summaryrefslogtreecommitdiff
path: root/arch/powerpc/platforms/powernv/opal.c
blob: 2241565b0739ff3bc6dc84f9bc6c63c70edf8b8c (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
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
/*
 * PowerNV OPAL high level interfaces
 *
 * Copyright 2011 IBM Corp.
 *
 * 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.
 */

#define pr_fmt(fmt)	"opal: " fmt

#include <linux/printk.h>
#include <linux/types.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/kobject.h>
#include <linux/delay.h>
#include <linux/memblock.h>
#include <linux/kthread.h>
#include <linux/freezer.h>

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

#include "powernv.h"

/* /sys/firmware/opal */
struct kobject *opal_kobj;

struct opal {
	u64 base;
	u64 entry;
	u64 size;
} opal;

struct mcheck_recoverable_range {
	u64 start_addr;
	u64 end_addr;
	u64 recover_addr;
};

static struct mcheck_recoverable_range *mc_recoverable_range;
static int mc_recoverable_range_len;

struct device_node *opal_node;
static DEFINE_SPINLOCK(opal_write_lock);
static unsigned int *opal_irqs;
static unsigned int opal_irq_count;
static ATOMIC_NOTIFIER_HEAD(opal_notifier_head);
static struct atomic_notifier_head opal_msg_notifier_head[OPAL_MSG_TYPE_MAX];
static DEFINE_SPINLOCK(opal_notifier_lock);
static uint64_t last_notified_mask = 0x0ul;
static atomic_t opal_notifier_hold = ATOMIC_INIT(0);
static uint32_t opal_heartbeat;

static void opal_reinit_cores(void)
{
	/* Do the actual re-init, This will clobber all FPRs, VRs, etc...
	 *
	 * It will preserve non volatile GPRs and HSPRG0/1. It will
	 * also restore HIDs and other SPRs to their original value
	 * but it might clobber a bunch.
	 */
#ifdef __BIG_ENDIAN__
	opal_reinit_cpus(OPAL_REINIT_CPUS_HILE_BE);
#else
	opal_reinit_cpus(OPAL_REINIT_CPUS_HILE_LE);
#endif
}

int __init early_init_dt_scan_opal(unsigned long node,
				   const char *uname, int depth, void *data)
{
	const void *basep, *entryp, *sizep;
	int basesz, entrysz, runtimesz;

	if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
		return 0;

	basep  = of_get_flat_dt_prop(node, "opal-base-address", &basesz);
	entryp = of_get_flat_dt_prop(node, "opal-entry-address", &entrysz);
	sizep = of_get_flat_dt_prop(node, "opal-runtime-size", &runtimesz);

	if (!basep || !entryp || !sizep)
		return 1;

	opal.base = of_read_number(basep, basesz/4);
	opal.entry = of_read_number(entryp, entrysz/4);
	opal.size = of_read_number(sizep, runtimesz/4);

	pr_debug("OPAL Base  = 0x%llx (basep=%p basesz=%d)\n",
		 opal.base, basep, basesz);
	pr_debug("OPAL Entry = 0x%llx (entryp=%p basesz=%d)\n",
		 opal.entry, entryp, entrysz);
	pr_debug("OPAL Entry = 0x%llx (sizep=%p runtimesz=%d)\n",
		 opal.size, sizep, runtimesz);

	powerpc_firmware_features |= FW_FEATURE_OPAL;
	if (of_flat_dt_is_compatible(node, "ibm,opal-v3")) {
		powerpc_firmware_features |= FW_FEATURE_OPALv2;
		powerpc_firmware_features |= FW_FEATURE_OPALv3;
		pr_info("OPAL V3 detected !\n");
	} else if (of_flat_dt_is_compatible(node, "ibm,opal-v2")) {
		powerpc_firmware_features |= FW_FEATURE_OPALv2;
		pr_info("OPAL V2 detected !\n");
	} else {
		pr_info("OPAL V1 detected !\n");
	}

	/* Reinit all cores with the right endian */
	opal_reinit_cores();

