1/* Common code for 32 and 64-bit NUMA */
2#include <linux/kernel.h>
3#include <linux/mm.h>
4#include <linux/string.h>
5#include <linux/init.h>
6#include <linux/bootmem.h>
7#include <linux/memblock.h>
8#include <linux/mmzone.h>
9#include <linux/ctype.h>
10#include <linux/module.h>
11#include <linux/nodemask.h>
12#include <linux/sched.h>
13#include <linux/topology.h>
14
15#include <asm/e820.h>
16#include <asm/proto.h>
17#include <asm/dma.h>
18#include <asm/acpi.h>
19#include <asm/amd_nb.h>
20
21#include "numa_internal.h"
22
23int __initdata numa_off;
24nodemask_t numa_nodes_parsed __initdata;
25
26struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
27EXPORT_SYMBOL(node_data);
28
29static struct numa_meminfo numa_meminfo
30#ifndef CONFIG_MEMORY_HOTPLUG
31__initdata
32#endif
33;
34
35static int numa_distance_cnt;
36static u8 *numa_distance;
37
38static __init int numa_setup(char *opt)
39{
40	if (!opt)
41		return -EINVAL;
42	if (!strncmp(opt, "off", 3))
43		numa_off = 1;
44#ifdef CONFIG_NUMA_EMU
45	if (!strncmp(opt, "fake=", 5))
46		numa_emu_cmdline(opt + 5);
47#endif
48#ifdef CONFIG_ACPI_NUMA
49	if (!strncmp(opt, "noacpi", 6))
50		acpi_numa = -1;
51#endif
52	return 0;
53}
54early_param("numa", numa_setup);
55
56/*
57 * apicid, cpu, node mappings
58 */
59s16 __apicid_to_node[MAX_LOCAL_APIC] = {
60	[0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
61};
62
63int numa_cpu_node(int cpu)
64{
65	int apicid = early_per_cpu(x86_cpu_to_apicid, cpu);
66
67	if (apicid != BAD_APICID)
68		return __apicid_to_node[apicid];
69	return NUMA_NO_NODE;
70}
71
72cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
73EXPORT_SYMBOL(node_to_cpumask_map);
74
75/*
76 * Map cpu index to node index
77 */
78DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
79EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
80
81void numa_set_node(int cpu, int node)
82{
83	int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
84
85	/* early setting, no percpu area yet */
86	if (cpu_to_node_map) {
87		cpu_to_node_map[cpu] = node;
88		return;
89	}
90
91#ifdef CONFIG_DEBUG_PER_CPU_MAPS
92	if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
93		printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
94		dump_stack();
95		return;
96	}
97#endif
98	per_cpu(x86_cpu_to_node_map, cpu) = node;
99
100	set_cpu_numa_node(cpu, node);
101}
102
103void numa_clear_node(int cpu)
104{
105	numa_set_node(cpu, NUMA_NO_NODE);
106}
107
108/*
109 * Allocate node_to_cpumask_map based on number of available nodes
110 * Requires node_possible_map to be valid.
111 *
112 * Note: cpumask_of_node() is not valid until after this is done.
113 * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
114 */
115void __init setup_node_to_cpumask_map(void)
116{
117	unsigned int node;
118
119	/* setup nr_node_ids if not done yet */
120	if (nr_node_ids == MAX_NUMNODES)
121		setup_nr_node_ids();
122
123	/* allocate the map */
124	for (node = 0; node < nr_node_ids; node++)
125		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
126
127	/* cpumask_of_node() will now work */
128	pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
129}
130
131static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
132				     struct numa_meminfo *mi)
133{
134	/* ignore zero length blks */
135	if (start == end)
136		return 0;
137
138	/* whine about and ignore invalid blks */
139	if (start > end || nid < 0 || nid >= MAX_NUMNODES) {
140		pr_warning("NUMA: Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
141			   nid, start, end - 1);
142		return 0;
143	}
144
145	if (mi->nr_blks >= NR_NODE_MEMBLKS) {
146		pr_err("NUMA: too many memblk ranges\n");
147		return -EINVAL;
148	}
149
150	mi->blk[mi->nr_blks].start = start;
151	mi->blk[mi->nr_blks].end = end;
152	mi->blk[mi->nr_blks].nid = nid;
153	mi->nr_blks++;
154	return 0;
155}
156
157/**
158 * numa_remove_memblk_from - Remove one numa_memblk from a numa_meminfo
159 * @idx: Index of memblk to remove
160 * @mi: numa_meminfo to remove memblk from
161 *
162 * Remove @idx'th numa_memblk from @mi by shifting @mi->blk[] and
163 * decrementing @mi->nr_blks.
