xref: /openbmc/linux/arch/powerpc/mm/numa.c (revision 6562c9ac)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * pSeries NUMA support
4  *
5  * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
6  */
7 #define pr_fmt(fmt) "numa: " fmt
8 
9 #include <linux/threads.h>
10 #include <linux/memblock.h>
11 #include <linux/init.h>
12 #include <linux/mm.h>
13 #include <linux/mmzone.h>
14 #include <linux/export.h>
15 #include <linux/nodemask.h>
16 #include <linux/cpu.h>
17 #include <linux/notifier.h>
18 #include <linux/of.h>
19 #include <linux/pfn.h>
20 #include <linux/cpuset.h>
21 #include <linux/node.h>
22 #include <linux/stop_machine.h>
23 #include <linux/proc_fs.h>
24 #include <linux/seq_file.h>
25 #include <linux/uaccess.h>
26 #include <linux/slab.h>
27 #include <asm/cputhreads.h>
28 #include <asm/sparsemem.h>
29 #include <asm/smp.h>
30 #include <asm/topology.h>
31 #include <asm/firmware.h>
32 #include <asm/paca.h>
33 #include <asm/hvcall.h>
34 #include <asm/setup.h>
35 #include <asm/vdso.h>
36 #include <asm/drmem.h>
37 
38 static int numa_enabled = 1;
39 
40 static char *cmdline __initdata;
41 
42 int numa_cpu_lookup_table[NR_CPUS];
43 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
44 struct pglist_data *node_data[MAX_NUMNODES];
45 
46 EXPORT_SYMBOL(numa_cpu_lookup_table);
47 EXPORT_SYMBOL(node_to_cpumask_map);
48 EXPORT_SYMBOL(node_data);
49 
50 static int primary_domain_index;
51 static int n_mem_addr_cells, n_mem_size_cells;
52 
53 #define FORM0_AFFINITY 0
54 #define FORM1_AFFINITY 1
55 #define FORM2_AFFINITY 2
56 static int affinity_form;
57 
58 #define MAX_DISTANCE_REF_POINTS 4
59 static int distance_ref_points_depth;
60 static const __be32 *distance_ref_points;
61 static int distance_lookup_table[MAX_NUMNODES][MAX_DISTANCE_REF_POINTS];
62 static int numa_distance_table[MAX_NUMNODES][MAX_NUMNODES] = {
63 	[0 ... MAX_NUMNODES - 1] = { [0 ... MAX_NUMNODES - 1] = -1 }
64 };
65 static int numa_id_index_table[MAX_NUMNODES] = { [0 ... MAX_NUMNODES - 1] = NUMA_NO_NODE };
66 
67 /*
68  * Allocate node_to_cpumask_map based on number of available nodes
69  * Requires node_possible_map to be valid.
70  *
71  * Note: cpumask_of_node() is not valid until after this is done.
72  */
73 static void __init setup_node_to_cpumask_map(void)
74 {
75 	unsigned int node;
76 
77 	/* setup nr_node_ids if not done yet */
78 	if (nr_node_ids == MAX_NUMNODES)
79 		setup_nr_node_ids();
80 
81 	/* allocate the map */
82 	for_each_node(node)
83 		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
84 
85 	/* cpumask_of_node() will now work */
86 	pr_debug("Node to cpumask map for %u nodes\n", nr_node_ids);
87 }
88 
89 static int __init fake_numa_create_new_node(unsigned long end_pfn,
90 						unsigned int *nid)
91 {
92 	unsigned long long mem;
93 	char *p = cmdline;
94 	static unsigned int fake_nid;
95 	static unsigned long long curr_boundary;
96 
97 	/*
98 	 * Modify node id, iff we started creating NUMA nodes
99 	 * We want to continue from where we left of the last time
100 	 */
101 	if (fake_nid)
102 		*nid = fake_nid;
103 	/*
104 	 * In case there are no more arguments to parse, the
105 	 * node_id should be the same as the last fake node id
106 	 * (we've handled this above).
107 	 */
108 	if (!p)
109 		return 0;
110 
111 	mem = memparse(p, &p);
112 	if (!mem)
113 		return 0;
114 
115 	if (mem < curr_boundary)
116 		return 0;
117 
118 	curr_boundary = mem;
119 
120 	if ((end_pfn << PAGE_SHIFT) > mem) {
121 		/*
122 		 * Skip commas and spaces
123 		 */
124 		while (*p == ',' || *p == ' ' || *p == '\t')
125 			p++;
126 
127 		cmdline = p;
128 		fake_nid++;
129 		*nid = fake_nid;
130 		pr_debug("created new fake_node with id %d\n", fake_nid);
131 		return 1;
132 	}
133 	return 0;
134 }
135 
136 static void __init reset_numa_cpu_lookup_table(void)
137 {
138 	unsigned int cpu;
139 
140 	for_each_possible_cpu(cpu)
141 		numa_cpu_lookup_table[cpu] = -1;
142 }
143 
144 void map_cpu_to_node(int cpu, int node)
145 {
146 	update_numa_cpu_lookup_table(cpu, node);
147 
148 	if (!(cpumask_test_cpu(cpu, node_to_cpumask_map[node]))) {
149 		pr_debug("adding cpu %d to node %d\n", cpu, node);
150 		cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
151 	}
152 }
153 
154 #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PPC_SPLPAR)
155 void unmap_cpu_from_node(unsigned long cpu)
156 {
157 	int node = numa_cpu_lookup_table[cpu];
158 
159 	if (cpumask_test_cpu(cpu, node_to_cpumask_map[node])) {
160 		cpumask_clear_cpu(cpu, node_to_cpumask_map[node]);
161 		pr_debug("removing cpu %lu from node %d\n", cpu, node);
162 	} else {
163 		pr_warn("Warning: cpu %lu not found in node %d\n", cpu, node);
164 	}
165 }
166 #endif /* CONFIG_HOTPLUG_CPU || CONFIG_PPC_SPLPAR */
167 
168 static int __associativity_to_nid(const __be32 *associativity,
169 				  int max_array_sz)
170 {
171 	int nid;
172 	/*
173 	 * primary_domain_index is 1 based array index.
174 	 */
175 	int index = primary_domain_index  - 1;
176 
177 	if (!numa_enabled || index >= max_array_sz)
178 		return NUMA_NO_NODE;
179 
180 	nid = of_read_number(&associativity[index], 1);
181 
182 	/* POWER4 LPAR uses 0xffff as invalid node */
183 	if (nid == 0xffff || nid >= nr_node_ids)
184 		nid = NUMA_NO_NODE;
185 	return nid;
186 }
187 /*
188  * Returns nid in the range [0..nr_node_ids], or -1 if no useful NUMA
189  * info is found.
