xref: /linux/arch/powerpc/mm/numa.c (revision 78c3925c048c752334873f56c3a3d1c9d53e0416)
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/of_address.h>
20 #include <linux/pfn.h>
21 #include <linux/cpuset.h>
22 #include <linux/node.h>
23 #include <linux/stop_machine.h>
24 #include <linux/proc_fs.h>
25 #include <linux/seq_file.h>
26 #include <linux/uaccess.h>
27 #include <linux/slab.h>
28 #include <asm/cputhreads.h>
29 #include <asm/sparsemem.h>
30 #include <asm/smp.h>
31 #include <asm/topology.h>
32 #include <asm/firmware.h>
33 #include <asm/paca.h>
34 #include <asm/hvcall.h>
35 #include <asm/setup.h>
36 #include <asm/vdso.h>
37 #include <asm/vphn.h>
38 #include <asm/drmem.h>
39 
40 static int numa_enabled = 1;
41 
42 static char *cmdline __initdata;
43 
44 int numa_cpu_lookup_table[NR_CPUS];
45 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
46 struct pglist_data *node_data[MAX_NUMNODES];
47 
48 EXPORT_SYMBOL(numa_cpu_lookup_table);
49 EXPORT_SYMBOL(node_to_cpumask_map);
50 EXPORT_SYMBOL(node_data);
51 
52 static int primary_domain_index;
53 static int n_mem_addr_cells, n_mem_size_cells;
54 
55 #define FORM0_AFFINITY 0
56 #define FORM1_AFFINITY 1
57 #define FORM2_AFFINITY 2
58 static int affinity_form;
59 
60 #define MAX_DISTANCE_REF_POINTS 4
61 static int distance_ref_points_depth;
62 static const __be32 *distance_ref_points;
63 static int distance_lookup_table[MAX_NUMNODES][MAX_DISTANCE_REF_POINTS];
64 static int numa_distance_table[MAX_NUMNODES][MAX_NUMNODES] = {
65 	[0 ... MAX_NUMNODES - 1] = { [0 ... MAX_NUMNODES - 1] = -1 }
66 };
67 static int numa_id_index_table[MAX_NUMNODES] = { [0 ... MAX_NUMNODES - 1] = NUMA_NO_NODE };
68 
69 /*
70  * Allocate node_to_cpumask_map based on number of available nodes
71  * Requires node_possible_map to be valid.
72  *
73  * Note: cpumask_of_node() is not valid until after this is done.
74  */
75 static void __init setup_node_to_cpumask_map(void)
76 {
77 	unsigned int node;
78 
79 	/* setup nr_node_ids if not done yet */
80 	if (nr_node_ids == MAX_NUMNODES)
81 		setup_nr_node_ids();
82 
83 	/* allocate the map */
84 	for_each_node(node)
85 		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
86 
87 	/* cpumask_of_node() will now work */
88 	pr_debug("Node to cpumask map for %u nodes\n", nr_node_ids);
89 }
90 
91 static int __init fake_numa_create_new_node(unsigned long end_pfn,
92 						unsigned int *nid)
93 {
94 	unsigned long long mem;
95 	char *p = cmdline;
96 	static unsigned int fake_nid;
97 	static unsigned long long curr_boundary;
98 
99 	/*
100 	 * Modify node id, iff we started creating NUMA nodes
101 	 * We want to continue from where we left of the last time
102 	 */
103 	if (fake_nid)
104 		*nid = fake_nid;
105 	/*
106 	 * In case there are no more arguments to parse, the
107 	 * node_id should be the same as the last fake node id
108 	 * (we've handled this above).
109 	 */
110 	if (!p)
111 		return 0;
112 
113 	mem = memparse(p, &p);
114 	if (!mem)
115 		return 0;
116 
117 	if (mem < curr_boundary)
118 		return 0;
119 
120 	curr_boundary = mem;
121 
122 	if ((end_pfn << PAGE_SHIFT) > mem) {
123 		/*
124 		 * Skip commas and spaces
125 		 */
126 		while (*p == ',' || *p == ' ' || *p == '\t')
127 			p++;
128 
129 		cmdline = p;
130 		fake_nid++;
131 		*nid = fake_nid;
132 		pr_debug("created new fake_node with id %d\n", fake_nid);
133 		return 1;
134 	}
135 	return 0;
136 }
137 
138 static void __init reset_numa_cpu_lookup_table(void)
139 {
140 	unsigned int cpu;
141 
142 	for_each_possible_cpu(cpu)
143 		numa_cpu_lookup_table[cpu] = -1;
144 }
145 
146 void map_cpu_to_node(int cpu, int node)
147 {
148 	update_numa_cpu_lookup_table(cpu, node);
149 
150 	if (!(cpumask_test_cpu(cpu, node_to_cpumask_map[node]))) {
151 		pr_debug("adding cpu %d to node %d\n", cpu, node);
152 		cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
153 	}
154 }
155 
156 #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PPC_SPLPAR)
157 void unmap_cpu_from_node(unsigned long cpu)
158 {
159 	int node = numa_cpu_lookup_table[cpu];
160 
161 	if (cpumask_test_cpu(cpu, node_to_cpumask_map[node])) {
162 		cpumask_clear_cpu(cpu, node_to_cpumask_map[node]);
163 		pr_debug("removing cpu %lu from node %d\n", cpu, node);
164 	} else {
165 		pr_warn("Warning: cpu %lu not found in node %d\n", cpu, node);
166 	}
167 }
168 #endif /* CONFIG_HOTPLUG_CPU || CONFIG_PPC_SPLPAR */
169 
170 static int __associativity_to_nid(const __be32 *associativity,
171 				  int max_array_sz)
172 {
173 	int nid;
174 	/*
175 	 * primary_domain_index is 1 based array index.
176 	 */
177 	int index = primary_domain_index  - 1;
178 
179 	if (!numa_enabled || index >= max_array_sz)
180 		return NUMA_NO_NODE;
181 
182 	nid = of_read_number(&associativity[index], 1);
183 
184 	/* POWER4 LPAR uses 0xffff as invalid node */
185 	if (nid == 0xffff || nid >= nr_node_ids)
186 		nid = NUMA_NO_NODE;
187 	return nid;
188 }
189 /*
190  * Returns nid in the range [0..nr_node_ids], or -1 if no useful NUMA
191  * info is found.
