xref: /linux/arch/x86/mm/numa.c (revision dbcedec3a31119d7594baacc743300d127c99c56)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Common code for 32 and 64-bit NUMA */
3 #include <linux/acpi.h>
4 #include <linux/kernel.h>
5 #include <linux/mm.h>
6 #include <linux/of.h>
7 #include <linux/string.h>
8 #include <linux/init.h>
9 #include <linux/memblock.h>
10 #include <linux/mmzone.h>
11 #include <linux/ctype.h>
12 #include <linux/nodemask.h>
13 #include <linux/sched.h>
14 #include <linux/topology.h>
15 #include <linux/sort.h>
16 
17 #include <asm/e820/api.h>
18 #include <asm/proto.h>
19 #include <asm/dma.h>
20 #include <asm/amd_nb.h>
21 
22 #include "numa_internal.h"
23 
24 int numa_off;
25 nodemask_t numa_nodes_parsed __initdata;
26 
27 struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
28 EXPORT_SYMBOL(node_data);
29 
30 static struct numa_meminfo numa_meminfo __initdata_or_meminfo;
31 static struct numa_meminfo numa_reserved_meminfo __initdata_or_meminfo;
32 
33 static int numa_distance_cnt;
34 static u8 *numa_distance;
35 
36 static __init int numa_setup(char *opt)
37 {
38 	if (!opt)
39 		return -EINVAL;
40 	if (!strncmp(opt, "off", 3))
41 		numa_off = 1;
42 	if (!strncmp(opt, "fake=", 5))
43 		return numa_emu_cmdline(opt + 5);
44 	if (!strncmp(opt, "noacpi", 6))
45 		disable_srat();
46 	if (!strncmp(opt, "nohmat", 6))
47 		disable_hmat();
48 	return 0;
49 }
50 early_param("numa", numa_setup);
51 
52 /*
53  * apicid, cpu, node mappings
54  */
55 s16 __apicid_to_node[MAX_LOCAL_APIC] = {
56 	[0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
57 };
58 
59 int numa_cpu_node(int cpu)
60 {
61 	u32 apicid = early_per_cpu(x86_cpu_to_apicid, cpu);
62 
63 	if (apicid != BAD_APICID)
64 		return __apicid_to_node[apicid];
65 	return NUMA_NO_NODE;
66 }
67 
68 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
69 EXPORT_SYMBOL(node_to_cpumask_map);
70 
71 /*
72  * Map cpu index to node index
73  */
74 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
75 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
76 
77 void numa_set_node(int cpu, int node)
78 {
79 	int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
80 
81 	/* early setting, no percpu area yet */
82 	if (cpu_to_node_map) {
83 		cpu_to_node_map[cpu] = node;
84 		return;
85 	}
86 
87 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
88 	if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
89 		printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
90 		dump_stack();
91 		return;
92 	}
93 #endif
94 	per_cpu(x86_cpu_to_node_map, cpu) = node;
95 
96 	set_cpu_numa_node(cpu, node);
97 }
98 
99 void numa_clear_node(int cpu)
100 {
101 	numa_set_node(cpu, NUMA_NO_NODE);
102 }
103 
104 /*
105  * Allocate node_to_cpumask_map based on number of available nodes
106  * Requires node_possible_map to be valid.
107  *
108  * Note: cpumask_of_node() is not valid until after this is done.
109  * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
110  */
111 void __init setup_node_to_cpumask_map(void)
112 {
113 	unsigned int node;
114 
115 	/* setup nr_node_ids if not done yet */
116 	if (nr_node_ids == MAX_NUMNODES)
117 		setup_nr_node_ids();
118 
119 	/* allocate the map */
120 	for (node = 0; node < nr_node_ids; node++)
121 		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
122 
123 	/* cpumask_of_node() will now work */
124 	pr_debug("Node to cpumask map for %u nodes\n", nr_node_ids);
125 }
126 
127 static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
128 				     struct numa_meminfo *mi)
129 {
130 	/* ignore zero length blks */
131 	if (start == end)
132 		return 0;
133 
134 	/* whine about and ignore invalid blks */
135 	if (start > end || nid < 0 || nid >= MAX_NUMNODES) {
136 		pr_warn("Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
137 			nid, start, end - 1);
138 		return 0;
139 	}
140 
141 	if (mi->nr_blks >= NR_NODE_MEMBLKS) {
142 		pr_err("too many memblk ranges\n");
143 		return -EINVAL;
144 	}
145 
146 	mi->blk[mi->nr_blks].start = start;
147 	mi->blk[mi->nr_blks].end = end;
148 	mi->blk[mi->nr_blks].nid = nid;
149 	mi->nr_blks++;
150 	return 0;
151 }
152 
153 /**
154  * numa_remove_memblk_from - Remove one numa_memblk from a numa_meminfo
155  * @idx: Index of memblk to remove
156  * @mi: numa_meminfo to remove memblk from
157  *
158  * Remove @idx'th numa_memblk from @mi by shifting @mi->blk[] and
159  * decrementing @mi->nr_blks.
