summaryrefslogtreecommitdiff
path: root/arch/arm/mm/mmu.c
blob: 3f774856ca6763e9f6e34e44a829ea6a1371d01c (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
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/arch/arm/mm/mmu.c
 *
 *  Copyright (C) 1995-2005 Russell King
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/memblock.h>
#include <linux/fs.h>
#include <linux/vmalloc.h>
#include <linux/sizes.h>

#include <asm/cp15.h>
#include <asm/cputype.h>
#include <asm/cachetype.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/smp_plat.h>
#include <asm/tcm.h>
#include <asm/tlb.h>
#include <asm/highmem.h>
#include <asm/system_info.h>
#include <asm/traps.h>
#include <asm/procinfo.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/kasan_def.h>

#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <asm/mach/pci.h>
#include <asm/fixmap.h>

#include "fault.h"
#include "mm.h"

extern unsigned long __atags_pointer;

/*
 * empty_zero_page is a special page that is used for
 * zero-initialized data and COW.
 */
struct page *empty_zero_page;
EXPORT_SYMBOL(empty_zero_page);

/*
 * The pmd table for the upper-most set of pages.
 */
pmd_t *top_pmd;

pmdval_t user_pmd_table = _PAGE_USER_TABLE;

#define CPOLICY_UNCACHED	0
#define CPOLICY_BUFFERED	1
#define CPOLICY_WRITETHROUGH	2
#define CPOLICY_WRITEBACK	3
#define CPOLICY_WRITEALLOC	4

static unsigned int cachepolicy __initdata = CPOLICY_WRITEBACK;
static unsigned int ecc_mask __initdata = 0;
pgprot_t pgprot_user;
pgprot_t pgprot_kernel;

EXPORT_SYMBOL(pgprot_user);
EXPORT_SYMBOL(pgprot_kernel);

struct cachepolicy {
	const char	policy[16];
	unsigned int	cr_mask;
	pmdval_t	pmd;
	pteval_t	pte;
};

static struct cachepolicy cache_policies[] __initdata = {
	{
		.policy		= "uncached",
		.cr_mask	= CR_W|CR_C,
		.pmd		= PMD_SECT_UNCACHED,
		.pte		= L_PTE_MT_UNCACHED,
	}, {
		.policy		= "buffered",
		.cr_mask	= CR_C,
		.pmd		= PMD_SECT_BUFFERED,
		.pte		= L_PTE_MT_BUFFERABLE,
	}, {
		.policy		= "writethrough",
		.cr_mask	= 0,
		.pmd		= PMD_SECT_WT,
		.pte		= L_PTE_MT_WRITETHROUGH,
	}, {
		.policy		= "writeback",
		.cr_mask	= 0,
		.pmd		= PMD_SECT_WB,
		.pte		= L_PTE_MT_WRITEBACK,
	}, {
		.policy		= "writealloc",
		.cr_mask	= 0,
		.pmd		= PMD_SECT_WBWA,
		.pte		= L_PTE_MT_WRITEALLOC,
	}
};

#ifdef CONFIG_CPU_CP15
static unsigned long initial_pmd_value __initdata = 0;

/*
 * Initialise the cache_policy variable with the initial state specified
 * via the "pmd" value.  This is used to ensure that on ARMv6 and later,
 * the C code sets the page tables up with the same policy as the head
 * assembly code, which avoids an illegal state where the TLBs can get
 * confused.  See comments in early_cachepolicy() for more information.
 */
void __init init_default_cache_policy(unsigned long pmd)
{
	int i;

	initial_pmd_value = pmd;

	pmd &= PMD_SECT_CACHE_MASK;

	for (i = 0; i < ARRAY_SIZE(cache_policies); i++)
		if (cache_policies[i].pmd == pmd) {
			cachepolicy = i;
			break;
		}

	if (i == ARRAY_SIZE(cache_policies))
		pr_err("ERROR: could not find cache policy\n");
}

/*
 * These are useful for identifying cache coherency problems by allowing
 * the cache or the cache and writebuffer to be turned off.  (Note: the
 * write buffer should not be on and the cache off).
 */
static int __init early_cachepolicy(char *p)
{
	int i, selected = -1;

	for (i = 0; i < ARRAY_SIZE(cache_policies); i++) {
		int len = strlen(cache_policies[i].policy);

		if (memcmp(p, cache_policies[i].policy, len) == 0) {
			selected = i;
			break;
		}
	}

	if (selected == -1)
		pr_err("ERROR: unknown or unsupported cache policy\n");

	/*
	 * This restriction is partly to do with the way we boot; it is
	 * unpredictable to have memory mapped using two different sets of
	 * memory attributes (shared, type, and cache attribs).  We can not
	 * change these attributes once the initial assembly has setup the
	 * page tables.
	 */
	if (cpu_architecture() >= CPU_ARCH_ARMv6 && selected != cachepolicy) {
		pr_warn("Only cachepolicy=%s supported on ARMv6 and later\n",
			cache_policies[cachepolicy].policy);
		return 0;
	}

	if (selected != cachepolicy) {
		unsigned long cr = __clear_cr(cache_policies[selected].cr_mask);
		cachepolicy = selected;
		flush_cache_all();
		set_cr(cr);
	}
	return 0;
}
early_param("cachepolicy", early_cachepolicy);

static int __init early_nocache(char *__unused)
{
	char *p = "buffered";
	pr_warn("nocache is deprecated; use cachepolicy=%s\n", p);
	early_cachepolicy(p);
	return 0;
}
early_param("nocache", early_nocache);

static int __init early_nowrite(char *__unused)
{
	char *p = "uncached";
	pr_warn("nowb is deprecated; use cachepolicy=%s\n", p);
	early_cachepolicy(p);
	return 0;
}
early_param("nowb", early_nowrite);

#ifndef CONFIG_ARM_LPAE
static int __init early_ecc(char *p)
{
	if (memcmp(p, "on", 2) == 0)
		ecc_mask = PMD_PROTECTION;
	else if (memcmp(p, "off", 3) == 0)
		ecc_mask = 0;
	return 0;
}
early_param("ecc", early_ecc);
#endif

#else /* ifdef CONFIG_CPU_CP15 */

static int __init early_cachepolicy(char *p)
{
	pr_warn("cachepolicy kernel parameter not supported without cp15\n");
	return 0;
}
early_param("cachepolicy", early_cachepolicy);

static int __init noalign_setup(char *__unused)
{
	pr_warn("noalign kernel parameter not supported without cp15\n");
	return 1;
}
__setup("noalign", noalign_setup);

#endif /* ifdef CONFIG_CPU_CP15 / else */

#define PROT_PTE_DEVICE		L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN
#define PROT_PTE_S2_DEVICE	PROT_PTE_DEVICE
#define PROT_SECT_DEVICE	PMD_TYPE_SECT|PMD_SECT_AP_WRITE

