summaryrefslogtreecommitdiffstats
path: root/drivers/iommu/io-pgtable-arm.c
blob: 381ca5a37a7b7de9b338236b28202c6c46f306df (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
/*
 * CPU-agnostic ARM page table allocator.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Copyright (C) 2014 ARM Limited
 *
 * Author: Will Deacon <will.deacon@arm.com>
 */

#define pr_fmt(fmt)	"arm-lpae io-pgtable: " fmt

#include <linux/iommu.h>
#include <linux/kernel.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/dma-mapping.h>

#include <asm/barrier.h>

#include "io-pgtable.h"

#define ARM_LPAE_MAX_ADDR_BITS		48
#define ARM_LPAE_S2_MAX_CONCAT_PAGES	16
#define ARM_LPAE_MAX_LEVELS		4

/* Struct accessors */
#define io_pgtable_to_data(x)						\
	container_of((x), struct arm_lpae_io_pgtable, iop)

#define io_pgtable_ops_to_data(x)					\
	io_pgtable_to_data(io_pgtable_ops_to_pgtable(x))

/*
 * For consistency with the architecture, we always consider
 * ARM_LPAE_MAX_LEVELS levels, with the walk starting at level n >=0
 */
#define ARM_LPAE_START_LVL(d)		(ARM_LPAE_MAX_LEVELS - (d)->levels)

/*
 * Calculate the right shift amount to get to the portion describing level l
 * in a virtual address mapped by the pagetable in d.
 */
#define ARM_LPAE_LVL_SHIFT(l,d)						\
	((((d)->levels - ((l) - ARM_LPAE_START_LVL(d) + 1))		\
	  * (d)->bits_per_level) + (d)->pg_shift)

#define ARM_LPAE_GRANULE(d)		(1UL << (d)->pg_shift)

#define ARM_LPAE_PAGES_PER_PGD(d)					\
	DIV_ROUND_UP((d)->pgd_size, ARM_LPAE_GRANULE(d))

/*
 * Calculate the index at level l used to map virtual address a using the
 * pagetable in d.
 */
#define ARM_LPAE_PGD_IDX(l,d)						\
	((l) == ARM_LPAE_START_LVL(d) ? ilog2(ARM_LPAE_PAGES_PER_PGD(d)) : 0)

#define ARM_LPAE_LVL_IDX(a,l,d)						\
	(((u64)(a) >> ARM_LPAE_LVL_SHIFT(l,d)) &			\
	 ((1 << ((d)->bits_per_level + ARM_LPAE_PGD_IDX(l,d))) - 1))

/* Calculate the block/page mapping size at level l for pagetable in d. */
#define ARM_LPAE_BLOCK_SIZE(l,d)					\
	(1 << (ilog2(sizeof(arm_lpae_iopte)) +				\
		((ARM_LPAE_MAX_LEVELS - (l)) * (d)->bits_per_level)))

/* Page table bits */
#define ARM_LPAE_PTE_TYPE_SHIFT		0
#define ARM_LPAE_PTE_TYPE_MASK		0x3

#define ARM_LPAE_PTE_TYPE_BLOCK		1
#define ARM_LPAE_PTE_TYPE_TABLE		3
#define ARM_LPAE_PTE_TYPE_PAGE		3

#define ARM_LPAE_PTE_NSTABLE		(((arm_lpae_iopte)1) << 63)
#define ARM_LPAE_PTE_XN			(((arm_lpae_iopte)3) << 53)
#define ARM_LPAE_PTE_AF			(((arm_lpae_iopte)1) << 10)
#define ARM_LPAE_PTE_SH_NS		(((arm_lpae_iopte)0) << 8)
#define ARM_LPAE_PTE_SH_OS		(((arm_lpae_iopte)2) << 8)
#define ARM_LPAE_PTE_SH_IS		(((arm_lpae_iopte)3) << 8)
#define ARM_LPAE_PTE_NS			(((arm_lpae_iopte)1) << 5)
#define ARM_LPAE_PTE_VALID		(((arm_lpae_iopte)1) << 0)

#define ARM_LPAE_PTE_ATTR_LO_MASK	(((arm_lpae_iopte)0x3ff) << 2)
/* Ignore the contiguous bit for block splitting */
#define ARM_LPAE_PTE_ATTR_HI_MASK	(((arm_lpae_iopte)6) << 52)
#define ARM_LPAE_PTE_ATTR_MASK		(ARM_LPAE_PTE_ATTR_LO_MASK |	\
					 ARM_LPAE_PTE_ATTR_HI_MASK)

/* Stage-1 PTE */
#define ARM_LPAE_PTE_AP_UNPRIV		(((arm_lpae_iopte)1) << 6)
#define ARM_LPAE_PTE_AP_RDONLY		(((arm_lpae_iopte)2) << 6)
#define ARM_LPAE_PTE_ATTRINDX_SHIFT	2
#define ARM_LPAE_PTE_nG			(((arm_lpae_iopte)1) << 11)

