summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/prom.c
blob: f00f83109ab309bbe38cca6a989155795413d4a7 (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
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
/*
 * Procedures for creating, accessing and interpreting the device tree.
 *
 * Paul Mackerras	August 1996.
 * Copyright (C) 1996-2005 Paul Mackerras.
 * 
 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
 *    {engebret|bergner}@us.ibm.com 
 *
 *      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.
 */

#undef DEBUG

#include <stdarg.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/threads.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/stringify.h>
#include <linux/delay.h>
#include <linux/initrd.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/kexec.h>
#include <linux/debugfs.h>
#include <linux/irq.h>
#include <linux/lmb.h>

#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/page.h>
#include <asm/processor.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/kdump.h>
#include <asm/smp.h>
#include <asm/system.h>
#include <asm/mmu.h>
#include <asm/pgtable.h>
#include <asm/pci.h>
#include <asm/iommu.h>
#include <asm/btext.h>
#include <asm/sections.h>
#include <asm/machdep.h>
#include <asm/pSeries_reconfig.h>
#include <asm/pci-bridge.h>
#include <asm/phyp_dump.h>
#include <asm/kexec.h>
#include <mm/mmu_decl.h>

#ifdef DEBUG
#define DBG(fmt...) printk(KERN_ERR fmt)
#else
#define DBG(fmt...)
#endif


static int __initdata dt_root_addr_cells;
static int __initdata dt_root_size_cells;

#ifdef CONFIG_PPC64
int __initdata iommu_is_off;
int __initdata iommu_force_on;
unsigned long tce_alloc_start, tce_alloc_end;
#endif

typedef u32 cell_t;

#if 0
static struct boot_param_header *initial_boot_params __initdata;
#else
struct boot_param_header *initial_boot_params;
#endif

extern struct device_node *allnodes;	/* temporary while merging */

extern rwlock_t devtree_lock;	/* temporary while merging */

/* export that to outside world */
struct device_node *of_chosen;

static inline char *find_flat_dt_string(u32 offset)
{
	return ((char *)initial_boot_params) +
		initial_boot_params->off_dt_strings + offset;
}

/**
 * This function is used to scan the flattened device-tree, it is
 * used to extract the memory informations at boot before we can
 * unflatten the tree
 */
int __init of_scan_flat_dt(int (*it)(unsigned long node,
				     const char *uname, int depth,
				     void *data),
			   void *data)
{
	unsigned long p = ((unsigned long)initial_boot_params) +
		initial_boot_params->off_dt_struct;
	int rc = 0;
	int depth = -1;

	do {
		u32 tag = *((u32 *)p);
		char *pathp;
		
		p += 4;
		if (tag == OF_DT_END_NODE) {
			depth --;
			continue;
		}
		if (tag == OF_DT_NOP)
			continue;
		if (tag == OF_DT_END)
			break;
		if (tag == OF_DT_PROP) {
			u32 sz = *((u32 *)p);
			p += 8;
			if (initial_boot_params->version < 0x10)
				p = _ALIGN(p, sz >= 8 ? 8 : 4);
			p += sz;
			p = _ALIGN(p, 4);
			continue;
		}
		if (tag != OF_DT_BEGIN_NODE) {
			printk(KERN_WARNING "Invalid tag %x scanning flattened"
			       " device tree !\n", tag);
			return -EINVAL;
		}
		depth++;
		pathp = (char *)p;
		p = _ALIGN(p + strlen(pathp) + 1, 4);
		if ((*pathp) == '/') {
			char *lp, *np;
			for (lp = NULL, np = pathp; *np; np++)
				if ((*np) == '/')
					lp = np+1;
			if (lp != NULL)
				pathp = lp;
		}
		rc = it(p, pathp, depth, data);
		if (rc != 0)
			break;		
	} while(1);

	return rc;
}

unsigned long __init of_get_flat_dt_root(void)
{
	unsigned long p = ((unsigned long)initial_boot_params) +
		initial_boot_params->off_dt_struct;

	while(*((u32 *)p) == OF_DT_NOP)
		p += 4;
	BUG_ON (*((u32 *)p) != OF_DT_BEGIN_NODE);
	p += 4;
	return _ALIGN(p + strlen((char *)p) + 1, 4);
}

/**
 * This  function can be used within scan_flattened_dt callback to get
 * access to properties
 */
void* __init of_get_flat_dt_prop(unsigned long node, const char *name,
				 unsigned long *size)
{
	unsigned long p = node;

	do {
		u32 tag = *((u32 *)p);
		u32 sz, noff;
		const char *nstr;

		p += 4;
		if (tag == OF_DT_NOP)
			continue;
		if (tag != OF_DT_PROP)
			return NULL;

		sz = *((u32 *)p);
		noff = *((u32 *)(p + 4));
		p += 8;
		if (initial_boot_params->version < 0x10)
			p = _ALIGN(p, sz >= 8 ? 8 : 4);

		nstr = find_flat_dt_string(noff);
		if (nstr == NULL) {
			printk(KERN_WARNING "Can't find property index"
			       " name !\n");
			return NULL;
		}
		if (strcmp(name, nstr) == 0) {
			if (size)
				*size = sz;
			return (void *)p;
		}
		p += sz;
		p = _ALIGN(p, 4);
	} while(1);
}

int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
{
	const char* cp;
	unsigned long cplen, l;

	cp = of_get_flat_dt_prop(node, "compatible", &cplen);
	if (cp == NULL)
		return 0;
	while (cplen > 0) {
		if (strncasecmp(cp, compat, strlen(compat)) == 0)
			return 1;
		l = strlen(cp) + 1;
		cp += l;
		cplen -= l;
	}

	return 0;
}

static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
				       unsigned long align)
{
	void *res;

	*mem = _ALIGN(*mem, align);
	res = (void *)*mem;
	*mem += size;

	return res;
}

static unsigned long __init unflatten_dt_node(unsigned long mem,
					      unsigned long *p,
					      struct device_node *dad,
					      struct device_node ***allnextpp,
					      unsigned long fpsize)
{
	struct device_node *np;
	struct property *pp, **prev_pp = NULL;
	char *pathp;
	u32 tag;
	unsigned int l, allocl;
	int has_name = 0;
	int new_format = 0;

	tag = *((u32 *)(*p));
	if (tag != OF_DT_BEGIN_NODE) {
		printk("Weird tag at start of node: %x\n", tag);
		return mem;
	}
	*p += 4;
	pathp = (char *)*p;
	l = allocl = strlen(pathp) + 1;
	*p = _ALIGN(*p + l, 4);