static struct mem_type mem_types[] __ro_after_init = {
	[MT_DEVICE] = {		  /* Strongly ordered / ARMv6 shared device */
		.prot_pte	= PROT_PTE_DEVICE | L_PTE_MT_DEV_SHARED |
				  L_PTE_SHARED,
		.prot_l1	= PMD_TYPE_TABLE,
		.prot_sect	= PROT_SECT_DEVICE | PMD_SECT_S,
		.domain		= DOMAIN_IO,
	},
	[MT_DEVICE_NONSHARED] = { /* ARMv6 non-shared device */
		.prot_pte	= PROT_PTE_DEVICE | L_PTE_MT_DEV_NONSHARED,
		.prot_l1	= PMD_TYPE_TABLE,
		.prot_sect	= PROT_SECT_DEVICE,
		.domain		= DOMAIN_IO,
	},
	[MT_DEVICE_CACHED] = {	  /* ioremap_cache */
		.prot_pte	= PROT_PTE_DEVICE | L_PTE_MT_DEV_CACHED,
		.prot_l1	= PMD_TYPE_TABLE,
		.prot_sect	= PROT_SECT_DEVICE | PMD_SECT_WB,
		.domain		= DOMAIN_IO,
	},
	[MT_DEVICE_WC] = {	/* ioremap_wc */
		.prot_pte	= PROT_PTE_DEVICE | L_PTE_MT_DEV_WC,
		.prot_l1	= PMD_TYPE_TABLE,
		.prot_sect	= PROT_SECT_DEVICE,
		.domain		= DOMAIN_IO,
	},
	[MT_UNCACHED] = {
		.prot_pte	= PROT_PTE_DEVICE,
		.prot_l1	= PMD_TYPE_TABLE,
		.prot_sect	= PMD_TYPE_SECT | PMD_SECT_XN,
		.domain		= DOMAIN_IO,
	},
	[MT_CACHECLEAN] = {
		.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
		.domain    = DOMAIN_KERNEL,
	},
#ifndef CONFIG_ARM_LPAE
	[MT_MINICLEAN] = {
		.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_MINICACHE,
		.domain    = DOMAIN_KERNEL,
	},
#endif
	[MT_LOW_VECTORS] = {
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
				L_PTE_RDONLY,
		.prot_l1   = PMD_TYPE_TABLE,
		.domain    = DOMAIN_VECTORS,
	},
	[MT_HIGH_VECTORS] = {
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
				L_PTE_USER | L_PTE_RDONLY,
		.prot_l1   = PMD_TYPE_TABLE,
		.domain    = DOMAIN_VECTORS,
	},
	[MT_MEMORY_RWX] = {
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
		.prot_l1   = PMD_TYPE_TABLE,
		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
		.domain    = DOMAIN_KERNEL,
	},
	[MT_MEMORY_RW] = {
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
			     L_PTE_XN,
		.prot_l1   = PMD_TYPE_TABLE,
		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
		.domain    = DOMAIN_KERNEL,
	},
	[MT_MEMORY_RO] = {
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
			     L_PTE_XN | L_PTE_RDONLY,
		.prot_l1   = PMD_TYPE_TABLE,
#ifdef CONFIG_ARM_LPAE
		.prot_sect = PMD_TYPE_SECT | L_PMD_SECT_RDONLY | PMD_SECT_AP2,
#else
		.prot_sect = PMD_TYPE_SECT,
#endif
		.domain    = DOMAIN_KERNEL,
	},
	[MT_ROM] = {
		.prot_sect = PMD_TYPE_SECT,
		.domain    = DOMAIN_KERNEL,
	},
	[MT_MEMORY_RWX_NONCACHED] = {
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
				L_PTE_MT_BUFFERABLE,
		.prot_l1   = PMD_TYPE_TABLE,
		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
		.domain    = DOMAIN_KERNEL,
	},
	[MT_MEMORY_RW_DTCM] = {
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
				L_PTE_XN,
		.prot_l1   = PMD_TYPE_TABLE,
		.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
		.domain    = DOMAIN_KERNEL,
	},
	[MT_MEMORY_RWX_ITCM] = {
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
		.prot_l1   = PMD_TYPE_TABLE,
		.domain    = DOMAIN_KERNEL,
	},
	[MT_MEMORY_RW_SO] = {
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
				L_PTE_MT_UNCACHED | L_PTE_XN,
		.prot_l1   = PMD_TYPE_TABLE,
		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_S |
				PMD_SECT_UNCACHED | PMD_SECT_XN,
		.domain    = DOMAIN_KERNEL,
	},
	[MT_MEMORY_DMA_READY] = {
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
				L_PTE_XN,
		.prot_l1   = PMD_TYPE_TABLE,
		.domain    = DOMAIN_KERNEL,
	},
};

const struct mem_type *get_mem_type(unsigned int type)
{
	return type < ARRAY_SIZE(mem_types) ? &mem_types[type] : NULL;
}
EXPORT_SYMBOL(get_mem_type);

static pte_t *(*pte_offset_fixmap)(pmd_t *dir, unsigned long addr);

static pte_t bm_pte[PTRS_PER_PTE + PTE_HWTABLE_PTRS]
	__aligned(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE) __initdata;

static pte_t * __init pte_offset_early_fixmap(pmd_t *dir, unsigned long addr)
{
	return &bm_pte[pte_index(addr)];
}

static pte_t *pte_offset_late_fixmap(pmd_t *dir, unsigned long addr)
{
	return pte_offset_kernel(dir, addr);
}

static inline pmd_t * __init fixmap_pmd(unsigned long addr)
{
	return pmd_off_k(addr);
}

void __init early_fixmap_init(void)
{
	pmd_t *pmd;

	/*
	 * The early fixmap range spans multiple pmds, for which
	 * we are not prepared:
	 */
	BUILD_BUG_ON((__fix_to_virt(__end_of_early_ioremap_region) >> PMD_SHIFT)
		     != FIXADDR_TOP >> PMD_SHIFT);

	pmd = fixmap_pmd(FIXADDR_TOP);
	pmd_populate_kernel(&init_mm, pmd, bm_pte);

	pte_offset_fixmap = pte_offset_early_fixmap;
}

/*
 * To avoid TLB flush broadcasts, this uses local_flush_tlb_kernel_range().
 * As a result, this can only be called with preemption disabled, as under
 * stop_machine().
 */
void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
{
	unsigned long vaddr = __fix_to_virt(idx);
	pte_t *pte = pte_offset_fixmap(pmd_off_k(vaddr), vaddr);

	/* Make sure fixmap region does not exceed available allocation. */
	BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) < FIXADDR_START);
	BUG_ON(idx >= __end_of_fixed_addresses);

	/* We support only device mappings before pgprot_kernel is set. */
	if (WARN_ON(pgprot_val(prot) != pgprot_val(FIXMAP_PAGE_IO) &&
		    pgprot_val(prot) && pgprot_val(pgprot_kernel) == 0))
		return;

	if (pgprot_val(prot))
		set_pte_at(NULL, vaddr, pte,
			pfn_pte(phys >> PAGE_SHIFT, prot));
	else
		pte_clear(NULL, vaddr, pte);
	local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
}

static pgprot_t protection_map[16] __ro_after_init = {
	[VM_NONE]					= __PAGE_NONE,
	[VM_READ]					= __PAGE_READONLY,
	[VM_WRITE]					= __PAGE_COPY,
	[VM_WRITE | VM_READ]				= __PAGE_COPY,
	[VM_EXEC]					= __PAGE_READONLY_EXEC,
	[VM_EXEC | VM_READ]				= __PAGE_READONLY_EXEC,
	[VM_EXEC | VM_WRITE]				= __PAGE_COPY_EXEC,
	[VM_EXEC | VM_WRITE | VM_READ]			= __PAGE_COPY_EXEC,
	[VM_SHARED]					= __PAGE_NONE,
	[VM_SHARED | VM_READ]				= __PAGE_READONLY,
	[VM_SHARED | VM_WRITE]				= __PAGE_SHARED,
	[VM_SHARED | VM_WRITE | VM_READ]		= __PAGE_SHARED,
	[VM_SHARED | VM_EXEC]				= __PAGE_READONLY_EXEC,
	[VM_SHARED | VM_EXEC | VM_READ]			= __PAGE_READONLY_EXEC,
	[VM_SHARED | VM_EXEC | VM_WRITE]		= __PAGE_SHARED_EXEC,
	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= __PAGE_SHARED_EXEC
};
DECLARE_VM_GET_PAGE_PROT

