summaryrefslogtreecommitdiff
path: root/drivers/iommu/exynos-iommu.c
blob: 9c94e16fb1277f793bb8d24062b09afb8ab49d74 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2011,2016 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 */

#ifdef CONFIG_EXYNOS_IOMMU_DEBUG
#define DEBUG
#endif

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/iommu.h>
#include <linux/interrupt.h>
#include <linux/kmemleak.h>
#include <linux/list.h>
#include <linux/of.h>
#include <linux/of_iommu.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/dma-iommu.h>

typedef u32 sysmmu_iova_t;
typedef u32 sysmmu_pte_t;

/* We do not consider super section mapping (16MB) */
#define SECT_ORDER 20
#define LPAGE_ORDER 16
#define SPAGE_ORDER 12

#define SECT_SIZE (1 << SECT_ORDER)
#define LPAGE_SIZE (1 << LPAGE_ORDER)
#define SPAGE_SIZE (1 << SPAGE_ORDER)

#define SECT_MASK (~(SECT_SIZE - 1))
#define LPAGE_MASK (~(LPAGE_SIZE - 1))
#define SPAGE_MASK (~(SPAGE_SIZE - 1))

#define lv1ent_fault(sent) ((*(sent) == ZERO_LV2LINK) || \
			   ((*(sent) & 3) == 0) || ((*(sent) & 3) == 3))
#define lv1ent_zero(sent) (*(sent) == ZERO_LV2LINK)
#define lv1ent_page_zero(sent) ((*(sent) & 3) == 1)
#define lv1ent_page(sent) ((*(sent) != ZERO_LV2LINK) && \
			  ((*(sent) & 3) == 1))
#define lv1ent_section(sent) ((*(sent) & 3) == 2)

#define lv2ent_fault(pent) ((*(pent) & 3) == 0)
#define lv2ent_small(pent) ((*(pent) & 2) == 2)
#define lv2ent_large(pent) ((*(pent) & 3) == 1)

/*
 * v1.x - v3.x SYSMMU supports 32bit physical and 32bit virtual address spaces
 * v5.0 introduced support for 36bit physical address space by shifting
 * all page entry values by 4 bits.
 * All SYSMMU controllers in the system support the address spaces of the same
 * size, so PG_ENT_SHIFT can be initialized on first SYSMMU probe to proper
 * value (0 or 4).
 */
static short PG_ENT_SHIFT = -1;
#define SYSMMU_PG_ENT_SHIFT 0
#define SYSMMU_V5_PG_ENT_SHIFT 4

static const sysmmu_pte_t *LV1_PROT;
static const sysmmu_pte_t SYSMMU_LV1_PROT[] = {
	((0 << 15) | (0 << 10)), /* no access */
	((1 << 15) | (1 << 10)), /* IOMMU_READ only */
	((0 << 15) | (1 << 10)), /* IOMMU_WRITE not supported, use read/write */
	((0 << 15) | (1 << 10)), /* IOMMU_READ | IOMMU_WRITE */
};
static const sysmmu_pte_t SYSMMU_V5_LV1_PROT[] = {
	(0 << 4), /* no access */
	(1 << 4), /* IOMMU_READ only */
	(2 << 4), /* IOMMU_WRITE only */
	(3 << 4), /* IOMMU_READ | IOMMU_WRITE */
};

static const sysmmu_pte_t *LV2_PROT;
static const sysmmu_pte_t SYSMMU_LV2_PROT[] = {
	((0 << 9) | (0 << 4)), /* no access */
	((1 << 9) | (1 << 4)), /* IOMMU_READ only */
	((0 << 9) | (1 << 4)), /* IOMMU_WRITE not supported, use read/write */
	((0 << 9) | (1 << 4)), /* IOMMU_READ | IOMMU_WRITE */
};
static const sysmmu_pte_t SYSMMU_V5_LV2_PROT[] = {
	(0 << 2), /* no access */
	(1 << 2), /* IOMMU_READ only */
	(2 << 2), /* IOMMU_WRITE only */
	(3 << 2), /* IOMMU_READ | IOMMU_WRITE */
};

#define SYSMMU_SUPPORTED_PROT_BITS (IOMMU_READ | IOMMU_WRITE)

#define sect_to_phys(ent) (((phys_addr_t) ent) << PG_ENT_SHIFT)
#define section_phys(sent) (sect_to_phys(*(sent)) & SECT_MASK)
#define section_offs(iova) (iova & (SECT_SIZE - 1))
#define lpage_phys(pent) (sect_to_phys(*(pent)) & LPAGE_MASK)
#define lpage_offs(iova) (iova & (LPAGE_SIZE - 1))
#define spage_phys(pent) (sect_to_phys(*(pent)) & SPAGE_MASK)
#define spage_offs(iova) (iova & (SPAGE_SIZE - 1))

#define NUM_LV1ENTRIES 4096
#define NUM_LV2ENTRIES (SECT_SIZE / SPAGE_SIZE)

static u32 lv1ent_offset(sysmmu_iova_t iova)
{
	return iova >> SECT_ORDER;
}

static u32 lv2ent_offset(sysmmu_iova_t iova)
{
	return (iova >> SPAGE_ORDER) & (NUM_LV2ENTRIES - 1);
}

#define LV1TABLE_SIZE (NUM_LV1ENTRIES * sizeof(sysmmu_pte_t))
#define LV2TABLE_SIZE (NUM_LV2ENTRIES * sizeof(sysmmu_pte_t))

#define SPAGES_PER_LPAGE (LPAGE_SIZE / SPAGE_SIZE)
#define lv2table_base(sent) (sect_to_phys(*(sent) & 0xFFFFFFC0))

#define mk_lv1ent_sect(pa, prot) ((pa >> PG_ENT_SHIFT) | LV1_PROT[prot] | 2)
#define mk_lv1ent_page(pa) ((pa >> PG_ENT_SHIFT) | 1)
#define mk_lv2ent_lpage(pa, prot) ((pa >> PG_ENT_SHIFT) | LV2_PROT[prot] | 1)
#define mk_lv2ent_spage(pa, prot) ((pa >> PG_ENT_SHIFT) | LV2_PROT[prot] | 2)

#define CTRL_ENABLE	0x5
#define CTRL_BLOCK	0x7
#define CTRL_DISABLE	0x0

#define CFG_LRU		0x1
#define CFG_EAP		(1 << 2)
#define CFG_QOS(n)	((n & 0xF) << 7)
#define CFG_ACGEN	(1 << 24) /* System MMU 3.3 only */
#define CFG_SYSSEL	(1 << 22) /* System MMU 3.2 only */
#define CFG_FLPDCACHE	(1 << 20) /* System MMU 3.2+ only */

