xref: /linux/arch/powerpc/mm/numa.c (revision 94a2597c01a4bd495789e1546374c26b19f6eafd)
1 /*
2  * pSeries NUMA support
3  *
4  * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 #include <linux/threads.h>
12 #include <linux/bootmem.h>
13 #include <linux/init.h>
14 #include <linux/mm.h>
15 #include <linux/mmzone.h>
16 #include <linux/export.h>
17 #include <linux/nodemask.h>
18 #include <linux/cpu.h>
19 #include <linux/notifier.h>
20 #include <linux/memblock.h>
21 #include <linux/of.h>
22 #include <linux/pfn.h>
23 #include <linux/cpuset.h>
24 #include <linux/node.h>
25 #include <asm/sparsemem.h>
26 #include <asm/prom.h>
27 #include <asm/smp.h>
28 #include <asm/firmware.h>
29 #include <asm/paca.h>
30 #include <asm/hvcall.h>
31 #include <asm/setup.h>
32 
33 static int numa_enabled = 1;
34 
35 static char *cmdline __initdata;
36 
37 static int numa_debug;
38 #define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }
39 
40 int numa_cpu_lookup_table[NR_CPUS];
41 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
42 struct pglist_data *node_data[MAX_NUMNODES];
43 
44 EXPORT_SYMBOL(numa_cpu_lookup_table);
45 EXPORT_SYMBOL(node_to_cpumask_map);
46 EXPORT_SYMBOL(node_data);
47 
48 static int min_common_depth;
49 static int n_mem_addr_cells, n_mem_size_cells;
50 static int form1_affinity;
51 
52 #define MAX_DISTANCE_REF_POINTS 4
53 static int distance_ref_points_depth;
54 static const unsigned int *distance_ref_points;
55 static int distance_lookup_table[MAX_NUMNODES][MAX_DISTANCE_REF_POINTS];
56 
57 /*
58  * Allocate node_to_cpumask_map based on number of available nodes
59  * Requires node_possible_map to be valid.
60  *
61  * Note: cpumask_of_node() is not valid until after this is done.
62  */
63 static void __init setup_node_to_cpumask_map(void)
64 {
65 	unsigned int node, num = 0;
66 
67 	/* setup nr_node_ids if not done yet */
68 	if (nr_node_ids == MAX_NUMNODES) {
69 		for_each_node_mask(node, node_possible_map)
70 			num = node;
71 		nr_node_ids = num + 1;
72 	}
73 
74 	/* allocate the map */
75 	for (node = 0; node < nr_node_ids; node++)
76 		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
77 
78 	/* cpumask_of_node() will now work */
79 	dbg("Node to cpumask map for %d nodes\n", nr_node_ids);
80 }
81 
82 static int __cpuinit fake_numa_create_new_node(unsigned long end_pfn,
83 						unsigned int *nid)
84 {
85 	unsigned long long mem;
86 	char *p = cmdline;
87 	static unsigned int fake_nid;
88 	static unsigned long long curr_boundary;
89 
90 	/*
91 	 * Modify node id, iff we started creating NUMA nodes
92 	 * We want to continue from where we left of the last time
93 	 */
94 	if (fake_nid)
95 		*nid = fake_nid;
96 	/*
97 	 * In case there are no more arguments to parse, the
98 	 * node_id should be the same as the last fake node id
99 	 * (we've handled this above).
100 	 */
101 	if (!p)
102 		return 0;
103 
104 	mem = memparse(p, &p);
105 	if (!mem)
106 		return 0;
107 
108 	if (mem < curr_boundary)
109 		return 0;
110 
111 	curr_boundary = mem;
112 
113 	if ((end_pfn << PAGE_SHIFT) > mem) {
114 		/*
115 		 * Skip commas and spaces
116 		 */
117 		while (*p == ',' || *p == ' ' || *p == '\t')
118 			p++;
119 
120 		cmdline = p;
121 		fake_nid++;
122 		*nid = fake_nid;
123 		dbg("created new fake_node with id %d\n", fake_nid);
124 		return 1;
125 	}
126 	return 0;
127 }
128 
129 /*
130  * get_node_active_region - Return active region containing pfn
131  * Active range returned is empty if none found.
132  * @pfn: The page to return the region for
133  * @node_ar: Returned set to the active region containing @pfn
134  */
135 static void __init get_node_active_region(unsigned long pfn,
136 					  struct node_active_region *node_ar)
137 {
138 	unsigned long start_pfn, end_pfn;
139 	int i, nid;
140 
141 	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
142 		if (pfn >= start_pfn && pfn < end_pfn) {
143 			node_ar->nid = nid;
144 			node_ar->start_pfn = start_pfn;
145 			node_ar->end_pfn = end_pfn;
146 			break;
147 		}
148 	}
149 }
150 
151 static void map_cpu_to_node(int cpu, int node)
152 {
153 	numa_cpu_lookup_table[cpu] = node;
154 
155 	dbg("adding cpu %d to node %d\n", cpu, node);
156 
157 	if (!(cpumask_test_cpu(cpu, node_to_cpumask_map[node])))
158 		cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
159 }
160 
161 #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PPC_SPLPAR)
162 static void unmap_cpu_from_node(unsigned long cpu)
163 {
164 	int node = numa_cpu_lookup_table[cpu];
165 
166 	dbg("removing cpu %lu from node %d\n", cpu, node);
167 
168 	if (cpumask_test_cpu(cpu, node_to_cpumask_map[node])) {
169 		cpumask_clear_cpu(cpu, node_to_cpumask_map[node]);
170 	} else {
171 		printk(KERN_ERR "WARNING: cpu %lu not found in node %d\n",
172 		       cpu, node);
173 	}
174 }
175 #endif /* CONFIG_HOTPLUG_CPU || CONFIG_PPC_SPLPAR */
176 
177 /* must hold reference to node during call */
178 static const int *of_get_associativity(struct device_node *dev)
179 {
180 	return of_get_property(dev, "ibm,associativity", NULL);
181 }
182 
183 /*
184  * Returns the property linux,drconf-usable-memory if
185  * it exists (the property exists only in kexec/kdump kernels,
186  * added by kexec-tools)
187  */
188 static const u32 *of_get_usable_memory(struct device_node *memory)
189 {
190 	const u32 *prop;
191 	u32 len;
192 	prop = of_get_property(memory, "linux,drconf-usable-memory", &len);
193 	if (!prop || len < sizeof(unsigned int))
194 		return 0;
195 	return prop;
196 }
197 
198 int __node_distance(int a, int b)
199 {
200 	int i;
201 	int distance = LOCAL_DISTANCE;
202 
203 	if (!form1_affinity)
204 		return distance;
205 
206 	for (i = 0; i < distance_ref_points_depth; i++) {
207 		if (distance_lookup_table[a][i] == distance_lookup_table[b][i])
208 			break;
209 
210 		/* Double the distance for each NUMA level */
211 		distance *= 2;
212 	}
213 
214 	return distance;
215 }
216 
217 static void initialize_distance_lookup_table(int nid,
218 		const unsigned int *associativity)
219 {
220 	int i;
221 
222 	if (!form1_affinity)
223 		return;
224 
225 	for (i = 0; i < distance_ref_points_depth; i++) {
226 		distance_lookup_table[nid][i] =
227 			associativity[distance_ref_points[i]];
228 	}
229 }
230 
231 /* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa
232  * info is found.