/*
 * Adjust the PMD section entries according to the CPU in use.
 */
static void __init build_mem_type_table(void)
{
	struct cachepolicy *cp;
	unsigned int cr = get_cr();
	pteval_t user_pgprot, kern_pgprot, vecs_pgprot;
	int cpu_arch = cpu_architecture();
	int i;

	if (cpu_arch < CPU_ARCH_ARMv6) {
#if defined(CONFIG_CPU_DCACHE_DISABLE)
		if (cachepolicy > CPOLICY_BUFFERED)
			cachepolicy = CPOLICY_BUFFERED;
#elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH)
		if (cachepolicy > CPOLICY_WRITETHROUGH)
			cachepolicy = CPOLICY_WRITETHROUGH;
#endif
	}
	if (cpu_arch < CPU_ARCH_ARMv5) {
		if (cachepolicy >= CPOLICY_WRITEALLOC)
			cachepolicy = CPOLICY_WRITEBACK;
		ecc_mask = 0;
	}

	if (is_smp()) {
		if (cachepolicy != CPOLICY_WRITEALLOC) {
			pr_warn("Forcing write-allocate cache policy for SMP\n");
			cachepolicy = CPOLICY_WRITEALLOC;
		}
		if (!(initial_pmd_value & PMD_SECT_S)) {
			pr_warn("Forcing shared mappings for SMP\n");
			initial_pmd_value |= PMD_SECT_S;
		}
	}

	/*
	 * Strip out features not present on earlier architectures.
	 * Pre-ARMv5 CPUs don't have TEX bits.  Pre-ARMv6 CPUs or those
	 * without extended page tables don't have the 'Shared' bit.
	 */
	if (cpu_arch < CPU_ARCH_ARMv5)
		for (i = 0; i < ARRAY_SIZE(mem_types); i++)
			mem_types[i].prot_sect &= ~PMD_SECT_TEX(7);
	if ((cpu_arch < CPU_ARCH_ARMv6 || !(cr & CR_XP)) && !cpu_is_xsc3())
		for (i = 0; i < ARRAY_SIZE(mem_types); i++)
			mem_types[i].prot_sect &= ~PMD_SECT_S;

	/*
	 * ARMv5 and lower, bit 4 must be set for page tables (was: cache
	 * "update-able on write" bit on ARM610).  However, Xscale and
	 * Xscale3 require this bit to be cleared.
	 */
	if (cpu_is_xscale_family()) {
		for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
			mem_types[i].prot_sect &= ~PMD_BIT4;
			mem_types[i].prot_l1 &= ~PMD_BIT4;
		}
	} else if (cpu_arch < CPU_ARCH_ARMv6) {
		for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
			if (mem_types[i].prot_l1)
				mem_types[i].prot_l1 |= PMD_BIT4;
			if (mem_types[i].prot_sect)
				mem_types[i].prot_sect |= PMD_BIT4;
		}
	}

	/*
	 * Mark the device areas according to the CPU/architecture.
	 */
	if (cpu_is_xsc3() || (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP))) {
		if (!cpu_is_xsc3()) {
			/*
			 * Mark device regions on ARMv6+ as execute-never
			 * to prevent speculative instruction fetches.
			 */
			mem_types[MT_DEVICE].prot_sect |= PMD_SECT_XN;
			mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_XN;
			mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_XN;
			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_XN;

			/* Also setup NX memory mapping */
			mem_types[MT_MEMORY_RW].prot_sect |= PMD_SECT_XN;
			mem_types[MT_MEMORY_RO].prot_sect |= PMD_SECT_XN;
		}
		if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) {
			/*
			 * For ARMv7 with TEX remapping,
			 * - shared device is SXCB=1100
			 * - nonshared device is SXCB=0100
			 * - write combine device mem is SXCB=0001
			 * (Uncached Normal memory)
			 */
			mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1);
			mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(1);
			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
		} else if (cpu_is_xsc3()) {
			/*
			 * For Xscale3,
			 * - shared device is TEXCB=00101
			 * - nonshared device is TEXCB=01000
			 * - write combine device mem is TEXCB=00100
			 * (Inner/Outer Uncacheable in xsc3 parlance)
			 */
			mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1) | PMD_SECT_BUFFERED;
			mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2);
			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
		} else {
			/*
			 * For ARMv6 and ARMv7 without TEX remapping,
			 * - shared device is TEXCB=00001
			 * - nonshared device is TEXCB=01000
			 * - write combine device mem is TEXCB=00100
			 * (Uncached Normal in ARMv6 parlance).
			 */
			mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED;
			mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2);
			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
		}
	} else {
		/*
		 * On others, write combining is "Uncached/Buffered"
		 */
		mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
	}

	/*
	 * Now deal with the memory-type mappings
	 */
	cp = &cache_policies[cachepolicy];
	vecs_pgprot = kern_pgprot = user_pgprot = cp->pte;

#ifndef CONFIG_ARM_LPAE
	/*
	 * We don't use domains on ARMv6 (since this causes problems with
	 * v6/v7 kernels), so we must use a separate memory type for user
	 * r/o, kernel r/w to map the vectors page.
	 */
	if (cpu_arch == CPU_ARCH_ARMv6)
		vecs_pgprot |= L_PTE_MT_VECTORS;

	/*
	 * Check is it with support for the PXN bit
	 * in the Short-descriptor translation table format descriptors.
	 */
	if (cpu_arch == CPU_ARCH_ARMv7 &&
		(read_cpuid_ext(CPUID_EXT_MMFR0) & 0xF) >= 4) {
		user_pmd_table |= PMD_PXNTABLE;
	}
#endif

	/*
	 * ARMv6 and above have extended page tables.
	 */
	if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) {
#ifndef CONFIG_ARM_LPAE
		/*
		 * Mark cache clean areas and XIP ROM read only
		 * from SVC mode and no access from userspace.
		 */
		mem_types[MT_ROM].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
		mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
		mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
		mem_types[MT_MEMORY_RO].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
#endif

		/*
		 * If the initial page tables were created with the S bit
		 * set, then we need to do the same here for the same
		 * reasons given in early_cachepolicy().
		 */
		if (initial_pmd_value & PMD_SECT_S) {
			user_pgprot |= L_PTE_SHARED;
			kern_pgprot |= L_PTE_SHARED;
			vecs_pgprot |= L_PTE_SHARED;
			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_S;
			mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_SHARED;
			mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_S;
			mem_types[MT_DEVICE_CACHED].prot_pte |= L_PTE_SHARED;
			mem_types[MT_MEMORY_RWX].prot_sect |= PMD_SECT_S;
			mem_types[MT_MEMORY_RWX].prot_pte |= L_PTE_SHARED;
			mem_types[MT_MEMORY_RW].prot_sect |= PMD_SECT_S;
			mem_types[MT_MEMORY_RW].prot_pte |= L_PTE_SHARED;
			mem_types[MT_MEMORY_RO].prot_sect |= PMD_SECT_S;
			mem_types[MT_MEMORY_RO].prot_pte |= L_PTE_SHARED;
			mem_types[MT_MEMORY_DMA_READY].prot_pte |= L_PTE_SHARED;
			mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |= PMD_SECT_S;
			mem_types[MT_MEMORY_RWX_NONCACHED].prot_pte |= L_PTE_SHARED;
		}
	}

	/*
	 * Non-cacheable Normal - intended for memory areas that must
	 * not cause dirty cache line writebacks when used
	 */
	if (cpu_arch >= CPU_ARCH_ARMv6) {
		if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) {
			/* Non-cacheable Normal is XCB = 001 */
			mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |=
				PMD_SECT_BUFFERED;
		} else {
			/* For both ARMv6 and non-TEX-remapping ARMv7 */
			mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |=
				PMD_SECT_TEX(1);
		}
	} else {
		mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |= PMD_SECT_BUFFERABLE;
	}

#ifdef CONFIG_ARM_LPAE
	/*
	 * Do not generate access flag faults for the kernel mappings.
	 */
	for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
		mem_types[i].prot_pte |= PTE_EXT_AF;
		if (mem_types[i].prot_sect)
			mem_types[i].prot_sect |= PMD_SECT_AF;
	}
	kern_pgprot |= PTE_EXT_AF;
	vecs_pgprot |= PTE_EXT_AF;

