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/module.h>
17#include <linux/nodemask.h>
18#include <linux/cpu.h>
19#include <linux/notifier.h>
20#include <asm/sparsemem.h>
21#include <asm/lmb.h>
22#include <asm/system.h>
23#include <asm/smp.h>
24
25static int numa_enabled = 1;
26
27static int numa_debug;
28#define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }
29
30int numa_cpu_lookup_table[NR_CPUS];
31cpumask_t numa_cpumask_lookup_table[MAX_NUMNODES];
32struct pglist_data *node_data[MAX_NUMNODES];
33
34EXPORT_SYMBOL(numa_cpu_lookup_table);
35EXPORT_SYMBOL(numa_cpumask_lookup_table);
36EXPORT_SYMBOL(node_data);
37
38static bootmem_data_t __initdata plat_node_bdata[MAX_NUMNODES];
39static int min_common_depth;
40static int n_mem_addr_cells, n_mem_size_cells;
41
42static void __cpuinit map_cpu_to_node(int cpu, int node)
43{
44	numa_cpu_lookup_table[cpu] = node;
45
46	dbg("adding cpu %d to node %d\n", cpu, node);
47
48	if (!(cpu_isset(cpu, numa_cpumask_lookup_table[node])))
49		cpu_set(cpu, numa_cpumask_lookup_table[node]);
50}
51
52#ifdef CONFIG_HOTPLUG_CPU
53static void unmap_cpu_from_node(unsigned long cpu)
54{
55	int node = numa_cpu_lookup_table[cpu];
56
57	dbg("removing cpu %lu from node %d\n", cpu, node);
58
59	if (cpu_isset(cpu, numa_cpumask_lookup_table[node])) {
60		cpu_clear(cpu, numa_cpumask_lookup_table[node]);
61	} else {
62		printk(KERN_ERR "WARNING: cpu %lu not found in node %d\n",
63		       cpu, node);
64	}
65}
66#endif /* CONFIG_HOTPLUG_CPU */
67
68static struct device_node * __cpuinit find_cpu_node(unsigned int cpu)
69{
70	unsigned int hw_cpuid = get_hard_smp_processor_id(cpu);
71	struct device_node *cpu_node = NULL;
72	const unsigned int *interrupt_server, *reg;
73	int len;
74
75	while ((cpu_node = of_find_node_by_type(cpu_node, "cpu")) != NULL) {
76		/* Try interrupt server first */
77		interrupt_server = of_get_property(cpu_node,
78					"ibm,ppc-interrupt-server#s", &len);
79
80		len = len / sizeof(u32);
81
82		if (interrupt_server && (len > 0)) {
83			while (len--) {
84				if (interrupt_server[len] == hw_cpuid)
85					return cpu_node;
86			}
87		} else {
88			reg = of_get_property(cpu_node, "reg", &len);
89			if (reg && (len > 0) && (reg[0] == hw_cpuid))
90				return cpu_node;
91		}
92	}
93
94	return NULL;
95}
96
97/* must hold reference to node during call */
98static const int *of_get_associativity(struct device_node *dev)
99{
100	return of_get_property(dev, "ibm,associativity", NULL);
101}
102
103/* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa
104 * info is found.
105 */
106static int of_node_to_nid_single(struct device_node *device)
107{
108	int nid = -1;
109	const unsigned int *tmp;
110
111	if (min_common_depth == -1)
112		goto out;
113
114	tmp = of_get_associativity(device);
115	if (!tmp)
116		goto out;
117
118	if (tmp[0] >= min_common_depth)
119		nid = tmp[min_common_depth];
120
121	/* POWER4 LPAR uses 0xffff as invalid node */
122	if (nid == 0xffff || nid >= MAX_NUMNODES)
123		nid = -1;
124out:
125	return nid;
126}
127
128/* Walk the device tree upwards, looking for an associativity id */
129int of_node_to_nid(struct device_node *device)
130{
131	struct device_node *tmp;
132	int nid = -1;
133
134	of_node_get(device);
135	while (device) {
136		nid = of_node_to_nid_single(device);
137		if (nid != -1)
138			break;
139
140	        tmp = device;
141		device = of_get_parent(tmp);
142		of_node_put(tmp);
143	}
144	of_node_put(device);
145
146	return nid;
147}
148EXPORT_SYMBOL_GPL(of_node_to_nid);
149
150/*
151 * In theory, the "ibm,associativity" property may contain multiple
152 * associativity lists because a resource may be multiply connected
153 * into the machine.  This resource then has different associativity
154 * characteristics relative to its multiple connections.  We ignore
155 * this for now.  We also assume that all cpu and memory sets have
156 * their distances represented at a common level.  This won't be
157 * true for hierarchical NUMA.
