aboutsummaryrefslogtreecommitdiff
path: root/arch/sh/mm/pmb.c
blob: e43ec600afcfbc9b853522ea4df330d1991de589 (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
/*
 * arch/sh/mm/pmb.c
 *
 * Privileged Space Mapping Buffer (PMB) Support.
 *
 * Copyright (C) 2005 - 2010  Paul Mundt
 * Copyright (C) 2010  Matt Fleming
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sysdev.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/debugfs.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <asm/cacheflush.h>
#include <asm/sizes.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>

struct pmb_entry;

struct pmb_entry {
	unsigned long vpn;
	unsigned long ppn;
	unsigned long flags;
	unsigned long size;

	spinlock_t lock;

	/*
	 * 0 .. NR_PMB_ENTRIES for specific entry selection, or
	 * PMB_NO_ENTRY to search for a free one
	 */
	int entry;

	/* Adjacent entry link for contiguous multi-entry mappings */
	struct pmb_entry *link;
};

static struct {
	unsigned long size;
	int flag;
} pmb_sizes[] = {
	{ .size	= SZ_512M, .flag = PMB_SZ_512M, },
	{ .size = SZ_128M, .flag = PMB_SZ_128M, },
	{ .size = SZ_64M,  .flag = PMB_SZ_64M,  },
	{ .size = SZ_16M,  .flag = PMB_SZ_16M,  },
};

static void pmb_unmap_entry(struct pmb_entry *, int depth);

static DEFINE_RWLOCK(pmb_rwlock);
static struct pmb_entry pmb_entry_list[NR_PMB_ENTRIES];
static DECLARE_BITMAP(pmb_map, NR_PMB_ENTRIES);

static unsigned int pmb_iomapping_enabled;

static __always_inline unsigned long mk_pmb_entry(unsigned int entry)
{
	return (entry & PMB_E_MASK) << PMB_E_SHIFT;
}

static __always_inline unsigned long mk_pmb_addr(unsigned int entry)
{
	return mk_pmb_entry(entry) | PMB_ADDR;
}

static __always_inline unsigned long mk_pmb_data(unsigned int entry)
{
	return mk_pmb_entry(entry) | PMB_DATA;
}

static __always_inline unsigned int pmb_ppn_in_range(unsigned long ppn)
{
	return ppn >= __pa(memory_start) && ppn < __pa(memory_end);
}

/*
 * Ensure that the PMB entries match our cache configuration.
 *
 * When we are in 32-bit address extended mode, CCR.CB becomes
 * invalid, so care must be taken to manually adjust cacheable
 * translations.
 */
static __always_inline unsigned long pmb_cache_flags(void)
{
	unsigned long flags = 0;

#if defined(CONFIG_CACHE_OFF)
	flags |= PMB_WT | PMB_UB;
#elif defined(CONFIG_CACHE_WRITETHROUGH)
	flags |= PMB_C | PMB_WT | PMB_UB;
#elif defined(CONFIG_CACHE_WRITEBACK)
	flags |= PMB_C;
#endif

	return flags;
}

/*
 * Convert typical pgprot value to the PMB equivalent
 */
static inline unsigned long pgprot_to_pmb_flags(pgprot_t prot)
{
	unsigned long pmb_flags = 0;
	u64 flags = pgprot_val(prot);

	if (flags & _PAGE_CACHABLE)
		pmb_flags |= PMB_C;
	if (flags & _PAGE_WT)
		pmb_flags |= PMB_WT | PMB_UB;

	return pmb_flags;
}

static inline bool pmb_can_merge(struct pmb_entry *a, struct pmb_entry *b)
{
	return (b->vpn == (a->vpn + a->size)) &&
	       (b->ppn == (a->ppn + a->size)) &&
	       (b->flags == a->flags);
}

static bool pmb_mapping_exists(unsigned long vaddr, phys_addr_t phys,
			       unsigned long size)
{
	int i;

	read_lock(&pmb_rwlock);

	for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
		struct pmb_entry *pmbe, *iter;
		unsigned long span;

		if (!test_bit(i, pmb_map))
			continue;

		pmbe = &pmb_entry_list[i];