/* common registers */
#define REG_MMU_CTRL		0x000
#define REG_MMU_CFG		0x004
#define REG_MMU_STATUS		0x008
#define REG_MMU_VERSION		0x034

#define MMU_MAJ_VER(val)	((val) >> 7)
#define MMU_MIN_VER(val)	((val) & 0x7F)
#define MMU_RAW_VER(reg)	(((reg) >> 21) & ((1 << 11) - 1)) /* 11 bits */

#define MAKE_MMU_VER(maj, min)	((((maj) & 0xF) << 7) | ((min) & 0x7F))

/* v1.x - v3.x registers */
#define REG_MMU_FLUSH		0x00C
#define REG_MMU_FLUSH_ENTRY	0x010
#define REG_PT_BASE_ADDR	0x014
#define REG_INT_STATUS		0x018
#define REG_INT_CLEAR		0x01C

#define REG_PAGE_FAULT_ADDR	0x024
#define REG_AW_FAULT_ADDR	0x028
#define REG_AR_FAULT_ADDR	0x02C
#define REG_DEFAULT_SLAVE_ADDR	0x030

/* v5.x registers */
#define REG_V5_PT_BASE_PFN	0x00C
#define REG_V5_MMU_FLUSH_ALL	0x010
#define REG_V5_MMU_FLUSH_ENTRY	0x014
#define REG_V5_MMU_FLUSH_RANGE	0x018
#define REG_V5_MMU_FLUSH_START	0x020
#define REG_V5_MMU_FLUSH_END	0x024
#define REG_V5_INT_STATUS	0x060
#define REG_V5_INT_CLEAR	0x064
#define REG_V5_FAULT_AR_VA	0x070
#define REG_V5_FAULT_AW_VA	0x080

#define has_sysmmu(dev)		(dev->archdata.iommu != NULL)

static struct device *dma_dev;
static struct kmem_cache *lv2table_kmem_cache;
static sysmmu_pte_t *zero_lv2_table;
#define ZERO_LV2LINK mk_lv1ent_page(virt_to_phys(zero_lv2_table))

static sysmmu_pte_t *section_entry(sysmmu_pte_t *pgtable, sysmmu_iova_t iova)
{
	return pgtable + lv1ent_offset(iova);
}

static sysmmu_pte_t *page_entry(sysmmu_pte_t *sent, sysmmu_iova_t iova)
{
	return (sysmmu_pte_t *)phys_to_virt(
				lv2table_base(sent)) + lv2ent_offset(iova);
}

/*
 * IOMMU fault information register
 */
struct sysmmu_fault_info {
	unsigned int bit;	/* bit number in STATUS register */
	unsigned short addr_reg; /* register to read VA fault address */
	const char *name;	/* human readable fault name */
	unsigned int type;	/* fault type for report_iommu_fault */
};

static const struct sysmmu_fault_info sysmmu_faults[] = {
	{ 0, REG_PAGE_FAULT_ADDR, "PAGE", IOMMU_FAULT_READ },
	{ 1, REG_AR_FAULT_ADDR, "AR MULTI-HIT", IOMMU_FAULT_READ },
	{ 2, REG_AW_FAULT_ADDR, "AW MULTI-HIT", IOMMU_FAULT_WRITE },
	{ 3, REG_DEFAULT_SLAVE_ADDR, "BUS ERROR", IOMMU_FAULT_READ },
	{ 4, REG_AR_FAULT_ADDR, "AR SECURITY PROTECTION", IOMMU_FAULT_READ },
	{ 5, REG_AR_FAULT_ADDR, "AR ACCESS PROTECTION", IOMMU_FAULT_READ },
	{ 6, REG_AW_FAULT_ADDR, "AW SECURITY PROTECTION", IOMMU_FAULT_WRITE },
	{ 7, REG_AW_FAULT_ADDR, "AW ACCESS PROTECTION", IOMMU_FAULT_WRITE },
};

static const struct sysmmu_fault_info sysmmu_v5_faults[] = {
	{ 0, REG_V5_FAULT_AR_VA, "AR PTW", IOMMU_FAULT_READ },
	{ 1, REG_V5_FAULT_AR_VA, "AR PAGE", IOMMU_FAULT_READ },
	{ 2, REG_V5_FAULT_AR_VA, "AR MULTI-HIT", IOMMU_FAULT_READ },
	{ 3, REG_V5_FAULT_AR_VA, "AR ACCESS PROTECTION", IOMMU_FAULT_READ },
	{ 4, REG_V5_FAULT_AR_VA, "AR SECURITY PROTECTION", IOMMU_FAULT_READ },
	{ 16, REG_V5_FAULT_AW_VA, "AW PTW", IOMMU_FAULT_WRITE },
	{ 17, REG_V5_FAULT_AW_VA, "AW PAGE", IOMMU_FAULT_WRITE },
	{ 18, REG_V5_FAULT_AW_VA, "AW MULTI-HIT", IOMMU_FAULT_WRITE },
	{ 19, REG_V5_FAULT_AW_VA, "AW ACCESS PROTECTION", IOMMU_FAULT_WRITE },
	{ 20, REG_V5_FAULT_AW_VA, "AW SECURITY PROTECTION", IOMMU_FAULT_WRITE },
};

/*
 * This structure is attached to dev.archdata.iommu of the master device
 * on device add, contains a list of SYSMMU controllers defined by device tree,
 * which are bound to given master device. It is usually referenced by 'owner'
 * pointer.
*/
struct exynos_iommu_owner {
	struct list_head controllers;	/* list of sysmmu_drvdata.owner_node */
	struct iommu_domain *domain;	/* domain this device is attached */
	struct mutex rpm_lock;		/* for runtime pm of all sysmmus */
};

/*
 * This structure exynos specific generalization of struct iommu_domain.
 * It contains list of SYSMMU controllers from all master devices, which has
 * been attached to this domain and page tables of IO address space defined by
 * it. It is usually referenced by 'domain' pointer.
 */
struct exynos_iommu_domain {
	struct list_head clients; /* list of sysmmu_drvdata.domain_node */
	sysmmu_pte_t *pgtable;	/* lv1 page table, 16KB */
	short *lv2entcnt;	/* free lv2 entry counter for each section */
	spinlock_t lock;	/* lock for modyfying list of clients */
	spinlock_t pgtablelock;	/* lock for modifying page table @ pgtable */
	struct iommu_domain domain; /* generic domain data structure */
};

