aboutsummaryrefslogtreecommitdiffstats
path: root/mm/memblock.c
blob: d4382095f8bdcda1493feb7fc835a93432027f42 (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
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
/*
 * Procedures for maintaining information about logical memory blocks.
 *
 * Peter Bergner, IBM Corp.	June 2001.
 * Copyright (C) 2001 Peter Bergner.
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/poison.h>
#include <linux/pfn.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/memblock.h>

static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;

struct memblock memblock __initdata_memblock = {
	.memory.regions		= memblock_memory_init_regions,
	.memory.cnt		= 1,	/* empty dummy entry */
	.memory.max		= INIT_MEMBLOCK_REGIONS,

	.reserved.regions	= memblock_reserved_init_regions,
	.reserved.cnt		= 1,	/* empty dummy entry */
	.reserved.max		= INIT_MEMBLOCK_REGIONS,

	.current_limit		= MEMBLOCK_ALLOC_ANYWHERE,
};

int memblock_debug __initdata_memblock;
static int memblock_can_resize __initdata_memblock;
static int memblock_memory_in_slab __initdata_memblock = 0;
static int memblock_reserved_in_slab __initdata_memblock = 0;

/* inline so we don't get a warning when pr_debug is compiled out */
static inline const char *memblock_type_name(struct memblock_type *type)
{
	if (type == &memblock.memory)
		return "memory";
	else if (type == &memblock.reserved)
		return "reserved";
	else
		return "unknown";
}

/* adjust *@size so that (@base + *@size) doesn't overflow, return new size */
static inline phys_addr_t memblock_cap_size(phys_addr_t base, phys_addr_t *size)
{
	return *size = min(*size, (phys_addr_t)ULLONG_MAX - base);
}

/*
 * Address comparison utilities
 */
static unsigned long __init_memblock memblock_addrs_overlap(phys_addr_t base1, phys_addr_t size1,
				       phys_addr_t base2, phys_addr_t size2)
{
	return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
}

static long __init_memblock memblock_overlaps_region(struct memblock_type *type,
					phys_addr_t base, phys_addr_t size)
{
	unsigned long i;

	for (i = 0; i < type->cnt; i++) {
		phys_addr_t rgnbase = type->regions[i].base;
		phys_addr_t rgnsize = type->regions[i].size;
		if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
			break;
	}

	return (i < type->cnt) ? i : -1;
}

/**
 * memblock_find_in_range_node - find free area in given range and node
 * @start: start of candidate range
 * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
 * @size: size of free area to find
 * @align: alignment of free area to find
 * @nid: nid of the free area to find, %MAX_NUMNODES for any node
 *
 * Find @size free area aligned to @align in the specified range and node.
 *
 * RETURNS:
 * Found address on success, %0 on failure.
 */
phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
					phys_addr_t end, phys_addr_t size,
					phys_addr_t align, int nid)
{
	phys_addr_t this_start, this_end, cand;
	u64 i;

	/* pump up @end */
	if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
		end = memblock.current_limit;

	/* avoid allocating the first page */
	start = max_t(phys_addr_t, start, PAGE_SIZE);
	end = max(start, end);

	for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) {
		this_start = clamp(this_start, start, end);
		this_end = clamp(this_end, start, end);

		if (this_end < size)
			continue;

		cand = round_down(this_end - size, align);
		if (cand >= this_start)
			return cand;
	}
	return 0;
}

/**
 * memblock_find_in_range - find free area in given range
 * @start: start of candidate range
 * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
 * @size: size of free area to find
 * @align: alignment of free area to find
 *
 * Find @size free area aligned to @align in the specified range.
 *
 * RETURNS:
 * Found address on success, %0 on failure.
 */
phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
					phys_addr_t end, phys_addr_t size,
					phys_addr_t align)
{
	return memblock_find_in_range_node(start, end, size, align,
					   MAX_NUMNODES);
}

/*
 * Free memblock.reserved.regions
 */
int __init_memblock memblock_free_reserved_regions(void)
{
	if (memblock.reserved.regions == memblock_reserved_init_regions)
		return 0;

	return memblock_free(__pa(memblock.reserved.regions),
		 sizeof(struct memblock_region) * memblock.reserved.max);
}