/* Stage-2 PTE */
#define ARM_LPAE_PTE_HAP_FAULT		(((arm_lpae_iopte)0) << 6)
#define ARM_LPAE_PTE_HAP_READ		(((arm_lpae_iopte)1) << 6)
#define ARM_LPAE_PTE_HAP_WRITE		(((arm_lpae_iopte)2) << 6)
#define ARM_LPAE_PTE_MEMATTR_OIWB	(((arm_lpae_iopte)0xf) << 2)
#define ARM_LPAE_PTE_MEMATTR_NC		(((arm_lpae_iopte)0x5) << 2)
#define ARM_LPAE_PTE_MEMATTR_DEV	(((arm_lpae_iopte)0x1) << 2)

/* Register bits */
#define ARM_32_LPAE_TCR_EAE		(1 << 31)
#define ARM_64_LPAE_S2_TCR_RES1		(1 << 31)

#define ARM_LPAE_TCR_EPD1		(1 << 23)

#define ARM_LPAE_TCR_TG0_4K		(0 << 14)
#define ARM_LPAE_TCR_TG0_64K		(1 << 14)
#define ARM_LPAE_TCR_TG0_16K		(2 << 14)

#define ARM_LPAE_TCR_SH0_SHIFT		12
#define ARM_LPAE_TCR_SH0_MASK		0x3
#define ARM_LPAE_TCR_SH_NS		0
#define ARM_LPAE_TCR_SH_OS		2
#define ARM_LPAE_TCR_SH_IS		3

#define ARM_LPAE_TCR_ORGN0_SHIFT	10
#define ARM_LPAE_TCR_IRGN0_SHIFT	8
#define ARM_LPAE_TCR_RGN_MASK		0x3
#define ARM_LPAE_TCR_RGN_NC		0
#define ARM_LPAE_TCR_RGN_WBWA		1
#define ARM_LPAE_TCR_RGN_WT		2
#define ARM_LPAE_TCR_RGN_WB		3

#define ARM_LPAE_TCR_SL0_SHIFT		6
#define ARM_LPAE_TCR_SL0_MASK		0x3

#define ARM_LPAE_TCR_T0SZ_SHIFT		0
#define ARM_LPAE_TCR_SZ_MASK		0xf

#define ARM_LPAE_TCR_PS_SHIFT		16
#define ARM_LPAE_TCR_PS_MASK		0x7

#define ARM_LPAE_TCR_IPS_SHIFT		32
#define ARM_LPAE_TCR_IPS_MASK		0x7

#define ARM_LPAE_TCR_PS_32_BIT		0x0ULL
#define ARM_LPAE_TCR_PS_36_BIT		0x1ULL
#define ARM_LPAE_TCR_PS_40_BIT		0x2ULL
#define ARM_LPAE_TCR_PS_42_BIT		0x3ULL
#define ARM_LPAE_TCR_PS_44_BIT		0x4ULL
#define ARM_LPAE_TCR_PS_48_BIT		0x5ULL

#define ARM_LPAE_MAIR_ATTR_SHIFT(n)	((n) << 3)
#define ARM_LPAE_MAIR_ATTR_MASK		0xff
#define ARM_LPAE_MAIR_ATTR_DEVICE	0x04
#define ARM_LPAE_MAIR_ATTR_NC		0x44
#define ARM_LPAE_MAIR_ATTR_WBRWA	0xff
#define ARM_LPAE_MAIR_ATTR_IDX_NC	0
#define ARM_LPAE_MAIR_ATTR_IDX_CACHE	1
#define ARM_LPAE_MAIR_ATTR_IDX_DEV	2

/* IOPTE accessors */
#define iopte_deref(pte,d)					\
	(__va((pte) & ((1ULL << ARM_LPAE_MAX_ADDR_BITS) - 1)	\
	& ~(ARM_LPAE_GRANULE(d) - 1ULL)))

#define iopte_type(pte,l)					\
	(((pte) >> ARM_LPAE_PTE_TYPE_SHIFT) & ARM_LPAE_PTE_TYPE_MASK)

#define iopte_prot(pte)	((pte) & ARM_LPAE_PTE_ATTR_MASK)

#define iopte_leaf(pte,l)					\
	(l == (ARM_LPAE_MAX_LEVELS - 1) ?			\
		(iopte_type(pte,l) == ARM_LPAE_PTE_TYPE_PAGE) :	\
		(iopte_type(pte,l) == ARM_LPAE_PTE_TYPE_BLOCK))

#define iopte_to_pfn(pte,d)					\
	(((pte) & ((1ULL << ARM_LPAE_MAX_ADDR_BITS) - 1)) >> (d)->pg_shift)