	/* version 0x10 has a more compact unit name here instead of the full
	 * path. we accumulate the full path size using "fpsize", we'll rebuild
	 * it later. We detect this because the first character of the name is
	 * not '/'.
	 */
	if ((*pathp) != '/') {
		new_format = 1;
		if (fpsize == 0) {
			/* root node: special case. fpsize accounts for path
			 * plus terminating zero. root node only has '/', so
			 * fpsize should be 2, but we want to avoid the first
			 * level nodes to have two '/' so we use fpsize 1 here
			 */
			fpsize = 1;
			allocl = 2;
		} else {
			/* account for '/' and path size minus terminal 0
			 * already in 'l'
			 */
			fpsize += l;
			allocl = fpsize;
		}
	}


	np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
				__alignof__(struct device_node));
	if (allnextpp) {
		memset(np, 0, sizeof(*np));
		np->full_name = ((char*)np) + sizeof(struct device_node);
		if (new_format) {
			char *p = np->full_name;
			/* rebuild full path for new format */
			if (dad && dad->parent) {
				strcpy(p, dad->full_name);
#ifdef DEBUG
				if ((strlen(p) + l + 1) != allocl) {
					DBG("%s: p: %d, l: %d, a: %d\n",
					    pathp, (int)strlen(p), l, allocl);
				}
#endif
				p += strlen(p);
			}
			*(p++) = '/';
			memcpy(p, pathp, l);
		} else
			memcpy(np->full_name, pathp, l);
		prev_pp = &np->properties;
		**allnextpp = np;
		*allnextpp = &np->allnext;
		if (dad != NULL) {
			np->parent = dad;
			/* we temporarily use the next field as `last_child'*/
			if (dad->next == 0)
				dad->child = np;
			else
				dad->next->sibling = np;
			dad->next = np;
		}
		kref_init(&np->kref);
	}
	while(1) {
		u32 sz, noff;
		char *pname;

		tag = *((u32 *)(*p));
		if (tag == OF_DT_NOP) {
			*p += 4;
			continue;
		}
		if (tag != OF_DT_PROP)
			break;
		*p += 4;
		sz = *((u32 *)(*p));
		noff = *((u32 *)((*p) + 4));
		*p += 8;
		if (initial_boot_params->version < 0x10)
			*p = _ALIGN(*p, sz >= 8 ? 8 : 4);

		pname = find_flat_dt_string(noff);
		if (pname == NULL) {
			printk("Can't find property name in list !\n");
			break;
		}
		if (strcmp(pname, "name") == 0)
			has_name = 1;
		l = strlen(pname) + 1;
		pp = unflatten_dt_alloc(&mem, sizeof(struct property),
					__alignof__(struct property));
		if (allnextpp) {
			if (strcmp(pname, "linux,phandle") == 0) {
				np->node = *((u32 *)*p);
				if (np->linux_phandle == 0)
					np->linux_phandle = np->node;
			}
			if (strcmp(pname, "ibm,phandle") == 0)
				np->linux_phandle = *((u32 *)*p);
			pp->name = pname;
			pp->length = sz;
			pp->value = (void *)*p;
			*prev_pp = pp;
			prev_pp = &pp->next;
		}
		*p = _ALIGN((*p) + sz, 4);
	}
	/* with version 0x10 we may not have the name property, recreate
	 * it here from the unit name if absent
	 */
	if (!has_name) {
		char *p = pathp, *ps = pathp, *pa = NULL;
		int sz;

		while (*p) {
			if ((*p) == '@')
				pa = p;
			if ((*p) == '/')
				ps = p + 1;
			p++;
		}
		if (pa < ps)
			pa = p;
		sz = (pa - ps) + 1;
		pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
					__alignof__(struct property));
		if (allnextpp) {
			pp->name = "name";
			pp->length = sz;
			pp->value = pp + 1;
			*prev_pp = pp;
			prev_pp = &pp->next;
			memcpy(pp->value, ps, sz - 1);
			((char *)pp->value)[sz - 1] = 0;
			DBG("fixed up name for %s -> %s\n", pathp,
				(char *)pp->value);
		}
	}
	if (allnextpp) {
		*prev_pp = NULL;
		np->name = of_get_property(np, "name", NULL);
		np->type = of_get_property(np, "device_type", NULL);

		if (!np->name)
			np->name = "<NULL>";
		if (!np->type)
			np->type = "<NULL>";
	}
	while (tag == OF_DT_BEGIN_NODE) {
		mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
		tag = *((u32 *)(*p));
	}
	if (tag != OF_DT_END_NODE) {
		printk("Weird tag at end of node: %x\n", tag);
		return mem;
	}
	*p += 4;
	return mem;
}

static int __init early_parse_mem(char *p)
{
	if (!p)
		return 1;

	memory_limit = PAGE_ALIGN(memparse(p, &p));
	DBG("memory limit = 0x%lx\n", memory_limit);

	return 0;
}
early_param("mem", early_parse_mem);

/**
 * move_device_tree - move tree to an unused area, if needed.
 *
 * The device tree may be allocated beyond our memory limit, or inside the
 * crash kernel region for kdump. If so, move it out of the way.
 */
static void __init move_device_tree(void)
{
	unsigned long start, size;
	void *p;

	DBG("-> move_device_tree\n");

	start = __pa(initial_boot_params);
	size = initial_boot_params->totalsize;

	if ((memory_limit && (start + size) > memory_limit) ||
			overlaps_crashkernel(start, size)) {
		p = __va(lmb_alloc_base(size, PAGE_SIZE, lmb.rmo_size));
		memcpy(p, initial_boot_params, size);
		initial_boot_params = (struct boot_param_header *)p;
		DBG("Moved device tree to 0x%p\n", p);
	}

	DBG("<- move_device_tree\n");
}

/**
 * unflattens the device-tree passed by the firmware, creating the
 * tree of struct device_node. It also fills the "name" and "type"
 * pointers of the nodes so the normal device-tree walking functions
 * can be used (this used to be done by finish_device_tree)
 */
void __init unflatten_device_tree(void)
{
	unsigned long start, mem, size;
	struct device_node **allnextp = &allnodes;