160  */
161 void __init numa_remove_memblk_from(int idx, struct numa_meminfo *mi)
162 {
163 	mi->nr_blks--;
164 	memmove(&mi->blk[idx], &mi->blk[idx + 1],
165 		(mi->nr_blks - idx) * sizeof(mi->blk[0]));
166 }
167 
168 /**
169  * numa_move_tail_memblk - Move a numa_memblk from one numa_meminfo to another
170  * @dst: numa_meminfo to append block to
171  * @idx: Index of memblk to remove
172  * @src: numa_meminfo to remove memblk from
173  */
174 static void __init numa_move_tail_memblk(struct numa_meminfo *dst, int idx,
175 					 struct numa_meminfo *src)
176 {
177 	dst->blk[dst->nr_blks++] = src->blk[idx];
178 	numa_remove_memblk_from(idx, src);
179 }
180 
181 /**
182  * numa_add_memblk - Add one numa_memblk to numa_meminfo
183  * @nid: NUMA node ID of the new memblk
184  * @start: Start address of the new memblk
185  * @end: End address of the new memblk
186  *
187  * Add a new memblk to the default numa_meminfo.
188  *
189  * RETURNS:
190  * 0 on success, -errno on failure.
191  */
192 int __init numa_add_memblk(int nid, u64 start, u64 end)
193 {
194 	return numa_add_memblk_to(nid, start, end, &numa_meminfo);
195 }
196 
197 /* Allocate NODE_DATA for a node on the local memory */
198 static void __init alloc_node_data(int nid)
199 {
200 	const size_t nd_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
201 	u64 nd_pa;
202 	void *nd;
203 	int tnid;
204 
205 	/*
206 	 * Allocate node data.  Try node-local memory and then any node.
207 	 * Never allocate in DMA zone.
208 	 */
209 	nd_pa = memblock_phys_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
210 	if (!nd_pa) {
211 		pr_err("Cannot find %zu bytes in any node (initial node: %d)\n",
212 		       nd_size, nid);
213 		return;
214 	}
215 	nd = __va(nd_pa);
216 
217 	/* report and initialize */
218 	printk(KERN_INFO "NODE_DATA(%d) allocated [mem %#010Lx-%#010Lx]\n", nid,
219 	       nd_pa, nd_pa + nd_size - 1);
220 	tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
221 	if (tnid != nid)
222 		printk(KERN_INFO "    NODE_DATA(%d) on node %d\n", nid, tnid);
223 
224 	node_data[nid] = nd;
225 	memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
226 
227 	node_set_online(nid);
228 }
229 
230 /**
231  * numa_cleanup_meminfo - Cleanup a numa_meminfo
232  * @mi: numa_meminfo to clean up
233  *
234  * Sanitize @mi by merging and removing unnecessary memblks.  Also check for
235  * conflicts and clear unused memblks.
236  *
237  * RETURNS:
238  * 0 on success, -errno on failure.
239  */
240 int __init numa_cleanup_meminfo(struct numa_meminfo *mi)
241 {
242 	const u64 low = 0;
243 	const u64 high = PFN_PHYS(max_pfn);
244 	int i, j, k;
245 
246 	/* first, trim all entries */
247 	for (i = 0; i < mi->nr_blks; i++) {
248 		struct numa_memblk *bi = &mi->blk[i];
249 
250 		/* move / save reserved memory ranges */
251 		if (!memblock_overlaps_region(&memblock.memory,
252 					bi->start, bi->end - bi->start)) {
253 			numa_move_tail_memblk(&numa_reserved_meminfo, i--, mi);
254 			continue;
255 		}
256 
257 		/* make sure all non-reserved blocks are inside the limits */
258 		bi->start = max(bi->start, low);
259 
260 		/* preserve info for non-RAM areas above 'max_pfn': */
261 		if (bi->end > high) {
262 			numa_add_memblk_to(bi->nid, high, bi->end,
263 					   &numa_reserved_meminfo);
264 			bi->end = high;
265 		}
266 
267 		/* and there's no empty block */
268 		if (bi->start >= bi->end)
269 			numa_remove_memblk_from(i--, mi);
270 	}
271 
272 	/* merge neighboring / overlapping entries */
273 	for (i = 0; i < mi->nr_blks; i++) {
274 		struct numa_memblk *bi = &mi->blk[i];
275 
276 		for (j = i + 1; j < mi->nr_blks; j++) {
277 			struct numa_memblk *bj = &mi->blk[j];
278 			u64 start, end;
279 
280 			/*
281 			 * See whether there are overlapping blocks.  Whine
282 			 * about but allow overlaps of the same nid.  They
283 			 * will be merged below.
