summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/mce.c
blob: 742e4658c5dc1d4ec2df625eb82ea34473f24e39 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
/*
 * Machine check exception handling.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright 2013 IBM Corporation
 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
 */

#undef DEBUG
#define pr_fmt(fmt) "mce: " fmt

#include <linux/hardirq.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/percpu.h>
#include <linux/export.h>
#include <linux/irq_work.h>

#include <asm/machdep.h>
#include <asm/mce.h>

static DEFINE_PER_CPU(int, mce_nest_count);
static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event);

/* Queue for delayed MCE events. */
static DEFINE_PER_CPU(int, mce_queue_count);
static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event_queue);

/* Queue for delayed MCE UE events. */
static DEFINE_PER_CPU(int, mce_ue_count);
static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT],
					mce_ue_event_queue);

static void machine_check_process_queued_event(struct irq_work *work);
void machine_check_ue_event(struct machine_check_event *evt);
static void machine_process_ue_event(struct work_struct *work);

static struct irq_work mce_event_process_work = {
        .func = machine_check_process_queued_event,
};

DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);

static void mce_set_error_info(struct machine_check_event *mce,
			       struct mce_error_info *mce_err)
{
	mce->error_type = mce_err->error_type;
	switch (mce_err->error_type) {
	case MCE_ERROR_TYPE_UE:
		mce->u.ue_error.ue_error_type = mce_err->u.ue_error_type;
		break;
	case MCE_ERROR_TYPE_SLB:
		mce->u.slb_error.slb_error_type = mce_err->u.slb_error_type;
		break;
	case MCE_ERROR_TYPE_ERAT:
		mce->u.erat_error.erat_error_type = mce_err->u.erat_error_type;
		break;
	case MCE_ERROR_TYPE_TLB:
		mce->u.tlb_error.tlb_error_type = mce_err->u.tlb_error_type;
		break;
	case MCE_ERROR_TYPE_USER:
		mce->u.user_error.user_error_type = mce_err->u.user_error_type;
		break;
	case MCE_ERROR_TYPE_RA:
		mce->u.ra_error.ra_error_type = mce_err->u.ra_error_type;
		break;
	case MCE_ERROR_TYPE_LINK:
		mce->u.link_error.link_error_type = mce_err->u.link_error_type;
		break;
	case MCE_ERROR_TYPE_UNKNOWN:
	default:
		break;
	}
}

/*
 * Decode and save high level MCE information into per cpu buffer which
 * is an array of machine_check_event structure.
 */
void 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)
{
	int index = __this_cpu_inc_return(mce_nest_count) - 1;
	struct machine_check_event *mce = this_cpu_ptr(&mce_event[index]);

	/*
	 * Return if we don't have enough space to log mce event.
	 * mce_nest_count may go beyond MAX_MC_EVT but that's ok,
	 * the check below will stop buffer overrun.
	 */
	if (index >= MAX_MC_EVT)
		return;

	/* Populate generic machine check info */
	mce->version = MCE_V1;
	mce->srr0 = nip;
	mce->srr1 = regs->msr;
	mce->gpr3 = regs->gpr[3];
	mce->in_use = 1;

	/* Mark it recovered if we have handled it and MSR(RI=1). */
	if (handled && (regs->msr & MSR_RI))
		mce->disposition = MCE_DISPOSITION_RECOVERED;
	else
		mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;

	mce->initiator = mce_err->initiator;
	mce->severity = mce_err->severity;

	/*
	 * Populate the mce error_type and type-specific error_type.
	 */
	mce_set_error_info(mce, mce_err);

	if (!addr)
		return;

	if (mce->error_type == MCE_ERROR_TYPE_TLB) {
		mce->u.tlb_error.effective_address_provided = true;
		mce->u.tlb_error.effective_address = addr;
	} else if (mce->error_type == MCE_ERROR_TYPE_SLB) {
		mce->u.slb_error.effective_address_provided = true;
		mce->u.slb_error.effective_address = addr;
	} else if (mce->error_type == MCE_ERROR_TYPE_ERAT) {
		mce->u.erat_error.effective_address_provided = true;
		mce->u.erat_error.effective_address = addr;
	} else if (mce->error_type == MCE_ERROR_TYPE_USER) {
		mce->u.user_error.effective_address_provided = true;
		mce->u.user_error.effective_address = addr;
	} else if (mce->error_type == MCE_ERROR_TYPE_RA) {
		mce->u.ra_error.effective_address_provided = true;
		mce->u.ra_error.effective_address = addr;
	} else if (mce->error_type == MCE_ERROR_TYPE_LINK) {
		mce->u.link_error.effective_address_provided = true;
		mce->u.link_error.effective_address = addr;
	} else if (mce->error_type == MCE_ERROR_TYPE_UE) {
		mce->u.ue_error.effective_address_provided = true;
		mce->u.ue_error.effective_address = addr;
		if (phys_addr != ULONG_MAX) {
			mce->u.ue_error.physical_address_provided = true;
			mce->u.ue_error.physical_address = phys_addr;
			machine_check_ue_event(mce);
		}
	}
	return;
}