233  */
234 static int associativity_to_nid(const unsigned int *associativity)
235 {
236 	int nid = -1;
237 
238 	if (min_common_depth == -1)
239 		goto out;
240 
241 	if (associativity[0] >= min_common_depth)
242 		nid = associativity[min_common_depth];
243 
244 	/* POWER4 LPAR uses 0xffff as invalid node */
245 	if (nid == 0xffff || nid >= MAX_NUMNODES)
246 		nid = -1;
247 
248 	if (nid > 0 && associativity[0] >= distance_ref_points_depth)
249 		initialize_distance_lookup_table(nid, associativity);
250 
251 out:
252 	return nid;
253 }
254 
255 /* Returns the nid associated with the given device tree node,
256  * or -1 if not found.
257  */
258 static int of_node_to_nid_single(struct device_node *device)
259 {
260 	int nid = -1;
261 	const unsigned int *tmp;
262 
263 	tmp = of_get_associativity(device);
264 	if (tmp)
265 		nid = associativity_to_nid(tmp);
266 	return nid;
267 }
268 
269 /* Walk the device tree upwards, looking for an associativity id */
270 int of_node_to_nid(struct device_node *device)
271 {
272 	struct device_node *tmp;
273 	int nid = -1;
274 
275 	of_node_get(device);
276 	while (device) {
277 		nid = of_node_to_nid_single(device);
278 		if (nid != -1)
279 			break;
280 
281 	        tmp = device;
282 		device = of_get_parent(tmp);
283 		of_node_put(tmp);
284 	}
285 	of_node_put(device);
286 
287 	return nid;
288 }
289 EXPORT_SYMBOL_GPL(of_node_to_nid);
290 
291 static int __init find_min_common_depth(void)
292 {
293 	int depth;
294 	struct device_node *chosen;
295 	struct device_node *root;
296 	const char *vec5;
297 
298 	if (firmware_has_feature(FW_FEATURE_OPAL))
299 		root = of_find_node_by_path("/ibm,opal");
300 	else
301 		root = of_find_node_by_path("/rtas");
302 	if (!root)
303 		root = of_find_node_by_path("/");
304 
305 	/*
306 	 * This property is a set of 32-bit integers, each representing
307 	 * an index into the ibm,associativity nodes.
308 	 *
309 	 * With form 0 affinity the first integer is for an SMP configuration
310 	 * (should be all 0's) and the second is for a normal NUMA
311 	 * configuration. We have only one level of NUMA.
312 	 *
313 	 * With form 1 affinity the first integer is the most significant
314 	 * NUMA boundary and the following are progressively less significant
315 	 * boundaries. There can be more than one level of NUMA.
316 	 */
317 	distance_ref_points = of_get_property(root,
318 					"ibm,associativity-reference-points",
319 					&distance_ref_points_depth);
320 
321 	if (!distance_ref_points) {
322 		dbg("NUMA: ibm,associativity-reference-points not found.\n");
323 		goto err;
324 	}
325 
326 	distance_ref_points_depth /= sizeof(int);
327 
328 #define VEC5_AFFINITY_BYTE	5
329 #define VEC5_AFFINITY		0x80
330 
331 	if (firmware_has_feature(FW_FEATURE_OPAL))
332 		form1_affinity = 1;
333 	else {
334 		chosen = of_find_node_by_path("/chosen");
335 		if (chosen) {
336 			vec5 = of_get_property(chosen,
337 					       "ibm,architecture-vec-5", NULL);
338 			if (vec5 && (vec5[VEC5_AFFINITY_BYTE] &
339 							VEC5_AFFINITY)) {
340 				dbg("Using form 1 affinity\n");
341 				form1_affinity = 1;
342 			}
343 		}
344 	}
345 
346 	if (form1_affinity) {
347 		depth = distance_ref_points[0];
348 	} else {
349 		if (distance_ref_points_depth < 2) {
350 			printk(KERN_WARNING "NUMA: "
351 				"short ibm,associativity-reference-points\n");
352 			goto err;
353 		}
354 
355 		depth = distance_ref_points[1];
356 	}
357 
358 	/*
359 	 * Warn and cap if the hardware supports more than
360 	 * MAX_DISTANCE_REF_POINTS domains.
361 	 */
362 	if (distance_ref_points_depth > MAX_DISTANCE_REF_POINTS) {
363 		printk(KERN_WARNING "NUMA: distance array capped at "
364 			"%d entries\n", MAX_DISTANCE_REF_POINTS);
365 		distance_ref_points_depth = MAX_DISTANCE_REF_POINTS;
366 	}
367 
368 	of_node_put(root);
369 	return depth;
370 
371 err:
372 	of_node_put(root);
373 	return -1;
374 }
375 
376 static void __init get_n_mem_cells(int *n_addr_cells, int *n_size_cells)
377 {
378 	struct device_node *memory = NULL;
379 
380 	memory = of_find_node_by_type(memory, "memory");
381 	if (!memory)
382 		panic("numa.c: No memory nodes found!");
383 
384 	*n_addr_cells = of_n_addr_cells(memory);
385 	*n_size_cells = of_n_size_cells(memory);
386 	of_node_put(memory);
387 }
388 
389 static unsigned long read_n_cells(int n, const unsigned int **buf)
390 {
391 	unsigned long result = 0;
392 
393 	while (n--) {
394 		result = (result << 32) | **buf;
395 		(*buf)++;
396 	}
397 	return result;
398 }
399 
400 struct of_drconf_cell {
401 	u64	base_addr;
402 	u32	drc_index;
403 	u32	reserved;
404 	u32	aa_index;
405 	u32	flags;
406 };
407 
408 #define DRCONF_MEM_ASSIGNED	0x00000008
409 #define DRCONF_MEM_AI_INVALID	0x00000040
410 #define DRCONF_MEM_RESERVED	0x00000080
411 
412 /*
413  * Read the next memblock list entry from the ibm,dynamic-memory property
414  * and return the information in the provided of_drconf_cell structure.
