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 
21 static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX];
22 static DEFINE_SPINLOCK(ras_log_buf_lock);
23 
24 static int ras_check_exception_token;
25 
26 #define EPOW_SENSOR_TOKEN	9
27 #define EPOW_SENSOR_INDEX	0
28 
29 /* EPOW events counter variable */
30 static int num_epow_events;
31 
32 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id);
33 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id);
34 static irqreturn_t ras_error_interrupt(int irq, void *dev_id);
35 
36 /* RTAS pseries MCE errorlog section. */
37 struct pseries_mc_errorlog {
38 	__be32	fru_id;
39 	__be32	proc_id;
40 	u8	error_type;
41 	/*
42 	 * sub_err_type (1 byte). Bit fields depends on error_type
43 	 *
44 	 *   MSB0
45 	 *   |
46 	 *   V
47 	 *   01234567
48 	 *   XXXXXXXX
49 	 *
50 	 * For error_type == MC_ERROR_TYPE_UE
51 	 *   XXXXXXXX
52 	 *   X		1: Permanent or Transient UE.
53 	 *    X		1: Effective address provided.
54 	 *     X	1: Logical address provided.
55 	 *      XX	2: Reserved.
56 	 *        XXX	3: Type of UE error.
57 	 *
58 	 * For error_type == MC_ERROR_TYPE_SLB/ERAT/TLB
59 	 *   XXXXXXXX
60 	 *   X		1: Effective address provided.
61 	 *    XXXXX	5: Reserved.
62 	 *         XX	2: Type of SLB/ERAT/TLB error.
63 	 *
64 	 * For error_type == MC_ERROR_TYPE_CTRL_MEM_ACCESS
65 	 *   XXXXXXXX
66 	 *   X		1: Error causing address provided.
67 	 *    XXX	3: Type of error.
68 	 *       XXXX	4: Reserved.
69 	 */
70 	u8	sub_err_type;
71 	u8	reserved_1[6];
72 	__be64	effective_address;
73 	__be64	logical_address;
74 } __packed;
75 
76 /* RTAS pseries MCE error types */
77 #define MC_ERROR_TYPE_UE		0x00
78 #define MC_ERROR_TYPE_SLB		0x01
79 #define MC_ERROR_TYPE_ERAT		0x02
80 #define MC_ERROR_TYPE_UNKNOWN		0x03
81 #define MC_ERROR_TYPE_TLB		0x04
82 #define MC_ERROR_TYPE_D_CACHE		0x05
83 #define MC_ERROR_TYPE_I_CACHE		0x07
84 #define MC_ERROR_TYPE_CTRL_MEM_ACCESS	0x08
85 
86 /* RTAS pseries MCE error sub types */
87 #define MC_ERROR_UE_INDETERMINATE		0
88 #define MC_ERROR_UE_IFETCH			1
89 #define MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH	2
90 #define MC_ERROR_UE_LOAD_STORE			3
91 #define MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE	4
92 
93 #define UE_EFFECTIVE_ADDR_PROVIDED		0x40
94 #define UE_LOGICAL_ADDR_PROVIDED		0x20
95 #define MC_EFFECTIVE_ADDR_PROVIDED		0x80
96 
97 #define MC_ERROR_SLB_PARITY		0
98 #define MC_ERROR_SLB_MULTIHIT		1
99 #define MC_ERROR_SLB_INDETERMINATE	2
100 
101 #define MC_ERROR_ERAT_PARITY		1
102 #define MC_ERROR_ERAT_MULTIHIT		2
103 #define MC_ERROR_ERAT_INDETERMINATE	3
104 
105 #define MC_ERROR_TLB_PARITY		1
106 #define MC_ERROR_TLB_MULTIHIT		2
107 #define MC_ERROR_TLB_INDETERMINATE	3
108 
109 #define MC_ERROR_CTRL_MEM_ACCESS_PTABLE_WALK	0
110 #define MC_ERROR_CTRL_MEM_ACCESS_OP_ACCESS	1
111 
rtas_mc_error_sub_type(const struct pseries_mc_errorlog * mlog)112 static inline u8 rtas_mc_error_sub_type(const struct pseries_mc_errorlog *mlog)
113 {
114 	switch (mlog->error_type) {
115 	case	MC_ERROR_TYPE_UE:
116 		return (mlog->sub_err_type & 0x07);
117 	case	MC_ERROR_TYPE_SLB:
118 	case	MC_ERROR_TYPE_ERAT:
119 	case	MC_ERROR_TYPE_TLB:
120 		return (mlog->sub_err_type & 0x03);
121 	case	MC_ERROR_TYPE_CTRL_MEM_ACCESS:
122 		return (mlog->sub_err_type & 0x70) >> 4;
123 	default:
124 		return 0;
125 	}
126 }
127 
128 /*
129  * Enable the hotplug interrupt late because processing them may touch other
130  * devices or systems (e.g. hugepages) that have not been initialized at the
131  * subsys stage.
