xref: /linux/arch/powerpc/mm/numa.c (revision 2f804aca48322f02a8f44cca540663845ee80fb1)
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/drmem.h>
38 
39 static int numa_enabled = 1;
40 
41 static char *cmdline __initdata;
42 
43 int numa_cpu_lookup_table[NR_CPUS];
44 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
45 struct pglist_data *node_data[MAX_NUMNODES];
46 
47 EXPORT_SYMBOL(numa_cpu_lookup_table);
48 EXPORT_SYMBOL(node_to_cpumask_map);
49 EXPORT_SYMBOL(node_data);
50 
51 static int primary_domain_index;
52 static int n_mem_addr_cells, n_mem_size_cells;
53 
54 #define FORM0_AFFINITY 0
55 #define FORM1_AFFINITY 1
56 #define FORM2_AFFINITY 2
57 static int affinity_form;
58 
59 #define MAX_DISTANCE_REF_POINTS 4
60 static int distance_ref_points_depth;
61 static const __be32 *distance_ref_points;
62 static int distance_lookup_table[MAX_NUMNODES][MAX_DISTANCE_REF_POINTS];
63 static int numa_distance_table[MAX_NUMNODES][MAX_NUMNODES] = {
64 	[0 ... MAX_NUMNODES - 1] = { [0 ... MAX_NUMNODES - 1] = -1 }
65 };
66 static int numa_id_index_table[MAX_NUMNODES] = { [0 ... MAX_NUMNODES - 1] = NUMA_NO_NODE };
67 
68 /*
69  * Allocate node_to_cpumask_map based on number of available nodes
70  * Requires node_possible_map to be valid.
71  *
72  * Note: cpumask_of_node() is not valid until after this is done.
73  */
74 static void __init setup_node_to_cpumask_map(void)
75 {
76 	unsigned int node;
77 
78 	/* setup nr_node_ids if not done yet */
79 	if (nr_node_ids == MAX_NUMNODES)
80 		setup_nr_node_ids();
81 
82 	/* allocate the map */
83 	for_each_node(node)
84 		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
85 
86 	/* cpumask_of_node() will now work */
87 	pr_debug("Node to cpumask map for %u nodes\n", nr_node_ids);
88 }
89 
90 static int __init fake_numa_create_new_node(unsigned long end_pfn,
91 						unsigned int *nid)
92 {
93 	unsigned long long mem;
94 	char *p = cmdline;
95 	static unsigned int fake_nid;
96 	static unsigned long long curr_boundary;
97 
98 	/*
99 	 * Modify node id, iff we started creating NUMA nodes
100 	 * We want to continue from where we left of the last time
101 	 */
102 	if (fake_nid)
103 		*nid = fake_nid;
104 	/*
105 	 * In case there are no more arguments to parse, the
106 	 * node_id should be the same as the last fake node id
107 	 * (we've handled this above).
108 	 */
109 	if (!p)
110 		return 0;
111 
112 	mem = memparse(p, &p);
113 	if (!mem)
114 		return 0;
115 
116 	if (mem < curr_boundary)
117 		return 0;
118 
119 	curr_boundary = mem;
120 
121 	if ((end_pfn << PAGE_SHIFT) > mem) {
122 		/*
123 		 * Skip commas and spaces
124 		 */
125 		while (*p == ',' || *p == ' ' || *p == '\t')
126 			p++;
127 
128 		cmdline = p;
129 		fake_nid++;
130 		*nid = fake_nid;
131 		pr_debug("created new fake_node with id %d\n", fake_nid);
132 		return 1;
133 	}
134 	return 0;
135 }
136 
137 static void __init reset_numa_cpu_lookup_table(void)
138 {
139 	unsigned int cpu;
140 
141 	for_each_possible_cpu(cpu)
142 		numa_cpu_lookup_table[cpu] = -1;
143 }
144 
145 void map_cpu_to_node(int cpu, int node)
146 {
147 	update_numa_cpu_lookup_table(cpu, node);
148 
149 	if (!(cpumask_test_cpu(cpu, node_to_cpumask_map[node]))) {
150 		pr_debug("adding cpu %d to node %d\n", cpu, node);
151 		cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
152 	}
153 }
154 
155 #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PPC_SPLPAR)
156 void unmap_cpu_from_node(unsigned long cpu)
157 {
158 	int node = numa_cpu_lookup_table[cpu];
159 
160 	if (cpumask_test_cpu(cpu, node_to_cpumask_map[node])) {
161 		cpumask_clear_cpu(cpu, node_to_cpumask_map[node]);
162 		pr_debug("removing cpu %lu from node %d\n", cpu, node);
163 	} else {
164 		pr_warn("Warning: cpu %lu not found in node %d\n", cpu, node);
165 	}
166 }
167 #endif /* CONFIG_HOTPLUG_CPU || CONFIG_PPC_SPLPAR */
168 
169 static int __associativity_to_nid(const __be32 *associativity,
170 				  int max_array_sz)
171 {
172 	int nid;
173 	/*
174 	 * primary_domain_index is 1 based array index.
175 	 */
176 	int index = primary_domain_index  - 1;
177 
178 	if (!numa_enabled || index >= max_array_sz)
179 		return NUMA_NO_NODE;
180 
181 	nid = of_read_number(&associativity[index], 1);
182 
183 	/* POWER4 LPAR uses 0xffff as invalid node */
184 	if (nid == 0xffff || nid >= nr_node_ids)
185 		nid = NUMA_NO_NODE;
186 	return nid;
187 }
188 /*
189  * Returns nid in the range [0..nr_node_ids], or -1 if no useful NUMA
190  * info is found.