		/*
		 * See if VPN and PPN are bounded by an existing mapping.
		 */
		if ((vaddr < pmbe->vpn) || (vaddr >= (pmbe->vpn + pmbe->size)))
			continue;
		if ((phys < pmbe->ppn) || (phys >= (pmbe->ppn + pmbe->size)))
			continue;

		/*
		 * Now see if we're in range of a simple mapping.
		 */
		if (size <= pmbe->size) {
			read_unlock(&pmb_rwlock);
			return true;
		}

		span = pmbe->size;

		/*
		 * Finally for sizes that involve compound mappings, walk
		 * the chain.
		 */
		for (iter = pmbe->link; iter; iter = iter->link)
			span += iter->size;

		/*
		 * Nothing else to do if the range requirements are met.
		 */
		if (size <= span) {
			read_unlock(&pmb_rwlock);
			return true;
		}
	}

	read_unlock(&pmb_rwlock);
	return false;
}

static bool pmb_size_valid(unsigned long size)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
		if (pmb_sizes[i].size == size)
			return true;

	return false;
}

static inline bool pmb_addr_valid(unsigned long addr, unsigned long size)
{
	return (addr >= P1SEG && (addr + size - 1) < P3SEG);
}

static inline bool pmb_prot_valid(pgprot_t prot)
{
	return (pgprot_val(prot) & _PAGE_USER) == 0;
}

static int pmb_size_to_flags(unsigned long size)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
		if (pmb_sizes[i].size == size)
			return pmb_sizes[i].flag;

	return 0;
}

static int pmb_alloc_entry(void)
{
	int pos;

	pos = find_first_zero_bit(pmb_map, NR_PMB_ENTRIES);
	if (pos >= 0 && pos < NR_PMB_ENTRIES)
		__set_bit(pos, pmb_map);
	else
		pos = -ENOSPC;

	return pos;
}

static struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
				   unsigned long flags, int entry)
{
	struct pmb_entry *pmbe;
	unsigned long irqflags;
	void *ret = NULL;
	int pos;

	write_lock_irqsave(&pmb_rwlock, irqflags);

	if (entry == PMB_NO_ENTRY) {
		pos = pmb_alloc_entry();
		if (unlikely(pos < 0)) {
			ret = ERR_PTR(pos);
			goto out;
		}
	} else {
		if (__test_and_set_bit(entry, pmb_map)) {
			ret = ERR_PTR(-ENOSPC);
			goto out;
		}

		pos = entry;
	}

	write_unlock_irqrestore(&pmb_rwlock, irqflags);

	pmbe = &pmb_entry_list[pos];

	memset(pmbe, 0, sizeof(struct pmb_entry));

	spin_lock_init(&pmbe->lock);

	pmbe->vpn	= vpn;
	pmbe->ppn	= ppn;
	pmbe->flags	= flags;
	pmbe->entry	= pos;

	return pmbe;

out:
	write_unlock_irqrestore(&pmb_rwlock, irqflags);
	return ret;
}

static void pmb_free(struct pmb_entry *pmbe)
{
	__clear_bit(pmbe->entry, pmb_map);

	pmbe->entry	= PMB_NO_ENTRY;
	pmbe->link	= NULL;
}

/*
 * Must be run uncached.
 */
static void __set_pmb_entry(struct pmb_entry *pmbe)
{
	unsigned long addr, data;

	addr = mk_pmb_addr(pmbe->entry);
	data = mk_pmb_data(pmbe->entry);

	jump_to_uncached();

	/* Set V-bit */
	__raw_writel(pmbe->vpn | PMB_V, addr);
	__raw_writel(pmbe->ppn | pmbe->flags | PMB_V, data);

	back_to_cached();
}

static void __clear_pmb_entry(struct pmb_entry *pmbe)
{
	unsigned long addr, data;
	unsigned long addr_val, data_val;

	addr = mk_pmb_addr(pmbe->entry);
	data = mk_pmb_data(pmbe->entry);

	addr_val = __raw_readl(addr);
	data_val = __raw_readl(data);