	/*
	 * Set PXN for user mappings
	 */
	user_pgprot |= PTE_EXT_PXN;
#endif

	for (i = 0; i < 16; i++) {
		pteval_t v = pgprot_val(protection_map[i]);
		protection_map[i] = __pgprot(v | user_pgprot);
	}

	mem_types[MT_LOW_VECTORS].prot_pte |= vecs_pgprot;
	mem_types[MT_HIGH_VECTORS].prot_pte |= vecs_pgprot;

	pgprot_user   = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | user_pgprot);
	pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
				 L_PTE_DIRTY | kern_pgprot);

	mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
	mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;
	mem_types[MT_MEMORY_RWX].prot_sect |= ecc_mask | cp->pmd;
	mem_types[MT_MEMORY_RWX].prot_pte |= kern_pgprot;
	mem_types[MT_MEMORY_RW].prot_sect |= ecc_mask | cp->pmd;
	mem_types[MT_MEMORY_RW].prot_pte |= kern_pgprot;
	mem_types[MT_MEMORY_RO].prot_sect |= ecc_mask | cp->pmd;
	mem_types[MT_MEMORY_RO].prot_pte |= kern_pgprot;
	mem_types[MT_MEMORY_DMA_READY].prot_pte |= kern_pgprot;
	mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |= ecc_mask;
	mem_types[MT_ROM].prot_sect |= cp->pmd;

	switch (cp->pmd) {
	case PMD_SECT_WT:
		mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WT;
		break;
	case PMD_SECT_WB:
	case PMD_SECT_WBWA:
		mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WB;
		break;
	}
	pr_info("Memory policy: %sData cache %s\n",
		ecc_mask ? "ECC enabled, " : "", cp->policy);

	for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
		struct mem_type *t = &mem_types[i];
		if (t->prot_l1)
			t->prot_l1 |= PMD_DOMAIN(t->domain);
		if (t->prot_sect)
			t->prot_sect |= PMD_DOMAIN(t->domain);
	}
}

#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
			      unsigned long size, pgprot_t vma_prot)
{
	if (!pfn_valid(pfn))
		return pgprot_noncached(vma_prot);
	else if (file->f_flags & O_SYNC)
		return pgprot_writecombine(vma_prot);
	return vma_prot;
}
EXPORT_SYMBOL(phys_mem_access_prot);
#endif

#define vectors_base()	(vectors_high() ? 0xffff0000 : 0)

static void __init *early_alloc(unsigned long sz)
{
	void *ptr = memblock_alloc(sz, sz);

	if (!ptr)
		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
		      __func__, sz, sz);

	return ptr;
}

static void *__init late_alloc(unsigned long sz)
{
	void *ptdesc = pagetable_alloc(GFP_PGTABLE_KERNEL & ~__GFP_HIGHMEM,
			get_order(sz));

	if (!ptdesc || !pagetable_pte_ctor(ptdesc))
		BUG();
	return ptdesc_to_virt(ptdesc);
}

static pte_t * __init arm_pte_alloc(pmd_t *pmd, unsigned long addr,
				unsigned long prot,
				void *(*alloc)(unsigned long sz))
{
	if (pmd_none(*pmd)) {
		pte_t *pte = alloc(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE);
		__pmd_populate(pmd, __pa(pte), prot);
	}
	BUG_ON(pmd_bad(*pmd));
	return pte_offset_kernel(pmd, addr);
}

static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr,
				      unsigned long prot)
{
	return arm_pte_alloc(pmd, addr, prot, early_alloc);
}

static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr,
				  unsigned long end, unsigned long pfn,
				  const struct mem_type *type,
				  void *(*alloc)(unsigned long sz),
				  bool ng)
{
	pte_t *pte = arm_pte_alloc(pmd, addr, type->prot_l1, alloc);
	do {
		set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)),
			    ng ? PTE_EXT_NG : 0);
		pfn++;
	} while (pte++, addr += PAGE_SIZE, addr != end);
}

static void __init __map_init_section(pmd_t *pmd, unsigned long addr,
			unsigned long end, phys_addr_t phys,
			const struct mem_type *type, bool ng)
{
	pmd_t *p = pmd;

#ifndef CONFIG_ARM_LPAE
	/*
	 * In classic MMU format, puds and pmds are folded in to
	 * the pgds. pmd_offset gives the PGD entry. PGDs refer to a
	 * group of L1 entries making up one logical pointer to
	 * an L2 table (2MB), where as PMDs refer to the individual
	 * L1 entries (1MB). Hence increment to get the correct
	 * offset for odd 1MB sections.
	 * (See arch/arm/include/asm/pgtable-2level.h)
	 */
	if (addr & SECTION_SIZE)
		pmd++;
#endif
	do {
		*pmd = __pmd(phys | type->prot_sect | (ng ? PMD_SECT_nG : 0));
		phys += SECTION_SIZE;
	} while (pmd++, addr += SECTION_SIZE, addr != end);

	flush_pmd_entry(p);
}

static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
				      unsigned long end, phys_addr_t phys,
				      const struct mem_type *type,
				      void *(*alloc)(unsigned long sz), bool ng)
{
	pmd_t *pmd = pmd_offset(pud, addr);
	unsigned long next;

	do {
		/*
		 * With LPAE, we must loop over to map
		 * all the pmds for the given range.
		 */
		next = pmd_addr_end(addr, end);

		/*
		 * Try a section mapping - addr, next and phys must all be
		 * aligned to a section boundary.
		 */
		if (type->prot_sect &&
				((addr | next | phys) & ~SECTION_MASK) == 0) {
			__map_init_section(pmd, addr, next, phys, type, ng);
		} else {
			alloc_init_pte(pmd, addr, next,
				       __phys_to_pfn(phys), type, alloc, ng);
		}

		phys += next - addr;

	} while (pmd++, addr = next, addr != end);
}

static void __init alloc_init_pud(p4d_t *p4d, unsigned long addr,
				  unsigned long end, phys_addr_t phys,
				  const struct mem_type *type,
				  void *(*alloc)(unsigned long sz), bool ng)
{
	pud_t *pud = pud_offset(p4d, addr);
	unsigned long next;

	do {
		next = pud_addr_end(addr, end);
		alloc_init_pmd(pud, addr, next, phys, type, alloc, ng);
		phys += next - addr;
	} while (pud++, addr = next, addr != end);
}

static void __init alloc_init_p4d(pgd_t *pgd, unsigned long addr,
				  unsigned long end, phys_addr_t phys,
				  const struct mem_type *type,
				  void *(*alloc)(unsigned long sz), bool ng)
{
	p4d_t *p4d = p4d_offset(pgd, addr);
	unsigned long next;

	do {
		next = p4d_addr_end(addr, end);
		alloc_init_pud(p4d, addr, next, phys, type, alloc, ng);
		phys += next - addr;
	} while (p4d++, addr = next, addr != end);
}

#ifndef CONFIG_ARM_LPAE
static void __init create_36bit_mapping(struct mm_struct *mm,
					struct map_desc *md,
					const struct mem_type *type,
					bool ng)
{
	unsigned long addr, length, end;
	phys_addr_t phys;
	pgd_t *pgd;

	addr = md->virtual;
	phys = __pfn_to_phys(md->pfn);
	length = PAGE_ALIGN(md->length);

	if (!(cpu_architecture() >= CPU_ARCH_ARMv6 || cpu_is_xsc3())) {
		pr_err("MM: CPU does not support supersection mapping for 0x%08llx at 0x%08lx\n",
		       (long long)__pfn_to_phys((u64)md->pfn), addr);
		return;
	}