/*
 * Reserve memblock.reserved.regions
 */
int __init_memblock memblock_reserve_reserved_regions(void)
{
	if (memblock.reserved.regions == memblock_reserved_init_regions)
		return 0;

	return memblock_reserve(__pa(memblock.reserved.regions),
		 sizeof(struct memblock_region) * memblock.reserved.max);
}

static void __init_memblock memblock_remove_region(struct memblock_type *type, unsigned long r)
{
	type->total_size -= type->regions[r].size;
	memmove(&type->regions[r], &type->regions[r + 1],
		(type->cnt - (r + 1)) * sizeof(type->regions[r]));
	type->cnt--;

	/* Special case for empty arrays */
	if (type->cnt == 0) {
		WARN_ON(type->total_size != 0);
		type->cnt = 1;
		type->regions[0].base = 0;
		type->regions[0].size = 0;
		memblock_set_region_node(&type->regions[0], MAX_NUMNODES);
	}
}

/**
 * memblock_double_array - double the size of the memblock regions array
 * @type: memblock type of the regions array being doubled
 * @new_area_start: starting address of memory range to avoid overlap with
 * @new_area_size: size of memory range to avoid overlap with
 *
 * Double the size of the @type regions array. If memblock is being used to
 * allocate memory for a new reserved regions array and there is a previously
 * allocated memory range [@new_area_start,@new_area_start+@new_area_size]
 * waiting to be reserved, ensure the memory used by the new array does
 * not overlap.
 *
 * RETURNS:
 * 0 on success, -1 on failure.
 */
static int __init_memblock memblock_double_array(struct memblock_type *type,
						phys_addr_t new_area_start,
						phys_addr_t new_area_size)
{
	struct memblock_region *new_array, *old_array;
	phys_addr_t old_size, new_size, addr;
	int use_slab = slab_is_available();
	int *in_slab;

	/* We don't allow resizing until we know about the reserved regions
	 * of memory that aren't suitable for allocation
	 */
	if (!memblock_can_resize)
		return -1;

	/* Calculate new doubled size */
	old_size = type->max * sizeof(struct memblock_region);
	new_size = old_size << 1;

	/* Retrieve the slab flag */
	if (type == &memblock.memory)
		in_slab = &memblock_memory_in_slab;
	else
		in_slab = &memblock_reserved_in_slab;

	/* Try to find some space for it.
	 *
	 * WARNING: We assume that either slab_is_available() and we use it or
	 * we use MEMBLOCK for allocations. That means that this is unsafe to use
	 * when bootmem is currently active (unless bootmem itself is implemented
	 * on top of MEMBLOCK which isn't the case yet)
	 *
	 * This should however not be an issue for now, as we currently only
	 * call into MEMBLOCK while it's still active, or much later when slab is
	 * active for memory hotplug operations
	 */
	if (use_slab) {
		new_array = kmalloc(new_size, GFP_KERNEL);
		addr = new_array ? __pa(new_array) : 0;
	} else {
		/* only exclude range when trying to double reserved.regions */
		if (type != &memblock.reserved)
			new_area_start = new_area_size = 0;

		addr = memblock_find_in_range(new_area_start + new_area_size,
						memblock.current_limit,
						new_size, sizeof(phys_addr_t));
		if (!addr && new_area_size)
			addr = memblock_find_in_range(0,
					min(new_area_start, memblock.current_limit),
					new_size, sizeof(phys_addr_t));

		new_array = addr ? __va(addr) : 0;
	}
	if (!addr) {
		pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
		       memblock_type_name(type), type->max, type->max * 2);
		return -1;
	}

	memblock_dbg("memblock: %s array is doubled to %ld at [%#010llx-%#010llx]",
		 memblock_type_name(type), type->max * 2, (u64)addr, (u64)addr + new_size - 1);

	/* Found space, we now need to move the array over before
	 * we add the reserved region since it may be our reserved
	 * array itself that is full.
	 */
	memcpy(new_array, type->regions, old_size);
	memset(new_array + type->max, 0, old_size);
	old_array = type->regions;
	type->regions = new_array;
	type->max <<= 1;

	/* Free old array. We needn't free it if the array is the
	 * static one
	 */
	if (*in_slab)
		kfree(old_array);
	else if (old_array != memblock_memory_init_regions &&
		 old_array != memblock_reserved_init_regions)
		memblock_free(__pa(old_array), old_size);

