aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/plat-omap/iovmm.c
blob: 936aef1971cd320afd086f099d59a4d0b9958281 (plain) (blame)
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
/*
 * omap iommu: simple virtual address space management
 *
 * Copyright (C) 2008-2009 Nokia Corporation
 *
 * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
 *
 * 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/err.h>
#include <linux/vmalloc.h>
#include <linux/device.h>
#include <linux/scatterlist.h>

#include <asm/cacheflush.h>
#include <asm/mach/map.h>

#include <plat/iommu.h>
#include <plat/iovmm.h>

#include "iopgtable.h"

/*
 * A device driver needs to create address mappings between:
 *
 * - iommu/device address
 * - physical address
 * - mpu virtual address
 *
 * There are 4 possible patterns for them:
 *
 *    |iova/			  mapping		iommu_		page
 *    | da	pa	va	(d)-(p)-(v)		function	type
 *  ---------------------------------------------------------------------------
 *  1 | c	c	c	 1 - 1 - 1	  _kmap() / _kunmap()	s
 *  2 | c	c,a	c	 1 - 1 - 1	_kmalloc()/ _kfree()	s
 *  3 | c	d	c	 1 - n - 1	  _vmap() / _vunmap()	s
 *  4 | c	d,a	c	 1 - n - 1	_vmalloc()/ _vfree()	n*
 *
 *
 *	'iova':	device iommu virtual address
 *	'da':	alias of 'iova'
 *	'pa':	physical address
 *	'va':	mpu virtual address
 *
 *	'c':	contiguous memory area
 *	'd':	discontiguous memory area
 *	'a':	anonymous memory allocation
 *	'()':	optional feature
 *
 *	'n':	a normal page(4KB) size is used.
 *	's':	multiple iommu superpage(16MB, 1MB, 64KB, 4KB) size is used.
 *
 *	'*':	not yet, but feasible.
 */

static struct kmem_cache *iovm_area_cachep;

/* return total bytes of sg buffers */
static size_t sgtable_len(const struct sg_table *sgt)
{
	unsigned int i, total = 0;
	struct scatterlist *sg;

	if (!sgt)
		return 0;

	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
		size_t bytes;

		bytes = sg_dma_len(sg);

		if (!iopgsz_ok(bytes)) {
			pr_err("%s: sg[%d] not iommu pagesize(%x)\n",
			       __func__, i, bytes);
			return 0;
		}

		total += bytes;
	}

	return total;
}
#define sgtable_ok(x)	(!!sgtable_len(x))

/*
 * calculate the optimal number sg elements from total bytes based on
 * iommu superpages
 */
static unsigned int sgtable_nents(size_t bytes)
{
	int i;
	unsigned int nr_entries;
	const unsigned long pagesize[] = { SZ_16M, SZ_1M, SZ_64K, SZ_4K, };

	if (!IS_ALIGNED(bytes, PAGE_SIZE)) {
		pr_err("%s: wrong size %08x\n", __func__, bytes);
		return 0;
	}

	nr_entries = 0;
	for (i = 0; i < ARRAY_SIZE(pagesize); i++) {
		if (bytes >= pagesize[i]) {
			nr_entries += (bytes / pagesize[i]);
			bytes %= pagesize[i];
		}
	}
	BUG_ON(bytes);

	return nr_entries;
}

/* allocate and initialize sg_table header(a kind of 'superblock') */
static struct sg_table *sgtable_alloc(const size_t bytes, u32 flags)
{
	unsigned int nr_entries;
	int err;
	struct sg_table *sgt;

	if (!bytes)
		return ERR_PTR(-EINVAL);

	if (!IS_ALIGNED(bytes, PAGE_SIZE))
		return ERR_PTR(-EINVAL);

	/* FIXME: IOVMF_DA_FIXED should support 'superpages' */
	if ((flags & IOVMF_LINEAR) && (flags & IOVMF_DA_ANON)) {
		nr_entries = sgtable_nents(bytes);
		if (!nr_entries)
			return ERR_PTR(-EINVAL);
	} else
		nr_entries =  bytes / PAGE_SIZE;