190  */
191 static int associativity_to_nid(const __be32 *associativity)
192 {
193 	int array_sz = of_read_number(associativity, 1);
194 
195 	/* Skip the first element in the associativity array */
196 	return __associativity_to_nid((associativity + 1), array_sz);
197 }
198 
199 static int __cpu_form2_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
200 {
201 	int dist;
202 	int node1, node2;
203 
204 	node1 = associativity_to_nid(cpu1_assoc);
205 	node2 = associativity_to_nid(cpu2_assoc);
206 
207 	dist = numa_distance_table[node1][node2];
208 	if (dist <= LOCAL_DISTANCE)
209 		return 0;
210 	else if (dist <= REMOTE_DISTANCE)
211 		return 1;
212 	else
213 		return 2;
214 }
215 
216 static int __cpu_form1_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
217 {
218 	int dist = 0;
219 
220 	int i, index;
221 
222 	for (i = 0; i < distance_ref_points_depth; i++) {
223 		index = be32_to_cpu(distance_ref_points[i]);
224 		if (cpu1_assoc[index] == cpu2_assoc[index])
225 			break;
226 		dist++;
227 	}
228 
229 	return dist;
230 }
231 
232 int cpu_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
233 {
234 	/* We should not get called with FORM0 */
235 	VM_WARN_ON(affinity_form == FORM0_AFFINITY);
236 	if (affinity_form == FORM1_AFFINITY)
237 		return __cpu_form1_relative_distance(cpu1_assoc, cpu2_assoc);
238 	return __cpu_form2_relative_distance(cpu1_assoc, cpu2_assoc);
239 }
240 
241 /* must hold reference to node during call */
242 static const __be32 *of_get_associativity(struct device_node *dev)
243 {
244 	return of_get_property(dev, "ibm,associativity", NULL);
245 }
246 
247 int __node_distance(int a, int b)
248 {
249 	int i;
250 	int distance = LOCAL_DISTANCE;
251 
252 	if (affinity_form == FORM2_AFFINITY)
253 		return numa_distance_table[a][b];
254 	else if (affinity_form == FORM0_AFFINITY)
255 		return ((a == b) ? LOCAL_DISTANCE : REMOTE_DISTANCE);
256 
257 	for (i = 0; i < distance_ref_points_depth; i++) {
258 		if (distance_lookup_table[a][i] == distance_lookup_table[b][i])
259 			break;
260 
261 		/* Double the distance for each NUMA level */
262 		distance *= 2;
263 	}
264 
265 	return distance;
266 }
267 EXPORT_SYMBOL(__node_distance);
268 
269 /* Returns the nid associated with the given device tree node,
270  * or -1 if not found.
271  */
272 static int of_node_to_nid_single(struct device_node *device)
273 {
274 	int nid = NUMA_NO_NODE;
275 	const __be32 *tmp;
276 
277 	tmp = of_get_associativity(device);
278 	if (tmp)
279 		nid = associativity_to_nid(tmp);
280 	return nid;
281 }
282 
283 /* Walk the device tree upwards, looking for an associativity id */
284 int of_node_to_nid(struct device_node *device)
285 {
286 	int nid = NUMA_NO_NODE;
287 
288 	of_node_get(device);
289 	while (device) {
290 		nid = of_node_to_nid_single(device);
291 		if (nid != -1)
292 			break;
293 
294 		device = of_get_next_parent(device);
295 	}
296 	of_node_put(device);
297 
298 	return nid;
299 }
300 EXPORT_SYMBOL(of_node_to_nid);
301 
302 static void __initialize_form1_numa_distance(const __be32 *associativity,
303 					     int max_array_sz)
304 {
305 	int i, nid;
306 
307 	if (affinity_form != FORM1_AFFINITY)
308 		return;
309 
310 	nid = __associativity_to_nid(associativity, max_array_sz);
311 	if (nid != NUMA_NO_NODE) {
312 		for (i = 0; i < distance_ref_points_depth; i++) {
313 			const __be32 *entry;
314 			int index = be32_to_cpu(distance_ref_points[i]) - 1;
315 
316 			/*
317 			 * broken hierarchy, return with broken distance table
318 			 */
319 			if (WARN(index >= max_array_sz, "Broken ibm,associativity property"))
320 				return;
321 
322 			entry = &associativity[index];
323 			distance_lookup_table[nid][i] = of_read_number(entry, 1);
324 		}
325 	}
326 }
327 
328 static void initialize_form1_numa_distance(const __be32 *associativity)
329 {
330 	int array_sz;
331 
332 	array_sz = of_read_number(associativity, 1);
333 	/* Skip the first element in the associativity array */
334 	__initialize_form1_numa_distance(associativity + 1, array_sz);
335 }
336 
337 /*
338  * Used to update distance information w.r.t newly added node.
339  */
340 void update_numa_distance(struct device_node *node)
341 {
342 	int nid;
343 
344 	if (affinity_form == FORM0_AFFINITY)
345 		return;
346 	else if (affinity_form == FORM1_AFFINITY) {
347 		const __be32 *associativity;
348 
349 		associativity = of_get_associativity(node);
350 		if (!associativity)
351 			return;
352 
353 		initialize_form1_numa_distance(associativity);
354 		return;
355 	}
356 
357 	/* FORM2 affinity  */
358 	nid = of_node_to_nid_single(node);
359 	if (nid == NUMA_NO_NODE)
360 		return;
361 
362 	/*
363 	 * With FORM2 we expect NUMA distance of all possible NUMA
364 	 * nodes to be provided during boot.