284 			 */
285 			if (bi->end > bj->start && bi->start < bj->end) {
286 				if (bi->nid != bj->nid) {
287 					pr_err("node %d [mem %#010Lx-%#010Lx] overlaps with node %d [mem %#010Lx-%#010Lx]\n",
288 					       bi->nid, bi->start, bi->end - 1,
289 					       bj->nid, bj->start, bj->end - 1);
290 					return -EINVAL;
291 				}
292 				pr_warn("Warning: node %d [mem %#010Lx-%#010Lx] overlaps with itself [mem %#010Lx-%#010Lx]\n",
293 					bi->nid, bi->start, bi->end - 1,
294 					bj->start, bj->end - 1);
295 			}
296 
297 			/*
298 			 * Join together blocks on the same node, holes
299 			 * between which don't overlap with memory on other
300 			 * nodes.
301 			 */
302 			if (bi->nid != bj->nid)
303 				continue;
304 			start = min(bi->start, bj->start);
305 			end = max(bi->end, bj->end);
306 			for (k = 0; k < mi->nr_blks; k++) {
307 				struct numa_memblk *bk = &mi->blk[k];
308 
309 				if (bi->nid == bk->nid)
310 					continue;
311 				if (start < bk->end && end > bk->start)
312 					break;
313 			}
314 			if (k < mi->nr_blks)
315 				continue;
316 			printk(KERN_INFO "NUMA: Node %d [mem %#010Lx-%#010Lx] + [mem %#010Lx-%#010Lx] -> [mem %#010Lx-%#010Lx]\n",
317 			       bi->nid, bi->start, bi->end - 1, bj->start,
318 			       bj->end - 1, start, end - 1);
319 			bi->start = start;
320 			bi->end = end;
321 			numa_remove_memblk_from(j--, mi);
322 		}
323 	}
324 
325 	/* clear unused ones */
326 	for (i = mi->nr_blks; i < ARRAY_SIZE(mi->blk); i++) {
327 		mi->blk[i].start = mi->blk[i].end = 0;
328 		mi->blk[i].nid = NUMA_NO_NODE;
329 	}
330 
331 	return 0;
332 }
333 
334 /*
335  * Set nodes, which have memory in @mi, in *@nodemask.
336  */
337 static void __init numa_nodemask_from_meminfo(nodemask_t *nodemask,
338 					      const struct numa_meminfo *mi)
339 {
340 	int i;
341 
342 	for (i = 0; i < ARRAY_SIZE(mi->blk); i++)
343 		if (mi->blk[i].start != mi->blk[i].end &&
344 		    mi->blk[i].nid != NUMA_NO_NODE)
345 			node_set(mi->blk[i].nid, *nodemask);
346 }
347 
348 /**
349  * numa_reset_distance - Reset NUMA distance table
350  *
351  * The current table is freed.  The next numa_set_distance() call will
352  * create a new one.
353  */
354 void __init numa_reset_distance(void)
355 {
356 	size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]);
357 
358 	/* numa_distance could be 1LU marking allocation failure, test cnt */
359 	if (numa_distance_cnt)
360 		memblock_free(numa_distance, size);
361 	numa_distance_cnt = 0;
362 	numa_distance = NULL;	/* enable table creation */
363 }
364 
365 static int __init numa_alloc_distance(void)
366 {
367 	nodemask_t nodes_parsed;
368 	size_t size;
369 	int i, j, cnt = 0;
370 	u64 phys;
371 
372 	/* size the new table and allocate it */
373 	nodes_parsed = numa_nodes_parsed;
374 	numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
375 
376 	for_each_node_mask(i, nodes_parsed)
377 		cnt = i;
378 	cnt++;
379 	size = cnt * cnt * sizeof(numa_distance[0]);
380 
381 	phys = memblock_phys_alloc_range(size, PAGE_SIZE, 0,
382 					 PFN_PHYS(max_pfn_mapped));
383 	if (!phys) {
384 		pr_warn("Warning: can't allocate distance table!\n");
385 		/* don't retry until explicitly reset */
386 		numa_distance = (void *)1LU;
387 		return -ENOMEM;
388 	}
389 
390 	numa_distance = __va(phys);
391 	numa_distance_cnt = cnt;
392 
393 	/* fill with the default distances */
394 	for (i = 0; i < cnt; i++)
395 		for (j = 0; j < cnt; j++)
396 			numa_distance[i * cnt + j] = i == j ?