	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
	if (!sgt)
		return ERR_PTR(-ENOMEM);

	err = sg_alloc_table(sgt, nr_entries, GFP_KERNEL);
	if (err)
		return ERR_PTR(err);

	pr_debug("%s: sgt:%p(%d entries)\n", __func__, sgt, nr_entries);

	return sgt;
}

/* free sg_table header(a kind of superblock) */
static void sgtable_free(struct sg_table *sgt)
{
	if (!sgt)
		return;

	sg_free_table(sgt);
	kfree(sgt);

	pr_debug("%s: sgt:%p\n", __func__, sgt);
}

/* map 'sglist' to a contiguous mpu virtual area and return 'va' */
static void *vmap_sg(const struct sg_table *sgt)
{
	u32 va;
	size_t total;
	unsigned int i;
	struct scatterlist *sg;
	struct vm_struct *new;
	const struct mem_type *mtype;

	mtype = get_mem_type(MT_DEVICE);
	if (!mtype)
		return ERR_PTR(-EINVAL);

	total = sgtable_len(sgt);
	if (!total)
		return ERR_PTR(-EINVAL);

	new = __get_vm_area(total, VM_IOREMAP, VMALLOC_START, VMALLOC_END);
	if (!new)
		return ERR_PTR(-ENOMEM);
	va = (u32)new->addr;

	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
		size_t bytes;
		u32 pa;
		int err;

		pa = sg_phys(sg);
		bytes = sg_dma_len(sg);

		BUG_ON(bytes != PAGE_SIZE);

		err = ioremap_page(va,  pa, mtype);
		if (err)
			goto err_out;

		va += bytes;
	}

	flush_cache_vmap((unsigned long)new->addr,
				(unsigned long)(new->addr + total));
	return new->addr;

err_out:
	WARN_ON(1); /* FIXME: cleanup some mpu mappings */
	vunmap(new->addr);
	return ERR_PTR(-EAGAIN);
}

static inline void vunmap_sg(const void *va)
{
	vunmap(va);
}

static struct iovm_struct *__find_iovm_area(struct iommu *obj, const u32 da)
{
	struct iovm_struct *tmp;

	list_for_each_entry(tmp, &obj->mmap, list) {
		if ((da >= tmp->da_start) && (da < tmp->da_end)) {
			size_t len;

			len = tmp->da_end - tmp->da_start;

			dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n",
				__func__, tmp->da_start, da, tmp->da_end, len,
				tmp->flags);

			return tmp;
		}
	}

	return NULL;
}

/**
 * find_iovm_area  -  find iovma which includes @da
 * @da:		iommu device virtual address
 *
 * Find the existing iovma starting at @da
 */
struct iovm_struct *find_iovm_area(struct iommu *obj, u32 da)
{
	struct iovm_struct *area;

	mutex_lock(&obj->mmap_lock);
	area = __find_iovm_area(obj, da);
	mutex_unlock(&obj->mmap_lock);

	return area;
}
EXPORT_SYMBOL_GPL(find_iovm_area);

/*
 * This finds the hole(area) which fits the requested address and len
 * in iovmas mmap, and returns the new allocated iovma.
 */
static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
					   size_t bytes, u32 flags)
{
	struct iovm_struct *new, *tmp;
	u32 start, prev_end, alignement;

	if (!obj || !bytes)
		return ERR_PTR(-EINVAL);

	start = da;
	alignement = PAGE_SIZE;

	if (flags & IOVMF_DA_ANON) {
		/*
		 * Reserve the first page for NULL
		 */
		start = PAGE_SIZE;
		if (flags & IOVMF_LINEAR)
			alignement = iopgsz_max(bytes);
		start = roundup(start, alignement);
	}

	tmp = NULL;
	if (list_empty(&obj->mmap))
		goto found;

	prev_end = 0;
	list_for_each_entry(tmp, &obj->mmap, list) {

		if ((prev_end <= start) && (start + bytes < tmp->da_start))
			goto found;

		if (flags & IOVMF_DA_ANON)
			start = roundup(tmp->da_end, alignement);

		prev_end = tmp->da_end;
	}

	if ((start >= prev_end) && (ULONG_MAX - start >= bytes))
		goto found;

	dev_dbg(obj->dev, "%s: no space to fit %08x(%x) flags: %08x\n",
		__func__, da, bytes, flags);

	return ERR_PTR(-EINVAL);

found:
	new = kmem_cache_zalloc(iovm_area_cachep, GFP_KERNEL);
	if (!new)
		return ERR_PTR(-ENOMEM);

	new->iommu = obj;
	new->da_start = start;
	new->da_end = start + bytes;
	new->flags = flags;