	/* Restore some bits */
	if (cur_cpu_spec->cpu_restore)
		cur_cpu_spec->cpu_restore();

	return 1;
}

int __init early_init_dt_scan_recoverable_ranges(unsigned long node,
				   const char *uname, int depth, void *data)
{
	int i, psize, size;
	const __be32 *prop;

	if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
		return 0;

	prop = of_get_flat_dt_prop(node, "mcheck-recoverable-ranges", &psize);

	if (!prop)
		return 1;

	pr_debug("Found machine check recoverable ranges.\n");

	/*
	 * Calculate number of available entries.
	 *
	 * Each recoverable address range entry is (start address, len,
	 * recovery address), 2 cells each for start and recovery address,
	 * 1 cell for len, totalling 5 cells per entry.
	 */
	mc_recoverable_range_len = psize / (sizeof(*prop) * 5);

	/* Sanity check */
	if (!mc_recoverable_range_len)
		return 1;

	/* Size required to hold all the entries. */
	size = mc_recoverable_range_len *
			sizeof(struct mcheck_recoverable_range);

	/*
	 * Allocate a buffer to hold the MC recoverable ranges. We would be
	 * accessing them in real mode, hence it needs to be within
	 * RMO region.
	 */
	mc_recoverable_range =__va(memblock_alloc_base(size, __alignof__(u64),
							ppc64_rma_size));
	memset(mc_recoverable_range, 0, size);

	for (i = 0; i < mc_recoverable_range_len; i++) {
		mc_recoverable_range[i].start_addr =
					of_read_number(prop + (i * 5) + 0, 2);
		mc_recoverable_range[i].end_addr =
					mc_recoverable_range[i].start_addr +
					of_read_number(prop + (i * 5) + 2, 1);
		mc_recoverable_range[i].recover_addr =
					of_read_number(prop + (i * 5) + 3, 2);

		pr_debug("Machine check recoverable range: %llx..%llx: %llx\n",
				mc_recoverable_range[i].start_addr,
				mc_recoverable_range[i].end_addr,
				mc_recoverable_range[i].recover_addr);
	}
	return 1;
}

static int __init opal_register_exception_handlers(void)
{
#ifdef __BIG_ENDIAN__
	u64 glue;

	if (!(powerpc_firmware_features & FW_FEATURE_OPAL))
		return -ENODEV;

	/* Hookup some exception handlers except machine check. We use the
	 * fwnmi area at 0x7000 to provide the glue space to OPAL
	 */
	glue = 0x7000;

	/*
	 * Check if we are running on newer firmware that exports
	 * OPAL_HANDLE_HMI token. If yes, then don't ask OPAL to patch
	 * the HMI interrupt and we catch it directly in Linux.
	 *
	 * For older firmware (i.e currently released POWER8 System Firmware
	 * as of today <= SV810_087), we fallback to old behavior and let OPAL
	 * patch the HMI vector and handle it inside OPAL firmware.
	 *
	 * For newer firmware (in development/yet to be released) we will
	 * start catching/handling HMI directly in Linux.
	 */
	if (!opal_check_token(OPAL_HANDLE_HMI)) {
		pr_info("Old firmware detected, OPAL handles HMIs.\n");
		opal_register_exception_handler(
				OPAL_HYPERVISOR_MAINTENANCE_HANDLER,
				0, glue);
		glue += 128;
	}

	opal_register_exception_handler(OPAL_SOFTPATCH_HANDLER, 0, glue);
#endif

	return 0;
}
machine_early_initcall(powernv, opal_register_exception_handlers);

int opal_notifier_register(struct notifier_block *nb)
{
	if (!nb) {
		pr_warning("%s: Invalid argument (%p)\n",
			   __func__, nb);
		return -EINVAL;
	}

	atomic_notifier_chain_register(&opal_notifier_head, nb);
	return 0;
}
EXPORT_SYMBOL_GPL(opal_notifier_register);

int opal_notifier_unregister(struct notifier_block *nb)
{
	if (!nb) {
		pr_warning("%s: Invalid argument (%p)\n",
			   __func__, nb);
		return -EINVAL;
	}

	atomic_notifier_chain_unregister(&opal_notifier_head, nb);
	return 0;
}
EXPORT_SYMBOL_GPL(opal_notifier_unregister);

static void opal_do_notifier(uint64_t events)
{
	unsigned long flags;
	uint64_t changed_mask;

	if (atomic_read(&opal_notifier_hold))
		return;

	spin_lock_irqsave(&opal_notifier_lock, flags);
	changed_mask = last_notified_mask ^ events;
	last_notified_mask = events;
	spin_unlock_irqrestore(&opal_notifier_lock, flags);