132  */
init_ras_hotplug_IRQ(void)133 static int __init init_ras_hotplug_IRQ(void)
134 {
135 	struct device_node *np;
136 
137 	/* Hotplug Events */
138 	np = of_find_node_by_path("/event-sources/hot-plug-events");
139 	if (np != NULL) {
140 		if (dlpar_workqueue_init() == 0)
141 			request_event_sources_irqs(np, ras_hotplug_interrupt,
142 						   "RAS_HOTPLUG");
143 		of_node_put(np);
144 	}
145 
146 	return 0;
147 }
148 machine_late_initcall(pseries, init_ras_hotplug_IRQ);
149 
150 /*
151  * Initialize handlers for the set of interrupts caused by hardware errors
152  * and power system events.
153  */
init_ras_IRQ(void)154 static int __init init_ras_IRQ(void)
155 {
156 	struct device_node *np;
157 
158 	ras_check_exception_token = rtas_function_token(RTAS_FN_CHECK_EXCEPTION);
159 
160 	/* Internal Errors */
161 	np = of_find_node_by_path("/event-sources/internal-errors");
162 	if (np != NULL) {
163 		request_event_sources_irqs(np, ras_error_interrupt,
164 					   "RAS_ERROR");
165 		of_node_put(np);
166 	}
167 
168 	/* EPOW Events */
169 	np = of_find_node_by_path("/event-sources/epow-events");
170 	if (np != NULL) {
171 		request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW");
172 		of_node_put(np);
173 	}
174 
175 	return 0;
176 }
177 machine_subsys_initcall(pseries, init_ras_IRQ);
178 
179 #define EPOW_SHUTDOWN_NORMAL				1
180 #define EPOW_SHUTDOWN_ON_UPS				2
181 #define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS	3
182 #define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH	4
183 
handle_system_shutdown(char event_modifier)184 static void handle_system_shutdown(char event_modifier)
185 {
186 	switch (event_modifier) {
187 	case EPOW_SHUTDOWN_NORMAL:
188 		pr_emerg("Power off requested\n");
189 		orderly_poweroff(true);
190 		break;
191 
192 	case EPOW_SHUTDOWN_ON_UPS:
193 		pr_emerg("Loss of system power detected. System is running on"
194 			 " UPS/battery. Check RTAS error log for details\n");
195 		break;
196 
197 	case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
198 		pr_emerg("Loss of system critical functions detected. Check"
199 			 " RTAS error log for details\n");
200 		orderly_poweroff(true);
201 		break;
202 
203 	case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH:
204 		pr_emerg("High ambient temperature detected. Check RTAS"
205 			 " error log for details\n");
206 		orderly_poweroff(true);
207 		break;
208 
209 	default:
210 		pr_err("Unknown power/cooling shutdown event (modifier = %d)\n",
211 			event_modifier);
212 	}
213 }
214 
215 struct epow_errorlog {
216 	unsigned char sensor_value;
217 	unsigned char event_modifier;
218 	unsigned char extended_modifier;
219 	unsigned char reserved;
220 	unsigned char platform_reason;
221 };
222 
223 #define EPOW_RESET			0
224 #define EPOW_WARN_COOLING		1
225 #define EPOW_WARN_POWER			2
226 #define EPOW_SYSTEM_SHUTDOWN		3
227 #define EPOW_SYSTEM_HALT		4
228 #define EPOW_MAIN_ENCLOSURE		5
229 #define EPOW_POWER_OFF			7
230 
rtas_parse_epow_errlog(struct rtas_error_log * log)231 static void rtas_parse_epow_errlog(struct rtas_error_log *log)
232 {
233 	struct pseries_errorlog *pseries_log;
234 	struct epow_errorlog *epow_log;
235 	char action_code;
236 	char modifier;
237 
238 	pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW);
239 	if (pseries_log == NULL)
240 		return;
241 
242 	epow_log = (struct epow_errorlog *)pseries_log->data;
243 	action_code = epow_log->sensor_value & 0xF;	/* bottom 4 bits */
244 	modifier = epow_log->event_modifier & 0xF;	/* bottom 4 bits */