158 *
159 * In any case the ibm,associativity-reference-points should give
160 * the correct depth for a normal NUMA system.
161 *
162 * - Dave Hansen <haveblue@us.ibm.com>
163 */
164static int __init find_min_common_depth(void)
165{
166	int depth;
167	const unsigned int *ref_points;
168	struct device_node *rtas_root;
169	unsigned int len;
170
171	rtas_root = of_find_node_by_path("/rtas");
172
173	if (!rtas_root)
174		return -1;
175
176	/*
177	 * this property is 2 32-bit integers, each representing a level of
178	 * depth in the associativity nodes.  The first is for an SMP
179	 * configuration (should be all 0's) and the second is for a normal
180	 * NUMA configuration.
181	 */
182	ref_points = of_get_property(rtas_root,
183			"ibm,associativity-reference-points", &len);
184
185	if ((len >= 1) && ref_points) {
186		depth = ref_points[1];
187	} else {
188		dbg("NUMA: ibm,associativity-reference-points not found.\n");
189		depth = -1;
190	}
191	of_node_put(rtas_root);
192
193	return depth;
194}
195
196static void __init get_n_mem_cells(int *n_addr_cells, int *n_size_cells)
197{
198	struct device_node *memory = NULL;
199
200	memory = of_find_node_by_type(memory, "memory");
201	if (!memory)
202		panic("numa.c: No memory nodes found!");
203
204	*n_addr_cells = of_n_addr_cells(memory);
205	*n_size_cells = of_n_size_cells(memory);
206	of_node_put(memory);
207}
208
209static unsigned long __devinit read_n_cells(int n, const unsigned int **buf)
210{
211	unsigned long result = 0;
212
213	while (n--) {
214		result = (result << 32) | **buf;
215		(*buf)++;
216	}
217	return result;
218}
219
220/*
221 * Figure out to which domain a cpu belongs and stick it there.
222 * Return the id of the domain used.
223 */
224static int __cpuinit numa_setup_cpu(unsigned long lcpu)
225{
226	int nid = 0;
227	struct device_node *cpu = find_cpu_node(lcpu);
228
229	if (!cpu) {
230		WARN_ON(1);
231		goto out;
232	}
233
234	nid = of_node_to_nid_single(cpu);
235
236	if (nid < 0 || !node_online(nid))
237		nid = any_online_node(NODE_MASK_ALL);
238out:
239	map_cpu_to_node(lcpu, nid);
240
241	of_node_put(cpu);
242
243	return nid;
244}
245
246static int __cpuinit cpu_numa_callback(struct notifier_block *nfb,
247			     unsigned long action,
248			     void *hcpu)
249{
250	unsigned long lcpu = (unsigned long)hcpu;
251	int ret = NOTIFY_DONE;
252
253	switch (action) {
254	case CPU_UP_PREPARE:
255	case CPU_UP_PREPARE_FROZEN:
256		numa_setup_cpu(lcpu);
257		ret = NOTIFY_OK;
258		break;
259#ifdef CONFIG_HOTPLUG_CPU
260	case CPU_DEAD:
261	case CPU_DEAD_FROZEN:
262	case CPU_UP_CANCELED:
263	case CPU_UP_CANCELED_FROZEN:
264		unmap_cpu_from_node(lcpu);
265		break;
266		ret = NOTIFY_OK;
267#endif
268	}
269	return ret;
270}
271
272/*
273 * Check and possibly modify a memory region to enforce the memory limit.
274 *
275 * Returns the size the region should have to enforce the memory limit.
