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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/string.h>
7 #include <linux/init.h>
8 #include <linux/memblock.h>
9 #include <linux/mmzone.h>
10 #include <linux/ctype.h>
11 #include <linux/nodemask.h>
12 #include <linux/sched.h>
13 #include <linux/topology.h>
14 
15 #include <asm/e820/api.h>
16 #include <asm/proto.h>
17 #include <asm/dma.h>
18 #include <asm/amd_nb.h>
19 
20 #include "numa_internal.h"
21 
22 int numa_off;
23 nodemask_t numa_nodes_parsed __initdata;
24 
25 struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
26 EXPORT_SYMBOL(node_data);
27 
28 static struct numa_meminfo numa_meminfo __initdata_or_meminfo;
29 static struct numa_meminfo numa_reserved_meminfo __initdata_or_meminfo;
30 
31 static int numa_distance_cnt;
32 static u8 *numa_distance;
33 
numa_setup(char * opt)34 static __init int numa_setup(char *opt)
35 {
36 	if (!opt)
37 		return -EINVAL;
38 	if (!strncmp(opt, "off", 3))
39 		numa_off = 1;
40 	if (!strncmp(opt, "fake=", 5))
41 		return numa_emu_cmdline(opt + 5);
42 	if (!strncmp(opt, "noacpi", 6))
43 		disable_srat();
44 	if (!strncmp(opt, "nohmat", 6))
45 		disable_hmat();
46 	return 0;
47 }
48 early_param("numa", numa_setup);
49 
50 /*
51  * apicid, cpu, node mappings
52  */
53 s16 __apicid_to_node[MAX_LOCAL_APIC] = {
54 	[0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
55 };
56 
numa_cpu_node(int cpu)57 int numa_cpu_node(int cpu)
58 {
59 	int apicid = early_per_cpu(x86_cpu_to_apicid, cpu);
60 
61 	if (apicid != BAD_APICID)
62 		return __apicid_to_node[apicid];
63 	return NUMA_NO_NODE;
64 }
65 
66 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
67 EXPORT_SYMBOL(node_to_cpumask_map);
68 
69 /*
70  * Map cpu index to node index
71  */
72 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
73 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
74 
numa_set_node(int cpu,int node)75 void numa_set_node(int cpu, int node)
76 {
77 	int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
78 
79 	/* early setting, no percpu area yet */
80 	if (cpu_to_node_map) {
81 		cpu_to_node_map[cpu] = node;
82 		return;
83 	}
84 
85 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
86 	if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
87 		printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
88 		dump_stack();
89 		return;
90 	}
91 #endif
92 	per_cpu(x86_cpu_to_node_map, cpu) = node;
93 
94 	set_cpu_numa_node(cpu, node);
95 }
96 
numa_clear_node(int cpu)97 void numa_clear_node(int cpu)
98 {
99 	numa_set_node(cpu, NUMA_NO_NODE);
100 }
101 
102 /*
103  * Allocate node_to_cpumask_map based on number of available nodes
104  * Requires node_possible_map to be valid.
105  *
106  * Note: cpumask_of_node() is not valid until after this is done.
107  * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
108  */
setup_node_to_cpumask_map(void)109 void __init setup_node_to_cpumask_map(void)
110 {
111 	unsigned int node;
112 
113 	/* setup nr_node_ids if not done yet */
114 	if (nr_node_ids == MAX_NUMNODES)
115 		setup_nr_node_ids();
116 
117 	/* allocate the map */
118 	for (node = 0; node < nr_node_ids; node++)
119 		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
120 
121 	/* cpumask_of_node() will now work */
122 	pr_debug("Node to cpumask map for %u nodes\n", nr_node_ids);
123 }
124 
numa_add_memblk_to(int nid,u64 start,u64 end,struct numa_meminfo * mi)125 static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
126 				     struct numa_meminfo *mi)
127 {
128 	/* ignore zero length blks */
129 	if (start == end)
130 		return 0;
131 
132 	/* whine about and ignore invalid blks */
133 	if (start > end || nid < 0 || nid >= MAX_NUMNODES) {
134 		pr_warn("Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
135 			nid, start, end - 1);
136 		return 0;
137 	}
138 
139 	if (mi->nr_blks >= NR_NODE_MEMBLKS) {
140 		pr_err("too many memblk ranges\n");
141 		return -EINVAL;
142 	}
143 
144 	mi->blk[mi->nr_blks].start = start;
145 	mi->blk[mi->nr_blks].end = end;
146 	mi->blk[mi->nr_blks].nid = nid;
147 	mi->nr_blks++;
148 	return 0;
149 }
150 
151 /**
152  * numa_remove_memblk_from - Remove one numa_memblk from a numa_meminfo
153  * @idx: Index of memblk to remove
154  * @mi: numa_meminfo to remove memblk from
155  *
156  * Remove @idx'th numa_memblk from @mi by shifting @mi->blk[] and
157  * decrementing @mi->nr_blks.