	/*
	 * We feed with the event bits and changed bits for
	 * enough information to the callback.
	 */
	atomic_notifier_call_chain(&opal_notifier_head,
				   events, (void *)changed_mask);
}

void opal_notifier_update_evt(uint64_t evt_mask,
			      uint64_t evt_val)
{
	unsigned long flags;

	spin_lock_irqsave(&opal_notifier_lock, flags);
	last_notified_mask &= ~evt_mask;
	last_notified_mask |= evt_val;
	spin_unlock_irqrestore(&opal_notifier_lock, flags);
}

void opal_notifier_enable(void)
{
	int64_t rc;
	__be64 evt = 0;

	atomic_set(&opal_notifier_hold, 0);

	/* Process pending events */
	rc = opal_poll_events(&evt);
	if (rc == OPAL_SUCCESS && evt)
		opal_do_notifier(be64_to_cpu(evt));
}

void opal_notifier_disable(void)
{
	atomic_set(&opal_notifier_hold, 1);
}

/*
 * Opal message notifier based on message type. Allow subscribers to get
 * notified for specific messgae type.
 */
int opal_message_notifier_register(enum opal_msg_type msg_type,
					struct notifier_block *nb)
{
	if (!nb || msg_type >= OPAL_MSG_TYPE_MAX) {
		pr_warning("%s: Invalid arguments, msg_type:%d\n",
			   __func__, msg_type);
		return -EINVAL;
	}

	return atomic_notifier_chain_register(
				&opal_msg_notifier_head[msg_type], nb);
}

int opal_message_notifier_unregister(enum opal_msg_type msg_type,
				     struct notifier_block *nb)
{
	return atomic_notifier_chain_unregister(
			&opal_msg_notifier_head[msg_type], nb);
}

static void opal_message_do_notify(uint32_t msg_type, void *msg)
{
	/* notify subscribers */
	atomic_notifier_call_chain(&opal_msg_notifier_head[msg_type],
					msg_type, msg);
}

static void opal_handle_message(void)
{
	s64 ret;
	/*
	 * TODO: pre-allocate a message buffer depending on opal-msg-size
	 * value in /proc/device-tree.
	 */
	static struct opal_msg msg;
	u32 type;

	ret = opal_get_msg(__pa(&msg), sizeof(msg));
	/* No opal message pending. */
	if (ret == OPAL_RESOURCE)
		return;

	/* check for errors. */
	if (ret) {
		pr_warning("%s: Failed to retrieve opal message, err=%lld\n",
				__func__, ret);
		return;
	}

	type = be32_to_cpu(msg.msg_type);

	/* Sanity check */
	if (type >= OPAL_MSG_TYPE_MAX) {
		pr_warning("%s: Unknown message type: %u\n", __func__, type);
		return;
	}
	opal_message_do_notify(type, (void *)&msg);
}

static int opal_message_notify(struct notifier_block *nb,
			  unsigned long events, void *change)
{
	if (events & OPAL_EVENT_MSG_PENDING)
		opal_handle_message();
	return 0;
}

static struct notifier_block opal_message_nb = {
	.notifier_call	= opal_message_notify,
	.next		= NULL,
	.priority	= 0,
};

static int __init opal_message_init(void)
{
	int ret, i;

	for (i = 0; i < OPAL_MSG_TYPE_MAX; i++)
		ATOMIC_INIT_NOTIFIER_HEAD(&opal_msg_notifier_head[i]);

	ret = opal_notifier_register(&opal_message_nb);
	if (ret) {
		pr_err("%s: Can't register OPAL event notifier (%d)\n",
		       __func__, ret);
		return ret;
	}
	return 0;
}
machine_early_initcall(powernv, opal_message_init);

int opal_get_chars(uint32_t vtermno, char *buf, int count)
{
	s64 rc;
	__be64 evt, len;

	if (!opal.entry)
		return -ENODEV;
	opal_poll_events(&evt);
	if ((be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_INPUT) == 0)
		return 0;
	len = cpu_to_be64(count);
	rc = opal_console_read(vtermno, &len, buf);
	if (rc == OPAL_SUCCESS)
		return be64_to_cpu(len);
	return 0;
}

int opal_put_chars(uint32_t vtermno, const char *data, int total_len)
{
	int written = 0;
	__be64 olen;
	s64 len, rc;
	unsigned long flags;
	__be64 evt;

	if (!opal.entry)
		return -ENODEV;

