1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2001 Dave Engebretsen IBM Corporation
4 */
5
6#include <linux/sched.h>
7#include <linux/interrupt.h>
8#include <linux/irq.h>
9#include <linux/of.h>
10#include <linux/fs.h>
11#include <linux/reboot.h>
12#include <linux/irq_work.h>
13
14#include <asm/machdep.h>
15#include <asm/rtas.h>
16#include <asm/firmware.h>
17#include <asm/mce.h>
18
19#include "pseries.h"
20
21static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX];
22static DEFINE_SPINLOCK(ras_log_buf_lock);
23
24static int ras_check_exception_token;
25
26static void mce_process_errlog_event(struct irq_work *work);
27static struct irq_work mce_errlog_process_work = {
28	.func = mce_process_errlog_event,
29};
30
31#define EPOW_SENSOR_TOKEN	9
32#define EPOW_SENSOR_INDEX	0
33
34/* EPOW events counter variable */
35static int num_epow_events;
36
37static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id);
38static irqreturn_t ras_epow_interrupt(int irq, void *dev_id);
39static irqreturn_t ras_error_interrupt(int irq, void *dev_id);
40
41/* RTAS pseries MCE errorlog section. */
42struct pseries_mc_errorlog {
43	__be32	fru_id;
44	__be32	proc_id;
45	u8	error_type;
46	/*
47	 * sub_err_type (1 byte). Bit fields depends on error_type
48	 *
49	 *   MSB0
50	 *   |
51	 *   V
52	 *   01234567
53	 *   XXXXXXXX
54	 *
55	 * For error_type == MC_ERROR_TYPE_UE
56	 *   XXXXXXXX
57	 *   X		1: Permanent or Transient UE.
58	 *    X		1: Effective address provided.
59	 *     X	1: Logical address provided.
60	 *      XX	2: Reserved.
61	 *        XXX	3: Type of UE error.
62	 *
63	 * For error_type != MC_ERROR_TYPE_UE
64	 *   XXXXXXXX
65	 *   X		1: Effective address provided.
66	 *    XXXXX	5: Reserved.
67	 *         XX	2: Type of SLB/ERAT/TLB error.
68	 */
69	u8	sub_err_type;
70	u8	reserved_1[6];
71	__be64	effective_address;
72	__be64	logical_address;
73} __packed;
74
75/* RTAS pseries MCE error types */
76#define MC_ERROR_TYPE_UE		0x00
77#define MC_ERROR_TYPE_SLB		0x01
78#define MC_ERROR_TYPE_ERAT		0x02
79#define MC_ERROR_TYPE_UNKNOWN		0x03
80#define MC_ERROR_TYPE_TLB		0x04
81#define MC_ERROR_TYPE_D_CACHE		0x05
82#define MC_ERROR_TYPE_I_CACHE		0x07
83
84/* RTAS pseries MCE error sub types */
85#define MC_ERROR_UE_INDETERMINATE		0
86#define MC_ERROR_UE_IFETCH			1
87#define MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH	2
88#define MC_ERROR_UE_LOAD_STORE			3
89#define MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE	4
90
91#define UE_EFFECTIVE_ADDR_PROVIDED		0x40
92#define UE_LOGICAL_ADDR_PROVIDED		0x20
93
94#define MC_ERROR_SLB_PARITY		0
95#define MC_ERROR_SLB_MULTIHIT		1
96#define MC_ERROR_SLB_INDETERMINATE	2
97
98#define MC_ERROR_ERAT_PARITY		1
99#define MC_ERROR_ERAT_MULTIHIT		2
100#define MC_ERROR_ERAT_INDETERMINATE	3
101
102#define MC_ERROR_TLB_PARITY		1
103#define MC_ERROR_TLB_MULTIHIT		2
104#define MC_ERROR_TLB_INDETERMINATE	3
105
106static inline u8 rtas_mc_error_sub_type(const struct pseries_mc_errorlog *mlog)
107{
108	switch (mlog->error_type) {
109	case	MC_ERROR_TYPE_UE:
110		return (mlog->sub_err_type & 0x07);
111	case	MC_ERROR_TYPE_SLB:
112	case	MC_ERROR_TYPE_ERAT:
113	case	MC_ERROR_TYPE_TLB:
114		return (mlog->sub_err_type & 0x03);
115	default:
116		return 0;
117	}
118}
119
120/*
121 * Enable the hotplug interrupt late because processing them may touch other
122 * devices or systems (e.g. hugepages) that have not been initialized at the
123 * subsys stage.
