summaryrefslogtreecommitdiff
path: root/arch/x86/mm/numa_64.c
blob: 4fd3368adc8f0d521e057566bf09314129c53d0e (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
/*
 * Generic VM initialization for x86-64 NUMA setups.
 * Copyright 2002,2003 Andi Kleen, SuSE Labs.
 */
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/mmzone.h>
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/nodemask.h>
#include <linux/sched.h>
#include <linux/acpi.h>

#include <asm/e820.h>
#include <asm/proto.h>
#include <asm/dma.h>
#include <asm/numa.h>
#include <asm/acpi.h>
#include <asm/amd_nb.h>

struct numa_memblk {
	u64			start;
	u64			end;
	int			nid;
};

struct numa_meminfo {
	int			nr_blks;
	struct numa_memblk	blk[NR_NODE_MEMBLKS];
};

struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
EXPORT_SYMBOL(node_data);

nodemask_t cpu_nodes_parsed __initdata;
nodemask_t mem_nodes_parsed __initdata;

struct memnode memnode;

static unsigned long __initdata nodemap_addr;
static unsigned long __initdata nodemap_size;

static struct numa_meminfo numa_meminfo __initdata;

struct bootnode numa_nodes[MAX_NUMNODES] __initdata;

/*
 * Given a shift value, try to populate memnodemap[]
 * Returns :
 * 1 if OK
 * 0 if memnodmap[] too small (of shift too small)
 * -1 if node overlap or lost ram (shift too big)
 */
static int __init populate_memnodemap(const struct numa_meminfo *mi, int shift)
{
	unsigned long addr, end;
	int i, res = -1;

	memset(memnodemap, 0xff, sizeof(s16)*memnodemapsize);
	for (i = 0; i < mi->nr_blks; i++) {
		addr = mi->blk[i].start;
		end = mi->blk[i].end;
		if (addr >= end)
			continue;
		if ((end >> shift) >= memnodemapsize)
			return 0;
		do {
			if (memnodemap[addr >> shift] != NUMA_NO_NODE)
				return -1;
			memnodemap[addr >> shift] = mi->blk[i].nid;
			addr += (1UL << shift);
		} while (addr < end);
		res = 1;
	}
	return res;
}

static int __init allocate_cachealigned_memnodemap(void)
{
	unsigned long addr;

	memnodemap = memnode.embedded_map;
	if (memnodemapsize <= ARRAY_SIZE(memnode.embedded_map))
		return 0;

	addr = 0x8000;
	nodemap_size = roundup(sizeof(s16) * memnodemapsize, L1_CACHE_BYTES);
	nodemap_addr = memblock_find_in_range(addr, get_max_mapped(),
				      nodemap_size, L1_CACHE_BYTES);
	if (nodemap_addr == MEMBLOCK_ERROR) {
		printk(KERN_ERR
		       "NUMA: Unable to allocate Memory to Node hash map\n");
		nodemap_addr = nodemap_size = 0;
		return -1;
	}
	memnodemap = phys_to_virt(nodemap_addr);
	memblock_x86_reserve_range(nodemap_addr, nodemap_addr + nodemap_size, "MEMNODEMAP");

	printk(KERN_DEBUG "NUMA: Allocated memnodemap from %lx - %lx\n",
	       nodemap_addr, nodemap_addr + nodemap_size);
	return 0;
}

/*
 * The LSB of all start and end addresses in the node map is the value of the
 * maximum possible shift.
 */
static int __init extract_lsb_from_nodes(const struct numa_meminfo *mi)
{
	int i, nodes_used = 0;
	unsigned long start, end;
	unsigned long bitfield = 0, memtop = 0;

	for (i = 0; i < mi->nr_blks; i++) {
		start = mi->blk[i].start;
		end = mi->blk[i].end;
		if (start >= end)
			continue;
		bitfield |= start;
		nodes_used++;
		if (end > memtop)
			memtop = end;
	}
	if (nodes_used <= 1)
		i = 63;
	else
		i = find_first_bit(&bitfield, sizeof(unsigned long)*8);
	memnodemapsize = (memtop >> i)+1;
	return i;
}

