xref: /openbmc/linux/arch/powerpc/kernel/mce.c (revision 2115732e)
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 
30 static void machine_check_ue_event(struct machine_check_event *evt);
31 static void machine_process_ue_event(struct work_struct *work);
32 
33 static DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
34 
35 static BLOCKING_NOTIFIER_HEAD(mce_notifier_list);
36 
mce_register_notifier(struct notifier_block * nb)37 int mce_register_notifier(struct notifier_block *nb)
38 {
39 	return blocking_notifier_chain_register(&mce_notifier_list, nb);
40 }
41 EXPORT_SYMBOL_GPL(mce_register_notifier);
42 
mce_unregister_notifier(struct notifier_block * nb)43 int mce_unregister_notifier(struct notifier_block *nb)
44 {
45 	return blocking_notifier_chain_unregister(&mce_notifier_list, nb);
46 }
47 EXPORT_SYMBOL_GPL(mce_unregister_notifier);
48 
mce_set_error_info(struct machine_check_event * mce,struct mce_error_info * mce_err)49 static 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 
mce_irq_work_queue(void)81 void 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  */
save_mce_event(struct pt_regs * regs,long handled,struct mce_error_info * mce_err,uint64_t nip,uint64_t addr,uint64_t phys_addr)92 void 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  */
get_mce_event(struct machine_check_event * mce,bool release)191 int 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 
release_mce_event(void)218 void release_mce_event(void)
219 {
220 	get_mce_event(NULL, true);
221 }
222 
machine_check_ue_work(void)223 static 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  */
machine_check_ue_event(struct machine_check_event * evt)231 static 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  */
machine_check_queue_event(void)248 void 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 
mce_common_process_ue(struct pt_regs * regs,struct mce_error_info * mce_err)268 void 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  */
machine_process_ue_event(struct work_struct * work)284 static 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  */
machine_check_process_queued_event(void)327 static 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 
set_mce_pending_irq_work(void)352 void set_mce_pending_irq_work(void)
353 {
354 	local_paca->mce_pending_irq_work = 1;
355 }
356 
clear_mce_pending_irq_work(void)357 void clear_mce_pending_irq_work(void)
358 {
359 	local_paca->mce_pending_irq_work = 0;
360 }
361 
mce_run_irq_context_handlers(void)362 void 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 
machine_check_print_event_info(struct machine_check_event * evt,bool user_mode,bool in_guest)373 void 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 }
602 EXPORT_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  */
DEFINE_INTERRUPT_HANDLER_NMI(machine_check_early)609 DEFINE_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 */
625 static 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 
init_debug_trig_function(void)631 static 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  */
hmi_handle_debugtrig(struct pt_regs * regs)690 long 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  */
DEFINE_INTERRUPT_HANDLER_NMI(hmi_exception_realmode)732 DEFINE_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 
mce_init(void)752 void __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;
769 err:
770 	panic("Failed to allocate memory for MCE event data\n");
771 }
772