	/* N.B.	ARMv6 supersections are only defined to work with domain 0.
	 *	Since domain assignments can in fact be arbitrary, the
	 *	'domain == 0' check below is required to insure that ARMv6
	 *	supersections are only allocated for domain 0 regardless
	 *	of the actual domain assignments in use.
	 */
	if (type->domain) {
		pr_err("MM: invalid domain in supersection mapping for 0x%08llx at 0x%08lx\n",
		       (long long)__pfn_to_phys((u64)md->pfn), addr);
		return;
	}

	if ((addr | length | __pfn_to_phys(md->pfn)) & ~SUPERSECTION_MASK) {
		pr_err("MM: cannot create mapping for 0x%08llx at 0x%08lx invalid alignment\n",
		       (long long)__pfn_to_phys((u64)md->pfn), addr);
		return;
	}

	/*
	 * Shift bits [35:32] of address into bits [23:20] of PMD
	 * (See ARMv6 spec).
	 */
	phys |= (((md->pfn >> (32 - PAGE_SHIFT)) & 0xF) << 20);

	pgd = pgd_offset(mm, addr);
	end = addr + length;
	do {
		p4d_t *p4d = p4d_offset(pgd, addr);
		pud_t *pud = pud_offset(p4d, addr);
		pmd_t *pmd = pmd_offset(pud, addr);
		int i;

		for (i = 0; i < 16; i++)
			*pmd++ = __pmd(phys | type->prot_sect | PMD_SECT_SUPER |
				       (ng ? PMD_SECT_nG : 0));

		addr += SUPERSECTION_SIZE;
		phys += SUPERSECTION_SIZE;
		pgd += SUPERSECTION_SIZE >> PGDIR_SHIFT;
	} while (addr != end);
}
#endif	/* !CONFIG_ARM_LPAE */

static void __init __create_mapping(struct mm_struct *mm, struct map_desc *md,
				    void *(*alloc)(unsigned long sz),
				    bool ng)
{
	unsigned long addr, length, end;
	phys_addr_t phys;
	const struct mem_type *type;
	pgd_t *pgd;

	type = &mem_types[md->type];

#ifndef CONFIG_ARM_LPAE
	/*
	 * Catch 36-bit addresses
	 */
	if (md->pfn >= 0x100000) {
		create_36bit_mapping(mm, md, type, ng);
		return;
	}
#endif

	addr = md->virtual & PAGE_MASK;
	phys = __pfn_to_phys(md->pfn);
	length = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));

	if (type->prot_l1 == 0 && ((addr | phys | length) & ~SECTION_MASK)) {
		pr_warn("BUG: map for 0x%08llx at 0x%08lx can not be mapped using pages, ignoring.\n",
			(long long)__pfn_to_phys(md->pfn), addr);
		return;
	}

	pgd = pgd_offset(mm, addr);
	end = addr + length;
	do {
		unsigned long next = pgd_addr_end(addr, end);

		alloc_init_p4d(pgd, addr, next, phys, type, alloc, ng);

		phys += next - addr;
		addr = next;
	} while (pgd++, addr != end);
}

/*
 * Create the page directory entries and any necessary
 * page tables for the mapping specified by `md'.  We
 * are able to cope here with varying sizes and address
 * offsets, and we take full advantage of sections and
 * supersections.
 */
static void __init create_mapping(struct map_desc *md)
{
	if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) {
		pr_warn("BUG: not creating mapping for 0x%08llx at 0x%08lx in user region\n",
			(long long)__pfn_to_phys((u64)md->pfn), md->virtual);
		return;
	}

	if (md->type == MT_DEVICE &&
	    md->virtual >= PAGE_OFFSET && md->virtual < FIXADDR_START &&
	    (md->virtual < VMALLOC_START || md->virtual >= VMALLOC_END)) {
		pr_warn("BUG: mapping for 0x%08llx at 0x%08lx out of vmalloc space\n",
			(long long)__pfn_to_phys((u64)md->pfn), md->virtual);
	}

	__create_mapping(&init_mm, md, early_alloc, false);
}

void __init create_mapping_late(struct mm_struct *mm, struct map_desc *md,
				bool ng)
{
#ifdef CONFIG_ARM_LPAE
	p4d_t *p4d;
	pud_t *pud;

	p4d = p4d_alloc(mm, pgd_offset(mm, md->virtual), md->virtual);
	if (WARN_ON(!p4d))
		return;
	pud = pud_alloc(mm, p4d, md->virtual);
	if (WARN_ON(!pud))
		return;
	pmd_alloc(mm, pud, 0);
#endif
	__create_mapping(mm, md, late_alloc, ng);
}

/*
 * Create the architecture specific mappings
 */
void __init iotable_init(struct map_desc *io_desc, int nr)
{
	struct map_desc *md;
	struct vm_struct *vm;
	struct static_vm *svm;

	if (!nr)
		return;

	svm = memblock_alloc(sizeof(*svm) * nr, __alignof__(*svm));
	if (!svm)
		panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
		      __func__, sizeof(*svm) * nr, __alignof__(*svm));

	for (md = io_desc; nr; md++, nr--) {
		create_mapping(md);

		vm = &svm->vm;
		vm->addr = (void *)(md->virtual & PAGE_MASK);
		vm->size = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
		vm->phys_addr = __pfn_to_phys(md->pfn);
		vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
		vm->flags |= VM_ARM_MTYPE(md->type);
		vm->caller = iotable_init;
		add_static_vm_early(svm++);
	}
}

void __init vm_reserve_area_early(unsigned long addr, unsigned long size,
				  void *caller)
{
	struct vm_struct *vm;
	struct static_vm *svm;

	svm = memblock_alloc(sizeof(*svm), __alignof__(*svm));
	if (!svm)
		panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
		      __func__, sizeof(*svm), __alignof__(*svm));

	vm = &svm->vm;
	vm->addr = (void *)addr;
	vm->size = size;
	vm->flags = VM_IOREMAP | VM_ARM_EMPTY_MAPPING;
	vm->caller = caller;
	add_static_vm_early(svm);
}

#ifndef CONFIG_ARM_LPAE

/*
 * The Linux PMD is made of two consecutive section entries covering 2MB
 * (see definition in include/asm/pgtable-2level.h).  However a call to
 * create_mapping() may optimize static mappings by using individual
 * 1MB section mappings.  This leaves the actual PMD potentially half
 * initialized if the top or bottom section entry isn't used, leaving it
 * open to problems if a subsequent ioremap() or vmalloc() tries to use
 * the virtual space left free by that unused section entry.
 *
 * Let's avoid the issue by inserting dummy vm entries covering the unused
 * PMD halves once the static mappings are in place.
 */

static void __init pmd_empty_section_gap(unsigned long addr)
{
	vm_reserve_area_early(addr, SECTION_SIZE, pmd_empty_section_gap);
}

static void __init fill_pmd_gaps(void)
{
	struct static_vm *svm;
	struct vm_struct *vm;
	unsigned long addr, next = 0;
	pmd_t *pmd;

	list_for_each_entry(svm, &static_vmlist, list) {
		vm = &svm->vm;
		addr = (unsigned long)vm->addr;
		if (addr < next)
			continue;

		/*
		 * Check if this vm starts on an odd section boundary.
		 * If so and the first section entry for this PMD is free
		 * then we block the corresponding virtual address.
		 */
		if ((addr & ~PMD_MASK) == SECTION_SIZE) {
			pmd = pmd_off_k(addr);
			if (pmd_none(*pmd))
				pmd_empty_section_gap(addr & PMD_MASK);
		}

		/*
		 * Then check if this vm ends on an odd section boundary.
		 * If so and the second section entry for this PMD is empty
		 * then we block the corresponding virtual address.
		 */
		addr += vm->size;
		if ((addr & ~PMD_MASK) == SECTION_SIZE) {
			pmd = pmd_off_k(addr) + 1;
			if (pmd_none(*pmd))
				pmd_empty_section_gap(addr);
		}

		/* no need to look at any vm entry until we hit the next PMD */
		next = (addr + PMD_SIZE - 1) & PMD_MASK;
	}
}