/*
 * This structure hold all data of a single SYSMMU controller, this includes
 * hw resources like registers and clocks, pointers and list nodes to connect
 * it to all other structures, internal state and parameters read from device
 * tree. It is usually referenced by 'data' pointer.
 */
struct sysmmu_drvdata {
	struct device *sysmmu;		/* SYSMMU controller device */
	struct device *master;		/* master device (owner) */
	struct device_link *link;	/* runtime PM link to master */
	void __iomem *sfrbase;		/* our registers */
	struct clk *clk;		/* SYSMMU's clock */
	struct clk *aclk;		/* SYSMMU's aclk clock */
	struct clk *pclk;		/* SYSMMU's pclk clock */
	struct clk *clk_master;		/* master's device clock */
	spinlock_t lock;		/* lock for modyfying state */
	bool active;			/* current status */
	struct exynos_iommu_domain *domain; /* domain we belong to */
	struct list_head domain_node;	/* node for domain clients list */
	struct list_head owner_node;	/* node for owner controllers list */
	phys_addr_t pgtable;		/* assigned page table structure */
	unsigned int version;		/* our version */

	struct iommu_device iommu;	/* IOMMU core handle */
};

static struct exynos_iommu_domain *to_exynos_domain(struct iommu_domain *dom)
{
	return container_of(dom, struct exynos_iommu_domain, domain);
}

static void sysmmu_unblock(struct sysmmu_drvdata *data)
{
	writel(CTRL_ENABLE, data->sfrbase + REG_MMU_CTRL);
}

static bool sysmmu_block(struct sysmmu_drvdata *data)
{
	int i = 120;

	writel(CTRL_BLOCK, data->sfrbase + REG_MMU_CTRL);
	while ((i > 0) && !(readl(data->sfrbase + REG_MMU_STATUS) & 1))
		--i;

	if (!(readl(data->sfrbase + REG_MMU_STATUS) & 1)) {
		sysmmu_unblock(data);
		return false;
	}

	return true;
}

static void __sysmmu_tlb_invalidate(struct sysmmu_drvdata *data)
{
	if (MMU_MAJ_VER(data->version) < 5)
		writel(0x1, data->sfrbase + REG_MMU_FLUSH);
	else
		writel(0x1, data->sfrbase + REG_V5_MMU_FLUSH_ALL);
}

static void __sysmmu_tlb_invalidate_entry(struct sysmmu_drvdata *data,
				sysmmu_iova_t iova, unsigned int num_inv)
{
	unsigned int i;

	if (MMU_MAJ_VER(data->version) < 5) {
		for (i = 0; i < num_inv; i++) {
			writel((iova & SPAGE_MASK) | 1,
				     data->sfrbase + REG_MMU_FLUSH_ENTRY);
			iova += SPAGE_SIZE;
		}
	} else {
		if (num_inv == 1) {
			writel((iova & SPAGE_MASK) | 1,
				     data->sfrbase + REG_V5_MMU_FLUSH_ENTRY);
		} else {
			writel((iova & SPAGE_MASK),
				     data->sfrbase + REG_V5_MMU_FLUSH_START);
			writel((iova & SPAGE_MASK) + (num_inv - 1) * SPAGE_SIZE,
				     data->sfrbase + REG_V5_MMU_FLUSH_END);
			writel(1, data->sfrbase + REG_V5_MMU_FLUSH_RANGE);
		}
	}
}

static void __sysmmu_set_ptbase(struct sysmmu_drvdata *data, phys_addr_t pgd)
{
	if (MMU_MAJ_VER(data->version) < 5)
		writel(pgd, data->sfrbase + REG_PT_BASE_ADDR);
	else
		writel(pgd >> PAGE_SHIFT,
			     data->sfrbase + REG_V5_PT_BASE_PFN);

	__sysmmu_tlb_invalidate(data);
}

static void __sysmmu_enable_clocks(struct sysmmu_drvdata *data)
{
	BUG_ON(clk_prepare_enable(data->clk_master));
	BUG_ON(clk_prepare_enable(data->clk));
	BUG_ON(clk_prepare_enable(data->pclk));
	BUG_ON(clk_prepare_enable(data->aclk));
}

static void __sysmmu_disable_clocks(struct sysmmu_drvdata *data)
{
	clk_disable_unprepare(data->aclk);
	clk_disable_unprepare(data->pclk);
	clk_disable_unprepare(data->clk);
	clk_disable_unprepare(data->clk_master);
}

static void __sysmmu_get_version(struct sysmmu_drvdata *data)
{
	u32 ver;

	__sysmmu_enable_clocks(data);

	ver = readl(data->sfrbase + REG_MMU_VERSION);

	/* controllers on some SoCs don't report proper version */
	if (ver == 0x80000001u)
		data->version = MAKE_MMU_VER(1, 0);
	else
		data->version = MMU_RAW_VER(ver);

	dev_dbg(data->sysmmu, "hardware version: %d.%d\n",
		MMU_MAJ_VER(data->version), MMU_MIN_VER(data->version));

	__sysmmu_disable_clocks(data);
}

static void show_fault_information(struct sysmmu_drvdata *data,
				   const struct sysmmu_fault_info *finfo,
				   sysmmu_iova_t fault_addr)
{
	sysmmu_pte_t *ent;

	dev_err(data->sysmmu, "%s: %s FAULT occurred at %#x\n",
		dev_name(data->master), finfo->name, fault_addr);
	dev_dbg(data->sysmmu, "Page table base: %pa\n", &data->pgtable);
	ent = section_entry(phys_to_virt(data->pgtable), fault_addr);
	dev_dbg(data->sysmmu, "\tLv1 entry: %#x\n", *ent);
	if (lv1ent_page(ent)) {
		ent = page_entry(ent, fault_addr);
		dev_dbg(data->sysmmu, "\t Lv2 entry: %#x\n", *ent);
	}
}

static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
{
	/* SYSMMU is in blocked state when interrupt occurred. */
	struct sysmmu_drvdata *data = dev_id;
	const struct sysmmu_fault_info *finfo;
	unsigned int i, n, itype;
	sysmmu_iova_t fault_addr = -1;
	unsigned short reg_status, reg_clear;
	int ret = -ENOSYS;