158  */
numa_remove_memblk_from(int idx,struct numa_meminfo * mi)159 void __init numa_remove_memblk_from(int idx, struct numa_meminfo *mi)
160 {
161 	mi->nr_blks--;
162 	memmove(&mi->blk[idx], &mi->blk[idx + 1],
163 		(mi->nr_blks - idx) * sizeof(mi->blk[0]));
164 }
165 
166 /**
167  * numa_move_tail_memblk - Move a numa_memblk from one numa_meminfo to another
168  * @dst: numa_meminfo to append block to
169  * @idx: Index of memblk to remove
170  * @src: numa_meminfo to remove memblk from
171  */
numa_move_tail_memblk(struct numa_meminfo * dst,int idx,struct numa_meminfo * src)172 static void __init numa_move_tail_memblk(struct numa_meminfo *dst, int idx,
173 					 struct numa_meminfo *src)
174 {
175 	dst->blk[dst->nr_blks++] = src->blk[idx];
176 	numa_remove_memblk_from(idx, src);
177 }
178 
179 /**
180  * numa_add_memblk - Add one numa_memblk to numa_meminfo
181  * @nid: NUMA node ID of the new memblk
182  * @start: Start address of the new memblk
183  * @end: End address of the new memblk
184  *
185  * Add a new memblk to the default numa_meminfo.
186  *
187  * RETURNS:
188  * 0 on success, -errno on failure.
189  */
numa_add_memblk(int nid,u64 start,u64 end)190 int __init numa_add_memblk(int nid, u64 start, u64 end)
191 {
192 	return numa_add_memblk_to(nid, start, end, &numa_meminfo);
193 }
194 
195 /* Allocate NODE_DATA for a node on the local memory */
alloc_node_data(int nid)196 static void __init alloc_node_data(int nid)
197 {
198 	const size_t nd_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
199 	u64 nd_pa;
200 	void *nd;
201 	int tnid;
202 
203 	/*
204 	 * Allocate node data.  Try node-local memory and then any node.
205 	 * Never allocate in DMA zone.
206 	 */
207 	nd_pa = memblock_phys_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
208 	if (!nd_pa) {
209 		pr_err("Cannot find %zu bytes in any node (initial node: %d)\n",
210 		       nd_size, nid);
211 		return;
212 	}
213 	nd = __va(nd_pa);
214 
215 	/* report and initialize */
216 	printk(KERN_INFO "NODE_DATA(%d) allocated [mem %#010Lx-%#010Lx]\n", nid,
217 	       nd_pa, nd_pa + nd_size - 1);
218 	tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
219 	if (tnid != nid)
220 		printk(KERN_INFO "    NODE_DATA(%d) on node %d\n", nid, tnid);
221 
222 	node_data[nid] = nd;
223 	memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
224 
225 	node_set_online(nid);
226 }
227 
228 /**
229  * numa_cleanup_meminfo - Cleanup a numa_meminfo
230  * @mi: numa_meminfo to clean up
231  *
232  * Sanitize @mi by merging and removing unnecessary memblks.  Also check for
233  * conflicts and clear unused memblks.
234  *
235  * RETURNS:
236  * 0 on success, -errno on failure.