	DBG(" -> unflatten_device_tree()\n");

	/* First pass, scan for size */
	start = ((unsigned long)initial_boot_params) +
		initial_boot_params->off_dt_struct;
	size = unflatten_dt_node(0, &start, NULL, NULL, 0);
	size = (size | 3) + 1;

	DBG("  size is %lx, allocating...\n", size);

	/* Allocate memory for the expanded device tree */
	mem = lmb_alloc(size + 4, __alignof__(struct device_node));
	mem = (unsigned long) __va(mem);

	((u32 *)mem)[size / 4] = 0xdeadbeef;

	DBG("  unflattening %lx...\n", mem);

	/* Second pass, do actual unflattening */
	start = ((unsigned long)initial_boot_params) +
		initial_boot_params->off_dt_struct;
	unflatten_dt_node(mem, &start, NULL, &allnextp, 0);
	if (*((u32 *)start) != OF_DT_END)
		printk(KERN_WARNING "Weird tag at end of tree: %08x\n", *((u32 *)start));
	if (((u32 *)mem)[size / 4] != 0xdeadbeef)
		printk(KERN_WARNING "End of tree marker overwritten: %08x\n",
		       ((u32 *)mem)[size / 4] );
	*allnextp = NULL;

	/* Get pointer to OF "/chosen" node for use everywhere */
	of_chosen = of_find_node_by_path("/chosen");
	if (of_chosen == NULL)
		of_chosen = of_find_node_by_path("/chosen@0");

	DBG(" <- unflatten_device_tree()\n");
}

/*
 * ibm,pa-features is a per-cpu property that contains a string of
 * attribute descriptors, each of which has a 2 byte header plus up
 * to 254 bytes worth of processor attribute bits.  First header
 * byte specifies the number of bytes following the header.
 * Second header byte is an "attribute-specifier" type, of which
 * zero is the only currently-defined value.
 * Implementation:  Pass in the byte and bit offset for the feature
 * that we are interested in.  The function will return -1 if the
 * pa-features property is missing, or a 1/0 to indicate if the feature
 * is supported/not supported.  Note that the bit numbers are
 * big-endian to match the definition in PAPR.
 */
static struct ibm_pa_feature {
	unsigned long	cpu_features;	/* CPU_FTR_xxx bit */
	unsigned int	cpu_user_ftrs;	/* PPC_FEATURE_xxx bit */
	unsigned char	pabyte;		/* byte number in ibm,pa-features */
	unsigned char	pabit;		/* bit number (big-endian) */
	unsigned char	invert;		/* if 1, pa bit set => clear feature */
} ibm_pa_features[] __initdata = {
	{0, PPC_FEATURE_HAS_MMU,	0, 0, 0},
	{0, PPC_FEATURE_HAS_FPU,	0, 1, 0},
	{CPU_FTR_SLB, 0,		0, 2, 0},
	{CPU_FTR_CTRL, 0,		0, 3, 0},
	{CPU_FTR_NOEXECUTE, 0,		0, 6, 0},
	{CPU_FTR_NODSISRALIGN, 0,	1, 1, 1},
	{CPU_FTR_CI_LARGE_PAGE, 0,	1, 2, 0},
	{CPU_FTR_REAL_LE, PPC_FEATURE_TRUE_LE, 5, 0, 0},
};

static void __init scan_features(unsigned long node, unsigned char *ftrs,
				 unsigned long tablelen,
				 struct ibm_pa_feature *fp,
				 unsigned long ft_size)
{
	unsigned long i, len, bit;

	/* find descriptor with type == 0 */
	for (;;) {
		if (tablelen < 3)
			return;
		len = 2 + ftrs[0];
		if (tablelen < len)
			return;		/* descriptor 0 not found */
		if (ftrs[1] == 0)
			break;
		tablelen -= len;
		ftrs += len;
	}

	/* loop over bits we know about */
	for (i = 0; i < ft_size; ++i, ++fp) {
		if (fp->pabyte >= ftrs[0])
			continue;
		bit = (ftrs[2 + fp->pabyte] >> (7 - fp->pabit)) & 1;
		if (bit ^ fp->invert) {
			cur_cpu_spec->cpu_features |= fp->cpu_features;
			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftrs;
		} else {
			cur_cpu_spec->cpu_features &= ~fp->cpu_features;
			cur_cpu_spec->cpu_user_features &= ~fp->cpu_user_ftrs;
		}
	}
}

static void __init check_cpu_pa_features(unsigned long node)
{
	unsigned char *pa_ftrs;
	unsigned long tablelen;

	pa_ftrs = of_get_flat_dt_prop(node, "ibm,pa-features", &tablelen);
	if (pa_ftrs == NULL)
		return;

	scan_features(node, pa_ftrs, tablelen,
		      ibm_pa_features, ARRAY_SIZE(ibm_pa_features));
}

#ifdef CONFIG_PPC64
static void __init check_cpu_slb_size(unsigned long node)
{
	u32 *slb_size_ptr;

	slb_size_ptr = of_get_flat_dt_prop(node, "slb-size", NULL);
	if (slb_size_ptr != NULL) {
		mmu_slb_size = *slb_size_ptr;
		return;
	}
	slb_size_ptr = of_get_flat_dt_prop(node, "ibm,slb-size", NULL);
	if (slb_size_ptr != NULL) {
		mmu_slb_size = *slb_size_ptr;
	}
}
#else
#define check_cpu_slb_size(node) do { } while(0)
#endif

static struct feature_property {
	const char *name;
	u32 min_value;
	unsigned long cpu_feature;
	unsigned long cpu_user_ftr;
} feature_properties[] __initdata = {
#ifdef CONFIG_ALTIVEC
	{"altivec", 0, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
	{"ibm,vmx", 1, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_VSX
	/* Yes, this _really_ is ibm,vmx == 2 to enable VSX */
	{"ibm,vmx", 2, CPU_FTR_VSX, PPC_FEATURE_HAS_VSX},
#endif /* CONFIG_VSX */
#ifdef CONFIG_PPC64
	{"ibm,dfp", 1, 0, PPC_FEATURE_HAS_DFP},
	{"ibm,purr", 1, CPU_FTR_PURR, 0},
	{"ibm,spurr", 1, CPU_FTR_SPURR, 0},
#endif /* CONFIG_PPC64 */
};