#define pfn_to_iopte(pfn,d)					\
	(((pfn) << (d)->pg_shift) & ((1ULL << ARM_LPAE_MAX_ADDR_BITS) - 1))

struct arm_lpae_io_pgtable {
	struct io_pgtable	iop;

	int			levels;
	size_t			pgd_size;
	unsigned long		pg_shift;
	unsigned long		bits_per_level;

	void			*pgd;
};

typedef u64 arm_lpae_iopte;

static bool selftest_running = false;

static dma_addr_t __arm_lpae_dma_addr(void *pages)
{
	return (dma_addr_t)virt_to_phys(pages);
}

static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp,
				    struct io_pgtable_cfg *cfg)
{
	struct device *dev = cfg->iommu_dev;
	dma_addr_t dma;
	void *pages = alloc_pages_exact(size, gfp | __GFP_ZERO);

	if (!pages)
		return NULL;

	if (!selftest_running) {
		dma = dma_map_single(dev, pages, size, DMA_TO_DEVICE);
		if (dma_mapping_error(dev, dma))
			goto out_free;
		/*
		 * We depend on the IOMMU being able to work with any physical
		 * address directly, so if the DMA layer suggests otherwise by
		 * translating or truncating them, that bodes very badly...
		 */
		if (dma != virt_to_phys(pages))
			goto out_unmap;
	}

	return pages;

out_unmap:
	dev_err(dev, "Cannot accommodate DMA translation for IOMMU page tables\n");
	dma_unmap_single(dev, dma, size, DMA_TO_DEVICE);
out_free:
	free_pages_exact(pages, size);
	return NULL;
}

static void __arm_lpae_free_pages(void *pages, size_t size,
				  struct io_pgtable_cfg *cfg)
{
	if (!selftest_running)
		dma_unmap_single(cfg->iommu_dev, __arm_lpae_dma_addr(pages),
				 size, DMA_TO_DEVICE);
	free_pages_exact(pages, size);
}

static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, arm_lpae_iopte pte,
			       struct io_pgtable_cfg *cfg)
{
	*ptep = pte;

	if (!selftest_running)
		dma_sync_single_for_device(cfg->iommu_dev,
					   __arm_lpae_dma_addr(ptep),
					   sizeof(pte), DMA_TO_DEVICE);
}

static int __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
			    unsigned long iova, size_t size, int lvl,
			    arm_lpae_iopte *ptep);

static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
			     unsigned long iova, phys_addr_t paddr,
			     arm_lpae_iopte prot, int lvl,
			     arm_lpae_iopte *ptep)
{
	arm_lpae_iopte pte = prot;
	struct io_pgtable_cfg *cfg = &data->iop.cfg;

	if (iopte_leaf(*ptep, lvl)) {
		/* We require an unmap first */
		WARN_ON(!selftest_running);
		return -EEXIST;
	} else if (iopte_type(*ptep, lvl) == ARM_LPAE_PTE_TYPE_TABLE) {
		/*
		 * We need to unmap and free the old table before
		 * overwriting it with a block entry.
		 */
		arm_lpae_iopte *tblp;
		size_t sz = ARM_LPAE_BLOCK_SIZE(lvl, data);

		tblp = ptep - ARM_LPAE_LVL_IDX(iova, lvl, data);
		if (WARN_ON(__arm_lpae_unmap(data, iova, sz, lvl, tblp) != sz))
			return -EINVAL;
	}

	if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)
		pte |= ARM_LPAE_PTE_NS;

	if (lvl == ARM_LPAE_MAX_LEVELS - 1)
		pte |= ARM_LPAE_PTE_TYPE_PAGE;
	else
		pte |= ARM_LPAE_PTE_TYPE_BLOCK;

	pte |= ARM_LPAE_PTE_AF | ARM_LPAE_PTE_SH_IS;
	pte |= pfn_to_iopte(paddr >> data->pg_shift, data);

	__arm_lpae_set_pte(ptep, pte, cfg);
	return 0;
}

static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
			  phys_addr_t paddr, size_t size, arm_lpae_iopte prot,
			  int lvl, arm_lpae_iopte *ptep)
{
	arm_lpae_iopte *cptep, pte;
	size_t block_size = ARM_LPAE_BLOCK_SIZE(lvl, data);
	struct io_pgtable_cfg *cfg = &data->iop.cfg;

	/* Find our entry at the current level */
	ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);

	/* If we can install a leaf entry at this level, then do so */
	if (size == block_size && (size & cfg->pgsize_bitmap))
		return arm_lpae_init_pte(data, iova, paddr, prot, lvl, ptep);

	/* We can't allocate tables at the final level */
	if (WARN_ON(lvl >= ARM_LPAE_MAX_LEVELS - 1))
		return -EINVAL;

	/* Grab a pointer to the next level */
	pte = *ptep;
	if (!pte) {
		cptep = __arm_lpae_alloc_pages(ARM_LPAE_GRANULE(data),
					       GFP_ATOMIC, cfg);
		if (!cptep)
			return -ENOMEM;

		pte = __pa(cptep) | ARM_LPAE_PTE_TYPE_TABLE;
		if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)
			pte |= ARM_LPAE_PTE_NSTABLE;
		__arm_lpae_set_pte(ptep, pte, cfg);
	} else {
		cptep = iopte_deref(pte, data);
	}