164 */
165void __init numa_remove_memblk_from(int idx, struct numa_meminfo *mi)
166{
167	mi->nr_blks--;
168	memmove(&mi->blk[idx], &mi->blk[idx + 1],
169		(mi->nr_blks - idx) * sizeof(mi->blk[0]));
170}
171
172/**
173 * numa_add_memblk - Add one numa_memblk to numa_meminfo
174 * @nid: NUMA node ID of the new memblk
175 * @start: Start address of the new memblk
176 * @end: End address of the new memblk
177 *
178 * Add a new memblk to the default numa_meminfo.
179 *
180 * RETURNS:
181 * 0 on success, -errno on failure.
182 */
183int __init numa_add_memblk(int nid, u64 start, u64 end)
184{
185	return numa_add_memblk_to(nid, start, end, &numa_meminfo);
186}
187
188/* Allocate NODE_DATA for a node on the local memory */
189static void __init alloc_node_data(int nid)
190{
191	const size_t nd_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
192	u64 nd_pa;
193	void *nd;
194	int tnid;
195
196	/*
197	 * Allocate node data.  Try node-local memory and then any node.
198	 * Never allocate in DMA zone.
199	 */
200	nd_pa = memblock_alloc_nid(nd_size, SMP_CACHE_BYTES, nid);
201	if (!nd_pa) {
202		nd_pa = __memblock_alloc_base(nd_size, SMP_CACHE_BYTES,
203					      MEMBLOCK_ALLOC_ACCESSIBLE);
204		if (!nd_pa) {
205			pr_err("Cannot find %zu bytes in node %d\n",
206			       nd_size, nid);
207			return;
208		}
209	}
210	nd = __va(nd_pa);
211
212	/* report and initialize */
213	printk(KERN_INFO "NODE_DATA(%d) allocated [mem %#010Lx-%#010Lx]\n", nid,
214	       nd_pa, nd_pa + nd_size - 1);
215	tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
216	if (tnid != nid)
217		printk(KERN_INFO "    NODE_DATA(%d) on node %d\n", nid, tnid);
218
219	node_data[nid] = nd;
220	memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
221
222	node_set_online(nid);
223}
224
225/**
226 * numa_cleanup_meminfo - Cleanup a numa_meminfo
227 * @mi: numa_meminfo to clean up
228 *
229 * Sanitize @mi by merging and removing unncessary memblks.  Also check for
230 * conflicts and clear unused memblks.
231 *
232 * RETURNS:
233 * 0 on success, -errno on failure.
234 */
235int __init numa_cleanup_meminfo(struct numa_meminfo *mi)
236{
237	const u64 low = 0;
238	const u64 high = PFN_PHYS(max_pfn);
239	int i, j, k;
240
241	/* first, trim all entries */
242	for (i = 0; i < mi->nr_blks; i++) {
243		struct numa_memblk *bi = &mi->blk[i];
244
245		/* make sure all blocks are inside the limits */
246		bi->start = max(bi->start, low);
247		bi->end = min(bi->end, high);
248
249		/* and there's no empty block */
250		if (bi->start >= bi->end)
251			numa_remove_memblk_from(i--, mi);
252	}
253
254	/* merge neighboring / overlapping entries */
255	for (i = 0; i < mi->nr_blks; i++) {
256		struct numa_memblk *bi = &mi->blk[i];
257
258		for (j = i + 1; j < mi->nr_blks; j++) {
259			struct numa_memblk *bj = &mi->blk[j];
260			u64 start, end;
261
262			/*
263			 * See whether there are overlapping blocks.  Whine
264			 * about but allow overlaps of the same nid.  They
265			 * will be merged below.