191  */
192 static int associativity_to_nid(const __be32 *associativity)
193 {
194 	int array_sz = of_read_number(associativity, 1);
195 
196 	/* Skip the first element in the associativity array */
197 	return __associativity_to_nid((associativity + 1), array_sz);
198 }
199 
200 static int __cpu_form2_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
201 {
202 	int dist;
203 	int node1, node2;
204 
205 	node1 = associativity_to_nid(cpu1_assoc);
206 	node2 = associativity_to_nid(cpu2_assoc);
207 
208 	dist = numa_distance_table[node1][node2];
209 	if (dist <= LOCAL_DISTANCE)
210 		return 0;
211 	else if (dist <= REMOTE_DISTANCE)
212 		return 1;
213 	else
214 		return 2;
215 }
216 
217 static int __cpu_form1_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
218 {
219 	int dist = 0;
220 
221 	int i, index;
222 
223 	for (i = 0; i < distance_ref_points_depth; i++) {
224 		index = be32_to_cpu(distance_ref_points[i]);
225 		if (cpu1_assoc[index] == cpu2_assoc[index])
226 			break;
227 		dist++;
228 	}
229 
230 	return dist;
231 }
232 
233 int cpu_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
234 {
235 	/* We should not get called with FORM0 */
236 	VM_WARN_ON(affinity_form == FORM0_AFFINITY);
237 	if (affinity_form == FORM1_AFFINITY)
238 		return __cpu_form1_relative_distance(cpu1_assoc, cpu2_assoc);
239 	return __cpu_form2_relative_distance(cpu1_assoc, cpu2_assoc);
240 }
241 
242 /* must hold reference to node during call */
243 static const __be32 *of_get_associativity(struct device_node *dev)
244 {
245 	return of_get_property(dev, "ibm,associativity", NULL);
246 }
247 
248 int __node_distance(int a, int b)
249 {
250 	int i;
251 	int distance = LOCAL_DISTANCE;
252 
253 	if (affinity_form == FORM2_AFFINITY)
254 		return numa_distance_table[a][b];
255 	else if (affinity_form == FORM0_AFFINITY)
256 		return ((a == b) ? LOCAL_DISTANCE : REMOTE_DISTANCE);
257 
258 	for (i = 0; i < distance_ref_points_depth; i++) {
259 		if (distance_lookup_table[a][i] == distance_lookup_table[b][i])
260 			break;
261 
262 		/* Double the distance for each NUMA level */
263 		distance *= 2;
264 	}
265 
266 	return distance;
267 }
268 EXPORT_SYMBOL(__node_distance);
269 
270 /* Returns the nid associated with the given device tree node,
271  * or -1 if not found.
272  */
273 static int of_node_to_nid_single(struct device_node *device)
274 {
275 	int nid = NUMA_NO_NODE;
276 	const __be32 *tmp;
277 
278 	tmp = of_get_associativity(device);
279 	if (tmp)
280 		nid = associativity_to_nid(tmp);
281 	return nid;
282 }
283 
284 /* Walk the device tree upwards, looking for an associativity id */
285 int of_node_to_nid(struct device_node *device)
286 {
287 	int nid = NUMA_NO_NODE;
288 
289 	of_node_get(device);
290 	while (device) {
291 		nid = of_node_to_nid_single(device);
292 		if (nid != -1)
293 			break;
294 
295 		device = of_get_next_parent(device);
296 	}
297 	of_node_put(device);
298 
299 	return nid;
300 }
301 EXPORT_SYMBOL(of_node_to_nid);
302 
303 static void __initialize_form1_numa_distance(const __be32 *associativity,
304 					     int max_array_sz)
305 {
306 	int i, nid;
307 
308 	if (affinity_form != FORM1_AFFINITY)
309 		return;
310 
311 	nid = __associativity_to_nid(associativity, max_array_sz);
312 	if (nid != NUMA_NO_NODE) {
313 		for (i = 0; i < distance_ref_points_depth; i++) {
314 			const __be32 *entry;
315 			int index = be32_to_cpu(distance_ref_points[i]) - 1;
316 
317 			/*
318 			 * broken hierarchy, return with broken distance table
319 			 */
320 			if (WARN(index >= max_array_sz, "Broken ibm,associativity property"))
321 				return;
322 
323 			entry = &associativity[index];
324 			distance_lookup_table[nid][i] = of_read_number(entry, 1);
325 		}
326 	}
327 }
328 
329 static void initialize_form1_numa_distance(const __be32 *associativity)
330 {
331 	int array_sz;
332 
333 	array_sz = of_read_number(associativity, 1);
334 	/* Skip the first element in the associativity array */
335 	__initialize_form1_numa_distance(associativity + 1, array_sz);
336 }
337 
338 /*
339  * Used to update distance information w.r.t newly added node.
340  */
341 void update_numa_distance(struct device_node *node)
342 {
343 	int nid;
344 
345 	if (affinity_form == FORM0_AFFINITY)
346 		return;
347 	else if (affinity_form == FORM1_AFFINITY) {
348 		const __be32 *associativity;
349 
350 		associativity = of_get_associativity(node);
351 		if (!associativity)
352 			return;
353 
354 		initialize_form1_numa_distance(associativity);
355 		return;
356 	}
357 
358 	/* FORM2 affinity  */
359 	nid = of_node_to_nid_single(node);
360 	if (nid == NUMA_NO_NODE)
361 		return;
362 
363 	/*
364 	 * With FORM2 we expect NUMA distance of all possible NUMA
365 	 * nodes to be provided during boot.