#if defined(CONFIG_44x) && defined(CONFIG_PPC_FPU)
static inline void identical_pvr_fixup(unsigned long node)
{
	unsigned int pvr;
	char *model = of_get_flat_dt_prop(node, "model", NULL);

	/*
	 * Since 440GR(x)/440EP(x) processors have the same pvr,
	 * we check the node path and set bit 28 in the cur_cpu_spec
	 * pvr for EP(x) processor version. This bit is always 0 in
	 * the "real" pvr. Then we call identify_cpu again with
	 * the new logical pvr to enable FPU support.
	 */
	if (model && strstr(model, "440EP")) {
		pvr = cur_cpu_spec->pvr_value | 0x8;
		identify_cpu(0, pvr);
		DBG("Using logical pvr %x for %s\n", pvr, model);
	}
}
#else
#define identical_pvr_fixup(node) do { } while(0)
#endif

static void __init check_cpu_feature_properties(unsigned long node)
{
	unsigned long i;
	struct feature_property *fp = feature_properties;
	const u32 *prop;

	for (i = 0; i < ARRAY_SIZE(feature_properties); ++i, ++fp) {
		prop = of_get_flat_dt_prop(node, fp->name, NULL);
		if (prop && *prop >= fp->min_value) {
			cur_cpu_spec->cpu_features |= fp->cpu_feature;
			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftr;
		}
	}
}

static int __init early_init_dt_scan_cpus(unsigned long node,
					  const char *uname, int depth,
					  void *data)
{
	static int logical_cpuid = 0;
	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
	const u32 *prop;
	const u32 *intserv;
	int i, nthreads;
	unsigned long len;
	int found = 0;

	/* We are scanning "cpu" nodes only */
	if (type == NULL || strcmp(type, "cpu") != 0)
		return 0;

	/* Get physical cpuid */
	intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
	if (intserv) {
		nthreads = len / sizeof(int);
	} else {
		intserv = of_get_flat_dt_prop(node, "reg", NULL);
		nthreads = 1;
	}

	/*
	 * Now see if any of these threads match our boot cpu.
	 * NOTE: This must match the parsing done in smp_setup_cpu_maps.
	 */
	for (i = 0; i < nthreads; i++) {
		/*
		 * version 2 of the kexec param format adds the phys cpuid of
		 * booted proc.
		 */
		if (initial_boot_params && initial_boot_params->version >= 2) {
			if (intserv[i] ==
					initial_boot_params->boot_cpuid_phys) {
				found = 1;
				break;
			}
		} else {
			/*
			 * Check if it's the boot-cpu, set it's hw index now,
			 * unfortunately this format did not support booting
			 * off secondary threads.
			 */
			if (of_get_flat_dt_prop(node,
					"linux,boot-cpu", NULL) != NULL) {
				found = 1;
				break;
			}
		}

#ifdef CONFIG_SMP
		/* logical cpu id is always 0 on UP kernels */
		logical_cpuid++;
#endif
	}

	if (found) {
		DBG("boot cpu: logical %d physical %d\n", logical_cpuid,
			intserv[i]);
		boot_cpuid = logical_cpuid;
		set_hard_smp_processor_id(boot_cpuid, intserv[i]);

		/*
		 * PAPR defines "logical" PVR values for cpus that
		 * meet various levels of the architecture:
		 * 0x0f000001	Architecture version 2.04
		 * 0x0f000002	Architecture version 2.05
		 * If the cpu-version property in the cpu node contains
		 * such a value, we call identify_cpu again with the
		 * logical PVR value in order to use the cpu feature
		 * bits appropriate for the architecture level.
		 *
		 * A POWER6 partition in "POWER6 architected" mode
		 * uses the 0x0f000002 PVR value; in POWER5+ mode
		 * it uses 0x0f000001.
		 */
		prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
		if (prop && (*prop & 0xff000000) == 0x0f000000)
			identify_cpu(0, *prop);

		identical_pvr_fixup(node);
	}

	check_cpu_feature_properties(node);
	check_cpu_pa_features(node);
	check_cpu_slb_size(node);

#ifdef CONFIG_PPC_PSERIES
	if (nthreads > 1)
		cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
	else
		cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
#endif

	return 0;
}

#ifdef CONFIG_BLK_DEV_INITRD
static void __init early_init_dt_check_for_initrd(unsigned long node)
{
	unsigned long l;
	u32 *prop;

	DBG("Looking for initrd properties... ");

	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &l);
	if (prop) {
		initrd_start = (unsigned long)__va(of_read_ulong(prop, l/4));

		prop = of_get_flat_dt_prop(node, "linux,initrd-end", &l);
		if (prop) {
			initrd_end = (unsigned long)
					__va(of_read_ulong(prop, l/4));
			initrd_below_start_ok = 1;
		} else {
			initrd_start = 0;
		}
	}

	DBG("initrd_start=0x%lx  initrd_end=0x%lx\n", initrd_start, initrd_end);
}
#else
static inline void early_init_dt_check_for_initrd(unsigned long node)
{
}
#endif /* CONFIG_BLK_DEV_INITRD */

static int __init early_init_dt_scan_chosen(unsigned long node,
					    const char *uname, int depth, void *data)
{
	unsigned long *lprop;
	unsigned long l;
	char *p;

	DBG("search \"chosen\", depth: %d, uname: %s\n", depth, uname);

	if (depth != 1 ||
	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
		return 0;

#ifdef CONFIG_PPC64
	/* check if iommu is forced on or off */
	if (of_get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
		iommu_is_off = 1;
	if (of_get_flat_dt_prop(node, "linux,iommu-force-on", NULL) != NULL)
		iommu_force_on = 1;
#endif

	/* mem=x on the command line is the preferred mechanism */
 	lprop = of_get_flat_dt_prop(node, "linux,memory-limit", NULL);
 	if (lprop)
 		memory_limit = *lprop;

#ifdef CONFIG_PPC64
 	lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-start", NULL);
 	if (lprop)
 		tce_alloc_start = *lprop;
 	lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-end", NULL);
 	if (lprop)
 		tce_alloc_end = *lprop;
#endif

#ifdef CONFIG_KEXEC
	lprop = of_get_flat_dt_prop(node, "linux,crashkernel-base", NULL);
	if (lprop)
		crashk_res.start = *lprop;

	lprop = of_get_flat_dt_prop(node, "linux,crashkernel-size", NULL);
	if (lprop)
		crashk_res.end = crashk_res.start + *lprop - 1;
#endif

	early_init_dt_check_for_initrd(node);