245 
246 	switch (action_code) {
247 	case EPOW_RESET:
248 		if (num_epow_events) {
249 			pr_info("Non critical power/cooling issue cleared\n");
250 			num_epow_events--;
251 		}
252 		break;
253 
254 	case EPOW_WARN_COOLING:
255 		pr_info("Non-critical cooling issue detected. Check RTAS error"
256 			" log for details\n");
257 		break;
258 
259 	case EPOW_WARN_POWER:
260 		pr_info("Non-critical power issue detected. Check RTAS error"
261 			" log for details\n");
262 		break;
263 
264 	case EPOW_SYSTEM_SHUTDOWN:
265 		handle_system_shutdown(modifier);
266 		break;
267 
268 	case EPOW_SYSTEM_HALT:
269 		pr_emerg("Critical power/cooling issue detected. Check RTAS"
270 			 " error log for details. Powering off.\n");
271 		orderly_poweroff(true);
272 		break;
273 
274 	case EPOW_MAIN_ENCLOSURE:
275 	case EPOW_POWER_OFF:
276 		pr_emerg("System about to lose power. Check RTAS error log "
277 			 " for details. Powering off immediately.\n");
278 		emergency_sync();
279 		kernel_power_off();
280 		break;
281 
282 	default:
283 		pr_err("Unknown power/cooling event (action code  = %d)\n",
284 			action_code);
285 	}
286 
287 	/* Increment epow events counter variable */
288 	if (action_code != EPOW_RESET)
289 		num_epow_events++;
290 }
291 
ras_hotplug_interrupt(int irq,void * dev_id)292 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id)
293 {
294 	struct pseries_errorlog *pseries_log;
295 	struct pseries_hp_errorlog *hp_elog;
296 
297 	spin_lock(&ras_log_buf_lock);
298 
299 	rtas_call(ras_check_exception_token, 6, 1, NULL,
300 		  RTAS_VECTOR_EXTERNAL_INTERRUPT, virq_to_hw(irq),
301 		  RTAS_HOTPLUG_EVENTS, 0, __pa(&ras_log_buf),
302 		  rtas_get_error_log_max());
303 
304 	pseries_log = get_pseries_errorlog((struct rtas_error_log *)ras_log_buf,
305 					   PSERIES_ELOG_SECT_ID_HOTPLUG);
306 	hp_elog = (struct pseries_hp_errorlog *)pseries_log->data;
307 
308 	/*
309 	 * Since PCI hotplug is not currently supported on pseries, put PCI
310 	 * hotplug events on the ras_log_buf to be handled by rtas_errd.
311 	 */
312 	if (hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_MEM ||
313 	    hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_CPU ||
314 	    hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_PMEM)
315 		queue_hotplug_event(hp_elog);
316 	else
317 		log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
318 
319 	spin_unlock(&ras_log_buf_lock);
320 	return IRQ_HANDLED;
321 }
322 
323 /* Handle environmental and power warning (EPOW) interrupts. */
ras_epow_interrupt(int irq,void * dev_id)324 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id)
325 {
326 	int state;
327 	int critical;
328 
329 	rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX, &state);
330 
331 	if (state > 3)
332 		critical = 1;		/* Time Critical */
333 	else
334 		critical = 0;
335 
336 	spin_lock(&ras_log_buf_lock);
337 
338 	rtas_call(ras_check_exception_token, 6, 1, NULL, RTAS_VECTOR_EXTERNAL_INTERRUPT,
339 		  virq_to_hw(irq), RTAS_EPOW_WARNING, critical, __pa(&ras_log_buf),
340 		  rtas_get_error_log_max());
341 
342 	log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
343 
344 	rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf);
345 
346 	spin_unlock(&ras_log_buf_lock);
347 	return IRQ_HANDLED;
348 }
349 
350 /*
351  * Handle hardware error interrupts.
352  *
353  * RTAS check-exception is called to collect data on the exception.  If
354  * the error is deemed recoverable, we log a warning and return.