366 	 */
367 	WARN(numa_distance_table[nid][nid] == -1,
368 	     "NUMA distance details for node %d not provided\n", nid);
369 }
370 EXPORT_SYMBOL_GPL(update_numa_distance);
371 
372 /*
373  * ibm,numa-lookup-index-table= {N, domainid1, domainid2, ..... domainidN}
374  * ibm,numa-distance-table = { N, 1, 2, 4, 5, 1, 6, .... N elements}
375  */
376 static void __init initialize_form2_numa_distance_lookup_table(void)
377 {
378 	int i, j;
379 	struct device_node *root;
380 	const __u8 *form2_distances;
381 	const __be32 *numa_lookup_index;
382 	int form2_distances_length;
383 	int max_numa_index, distance_index;
384 
385 	if (firmware_has_feature(FW_FEATURE_OPAL))
386 		root = of_find_node_by_path("/ibm,opal");
387 	else
388 		root = of_find_node_by_path("/rtas");
389 	if (!root)
390 		root = of_find_node_by_path("/");
391 
392 	numa_lookup_index = of_get_property(root, "ibm,numa-lookup-index-table", NULL);
393 	max_numa_index = of_read_number(&numa_lookup_index[0], 1);
394 
395 	/* first element of the array is the size and is encode-int */
396 	form2_distances = of_get_property(root, "ibm,numa-distance-table", NULL);
397 	form2_distances_length = of_read_number((const __be32 *)&form2_distances[0], 1);
398 	/* Skip the size which is encoded int */
399 	form2_distances += sizeof(__be32);
400 
401 	pr_debug("form2_distances_len = %d, numa_dist_indexes_len = %d\n",
402 		 form2_distances_length, max_numa_index);
403 
404 	for (i = 0; i < max_numa_index; i++)
405 		/* +1 skip the max_numa_index in the property */
406 		numa_id_index_table[i] = of_read_number(&numa_lookup_index[i + 1], 1);
407 
408 
409 	if (form2_distances_length != max_numa_index * max_numa_index) {
410 		WARN(1, "Wrong NUMA distance information\n");
411 		form2_distances = NULL; // don't use it
412 	}
413 	distance_index = 0;
414 	for (i = 0;  i < max_numa_index; i++) {
415 		for (j = 0; j < max_numa_index; j++) {
416 			int nodeA = numa_id_index_table[i];
417 			int nodeB = numa_id_index_table[j];
418 			int dist;
419 
420 			if (form2_distances)
421 				dist = form2_distances[distance_index++];
422 			else if (nodeA == nodeB)
423 				dist = LOCAL_DISTANCE;
424 			else
425 				dist = REMOTE_DISTANCE;
426 			numa_distance_table[nodeA][nodeB] = dist;
427 			pr_debug("dist[%d][%d]=%d ", nodeA, nodeB, dist);
428 		}
429 	}
430 
431 	of_node_put(root);
432 }
433 
434 static int __init find_primary_domain_index(void)
435 {
436 	int index;
437 	struct device_node *root;
438 
439 	/*
440 	 * Check for which form of affinity.
441 	 */
442 	if (firmware_has_feature(FW_FEATURE_OPAL)) {
443 		affinity_form = FORM1_AFFINITY;
444 	} else if (firmware_has_feature(FW_FEATURE_FORM2_AFFINITY)) {
445 		pr_debug("Using form 2 affinity\n");
446 		affinity_form = FORM2_AFFINITY;
447 	} else if (firmware_has_feature(FW_FEATURE_FORM1_AFFINITY)) {
448 		pr_debug("Using form 1 affinity\n");
449 		affinity_form = FORM1_AFFINITY;
450 	} else
451 		affinity_form = FORM0_AFFINITY;
452 
453 	if (firmware_has_feature(FW_FEATURE_OPAL))
454 		root = of_find_node_by_path("/ibm,opal");
455 	else
456 		root = of_find_node_by_path("/rtas");
457 	if (!root)
458 		root = of_find_node_by_path("/");
459 
460 	/*
461 	 * This property is a set of 32-bit integers, each representing
462 	 * an index into the ibm,associativity nodes.
463 	 *
464 	 * With form 0 affinity the first integer is for an SMP configuration
465 	 * (should be all 0's) and the second is for a normal NUMA
466 	 * configuration. We have only one level of NUMA.
467 	 *
468 	 * With form 1 affinity the first integer is the most significant
469 	 * NUMA boundary and the following are progressively less significant
470 	 * boundaries. There can be more than one level of NUMA.
471 	 */
472 	distance_ref_points = of_get_property(root,
473 					"ibm,associativity-reference-points",
474 					&distance_ref_points_depth);
475 
476 	if (!distance_ref_points) {
477 		pr_debug("ibm,associativity-reference-points not found.\n");
478 		goto err;
479 	}
480 
481 	distance_ref_points_depth /= sizeof(int);
482 	if (affinity_form == FORM0_AFFINITY) {
483 		if (distance_ref_points_depth < 2) {
484 			pr_warn("short ibm,associativity-reference-points\n");
485 			goto err;
486 		}
487 
488 		index = of_read_number(&distance_ref_points[1], 1);
489 	} else {
490 		/*
491 		 * Both FORM1 and FORM2 affinity find the primary domain details
492 		 * at the same offset.
493 		 */
494 		index = of_read_number(distance_ref_points, 1);
495 	}
496 	/*
497 	 * Warn and cap if the hardware supports more than
498 	 * MAX_DISTANCE_REF_POINTS domains.
499 	 */
500 	if (distance_ref_points_depth > MAX_DISTANCE_REF_POINTS) {
501 		pr_warn("distance array capped at %d entries\n",
502 			MAX_DISTANCE_REF_POINTS);
503 		distance_ref_points_depth = MAX_DISTANCE_REF_POINTS;
504 	}
505 
506 	of_node_put(root);
507 	return index;
508 
509 err:
510 	of_node_put(root);
511 	return -1;
512 }
513 
514 static void __init get_n_mem_cells(int *n_addr_cells, int *n_size_cells)
515 {
516 	struct device_node *memory = NULL;
517 
518 	memory = of_find_node_by_type(memory, "memory");
519 	if (!memory)
520 		panic("numa.c: No memory nodes found!");
521 
522 	*n_addr_cells = of_n_addr_cells(memory);
523 	*n_size_cells = of_n_size_cells(memory);
524 	of_node_put(memory);
525 }
526 
527 static unsigned long read_n_cells(int n, const __be32 **buf)
528 {
529 	unsigned long result = 0;
530 
531 	while (n--) {
532 		result = (result << 32) | of_read_number(*buf, 1);
533 		(*buf)++;
534 	}
535 	return result;
536 }
537 
538 struct assoc_arrays {
539 	u32	n_arrays;
540 	u32	array_sz;
541 	const __be32 *arrays;
542 };
543 
544 /*
545  * Retrieve and validate the list of associativity arrays for drconf
546  * memory from the ibm,associativity-lookup-arrays property of the
547  * device tree..
548  *
549  * The layout of the ibm,associativity-lookup-arrays property is a number N
550  * indicating the number of associativity arrays, followed by a number M
551  * indicating the size of each associativity array, followed by a list
552  * of N associativity arrays.
553  */
554 static int of_get_assoc_arrays(struct assoc_arrays *aa)
555 {
556 	struct device_node *memory;
557 	const __be32 *prop;
558 	u32 len;
559 
560 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
561 	if (!memory)
562 		return -1;
563 
564 	prop = of_get_property(memory, "ibm,associativity-lookup-arrays", &len);
565 	if (!prop || len < 2 * sizeof(unsigned int)) {
566 		of_node_put(memory);
567 		return -1;
568 	}
569 
570 	aa->n_arrays = of_read_number(prop++, 1);
571 	aa->array_sz = of_read_number(prop++, 1);
572 
573 	of_node_put(memory);
574 
575 	/* Now that we know the number of arrays and size of each array,
576 	 * revalidate the size of the property read in.