	/* Reserve the new array if that comes from the memblock.
	 * Otherwise, we needn't do it
	 */
	if (!use_slab)
		BUG_ON(memblock_reserve(addr, new_size));

	/* Update slab flag */
	*in_slab = use_slab;

	return 0;
}

/**
 * memblock_merge_regions - merge neighboring compatible regions
 * @type: memblock type to scan
 *
 * Scan @type and merge neighboring compatible regions.
 */
static void __init_memblock memblock_merge_regions(struct memblock_type *type)
{
	int i = 0;

	/* cnt never goes below 1 */
	while (i < type->cnt - 1) {
		struct memblock_region *this = &type->regions[i];
		struct memblock_region *next = &type->regions[i + 1];

		if (this->base + this->size != next->base ||
		    memblock_get_region_node(this) !=
		    memblock_get_region_node(next)) {
			BUG_ON(this->base + this->size > next->base);
			i++;
			continue;
		}

		this->size += next->size;
		memmove(next, next + 1, (type->cnt - (i + 1)) * sizeof(*next));
		type->cnt--;
	}
}

/**
 * memblock_insert_region - insert new memblock region
 * @type: memblock type to insert into
 * @idx: index for the insertion point
 * @base: base address of the new region
 * @size: size of the new region
 *
 * Insert new memblock region [@base,@base+@size) into @type at @idx.
 * @type must already have extra room to accomodate the new region.
 */
static void __init_memblock memblock_insert_region(struct memblock_type *type,
						   int idx, phys_addr_t base,
						   phys_addr_t size, int nid)
{
	struct memblock_region *rgn = &type->regions[idx];

	BUG_ON(type->cnt >= type->max);
	memmove(rgn + 1, rgn, (type->cnt - idx) * sizeof(*rgn));
	rgn->base = base;
	rgn->size = size;
	memblock_set_region_node(rgn, nid);
	type->cnt++;
	type->total_size += size;
}

/**
 * memblock_add_region - add new memblock region
 * @type: memblock type to add new region into
 * @base: base address of the new region
 * @size: size of the new region
 * @nid: nid of the new region
 *
 * Add new memblock region [@base,@base+@size) into @type.  The new region
 * is allowed to overlap with existing ones - overlaps don't affect already
 * existing regions.  @type is guaranteed to be minimal (all neighbouring
 * compatible regions are merged) after the addition.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
static int __init_memblock memblock_add_region(struct memblock_type *type,
				phys_addr_t base, phys_addr_t size, int nid)
{
	bool insert = false;
	phys_addr_t obase = base;
	phys_addr_t end = base + memblock_cap_size(base, &size);
	int i, nr_new;

	if (!size)
		return 0;

	/* special case for empty array */
	if (type->regions[0].size == 0) {
		WARN_ON(type->cnt != 1 || type->total_size);
		type->regions[0].base = base;
		type->regions[0].size = size;
		memblock_set_region_node(&type->regions[0], nid);
		type->total_size = size;
		return 0;
	}
repeat:
	/*
	 * The following is executed twice.  Once with %false @insert and
	 * then with %true.  The first counts the number of regions needed
	 * to accomodate the new area.  The second actually inserts them.
	 */
	base = obase;
	nr_new = 0;

	for (i = 0; i < type->cnt; i++) {
		struct memblock_region *rgn = &type->regions[i];
		phys_addr_t rbase = rgn->base;
		phys_addr_t rend = rbase + rgn->size;

		if (rbase >= end)
			break;
		if (rend <= base)
			continue;
		/*
		 * @rgn overlaps.  If it separates the lower part of new
		 * area, insert that portion.
		 */
		if (rbase > base) {
			nr_new++;
			if (insert)
				memblock_insert_region(type, i++, base,
						       rbase - base, nid);
		}
		/* area below @rend is dealt with, forget about it */
		base = min(rend, end);
	}

	/* insert the remaining portion */
	if (base < end) {
		nr_new++;
		if (insert)
			memblock_insert_region(type, i, base, end - base, nid);
	}