	/* Rinse, repeat */
	return __arm_lpae_map(data, iova, paddr, size, prot, lvl + 1, cptep);
}

static arm_lpae_iopte arm_lpae_prot_to_pte(struct arm_lpae_io_pgtable *data,
					   int prot)
{
	arm_lpae_iopte pte;

	if (data->iop.fmt == ARM_64_LPAE_S1 ||
	    data->iop.fmt == ARM_32_LPAE_S1) {
		pte = ARM_LPAE_PTE_AP_UNPRIV | ARM_LPAE_PTE_nG;

		if (!(prot & IOMMU_WRITE) && (prot & IOMMU_READ))
			pte |= ARM_LPAE_PTE_AP_RDONLY;

		if (prot & IOMMU_CACHE)
			pte |= (ARM_LPAE_MAIR_ATTR_IDX_CACHE
				<< ARM_LPAE_PTE_ATTRINDX_SHIFT);
	} else {
		pte = ARM_LPAE_PTE_HAP_FAULT;
		if (prot & IOMMU_READ)
			pte |= ARM_LPAE_PTE_HAP_READ;
		if (prot & IOMMU_WRITE)
			pte |= ARM_LPAE_PTE_HAP_WRITE;
		if (prot & IOMMU_CACHE)
			pte |= ARM_LPAE_PTE_MEMATTR_OIWB;
		else
			pte |= ARM_LPAE_PTE_MEMATTR_NC;
	}

	if (prot & IOMMU_NOEXEC)
		pte |= ARM_LPAE_PTE_XN;

	return pte;
}

static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova,
			phys_addr_t paddr, size_t size, int iommu_prot)
{
	struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
	arm_lpae_iopte *ptep = data->pgd;
	int ret, lvl = ARM_LPAE_START_LVL(data);
	arm_lpae_iopte prot;

	/* If no access, then nothing to do */
	if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))
		return 0;

	prot = arm_lpae_prot_to_pte(data, iommu_prot);
	ret = __arm_lpae_map(data, iova, paddr, size, prot, lvl, ptep);
	/*
	 * Synchronise all PTE updates for the new mapping before there's
	 * a chance for anything to kick off a table walk for the new iova.
	 */
	wmb();

	return ret;
}

static void __arm_lpae_free_pgtable(struct arm_lpae_io_pgtable *data, int lvl,
				    arm_lpae_iopte *ptep)
{
	arm_lpae_iopte *start, *end;
	unsigned long table_size;

	if (lvl == ARM_LPAE_START_LVL(data))
		table_size = data->pgd_size;
	else
		table_size = ARM_LPAE_GRANULE(data);

	start = ptep;

	/* Only leaf entries at the last level */
	if (lvl == ARM_LPAE_MAX_LEVELS - 1)
		end = ptep;
	else
		end = (void *)ptep + table_size;

	while (ptep != end) {
		arm_lpae_iopte pte = *ptep++;

		if (!pte || iopte_leaf(pte, lvl))
			continue;

		__arm_lpae_free_pgtable(data, lvl + 1, iopte_deref(pte, data));
	}

	__arm_lpae_free_pages(start, table_size, &data->iop.cfg);
}

static void arm_lpae_free_pgtable(struct io_pgtable *iop)
{
	struct arm_lpae_io_pgtable *data = io_pgtable_to_data(iop);

	__arm_lpae_free_pgtable(data, ARM_LPAE_START_LVL(data), data->pgd);
	kfree(data);
}

static int arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
				    unsigned long iova, size_t size,
				    arm_lpae_iopte prot, int lvl,
				    arm_lpae_iopte *ptep, size_t blk_size)
{
	unsigned long blk_start, blk_end;
	phys_addr_t blk_paddr;
	arm_lpae_iopte table = 0;
	struct io_pgtable_cfg *cfg = &data->iop.cfg;

	blk_start = iova & ~(blk_size - 1);
	blk_end = blk_start + blk_size;
	blk_paddr = iopte_to_pfn(*ptep, data) << data->pg_shift;

	for (; blk_start < blk_end; blk_start += size, blk_paddr += size) {
		arm_lpae_iopte *tablep;

		/* Unmap! */
		if (blk_start == iova)
			continue;

		/* __arm_lpae_map expects a pointer to the start of the table */
		tablep = &table - ARM_LPAE_LVL_IDX(blk_start, lvl, data);
		if (__arm_lpae_map(data, blk_start, blk_paddr, size, prot, lvl,
				   tablep) < 0) {
			if (table) {
				/* Free the table we allocated */
				tablep = iopte_deref(table, data);
				__arm_lpae_free_pgtable(data, lvl + 1, tablep);
			}
			return 0; /* Bytes unmapped */
		}
	}

	__arm_lpae_set_pte(ptep, table, cfg);
	iova &= ~(blk_size - 1);
	cfg->tlb->tlb_add_flush(iova, blk_size, blk_size, true, data->iop.cookie);
	return size;
}

static int __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
			    unsigned long iova, size_t size, int lvl,
			    arm_lpae_iopte *ptep)
{
	arm_lpae_iopte pte;
	const struct iommu_gather_ops *tlb = data->iop.cfg.tlb;
	void *cookie = data->iop.cookie;
	size_t blk_size = ARM_LPAE_BLOCK_SIZE(lvl, data);