124 */
125int __init init_ras_hotplug_IRQ(void)
126{
127	struct device_node *np;
128
129	/* Hotplug Events */
130	np = of_find_node_by_path("/event-sources/hot-plug-events");
131	if (np != NULL) {
132		if (dlpar_workqueue_init() == 0)
133			request_event_sources_irqs(np, ras_hotplug_interrupt,
134						   "RAS_HOTPLUG");
135		of_node_put(np);
136	}
137
138	return 0;
139}
140machine_late_initcall(pseries, init_ras_hotplug_IRQ);
141
142/*
143 * Initialize handlers for the set of interrupts caused by hardware errors
144 * and power system events.
145 */
146static int __init init_ras_IRQ(void)
147{
148	struct device_node *np;
149
150	ras_check_exception_token = rtas_token("check-exception");
151
152	/* Internal Errors */
153	np = of_find_node_by_path("/event-sources/internal-errors");
154	if (np != NULL) {
155		request_event_sources_irqs(np, ras_error_interrupt,
156					   "RAS_ERROR");
157		of_node_put(np);
158	}
159
160	/* EPOW Events */
161	np = of_find_node_by_path("/event-sources/epow-events");
162	if (np != NULL) {
163		request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW");
164		of_node_put(np);
165	}
166
167	return 0;
168}
169machine_subsys_initcall(pseries, init_ras_IRQ);
170
171#define EPOW_SHUTDOWN_NORMAL				1
172#define EPOW_SHUTDOWN_ON_UPS				2
173#define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS	3
174#define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH	4
175
176static void handle_system_shutdown(char event_modifier)
177{
178	switch (event_modifier) {
179	case EPOW_SHUTDOWN_NORMAL:
180		pr_emerg("Power off requested\n");
181		orderly_poweroff(true);
182		break;
183
184	case EPOW_SHUTDOWN_ON_UPS:
185		pr_emerg("Loss of system power detected. System is running on"
186			 " UPS/battery. Check RTAS error log for details\n");
187		break;
188
189	case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
190		pr_emerg("Loss of system critical functions detected. Check"
191			 " RTAS error log for details\n");
192		orderly_poweroff(true);
193		break;
194
195	case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH:
196		pr_emerg("High ambient temperature detected. Check RTAS"
197			 " error log for details\n");
198		orderly_poweroff(true);
199		break;
200
201	default:
202		pr_err("Unknown power/cooling shutdown event (modifier = %d)\n",
203			event_modifier);
204	}
205}
206
207struct epow_errorlog {
208	unsigned char sensor_value;
209	unsigned char event_modifier;
210	unsigned char extended_modifier;
211	unsigned char reserved;
212	unsigned char platform_reason;
213};
214
215#define EPOW_RESET			0
216#define EPOW_WARN_COOLING		1
217#define EPOW_WARN_POWER			2
218#define EPOW_SYSTEM_SHUTDOWN		3
219#define EPOW_SYSTEM_HALT		4
220#define EPOW_MAIN_ENCLOSURE		5
221#define EPOW_POWER_OFF			7
222
223static void rtas_parse_epow_errlog(struct rtas_error_log *log)
224{
225	struct pseries_errorlog *pseries_log;
226	struct epow_errorlog *epow_log;
227	char action_code;
228	char modifier;
229
230	pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW);
231	if (pseries_log == NULL)
232		return;
233
234	epow_log = (struct epow_errorlog *)pseries_log->data;
235	action_code = epow_log->sensor_value & 0xF;	/* bottom 4 bits */
236	modifier = epow_log->event_modifier & 0xF;	/* bottom 4 bits */