365 	 */
366 	WARN(numa_distance_table[nid][nid] == -1,
367 	     "NUMA distance details for node %d not provided\n", nid);
368 }
369 
370 /*
371  * ibm,numa-lookup-index-table= {N, domainid1, domainid2, ..... domainidN}
372  * ibm,numa-distance-table = { N, 1, 2, 4, 5, 1, 6, .... N elements}
373  */
374 static void __init initialize_form2_numa_distance_lookup_table(void)
375 {
376 	int i, j;
377 	struct device_node *root;
378 	const __u8 *form2_distances;
379 	const __be32 *numa_lookup_index;
380 	int form2_distances_length;
381 	int max_numa_index, distance_index;
382 
383 	if (firmware_has_feature(FW_FEATURE_OPAL))
384 		root = of_find_node_by_path("/ibm,opal");
385 	else
386 		root = of_find_node_by_path("/rtas");
387 	if (!root)
388 		root = of_find_node_by_path("/");
389 
390 	numa_lookup_index = of_get_property(root, "ibm,numa-lookup-index-table", NULL);
391 	max_numa_index = of_read_number(&numa_lookup_index[0], 1);
392 
393 	/* first element of the array is the size and is encode-int */
394 	form2_distances = of_get_property(root, "ibm,numa-distance-table", NULL);
395 	form2_distances_length = of_read_number((const __be32 *)&form2_distances[0], 1);
396 	/* Skip the size which is encoded int */
397 	form2_distances += sizeof(__be32);
398 
399 	pr_debug("form2_distances_len = %d, numa_dist_indexes_len = %d\n",
400 		 form2_distances_length, max_numa_index);
401 
402 	for (i = 0; i < max_numa_index; i++)
403 		/* +1 skip the max_numa_index in the property */
404 		numa_id_index_table[i] = of_read_number(&numa_lookup_index[i + 1], 1);
405 
406 
407 	if (form2_distances_length != max_numa_index * max_numa_index) {
408 		WARN(1, "Wrong NUMA distance information\n");
409 		form2_distances = NULL; // don't use it
410 	}
411 	distance_index = 0;
412 	for (i = 0;  i < max_numa_index; i++) {
413 		for (j = 0; j < max_numa_index; j++) {
414 			int nodeA = numa_id_index_table[i];
415 			int nodeB = numa_id_index_table[j];
416 			int dist;
417 
418 			if (form2_distances)
419 				dist = form2_distances[distance_index++];
420 			else if (nodeA == nodeB)
421 				dist = LOCAL_DISTANCE;
422 			else
423 				dist = REMOTE_DISTANCE;
424 			numa_distance_table[nodeA][nodeB] = dist;
425 			pr_debug("dist[%d][%d]=%d ", nodeA, nodeB, dist);
426 		}
427 	}
428 
429 	of_node_put(root);
430 }
431 
432 static int __init find_primary_domain_index(void)
433 {
434 	int index;
435 	struct device_node *root;
436 
437 	/*
438 	 * Check for which form of affinity.
439 	 */
440 	if (firmware_has_feature(FW_FEATURE_OPAL)) {
441 		affinity_form = FORM1_AFFINITY;
442 	} else if (firmware_has_feature(FW_FEATURE_FORM2_AFFINITY)) {
443 		pr_debug("Using form 2 affinity\n");
444 		affinity_form = FORM2_AFFINITY;
445 	} else if (firmware_has_feature(FW_FEATURE_FORM1_AFFINITY)) {
446 		pr_debug("Using form 1 affinity\n");
447 		affinity_form = FORM1_AFFINITY;
448 	} else
449 		affinity_form = FORM0_AFFINITY;
450 
451 	if (firmware_has_feature(FW_FEATURE_OPAL))
452 		root = of_find_node_by_path("/ibm,opal");
453 	else
454 		root = of_find_node_by_path("/rtas");
455 	if (!root)
456 		root = of_find_node_by_path("/");
457 
458 	/*
459 	 * This property is a set of 32-bit integers, each representing
460 	 * an index into the ibm,associativity nodes.
461 	 *
462 	 * With form 0 affinity the first integer is for an SMP configuration
463 	 * (should be all 0's) and the second is for a normal NUMA
464 	 * configuration. We have only one level of NUMA.
465 	 *
466 	 * With form 1 affinity the first integer is the most significant
467 	 * NUMA boundary and the following are progressively less significant
468 	 * boundaries. There can be more than one level of NUMA.
469 	 */
470 	distance_ref_points = of_get_property(root,
471 					"ibm,associativity-reference-points",
472 					&distance_ref_points_depth);
473 
474 	if (!distance_ref_points) {
475 		pr_debug("ibm,associativity-reference-points not found.\n");
476 		goto err;
477 	}
478 
479 	distance_ref_points_depth /= sizeof(int);
480 	if (affinity_form == FORM0_AFFINITY) {
481 		if (distance_ref_points_depth < 2) {
482 			pr_warn("short ibm,associativity-reference-points\n");
483 			goto err;
484 		}
485 
486 		index = of_read_number(&distance_ref_points[1], 1);
487 	} else {
488 		/*
489 		 * Both FORM1 and FORM2 affinity find the primary domain details
490 		 * at the same offset.
491 		 */
492 		index = of_read_number(distance_ref_points, 1);
493 	}
494 	/*
495 	 * Warn and cap if the hardware supports more than
496 	 * MAX_DISTANCE_REF_POINTS domains.
497 	 */
498 	if (distance_ref_points_depth > MAX_DISTANCE_REF_POINTS) {
499 		pr_warn("distance array capped at %d entries\n",
500 			MAX_DISTANCE_REF_POINTS);
501 		distance_ref_points_depth = MAX_DISTANCE_REF_POINTS;
502 	}
503 
504 	of_node_put(root);
505 	return index;
506 
507 err:
508 	of_node_put(root);
509 	return -1;
510 }
511 
512 static void __init get_n_mem_cells(int *n_addr_cells, int *n_size_cells)
513 {
514 	struct device_node *memory = NULL;
515 
516 	memory = of_find_node_by_type(memory, "memory");
517 	if (!memory)
518 		panic("numa.c: No memory nodes found!");
519 
520 	*n_addr_cells = of_n_addr_cells(memory);
521 	*n_size_cells = of_n_size_cells(memory);
522 	of_node_put(memory);
523 }
524 
525 static unsigned long read_n_cells(int n, const __be32 **buf)
526 {
527 	unsigned long result = 0;
528 
529 	while (n--) {
530 		result = (result << 32) | of_read_number(*buf, 1);
531 		(*buf)++;
532 	}
533 	return result;
534 }
535 
536 struct assoc_arrays {
537 	u32	n_arrays;
538 	u32	array_sz;
539 	const __be32 *arrays;
540 };
541 
542 /*
543  * Retrieve and validate the list of associativity arrays for drconf
544  * memory from the ibm,associativity-lookup-arrays property of the
545  * device tree..
546  *
547  * The layout of the ibm,associativity-lookup-arrays property is a number N
548  * indicating the number of associativity arrays, followed by a number M
549  * indicating the size of each associativity array, followed by a list
550  * of N associativity arrays.