266			 */
267			if (bi->end > bj->start && bi->start < bj->end) {
268				if (bi->nid != bj->nid) {
269					pr_err("NUMA: node %d [mem %#010Lx-%#010Lx] overlaps with node %d [mem %#010Lx-%#010Lx]\n",
270					       bi->nid, bi->start, bi->end - 1,
271					       bj->nid, bj->start, bj->end - 1);
272					return -EINVAL;
273				}
274				pr_warning("NUMA: Warning: node %d [mem %#010Lx-%#010Lx] overlaps with itself [mem %#010Lx-%#010Lx]\n",
275					   bi->nid, bi->start, bi->end - 1,
276					   bj->start, bj->end - 1);
277			}
278
279			/*
280			 * Join together blocks on the same node, holes
281			 * between which don't overlap with memory on other
282			 * nodes.
283			 */
284			if (bi->nid != bj->nid)
285				continue;
286			start = min(bi->start, bj->start);
287			end = max(bi->end, bj->end);
288			for (k = 0; k < mi->nr_blks; k++) {
289				struct numa_memblk *bk = &mi->blk[k];
290
291				if (bi->nid == bk->nid)
292					continue;
293				if (start < bk->end && end > bk->start)
294					break;
295			}
296			if (k < mi->nr_blks)
297				continue;
298			printk(KERN_INFO "NUMA: Node %d [mem %#010Lx-%#010Lx] + [mem %#010Lx-%#010Lx] -> [mem %#010Lx-%#010Lx]\n",
299			       bi->nid, bi->start, bi->end - 1, bj->start,
300			       bj->end - 1, start, end - 1);
301			bi->start = start;
302			bi->end = end;
303			numa_remove_memblk_from(j--, mi);
304		}
305	}
306
307	/* clear unused ones */
308	for (i = mi->nr_blks; i < ARRAY_SIZE(mi->blk); i++) {
309		mi->blk[i].start = mi->blk[i].end = 0;
310		mi->blk[i].nid = NUMA_NO_NODE;
311	}
312
313	return 0;
314}
315
316/*
317 * Set nodes, which have memory in @mi, in *@nodemask.
318 */
319static void __init numa_nodemask_from_meminfo(nodemask_t *nodemask,
320					      const struct numa_meminfo *mi)
321{
322	int i;
323
324	for (i = 0; i < ARRAY_SIZE(mi->blk); i++)
325		if (mi->blk[i].start != mi->blk[i].end &&
326		    mi->blk[i].nid != NUMA_NO_NODE)
327			node_set(mi->blk[i].nid, *nodemask);
328}
329
330/**
331 * numa_reset_distance - Reset NUMA distance table
332 *
333 * The current table is freed.  The next numa_set_distance() call will
334 * create a new one.
335 */
336void __init numa_reset_distance(void)
337{
338	size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]);
339
340	/* numa_distance could be 1LU marking allocation failure, test cnt */
341	if (numa_distance_cnt)
342		memblock_free(__pa(numa_distance), size);
343	numa_distance_cnt = 0;
344	numa_distance = NULL;	/* enable table creation */
345}
346
347static int __init numa_alloc_distance(void)
348{
349	nodemask_t nodes_parsed;
350	size_t size;
351	int i, j, cnt = 0;
352	u64 phys;
353
354	/* size the new table and allocate it */
355	nodes_parsed = numa_nodes_parsed;
356	numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
357
358	for_each_node_mask(i, nodes_parsed)
359		cnt = i;
360	cnt++;
361	size = cnt * cnt * sizeof(numa_distance[0]);
362
363	phys = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
364				      size, PAGE_SIZE);
365	if (!phys) {
366		pr_warning("NUMA: Warning: can't allocate distance table!\n");
367		/* don't retry until explicitly reset */
368		numa_distance = (void *)1LU;
369		return -ENOMEM;
370	}
371	memblock_reserve(phys, size);
372
373	numa_distance = __va(phys);
374	numa_distance_cnt = cnt;
375
376	/* fill with the default distances */
377	for (i = 0; i < cnt; i++)
378		for (j = 0; j < cnt; j++)
379			numa_distance[i * cnt + j] = i == j ?