static int __init compute_hash_shift(const struct numa_meminfo *mi)
{
	int shift;

	shift = extract_lsb_from_nodes(mi);
	if (allocate_cachealigned_memnodemap())
		return -1;
	printk(KERN_DEBUG "NUMA: Using %d for the hash shift.\n",
		shift);

	if (populate_memnodemap(mi, shift) != 1) {
		printk(KERN_INFO "Your memory is not aligned you need to "
		       "rebuild your kernel with a bigger NODEMAPSIZE "
		       "shift=%d\n", shift);
		return -1;
	}
	return shift;
}

int __meminit  __early_pfn_to_nid(unsigned long pfn)
{
	return phys_to_nid(pfn << PAGE_SHIFT);
}

static void * __init early_node_mem(int nodeid, unsigned long start,
				    unsigned long end, unsigned long size,
				    unsigned long align)
{
	unsigned long mem;

	/*
	 * put it on high as possible
	 * something will go with NODE_DATA
	 */
	if (start < (MAX_DMA_PFN<<PAGE_SHIFT))
		start = MAX_DMA_PFN<<PAGE_SHIFT;
	if (start < (MAX_DMA32_PFN<<PAGE_SHIFT) &&
	    end > (MAX_DMA32_PFN<<PAGE_SHIFT))
		start = MAX_DMA32_PFN<<PAGE_SHIFT;
	mem = memblock_x86_find_in_range_node(nodeid, start, end, size, align);
	if (mem != MEMBLOCK_ERROR)
		return __va(mem);

	/* extend the search scope */
	end = max_pfn_mapped << PAGE_SHIFT;
	start = MAX_DMA_PFN << PAGE_SHIFT;
	mem = memblock_find_in_range(start, end, size, align);
	if (mem != MEMBLOCK_ERROR)
		return __va(mem);

	printk(KERN_ERR "Cannot find %lu bytes in node %d\n",
		       size, nodeid);

	return NULL;
}

static __init int conflicting_memblks(unsigned long start, unsigned long end)
{
	struct numa_meminfo *mi = &numa_meminfo;
	int i;

	for (i = 0; i < mi->nr_blks; i++) {
		struct numa_memblk *blk = &mi->blk[i];

		if (blk->start == blk->end)
			continue;
		if (blk->end > start && blk->start < end)
			return blk->nid;
		if (blk->end == end && blk->start == start)
			return blk->nid;
	}
	return -1;
}

int __init numa_add_memblk(int nid, u64 start, u64 end)
{
	struct numa_meminfo *mi = &numa_meminfo;
	int i;

	i = conflicting_memblks(start, end);
	if (i == nid) {
		printk(KERN_WARNING "NUMA: Warning: node %d (%Lx-%Lx) overlaps with itself (%Lx-%Lx)\n",
		       nid, start, end, numa_nodes[i].start, numa_nodes[i].end);
	} else if (i >= 0) {
		printk(KERN_ERR "NUMA: node %d (%Lx-%Lx) overlaps with node %d (%Lx-%Lx)\n",
		       nid, start, end, i,
		       numa_nodes[i].start, numa_nodes[i].end);
		return -EINVAL;
	}

	mi->blk[mi->nr_blks].start = start;
	mi->blk[mi->nr_blks].end = end;
	mi->blk[mi->nr_blks].nid = nid;
	mi->nr_blks++;
	return 0;
}

static void __init numa_remove_memblk_from(int idx, struct numa_meminfo *mi)
{
	mi->nr_blks--;
	memmove(&mi->blk[idx], &mi->blk[idx + 1],
		(mi->nr_blks - idx) * sizeof(mi->blk[0]));
}

static __init void cutoff_node(int i, unsigned long start, unsigned long end)
{
	struct bootnode *nd = &numa_nodes[i];

	if (nd->start < start) {
		nd->start = start;
		if (nd->end < nd->start)
			nd->start = nd->end;
	}
	if (nd->end > end) {
		nd->end = end;
		if (nd->start > nd->end)
			nd->start = nd->end;
	}
}