	/* Retreive command line */
 	p = of_get_flat_dt_prop(node, "bootargs", &l);
	if (p != NULL && l > 0)
		strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE));

#ifdef CONFIG_CMDLINE
	if (p == NULL || l == 0 || (l == 1 && (*p) == 0))
		strlcpy(cmd_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
#endif /* CONFIG_CMDLINE */

	DBG("Command line is: %s\n", cmd_line);

	/* break now */
	return 1;
}

static int __init early_init_dt_scan_root(unsigned long node,
					  const char *uname, int depth, void *data)
{
	u32 *prop;

	if (depth != 0)
		return 0;

	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
	dt_root_size_cells = (prop == NULL) ? 1 : *prop;
	DBG("dt_root_size_cells = %x\n", dt_root_size_cells);

	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
	dt_root_addr_cells = (prop == NULL) ? 2 : *prop;
	DBG("dt_root_addr_cells = %x\n", dt_root_addr_cells);
	
	/* break now */
	return 1;
}

static u64 __init dt_mem_next_cell(int s, cell_t **cellp)
{
	cell_t *p = *cellp;

	*cellp = p + s;
	return of_read_number(p, s);
}

#ifdef CONFIG_PPC_PSERIES
/*
 * Interpret the ibm,dynamic-memory property in the
 * /ibm,dynamic-reconfiguration-memory node.
 * This contains a list of memory blocks along with NUMA affinity
 * information.
 */
static int __init early_init_dt_scan_drconf_memory(unsigned long node)
{
	cell_t *dm, *ls, *usm;
	unsigned long l, n, flags;
	u64 base, size, lmb_size;
	unsigned int is_kexec_kdump = 0, rngs;

	ls = of_get_flat_dt_prop(node, "ibm,lmb-size", &l);
	if (ls == NULL || l < dt_root_size_cells * sizeof(cell_t))
		return 0;
	lmb_size = dt_mem_next_cell(dt_root_size_cells, &ls);

	dm = of_get_flat_dt_prop(node, "ibm,dynamic-memory", &l);
	if (dm == NULL || l < sizeof(cell_t))
		return 0;

	n = *dm++;	/* number of entries */
	if (l < (n * (dt_root_addr_cells + 4) + 1) * sizeof(cell_t))
		return 0;

	/* check if this is a kexec/kdump kernel. */
	usm = of_get_flat_dt_prop(node, "linux,drconf-usable-memory",
						 &l);
	if (usm != NULL)
		is_kexec_kdump = 1;

	for (; n != 0; --n) {
		base = dt_mem_next_cell(dt_root_addr_cells, &dm);
		flags = dm[3];
		/* skip DRC index, pad, assoc. list index, flags */
		dm += 4;
		/* skip this block if the reserved bit is set in flags (0x80)
		   or if the block is not assigned to this partition (0x8) */
		if ((flags & 0x80) || !(flags & 0x8))
			continue;
		size = lmb_size;
		rngs = 1;
		if (is_kexec_kdump) {
			/*
			 * For each lmb in ibm,dynamic-memory, a corresponding
			 * entry in linux,drconf-usable-memory property contains
			 * a counter 'p' followed by 'p' (base, size) duple.
			 * Now read the counter from
			 * linux,drconf-usable-memory property
			 */
			rngs = dt_mem_next_cell(dt_root_size_cells, &usm);
			if (!rngs) /* there are no (base, size) duple */
				continue;
		}
		do {
			if (is_kexec_kdump) {
				base = dt_mem_next_cell(dt_root_addr_cells,
							 &usm);
				size = dt_mem_next_cell(dt_root_size_cells,
							 &usm);
			}
			if (iommu_is_off) {
				if (base >= 0x80000000ul)
					continue;
				if ((base + size) > 0x80000000ul)
					size = 0x80000000ul - base;
			}
			lmb_add(base, size);
		} while (--rngs);
	}
	lmb_dump_all();
	return 0;
}
#else
#define early_init_dt_scan_drconf_memory(node)	0
#endif /* CONFIG_PPC_PSERIES */

static int __init early_init_dt_scan_memory(unsigned long node,
					    const char *uname, int depth, void *data)
{
	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
	cell_t *reg, *endp;
	unsigned long l;

	/* Look for the ibm,dynamic-reconfiguration-memory node */
	if (depth == 1 &&
	    strcmp(uname, "ibm,dynamic-reconfiguration-memory") == 0)
		return early_init_dt_scan_drconf_memory(node);

	/* We are scanning "memory" nodes only */
	if (type == NULL) {
		/*
		 * The longtrail doesn't have a device_type on the
		 * /memory node, so look for the node called /memory@0.
		 */
		if (depth != 1 || strcmp(uname, "memory@0") != 0)
			return 0;
	} else if (strcmp(type, "memory") != 0)
		return 0;

	reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
	if (reg == NULL)
		reg = of_get_flat_dt_prop(node, "reg", &l);
	if (reg == NULL)
		return 0;

	endp = reg + (l / sizeof(cell_t));

	DBG("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
	    uname, l, reg[0], reg[1], reg[2], reg[3]);

	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
		u64 base, size;

		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
		size = dt_mem_next_cell(dt_root_size_cells, &reg);

		if (size == 0)
			continue;
		DBG(" - %llx ,  %llx\n", (unsigned long long)base,
		    (unsigned long long)size);
#ifdef CONFIG_PPC64
		if (iommu_is_off) {
			if (base >= 0x80000000ul)
				continue;
			if ((base + size) > 0x80000000ul)
				size = 0x80000000ul - base;
		}
#endif
		lmb_add(base, size);

		memstart_addr = min((u64)memstart_addr, base);
	}

	return 0;
}

static void __init early_reserve_mem(void)
{
	u64 base, size;
	u64 *reserve_map;
	unsigned long self_base;
	unsigned long self_size;

	reserve_map = (u64 *)(((unsigned long)initial_boot_params) +
					initial_boot_params->off_mem_rsvmap);

	/* before we do anything, lets reserve the dt blob */
	self_base = __pa((unsigned long)initial_boot_params);
	self_size = initial_boot_params->totalsize;
	lmb_reserve(self_base, self_size);