380				LOCAL_DISTANCE : REMOTE_DISTANCE;
381	printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);
382
383	return 0;
384}
385
386/**
387 * numa_set_distance - Set NUMA distance from one NUMA to another
388 * @from: the 'from' node to set distance
389 * @to: the 'to'  node to set distance
390 * @distance: NUMA distance
391 *
392 * Set the distance from node @from to @to to @distance.  If distance table
393 * doesn't exist, one which is large enough to accommodate all the currently
394 * known nodes will be created.
395 *
396 * If such table cannot be allocated, a warning is printed and further
397 * calls are ignored until the distance table is reset with
398 * numa_reset_distance().
399 *
400 * If @from or @to is higher than the highest known node or lower than zero
401 * at the time of table creation or @distance doesn't make sense, the call
402 * is ignored.
403 * This is to allow simplification of specific NUMA config implementations.
404 */
405void __init numa_set_distance(int from, int to, int distance)
406{
407	if (!numa_distance && numa_alloc_distance() < 0)
408		return;
409
410	if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
411			from < 0 || to < 0) {
412		pr_warn_once("NUMA: Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
413			    from, to, distance);
414		return;
415	}
416
417	if ((u8)distance != distance ||
418	    (from == to && distance != LOCAL_DISTANCE)) {
419		pr_warn_once("NUMA: Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
420			     from, to, distance);
421		return;
422	}
423
424	numa_distance[from * numa_distance_cnt + to] = distance;
425}
426
427int __node_distance(int from, int to)
428{
429	if (from >= numa_distance_cnt || to >= numa_distance_cnt)
430		return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
431	return numa_distance[from * numa_distance_cnt + to];
432}
433EXPORT_SYMBOL(__node_distance);
434
435/*
436 * Sanity check to catch more bad NUMA configurations (they are amazingly
437 * common).  Make sure the nodes cover all memory.
438 */
439static bool __init numa_meminfo_cover_memory(const struct numa_meminfo *mi)
440{
441	u64 numaram, e820ram;
442	int i;
443
444	numaram = 0;
445	for (i = 0; i < mi->nr_blks; i++) {
446		u64 s = mi->blk[i].start >> PAGE_SHIFT;
447		u64 e = mi->blk[i].end >> PAGE_SHIFT;
448		numaram += e - s;
449		numaram -= __absent_pages_in_range(mi->blk[i].nid, s, e);
450		if ((s64)numaram < 0)
451			numaram = 0;
452	}
453
454	e820ram = max_pfn - absent_pages_in_range(0, max_pfn);
455
456	/* We seem to lose 3 pages somewhere. Allow 1M of slack. */
457	if ((s64)(e820ram - numaram) >= (1 << (20 - PAGE_SHIFT))) {
458		printk(KERN_ERR "NUMA: nodes only cover %LuMB of your %LuMB e820 RAM. Not used.\n",
459		       (numaram << PAGE_SHIFT) >> 20,
460		       (e820ram << PAGE_SHIFT) >> 20);
461		return false;
462	}
463	return true;
464}
465
466static void __init numa_clear_kernel_node_hotplug(void)
467{
468	int i, nid;
469	nodemask_t numa_kernel_nodes = NODE_MASK_NONE;
470	unsigned long start, end;
471	struct memblock_region *r;
472
473	/*
474	 * At this time, all memory regions reserved by memblock are
475	 * used by the kernel. Set the nid in memblock.reserved will
476	 * mark out all the nodes the kernel resides in.
477	 */
478	for (i = 0; i < numa_meminfo.nr_blks; i++) {
479		struct numa_memblk *mb = &numa_meminfo.blk[i];
480
481		memblock_set_node(mb->start, mb->end - mb->start,
482				  &memblock.reserved, mb->nid);
483	}
484
485	/*
486	 * Mark all kernel nodes.
487	 *
488	 * When booting with mem=nn[kMG] or in a kdump kernel, numa_meminfo
489	 * may not include all the memblock.reserved memory ranges because
490	 * trim_snb_memory() reserves specific pages for Sandy Bridge graphics.