237  */
numa_cleanup_meminfo(struct numa_meminfo * mi)238 int __init numa_cleanup_meminfo(struct numa_meminfo *mi)
239 {
240 	const u64 low = 0;
241 	const u64 high = PFN_PHYS(max_pfn);
242 	int i, j, k;
243 
244 	/* first, trim all entries */
245 	for (i = 0; i < mi->nr_blks; i++) {
246 		struct numa_memblk *bi = &mi->blk[i];
247 
248 		/* move / save reserved memory ranges */
249 		if (!memblock_overlaps_region(&memblock.memory,
250 					bi->start, bi->end - bi->start)) {
251 			numa_move_tail_memblk(&numa_reserved_meminfo, i--, mi);
252 			continue;
253 		}
254 
255 		/* make sure all non-reserved blocks are inside the limits */
256 		bi->start = max(bi->start, low);
257 
258 		/* preserve info for non-RAM areas above 'max_pfn': */
259 		if (bi->end > high) {
260 			numa_add_memblk_to(bi->nid, high, bi->end,
261 					   &numa_reserved_meminfo);
262 			bi->end = high;
263 		}
264 
265 		/* and there's no empty block */
266 		if (bi->start >= bi->end)
267 			numa_remove_memblk_from(i--, mi);
268 	}
269 
270 	/* merge neighboring / overlapping entries */
271 	for (i = 0; i < mi->nr_blks; i++) {
272 		struct numa_memblk *bi = &mi->blk[i];
273 
274 		for (j = i + 1; j < mi->nr_blks; j++) {
275 			struct numa_memblk *bj = &mi->blk[j];
276 			u64 start, end;
277 
278 			/*
279 			 * See whether there are overlapping blocks.  Whine
280 			 * about but allow overlaps of the same nid.  They
281 			 * will be merged below.
282 			 */
283 			if (bi->end > bj->start && bi->start < bj->end) {
284 				if (bi->nid != bj->nid) {
285 					pr_err("node %d [mem %#010Lx-%#010Lx] overlaps with node %d [mem %#010Lx-%#010Lx]\n",
286 					       bi->nid, bi->start, bi->end - 1,
287 					       bj->nid, bj->start, bj->end - 1);
288 					return -EINVAL;
289 				}
290 				pr_warn("Warning: node %d [mem %#010Lx-%#010Lx] overlaps with itself [mem %#010Lx-%#010Lx]\n",
291 					bi->nid, bi->start, bi->end - 1,
292 					bj->start, bj->end - 1);
293 			}
294 
295 			/*
296 			 * Join together blocks on the same node, holes
297 			 * between which don't overlap with memory on other
298 			 * nodes.
299 			 */
300 			if (bi->nid != bj->nid)
301 				continue;
302 			start = min(bi->start, bj->start);
303 			end = max(bi->end, bj->end);
304 			for (k = 0; k < mi->nr_blks; k++) {
305 				struct numa_memblk *bk = &mi->blk[k];
306 
307 				if (bi->nid == bk->nid)
308 					continue;
309 				if (start < bk->end && end > bk->start)
310 					break;
311 			}
312 			if (k < mi->nr_blks)
313 				continue;
314 			printk(KERN_INFO "NUMA: Node %d [mem %#010Lx-%#010Lx] + [mem %#010Lx-%#010Lx] -> [mem %#010Lx-%#010Lx]\n",
315 			       bi->nid, bi->start, bi->end - 1, bj->start,
316 			       bj->end - 1, start, end - 1);
317 			bi->start = start;
318 			bi->end = end;
319 			numa_remove_memblk_from(j--, mi);
320 		}
321 	}
322 
323 	/* clear unused ones */
324 	for (i = mi->nr_blks; i < ARRAY_SIZE(mi->blk); i++) {
325 		mi->blk[i].start = mi->blk[i].end = 0;
326 		mi->blk[i].nid = NUMA_NO_NODE;
327 	}
328 
329 	return 0;
330 }
331 
332 /*
333  * Set nodes, which have memory in @mi, in *@nodemask.
334  */
numa_nodemask_from_meminfo(nodemask_t * nodemask,const struct numa_meminfo * mi)335 static void __init numa_nodemask_from_meminfo(nodemask_t *nodemask,
336 					      const struct numa_meminfo *mi)
337 {
338 	int i;
339 
340 	for (i = 0; i < ARRAY_SIZE(mi->blk); i++)
341 		if (mi->blk[i].start != mi->blk[i].end &&
342 		    mi->blk[i].nid != NUMA_NO_NODE)
343 			node_set(mi->blk[i].nid, *nodemask);
344 }
345 
346 /**
347  * numa_reset_distance - Reset NUMA distance table
348  *
349  * The current table is freed.  The next numa_set_distance() call will
350  * create a new one.