551  */
552 static int of_get_assoc_arrays(struct assoc_arrays *aa)
553 {
554 	struct device_node *memory;
555 	const __be32 *prop;
556 	u32 len;
557 
558 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
559 	if (!memory)
560 		return -1;
561 
562 	prop = of_get_property(memory, "ibm,associativity-lookup-arrays", &len);
563 	if (!prop || len < 2 * sizeof(unsigned int)) {
564 		of_node_put(memory);
565 		return -1;
566 	}
567 
568 	aa->n_arrays = of_read_number(prop++, 1);
569 	aa->array_sz = of_read_number(prop++, 1);
570 
571 	of_node_put(memory);
572 
573 	/* Now that we know the number of arrays and size of each array,
574 	 * revalidate the size of the property read in.
575 	 */
576 	if (len < (aa->n_arrays * aa->array_sz + 2) * sizeof(unsigned int))
577 		return -1;
578 
579 	aa->arrays = prop;
580 	return 0;
581 }
582 
583 static int __init get_nid_and_numa_distance(struct drmem_lmb *lmb)
584 {
585 	struct assoc_arrays aa = { .arrays = NULL };
586 	int default_nid = NUMA_NO_NODE;
587 	int nid = default_nid;
588 	int rc, index;
589 
590 	if ((primary_domain_index < 0) || !numa_enabled)
591 		return default_nid;
592 
593 	rc = of_get_assoc_arrays(&aa);
594 	if (rc)
595 		return default_nid;
596 
597 	if (primary_domain_index <= aa.array_sz &&
598 	    !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
599 		const __be32 *associativity;
600 
601 		index = lmb->aa_index * aa.array_sz;
602 		associativity = &aa.arrays[index];
603 		nid = __associativity_to_nid(associativity, aa.array_sz);
604 		if (nid > 0 && affinity_form == FORM1_AFFINITY) {
605 			/*
606 			 * lookup array associativity entries have
607 			 * no length of the array as the first element.
608 			 */
609 			__initialize_form1_numa_distance(associativity, aa.array_sz);
610 		}
611 	}
612 	return nid;
613 }
614 
615 /*
616  * This is like of_node_to_nid_single() for memory represented in the
617  * ibm,dynamic-reconfiguration-memory node.
618  */
619 int of_drconf_to_nid_single(struct drmem_lmb *lmb)
620 {
621 	struct assoc_arrays aa = { .arrays = NULL };
622 	int default_nid = NUMA_NO_NODE;
623 	int nid = default_nid;
624 	int rc, index;
625 
626 	if ((primary_domain_index < 0) || !numa_enabled)
627 		return default_nid;
628 
629 	rc = of_get_assoc_arrays(&aa);
630 	if (rc)
631 		return default_nid;
632 
633 	if (primary_domain_index <= aa.array_sz &&
634 	    !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
635 		const __be32 *associativity;
636 
637 		index = lmb->aa_index * aa.array_sz;
638 		associativity = &aa.arrays[index];
639 		nid = __associativity_to_nid(associativity, aa.array_sz);
640 	}
641 	return nid;
642 }
643 
644 #ifdef CONFIG_PPC_SPLPAR
645 
646 static int __vphn_get_associativity(long lcpu, __be32 *associativity)
647 {
648 	long rc, hwid;
649 
650 	/*
651 	 * On a shared lpar, device tree will not have node associativity.
652 	 * At this time lppaca, or its __old_status field may not be
653 	 * updated. Hence kernel cannot detect if its on a shared lpar. So
654 	 * request an explicit associativity irrespective of whether the
655 	 * lpar is shared or dedicated. Use the device tree property as a
656 	 * fallback. cpu_to_phys_id is only valid between
657 	 * smp_setup_cpu_maps() and smp_setup_pacas().
658 	 */
659 	if (firmware_has_feature(FW_FEATURE_VPHN)) {
660 		if (cpu_to_phys_id)
661 			hwid = cpu_to_phys_id[lcpu];
662 		else
663 			hwid = get_hard_smp_processor_id(lcpu);
664 
665 		rc = hcall_vphn(hwid, VPHN_FLAG_VCPU, associativity);
666 		if (rc == H_SUCCESS)
667 			return 0;
668 	}
669 
670 	return -1;
671 }
672 
673 static int vphn_get_nid(long lcpu)
674 {
675 	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
676 
677 
678 	if (!__vphn_get_associativity(lcpu, associativity))
679 		return associativity_to_nid(associativity);
680 
681 	return NUMA_NO_NODE;
682 
683 }
684 #else
685 
686 static int __vphn_get_associativity(long lcpu, __be32 *associativity)
687 {
688 	return -1;
689 }
690 
691 static int vphn_get_nid(long unused)
692 {
693 	return NUMA_NO_NODE;
694 }
695 #endif  /* CONFIG_PPC_SPLPAR */
696 
697 /*
698  * Figure out to which domain a cpu belongs and stick it there.
699  * Return the id of the domain used.
700  */
701 static int numa_setup_cpu(unsigned long lcpu)
702 {
703 	struct device_node *cpu;
704 	int fcpu = cpu_first_thread_sibling(lcpu);
705 	int nid = NUMA_NO_NODE;
706 
707 	if (!cpu_present(lcpu)) {
708 		set_cpu_numa_node(lcpu, first_online_node);
709 		return first_online_node;
710 	}
711 
712 	/*
713 	 * If a valid cpu-to-node mapping is already available, use it
714 	 * directly instead of querying the firmware, since it represents
715 	 * the most recent mapping notified to us by the platform (eg: VPHN).
716 	 * Since cpu_to_node binding remains the same for all threads in the
717 	 * core. If a valid cpu-to-node mapping is already available, for
718 	 * the first thread in the core, use it.
719 	 */
720 	nid = numa_cpu_lookup_table[fcpu];
721 	if (nid >= 0) {
722 		map_cpu_to_node(lcpu, nid);
723 		return nid;
724 	}
725 
726 	nid = vphn_get_nid(lcpu);
727 	if (nid != NUMA_NO_NODE)
728 		goto out_present;
729 
730 	cpu = of_get_cpu_node(lcpu, NULL);
731 
732 	if (!cpu) {
733 		WARN_ON(1);
734 		if (cpu_present(lcpu))
735 			goto out_present;
736 		else
737 			goto out;
738 	}
739 
740 	nid = of_node_to_nid_single(cpu);
741 	of_node_put(cpu);
742 
743 out_present:
744 	if (nid < 0 || !node_possible(nid))
745 		nid = first_online_node;
746 
747 	/*
748 	 * Update for the first thread of the core. All threads of a core
749 	 * have to be part of the same node. This not only avoids querying
750 	 * for every other thread in the core, but always avoids a case
751 	 * where virtual node associativity change causes subsequent threads
752 	 * of a core to be associated with different nid. However if first
753 	 * thread is already online, expect it to have a valid mapping.