	WARN_ON(!data->active);

	if (MMU_MAJ_VER(data->version) < 5) {
		reg_status = REG_INT_STATUS;
		reg_clear = REG_INT_CLEAR;
		finfo = sysmmu_faults;
		n = ARRAY_SIZE(sysmmu_faults);
	} else {
		reg_status = REG_V5_INT_STATUS;
		reg_clear = REG_V5_INT_CLEAR;
		finfo = sysmmu_v5_faults;
		n = ARRAY_SIZE(sysmmu_v5_faults);
	}

	spin_lock(&data->lock);

	clk_enable(data->clk_master);

	itype = __ffs(readl(data->sfrbase + reg_status));
	for (i = 0; i < n; i++, finfo++)
		if (finfo->bit == itype)
			break;
	/* unknown/unsupported fault */
	BUG_ON(i == n);

	/* print debug message */
	fault_addr = readl(data->sfrbase + finfo->addr_reg);
	show_fault_information(data, finfo, fault_addr);

	if (data->domain)
		ret = report_iommu_fault(&data->domain->domain,
					data->master, fault_addr, finfo->type);
	/* fault is not recovered by fault handler */
	BUG_ON(ret != 0);

	writel(1 << itype, data->sfrbase + reg_clear);

	sysmmu_unblock(data);

	clk_disable(data->clk_master);

	spin_unlock(&data->lock);

	return IRQ_HANDLED;
}

static void __sysmmu_disable(struct sysmmu_drvdata *data)
{
	unsigned long flags;

	clk_enable(data->clk_master);

	spin_lock_irqsave(&data->lock, flags);
	writel(CTRL_DISABLE, data->sfrbase + REG_MMU_CTRL);
	writel(0, data->sfrbase + REG_MMU_CFG);
	data->active = false;
	spin_unlock_irqrestore(&data->lock, flags);

	__sysmmu_disable_clocks(data);
}

static void __sysmmu_init_config(struct sysmmu_drvdata *data)
{
	unsigned int cfg;

	if (data->version <= MAKE_MMU_VER(3, 1))
		cfg = CFG_LRU | CFG_QOS(15);
	else if (data->version <= MAKE_MMU_VER(3, 2))
		cfg = CFG_LRU | CFG_QOS(15) | CFG_FLPDCACHE | CFG_SYSSEL;
	else
		cfg = CFG_QOS(15) | CFG_FLPDCACHE | CFG_ACGEN;

	cfg |= CFG_EAP; /* enable access protection bits check */

	writel(cfg, data->sfrbase + REG_MMU_CFG);
}

static void __sysmmu_enable(struct sysmmu_drvdata *data)
{
	unsigned long flags;

	__sysmmu_enable_clocks(data);

	spin_lock_irqsave(&data->lock, flags);
	writel(CTRL_BLOCK, data->sfrbase + REG_MMU_CTRL);
	__sysmmu_init_config(data);
	__sysmmu_set_ptbase(data, data->pgtable);
	writel(CTRL_ENABLE, data->sfrbase + REG_MMU_CTRL);
	data->active = true;
	spin_unlock_irqrestore(&data->lock, flags);

	/*
	 * SYSMMU driver keeps master's clock enabled only for the short
	 * time, while accessing the registers. For performing address
	 * translation during DMA transaction it relies on the client
	 * driver to enable it.
	 */
	clk_disable(data->clk_master);
}

static void sysmmu_tlb_invalidate_flpdcache(struct sysmmu_drvdata *data,
					    sysmmu_iova_t iova)
{
	unsigned long flags;

	spin_lock_irqsave(&data->lock, flags);
	if (data->active && data->version >= MAKE_MMU_VER(3, 3)) {
		clk_enable(data->clk_master);
		if (sysmmu_block(data)) {
			if (data->version >= MAKE_MMU_VER(5, 0))
				__sysmmu_tlb_invalidate(data);
			else
				__sysmmu_tlb_invalidate_entry(data, iova, 1);
			sysmmu_unblock(data);
		}
		clk_disable(data->clk_master);
	}
	spin_unlock_irqrestore(&data->lock, flags);
}

static void sysmmu_tlb_invalidate_entry(struct sysmmu_drvdata *data,
					sysmmu_iova_t iova, size_t size)
{
	unsigned long flags;

	spin_lock_irqsave(&data->lock, flags);
	if (data->active) {
		unsigned int num_inv = 1;

		clk_enable(data->clk_master);

		/*
		 * L2TLB invalidation required
		 * 4KB page: 1 invalidation
		 * 64KB page: 16 invalidations
		 * 1MB page: 64 invalidations
		 * because it is set-associative TLB
		 * with 8-way and 64 sets.
		 * 1MB page can be cached in one of all sets.
		 * 64KB page can be one of 16 consecutive sets.
		 */
		if (MMU_MAJ_VER(data->version) == 2)
			num_inv = min_t(unsigned int, size / PAGE_SIZE, 64);

		if (sysmmu_block(data)) {
			__sysmmu_tlb_invalidate_entry(data, iova, num_inv);
			sysmmu_unblock(data);
		}
		clk_disable(data->clk_master);
	}
	spin_unlock_irqrestore(&data->lock, flags);
}

static const struct iommu_ops exynos_iommu_ops;

static int exynos_sysmmu_probe(struct platform_device *pdev)
{
	int irq, ret;
	struct device *dev = &pdev->dev;
	struct sysmmu_drvdata *data;
	struct resource *res;

	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	data->sfrbase = devm_ioremap_resource(dev, res);
	if (IS_ERR(data->sfrbase))
		return PTR_ERR(data->sfrbase);

	irq = platform_get_irq(pdev, 0);
	if (irq <= 0)
		return irq;

	ret = devm_request_irq(dev, irq, exynos_sysmmu_irq, 0,
				dev_name(dev), data);
	if (ret) {
		dev_err(dev, "Unabled to register handler of irq %d\n", irq);
		return ret;
	}

	data->clk = devm_clk_get(dev, "sysmmu");
	if (PTR_ERR(data->clk) == -ENOENT)
		data->clk = NULL;
	else if (IS_ERR(data->clk))
		return PTR_ERR(data->clk);

	data->aclk = devm_clk_get(dev, "aclk");
	if (PTR_ERR(data->aclk) == -ENOENT)
		data->aclk = NULL;
	else if (IS_ERR(data->aclk))
		return PTR_ERR(data->aclk);

	data->pclk = devm_clk_get(dev, "pclk");
	if (PTR_ERR(data->pclk) == -ENOENT)
		data->pclk = NULL;
	else if (IS_ERR(data->pclk))
		return PTR_ERR(data->pclk);

	if (!data->clk && (!data->aclk || !data->pclk)) {
		dev_err(dev, "Failed to get device clock(s)!\n");
		return -ENOSYS;
	}

	data->clk_master = devm_clk_get(dev, "master");
	if (PTR_ERR(data->clk_master) == -ENOENT)
		data->clk_master = NULL;
	else if (IS_ERR(data->clk_master))
		return PTR_ERR(data->clk_master);

	data->sysmmu = dev;
	spin_lock_init(&data->lock);

	ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL,
				     dev_name(data->sysmmu));
	if (ret)
		return ret;

	iommu_device_set_ops(&data->iommu, &exynos_iommu_ops);
	iommu_device_set_fwnode(&data->iommu, &dev->of_node->fwnode);

	ret = iommu_device_register(&data->iommu);
	if (ret)
		return ret;

	platform_set_drvdata(pdev, data);

	__sysmmu_get_version(data);
	if (PG_ENT_SHIFT < 0) {
		if (MMU_MAJ_VER(data->version) < 5) {
			PG_ENT_SHIFT = SYSMMU_PG_ENT_SHIFT;
			LV1_PROT = SYSMMU_LV1_PROT;
			LV2_PROT = SYSMMU_LV2_PROT;
		} else {
			PG_ENT_SHIFT = SYSMMU_V5_PG_ENT_SHIFT;
			LV1_PROT = SYSMMU_V5_LV1_PROT;
			LV2_PROT = SYSMMU_V5_LV2_PROT;
		}
	}

	/*
	 * use the first registered sysmmu device for performing
	 * dma mapping operations on iommu page tables (cpu cache flush)
	 */
	if (!dma_dev)
		dma_dev = &pdev->dev;

	pm_runtime_enable(dev);

	return 0;
}

static int __maybe_unused exynos_sysmmu_suspend(struct device *dev)
{
	struct sysmmu_drvdata *data = dev_get_drvdata(dev);
	struct device *master = data->master;

	if (master) {
		struct exynos_iommu_owner *owner = master->archdata.iommu;

		mutex_lock(&owner->rpm_lock);
		if (data->domain) {
			dev_dbg(data->sysmmu, "saving state\n");
			__sysmmu_disable(data);
		}
		mutex_unlock(&owner->rpm_lock);
	}
	return 0;
}

static int __maybe_unused exynos_sysmmu_resume(struct device *dev)
{
	struct sysmmu_drvdata *data = dev_get_drvdata(dev);
	struct device *master = data->master;

	if (master) {
		struct exynos_iommu_owner *owner = master->archdata.iommu;

		mutex_lock(&owner->rpm_lock);
		if (data->domain) {
			dev_dbg(data->sysmmu, "restoring state\n");
			__sysmmu_enable(data);
		}
		mutex_unlock(&owner->rpm_lock);
	}
	return 0;
}

static const struct dev_pm_ops sysmmu_pm_ops = {
	SET_RUNTIME_PM_OPS(exynos_sysmmu_suspend, exynos_sysmmu_resume, NULL)
	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
				pm_runtime_force_resume)
};

static const struct of_device_id sysmmu_of_match[] = {
	{ .compatible	= "samsung,exynos-sysmmu", },
	{ },
};

static struct platform_driver exynos_sysmmu_driver __refdata = {
	.probe	= exynos_sysmmu_probe,
	.driver	= {
		.name		= "exynos-sysmmu",
		.of_match_table	= sysmmu_of_match,
		.pm		= &sysmmu_pm_ops,
		.suppress_bind_attrs = true,
	}
};

static inline void update_pte(sysmmu_pte_t *ent, sysmmu_pte_t val)
{
	dma_sync_single_for_cpu(dma_dev, virt_to_phys(ent), sizeof(*ent),
				DMA_TO_DEVICE);
	*ent = cpu_to_le32(val);
	dma_sync_single_for_device(dma_dev, virt_to_phys(ent), sizeof(*ent),
				   DMA_TO_DEVICE);
}

static struct iommu_domain *exynos_iommu_domain_alloc(unsigned type)
{
	struct exynos_iommu_domain *domain;
	dma_addr_t handle;
	int i;

	/* Check if correct PTE offsets are initialized */
	BUG_ON(PG_ENT_SHIFT < 0 || !dma_dev);

	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
	if (!domain)
		return NULL;

	if (type == IOMMU_DOMAIN_DMA) {
		if (iommu_get_dma_cookie(&domain->domain) != 0)
			goto err_pgtable;
	} else if (type != IOMMU_DOMAIN_UNMANAGED) {
		goto err_pgtable;
	}

	domain->pgtable = (sysmmu_pte_t *)__get_free_pages(GFP_KERNEL, 2);
	if (!domain->pgtable)
		goto err_dma_cookie;

	domain->lv2entcnt = (short *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
	if (!domain->lv2entcnt)
		goto err_counter;

	/* Workaround for System MMU v3.3 to prevent caching 1MiB mapping */
	for (i = 0; i < NUM_LV1ENTRIES; i++)
		domain->pgtable[i] = ZERO_LV2LINK;

	handle = dma_map_single(dma_dev, domain->pgtable, LV1TABLE_SIZE,
				DMA_TO_DEVICE);
	/* For mapping page table entries we rely on dma == phys */
	BUG_ON(handle != virt_to_phys(domain->pgtable));
	if (dma_mapping_error(dma_dev, handle))
		goto err_lv2ent;

	spin_lock_init(&domain->lock);
	spin_lock_init(&domain->pgtablelock);
	INIT_LIST_HEAD(&domain->clients);

	domain->domain.geometry.aperture_start = 0;
	domain->domain.geometry.aperture_end   = ~0UL;
	domain->domain.geometry.force_aperture = true;

	return &domain->domain;

err_lv2ent:
	free_pages((unsigned long)domain->lv2entcnt, 1);
err_counter:
	free_pages((unsigned long)domain->pgtable, 2);
err_dma_cookie:
	if (type == IOMMU_DOMAIN_DMA)
		iommu_put_dma_cookie(&domain->domain);
err_pgtable:
	kfree(domain);
	return NULL;
}

static void exynos_iommu_domain_free(struct iommu_domain *iommu_domain)
{
	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
	struct sysmmu_drvdata *data, *next;
	unsigned long flags;
	int i;