491	 */
492	for_each_memblock(reserved, r)
493		if (r->nid != MAX_NUMNODES)
494			node_set(r->nid, numa_kernel_nodes);
495
496	/* Clear MEMBLOCK_HOTPLUG flag for memory in kernel nodes. */
497	for (i = 0; i < numa_meminfo.nr_blks; i++) {
498		nid = numa_meminfo.blk[i].nid;
499		if (!node_isset(nid, numa_kernel_nodes))
500			continue;
501
502		start = numa_meminfo.blk[i].start;
503		end = numa_meminfo.blk[i].end;
504
505		memblock_clear_hotplug(start, end - start);
506	}
507}
508
509static int __init numa_register_memblks(struct numa_meminfo *mi)
510{
511	unsigned long uninitialized_var(pfn_align);
512	int i, nid;
513
514	/* Account for nodes with cpus and no memory */
515	node_possible_map = numa_nodes_parsed;
516	numa_nodemask_from_meminfo(&node_possible_map, mi);
517	if (WARN_ON(nodes_empty(node_possible_map)))
518		return -EINVAL;
519
520	for (i = 0; i < mi->nr_blks; i++) {
521		struct numa_memblk *mb = &mi->blk[i];
522		memblock_set_node(mb->start, mb->end - mb->start,
523				  &memblock.memory, mb->nid);
524	}
525
526	/*
527	 * At very early time, the kernel have to use some memory such as
528	 * loading the kernel image. We cannot prevent this anyway. So any
529	 * node the kernel resides in should be un-hotpluggable.
530	 *
531	 * And when we come here, alloc node data won't fail.
532	 */
533	numa_clear_kernel_node_hotplug();
534
535	/*
536	 * If sections array is gonna be used for pfn -> nid mapping, check
537	 * whether its granularity is fine enough.
538	 */
539#ifdef NODE_NOT_IN_PAGE_FLAGS
540	pfn_align = node_map_pfn_alignment();
541	if (pfn_align && pfn_align < PAGES_PER_SECTION) {
542		printk(KERN_WARNING "Node alignment %LuMB < min %LuMB, rejecting NUMA config\n",
543		       PFN_PHYS(pfn_align) >> 20,
544		       PFN_PHYS(PAGES_PER_SECTION) >> 20);
545		return -EINVAL;
546	}
547#endif
548	if (!numa_meminfo_cover_memory(mi))
549		return -EINVAL;
550
551	/* Finally register nodes. */
552	for_each_node_mask(nid, node_possible_map) {
553		u64 start = PFN_PHYS(max_pfn);
554		u64 end = 0;
555
556		for (i = 0; i < mi->nr_blks; i++) {
557			if (nid != mi->blk[i].nid)
558				continue;
559			start = min(mi->blk[i].start, start);
560			end = max(mi->blk[i].end, end);
561		}
562
563		if (start >= end)
564			continue;
565
566		/*
567		 * Don't confuse VM with a node that doesn't have the
568		 * minimum amount of memory:
569		 */
570		if (end && (end - start) < NODE_MIN_SIZE)
571			continue;
572
573		alloc_node_data(nid);
574	}
575
576	/* Dump memblock with node info and return. */
577	memblock_dump_all();
578	return 0;
579}
580
581/*
582 * There are unfortunately some poorly designed mainboards around that
583 * only connect memory to a single CPU. This breaks the 1:1 cpu->node
584 * mapping. To avoid this fill in the mapping for all possible CPUs,
585 * as the number of CPUs is not known yet. We round robin the existing
586 * nodes.
587 */
588static void __init numa_init_array(void)
589{
590	int rr, i;
591
592	rr = first_node(node_online_map);
593	for (i = 0; i < nr_cpu_ids; i++) {
594		if (early_cpu_to_node(i) != NUMA_NO_NODE)
595			continue;
596		numa_set_node(i, rr);
597		rr = next_node(rr, node_online_map);
598		if (rr == MAX_NUMNODES)
599			rr = first_node(node_online_map);
600	}
601}
602
603static int __init numa_init(int (*init_func)(void))
604{
605	int i;
606	int ret;
607
608	for (i = 0; i < MAX_LOCAL_APIC; i++)
609		set_apicid_to_node(i, NUMA_NO_NODE);
610
611	nodes_clear(numa_nodes_parsed);
612	nodes_clear(node_possible_map);
613	nodes_clear(node_online_map);
614	memset(&numa_meminfo, 0, sizeof(numa_meminfo));
615	WARN_ON(memblock_set_node(0, ULLONG_MAX, &memblock.memory,
616				  MAX_NUMNODES));
617	WARN_ON(memblock_set_node(0, ULLONG_MAX, &memblock.reserved,
618				  MAX_NUMNODES));
619	/* In case that parsing SRAT failed. */
620	WARN_ON(memblock_clear_hotplug(0, ULLONG_MAX));
621	numa_reset_distance();
622
623	ret = init_func();
624	if (ret < 0)
625		return ret;
626
627	/*
628	 * We reset memblock back to the top-down direction
629	 * here because if we configured ACPI_NUMA, we have
630	 * parsed SRAT in init_func(). It is ok to have the
631	 * reset here even if we did't configure ACPI_NUMA
632	 * or acpi numa init fails and fallbacks to dummy
633	 * numa init.