397 				LOCAL_DISTANCE : REMOTE_DISTANCE;
398 	printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);
399 
400 	return 0;
401 }
402 
403 /**
404  * numa_set_distance - Set NUMA distance from one NUMA to another
405  * @from: the 'from' node to set distance
406  * @to: the 'to'  node to set distance
407  * @distance: NUMA distance
408  *
409  * Set the distance from node @from to @to to @distance.  If distance table
410  * doesn't exist, one which is large enough to accommodate all the currently
411  * known nodes will be created.
412  *
413  * If such table cannot be allocated, a warning is printed and further
414  * calls are ignored until the distance table is reset with
415  * numa_reset_distance().
416  *
417  * If @from or @to is higher than the highest known node or lower than zero
418  * at the time of table creation or @distance doesn't make sense, the call
419  * is ignored.
420  * This is to allow simplification of specific NUMA config implementations.
421  */
422 void __init numa_set_distance(int from, int to, int distance)
423 {
424 	if (!numa_distance && numa_alloc_distance() < 0)
425 		return;
426 
427 	if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
428 			from < 0 || to < 0) {
429 		pr_warn_once("Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
430 			     from, to, distance);
431 		return;
432 	}
433 
434 	if ((u8)distance != distance ||
435 	    (from == to && distance != LOCAL_DISTANCE)) {
436 		pr_warn_once("Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
437 			     from, to, distance);
438 		return;
439 	}
440 
441 	numa_distance[from * numa_distance_cnt + to] = distance;
442 }
443 
444 int __node_distance(int from, int to)
445 {
446 	if (from >= numa_distance_cnt || to >= numa_distance_cnt)
447 		return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
448 	return numa_distance[from * numa_distance_cnt + to];
449 }
450 EXPORT_SYMBOL(__node_distance);
451 
452 /*
453  * Mark all currently memblock-reserved physical memory (which covers the
454  * kernel's own memory ranges) as hot-unswappable.
455  */
456 static void __init numa_clear_kernel_node_hotplug(void)
457 {
458 	nodemask_t reserved_nodemask = NODE_MASK_NONE;
459 	struct memblock_region *mb_region;
460 	int i;
461 
462 	/*
463 	 * We have to do some preprocessing of memblock regions, to
464 	 * make them suitable for reservation.
465 	 *
466 	 * At this time, all memory regions reserved by memblock are
467 	 * used by the kernel, but those regions are not split up
468 	 * along node boundaries yet, and don't necessarily have their
469 	 * node ID set yet either.
470 	 *
471 	 * So iterate over all memory known to the x86 architecture,
472 	 * and use those ranges to set the nid in memblock.reserved.
473 	 * This will split up the memblock regions along node
474 	 * boundaries and will set the node IDs as well.
475 	 */
476 	for (i = 0; i < numa_meminfo.nr_blks; i++) {
477 		struct numa_memblk *mb = numa_meminfo.blk + i;
478 		int ret;
479 
480 		ret = memblock_set_node(mb->start, mb->end - mb->start, &memblock.reserved, mb->nid);
481 		WARN_ON_ONCE(ret);
482 	}
483 
484 	/*
485 	 * Now go over all reserved memblock regions, to construct a
486 	 * node mask of all kernel reserved memory areas.
487 	 *
488 	 * [ Note, when booting with mem=nn[kMG] or in a kdump kernel,
489 	 *   numa_meminfo might not include all memblock.reserved
490 	 *   memory ranges, because quirks such as trim_snb_memory()
491 	 *   reserve specific pages for Sandy Bridge graphics. ]
492 	 */
493 	for_each_reserved_mem_region(mb_region) {
494 		int nid = memblock_get_region_node(mb_region);
495 
496 		if (nid != MAX_NUMNODES)
497 			node_set(nid, reserved_nodemask);
498 	}
499 
500 	/*
501 	 * Finally, clear the MEMBLOCK_HOTPLUG flag for all memory
502 	 * belonging to the reserved node mask.