276 * This will either be the original value of size, a truncated value,
277 * or zero. If the returned value of size is 0 the region should be
278 * discarded as it lies wholy above the memory limit.
279 */
280static unsigned long __init numa_enforce_memory_limit(unsigned long start,
281						      unsigned long size)
282{
283	/*
284	 * We use lmb_end_of_DRAM() in here instead of memory_limit because
285	 * we've already adjusted it for the limit and it takes care of
286	 * having memory holes below the limit.
287	 */
288
289	if (! memory_limit)
290		return size;
291
292	if (start + size <= lmb_end_of_DRAM())
293		return size;
294
295	if (start >= lmb_end_of_DRAM())
296		return 0;
297
298	return lmb_end_of_DRAM() - start;
299}
300
301/*
302 * Extract NUMA information from the ibm,dynamic-reconfiguration-memory
303 * node.  This assumes n_mem_{addr,size}_cells have been set.
304 */
305static void __init parse_drconf_memory(struct device_node *memory)
306{
307	const unsigned int *lm, *dm, *aa;
308	unsigned int ls, ld, la;
309	unsigned int n, aam, aalen;
310	unsigned long lmb_size, size;
311	int nid, default_nid = 0;
312	unsigned int start, ai, flags;
313
314	lm = of_get_property(memory, "ibm,lmb-size", &ls);
315	dm = of_get_property(memory, "ibm,dynamic-memory", &ld);
316	aa = of_get_property(memory, "ibm,associativity-lookup-arrays", &la);
317	if (!lm || !dm || !aa ||
318	    ls < sizeof(unsigned int) || ld < sizeof(unsigned int) ||
319	    la < 2 * sizeof(unsigned int))
320		return;
321
322	lmb_size = read_n_cells(n_mem_size_cells, &lm);
323	n = *dm++;		/* number of LMBs */
324	aam = *aa++;		/* number of associativity lists */
325	aalen = *aa++;		/* length of each associativity list */
326	if (ld < (n * (n_mem_addr_cells + 4) + 1) * sizeof(unsigned int) ||
327	    la < (aam * aalen + 2) * sizeof(unsigned int))
328		return;
329
330	for (; n != 0; --n) {
331		start = read_n_cells(n_mem_addr_cells, &dm);
332		ai = dm[2];
333		flags = dm[3];
334		dm += 4;
335		/* 0x80 == reserved, 0x8 = assigned to us */
336		if ((flags & 0x80) || !(flags & 0x8))
337			continue;
338		nid = default_nid;
339		/* flags & 0x40 means associativity index is invalid */
340		if (min_common_depth > 0 && min_common_depth <= aalen &&
341		    (flags & 0x40) == 0 && ai < aam) {
342			/* this is like of_node_to_nid_single */
343			nid = aa[ai * aalen + min_common_depth - 1];
344			if (nid == 0xffff || nid >= MAX_NUMNODES)
345				nid = default_nid;
346		}
347		node_set_online(nid);
348
349		size = numa_enforce_memory_limit(start, lmb_size);
350		if (!size)
351			continue;
352
353		add_active_range(nid, start >> PAGE_SHIFT,
354				 (start >> PAGE_SHIFT) + (size >> PAGE_SHIFT));
355	}
356}
357
358static int __init parse_numa_properties(void)
359{
360	struct device_node *cpu = NULL;
361	struct device_node *memory = NULL;
362	int default_nid = 0;
363	unsigned long i;
364
365	if (numa_enabled == 0) {
366		printk(KERN_WARNING "NUMA disabled by user\n");
367		return -1;
368	}
369
370	min_common_depth = find_min_common_depth();
371
372	if (min_common_depth < 0)
373		return min_common_depth;
374
375	dbg("NUMA associativity depth for CPU/Memory: %d\n", min_common_depth);
376
377	/*
378	 * Even though we connect cpus to numa domains later in SMP
379	 * init, we need to know the node ids now. This is because
380	 * each node to be onlined must have NODE_DATA etc backing it.