355  * For nonrecoverable errors, an error is logged and we stop all processing
356  * as quickly as possible in order to prevent propagation of the failure.
357  */
ras_error_interrupt(int irq,void * dev_id)358 static irqreturn_t ras_error_interrupt(int irq, void *dev_id)
359 {
360 	struct rtas_error_log *rtas_elog;
361 	int status;
362 	int fatal;
363 
364 	spin_lock(&ras_log_buf_lock);
365 
366 	status = rtas_call(ras_check_exception_token, 6, 1, NULL,
367 			   RTAS_VECTOR_EXTERNAL_INTERRUPT,
368 			   virq_to_hw(irq),
369 			   RTAS_INTERNAL_ERROR, 1 /* Time Critical */,
370 			   __pa(&ras_log_buf),
371 				rtas_get_error_log_max());
372 
373 	rtas_elog = (struct rtas_error_log *)ras_log_buf;
374 
375 	if (status == 0 &&
376 	    rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC)
377 		fatal = 1;
378 	else
379 		fatal = 0;
380 
381 	/* format and print the extended information */
382 	log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal);
383 
384 	if (fatal) {
385 		pr_emerg("Fatal hardware error detected. Check RTAS error"
386 			 " log for details. Powering off immediately\n");
387 		emergency_sync();
388 		kernel_power_off();
389 	} else {
390 		pr_err("Recoverable hardware error detected\n");
391 	}
392 
393 	spin_unlock(&ras_log_buf_lock);
394 	return IRQ_HANDLED;
395 }
396 
397 /*
398  * Some versions of FWNMI place the buffer inside the 4kB page starting at
399  * 0x7000. Other versions place it inside the rtas buffer. We check both.
400  * Minimum size of the buffer is 16 bytes.
401  */
402 #define VALID_FWNMI_BUFFER(A) \
403 	((((A) >= 0x7000) && ((A) <= 0x8000 - 16)) || \
404 	(((A) >= rtas.base) && ((A) <= (rtas.base + rtas.size - 16))))
405 
fwnmi_get_errlog(void)406 static inline struct rtas_error_log *fwnmi_get_errlog(void)
407 {
408 	return (struct rtas_error_log *)local_paca->mce_data_buf;
409 }
410 
fwnmi_get_savep(struct pt_regs * regs)411 static __be64 *fwnmi_get_savep(struct pt_regs *regs)
412 {
413 	unsigned long savep_ra;
414 
415 	/* Mask top two bits */
416 	savep_ra = regs->gpr[3] & ~(0x3UL << 62);
417 	if (!VALID_FWNMI_BUFFER(savep_ra)) {
418 		printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]);
419 		return NULL;
420 	}
421 
422 	return __va(savep_ra);
423 }
424 
425 /*
426  * Get the error information for errors coming through the
427  * FWNMI vectors.  The pt_regs' r3 will be updated to reflect
428  * the actual r3 if possible, and a ptr to the error log entry
429  * will be returned if found.
430  *
431  * Use one buffer mce_data_buf per cpu to store RTAS error.
432  *
433  * The mce_data_buf does not have any locks or protection around it,
434  * if a second machine check comes in, or a system reset is done
435  * before we have logged the error, then we will get corruption in the
436  * error log.  This is preferable over holding off on calling
437  * ibm,nmi-interlock which would result in us checkstopping if a
438  * second machine check did come in.
439  */
fwnmi_get_errinfo(struct pt_regs * regs)440 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
441 {
442 	struct rtas_error_log *h;
443 	__be64 *savep;
444 
445 	savep = fwnmi_get_savep(regs);
446 	if (!savep)
447 		return NULL;
448 
449 	regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */
450 
451 	h = (struct rtas_error_log *)&savep[1];
452 	/* Use the per cpu buffer from paca to store rtas error log */
453 	memset(local_paca->mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
454 	if (!rtas_error_extended(h)) {
455 		memcpy(local_paca->mce_data_buf, h, sizeof(__u64));
456 	} else {
457 		int len, error_log_length;
458 
459 		error_log_length = 8 + rtas_error_extended_log_length(h);
460 		len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX);
461 		memcpy(local_paca->mce_data_buf, h, len);
462 	}
463 
464 	return (struct rtas_error_log *)local_paca->mce_data_buf;
465 }
466 
467 /* Call this when done with the data returned by FWNMI_get_errinfo.
