summaryrefslogtreecommitdiffstats
path: root/arch/arm/mm/mmu.c
blob: 53cdbd39ec8e23c1facab667f56fa9441aa870c6 (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
/*
 *  linux/arch/arm/mm/mmu.c
 *
 *  Copyright (C) 1995-2005 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#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/sections.h>
#include <asm/cachetype.h>
#include <asm/setup.h>
#include <asm/smp_plat.h>
#include <asm/tlb.h>
#include <asm/highmem.h>
#include <asm/system_info.h>
#include <asm/traps.h>

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

#include "mm.h"
#include "tcm.h"

/*
 * 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;

#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;
pgprot_t pgprot_hyp_device;
pgprot_t pgprot_s2;
pgprot_t pgprot_s2_device;

EXPORT_SYMBOL(pgprot_user);
EXPORT_SYMBOL(pgprot_kernel);

struct cachepolicy {
	const char	policy[16];
	unsigned int	cr_mask;
	pmdval_t	pmd;
	pteval_t	pte;
	pteval_t	pte_s2;
};

#ifdef CONFIG_ARM_LPAE
#define s2_policy(policy)	policy
#else
#define s2_policy(policy)	0
#endif

static struct cachepolicy cache_policies[] __initdata = {
	{
		.policy		= "uncached",
		.cr_mask	= CR_W|CR_C,
		.pmd		= PMD_SECT_UNCACHED,
		.pte		= L_PTE_MT_UNCACHED,
		.pte_s2		= s2_policy(L_PTE_S2_MT_UNCACHED),
	}, {
		.policy		= "buffered",
		.cr_mask	= CR_C,
		.pmd		= PMD_SECT_BUFFERED,
		.pte		= L_PTE_MT_BUFFERABLE,
		.pte_s2		= s2_policy(L_PTE_S2_MT_UNCACHED),
	}, {
		.policy		= "writethrough",
		.cr_mask	= 0,
		.pmd		= PMD_SECT_WT,
		.pte		= L_PTE_MT_WRITETHROUGH,
		.pte_s2		= s2_policy(L_PTE_S2_MT_WRITETHROUGH),
	}, {
		.policy		= "writeback",
		.cr_mask	= 0,
		.pmd		= PMD_SECT_WB,
		.pte		= L_PTE_MT_WRITEBACK,
		.pte_s2		= s2_policy(L_PTE_S2_MT_WRITEBACK),
	}, {
		.policy		= "writealloc",
		.cr_mask	= 0,
		.pmd		= PMD_SECT_WBWA,
		.pte		= L_PTE_MT_WRITEALLOC,
		.pte_s2		= s2_policy(L_PTE_S2_MT_WRITEBACK),
	}
};

#ifdef CONFIG_CPU_CP15
/*
 * 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;

	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) {
			cachepolicy = i;
			cr_alignment &= ~cache_policies[i].cr_mask;
			cr_no_alignment &= ~cache_policies[i].cr_mask;
			break;
		}
	}
	if (i == ARRAY_SIZE(cache_policies))
		printk(KERN_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) {
		printk(KERN_WARNING "Only cachepolicy=writeback supported on ARMv6 and later\n");
		cachepolicy = CPOLICY_WRITEBACK;
	}
	flush_cache_all();
	set_cr(cr_alignment);
	return 0;
}
early_param("cachepolicy", early_cachepolicy);

static int __init early_nocache(char *__unused)
{
	char *p = "buffered";
	printk(KERN_WARNING "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";
	printk(KERN_WARNING "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

static int __init noalign_setup(char *__unused)
{
	cr_alignment &= ~CR_A;
	cr_no_alignment &= ~CR_A;
	set_cr(cr_alignment);
	return 1;
}
__setup("noalign", noalign_setup);

#ifndef CONFIG_SMP
void adjust_cr(unsigned long mask, unsigned long set)
{
	unsigned long flags;

	mask &= ~CR_A;

	set &= mask;

	local_irq_save(flags);

	cr_no_alignment = (cr_no_alignment & ~mask) | set;
	cr_alignment = (cr_alignment & ~mask) | set;

	set_cr((get_cr() & ~mask) | set);

	local_irq_restore(flags);
}
#endif

#else /* ifdef CONFIG_CPU_CP15 */

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

static int __init noalign_setup(char *__unused)
{
	pr_warning("noalign kernel parameter not supported without cp15\n");
}
__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_SECT_DEVICE	PMD_TYPE_SECT|PMD_SECT_AP_WRITE

static struct mem_type mem_types[] = {
	[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_cached */
		.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_USER,
	},
	[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_USER,
	},
	[MT_MEMORY] = {
		.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_ROM] = {
		.prot_sect = PMD_TYPE_SECT,
		.domain    = DOMAIN_KERNEL,
	},
	[MT_MEMORY_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_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_ITCM] = {
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
		.prot_l1   = PMD_TYPE_TABLE,
		.domain    = DOMAIN_KERNEL,
	},
	[MT_MEMORY_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,
		.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);

/*
 * 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;
	pteval_t hyp_device_pgprot, s2_pgprot, s2_device_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())
		cachepolicy = CPOLICY_WRITEALLOC;

