summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/rtas.c
blob: 6931339722948bb154792930dd14d72c2ec78295 (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
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *
 * Procedures for interfacing to the RTAS on CHRP machines.
 *
 * Peter Bergner, IBM	March 2001.
 * Copyright (C) 2001 IBM.
 */

#include <linux/stdarg.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/capability.h>
#include <linux/delay.h>
#include <linux/cpu.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/completion.h>
#include <linux/cpumask.h>
#include <linux/memblock.h>
#include <linux/slab.h>
#include <linux/reboot.h>
#include <linux/syscalls.h>
#include <linux/of.h>
#include <linux/of_fdt.h>

#include <asm/interrupt.h>
#include <asm/rtas.h>
#include <asm/hvcall.h>
#include <asm/machdep.h>
#include <asm/firmware.h>
#include <asm/page.h>
#include <asm/param.h>
#include <asm/delay.h>
#include <linux/uaccess.h>
#include <asm/udbg.h>
#include <asm/syscalls.h>
#include <asm/smp.h>
#include <linux/atomic.h>
#include <asm/time.h>
#include <asm/mmu.h>
#include <asm/topology.h>
#include <asm/paca.h>

/* This is here deliberately so it's only used in this file */
void enter_rtas(unsigned long);

static inline void do_enter_rtas(unsigned long args)
{
	unsigned long msr;

	/*
	 * Make sure MSR[RI] is currently enabled as it will be forced later
	 * in enter_rtas.
	 */
	msr = mfmsr();
	BUG_ON(!(msr & MSR_RI));

	BUG_ON(!irqs_disabled());

	hard_irq_disable(); /* Ensure MSR[EE] is disabled on PPC64 */

	enter_rtas(args);

	srr_regs_clobbered(); /* rtas uses SRRs, invalidate */
}

struct rtas_t rtas = {
	.lock = __ARCH_SPIN_LOCK_UNLOCKED
};
EXPORT_SYMBOL(rtas);

DEFINE_SPINLOCK(rtas_data_buf_lock);
EXPORT_SYMBOL(rtas_data_buf_lock);

char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned;
EXPORT_SYMBOL(rtas_data_buf);

unsigned long rtas_rmo_buf;

/*
 * If non-NULL, this gets called when the kernel terminates.
 * This is done like this so rtas_flash can be a module.
 */
void (*rtas_flash_term_hook)(int);
EXPORT_SYMBOL(rtas_flash_term_hook);

/* RTAS use home made raw locking instead of spin_lock_irqsave
 * because those can be called from within really nasty contexts
 * such as having the timebase stopped which would lockup with
 * normal locks and spinlock debugging enabled
 */
static unsigned long lock_rtas(void)
{
	unsigned long flags;

	local_irq_save(flags);
	preempt_disable();
	arch_spin_lock(&rtas.lock);
	return flags;
}

static void unlock_rtas(unsigned long flags)
{
	arch_spin_unlock(&rtas.lock);
	local_irq_restore(flags);
	preempt_enable();
}

/*
 * call_rtas_display_status and call_rtas_display_status_delay
 * are designed only for very early low-level debugging, which
 * is why the token is hard-coded to 10.
 */
static void call_rtas_display_status(unsigned char c)
{
	unsigned long s;

	if (!rtas.base)
		return;

	s = lock_rtas();
	rtas_call_unlocked(&rtas.args, 10, 1, 1, NULL, c);
	unlock_rtas(s);
}

static void call_rtas_display_status_delay(char c)
{
	static int pending_newline = 0;  /* did last write end with unprinted newline? */
	static int width = 16;

	if (c == '\n') {	
		while (width-- > 0)
			call_rtas_display_status(' ');
		width = 16;
		mdelay(500);
		pending_newline = 1;
	} else {
		if (pending_newline) {
			call_rtas_display_status('\r');
			call_rtas_display_status('\n');
		} 
		pending_newline = 0;
		if (width--) {
			call_rtas_display_status(c);
			udelay(10000);
		}
	}
}

void __init udbg_init_rtas_panel(void)
{
	udbg_putc = call_rtas_display_status_delay;
}

#ifdef CONFIG_UDBG_RTAS_CONSOLE

/* If you think you're dying before early_init_dt_scan_rtas() does its
 * work, you can hard code the token values for your firmware here and
 * hardcode rtas.base/entry etc.
 */
static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE;
static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE;

static void udbg_rtascon_putc(char c)
{
	int tries;

	if (!rtas.base)
		return;

	/* Add CRs before LFs */
	if (c == '\n')
		udbg_rtascon_putc('\r');