415  */
416 static void read_drconf_cell(struct of_drconf_cell *drmem, const u32 **cellp)
417 {
418 	const u32 *cp;
419 
420 	drmem->base_addr = read_n_cells(n_mem_addr_cells, cellp);
421 
422 	cp = *cellp;
423 	drmem->drc_index = cp[0];
424 	drmem->reserved = cp[1];
425 	drmem->aa_index = cp[2];
426 	drmem->flags = cp[3];
427 
428 	*cellp = cp + 4;
429 }
430 
431 /*
432  * Retrieve and validate the ibm,dynamic-memory property of the device tree.
433  *
434  * The layout of the ibm,dynamic-memory property is a number N of memblock
435  * list entries followed by N memblock list entries.  Each memblock list entry
436  * contains information as laid out in the of_drconf_cell struct above.
437  */
438 static int of_get_drconf_memory(struct device_node *memory, const u32 **dm)
439 {
440 	const u32 *prop;
441 	u32 len, entries;
442 
443 	prop = of_get_property(memory, "ibm,dynamic-memory", &len);
444 	if (!prop || len < sizeof(unsigned int))
445 		return 0;
446 
447 	entries = *prop++;
448 
449 	/* Now that we know the number of entries, revalidate the size
450 	 * of the property read in to ensure we have everything
451 	 */
452 	if (len < (entries * (n_mem_addr_cells + 4) + 1) * sizeof(unsigned int))
453 		return 0;
454 
455 	*dm = prop;
456 	return entries;
457 }
458 
459 /*
460  * Retrieve and validate the ibm,lmb-size property for drconf memory
461  * from the device tree.
462  */
463 static u64 of_get_lmb_size(struct device_node *memory)
464 {
465 	const u32 *prop;
466 	u32 len;
467 
468 	prop = of_get_property(memory, "ibm,lmb-size", &len);
469 	if (!prop || len < sizeof(unsigned int))
470 		return 0;
471 
472 	return read_n_cells(n_mem_size_cells, &prop);
473 }
474 
475 struct assoc_arrays {
476 	u32	n_arrays;
477 	u32	array_sz;
478 	const u32 *arrays;
479 };
480 
481 /*
482  * Retrieve and validate the list of associativity arrays for drconf
483  * memory from the ibm,associativity-lookup-arrays property of the
484  * device tree..
485  *
486  * The layout of the ibm,associativity-lookup-arrays property is a number N
487  * indicating the number of associativity arrays, followed by a number M
488  * indicating the size of each associativity array, followed by a list
489  * of N associativity arrays.
490  */
491 static int of_get_assoc_arrays(struct device_node *memory,
492 			       struct assoc_arrays *aa)
493 {
494 	const u32 *prop;
495 	u32 len;
496 
497 	prop = of_get_property(memory, "ibm,associativity-lookup-arrays", &len);
498 	if (!prop || len < 2 * sizeof(unsigned int))
499 		return -1;
500 
501 	aa->n_arrays = *prop++;
502 	aa->array_sz = *prop++;
503 
504 	/* Now that we know the number of arrays and size of each array,
505 	 * revalidate the size of the property read in.
506 	 */
507 	if (len < (aa->n_arrays * aa->array_sz + 2) * sizeof(unsigned int))
508 		return -1;
509 
510 	aa->arrays = prop;
511 	return 0;
512 }
513 
514 /*
515  * This is like of_node_to_nid_single() for memory represented in the
516  * ibm,dynamic-reconfiguration-memory node.
517  */
518 static int of_drconf_to_nid_single(struct of_drconf_cell *drmem,
519 				   struct assoc_arrays *aa)
520 {
521 	int default_nid = 0;
522 	int nid = default_nid;
523 	int index;
524 
525 	if (min_common_depth > 0 && min_common_depth <= aa->array_sz &&
526 	    !(drmem->flags & DRCONF_MEM_AI_INVALID) &&
527 	    drmem->aa_index < aa->n_arrays) {
528 		index = drmem->aa_index * aa->array_sz + min_common_depth - 1;
529 		nid = aa->arrays[index];
530 
531 		if (nid == 0xffff || nid >= MAX_NUMNODES)
532 			nid = default_nid;
533 	}
534 
535 	return nid;
536 }
537 
538 /*
539  * Figure out to which domain a cpu belongs and stick it there.
540  * Return the id of the domain used.
541  */
542 static int __cpuinit numa_setup_cpu(unsigned long lcpu)
543 {
544 	int nid = 0;
545 	struct device_node *cpu = of_get_cpu_node(lcpu, NULL);
546 
547 	if (!cpu) {
548 		WARN_ON(1);
549 		goto out;
550 	}
551 
552 	nid = of_node_to_nid_single(cpu);
553 
554 	if (nid < 0 || !node_online(nid))
555 		nid = first_online_node;
556 out:
557 	map_cpu_to_node(lcpu, nid);
558 
559 	of_node_put(cpu);
560 
561 	return nid;
562 }
563 
564 static int __cpuinit cpu_numa_callback(struct notifier_block *nfb,
565 			     unsigned long action,
566 			     void *hcpu)
567 {
568 	unsigned long lcpu = (unsigned long)hcpu;
569 	int ret = NOTIFY_DONE;
570 
571 	switch (action) {
572 	case CPU_UP_PREPARE:
573 	case CPU_UP_PREPARE_FROZEN:
574 		numa_setup_cpu(lcpu);
575 		ret = NOTIFY_OK;
576 		break;
577 #ifdef CONFIG_HOTPLUG_CPU
578 	case CPU_DEAD:
579 	case CPU_DEAD_FROZEN:
580 	case CPU_UP_CANCELED:
581 	case CPU_UP_CANCELED_FROZEN:
582 		unmap_cpu_from_node(lcpu);
583 		break;
584 		ret = NOTIFY_OK;
585 #endif
586 	}
587 	return ret;
588 }
589 
590 /*
591  * Check and possibly modify a memory region to enforce the memory limit.
592  *
593  * Returns the size the region should have to enforce the memory limit.
594  * This will either be the original value of size, a truncated value,
595  * or zero. If the returned value of size is 0 the region should be
596  * discarded as it lies wholly above the memory limit.
597  */
598 static unsigned long __init numa_enforce_memory_limit(unsigned long start,
599 						      unsigned long size)
600 {
601 	/*
602 	 * We use memblock_end_of_DRAM() in here instead of memory_limit because
603 	 * we've already adjusted it for the limit and it takes care of
604 	 * having memory holes below the limit.  Also, in the case of
605 	 * iommu_is_off, memory_limit is not set but is implicitly enforced.