577 	 */
578 	if (len < (aa->n_arrays * aa->array_sz + 2) * sizeof(unsigned int))
579 		return -1;
580 
581 	aa->arrays = prop;
582 	return 0;
583 }
584 
585 static int __init get_nid_and_numa_distance(struct drmem_lmb *lmb)
586 {
587 	struct assoc_arrays aa = { .arrays = NULL };
588 	int default_nid = NUMA_NO_NODE;
589 	int nid = default_nid;
590 	int rc, index;
591 
592 	if ((primary_domain_index < 0) || !numa_enabled)
593 		return default_nid;
594 
595 	rc = of_get_assoc_arrays(&aa);
596 	if (rc)
597 		return default_nid;
598 
599 	if (primary_domain_index <= aa.array_sz &&
600 	    !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
601 		const __be32 *associativity;
602 
603 		index = lmb->aa_index * aa.array_sz;
604 		associativity = &aa.arrays[index];
605 		nid = __associativity_to_nid(associativity, aa.array_sz);
606 		if (nid > 0 && affinity_form == FORM1_AFFINITY) {
607 			/*
608 			 * lookup array associativity entries have
609 			 * no length of the array as the first element.
610 			 */
611 			__initialize_form1_numa_distance(associativity, aa.array_sz);
612 		}
613 	}
614 	return nid;
615 }
616 
617 /*
618  * This is like of_node_to_nid_single() for memory represented in the
619  * ibm,dynamic-reconfiguration-memory node.
620  */
621 int of_drconf_to_nid_single(struct drmem_lmb *lmb)
622 {
623 	struct assoc_arrays aa = { .arrays = NULL };
624 	int default_nid = NUMA_NO_NODE;
625 	int nid = default_nid;
626 	int rc, index;
627 
628 	if ((primary_domain_index < 0) || !numa_enabled)
629 		return default_nid;
630 
631 	rc = of_get_assoc_arrays(&aa);
632 	if (rc)
633 		return default_nid;
634 
635 	if (primary_domain_index <= aa.array_sz &&
636 	    !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
637 		const __be32 *associativity;
638 
639 		index = lmb->aa_index * aa.array_sz;
640 		associativity = &aa.arrays[index];
641 		nid = __associativity_to_nid(associativity, aa.array_sz);
642 	}
643 	return nid;
644 }
645 
646 #ifdef CONFIG_PPC_SPLPAR
647 
648 static int __vphn_get_associativity(long lcpu, __be32 *associativity)
649 {
650 	long rc, hwid;
651 
652 	/*
653 	 * On a shared lpar, device tree will not have node associativity.
654 	 * At this time lppaca, or its __old_status field may not be
655 	 * updated. Hence kernel cannot detect if its on a shared lpar. So
656 	 * request an explicit associativity irrespective of whether the
657 	 * lpar is shared or dedicated. Use the device tree property as a
658 	 * fallback. cpu_to_phys_id is only valid between
659 	 * smp_setup_cpu_maps() and smp_setup_pacas().
660 	 */
661 	if (firmware_has_feature(FW_FEATURE_VPHN)) {
662 		if (cpu_to_phys_id)
663 			hwid = cpu_to_phys_id[lcpu];
664 		else
665 			hwid = get_hard_smp_processor_id(lcpu);
666 
667 		rc = hcall_vphn(hwid, VPHN_FLAG_VCPU, associativity);
668 		if (rc == H_SUCCESS)
669 			return 0;
670 	}
671 
672 	return -1;
673 }
674 
675 static int vphn_get_nid(long lcpu)
676 {
677 	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
678 
679 
680 	if (!__vphn_get_associativity(lcpu, associativity))
681 		return associativity_to_nid(associativity);
682 
683 	return NUMA_NO_NODE;
684 
685 }
686 #else
687 
688 static int __vphn_get_associativity(long lcpu, __be32 *associativity)
689 {
690 	return -1;
691 }
692 
693 static int vphn_get_nid(long unused)
694 {
695 	return NUMA_NO_NODE;
696 }
697 #endif  /* CONFIG_PPC_SPLPAR */
698 
699 /*
700  * Figure out to which domain a cpu belongs and stick it there.
701  * Return the id of the domain used.
702  */
703 static int numa_setup_cpu(unsigned long lcpu)
704 {
705 	struct device_node *cpu;
706 	int fcpu = cpu_first_thread_sibling(lcpu);
707 	int nid = NUMA_NO_NODE;
708 
709 	if (!cpu_present(lcpu)) {
710 		set_cpu_numa_node(lcpu, first_online_node);
711 		return first_online_node;
712 	}
713 
714 	/*
715 	 * If a valid cpu-to-node mapping is already available, use it
716 	 * directly instead of querying the firmware, since it represents
717 	 * the most recent mapping notified to us by the platform (eg: VPHN).
718 	 * Since cpu_to_node binding remains the same for all threads in the
719 	 * core. If a valid cpu-to-node mapping is already available, for
720 	 * the first thread in the core, use it.
721 	 */
722 	nid = numa_cpu_lookup_table[fcpu];
723 	if (nid >= 0) {
724 		map_cpu_to_node(lcpu, nid);
725 		return nid;
726 	}
727 
728 	nid = vphn_get_nid(lcpu);
729 	if (nid != NUMA_NO_NODE)
730 		goto out_present;
731 
732 	cpu = of_get_cpu_node(lcpu, NULL);
733 
734 	if (!cpu) {
735 		WARN_ON(1);
736 		if (cpu_present(lcpu))
737 			goto out_present;
738 		else
739 			goto out;
740 	}
741 
742 	nid = of_node_to_nid_single(cpu);
743 	of_node_put(cpu);
744 
745 out_present:
746 	if (nid < 0 || !node_possible(nid))
747 		nid = first_online_node;
748 
749 	/*
750 	 * Update for the first thread of the core. All threads of a core
751 	 * have to be part of the same node. This not only avoids querying
752 	 * for every other thread in the core, but always avoids a case
753 	 * where virtual node associativity change causes subsequent threads
754 	 * of a core to be associated with different nid. However if first
755 	 * thread is already online, expect it to have a valid mapping.
