]> git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - arch/powerpc/mm/numa.c
[PATCH] ppc64: Add NUMA cpu summary at boot
[mirror_ubuntu-zesty-kernel.git] / arch / powerpc / mm / numa.c
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
25 static int numa_enabled = 1;
26
27 static int numa_debug;
28 #define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }
29
30 int numa_cpu_lookup_table[NR_CPUS];
31 cpumask_t numa_cpumask_lookup_table[MAX_NUMNODES];
32 struct pglist_data *node_data[MAX_NUMNODES];
33
34 EXPORT_SYMBOL(numa_cpu_lookup_table);
35 EXPORT_SYMBOL(numa_cpumask_lookup_table);
36 EXPORT_SYMBOL(node_data);
37
38 static bootmem_data_t __initdata plat_node_bdata[MAX_NUMNODES];
39 static int min_common_depth;
40 static int n_mem_addr_cells, n_mem_size_cells;
41
42 /*
43 * We need somewhere to store start/end/node for each region until we have
44 * allocated the real node_data structures.
45 */
46 #define MAX_REGIONS (MAX_LMB_REGIONS*2)
47 static struct {
48 unsigned long start_pfn;
49 unsigned long end_pfn;
50 int nid;
51 } init_node_data[MAX_REGIONS] __initdata;
52
53 int __init early_pfn_to_nid(unsigned long pfn)
54 {
55 unsigned int i;
56
57 for (i = 0; init_node_data[i].end_pfn; i++) {
58 unsigned long start_pfn = init_node_data[i].start_pfn;
59 unsigned long end_pfn = init_node_data[i].end_pfn;
60
61 if ((start_pfn <= pfn) && (pfn < end_pfn))
62 return init_node_data[i].nid;
63 }
64
65 return -1;
66 }
67
68 void __init add_region(unsigned int nid, unsigned long start_pfn,
69 unsigned long pages)
70 {
71 unsigned int i;
72
73 dbg("add_region nid %d start_pfn 0x%lx pages 0x%lx\n",
74 nid, start_pfn, pages);
75
76 for (i = 0; init_node_data[i].end_pfn; i++) {
77 if (init_node_data[i].nid != nid)
78 continue;
79 if (init_node_data[i].end_pfn == start_pfn) {
80 init_node_data[i].end_pfn += pages;
81 return;
82 }
83 if (init_node_data[i].start_pfn == (start_pfn + pages)) {
84 init_node_data[i].start_pfn -= pages;
85 return;
86 }
87 }
88
89 /*
90 * Leave last entry NULL so we dont iterate off the end (we use
91 * entry.end_pfn to terminate the walk).
92 */
93 if (i >= (MAX_REGIONS - 1)) {
94 printk(KERN_ERR "WARNING: too many memory regions in "
95 "numa code, truncating\n");
96 return;
97 }
98
99 init_node_data[i].start_pfn = start_pfn;
100 init_node_data[i].end_pfn = start_pfn + pages;
101 init_node_data[i].nid = nid;
102 }
103
104 /* We assume init_node_data has no overlapping regions */
105 void __init get_region(unsigned int nid, unsigned long *start_pfn,
106 unsigned long *end_pfn, unsigned long *pages_present)
107 {
108 unsigned int i;
109
110 *start_pfn = -1UL;
111 *end_pfn = *pages_present = 0;
112
113 for (i = 0; init_node_data[i].end_pfn; i++) {
114 if (init_node_data[i].nid != nid)
115 continue;
116
117 *pages_present += init_node_data[i].end_pfn -
118 init_node_data[i].start_pfn;
119
120 if (init_node_data[i].start_pfn < *start_pfn)
121 *start_pfn = init_node_data[i].start_pfn;
122
123 if (init_node_data[i].end_pfn > *end_pfn)
124 *end_pfn = init_node_data[i].end_pfn;
125 }
126
127 /* We didnt find a matching region, return start/end as 0 */
128 if (*start_pfn == -1UL)
129 *start_pfn = 0;
130 }
131
132 static inline void map_cpu_to_node(int cpu, int node)
133 {
134 numa_cpu_lookup_table[cpu] = node;
135
136 if (!(cpu_isset(cpu, numa_cpumask_lookup_table[node])))
137 cpu_set(cpu, numa_cpumask_lookup_table[node]);
138 }
139
140 #ifdef CONFIG_HOTPLUG_CPU
141 static void unmap_cpu_from_node(unsigned long cpu)
142 {
143 int node = numa_cpu_lookup_table[cpu];
144
145 dbg("removing cpu %lu from node %d\n", cpu, node);
146
147 if (cpu_isset(cpu, numa_cpumask_lookup_table[node])) {
148 cpu_clear(cpu, numa_cpumask_lookup_table[node]);
149 } else {
150 printk(KERN_ERR "WARNING: cpu %lu not found in node %d\n",
151 cpu, node);
152 }
153 }
154 #endif /* CONFIG_HOTPLUG_CPU */