351  */
numa_reset_distance(void)352 void __init numa_reset_distance(void)
353 {
354 	size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]);
355 
356 	/* numa_distance could be 1LU marking allocation failure, test cnt */
357 	if (numa_distance_cnt)
358 		memblock_free(__pa(numa_distance), size);
359 	numa_distance_cnt = 0;
360 	numa_distance = NULL;	/* enable table creation */
361 }
362 
numa_alloc_distance(void)363 static int __init numa_alloc_distance(void)
364 {
365 	nodemask_t nodes_parsed;
366 	size_t size;
367 	int i, j, cnt = 0;
368 	u64 phys;
369 
370 	/* size the new table and allocate it */
371 	nodes_parsed = numa_nodes_parsed;
372 	numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
373 
374 	for_each_node_mask(i, nodes_parsed)
375 		cnt = i;
376 	cnt++;
377 	size = cnt * cnt * sizeof(numa_distance[0]);
378 
379 	phys = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
380 				      size, PAGE_SIZE);
381 	if (!phys) {
382 		pr_warn("Warning: can't allocate distance table!\n");
383 		/* don't retry until explicitly reset */
384 		numa_distance = (void *)1LU;
385 		return -ENOMEM;
386 	}
387 	memblock_reserve(phys, size);
388 
389 	numa_distance = __va(phys);
390 	numa_distance_cnt = cnt;
391 
392 	/* fill with the default distances */
393 	for (i = 0; i < cnt; i++)
394 		for (j = 0; j < cnt; j++)
395 			numa_distance[i * cnt + j] = i == j ?
396 				LOCAL_DISTANCE : REMOTE_DISTANCE;
397 	printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);
398 
399 	return 0;
400 }
401 
402 /**
403  * numa_set_distance - Set NUMA distance from one NUMA to another
404  * @from: the 'from' node to set distance
405  * @to: the 'to'  node to set distance
406  * @distance: NUMA distance
407  *
408  * Set the distance from node @from to @to to @distance.  If distance table
409  * doesn't exist, one which is large enough to accommodate all the currently
410  * known nodes will be created.
411  *
412  * If such table cannot be allocated, a warning is printed and further
413  * calls are ignored until the distance table is reset with
414  * numa_reset_distance().
415  *
416  * If @from or @to is higher than the highest known node or lower than zero
417  * at the time of table creation or @distance doesn't make sense, the call
418  * is ignored.
419  * This is to allow simplification of specific NUMA config implementations.
420  */
numa_set_distance(int from,int to,int distance)421 void __init numa_set_distance(int from, int to, int distance)
422 {
423 	if (!numa_distance && numa_alloc_distance() < 0)
424 		return;
425 
426 	if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
427 			from < 0 || to < 0) {
428 		pr_warn_once("Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
429 			     from, to, distance);
430 		return;
431 	}
432 
433 	if ((u8)distance != distance ||
434 	    (from == to && distance != LOCAL_DISTANCE)) {
435 		pr_warn_once("Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
436 			     from, to, distance);
437 		return;
438 	}
439 
440 	numa_distance[from * numa_distance_cnt + to] = distance;
441 }
442 
__node_distance(int from,int to)443 int __node_distance(int from, int to)
444 {
445 	if (from >= numa_distance_cnt || to >= numa_distance_cnt)
446 		return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
447 	return numa_distance[from * numa_distance_cnt + to];
448 }
449 EXPORT_SYMBOL(__node_distance);
450 
451 /*
452  * Sanity check to catch more bad NUMA configurations (they are amazingly
453  * common).  Make sure the nodes cover all memory.
454  */
numa_meminfo_cover_memory(const struct numa_meminfo * mi)455 static bool __init numa_meminfo_cover_memory(const struct numa_meminfo *mi)
456 {
457 	u64 numaram, e820ram;
458 	int i;
459 
460 	numaram = 0;
461 	for (i = 0; i < mi->nr_blks; i++) {
462 		u64 s = mi->blk[i].start >> PAGE_SHIFT;
463 		u64 e = mi->blk[i].end >> PAGE_SHIFT;
464 		numaram += e - s;
465 		numaram -= __absent_pages_in_range(mi->blk[i].nid, s, e);
466 		if ((s64)numaram < 0)
467 			numaram = 0;
468 	}
469 
470 	e820ram = max_pfn - absent_pages_in_range(0, max_pfn);
471 
472 	/* We seem to lose 3 pages somewhere. Allow 1M of slack. */
473 	if ((s64)(e820ram - numaram) >= (1 << (20 - PAGE_SHIFT))) {
474 		printk(KERN_ERR "NUMA: nodes only cover %LuMB of your %LuMB e820 RAM. Not used.\n",
475 		       (numaram << PAGE_SHIFT) >> 20,
476 		       (e820ram << PAGE_SHIFT) >> 20);
477 		return false;
478 	}
479 	return true;
480 }
481 
482 /*
483  * Mark all currently memblock-reserved physical memory (which covers the
484  * kernel's own memory ranges) as hot-unswappable.