	/*
	 * keep ascending order of iovmas
	 */
	if (tmp)
		list_add_tail(&new->list, &tmp->list);
	else
		list_add(&new->list, &obj->mmap);

	dev_dbg(obj->dev, "%s: found %08x-%08x-%08x(%x) %08x\n",
		__func__, new->da_start, start, new->da_end, bytes, flags);

	return new;
}

static void free_iovm_area(struct iommu *obj, struct iovm_struct *area)
{
	size_t bytes;

	BUG_ON(!obj || !area);

	bytes = area->da_end - area->da_start;

	dev_dbg(obj->dev, "%s: %08x-%08x(%x) %08x\n",
		__func__, area->da_start, area->da_end, bytes, area->flags);

	list_del(&area->list);
	kmem_cache_free(iovm_area_cachep, area);
}

/**
 * da_to_va - convert (d) to (v)
 * @obj:	objective iommu
 * @da:		iommu device virtual address
 * @va:		mpu virtual address
 *
 * Returns mpu virtual addr which corresponds to a given device virtual addr
 */
void *da_to_va(struct iommu *obj, u32 da)
{
	void *va = NULL;
	struct iovm_struct *area;

	mutex_lock(&obj->mmap_lock);

	area = __find_iovm_area(obj, da);
	if (!area) {
		dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
		goto out;
	}
	va = area->va;
out:
	mutex_unlock(&obj->mmap_lock);

	return va;
}
EXPORT_SYMBOL_GPL(da_to_va);

static void sgtable_fill_vmalloc(struct sg_table *sgt, void *_va)
{
	unsigned int i;
	struct scatterlist *sg;
	void *va = _va;
	void *va_end;

	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
		struct page *pg;
		const size_t bytes = PAGE_SIZE;

		/*
		 * iommu 'superpage' isn't supported with 'iommu_vmalloc()'
		 */
		pg = vmalloc_to_page(va);
		BUG_ON(!pg);
		sg_set_page(sg, pg, bytes, 0);

		va += bytes;
	}

	va_end = _va + PAGE_SIZE * i;
}

static inline void sgtable_drain_vmalloc(struct sg_table *sgt)
{
	/*
	 * Actually this is not necessary at all, just exists for
	 * consistency of the code readability.
	 */
	BUG_ON(!sgt);
}

static void sgtable_fill_kmalloc(struct sg_table *sgt, u32 pa, size_t len)
{
	unsigned int i;
	struct scatterlist *sg;
	void *va;

	va = phys_to_virt(pa);

	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
		size_t bytes;

		bytes = iopgsz_max(len);

		BUG_ON(!iopgsz_ok(bytes));

		sg_set_buf(sg, phys_to_virt(pa), bytes);
		/*
		 * 'pa' is cotinuous(linear).
		 */
		pa += bytes;
		len -= bytes;
	}
	BUG_ON(len);
}

static inline void sgtable_drain_kmalloc(struct sg_table *sgt)
{
	/*
	 * Actually this is not necessary at all, just exists for
	 * consistency of the code readability
	 */
	BUG_ON(!sgt);
}

/* create 'da' <-> 'pa' mapping from 'sgt' */
static int map_iovm_area(struct iommu *obj, struct iovm_struct *new,
			 const struct sg_table *sgt, u32 flags)
{
	int err;
	unsigned int i, j;
	struct scatterlist *sg;
	u32 da = new->da_start;

	if (!obj || !sgt)
		return -EINVAL;

	BUG_ON(!sgtable_ok(sgt));

	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
		u32 pa;
		int pgsz;
		size_t bytes;
		struct iotlb_entry e;

		pa = sg_phys(sg);
		bytes = sg_dma_len(sg);

		flags &= ~IOVMF_PGSZ_MASK;
		pgsz = bytes_to_iopgsz(bytes);
		if (pgsz < 0)
			goto err_out;
		flags |= pgsz;

		pr_debug("%s: [%d] %08x %08x(%x)\n", __func__,
			 i, da, pa, bytes);

		iotlb_init_entry(&e, da, pa, flags);
		err = iopgtable_store_entry(obj, &e);
		if (err)
			goto err_out;

		da += bytes;
	}
	return 0;

err_out:
	da = new->da_start;

	for_each_sg(sgt->sgl, sg, i, j) {
		size_t bytes;

		bytes = iopgtable_clear_entry(obj, da);