#else
#define fill_pmd_gaps() do { } while (0)
#endif

#if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
static void __init pci_reserve_io(void)
{
	struct static_vm *svm;

	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
	if (svm)
		return;

	vm_reserve_area_early(PCI_IO_VIRT_BASE, SZ_2M, pci_reserve_io);
}
#else
#define pci_reserve_io() do { } while (0)
#endif

#ifdef CONFIG_DEBUG_LL
void __init debug_ll_io_init(void)
{
	struct map_desc map;

	debug_ll_addr(&map.pfn, &map.virtual);
	if (!map.pfn || !map.virtual)
		return;
	map.pfn = __phys_to_pfn(map.pfn);
	map.virtual &= PAGE_MASK;
	map.length = PAGE_SIZE;
	map.type = MT_DEVICE;
	iotable_init(&map, 1);
}
#endif

static unsigned long __initdata vmalloc_size = 240 * SZ_1M;

/*
 * vmalloc=size forces the vmalloc area to be exactly 'size'
 * bytes. This can be used to increase (or decrease) the vmalloc
 * area - the default is 240MiB.
 */
static int __init early_vmalloc(char *arg)
{
	unsigned long vmalloc_reserve = memparse(arg, NULL);
	unsigned long vmalloc_max;

	if (vmalloc_reserve < SZ_16M) {
		vmalloc_reserve = SZ_16M;
		pr_warn("vmalloc area is too small, limiting to %luMiB\n",
			vmalloc_reserve >> 20);
	}

	vmalloc_max = VMALLOC_END - (PAGE_OFFSET + SZ_32M + VMALLOC_OFFSET);
	if (vmalloc_reserve > vmalloc_max) {
		vmalloc_reserve = vmalloc_max;
		pr_warn("vmalloc area is too big, limiting to %luMiB\n",
			vmalloc_reserve >> 20);
	}

	vmalloc_size = vmalloc_reserve;
	return 0;
}
early_param("vmalloc", early_vmalloc);

phys_addr_t arm_lowmem_limit __initdata = 0;

void __init adjust_lowmem_bounds(void)
{
	phys_addr_t block_start, block_end, memblock_limit = 0;
	u64 vmalloc_limit, i;
	phys_addr_t lowmem_limit = 0;

	/*
	 * Let's use our own (unoptimized) equivalent of __pa() that is
	 * not affected by wrap-arounds when sizeof(phys_addr_t) == 4.
	 * The result is used as the upper bound on physical memory address
	 * and may itself be outside the valid range for which phys_addr_t
	 * and therefore __pa() is defined.
	 */
	vmalloc_limit = (u64)VMALLOC_END - vmalloc_size - VMALLOC_OFFSET -
			PAGE_OFFSET + PHYS_OFFSET;

	/*
	 * The first usable region must be PMD aligned. Mark its start
	 * as MEMBLOCK_NOMAP if it isn't
	 */
	for_each_mem_range(i, &block_start, &block_end) {
		if (!IS_ALIGNED(block_start, PMD_SIZE)) {
			phys_addr_t len;

			len = round_up(block_start, PMD_SIZE) - block_start;
			memblock_mark_nomap(block_start, len);
		}
		break;
	}

	for_each_mem_range(i, &block_start, &block_end) {
		if (block_start < vmalloc_limit) {
			if (block_end > lowmem_limit)
				/*
				 * Compare as u64 to ensure vmalloc_limit does
				 * not get truncated. block_end should always
				 * fit in phys_addr_t so there should be no
				 * issue with assignment.
				 */
				lowmem_limit = min_t(u64,
							 vmalloc_limit,
							 block_end);

			/*
			 * Find the first non-pmd-aligned page, and point
			 * memblock_limit at it. This relies on rounding the
			 * limit down to be pmd-aligned, which happens at the
			 * end of this function.
			 *
			 * With this algorithm, the start or end of almost any
			 * bank can be non-pmd-aligned. The only exception is
			 * that the start of the bank 0 must be section-
			 * aligned, since otherwise memory would need to be
			 * allocated when mapping the start of bank 0, which
			 * occurs before any free memory is mapped.
			 */
			if (!memblock_limit) {
				if (!IS_ALIGNED(block_start, PMD_SIZE))
					memblock_limit = block_start;
				else if (!IS_ALIGNED(block_end, PMD_SIZE))
					memblock_limit = lowmem_limit;
			}

		}
	}

	arm_lowmem_limit = lowmem_limit;

	high_memory = __va(arm_lowmem_limit - 1) + 1;

	if (!memblock_limit)
		memblock_limit = arm_lowmem_limit;

	/*
	 * Round the memblock limit down to a pmd size.  This
	 * helps to ensure that we will allocate memory from the
	 * last full pmd, which should be mapped.
	 */
	memblock_limit = round_down(memblock_limit, PMD_SIZE);

	if (!IS_ENABLED(CONFIG_HIGHMEM) || cache_is_vipt_aliasing()) {
		if (memblock_end_of_DRAM() > arm_lowmem_limit) {
			phys_addr_t end = memblock_end_of_DRAM();

			pr_notice("Ignoring RAM at %pa-%pa\n",
				  &memblock_limit, &end);
			pr_notice("Consider using a HIGHMEM enabled kernel.\n");

			memblock_remove(memblock_limit, end - memblock_limit);
		}
	}

	memblock_set_current_limit(memblock_limit);
}

static __init void prepare_page_table(void)
{
	unsigned long addr;
	phys_addr_t end;

	/*
	 * Clear out all the mappings below the kernel image.
	 */
#ifdef CONFIG_KASAN
	/*
	 * KASan's shadow memory inserts itself between the TASK_SIZE
	 * and MODULES_VADDR. Do not clear the KASan shadow memory mappings.
	 */
	for (addr = 0; addr < KASAN_SHADOW_START; addr += PMD_SIZE)
		pmd_clear(pmd_off_k(addr));
	/*
	 * Skip over the KASan shadow area. KASAN_SHADOW_END is sometimes
	 * equal to MODULES_VADDR and then we exit the pmd clearing. If we
	 * are using a thumb-compiled kernel, there there will be 8MB more
	 * to clear as KASan always offset to 16 MB below MODULES_VADDR.
	 */
	for (addr = KASAN_SHADOW_END; addr < MODULES_VADDR; addr += PMD_SIZE)
		pmd_clear(pmd_off_k(addr));
#else
	for (addr = 0; addr < MODULES_VADDR; addr += PMD_SIZE)
		pmd_clear(pmd_off_k(addr));
#endif

#ifdef CONFIG_XIP_KERNEL
	/* The XIP kernel is mapped in the module area -- skip over it */
	addr = ((unsigned long)_exiprom + PMD_SIZE - 1) & PMD_MASK;
#endif
	for ( ; addr < PAGE_OFFSET; addr += PMD_SIZE)
		pmd_clear(pmd_off_k(addr));

	/*
	 * Find the end of the first block of lowmem.
	 */
	end = memblock.memory.regions[0].base + memblock.memory.regions[0].size;
	if (end >= arm_lowmem_limit)
		end = arm_lowmem_limit;

	/*
	 * Clear out all the kernel space mappings, except for the first
	 * memory bank, up to the vmalloc region.
	 */
	for (addr = __phys_to_virt(end);
	     addr < VMALLOC_START; addr += PMD_SIZE)
		pmd_clear(pmd_off_k(addr));
}

#ifdef CONFIG_ARM_LPAE
/* the first page is reserved for pgd */
#define SWAPPER_PG_DIR_SIZE	(PAGE_SIZE + \
				 PTRS_PER_PGD * PTRS_PER_PMD * sizeof(pmd_t))
#else
#define SWAPPER_PG_DIR_SIZE	(PTRS_PER_PGD * sizeof(pgd_t))
#endif