/* Initialize bootmem allocator for a node */
void __init
setup_node_bootmem(int nodeid, unsigned long start, unsigned long end)
{
	unsigned long start_pfn, last_pfn, nodedata_phys;
	const int pgdat_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
	int nid;

	if (!end)
		return;

	/*
	 * Don't confuse VM with a node that doesn't have the
	 * minimum amount of memory:
	 */
	if (end && (end - start) < NODE_MIN_SIZE)
		return;

	start = roundup(start, ZONE_ALIGN);

	printk(KERN_INFO "Initmem setup node %d %016lx-%016lx\n", nodeid,
	       start, end);

	start_pfn = start >> PAGE_SHIFT;
	last_pfn = end >> PAGE_SHIFT;

	node_data[nodeid] = early_node_mem(nodeid, start, end, pgdat_size,
					   SMP_CACHE_BYTES);
	if (node_data[nodeid] == NULL)
		return;
	nodedata_phys = __pa(node_data[nodeid]);
	memblock_x86_reserve_range(nodedata_phys, nodedata_phys + pgdat_size, "NODE_DATA");
	printk(KERN_INFO "  NODE_DATA [%016lx - %016lx]\n", nodedata_phys,
		nodedata_phys + pgdat_size - 1);
	nid = phys_to_nid(nodedata_phys);
	if (nid != nodeid)
		printk(KERN_INFO "    NODE_DATA(%d) on node %d\n", nodeid, nid);

	memset(NODE_DATA(nodeid), 0, sizeof(pg_data_t));
	NODE_DATA(nodeid)->node_id = nodeid;
	NODE_DATA(nodeid)->node_start_pfn = start_pfn;
	NODE_DATA(nodeid)->node_spanned_pages = last_pfn - start_pfn;

	node_set_online(nodeid);
}

static int __init numa_cleanup_meminfo(struct numa_meminfo *mi)
{
	int i, j, k;

	for (i = 0; i < mi->nr_blks; i++) {
		struct numa_memblk *bi = &mi->blk[i];

		for (j = i + 1; j < mi->nr_blks; j++) {
			struct numa_memblk *bj = &mi->blk[j];
			unsigned long start, end;

			/*
			 * Join together blocks on the same node, holes
			 * between which don't overlap with memory on other
			 * nodes.
			 */
			if (bi->nid != bj->nid)
				continue;
			start = min(bi->start, bj->start);
			end = max(bi->end, bj->end);
			for (k = 0; k < mi->nr_blks; k++) {
				struct numa_memblk *bk = &mi->blk[k];

				if (bi->nid == bk->nid)
					continue;
				if (start < bk->end && end > bk->start)
					break;
			}
			if (k < mi->nr_blks)
				continue;
			printk(KERN_INFO "NUMA: Node %d [%Lx,%Lx) + [%Lx,%Lx) -> [%lx,%lx)\n",
			       bi->nid, bi->start, bi->end, bj->start, bj->end,
			       start, end);
			bi->start = start;
			bi->end = end;
			numa_remove_memblk_from(j--, mi);
		}
	}

	return 0;
}

/*
 * Sanity check to catch more bad NUMA configurations (they are amazingly
 * common).  Make sure the nodes cover all memory.
 */
static int __init nodes_cover_memory(const struct bootnode *nodes)
{
	unsigned long numaram, e820ram;
	int i;

	numaram = 0;
	for_each_node_mask(i, mem_nodes_parsed) {
		unsigned long s = nodes[i].start >> PAGE_SHIFT;
		unsigned long e = nodes[i].end >> PAGE_SHIFT;
		numaram += e - s;
		numaram -= __absent_pages_in_range(i, s, e);
		if ((long)numaram < 0)
			numaram = 0;
	}

	e820ram = max_pfn - (memblock_x86_hole_size(0,
					max_pfn << PAGE_SHIFT) >> PAGE_SHIFT);
	/* We seem to lose 3 pages somewhere. Allow 1M of slack. */
	if ((long)(e820ram - numaram) >= (1 << (20 - PAGE_SHIFT))) {
		printk(KERN_ERR "NUMA: nodes only cover %luMB of your %luMB e820 RAM. Not used.\n",
		       (numaram << PAGE_SHIFT) >> 20,
		       (e820ram << PAGE_SHIFT) >> 20);
		return 0;
	}
	return 1;
}

static int __init numa_register_memblks(struct numa_meminfo *mi)
{
	int i;