485  */
numa_clear_kernel_node_hotplug(void)486 static void __init numa_clear_kernel_node_hotplug(void)
487 {
488 	nodemask_t reserved_nodemask = NODE_MASK_NONE;
489 	struct memblock_region *mb_region;
490 	int i;
491 
492 	/*
493 	 * We have to do some preprocessing of memblock regions, to
494 	 * make them suitable for reservation.
495 	 *
496 	 * At this time, all memory regions reserved by memblock are
497 	 * used by the kernel, but those regions are not split up
498 	 * along node boundaries yet, and don't necessarily have their
499 	 * node ID set yet either.
500 	 *
501 	 * So iterate over all memory known to the x86 architecture,
502 	 * and use those ranges to set the nid in memblock.reserved.
503 	 * This will split up the memblock regions along node
504 	 * boundaries and will set the node IDs as well.
505 	 */
506 	for (i = 0; i < numa_meminfo.nr_blks; i++) {
507 		struct numa_memblk *mb = numa_meminfo.blk + i;
508 		int ret;
509 
510 		ret = memblock_set_node(mb->start, mb->end - mb->start, &memblock.reserved, mb->nid);
511 		WARN_ON_ONCE(ret);
512 	}
513 
514 	/*
515 	 * Now go over all reserved memblock regions, to construct a
516 	 * node mask of all kernel reserved memory areas.
517 	 *
518 	 * [ Note, when booting with mem=nn[kMG] or in a kdump kernel,
519 	 *   numa_meminfo might not include all memblock.reserved
520 	 *   memory ranges, because quirks such as trim_snb_memory()
521 	 *   reserve specific pages for Sandy Bridge graphics. ]
522 	 */
523 	for_each_reserved_mem_region(mb_region) {
524 		int nid = memblock_get_region_node(mb_region);
525 
526 		if (nid != MAX_NUMNODES)
527 			node_set(nid, reserved_nodemask);
528 	}
529 
530 	/*
531 	 * Finally, clear the MEMBLOCK_HOTPLUG flag for all memory
532 	 * belonging to the reserved node mask.
533 	 *
534 	 * Note that this will include memory regions that reside
535 	 * on nodes that contain kernel memory - entire nodes
536 	 * become hot-unpluggable:
537 	 */
538 	for (i = 0; i < numa_meminfo.nr_blks; i++) {
539 		struct numa_memblk *mb = numa_meminfo.blk + i;
540 
541 		if (!node_isset(mb->nid, reserved_nodemask))
542 			continue;
543 
544 		memblock_clear_hotplug(mb->start, mb->end - mb->start);
545 	}
546 }
547 
numa_register_memblks(struct numa_meminfo * mi)548 static int __init numa_register_memblks(struct numa_meminfo *mi)
549 {
550 	int i, nid;
551 
552 	/* Account for nodes with cpus and no memory */
553 	node_possible_map = numa_nodes_parsed;
554 	numa_nodemask_from_meminfo(&node_possible_map, mi);
555 	if (WARN_ON(nodes_empty(node_possible_map)))
556 		return -EINVAL;
557 
558 	for (i = 0; i < mi->nr_blks; i++) {
559 		struct numa_memblk *mb = &mi->blk[i];
560 		memblock_set_node(mb->start, mb->end - mb->start,
561 				  &memblock.memory, mb->nid);
562 	}
563 
564 	/*
565 	 * At very early time, the kernel have to use some memory such as
566 	 * loading the kernel image. We cannot prevent this anyway. So any
567 	 * node the kernel resides in should be un-hotpluggable.
568 	 *
569 	 * And when we come here, alloc node data won't fail.
570 	 */
571 	numa_clear_kernel_node_hotplug();
572 
573 	/*
574 	 * If sections array is gonna be used for pfn -> nid mapping, check
575 	 * whether its granularity is fine enough.