381	 */
382	for_each_present_cpu(i) {
383		int nid;
384
385		cpu = find_cpu_node(i);
386		BUG_ON(!cpu);
387		nid = of_node_to_nid_single(cpu);
388		of_node_put(cpu);
389
390		/*
391		 * Don't fall back to default_nid yet -- we will plug
392		 * cpus into nodes once the memory scan has discovered
393		 * the topology.
394		 */
395		if (nid < 0)
396			continue;
397		node_set_online(nid);
398	}
399
400	get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells);
401	memory = NULL;
402	while ((memory = of_find_node_by_type(memory, "memory")) != NULL) {
403		unsigned long start;
404		unsigned long size;
405		int nid;
406		int ranges;
407		const unsigned int *memcell_buf;
408		unsigned int len;
409
410		memcell_buf = of_get_property(memory,
411			"linux,usable-memory", &len);
412		if (!memcell_buf || len <= 0)
413			memcell_buf = of_get_property(memory, "reg", &len);
414		if (!memcell_buf || len <= 0)
415			continue;
416
417		/* ranges in cell */
418		ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
419new_range:
420		/* these are order-sensitive, and modify the buffer pointer */
421		start = read_n_cells(n_mem_addr_cells, &memcell_buf);
422		size = read_n_cells(n_mem_size_cells, &memcell_buf);
423
424		/*
425		 * Assumption: either all memory nodes or none will
426		 * have associativity properties.  If none, then
427		 * everything goes to default_nid.
428		 */
429		nid = of_node_to_nid_single(memory);
430		if (nid < 0)
431			nid = default_nid;
432		node_set_online(nid);
433
434		if (!(size = numa_enforce_memory_limit(start, size))) {
435			if (--ranges)
436				goto new_range;
437			else
438				continue;
439		}
440
441		add_active_range(nid, start >> PAGE_SHIFT,
442				(start >> PAGE_SHIFT) + (size >> PAGE_SHIFT));
443
444		if (--ranges)
445			goto new_range;
446	}
447
448	/*
449	 * Now do the same thing for each LMB listed in the ibm,dynamic-memory
450	 * property in the ibm,dynamic-reconfiguration-memory node.
451	 */
452	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
453	if (memory)
454		parse_drconf_memory(memory);
455
456	return 0;
457}
458
459static void __init setup_nonnuma(void)
460{
461	unsigned long top_of_ram = lmb_end_of_DRAM();
462	unsigned long total_ram = lmb_phys_mem_size();
463	unsigned long start_pfn, end_pfn;
464	unsigned int i;
465
466	printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
467	       top_of_ram, total_ram);
468	printk(KERN_DEBUG "Memory hole size: %ldMB\n",
469	       (top_of_ram - total_ram) >> 20);
470
471	for (i = 0; i < lmb.memory.cnt; ++i) {
472		start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
473		end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
474		add_active_range(0, start_pfn, end_pfn);
475	}
476	node_set_online(0);
477}
478
479void __init dump_numa_cpu_topology(void)
480{
481	unsigned int node;
482	unsigned int cpu, count;
483
484	if (min_common_depth == -1 || !numa_enabled)
485		return;
486
487	for_each_online_node(node) {
488		printk(KERN_DEBUG "Node %d CPUs:", node);
489
490		count = 0;
491		/*
492		 * If we used a CPU iterator here we would miss printing
493		 * the holes in the cpumap.
494		 */
495		for (cpu = 0; cpu < NR_CPUS; cpu++) {
496			if (cpu_isset(cpu, numa_cpumask_lookup_table[node])) {
497				if (count == 0)
498					printk(" %u", cpu);
499				++count;
500			} else {
501				if (count > 1)
502					printk("-%u", cpu - 1);
503				count = 0;
504			}
505		}
506
507		if (count > 1)
508			printk("-%u", NR_CPUS - 1);
509		printk("\n");
510	}
511}
512
513static void __init dump_numa_memory_topology(void)
514{
515	unsigned int node;
516	unsigned int count;
517
518	if (min_common_depth == -1 || !numa_enabled)
519		return;
520
521	for_each_online_node(node) {
522		unsigned long i;
523
524		printk(KERN_DEBUG "Node %d Memory:", node);
525
526		count = 0;
527
528		for (i = 0; i < lmb_end_of_DRAM();
529		     i += (1 << SECTION_SIZE_BITS)) {
530			if (early_pfn_to_nid(i >> PAGE_SHIFT) == node) {
531				if (count == 0)
532					printk(" 0x%lx", i);
533				++count;
534			} else {
535				if (count > 0)
536					printk("-0x%lx", i);
537				count = 0;
538			}
539		}
540
541		if (count > 0)
542			printk("-0x%lx", i);
543		printk("\n");
544	}
545}
546
547/*
548 * Allocate some memory, satisfying the lmb or bootmem allocator where
549 * required. nid is the preferred node and end is the physical address of
550 * the highest address in the node.