	/* if there is more than one character to be displayed, wait a bit */
	for (tries = 0; tries < 16; tries++) {
		if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0)
			break;
		udelay(1000);
	}
}

static int udbg_rtascon_getc_poll(void)
{
	int c;

	if (!rtas.base)
		return -1;

	if (rtas_call(rtas_getchar_token, 0, 2, &c))
		return -1;

	return c;
}

static int udbg_rtascon_getc(void)
{
	int c;

	while ((c = udbg_rtascon_getc_poll()) == -1)
		;

	return c;
}


void __init udbg_init_rtas_console(void)
{
	udbg_putc = udbg_rtascon_putc;
	udbg_getc = udbg_rtascon_getc;
	udbg_getc_poll = udbg_rtascon_getc_poll;
}
#endif /* CONFIG_UDBG_RTAS_CONSOLE */

void rtas_progress(char *s, unsigned short hex)
{
	struct device_node *root;
	int width;
	const __be32 *p;
	char *os;
	static int display_character, set_indicator;
	static int display_width, display_lines, form_feed;
	static const int *row_width;
	static DEFINE_SPINLOCK(progress_lock);
	static int current_line;
	static int pending_newline = 0;  /* did last write end with unprinted newline? */

	if (!rtas.base)
		return;

	if (display_width == 0) {
		display_width = 0x10;
		if ((root = of_find_node_by_path("/rtas"))) {
			if ((p = of_get_property(root,
					"ibm,display-line-length", NULL)))
				display_width = be32_to_cpu(*p);
			if ((p = of_get_property(root,
					"ibm,form-feed", NULL)))
				form_feed = be32_to_cpu(*p);
			if ((p = of_get_property(root,
					"ibm,display-number-of-lines", NULL)))
				display_lines = be32_to_cpu(*p);
			row_width = of_get_property(root,
					"ibm,display-truncation-length", NULL);
			of_node_put(root);
		}
		display_character = rtas_token("display-character");
		set_indicator = rtas_token("set-indicator");
	}

	if (display_character == RTAS_UNKNOWN_SERVICE) {
		/* use hex display if available */
		if (set_indicator != RTAS_UNKNOWN_SERVICE)
			rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex);
		return;
	}

	spin_lock(&progress_lock);

	/*
	 * Last write ended with newline, but we didn't print it since
	 * it would just clear the bottom line of output. Print it now
	 * instead.
	 *
	 * If no newline is pending and form feed is supported, clear the
	 * display with a form feed; otherwise, print a CR to start output
	 * at the beginning of the line.
	 */
	if (pending_newline) {
		rtas_call(display_character, 1, 1, NULL, '\r');
		rtas_call(display_character, 1, 1, NULL, '\n');
		pending_newline = 0;
	} else {
		current_line = 0;
		if (form_feed)
			rtas_call(display_character, 1, 1, NULL,
				  (char)form_feed);
		else
			rtas_call(display_character, 1, 1, NULL, '\r');
	}
 
	if (row_width)
		width = row_width[current_line];
	else
		width = display_width;
	os = s;
	while (*os) {
		if (*os == '\n' || *os == '\r') {
			/* If newline is the last character, save it
			 * until next call to avoid bumping up the
			 * display output.
			 */
			if (*os == '\n' && !os[1]) {
				pending_newline = 1;
				current_line++;
				if (current_line > display_lines-1)
					current_line = display_lines-1;
				spin_unlock(&progress_lock);
				return;
			}
 
			/* RTAS wants CR-LF, not just LF */
 
			if (*os == '\n') {
				rtas_call(display_character, 1, 1, NULL, '\r');
				rtas_call(display_character, 1, 1, NULL, '\n');
			} else {
				/* CR might be used to re-draw a line, so we'll
				 * leave it alone and not add LF.
				 */
				rtas_call(display_character, 1, 1, NULL, *os);
			}
 
			if (row_width)
				width = row_width[current_line];
			else
				width = display_width;
		} else {
			width--;
			rtas_call(display_character, 1, 1, NULL, *os);
		}
 
		os++;
 
		/* if we overwrite the screen length */
		if (width <= 0)
			while ((*os != 0) && (*os != '\n') && (*os != '\r'))
				os++;
	}
 
	spin_unlock(&progress_lock);
}
EXPORT_SYMBOL(rtas_progress);		/* needed by rtas_flash module */

int rtas_token(const char *service)
{
	const __be32 *tokp;
	if (rtas.dev == NULL)
		return RTAS_UNKNOWN_SERVICE;
	tokp = of_get_property(rtas.dev, service, NULL);
	return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE;
}
EXPORT_SYMBOL(rtas_token);

int rtas_service_present(const char *service)
{
	return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
}
EXPORT_SYMBOL(rtas_service_present);

#ifdef CONFIG_RTAS_ERROR_LOGGING
/*
 * Return the firmware-specified size of the error log buffer
 *  for all rtas calls that require an error buffer argument.
 *  This includes 'check-exception' and 'rtas-last-error'.
 */
int rtas_get_error_log_max(void)
{
	static int rtas_error_log_max;
	if (rtas_error_log_max)
		return rtas_error_log_max;

	rtas_error_log_max = rtas_token ("rtas-error-log-max");
	if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) ||
	    (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) {
		printk (KERN_WARNING "RTAS: bad log buffer size %d\n",
			rtas_error_log_max);
		rtas_error_log_max = RTAS_ERROR_LOG_MAX;
	}
	return rtas_error_log_max;
}
EXPORT_SYMBOL(rtas_get_error_log_max);


static char rtas_err_buf[RTAS_ERROR_LOG_MAX];
static int rtas_last_error_token;