	WARN_ON(!list_empty(&domain->clients));

	spin_lock_irqsave(&domain->lock, flags);

	list_for_each_entry_safe(data, next, &domain->clients, domain_node) {
		spin_lock(&data->lock);
		__sysmmu_disable(data);
		data->pgtable = 0;
		data->domain = NULL;
		list_del_init(&data->domain_node);
		spin_unlock(&data->lock);
	}

	spin_unlock_irqrestore(&domain->lock, flags);

	if (iommu_domain->type == IOMMU_DOMAIN_DMA)
		iommu_put_dma_cookie(iommu_domain);

	dma_unmap_single(dma_dev, virt_to_phys(domain->pgtable), LV1TABLE_SIZE,
			 DMA_TO_DEVICE);

	for (i = 0; i < NUM_LV1ENTRIES; i++)
		if (lv1ent_page(domain->pgtable + i)) {
			phys_addr_t base = lv2table_base(domain->pgtable + i);

			dma_unmap_single(dma_dev, base, LV2TABLE_SIZE,
					 DMA_TO_DEVICE);
			kmem_cache_free(lv2table_kmem_cache,
					phys_to_virt(base));
		}

	free_pages((unsigned long)domain->pgtable, 2);
	free_pages((unsigned long)domain->lv2entcnt, 1);
	kfree(domain);
}

static void exynos_iommu_detach_device(struct iommu_domain *iommu_domain,
				    struct device *dev)
{
	struct exynos_iommu_owner *owner = dev->archdata.iommu;
	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
	phys_addr_t pagetable = virt_to_phys(domain->pgtable);
	struct sysmmu_drvdata *data, *next;
	unsigned long flags;

	if (!has_sysmmu(dev) || owner->domain != iommu_domain)
		return;

	mutex_lock(&owner->rpm_lock);

	list_for_each_entry(data, &owner->controllers, owner_node) {
		pm_runtime_get_noresume(data->sysmmu);
		if (pm_runtime_active(data->sysmmu))
			__sysmmu_disable(data);
		pm_runtime_put(data->sysmmu);
	}

	spin_lock_irqsave(&domain->lock, flags);
	list_for_each_entry_safe(data, next, &domain->clients, domain_node) {
		spin_lock(&data->lock);
		data->pgtable = 0;
		data->domain = NULL;
		list_del_init(&data->domain_node);
		spin_unlock(&data->lock);
	}
	owner->domain = NULL;
	spin_unlock_irqrestore(&domain->lock, flags);

	mutex_unlock(&owner->rpm_lock);

	dev_dbg(dev, "%s: Detached IOMMU with pgtable %pa\n", __func__,
		&pagetable);
}

static int exynos_iommu_attach_device(struct iommu_domain *iommu_domain,
				   struct device *dev)
{
	struct exynos_iommu_owner *owner = dev->archdata.iommu;
	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
	struct sysmmu_drvdata *data;
	phys_addr_t pagetable = virt_to_phys(domain->pgtable);
	unsigned long flags;

	if (!has_sysmmu(dev))
		return -ENODEV;

	if (owner->domain)
		exynos_iommu_detach_device(owner->domain, dev);

	mutex_lock(&owner->rpm_lock);

	spin_lock_irqsave(&domain->lock, flags);
	list_for_each_entry(data, &owner->controllers, owner_node) {
		spin_lock(&data->lock);
		data->pgtable = pagetable;
		data->domain = domain;
		list_add_tail(&data->domain_node, &domain->clients);
		spin_unlock(&data->lock);
	}
	owner->domain = iommu_domain;
	spin_unlock_irqrestore(&domain->lock, flags);

	list_for_each_entry(data, &owner->controllers, owner_node) {
		pm_runtime_get_noresume(data->sysmmu);
		if (pm_runtime_active(data->sysmmu))
			__sysmmu_enable(data);
		pm_runtime_put(data->sysmmu);
	}

	mutex_unlock(&owner->rpm_lock);

	dev_dbg(dev, "%s: Attached IOMMU with pgtable %pa\n", __func__,
		&pagetable);

	return 0;
}

static sysmmu_pte_t *alloc_lv2entry(struct exynos_iommu_domain *domain,
		sysmmu_pte_t *sent, sysmmu_iova_t iova, short *pgcounter)
{
	if (lv1ent_section(sent)) {
		WARN(1, "Trying mapping on %#08x mapped with 1MiB page", iova);
		return ERR_PTR(-EADDRINUSE);
	}

	if (lv1ent_fault(sent)) {
		dma_addr_t handle;
		sysmmu_pte_t *pent;
		bool need_flush_flpd_cache = lv1ent_zero(sent);

		pent = kmem_cache_zalloc(lv2table_kmem_cache, GFP_ATOMIC);
		BUG_ON((uintptr_t)pent & (LV2TABLE_SIZE - 1));
		if (!pent)
			return ERR_PTR(-ENOMEM);

		update_pte(sent, mk_lv1ent_page(virt_to_phys(pent)));
		kmemleak_ignore(pent);
		*pgcounter = NUM_LV2ENTRIES;
		handle = dma_map_single(dma_dev, pent, LV2TABLE_SIZE,
					DMA_TO_DEVICE);
		if (dma_mapping_error(dma_dev, handle)) {
			kmem_cache_free(lv2table_kmem_cache, pent);
			return ERR_PTR(-EADDRINUSE);
		}

		/*
		 * If pre-fetched SLPD is a faulty SLPD in zero_l2_table,
		 * FLPD cache may cache the address of zero_l2_table. This
		 * function replaces the zero_l2_table with new L2 page table
		 * to write valid mappings.
		 * Accessing the valid area may cause page fault since FLPD
		 * cache may still cache zero_l2_table for the valid area
		 * instead of new L2 page table that has the mapping
		 * information of the valid area.
		 * Thus any replacement of zero_l2_table with other valid L2
		 * page table must involve FLPD cache invalidation for System
		 * MMU v3.3.
		 * FLPD cache invalidation is performed with TLB invalidation
		 * by VPN without blocking. It is safe to invalidate TLB without
		 * blocking because the target address of TLB invalidation is
		 * not currently mapped.
		 */
		if (need_flush_flpd_cache) {
			struct sysmmu_drvdata *data;

			spin_lock(&domain->lock);
			list_for_each_entry(data, &domain->clients, domain_node)
				sysmmu_tlb_invalidate_flpdcache(data, iova);
			spin_unlock(&domain->lock);
		}
	}

	return page_entry(sent, iova);
}

static int lv1set_section(struct exynos_iommu_domain *domain,
			  sysmmu_pte_t *sent, sysmmu_iova_t iova,
			  phys_addr_t paddr, int prot, short *pgcnt)
{
	if (lv1ent_section(sent)) {
		WARN(1, "Trying mapping on 1MiB@%#08x that is mapped",
			iova);
		return -EADDRINUSE;
	}

	if (lv1ent_page(sent)) {
		if (*pgcnt != NUM_LV2ENTRIES) {
			WARN(1, "Trying mapping on 1MiB@%#08x that is mapped",
				iova);
			return -EADDRINUSE;
		}