576 	 */
577 	if (IS_ENABLED(NODE_NOT_IN_PAGE_FLAGS)) {
578 		unsigned long pfn_align = node_map_pfn_alignment();
579 
580 		if (pfn_align && pfn_align < PAGES_PER_SECTION) {
581 			pr_warn("Node alignment %LuMB < min %LuMB, rejecting NUMA config\n",
582 				PFN_PHYS(pfn_align) >> 20,
583 				PFN_PHYS(PAGES_PER_SECTION) >> 20);
584 			return -EINVAL;
585 		}
586 	}
587 	if (!numa_meminfo_cover_memory(mi))
588 		return -EINVAL;
589 
590 	/* Finally register nodes. */
591 	for_each_node_mask(nid, node_possible_map) {
592 		u64 start = PFN_PHYS(max_pfn);
593 		u64 end = 0;
594 
595 		for (i = 0; i < mi->nr_blks; i++) {
596 			if (nid != mi->blk[i].nid)
597 				continue;
598 			start = min(mi->blk[i].start, start);
599 			end = max(mi->blk[i].end, end);
600 		}
601 
602 		if (start >= end)
603 			continue;
604 
605 		/*
606 		 * Don't confuse VM with a node that doesn't have the
607 		 * minimum amount of memory:
608 		 */
609 		if (end && (end - start) < NODE_MIN_SIZE)
610 			continue;
611 
612 		alloc_node_data(nid);
613 	}
614 
615 	/* Dump memblock with node info and return. */
616 	memblock_dump_all();
617 	return 0;
618 }
619 
620 /*
621  * There are unfortunately some poorly designed mainboards around that
622  * only connect memory to a single CPU. This breaks the 1:1 cpu->node
623  * mapping. To avoid this fill in the mapping for all possible CPUs,
624  * as the number of CPUs is not known yet. We round robin the existing
625  * nodes.
626  */
numa_init_array(void)627 static void __init numa_init_array(void)
628 {
629 	int rr, i;
630 
631 	rr = first_node(node_online_map);
632 	for (i = 0; i < nr_cpu_ids; i++) {
633 		if (early_cpu_to_node(i) != NUMA_NO_NODE)
634 			continue;
635 		numa_set_node(i, rr);
636 		rr = next_node_in(rr, node_online_map);
637 	}
638 }
639 
numa_init(int (* init_func)(void))640 static int __init numa_init(int (*init_func)(void))
641 {
642 	int i;
643 	int ret;
644 
645 	for (i = 0; i < MAX_LOCAL_APIC; i++)
646 		set_apicid_to_node(i, NUMA_NO_NODE);
647 
648 	nodes_clear(numa_nodes_parsed);
649 	nodes_clear(node_possible_map);
650 	nodes_clear(node_online_map);
651 	memset(&numa_meminfo, 0, sizeof(numa_meminfo));
652 	WARN_ON(memblock_set_node(0, ULLONG_MAX, &memblock.memory,
653 				  MAX_NUMNODES));
654 	WARN_ON(memblock_set_node(0, ULLONG_MAX, &memblock.reserved,
655 				  MAX_NUMNODES));
656 	/* In case that parsing SRAT failed. */
657 	WARN_ON(memblock_clear_hotplug(0, ULLONG_MAX));
658 	numa_reset_distance();
659 
660 	ret = init_func();
661 	if (ret < 0)
662 		return ret;
663 
664 	/*
665 	 * We reset memblock back to the top-down direction
666 	 * here because if we configured ACPI_NUMA, we have
667 	 * parsed SRAT in init_func(). It is ok to have the
668 	 * reset here even if we did't configure ACPI_NUMA
669 	 * or acpi numa init fails and fallbacks to dummy
670 	 * numa init.
671 	 */
672 	memblock_set_bottom_up(false);
673 
674 	ret = numa_cleanup_meminfo(&numa_meminfo);
675 	if (ret < 0)
676 		return ret;
677 
678 	numa_emulation(&numa_meminfo, numa_distance_cnt);
679 
680 	ret = numa_register_memblks(&numa_meminfo);
681 	if (ret < 0)
682 		return ret;
683 
684 	for (i = 0; i < nr_cpu_ids; i++) {
685 		int nid = early_cpu_to_node(i);
686 
687 		if (nid == NUMA_NO_NODE)
688 			continue;
689 		if (!node_online(nid))
690 			numa_clear_node(i);
691 	}
692 	numa_init_array();
693 
694 	return 0;
695 }
696 
697 /**
698  * dummy_numa_init - Fallback dummy NUMA init
699  *
700  * Used if there's no underlying NUMA architecture, NUMA initialization
701  * fails, or NUMA is disabled on the command line.
702  *
703  * Must online at least one node and add memory blocks that cover all
704  * allowed memory.  This function must not fail.