192  */
193 static int associativity_to_nid(const __be32 *associativity)
194 {
195 	int array_sz = of_read_number(associativity, 1);
196 
197 	/* Skip the first element in the associativity array */
198 	return __associativity_to_nid((associativity + 1), array_sz);
199 }
200 
201 static int __cpu_form2_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
202 {
203 	int dist;
204 	int node1, node2;
205 
206 	node1 = associativity_to_nid(cpu1_assoc);
207 	node2 = associativity_to_nid(cpu2_assoc);
208 
209 	dist = numa_distance_table[node1][node2];
210 	if (dist <= LOCAL_DISTANCE)
211 		return 0;
212 	else if (dist <= REMOTE_DISTANCE)
213 		return 1;
214 	else
215 		return 2;
216 }
217 
218 static int __cpu_form1_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
219 {
220 	int dist = 0;
221 
222 	int i, index;
223 
224 	for (i = 0; i < distance_ref_points_depth; i++) {
225 		index = be32_to_cpu(distance_ref_points[i]);
226 		if (cpu1_assoc[index] == cpu2_assoc[index])
227 			break;
228 		dist++;
229 	}
230 
231 	return dist;
232 }
233 
234 int cpu_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
235 {
236 	/* We should not get called with FORM0 */
237 	VM_WARN_ON(affinity_form == FORM0_AFFINITY);
238 	if (affinity_form == FORM1_AFFINITY)
239 		return __cpu_form1_relative_distance(cpu1_assoc, cpu2_assoc);
240 	return __cpu_form2_relative_distance(cpu1_assoc, cpu2_assoc);
241 }
242 
243 /* must hold reference to node during call */
244 static const __be32 *of_get_associativity(struct device_node *dev)
245 {
246 	return of_get_property(dev, "ibm,associativity", NULL);
247 }
248 
249 int __node_distance(int a, int b)
250 {
251 	int i;
252 	int distance = LOCAL_DISTANCE;
253 
254 	if (affinity_form == FORM2_AFFINITY)
255 		return numa_distance_table[a][b];
256 	else if (affinity_form == FORM0_AFFINITY)
257 		return ((a == b) ? LOCAL_DISTANCE : REMOTE_DISTANCE);
258 
259 	for (i = 0; i < distance_ref_points_depth; i++) {
260 		if (distance_lookup_table[a][i] == distance_lookup_table[b][i])
261 			break;
262 
263 		/* Double the distance for each NUMA level */
264 		distance *= 2;
265 	}
266 
267 	return distance;
268 }
269 EXPORT_SYMBOL(__node_distance);
270 
271 /* Returns the nid associated with the given device tree node,
272  * or -1 if not found.
273  */
274 static int of_node_to_nid_single(struct device_node *device)
275 {
276 	int nid = NUMA_NO_NODE;
277 	const __be32 *tmp;
278 
279 	tmp = of_get_associativity(device);
280 	if (tmp)
281 		nid = associativity_to_nid(tmp);
282 	return nid;
283 }
284 
285 /* Walk the device tree upwards, looking for an associativity id */
286 int of_node_to_nid(struct device_node *device)
287 {
288 	int nid = NUMA_NO_NODE;
289 
290 	of_node_get(device);
291 	while (device) {
292 		nid = of_node_to_nid_single(device);
293 		if (nid != -1)
294 			break;
295 
296 		device = of_get_next_parent(device);
297 	}
298 	of_node_put(device);
299 
300 	return nid;
301 }
302 EXPORT_SYMBOL(of_node_to_nid);
303 
304 static void __initialize_form1_numa_distance(const __be32 *associativity,
305 					     int max_array_sz)
306 {
307 	int i, nid;
308 
309 	if (affinity_form != FORM1_AFFINITY)
310 		return;
311 
312 	nid = __associativity_to_nid(associativity, max_array_sz);
313 	if (nid != NUMA_NO_NODE) {
314 		for (i = 0; i < distance_ref_points_depth; i++) {
315 			const __be32 *entry;
316 			int index = be32_to_cpu(distance_ref_points[i]) - 1;
317 
318 			/*
319 			 * broken hierarchy, return with broken distance table
320 			 */
321 			if (WARN(index >= max_array_sz, "Broken ibm,associativity property"))
322 				return;
323 
324 			entry = &associativity[index];
325 			distance_lookup_table[nid][i] = of_read_number(entry, 1);
326 		}
327 	}
328 }
329 
330 static void initialize_form1_numa_distance(const __be32 *associativity)
331 {
332 	int array_sz;
333 
334 	array_sz = of_read_number(associativity, 1);
335 	/* Skip the first element in the associativity array */
336 	__initialize_form1_numa_distance(associativity + 1, array_sz);
337 }
338 
339 /*
340  * Used to update distance information w.r.t newly added node.
341  */
342 void update_numa_distance(struct device_node *node)
343 {
344 	int nid;
345 
346 	if (affinity_form == FORM0_AFFINITY)
347 		return;
348 	else if (affinity_form == FORM1_AFFINITY) {
349 		const __be32 *associativity;
350 
351 		associativity = of_get_associativity(node);
352 		if (!associativity)
353 			return;
354 
355 		initialize_form1_numa_distance(associativity);
356 		return;
357 	}
358 
359 	/* FORM2 affinity  */
360 	nid = of_node_to_nid_single(node);
361 	if (nid == NUMA_NO_NODE)
362 		return;
363 
364 	/*
365 	 * With FORM2 we expect NUMA distance of all possible NUMA
366 	 * nodes to be provided during boot.