	/*
	 * 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() || cpu_is_xsc3()) {
		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;
		}
		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;
	s2_pgprot = cp->pte_s2;
	hyp_device_pgprot = s2_device_pgprot = mem_types[MT_DEVICE].prot_pte;

	/*
	 * 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;
#endif

		if (is_smp()) {
			/*
			 * Mark memory with the "shared" attribute
			 * for SMP systems
			 */
			user_pgprot |= L_PTE_SHARED;
			kern_pgprot |= L_PTE_SHARED;
			vecs_pgprot |= L_PTE_SHARED;
			s2_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].prot_sect |= PMD_SECT_S;
			mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED;
			mem_types[MT_MEMORY_DMA_READY].prot_pte |= L_PTE_SHARED;
			mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S;
			mem_types[MT_MEMORY_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_NONCACHED].prot_sect |=
				PMD_SECT_BUFFERED;
		} else {
			/* For both ARMv6 and non-TEX-remapping ARMv7 */
			mem_types[MT_MEMORY_NONCACHED].prot_sect |=
				PMD_SECT_TEX(1);
		}
	} else {
		mem_types[MT_MEMORY_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;
#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);
	pgprot_s2  = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | s2_pgprot);
	pgprot_s2_device  = __pgprot(s2_device_pgprot);
	pgprot_hyp_device  = __pgprot(hyp_device_pgprot);

	mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
	mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;
	mem_types[MT_MEMORY].prot_sect |= ecc_mask | cp->pmd;
	mem_types[MT_MEMORY].prot_pte |= kern_pgprot;
	mem_types[MT_MEMORY_DMA_READY].prot_pte |= kern_pgprot;
	mem_types[MT_MEMORY_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;
	}
	printk("Memory policy: ECC %sabled, Data cache %s\n",
		ecc_mask ? "en" : "dis", 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_aligned(unsigned long sz, unsigned long align)
{
	void *ptr = __va(memblock_alloc(sz, align));
	memset(ptr, 0, sz);
	return ptr;
}

static void __init *early_alloc(unsigned long sz)
{
	return early_alloc_aligned(sz, sz);
}

static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr, unsigned long prot)
{
	if (pmd_none(*pmd)) {
		pte_t *pte = early_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 void __init alloc_init_pte(pmd_t *pmd, unsigned long addr,
				  unsigned long end, unsigned long pfn,
				  const struct mem_type *type)
{
	pte_t *pte = early_pte_alloc(pmd, addr, type->prot_l1);
	do {
		set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)), 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)
{
	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);
		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)
{
	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);
		} else {
			alloc_init_pte(pmd, addr, next,
						__phys_to_pfn(phys), type);
		}

		phys += next - addr;

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

static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
				  unsigned long end, phys_addr_t phys,
				  const struct mem_type *type)
{
	pud_t *pud = pud_offset(pgd, addr);
	unsigned long next;

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

#ifndef CONFIG_ARM_LPAE
static void __init create_36bit_mapping(struct map_desc *md,
					const struct mem_type *type)
{
	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())) {
		printk(KERN_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) {
		printk(KERN_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) {
		printk(KERN_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_k(addr);
	end = addr + length;
	do {
		pud_t *pud = pud_offset(pgd, 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);

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

/*
 * 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)
{
	unsigned long addr, length, end;
	phys_addr_t phys;
	const struct mem_type *type;
	pgd_t *pgd;

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

	type = &mem_types[md->type];

#ifndef CONFIG_ARM_LPAE
	/*
	 * Catch 36-bit addresses
	 */
	if (md->pfn >= 0x100000) {
		create_36bit_mapping(md, type);
		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)) {
		printk(KERN_WARNING "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_k(addr);
	end = addr + length;
	do {
		unsigned long next = pgd_addr_end(addr, end);

		alloc_init_pud(pgd, addr, next, phys, type);

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

/*
 * 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 = early_alloc_aligned(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 = early_alloc_aligned(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 void * __initdata vmalloc_min =
	(void *)(VMALLOC_END - (240 << 20) - VMALLOC_OFFSET);

/*
 * 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 240m.
 */
static int __init early_vmalloc(char *arg)
{
	unsigned long vmalloc_reserve = memparse(arg, NULL);

	if (vmalloc_reserve < SZ_16M) {
		vmalloc_reserve = SZ_16M;
		printk(KERN_WARNING
			"vmalloc area too small, limiting to %luMB\n",
			vmalloc_reserve >> 20);
	}

	if (vmalloc_reserve > VMALLOC_END - (PAGE_OFFSET + SZ_32M)) {
		vmalloc_reserve = VMALLOC_END - (PAGE_OFFSET + SZ_32M);
		printk(KERN_WARNING
			"vmalloc area is too big, limiting to %luMB\n",
			vmalloc_reserve >> 20);
	}

	vmalloc_min = (void *)(VMALLOC_END - vmalloc_reserve);
	return 0;
}
early_param("vmalloc", early_vmalloc);

phys_addr_t arm_lowmem_limit __initdata = 0;

void __init sanity_check_meminfo(void)
{
	phys_addr_t memblock_limit = 0;
	int i, j, highmem = 0;
	phys_addr_t vmalloc_limit = __pa(vmalloc_min - 1) + 1;

	for (i = 0, j = 0; i < meminfo.nr_banks; i++) {
		struct membank *bank = &meminfo.bank[j];
		phys_addr_t size_limit;