705  */
dummy_numa_init(void)706 static int __init dummy_numa_init(void)
707 {
708 	printk(KERN_INFO "%s\n",
709 	       numa_off ? "NUMA turned off" : "No NUMA configuration found");
710 	printk(KERN_INFO "Faking a node at [mem %#018Lx-%#018Lx]\n",
711 	       0LLU, PFN_PHYS(max_pfn) - 1);
712 
713 	node_set(0, numa_nodes_parsed);
714 	numa_add_memblk(0, 0, PFN_PHYS(max_pfn));
715 
716 	return 0;
717 }
718 
719 /**
720  * x86_numa_init - Initialize NUMA
721  *
722  * Try each configured NUMA initialization method until one succeeds.  The
723  * last fallback is dummy single node config encompassing whole memory and
724  * never fails.
725  */
x86_numa_init(void)726 void __init x86_numa_init(void)
727 {
728 	if (!numa_off) {
729 #ifdef CONFIG_ACPI_NUMA
730 		if (!numa_init(x86_acpi_numa_init))
731 			return;
732 #endif
733 #ifdef CONFIG_AMD_NUMA
734 		if (!numa_init(amd_numa_init))
735 			return;
736 #endif
737 	}
738 
739 	numa_init(dummy_numa_init);
740 }
741 
init_memory_less_node(int nid)742 static void __init init_memory_less_node(int nid)
743 {
744 	/* Allocate and initialize node data. Memory-less node is now online.*/
745 	alloc_node_data(nid);
746 	free_area_init_memoryless_node(nid);
747 
748 	/*
749 	 * All zonelists will be built later in start_kernel() after per cpu
750 	 * areas are initialized.
751 	 */
752 }
753 
754 /*
755  * A node may exist which has one or more Generic Initiators but no CPUs and no
756  * memory.
757  *
758  * This function must be called after init_cpu_to_node(), to ensure that any
759  * memoryless CPU nodes have already been brought online, and before the
760  * node_data[nid] is needed for zone list setup in build_all_zonelists().
761  *
762  * When this function is called, any nodes containing either memory and/or CPUs
763  * will already be online and there is no need to do anything extra, even if
764  * they also contain one or more Generic Initiators.
765  */
init_gi_nodes(void)766 void __init init_gi_nodes(void)
767 {
768 	int nid;
769 
770 	for_each_node_state(nid, N_GENERIC_INITIATOR)
771 		if (!node_online(nid))
772 			init_memory_less_node(nid);
773 }
774 
775 /*
776  * Setup early cpu_to_node.
777  *
778  * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
779  * and apicid_to_node[] tables have valid entries for a CPU.
780  * This means we skip cpu_to_node[] initialisation for NUMA
781  * emulation and faking node case (when running a kernel compiled
782  * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
783  * is already initialized in a round robin manner at numa_init_array,
784  * prior to this call, and this initialization is good enough
785  * for the fake NUMA cases.
786  *
787  * Called before the per_cpu areas are setup.
788  */
init_cpu_to_node(void)789 void __init init_cpu_to_node(void)
790 {
791 	int cpu;
792 	u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
793 
794 	BUG_ON(cpu_to_apicid == NULL);
795 
796 	for_each_possible_cpu(cpu) {
797 		int node = numa_cpu_node(cpu);
798 
799 		if (node == NUMA_NO_NODE)
800 			continue;
801 
802 		if (!node_online(node))
803 			init_memory_less_node(node);
804 
805 		numa_set_node(cpu, node);
806 	}
807 }
808 
809 #ifndef CONFIG_DEBUG_PER_CPU_MAPS
810 
811 # ifndef CONFIG_NUMA_EMU
numa_add_cpu(int cpu)812 void numa_add_cpu(int cpu)
813 {
814 	cpumask_set_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
815 }
816 
numa_remove_cpu(int cpu)817 void numa_remove_cpu(int cpu)
818 {
819 	cpumask_clear_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
820 }
821 # endif	/* !CONFIG_NUMA_EMU */
822 
823 #else	/* !CONFIG_DEBUG_PER_CPU_MAPS */
824 
__cpu_to_node(int cpu)825 int __cpu_to_node(int cpu)
826 {
827 	if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
828 		printk(KERN_WARNING
829 			"cpu_to_node(%d): usage too early!\n", cpu);
830 		dump_stack();
831 		return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
832 	}
833 	return per_cpu(x86_cpu_to_node_map, cpu);
834 }
835 EXPORT_SYMBOL(__cpu_to_node);
836 
837 /*
838  * Same function as cpu_to_node() but used if called before the
839  * per_cpu areas are setup.