237
238	switch (action_code) {
239	case EPOW_RESET:
240		if (num_epow_events) {
241			pr_info("Non critical power/cooling issue cleared\n");
242			num_epow_events--;
243		}
244		break;
245
246	case EPOW_WARN_COOLING:
247		pr_info("Non-critical cooling issue detected. Check RTAS error"
248			" log for details\n");
249		break;
250
251	case EPOW_WARN_POWER:
252		pr_info("Non-critical power issue detected. Check RTAS error"
253			" log for details\n");
254		break;
255
256	case EPOW_SYSTEM_SHUTDOWN:
257		handle_system_shutdown(modifier);
258		break;
259
260	case EPOW_SYSTEM_HALT:
261		pr_emerg("Critical power/cooling issue detected. Check RTAS"
262			 " error log for details. Powering off.\n");
263		orderly_poweroff(true);
264		break;
265
266	case EPOW_MAIN_ENCLOSURE:
267	case EPOW_POWER_OFF:
268		pr_emerg("System about to lose power. Check RTAS error log "
269			 " for details. Powering off immediately.\n");
270		emergency_sync();
271		kernel_power_off();
272		break;
273
274	default:
275		pr_err("Unknown power/cooling event (action code  = %d)\n",
276			action_code);
277	}
278
279	/* Increment epow events counter variable */
280	if (action_code != EPOW_RESET)
281		num_epow_events++;
282}
283
284static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id)
285{
286	struct pseries_errorlog *pseries_log;
287	struct pseries_hp_errorlog *hp_elog;
288
289	spin_lock(&ras_log_buf_lock);
290
291	rtas_call(ras_check_exception_token, 6, 1, NULL,
292		  RTAS_VECTOR_EXTERNAL_INTERRUPT, virq_to_hw(irq),
293		  RTAS_HOTPLUG_EVENTS, 0, __pa(&ras_log_buf),
294		  rtas_get_error_log_max());
295
296	pseries_log = get_pseries_errorlog((struct rtas_error_log *)ras_log_buf,
297					   PSERIES_ELOG_SECT_ID_HOTPLUG);
298	hp_elog = (struct pseries_hp_errorlog *)pseries_log->data;
299
300	/*
301	 * Since PCI hotplug is not currently supported on pseries, put PCI
302	 * hotplug events on the ras_log_buf to be handled by rtas_errd.
303	 */
304	if (hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_MEM ||
305	    hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_CPU ||
306	    hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_PMEM)
307		queue_hotplug_event(hp_elog);
308	else
309		log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
310
311	spin_unlock(&ras_log_buf_lock);
312	return IRQ_HANDLED;
313}
314
315/* Handle environmental and power warning (EPOW) interrupts. */
316static irqreturn_t ras_epow_interrupt(int irq, void *dev_id)
317{
318	int status;
319	int state;
320	int critical;
321
322	status = rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX,
323				      &state);
324
325	if (state > 3)
326		critical = 1;		/* Time Critical */
327	else
328		critical = 0;
329
330	spin_lock(&ras_log_buf_lock);
331
332	status = rtas_call(ras_check_exception_token, 6, 1, NULL,
333			   RTAS_VECTOR_EXTERNAL_INTERRUPT,
334			   virq_to_hw(irq),
335			   RTAS_EPOW_WARNING,
336			   critical, __pa(&ras_log_buf),
337				rtas_get_error_log_max());
338
339	log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
340
341	rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf);
342
343	spin_unlock(&ras_log_buf_lock);
344	return IRQ_HANDLED;
345}
346
347/*
348 * Handle hardware error interrupts.