		kmem_cache_free(lv2table_kmem_cache, page_entry(sent, 0));
		*pgcnt = 0;
	}

	update_pte(sent, mk_lv1ent_sect(paddr, prot));

	spin_lock(&domain->lock);
	if (lv1ent_page_zero(sent)) {
		struct sysmmu_drvdata *data;
		/*
		 * Flushing FLPD cache in System MMU v3.3 that may cache a FLPD
		 * entry by speculative prefetch of SLPD which has no mapping.
		 */
		list_for_each_entry(data, &domain->clients, domain_node)
			sysmmu_tlb_invalidate_flpdcache(data, iova);
	}
	spin_unlock(&domain->lock);

	return 0;
}

static int lv2set_page(sysmmu_pte_t *pent, phys_addr_t paddr, size_t size,
		       int prot, short *pgcnt)
{
	if (size == SPAGE_SIZE) {
		if (WARN_ON(!lv2ent_fault(pent)))
			return -EADDRINUSE;

		update_pte(pent, mk_lv2ent_spage(paddr, prot));
		*pgcnt -= 1;
	} else { /* size == LPAGE_SIZE */
		int i;
		dma_addr_t pent_base = virt_to_phys(pent);

		dma_sync_single_for_cpu(dma_dev, pent_base,
					sizeof(*pent) * SPAGES_PER_LPAGE,
					DMA_TO_DEVICE);
		for (i = 0; i < SPAGES_PER_LPAGE; i++, pent++) {
			if (WARN_ON(!lv2ent_fault(pent))) {
				if (i > 0)
					memset(pent - i, 0, sizeof(*pent) * i);
				return -EADDRINUSE;
			}

			*pent = mk_lv2ent_lpage(paddr, prot);
		}
		dma_sync_single_for_device(dma_dev, pent_base,
					   sizeof(*pent) * SPAGES_PER_LPAGE,
					   DMA_TO_DEVICE);
		*pgcnt -= SPAGES_PER_LPAGE;
	}

	return 0;
}

/*
 * *CAUTION* to the I/O virtual memory managers that support exynos-iommu:
 *
 * System MMU v3.x has advanced logic to improve address translation
 * performance with caching more page table entries by a page table walk.
 * However, the logic has a bug that while caching faulty page table entries,
 * System MMU reports page fault if the cached fault entry is hit even though
 * the fault entry is updated to a valid entry after the entry is cached.
 * To prevent caching faulty page table entries which may be updated to valid
 * entries later, the virtual memory manager should care about the workaround
 * for the problem. The following describes the workaround.
 *
 * Any two consecutive I/O virtual address regions must have a hole of 128KiB
 * at maximum to prevent misbehavior of System MMU 3.x (workaround for h/w bug).
 *
 * Precisely, any start address of I/O virtual region must be aligned with
 * the following sizes for System MMU v3.1 and v3.2.
 * System MMU v3.1: 128KiB
 * System MMU v3.2: 256KiB
 *
 * Because System MMU v3.3 caches page table entries more aggressively, it needs
 * more workarounds.
 * - Any two consecutive I/O virtual regions must have a hole of size larger
 *   than or equal to 128KiB.
 * - Start address of an I/O virtual region must be aligned by 128KiB.
 */
static int exynos_iommu_map(struct iommu_domain *iommu_domain,
			    unsigned long l_iova, phys_addr_t paddr, size_t size,
			    int prot)
{
	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
	sysmmu_pte_t *entry;
	sysmmu_iova_t iova = (sysmmu_iova_t)l_iova;
	unsigned long flags;
	int ret = -ENOMEM;

	BUG_ON(domain->pgtable == NULL);
	prot &= SYSMMU_SUPPORTED_PROT_BITS;

	spin_lock_irqsave(&domain->pgtablelock, flags);

	entry = section_entry(domain->pgtable, iova);

	if (size == SECT_SIZE) {
		ret = lv1set_section(domain, entry, iova, paddr, prot,
				     &domain->lv2entcnt[lv1ent_offset(iova)]);
	} else {
		sysmmu_pte_t *pent;

		pent = alloc_lv2entry(domain, entry, iova,
				      &domain->lv2entcnt[lv1ent_offset(iova)]);

		if (IS_ERR(pent))
			ret = PTR_ERR(pent);
		else
			ret = lv2set_page(pent, paddr, size, prot,
				       &domain->lv2entcnt[lv1ent_offset(iova)]);
	}

	if (ret)
		pr_err("%s: Failed(%d) to map %#zx bytes @ %#x\n",
			__func__, ret, size, iova);

	spin_unlock_irqrestore(&domain->pgtablelock, flags);

	return ret;
}

static void exynos_iommu_tlb_invalidate_entry(struct exynos_iommu_domain *domain,
					      sysmmu_iova_t iova, size_t size)
{
	struct sysmmu_drvdata *data;
	unsigned long flags;

	spin_lock_irqsave(&domain->lock, flags);

	list_for_each_entry(data, &domain->clients, domain_node)
		sysmmu_tlb_invalidate_entry(data, iova, size);

	spin_unlock_irqrestore(&domain->lock, flags);
}

static size_t exynos_iommu_unmap(struct iommu_domain *iommu_domain,
				 unsigned long l_iova, size_t size,
				 struct iommu_iotlb_gather *gather)
{
	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
	sysmmu_iova_t iova = (sysmmu_iova_t)l_iova;
	sysmmu_pte_t *ent;
	size_t err_pgsize;
	unsigned long flags;

	BUG_ON(domain->pgtable == NULL);

	spin_lock_irqsave(&domain->pgtablelock, flags);

	ent = section_entry(domain->pgtable, iova);

	if (lv1ent_section(ent)) {
		if (WARN_ON(size < SECT_SIZE)) {
			err_pgsize = SECT_SIZE;
			goto err;
		}

		/* workaround for h/w bug in System MMU v3.3 */
		update_pte(ent, ZERO_LV2LINK);
		size = SECT_SIZE;
		goto done;
	}

	if (unlikely(lv1ent_fault(ent))) {
		if (size > SECT_SIZE)
			size = SECT_SIZE;
		goto done;
	}

	/* lv1ent_page(sent) == true here */

	ent = page_entry(ent, iova);

	if (unlikely(lv2ent_fault(ent))) {
		size = SPAGE_SIZE;
		goto done;
	}

	if (lv2ent_small(ent)) {
		update_pte(ent, 0);
		size = SPAGE_SIZE;
		domain->lv2entcnt[lv1ent_offset(iova)] += 1;
		goto done;
	}