	/* Account for nodes with cpus and no memory */
	nodes_or(node_possible_map, mem_nodes_parsed, cpu_nodes_parsed);
	if (WARN_ON(nodes_empty(node_possible_map)))
		return -EINVAL;

	memnode_shift = compute_hash_shift(mi);
	if (memnode_shift < 0) {
		printk(KERN_ERR "NUMA: No NUMA node hash function found. Contact maintainer\n");
		return -EINVAL;
	}

	for (i = 0; i < mi->nr_blks; i++)
		memblock_x86_register_active_regions(mi->blk[i].nid,
					mi->blk[i].start >> PAGE_SHIFT,
					mi->blk[i].end >> PAGE_SHIFT);

	/* for out of order entries */
	sort_node_map();
	if (!nodes_cover_memory(numa_nodes))
		return -EINVAL;

	init_memory_mapping_high();

	/* Finally register nodes. */
	for_each_node_mask(i, node_possible_map)
		setup_node_bootmem(i, numa_nodes[i].start, numa_nodes[i].end);

	/*
	 * Try again in case setup_node_bootmem missed one due to missing
	 * bootmem.
	 */
	for_each_node_mask(i, node_possible_map)
		if (!node_online(i))
			setup_node_bootmem(i, numa_nodes[i].start,
					   numa_nodes[i].end);

	return 0;
}

#ifdef CONFIG_NUMA_EMU
/* Numa emulation */
static struct bootnode nodes[MAX_NUMNODES] __initdata;
static struct bootnode physnodes[MAX_NUMNODES] __cpuinitdata;
static char *cmdline __initdata;

void __init numa_emu_cmdline(char *str)
{
	cmdline = str;
}

static int __init setup_physnodes(unsigned long start, unsigned long end)
{
	int ret = 0;
	int i;

	memset(physnodes, 0, sizeof(physnodes));

	for_each_node_mask(i, mem_nodes_parsed) {
		physnodes[i].start = numa_nodes[i].start;
		physnodes[i].end = numa_nodes[i].end;
	}

	/*
	 * Basic sanity checking on the physical node map: there may be errors
	 * if the SRAT or AMD code incorrectly reported the topology or the mem=
	 * kernel parameter is used.
	 */
	for (i = 0; i < MAX_NUMNODES; i++) {
		if (physnodes[i].start == physnodes[i].end)
			continue;
		if (physnodes[i].start > end) {
			physnodes[i].end = physnodes[i].start;
			continue;
		}
		if (physnodes[i].end < start) {
			physnodes[i].start = physnodes[i].end;
			continue;
		}
		if (physnodes[i].start < start)
			physnodes[i].start = start;
		if (physnodes[i].end > end)
			physnodes[i].end = end;
		ret++;
	}

	/*
	 * If no physical topology was detected, a single node is faked to cover
	 * the entire address space.
	 */
	if (!ret) {
		physnodes[ret].start = start;
		physnodes[ret].end = end;
		ret = 1;
	}
	return ret;
}

static void __init fake_physnodes(int acpi, int amd, int nr_nodes)
{
	int i;

	BUG_ON(acpi && amd);
#ifdef CONFIG_ACPI_NUMA
	if (acpi)
		acpi_fake_nodes(nodes, nr_nodes);
#endif
#ifdef CONFIG_AMD_NUMA
	if (amd)
		amd_fake_nodes(nodes, nr_nodes);
#endif
	if (!acpi && !amd)
		for (i = 0; i < nr_cpu_ids; i++)
			numa_set_node(i, 0);
}