		BUG_ON(!iopgsz_ok(bytes));

		da += bytes;
	}
	return err;
}

/* release 'da' <-> 'pa' mapping */
static void unmap_iovm_area(struct iommu *obj, struct iovm_struct *area)
{
	u32 start;
	size_t total = area->da_end - area->da_start;

	BUG_ON((!total) || !IS_ALIGNED(total, PAGE_SIZE));

	start = area->da_start;
	while (total > 0) {
		size_t bytes;

		bytes = iopgtable_clear_entry(obj, start);
		if (bytes == 0)
			bytes = PAGE_SIZE;
		else
			dev_dbg(obj->dev, "%s: unmap %08x(%x) %08x\n",
				__func__, start, bytes, area->flags);

		BUG_ON(!IS_ALIGNED(bytes, PAGE_SIZE));

		total -= bytes;
		start += bytes;
	}
	BUG_ON(total);
}

/* template function for all unmapping */
static struct sg_table *unmap_vm_area(struct iommu *obj, const u32 da,
				      void (*fn)(const void *), u32 flags)
{
	struct sg_table *sgt = NULL;
	struct iovm_struct *area;

	if (!IS_ALIGNED(da, PAGE_SIZE)) {
		dev_err(obj->dev, "%s: alignment err(%08x)\n", __func__, da);
		return NULL;
	}

	mutex_lock(&obj->mmap_lock);

	area = __find_iovm_area(obj, da);
	if (!area) {
		dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
		goto out;
	}

	if ((area->flags & flags) != flags) {
		dev_err(obj->dev, "%s: wrong flags(%08x)\n", __func__,
			area->flags);
		goto out;
	}
	sgt = (struct sg_table *)area->sgt;

	unmap_iovm_area(obj, area);

	fn(area->va);

	dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n", __func__,
		area->da_start, da, area->da_end,
		area->da_end - area->da_start, area->flags);

	free_iovm_area(obj, area);
out:
	mutex_unlock(&obj->mmap_lock);

	return sgt;
}

static u32 map_iommu_region(struct iommu *obj, u32 da,
	      const struct sg_table *sgt, void *va, size_t bytes, u32 flags)
{
	int err = -ENOMEM;
	struct iovm_struct *new;

	mutex_lock(&obj->mmap_lock);

	new = alloc_iovm_area(obj, da, bytes, flags);
	if (IS_ERR(new)) {
		err = PTR_ERR(new);
		goto err_alloc_iovma;
	}
	new->va = va;
	new->sgt = sgt;

	if (map_iovm_area(obj, new, sgt, new->flags))
		goto err_map;

	mutex_unlock(&obj->mmap_lock);

	dev_dbg(obj->dev, "%s: da:%08x(%x) flags:%08x va:%p\n",
		__func__, new->da_start, bytes, new->flags, va);

	return new->da_start;

err_map:
	free_iovm_area(obj, new);
err_alloc_iovma:
	mutex_unlock(&obj->mmap_lock);
	return err;
}

static inline u32 __iommu_vmap(struct iommu *obj, u32 da,
		 const struct sg_table *sgt, void *va, size_t bytes, u32 flags)
{
	return map_iommu_region(obj, da, sgt, va, bytes, flags);
}

/**
 * iommu_vmap  -  (d)-(p)-(v) address mapper
 * @obj:	objective iommu
 * @sgt:	address of scatter gather table
 * @flags:	iovma and page property
 *
 * Creates 1-n-1 mapping with given @sgt and returns @da.
 * All @sgt element must be io page size aligned.
 */
u32 iommu_vmap(struct iommu *obj, u32 da, const struct sg_table *sgt,
		 u32 flags)
{
	size_t bytes;
	void *va = NULL;

	if (!obj || !obj->dev || !sgt)
		return -EINVAL;

	bytes = sgtable_len(sgt);
	if (!bytes)
		return -EINVAL;
	bytes = PAGE_ALIGN(bytes);

	if (flags & IOVMF_MMIO) {
		va = vmap_sg(sgt);
		if (IS_ERR(va))
			return PTR_ERR(va);
	}

	flags &= IOVMF_HW_MASK;
	flags |= IOVMF_DISCONT;
	flags |= IOVMF_MMIO;
	flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);

	da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
	if (IS_ERR_VALUE(da))
		vunmap_sg(va);

	return da;
}
EXPORT_SYMBOL_GPL(iommu_vmap);