	/* Clear V-bit */
	writel_uncached(addr_val & ~PMB_V, addr);
	writel_uncached(data_val & ~PMB_V, data);
}

#ifdef CONFIG_PM
static void set_pmb_entry(struct pmb_entry *pmbe)
{
	unsigned long flags;

	spin_lock_irqsave(&pmbe->lock, flags);
	__set_pmb_entry(pmbe);
	spin_unlock_irqrestore(&pmbe->lock, flags);
}
#endif /* CONFIG_PM */

int pmb_bolt_mapping(unsigned long vaddr, phys_addr_t phys,
		     unsigned long size, pgprot_t prot)
{
	struct pmb_entry *pmbp, *pmbe;
	unsigned long orig_addr, orig_size;
	unsigned long flags, pmb_flags;
	int i, mapped;

	if (!pmb_addr_valid(vaddr, size))
		return -EFAULT;
	if (pmb_mapping_exists(vaddr, phys, size))
		return 0;

	orig_addr = vaddr;
	orig_size = size;

	flush_tlb_kernel_range(vaddr, vaddr + size);

	pmb_flags = pgprot_to_pmb_flags(prot);
	pmbp = NULL;

	do {
		for (i = mapped = 0; i < ARRAY_SIZE(pmb_sizes); i++) {
			if (size < pmb_sizes[i].size)
				continue;

			pmbe = pmb_alloc(vaddr, phys, pmb_flags |
					 pmb_sizes[i].flag, PMB_NO_ENTRY);
			if (IS_ERR(pmbe)) {
				pmb_unmap_entry(pmbp, mapped);
				return PTR_ERR(pmbe);
			}

			spin_lock_irqsave(&pmbe->lock, flags);

			pmbe->size = pmb_sizes[i].size;

			__set_pmb_entry(pmbe);

			phys	+= pmbe->size;
			vaddr	+= pmbe->size;
			size	-= pmbe->size;

			/*
			 * Link adjacent entries that span multiple PMB
			 * entries for easier tear-down.
			 */
			if (likely(pmbp)) {
				spin_lock(&pmbp->lock);
				pmbp->link = pmbe;
				spin_unlock(&pmbp->lock);
			}

			pmbp = pmbe;

			/*
			 * Instead of trying smaller sizes on every
			 * iteration (even if we succeed in allocating
			 * space), try using pmb_sizes[i].size again.
			 */
			i--;
			mapped++;

			spin_unlock_irqrestore(&pmbe->lock, flags);
		}
	} while (size >= SZ_16M);

	flush_cache_vmap(orig_addr, orig_addr + orig_size);

	return 0;
}

void __iomem *pmb_remap_caller(phys_addr_t phys, unsigned long size,
			       pgprot_t prot, void *caller)
{
	unsigned long vaddr;
	phys_addr_t offset, last_addr;
	phys_addr_t align_mask;
	unsigned long aligned;
	struct vm_struct *area;
	int i, ret;

	if (!pmb_iomapping_enabled)
		return NULL;

	/*
	 * Small mappings need to go through the TLB.
	 */
	if (size < SZ_16M)
		return ERR_PTR(-EINVAL);
	if (!pmb_prot_valid(prot))
		return ERR_PTR(-EINVAL);

	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
		if (size >= pmb_sizes[i].size)
			break;

	last_addr = phys + size;
	align_mask = ~(pmb_sizes[i].size - 1);
	offset = phys & ~align_mask;
	phys &= align_mask;
	aligned = ALIGN(last_addr, pmb_sizes[i].size) - phys;