/** Return a copy of the detailed error text associated with the
 *  most recent failed call to rtas.  Because the error text
 *  might go stale if there are any other intervening rtas calls,
 *  this routine must be called atomically with whatever produced
 *  the error (i.e. with rtas.lock still held from the previous call).
 */
static char *__fetch_rtas_last_error(char *altbuf)
{
	struct rtas_args err_args, save_args;
	u32 bufsz;
	char *buf = NULL;

	if (rtas_last_error_token == -1)
		return NULL;

	bufsz = rtas_get_error_log_max();

	err_args.token = cpu_to_be32(rtas_last_error_token);
	err_args.nargs = cpu_to_be32(2);
	err_args.nret = cpu_to_be32(1);
	err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf));
	err_args.args[1] = cpu_to_be32(bufsz);
	err_args.args[2] = 0;

	save_args = rtas.args;
	rtas.args = err_args;

	do_enter_rtas(__pa(&rtas.args));

	err_args = rtas.args;
	rtas.args = save_args;

	/* Log the error in the unlikely case that there was one. */
	if (unlikely(err_args.args[2] == 0)) {
		if (altbuf) {
			buf = altbuf;
		} else {
			buf = rtas_err_buf;
			if (slab_is_available())
				buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
		}
		if (buf)
			memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
	}

	return buf;
}

#define get_errorlog_buffer()	kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)

#else /* CONFIG_RTAS_ERROR_LOGGING */
#define __fetch_rtas_last_error(x)	NULL
#define get_errorlog_buffer()		NULL
#endif


static void
va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
		      va_list list)
{
	int i;

	args->token = cpu_to_be32(token);
	args->nargs = cpu_to_be32(nargs);
	args->nret  = cpu_to_be32(nret);
	args->rets  = &(args->args[nargs]);

	for (i = 0; i < nargs; ++i)
		args->args[i] = cpu_to_be32(va_arg(list, __u32));

	for (i = 0; i < nret; ++i)
		args->rets[i] = 0;

	do_enter_rtas(__pa(args));
}

void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...)
{
	va_list list;

	va_start(list, nret);
	va_rtas_call_unlocked(args, token, nargs, nret, list);
	va_end(list);
}

int rtas_call(int token, int nargs, int nret, int *outputs, ...)
{
	va_list list;
	int i;
	unsigned long s;
	struct rtas_args *rtas_args;
	char *buff_copy = NULL;
	int ret;

	if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
		return -1;

	if ((mfmsr() & (MSR_IR|MSR_DR)) != (MSR_IR|MSR_DR)) {
		WARN_ON_ONCE(1);
		return -1;
	}

	s = lock_rtas();

	/* We use the global rtas args buffer */
	rtas_args = &rtas.args;

	va_start(list, outputs);
	va_rtas_call_unlocked(rtas_args, token, nargs, nret, list);
	va_end(list);

	/* A -1 return code indicates that the last command couldn't
	   be completed due to a hardware error. */
	if (be32_to_cpu(rtas_args->rets[0]) == -1)
		buff_copy = __fetch_rtas_last_error(NULL);

	if (nret > 1 && outputs != NULL)
		for (i = 0; i < nret-1; ++i)
			outputs[i] = be32_to_cpu(rtas_args->rets[i+1]);
	ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0;

	unlock_rtas(s);

	if (buff_copy) {
		log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
		if (slab_is_available())
			kfree(buff_copy);
	}
	return ret;
}
EXPORT_SYMBOL(rtas_call);

/**
 * rtas_busy_delay_time() - From an RTAS status value, calculate the
 *                          suggested delay time in milliseconds.
 *
 * @status: a value returned from rtas_call() or similar APIs which return
 *          the status of a RTAS function call.
 *
 * Context: Any context.
 *
 * Return:
 * * 100000 - If @status is 9905.
 * * 10000  - If @status is 9904.
 * * 1000   - If @status is 9903.
 * * 100    - If @status is 9902.
 * * 10     - If @status is 9901.
 * * 1      - If @status is either 9900 or -2. This is "wrong" for -2, but
 *            some callers depend on this behavior, and the worst outcome
 *            is that they will delay for longer than necessary.
 * * 0      - If @status is not a busy or extended delay value.
 */
unsigned int rtas_busy_delay_time(int status)
{
	int order;
	unsigned int ms = 0;

	if (status == RTAS_BUSY) {
		ms = 1;
	} else if (status >= RTAS_EXTENDED_DELAY_MIN &&
		   status <= RTAS_EXTENDED_DELAY_MAX) {
		order = status - RTAS_EXTENDED_DELAY_MIN;
		for (ms = 1; order > 0; order--)
			ms *= 10;
	}

	return ms;
}
EXPORT_SYMBOL(rtas_busy_delay_time);