503 	 *
504 	 * Note that this will include memory regions that reside
505 	 * on nodes that contain kernel memory - entire nodes
506 	 * become hot-unpluggable:
507 	 */
508 	for (i = 0; i < numa_meminfo.nr_blks; i++) {
509 		struct numa_memblk *mb = numa_meminfo.blk + i;
510 
511 		if (!node_isset(mb->nid, reserved_nodemask))
512 			continue;
513 
514 		memblock_clear_hotplug(mb->start, mb->end - mb->start);
515 	}
516 }
517 
518 static int __init numa_register_memblks(struct numa_meminfo *mi)
519 {
520 	int i, nid;
521 
522 	/* Account for nodes with cpus and no memory */
523 	node_possible_map = numa_nodes_parsed;
524 	numa_nodemask_from_meminfo(&node_possible_map, mi);
525 	if (WARN_ON(nodes_empty(node_possible_map)))
526 		return -EINVAL;
527 
528 	for (i = 0; i < mi->nr_blks; i++) {
529 		struct numa_memblk *mb = &mi->blk[i];
530 		memblock_set_node(mb->start, mb->end - mb->start,
531 				  &memblock.memory, mb->nid);
532 	}
533 
534 	/*
535 	 * At very early time, the kernel have to use some memory such as
536 	 * loading the kernel image. We cannot prevent this anyway. So any
537 	 * node the kernel resides in should be un-hotpluggable.
538 	 *
539 	 * And when we come here, alloc node data won't fail.
540 	 */
541 	numa_clear_kernel_node_hotplug();
542 
543 	/*
544 	 * If sections array is gonna be used for pfn -> nid mapping, check
545 	 * whether its granularity is fine enough.
546 	 */
547 	if (IS_ENABLED(NODE_NOT_IN_PAGE_FLAGS)) {
548 		unsigned long pfn_align = node_map_pfn_alignment();
549 
550 		if (pfn_align && pfn_align < PAGES_PER_SECTION) {
551 			pr_warn("Node alignment %LuMB < min %LuMB, rejecting NUMA config\n",
552 				PFN_PHYS(pfn_align) >> 20,
553 				PFN_PHYS(PAGES_PER_SECTION) >> 20);
554 			return -EINVAL;
555 		}
556 	}
557 
558 	if (!memblock_validate_numa_coverage(SZ_1M))
559 		return -EINVAL;
560 
561 	/* Finally register nodes. */
562 	for_each_node_mask(nid, node_possible_map) {
563 		u64 start = PFN_PHYS(max_pfn);
564 		u64 end = 0;
565 
566 		for (i = 0; i < mi->nr_blks; i++) {
567 			if (nid != mi->blk[i].nid)
568 				continue;
569 			start = min(mi->blk[i].start, start);
570 			end = max(mi->blk[i].end, end);
571 		}
572 
573 		if (start >= end)
574 			continue;
575 
576 		alloc_node_data(nid);
577 	}
578 
579 	/* Dump memblock with node info and return. */
580 	memblock_dump_all();
581 	return 0;
582 }
583 
584 /*
585  * There are unfortunately some poorly designed mainboards around that
586  * only connect memory to a single CPU. This breaks the 1:1 cpu->node
587  * mapping. To avoid this fill in the mapping for all possible CPUs,
588  * as the number of CPUs is not known yet. We round robin the existing
589  * nodes.
590  */
591 static void __init numa_init_array(void)
592 {
593 	int rr, i;
594 
595 	rr = first_node(node_online_map);
596 	for (i = 0; i < nr_cpu_ids; i++) {
597 		if (early_cpu_to_node(i) != NUMA_NO_NODE)
598 			continue;
599 		numa_set_node(i, rr);
600 		rr = next_node_in(rr, node_online_map);
601 	}
602 }
603 
604 static int __init numa_init(int (*init_func)(void))
605 {
606 	int i;
607 	int ret;
608 
609 	for (i = 0; i < MAX_LOCAL_APIC; i++)
610 		set_apicid_to_node(i, NUMA_NO_NODE);
611 
612 	nodes_clear(numa_nodes_parsed);
613 	nodes_clear(node_possible_map);
614 	nodes_clear(node_online_map);
615 	memset(&numa_meminfo, 0, sizeof(numa_meminfo));
616 	WARN_ON(memblock_set_node(0, ULLONG_MAX, &memblock.memory,
617 				  MAX_NUMNODES));
618 	WARN_ON(memblock_set_node(0, ULLONG_MAX, &memblock.reserved,
619 				  MAX_NUMNODES));
620 	/* In case that parsing SRAT failed. */
621 	WARN_ON(memblock_clear_hotplug(0, ULLONG_MAX));
622 	numa_reset_distance();
623 
624 	ret = init_func();
625 	if (ret < 0)
626 		return ret;
627 
628 	/*
629 	 * We reset memblock back to the top-down direction
630 	 * here because if we configured ACPI_NUMA, we have
631 	 * parsed SRAT in init_func(). It is ok to have the
632 	 * reset here even if we did't configure ACPI_NUMA
633 	 * or acpi numa init fails and fallbacks to dummy
634 	 * numa init.