468  * It will release the saved data area for other CPUs in the
469  * partition to receive FWNMI errors.
470  */
fwnmi_release_errinfo(void)471 static void fwnmi_release_errinfo(void)
472 {
473 	struct rtas_args rtas_args;
474 	int ret;
475 
476 	/*
477 	 * On pseries, the machine check stack is limited to under 4GB, so
478 	 * args can be on-stack.
479 	 */
480 	rtas_call_unlocked(&rtas_args, ibm_nmi_interlock_token, 0, 1, NULL);
481 	ret = be32_to_cpu(rtas_args.rets[0]);
482 	if (ret != 0)
483 		printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret);
484 }
485 
pSeries_system_reset_exception(struct pt_regs * regs)486 int pSeries_system_reset_exception(struct pt_regs *regs)
487 {
488 #ifdef __LITTLE_ENDIAN__
489 	/*
490 	 * Some firmware byteswaps SRR registers and gives incorrect SRR1. Try
491 	 * to detect the bad SRR1 pattern here. Flip the NIP back to correct
492 	 * endian for reporting purposes. Unfortunately the MSR can't be fixed,
493 	 * so clear it. It will be missing MSR_RI so we won't try to recover.
494 	 */
495 	if ((be64_to_cpu(regs->msr) &
496 			(MSR_LE|MSR_RI|MSR_DR|MSR_IR|MSR_ME|MSR_PR|
497 			 MSR_ILE|MSR_HV|MSR_SF)) == (MSR_DR|MSR_SF)) {
498 		regs_set_return_ip(regs, be64_to_cpu((__be64)regs->nip));
499 		regs_set_return_msr(regs, 0);
500 	}
501 #endif
502 
503 	if (fwnmi_active) {
504 		__be64 *savep;
505 
506 		/*
507 		 * Firmware (PowerVM and KVM) saves r3 to a save area like
508 		 * machine check, which is not exactly what PAPR (2.9)
509 		 * suggests but there is no way to detect otherwise, so this
510 		 * is the interface now.
511 		 *
512 		 * System resets do not save any error log or require an
513 		 * "ibm,nmi-interlock" rtas call to release.
514 		 */
515 
516 		savep = fwnmi_get_savep(regs);
517 		if (savep)
518 			regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */
519 	}
520 
521 	if (smp_handle_nmi_ipi(regs))
522 		return 1;
523 
524 	return 0; /* need to perform reset */
525 }
526 
mce_handle_err_realmode(int disposition,u8 error_type)527 static int mce_handle_err_realmode(int disposition, u8 error_type)
528 {
529 #ifdef CONFIG_PPC_BOOK3S_64
530 	if (disposition == RTAS_DISP_NOT_RECOVERED) {
531 		switch (error_type) {
532 		case	MC_ERROR_TYPE_ERAT:
533 			flush_erat();
534 			disposition = RTAS_DISP_FULLY_RECOVERED;
535 			break;
536 		case	MC_ERROR_TYPE_SLB:
537 #ifdef CONFIG_PPC_64S_HASH_MMU
538 			/*
539 			 * Store the old slb content in paca before flushing.
540 			 * Print this when we go to virtual mode.
541 			 * There are chances that we may hit MCE again if there
542 			 * is a parity error on the SLB entry we trying to read
543 			 * for saving. Hence limit the slb saving to single
544 			 * level of recursion.