606 	 */
607 
608 	if (start + size <= memblock_end_of_DRAM())
609 		return size;
610 
611 	if (start >= memblock_end_of_DRAM())
612 		return 0;
613 
614 	return memblock_end_of_DRAM() - start;
615 }
616 
617 /*
618  * Reads the counter for a given entry in
619  * linux,drconf-usable-memory property
620  */
621 static inline int __init read_usm_ranges(const u32 **usm)
622 {
623 	/*
624 	 * For each lmb in ibm,dynamic-memory a corresponding
625 	 * entry in linux,drconf-usable-memory property contains
626 	 * a counter followed by that many (base, size) duple.
627 	 * read the counter from linux,drconf-usable-memory
628 	 */
629 	return read_n_cells(n_mem_size_cells, usm);
630 }
631 
632 /*
633  * Extract NUMA information from the ibm,dynamic-reconfiguration-memory
634  * node.  This assumes n_mem_{addr,size}_cells have been set.
635  */
636 static void __init parse_drconf_memory(struct device_node *memory)
637 {
638 	const u32 *uninitialized_var(dm), *usm;
639 	unsigned int n, rc, ranges, is_kexec_kdump = 0;
640 	unsigned long lmb_size, base, size, sz;
641 	int nid;
642 	struct assoc_arrays aa;
643 
644 	n = of_get_drconf_memory(memory, &dm);
645 	if (!n)
646 		return;
647 
648 	lmb_size = of_get_lmb_size(memory);
649 	if (!lmb_size)
650 		return;
651 
652 	rc = of_get_assoc_arrays(memory, &aa);
653 	if (rc)
654 		return;
655 
656 	/* check if this is a kexec/kdump kernel */
657 	usm = of_get_usable_memory(memory);
658 	if (usm != NULL)
659 		is_kexec_kdump = 1;
660 
661 	for (; n != 0; --n) {
662 		struct of_drconf_cell drmem;
663 
664 		read_drconf_cell(&drmem, &dm);
665 
666 		/* skip this block if the reserved bit is set in flags (0x80)
667 		   or if the block is not assigned to this partition (0x8) */
668 		if ((drmem.flags & DRCONF_MEM_RESERVED)
669 		    || !(drmem.flags & DRCONF_MEM_ASSIGNED))
670 			continue;
671 
672 		base = drmem.base_addr;
673 		size = lmb_size;
674 		ranges = 1;
675 
676 		if (is_kexec_kdump) {
677 			ranges = read_usm_ranges(&usm);
678 			if (!ranges) /* there are no (base, size) duple */
679 				continue;
680 		}
681 		do {
682 			if (is_kexec_kdump) {
683 				base = read_n_cells(n_mem_addr_cells, &usm);
684 				size = read_n_cells(n_mem_size_cells, &usm);
685 			}
686 			nid = of_drconf_to_nid_single(&drmem, &aa);
687 			fake_numa_create_new_node(
688 				((base + size) >> PAGE_SHIFT),
689 					   &nid);
690 			node_set_online(nid);
691 			sz = numa_enforce_memory_limit(base, size);
692 			if (sz)
693 				memblock_set_node(base, sz, nid);
694 		} while (--ranges);
695 	}
696 }
697 
698 static int __init parse_numa_properties(void)
699 {
700 	struct device_node *memory;
701 	int default_nid = 0;
702 	unsigned long i;
703 
704 	if (numa_enabled == 0) {
705 		printk(KERN_WARNING "NUMA disabled by user\n");
706 		return -1;
707 	}
708 
709 	min_common_depth = find_min_common_depth();
710 
711 	if (min_common_depth < 0)
712 		return min_common_depth;
713 
714 	dbg("NUMA associativity depth for CPU/Memory: %d\n", min_common_depth);
715 
716 	/*
717 	 * Even though we connect cpus to numa domains later in SMP
718 	 * init, we need to know the node ids now. This is because
719 	 * each node to be onlined must have NODE_DATA etc backing it.
720 	 */
721 	for_each_present_cpu(i) {
722 		struct device_node *cpu;
723 		int nid;
724 
725 		cpu = of_get_cpu_node(i, NULL);
726 		BUG_ON(!cpu);
727 		nid = of_node_to_nid_single(cpu);
728 		of_node_put(cpu);
729 
730 		/*
731 		 * Don't fall back to default_nid yet -- we will plug
732 		 * cpus into nodes once the memory scan has discovered
733 		 * the topology.
734 		 */
735 		if (nid < 0)
736 			continue;
737 		node_set_online(nid);
738 	}
739 
740 	get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells);
741 
742 	for_each_node_by_type(memory, "memory") {
743 		unsigned long start;
744 		unsigned long size;
745 		int nid;
746 		int ranges;
747 		const unsigned int *memcell_buf;
748 		unsigned int len;
749 
750 		memcell_buf = of_get_property(memory,
751 			"linux,usable-memory", &len);
752 		if (!memcell_buf || len <= 0)
753 			memcell_buf = of_get_property(memory, "reg", &len);
754 		if (!memcell_buf || len <= 0)
755 			continue;
756 
757 		/* ranges in cell */
758 		ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
759 new_range:
760 		/* these are order-sensitive, and modify the buffer pointer */
761 		start = read_n_cells(n_mem_addr_cells, &memcell_buf);
762 		size = read_n_cells(n_mem_size_cells, &memcell_buf);
763 
764 		/*
765 		 * Assumption: either all memory nodes or none will
766 		 * have associativity properties.  If none, then
767 		 * everything goes to default_nid.
768 		 */
769 		nid = of_node_to_nid_single(memory);
770 		if (nid < 0)
771 			nid = default_nid;
772 
773 		fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);
774 		node_set_online(nid);
775 
776 		if (!(size = numa_enforce_memory_limit(start, size))) {
777 			if (--ranges)
778 				goto new_range;
779 			else
780 				continue;
781 		}
782 
783 		memblock_set_node(start, size, nid);
784 
785 		if (--ranges)
786 			goto new_range;
787 	}
788 
789 	/*
790 	 * Now do the same thing for each MEMBLOCK listed in the
791 	 * ibm,dynamic-memory property in the
792 	 * ibm,dynamic-reconfiguration-memory node.