	/* lv1ent_large(ent) == true here */
	if (WARN_ON(size < LPAGE_SIZE)) {
		err_pgsize = LPAGE_SIZE;
		goto err;
	}

	dma_sync_single_for_cpu(dma_dev, virt_to_phys(ent),
				sizeof(*ent) * SPAGES_PER_LPAGE,
				DMA_TO_DEVICE);
	memset(ent, 0, sizeof(*ent) * SPAGES_PER_LPAGE);
	dma_sync_single_for_device(dma_dev, virt_to_phys(ent),
				   sizeof(*ent) * SPAGES_PER_LPAGE,
				   DMA_TO_DEVICE);
	size = LPAGE_SIZE;
	domain->lv2entcnt[lv1ent_offset(iova)] += SPAGES_PER_LPAGE;
done:
	spin_unlock_irqrestore(&domain->pgtablelock, flags);

	exynos_iommu_tlb_invalidate_entry(domain, iova, size);

	return size;
err:
	spin_unlock_irqrestore(&domain->pgtablelock, flags);

	pr_err("%s: Failed: size(%#zx) @ %#x is smaller than page size %#zx\n",
		__func__, size, iova, err_pgsize);

	return 0;
}

static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *iommu_domain,
					  dma_addr_t iova)
{
	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
	sysmmu_pte_t *entry;
	unsigned long flags;
	phys_addr_t phys = 0;

	spin_lock_irqsave(&domain->pgtablelock, flags);

	entry = section_entry(domain->pgtable, iova);

	if (lv1ent_section(entry)) {
		phys = section_phys(entry) + section_offs(iova);
	} else if (lv1ent_page(entry)) {
		entry = page_entry(entry, iova);

		if (lv2ent_large(entry))
			phys = lpage_phys(entry) + lpage_offs(iova);
		else if (lv2ent_small(entry))
			phys = spage_phys(entry) + spage_offs(iova);
	}

	spin_unlock_irqrestore(&domain->pgtablelock, flags);

	return phys;
}

static int exynos_iommu_add_device(struct device *dev)
{
	struct exynos_iommu_owner *owner = dev->archdata.iommu;
	struct sysmmu_drvdata *data;
	struct iommu_group *group;

	if (!has_sysmmu(dev))
		return -ENODEV;

	group = iommu_group_get_for_dev(dev);

	if (IS_ERR(group))
		return PTR_ERR(group);

	list_for_each_entry(data, &owner->controllers, owner_node) {
		/*
		 * SYSMMU will be runtime activated via device link
		 * (dependency) to its master device, so there are no
		 * direct calls to pm_runtime_get/put in this driver.
		 */
		data->link = device_link_add(dev, data->sysmmu,
					     DL_FLAG_STATELESS |
					     DL_FLAG_PM_RUNTIME);
	}
	iommu_group_put(group);

	return 0;
}

static void exynos_iommu_remove_device(struct device *dev)
{
	struct exynos_iommu_owner *owner = dev->archdata.iommu;
	struct sysmmu_drvdata *data;

	if (!has_sysmmu(dev))
		return;

	if (owner->domain) {
		struct iommu_group *group = iommu_group_get(dev);

		if (group) {
			WARN_ON(owner->domain !=
				iommu_group_default_domain(group));
			exynos_iommu_detach_device(owner->domain, dev);
			iommu_group_put(group);
		}
	}
	iommu_group_remove_device(dev);

	list_for_each_entry(data, &owner->controllers, owner_node)
		device_link_del(data->link);
}

static int exynos_iommu_of_xlate(struct device *dev,
				 struct of_phandle_args *spec)
{
	struct exynos_iommu_owner *owner = dev->archdata.iommu;
	struct platform_device *sysmmu = of_find_device_by_node(spec->np);
	struct sysmmu_drvdata *data, *entry;

	if (!sysmmu)
		return -ENODEV;

	data = platform_get_drvdata(sysmmu);
	if (!data)
		return -ENODEV;

	if (!owner) {
		owner = kzalloc(sizeof(*owner), GFP_KERNEL);
		if (!owner)
			return -ENOMEM;

		INIT_LIST_HEAD(&owner->controllers);
		mutex_init(&owner->rpm_lock);
		dev->archdata.iommu = owner;
	}

	list_for_each_entry(entry, &owner->controllers, owner_node)
		if (entry == data)
			return 0;

	list_add_tail(&data->owner_node, &owner->controllers);
	data->master = dev;

	return 0;
}

static const struct iommu_ops exynos_iommu_ops = {
	.domain_alloc = exynos_iommu_domain_alloc,
	.domain_free = exynos_iommu_domain_free,
	.attach_dev = exynos_iommu_attach_device,
	.detach_dev = exynos_iommu_detach_device,
	.map = exynos_iommu_map,
	.unmap = exynos_iommu_unmap,
	.iova_to_phys = exynos_iommu_iova_to_phys,
	.device_group = generic_device_group,
	.add_device = exynos_iommu_add_device,
	.remove_device = exynos_iommu_remove_device,
	.pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE,
	.of_xlate = exynos_iommu_of_xlate,
};

static int __init exynos_iommu_init(void)
{
	struct device_node *np;
	int ret;

	np = of_find_matching_node(NULL, sysmmu_of_match);
	if (!np)
		return 0;

	of_node_put(np);

	lv2table_kmem_cache = kmem_cache_create("exynos-iommu-lv2table",
				LV2TABLE_SIZE, LV2TABLE_SIZE, 0, NULL);
	if (!lv2table_kmem_cache) {
		pr_err("%s: Failed to create kmem cache\n", __func__);
		return -ENOMEM;
	}

	ret = platform_driver_register(&exynos_sysmmu_driver);
	if (ret) {
		pr_err("%s: Failed to register driver\n", __func__);
		goto err_reg_driver;
	}

	zero_lv2_table = kmem_cache_zalloc(lv2table_kmem_cache, GFP_KERNEL);
	if (zero_lv2_table == NULL) {
		pr_err("%s: Failed to allocate zero level2 page table\n",
			__func__);
		ret = -ENOMEM;
		goto err_zero_lv2;
	}

	ret = bus_set_iommu(&platform_bus_type, &exynos_iommu_ops);
	if (ret) {
		pr_err("%s: Failed to register exynos-iommu driver.\n",
								__func__);
		goto err_set_iommu;
	}

	return 0;
err_set_iommu:
	kmem_cache_free(lv2table_kmem_cache, zero_lv2_table);
err_zero_lv2:
	platform_driver_unregister(&exynos_sysmmu_driver);
err_reg_driver:
	kmem_cache_destroy(lv2table_kmem_cache);
	return ret;
}
core_initcall(exynos_iommu_init);