/*
 * Setups up nid to range from addr to addr + size.  If the end
 * boundary is greater than max_addr, then max_addr is used instead.
 * The return value is 0 if there is additional memory left for
 * allocation past addr and -1 otherwise.  addr is adjusted to be at
 * the end of the node.
 */
static int __init setup_node_range(int nid, u64 *addr, u64 size, u64 max_addr)
{
	int ret = 0;
	nodes[nid].start = *addr;
	*addr += size;
	if (*addr >= max_addr) {
		*addr = max_addr;
		ret = -1;
	}
	nodes[nid].end = *addr;
	node_set(nid, node_possible_map);
	printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n", nid,
	       nodes[nid].start, nodes[nid].end,
	       (nodes[nid].end - nodes[nid].start) >> 20);
	return ret;
}

/*
 * Sets up nr_nodes fake nodes interleaved over physical nodes ranging from addr
 * to max_addr.  The return value is the number of nodes allocated.
 */
static int __init split_nodes_interleave(u64 addr, u64 max_addr, int nr_nodes)
{
	nodemask_t physnode_mask = NODE_MASK_NONE;
	u64 size;
	int big;
	int ret = 0;
	int i;

	if (nr_nodes <= 0)
		return -1;
	if (nr_nodes > MAX_NUMNODES) {
		pr_info("numa=fake=%d too large, reducing to %d\n",
			nr_nodes, MAX_NUMNODES);
		nr_nodes = MAX_NUMNODES;
	}

	size = (max_addr - addr - memblock_x86_hole_size(addr, max_addr)) / nr_nodes;
	/*
	 * Calculate the number of big nodes that can be allocated as a result
	 * of consolidating the remainder.
	 */
	big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * nr_nodes) /
		FAKE_NODE_MIN_SIZE;

	size &= FAKE_NODE_MIN_HASH_MASK;
	if (!size) {
		pr_err("Not enough memory for each node.  "
			"NUMA emulation disabled.\n");
		return -1;
	}

	for (i = 0; i < MAX_NUMNODES; i++)
		if (physnodes[i].start != physnodes[i].end)
			node_set(i, physnode_mask);

	/*
	 * Continue to fill physical nodes with fake nodes until there is no
	 * memory left on any of them.
	 */
	while (nodes_weight(physnode_mask)) {
		for_each_node_mask(i, physnode_mask) {
			u64 end = physnodes[i].start + size;
			u64 dma32_end = PFN_PHYS(MAX_DMA32_PFN);

			if (ret < big)
				end += FAKE_NODE_MIN_SIZE;

			/*
			 * Continue to add memory to this fake node if its
			 * non-reserved memory is less than the per-node size.
			 */
			while (end - physnodes[i].start -
				memblock_x86_hole_size(physnodes[i].start, end) < size) {
				end += FAKE_NODE_MIN_SIZE;
				if (end > physnodes[i].end) {
					end = physnodes[i].end;
					break;
				}
			}

			/*
			 * If there won't be at least FAKE_NODE_MIN_SIZE of
			 * non-reserved memory in ZONE_DMA32 for the next node,
			 * this one must extend to the boundary.
			 */
			if (end < dma32_end && dma32_end - end -
			    memblock_x86_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE)
				end = dma32_end;

			/*
			 * If there won't be enough non-reserved memory for the
			 * next node, this one must extend to the end of the
			 * physical node.
			 */
			if (physnodes[i].end - end -
			    memblock_x86_hole_size(end, physnodes[i].end) < size)
				end = physnodes[i].end;

			/*
			 * Avoid allocating more nodes than requested, which can
			 * happen as a result of rounding down each node's size
			 * to FAKE_NODE_MIN_SIZE.
			 */
			if (nodes_weight(physnode_mask) + ret >= nr_nodes)
				end = physnodes[i].end;

			if (setup_node_range(ret++, &physnodes[i].start,
						end - physnodes[i].start,
						physnodes[i].end) < 0)
				node_clear(i, physnode_mask);
		}
	}
	return ret;
}