793 	 */
794 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
795 	if (memory)
796 		parse_drconf_memory(memory);
797 
798 	return 0;
799 }
800 
801 static void __init setup_nonnuma(void)
802 {
803 	unsigned long top_of_ram = memblock_end_of_DRAM();
804 	unsigned long total_ram = memblock_phys_mem_size();
805 	unsigned long start_pfn, end_pfn;
806 	unsigned int nid = 0;
807 	struct memblock_region *reg;
808 
809 	printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
810 	       top_of_ram, total_ram);
811 	printk(KERN_DEBUG "Memory hole size: %ldMB\n",
812 	       (top_of_ram - total_ram) >> 20);
813 
814 	for_each_memblock(memory, reg) {
815 		start_pfn = memblock_region_memory_base_pfn(reg);
816 		end_pfn = memblock_region_memory_end_pfn(reg);
817 
818 		fake_numa_create_new_node(end_pfn, &nid);
819 		memblock_set_node(PFN_PHYS(start_pfn),
820 				  PFN_PHYS(end_pfn - start_pfn), nid);
821 		node_set_online(nid);
822 	}
823 }
824 
825 void __init dump_numa_cpu_topology(void)
826 {
827 	unsigned int node;
828 	unsigned int cpu, count;
829 
830 	if (min_common_depth == -1 || !numa_enabled)
831 		return;
832 
833 	for_each_online_node(node) {
834 		printk(KERN_DEBUG "Node %d CPUs:", node);
835 
836 		count = 0;
837 		/*
838 		 * If we used a CPU iterator here we would miss printing
839 		 * the holes in the cpumap.
840 		 */
841 		for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
842 			if (cpumask_test_cpu(cpu,
843 					node_to_cpumask_map[node])) {
844 				if (count == 0)
845 					printk(" %u", cpu);
846 				++count;
847 			} else {
848 				if (count > 1)
849 					printk("-%u", cpu - 1);
850 				count = 0;
851 			}
852 		}
853 
854 		if (count > 1)
855 			printk("-%u", nr_cpu_ids - 1);
856 		printk("\n");
857 	}
858 }
859 
860 static void __init dump_numa_memory_topology(void)
861 {
862 	unsigned int node;
863 	unsigned int count;
864 
865 	if (min_common_depth == -1 || !numa_enabled)
866 		return;
867 
868 	for_each_online_node(node) {
869 		unsigned long i;
870 
871 		printk(KERN_DEBUG "Node %d Memory:", node);
872 
873 		count = 0;
874 
875 		for (i = 0; i < memblock_end_of_DRAM();
876 		     i += (1 << SECTION_SIZE_BITS)) {
877 			if (early_pfn_to_nid(i >> PAGE_SHIFT) == node) {
878 				if (count == 0)
879 					printk(" 0x%lx", i);
880 				++count;
881 			} else {
882 				if (count > 0)
883 					printk("-0x%lx", i);
884 				count = 0;
885 			}
886 		}
887 
888 		if (count > 0)
889 			printk("-0x%lx", i);
890 		printk("\n");
891 	}
892 }
893 
894 /*
895  * Allocate some memory, satisfying the memblock or bootmem allocator where
896  * required. nid is the preferred node and end is the physical address of
897  * the highest address in the node.
898  *
899  * Returns the virtual address of the memory.
900  */
901 static void __init *careful_zallocation(int nid, unsigned long size,
902 				       unsigned long align,
903 				       unsigned long end_pfn)
904 {
905 	void *ret;
906 	int new_nid;
907 	unsigned long ret_paddr;
908 
909 	ret_paddr = __memblock_alloc_base(size, align, end_pfn << PAGE_SHIFT);
910 
911 	/* retry over all memory */
912 	if (!ret_paddr)
913 		ret_paddr = __memblock_alloc_base(size, align, memblock_end_of_DRAM());
914 
915 	if (!ret_paddr)
916 		panic("numa.c: cannot allocate %lu bytes for node %d",
917 		      size, nid);
918 
919 	ret = __va(ret_paddr);
920 
921 	/*
922 	 * We initialize the nodes in numeric order: 0, 1, 2...
923 	 * and hand over control from the MEMBLOCK allocator to the
924 	 * bootmem allocator.  If this function is called for
925 	 * node 5, then we know that all nodes <5 are using the
926 	 * bootmem allocator instead of the MEMBLOCK allocator.
927 	 *
928 	 * So, check the nid from which this allocation came
929 	 * and double check to see if we need to use bootmem
930 	 * instead of the MEMBLOCK.  We don't free the MEMBLOCK memory
931 	 * since it would be useless.
932 	 */
933 	new_nid = early_pfn_to_nid(ret_paddr >> PAGE_SHIFT);
934 	if (new_nid < nid) {
935 		ret = __alloc_bootmem_node(NODE_DATA(new_nid),
936 				size, align, 0);
937 
938 		dbg("alloc_bootmem %p %lx\n", ret, size);
939 	}
940 
941 	memset(ret, 0, size);
942 	return ret;
943 }
944 
945 static struct notifier_block __cpuinitdata ppc64_numa_nb = {
946 	.notifier_call = cpu_numa_callback,
947 	.priority = 1 /* Must run before sched domains notifier. */
948 };
949 
950 static void __init mark_reserved_regions_for_nid(int nid)
951 {
952 	struct pglist_data *node = NODE_DATA(nid);
953 	struct memblock_region *reg;
954 
955 	for_each_memblock(reserved, reg) {
956 		unsigned long physbase = reg->base;
957 		unsigned long size = reg->size;
958 		unsigned long start_pfn = physbase >> PAGE_SHIFT;
959 		unsigned long end_pfn = PFN_UP(physbase + size);
960 		struct node_active_region node_ar;
961 		unsigned long node_end_pfn = node->node_start_pfn +
962 					     node->node_spanned_pages;
963 
964 		/*
965 		 * Check to make sure that this memblock.reserved area is
966 		 * within the bounds of the node that we care about.
967 		 * Checking the nid of the start and end points is not
968 		 * sufficient because the reserved area could span the
969 		 * entire node.
970 		 */
971 		if (end_pfn <= node->node_start_pfn ||
972 		    start_pfn >= node_end_pfn)
973 			continue;
974 
975 		get_node_active_region(start_pfn, &node_ar);
976 		while (start_pfn < end_pfn &&
977 			node_ar.start_pfn < node_ar.end_pfn) {
978 			unsigned long reserve_size = size;
979 			/*
980 			 * if reserved region extends past active region
981 			 * then trim size to active region
982 			 */
983 			if (end_pfn > node_ar.end_pfn)
984 				reserve_size = (node_ar.end_pfn << PAGE_SHIFT)
985 					- physbase;
986 			/*
987 			 * Only worry about *this* node, others may not
988 			 * yet have valid NODE_DATA().