/**
 * rtas_busy_delay() - helper for RTAS busy and extended delay statuses
 *
 * @status: a value returned from rtas_call() or similar APIs which return
 *          the status of a RTAS function call.
 *
 * Context: Process context. May sleep or schedule.
 *
 * Return:
 * * true  - @status is RTAS_BUSY or an extended delay hint. The
 *           caller may assume that the CPU has been yielded if necessary,
 *           and that an appropriate delay for @status has elapsed.
 *           Generally the caller should reattempt the RTAS call which
 *           yielded @status.
 *
 * * false - @status is not @RTAS_BUSY nor an extended delay hint. The
 *           caller is responsible for handling @status.
 */
bool rtas_busy_delay(int status)
{
	unsigned int ms;
	bool ret;

	switch (status) {
	case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX:
		ret = true;
		ms = rtas_busy_delay_time(status);
		/*
		 * The extended delay hint can be as high as 100 seconds.
		 * Surely any function returning such a status is either
		 * buggy or isn't going to be significantly slowed by us
		 * polling at 1HZ. Clamp the sleep time to one second.
		 */
		ms = clamp(ms, 1U, 1000U);
		/*
		 * The delay hint is an order-of-magnitude suggestion, not
		 * a minimum. It is fine, possibly even advantageous, for
		 * us to pause for less time than hinted. For small values,
		 * use usleep_range() to ensure we don't sleep much longer
		 * than actually needed.
		 *
		 * See Documentation/timers/timers-howto.rst for
		 * explanation of the threshold used here. In effect we use
		 * usleep_range() for 9900 and 9901, msleep() for
		 * 9902-9905.
		 */
		if (ms <= 20)
			usleep_range(ms * 100, ms * 1000);
		else
			msleep(ms);
		break;
	case RTAS_BUSY:
		ret = true;
		/*
		 * We should call again immediately if there's no other
		 * work to do.
		 */
		cond_resched();
		break;
	default:
		ret = false;
		/*
		 * Not a busy or extended delay status; the caller should
		 * handle @status itself. Ensure we warn on misuses in
		 * atomic context regardless.
		 */
		might_sleep();
		break;
	}

	return ret;
}
EXPORT_SYMBOL(rtas_busy_delay);

static int rtas_error_rc(int rtas_rc)
{
	int rc;

	switch (rtas_rc) {
		case -1: 		/* Hardware Error */
			rc = -EIO;
			break;
		case -3:		/* Bad indicator/domain/etc */
			rc = -EINVAL;
			break;
		case -9000:		/* Isolation error */
			rc = -EFAULT;
			break;
		case -9001:		/* Outstanding TCE/PTE */
			rc = -EEXIST;
			break;
		case -9002:		/* No usable slot */
			rc = -ENODEV;
			break;
		default:
			printk(KERN_ERR "%s: unexpected RTAS error %d\n",
					__func__, rtas_rc);
			rc = -ERANGE;
			break;
	}
	return rc;
}

int rtas_get_power_level(int powerdomain, int *level)
{
	int token = rtas_token("get-power-level");
	int rc;

	if (token == RTAS_UNKNOWN_SERVICE)
		return -ENOENT;

	while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
		udelay(1);

	if (rc < 0)
		return rtas_error_rc(rc);
	return rc;
}
EXPORT_SYMBOL(rtas_get_power_level);

int rtas_set_power_level(int powerdomain, int level, int *setlevel)
{
	int token = rtas_token("set-power-level");
	int rc;

	if (token == RTAS_UNKNOWN_SERVICE)
		return -ENOENT;

	do {
		rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
	} while (rtas_busy_delay(rc));

	if (rc < 0)
		return rtas_error_rc(rc);
	return rc;
}
EXPORT_SYMBOL(rtas_set_power_level);

int rtas_get_sensor(int sensor, int index, int *state)
{
	int token = rtas_token("get-sensor-state");
	int rc;

	if (token == RTAS_UNKNOWN_SERVICE)
		return -ENOENT;

	do {
		rc = rtas_call(token, 2, 2, state, sensor, index);
	} while (rtas_busy_delay(rc));

	if (rc < 0)
		return rtas_error_rc(rc);
	return rc;
}
EXPORT_SYMBOL(rtas_get_sensor);

int rtas_get_sensor_fast(int sensor, int index, int *state)
{
	int token = rtas_token("get-sensor-state");
	int rc;

	if (token == RTAS_UNKNOWN_SERVICE)
		return -ENOENT;

	rc = rtas_call(token, 2, 2, state, sensor, index);
	WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
				    rc <= RTAS_EXTENDED_DELAY_MAX));

	if (rc < 0)
		return rtas_error_rc(rc);
	return rc;
}

bool rtas_indicator_present(int token, int *maxindex)
{
	int proplen, count, i;
	const struct indicator_elem {
		__be32 token;
		__be32 maxindex;
	} *indicators;

	indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen);
	if (!indicators)
		return false;