634	 */
635	memblock_set_bottom_up(false);
636
637	ret = numa_cleanup_meminfo(&numa_meminfo);
638	if (ret < 0)
639		return ret;
640
641	numa_emulation(&numa_meminfo, numa_distance_cnt);
642
643	ret = numa_register_memblks(&numa_meminfo);
644	if (ret < 0)
645		return ret;
646
647	for (i = 0; i < nr_cpu_ids; i++) {
648		int nid = early_cpu_to_node(i);
649
650		if (nid == NUMA_NO_NODE)
651			continue;
652		if (!node_online(nid))
653			numa_clear_node(i);
654	}
655	numa_init_array();
656
657	return 0;
658}
659
660/**
661 * dummy_numa_init - Fallback dummy NUMA init
662 *
663 * Used if there's no underlying NUMA architecture, NUMA initialization
664 * fails, or NUMA is disabled on the command line.
665 *
666 * Must online at least one node and add memory blocks that cover all
667 * allowed memory.  This function must not fail.
668 */
669static int __init dummy_numa_init(void)
670{
671	printk(KERN_INFO "%s\n",
672	       numa_off ? "NUMA turned off" : "No NUMA configuration found");
673	printk(KERN_INFO "Faking a node at [mem %#018Lx-%#018Lx]\n",
674	       0LLU, PFN_PHYS(max_pfn) - 1);
675
676	node_set(0, numa_nodes_parsed);
677	numa_add_memblk(0, 0, PFN_PHYS(max_pfn));
678
679	return 0;
680}
681
682/**
683 * x86_numa_init - Initialize NUMA
684 *
685 * Try each configured NUMA initialization method until one succeeds.  The
686 * last fallback is dummy single node config encomapssing whole memory and
687 * never fails.
688 */
689void __init x86_numa_init(void)
690{
691	if (!numa_off) {
692#ifdef CONFIG_ACPI_NUMA
693		if (!numa_init(x86_acpi_numa_init))
694			return;
695#endif
696#ifdef CONFIG_AMD_NUMA
697		if (!numa_init(amd_numa_init))
698			return;
699#endif
700	}
701
702	numa_init(dummy_numa_init);
703}
704
705static __init int find_near_online_node(int node)
706{
707	int n, val;
708	int min_val = INT_MAX;
709	int best_node = -1;
710
711	for_each_online_node(n) {
712		val = node_distance(node, n);
713
714		if (val < min_val) {
715			min_val = val;
716			best_node = n;
717		}
718	}
719
720	return best_node;
721}
722
723/*
724 * Setup early cpu_to_node.
725 *
726 * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
727 * and apicid_to_node[] tables have valid entries for a CPU.
728 * This means we skip cpu_to_node[] initialisation for NUMA
729 * emulation and faking node case (when running a kernel compiled
730 * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
731 * is already initialized in a round robin manner at numa_init_array,
732 * prior to this call, and this initialization is good enough
733 * for the fake NUMA cases.
734 *
735 * Called before the per_cpu areas are setup.