/*
 * get_mce_event:
 *	mce	Pointer to machine_check_event structure to be filled.
 *	release Flag to indicate whether to free the event slot or not.
 *		0 <= do not release the mce event. Caller will invoke
 *		     release_mce_event() once event has been consumed.
 *		1 <= release the slot.
 *
 *	return	1 = success
 *		0 = failure
 *
 * get_mce_event() will be called by platform specific machine check
 * handle routine and in KVM.
 * When we call get_mce_event(), we are still in interrupt context and
 * preemption will not be scheduled until ret_from_expect() routine
 * is called.
 */
int get_mce_event(struct machine_check_event *mce, bool release)
{
	int index = __this_cpu_read(mce_nest_count) - 1;
	struct machine_check_event *mc_evt;
	int ret = 0;

	/* Sanity check */
	if (index < 0)
		return ret;

	/* Check if we have MCE info to process. */
	if (index < MAX_MC_EVT) {
		mc_evt = this_cpu_ptr(&mce_event[index]);
		/* Copy the event structure and release the original */
		if (mce)
			*mce = *mc_evt;
		if (release)
			mc_evt->in_use = 0;
		ret = 1;
	}
	/* Decrement the count to free the slot. */
	if (release)
		__this_cpu_dec(mce_nest_count);

	return ret;
}

void release_mce_event(void)
{
	get_mce_event(NULL, true);
}


/*
 * Queue up the MCE event which then can be handled later.
 */
void machine_check_ue_event(struct machine_check_event *evt)
{
	int index;

	index = __this_cpu_inc_return(mce_ue_count) - 1;
	/* If queue is full, just return for now. */
	if (index >= MAX_MC_EVT) {
		__this_cpu_dec(mce_ue_count);
		return;
	}
	memcpy(this_cpu_ptr(&mce_ue_event_queue[index]), evt, sizeof(*evt));

	/* Queue work to process this event later. */
	schedule_work(&mce_ue_event_work);
}

/*
 * Queue up the MCE event which then can be handled later.
 */
void machine_check_queue_event(void)
{
	int index;
	struct machine_check_event evt;

	if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
		return;

	index = __this_cpu_inc_return(mce_queue_count) - 1;
	/* If queue is full, just return for now. */
	if (index >= MAX_MC_EVT) {
		__this_cpu_dec(mce_queue_count);
		return;
	}
	memcpy(this_cpu_ptr(&mce_event_queue[index]), &evt, sizeof(evt));

	/* Queue irq work to process this event later. */
	irq_work_queue(&mce_event_process_work);
}
/*
 * process pending MCE event from the mce event queue. This function will be
 * called during syscall exit.
 */
static void machine_process_ue_event(struct work_struct *work)
{
	int index;
	struct machine_check_event *evt;

	while (__this_cpu_read(mce_ue_count) > 0) {
		index = __this_cpu_read(mce_ue_count) - 1;
		evt = this_cpu_ptr(&mce_ue_event_queue[index]);
#ifdef CONFIG_MEMORY_FAILURE
		/*
		 * This should probably queued elsewhere, but
		 * oh! well
		 */
		if (evt->error_type == MCE_ERROR_TYPE_UE) {
			if (evt->u.ue_error.physical_address_provided) {
				unsigned long pfn;

				pfn = evt->u.ue_error.physical_address >>
					PAGE_SHIFT;
				memory_failure(pfn, SIGBUS, 0);
			} else
				pr_warn("Failed to identify bad address from "
					"where the uncorrectable error (UE) "
					"was generated\n");
		}
#endif
		__this_cpu_dec(mce_ue_count);
	}
}
/*
 * process pending MCE event from the mce event queue. This function will be
 * called during syscall exit.
 */
static void machine_check_process_queued_event(struct irq_work *work)
{
	int index;
	struct machine_check_event *evt;