635 	 */
636 	memblock_set_bottom_up(false);
637 
638 	ret = numa_cleanup_meminfo(&numa_meminfo);
639 	if (ret < 0)
640 		return ret;
641 
642 	numa_emulation(&numa_meminfo, numa_distance_cnt);
643 
644 	ret = numa_register_memblks(&numa_meminfo);
645 	if (ret < 0)
646 		return ret;
647 
648 	for (i = 0; i < nr_cpu_ids; i++) {
649 		int nid = early_cpu_to_node(i);
650 
651 		if (nid == NUMA_NO_NODE)
652 			continue;
653 		if (!node_online(nid))
654 			numa_clear_node(i);
655 	}
656 	numa_init_array();
657 
658 	return 0;
659 }
660 
661 /**
662  * dummy_numa_init - Fallback dummy NUMA init
663  *
664  * Used if there's no underlying NUMA architecture, NUMA initialization
665  * fails, or NUMA is disabled on the command line.
666  *
667  * Must online at least one node and add memory blocks that cover all
668  * allowed memory.  This function must not fail.
669  */
670 static int __init dummy_numa_init(void)
671 {
672 	printk(KERN_INFO "%s\n",
673 	       numa_off ? "NUMA turned off" : "No NUMA configuration found");
674 	printk(KERN_INFO "Faking a node at [mem %#018Lx-%#018Lx]\n",
675 	       0LLU, PFN_PHYS(max_pfn) - 1);
676 
677 	node_set(0, numa_nodes_parsed);
678 	numa_add_memblk(0, 0, PFN_PHYS(max_pfn));
679 
680 	return 0;
681 }
682 
683 /**
684  * x86_numa_init - Initialize NUMA
685  *
686  * Try each configured NUMA initialization method until one succeeds.  The
687  * last fallback is dummy single node config encompassing whole memory and
688  * never fails.
689  */
690 void __init x86_numa_init(void)
691 {
692 	if (!numa_off) {
693 #ifdef CONFIG_ACPI_NUMA
694 		if (!numa_init(x86_acpi_numa_init))
695 			return;
696 #endif
697 #ifdef CONFIG_AMD_NUMA
698 		if (!numa_init(amd_numa_init))
699 			return;
700 #endif
701 		if (acpi_disabled && !numa_init(of_numa_init))
702 			return;
703 	}
704 
705 	numa_init(dummy_numa_init);
706 }
707 
708 
709 /*
710  * A node may exist which has one or more Generic Initiators but no CPUs and no
711  * memory.
712  *
713  * This function must be called after init_cpu_to_node(), to ensure that any
714  * memoryless CPU nodes have already been brought online, and before the
715  * node_data[nid] is needed for zone list setup in build_all_zonelists().
716  *
717  * When this function is called, any nodes containing either memory and/or CPUs
718  * will already be online and there is no need to do anything extra, even if
719  * they also contain one or more Generic Initiators.
720  */
721 void __init init_gi_nodes(void)
722 {
723 	int nid;
724 
725 	/*
726 	 * Exclude this node from
727 	 * bringup_nonboot_cpus
728 	 *  cpu_up
729 	 *   __try_online_node
730 	 *    register_one_node
731 	 * because node_subsys is not initialized yet.
732 	 * TODO remove dependency on node_online
733 	 */
734 	for_each_node_state(nid, N_GENERIC_INITIATOR)
735 		if (!node_online(nid))
736 			node_set_online(nid);
737 }
738 
739 /*
740  * Setup early cpu_to_node.
741  *
742  * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
743  * and apicid_to_node[] tables have valid entries for a CPU.
