"Multihit",
390	};
391	static const char *mc_tlb_types[] = {
392		"Indeterminate",
393		"Parity",
394		"Multihit",
395	};
396	static const char *mc_user_types[] = {
397		"Indeterminate",
398		"tlbie(l) invalid",
399		"scv invalid",
400	};
401	static const char *mc_ra_types[] = {
402		"Indeterminate",
403		"Instruction fetch (bad)",
404		"Instruction fetch (foreign)",
405		"Page table walk ifetch (bad)",
406		"Page table walk ifetch (foreign)",
407		"Load (bad)",
408		"Store (bad)",
409		"Page table walk Load/Store (bad)",
410		"Page table walk Load/Store (foreign)",
411		"Load/Store (foreign)",
412	};
413	static const char *mc_link_types[] = {
414		"Indeterminate",
415		"Instruction fetch (timeout)",
416		"Page table walk ifetch (timeout)",
417		"Load (timeout)",
418		"Store (timeout)",
419		"Page table walk Load/Store (timeout)",
420	};
421	static const char *mc_error_class[] = {
422		"Unknown",
423		"Hardware error",
424		"Probable Hardware error (some chance of software cause)",
425		"Software error",
426		"Probable Software error (some chance of hardware cause)",
427	};
428
429	/* Print things out */
430	if (evt->version != MCE_V1) {
431		pr_err("Machine Check Exception, Unknown event version %d !\n",
432		       evt->version);
433		return;
434	}
435	switch (evt->severity) {
436	case MCE_SEV_NO_ERROR:
437		level = KERN_INFO;
438		sevstr = "Harmless";
439		break;
440	case MCE_SEV_WARNING:
441		level = KERN_WARNING;
442		sevstr = "Warning";
443		break;
444	case MCE_SEV_SEVERE:
445		level = KERN_ERR;
446		sevstr = "Severe";
447		break;
448	case MCE_SEV_FATAL:
449	default:
450		level = KERN_ERR;
451		sevstr = "Fatal";
452		break;
453	}
454
455	switch(evt->initiator) {
456	case MCE_INITIATOR_CPU:
457		initiator = "CPU";
458		break;
459	case MCE_INITIATOR_PCI:
460		initiator = "PCI";
461		break;
462	case MCE_INITIATOR_ISA:
463		initiator = "ISA";
464		break;
465	case MCE_INITIATOR_MEMORY:
466		initiator = "Memory";
467		break;
468	case MCE_INITIATOR_POWERMGM:
469		initiator = "Power Management";
470		break;
471	case MCE_INITIATOR_UNKNOWN:
472	default:
473		initiator = "Unknown";
474		break;
475	}
476
477	switch (evt->error_type) {
478	case MCE_ERROR_TYPE_UE:
479		err_type = "UE";
480		subtype = evt->u.ue_error.ue_error_type <
481			ARRAY_SIZE(mc_ue_types) ?
482			mc_ue_types[evt->u.ue_error.ue_error_type]
483			: "Unknown";
484		if (evt->u.ue_error.effective_address_provided)
485			ea = evt->u.ue_error.effective_address;
486		if (evt->u.ue_error.physical_address_provided)
487			pa = evt->u.ue_error.physical_address;
488		break;
489	case MCE_ERROR_TYPE_SLB:
490		err_type = "SLB";
491		subtype = evt->u.slb_error.slb_error_type <
492			ARRAY_SIZE(mc_slb_types) ?
493			mc_slb_types[evt->u.slb_error.slb_error_type]
494			: "Unknown";
495		if (evt->u.slb_error.effective_address_provided)
496			ea = evt->u.slb_error.effective_address;
497		break;
498	case MCE_ERROR_TYPE_ERAT:
499		err_type = "ERAT";
500		subtype = evt->u.erat_error.erat_error_type <
501			ARRAY_SIZE(mc_erat_types) ?
502			mc_erat_types[evt->u.erat_error.erat_error_type]
503			: "Unknown";
504		if (evt->u.erat_error.effective_address_provided)
505			ea = evt->u.erat_error.effective_address;
506		break;
507	case MCE_ERROR_TYPE_TLB:
508		err_type = "TLB";
509		subtype = evt->u.tlb_error.tlb_error_type <
510			ARRAY_SIZE(mc_tlb_types) ?
511			mc_tlb_types[evt->u.tlb_error.tlb_error_type]
512			: "Unknown";
513		if (evt->u.tlb_error.effective_address_provided)
514			ea = evt->u.tlb_error.effective_address;
515		break;
516	case MCE_ERROR_TYPE_USER:
517		err_type = "User";