	/* Something went horribly wrong and we ran out of page table */
	if (WARN_ON(lvl == ARM_LPAE_MAX_LEVELS))
		return 0;

	ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
	pte = *ptep;
	if (WARN_ON(!pte))
		return 0;

	/* If the size matches this level, we're in the right place */
	if (size == blk_size) {
		__arm_lpae_set_pte(ptep, 0, &data->iop.cfg);

		if (!iopte_leaf(pte, lvl)) {
			/* Also flush any partial walks */
			tlb->tlb_add_flush(iova, size, ARM_LPAE_GRANULE(data),
					   false, cookie);
			tlb->tlb_sync(cookie);
			ptep = iopte_deref(pte, data);
			__arm_lpae_free_pgtable(data, lvl + 1, ptep);
		} else {
			tlb->tlb_add_flush(iova, size, size, true, cookie);
		}

		return size;
	} else if (iopte_leaf(pte, lvl)) {
		/*
		 * Insert a table at the next level to map the old region,
		 * minus the part we want to unmap
		 */
		return arm_lpae_split_blk_unmap(data, iova, size,
						iopte_prot(pte), lvl, ptep,
						blk_size);
	}

	/* Keep on walkin' */
	ptep = iopte_deref(pte, data);
	return __arm_lpae_unmap(data, iova, size, lvl + 1, ptep);
}

static int arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
			  size_t size)
{
	size_t unmapped;
	struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
	struct io_pgtable *iop = &data->iop;
	arm_lpae_iopte *ptep = data->pgd;
	int lvl = ARM_LPAE_START_LVL(data);

	unmapped = __arm_lpae_unmap(data, iova, size, lvl, ptep);
	if (unmapped)
		iop->cfg.tlb->tlb_sync(iop->cookie);

	return unmapped;
}

static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
					 unsigned long iova)
{
	struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
	arm_lpae_iopte pte, *ptep = data->pgd;
	int lvl = ARM_LPAE_START_LVL(data);

	do {
		/* Valid IOPTE pointer? */
		if (!ptep)
			return 0;

		/* Grab the IOPTE we're interested in */
		pte = *(ptep + ARM_LPAE_LVL_IDX(iova, lvl, data));

		/* Valid entry? */
		if (!pte)
			return 0;

		/* Leaf entry? */
		if (iopte_leaf(pte,lvl))
			goto found_translation;

		/* Take it to the next level */
		ptep = iopte_deref(pte, data);
	} while (++lvl < ARM_LPAE_MAX_LEVELS);

	/* Ran out of page tables to walk */
	return 0;

found_translation:
	iova &= (ARM_LPAE_GRANULE(data) - 1);
	return ((phys_addr_t)iopte_to_pfn(pte,data) << data->pg_shift) | iova;
}

static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg)
{
	unsigned long granule;

	/*
	 * We need to restrict the supported page sizes to match the
	 * translation regime for a particular granule. Aim to match
	 * the CPU page size if possible, otherwise prefer smaller sizes.
	 * While we're at it, restrict the block sizes to match the
	 * chosen granule.
	 */
	if (cfg->pgsize_bitmap & PAGE_SIZE)
		granule = PAGE_SIZE;
	else if (cfg->pgsize_bitmap & ~PAGE_MASK)
		granule = 1UL << __fls(cfg->pgsize_bitmap & ~PAGE_MASK);
	else if (cfg->pgsize_bitmap & PAGE_MASK)
		granule = 1UL << __ffs(cfg->pgsize_bitmap & PAGE_MASK);
	else
		granule = 0;

	switch (granule) {
	case SZ_4K:
		cfg->pgsize_bitmap &= (SZ_4K | SZ_2M | SZ_1G);
		break;
	case SZ_16K:
		cfg->pgsize_bitmap &= (SZ_16K | SZ_32M);
		break;
	case SZ_64K:
		cfg->pgsize_bitmap &= (SZ_64K | SZ_512M);
		break;
	default:
		cfg->pgsize_bitmap = 0;
	}
}

static struct arm_lpae_io_pgtable *
arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
{
	unsigned long va_bits, pgd_bits;
	struct arm_lpae_io_pgtable *data;

	arm_lpae_restrict_pgsizes(cfg);

	if (!(cfg->pgsize_bitmap & (SZ_4K | SZ_16K | SZ_64K)))
		return NULL;

	if (cfg->ias > ARM_LPAE_MAX_ADDR_BITS)
		return NULL;

	if (cfg->oas > ARM_LPAE_MAX_ADDR_BITS)
		return NULL;

	if (!selftest_running && cfg->iommu_dev->dma_pfn_offset) {
		dev_err(cfg->iommu_dev, "Cannot accommodate DMA offset for IOMMU page tables\n");
		return NULL;
	}

	data = kmalloc(sizeof(*data), GFP_KERNEL);
	if (!data)
		return NULL;

	data->pg_shift = __ffs(cfg->pgsize_bitmap);
	data->bits_per_level = data->pg_shift - ilog2(sizeof(arm_lpae_iopte));

	va_bits = cfg->ias - data->pg_shift;
	data->levels = DIV_ROUND_UP(va_bits, data->bits_per_level);