349 *
350 * RTAS check-exception is called to collect data on the exception.  If
351 * the error is deemed recoverable, we log a warning and return.
352 * For nonrecoverable errors, an error is logged and we stop all processing
353 * as quickly as possible in order to prevent propagation of the failure.
354 */
355static irqreturn_t ras_error_interrupt(int irq, void *dev_id)
356{
357	struct rtas_error_log *rtas_elog;
358	int status;
359	int fatal;
360
361	spin_lock(&ras_log_buf_lock);
362
363	status = rtas_call(ras_check_exception_token, 6, 1, NULL,
364			   RTAS_VECTOR_EXTERNAL_INTERRUPT,
365			   virq_to_hw(irq),
366			   RTAS_INTERNAL_ERROR, 1 /* Time Critical */,
367			   __pa(&ras_log_buf),
368				rtas_get_error_log_max());
369
370	rtas_elog = (struct rtas_error_log *)ras_log_buf;
371
372	if (status == 0 &&
373	    rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC)
374		fatal = 1;
375	else
376		fatal = 0;
377
378	/* format and print the extended information */
379	log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal);
380
381	if (fatal) {
382		pr_emerg("Fatal hardware error detected. Check RTAS error"
383			 " log for details. Powering off immediately\n");
384		emergency_sync();
385		kernel_power_off();
386	} else {
387		pr_err("Recoverable hardware error detected\n");
388	}
389
390	spin_unlock(&ras_log_buf_lock);
391	return IRQ_HANDLED;
392}
393
394/*
395 * Some versions of FWNMI place the buffer inside the 4kB page starting at
396 * 0x7000. Other versions place it inside the rtas buffer. We check both.
397 * Minimum size of the buffer is 16 bytes.
398 */
399#define VALID_FWNMI_BUFFER(A) \
400	((((A) >= 0x7000) && ((A) <= 0x8000 - 16)) || \
401	(((A) >= rtas.base) && ((A) <= (rtas.base + rtas.size - 16))))
402
403static inline struct rtas_error_log *fwnmi_get_errlog(void)
404{
405	return (struct rtas_error_log *)local_paca->mce_data_buf;
406}
407
408static __be64 *fwnmi_get_savep(struct pt_regs *regs)
409{
410	unsigned long savep_ra;
411
412	/* Mask top two bits */
413	savep_ra = regs->gpr[3] & ~(0x3UL << 62);
414	if (!VALID_FWNMI_BUFFER(savep_ra)) {
415		printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]);
416		return NULL;
417	}
418
419	return __va(savep_ra);
420}
421
422/*
423 * Get the error information for errors coming through the
424 * FWNMI vectors.  The pt_regs' r3 will be updated to reflect
425 * the actual r3 if possible, and a ptr to the error log entry
426 * will be returned if found.
427 *
428 * Use one buffer mce_data_buf per cpu to store RTAS error.
429 *
430 * The mce_data_buf does not have any locks or protection around it,
431 * if a second machine check comes in, or a system reset is done
432 * before we have logged the error, then we will get corruption in the
433 * error log.  This is preferable over holding off on calling
434 * ibm,nmi-interlock which would result in us checkstopping if a
435 * second machine check did come in.
436 */
437static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
438{
439	struct rtas_error_log *h;
440	__be64 *savep;
441
442	savep = fwnmi_get_savep(regs);
443	if (!savep)
444		return NULL;
445
446	regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */
447
448	h = (struct rtas_error_log *)&savep[1];
449	/* Use the per cpu buffer from paca to store rtas error log */
450	memset(local_paca->mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
451	if (!rtas_error_extended(h)) {
452		memcpy(local_paca->mce_data_buf, h, sizeof(__u64));
453	} else {
454		int len, error_log_length;
455
456		error_log_length = 8 + rtas_error_extended_log_length(h);
457		len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX);
458		memcpy(local_paca->mce_data_buf, h, len);
459	}
460
461	return (struct rtas_error_log *)local_paca->mce_data_buf;
462}
463
464/* Call this when done with the data returned by FWNMI_get_errinfo.