/*
 * Returns the end address of a node so that there is at least `size' amount of
 * non-reserved memory or `max_addr' is reached.
 */
static u64 __init find_end_of_node(u64 start, u64 max_addr, u64 size)
{
	u64 end = start + size;

	while (end - start - memblock_x86_hole_size(start, end) < size) {
		end += FAKE_NODE_MIN_SIZE;
		if (end > max_addr) {
			end = max_addr;
			break;
		}
	}
	return end;
}

/*
 * Sets up fake nodes of `size' interleaved over physical nodes ranging from
 * `addr' to `max_addr'.  The return value is the number of nodes allocated.
 */
static int __init split_nodes_size_interleave(u64 addr, u64 max_addr, u64 size)
{
	nodemask_t physnode_mask = NODE_MASK_NONE;
	u64 min_size;
	int ret = 0;
	int i;

	if (!size)
		return -1;
	/*
	 * The limit on emulated nodes is MAX_NUMNODES, so the size per node is
	 * increased accordingly if the requested size is too small.  This
	 * creates a uniform distribution of node sizes across the entire
	 * machine (but not necessarily over physical nodes).
	 */
	min_size = (max_addr - addr - memblock_x86_hole_size(addr, max_addr)) /
						MAX_NUMNODES;
	min_size = max(min_size, FAKE_NODE_MIN_SIZE);
	if ((min_size & FAKE_NODE_MIN_HASH_MASK) < min_size)
		min_size = (min_size + FAKE_NODE_MIN_SIZE) &
						FAKE_NODE_MIN_HASH_MASK;
	if (size < min_size) {
		pr_err("Fake node size %LuMB too small, increasing to %LuMB\n",
			size >> 20, min_size >> 20);
		size = min_size;
	}
	size &= FAKE_NODE_MIN_HASH_MASK;

	for (i = 0; i < MAX_NUMNODES; i++)
		if (physnodes[i].start != physnodes[i].end)
			node_set(i, physnode_mask);
	/*
	 * Fill physical nodes with fake nodes of size until there is no memory
	 * left on any of them.
	 */
	while (nodes_weight(physnode_mask)) {
		for_each_node_mask(i, physnode_mask) {
			u64 dma32_end = MAX_DMA32_PFN << PAGE_SHIFT;
			u64 end;

			end = find_end_of_node(physnodes[i].start,
						physnodes[i].end, size);
			/*
			 * If there won't be at least FAKE_NODE_MIN_SIZE of
			 * non-reserved memory in ZONE_DMA32 for the next node,
			 * this one must extend to the boundary.
			 */
			if (end < dma32_end && dma32_end - end -
			    memblock_x86_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE)
				end = dma32_end;

			/*
			 * If there won't be enough non-reserved memory for the
			 * next node, this one must extend to the end of the
			 * physical node.
			 */
			if (physnodes[i].end - end -
			    memblock_x86_hole_size(end, physnodes[i].end) < size)
				end = physnodes[i].end;

			/*
			 * Setup the fake node that will be allocated as bootmem
			 * later.  If setup_node_range() returns non-zero, there
			 * is no more memory available on this physical node.
			 */
			if (setup_node_range(ret++, &physnodes[i].start,
						end - physnodes[i].start,
						physnodes[i].end) < 0)
				node_clear(i, physnode_mask);
		}
	}
	return ret;
}

/*
 * Sets up the system RAM area from start_pfn to last_pfn according to the
 * numa=fake command-line option.
 */
static int __init numa_emulation(unsigned long start_pfn,
			unsigned long last_pfn, int acpi, int amd)
{
	static struct numa_meminfo ei __initdata;
	u64 addr = start_pfn << PAGE_SHIFT;
	u64 max_addr = last_pfn << PAGE_SHIFT;
	int num_nodes;
	int i;