367 	 */
368 	WARN(numa_distance_table[nid][nid] == -1,
369 	     "NUMA distance details for node %d not provided\n", nid);
370 }
371 EXPORT_SYMBOL_GPL(update_numa_distance);
372 
373 /*
374  * ibm,numa-lookup-index-table= {N, domainid1, domainid2, ..... domainidN}
375  * ibm,numa-distance-table = { N, 1, 2, 4, 5, 1, 6, .... N elements}
376  */
377 static void __init initialize_form2_numa_distance_lookup_table(void)
378 {
379 	int i, j;
380 	struct device_node *root;
381 	const __u8 *form2_distances;
382 	const __be32 *numa_lookup_index;
383 	int form2_distances_length;
384 	int max_numa_index, distance_index;
385 
386 	if (firmware_has_feature(FW_FEATURE_OPAL))
387 		root = of_find_node_by_path("/ibm,opal");
388 	else
389 		root = of_find_node_by_path("/rtas");
390 	if (!root)
391 		root = of_find_node_by_path("/");
392 
393 	numa_lookup_index = of_get_property(root, "ibm,numa-lookup-index-table", NULL);
394 	max_numa_index = of_read_number(&numa_lookup_index[0], 1);
395 
396 	/* first element of the array is the size and is encode-int */
397 	form2_distances = of_get_property(root, "ibm,numa-distance-table", NULL);
398 	form2_distances_length = of_read_number((const __be32 *)&form2_distances[0], 1);
399 	/* Skip the size which is encoded int */
400 	form2_distances += sizeof(__be32);
401 
402 	pr_debug("form2_distances_len = %d, numa_dist_indexes_len = %d\n",
403 		 form2_distances_length, max_numa_index);
404 
405 	for (i = 0; i < max_numa_index; i++)
406 		/* +1 skip the max_numa_index in the property */
407 		numa_id_index_table[i] = of_read_number(&numa_lookup_index[i + 1], 1);
408 
409 
410 	if (form2_distances_length != max_numa_index * max_numa_index) {
411 		WARN(1, "Wrong NUMA distance information\n");
412 		form2_distances = NULL; // don't use it
413 	}
414 	distance_index = 0;
415 	for (i = 0;  i < max_numa_index; i++) {
416 		for (j = 0; j < max_numa_index; j++) {
417 			int nodeA = numa_id_index_table[i];
418 			int nodeB = numa_id_index_table[j];
419 			int dist;
420 
421 			if (form2_distances)
422 				dist = form2_distances[distance_index++];
423 			else if (nodeA == nodeB)
424 				dist = LOCAL_DISTANCE;
425 			else
426 				dist = REMOTE_DISTANCE;
427 			numa_distance_table[nodeA][nodeB] = dist;
428 			pr_debug("dist[%d][%d]=%d ", nodeA, nodeB, dist);
429 		}
430 	}
431 
432 	of_node_put(root);
433 }
434 
435 static int __init find_primary_domain_index(void)
436 {
437 	int index;
438 	struct device_node *root;
439 
440 	/*
441 	 * Check for which form of affinity.
442 	 */
443 	if (firmware_has_feature(FW_FEATURE_OPAL)) {
444 		affinity_form = FORM1_AFFINITY;
445 	} else if (firmware_has_feature(FW_FEATURE_FORM2_AFFINITY)) {
446 		pr_debug("Using form 2 affinity\n");
447 		affinity_form = FORM2_AFFINITY;
448 	} else if (firmware_has_feature(FW_FEATURE_FORM1_AFFINITY)) {
449 		pr_debug("Using form 1 affinity\n");
450 		affinity_form = FORM1_AFFINITY;
451 	} else
452 		affinity_form = FORM0_AFFINITY;
453 
454 	if (firmware_has_feature(FW_FEATURE_OPAL))
455 		root = of_find_node_by_path("/ibm,opal");
456 	else
457 		root = of_find_node_by_path("/rtas");
458 	if (!root)
459 		root = of_find_node_by_path("/");
460 
461 	/*
462 	 * This property is a set of 32-bit integers, each representing
463 	 * an index into the ibm,associativity nodes.
464 	 *
465 	 * With form 0 affinity the first integer is for an SMP configuration
466 	 * (should be all 0's) and the second is for a normal NUMA
467 	 * configuration. We have only one level of NUMA.
468 	 *
469 	 * With form 1 affinity the first integer is the most significant
470 	 * NUMA boundary and the following are progressively less significant
471 	 * boundaries. There can be more than one level of NUMA.
472 	 */
473 	distance_ref_points = of_get_property(root,
474 					"ibm,associativity-reference-points",
475 					&distance_ref_points_depth);
476 
477 	if (!distance_ref_points) {
478 		pr_debug("ibm,associativity-reference-points not found.\n");
479 		goto err;
480 	}
481 
482 	distance_ref_points_depth /= sizeof(int);
483 	if (affinity_form == FORM0_AFFINITY) {
484 		if (distance_ref_points_depth < 2) {
485 			pr_warn("short ibm,associativity-reference-points\n");
486 			goto err;
487 		}
488 
489 		index = of_read_number(&distance_ref_points[1], 1);
490 	} else {
491 		/*
492 		 * Both FORM1 and FORM2 affinity find the primary domain details
493 		 * at the same offset.
494 		 */
495 		index = of_read_number(distance_ref_points, 1);
496 	}
497 	/*
498 	 * Warn and cap if the hardware supports more than
499 	 * MAX_DISTANCE_REF_POINTS domains.
500 	 */
501 	if (distance_ref_points_depth > MAX_DISTANCE_REF_POINTS) {
502 		pr_warn("distance array capped at %d entries\n",
503 			MAX_DISTANCE_REF_POINTS);
504 		distance_ref_points_depth = MAX_DISTANCE_REF_POINTS;
505 	}
506 
507 	of_node_put(root);
508 	return index;
509 
510 err:
511 	of_node_put(root);
512 	return -1;
513 }
514 
515 static void __init get_n_mem_cells(int *n_addr_cells, int *n_size_cells)
516 {
517 	struct device_node *memory = NULL;
518 
519 	memory = of_find_node_by_type(memory, "memory");
520 	if (!memory)
521 		panic("numa.c: No memory nodes found!");
522 
523 	*n_addr_cells = of_n_addr_cells(memory);
524 	*n_size_cells = of_n_size_cells(memory);
525 	of_node_put(memory);
526 }
527 
528 static unsigned long read_n_cells(int n, const __be32 **buf)
529 {
530 	unsigned long result = 0;
531 
532 	while (n--) {
533 		result = (result << 32) | of_read_number(*buf, 1);
534 		(*buf)++;
535 	}
536 	return result;
537 }
538 
539 struct assoc_arrays {
540 	u32	n_arrays;
541 	u32	array_sz;
542 	const __be32 *arrays;
543 };
544 
545 /*
546  * Retrieve and validate the list of associativity arrays for drconf
547  * memory from the ibm,associativity-lookup-arrays property of the
548  * device tree..
549  *
550  * The layout of the ibm,associativity-lookup-arrays property is a number N
551  * indicating the number of associativity arrays, followed by a number M
552  * indicating the size of each associativity array, followed by a list
553  * of N associativity arrays.