518		subtype = evt->u.user_error.user_error_type <
519			ARRAY_SIZE(mc_user_types) ?
520			mc_user_types[evt->u.user_error.user_error_type]
521			: "Unknown";
522		if (evt->u.user_error.effective_address_provided)
523			ea = evt->u.user_error.effective_address;
524		break;
525	case MCE_ERROR_TYPE_RA:
526		err_type = "Real address";
527		subtype = evt->u.ra_error.ra_error_type <
528			ARRAY_SIZE(mc_ra_types) ?
529			mc_ra_types[evt->u.ra_error.ra_error_type]
530			: "Unknown";
531		if (evt->u.ra_error.effective_address_provided)
532			ea = evt->u.ra_error.effective_address;
533		break;
534	case MCE_ERROR_TYPE_LINK:
535		err_type = "Link";
536		subtype = evt->u.link_error.link_error_type <
537			ARRAY_SIZE(mc_link_types) ?
538			mc_link_types[evt->u.link_error.link_error_type]
539			: "Unknown";
540		if (evt->u.link_error.effective_address_provided)
541			ea = evt->u.link_error.effective_address;
542		break;
543	case MCE_ERROR_TYPE_DCACHE:
544		err_type = "D-Cache";
545		subtype = "Unknown";
546		break;
547	case MCE_ERROR_TYPE_ICACHE:
548		err_type = "I-Cache";
549		subtype = "Unknown";
550		break;
551	default:
552	case MCE_ERROR_TYPE_UNKNOWN:
553		err_type = "Unknown";
554		subtype = "";
555		break;
556	}
557
558	dar_str[0] = pa_str[0] = '\0';
559	if (ea && evt->srr0 != ea) {
560		/* Load/Store address */
561		n = sprintf(dar_str, "DAR: %016llx ", ea);
562		if (pa)
563			sprintf(dar_str + n, "paddr: %016llx ", pa);
564	} else if (pa) {
565		sprintf(pa_str, " paddr: %016llx", pa);
566	}
567
568	printk("%sMCE: CPU%d: machine check (%s) %s %s %s %s[%s]\n",
569		level, evt->cpu, sevstr, in_guest ? "Guest" : "",
570		err_type, subtype, dar_str,
571		evt->disposition == MCE_DISPOSITION_RECOVERED ?
572		"Recovered" : "Not recovered");
573
574	if (in_guest || user_mode) {
575		printk("%sMCE: CPU%d: PID: %d Comm: %s %sNIP: [%016llx]%s\n",
576			level, evt->cpu, current->pid, current->comm,
577			in_guest ? "Guest " : "", evt->srr0, pa_str);
578	} else {
579		printk("%sMCE: CPU%d: NIP: [%016llx] %pS%s\n",
580			level, evt->cpu, evt->srr0, (void *)evt->srr0, pa_str);
581	}
582
583	printk("%sMCE: CPU%d: Initiator %s\n", level, evt->cpu, initiator);
584
585	subtype = evt->error_class < ARRAY_SIZE(mc_error_class) ?
586		mc_error_class[evt->error_class] : "Unknown";
587	printk("%sMCE: CPU%d: %s\n", level, evt->cpu, subtype);
588
589#ifdef CONFIG_PPC_BOOK3S_64
590	/* Display faulty slb contents for SLB errors. */
591	if (evt->error_type == MCE_ERROR_TYPE_SLB && !in_guest)
592		slb_dump_contents(local_paca->mce_faulty_slbs);
593#endif
594}
595EXPORT_SYMBOL_GPL(machine_check_print_event_info);
596
597/*
598 * This function is called in real mode. Strictly no printk's please.
599 *
600 * regs->nip and regs->msr contains srr0 and ssr1.
601 */
602DEFINE_INTERRUPT_HANDLER_NMI(machine_check_early)
603{
604	long handled = 0;
605
606	hv_nmi_check_nonrecoverable(regs);
607
608	/*
609	 * See if platform is capable of handling machine check.