754 	 */
755 	if (fcpu != lcpu) {
756 		WARN_ON(cpu_online(fcpu));
757 		map_cpu_to_node(fcpu, nid);
758 	}
759 
760 	map_cpu_to_node(lcpu, nid);
761 out:
762 	return nid;
763 }
764 
765 static void verify_cpu_node_mapping(int cpu, int node)
766 {
767 	int base, sibling, i;
768 
769 	/* Verify that all the threads in the core belong to the same node */
770 	base = cpu_first_thread_sibling(cpu);
771 
772 	for (i = 0; i < threads_per_core; i++) {
773 		sibling = base + i;
774 
775 		if (sibling == cpu || cpu_is_offline(sibling))
776 			continue;
777 
778 		if (cpu_to_node(sibling) != node) {
779 			WARN(1, "CPU thread siblings %d and %d don't belong"
780 				" to the same node!\n", cpu, sibling);
781 			break;
782 		}
783 	}
784 }
785 
786 /* Must run before sched domains notifier. */
787 static int ppc_numa_cpu_prepare(unsigned int cpu)
788 {
789 	int nid;
790 
791 	nid = numa_setup_cpu(cpu);
792 	verify_cpu_node_mapping(cpu, nid);
793 	return 0;
794 }
795 
796 static int ppc_numa_cpu_dead(unsigned int cpu)
797 {
798 	return 0;
799 }
800 
801 /*
802  * Check and possibly modify a memory region to enforce the memory limit.
803  *
804  * Returns the size the region should have to enforce the memory limit.
805  * This will either be the original value of size, a truncated value,
806  * or zero. If the returned value of size is 0 the region should be
807  * discarded as it lies wholly above the memory limit.
808  */
809 static unsigned long __init numa_enforce_memory_limit(unsigned long start,
810 						      unsigned long size)
811 {
812 	/*
813 	 * We use memblock_end_of_DRAM() in here instead of memory_limit because
814 	 * we've already adjusted it for the limit and it takes care of
815 	 * having memory holes below the limit.  Also, in the case of
816 	 * iommu_is_off, memory_limit is not set but is implicitly enforced.
817 	 */
818 
819 	if (start + size <= memblock_end_of_DRAM())
820 		return size;
821 
822 	if (start >= memblock_end_of_DRAM())
823 		return 0;
824 
825 	return memblock_end_of_DRAM() - start;
826 }
827 
828 /*
829  * Reads the counter for a given entry in
830  * linux,drconf-usable-memory property
831  */
832 static inline int __init read_usm_ranges(const __be32 **usm)
833 {
834 	/*
835 	 * For each lmb in ibm,dynamic-memory a corresponding
836 	 * entry in linux,drconf-usable-memory property contains
837 	 * a counter followed by that many (base, size) duple.
838 	 * read the counter from linux,drconf-usable-memory
839 	 */
840 	return read_n_cells(n_mem_size_cells, usm);
841 }
842 
843 /*
844  * Extract NUMA information from the ibm,dynamic-reconfiguration-memory
845  * node.  This assumes n_mem_{addr,size}_cells have been set.
846  */
847 static int __init numa_setup_drmem_lmb(struct drmem_lmb *lmb,
848 					const __be32 **usm,
849 					void *data)
850 {
851 	unsigned int ranges, is_kexec_kdump = 0;
852 	unsigned long base, size, sz;
853 	int nid;
854 
855 	/*
856 	 * Skip this block if the reserved bit is set in flags (0x80)
857 	 * or if the block is not assigned to this partition (0x8)
858 	 */
859 	if ((lmb->flags & DRCONF_MEM_RESERVED)
860 	    || !(lmb->flags & DRCONF_MEM_ASSIGNED))
861 		return 0;
862 
863 	if (*usm)
864 		is_kexec_kdump = 1;
865 
866 	base = lmb->base_addr;
867 	size = drmem_lmb_size();
868 	ranges = 1;
869 
870 	if (is_kexec_kdump) {
871 		ranges = read_usm_ranges(usm);
872 		if (!ranges) /* there are no (base, size) duple */
873 			return 0;
874 	}
875 
876 	do {
877 		if (is_kexec_kdump) {
878 			base = read_n_cells(n_mem_addr_cells, usm);
879 			size = read_n_cells(n_mem_size_cells, usm);
880 		}
881 
882 		nid = get_nid_and_numa_distance(lmb);
883 		fake_numa_create_new_node(((base + size) >> PAGE_SHIFT),
884 					  &nid);
885 		node_set_online(nid);
886 		sz = numa_enforce_memory_limit(base, size);
887 		if (sz)
888 			memblock_set_node(base, sz, &memblock.memory, nid);
889 	} while (--ranges);
890 
891 	return 0;
892 }
893 
894 static int __init parse_numa_properties(void)
895 {
896 	struct device_node *memory;
897 	int default_nid = 0;
898 	unsigned long i;
899 	const __be32 *associativity;
900 
901 	if (numa_enabled == 0) {
902 		pr_warn("disabled by user\n");
903 		return -1;
904 	}
905 
906 	primary_domain_index = find_primary_domain_index();
907 
908 	if (primary_domain_index < 0) {
909 		/*
910 		 * if we fail to parse primary_domain_index from device tree
911 		 * mark the numa disabled, boot with numa disabled.
912 		 */
913 		numa_enabled = false;
914 		return primary_domain_index;
915 	}
916 
917 	pr_debug("associativity depth for CPU/Memory: %d\n", primary_domain_index);
918 
919 	/*
920 	 * If it is FORM2 initialize the distance table here.
921 	 */
922 	if (affinity_form == FORM2_AFFINITY)
923 		initialize_form2_numa_distance_lookup_table();
924 
925 	/*
926 	 * Even though we connect cpus to numa domains later in SMP
927 	 * init, we need to know the node ids now. This is because
928 	 * each node to be onlined must have NODE_DATA etc backing it.