554  */
555 static int of_get_assoc_arrays(struct assoc_arrays *aa)
556 {
557 	struct device_node *memory;
558 	const __be32 *prop;
559 	u32 len;
560 
561 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
562 	if (!memory)
563 		return -1;
564 
565 	prop = of_get_property(memory, "ibm,associativity-lookup-arrays", &len);
566 	if (!prop || len < 2 * sizeof(unsigned int)) {
567 		of_node_put(memory);
568 		return -1;
569 	}
570 
571 	aa->n_arrays = of_read_number(prop++, 1);
572 	aa->array_sz = of_read_number(prop++, 1);
573 
574 	of_node_put(memory);
575 
576 	/* Now that we know the number of arrays and size of each array,
577 	 * revalidate the size of the property read in.
578 	 */
579 	if (len < (aa->n_arrays * aa->array_sz + 2) * sizeof(unsigned int))
580 		return -1;
581 
582 	aa->arrays = prop;
583 	return 0;
584 }
585 
586 static int __init get_nid_and_numa_distance(struct drmem_lmb *lmb)
587 {
588 	struct assoc_arrays aa = { .arrays = NULL };
589 	int default_nid = NUMA_NO_NODE;
590 	int nid = default_nid;
591 	int rc, index;
592 
593 	if ((primary_domain_index < 0) || !numa_enabled)
594 		return default_nid;
595 
596 	rc = of_get_assoc_arrays(&aa);
597 	if (rc)
598 		return default_nid;
599 
600 	if (primary_domain_index <= aa.array_sz &&
601 	    !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
602 		const __be32 *associativity;
603 
604 		index = lmb->aa_index * aa.array_sz;
605 		associativity = &aa.arrays[index];
606 		nid = __associativity_to_nid(associativity, aa.array_sz);
607 		if (nid > 0 && affinity_form == FORM1_AFFINITY) {
608 			/*
609 			 * lookup array associativity entries have
610 			 * no length of the array as the first element.
611 			 */
612 			__initialize_form1_numa_distance(associativity, aa.array_sz);
613 		}
614 	}
615 	return nid;
616 }
617 
618 /*
619  * This is like of_node_to_nid_single() for memory represented in the
620  * ibm,dynamic-reconfiguration-memory node.
621  */
622 int of_drconf_to_nid_single(struct drmem_lmb *lmb)
623 {
624 	struct assoc_arrays aa = { .arrays = NULL };
625 	int default_nid = NUMA_NO_NODE;
626 	int nid = default_nid;
627 	int rc, index;
628 
629 	if ((primary_domain_index < 0) || !numa_enabled)
630 		return default_nid;
631 
632 	rc = of_get_assoc_arrays(&aa);
633 	if (rc)
634 		return default_nid;
635 
636 	if (primary_domain_index <= aa.array_sz &&
637 	    !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
638 		const __be32 *associativity;
639 
640 		index = lmb->aa_index * aa.array_sz;
641 		associativity = &aa.arrays[index];
642 		nid = __associativity_to_nid(associativity, aa.array_sz);
643 	}
644 	return nid;
645 }
646 
647 #ifdef CONFIG_PPC_SPLPAR
648 
649 static int __vphn_get_associativity(long lcpu, __be32 *associativity)
650 {
651 	long rc, hwid;
652 
653 	/*
654 	 * On a shared lpar, device tree will not have node associativity.
655 	 * At this time lppaca, or its __old_status field may not be
656 	 * updated. Hence kernel cannot detect if its on a shared lpar. So
657 	 * request an explicit associativity irrespective of whether the
658 	 * lpar is shared or dedicated. Use the device tree property as a
659 	 * fallback. cpu_to_phys_id is only valid between
660 	 * smp_setup_cpu_maps() and smp_setup_pacas().
661 	 */
662 	if (firmware_has_feature(FW_FEATURE_VPHN)) {
663 		if (cpu_to_phys_id)
664 			hwid = cpu_to_phys_id[lcpu];
665 		else
666 			hwid = get_hard_smp_processor_id(lcpu);
667 
668 		rc = hcall_vphn(hwid, VPHN_FLAG_VCPU, associativity);
669 		if (rc == H_SUCCESS)
670 			return 0;
671 	}
672 
673 	return -1;
674 }
675 
676 static int vphn_get_nid(long lcpu)
677 {
678 	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
679 
680 
681 	if (!__vphn_get_associativity(lcpu, associativity))
682 		return associativity_to_nid(associativity);
683 
684 	return NUMA_NO_NODE;
685 
686 }
687 #else
688 
689 static int __vphn_get_associativity(long lcpu, __be32 *associativity)
690 {
691 	return -1;
692 }
693 
694 static int vphn_get_nid(long unused)
695 {
696 	return NUMA_NO_NODE;
697 }
698 #endif  /* CONFIG_PPC_SPLPAR */
699 
700 /*
701  * Figure out to which domain a cpu belongs and stick it there.
702  * Return the id of the domain used.
703  */
704 static int numa_setup_cpu(unsigned long lcpu)
705 {
706 	struct device_node *cpu;
707 	int fcpu = cpu_first_thread_sibling(lcpu);
708 	int nid = NUMA_NO_NODE;
709 
710 	if (!cpu_present(lcpu)) {
711 		set_cpu_numa_node(lcpu, first_online_node);
712 		return first_online_node;
713 	}
714 
715 	/*
716 	 * If a valid cpu-to-node mapping is already available, use it
717 	 * directly instead of querying the firmware, since it represents
718 	 * the most recent mapping notified to us by the platform (eg: VPHN).
719 	 * Since cpu_to_node binding remains the same for all threads in the
720 	 * core. If a valid cpu-to-node mapping is already available, for
721 	 * the first thread in the core, use it.
722 	 */
723 	nid = numa_cpu_lookup_table[fcpu];
724 	if (nid >= 0) {
725 		map_cpu_to_node(lcpu, nid);
726 		return nid;
727 	}
728 
729 	nid = vphn_get_nid(lcpu);
730 	if (nid != NUMA_NO_NODE)
731 		goto out_present;
732 
733 	cpu = of_get_cpu_node(lcpu, NULL);
734 
735 	if (!cpu) {
736 		WARN_ON(1);
737 		if (cpu_present(lcpu))
738 			goto out_present;
739 		else
740 			goto out;
741 	}
742 
743 	nid = of_node_to_nid_single(cpu);
744 	of_node_put(cpu);
745 
746 out_present:
747 	if (nid < 0 || !node_possible(nid))
748 		nid = first_online_node;
749 
750 	/*
751 	 * Update for the first thread of the core. All threads of a core
752 	 * have to be part of the same node. This not only avoids querying
753 	 * for every other thread in the core, but always avoids a case
754 	 * where virtual node associativity change causes subsequent threads
755 	 * of a core to be associated with different nid. However if first
756 	 * thread is already online, expect it to have a valid mapping.