#ifdef CONFIG_BLK_DEV_INITRD
	/* then reserve the initrd, if any */
	if (initrd_start && (initrd_end > initrd_start))
		lmb_reserve(__pa(initrd_start), initrd_end - initrd_start);
#endif /* CONFIG_BLK_DEV_INITRD */

#ifdef CONFIG_PPC32
	/* 
	 * Handle the case where we might be booting from an old kexec
	 * image that setup the mem_rsvmap as pairs of 32-bit values
	 */
	if (*reserve_map > 0xffffffffull) {
		u32 base_32, size_32;
		u32 *reserve_map_32 = (u32 *)reserve_map;

		while (1) {
			base_32 = *(reserve_map_32++);
			size_32 = *(reserve_map_32++);
			if (size_32 == 0)
				break;
			/* skip if the reservation is for the blob */
			if (base_32 == self_base && size_32 == self_size)
				continue;
			DBG("reserving: %x -> %x\n", base_32, size_32);
			lmb_reserve(base_32, size_32);
		}
		return;
	}
#endif
	while (1) {
		base = *(reserve_map++);
		size = *(reserve_map++);
		if (size == 0)
			break;
		DBG("reserving: %llx -> %llx\n", base, size);
		lmb_reserve(base, size);
	}

#if 0
	DBG("memory reserved, lmbs :\n");
      	lmb_dump_all();
#endif
}

#ifdef CONFIG_PHYP_DUMP
/**
 * phyp_dump_calculate_reserve_size() - reserve variable boot area 5% or arg
 *
 * Function to find the largest size we need to reserve
 * during early boot process.
 *
 * It either looks for boot param and returns that OR
 * returns larger of 256 or 5% rounded down to multiples of 256MB.
 *
 */
static inline unsigned long phyp_dump_calculate_reserve_size(void)
{
	unsigned long tmp;

	if (phyp_dump_info->reserve_bootvar)
		return phyp_dump_info->reserve_bootvar;

	/* divide by 20 to get 5% of value */
	tmp = lmb_end_of_DRAM();
	do_div(tmp, 20);

	/* round it down in multiples of 256 */
	tmp = tmp & ~0x0FFFFFFFUL;

	return (tmp > PHYP_DUMP_RMR_END ? tmp : PHYP_DUMP_RMR_END);
}

/**
 * phyp_dump_reserve_mem() - reserve all not-yet-dumped mmemory
 *
 * This routine may reserve memory regions in the kernel only
 * if the system is supported and a dump was taken in last
 * boot instance or if the hardware is supported and the
 * scratch area needs to be setup. In other instances it returns
 * without reserving anything. The memory in case of dump being
 * active is freed when the dump is collected (by userland tools).
 */
static void __init phyp_dump_reserve_mem(void)
{
	unsigned long base, size;
	unsigned long variable_reserve_size;

	if (!phyp_dump_info->phyp_dump_configured) {
		printk(KERN_ERR "Phyp-dump not supported on this hardware\n");
		return;
	}

	if (!phyp_dump_info->phyp_dump_at_boot) {
		printk(KERN_INFO "Phyp-dump disabled at boot time\n");
		return;
	}

	variable_reserve_size = phyp_dump_calculate_reserve_size();

	if (phyp_dump_info->phyp_dump_is_active) {
		/* Reserve *everything* above RMR.Area freed by userland tools*/
		base = variable_reserve_size;
		size = lmb_end_of_DRAM() - base;

		/* XXX crashed_ram_end is wrong, since it may be beyond
		 * the memory_limit, it will need to be adjusted. */
		lmb_reserve(base, size);

		phyp_dump_info->init_reserve_start = base;
		phyp_dump_info->init_reserve_size = size;
	} else {
		size = phyp_dump_info->cpu_state_size +
			phyp_dump_info->hpte_region_size +
			variable_reserve_size;
		base = lmb_end_of_DRAM() - size;
		lmb_reserve(base, size);
		phyp_dump_info->init_reserve_start = base;
		phyp_dump_info->init_reserve_size = size;
	}
}
#else
static inline void __init phyp_dump_reserve_mem(void) {}
#endif /* CONFIG_PHYP_DUMP  && CONFIG_PPC_RTAS */


void __init early_init_devtree(void *params)
{
	unsigned long limit;

	DBG(" -> early_init_devtree(%p)\n", params);

	/* Setup flat device-tree pointer */
	initial_boot_params = params;

#ifdef CONFIG_PPC_RTAS
	/* Some machines might need RTAS info for debugging, grab it now. */
	of_scan_flat_dt(early_init_dt_scan_rtas, NULL);
#endif

#ifdef CONFIG_PHYP_DUMP
	/* scan tree to see if dump occured during last boot */
	of_scan_flat_dt(early_init_dt_scan_phyp_dump, NULL);
#endif

	/* Retrieve various informations from the /chosen node of the
	 * device-tree, including the platform type, initrd location and
	 * size, TCE reserve, and more ...
	 */
	of_scan_flat_dt(early_init_dt_scan_chosen, NULL);

	/* Scan memory nodes and rebuild LMBs */
	lmb_init();
	of_scan_flat_dt(early_init_dt_scan_root, NULL);
	of_scan_flat_dt(early_init_dt_scan_memory, NULL);

	/* Save command line for /proc/cmdline and then parse parameters */
	strlcpy(boot_command_line, cmd_line, COMMAND_LINE_SIZE);
	parse_early_param();

	/* Reserve LMB regions used by kernel, initrd, dt, etc... */
	lmb_reserve(PHYSICAL_START, __pa(klimit) - PHYSICAL_START);
	/* If relocatable, reserve first 32k for interrupt vectors etc. */
	if (PHYSICAL_START > MEMORY_START)
		lmb_reserve(MEMORY_START, 0x8000);
	reserve_kdump_trampoline();
	reserve_crashkernel();
	early_reserve_mem();
	phyp_dump_reserve_mem();

	limit = memory_limit;
	if (! limit) {
		unsigned long memsize;

		/* Ensure that total memory size is page-aligned, because
		 * otherwise mark_bootmem() gets upset. */
		lmb_analyze();
		memsize = lmb_phys_mem_size();
		if ((memsize & PAGE_MASK) != memsize)
			limit = memsize & PAGE_MASK;
	}
	lmb_enforce_memory_limit(limit);

	lmb_analyze();

	DBG("Phys. mem: %lx\n", lmb_phys_mem_size());