	/*
	 * XXX: This should really start from uncached_end, but this
	 * causes the MMU to reset, so for now we restrict it to the
	 * 0xb000...0xc000 range.
	 */
	area = __get_vm_area_caller(aligned, VM_IOREMAP, 0xb0000000,
				    P3SEG, caller);
	if (!area)
		return NULL;

	area->phys_addr = phys;
	vaddr = (unsigned long)area->addr;

	ret = pmb_bolt_mapping(vaddr, phys, size, prot);
	if (unlikely(ret != 0))
		return ERR_PTR(ret);

	return (void __iomem *)(offset + (char *)vaddr);
}

int pmb_unmap(void __iomem *addr)
{
	struct pmb_entry *pmbe = NULL;
	unsigned long vaddr = (unsigned long __force)addr;
	int i, found = 0;

	read_lock(&pmb_rwlock);

	for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
		if (test_bit(i, pmb_map)) {
			pmbe = &pmb_entry_list[i];
			if (pmbe->vpn == vaddr) {
				found = 1;
				break;
			}
		}
	}

	read_unlock(&pmb_rwlock);

	if (found) {
		pmb_unmap_entry(pmbe, NR_PMB_ENTRIES);
		return 0;
	}

	return -EINVAL;
}

static void __pmb_unmap_entry(struct pmb_entry *pmbe, int depth)
{
	do {
		struct pmb_entry *pmblink = pmbe;

		/*
		 * We may be called before this pmb_entry has been
		 * entered into the PMB table via set_pmb_entry(), but
		 * that's OK because we've allocated a unique slot for
		 * this entry in pmb_alloc() (even if we haven't filled
		 * it yet).
		 *
		 * Therefore, calling __clear_pmb_entry() is safe as no
		 * other mapping can be using that slot.
		 */
		__clear_pmb_entry(pmbe);

		flush_cache_vunmap(pmbe->vpn, pmbe->vpn + pmbe->size);

		pmbe = pmblink->link;

		pmb_free(pmblink);
	} while (pmbe && --depth);
}

static void pmb_unmap_entry(struct pmb_entry *pmbe, int depth)
{
	unsigned long flags;

	if (unlikely(!pmbe))
		return;

	write_lock_irqsave(&pmb_rwlock, flags);
	__pmb_unmap_entry(pmbe, depth);
	write_unlock_irqrestore(&pmb_rwlock, flags);
}

static void __init pmb_notify(void)
{
	int i;

	pr_info("PMB: boot mappings:\n");

	read_lock(&pmb_rwlock);

	for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
		struct pmb_entry *pmbe;

		if (!test_bit(i, pmb_map))
			continue;

		pmbe = &pmb_entry_list[i];

		pr_info("       0x%08lx -> 0x%08lx [ %4ldMB %2scached ]\n",
			pmbe->vpn >> PAGE_SHIFT, pmbe->ppn >> PAGE_SHIFT,
			pmbe->size >> 20, (pmbe->flags & PMB_C) ? "" : "un");
	}

	read_unlock(&pmb_rwlock);
}

/*
 * Sync our software copy of the PMB mappings with those in hardware. The
 * mappings in the hardware PMB were either set up by the bootloader or
 * very early on by the kernel.
 */
static void __init pmb_synchronize(void)
{
	struct pmb_entry *pmbp = NULL;
	int i, j;

	/*
	 * Run through the initial boot mappings, log the established
	 * ones, and blow away anything that falls outside of the valid
	 * PPN range. Specifically, we only care about existing mappings
	 * that impact the cached/uncached sections.
	 *
	 * Note that touching these can be a bit of a minefield; the boot
	 * loader can establish multi-page mappings with the same caching
	 * attributes, so we need to ensure that we aren't modifying a
	 * mapping that we're presently executing from, or may execute
	 * from in the case of straddling page boundaries.
	 *
	 * In the future we will have to tidy up after the boot loader by
	 * jumping between the cached and uncached mappings and tearing
	 * down alternating mappings while executing from the other.
	 */
	for (i = 0; i < NR_PMB_ENTRIES; i++) {
		unsigned long addr, data;
		unsigned long addr_val, data_val;
		unsigned long ppn, vpn, flags;
		unsigned long irqflags;
		unsigned int size;
		struct pmb_entry *pmbe;

		addr = mk_pmb_addr(i);
		data = mk_pmb_data(i);

		addr_val = __raw_readl(addr);
		data_val = __raw_readl(data);