756 	 */
757 	if (fcpu != lcpu) {
758 		WARN_ON(cpu_online(fcpu));
759 		map_cpu_to_node(fcpu, nid);
760 	}
761 
762 	map_cpu_to_node(lcpu, nid);
763 out:
764 	return nid;
765 }
766 
767 static void verify_cpu_node_mapping(int cpu, int node)
768 {
769 	int base, sibling, i;
770 
771 	/* Verify that all the threads in the core belong to the same node */
772 	base = cpu_first_thread_sibling(cpu);
773 
774 	for (i = 0; i < threads_per_core; i++) {
775 		sibling = base + i;
776 
777 		if (sibling == cpu || cpu_is_offline(sibling))
778 			continue;
779 
780 		if (cpu_to_node(sibling) != node) {
781 			WARN(1, "CPU thread siblings %d and %d don't belong"
782 				" to the same node!\n", cpu, sibling);
783 			break;
784 		}
785 	}
786 }
787 
788 /* Must run before sched domains notifier. */
789 static int ppc_numa_cpu_prepare(unsigned int cpu)
790 {
791 	int nid;
792 
793 	nid = numa_setup_cpu(cpu);
794 	verify_cpu_node_mapping(cpu, nid);
795 	return 0;
796 }
797 
798 static int ppc_numa_cpu_dead(unsigned int cpu)
799 {
800 	return 0;
801 }
802 
803 /*
804  * Check and possibly modify a memory region to enforce the memory limit.
805  *
806  * Returns the size the region should have to enforce the memory limit.
807  * This will either be the original value of size, a truncated value,
808  * or zero. If the returned value of size is 0 the region should be
809  * discarded as it lies wholly above the memory limit.
810  */
811 static unsigned long __init numa_enforce_memory_limit(unsigned long start,
812 						      unsigned long size)
813 {
814 	/*
815 	 * We use memblock_end_of_DRAM() in here instead of memory_limit because
816 	 * we've already adjusted it for the limit and it takes care of
817 	 * having memory holes below the limit.  Also, in the case of
818 	 * iommu_is_off, memory_limit is not set but is implicitly enforced.
819 	 */
820 
821 	if (start + size <= memblock_end_of_DRAM())
822 		return size;
823 
824 	if (start >= memblock_end_of_DRAM())
825 		return 0;
826 
827 	return memblock_end_of_DRAM() - start;
828 }
829 
830 /*
831  * Reads the counter for a given entry in
832  * linux,drconf-usable-memory property
833  */
834 static inline int __init read_usm_ranges(const __be32 **usm)
835 {
836 	/*
837 	 * For each lmb in ibm,dynamic-memory a corresponding
838 	 * entry in linux,drconf-usable-memory property contains
839 	 * a counter followed by that many (base, size) duple.
840 	 * read the counter from linux,drconf-usable-memory
841 	 */
842 	return read_n_cells(n_mem_size_cells, usm);
843 }
844 
845 /*
846  * Extract NUMA information from the ibm,dynamic-reconfiguration-memory
847  * node.  This assumes n_mem_{addr,size}_cells have been set.
848  */
849 static int __init numa_setup_drmem_lmb(struct drmem_lmb *lmb,
850 					const __be32 **usm,
851 					void *data)
852 {
853 	unsigned int ranges, is_kexec_kdump = 0;
854 	unsigned long base, size, sz;
855 	int nid;
856 
857 	/*
858 	 * Skip this block if the reserved bit is set in flags (0x80)
859 	 * or if the block is not assigned to this partition (0x8)
860 	 */
861 	if ((lmb->flags & DRCONF_MEM_RESERVED)
862 	    || !(lmb->flags & DRCONF_MEM_ASSIGNED))
863 		return 0;
864 
865 	if (*usm)
866 		is_kexec_kdump = 1;
867 
868 	base = lmb->base_addr;
869 	size = drmem_lmb_size();
870 	ranges = 1;
871 
872 	if (is_kexec_kdump) {
873 		ranges = read_usm_ranges(usm);
874 		if (!ranges) /* there are no (base, size) duple */
875 			return 0;
876 	}
877 
878 	do {
879 		if (is_kexec_kdump) {
880 			base = read_n_cells(n_mem_addr_cells, usm);
881 			size = read_n_cells(n_mem_size_cells, usm);
882 		}
883 
884 		nid = get_nid_and_numa_distance(lmb);
885 		fake_numa_create_new_node(((base + size) >> PAGE_SHIFT),
886 					  &nid);
887 		node_set_online(nid);
888 		sz = numa_enforce_memory_limit(base, size);
889 		if (sz)
890 			memblock_set_node(base, sz, &memblock.memory, nid);
891 	} while (--ranges);
892 
893 	return 0;
894 }
895 
896 static int __init parse_numa_properties(void)
897 {
898 	struct device_node *memory;
899 	int default_nid = 0;
900 	unsigned long i;
901 	const __be32 *associativity;
902 
903 	if (numa_enabled == 0) {
904 		pr_warn("disabled by user\n");
905 		return -1;
906 	}
907 
908 	primary_domain_index = find_primary_domain_index();
909 
910 	if (primary_domain_index < 0) {
911 		/*
912 		 * if we fail to parse primary_domain_index from device tree
913 		 * mark the numa disabled, boot with numa disabled.
914 		 */
915 		numa_enabled = false;
916 		return primary_domain_index;
917 	}
918 
919 	pr_debug("associativity depth for CPU/Memory: %d\n", primary_domain_index);
920 
921 	/*
922 	 * If it is FORM2 initialize the distance table here.
923 	 */
924 	if (affinity_form == FORM2_AFFINITY)
925 		initialize_form2_numa_distance_lookup_table();
926 
927 	/*
928 	 * Even though we connect cpus to numa domains later in SMP
929 	 * init, we need to know the node ids now. This is because
930 	 * each node to be onlined must have NODE_DATA etc backing it.