	/*
	 * If this was the first round, resize array and repeat for actual
	 * insertions; otherwise, merge and return.
	 */
	if (!insert) {
		while (type->cnt + nr_new > type->max)
			if (memblock_double_array(type, obase, size) < 0)
				return -ENOMEM;
		insert = true;
		goto repeat;
	} else {
		memblock_merge_regions(type);
		return 0;
	}
}

int __init_memblock memblock_add_node(phys_addr_t base, phys_addr_t size,
				       int nid)
{
	return memblock_add_region(&memblock.memory, base, size, nid);
}

int __init_memblock memblock_add(phys_addr_t base, phys_addr_t size)
{
	return memblock_add_region(&memblock.memory, base, size, MAX_NUMNODES);
}

/**
 * memblock_isolate_range - isolate given range into disjoint memblocks
 * @type: memblock type to isolate range for
 * @base: base of range to isolate
 * @size: size of range to isolate
 * @start_rgn: out parameter for the start of isolated region
 * @end_rgn: out parameter for the end of isolated region
 *
 * Walk @type and ensure that regions don't cross the boundaries defined by
 * [@base,@base+@size).  Crossing regions are split at the boundaries,
 * which may create at most two more regions.  The index of the first
 * region inside the range is returned in *@start_rgn and end in *@end_rgn.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
static int __init_memblock memblock_isolate_range(struct memblock_type *type,
					phys_addr_t base, phys_addr_t size,
					int *start_rgn, int *end_rgn)
{
	phys_addr_t end = base + memblock_cap_size(base, &size);
	int i;

	*start_rgn = *end_rgn = 0;

	if (!size)
		return 0;

	/* we'll create at most two more regions */
	while (type->cnt + 2 > type->max)
		if (memblock_double_array(type, base, size) < 0)
			return -ENOMEM;

	for (i = 0; i < type->cnt; i++) {
		struct memblock_region *rgn = &type->regions[i];
		phys_addr_t rbase = rgn->base;
		phys_addr_t rend = rbase + rgn->size;

		if (rbase >= end)
			break;
		if (rend <= base)
			continue;

		if (rbase < base) {
			/*
			 * @rgn intersects from below.  Split and continue
			 * to process the next region - the new top half.
			 */
			rgn->base = base;
			rgn->size -= base - rbase;
			type->total_size -= base - rbase;
			memblock_insert_region(type, i, rbase, base - rbase,
					       memblock_get_region_node(rgn));
		} else if (rend > end) {
			/*
			 * @rgn intersects from above.  Split and redo the
			 * current region - the new bottom half.
			 */
			rgn->base = end;
			rgn->size -= end - rbase;
			type->total_size -= end - rbase;
			memblock_insert_region(type, i--, rbase, end - rbase,
					       memblock_get_region_node(rgn));
		} else {
			/* @rgn is fully contained, record it */
			if (!*end_rgn)
				*start_rgn = i;
			*end_rgn = i + 1;
		}
	}

	return 0;
}

static int __init_memblock __memblock_remove(struct memblock_type *type,
					     phys_addr_t base, phys_addr_t size)
{
	int start_rgn, end_rgn;
	int i, ret;

	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
	if (ret)
		return ret;

	for (i = end_rgn - 1; i >= start_rgn; i--)
		memblock_remove_region(type, i);
	return 0;
}

int __init_memblock memblock_remove(phys_addr_t base, phys_addr_t size)
{
	return __memblock_remove(&memblock.memory, base, size);
}

int __init_memblock memblock_free(phys_addr_t base, phys_addr_t size)
{
	memblock_dbg("   memblock_free: [%#016llx-%#016llx] %pF\n",
		     (unsigned long long)base,
		     (unsigned long long)base + size,
		     (void *)_RET_IP_);

	return __memblock_remove(&memblock.reserved, base, size);
}

int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
{
	struct memblock_type *_rgn = &memblock.reserved;

	memblock_dbg("memblock_reserve: [%#016llx-%#016llx] %pF\n",
		     (unsigned long long)base,
		     (unsigned long long)base + size,
		     (void *)_RET_IP_);