	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);

	/*
	 * For now just print it to console.
	 * TODO: log this error event to FSP or nvram.
	 */
	while (__this_cpu_read(mce_queue_count) > 0) {
		index = __this_cpu_read(mce_queue_count) - 1;
		evt = this_cpu_ptr(&mce_event_queue[index]);
		machine_check_print_event_info(evt, false);
		__this_cpu_dec(mce_queue_count);
	}
}

void machine_check_print_event_info(struct machine_check_event *evt,
				    bool user_mode)
{
	const char *level, *sevstr, *subtype;
	static const char *mc_ue_types[] = {
		"Indeterminate",
		"Instruction fetch",
		"Page table walk ifetch",
		"Load/Store",
		"Page table walk Load/Store",
	};
	static const char *mc_slb_types[] = {
		"Indeterminate",
		"Parity",
		"Multihit",
	};
	static const char *mc_erat_types[] = {
		"Indeterminate",
		"Parity",
		"Multihit",
	};
	static const char *mc_tlb_types[] = {
		"Indeterminate",
		"Parity",
		"Multihit",
	};
	static const char *mc_user_types[] = {
		"Indeterminate",
		"tlbie(l) invalid",
	};
	static const char *mc_ra_types[] = {
		"Indeterminate",
		"Instruction fetch (bad)",
		"Instruction fetch (foreign)",
		"Page table walk ifetch (bad)",
		"Page table walk ifetch (foreign)",
		"Load (bad)",
		"Store (bad)",
		"Page table walk Load/Store (bad)",
		"Page table walk Load/Store (foreign)",
		"Load/Store (foreign)",
	};
	static const char *mc_link_types[] = {
		"Indeterminate",
		"Instruction fetch (timeout)",
		"Page table walk ifetch (timeout)",
		"Load (timeout)",
		"Store (timeout)",
		"Page table walk Load/Store (timeout)",
	};

	/* Print things out */
	if (evt->version != MCE_V1) {
		pr_err("Machine Check Exception, Unknown event version %d !\n",
		       evt->version);
		return;
	}
	switch (evt->severity) {
	case MCE_SEV_NO_ERROR:
		level = KERN_INFO;
		sevstr = "Harmless";
		break;
	case MCE_SEV_WARNING:
		level = KERN_WARNING;
		sevstr = "";
		break;
	case MCE_SEV_ERROR_SYNC:
		level = KERN_ERR;
		sevstr = "Severe";
		break;
	case MCE_SEV_FATAL:
	default:
		level = KERN_ERR;
		sevstr = "Fatal";
		break;
	}

	printk("%s%s Machine check interrupt [%s]\n", level, sevstr,
	       evt->disposition == MCE_DISPOSITION_RECOVERED ?
	       "Recovered" : "Not recovered");

	if (user_mode) {
		printk("%s  NIP: [%016llx] PID: %d Comm: %s\n", level,
			evt->srr0, current->pid, current->comm);
	} else {
		printk("%s  NIP [%016llx]: %pS\n", level, evt->srr0,
		       (void *)evt->srr0);
	}