757 	 */
758 	if (fcpu != lcpu) {
759 		WARN_ON(cpu_online(fcpu));
760 		map_cpu_to_node(fcpu, nid);
761 	}
762 
763 	map_cpu_to_node(lcpu, nid);
764 out:
765 	return nid;
766 }
767 
768 static void verify_cpu_node_mapping(int cpu, int node)
769 {
770 	int base, sibling, i;
771 
772 	/* Verify that all the threads in the core belong to the same node */
773 	base = cpu_first_thread_sibling(cpu);
774 
775 	for (i = 0; i < threads_per_core; i++) {
776 		sibling = base + i;
777 
778 		if (sibling == cpu || cpu_is_offline(sibling))
779 			continue;
780 
781 		if (cpu_to_node(sibling) != node) {
782 			WARN(1, "CPU thread siblings %d and %d don't belong"
783 				" to the same node!\n", cpu, sibling);
784 			break;
785 		}
786 	}
787 }
788 
789 /* Must run before sched domains notifier. */
790 static int ppc_numa_cpu_prepare(unsigned int cpu)
791 {
792 	int nid;
793 
794 	nid = numa_setup_cpu(cpu);
795 	verify_cpu_node_mapping(cpu, nid);
796 	return 0;
797 }
798 
799 static int ppc_numa_cpu_dead(unsigned int cpu)
800 {
801 	return 0;
802 }
803 
804 /*
805  * Check and possibly modify a memory region to enforce the memory limit.
806  *
807  * Returns the size the region should have to enforce the memory limit.
808  * This will either be the original value of size, a truncated value,
809  * or zero. If the returned value of size is 0 the region should be
810  * discarded as it lies wholly above the memory limit.
811  */
812 static unsigned long __init numa_enforce_memory_limit(unsigned long start,
813 						      unsigned long size)
814 {
815 	/*
816 	 * We use memblock_end_of_DRAM() in here instead of memory_limit because
817 	 * we've already adjusted it for the limit and it takes care of
818 	 * having memory holes below the limit.  Also, in the case of
819 	 * iommu_is_off, memory_limit is not set but is implicitly enforced.
820 	 */
821 
822 	if (start + size <= memblock_end_of_DRAM())
823 		return size;
824 
825 	if (start >= memblock_end_of_DRAM())
826 		return 0;
827 
828 	return memblock_end_of_DRAM() - start;
829 }
830 
831 /*
832  * Reads the counter for a given entry in
833  * linux,drconf-usable-memory property
834  */
835 static inline int __init read_usm_ranges(const __be32 **usm)
836 {
837 	/*
838 	 * For each lmb in ibm,dynamic-memory a corresponding
839 	 * entry in linux,drconf-usable-memory property contains
840 	 * a counter followed by that many (base, size) duple.
841 	 * read the counter from linux,drconf-usable-memory
842 	 */
843 	return read_n_cells(n_mem_size_cells, usm);
844 }
845 
846 /*
847  * Extract NUMA information from the ibm,dynamic-reconfiguration-memory
848  * node.  This assumes n_mem_{addr,size}_cells have been set.
849  */
850 static int __init numa_setup_drmem_lmb(struct drmem_lmb *lmb,
851 					const __be32 **usm,
852 					void *data)
853 {
854 	unsigned int ranges, is_kexec_kdump = 0;
855 	unsigned long base, size, sz;
856 	int nid;
857 
858 	/*
859 	 * Skip this block if the reserved bit is set in flags (0x80)
860 	 * or if the block is not assigned to this partition (0x8)
861 	 */
862 	if ((lmb->flags & DRCONF_MEM_RESERVED)
863 	    || !(lmb->flags & DRCONF_MEM_ASSIGNED))
864 		return 0;
865 
866 	if (*usm)
867 		is_kexec_kdump = 1;
868 
869 	base = lmb->base_addr;
870 	size = drmem_lmb_size();
871 	ranges = 1;
872 
873 	if (is_kexec_kdump) {
874 		ranges = read_usm_ranges(usm);
875 		if (!ranges) /* there are no (base, size) duple */
876 			return 0;
877 	}
878 
879 	do {
880 		if (is_kexec_kdump) {
881 			base = read_n_cells(n_mem_addr_cells, usm);
882 			size = read_n_cells(n_mem_size_cells, usm);
883 		}
884 
885 		nid = get_nid_and_numa_distance(lmb);
886 		fake_numa_create_new_node(((base + size) >> PAGE_SHIFT),
887 					  &nid);
888 		node_set_online(nid);
889 		sz = numa_enforce_memory_limit(base, size);
890 		if (sz)
891 			memblock_set_node(base, sz, &memblock.memory, nid);
892 	} while (--ranges);
893 
894 	return 0;
895 }
896 
897 static int __init parse_numa_properties(void)
898 {
899 	struct device_node *memory;
900 	int default_nid = 0;
901 	unsigned long i;
902 	const __be32 *associativity;
903 
904 	if (numa_enabled == 0) {
905 		pr_warn("disabled by user\n");
906 		return -1;
907 	}
908 
909 	primary_domain_index = find_primary_domain_index();
910 
911 	if (primary_domain_index < 0) {
912 		/*
913 		 * if we fail to parse primary_domain_index from device tree
914 		 * mark the numa disabled, boot with numa disabled.
915 		 */
916 		numa_enabled = false;
917 		return primary_domain_index;
918 	}
919 
920 	pr_debug("associativity depth for CPU/Memory: %d\n", primary_domain_index);
921 
922 	/*
923 	 * If it is FORM2 initialize the distance table here.
924 	 */
925 	if (affinity_form == FORM2_AFFINITY)
926 		initialize_form2_numa_distance_lookup_table();
927 
928 	/*
929 	 * Even though we connect cpus to numa domains later in SMP
930 	 * init, we need to know the node ids now. This is because
931 	 * each node to be onlined must have NODE_DATA etc backing it.