	return memblock_add_region(_rgn, base, size, MAX_NUMNODES);
}

/**
 * __next_free_mem_range - next function for for_each_free_mem_range()
 * @idx: pointer to u64 loop variable
 * @nid: nid: node selector, %MAX_NUMNODES for all nodes
 * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
 * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
 * @out_nid: ptr to int for nid of the range, can be %NULL
 *
 * Find the first free area from *@idx which matches @nid, fill the out
 * parameters, and update *@idx for the next iteration.  The lower 32bit of
 * *@idx contains index into memory region and the upper 32bit indexes the
 * areas before each reserved region.  For example, if reserved regions
 * look like the following,
 *
 *	0:[0-16), 1:[32-48), 2:[128-130)
 *
 * The upper 32bit indexes the following regions.
 *
 *	0:[0-0), 1:[16-32), 2:[48-128), 3:[130-MAX)
 *
 * As both region arrays are sorted, the function advances the two indices
 * in lockstep and returns each intersection.
 */
void __init_memblock __next_free_mem_range(u64 *idx, int nid,
					   phys_addr_t *out_start,
					   phys_addr_t *out_end, int *out_nid)
{
	struct memblock_type *mem = &memblock.memory;
	struct memblock_type *rsv = &memblock.reserved;
	int mi = *idx & 0xffffffff;
	int ri = *idx >> 32;

	for ( ; mi < mem->cnt; mi++) {
		struct memblock_region *m = &mem->regions[mi];
		phys_addr_t m_start = m->base;
		phys_addr_t m_end = m->base + m->size;

		/* only memory regions are associated with nodes, check it */
		if (nid != MAX_NUMNODES && nid != memblock_get_region_node(m))
			continue;

		/* scan areas before each reservation for intersection */
		for ( ; ri < rsv->cnt + 1; ri++) {
			struct memblock_region *r = &rsv->regions[ri];
			phys_addr_t r_start = ri ? r[-1].base + r[-1].size : 0;
			phys_addr_t r_end = ri < rsv->cnt ? r->base : ULLONG_MAX;

			/* if ri advanced past mi, break out to advance mi */
			if (r_start >= m_end)
				break;
			/* if the two regions intersect, we're done */
			if (m_start < r_end) {
				if (out_start)
					*out_start = max(m_start, r_start);
				if (out_end)
					*out_end = min(m_end, r_end);
				if (out_nid)
					*out_nid = memblock_get_region_node(m);
				/*
				 * The region which ends first is advanced
				 * for the next iteration.
				 */
				if (m_end <= r_end)
					mi++;
				else
					ri++;
				*idx = (u32)mi | (u64)ri << 32;
				return;
			}
		}
	}

	/* signal end of iteration */
	*idx = ULLONG_MAX;
}

/**
 * __next_free_mem_range_rev - next function for for_each_free_mem_range_reverse()
 * @idx: pointer to u64 loop variable
 * @nid: nid: node selector, %MAX_NUMNODES for all nodes
 * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
 * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
 * @out_nid: ptr to int for nid of the range, can be %NULL
 *
 * Reverse of __next_free_mem_range().
 */
void __init_memblock __next_free_mem_range_rev(u64 *idx, int nid,
					   phys_addr_t *out_start,
					   phys_addr_t *out_end, int *out_nid)
{
	struct memblock_type *mem = &memblock.memory;
	struct memblock_type *rsv = &memblock.reserved;
	int mi = *idx & 0xffffffff;
	int ri = *idx >> 32;

	if (*idx == (u64)ULLONG_MAX) {
		mi = mem->cnt - 1;
		ri = rsv->cnt;
	}

	for ( ; mi >= 0; mi--) {
		struct memblock_region *m = &mem->regions[mi];
		phys_addr_t m_start = m->base;
		phys_addr_t m_end = m->base + m->size;

		/* only memory regions are associated with nodes, check it */
		if (nid != MAX_NUMNODES && nid != memblock_get_region_node(m))
			continue;

		/* scan areas before each reservation for intersection */
		for ( ; ri >= 0; ri--) {
			struct memblock_region *r = &rsv->regions[ri];
			phys_addr_t r_start = ri ? r[-1].base + r[-1].size : 0;
			phys_addr_t r_end = ri < rsv->cnt ? r->base : ULLONG_MAX;

			/* if ri advanced past mi, break out to advance mi */
			if (r_end <= m_start)
				break;
			/* if the two regions intersect, we're done */
			if (m_end > r_start) {
				if (out_start)
					*out_start = max(m_start, r_start);
				if (out_end)
					*out_end = min(m_end, r_end);
				if (out_nid)
					*out_nid = memblock_get_region_node(m);

				if (m_start >= r_start)
					mi--;
				else
					ri--;
				*idx = (u32)mi | (u64)ri << 32;
				return;
			}
		}
	}