	/* We want put_chars to be atomic to avoid mangling of hvsi
	 * packets. To do that, we first test for room and return
	 * -EAGAIN if there isn't enough.
	 *
	 * Unfortunately, opal_console_write_buffer_space() doesn't
	 * appear to work on opal v1, so we just assume there is
	 * enough room and be done with it
	 */
	spin_lock_irqsave(&opal_write_lock, flags);
	if (firmware_has_feature(FW_FEATURE_OPALv2)) {
		rc = opal_console_write_buffer_space(vtermno, &olen);
		len = be64_to_cpu(olen);
		if (rc || len < total_len) {
			spin_unlock_irqrestore(&opal_write_lock, flags);
			/* Closed -> drop characters */
			if (rc)
				return total_len;
			opal_poll_events(NULL);
			return -EAGAIN;
		}
	}

	/* We still try to handle partial completions, though they
	 * should no longer happen.
	 */
	rc = OPAL_BUSY;
	while(total_len > 0 && (rc == OPAL_BUSY ||
				rc == OPAL_BUSY_EVENT || rc == OPAL_SUCCESS)) {
		olen = cpu_to_be64(total_len);
		rc = opal_console_write(vtermno, &olen, data);
		len = be64_to_cpu(olen);

		/* Closed or other error drop */
		if (rc != OPAL_SUCCESS && rc != OPAL_BUSY &&
		    rc != OPAL_BUSY_EVENT) {
			written = total_len;
			break;
		}
		if (rc == OPAL_SUCCESS) {
			total_len -= len;
			data += len;
			written += len;
		}
		/* This is a bit nasty but we need that for the console to
		 * flush when there aren't any interrupts. We will clean
		 * things a bit later to limit that to synchronous path
		 * such as the kernel console and xmon/udbg
		 */
		do
			opal_poll_events(&evt);
		while(rc == OPAL_SUCCESS &&
			(be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_OUTPUT));
	}
	spin_unlock_irqrestore(&opal_write_lock, flags);
	return written;
}

static int opal_recover_mce(struct pt_regs *regs,
					struct machine_check_event *evt)
{
	int recovered = 0;
	uint64_t ea = get_mce_fault_addr(evt);

	if (!(regs->msr & MSR_RI)) {
		/* If MSR_RI isn't set, we cannot recover */
		recovered = 0;
	} else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
		/* Platform corrected itself */
		recovered = 1;
	} else if (ea && !is_kernel_addr(ea)) {
		/*
		 * Faulting address is not in kernel text. We should be fine.
		 * We need to find which process uses this address.
		 * For now, kill the task if we have received exception when
		 * in userspace.
		 *
		 * TODO: Queue up this address for hwpoisioning later.
		 */
		if (user_mode(regs) && !is_global_init(current)) {
			_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
			recovered = 1;
		} else
			recovered = 0;
	} else if (user_mode(regs) && !is_global_init(current) &&
		evt->severity == MCE_SEV_ERROR_SYNC) {
		/*
		 * If we have received a synchronous error when in userspace
		 * kill the task.
		 */
		_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
		recovered = 1;
	}
	return recovered;
}

int opal_machine_check(struct pt_regs *regs)
{
	struct machine_check_event evt;

	if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
		return 0;

	/* Print things out */
	if (evt.version != MCE_V1) {
		pr_err("Machine Check Exception, Unknown event version %d !\n",
		       evt.version);
		return 0;
	}
	machine_check_print_event_info(&evt);

	if (opal_recover_mce(regs, &evt))
		return 1;
	return 0;
}

/* Early hmi handler called in real mode. */
int opal_hmi_exception_early(struct pt_regs *regs)
{
	s64 rc;