929 	 */
930 	for_each_present_cpu(i) {
931 		__be32 vphn_assoc[VPHN_ASSOC_BUFSIZE];
932 		struct device_node *cpu;
933 		int nid = NUMA_NO_NODE;
934 
935 		memset(vphn_assoc, 0, VPHN_ASSOC_BUFSIZE * sizeof(__be32));
936 
937 		if (__vphn_get_associativity(i, vphn_assoc) == 0) {
938 			nid = associativity_to_nid(vphn_assoc);
939 			initialize_form1_numa_distance(vphn_assoc);
940 		} else {
941 
942 			/*
943 			 * Don't fall back to default_nid yet -- we will plug
944 			 * cpus into nodes once the memory scan has discovered
945 			 * the topology.
946 			 */
947 			cpu = of_get_cpu_node(i, NULL);
948 			BUG_ON(!cpu);
949 
950 			associativity = of_get_associativity(cpu);
951 			if (associativity) {
952 				nid = associativity_to_nid(associativity);
953 				initialize_form1_numa_distance(associativity);
954 			}
955 			of_node_put(cpu);
956 		}
957 
958 		/* node_set_online() is an UB if 'nid' is negative */
959 		if (likely(nid >= 0))
960 			node_set_online(nid);
961 	}
962 
963 	get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells);
964 
965 	for_each_node_by_type(memory, "memory") {
966 		unsigned long start;
967 		unsigned long size;
968 		int nid;
969 		int ranges;
970 		const __be32 *memcell_buf;
971 		unsigned int len;
972 
973 		memcell_buf = of_get_property(memory,
974 			"linux,usable-memory", &len);
975 		if (!memcell_buf || len <= 0)
976 			memcell_buf = of_get_property(memory, "reg", &len);
977 		if (!memcell_buf || len <= 0)
978 			continue;
979 
980 		/* ranges in cell */
981 		ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
982 new_range:
983 		/* these are order-sensitive, and modify the buffer pointer */
984 		start = read_n_cells(n_mem_addr_cells, &memcell_buf);
985 		size = read_n_cells(n_mem_size_cells, &memcell_buf);
986 
987 		/*
988 		 * Assumption: either all memory nodes or none will
989 		 * have associativity properties.  If none, then
990 		 * everything goes to default_nid.
991 		 */
992 		associativity = of_get_associativity(memory);
993 		if (associativity) {
994 			nid = associativity_to_nid(associativity);
995 			initialize_form1_numa_distance(associativity);
996 		} else
997 			nid = default_nid;
998 
999 		fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);
1000 		node_set_online(nid);
1001 
1002 		size = numa_enforce_memory_limit(start, size);
1003 		if (size)
1004 			memblock_set_node(start, size, &memblock.memory, nid);
1005 
1006 		if (--ranges)
1007 			goto new_range;
1008 	}
1009 
1010 	/*
1011 	 * Now do the same thing for each MEMBLOCK listed in the
1012 	 * ibm,dynamic-memory property in the
1013 	 * ibm,dynamic-reconfiguration-memory node.
1014 	 */
1015 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1016 	if (memory) {
1017 		walk_drmem_lmbs(memory, NULL, numa_setup_drmem_lmb);
1018 		of_node_put(memory);
1019 	}
1020 
1021 	return 0;
1022 }
1023 
1024 static void __init setup_nonnuma(void)
1025 {
1026 	unsigned long top_of_ram = memblock_end_of_DRAM();
1027 	unsigned long total_ram = memblock_phys_mem_size();
1028 	unsigned long start_pfn, end_pfn;
1029 	unsigned int nid = 0;
1030 	int i;
1031 
1032 	pr_debug("Top of RAM: 0x%lx, Total RAM: 0x%lx\n", top_of_ram, total_ram);
1033 	pr_debug("Memory hole size: %ldMB\n", (top_of_ram - total_ram) >> 20);
1034 
1035 	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
1036 		fake_numa_create_new_node(end_pfn, &nid);
1037 		memblock_set_node(PFN_PHYS(start_pfn),
1038 				  PFN_PHYS(end_pfn - start_pfn),
1039 				  &memblock.memory, nid);
1040 		node_set_online(nid);
1041 	}
1042 }
1043 
1044 void __init dump_numa_cpu_topology(void)
1045 {
1046 	unsigned int node;
1047 	unsigned int cpu, count;
1048 
1049 	if (!numa_enabled)
1050 		return;
1051 
1052 	for_each_online_node(node) {
1053 		pr_info("Node %d CPUs:", node);
1054 
1055 		count = 0;
1056 		/*
1057 		 * If we used a CPU iterator here we would miss printing
1058 		 * the holes in the cpumap.
1059 		 */
1060 		for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
1061 			if (cpumask_test_cpu(cpu,
1062 					node_to_cpumask_map[node])) {
1063 				if (count == 0)
1064 					pr_cont(" %u", cpu);
1065 				++count;
1066 			} else {
1067 				if (count > 1)
1068 					pr_cont("-%u", cpu - 1);
1069 				count = 0;
1070 			}
1071 		}
1072 
1073 		if (count > 1)
1074 			pr_cont("-%u", nr_cpu_ids - 1);
1075 		pr_cont("\n");
1076 	}
1077 }
1078 
1079 /* Initialize NODE_DATA for a node on the local memory */
1080 static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
1081 {
1082 	u64 spanned_pages = end_pfn - start_pfn;
1083 	const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);
1084 	u64 nd_pa;
1085 	void *nd;
1086 	int tnid;
1087 
1088 	nd_pa = memblock_phys_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
1089 	if (!nd_pa)
1090 		panic("Cannot allocate %zu bytes for node %d data\n",
1091 		      nd_size, nid);
1092 
1093 	nd = __va(nd_pa);
1094 
1095 	/* report and initialize */
1096 	pr_info("  NODE_DATA [mem %#010Lx-%#010Lx]\n",
1097 		nd_pa, nd_pa + nd_size - 1);
1098 	tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
1099 	if (tnid != nid)
1100 		pr_info("    NODE_DATA(%d) on node %d\n", nid, tnid);
1101 
1102 	node_data[nid] = nd;
1103 	memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
1104 	NODE_DATA(nid)->node_id = nid;
1105 	NODE_DATA(nid)->node_start_pfn = start_pfn;
1106 	NODE_DATA(nid)->node_spanned_pages = spanned_pages;
1107 }
1108 
1109 static void __init find_possible_nodes(void)
1110 {
1111 	struct device_node *rtas;
1112 	const __be32 *domains = NULL;
1113 	int prop_length, max_nodes;
1114 	u32 i;
1115 
1116 	if (!numa_enabled)
1117 		return;
1118 
1119 	rtas = of_find_node_by_path("/rtas");
1120 	if (!rtas)
1121 		return;
1122 
1123 	/*
1124 	 * ibm,current-associativity-domains is a fairly recent property. If
1125 	 * it doesn't exist, then fallback on ibm,max-associativity-domains.