551 *
552 * Returns the physical address of the memory.
553 */
554static void __init *careful_allocation(int nid, unsigned long size,
555				       unsigned long align,
556				       unsigned long end_pfn)
557{
558	int new_nid;
559	unsigned long ret = __lmb_alloc_base(size, align, end_pfn << PAGE_SHIFT);
560
561	/* retry over all memory */
562	if (!ret)
563		ret = __lmb_alloc_base(size, align, lmb_end_of_DRAM());
564
565	if (!ret)
566		panic("numa.c: cannot allocate %lu bytes on node %d",
567		      size, nid);
568
569	/*
570	 * If the memory came from a previously allocated node, we must
571	 * retry with the bootmem allocator.
572	 */
573	new_nid = early_pfn_to_nid(ret >> PAGE_SHIFT);
574	if (new_nid < nid) {
575		ret = (unsigned long)__alloc_bootmem_node(NODE_DATA(new_nid),
576				size, align, 0);
577
578		if (!ret)
579			panic("numa.c: cannot allocate %lu bytes on node %d",
580			      size, new_nid);
581
582		ret = __pa(ret);
583
584		dbg("alloc_bootmem %lx %lx\n", ret, size);
585	}
586
587	return (void *)ret;
588}
589
590static struct notifier_block __cpuinitdata ppc64_numa_nb = {
591	.notifier_call = cpu_numa_callback,
592	.priority = 1 /* Must run before sched domains notifier. */
593};
594
595void __init do_init_bootmem(void)
596{
597	int nid;
598	unsigned int i;
599
600	min_low_pfn = 0;
601	max_low_pfn = lmb_end_of_DRAM() >> PAGE_SHIFT;
602	max_pfn = max_low_pfn;
603
604	if (parse_numa_properties())
605		setup_nonnuma();
606	else
607		dump_numa_memory_topology();
608
609	register_cpu_notifier(&ppc64_numa_nb);
610	cpu_numa_callback(&ppc64_numa_nb, CPU_UP_PREPARE,
611			  (void *)(unsigned long)boot_cpuid);
612
613	for_each_online_node(nid) {
614		unsigned long start_pfn, end_pfn;
615		unsigned long bootmem_paddr;
616		unsigned long bootmap_pages;
617
618		get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
619
620		/* Allocate the node structure node local if possible */
621		NODE_DATA(nid) = careful_allocation(nid,
622					sizeof(struct pglist_data),
623					SMP_CACHE_BYTES, end_pfn);
624		NODE_DATA(nid) = __va(NODE_DATA(nid));
625		memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));
626
627  		dbg("node %d\n", nid);
628		dbg("NODE_DATA() = %p\n", NODE_DATA(nid));
629
630		NODE_DATA(nid)->bdata = &plat_node_bdata[nid];
631		NODE_DATA(nid)->node_start_pfn = start_pfn;
632		NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
633
634		if (NODE_DATA(nid)->node_spanned_pages == 0)
635  			continue;
636
637  		dbg("start_paddr = %lx\n", start_pfn << PAGE_SHIFT);
638  		dbg("end_paddr = %lx\n", end_pfn << PAGE_SHIFT);
639
640		bootmap_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
641		bootmem_paddr = (unsigned long)careful_allocation(nid,
642					bootmap_pages << PAGE_SHIFT,
643					PAGE_SIZE, end_pfn);
644		memset(__va(bootmem_paddr), 0, bootmap_pages << PAGE_SHIFT);
645
646		dbg("bootmap_paddr = %lx\n", bootmem_paddr);
647
648		init_bootmem_node(NODE_DATA(nid), bootmem_paddr >> PAGE_SHIFT,
649				  start_pfn, end_pfn);
650
651		free_bootmem_with_active_regions(nid, end_pfn);
652
653		/* Mark reserved regions on this node */
654		for (i = 0; i < lmb.reserved.cnt; i++) {