		/*
		 * Skip over any bogus entries
		 */
		if (!(data_val & PMB_V) || !(addr_val & PMB_V))
			continue;

		ppn = data_val & PMB_PFN_MASK;
		vpn = addr_val & PMB_PFN_MASK;

		/*
		 * Only preserve in-range mappings.
		 */
		if (!pmb_ppn_in_range(ppn)) {
			/*
			 * Invalidate anything out of bounds.
			 */
			writel_uncached(addr_val & ~PMB_V, addr);
			writel_uncached(data_val & ~PMB_V, data);
			continue;
		}

		/*
		 * Update the caching attributes if necessary
		 */
		if (data_val & PMB_C) {
			data_val &= ~PMB_CACHE_MASK;
			data_val |= pmb_cache_flags();

			writel_uncached(data_val, data);
		}

		size = data_val & PMB_SZ_MASK;
		flags = size | (data_val & PMB_CACHE_MASK);

		pmbe = pmb_alloc(vpn, ppn, flags, i);
		if (IS_ERR(pmbe)) {
			WARN_ON_ONCE(1);
			continue;
		}

		spin_lock_irqsave(&pmbe->lock, irqflags);

		for (j = 0; j < ARRAY_SIZE(pmb_sizes); j++)
			if (pmb_sizes[j].flag == size)
				pmbe->size = pmb_sizes[j].size;

		if (pmbp) {
			spin_lock(&pmbp->lock);

			/*
			 * Compare the previous entry against the current one to
			 * see if the entries span a contiguous mapping. If so,
			 * setup the entry links accordingly. Compound mappings
			 * are later coalesced.
			 */
			if (pmb_can_merge(pmbp, pmbe))
				pmbp->link = pmbe;

			spin_unlock(&pmbp->lock);
		}

		pmbp = pmbe;

		spin_unlock_irqrestore(&pmbe->lock, irqflags);
	}
}

static void __init pmb_merge(struct pmb_entry *head)
{
	unsigned long span, newsize;
	struct pmb_entry *tail;
	int i = 1, depth = 0;

	span = newsize = head->size;

	tail = head->link;
	while (tail) {
		span += tail->size;

		if (pmb_size_valid(span)) {
			newsize = span;
			depth = i;
		}

		/* This is the end of the line.. */
		if (!tail->link)
			break;

		tail = tail->link;
		i++;
	}

	/*
	 * The merged page size must be valid.
	 */
	if (!pmb_size_valid(newsize))
		return;

	head->flags &= ~PMB_SZ_MASK;
	head->flags |= pmb_size_to_flags(newsize);

	head->size = newsize;

	__pmb_unmap_entry(head->link, depth);
	__set_pmb_entry(head);
}

static void __init pmb_coalesce(void)
{
	unsigned long flags;
	int i;

	write_lock_irqsave(&pmb_rwlock, flags);

	for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
		struct pmb_entry *pmbe;

		if (!test_bit(i, pmb_map))
			continue;

		pmbe = &pmb_entry_list[i];

		/*
		 * We're only interested in compound mappings
		 */
		if (!pmbe->link)
			continue;

		/*
		 * Nothing to do if it already uses the largest possible
		 * page size.
		 */
		if (pmbe->size == SZ_512M)
			continue;

		pmb_merge(pmbe);
	}

	write_unlock_irqrestore(&pmb_rwlock, flags);
}

#ifdef CONFIG_UNCACHED_MAPPING
static void __init pmb_resize(void)
{
	int i;

	/*
	 * If the uncached mapping was constructed by the kernel, it will
	 * already be a reasonable size.
	 */
	if (uncached_size == SZ_16M)
		return;

	read_lock(&pmb_rwlock);

	for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
		struct pmb_entry *pmbe;
		unsigned long flags;

		if (!test_bit(i, pmb_map))
			continue;

		pmbe = &pmb_entry_list[i];

		if (pmbe->vpn != uncached_start)
			continue;

		/*
		 * Found it, now resize it.
		 */
		spin_lock_irqsave(&pmbe->lock, flags);

		pmbe->size = SZ_16M;
		pmbe->flags &= ~PMB_SZ_MASK;
		pmbe->flags |= pmb_size_to_flags(pmbe->size);

		uncached_resize(pmbe->size);