545 			 */
546 			if (local_paca->in_mce == 1)
547 				slb_save_contents(local_paca->mce_faulty_slbs);
548 			flush_and_reload_slb();
549 			disposition = RTAS_DISP_FULLY_RECOVERED;
550 #endif
551 			break;
552 		default:
553 			break;
554 		}
555 	} else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
556 		/* Platform corrected itself but could be degraded */
557 		pr_err("MCE: limited recovery, system may be degraded\n");
558 		disposition = RTAS_DISP_FULLY_RECOVERED;
559 	}
560 #endif
561 	return disposition;
562 }
563 
mce_handle_err_virtmode(struct pt_regs * regs,struct rtas_error_log * errp,struct pseries_mc_errorlog * mce_log,int disposition)564 static int mce_handle_err_virtmode(struct pt_regs *regs,
565 				   struct rtas_error_log *errp,
566 				   struct pseries_mc_errorlog *mce_log,
567 				   int disposition)
568 {
569 	struct mce_error_info mce_err = { 0 };
570 	int initiator = rtas_error_initiator(errp);
571 	int severity = rtas_error_severity(errp);
572 	unsigned long eaddr = 0, paddr = 0;
573 	u8 error_type, err_sub_type;
574 
575 	if (!mce_log)
576 		goto out;
577 
578 	error_type = mce_log->error_type;
579 	err_sub_type = rtas_mc_error_sub_type(mce_log);
580 
581 	if (initiator == RTAS_INITIATOR_UNKNOWN)
582 		mce_err.initiator = MCE_INITIATOR_UNKNOWN;
583 	else if (initiator == RTAS_INITIATOR_CPU)
584 		mce_err.initiator = MCE_INITIATOR_CPU;
585 	else if (initiator == RTAS_INITIATOR_PCI)
586 		mce_err.initiator = MCE_INITIATOR_PCI;
587 	else if (initiator == RTAS_INITIATOR_ISA)
588 		mce_err.initiator = MCE_INITIATOR_ISA;
589 	else if (initiator == RTAS_INITIATOR_MEMORY)
590 		mce_err.initiator = MCE_INITIATOR_MEMORY;
591 	else if (initiator == RTAS_INITIATOR_POWERMGM)
592 		mce_err.initiator = MCE_INITIATOR_POWERMGM;
593 	else
594 		mce_err.initiator = MCE_INITIATOR_UNKNOWN;
595 
596 	if (severity == RTAS_SEVERITY_NO_ERROR)
597 		mce_err.severity = MCE_SEV_NO_ERROR;
598 	else if (severity == RTAS_SEVERITY_EVENT)
599 		mce_err.severity = MCE_SEV_WARNING;
600 	else if (severity == RTAS_SEVERITY_WARNING)
601 		mce_err.severity = MCE_SEV_WARNING;
602 	else if (severity == RTAS_SEVERITY_ERROR_SYNC)
603 		mce_err.severity = MCE_SEV_SEVERE;
604 	else if (severity == RTAS_SEVERITY_ERROR)
605 		mce_err.severity = MCE_SEV_SEVERE;
606 	else
607 		mce_err.severity = MCE_SEV_FATAL;
608 
609 	if (severity <= RTAS_SEVERITY_ERROR_SYNC)
610 		mce_err.sync_error = true;
611 	else
612 		mce_err.sync_error = false;
613 
614 	mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN;
615 	mce_err.error_class = MCE_ECLASS_UNKNOWN;
616 
617 	switch (error_type) {
618 	case MC_ERROR_TYPE_UE:
619 		mce_err.error_type = MCE_ERROR_TYPE_UE;
620 		mce_common_process_ue(regs, &mce_err);
621 		if (mce_err.ignore_event)
622 			disposition = RTAS_DISP_FULLY_RECOVERED;
623 		switch (err_sub_type) {
624 		case MC_ERROR_UE_IFETCH:
625 			mce_err.u.ue_error_type = MCE_UE_ERROR_IFETCH;
626 			break;
627 		case MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH:
628 			mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH;
629 			break;
630 		case MC_ERROR_UE_LOAD_STORE:
631 			mce_err.u.ue_error_type = MCE_UE_ERROR_LOAD_STORE;
632 			break;
633 		case MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE:
634 			mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE;
635 			break;
636 		case MC_ERROR_UE_INDETERMINATE:
637 		default:
638 			mce_err.u.ue_error_type = MCE_UE_ERROR_INDETERMINATE;
639 			break;
640 		}
641 		if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED)
642 			eaddr = be64_to_cpu(mce_log->effective_address);
643 
644 		if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) {
645 			paddr = be64_to_cpu(mce_log->logical_address);
646 		} else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) {
647 			unsigned long pfn;