	*idx = ULLONG_MAX;
}

#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
/*
 * Common iterator interface used to define for_each_mem_range().
 */
void __init_memblock __next_mem_pfn_range(int *idx, int nid,
				unsigned long *out_start_pfn,
				unsigned long *out_end_pfn, int *out_nid)
{
	struct memblock_type *type = &memblock.memory;
	struct memblock_region *r;

	while (++*idx < type->cnt) {
		r = &type->regions[*idx];

		if (PFN_UP(r->base) >= PFN_DOWN(r->base + r->size))
			continue;
		if (nid == MAX_NUMNODES || nid == r->nid)
			break;
	}
	if (*idx >= type->cnt) {
		*idx = -1;
		return;
	}

	if (out_start_pfn)
		*out_start_pfn = PFN_UP(r->base);
	if (out_end_pfn)
		*out_end_pfn = PFN_DOWN(r->base + r->size);
	if (out_nid)
		*out_nid = r->nid;
}

/**
 * memblock_set_node - set node ID on memblock regions
 * @base: base of area to set node ID for
 * @size: size of area to set node ID for
 * @nid: node ID to set
 *
 * Set the nid of memblock memory regions in [@base,@base+@size) to @nid.
 * Regions which cross the area boundaries are split as necessary.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
				      int nid)
{
	struct memblock_type *type = &memblock.memory;
	int start_rgn, end_rgn;
	int i, ret;

	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
	if (ret)
		return ret;

	for (i = start_rgn; i < end_rgn; i++)
		type->regions[i].nid = nid;

	memblock_merge_regions(type);
	return 0;
}
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */

static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size,
					phys_addr_t align, phys_addr_t max_addr,
					int nid)
{
	phys_addr_t found;

	/* align @size to avoid excessive fragmentation on reserved array */
	size = round_up(size, align);

	found = memblock_find_in_range_node(0, max_addr, size, align, nid);
	if (found && !memblock_reserve(found, size))
		return found;

	return 0;
}

phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid)
{
	return memblock_alloc_base_nid(size, align, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
}

phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
{
	return memblock_alloc_base_nid(size, align, max_addr, MAX_NUMNODES);
}

phys_addr_t __init memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
{
	phys_addr_t alloc;

	alloc = __memblock_alloc_base(size, align, max_addr);

	if (alloc == 0)
		panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
		      (unsigned long long) size, (unsigned long long) max_addr);

	return alloc;
}

phys_addr_t __init memblock_alloc(phys_addr_t size, phys_addr_t align)
{
	return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
}

phys_addr_t __init memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
{
	phys_addr_t res = memblock_alloc_nid(size, align, nid);

	if (res)
		return res;
	return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
}


/*
 * Remaining API functions
 */

phys_addr_t __init memblock_phys_mem_size(void)
{
	return memblock.memory.total_size;
}

/* lowest address */
phys_addr_t __init_memblock memblock_start_of_DRAM(void)
{
	return memblock.memory.regions[0].base;
}

phys_addr_t __init_memblock memblock_end_of_DRAM(void)
{
	int idx = memblock.memory.cnt - 1;

	return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
}

void __init memblock_enforce_memory_limit(phys_addr_t limit)
{
	unsigned long i;
	phys_addr_t max_addr = (phys_addr_t)ULLONG_MAX;

	if (!limit)
		return;

	/* find out max address */
	for (i = 0; i < memblock.memory.cnt; i++) {
		struct memblock_region *r = &memblock.memory.regions[i];

		if (limit <= r->size) {
			max_addr = r->base + limit;
			break;
		}
		limit -= r->size;
	}

	/* truncate both memory and reserved regions */
	__memblock_remove(&memblock.memory, max_addr, (phys_addr_t)ULLONG_MAX);
	__memblock_remove(&memblock.reserved, max_addr, (phys_addr_t)ULLONG_MAX);
}

static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr)
{
	unsigned int left = 0, right = type->cnt;

	do {
		unsigned int mid = (right + left) / 2;

		if (addr < type->regions[mid].base)
			right = mid;
		else if (addr >= (type->regions[mid].base +
				  type->regions[mid].size))
			left = mid + 1;
		else
			return mid;
	} while (left < right);
	return -1;
}

int __init memblock_is_reserved(phys_addr_t addr)
{
	return memblock_search(&memblock.reserved, addr) != -1;
}

int __init_memblock memblock_is_memory(phys_addr_t addr)
{
	return memblock_search(&memblock.memory, addr) != -1;
}