		__set_pmb_entry(pmbe);

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

	read_lock(&pmb_rwlock);
}
#endif

static int __init early_pmb(char *p)
{
	if (!p)
		return 0;

	if (strstr(p, "iomap"))
		pmb_iomapping_enabled = 1;

	return 0;
}
early_param("pmb", early_pmb);

void __init pmb_init(void)
{
	/* Synchronize software state */
	pmb_synchronize();

	/* Attempt to combine compound mappings */
	pmb_coalesce();

#ifdef CONFIG_UNCACHED_MAPPING
	/* Resize initial mappings, if necessary */
	pmb_resize();
#endif

	/* Log them */
	pmb_notify();

	writel_uncached(0, PMB_IRMCR);

	/* Flush out the TLB */
	local_flush_tlb_all();
	ctrl_barrier();
}

bool __in_29bit_mode(void)
{
        return (__raw_readl(PMB_PASCR) & PASCR_SE) == 0;
}

static int pmb_seq_show(struct seq_file *file, void *iter)
{
	int i;

	seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n"
			 "CB: Copy-Back, B: Buffered, UB: Unbuffered\n");
	seq_printf(file, "ety   vpn  ppn  size   flags\n");

	for (i = 0; i < NR_PMB_ENTRIES; i++) {
		unsigned long addr, data;
		unsigned int size;
		char *sz_str = NULL;

		addr = __raw_readl(mk_pmb_addr(i));
		data = __raw_readl(mk_pmb_data(i));

		size = data & PMB_SZ_MASK;
		sz_str = (size == PMB_SZ_16M)  ? " 16MB":
			 (size == PMB_SZ_64M)  ? " 64MB":
			 (size == PMB_SZ_128M) ? "128MB":
					         "512MB";

		/* 02: V 0x88 0x08 128MB C CB  B */
		seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n",
			   i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ',
			   (addr >> 24) & 0xff, (data >> 24) & 0xff,
			   sz_str, (data & PMB_C) ? 'C' : ' ',
			   (data & PMB_WT) ? "WT" : "CB",
			   (data & PMB_UB) ? "UB" : " B");
	}

	return 0;
}

static int pmb_debugfs_open(struct inode *inode, struct file *file)
{
	return single_open(file, pmb_seq_show, NULL);
}

static const struct file_operations pmb_debugfs_fops = {
	.owner		= THIS_MODULE,
	.open		= pmb_debugfs_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int __init pmb_debugfs_init(void)
{
	struct dentry *dentry;

	dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO,
				     sh_debugfs_root, NULL, &pmb_debugfs_fops);
	if (!dentry)
		return -ENOMEM;
	if (IS_ERR(dentry))
		return PTR_ERR(dentry);

	return 0;
}
subsys_initcall(pmb_debugfs_init);

#ifdef CONFIG_PM
static int pmb_sysdev_suspend(struct sys_device *dev, pm_message_t state)
{
	static pm_message_t prev_state;
	int i;

	/* Restore the PMB after a resume from hibernation */
	if (state.event == PM_EVENT_ON &&
	    prev_state.event == PM_EVENT_FREEZE) {
		struct pmb_entry *pmbe;

		read_lock(&pmb_rwlock);

		for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
			if (test_bit(i, pmb_map)) {
				pmbe = &pmb_entry_list[i];
				set_pmb_entry(pmbe);
			}
		}

		read_unlock(&pmb_rwlock);
	}

	prev_state = state;

	return 0;
}

static int pmb_sysdev_resume(struct sys_device *dev)
{
	return pmb_sysdev_suspend(dev, PMSG_ON);
}

static struct sysdev_driver pmb_sysdev_driver = {
	.suspend = pmb_sysdev_suspend,
	.resume = pmb_sysdev_resume,
};

static int __init pmb_sysdev_init(void)
{
	return sysdev_driver_register(&cpu_sysdev_class, &pmb_sysdev_driver);
}
subsys_initcall(pmb_sysdev_init);
#endif