	count = proplen / sizeof(struct indicator_elem);

	for (i = 0; i < count; i++) {
		if (__be32_to_cpu(indicators[i].token) != token)
			continue;
		if (maxindex)
			*maxindex = __be32_to_cpu(indicators[i].maxindex);
		return true;
	}

	return false;
}
EXPORT_SYMBOL(rtas_indicator_present);

int rtas_set_indicator(int indicator, int index, int new_value)
{
	int token = rtas_token("set-indicator");
	int rc;

	if (token == RTAS_UNKNOWN_SERVICE)
		return -ENOENT;

	do {
		rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
	} while (rtas_busy_delay(rc));

	if (rc < 0)
		return rtas_error_rc(rc);
	return rc;
}
EXPORT_SYMBOL(rtas_set_indicator);

/*
 * Ignoring RTAS extended delay
 */
int rtas_set_indicator_fast(int indicator, int index, int new_value)
{
	int rc;
	int token = rtas_token("set-indicator");

	if (token == RTAS_UNKNOWN_SERVICE)
		return -ENOENT;

	rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);

	WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
				    rc <= RTAS_EXTENDED_DELAY_MAX));

	if (rc < 0)
		return rtas_error_rc(rc);

	return rc;
}

/**
 * rtas_ibm_suspend_me() - Call ibm,suspend-me to suspend the LPAR.
 *
 * @fw_status: RTAS call status will be placed here if not NULL.
 *
 * rtas_ibm_suspend_me() should be called only on a CPU which has
 * received H_CONTINUE from the H_JOIN hcall. All other active CPUs
 * should be waiting to return from H_JOIN.
 *
 * rtas_ibm_suspend_me() may suspend execution of the OS
 * indefinitely. Callers should take appropriate measures upon return, such as
 * resetting watchdog facilities.
 *
 * Callers may choose to retry this call if @fw_status is
 * %RTAS_THREADS_ACTIVE.
 *
 * Return:
 * 0          - The partition has resumed from suspend, possibly after
 *              migration to a different host.
 * -ECANCELED - The operation was aborted.
 * -EAGAIN    - There were other CPUs not in H_JOIN at the time of the call.
 * -EBUSY     - Some other condition prevented the suspend from succeeding.
 * -EIO       - Hardware/platform error.
 */
int rtas_ibm_suspend_me(int *fw_status)
{
	int fwrc;
	int ret;

	fwrc = rtas_call(rtas_token("ibm,suspend-me"), 0, 1, NULL);

	switch (fwrc) {
	case 0:
		ret = 0;
		break;
	case RTAS_SUSPEND_ABORTED:
		ret = -ECANCELED;
		break;
	case RTAS_THREADS_ACTIVE:
		ret = -EAGAIN;
		break;
	case RTAS_NOT_SUSPENDABLE:
	case RTAS_OUTSTANDING_COPROC:
		ret = -EBUSY;
		break;
	case -1:
	default:
		ret = -EIO;
		break;
	}

	if (fw_status)
		*fw_status = fwrc;

	return ret;
}

void __noreturn rtas_restart(char *cmd)
{
	if (rtas_flash_term_hook)
		rtas_flash_term_hook(SYS_RESTART);
	printk("RTAS system-reboot returned %d\n",
	       rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
	for (;;);
}

void rtas_power_off(void)
{
	if (rtas_flash_term_hook)
		rtas_flash_term_hook(SYS_POWER_OFF);
	/* allow power on only with power button press */
	printk("RTAS power-off returned %d\n",
	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
	for (;;);
}

void __noreturn rtas_halt(void)
{
	if (rtas_flash_term_hook)
		rtas_flash_term_hook(SYS_HALT);
	/* allow power on only with power button press */
	printk("RTAS power-off returned %d\n",
	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
	for (;;);
}

/* Must be in the RMO region, so we place it here */
static char rtas_os_term_buf[2048];

void rtas_os_term(char *str)
{
	int status;

	/*
	 * Firmware with the ibm,extended-os-term property is guaranteed
	 * to always return from an ibm,os-term call. Earlier versions without
	 * this property may terminate the partition which we want to avoid
	 * since it interferes with panic_timeout.
	 */
	if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") ||
	    RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-os-term"))
		return;

	snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);

	do {
		status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
				   __pa(rtas_os_term_buf));
	} while (rtas_busy_delay(status));

	if (status != 0)
		printk(KERN_EMERG "ibm,os-term call failed %d\n", status);
}

/**
 * rtas_activate_firmware() - Activate a new version of firmware.
 *
 * Context: This function may sleep.
 *
 * Activate a new version of partition firmware. The OS must call this
 * after resuming from a partition hibernation or migration in order
 * to maintain the ability to perform live firmware updates. It's not
 * catastrophic for this method to be absent or to fail; just log the
 * condition in that case.
 */
void rtas_activate_firmware(void)
{
	int token;
	int fwrc;