1126 	 * Current denotes what the platform can support compared to max
1127 	 * which denotes what the Hypervisor can support.
1128 	 *
1129 	 * If the LPAR is migratable, new nodes might be activated after a LPM,
1130 	 * so we should consider the max number in that case.
1131 	 */
1132 	if (!of_get_property(of_root, "ibm,migratable-partition", NULL))
1133 		domains = of_get_property(rtas,
1134 					  "ibm,current-associativity-domains",
1135 					  &prop_length);
1136 	if (!domains) {
1137 		domains = of_get_property(rtas, "ibm,max-associativity-domains",
1138 					&prop_length);
1139 		if (!domains)
1140 			goto out;
1141 	}
1142 
1143 	max_nodes = of_read_number(&domains[primary_domain_index], 1);
1144 	pr_info("Partition configured for %d NUMA nodes.\n", max_nodes);
1145 
1146 	for (i = 0; i < max_nodes; i++) {
1147 		if (!node_possible(i))
1148 			node_set(i, node_possible_map);
1149 	}
1150 
1151 	prop_length /= sizeof(int);
1152 	if (prop_length > primary_domain_index + 2)
1153 		coregroup_enabled = 1;
1154 
1155 out:
1156 	of_node_put(rtas);
1157 }
1158 
1159 void __init mem_topology_setup(void)
1160 {
1161 	int cpu;
1162 
1163 	/*
1164 	 * Linux/mm assumes node 0 to be online at boot. However this is not
1165 	 * true on PowerPC, where node 0 is similar to any other node, it
1166 	 * could be cpuless, memoryless node. So force node 0 to be offline
1167 	 * for now. This will prevent cpuless, memoryless node 0 showing up
1168 	 * unnecessarily as online. If a node has cpus or memory that need
1169 	 * to be online, then node will anyway be marked online.
1170 	 */
1171 	node_set_offline(0);
1172 
1173 	if (parse_numa_properties())
1174 		setup_nonnuma();
1175 
1176 	/*
1177 	 * Modify the set of possible NUMA nodes to reflect information
1178 	 * available about the set of online nodes, and the set of nodes
1179 	 * that we expect to make use of for this platform's affinity
1180 	 * calculations.
1181 	 */
1182 	nodes_and(node_possible_map, node_possible_map, node_online_map);
1183 
1184 	find_possible_nodes();
1185 
1186 	setup_node_to_cpumask_map();
1187 
1188 	reset_numa_cpu_lookup_table();
1189 
1190 	for_each_possible_cpu(cpu) {
1191 		/*
1192 		 * Powerpc with CONFIG_NUMA always used to have a node 0,
1193 		 * even if it was memoryless or cpuless. For all cpus that
1194 		 * are possible but not present, cpu_to_node() would point
1195 		 * to node 0. To remove a cpuless, memoryless dummy node,
1196 		 * powerpc need to make sure all possible but not present
1197 		 * cpu_to_node are set to a proper node.
1198 		 */
1199 		numa_setup_cpu(cpu);
1200 	}
1201 }
1202 
1203 void __init initmem_init(void)
1204 {
1205 	int nid;
1206 
1207 	max_low_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
1208 	max_pfn = max_low_pfn;
1209 
1210 	memblock_dump_all();
1211 
1212 	for_each_online_node(nid) {
1213 		unsigned long start_pfn, end_pfn;
1214 
1215 		get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
1216 		setup_node_data(nid, start_pfn, end_pfn);
1217 	}
1218 
1219 	sparse_init();
1220 
1221 	/*
1222 	 * We need the numa_cpu_lookup_table to be accurate for all CPUs,
1223 	 * even before we online them, so that we can use cpu_to_{node,mem}
1224 	 * early in boot, cf. smp_prepare_cpus().
1225 	 * _nocalls() + manual invocation is used because cpuhp is not yet
1226 	 * initialized for the boot CPU.
1227 	 */
1228 	cpuhp_setup_state_nocalls(CPUHP_POWER_NUMA_PREPARE, "powerpc/numa:prepare",
1229 				  ppc_numa_cpu_prepare, ppc_numa_cpu_dead);
1230 }
1231 
1232 static int __init early_numa(char *p)
1233 {
1234 	if (!p)
1235 		return 0;
1236 
1237 	if (strstr(p, "off"))
1238 		numa_enabled = 0;
1239 
1240 	p = strstr(p, "fake=");
1241 	if (p)
1242 		cmdline = p + strlen("fake=");
1243 
1244 	return 0;
1245 }
1246 early_param("numa", early_numa);
1247 
1248 #ifdef CONFIG_MEMORY_HOTPLUG
1249 /*
1250  * Find the node associated with a hot added memory section for
1251  * memory represented in the device tree by the property
1252  * ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory.
1253  */
1254 static int hot_add_drconf_scn_to_nid(unsigned long scn_addr)
1255 {
1256 	struct drmem_lmb *lmb;
1257 	unsigned long lmb_size;
1258 	int nid = NUMA_NO_NODE;
1259 
1260 	lmb_size = drmem_lmb_size();
1261 
1262 	for_each_drmem_lmb(lmb) {
1263 		/* skip this block if it is reserved or not assigned to
1264 		 * this partition */
1265 		if ((lmb->flags & DRCONF_MEM_RESERVED)
1266 		    || !(lmb->flags & DRCONF_MEM_ASSIGNED))
1267 			continue;
1268 
1269 		if ((scn_addr < lmb->base_addr)
1270 		    || (scn_addr >= (lmb->base_addr + lmb_size)))
1271 			continue;
1272 
1273 		nid = of_drconf_to_nid_single(lmb);
1274 		break;
1275 	}
1276 
1277 	return nid;
1278 }
1279 
1280 /*
1281  * Find the node associated with a hot added memory section for memory
1282  * represented in the device tree as a node (i.e. memory@XXXX) for
1283  * each memblock.