989 			 */
990 			if (node_ar.nid == nid) {
991 				dbg("reserve_bootmem %lx %lx nid=%d\n",
992 					physbase, reserve_size, node_ar.nid);
993 				reserve_bootmem_node(NODE_DATA(node_ar.nid),
994 						physbase, reserve_size,
995 						BOOTMEM_DEFAULT);
996 			}
997 			/*
998 			 * if reserved region is contained in the active region
999 			 * then done.
1000 			 */
1001 			if (end_pfn <= node_ar.end_pfn)
1002 				break;
1003 
1004 			/*
1005 			 * reserved region extends past the active region
1006 			 *   get next active region that contains this
1007 			 *   reserved region
1008 			 */
1009 			start_pfn = node_ar.end_pfn;
1010 			physbase = start_pfn << PAGE_SHIFT;
1011 			size = size - reserve_size;
1012 			get_node_active_region(start_pfn, &node_ar);
1013 		}
1014 	}
1015 }
1016 
1017 
1018 void __init do_init_bootmem(void)
1019 {
1020 	int nid;
1021 
1022 	min_low_pfn = 0;
1023 	max_low_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
1024 	max_pfn = max_low_pfn;
1025 
1026 	if (parse_numa_properties())
1027 		setup_nonnuma();
1028 	else
1029 		dump_numa_memory_topology();
1030 
1031 	for_each_online_node(nid) {
1032 		unsigned long start_pfn, end_pfn;
1033 		void *bootmem_vaddr;
1034 		unsigned long bootmap_pages;
1035 
1036 		get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
1037 
1038 		/*
1039 		 * Allocate the node structure node local if possible
1040 		 *
1041 		 * Be careful moving this around, as it relies on all
1042 		 * previous nodes' bootmem to be initialized and have
1043 		 * all reserved areas marked.
1044 		 */
1045 		NODE_DATA(nid) = careful_zallocation(nid,
1046 					sizeof(struct pglist_data),
1047 					SMP_CACHE_BYTES, end_pfn);
1048 
1049   		dbg("node %d\n", nid);
1050 		dbg("NODE_DATA() = %p\n", NODE_DATA(nid));
1051 
1052 		NODE_DATA(nid)->bdata = &bootmem_node_data[nid];
1053 		NODE_DATA(nid)->node_start_pfn = start_pfn;
1054 		NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
1055 
1056 		if (NODE_DATA(nid)->node_spanned_pages == 0)
1057   			continue;
1058 
1059   		dbg("start_paddr = %lx\n", start_pfn << PAGE_SHIFT);
1060   		dbg("end_paddr = %lx\n", end_pfn << PAGE_SHIFT);
1061 
1062 		bootmap_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
1063 		bootmem_vaddr = careful_zallocation(nid,
1064 					bootmap_pages << PAGE_SHIFT,
1065 					PAGE_SIZE, end_pfn);
1066 
1067 		dbg("bootmap_vaddr = %p\n", bootmem_vaddr);
1068 
1069 		init_bootmem_node(NODE_DATA(nid),
1070 				  __pa(bootmem_vaddr) >> PAGE_SHIFT,
1071 				  start_pfn, end_pfn);
1072 
1073 		free_bootmem_with_active_regions(nid, end_pfn);
1074 		/*
1075 		 * Be very careful about moving this around.  Future
1076 		 * calls to careful_zallocation() depend on this getting
1077 		 * done correctly.
1078 		 */
1079 		mark_reserved_regions_for_nid(nid);
1080 		sparse_memory_present_with_active_regions(nid);
1081 	}
1082 
1083 	init_bootmem_done = 1;
1084 
1085 	/*
1086 	 * Now bootmem is initialised we can create the node to cpumask
1087 	 * lookup tables and setup the cpu callback to populate them.
1088 	 */
1089 	setup_node_to_cpumask_map();
1090 
1091 	register_cpu_notifier(&ppc64_numa_nb);
1092 	cpu_numa_callback(&ppc64_numa_nb, CPU_UP_PREPARE,
1093 			  (void *)(unsigned long)boot_cpuid);
1094 }
1095 
1096 void __init paging_init(void)
1097 {
1098 	unsigned long max_zone_pfns[MAX_NR_ZONES];
1099 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
1100 	max_zone_pfns[ZONE_DMA] = memblock_end_of_DRAM() >> PAGE_SHIFT;
1101 	free_area_init_nodes(max_zone_pfns);
1102 }
1103 
1104 static int __init early_numa(char *p)
1105 {
1106 	if (!p)
1107 		return 0;
1108 
1109 	if (strstr(p, "off"))
1110 		numa_enabled = 0;
1111 
1112 	if (strstr(p, "debug"))
1113 		numa_debug = 1;
1114 
1115 	p = strstr(p, "fake=");
1116 	if (p)
1117 		cmdline = p + strlen("fake=");
1118 
1119 	return 0;
1120 }
1121 early_param("numa", early_numa);
1122 
1123 #ifdef CONFIG_MEMORY_HOTPLUG
1124 /*
1125  * Find the node associated with a hot added memory section for
1126  * memory represented in the device tree by the property
1127  * ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory.
1128  */
1129 static int hot_add_drconf_scn_to_nid(struct device_node *memory,
1130 				     unsigned long scn_addr)
1131 {
1132 	const u32 *dm;
1133 	unsigned int drconf_cell_cnt, rc;
1134 	unsigned long lmb_size;
1135 	struct assoc_arrays aa;
1136 	int nid = -1;
1137 
1138 	drconf_cell_cnt = of_get_drconf_memory(memory, &dm);
1139 	if (!drconf_cell_cnt)
1140 		return -1;
1141 
1142 	lmb_size = of_get_lmb_size(memory);
1143 	if (!lmb_size)
1144 		return -1;
1145 
1146 	rc = of_get_assoc_arrays(memory, &aa);
1147 	if (rc)
1148 		return -1;
1149 
1150 	for (; drconf_cell_cnt != 0; --drconf_cell_cnt) {
1151 		struct of_drconf_cell drmem;
1152 
1153 		read_drconf_cell(&drmem, &dm);
1154 
1155 		/* skip this block if it is reserved or not assigned to
1156 		 * this partition */
1157 		if ((drmem.flags & DRCONF_MEM_RESERVED)
1158 		    || !(drmem.flags & DRCONF_MEM_ASSIGNED))
1159 			continue;
1160 
1161 		if ((scn_addr < drmem.base_addr)
1162 		    || (scn_addr >= (drmem.base_addr + lmb_size)))
1163 			continue;
1164 
1165 		nid = of_drconf_to_nid_single(&drmem, &aa);
1166 		break;
1167 	}
1168 
1169 	return nid;
1170 }
1171 
1172 /*
1173  * Find the node associated with a hot added memory section for memory
1174  * represented in the device tree as a node (i.e. memory@XXXX) for
1175  * each memblock.