	/* Calculate the actual size of our pgd (without concatenation) */
	pgd_bits = va_bits - (data->bits_per_level * (data->levels - 1));
	data->pgd_size = 1UL << (pgd_bits + ilog2(sizeof(arm_lpae_iopte)));

	data->iop.ops = (struct io_pgtable_ops) {
		.map		= arm_lpae_map,
		.unmap		= arm_lpae_unmap,
		.iova_to_phys	= arm_lpae_iova_to_phys,
	};

	return data;
}

static struct io_pgtable *
arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
{
	u64 reg;
	struct arm_lpae_io_pgtable *data = arm_lpae_alloc_pgtable(cfg);

	if (!data)
		return NULL;

	/* TCR */
	reg = (ARM_LPAE_TCR_SH_IS << ARM_LPAE_TCR_SH0_SHIFT) |
	      (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_IRGN0_SHIFT) |
	      (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_ORGN0_SHIFT);

	switch (ARM_LPAE_GRANULE(data)) {
	case SZ_4K:
		reg |= ARM_LPAE_TCR_TG0_4K;
		break;
	case SZ_16K:
		reg |= ARM_LPAE_TCR_TG0_16K;
		break;
	case SZ_64K:
		reg |= ARM_LPAE_TCR_TG0_64K;
		break;
	}

	switch (cfg->oas) {
	case 32:
		reg |= (ARM_LPAE_TCR_PS_32_BIT << ARM_LPAE_TCR_IPS_SHIFT);
		break;
	case 36:
		reg |= (ARM_LPAE_TCR_PS_36_BIT << ARM_LPAE_TCR_IPS_SHIFT);
		break;
	case 40:
		reg |= (ARM_LPAE_TCR_PS_40_BIT << ARM_LPAE_TCR_IPS_SHIFT);
		break;
	case 42:
		reg |= (ARM_LPAE_TCR_PS_42_BIT << ARM_LPAE_TCR_IPS_SHIFT);
		break;
	case 44:
		reg |= (ARM_LPAE_TCR_PS_44_BIT << ARM_LPAE_TCR_IPS_SHIFT);
		break;
	case 48:
		reg |= (ARM_LPAE_TCR_PS_48_BIT << ARM_LPAE_TCR_IPS_SHIFT);
		break;
	default:
		goto out_free_data;
	}

	reg |= (64ULL - cfg->ias) << ARM_LPAE_TCR_T0SZ_SHIFT;

	/* Disable speculative walks through TTBR1 */
	reg |= ARM_LPAE_TCR_EPD1;
	cfg->arm_lpae_s1_cfg.tcr = reg;

	/* MAIRs */
	reg = (ARM_LPAE_MAIR_ATTR_NC
	       << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_NC)) |
	      (ARM_LPAE_MAIR_ATTR_WBRWA
	       << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_CACHE)) |
	      (ARM_LPAE_MAIR_ATTR_DEVICE
	       << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_DEV));

	cfg->arm_lpae_s1_cfg.mair[0] = reg;
	cfg->arm_lpae_s1_cfg.mair[1] = 0;

	/* Looking good; allocate a pgd */
	data->pgd = __arm_lpae_alloc_pages(data->pgd_size, GFP_KERNEL, cfg);
	if (!data->pgd)
		goto out_free_data;

	/* Ensure the empty pgd is visible before any actual TTBR write */
	wmb();

	/* TTBRs */
	cfg->arm_lpae_s1_cfg.ttbr[0] = virt_to_phys(data->pgd);
	cfg->arm_lpae_s1_cfg.ttbr[1] = 0;
	return &data->iop;

out_free_data:
	kfree(data);
	return NULL;
}

static struct io_pgtable *
arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
{
	u64 reg, sl;
	struct arm_lpae_io_pgtable *data = arm_lpae_alloc_pgtable(cfg);

	if (!data)
		return NULL;

	/*
	 * Concatenate PGDs at level 1 if possible in order to reduce
	 * the depth of the stage-2 walk.
	 */
	if (data->levels == ARM_LPAE_MAX_LEVELS) {
		unsigned long pgd_pages;

		pgd_pages = data->pgd_size >> ilog2(sizeof(arm_lpae_iopte));
		if (pgd_pages <= ARM_LPAE_S2_MAX_CONCAT_PAGES) {
			data->pgd_size = pgd_pages << data->pg_shift;
			data->levels--;
		}
	}