465 * It will release the saved data area for other CPUs in the
466 * partition to receive FWNMI errors.
467 */
468static void fwnmi_release_errinfo(void)
469{
470	struct rtas_args rtas_args;
471	int ret;
472
473	/*
474	 * On pseries, the machine check stack is limited to under 4GB, so
475	 * args can be on-stack.
476	 */
477	rtas_call_unlocked(&rtas_args, ibm_nmi_interlock_token, 0, 1, NULL);
478	ret = be32_to_cpu(rtas_args.rets[0]);
479	if (ret != 0)
480		printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret);
481}
482
483int pSeries_system_reset_exception(struct pt_regs *regs)
484{
485#ifdef __LITTLE_ENDIAN__
486	/*
487	 * Some firmware byteswaps SRR registers and gives incorrect SRR1. Try
488	 * to detect the bad SRR1 pattern here. Flip the NIP back to correct
489	 * endian for reporting purposes. Unfortunately the MSR can't be fixed,
490	 * so clear it. It will be missing MSR_RI so we won't try to recover.
491	 */
492	if ((be64_to_cpu(regs->msr) &
493			(MSR_LE|MSR_RI|MSR_DR|MSR_IR|MSR_ME|MSR_PR|
494			 MSR_ILE|MSR_HV|MSR_SF)) == (MSR_DR|MSR_SF)) {
495		regs->nip = be64_to_cpu((__be64)regs->nip);
496		regs->msr = 0;
497	}
498#endif
499
500	if (fwnmi_active) {
501		__be64 *savep;
502
503		/*
504		 * Firmware (PowerVM and KVM) saves r3 to a save area like
505		 * machine check, which is not exactly what PAPR (2.9)
506		 * suggests but there is no way to detect otherwise, so this
507		 * is the interface now.
508		 *
509		 * System resets do not save any error log or require an
510		 * "ibm,nmi-interlock" rtas call to release.
511		 */
512
513		savep = fwnmi_get_savep(regs);
514		if (savep)
515			regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */
516	}
517
518	if (smp_handle_nmi_ipi(regs))
519		return 1;
520
521	return 0; /* need to perform reset */
522}
523
524static int mce_handle_err_realmode(int disposition, u8 error_type)
525{
526#ifdef CONFIG_PPC_BOOK3S_64
527	if (disposition == RTAS_DISP_NOT_RECOVERED) {
528		switch (error_type) {
529		case	MC_ERROR_TYPE_SLB:
530		case	MC_ERROR_TYPE_ERAT:
531			/*
532			 * Store the old slb content in paca before flushing.
533			 * Print this when we go to virtual mode.
534			 * There are chances that we may hit MCE again if there
535			 * is a parity error on the SLB entry we trying to read
536			 * for saving. Hence limit the slb saving to single
537			 * level of recursion.