931 	 */
932 	for_each_present_cpu(i) {
933 		__be32 vphn_assoc[VPHN_ASSOC_BUFSIZE];
934 		struct device_node *cpu;
935 		int nid = NUMA_NO_NODE;
936 
937 		memset(vphn_assoc, 0, VPHN_ASSOC_BUFSIZE * sizeof(__be32));
938 
939 		if (__vphn_get_associativity(i, vphn_assoc) == 0) {
940 			nid = associativity_to_nid(vphn_assoc);
941 			initialize_form1_numa_distance(vphn_assoc);
942 		} else {
943 
944 			/*
945 			 * Don't fall back to default_nid yet -- we will plug
946 			 * cpus into nodes once the memory scan has discovered
947 			 * the topology.
948 			 */
949 			cpu = of_get_cpu_node(i, NULL);
950 			BUG_ON(!cpu);
951 
952 			associativity = of_get_associativity(cpu);
953 			if (associativity) {
954 				nid = associativity_to_nid(associativity);
955 				initialize_form1_numa_distance(associativity);
956 			}
957 			of_node_put(cpu);
958 		}
959 
960 		/* node_set_online() is an UB if 'nid' is negative */
961 		if (likely(nid >= 0))
962 			node_set_online(nid);
963 	}
964 
965 	get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells);
966 
967 	for_each_node_by_type(memory, "memory") {
968 		unsigned long start;
969 		unsigned long size;
970 		int nid;
971 		int ranges;
972 		const __be32 *memcell_buf;
973 		unsigned int len;
974 
975 		memcell_buf = of_get_property(memory,
976 			"linux,usable-memory", &len);
977 		if (!memcell_buf || len <= 0)
978 			memcell_buf = of_get_property(memory, "reg", &len);
979 		if (!memcell_buf || len <= 0)
980 			continue;
981 
982 		/* ranges in cell */
983 		ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
984 new_range:
985 		/* these are order-sensitive, and modify the buffer pointer */
986 		start = read_n_cells(n_mem_addr_cells, &memcell_buf);
987 		size = read_n_cells(n_mem_size_cells, &memcell_buf);
988 
989 		/*
990 		 * Assumption: either all memory nodes or none will
991 		 * have associativity properties.  If none, then
992 		 * everything goes to default_nid.
993 		 */
994 		associativity = of_get_associativity(memory);
995 		if (associativity) {
996 			nid = associativity_to_nid(associativity);
997 			initialize_form1_numa_distance(associativity);
998 		} else
999 			nid = default_nid;
1000 
1001 		fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);
1002 		node_set_online(nid);
1003 
1004 		size = numa_enforce_memory_limit(start, size);
1005 		if (size)
1006 			memblock_set_node(start, size, &memblock.memory, nid);
1007 
1008 		if (--ranges)
1009 			goto new_range;
1010 	}
1011 
1012 	/*
1013 	 * Now do the same thing for each MEMBLOCK listed in the
1014 	 * ibm,dynamic-memory property in the
1015 	 * ibm,dynamic-reconfiguration-memory node.
1016 	 */
1017 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1018 	if (memory) {
1019 		walk_drmem_lmbs(memory, NULL, numa_setup_drmem_lmb);
1020 		of_node_put(memory);
1021 	}
1022 
1023 	return 0;
1024 }
1025 
1026 static void __init setup_nonnuma(void)
1027 {
1028 	unsigned long top_of_ram = memblock_end_of_DRAM();
1029 	unsigned long total_ram = memblock_phys_mem_size();
1030 	unsigned long start_pfn, end_pfn;
1031 	unsigned int nid = 0;
1032 	int i;
1033 
1034 	pr_debug("Top of RAM: 0x%lx, Total RAM: 0x%lx\n", top_of_ram, total_ram);
1035 	pr_debug("Memory hole size: %ldMB\n", (top_of_ram - total_ram) >> 20);
1036 
1037 	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
1038 		fake_numa_create_new_node(end_pfn, &nid);
1039 		memblock_set_node(PFN_PHYS(start_pfn),
1040 				  PFN_PHYS(end_pfn - start_pfn),
1041 				  &memblock.memory, nid);
1042 		node_set_online(nid);
1043 	}
1044 }
1045 
1046 void __init dump_numa_cpu_topology(void)
1047 {
1048 	unsigned int node;
1049 	unsigned int cpu, count;
1050 
1051 	if (!numa_enabled)
1052 		return;
1053 
1054 	for_each_online_node(node) {
1055 		pr_info("Node %d CPUs:", node);
1056 
1057 		count = 0;
1058 		/*
1059 		 * If we used a CPU iterator here we would miss printing
1060 		 * the holes in the cpumap.
1061 		 */
1062 		for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
1063 			if (cpumask_test_cpu(cpu,
1064 					node_to_cpumask_map[node])) {
1065 				if (count == 0)
1066 					pr_cont(" %u", cpu);
1067 				++count;
1068 			} else {
1069 				if (count > 1)
1070 					pr_cont("-%u", cpu - 1);
1071 				count = 0;
1072 			}
1073 		}
1074 
1075 		if (count > 1)
1076 			pr_cont("-%u", nr_cpu_ids - 1);
1077 		pr_cont("\n");
1078 	}
1079 }
1080 
1081 /* Initialize NODE_DATA for a node on the local memory */
1082 static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
1083 {
1084 	u64 spanned_pages = end_pfn - start_pfn;
1085 	const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);
1086 	u64 nd_pa;
1087 	void *nd;
1088 	int tnid;
1089 
1090 	nd_pa = memblock_phys_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
1091 	if (!nd_pa)
1092 		panic("Cannot allocate %zu bytes for node %d data\n",
1093 		      nd_size, nid);
1094 
1095 	nd = __va(nd_pa);
1096 
1097 	/* report and initialize */
1098 	pr_info("  NODE_DATA [mem %#010Lx-%#010Lx]\n",
1099 		nd_pa, nd_pa + nd_size - 1);
1100 	tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
1101 	if (tnid != nid)
1102 		pr_info("    NODE_DATA(%d) on node %d\n", nid, tnid);
1103 
1104 	node_data[nid] = nd;
1105 	memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
1106 	NODE_DATA(nid)->node_id = nid;
1107 	NODE_DATA(nid)->node_start_pfn = start_pfn;
1108 	NODE_DATA(nid)->node_spanned_pages = spanned_pages;
1109 }
1110 
1111 static void __init find_possible_nodes(void)
1112 {
1113 	struct device_node *rtas;
1114 	const __be32 *domains = NULL;
1115 	int prop_length, max_nodes;
1116 	u32 i;
1117 
1118 	if (!numa_enabled)
1119 		return;
1120 
1121 	rtas = of_find_node_by_path("/rtas");
1122 	if (!rtas)
1123 		return;
1124 
1125 	/*
1126 	 * ibm,current-associativity-domains is a fairly recent property. If
1127 	 * it doesn't exist, then fallback on ibm,max-associativity-domains.