932 	 */
933 	for_each_present_cpu(i) {
934 		__be32 vphn_assoc[VPHN_ASSOC_BUFSIZE];
935 		struct device_node *cpu;
936 		int nid = NUMA_NO_NODE;
937 
938 		memset(vphn_assoc, 0, VPHN_ASSOC_BUFSIZE * sizeof(__be32));
939 
940 		if (__vphn_get_associativity(i, vphn_assoc) == 0) {
941 			nid = associativity_to_nid(vphn_assoc);
942 			initialize_form1_numa_distance(vphn_assoc);
943 		} else {
944 
945 			/*
946 			 * Don't fall back to default_nid yet -- we will plug
947 			 * cpus into nodes once the memory scan has discovered
948 			 * the topology.
949 			 */
950 			cpu = of_get_cpu_node(i, NULL);
951 			BUG_ON(!cpu);
952 
953 			associativity = of_get_associativity(cpu);
954 			if (associativity) {
955 				nid = associativity_to_nid(associativity);
956 				initialize_form1_numa_distance(associativity);
957 			}
958 			of_node_put(cpu);
959 		}
960 
961 		/* node_set_online() is an UB if 'nid' is negative */
962 		if (likely(nid >= 0))
963 			node_set_online(nid);
964 	}
965 
966 	get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells);
967 
968 	for_each_node_by_type(memory, "memory") {
969 		unsigned long start;
970 		unsigned long size;
971 		int nid;
972 		int ranges;
973 		const __be32 *memcell_buf;
974 		unsigned int len;
975 
976 		memcell_buf = of_get_property(memory,
977 			"linux,usable-memory", &len);
978 		if (!memcell_buf || len <= 0)
979 			memcell_buf = of_get_property(memory, "reg", &len);
980 		if (!memcell_buf || len <= 0)
981 			continue;
982 
983 		/* ranges in cell */
984 		ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
985 new_range:
986 		/* these are order-sensitive, and modify the buffer pointer */
987 		start = read_n_cells(n_mem_addr_cells, &memcell_buf);
988 		size = read_n_cells(n_mem_size_cells, &memcell_buf);
989 
990 		/*
991 		 * Assumption: either all memory nodes or none will
992 		 * have associativity properties.  If none, then
993 		 * everything goes to default_nid.
994 		 */
995 		associativity = of_get_associativity(memory);
996 		if (associativity) {
997 			nid = associativity_to_nid(associativity);
998 			initialize_form1_numa_distance(associativity);
999 		} else
1000 			nid = default_nid;
1001 
1002 		fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);
1003 		node_set_online(nid);
1004 
1005 		size = numa_enforce_memory_limit(start, size);
1006 		if (size)
1007 			memblock_set_node(start, size, &memblock.memory, nid);
1008 
1009 		if (--ranges)
1010 			goto new_range;
1011 	}
1012 
1013 	/*
1014 	 * Now do the same thing for each MEMBLOCK listed in the
1015 	 * ibm,dynamic-memory property in the
1016 	 * ibm,dynamic-reconfiguration-memory node.
1017 	 */
1018 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1019 	if (memory) {
1020 		walk_drmem_lmbs(memory, NULL, numa_setup_drmem_lmb);
1021 		of_node_put(memory);
1022 	}
1023 
1024 	return 0;
1025 }
1026 
1027 static void __init setup_nonnuma(void)
1028 {
1029 	unsigned long top_of_ram = memblock_end_of_DRAM();
1030 	unsigned long total_ram = memblock_phys_mem_size();
1031 	unsigned long start_pfn, end_pfn;
1032 	unsigned int nid = 0;
1033 	int i;
1034 
1035 	pr_debug("Top of RAM: 0x%lx, Total RAM: 0x%lx\n", top_of_ram, total_ram);
1036 	pr_debug("Memory hole size: %ldMB\n", (top_of_ram - total_ram) >> 20);
1037 
1038 	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
1039 		fake_numa_create_new_node(end_pfn, &nid);
1040 		memblock_set_node(PFN_PHYS(start_pfn),
1041 				  PFN_PHYS(end_pfn - start_pfn),
1042 				  &memblock.memory, nid);
1043 		node_set_online(nid);
1044 	}
1045 }
1046 
1047 void __init dump_numa_cpu_topology(void)
1048 {
1049 	unsigned int node;
1050 	unsigned int cpu, count;
1051 
1052 	if (!numa_enabled)
1053 		return;
1054 
1055 	for_each_online_node(node) {
1056 		pr_info("Node %d CPUs:", node);
1057 
1058 		count = 0;
1059 		/*
1060 		 * If we used a CPU iterator here we would miss printing
1061 		 * the holes in the cpumap.
1062 		 */
1063 		for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
1064 			if (cpumask_test_cpu(cpu,
1065 					node_to_cpumask_map[node])) {
1066 				if (count == 0)
1067 					pr_cont(" %u", cpu);
1068 				++count;
1069 			} else {
1070 				if (count > 1)
1071 					pr_cont("-%u", cpu - 1);
1072 				count = 0;
1073 			}
1074 		}
1075 
1076 		if (count > 1)
1077 			pr_cont("-%u", nr_cpu_ids - 1);
1078 		pr_cont("\n");
1079 	}
1080 }
1081 
1082 /* Initialize NODE_DATA for a node on the local memory */
1083 static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
1084 {
1085 	u64 spanned_pages = end_pfn - start_pfn;
1086 	const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);
1087 	u64 nd_pa;
1088 	void *nd;
1089 	int tnid;
1090 
1091 	nd_pa = memblock_phys_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
1092 	if (!nd_pa)
1093 		panic("Cannot allocate %zu bytes for node %d data\n",
1094 		      nd_size, nid);
1095 
1096 	nd = __va(nd_pa);
1097 
1098 	/* report and initialize */
1099 	pr_info("  NODE_DATA [mem %#010Lx-%#010Lx]\n",
1100 		nd_pa, nd_pa + nd_size - 1);
1101 	tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
1102 	if (tnid != nid)
1103 		pr_info("    NODE_DATA(%d) on node %d\n", nid, tnid);
1104 
1105 	node_data[nid] = nd;
1106 	memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
1107 	NODE_DATA(nid)->node_id = nid;
1108 	NODE_DATA(nid)->node_start_pfn = start_pfn;
1109 	NODE_DATA(nid)->node_spanned_pages = spanned_pages;
1110 }
1111 
1112 static void __init find_possible_nodes(void)
1113 {
1114 	struct device_node *rtas, *root;
1115 	const __be32 *domains = NULL;
1116 	int prop_length, max_nodes;
1117 	u32 i;
1118 
1119 	if (!numa_enabled)
1120 		return;
1121 
1122 	rtas = of_find_node_by_path("/rtas");
1123 	if (!rtas)
1124 		return;
1125 
1126 	/*
1127 	 * ibm,current-associativity-domains is a fairly recent property. If
1128 	 * it doesn't exist, then fallback on ibm,max-associativity-domains.