538			 */
539			if (local_paca->in_mce == 1)
540				slb_save_contents(local_paca->mce_faulty_slbs);
541			flush_and_reload_slb();
542			disposition = RTAS_DISP_FULLY_RECOVERED;
543			break;
544		default:
545			break;
546		}
547	} else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
548		/* Platform corrected itself but could be degraded */
549		pr_err("MCE: limited recovery, system may be degraded\n");
550		disposition = RTAS_DISP_FULLY_RECOVERED;
551	}
552#endif
553	return disposition;
554}
555
556static int mce_handle_err_virtmode(struct pt_regs *regs,
557				   struct rtas_error_log *errp,
558				   struct pseries_mc_errorlog *mce_log,
559				   int disposition)
560{
561	struct mce_error_info mce_err = { 0 };
562	int initiator = rtas_error_initiator(errp);
563	int severity = rtas_error_severity(errp);
564	unsigned long eaddr = 0, paddr = 0;
565	u8 error_type, err_sub_type;
566
567	if (!mce_log)
568		goto out;
569
570	error_type = mce_log->error_type;
571	err_sub_type = rtas_mc_error_sub_type(mce_log);
572
573	if (initiator == RTAS_INITIATOR_UNKNOWN)
574		mce_err.initiator = MCE_INITIATOR_UNKNOWN;
575	else if (initiator == RTAS_INITIATOR_CPU)
576		mce_err.initiator = MCE_INITIATOR_CPU;
577	else if (initiator == RTAS_INITIATOR_PCI)
578		mce_err.initiator = MCE_INITIATOR_PCI;
579	else if (initiator == RTAS_INITIATOR_ISA)
580		mce_err.initiator = MCE_INITIATOR_ISA;
581	else if (initiator == RTAS_INITIATOR_MEMORY)
582		mce_err.initiator = MCE_INITIATOR_MEMORY;
583	else if (initiator == RTAS_INITIATOR_POWERMGM)
584		mce_err.initiator = MCE_INITIATOR_POWERMGM;
585	else
586		mce_err.initiator = MCE_INITIATOR_UNKNOWN;
587
588	if (severity == RTAS_SEVERITY_NO_ERROR)
589		mce_err.severity = MCE_SEV_NO_ERROR;
590	else if (severity == RTAS_SEVERITY_EVENT)
591		mce_err.severity = MCE_SEV_WARNING;
592	else if (severity == RTAS_SEVERITY_WARNING)
593		mce_err.severity = MCE_SEV_WARNING;
594	else if (severity == RTAS_SEVERITY_ERROR_SYNC)
595		mce_err.severity = MCE_SEV_SEVERE;
596	else if (severity == RTAS_SEVERITY_ERROR)
597		mce_err.severity = MCE_SEV_SEVERE;
598	else if (severity == RTAS_SEVERITY_FATAL)
599		mce_err.severity = MCE_SEV_FATAL;
600	else
601		mce_err.severity = MCE_SEV_FATAL;
602
603	if (severity <= RTAS_SEVERITY_ERROR_SYNC)
604		mce_err.sync_error = true;
605	else
606		mce_err.sync_error = false;
607
608	mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN;
609	mce_err.error_class = MCE_ECLASS_UNKNOWN;
610
611	switch (error_type) {
612	case MC_ERROR_TYPE_UE:
613		mce_err.error_type = MCE_ERROR_TYPE_UE;
614		mce_common_process_ue(regs, &mce_err);
615		if (mce_err.ignore_event)
616			disposition = RTAS_DISP_FULLY_RECOVERED;
617		switch (err_sub_type) {
618		case MC_ERROR_UE_IFETCH:
619			mce_err.u.ue_error_type = MCE_UE_ERROR_IFETCH;
620			break;
621		case MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH:
622			mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH;
623			break;
624		case MC_ERROR_UE_LOAD_STORE:
625			mce_err.u.ue_error_type = MCE_UE_ERROR_LOAD_STORE;
626			break;
627		case MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE:
628			mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE;
629			break;
630		case MC_ERROR_UE_INDETERMINATE:
631		default:
632			mce_err.u.ue_error_type = MCE_UE_ERROR_INDETERMINATE;
633			break;
634		}
635		if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED)
636			eaddr = be64_to_cpu(mce_log->effective_address);
637
638		if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) {