	/*
	 * If the numa=fake command-line contains a 'M' or 'G', it represents
	 * the fixed node size.  Otherwise, if it is just a single number N,
	 * split the system RAM into N fake nodes.
	 */
	if (strchr(cmdline, 'M') || strchr(cmdline, 'G')) {
		u64 size;

		size = memparse(cmdline, &cmdline);
		num_nodes = split_nodes_size_interleave(addr, max_addr, size);
	} else {
		unsigned long n;

		n = simple_strtoul(cmdline, NULL, 0);
		num_nodes = split_nodes_interleave(addr, max_addr, n);
	}

	if (num_nodes < 0)
		return num_nodes;

	ei.nr_blks = num_nodes;
	for (i = 0; i < ei.nr_blks; i++) {
		ei.blk[i].start = nodes[i].start;
		ei.blk[i].end = nodes[i].end;
		ei.blk[i].nid = i;
	}

	memnode_shift = compute_hash_shift(&ei);
	if (memnode_shift < 0) {
		memnode_shift = 0;
		printk(KERN_ERR "No NUMA hash function found.  NUMA emulation "
		       "disabled.\n");
		return -1;
	}

	/*
	 * We need to vacate all active ranges that may have been registered for
	 * the e820 memory map.
	 */
	remove_all_active_ranges();
	for_each_node_mask(i, node_possible_map)
		memblock_x86_register_active_regions(i, nodes[i].start >> PAGE_SHIFT,
						nodes[i].end >> PAGE_SHIFT);
	init_memory_mapping_high();
	for_each_node_mask(i, node_possible_map)
		setup_node_bootmem(i, nodes[i].start, nodes[i].end);
	setup_physnodes(addr, max_addr);
	fake_physnodes(acpi, amd, num_nodes);
	numa_init_array();
	return 0;
}
#endif /* CONFIG_NUMA_EMU */

static int dummy_numa_init(void)
{
	printk(KERN_INFO "%s\n",
	       numa_off ? "NUMA turned off" : "No NUMA configuration found");
	printk(KERN_INFO "Faking a node at %016lx-%016lx\n",
	       0LU, max_pfn << PAGE_SHIFT);

	node_set(0, cpu_nodes_parsed);
	node_set(0, mem_nodes_parsed);
	numa_add_memblk(0, 0, (u64)max_pfn << PAGE_SHIFT);
	numa_nodes[0].start = 0;
	numa_nodes[0].end = (u64)max_pfn << PAGE_SHIFT;

	return 0;
}

void __init initmem_init(void)
{
	int (*numa_init[])(void) = { [2] = dummy_numa_init };
	int i, j;

	if (!numa_off) {
#ifdef CONFIG_ACPI_NUMA
		numa_init[0] = x86_acpi_numa_init;
#endif
#ifdef CONFIG_AMD_NUMA
		numa_init[1] = amd_numa_init;
#endif
	}

	for (i = 0; i < ARRAY_SIZE(numa_init); i++) {
		if (!numa_init[i])
			continue;

		for (j = 0; j < MAX_LOCAL_APIC; j++)
			set_apicid_to_node(j, NUMA_NO_NODE);

		nodes_clear(cpu_nodes_parsed);
		nodes_clear(mem_nodes_parsed);
		nodes_clear(node_possible_map);
		nodes_clear(node_online_map);
		memset(&numa_meminfo, 0, sizeof(numa_meminfo));
		memset(numa_nodes, 0, sizeof(numa_nodes));
		remove_all_active_ranges();

		if (numa_init[i]() < 0)
			continue;

		/* clean up the node list */
		for (j = 0; j < MAX_NUMNODES; j++)
			cutoff_node(j, 0, max_pfn << PAGE_SHIFT);