	/* VTCR */
	reg = ARM_64_LPAE_S2_TCR_RES1 |
	     (ARM_LPAE_TCR_SH_IS << ARM_LPAE_TCR_SH0_SHIFT) |
	     (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_IRGN0_SHIFT) |
	     (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_ORGN0_SHIFT);

	sl = ARM_LPAE_START_LVL(data);

	switch (ARM_LPAE_GRANULE(data)) {
	case SZ_4K:
		reg |= ARM_LPAE_TCR_TG0_4K;
		sl++; /* SL0 format is different for 4K granule size */
		break;
	case SZ_16K:
		reg |= ARM_LPAE_TCR_TG0_16K;
		break;
	case SZ_64K:
		reg |= ARM_LPAE_TCR_TG0_64K;
		break;
	}

	switch (cfg->oas) {
	case 32:
		reg |= (ARM_LPAE_TCR_PS_32_BIT << ARM_LPAE_TCR_PS_SHIFT);
		break;
	case 36:
		reg |= (ARM_LPAE_TCR_PS_36_BIT << ARM_LPAE_TCR_PS_SHIFT);
		break;
	case 40:
		reg |= (ARM_LPAE_TCR_PS_40_BIT << ARM_LPAE_TCR_PS_SHIFT);
		break;
	case 42:
		reg |= (ARM_LPAE_TCR_PS_42_BIT << ARM_LPAE_TCR_PS_SHIFT);
		break;
	case 44:
		reg |= (ARM_LPAE_TCR_PS_44_BIT << ARM_LPAE_TCR_PS_SHIFT);
		break;
	case 48:
		reg |= (ARM_LPAE_TCR_PS_48_BIT << ARM_LPAE_TCR_PS_SHIFT);
		break;
	default:
		goto out_free_data;
	}

	reg |= (64ULL - cfg->ias) << ARM_LPAE_TCR_T0SZ_SHIFT;
	reg |= (~sl & ARM_LPAE_TCR_SL0_MASK) << ARM_LPAE_TCR_SL0_SHIFT;
	cfg->arm_lpae_s2_cfg.vtcr = reg;

	/* Allocate pgd pages */
	data->pgd = __arm_lpae_alloc_pages(data->pgd_size, GFP_KERNEL, cfg);
	if (!data->pgd)
		goto out_free_data;

	/* Ensure the empty pgd is visible before any actual TTBR write */
	wmb();

	/* VTTBR */
	cfg->arm_lpae_s2_cfg.vttbr = virt_to_phys(data->pgd);
	return &data->iop;

out_free_data:
	kfree(data);
	return NULL;
}

static struct io_pgtable *
arm_32_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
{
	struct io_pgtable *iop;

	if (cfg->ias > 32 || cfg->oas > 40)
		return NULL;

	cfg->pgsize_bitmap &= (SZ_4K | SZ_2M | SZ_1G);
	iop = arm_64_lpae_alloc_pgtable_s1(cfg, cookie);
	if (iop) {
		cfg->arm_lpae_s1_cfg.tcr |= ARM_32_LPAE_TCR_EAE;
		cfg->arm_lpae_s1_cfg.tcr &= 0xffffffff;
	}

	return iop;
}

static struct io_pgtable *
arm_32_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
{
	struct io_pgtable *iop;

	if (cfg->ias > 40 || cfg->oas > 40)
		return NULL;

	cfg->pgsize_bitmap &= (SZ_4K | SZ_2M | SZ_1G);
	iop = arm_64_lpae_alloc_pgtable_s2(cfg, cookie);
	if (iop)
		cfg->arm_lpae_s2_cfg.vtcr &= 0xffffffff;

	return iop;
}

struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns = {
	.alloc	= arm_64_lpae_alloc_pgtable_s1,
	.free	= arm_lpae_free_pgtable,
};

struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = {
	.alloc	= arm_64_lpae_alloc_pgtable_s2,
	.free	= arm_lpae_free_pgtable,
};

struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns = {
	.alloc	= arm_32_lpae_alloc_pgtable_s1,
	.free	= arm_lpae_free_pgtable,
};

struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns = {
	.alloc	= arm_32_lpae_alloc_pgtable_s2,
	.free	= arm_lpae_free_pgtable,
};

#ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE_SELFTEST

static struct io_pgtable_cfg *cfg_cookie;

static void dummy_tlb_flush_all(void *cookie)
{
	WARN_ON(cookie != cfg_cookie);
}

static void dummy_tlb_add_flush(unsigned long iova, size_t size,
				size_t granule, bool leaf, void *cookie)
{
	WARN_ON(cookie != cfg_cookie);
	WARN_ON(!(size & cfg_cookie->pgsize_bitmap));
}

static void dummy_tlb_sync(void *cookie)
{
	WARN_ON(cookie != cfg_cookie);
}

static struct iommu_gather_ops dummy_tlb_ops __initdata = {
	.tlb_flush_all	= dummy_tlb_flush_all,
	.tlb_add_flush	= dummy_tlb_add_flush,
	.tlb_sync	= dummy_tlb_sync,
};

static void __init arm_lpae_dump_ops(struct io_pgtable_ops *ops)
{
	struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
	struct io_pgtable_cfg *cfg = &data->iop.cfg;

	pr_err("cfg: pgsize_bitmap 0x%lx, ias %u-bit\n",
		cfg->pgsize_bitmap, cfg->ias);
	pr_err("data: %d levels, 0x%zx pgd_size, %lu pg_shift, %lu bits_per_level, pgd @ %p\n",
		data->levels, data->pgd_size, data->pg_shift,
		data->bits_per_level, data->pgd);
}