	token = rtas_token("ibm,activate-firmware");
	if (token == RTAS_UNKNOWN_SERVICE) {
		pr_notice("ibm,activate-firmware method unavailable\n");
		return;
	}

	do {
		fwrc = rtas_call(token, 0, 1, NULL);
	} while (rtas_busy_delay(fwrc));

	if (fwrc)
		pr_err("ibm,activate-firmware failed (%i)\n", fwrc);
}

#ifdef CONFIG_PPC_PSERIES
/**
 * rtas_call_reentrant() - Used for reentrant rtas calls
 * @token:	Token for desired reentrant RTAS call
 * @nargs:	Number of Input Parameters
 * @nret:	Number of Output Parameters
 * @outputs:	Array of outputs
 * @...:	Inputs for desired RTAS call
 *
 * According to LoPAR documentation, only "ibm,int-on", "ibm,int-off",
 * "ibm,get-xive" and "ibm,set-xive" are currently reentrant.
 * Reentrant calls need their own rtas_args buffer, so not using rtas.args, but
 * PACA one instead.
 *
 * Return:	-1 on error,
 *		First output value of RTAS call if (nret > 0),
 *		0 otherwise,
 */
int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...)
{
	va_list list;
	struct rtas_args *args;
	unsigned long flags;
	int i, ret = 0;

	if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
		return -1;

	local_irq_save(flags);
	preempt_disable();

	/* We use the per-cpu (PACA) rtas args buffer */
	args = local_paca->rtas_args_reentrant;

	va_start(list, outputs);
	va_rtas_call_unlocked(args, token, nargs, nret, list);
	va_end(list);

	if (nret > 1 && outputs)
		for (i = 0; i < nret - 1; ++i)
			outputs[i] = be32_to_cpu(args->rets[i + 1]);

	if (nret > 0)
		ret = be32_to_cpu(args->rets[0]);

	local_irq_restore(flags);
	preempt_enable();

	return ret;
}

#endif /* CONFIG_PPC_PSERIES */

/**
 * get_pseries_errorlog() - Find a specific pseries error log in an RTAS
 *                          extended event log.
 * @log: RTAS error/event log
 * @section_id: two character section identifier
 *
 * Return: A pointer to the specified errorlog or NULL if not found.
 */
noinstr struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
						      uint16_t section_id)
{
	struct rtas_ext_event_log_v6 *ext_log =
		(struct rtas_ext_event_log_v6 *)log->buffer;
	struct pseries_errorlog *sect;
	unsigned char *p, *log_end;
	uint32_t ext_log_length = rtas_error_extended_log_length(log);
	uint8_t log_format = rtas_ext_event_log_format(ext_log);
	uint32_t company_id = rtas_ext_event_company_id(ext_log);

	/* Check that we understand the format */
	if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) ||
	    log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG ||
	    company_id != RTAS_V6EXT_COMPANY_ID_IBM)
		return NULL;

	log_end = log->buffer + ext_log_length;
	p = ext_log->vendor_log;

	while (p < log_end) {
		sect = (struct pseries_errorlog *)p;
		if (pseries_errorlog_id(sect) == section_id)
			return sect;
		p += pseries_errorlog_length(sect);
	}

	return NULL;
}

#ifdef CONFIG_PPC_RTAS_FILTER

/*
 * The sys_rtas syscall, as originally designed, allows root to pass
 * arbitrary physical addresses to RTAS calls. A number of RTAS calls
 * can be abused to write to arbitrary memory and do other things that
 * are potentially harmful to system integrity, and thus should only
 * be used inside the kernel and not exposed to userspace.
 *
 * All known legitimate users of the sys_rtas syscall will only ever
 * pass addresses that fall within the RMO buffer, and use a known
 * subset of RTAS calls.
 *
 * Accordingly, we filter RTAS requests to check that the call is
 * permitted, and that provided pointers fall within the RMO buffer.
 * The rtas_filters list contains an entry for each permitted call,
 * with the indexes of the parameters which are expected to contain
 * addresses and sizes of buffers allocated inside the RMO buffer.
 */
struct rtas_filter {
	const char *name;
	int token;
	/* Indexes into the args buffer, -1 if not used */
	int buf_idx1;
	int size_idx1;
	int buf_idx2;
	int size_idx2;

	int fixed_size;
};