#ifdef CONFIG_NUMA_EMU
		setup_physnodes(0, max_pfn << PAGE_SHIFT);
		if (cmdline && !numa_emulation(0, max_pfn, i == 0, i == 1))
			return;
		setup_physnodes(0, max_pfn << PAGE_SHIFT);
		nodes_clear(node_possible_map);
		nodes_clear(node_online_map);
#endif
		if (numa_cleanup_meminfo(&numa_meminfo) < 0)
			continue;

		if (numa_register_memblks(&numa_meminfo) < 0)
			continue;

		for (j = 0; j < nr_cpu_ids; j++) {
			int nid = early_cpu_to_node(j);

			if (nid == NUMA_NO_NODE)
				continue;
			if (!node_online(nid))
				numa_clear_node(j);
		}
		numa_init_array();
		return;
	}
	BUG();
}

unsigned long __init numa_free_all_bootmem(void)
{
	unsigned long pages = 0;
	int i;

	for_each_online_node(i)
		pages += free_all_bootmem_node(NODE_DATA(i));

	pages += free_all_memory_core_early(MAX_NUMNODES);

	return pages;
}

int __cpuinit numa_cpu_node(int cpu)
{
	int apicid = early_per_cpu(x86_cpu_to_apicid, cpu);

	if (apicid != BAD_APICID)
		return __apicid_to_node[apicid];
	return NUMA_NO_NODE;
}

/*
 * UGLINESS AHEAD: Currently, CONFIG_NUMA_EMU is 64bit only and makes use
 * of 64bit specific data structures.  The distinction is artificial and
 * should be removed.  numa_{add|remove}_cpu() are implemented in numa.c
 * for both 32 and 64bit when CONFIG_NUMA_EMU is disabled but here when
 * enabled.
 *
 * NUMA emulation is planned to be made generic and the following and other
 * related code should be moved to numa.c.
 */
#ifdef CONFIG_NUMA_EMU
# ifndef CONFIG_DEBUG_PER_CPU_MAPS
void __cpuinit numa_add_cpu(int cpu)
{
	unsigned long addr;
	int physnid, nid;

	nid = numa_cpu_node(cpu);
	if (nid == NUMA_NO_NODE)
		nid = early_cpu_to_node(cpu);
	BUG_ON(nid == NUMA_NO_NODE || !node_online(nid));

	/*
	 * Use the starting address of the emulated node to find which physical
	 * node it is allocated on.
	 */
	addr = node_start_pfn(nid) << PAGE_SHIFT;
	for (physnid = 0; physnid < MAX_NUMNODES; physnid++)
		if (addr >= physnodes[physnid].start &&
		    addr < physnodes[physnid].end)
			break;

	/*
	 * Map the cpu to each emulated node that is allocated on the physical
	 * node of the cpu's apic id.
	 */
	for_each_online_node(nid) {
		addr = node_start_pfn(nid) << PAGE_SHIFT;
		if (addr >= physnodes[physnid].start &&
		    addr < physnodes[physnid].end)
			cpumask_set_cpu(cpu, node_to_cpumask_map[nid]);
	}
}

void __cpuinit numa_remove_cpu(int cpu)
{
	int i;

	for_each_online_node(i)
		cpumask_clear_cpu(cpu, node_to_cpumask_map[i]);
}
# else	/* !CONFIG_DEBUG_PER_CPU_MAPS */
static void __cpuinit numa_set_cpumask(int cpu, int enable)
{
	int node = early_cpu_to_node(cpu);
	struct cpumask *mask;
	int i;

	if (node == NUMA_NO_NODE) {
		/* early_cpu_to_node() already emits a warning and trace */
		return;
	}
	for_each_online_node(i) {
		unsigned long addr;

		addr = node_start_pfn(i) << PAGE_SHIFT;
		if (addr < physnodes[node].start ||
					addr >= physnodes[node].end)
			continue;
		mask = debug_cpumask_set_cpu(cpu, enable);
		if (!mask)
			return;

		if (enable)
			cpumask_set_cpu(cpu, mask);
		else
			cpumask_clear_cpu(cpu, mask);
	}
}

void __cpuinit numa_add_cpu(int cpu)
{
	numa_set_cpumask(cpu, 1);
}

void __cpuinit numa_remove_cpu(int cpu)
{
	numa_set_cpumask(cpu, 0);
}
# endif	/* !CONFIG_DEBUG_PER_CPU_MAPS */
#endif	/* CONFIG_NUMA_EMU */