736 */
737void __init init_cpu_to_node(void)
738{
739	int cpu;
740	u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
741
742	BUG_ON(cpu_to_apicid == NULL);
743
744	for_each_possible_cpu(cpu) {
745		int node = numa_cpu_node(cpu);
746
747		if (node == NUMA_NO_NODE)
748			continue;
749		if (!node_online(node))
750			node = find_near_online_node(node);
751		numa_set_node(cpu, node);
752	}
753}
754
755#ifndef CONFIG_DEBUG_PER_CPU_MAPS
756
757# ifndef CONFIG_NUMA_EMU
758void numa_add_cpu(int cpu)
759{
760	cpumask_set_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
761}
762
763void numa_remove_cpu(int cpu)
764{
765	cpumask_clear_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
766}
767# endif	/* !CONFIG_NUMA_EMU */
768
769#else	/* !CONFIG_DEBUG_PER_CPU_MAPS */
770
771int __cpu_to_node(int cpu)
772{
773	if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
774		printk(KERN_WARNING
775			"cpu_to_node(%d): usage too early!\n", cpu);
776		dump_stack();
777		return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
778	}
779	return per_cpu(x86_cpu_to_node_map, cpu);
780}
781EXPORT_SYMBOL(__cpu_to_node);
782
783/*
784 * Same function as cpu_to_node() but used if called before the
785 * per_cpu areas are setup.
786 */
787int early_cpu_to_node(int cpu)
788{
789	if (early_per_cpu_ptr(x86_cpu_to_node_map))
790		return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
791
792	if (!cpu_possible(cpu)) {
793		printk(KERN_WARNING
794			"early_cpu_to_node(%d): no per_cpu area!\n", cpu);
795		dump_stack();
796		return NUMA_NO_NODE;
797	}
798	return per_cpu(x86_cpu_to_node_map, cpu);
799}
800
801void debug_cpumask_set_cpu(int cpu, int node, bool enable)
802{
803	struct cpumask *mask;
804
805	if (node == NUMA_NO_NODE) {
806		/* early_cpu_to_node() already emits a warning and trace */
807		return;
808	}
809	mask = node_to_cpumask_map[node];
810	if (!mask) {
811		pr_err("node_to_cpumask_map[%i] NULL\n", node);
812		dump_stack();
813		return;
814	}
815
816	if (enable)
817		cpumask_set_cpu(cpu, mask);
818	else
819		cpumask_clear_cpu(cpu, mask);
820
821	printk(KERN_DEBUG "%s cpu %d node %d: mask now %*pbl\n",
822		enable ? "numa_add_cpu" : "numa_remove_cpu",
823		cpu, node, cpumask_pr_args(mask));
824	return;
825}
826
827# ifndef CONFIG_NUMA_EMU
828static void numa_set_cpumask(int cpu, bool enable)
829{
830	debug_cpumask_set_cpu(cpu, early_cpu_to_node(cpu), enable);
831}
832
833void numa_add_cpu(int cpu)
834{
835	numa_set_cpumask(cpu, true);
836}
837
838void numa_remove_cpu(int cpu)
839{
840	numa_set_cpumask(cpu, false);
841}
842# endif	/* !CONFIG_NUMA_EMU */
843
844/*
845 * Returns a pointer to the bitmask of CPUs on Node 'node'.
846 */
847const struct cpumask *cpumask_of_node(int node)
848{
849	if (node >= nr_node_ids) {
850		printk(KERN_WARNING
851			"cpumask_of_node(%d): node > nr_node_ids(%d)\n",
852			node, nr_node_ids);
853		dump_stack();
854		return cpu_none_mask;
855	}
856	if (node_to_cpumask_map[node] == NULL) {
857		printk(KERN_WARNING
858			"cpumask_of_node(%d): no node_to_cpumask_map!\n",
859			node);
860		dump_stack();
861		return cpu_online_mask;
862	}
863	return node_to_cpumask_map[node];
864}
865EXPORT_SYMBOL(cpumask_of_node);
866
867#endif	/* !CONFIG_DEBUG_PER_CPU_MAPS */
868
869#ifdef CONFIG_MEMORY_HOTPLUG
870int memory_add_physaddr_to_nid(u64 start)
871{
872	struct numa_meminfo *mi = &numa_meminfo;
873	int nid = mi->blk[0].nid;
874	int i;
875
876	for (i = 0; i < mi->nr_blks; i++)
877		if (mi->blk[i].start <= start && mi->blk[i].end > start)
878			nid = mi->blk[i].nid;
879	return nid;
880}
881EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
882#endif
883