744  * This means we skip cpu_to_node[] initialisation for NUMA
745  * emulation and faking node case (when running a kernel compiled
746  * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
747  * is already initialized in a round robin manner at numa_init_array,
748  * prior to this call, and this initialization is good enough
749  * for the fake NUMA cases.
750  *
751  * Called before the per_cpu areas are setup.
752  */
753 void __init init_cpu_to_node(void)
754 {
755 	int cpu;
756 	u32 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
757 
758 	BUG_ON(cpu_to_apicid == NULL);
759 
760 	for_each_possible_cpu(cpu) {
761 		int node = numa_cpu_node(cpu);
762 
763 		if (node == NUMA_NO_NODE)
764 			continue;
765 
766 		/*
767 		 * Exclude this node from
768 		 * bringup_nonboot_cpus
769 		 *  cpu_up
770 		 *   __try_online_node
771 		 *    register_one_node
772 		 * because node_subsys is not initialized yet.
773 		 * TODO remove dependency on node_online
774 		 */
775 		if (!node_online(node))
776 			node_set_online(node);
777 
778 		numa_set_node(cpu, node);
779 	}
780 }
781 
782 #ifndef CONFIG_DEBUG_PER_CPU_MAPS
783 
784 # ifndef CONFIG_NUMA_EMU
785 void numa_add_cpu(int cpu)
786 {
787 	cpumask_set_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
788 }
789 
790 void numa_remove_cpu(int cpu)
791 {
792 	cpumask_clear_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
793 }
794 # endif	/* !CONFIG_NUMA_EMU */
795 
796 #else	/* !CONFIG_DEBUG_PER_CPU_MAPS */
797 
798 int __cpu_to_node(int cpu)
799 {
800 	if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
801 		printk(KERN_WARNING
802 			"cpu_to_node(%d): usage too early!\n", cpu);
803 		dump_stack();
804 		return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
805 	}
806 	return per_cpu(x86_cpu_to_node_map, cpu);
807 }
808 EXPORT_SYMBOL(__cpu_to_node);
809 
810 /*
811  * Same function as cpu_to_node() but used if called before the
812  * per_cpu areas are setup.
813  */
814 int early_cpu_to_node(int cpu)
815 {
816 	if (early_per_cpu_ptr(x86_cpu_to_node_map))
817 		return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
818 
819 	if (!cpu_possible(cpu)) {
820 		printk(KERN_WARNING
821 			"early_cpu_to_node(%d): no per_cpu area!\n", cpu);
822 		dump_stack();
823 		return NUMA_NO_NODE;
824 	}
825 	return per_cpu(x86_cpu_to_node_map, cpu);
826 }
827 
828 void debug_cpumask_set_cpu(int cpu, int node, bool enable)
829 {
830 	struct cpumask *mask;
831 
832 	if (node == NUMA_NO_NODE) {
833 		/* early_cpu_to_node() already emits a warning and trace */
834 		return;
835 	}
836 	mask = node_to_cpumask_map[node];
837 	if (!cpumask_available(mask)) {
838 		pr_err("node_to_cpumask_map[%i] NULL\n", node);
839 		dump_stack();
840 		return;
841 	}
842 
843 	if (enable)
844 		cpumask_set_cpu(cpu, mask);
845 	else
846 		cpumask_clear_cpu(cpu, mask);
847 
848 	printk(KERN_DEBUG "%s cpu %d node %d: mask now %*pbl\n",
849 		enable ? "numa_add_cpu" : "numa_remove_cpu",
850 		cpu, node, cpumask_pr_args(mask));
851 	return;
852 }
853 
854 # ifndef CONFIG_NUMA_EMU
855 static void numa_set_cpumask(int cpu, bool enable)
856 {
857 	debug_cpumask_set_cpu(cpu, early_cpu_to_node(cpu), enable);
858 }
859 
860 void numa_add_cpu(int cpu)
861 {
862 	numa_set_cpumask(cpu, true);
863 }
864 
865 void numa_remove_cpu(int cpu)
866 {
867 	numa_set_cpumask(cpu, false);
868 }
869 # endif	/* !CONFIG_NUMA_EMU */
870 
871 /*
872  * Returns a pointer to the bitmask of CPUs on Node 'node'.