1176  */
1177 int hot_add_node_scn_to_nid(unsigned long scn_addr)
1178 {
1179 	struct device_node *memory;
1180 	int nid = -1;
1181 
1182 	for_each_node_by_type(memory, "memory") {
1183 		unsigned long start, size;
1184 		int ranges;
1185 		const unsigned int *memcell_buf;
1186 		unsigned int len;
1187 
1188 		memcell_buf = of_get_property(memory, "reg", &len);
1189 		if (!memcell_buf || len <= 0)
1190 			continue;
1191 
1192 		/* ranges in cell */
1193 		ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
1194 
1195 		while (ranges--) {
1196 			start = read_n_cells(n_mem_addr_cells, &memcell_buf);
1197 			size = read_n_cells(n_mem_size_cells, &memcell_buf);
1198 
1199 			if ((scn_addr < start) || (scn_addr >= (start + size)))
1200 				continue;
1201 
1202 			nid = of_node_to_nid_single(memory);
1203 			break;
1204 		}
1205 
1206 		if (nid >= 0)
1207 			break;
1208 	}
1209 
1210 	of_node_put(memory);
1211 
1212 	return nid;
1213 }
1214 
1215 /*
1216  * Find the node associated with a hot added memory section.  Section
1217  * corresponds to a SPARSEMEM section, not an MEMBLOCK.  It is assumed that
1218  * sections are fully contained within a single MEMBLOCK.
1219  */
1220 int hot_add_scn_to_nid(unsigned long scn_addr)
1221 {
1222 	struct device_node *memory = NULL;
1223 	int nid, found = 0;
1224 
1225 	if (!numa_enabled || (min_common_depth < 0))
1226 		return first_online_node;
1227 
1228 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1229 	if (memory) {
1230 		nid = hot_add_drconf_scn_to_nid(memory, scn_addr);
1231 		of_node_put(memory);
1232 	} else {
1233 		nid = hot_add_node_scn_to_nid(scn_addr);
1234 	}
1235 
1236 	if (nid < 0 || !node_online(nid))
1237 		nid = first_online_node;
1238 
1239 	if (NODE_DATA(nid)->node_spanned_pages)
1240 		return nid;
1241 
1242 	for_each_online_node(nid) {
1243 		if (NODE_DATA(nid)->node_spanned_pages) {
1244 			found = 1;
1245 			break;
1246 		}
1247 	}
1248 
1249 	BUG_ON(!found);
1250 	return nid;
1251 }
1252 
1253 static u64 hot_add_drconf_memory_max(void)
1254 {
1255         struct device_node *memory = NULL;
1256         unsigned int drconf_cell_cnt = 0;
1257         u64 lmb_size = 0;
1258         const u32 *dm = 0;
1259 
1260         memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1261         if (memory) {
1262                 drconf_cell_cnt = of_get_drconf_memory(memory, &dm);
1263                 lmb_size = of_get_lmb_size(memory);
1264                 of_node_put(memory);
1265         }
1266         return lmb_size * drconf_cell_cnt;
1267 }
1268 
1269 /*
1270  * memory_hotplug_max - return max address of memory that may be added
1271  *
1272  * This is currently only used on systems that support drconfig memory
1273  * hotplug.
1274  */
1275 u64 memory_hotplug_max(void)
1276 {
1277         return max(hot_add_drconf_memory_max(), memblock_end_of_DRAM());
1278 }
1279 #endif /* CONFIG_MEMORY_HOTPLUG */
1280 
1281 /* Virtual Processor Home Node (VPHN) support */
1282 #ifdef CONFIG_PPC_SPLPAR
1283 static u8 vphn_cpu_change_counts[NR_CPUS][MAX_DISTANCE_REF_POINTS];
1284 static cpumask_t cpu_associativity_changes_mask;
1285 static int vphn_enabled;
1286 static void set_topology_timer(void);
1287 
1288 /*
1289  * Store the current values of the associativity change counters in the
1290  * hypervisor.
1291  */
1292 static void setup_cpu_associativity_change_counters(void)
1293 {
1294 	int cpu;
1295 
1296 	/* The VPHN feature supports a maximum of 8 reference points */
1297 	BUILD_BUG_ON(MAX_DISTANCE_REF_POINTS > 8);
1298 
1299 	for_each_possible_cpu(cpu) {
1300 		int i;
1301 		u8 *counts = vphn_cpu_change_counts[cpu];
1302 		volatile u8 *hypervisor_counts = lppaca[cpu].vphn_assoc_counts;
1303 
1304 		for (i = 0; i < distance_ref_points_depth; i++)
1305 			counts[i] = hypervisor_counts[i];
1306 	}
1307 }
1308 
1309 /*
1310  * The hypervisor maintains a set of 8 associativity change counters in
1311  * the VPA of each cpu that correspond to the associativity levels in the
1312  * ibm,associativity-reference-points property. When an associativity
1313  * level changes, the corresponding counter is incremented.
1314  *
1315  * Set a bit in cpu_associativity_changes_mask for each cpu whose home
1316  * node associativity levels have changed.
1317  *
1318  * Returns the number of cpus with unhandled associativity changes.
1319  */
1320 static int update_cpu_associativity_changes_mask(void)
1321 {
1322 	int cpu, nr_cpus = 0;
1323 	cpumask_t *changes = &cpu_associativity_changes_mask;
1324 
1325 	cpumask_clear(changes);
1326 
1327 	for_each_possible_cpu(cpu) {
1328 		int i, changed = 0;
1329 		u8 *counts = vphn_cpu_change_counts[cpu];
1330 		volatile u8 *hypervisor_counts = lppaca[cpu].vphn_assoc_counts;
1331 
1332 		for (i = 0; i < distance_ref_points_depth; i++) {
1333 			if (hypervisor_counts[i] != counts[i]) {
1334 				counts[i] = hypervisor_counts[i];
1335 				changed = 1;
1336 			}
1337 		}
1338 		if (changed) {
1339 			cpumask_set_cpu(cpu, changes);
1340 			nr_cpus++;
1341 		}
1342 	}
1343 
1344 	return nr_cpus;
1345 }
1346 
1347 /*
1348  * 6 64-bit registers unpacked into 12 32-bit associativity values. To form
1349  * the complete property we have to add the length in the first cell.