/**
 * memblock_is_region_memory - check if a region is a subset of memory
 * @base: base of region to check
 * @size: size of region to check
 *
 * Check if the region [@base, @base+@size) is a subset of a memory block.
 *
 * RETURNS:
 * 0 if false, non-zero if true
 */
int __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size)
{
	int idx = memblock_search(&memblock.memory, base);
	phys_addr_t end = base + memblock_cap_size(base, &size);

	if (idx == -1)
		return 0;
	return memblock.memory.regions[idx].base <= base &&
		(memblock.memory.regions[idx].base +
		 memblock.memory.regions[idx].size) >= end;
}

/**
 * memblock_is_region_reserved - check if a region intersects reserved memory
 * @base: base of region to check
 * @size: size of region to check
 *
 * Check if the region [@base, @base+@size) intersects a reserved memory block.
 *
 * RETURNS:
 * 0 if false, non-zero if true
 */
int __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size)
{
	memblock_cap_size(base, &size);
	return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
}


void __init_memblock memblock_set_current_limit(phys_addr_t limit)
{
	memblock.current_limit = limit;
}

static void __init_memblock memblock_dump(struct memblock_type *type, char *name)
{
	unsigned long long base, size;
	int i;

	pr_info(" %s.cnt  = 0x%lx\n", name, type->cnt);

	for (i = 0; i < type->cnt; i++) {
		struct memblock_region *rgn = &type->regions[i];
		char nid_buf[32] = "";

		base = rgn->base;
		size = rgn->size;
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
		if (memblock_get_region_node(rgn) != MAX_NUMNODES)
			snprintf(nid_buf, sizeof(nid_buf), " on node %d",
				 memblock_get_region_node(rgn));
#endif
		pr_info(" %s[%#x]\t[%#016llx-%#016llx], %#llx bytes%s\n",
			name, i, base, base + size - 1, size, nid_buf);
	}
}

void __init_memblock __memblock_dump_all(void)
{
	pr_info("MEMBLOCK configuration:\n");
	pr_info(" memory size = %#llx reserved size = %#llx\n",
		(unsigned long long)memblock.memory.total_size,
		(unsigned long long)memblock.reserved.total_size);

	memblock_dump(&memblock.memory, "memory");
	memblock_dump(&memblock.reserved, "reserved");
}

void __init memblock_allow_resize(void)
{
	memblock_can_resize = 1;
}

static int __init early_memblock(char *p)
{
	if (p && strstr(p, "debug"))
		memblock_debug = 1;
	return 0;
}
early_param("memblock", early_memblock);

#if defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK)

static int memblock_debug_show(struct seq_file *m, void *private)
{
	struct memblock_type *type = m->private;
	struct memblock_region *reg;
	int i;

	for (i = 0; i < type->cnt; i++) {
		reg = &type->regions[i];
		seq_printf(m, "%4d: ", i);
		if (sizeof(phys_addr_t) == 4)
			seq_printf(m, "0x%08lx..0x%08lx\n",
				   (unsigned long)reg->base,
				   (unsigned long)(reg->base + reg->size - 1));
		else
			seq_printf(m, "0x%016llx..0x%016llx\n",
				   (unsigned long long)reg->base,
				   (unsigned long long)(reg->base + reg->size - 1));

	}
	return 0;
}

static int memblock_debug_open(struct inode *inode, struct file *file)
{
	return single_open(file, memblock_debug_show, inode->i_private);
}

static const struct file_operations memblock_debug_fops = {
	.open = memblock_debug_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};

static int __init memblock_init_debugfs(void)
{
	struct dentry *root = debugfs_create_dir("memblock", NULL);
	if (!root)
		return -ENXIO;
	debugfs_create_file("memory", S_IRUGO, root, &memblock.memory, &memblock_debug_fops);
	debugfs_create_file("reserved", S_IRUGO, root, &memblock.reserved, &memblock_debug_fops);

	return 0;
}
__initcall(memblock_init_debugfs);

#endif /* CONFIG_DEBUG_FS */