	/* We may need to relocate the flat tree, do it now.
	 * FIXME .. and the initrd too? */
	move_device_tree();

	DBG("Scanning CPUs ...\n");

	/* Retreive CPU related informations from the flat tree
	 * (altivec support, boot CPU ID, ...)
	 */
	of_scan_flat_dt(early_init_dt_scan_cpus, NULL);

	DBG(" <- early_init_devtree()\n");
}


/**
 * Indicates whether the root node has a given value in its
 * compatible property.
 */
int machine_is_compatible(const char *compat)
{
	struct device_node *root;
	int rc = 0;

	root = of_find_node_by_path("/");
	if (root) {
		rc = of_device_is_compatible(root, compat);
		of_node_put(root);
	}
	return rc;
}
EXPORT_SYMBOL(machine_is_compatible);

/*******
 *
 * New implementation of the OF "find" APIs, return a refcounted
 * object, call of_node_put() when done.  The device tree and list
 * are protected by a rw_lock.
 *
 * Note that property management will need some locking as well,
 * this isn't dealt with yet.
 *
 *******/

/**
 *	of_find_node_by_phandle - Find a node given a phandle
 *	@handle:	phandle of the node to find
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.
 */
struct device_node *of_find_node_by_phandle(phandle handle)
{
	struct device_node *np;

	read_lock(&devtree_lock);
	for (np = allnodes; np != 0; np = np->allnext)
		if (np->linux_phandle == handle)
			break;
	of_node_get(np);
	read_unlock(&devtree_lock);
	return np;
}
EXPORT_SYMBOL(of_find_node_by_phandle);

/**
 *	of_find_next_cache_node - Find a node's subsidiary cache
 *	@np:	node of type "cpu" or "cache"
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.  Caller should hold a reference
 *	to np.
 */
struct device_node *of_find_next_cache_node(struct device_node *np)
{
	struct device_node *child;
	const phandle *handle;

	handle = of_get_property(np, "l2-cache", NULL);
	if (!handle)
		handle = of_get_property(np, "next-level-cache", NULL);

	if (handle)
		return of_find_node_by_phandle(*handle);

	/* OF on pmac has nodes instead of properties named "l2-cache"
	 * beneath CPU nodes.
	 */
	if (!strcmp(np->type, "cpu"))
		for_each_child_of_node(np, child)
			if (!strcmp(child->type, "cache"))
				return child;

	return NULL;
}

/**
 *	of_find_all_nodes - Get next node in global list
 *	@prev:	Previous node or NULL to start iteration
 *		of_node_put() will be called on it
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.
 */
struct device_node *of_find_all_nodes(struct device_node *prev)
{
	struct device_node *np;

	read_lock(&devtree_lock);
	np = prev ? prev->allnext : allnodes;
	for (; np != 0; np = np->allnext)
		if (of_node_get(np))
			break;
	of_node_put(prev);
	read_unlock(&devtree_lock);
	return np;
}
EXPORT_SYMBOL(of_find_all_nodes);

/**
 *	of_node_get - Increment refcount of a node
 *	@node:	Node to inc refcount, NULL is supported to
 *		simplify writing of callers
 *
 *	Returns node.
 */
struct device_node *of_node_get(struct device_node *node)
{
	if (node)
		kref_get(&node->kref);
	return node;
}
EXPORT_SYMBOL(of_node_get);

static inline struct device_node * kref_to_device_node(struct kref *kref)
{
	return container_of(kref, struct device_node, kref);
}

/**
 *	of_node_release - release a dynamically allocated node
 *	@kref:  kref element of the node to be released
 *
 *	In of_node_put() this function is passed to kref_put()
 *	as the destructor.
 */
static void of_node_release(struct kref *kref)
{
	struct device_node *node = kref_to_device_node(kref);
	struct property *prop = node->properties;

	/* We should never be releasing nodes that haven't been detached. */
	if (!of_node_check_flag(node, OF_DETACHED)) {
		printk("WARNING: Bad of_node_put() on %s\n", node->full_name);
		dump_stack();
		kref_init(&node->kref);
		return;
	}

	if (!of_node_check_flag(node, OF_DYNAMIC))
		return;

	while (prop) {
		struct property *next = prop->next;
		kfree(prop->name);
		kfree(prop->value);
		kfree(prop);
		prop = next;

		if (!prop) {
			prop = node->deadprops;
			node->deadprops = NULL;
		}
	}
	kfree(node->full_name);
	kfree(node->data);
	kfree(node);
}

/**
 *	of_node_put - Decrement refcount of a node
 *	@node:	Node to dec refcount, NULL is supported to
 *		simplify writing of callers
 *
 */
void of_node_put(struct device_node *node)
{
	if (node)
		kref_put(&node->kref, of_node_release);
}
EXPORT_SYMBOL(of_node_put);

/*
 * Plug a device node into the tree and global list.
 */
void of_attach_node(struct device_node *np)
{
	unsigned long flags;

	write_lock_irqsave(&devtree_lock, flags);
	np->sibling = np->parent->child;
	np->allnext = allnodes;
	np->parent->child = np;
	allnodes = np;
	write_unlock_irqrestore(&devtree_lock, flags);
}

/*
 * "Unplug" a node from the device tree.  The caller must hold
 * a reference to the node.  The memory associated with the node
 * is not freed until its refcount goes to zero.
 */
void of_detach_node(struct device_node *np)
{
	struct device_node *parent;
	unsigned long flags;

	write_lock_irqsave(&devtree_lock, flags);

	parent = np->parent;
	if (!parent)
		goto out_unlock;

	if (allnodes == np)
		allnodes = np->allnext;
	else {
		struct device_node *prev;
		for (prev = allnodes;
		     prev->allnext != np;
		     prev = prev->allnext)
			;
		prev->allnext = np->allnext;
	}

	if (parent->child == np)
		parent->child = np->sibling;
	else {
		struct device_node *prevsib;
		for (prevsib = np->parent->child;
		     prevsib->sibling != np;
		     prevsib = prevsib->sibling)
			;
		prevsib->sibling = np->sibling;
	}

	of_node_set_flag(np, OF_DETACHED);

out_unlock:
	write_unlock_irqrestore(&devtree_lock, flags);
}

#ifdef CONFIG_PPC_PSERIES
/*
 * Fix up the uninitialized fields in a new device node:
 * name, type and pci-specific fields
 */

static int of_finish_dynamic_node(struct device_node *node)
{
	struct device_node *parent = of_get_parent(node);
	int err = 0;
	const phandle *ibm_phandle;

	node->name = of_get_property(node, "name", NULL);
	node->type = of_get_property(node, "device_type", NULL);

	if (!node->name)
		node->name = "<NULL>";
	if (!node->type)
		node->type = "<NULL>";

	if (!parent) {
		err = -ENODEV;
		goto out;
	}

	/* We don't support that function on PowerMac, at least
	 * not yet
	 */
	if (machine_is(powermac))
		return -ENODEV;