	/*
	 * call opal hmi handler. Pass paca address as token.
	 * The return value OPAL_SUCCESS is an indication that there is
	 * an HMI event generated waiting to pull by Linux.
	 */
	rc = opal_handle_hmi();
	if (rc == OPAL_SUCCESS) {
		local_paca->hmi_event_available = 1;
		return 1;
	}
	return 0;
}

/* HMI exception handler called in virtual mode during check_irq_replay. */
int opal_handle_hmi_exception(struct pt_regs *regs)
{
	s64 rc;
	__be64 evt = 0;

	/*
	 * Check if HMI event is available.
	 * if Yes, then call opal_poll_events to pull opal messages and
	 * process them.
	 */
	if (!local_paca->hmi_event_available)
		return 0;

	local_paca->hmi_event_available = 0;
	rc = opal_poll_events(&evt);
	if (rc == OPAL_SUCCESS && evt)
		opal_do_notifier(be64_to_cpu(evt));

	return 1;
}

static uint64_t find_recovery_address(uint64_t nip)
{
	int i;

	for (i = 0; i < mc_recoverable_range_len; i++)
		if ((nip >= mc_recoverable_range[i].start_addr) &&
		    (nip < mc_recoverable_range[i].end_addr))
		    return mc_recoverable_range[i].recover_addr;
	return 0;
}

bool opal_mce_check_early_recovery(struct pt_regs *regs)
{
	uint64_t recover_addr = 0;

	if (!opal.base || !opal.size)
		goto out;

	if ((regs->nip >= opal.base) &&
			(regs->nip <= (opal.base + opal.size)))
		recover_addr = find_recovery_address(regs->nip);

	/*
	 * Setup regs->nip to rfi into fixup address.
	 */
	if (recover_addr)
		regs->nip = recover_addr;

out:
	return !!recover_addr;
}

static irqreturn_t opal_interrupt(int irq, void *data)
{
	__be64 events;

	opal_handle_interrupt(virq_to_hw(irq), &events);

	opal_do_notifier(be64_to_cpu(events));

	return IRQ_HANDLED;
}

static int opal_sysfs_init(void)
{
	opal_kobj = kobject_create_and_add("opal", firmware_kobj);
	if (!opal_kobj) {
		pr_warn("kobject_create_and_add opal failed\n");
		return -ENOMEM;
	}

	return 0;
}

static ssize_t symbol_map_read(struct file *fp, struct kobject *kobj,
			       struct bin_attribute *bin_attr,
			       char *buf, loff_t off, size_t count)
{
	return memory_read_from_buffer(buf, count, &off, bin_attr->private,
				       bin_attr->size);
}

static BIN_ATTR_RO(symbol_map, 0);

static void opal_export_symmap(void)
{
	const __be64 *syms;
	unsigned int size;
	struct device_node *fw;
	int rc;

	fw = of_find_node_by_path("/ibm,opal/firmware");
	if (!fw)
		return;
	syms = of_get_property(fw, "symbol-map", &size);
	if (!syms || size != 2 * sizeof(__be64))
		return;

	/* Setup attributes */
	bin_attr_symbol_map.private = __va(be64_to_cpu(syms[0]));
	bin_attr_symbol_map.size = be64_to_cpu(syms[1]);

	rc = sysfs_create_bin_file(opal_kobj, &bin_attr_symbol_map);
	if (rc)
		pr_warn("Error %d creating OPAL symbols file\n", rc);
}

static void __init opal_dump_region_init(void)
{
	void *addr;
	uint64_t size;
	int rc;

	if (!opal_check_token(OPAL_REGISTER_DUMP_REGION))
		return;

	/* Register kernel log buffer */
	addr = log_buf_addr_get();
	if (addr == NULL)
		return;

	size = log_buf_len_get();
	if (size == 0)
		return;

	rc = opal_register_dump_region(OPAL_DUMP_REGION_LOG_BUF,
				       __pa(addr), size);
	/* Don't warn if this is just an older OPAL that doesn't
	 * know about that call
	 */
	if (rc && rc != OPAL_UNSUPPORTED)
		pr_warn("DUMP: Failed to register kernel log buffer. "
			"rc = %d\n", rc);
}

static void opal_flash_init(struct device_node *opal_node)
{
	struct device_node *np;