1129 	 * Current denotes what the platform can support compared to max
1130 	 * which denotes what the Hypervisor can support.
1131 	 *
1132 	 * If the LPAR is migratable, new nodes might be activated after a LPM,
1133 	 * so we should consider the max number in that case.
1134 	 */
1135 	root = of_find_node_by_path("/");
1136 	if (!of_get_property(root, "ibm,migratable-partition", NULL))
1137 		domains = of_get_property(rtas,
1138 					  "ibm,current-associativity-domains",
1139 					  &prop_length);
1140 	of_node_put(root);
1141 	if (!domains) {
1142 		domains = of_get_property(rtas, "ibm,max-associativity-domains",
1143 					&prop_length);
1144 		if (!domains)
1145 			goto out;
1146 	}
1147 
1148 	max_nodes = of_read_number(&domains[primary_domain_index], 1);
1149 	pr_info("Partition configured for %d NUMA nodes.\n", max_nodes);
1150 
1151 	for (i = 0; i < max_nodes; i++) {
1152 		if (!node_possible(i))
1153 			node_set(i, node_possible_map);
1154 	}
1155 
1156 	prop_length /= sizeof(int);
1157 	if (prop_length > primary_domain_index + 2)
1158 		coregroup_enabled = 1;
1159 
1160 out:
1161 	of_node_put(rtas);
1162 }
1163 
1164 void __init mem_topology_setup(void)
1165 {
1166 	int cpu;
1167 
1168 	max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
1169 	min_low_pfn = MEMORY_START >> PAGE_SHIFT;
1170 
1171 	/*
1172 	 * Linux/mm assumes node 0 to be online at boot. However this is not
1173 	 * true on PowerPC, where node 0 is similar to any other node, it
1174 	 * could be cpuless, memoryless node. So force node 0 to be offline
1175 	 * for now. This will prevent cpuless, memoryless node 0 showing up
1176 	 * unnecessarily as online. If a node has cpus or memory that need
1177 	 * to be online, then node will anyway be marked online.
1178 	 */
1179 	node_set_offline(0);
1180 
1181 	if (parse_numa_properties())
1182 		setup_nonnuma();
1183 
1184 	/*
1185 	 * Modify the set of possible NUMA nodes to reflect information
1186 	 * available about the set of online nodes, and the set of nodes
1187 	 * that we expect to make use of for this platform's affinity
1188 	 * calculations.
1189 	 */
1190 	nodes_and(node_possible_map, node_possible_map, node_online_map);
1191 
1192 	find_possible_nodes();
1193 
1194 	setup_node_to_cpumask_map();
1195 
1196 	reset_numa_cpu_lookup_table();
1197 
1198 	for_each_possible_cpu(cpu) {
1199 		/*
1200 		 * Powerpc with CONFIG_NUMA always used to have a node 0,
1201 		 * even if it was memoryless or cpuless. For all cpus that
1202 		 * are possible but not present, cpu_to_node() would point
1203 		 * to node 0. To remove a cpuless, memoryless dummy node,
1204 		 * powerpc need to make sure all possible but not present
1205 		 * cpu_to_node are set to a proper node.
1206 		 */
1207 		numa_setup_cpu(cpu);
1208 	}
1209 }
1210 
1211 void __init initmem_init(void)
1212 {
1213 	int nid;
1214 
1215 	memblock_dump_all();
1216 
1217 	for_each_online_node(nid) {
1218 		unsigned long start_pfn, end_pfn;
1219 
1220 		get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
1221 		setup_node_data(nid, start_pfn, end_pfn);
1222 	}
1223 
1224 	sparse_init();
1225 
1226 	/*
1227 	 * We need the numa_cpu_lookup_table to be accurate for all CPUs,
1228 	 * even before we online them, so that we can use cpu_to_{node,mem}
1229 	 * early in boot, cf. smp_prepare_cpus().
1230 	 * _nocalls() + manual invocation is used because cpuhp is not yet
1231 	 * initialized for the boot CPU.
1232 	 */
1233 	cpuhp_setup_state_nocalls(CPUHP_POWER_NUMA_PREPARE, "powerpc/numa:prepare",
1234 				  ppc_numa_cpu_prepare, ppc_numa_cpu_dead);
1235 }
1236 
1237 static int __init early_numa(char *p)
1238 {
1239 	if (!p)
1240 		return 0;
1241 
1242 	if (strstr(p, "off"))
1243 		numa_enabled = 0;
1244 
1245 	p = strstr(p, "fake=");
1246 	if (p)
1247 		cmdline = p + strlen("fake=");
1248 
1249 	return 0;
1250 }
1251 early_param("numa", early_numa);
1252 
1253 #ifdef CONFIG_MEMORY_HOTPLUG
1254 /*
1255  * Find the node associated with a hot added memory section for
1256  * memory represented in the device tree by the property
1257  * ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory.
1258  */
1259 static int hot_add_drconf_scn_to_nid(unsigned long scn_addr)
1260 {
1261 	struct drmem_lmb *lmb;
1262 	unsigned long lmb_size;
1263 	int nid = NUMA_NO_NODE;
1264 
1265 	lmb_size = drmem_lmb_size();
1266 
1267 	for_each_drmem_lmb(lmb) {
1268 		/* skip this block if it is reserved or not assigned to
1269 		 * this partition */
1270 		if ((lmb->flags & DRCONF_MEM_RESERVED)
1271 		    || !(lmb->flags & DRCONF_MEM_ASSIGNED))
1272 			continue;
1273 
1274 		if ((scn_addr < lmb->base_addr)
1275 		    || (scn_addr >= (lmb->base_addr + lmb_size)))
1276 			continue;
1277 
1278 		nid = of_drconf_to_nid_single(lmb);
1279 		break;
1280 	}
1281 
1282 	return nid;
1283 }
1284 
1285 /*
1286  * Find the node associated with a hot added memory section for memory
1287  * represented in the device tree as a node (i.e. memory@XXXX) for
1288  * each memblock.