873  */
874 const struct cpumask *cpumask_of_node(int node)
875 {
876 	if ((unsigned)node >= nr_node_ids) {
877 		printk(KERN_WARNING
878 			"cpumask_of_node(%d): (unsigned)node >= nr_node_ids(%u)\n",
879 			node, nr_node_ids);
880 		dump_stack();
881 		return cpu_none_mask;
882 	}
883 	if (!cpumask_available(node_to_cpumask_map[node])) {
884 		printk(KERN_WARNING
885 			"cpumask_of_node(%d): no node_to_cpumask_map!\n",
886 			node);
887 		dump_stack();
888 		return cpu_online_mask;
889 	}
890 	return node_to_cpumask_map[node];
891 }
892 EXPORT_SYMBOL(cpumask_of_node);
893 
894 #endif	/* !CONFIG_DEBUG_PER_CPU_MAPS */
895 
896 #ifdef CONFIG_NUMA_KEEP_MEMINFO
897 static int meminfo_to_nid(struct numa_meminfo *mi, u64 start)
898 {
899 	int i;
900 
901 	for (i = 0; i < mi->nr_blks; i++)
902 		if (mi->blk[i].start <= start && mi->blk[i].end > start)
903 			return mi->blk[i].nid;
904 	return NUMA_NO_NODE;
905 }
906 
907 int phys_to_target_node(phys_addr_t start)
908 {
909 	int nid = meminfo_to_nid(&numa_meminfo, start);
910 
911 	/*
912 	 * Prefer online nodes, but if reserved memory might be
913 	 * hot-added continue the search with reserved ranges.
914 	 */
915 	if (nid != NUMA_NO_NODE)
916 		return nid;
917 
918 	return meminfo_to_nid(&numa_reserved_meminfo, start);
919 }
920 EXPORT_SYMBOL_GPL(phys_to_target_node);
921 
922 int memory_add_physaddr_to_nid(u64 start)
923 {
924 	int nid = meminfo_to_nid(&numa_meminfo, start);
925 
926 	if (nid == NUMA_NO_NODE)
927 		nid = numa_meminfo.blk[0].nid;
928 	return nid;
929 }
930 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
931 
932 static int __init cmp_memblk(const void *a, const void *b)
933 {
934 	const struct numa_memblk *ma = *(const struct numa_memblk **)a;
935 	const struct numa_memblk *mb = *(const struct numa_memblk **)b;
936 
937 	return (ma->start > mb->start) - (ma->start < mb->start);
938 }
939 
940 static struct numa_memblk *numa_memblk_list[NR_NODE_MEMBLKS] __initdata;
941 
942 /**
943  * numa_fill_memblks - Fill gaps in numa_meminfo memblks
944  * @start: address to begin fill
945  * @end: address to end fill
946  *
947  * Find and extend numa_meminfo memblks to cover the physical
948  * address range @start-@end
949  *
950  * RETURNS:
951  * 0		  : Success
952  * NUMA_NO_MEMBLK : No memblks exist in address range @start-@end
953  */
954 
955 int __init numa_fill_memblks(u64 start, u64 end)
956 {
957 	struct numa_memblk **blk = &numa_memblk_list[0];
958 	struct numa_meminfo *mi = &numa_meminfo;
959 	int count = 0;
960 	u64 prev_end;
961 
962 	/*
963 	 * Create a list of pointers to numa_meminfo memblks that
964 	 * overlap start, end. The list is used to make in-place
965 	 * changes that fill out the numa_meminfo memblks.
966 	 */
967 	for (int i = 0; i < mi->nr_blks; i++) {
968 		struct numa_memblk *bi = &mi->blk[i];
969 
970 		if (memblock_addrs_overlap(start, end - start, bi->start,
971 					   bi->end - bi->start)) {
972 			blk[count] = &mi->blk[i];
973 			count++;
974 		}
975 	}
976 	if (!count)
977 		return NUMA_NO_MEMBLK;
978 
979 	/* Sort the list of pointers in memblk->start order */
980 	sort(&blk[0], count, sizeof(blk[0]), cmp_memblk, NULL);
981 
982 	/* Make sure the first/last memblks include start/end */
983 	blk[0]->start = min(blk[0]->start, start);
984 	blk[count - 1]->end = max(blk[count - 1]->end, end);
985 
986 	/*
987 	 * Fill any gaps by tracking the previous memblks
988 	 * end address and backfilling to it if needed.
989 	 */
990 	prev_end = blk[0]->end;
991 	for (int i = 1; i < count; i++) {
992 		struct numa_memblk *curr = blk[i];
993 
994 		if (prev_end >= curr->start) {
995 			if (prev_end < curr->end)
996 				prev_end = curr->end;
997 		} else {
998 			curr->start = prev_end;
999 			prev_end = curr->end;
1000 		}
1001 	}
1002 	return 0;
1003 }
1004 
1005 #endif
1006