	/* fix up new node's linux_phandle field */
	if ((ibm_phandle = of_get_property(node, "ibm,phandle", NULL)))
		node->linux_phandle = *ibm_phandle;

out:
	of_node_put(parent);
	return err;
}

static int prom_reconfig_notifier(struct notifier_block *nb,
				  unsigned long action, void *node)
{
	int err;

	switch (action) {
	case PSERIES_RECONFIG_ADD:
		err = of_finish_dynamic_node(node);
		if (err < 0) {
			printk(KERN_ERR "finish_node returned %d\n", err);
			err = NOTIFY_BAD;
		}
		break;
	default:
		err = NOTIFY_DONE;
		break;
	}
	return err;
}

static struct notifier_block prom_reconfig_nb = {
	.notifier_call = prom_reconfig_notifier,
	.priority = 10, /* This one needs to run first */
};

static int __init prom_reconfig_setup(void)
{
	return pSeries_reconfig_notifier_register(&prom_reconfig_nb);
}
__initcall(prom_reconfig_setup);
#endif

/*
 * Add a property to a node
 */
int prom_add_property(struct device_node* np, struct property* prop)
{
	struct property **next;
	unsigned long flags;

	prop->next = NULL;	
	write_lock_irqsave(&devtree_lock, flags);
	next = &np->properties;
	while (*next) {
		if (strcmp(prop->name, (*next)->name) == 0) {
			/* duplicate ! don't insert it */
			write_unlock_irqrestore(&devtree_lock, flags);
			return -1;
		}
		next = &(*next)->next;
	}
	*next = prop;
	write_unlock_irqrestore(&devtree_lock, flags);

#ifdef CONFIG_PROC_DEVICETREE
	/* try to add to proc as well if it was initialized */
	if (np->pde)
		proc_device_tree_add_prop(np->pde, prop);
#endif /* CONFIG_PROC_DEVICETREE */

	return 0;
}

/*
 * Remove a property from a node.  Note that we don't actually
 * remove it, since we have given out who-knows-how-many pointers
 * to the data using get-property.  Instead we just move the property
 * to the "dead properties" list, so it won't be found any more.
 */
int prom_remove_property(struct device_node *np, struct property *prop)
{
	struct property **next;
	unsigned long flags;
	int found = 0;

	write_lock_irqsave(&devtree_lock, flags);
	next = &np->properties;
	while (*next) {
		if (*next == prop) {
			/* found the node */
			*next = prop->next;
			prop->next = np->deadprops;
			np->deadprops = prop;
			found = 1;
			break;
		}
		next = &(*next)->next;
	}
	write_unlock_irqrestore(&devtree_lock, flags);

	if (!found)
		return -ENODEV;

#ifdef CONFIG_PROC_DEVICETREE
	/* try to remove the proc node as well */
	if (np->pde)
		proc_device_tree_remove_prop(np->pde, prop);
#endif /* CONFIG_PROC_DEVICETREE */

	return 0;
}

/*
 * Update a property in a node.  Note that we don't actually
 * remove it, since we have given out who-knows-how-many pointers
 * to the data using get-property.  Instead we just move the property
 * to the "dead properties" list, and add the new property to the
 * property list
 */
int prom_update_property(struct device_node *np,
			 struct property *newprop,
			 struct property *oldprop)
{
	struct property **next;
	unsigned long flags;
	int found = 0;

	write_lock_irqsave(&devtree_lock, flags);
	next = &np->properties;
	while (*next) {
		if (*next == oldprop) {
			/* found the node */
			newprop->next = oldprop->next;
			*next = newprop;
			oldprop->next = np->deadprops;
			np->deadprops = oldprop;
			found = 1;
			break;
		}
		next = &(*next)->next;
	}
	write_unlock_irqrestore(&devtree_lock, flags);

	if (!found)
		return -ENODEV;

#ifdef CONFIG_PROC_DEVICETREE
	/* try to add to proc as well if it was initialized */
	if (np->pde)
		proc_device_tree_update_prop(np->pde, newprop, oldprop);
#endif /* CONFIG_PROC_DEVICETREE */

	return 0;
}


/* Find the device node for a given logical cpu number, also returns the cpu
 * local thread number (index in ibm,interrupt-server#s) if relevant and
 * asked for (non NULL)
 */
struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
{
	int hardid;
	struct device_node *np;

	hardid = get_hard_smp_processor_id(cpu);

	for_each_node_by_type(np, "cpu") {
		const u32 *intserv;
		unsigned int plen, t;

		/* Check for ibm,ppc-interrupt-server#s. If it doesn't exist
		 * fallback to "reg" property and assume no threads
		 */
		intserv = of_get_property(np, "ibm,ppc-interrupt-server#s",
				&plen);
		if (intserv == NULL) {
			const u32 *reg = of_get_property(np, "reg", NULL);
			if (reg == NULL)
				continue;
			if (*reg == hardid) {
				if (thread)
					*thread = 0;
				return np;
			}
		} else {
			plen /= sizeof(u32);
			for (t = 0; t < plen; t++) {
				if (hardid == intserv[t]) {
					if (thread)
						*thread = t;
					return np;
				}
			}
		}
	}
	return NULL;
}
EXPORT_SYMBOL(of_get_cpu_node);

#if defined(CONFIG_DEBUG_FS) && defined(DEBUG)
static struct debugfs_blob_wrapper flat_dt_blob;

static int __init export_flat_device_tree(void)
{
	struct dentry *d;

	flat_dt_blob.data = initial_boot_params;
	flat_dt_blob.size = initial_boot_params->totalsize;

	d = debugfs_create_blob("flat-device-tree", S_IFREG | S_IRUSR,
				powerpc_debugfs_root, &flat_dt_blob);
	if (!d)
		return 1;

	return 0;
}
__initcall(export_flat_device_tree);
#endif