655			unsigned long physbase = lmb.reserved.region[i].base;
656			unsigned long size = lmb.reserved.region[i].size;
657			unsigned long start_paddr = start_pfn << PAGE_SHIFT;
658			unsigned long end_paddr = end_pfn << PAGE_SHIFT;
659
660			if (early_pfn_to_nid(physbase >> PAGE_SHIFT) != nid &&
661			    early_pfn_to_nid((physbase+size-1) >> PAGE_SHIFT) != nid)
662				continue;
663
664			if (physbase < end_paddr &&
665			    (physbase+size) > start_paddr) {
666				/* overlaps */
667				if (physbase < start_paddr) {
668					size -= start_paddr - physbase;
669					physbase = start_paddr;
670				}
671
672				if (size > end_paddr - physbase)
673					size = end_paddr - physbase;
674
675				dbg("reserve_bootmem %lx %lx\n", physbase,
676				    size);
677				reserve_bootmem_node(NODE_DATA(nid), physbase,
678						     size);
679			}
680		}
681
682		sparse_memory_present_with_active_regions(nid);
683	}
684}
685
686void __init paging_init(void)
687{
688	unsigned long max_zone_pfns[MAX_NR_ZONES];
689	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
690	max_zone_pfns[ZONE_DMA] = lmb_end_of_DRAM() >> PAGE_SHIFT;
691	free_area_init_nodes(max_zone_pfns);
692}
693
694static int __init early_numa(char *p)
695{
696	if (!p)
697		return 0;
698
699	if (strstr(p, "off"))
700		numa_enabled = 0;
701
702	if (strstr(p, "debug"))
703		numa_debug = 1;
704
705	return 0;
706}
707early_param("numa", early_numa);
708
709#ifdef CONFIG_MEMORY_HOTPLUG
710/*
711 * Find the node associated with a hot added memory section.  Section
712 * corresponds to a SPARSEMEM section, not an LMB.  It is assumed that
713 * sections are fully contained within a single LMB.
714 */
715int hot_add_scn_to_nid(unsigned long scn_addr)
716{
717	struct device_node *memory = NULL;
718	nodemask_t nodes;
719	int default_nid = any_online_node(NODE_MASK_ALL);
720	int nid;
721
722	if (!numa_enabled || (min_common_depth < 0))
723		return default_nid;
724
725	while ((memory = of_find_node_by_type(memory, "memory")) != NULL) {
726		unsigned long start, size;
727		int ranges;
728		const unsigned int *memcell_buf;
729		unsigned int len;
730
731		memcell_buf = of_get_property(memory, "reg", &len);
732		if (!memcell_buf || len <= 0)
733			continue;
734
735		/* ranges in cell */
736		ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
737ha_new_range:
738		start = read_n_cells(n_mem_addr_cells, &memcell_buf);
739		size = read_n_cells(n_mem_size_cells, &memcell_buf);
740		nid = of_node_to_nid_single(memory);
741
742		/* Domains not present at boot default to 0 */
743		if (nid < 0 || !node_online(nid))
744			nid = default_nid;
745
746		if ((scn_addr >= start) && (scn_addr < (start + size))) {
747			of_node_put(memory);
748			goto got_nid;
749		}
750
751		if (--ranges)		/* process all ranges in cell */
752			goto ha_new_range;
753	}
754	BUG();	/* section address should be found above */
755	return 0;
756
757	/* Temporary code to ensure that returned node is not empty */
758got_nid:
759	nodes_setall(nodes);
760	while (NODE_DATA(nid)->node_spanned_pages == 0) {
761		node_clear(nid, nodes);
762		nid = any_online_node(nodes);
763	}
764	return nid;
765}
766#endif /* CONFIG_MEMORY_HOTPLUG */
767