	for_each_child_of_node(opal_node, np)
		if (of_device_is_compatible(np, "ibm,opal-flash"))
			of_platform_device_create(np, NULL, NULL);
}

static void opal_ipmi_init(struct device_node *opal_node)
{
	struct device_node *np;

	for_each_child_of_node(opal_node, np)
		if (of_device_is_compatible(np, "ibm,opal-ipmi"))
			of_platform_device_create(np, NULL, NULL);
}

static void opal_i2c_create_devs(void)
{
	struct device_node *np;

	for_each_compatible_node(np, NULL, "ibm,opal-i2c")
		of_platform_device_create(np, NULL, NULL);
}

static void __init opal_irq_init(struct device_node *dn)
{
	const __be32 *irqs;
	int i, irqlen;

	/* Get interrupt property */
	irqs = of_get_property(opal_node, "opal-interrupts", &irqlen);
	opal_irq_count = irqs ? (irqlen / 4) : 0;
	pr_debug("Found %d interrupts reserved for OPAL\n", opal_irq_count);
	if (!opal_irq_count)
		return;

	/* Install interrupt handlers */
	opal_irqs = kzalloc(opal_irq_count * sizeof(unsigned int), GFP_KERNEL);
	for (i = 0; irqs && i < opal_irq_count; i++, irqs++) {
		unsigned int irq, virq;
		int rc;

		/* Get hardware and virtual IRQ */
		irq = be32_to_cpup(irqs);
		virq = irq_create_mapping(NULL, irq);
		if (virq == NO_IRQ) {
			pr_warn("Failed to map irq 0x%x\n", irq);
			continue;
		}

		/* Install interrupt handler */
		rc = request_irq(virq, opal_interrupt, 0, "opal", NULL);
		if (rc) {
			irq_dispose_mapping(virq);
			pr_warn("Error %d requesting irq %d (0x%x)\n",
				 rc, virq, irq);
			continue;
		}

		/* Cache IRQ */
		opal_irqs[i] = virq;
	}
}

static int kopald(void *unused)
{
	set_freezable();
	do {
		try_to_freeze();
		opal_poll_events(NULL);
		msleep_interruptible(opal_heartbeat);
	} while (!kthread_should_stop());

	return 0;
}

static void opal_init_heartbeat(void)
{
	/* Old firwmware, we assume the HVC heartbeat is sufficient */
	if (of_property_read_u32(opal_node, "ibm,heartbeat-ms",
				 &opal_heartbeat) != 0)
		opal_heartbeat = 0;

	if (opal_heartbeat)
		kthread_run(kopald, NULL, "kopald");
}

static int __init opal_init(void)
{
	struct device_node *np, *consoles;
	int rc;

	opal_node = of_find_node_by_path("/ibm,opal");
	if (!opal_node) {
		pr_warn("Device node not found\n");
		return -ENODEV;
	}

	/* Register OPAL consoles if any ports */
	if (firmware_has_feature(FW_FEATURE_OPALv2))
		consoles = of_find_node_by_path("/ibm,opal/consoles");
	else
		consoles = of_node_get(opal_node);
	if (consoles) {
		for_each_child_of_node(consoles, np) {
			if (strcmp(np->name, "serial"))
				continue;
			of_platform_device_create(np, NULL, NULL);
		}
		of_node_put(consoles);
	}

	/* Create i2c platform devices */
	opal_i2c_create_devs();

	/* Setup a heatbeat thread if requested by OPAL */
	opal_init_heartbeat();

	/* Find all OPAL interrupts and request them */
	opal_irq_init(opal_node);

	/* Create "opal" kobject under /sys/firmware */
	rc = opal_sysfs_init();
	if (rc == 0) {
		/* Export symbol map to userspace */
		opal_export_symmap();
		/* Setup dump region interface */
		opal_dump_region_init();
		/* Setup error log interface */
		rc = opal_elog_init();
		/* Setup code update interface */
		opal_flash_update_init();
		/* Setup platform dump extract interface */
		opal_platform_dump_init();
		/* Setup system parameters interface */
		opal_sys_param_init();
		/* Setup message log interface. */
		opal_msglog_init();
	}