1350  */
1351 #define VPHN_ASSOC_BUFSIZE (6*sizeof(u64)/sizeof(u32) + 1)
1352 
1353 /*
1354  * Convert the associativity domain numbers returned from the hypervisor
1355  * to the sequence they would appear in the ibm,associativity property.
1356  */
1357 static int vphn_unpack_associativity(const long *packed, unsigned int *unpacked)
1358 {
1359 	int i, nr_assoc_doms = 0;
1360 	const u16 *field = (const u16*) packed;
1361 
1362 #define VPHN_FIELD_UNUSED	(0xffff)
1363 #define VPHN_FIELD_MSB		(0x8000)
1364 #define VPHN_FIELD_MASK		(~VPHN_FIELD_MSB)
1365 
1366 	for (i = 1; i < VPHN_ASSOC_BUFSIZE; i++) {
1367 		if (*field == VPHN_FIELD_UNUSED) {
1368 			/* All significant fields processed, and remaining
1369 			 * fields contain the reserved value of all 1's.
1370 			 * Just store them.
1371 			 */
1372 			unpacked[i] = *((u32*)field);
1373 			field += 2;
1374 		} else if (*field & VPHN_FIELD_MSB) {
1375 			/* Data is in the lower 15 bits of this field */
1376 			unpacked[i] = *field & VPHN_FIELD_MASK;
1377 			field++;
1378 			nr_assoc_doms++;
1379 		} else {
1380 			/* Data is in the lower 15 bits of this field
1381 			 * concatenated with the next 16 bit field
1382 			 */
1383 			unpacked[i] = *((u32*)field);
1384 			field += 2;
1385 			nr_assoc_doms++;
1386 		}
1387 	}
1388 
1389 	/* The first cell contains the length of the property */
1390 	unpacked[0] = nr_assoc_doms;
1391 
1392 	return nr_assoc_doms;
1393 }
1394 
1395 /*
1396  * Retrieve the new associativity information for a virtual processor's
1397  * home node.
1398  */
1399 static long hcall_vphn(unsigned long cpu, unsigned int *associativity)
1400 {
1401 	long rc;
1402 	long retbuf[PLPAR_HCALL9_BUFSIZE] = {0};
1403 	u64 flags = 1;
1404 	int hwcpu = get_hard_smp_processor_id(cpu);
1405 
1406 	rc = plpar_hcall9(H_HOME_NODE_ASSOCIATIVITY, retbuf, flags, hwcpu);
1407 	vphn_unpack_associativity(retbuf, associativity);
1408 
1409 	return rc;
1410 }
1411 
1412 static long vphn_get_associativity(unsigned long cpu,
1413 					unsigned int *associativity)
1414 {
1415 	long rc;
1416 
1417 	rc = hcall_vphn(cpu, associativity);
1418 
1419 	switch (rc) {
1420 	case H_FUNCTION:
1421 		printk(KERN_INFO
1422 			"VPHN is not supported. Disabling polling...\n");
1423 		stop_topology_update();
1424 		break;
1425 	case H_HARDWARE:
1426 		printk(KERN_ERR
1427 			"hcall_vphn() experienced a hardware fault "
1428 			"preventing VPHN. Disabling polling...\n");
1429 		stop_topology_update();
1430 	}
1431 
1432 	return rc;
1433 }
1434 
1435 /*
1436  * Update the node maps and sysfs entries for each cpu whose home node
1437  * has changed.
1438  */
1439 int arch_update_cpu_topology(void)
1440 {
1441 	int cpu, nid, old_nid;
1442 	unsigned int associativity[VPHN_ASSOC_BUFSIZE] = {0};
1443 	struct device *dev;
1444 
1445 	for_each_cpu(cpu,&cpu_associativity_changes_mask) {
1446 		vphn_get_associativity(cpu, associativity);
1447 		nid = associativity_to_nid(associativity);
1448 
1449 		if (nid < 0 || !node_online(nid))
1450 			nid = first_online_node;
1451 
1452 		old_nid = numa_cpu_lookup_table[cpu];
1453 
1454 		/* Disable hotplug while we update the cpu
1455 		 * masks and sysfs.
1456 		 */
1457 		get_online_cpus();
1458 		unregister_cpu_under_node(cpu, old_nid);
1459 		unmap_cpu_from_node(cpu);
1460 		map_cpu_to_node(cpu, nid);
1461 		register_cpu_under_node(cpu, nid);
1462 		put_online_cpus();
1463 
1464 		dev = get_cpu_device(cpu);
1465 		if (dev)
1466 			kobject_uevent(&dev->kobj, KOBJ_CHANGE);
1467 	}
1468 
1469 	return 1;
1470 }
1471 
1472 static void topology_work_fn(struct work_struct *work)
1473 {
1474 	rebuild_sched_domains();
1475 }
1476 static DECLARE_WORK(topology_work, topology_work_fn);
1477 
1478 void topology_schedule_update(void)
1479 {
1480 	schedule_work(&topology_work);
1481 }
1482 
1483 static void topology_timer_fn(unsigned long ignored)
1484 {
1485 	if (!vphn_enabled)
1486 		return;
1487 	if (update_cpu_associativity_changes_mask() > 0)
1488 		topology_schedule_update();
1489 	set_topology_timer();
1490 }
1491 static struct timer_list topology_timer =
1492 	TIMER_INITIALIZER(topology_timer_fn, 0, 0);
1493 
1494 static void set_topology_timer(void)
1495 {
1496 	topology_timer.data = 0;
1497 	topology_timer.expires = jiffies + 60 * HZ;
1498 	add_timer(&topology_timer);
1499 }
1500 
1501 /*
1502  * Start polling for VPHN associativity changes.
1503  */
1504 int start_topology_update(void)
1505 {
1506 	int rc = 0;
1507 
1508 	/* Disabled until races with load balancing are fixed */
1509 	if (0 && firmware_has_feature(FW_FEATURE_VPHN) &&
1510 	    get_lppaca()->shared_proc) {
1511 		vphn_enabled = 1;
1512 		setup_cpu_associativity_change_counters();
1513 		init_timer_deferrable(&topology_timer);
1514 		set_topology_timer();
1515 		rc = 1;
1516 	}
1517 
1518 	return rc;
1519 }
1520 __initcall(start_topology_update);
1521 
1522 /*
1523  * Disable polling for VPHN associativity changes.
1524  */
1525 int stop_topology_update(void)
1526 {
1527 	vphn_enabled = 0;
1528 	return del_timer_sync(&topology_timer);
1529 }
1530 #endif /* CONFIG_PPC_SPLPAR */
1531