1128 	 * Current denotes what the platform can support compared to max
1129 	 * which denotes what the Hypervisor can support.
1130 	 *
1131 	 * If the LPAR is migratable, new nodes might be activated after a LPM,
1132 	 * so we should consider the max number in that case.
1133 	 */
1134 	if (!of_get_property(of_root, "ibm,migratable-partition", NULL))
1135 		domains = of_get_property(rtas,
1136 					  "ibm,current-associativity-domains",
1137 					  &prop_length);
1138 	if (!domains) {
1139 		domains = of_get_property(rtas, "ibm,max-associativity-domains",
1140 					&prop_length);
1141 		if (!domains)
1142 			goto out;
1143 	}
1144 
1145 	max_nodes = of_read_number(&domains[primary_domain_index], 1);
1146 	pr_info("Partition configured for %d NUMA nodes.\n", max_nodes);
1147 
1148 	for (i = 0; i < max_nodes; i++) {
1149 		if (!node_possible(i))
1150 			node_set(i, node_possible_map);
1151 	}
1152 
1153 	prop_length /= sizeof(int);
1154 	if (prop_length > primary_domain_index + 2)
1155 		coregroup_enabled = 1;
1156 
1157 out:
1158 	of_node_put(rtas);
1159 }
1160 
1161 void __init mem_topology_setup(void)
1162 {
1163 	int cpu;
1164 
1165 	max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
1166 	min_low_pfn = MEMORY_START >> PAGE_SHIFT;
1167 
1168 	/*
1169 	 * Linux/mm assumes node 0 to be online at boot. However this is not
1170 	 * true on PowerPC, where node 0 is similar to any other node, it
1171 	 * could be cpuless, memoryless node. So force node 0 to be offline
1172 	 * for now. This will prevent cpuless, memoryless node 0 showing up
1173 	 * unnecessarily as online. If a node has cpus or memory that need
1174 	 * to be online, then node will anyway be marked online.
1175 	 */
1176 	node_set_offline(0);
1177 
1178 	if (parse_numa_properties())
1179 		setup_nonnuma();
1180 
1181 	/*
1182 	 * Modify the set of possible NUMA nodes to reflect information
1183 	 * available about the set of online nodes, and the set of nodes
1184 	 * that we expect to make use of for this platform's affinity
1185 	 * calculations.
1186 	 */
1187 	nodes_and(node_possible_map, node_possible_map, node_online_map);
1188 
1189 	find_possible_nodes();
1190 
1191 	setup_node_to_cpumask_map();
1192 
1193 	reset_numa_cpu_lookup_table();
1194 
1195 	for_each_possible_cpu(cpu) {
1196 		/*
1197 		 * Powerpc with CONFIG_NUMA always used to have a node 0,
1198 		 * even if it was memoryless or cpuless. For all cpus that
1199 		 * are possible but not present, cpu_to_node() would point
1200 		 * to node 0. To remove a cpuless, memoryless dummy node,
1201 		 * powerpc need to make sure all possible but not present
1202 		 * cpu_to_node are set to a proper node.
1203 		 */
1204 		numa_setup_cpu(cpu);
1205 	}
1206 }
1207 
1208 void __init initmem_init(void)
1209 {
1210 	int nid;
1211 
1212 	memblock_dump_all();
1213 
1214 	for_each_online_node(nid) {
1215 		unsigned long start_pfn, end_pfn;
1216 
1217 		get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
1218 		setup_node_data(nid, start_pfn, end_pfn);
1219 	}
1220 
1221 	sparse_init();
1222 
1223 	/*
1224 	 * We need the numa_cpu_lookup_table to be accurate for all CPUs,
1225 	 * even before we online them, so that we can use cpu_to_{node,mem}
1226 	 * early in boot, cf. smp_prepare_cpus().
1227 	 * _nocalls() + manual invocation is used because cpuhp is not yet
1228 	 * initialized for the boot CPU.
1229 	 */
1230 	cpuhp_setup_state_nocalls(CPUHP_POWER_NUMA_PREPARE, "powerpc/numa:prepare",
1231 				  ppc_numa_cpu_prepare, ppc_numa_cpu_dead);
1232 }
1233 
1234 static int __init early_numa(char *p)
1235 {
1236 	if (!p)
1237 		return 0;
1238 
1239 	if (strstr(p, "off"))
1240 		numa_enabled = 0;
1241 
1242 	p = strstr(p, "fake=");
1243 	if (p)
1244 		cmdline = p + strlen("fake=");
1245 
1246 	return 0;
1247 }
1248 early_param("numa", early_numa);
1249 
1250 #ifdef CONFIG_MEMORY_HOTPLUG
1251 /*
1252  * Find the node associated with a hot added memory section for
1253  * memory represented in the device tree by the property
1254  * ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory.
1255  */
1256 static int hot_add_drconf_scn_to_nid(unsigned long scn_addr)
1257 {
1258 	struct drmem_lmb *lmb;
1259 	unsigned long lmb_size;
1260 	int nid = NUMA_NO_NODE;
1261 
1262 	lmb_size = drmem_lmb_size();
1263 
1264 	for_each_drmem_lmb(lmb) {
1265 		/* skip this block if it is reserved or not assigned to
1266 		 * this partition */
1267 		if ((lmb->flags & DRCONF_MEM_RESERVED)
1268 		    || !(lmb->flags & DRCONF_MEM_ASSIGNED))
1269 			continue;
1270 
1271 		if ((scn_addr < lmb->base_addr)
1272 		    || (scn_addr >= (lmb->base_addr + lmb_size)))
1273 			continue;
1274 
1275 		nid = of_drconf_to_nid_single(lmb);
1276 		break;
1277 	}
1278 
1279 	return nid;
1280 }
1281 
1282 /*
1283  * Find the node associated with a hot added memory section for memory
1284  * represented in the device tree as a node (i.e. memory@XXXX) for
1285  * each memblock.