/*
 * Reserve the special regions of memory
 */
void __init arm_mm_memblock_reserve(void)
{
	/*
	 * Reserve the page tables.  These are already in use,
	 * and can only be in node 0.
	 */
	memblock_reserve(__pa(swapper_pg_dir), SWAPPER_PG_DIR_SIZE);

#ifdef CONFIG_SA1111
	/*
	 * Because of the SA1111 DMA bug, we want to preserve our
	 * precious DMA-able memory...
	 */
	memblock_reserve(PHYS_OFFSET, __pa(swapper_pg_dir) - PHYS_OFFSET);
#endif
}

/*
 * Set up the device mappings.  Since we clear out the page tables for all
 * mappings above VMALLOC_START, except early fixmap, we might remove debug
 * device mappings.  This means earlycon can be used to debug this function
 * Any other function or debugging method which may touch any device _will_
 * crash the kernel.
 */
static void __init devicemaps_init(const struct machine_desc *mdesc)
{
	struct map_desc map;
	unsigned long addr;
	void *vectors;

	/*
	 * Allocate the vector page early.
	 */
	vectors = early_alloc(PAGE_SIZE * 2);

	early_trap_init(vectors);

	/*
	 * Clear page table except top pmd used by early fixmaps
	 */
	for (addr = VMALLOC_START; addr < (FIXADDR_TOP & PMD_MASK); addr += PMD_SIZE)
		pmd_clear(pmd_off_k(addr));

	if (__atags_pointer) {
		/* create a read-only mapping of the device tree */
		map.pfn = __phys_to_pfn(__atags_pointer & SECTION_MASK);
		map.virtual = FDT_FIXED_BASE;
		map.length = FDT_FIXED_SIZE;
		map.type = MT_MEMORY_RO;
		create_mapping(&map);
	}

	/*
	 * Map the kernel if it is XIP.
	 * It is always first in the modulearea.
	 */
#ifdef CONFIG_XIP_KERNEL
	map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK);
	map.virtual = MODULES_VADDR;
	map.length = ((unsigned long)_exiprom - map.virtual + ~SECTION_MASK) & SECTION_MASK;
	map.type = MT_ROM;
	create_mapping(&map);
#endif

	/*
	 * Map the cache flushing regions.
	 */
#ifdef FLUSH_BASE
	map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS);
	map.virtual = FLUSH_BASE;
	map.length = SZ_1M;
	map.type = MT_CACHECLEAN;
	create_mapping(&map);
#endif
#ifdef FLUSH_BASE_MINICACHE
	map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + SZ_1M);
	map.virtual = FLUSH_BASE_MINICACHE;
	map.length = SZ_1M;
	map.type = MT_MINICLEAN;
	create_mapping(&map);
#endif

	/*
	 * Create a mapping for the machine vectors at the high-vectors
	 * location (0xffff0000).  If we aren't using high-vectors, also
	 * create a mapping at the low-vectors virtual address.
	 */
	map.pfn = __phys_to_pfn(virt_to_phys(vectors));
	map.virtual = 0xffff0000;
	map.length = PAGE_SIZE;
#ifdef CONFIG_KUSER_HELPERS
	map.type = MT_HIGH_VECTORS;
#else
	map.type = MT_LOW_VECTORS;
#endif
	create_mapping(&map);

	if (!vectors_high()) {
		map.virtual = 0;
		map.length = PAGE_SIZE * 2;
		map.type = MT_LOW_VECTORS;
		create_mapping(&map);
	}

	/* Now create a kernel read-only mapping */
	map.pfn += 1;
	map.virtual = 0xffff0000 + PAGE_SIZE;
	map.length = PAGE_SIZE;
	map.type = MT_LOW_VECTORS;
	create_mapping(&map);

	/*
	 * Ask the machine support to map in the statically mapped devices.
	 */
	if (mdesc->map_io)
		mdesc->map_io();
	else
		debug_ll_io_init();
	fill_pmd_gaps();

	/* Reserve fixed i/o space in VMALLOC region */
	pci_reserve_io();

	/*
	 * Finally flush the caches and tlb to ensure that we're in a
	 * consistent state wrt the writebuffer.  This also ensures that
	 * any write-allocated cache lines in the vector page are written
	 * back.  After this point, we can start to touch devices again.
	 */
	local_flush_tlb_all();
	flush_cache_all();

	/* Enable asynchronous aborts */
	early_abt_enable();
}

static void __init kmap_init(void)
{
#ifdef CONFIG_HIGHMEM
	pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE),
		PKMAP_BASE, _PAGE_KERNEL_TABLE);
#endif

	early_pte_alloc(pmd_off_k(FIXADDR_START), FIXADDR_START,
			_PAGE_KERNEL_TABLE);
}

static void __init map_lowmem(void)
{
	phys_addr_t start, end;
	u64 i;

	/* Map all the lowmem memory banks. */
	for_each_mem_range(i, &start, &end) {
		struct map_desc map;

		pr_debug("map lowmem start: 0x%08llx, end: 0x%08llx\n",
			 (long long)start, (long long)end);
		if (end > arm_lowmem_limit)
			end = arm_lowmem_limit;
		if (start >= end)
			break;

		/*
		 * If our kernel image is in the VMALLOC area we need to remove
		 * the kernel physical memory from lowmem since the kernel will
		 * be mapped separately.
		 *
		 * The kernel will typically be at the very start of lowmem,
		 * but any placement relative to memory ranges is possible.
		 *
		 * If the memblock contains the kernel, we have to chisel out
		 * the kernel memory from it and map each part separately. We
		 * get 6 different theoretical cases:
		 *
		 *                            +--------+ +--------+
		 *  +-- start --+  +--------+ | Kernel | | Kernel |
		 *  |           |  | Kernel | | case 2 | | case 5 |
		 *  |           |  | case 1 | +--------+ |        | +--------+
		 *  |  Memory   |  +--------+            |        | | Kernel |
		 *  |  range    |  +--------+            |        | | case 6 |
		 *  |           |  | Kernel | +--------+ |        | +--------+
		 *  |           |  | case 3 | | Kernel | |        |
		 *  +-- end ----+  +--------+ | case 4 | |        |
		 *                            +--------+ +--------+
		 */

		/* Case 5: kernel covers range, don't map anything, should be rare */
		if ((start > kernel_sec_start) && (end < kernel_sec_end))
			break;

		/* Cases where the kernel is starting inside the range */
		if ((kernel_sec_start >= start) && (kernel_sec_start <= end)) {
			/* Case 6: kernel is embedded in the range, we need two mappings */
			if ((start < kernel_sec_start) && (end > kernel_sec_end)) {
				/* Map memory below the kernel */
				map.pfn = __phys_to_pfn(start);
				map.virtual = __phys_to_virt(start);
				map.length = kernel_sec_start - start;
				map.type = MT_MEMORY_RW;
				create_mapping(&map);
				/* Map memory above the kernel */
				map.pfn = __phys_to_pfn(kernel_sec_end);
				map.virtual = __phys_to_virt(kernel_sec_end);
				map.length = end - kernel_sec_end;
				map.type = MT_MEMORY_RW;
				create_mapping(&map);
				break;
			}
			/* Case 1: kernel and range start at the same address, should be common */
			if (kernel_sec_start == start)
				start = kernel_sec_end;
			/* Case 3: kernel and range end at the same address, should be rare */
			if (kernel_sec_end == end)
				end = kernel_sec_start;
		} else if ((kernel_sec_start < start) && (kernel_sec_end > start) && (kernel_sec_end < end)) {
			/* Case 2: kernel ends inside range, starts below it */
			start = kernel_sec_end;
		} else if ((kernel_sec_start > start) && (kernel_sec_start < end) && (kernel_sec_end > end)) {
			/* Case 4: kernel starts inside range, ends above it */
			end = kernel_sec_start;
		}
		map.pfn = __phys_to_pfn(start);
		map.virtual = __phys_to_virt(start);
		map.length = end - start;
		map.type = MT_MEMORY_RW;
		create_mapping(&map);
	}
}