/**
 * iommu_vunmap  -  release virtual mapping obtained by 'iommu_vmap()'
 * @obj:	objective iommu
 * @da:		iommu device virtual address
 *
 * Free the iommu virtually contiguous memory area starting at
 * @da, which was returned by 'iommu_vmap()'.
 */
struct sg_table *iommu_vunmap(struct iommu *obj, u32 da)
{
	struct sg_table *sgt;
	/*
	 * 'sgt' is allocated before 'iommu_vmalloc()' is called.
	 * Just returns 'sgt' to the caller to free
	 */
	sgt = unmap_vm_area(obj, da, vunmap_sg, IOVMF_DISCONT | IOVMF_MMIO);
	if (!sgt)
		dev_dbg(obj->dev, "%s: No sgt\n", __func__);
	return sgt;
}
EXPORT_SYMBOL_GPL(iommu_vunmap);

/**
 * iommu_vmalloc  -  (d)-(p)-(v) address allocator and mapper
 * @obj:	objective iommu
 * @da:		contiguous iommu virtual memory
 * @bytes:	allocation size
 * @flags:	iovma and page property
 *
 * Allocate @bytes linearly and creates 1-n-1 mapping and returns
 * @da again, which might be adjusted if 'IOVMF_DA_ANON' is set.
 */
u32 iommu_vmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
{
	void *va;
	struct sg_table *sgt;

	if (!obj || !obj->dev || !bytes)
		return -EINVAL;

	bytes = PAGE_ALIGN(bytes);

	va = vmalloc(bytes);
	if (!va)
		return -ENOMEM;

	sgt = sgtable_alloc(bytes, flags);
	if (IS_ERR(sgt)) {
		da = PTR_ERR(sgt);
		goto err_sgt_alloc;
	}
	sgtable_fill_vmalloc(sgt, va);

	flags &= IOVMF_HW_MASK;
	flags |= IOVMF_DISCONT;
	flags |= IOVMF_ALLOC;
	flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);

	da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
	if (IS_ERR_VALUE(da))
		goto err_iommu_vmap;

	return da;

err_iommu_vmap:
	sgtable_drain_vmalloc(sgt);
	sgtable_free(sgt);
err_sgt_alloc:
	vfree(va);
	return da;
}
EXPORT_SYMBOL_GPL(iommu_vmalloc);

/**
 * iommu_vfree  -  release memory allocated by 'iommu_vmalloc()'
 * @obj:	objective iommu
 * @da:		iommu device virtual address
 *
 * Frees the iommu virtually continuous memory area starting at
 * @da, as obtained from 'iommu_vmalloc()'.
 */
void iommu_vfree(struct iommu *obj, const u32 da)
{
	struct sg_table *sgt;

	sgt = unmap_vm_area(obj, da, vfree, IOVMF_DISCONT | IOVMF_ALLOC);
	if (!sgt)
		dev_dbg(obj->dev, "%s: No sgt\n", __func__);
	sgtable_free(sgt);
}
EXPORT_SYMBOL_GPL(iommu_vfree);

static u32 __iommu_kmap(struct iommu *obj, u32 da, u32 pa, void *va,
			  size_t bytes, u32 flags)
{
	struct sg_table *sgt;

	sgt = sgtable_alloc(bytes, flags);
	if (IS_ERR(sgt))
		return PTR_ERR(sgt);

	sgtable_fill_kmalloc(sgt, pa, bytes);

	da = map_iommu_region(obj, da, sgt, va, bytes, flags);
	if (IS_ERR_VALUE(da)) {
		sgtable_drain_kmalloc(sgt);
		sgtable_free(sgt);
	}