	/* Initialize OPAL IPMI backend */
	opal_ipmi_init(opal_node);

	opal_flash_init(opal_node);

	return 0;
}
machine_subsys_initcall(powernv, opal_init);

void opal_shutdown(void)
{
	unsigned int i;
	long rc = OPAL_BUSY;

	/* First free interrupts, which will also mask them */
	for (i = 0; i < opal_irq_count; i++) {
		if (opal_irqs[i])
			free_irq(opal_irqs[i], NULL);
		opal_irqs[i] = 0;
	}

	/*
	 * Then sync with OPAL which ensure anything that can
	 * potentially write to our memory has completed such
	 * as an ongoing dump retrieval
	 */
	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
		rc = opal_sync_host_reboot();
		if (rc == OPAL_BUSY)
			opal_poll_events(NULL);
		else
			mdelay(10);
	}

	/* Unregister memory dump region */
	if (opal_check_token(OPAL_UNREGISTER_DUMP_REGION))
		opal_unregister_dump_region(OPAL_DUMP_REGION_LOG_BUF);
}

/* Export this so that test modules can use it */
EXPORT_SYMBOL_GPL(opal_invalid_call);
EXPORT_SYMBOL_GPL(opal_ipmi_send);
EXPORT_SYMBOL_GPL(opal_ipmi_recv);
EXPORT_SYMBOL_GPL(opal_flash_read);
EXPORT_SYMBOL_GPL(opal_flash_write);
EXPORT_SYMBOL_GPL(opal_flash_erase);

/* Convert a region of vmalloc memory to an opal sg list */
struct opal_sg_list *opal_vmalloc_to_sg_list(void *vmalloc_addr,
					     unsigned long vmalloc_size)
{
	struct opal_sg_list *sg, *first = NULL;
	unsigned long i = 0;

	sg = kzalloc(PAGE_SIZE, GFP_KERNEL);
	if (!sg)
		goto nomem;

	first = sg;

	while (vmalloc_size > 0) {
		uint64_t data = vmalloc_to_pfn(vmalloc_addr) << PAGE_SHIFT;
		uint64_t length = min(vmalloc_size, PAGE_SIZE);

		sg->entry[i].data = cpu_to_be64(data);
		sg->entry[i].length = cpu_to_be64(length);
		i++;

		if (i >= SG_ENTRIES_PER_NODE) {
			struct opal_sg_list *next;

			next = kzalloc(PAGE_SIZE, GFP_KERNEL);
			if (!next)
				goto nomem;

			sg->length = cpu_to_be64(
					i * sizeof(struct opal_sg_entry) + 16);
			i = 0;
			sg->next = cpu_to_be64(__pa(next));
			sg = next;
		}

		vmalloc_addr += length;
		vmalloc_size -= length;
	}

	sg->length = cpu_to_be64(i * sizeof(struct opal_sg_entry) + 16);

	return first;

nomem:
	pr_err("%s : Failed to allocate memory\n", __func__);
	opal_free_sg_list(first);
	return NULL;
}

void opal_free_sg_list(struct opal_sg_list *sg)
{
	while (sg) {
		uint64_t next = be64_to_cpu(sg->next);

		kfree(sg);

		if (next)
			sg = __va(next);
		else
			sg = NULL;
	}
}

int opal_error_code(int rc)
{
	switch (rc) {
	case OPAL_SUCCESS:		return 0;

	case OPAL_PARAMETER:		return -EINVAL;
	case OPAL_ASYNC_COMPLETION:	return -EINPROGRESS;
	case OPAL_BUSY_EVENT:		return -EBUSY;
	case OPAL_NO_MEM:		return -ENOMEM;

	case OPAL_UNSUPPORTED:		return -EIO;
	case OPAL_HARDWARE:		return -EIO;
	case OPAL_INTERNAL_ERROR:	return -EIO;
	default:
		pr_err("%s: unexpected OPAL error %d\n", __func__, rc);
		return -EIO;
	}
}

EXPORT_SYMBOL_GPL(opal_poll_events);
EXPORT_SYMBOL_GPL(opal_rtc_read);
EXPORT_SYMBOL_GPL(opal_rtc_write);
EXPORT_SYMBOL_GPL(opal_tpo_read);
EXPORT_SYMBOL_GPL(opal_tpo_write);
EXPORT_SYMBOL_GPL(opal_i2c_request);