639			paddr = be64_to_cpu(mce_log->logical_address);
640		} else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) {
641			unsigned long pfn;
642
643			pfn = addr_to_pfn(regs, eaddr);
644			if (pfn != ULONG_MAX)
645				paddr = pfn << PAGE_SHIFT;
646		}
647
648		break;
649	case MC_ERROR_TYPE_SLB:
650		mce_err.error_type = MCE_ERROR_TYPE_SLB;
651		switch (err_sub_type) {
652		case MC_ERROR_SLB_PARITY:
653			mce_err.u.slb_error_type = MCE_SLB_ERROR_PARITY;
654			break;
655		case MC_ERROR_SLB_MULTIHIT:
656			mce_err.u.slb_error_type = MCE_SLB_ERROR_MULTIHIT;
657			break;
658		case MC_ERROR_SLB_INDETERMINATE:
659		default:
660			mce_err.u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE;
661			break;
662		}
663		if (mce_log->sub_err_type & 0x80)
664			eaddr = be64_to_cpu(mce_log->effective_address);
665		break;
666	case MC_ERROR_TYPE_ERAT:
667		mce_err.error_type = MCE_ERROR_TYPE_ERAT;
668		switch (err_sub_type) {
669		case MC_ERROR_ERAT_PARITY:
670			mce_err.u.erat_error_type = MCE_ERAT_ERROR_PARITY;
671			break;
672		case MC_ERROR_ERAT_MULTIHIT:
673			mce_err.u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
674			break;
675		case MC_ERROR_ERAT_INDETERMINATE:
676		default:
677			mce_err.u.erat_error_type = MCE_ERAT_ERROR_INDETERMINATE;
678			break;
679		}
680		if (mce_log->sub_err_type & 0x80)
681			eaddr = be64_to_cpu(mce_log->effective_address);
682		break;
683	case MC_ERROR_TYPE_TLB:
684		mce_err.error_type = MCE_ERROR_TYPE_TLB;
685		switch (err_sub_type) {
686		case MC_ERROR_TLB_PARITY:
687			mce_err.u.tlb_error_type = MCE_TLB_ERROR_PARITY;
688			break;
689		case MC_ERROR_TLB_MULTIHIT:
690			mce_err.u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT;
691			break;
692		case MC_ERROR_TLB_INDETERMINATE:
693		default:
694			mce_err.u.tlb_error_type = MCE_TLB_ERROR_INDETERMINATE;
695			break;
696		}
697		if (mce_log->sub_err_type & 0x80)
698			eaddr = be64_to_cpu(mce_log->effective_address);
699		break;
700	case MC_ERROR_TYPE_D_CACHE:
701		mce_err.error_type = MCE_ERROR_TYPE_DCACHE;
702		break;
703	case MC_ERROR_TYPE_I_CACHE:
704		mce_err.error_type = MCE_ERROR_TYPE_DCACHE;
705		break;
706	case MC_ERROR_TYPE_UNKNOWN:
707	default:
708		mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN;
709		break;
710	}
711out:
712	save_mce_event(regs, disposition == RTAS_DISP_FULLY_RECOVERED,
713		       &mce_err, regs->nip, eaddr, paddr);
714	return disposition;
715}
716
717static int mce_handle_error(struct pt_regs *regs, struct rtas_error_log *errp)
718{
719	struct pseries_errorlog *pseries_log;
720	struct pseries_mc_errorlog *mce_log = NULL;
721	int disposition = rtas_error_disposition(errp);
722	u8 error_type;
723
724	if (!rtas_error_extended(errp))
725		goto out;
726
727	pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);
728	if (!pseries_log)
729		goto out;
730
731	mce_log = (struct pseries_mc_errorlog *)pseries_log->data;
732	error_type = mce_log->error_type;
733
734	disposition = mce_handle_err_realmode(disposition, error_type);
735
736	/*
737	 * Enable translation as we will be accessing per-cpu variables
738	 * in save_mce_event() which may fall outside RMO region, also
739	 * leave it enabled because subsequently we will be queuing work
740	 * to workqueues where again per-cpu variables accessed, besides
741	 * fwnmi_release_errinfo() crashes when called in realmode on
742	 * pseries.
743	 * Note: All the realmode handling like flushing SLB entries for
744	 *       SLB multihit is done by now.