840  */
early_cpu_to_node(int cpu)841 int early_cpu_to_node(int cpu)
842 {
843 	if (early_per_cpu_ptr(x86_cpu_to_node_map))
844 		return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
845 
846 	if (!cpu_possible(cpu)) {
847 		printk(KERN_WARNING
848 			"early_cpu_to_node(%d): no per_cpu area!\n", cpu);
849 		dump_stack();
850 		return NUMA_NO_NODE;
851 	}
852 	return per_cpu(x86_cpu_to_node_map, cpu);
853 }
854 
debug_cpumask_set_cpu(int cpu,int node,bool enable)855 void debug_cpumask_set_cpu(int cpu, int node, bool enable)
856 {
857 	struct cpumask *mask;
858 
859 	if (node == NUMA_NO_NODE) {
860 		/* early_cpu_to_node() already emits a warning and trace */
861 		return;
862 	}
863 	mask = node_to_cpumask_map[node];
864 	if (!cpumask_available(mask)) {
865 		pr_err("node_to_cpumask_map[%i] NULL\n", node);
866 		dump_stack();
867 		return;
868 	}
869 
870 	if (enable)
871 		cpumask_set_cpu(cpu, mask);
872 	else
873 		cpumask_clear_cpu(cpu, mask);
874 
875 	printk(KERN_DEBUG "%s cpu %d node %d: mask now %*pbl\n",
876 		enable ? "numa_add_cpu" : "numa_remove_cpu",
877 		cpu, node, cpumask_pr_args(mask));
878 	return;
879 }
880 
881 # ifndef CONFIG_NUMA_EMU
numa_set_cpumask(int cpu,bool enable)882 static void numa_set_cpumask(int cpu, bool enable)
883 {
884 	debug_cpumask_set_cpu(cpu, early_cpu_to_node(cpu), enable);
885 }
886 
numa_add_cpu(int cpu)887 void numa_add_cpu(int cpu)
888 {
889 	numa_set_cpumask(cpu, true);
890 }
891 
numa_remove_cpu(int cpu)892 void numa_remove_cpu(int cpu)
893 {
894 	numa_set_cpumask(cpu, false);
895 }
896 # endif	/* !CONFIG_NUMA_EMU */
897 
898 /*
899  * Returns a pointer to the bitmask of CPUs on Node 'node'.
900  */
cpumask_of_node(int node)901 const struct cpumask *cpumask_of_node(int node)
902 {
903 	if ((unsigned)node >= nr_node_ids) {
904 		printk(KERN_WARNING
905 			"cpumask_of_node(%d): (unsigned)node >= nr_node_ids(%u)\n",
906 			node, nr_node_ids);
907 		dump_stack();
908 		return cpu_none_mask;
909 	}
910 	if (!cpumask_available(node_to_cpumask_map[node])) {
911 		printk(KERN_WARNING
912 			"cpumask_of_node(%d): no node_to_cpumask_map!\n",
913 			node);
914 		dump_stack();
915 		return cpu_online_mask;
916 	}
917 	return node_to_cpumask_map[node];
918 }
919 EXPORT_SYMBOL(cpumask_of_node);
920 
921 #endif	/* !CONFIG_DEBUG_PER_CPU_MAPS */
922 
923 #ifdef CONFIG_NUMA_KEEP_MEMINFO
meminfo_to_nid(struct numa_meminfo * mi,u64 start)924 static int meminfo_to_nid(struct numa_meminfo *mi, u64 start)
925 {
926 	int i;
927 
928 	for (i = 0; i < mi->nr_blks; i++)
929 		if (mi->blk[i].start <= start && mi->blk[i].end > start)
930 			return mi->blk[i].nid;
931 	return NUMA_NO_NODE;
932 }
933 
phys_to_target_node(phys_addr_t start)934 int phys_to_target_node(phys_addr_t start)
935 {
936 	int nid = meminfo_to_nid(&numa_meminfo, start);
937 
938 	/*
939 	 * Prefer online nodes, but if reserved memory might be
940 	 * hot-added continue the search with reserved ranges.
941 	 */
942 	if (nid != NUMA_NO_NODE)
943 		return nid;
944 
945 	return meminfo_to_nid(&numa_reserved_meminfo, start);
946 }
947 EXPORT_SYMBOL_GPL(phys_to_target_node);
948 
memory_add_physaddr_to_nid(u64 start)949 int memory_add_physaddr_to_nid(u64 start)
950 {
951 	int nid = meminfo_to_nid(&numa_meminfo, start);
952 
953 	if (nid == NUMA_NO_NODE)
954 		nid = numa_meminfo.blk[0].nid;
955 	return nid;
956 }
957 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
958 #endif
959