1284  */
1285 static int hot_add_node_scn_to_nid(unsigned long scn_addr)
1286 {
1287 	struct device_node *memory;
1288 	int nid = NUMA_NO_NODE;
1289 
1290 	for_each_node_by_type(memory, "memory") {
1291 		unsigned long start, size;
1292 		int ranges;
1293 		const __be32 *memcell_buf;
1294 		unsigned int len;
1295 
1296 		memcell_buf = of_get_property(memory, "reg", &len);
1297 		if (!memcell_buf || len <= 0)
1298 			continue;
1299 
1300 		/* ranges in cell */
1301 		ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
1302 
1303 		while (ranges--) {
1304 			start = read_n_cells(n_mem_addr_cells, &memcell_buf);
1305 			size = read_n_cells(n_mem_size_cells, &memcell_buf);
1306 
1307 			if ((scn_addr < start) || (scn_addr >= (start + size)))
1308 				continue;
1309 
1310 			nid = of_node_to_nid_single(memory);
1311 			break;
1312 		}
1313 
1314 		if (nid >= 0)
1315 			break;
1316 	}
1317 
1318 	of_node_put(memory);
1319 
1320 	return nid;
1321 }
1322 
1323 /*
1324  * Find the node associated with a hot added memory section.  Section
1325  * corresponds to a SPARSEMEM section, not an MEMBLOCK.  It is assumed that
1326  * sections are fully contained within a single MEMBLOCK.
1327  */
1328 int hot_add_scn_to_nid(unsigned long scn_addr)
1329 {
1330 	struct device_node *memory = NULL;
1331 	int nid;
1332 
1333 	if (!numa_enabled)
1334 		return first_online_node;
1335 
1336 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1337 	if (memory) {
1338 		nid = hot_add_drconf_scn_to_nid(scn_addr);
1339 		of_node_put(memory);
1340 	} else {
1341 		nid = hot_add_node_scn_to_nid(scn_addr);
1342 	}
1343 
1344 	if (nid < 0 || !node_possible(nid))
1345 		nid = first_online_node;
1346 
1347 	return nid;
1348 }
1349 
1350 static u64 hot_add_drconf_memory_max(void)
1351 {
1352 	struct device_node *memory = NULL;
1353 	struct device_node *dn = NULL;
1354 	const __be64 *lrdr = NULL;
1355 
1356 	dn = of_find_node_by_path("/rtas");
1357 	if (dn) {
1358 		lrdr = of_get_property(dn, "ibm,lrdr-capacity", NULL);
1359 		of_node_put(dn);
1360 		if (lrdr)
1361 			return be64_to_cpup(lrdr);
1362 	}
1363 
1364 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1365 	if (memory) {
1366 		of_node_put(memory);
1367 		return drmem_lmb_memory_max();
1368 	}
1369 	return 0;
1370 }
1371 
1372 /*
1373  * memory_hotplug_max - return max address of memory that may be added
1374  *
1375  * This is currently only used on systems that support drconfig memory
1376  * hotplug.
1377  */
1378 u64 memory_hotplug_max(void)
1379 {
1380         return max(hot_add_drconf_memory_max(), memblock_end_of_DRAM());
1381 }
1382 #endif /* CONFIG_MEMORY_HOTPLUG */
1383 
1384 /* Virtual Processor Home Node (VPHN) support */
1385 #ifdef CONFIG_PPC_SPLPAR
1386 static int topology_inited;
1387 
1388 /*
1389  * Retrieve the new associativity information for a virtual processor's
1390  * home node.
1391  */
1392 static long vphn_get_associativity(unsigned long cpu,
1393 					__be32 *associativity)
1394 {
1395 	long rc;
1396 
1397 	rc = hcall_vphn(get_hard_smp_processor_id(cpu),
1398 				VPHN_FLAG_VCPU, associativity);
1399 
1400 	switch (rc) {
1401 	case H_SUCCESS:
1402 		pr_debug("VPHN hcall succeeded. Reset polling...\n");
1403 		goto out;
1404 
1405 	case H_FUNCTION:
1406 		pr_err_ratelimited("VPHN unsupported. Disabling polling...\n");
1407 		break;
1408 	case H_HARDWARE:
1409 		pr_err_ratelimited("hcall_vphn() experienced a hardware fault "
1410 			"preventing VPHN. Disabling polling...\n");
1411 		break;
1412 	case H_PARAMETER:
1413 		pr_err_ratelimited("hcall_vphn() was passed an invalid parameter. "
1414 			"Disabling polling...\n");
1415 		break;
1416 	default:
1417 		pr_err_ratelimited("hcall_vphn() returned %ld. Disabling polling...\n"
1418 			, rc);
1419 		break;
1420 	}
1421 out:
1422 	return rc;
1423 }
1424 
1425 void find_and_update_cpu_nid(int cpu)
1426 {
1427 	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
1428 	int new_nid;
1429 
1430 	/* Use associativity from first thread for all siblings */
1431 	if (vphn_get_associativity(cpu, associativity))
1432 		return;
1433 
1434 	/* Do not have previous associativity, so find it now. */
1435 	new_nid = associativity_to_nid(associativity);
1436 
1437 	if (new_nid < 0 || !node_possible(new_nid))
1438 		new_nid = first_online_node;
1439 	else
1440 		// Associate node <-> cpu, so cpu_up() calls
1441 		// try_online_node() on the right node.
1442 		set_cpu_numa_node(cpu, new_nid);
1443 
1444 	pr_debug("%s:%d cpu %d nid %d\n", __func__, __LINE__, cpu, new_nid);
1445 }
1446 
1447 int cpu_to_coregroup_id(int cpu)
1448 {
1449 	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
1450 	int index;
1451 
1452 	if (cpu < 0 || cpu > nr_cpu_ids)
1453 		return -1;
1454 
1455 	if (!coregroup_enabled)
1456 		goto out;
1457 
1458 	if (!firmware_has_feature(FW_FEATURE_VPHN))
1459 		goto out;
1460 
1461 	if (vphn_get_associativity(cpu, associativity))
1462 		goto out;
1463 
1464 	index = of_read_number(associativity, 1);
1465 	if (index > primary_domain_index + 1)
1466 		return of_read_number(&associativity[index - 1], 1);
1467 
1468 out:
1469 	return cpu_to_core_id(cpu);
1470 }
1471 
1472 static int topology_update_init(void)
1473 {
1474 	topology_inited = 1;
1475 	return 0;
1476 }
1477 device_initcall(topology_update_init);
1478 #endif /* CONFIG_PPC_SPLPAR */
1479