610	 */
611	if (ppc_md.machine_check_early)
612		handled = ppc_md.machine_check_early(regs);
613
614	return handled;
615}
616
617/* Possible meanings for HMER_DEBUG_TRIG bit being set on POWER9 */
618static enum {
619	DTRIG_UNKNOWN,
620	DTRIG_VECTOR_CI,	/* need to emulate vector CI load instr */
621	DTRIG_SUSPEND_ESCAPE,	/* need to escape from TM suspend mode */
622} hmer_debug_trig_function;
623
624static int init_debug_trig_function(void)
625{
626	int pvr;
627	struct device_node *cpun;
628	struct property *prop = NULL;
629	const char *str;
630
631	/* First look in the device tree */
632	preempt_disable();
633	cpun = of_get_cpu_node(smp_processor_id(), NULL);
634	if (cpun) {
635		of_property_for_each_string(cpun, "ibm,hmi-special-triggers",
636					    prop, str) {
637			if (strcmp(str, "bit17-vector-ci-load") == 0)
638				hmer_debug_trig_function = DTRIG_VECTOR_CI;
639			else if (strcmp(str, "bit17-tm-suspend-escape") == 0)
640				hmer_debug_trig_function = DTRIG_SUSPEND_ESCAPE;
641		}
642		of_node_put(cpun);
643	}
644	preempt_enable();
645
646	/* If we found the property, don't look at PVR */
647	if (prop)
648		goto out;
649
650	pvr = mfspr(SPRN_PVR);
651	/* Check for POWER9 Nimbus (scale-out) */
652	if ((PVR_VER(pvr) == PVR_POWER9) && (pvr & 0xe000) == 0) {
653		/* DD2.2 and later */
654		if ((pvr & 0xfff) >= 0x202)
655			hmer_debug_trig_function = DTRIG_SUSPEND_ESCAPE;
656		/* DD2.0 and DD2.1 - used for vector CI load emulation */
657		else if ((pvr & 0xfff) >= 0x200)
658			hmer_debug_trig_function = DTRIG_VECTOR_CI;
659	}
660
661 out:
662	switch (hmer_debug_trig_function) {
663	case DTRIG_VECTOR_CI:
664		pr_debug("HMI debug trigger used for vector CI load\n");
665		break;
666	case DTRIG_SUSPEND_ESCAPE:
667		pr_debug("HMI debug trigger used for TM suspend escape\n");
668		break;
669	default:
670		break;
671	}
672	return 0;
673}
674__initcall(init_debug_trig_function);
675
676/*
677 * Handle HMIs that occur as a result of a debug trigger.
678 * Return values:
679 * -1 means this is not a HMI cause that we know about
680 *  0 means no further handling is required
681 *  1 means further handling is required
682 */
683long hmi_handle_debugtrig(struct pt_regs *regs)
684{
685	unsigned long hmer = mfspr(SPRN_HMER);
686	long ret = 0;
687
688	/* HMER_DEBUG_TRIG bit is used for various workarounds on P9 */
689	if (!((hmer & HMER_DEBUG_TRIG)
690	      && hmer_debug_trig_function != DTRIG_UNKNOWN))
691		return -1;
692		
693	hmer &= ~HMER_DEBUG_TRIG;
694	/* HMER is a write-AND register */
695	mtspr(SPRN_HMER, ~HMER_DEBUG_TRIG);
696
697	switch (hmer_debug_trig_function) {
698	case DTRIG_VECTOR_CI:
699		/*
700		 * Now to avoid problems with soft-disable we
701		 * only do the emulation if we are coming from
702		 * host user space
703		 */
704		if (regs && user_mode(regs))
705			ret = local_paca->hmi_p9_special_emu = 1;
706
707		break;
708
709	default:
710		break;
711	}
712
713	/*
714	 * See if any other HMI causes remain to be handled
715	 */
716	if (hmer & mfspr(SPRN_HMEER))
717		return -1;
718
719	return ret;
720}
721
722/*
723 * Return values:
724 */
725DEFINE_INTERRUPT_HANDLER_NMI(hmi_exception_realmode)
726{	
727	int ret;
728
729	local_paca->hmi_irqs++;
730
731	ret = hmi_handle_debugtrig(regs);
732	if (ret >= 0)
733		return ret;
734
735	wait_for_subcore_guest_exit();
736
737	if (ppc_md.hmi_exception_early)
738		ppc_md.hmi_exception_early(regs);
739
740	wait_for_tb_resync();
741
742	return 1;
743}
744
745void __init mce_init(void)
746{
747	struct mce_info *mce_info;
748	u64 limit;
749	int i;
750
751	limit = min(ppc64_bolted_size(), ppc64_rma_size);
752	for_each_possible_cpu(i) {
753		mce_info = memblock_alloc_try_nid(sizeof(*mce_info),
754						  __alignof__(*mce_info),
755						  MEMBLOCK_LOW_LIMIT,
756						  limit, cpu_to_node(i));
757		if (!mce_info)
758			goto err;
759		paca_ptrs[i]->mce_info = mce_info;
760	}
761	return;
762err:
763	panic("Failed to allocate memory for MCE event data\n");
764}