#define __FAIL(ops, i)	({						\
		WARN(1, "selftest: test failed for fmt idx %d\n", (i));	\
		arm_lpae_dump_ops(ops);					\
		selftest_running = false;				\
		-EFAULT;						\
})

static int __init arm_lpae_run_tests(struct io_pgtable_cfg *cfg)
{
	static const enum io_pgtable_fmt fmts[] = {
		ARM_64_LPAE_S1,
		ARM_64_LPAE_S2,
	};

	int i, j;
	unsigned long iova;
	size_t size;
	struct io_pgtable_ops *ops;

	selftest_running = true;

	for (i = 0; i < ARRAY_SIZE(fmts); ++i) {
		cfg_cookie = cfg;
		ops = alloc_io_pgtable_ops(fmts[i], cfg, cfg);
		if (!ops) {
			pr_err("selftest: failed to allocate io pgtable ops\n");
			return -ENOMEM;
		}

		/*
		 * Initial sanity checks.
		 * Empty page tables shouldn't provide any translations.
		 */
		if (ops->iova_to_phys(ops, 42))
			return __FAIL(ops, i);

		if (ops->iova_to_phys(ops, SZ_1G + 42))
			return __FAIL(ops, i);

		if (ops->iova_to_phys(ops, SZ_2G + 42))
			return __FAIL(ops, i);

		/*
		 * Distinct mappings of different granule sizes.
		 */
		iova = 0;
		j = find_first_bit(&cfg->pgsize_bitmap, BITS_PER_LONG);
		while (j != BITS_PER_LONG) {
			size = 1UL << j;

			if (ops->map(ops, iova, iova, size, IOMMU_READ |
							    IOMMU_WRITE |
							    IOMMU_NOEXEC |
							    IOMMU_CACHE))
				return __FAIL(ops, i);

			/* Overlapping mappings */
			if (!ops->map(ops, iova, iova + size, size,
				      IOMMU_READ | IOMMU_NOEXEC))
				return __FAIL(ops, i);

			if (ops->iova_to_phys(ops, iova + 42) != (iova + 42))
				return __FAIL(ops, i);

			iova += SZ_1G;
			j++;
			j = find_next_bit(&cfg->pgsize_bitmap, BITS_PER_LONG, j);
		}

		/* Partial unmap */
		size = 1UL << __ffs(cfg->pgsize_bitmap);
		if (ops->unmap(ops, SZ_1G + size, size) != size)
			return __FAIL(ops, i);

		/* Remap of partial unmap */
		if (ops->map(ops, SZ_1G + size, size, size, IOMMU_READ))
			return __FAIL(ops, i);

		if (ops->iova_to_phys(ops, SZ_1G + size + 42) != (size + 42))
			return __FAIL(ops, i);

		/* Full unmap */
		iova = 0;
		j = find_first_bit(&cfg->pgsize_bitmap, BITS_PER_LONG);
		while (j != BITS_PER_LONG) {
			size = 1UL << j;

			if (ops->unmap(ops, iova, size) != size)
				return __FAIL(ops, i);

			if (ops->iova_to_phys(ops, iova + 42))
				return __FAIL(ops, i);

			/* Remap full block */
			if (ops->map(ops, iova, iova, size, IOMMU_WRITE))
				return __FAIL(ops, i);

			if (ops->iova_to_phys(ops, iova + 42) != (iova + 42))
				return __FAIL(ops, i);

			iova += SZ_1G;
			j++;
			j = find_next_bit(&cfg->pgsize_bitmap, BITS_PER_LONG, j);
		}

		free_io_pgtable_ops(ops);
	}

	selftest_running = false;
	return 0;
}

static int __init arm_lpae_do_selftests(void)
{
	static const unsigned long pgsize[] = {
		SZ_4K | SZ_2M | SZ_1G,
		SZ_16K | SZ_32M,
		SZ_64K | SZ_512M,
	};

	static const unsigned int ias[] = {
		32, 36, 40, 42, 44, 48,
	};

	int i, j, pass = 0, fail = 0;
	struct io_pgtable_cfg cfg = {
		.tlb = &dummy_tlb_ops,
		.oas = 48,
	};

	for (i = 0; i < ARRAY_SIZE(pgsize); ++i) {
		for (j = 0; j < ARRAY_SIZE(ias); ++j) {
			cfg.pgsize_bitmap = pgsize[i];
			cfg.ias = ias[j];
			pr_info("selftest: pgsize_bitmap 0x%08lx, IAS %u\n",
				pgsize[i], ias[j]);
			if (arm_lpae_run_tests(&cfg))
				fail++;
			else
				pass++;
		}
	}

	pr_info("selftest: completed with %d PASS %d FAIL\n", pass, fail);
	return fail ? -EFAULT : 0;
}
subsys_initcall(arm_lpae_do_selftests);
#endif
OpenPOWER on IntegriCloud