static struct rtas_filter rtas_filters[] __ro_after_init = {
	{ "ibm,activate-firmware", -1, -1, -1, -1, -1 },
	{ "ibm,configure-connector", -1, 0, -1, 1, -1, 4096 },	/* Special cased */
	{ "display-character", -1, -1, -1, -1, -1 },
	{ "ibm,display-message", -1, 0, -1, -1, -1 },
	{ "ibm,errinjct", -1, 2, -1, -1, -1, 1024 },
	{ "ibm,close-errinjct", -1, -1, -1, -1, -1 },
	{ "ibm,open-errinjct", -1, -1, -1, -1, -1 },
	{ "ibm,get-config-addr-info2", -1, -1, -1, -1, -1 },
	{ "ibm,get-dynamic-sensor-state", -1, 1, -1, -1, -1 },
	{ "ibm,get-indices", -1, 2, 3, -1, -1 },
	{ "get-power-level", -1, -1, -1, -1, -1 },
	{ "get-sensor-state", -1, -1, -1, -1, -1 },
	{ "ibm,get-system-parameter", -1, 1, 2, -1, -1 },
	{ "get-time-of-day", -1, -1, -1, -1, -1 },
	{ "ibm,get-vpd", -1, 0, -1, 1, 2 },
	{ "ibm,lpar-perftools", -1, 2, 3, -1, -1 },
	{ "ibm,platform-dump", -1, 4, 5, -1, -1 },		/* Special cased */
	{ "ibm,read-slot-reset-state", -1, -1, -1, -1, -1 },
	{ "ibm,scan-log-dump", -1, 0, 1, -1, -1 },
	{ "ibm,set-dynamic-indicator", -1, 2, -1, -1, -1 },
	{ "ibm,set-eeh-option", -1, -1, -1, -1, -1 },
	{ "set-indicator", -1, -1, -1, -1, -1 },
	{ "set-power-level", -1, -1, -1, -1, -1 },
	{ "set-time-for-power-on", -1, -1, -1, -1, -1 },
	{ "ibm,set-system-parameter", -1, 1, -1, -1, -1 },
	{ "set-time-of-day", -1, -1, -1, -1, -1 },
#ifdef CONFIG_CPU_BIG_ENDIAN
	{ "ibm,suspend-me", -1, -1, -1, -1, -1 },
	{ "ibm,update-nodes", -1, 0, -1, -1, -1, 4096 },
	{ "ibm,update-properties", -1, 0, -1, -1, -1, 4096 },
#endif
	{ "ibm,physical-attestation", -1, 0, 1, -1, -1 },
};

static bool in_rmo_buf(u32 base, u32 end)
{
	return base >= rtas_rmo_buf &&
		base < (rtas_rmo_buf + RTAS_USER_REGION_SIZE) &&
		base <= end &&
		end >= rtas_rmo_buf &&
		end < (rtas_rmo_buf + RTAS_USER_REGION_SIZE);
}

static bool block_rtas_call(int token, int nargs,
			    struct rtas_args *args)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) {
		struct rtas_filter *f = &rtas_filters[i];
		u32 base, size, end;

		if (token != f->token)
			continue;

		if (f->buf_idx1 != -1) {
			base = be32_to_cpu(args->args[f->buf_idx1]);
			if (f->size_idx1 != -1)
				size = be32_to_cpu(args->args[f->size_idx1]);
			else if (f->fixed_size)
				size = f->fixed_size;
			else
				size = 1;

			end = base + size - 1;

			/*
			 * Special case for ibm,platform-dump - NULL buffer
			 * address is used to indicate end of dump processing
			 */
			if (!strcmp(f->name, "ibm,platform-dump") &&
			    base == 0)
				return false;

			if (!in_rmo_buf(base, end))
				goto err;
		}

		if (f->buf_idx2 != -1) {
			base = be32_to_cpu(args->args[f->buf_idx2]);
			if (f->size_idx2 != -1)
				size = be32_to_cpu(args->args[f->size_idx2]);
			else if (f->fixed_size)
				size = f->fixed_size;
			else
				size = 1;
			end = base + size - 1;

			/*
			 * Special case for ibm,configure-connector where the
			 * address can be 0
			 */
			if (!strcmp(f->name, "ibm,configure-connector") &&
			    base == 0)
				return false;

			if (!in_rmo_buf(base, end))
				goto err;
		}

		return false;
	}

err:
	pr_err_ratelimited("sys_rtas: RTAS call blocked - exploit attempt?\n");
	pr_err_ratelimited("sys_rtas: token=0x%x, nargs=%d (called by %s)\n",
			   token, nargs, current->comm);
	return true;
}

static void __init rtas_syscall_filter_init(void)
{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(rtas_filters); i++)
		rtas_filters[i].token = rtas_token(rtas_filters[i].name);
}

#else

static bool block_rtas_call(int token, int nargs,
			    struct rtas_args *args)
{
	return false;
}

static void __init rtas_syscall_filter_init(void)
{
}

#endif /* CONFIG_PPC_RTAS_FILTER */

/* We assume to be passed big endian arguments */
SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
{
	struct rtas_args args;
	unsigned long flags;
	char *buff_copy, *errbuf = NULL;
	int nargs, nret, token;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	if (!rtas.entry)
		return -EINVAL;

	if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
		return -EFAULT;

	nargs = be32_to_cpu(args.nargs);
	nret  = be32_to_cpu(args.nret);
	token = be32_to_cpu(args.token);

	if (nargs >= ARRAY_SIZE(args.args)
	    || nret > ARRAY_SIZE(args.args)
	    || nargs + nret > ARRAY_SIZE(args.args))
		return -EINVAL;