648 
649 			pfn = addr_to_pfn(regs, eaddr);
650 			if (pfn != ULONG_MAX)
651 				paddr = pfn << PAGE_SHIFT;
652 		}
653 
654 		break;
655 	case MC_ERROR_TYPE_SLB:
656 		mce_err.error_type = MCE_ERROR_TYPE_SLB;
657 		switch (err_sub_type) {
658 		case MC_ERROR_SLB_PARITY:
659 			mce_err.u.slb_error_type = MCE_SLB_ERROR_PARITY;
660 			break;
661 		case MC_ERROR_SLB_MULTIHIT:
662 			mce_err.u.slb_error_type = MCE_SLB_ERROR_MULTIHIT;
663 			break;
664 		case MC_ERROR_SLB_INDETERMINATE:
665 		default:
666 			mce_err.u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE;
667 			break;
668 		}
669 		if (mce_log->sub_err_type & MC_EFFECTIVE_ADDR_PROVIDED)
670 			eaddr = be64_to_cpu(mce_log->effective_address);
671 		break;
672 	case MC_ERROR_TYPE_ERAT:
673 		mce_err.error_type = MCE_ERROR_TYPE_ERAT;
674 		switch (err_sub_type) {
675 		case MC_ERROR_ERAT_PARITY:
676 			mce_err.u.erat_error_type = MCE_ERAT_ERROR_PARITY;
677 			break;
678 		case MC_ERROR_ERAT_MULTIHIT:
679 			mce_err.u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
680 			break;
681 		case MC_ERROR_ERAT_INDETERMINATE:
682 		default:
683 			mce_err.u.erat_error_type = MCE_ERAT_ERROR_INDETERMINATE;
684 			break;
685 		}
686 		if (mce_log->sub_err_type & MC_EFFECTIVE_ADDR_PROVIDED)
687 			eaddr = be64_to_cpu(mce_log->effective_address);
688 		break;
689 	case MC_ERROR_TYPE_TLB:
690 		mce_err.error_type = MCE_ERROR_TYPE_TLB;
691 		switch (err_sub_type) {
692 		case MC_ERROR_TLB_PARITY:
693 			mce_err.u.tlb_error_type = MCE_TLB_ERROR_PARITY;
694 			break;
695 		case MC_ERROR_TLB_MULTIHIT:
696 			mce_err.u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT;
697 			break;
698 		case MC_ERROR_TLB_INDETERMINATE:
699 		default:
700 			mce_err.u.tlb_error_type = MCE_TLB_ERROR_INDETERMINATE;
701 			break;
702 		}
703 		if (mce_log->sub_err_type & MC_EFFECTIVE_ADDR_PROVIDED)
704 			eaddr = be64_to_cpu(mce_log->effective_address);
705 		break;
706 	case MC_ERROR_TYPE_D_CACHE:
707 		mce_err.error_type = MCE_ERROR_TYPE_DCACHE;
708 		break;
709 	case MC_ERROR_TYPE_I_CACHE:
710 		mce_err.error_type = MCE_ERROR_TYPE_ICACHE;
711 		break;
712 	case MC_ERROR_TYPE_CTRL_MEM_ACCESS:
713 		mce_err.error_type = MCE_ERROR_TYPE_RA;
714 		switch (err_sub_type) {
715 		case MC_ERROR_CTRL_MEM_ACCESS_PTABLE_WALK:
716 			mce_err.u.ra_error_type =
717 				MCE_RA_ERROR_PAGE_TABLE_WALK_LOAD_STORE_FOREIGN;
718 			break;
719 		case MC_ERROR_CTRL_MEM_ACCESS_OP_ACCESS:
720 			mce_err.u.ra_error_type =
721 				MCE_RA_ERROR_LOAD_STORE_FOREIGN;
722 			break;
723 		}
724 		if (mce_log->sub_err_type & MC_EFFECTIVE_ADDR_PROVIDED)
725 			eaddr = be64_to_cpu(mce_log->effective_address);
726 		break;
727 	case MC_ERROR_TYPE_UNKNOWN:
728 	default:
729 		mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN;
730 		break;
731 	}
732 out:
733 	save_mce_event(regs, disposition == RTAS_DISP_FULLY_RECOVERED,
734 		       &mce_err, regs->nip, eaddr, paddr);
735 	return disposition;
736 }
737 
mce_handle_error(struct pt_regs * regs,struct rtas_error_log * errp)738 static int mce_handle_error(struct pt_regs *regs, struct rtas_error_log *errp)
739 {
740 	struct pseries_errorlog *pseries_log;
741 	struct pseries_mc_errorlog *mce_log = NULL;
742 	int disposition = rtas_error_disposition(errp);
743 	u8 error_type;
744 
745 	if (!rtas_error_extended(errp))
746 		goto out;
747 
748 	pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);
749 	if (!pseries_log)
750 		goto out;
751 
752 	mce_log = (struct pseries_mc_errorlog *)pseries_log->data;
753 	error_type = mce_log->error_type;
754 
755 	disposition = mce_handle_err_realmode(disposition, error_type);
756 out:
757 	disposition = mce_handle_err_virtmode(regs, errp, mce_log,
758 					      disposition);
759 	return disposition;
760 }
761 
762 /*
763  * Process MCE rtas errlog event.