	printk("%s  Initiator: %s\n", level,
	       evt->initiator == MCE_INITIATOR_CPU ? "CPU" : "Unknown");
	switch (evt->error_type) {
	case MCE_ERROR_TYPE_UE:
		subtype = evt->u.ue_error.ue_error_type <
			ARRAY_SIZE(mc_ue_types) ?
			mc_ue_types[evt->u.ue_error.ue_error_type]
			: "Unknown";
		printk("%s  Error type: UE [%s]\n", level, subtype);
		if (evt->u.ue_error.effective_address_provided)
			printk("%s    Effective address: %016llx\n",
			       level, evt->u.ue_error.effective_address);
		if (evt->u.ue_error.physical_address_provided)
			printk("%s    Physical address:  %016llx\n",
			       level, evt->u.ue_error.physical_address);
		break;
	case MCE_ERROR_TYPE_SLB:
		subtype = evt->u.slb_error.slb_error_type <
			ARRAY_SIZE(mc_slb_types) ?
			mc_slb_types[evt->u.slb_error.slb_error_type]
			: "Unknown";
		printk("%s  Error type: SLB [%s]\n", level, subtype);
		if (evt->u.slb_error.effective_address_provided)
			printk("%s    Effective address: %016llx\n",
			       level, evt->u.slb_error.effective_address);
		break;
	case MCE_ERROR_TYPE_ERAT:
		subtype = evt->u.erat_error.erat_error_type <
			ARRAY_SIZE(mc_erat_types) ?
			mc_erat_types[evt->u.erat_error.erat_error_type]
			: "Unknown";
		printk("%s  Error type: ERAT [%s]\n", level, subtype);
		if (evt->u.erat_error.effective_address_provided)
			printk("%s    Effective address: %016llx\n",
			       level, evt->u.erat_error.effective_address);
		break;
	case MCE_ERROR_TYPE_TLB:
		subtype = evt->u.tlb_error.tlb_error_type <
			ARRAY_SIZE(mc_tlb_types) ?
			mc_tlb_types[evt->u.tlb_error.tlb_error_type]
			: "Unknown";
		printk("%s  Error type: TLB [%s]\n", level, subtype);
		if (evt->u.tlb_error.effective_address_provided)
			printk("%s    Effective address: %016llx\n",
			       level, evt->u.tlb_error.effective_address);
		break;
	case MCE_ERROR_TYPE_USER:
		subtype = evt->u.user_error.user_error_type <
			ARRAY_SIZE(mc_user_types) ?
			mc_user_types[evt->u.user_error.user_error_type]
			: "Unknown";
		printk("%s  Error type: User [%s]\n", level, subtype);
		if (evt->u.user_error.effective_address_provided)
			printk("%s    Effective address: %016llx\n",
			       level, evt->u.user_error.effective_address);
		break;
	case MCE_ERROR_TYPE_RA:
		subtype = evt->u.ra_error.ra_error_type <
			ARRAY_SIZE(mc_ra_types) ?
			mc_ra_types[evt->u.ra_error.ra_error_type]
			: "Unknown";
		printk("%s  Error type: Real address [%s]\n", level, subtype);
		if (evt->u.ra_error.effective_address_provided)
			printk("%s    Effective address: %016llx\n",
			       level, evt->u.ra_error.effective_address);
		break;
	case MCE_ERROR_TYPE_LINK:
		subtype = evt->u.link_error.link_error_type <
			ARRAY_SIZE(mc_link_types) ?
			mc_link_types[evt->u.link_error.link_error_type]
			: "Unknown";
		printk("%s  Error type: Link [%s]\n", level, subtype);
		if (evt->u.link_error.effective_address_provided)
			printk("%s    Effective address: %016llx\n",
			       level, evt->u.link_error.effective_address);
		break;
	default:
	case MCE_ERROR_TYPE_UNKNOWN:
		printk("%s  Error type: Unknown\n", level);
		break;
	}
}
EXPORT_SYMBOL_GPL(machine_check_print_event_info);

/*
 * This function is called in real mode. Strictly no printk's please.
 *
 * regs->nip and regs->msr contains srr0 and ssr1.
 */
long machine_check_early(struct pt_regs *regs)
{
	long handled = 0;

	__this_cpu_inc(irq_stat.mce_exceptions);

	if (cur_cpu_spec && cur_cpu_spec->machine_check_early)
		handled = cur_cpu_spec->machine_check_early(regs);
	return handled;
}

long hmi_exception_realmode(struct pt_regs *regs)
{
	__this_cpu_inc(irq_stat.hmi_exceptions);

#ifdef CONFIG_PPC_BOOK3S_64
	/* Workaround for P9 vector CI loads (see p9_hmi_special_emu) */
	if (pvr_version_is(PVR_POWER9)) {
		unsigned long hmer = mfspr(SPRN_HMER);

		/* Do we have the debug bit set */
		if (hmer & PPC_BIT(17)) {
			hmer &= ~PPC_BIT(17);
			mtspr(SPRN_HMER, hmer);

			/*
			 * Now to avoid problems with soft-disable we
			 * only do the emulation if we are coming from
			 * user space
			 */
			if (user_mode(regs))
				local_paca->hmi_p9_special_emu = 1;

			/*
			 * Don't bother going to OPAL if that's the
			 * only relevant bit.
			 */
			if (!(hmer & mfspr(SPRN_HMEER)))
				return local_paca->hmi_p9_special_emu;
		}
	}
#endif /* CONFIG_PPC_BOOK3S_64 */

	wait_for_subcore_guest_exit();

	if (ppc_md.hmi_exception_early)
		ppc_md.hmi_exception_early(regs);

	wait_for_tb_resync();

	return 1;
}