static void __init map_kernel(void)
{
	/*
	 * We use the well known kernel section start and end and split the area in the
	 * middle like this:
	 *  .                .
	 *  | RW memory      |
	 *  +----------------+ kernel_x_start
	 *  | Executable     |
	 *  | kernel memory  |
	 *  +----------------+ kernel_x_end / kernel_nx_start
	 *  | Non-executable |
	 *  | kernel memory  |
	 *  +----------------+ kernel_nx_end
	 *  | RW memory      |
	 *  .                .
	 *
	 * Notice that we are dealing with section sized mappings here so all of this
	 * will be bumped to the closest section boundary. This means that some of the
	 * non-executable part of the kernel memory is actually mapped as executable.
	 * This will only persist until we turn on proper memory management later on
	 * and we remap the whole kernel with page granularity.
	 */
	phys_addr_t kernel_x_start = kernel_sec_start;
	phys_addr_t kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE);
	phys_addr_t kernel_nx_start = kernel_x_end;
	phys_addr_t kernel_nx_end = kernel_sec_end;
	struct map_desc map;

	map.pfn = __phys_to_pfn(kernel_x_start);
	map.virtual = __phys_to_virt(kernel_x_start);
	map.length = kernel_x_end - kernel_x_start;
	map.type = MT_MEMORY_RWX;
	create_mapping(&map);

	/* If the nx part is small it may end up covered by the tail of the RWX section */
	if (kernel_x_end == kernel_nx_end)
		return;

	map.pfn = __phys_to_pfn(kernel_nx_start);
	map.virtual = __phys_to_virt(kernel_nx_start);
	map.length = kernel_nx_end - kernel_nx_start;
	map.type = MT_MEMORY_RW;
	create_mapping(&map);
}

#ifdef CONFIG_ARM_PV_FIXUP
typedef void pgtables_remap(long long offset, unsigned long pgd);
pgtables_remap lpae_pgtables_remap_asm;

/*
 * early_paging_init() recreates boot time page table setup, allowing machines
 * to switch over to a high (>4G) address space on LPAE systems
 */
static void __init early_paging_init(const struct machine_desc *mdesc)
{
	pgtables_remap *lpae_pgtables_remap;
	unsigned long pa_pgd;
	unsigned int cr, ttbcr;
	long long offset;

	if (!mdesc->pv_fixup)
		return;

	offset = mdesc->pv_fixup();
	if (offset == 0)
		return;

	/*
	 * Offset the kernel section physical offsets so that the kernel
	 * mapping will work out later on.
	 */
	kernel_sec_start += offset;
	kernel_sec_end += offset;

	/*
	 * Get the address of the remap function in the 1:1 identity
	 * mapping setup by the early page table assembly code.  We
	 * must get this prior to the pv update.  The following barrier
	 * ensures that this is complete before we fixup any P:V offsets.
	 */
	lpae_pgtables_remap = (pgtables_remap *)(unsigned long)__pa(lpae_pgtables_remap_asm);
	pa_pgd = __pa(swapper_pg_dir);
	barrier();

	pr_info("Switching physical address space to 0x%08llx\n",
		(u64)PHYS_OFFSET + offset);

	/* Re-set the phys pfn offset, and the pv offset */
	__pv_offset += offset;
	__pv_phys_pfn_offset += PFN_DOWN(offset);

	/* Run the patch stub to update the constants */
	fixup_pv_table(&__pv_table_begin,
		(&__pv_table_end - &__pv_table_begin) << 2);

	/*
	 * We changing not only the virtual to physical mapping, but also
	 * the physical addresses used to access memory.  We need to flush
	 * all levels of cache in the system with caching disabled to
	 * ensure that all data is written back, and nothing is prefetched
	 * into the caches.  We also need to prevent the TLB walkers
	 * allocating into the caches too.  Note that this is ARMv7 LPAE
	 * specific.
	 */
	cr = get_cr();
	set_cr(cr & ~(CR_I | CR_C));
	ttbcr = cpu_get_ttbcr();
	cpu_set_ttbcr(ttbcr & ~(3 << 8 | 3 << 10));
	flush_cache_all();

	/*
	 * Fixup the page tables - this must be in the idmap region as
	 * we need to disable the MMU to do this safely, and hence it
	 * needs to be assembly.  It's fairly simple, as we're using the
	 * temporary tables setup by the initial assembly code.
	 */
	lpae_pgtables_remap(offset, pa_pgd);

	/* Re-enable the caches and cacheable TLB walks */
	cpu_set_ttbcr(ttbcr);
	set_cr(cr);
}

#else

static void __init early_paging_init(const struct machine_desc *mdesc)
{
	long long offset;

	if (!mdesc->pv_fixup)
		return;

	offset = mdesc->pv_fixup();
	if (offset == 0)
		return;

	pr_crit("Physical address space modification is only to support Keystone2.\n");
	pr_crit("Please enable ARM_LPAE and ARM_PATCH_PHYS_VIRT support to use this\n");
	pr_crit("feature. Your kernel may crash now, have a good day.\n");
	add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
}

#endif

static void __init early_fixmap_shutdown(void)
{
	int i;
	unsigned long va = fix_to_virt(__end_of_permanent_fixed_addresses - 1);

	pte_offset_fixmap = pte_offset_late_fixmap;
	pmd_clear(fixmap_pmd(va));
	local_flush_tlb_kernel_page(va);

	for (i = 0; i < __end_of_permanent_fixed_addresses; i++) {
		pte_t *pte;
		struct map_desc map;

		map.virtual = fix_to_virt(i);
		pte = pte_offset_early_fixmap(pmd_off_k(map.virtual), map.virtual);

		/* Only i/o device mappings are supported ATM */
		if (pte_none(*pte) ||
		    (pte_val(*pte) & L_PTE_MT_MASK) != L_PTE_MT_DEV_SHARED)
			continue;

		map.pfn = pte_pfn(*pte);
		map.type = MT_DEVICE;
		map.length = PAGE_SIZE;

		create_mapping(&map);
	}
}

/*
 * paging_init() sets up the page tables, initialises the zone memory
 * maps, and sets up the zero page, bad page and bad page tables.
 */
void __init paging_init(const struct machine_desc *mdesc)
{
	void *zero_page;

	pr_debug("physical kernel sections: 0x%08llx-0x%08llx\n",
		 kernel_sec_start, kernel_sec_end);

	prepare_page_table();
	map_lowmem();
	memblock_set_current_limit(arm_lowmem_limit);
	pr_debug("lowmem limit is %08llx\n", (long long)arm_lowmem_limit);
	/*
	 * After this point early_alloc(), i.e. the memblock allocator, can
	 * be used
	 */
	map_kernel();
	dma_contiguous_remap();
	early_fixmap_shutdown();
	devicemaps_init(mdesc);
	kmap_init();
	tcm_init();

	top_pmd = pmd_off_k(0xffff0000);

	/* allocate the zero page. */
	zero_page = early_alloc(PAGE_SIZE);

	bootmem_init();

	empty_zero_page = virt_to_page(zero_page);
	__flush_dcache_folio(NULL, page_folio(empty_zero_page));
}

void __init early_mm_init(const struct machine_desc *mdesc)
{
	build_mem_type_table();
	early_paging_init(mdesc);
}

void set_ptes(struct mm_struct *mm, unsigned long addr,
			      pte_t *ptep, pte_t pteval, unsigned int nr)
{
	unsigned long ext = 0;

	if (addr < TASK_SIZE && pte_valid_user(pteval)) {
		if (!pte_special(pteval))
			__sync_icache_dcache(pteval);
		ext |= PTE_EXT_NG;
	}

	for (;;) {
		set_pte_ext(ptep, pteval, ext);
		if (--nr == 0)
			break;
		ptep++;
		pteval = pte_next_pfn(pteval);
	}
}