745	 */
746out:
747	mtmsr(mfmsr() | MSR_IR | MSR_DR);
748	disposition = mce_handle_err_virtmode(regs, errp, mce_log,
749					      disposition);
750	return disposition;
751}
752
753/*
754 * Process MCE rtas errlog event.
755 */
756static void mce_process_errlog_event(struct irq_work *work)
757{
758	struct rtas_error_log *err;
759
760	err = fwnmi_get_errlog();
761	log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);
762}
763
764/*
765 * See if we can recover from a machine check exception.
766 * This is only called on power4 (or above) and only via
767 * the Firmware Non-Maskable Interrupts (fwnmi) handler
768 * which provides the error analysis for us.
769 *
770 * Return 1 if corrected (or delivered a signal).
771 * Return 0 if there is nothing we can do.
772 */
773static int recover_mce(struct pt_regs *regs, struct machine_check_event *evt)
774{
775	int recovered = 0;
776
777	if (!(regs->msr & MSR_RI)) {
778		/* If MSR_RI isn't set, we cannot recover */
779		pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n");
780		recovered = 0;
781	} else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
782		/* Platform corrected itself */
783		recovered = 1;
784	} else if (evt->severity == MCE_SEV_FATAL) {
785		/* Fatal machine check */
786		pr_err("Machine check interrupt is fatal\n");
787		recovered = 0;
788	}
789
790	if (!recovered && evt->sync_error) {
791		/*
792		 * Try to kill processes if we get a synchronous machine check
793		 * (e.g., one caused by execution of this instruction). This
794		 * will devolve into a panic if we try to kill init or are in
795		 * an interrupt etc.
796		 *
797		 * TODO: Queue up this address for hwpoisioning later.
798		 * TODO: This is not quite right for d-side machine
799		 *       checks ->nip is not necessarily the important
800		 *       address.
801		 */
802		if ((user_mode(regs))) {
803			_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
804			recovered = 1;
805		} else if (die_will_crash()) {
806			/*
807			 * die() would kill the kernel, so better to go via
808			 * the platform reboot code that will log the
809			 * machine check.
810			 */
811			recovered = 0;
812		} else {
813			die("Machine check", regs, SIGBUS);
814			recovered = 1;
815		}
816	}
817
818	return recovered;
819}
820
821/*
822 * Handle a machine check.
823 *
824 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi)
825 * should be present.  If so the handler which called us tells us if the
826 * error was recovered (never true if RI=0).
827 *
828 * On hardware prior to Power 4 these exceptions were asynchronous which
829 * means we can't tell exactly where it occurred and so we can't recover.
830 */
831int pSeries_machine_check_exception(struct pt_regs *regs)
832{
833	struct machine_check_event evt;
834
835	if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
836		return 0;
837
838	/* Print things out */
839	if (evt.version != MCE_V1) {
840		pr_err("Machine Check Exception, Unknown event version %d !\n",
841		       evt.version);
842		return 0;
843	}
844	machine_check_print_event_info(&evt, user_mode(regs), false);
845
846	if (recover_mce(regs, &evt))
847		return 1;
848
849	return 0;
850}
851
852long pseries_machine_check_realmode(struct pt_regs *regs)
853{
854	struct rtas_error_log *errp;
855	int disposition;
856
857	if (fwnmi_active) {
858		errp = fwnmi_get_errinfo(regs);
859		/*
860		 * Call to fwnmi_release_errinfo() in real mode causes kernel
861		 * to panic. Hence we will call it as soon as we go into
862		 * virtual mode.
863		 */
864		disposition = mce_handle_error(regs, errp);
865		fwnmi_release_errinfo();
866
867		/* Queue irq work to log this rtas event later. */
868		irq_work_queue(&mce_errlog_process_work);
869
870		if (disposition == RTAS_DISP_FULLY_RECOVERED)
871			return 1;
872	}
873
874	return 0;
875}
876