		*bank = meminfo.bank[i];
		size_limit = bank->size;

		if (bank->start >= vmalloc_limit)
			highmem = 1;
		else
			size_limit = vmalloc_limit - bank->start;

		bank->highmem = highmem;

#ifdef CONFIG_HIGHMEM
		/*
		 * Split those memory banks which are partially overlapping
		 * the vmalloc area greatly simplifying things later.
		 */
		if (!highmem && bank->size > size_limit) {
			if (meminfo.nr_banks >= NR_BANKS) {
				printk(KERN_CRIT "NR_BANKS too low, "
						 "ignoring high memory\n");
			} else {
				memmove(bank + 1, bank,
					(meminfo.nr_banks - i) * sizeof(*bank));
				meminfo.nr_banks++;
				i++;
				bank[1].size -= size_limit;
				bank[1].start = vmalloc_limit;
				bank[1].highmem = highmem = 1;
				j++;
			}
			bank->size = size_limit;
		}
#else
		/*
		 * Highmem banks not allowed with !CONFIG_HIGHMEM.
		 */
		if (highmem) {
			printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx "
			       "(!CONFIG_HIGHMEM).\n",
			       (unsigned long long)bank->start,
			       (unsigned long long)bank->start + bank->size - 1);
			continue;
		}

		/*
		 * Check whether this memory bank would partially overlap
		 * the vmalloc area.
		 */
		if (bank->size > size_limit) {
			printk(KERN_NOTICE "Truncating RAM at %.8llx-%.8llx "
			       "to -%.8llx (vmalloc region overlap).\n",
			       (unsigned long long)bank->start,
			       (unsigned long long)bank->start + bank->size - 1,
			       (unsigned long long)bank->start + size_limit - 1);
			bank->size = size_limit;
		}
#endif
		if (!bank->highmem) {
			phys_addr_t bank_end = bank->start + bank->size;

			if (bank_end > arm_lowmem_limit)
				arm_lowmem_limit = bank_end;

			/*
			 * Find the first non-section-aligned page, and point
			 * memblock_limit at it. This relies on rounding the
			 * limit down to be section-aligned, which happens at
			 * the end of this function.
			 *
			 * With this algorithm, the start or end of almost any
			 * bank can be non-section-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(bank->start, SECTION_SIZE))
					memblock_limit = bank->start;
				else if (!IS_ALIGNED(bank_end, SECTION_SIZE))
					memblock_limit = bank_end;
			}
		}
		j++;
	}
#ifdef CONFIG_HIGHMEM
	if (highmem) {
		const char *reason = NULL;

		if (cache_is_vipt_aliasing()) {
			/*
			 * Interactions between kmap and other mappings
			 * make highmem support with aliasing VIPT caches
			 * rather difficult.
			 */
			reason = "with VIPT aliasing cache";
		}
		if (reason) {
			printk(KERN_CRIT "HIGHMEM is not supported %s, ignoring high memory\n",
				reason);
			while (j > 0 && meminfo.bank[j - 1].highmem)
				j--;
		}
	}
#endif
	meminfo.nr_banks = j;
	high_memory = __va(arm_lowmem_limit - 1) + 1;

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

	memblock_set_current_limit(memblock_limit);
}

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

	/*
	 * Clear out all the mappings below the kernel image.
	 */
	for (addr = 0; addr < MODULES_VADDR; addr += PMD_SIZE)
		pmd_clear(pmd_off_k(addr));

#ifdef CONFIG_XIP_KERNEL
	/* The XIP kernel is mapped in the module area -- skip over it */
	addr = ((unsigned long)_etext + 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, we will remove any debug device mappings.
 * This means you have to be careful how you debug this function, or any
 * called function.  This means you can't use any function or debugging
 * method which may touch any device, otherwise the kernel _will_ crash.
 */
static void __init devicemaps_init(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);

	for (addr = VMALLOC_START; addr; addr += PMD_SIZE)
		pmd_clear(pmd_off_k(addr));

	/*
	 * 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)_etext - 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();
}

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
}

static void __init map_lowmem(void)
{
	struct memblock_region *reg;

	/* Map all the lowmem memory banks. */
	for_each_memblock(memory, reg) {
		phys_addr_t start = reg->base;
		phys_addr_t end = start + reg->size;
		struct map_desc map;

		if (end > arm_lowmem_limit)
			end = arm_lowmem_limit;
		if (start >= end)
			break;

		map.pfn = __phys_to_pfn(start);
		map.virtual = __phys_to_virt(start);
		map.length = end - start;
		map.type = MT_MEMORY;

		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(struct machine_desc *mdesc)
{
	void *zero_page;

	build_mem_type_table();
	prepare_page_table();
	map_lowmem();
	dma_contiguous_remap();
	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_page(NULL, empty_zero_page);
}