	return da;
}

/**
 * iommu_kmap  -  (d)-(p)-(v) address mapper
 * @obj:	objective iommu
 * @da:		contiguous iommu virtual memory
 * @pa:		contiguous physical memory
 * @flags:	iovma and page property
 *
 * Creates 1-1-1 mapping and returns @da again, which can be
 * adjusted if 'IOVMF_DA_ANON' is set.
 */
u32 iommu_kmap(struct iommu *obj, u32 da, u32 pa, size_t bytes,
		 u32 flags)
{
	void *va;

	if (!obj || !obj->dev || !bytes)
		return -EINVAL;

	bytes = PAGE_ALIGN(bytes);

	va = ioremap(pa, bytes);
	if (!va)
		return -ENOMEM;

	flags &= IOVMF_HW_MASK;
	flags |= IOVMF_LINEAR;
	flags |= IOVMF_MMIO;
	flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);

	da = __iommu_kmap(obj, da, pa, va, bytes, flags);
	if (IS_ERR_VALUE(da))
		iounmap(va);

	return da;
}
EXPORT_SYMBOL_GPL(iommu_kmap);

/**
 * iommu_kunmap  -  release virtual mapping obtained by 'iommu_kmap()'
 * @obj:	objective iommu
 * @da:		iommu device virtual address
 *
 * Frees the iommu virtually contiguous memory area starting at
 * @da, which was passed to and was returned by'iommu_kmap()'.
 */
void iommu_kunmap(struct iommu *obj, u32 da)
{
	struct sg_table *sgt;
	typedef void (*func_t)(const void *);

	sgt = unmap_vm_area(obj, da, (func_t)__iounmap,
			    IOVMF_LINEAR | IOVMF_MMIO);
	if (!sgt)
		dev_dbg(obj->dev, "%s: No sgt\n", __func__);
	sgtable_free(sgt);
}
EXPORT_SYMBOL_GPL(iommu_kunmap);

/**
 * iommu_kmalloc  -  (d)-(p)-(v) address allocator and mapper
 * @obj:	objective iommu
 * @da:		contiguous iommu virtual memory
 * @bytes:	bytes for allocation
 * @flags:	iovma and page property
 *
 * Allocate @bytes linearly and creates 1-1-1 mapping and returns
 * @da again, which might be adjusted if 'IOVMF_DA_ANON' is set.
 */
u32 iommu_kmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
{
	void *va;
	u32 pa;

	if (!obj || !obj->dev || !bytes)
		return -EINVAL;

	bytes = PAGE_ALIGN(bytes);

	va = kmalloc(bytes, GFP_KERNEL | GFP_DMA);
	if (!va)
		return -ENOMEM;
	pa = virt_to_phys(va);

	flags &= IOVMF_HW_MASK;
	flags |= IOVMF_LINEAR;
	flags |= IOVMF_ALLOC;
	flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);

	da = __iommu_kmap(obj, da, pa, va, bytes, flags);
	if (IS_ERR_VALUE(da))
		kfree(va);

	return da;
}
EXPORT_SYMBOL_GPL(iommu_kmalloc);

/**
 * iommu_kfree  -  release virtual mapping obtained by 'iommu_kmalloc()'
 * @obj:	objective iommu
 * @da:		iommu device virtual address
 *
 * Frees the iommu virtually contiguous memory area starting at
 * @da, which was passed to and was returned by'iommu_kmalloc()'.
 */
void iommu_kfree(struct iommu *obj, u32 da)
{
	struct sg_table *sgt;

	sgt = unmap_vm_area(obj, da, kfree, IOVMF_LINEAR | IOVMF_ALLOC);
	if (!sgt)
		dev_dbg(obj->dev, "%s: No sgt\n", __func__);
	sgtable_free(sgt);
}
EXPORT_SYMBOL_GPL(iommu_kfree);


static int __init iovmm_init(void)
{
	const unsigned long flags = SLAB_HWCACHE_ALIGN;
	struct kmem_cache *p;

	p = kmem_cache_create("iovm_area_cache", sizeof(struct iovm_struct), 0,
			      flags, NULL);
	if (!p)
		return -ENOMEM;
	iovm_area_cachep = p;

	return 0;
}
module_init(iovmm_init);

static void __exit iovmm_exit(void)
{
	kmem_cache_destroy(iovm_area_cachep);
}
module_exit(iovmm_exit);

MODULE_DESCRIPTION("omap iommu: simple virtual address space management");
MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
MODULE_LICENSE("GPL v2");