764  */
pSeries_machine_check_log_err(void)765 void pSeries_machine_check_log_err(void)
766 {
767 	struct rtas_error_log *err;
768 
769 	err = fwnmi_get_errlog();
770 	log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);
771 }
772 
773 /*
774  * See if we can recover from a machine check exception.
775  * This is only called on power4 (or above) and only via
776  * the Firmware Non-Maskable Interrupts (fwnmi) handler
777  * which provides the error analysis for us.
778  *
779  * Return 1 if corrected (or delivered a signal).
780  * Return 0 if there is nothing we can do.
781  */
recover_mce(struct pt_regs * regs,struct machine_check_event * evt)782 static int recover_mce(struct pt_regs *regs, struct machine_check_event *evt)
783 {
784 	int recovered = 0;
785 
786 	if (regs_is_unrecoverable(regs)) {
787 		/* If MSR_RI isn't set, we cannot recover */
788 		pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n");
789 		recovered = 0;
790 	} else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
791 		/* Platform corrected itself */
792 		recovered = 1;
793 	} else if (evt->severity == MCE_SEV_FATAL) {
794 		/* Fatal machine check */
795 		pr_err("Machine check interrupt is fatal\n");
796 		recovered = 0;
797 	}
798 
799 	if (!recovered && evt->sync_error) {
800 		/*
801 		 * Try to kill processes if we get a synchronous machine check
802 		 * (e.g., one caused by execution of this instruction). This
803 		 * will devolve into a panic if we try to kill init or are in
804 		 * an interrupt etc.
805 		 *
806 		 * TODO: Queue up this address for hwpoisioning later.
807 		 * TODO: This is not quite right for d-side machine
808 		 *       checks ->nip is not necessarily the important
809 		 *       address.
810 		 */
811 		if ((user_mode(regs))) {
812 			_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
813 			recovered = 1;
814 		} else if (die_will_crash()) {
815 			/*
816 			 * die() would kill the kernel, so better to go via
817 			 * the platform reboot code that will log the
818 			 * machine check.
819 			 */
820 			recovered = 0;
821 		} else {
822 			die_mce("Machine check", regs, SIGBUS);
823 			recovered = 1;
824 		}
825 	}
826 
827 	return recovered;
828 }
829 
830 /*
831  * Handle a machine check.
832  *
833  * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi)
834  * should be present.  If so the handler which called us tells us if the
835  * error was recovered (never true if RI=0).
836  *
837  * On hardware prior to Power 4 these exceptions were asynchronous which
838  * means we can't tell exactly where it occurred and so we can't recover.
839  */
pSeries_machine_check_exception(struct pt_regs * regs)840 int pSeries_machine_check_exception(struct pt_regs *regs)
841 {
842 	struct machine_check_event evt;
843 
844 	if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
845 		return 0;
846 
847 	/* Print things out */
848 	if (evt.version != MCE_V1) {
849 		pr_err("Machine Check Exception, Unknown event version %d !\n",
850 		       evt.version);
851 		return 0;
852 	}
853 	machine_check_print_event_info(&evt, user_mode(regs), false);
854 
855 	if (recover_mce(regs, &evt))
856 		return 1;
857 
858 	return 0;
859 }
860 
pseries_machine_check_realmode(struct pt_regs * regs)861 long pseries_machine_check_realmode(struct pt_regs *regs)
862 {
863 	struct rtas_error_log *errp;
864 	int disposition;
865 
866 	if (fwnmi_active) {
867 		errp = fwnmi_get_errinfo(regs);
868 		/*
869 		 * Call to fwnmi_release_errinfo() in real mode causes kernel
870 		 * to panic. Hence we will call it as soon as we go into
871 		 * virtual mode.
872 		 */
873 		disposition = mce_handle_error(regs, errp);
874 
875 		fwnmi_release_errinfo();
876 
877 		if (disposition == RTAS_DISP_FULLY_RECOVERED)
878 			return 1;
879 	}
880 
881 	return 0;
882 }
883