	/* Copy in args. */
	if (copy_from_user(args.args, uargs->args,
			   nargs * sizeof(rtas_arg_t)) != 0)
		return -EFAULT;

	if (token == RTAS_UNKNOWN_SERVICE)
		return -EINVAL;

	args.rets = &args.args[nargs];
	memset(args.rets, 0, nret * sizeof(rtas_arg_t));

	if (block_rtas_call(token, nargs, &args))
		return -EINVAL;

	/* Need to handle ibm,suspend_me call specially */
	if (token == rtas_token("ibm,suspend-me")) {

		/*
		 * rtas_ibm_suspend_me assumes the streamid handle is in cpu
		 * endian, or at least the hcall within it requires it.
		 */
		int rc = 0;
		u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32)
		              | be32_to_cpu(args.args[1]);
		rc = rtas_syscall_dispatch_ibm_suspend_me(handle);
		if (rc == -EAGAIN)
			args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE);
		else if (rc == -EIO)
			args.rets[0] = cpu_to_be32(-1);
		else if (rc)
			return rc;
		goto copy_return;
	}

	buff_copy = get_errorlog_buffer();

	flags = lock_rtas();

	rtas.args = args;
	do_enter_rtas(__pa(&rtas.args));
	args = rtas.args;

	/* A -1 return code indicates that the last command couldn't
	   be completed due to a hardware error. */
	if (be32_to_cpu(args.rets[0]) == -1)
		errbuf = __fetch_rtas_last_error(buff_copy);

	unlock_rtas(flags);

	if (buff_copy) {
		if (errbuf)
			log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
		kfree(buff_copy);
	}

 copy_return:
	/* Copy out args. */
	if (copy_to_user(uargs->args + nargs,
			 args.args + nargs,
			 nret * sizeof(rtas_arg_t)) != 0)
		return -EFAULT;

	return 0;
}

/*
 * Call early during boot, before mem init, to retrieve the RTAS
 * information from the device-tree and allocate the RMO buffer for userland
 * accesses.
 */
void __init rtas_initialize(void)
{
	unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
	u32 base, size, entry;
	int no_base, no_size, no_entry;

	/* Get RTAS dev node and fill up our "rtas" structure with infos
	 * about it.
	 */
	rtas.dev = of_find_node_by_name(NULL, "rtas");
	if (!rtas.dev)
		return;

	no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base);
	no_size = of_property_read_u32(rtas.dev, "rtas-size", &size);
	if (no_base || no_size) {
		of_node_put(rtas.dev);
		rtas.dev = NULL;
		return;
	}

	rtas.base = base;
	rtas.size = size;
	no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry);
	rtas.entry = no_entry ? rtas.base : entry;

	/* If RTAS was found, allocate the RMO buffer for it and look for
	 * the stop-self token if any
	 */
#ifdef CONFIG_PPC64
	if (firmware_has_feature(FW_FEATURE_LPAR))
		rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX);
#endif
	rtas_rmo_buf = memblock_phys_alloc_range(RTAS_USER_REGION_SIZE, PAGE_SIZE,
						 0, rtas_region);
	if (!rtas_rmo_buf)
		panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n",
		      PAGE_SIZE, &rtas_region);

#ifdef CONFIG_RTAS_ERROR_LOGGING
	rtas_last_error_token = rtas_token("rtas-last-error");
#endif

	rtas_syscall_filter_init();
}

int __init early_init_dt_scan_rtas(unsigned long node,
		const char *uname, int depth, void *data)
{
	const u32 *basep, *entryp, *sizep;

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

	basep  = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
	entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
	sizep  = of_get_flat_dt_prop(node, "rtas-size", NULL);

#ifdef CONFIG_PPC64
	/* need this feature to decide the crashkernel offset */
	if (of_get_flat_dt_prop(node, "ibm,hypertas-functions", NULL))
		powerpc_firmware_features |= FW_FEATURE_LPAR;
#endif

	if (basep && entryp && sizep) {
		rtas.base = *basep;
		rtas.entry = *entryp;
		rtas.size = *sizep;
	}

#ifdef CONFIG_UDBG_RTAS_CONSOLE
	basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
	if (basep)
		rtas_putchar_token = *basep;

	basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
	if (basep)
		rtas_getchar_token = *basep;

	if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
	    rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
		udbg_init_rtas_console();

#endif

	/* break now */
	return 1;
}

static arch_spinlock_t timebase_lock;
static u64 timebase = 0;

void rtas_give_timebase(void)
{
	unsigned long flags;

	local_irq_save(flags);
	hard_irq_disable();
	arch_spin_lock(&timebase_lock);
	rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
	timebase = get_tb();
	arch_spin_unlock(&timebase_lock);

	while (timebase)
		barrier();
	rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
	local_irq_restore(flags);
}

void rtas_take_timebase(void)
{
	while (!timebase)
		barrier();
	arch_spin_lock(&timebase_lock);
	set_tb(timebase >> 32, timebase & 0xffffffff);
	timebase = 0;
	arch_spin_unlock(&timebase_lock);
}