1289  */
1290 static int hot_add_node_scn_to_nid(unsigned long scn_addr)
1291 {
1292 	struct device_node *memory;
1293 	int nid = NUMA_NO_NODE;
1294 
1295 	for_each_node_by_type(memory, "memory") {
1296 		int i = 0;
1297 
1298 		while (1) {
1299 			struct resource res;
1300 
1301 			if (of_address_to_resource(memory, i++, &res))
1302 				break;
1303 
1304 			if ((scn_addr < res.start) || (scn_addr > res.end))
1305 				continue;
1306 
1307 			nid = of_node_to_nid_single(memory);
1308 			break;
1309 		}
1310 
1311 		if (nid >= 0)
1312 			break;
1313 	}
1314 
1315 	of_node_put(memory);
1316 
1317 	return nid;
1318 }
1319 
1320 /*
1321  * Find the node associated with a hot added memory section.  Section
1322  * corresponds to a SPARSEMEM section, not an MEMBLOCK.  It is assumed that
1323  * sections are fully contained within a single MEMBLOCK.
1324  */
1325 int hot_add_scn_to_nid(unsigned long scn_addr)
1326 {
1327 	struct device_node *memory = NULL;
1328 	int nid;
1329 
1330 	if (!numa_enabled)
1331 		return first_online_node;
1332 
1333 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1334 	if (memory) {
1335 		nid = hot_add_drconf_scn_to_nid(scn_addr);
1336 		of_node_put(memory);
1337 	} else {
1338 		nid = hot_add_node_scn_to_nid(scn_addr);
1339 	}
1340 
1341 	if (nid < 0 || !node_possible(nid))
1342 		nid = first_online_node;
1343 
1344 	return nid;
1345 }
1346 
1347 static u64 hot_add_drconf_memory_max(void)
1348 {
1349 	struct device_node *memory = NULL;
1350 	struct device_node *dn = NULL;
1351 	const __be64 *lrdr = NULL;
1352 
1353 	dn = of_find_node_by_path("/rtas");
1354 	if (dn) {
1355 		lrdr = of_get_property(dn, "ibm,lrdr-capacity", NULL);
1356 		of_node_put(dn);
1357 		if (lrdr)
1358 			return be64_to_cpup(lrdr);
1359 	}
1360 
1361 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1362 	if (memory) {
1363 		of_node_put(memory);
1364 		return drmem_lmb_memory_max();
1365 	}
1366 	return 0;
1367 }
1368 
1369 /*
1370  * memory_hotplug_max - return max address of memory that may be added
1371  *
1372  * This is currently only used on systems that support drconfig memory
1373  * hotplug.
1374  */
1375 u64 memory_hotplug_max(void)
1376 {
1377         return max(hot_add_drconf_memory_max(), memblock_end_of_DRAM());
1378 }
1379 #endif /* CONFIG_MEMORY_HOTPLUG */
1380 
1381 /* Virtual Processor Home Node (VPHN) support */
1382 #ifdef CONFIG_PPC_SPLPAR
1383 static int topology_inited;
1384 
1385 /*
1386  * Retrieve the new associativity information for a virtual processor's
1387  * home node.
1388  */
1389 static long vphn_get_associativity(unsigned long cpu,
1390 					__be32 *associativity)
1391 {
1392 	long rc;
1393 
1394 	rc = hcall_vphn(get_hard_smp_processor_id(cpu),
1395 				VPHN_FLAG_VCPU, associativity);
1396 
1397 	switch (rc) {
1398 	case H_SUCCESS:
1399 		pr_debug("VPHN hcall succeeded. Reset polling...\n");
1400 		goto out;
1401 
1402 	case H_FUNCTION:
1403 		pr_err_ratelimited("VPHN unsupported. Disabling polling...\n");
1404 		break;
1405 	case H_HARDWARE:
1406 		pr_err_ratelimited("hcall_vphn() experienced a hardware fault "
1407 			"preventing VPHN. Disabling polling...\n");
1408 		break;
1409 	case H_PARAMETER:
1410 		pr_err_ratelimited("hcall_vphn() was passed an invalid parameter. "
1411 			"Disabling polling...\n");
1412 		break;
1413 	default:
1414 		pr_err_ratelimited("hcall_vphn() returned %ld. Disabling polling...\n"
1415 			, rc);
1416 		break;
1417 	}
1418 out:
1419 	return rc;
1420 }
1421 
1422 void find_and_update_cpu_nid(int cpu)
1423 {
1424 	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
1425 	int new_nid;
1426 
1427 	/* Use associativity from first thread for all siblings */
1428 	if (vphn_get_associativity(cpu, associativity))
1429 		return;
1430 
1431 	/* Do not have previous associativity, so find it now. */
1432 	new_nid = associativity_to_nid(associativity);
1433 
1434 	if (new_nid < 0 || !node_possible(new_nid))
1435 		new_nid = first_online_node;
1436 	else
1437 		// Associate node <-> cpu, so cpu_up() calls
1438 		// try_online_node() on the right node.
1439 		set_cpu_numa_node(cpu, new_nid);
1440 
1441 	pr_debug("%s:%d cpu %d nid %d\n", __func__, __LINE__, cpu, new_nid);
1442 }
1443 
1444 int cpu_to_coregroup_id(int cpu)
1445 {
1446 	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
1447 	int index;
1448 
1449 	if (cpu < 0 || cpu > nr_cpu_ids)
1450 		return -1;
1451 
1452 	if (!coregroup_enabled)
1453 		goto out;
1454 
1455 	if (!firmware_has_feature(FW_FEATURE_VPHN))
1456 		goto out;
1457 
1458 	if (vphn_get_associativity(cpu, associativity))
1459 		goto out;
1460 
1461 	index = of_read_number(associativity, 1);
1462 	if (index > primary_domain_index + 1)
1463 		return of_read_number(&associativity[index - 1], 1);
1464 
1465 out:
1466 	return cpu_to_core_id(cpu);
1467 }
1468 
1469 static int topology_update_init(void)
1470 {
1471 	topology_inited = 1;
1472 	return 0;
1473 }
1474 device_initcall(topology_update_init);
1475 #endif /* CONFIG_PPC_SPLPAR */
1476