1286  */
1287 static int hot_add_node_scn_to_nid(unsigned long scn_addr)
1288 {
1289 	struct device_node *memory;
1290 	int nid = NUMA_NO_NODE;
1291 
1292 	for_each_node_by_type(memory, "memory") {
1293 		int i = 0;
1294 
1295 		while (1) {
1296 			struct resource res;
1297 
1298 			if (of_address_to_resource(memory, i++, &res))
1299 				break;
1300 
1301 			if ((scn_addr < res.start) || (scn_addr > res.end))
1302 				continue;
1303 
1304 			nid = of_node_to_nid_single(memory);
1305 			break;
1306 		}
1307 
1308 		if (nid >= 0)
1309 			break;
1310 	}
1311 
1312 	of_node_put(memory);
1313 
1314 	return nid;
1315 }
1316 
1317 /*
1318  * Find the node associated with a hot added memory section.  Section
1319  * corresponds to a SPARSEMEM section, not an MEMBLOCK.  It is assumed that
1320  * sections are fully contained within a single MEMBLOCK.
1321  */
1322 int hot_add_scn_to_nid(unsigned long scn_addr)
1323 {
1324 	struct device_node *memory = NULL;
1325 	int nid;
1326 
1327 	if (!numa_enabled)
1328 		return first_online_node;
1329 
1330 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1331 	if (memory) {
1332 		nid = hot_add_drconf_scn_to_nid(scn_addr);
1333 		of_node_put(memory);
1334 	} else {
1335 		nid = hot_add_node_scn_to_nid(scn_addr);
1336 	}
1337 
1338 	if (nid < 0 || !node_possible(nid))
1339 		nid = first_online_node;
1340 
1341 	return nid;
1342 }
1343 
1344 static u64 hot_add_drconf_memory_max(void)
1345 {
1346 	struct device_node *memory = NULL;
1347 	struct device_node *dn = NULL;
1348 	const __be64 *lrdr = NULL;
1349 
1350 	dn = of_find_node_by_path("/rtas");
1351 	if (dn) {
1352 		lrdr = of_get_property(dn, "ibm,lrdr-capacity", NULL);
1353 		of_node_put(dn);
1354 		if (lrdr)
1355 			return be64_to_cpup(lrdr);
1356 	}
1357 
1358 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1359 	if (memory) {
1360 		of_node_put(memory);
1361 		return drmem_lmb_memory_max();
1362 	}
1363 	return 0;
1364 }
1365 
1366 /*
1367  * memory_hotplug_max - return max address of memory that may be added
1368  *
1369  * This is currently only used on systems that support drconfig memory
1370  * hotplug.
1371  */
1372 u64 memory_hotplug_max(void)
1373 {
1374         return max(hot_add_drconf_memory_max(), memblock_end_of_DRAM());
1375 }
1376 #endif /* CONFIG_MEMORY_HOTPLUG */
1377 
1378 /* Virtual Processor Home Node (VPHN) support */
1379 #ifdef CONFIG_PPC_SPLPAR
1380 static int topology_inited;
1381 
1382 /*
1383  * Retrieve the new associativity information for a virtual processor's
1384  * home node.
1385  */
1386 static long vphn_get_associativity(unsigned long cpu,
1387 					__be32 *associativity)
1388 {
1389 	long rc;
1390 
1391 	rc = hcall_vphn(get_hard_smp_processor_id(cpu),
1392 				VPHN_FLAG_VCPU, associativity);
1393 
1394 	switch (rc) {
1395 	case H_SUCCESS:
1396 		pr_debug("VPHN hcall succeeded. Reset polling...\n");
1397 		goto out;
1398 
1399 	case H_FUNCTION:
1400 		pr_err_ratelimited("VPHN unsupported. Disabling polling...\n");
1401 		break;
1402 	case H_HARDWARE:
1403 		pr_err_ratelimited("hcall_vphn() experienced a hardware fault "
1404 			"preventing VPHN. Disabling polling...\n");
1405 		break;
1406 	case H_PARAMETER:
1407 		pr_err_ratelimited("hcall_vphn() was passed an invalid parameter. "
1408 			"Disabling polling...\n");
1409 		break;
1410 	default:
1411 		pr_err_ratelimited("hcall_vphn() returned %ld. Disabling polling...\n"
1412 			, rc);
1413 		break;
1414 	}
1415 out:
1416 	return rc;
1417 }
1418 
1419 void find_and_update_cpu_nid(int cpu)
1420 {
1421 	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
1422 	int new_nid;
1423 
1424 	/* Use associativity from first thread for all siblings */
1425 	if (vphn_get_associativity(cpu, associativity))
1426 		return;
1427 
1428 	/* Do not have previous associativity, so find it now. */
1429 	new_nid = associativity_to_nid(associativity);
1430 
1431 	if (new_nid < 0 || !node_possible(new_nid))
1432 		new_nid = first_online_node;
1433 	else
1434 		// Associate node <-> cpu, so cpu_up() calls
1435 		// try_online_node() on the right node.
1436 		set_cpu_numa_node(cpu, new_nid);
1437 
1438 	pr_debug("%s:%d cpu %d nid %d\n", __func__, __LINE__, cpu, new_nid);
1439 }
1440 
1441 int cpu_to_coregroup_id(int cpu)
1442 {
1443 	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
1444 	int index;
1445 
1446 	if (cpu < 0 || cpu > nr_cpu_ids)
1447 		return -1;
1448 
1449 	if (!coregroup_enabled)
1450 		goto out;
1451 
1452 	if (!firmware_has_feature(FW_FEATURE_VPHN))
1453 		goto out;
1454 
1455 	if (vphn_get_associativity(cpu, associativity))
1456 		goto out;
1457 
1458 	index = of_read_number(associativity, 1);
1459 	if (index > primary_domain_index + 1)
1460 		return of_read_number(&associativity[index - 1], 1);
1461 
1462 out:
1463 	return cpu_to_core_id(cpu);
1464 }
1465 
1466 static int topology_update_init(void)
1467 {
1468 	topology_inited = 1;
1469 	return 0;
1470 }
1471 device_initcall(topology_update_init);
1472 #endif /* CONFIG_PPC_SPLPAR */
1473