155
156 static struct device_node *find_cpu_node(unsigned int cpu)
157 {
158 unsigned int hw_cpuid = get_hard_smp_processor_id(cpu);
159 struct device_node *cpu_node = NULL;
160 unsigned int *interrupt_server, *reg;
161 int len;
162
163 while ((cpu_node = of_find_node_by_type(cpu_node, "cpu")) != NULL) {
164 /* Try interrupt server first */
165 interrupt_server = (unsigned int *)get_property(cpu_node,
166 "ibm,ppc-interrupt-server#s", &len);
167
168 len = len / sizeof(u32);
169
170 if (interrupt_server && (len > 0)) {
171 while (len--) {
172 if (interrupt_server[len] == hw_cpuid)
173 return cpu_node;
174 }
175 } else {
176 reg = (unsigned int *)get_property(cpu_node,
177 "reg", &len);
178 if (reg && (len > 0) && (reg[0] == hw_cpuid))
179 return cpu_node;
180 }
181 }
182
183 return NULL;
184 }
185
186 /* must hold reference to node during call */
187 static int *of_get_associativity(struct device_node *dev)
188 {
189 return (unsigned int *)get_property(dev, "ibm,associativity", NULL);
190 }
191
192 static int of_node_numa_domain(struct device_node *device)
193 {
194 int numa_domain;
195 unsigned int *tmp;
196
197 if (min_common_depth == -1)
198 return 0;
199
200 tmp = of_get_associativity(device);
201 if (tmp && (tmp[0] >= min_common_depth)) {
202 numa_domain = tmp[min_common_depth];
203 } else {
204 dbg("WARNING: no NUMA information for %s\n",
205 device->full_name);
206 numa_domain = 0;
207 }
208 return numa_domain;
209 }
210
211 /*
212 * In theory, the "ibm,associativity" property may contain multiple
213 * associativity lists because a resource may be multiply connected
214 * into the machine. This resource then has different associativity
215 * characteristics relative to its multiple connections. We ignore
216 * this for now. We also assume that all cpu and memory sets have
217 * their distances represented at a common level. This won't be
218 * true for heirarchical NUMA.
219 *
220 * In any case the ibm,associativity-reference-points should give
221 * the correct depth for a normal NUMA system.
222 *
223 * - Dave Hansen <haveblue@us.ibm.com>
224 */
225 static int __init find_min_common_depth(void)
226 {
227 int depth;
228 unsigned int *ref_points;
229 struct device_node *rtas_root;
230 unsigned int len;
231
232 rtas_root = of_find_node_by_path("/rtas");
233
234 if (!rtas_root)
235 return -1;
236
237 /*
238 * this property is 2 32-bit integers, each representing a level of
239 * depth in the associativity nodes. The first is for an SMP
240 * configuration (should be all 0's) and the second is for a normal
241 * NUMA configuration.
242 */
243 ref_points = (unsigned int *)get_property(rtas_root,
244 "ibm,associativity-reference-points", &len);
245
246 if ((len >= 1) && ref_points) {
247 depth = ref_points[1];
248 } else {
249 dbg("WARNING: could not find NUMA "
250 "associativity reference point\n");
251 depth = -1;
252 }
253 of_node_put(rtas_root);
254
255 return depth;
256 }
257
258 static void __init get_n_mem_cells(int *n_addr_cells, int *n_size_cells)
259 {
260 struct device_node *memory = NULL;
261
262 memory = of_find_node_by_type(memory, "memory");
263 if (!memory)
264 panic("numa.c: No memory nodes found!");
265
266 *n_addr_cells = prom_n_addr_cells(memory);
267 *n_size_cells = prom_n_size_cells(memory);
268 of_node_put(memory);
269 }
270
271 static unsigned long __devinit read_n_cells(int n, unsigned int **buf)
272 {
273 unsigned long result = 0;
274
275 while (n--) {
276 result = (result << 32) | **buf;
277 (*buf)++;
278 }
279 return result;
280 }
281
282 /*
283 * Figure out to which domain a cpu belongs and stick it there.
284 * Return the id of the domain used.
285 */
286 static int numa_setup_cpu(unsigned long lcpu)
287 {
288 int numa_domain = 0;
289 struct device_node *cpu = find_cpu_node(lcpu);
290
291 if (!cpu) {
292 WARN_ON(1);
293 goto out;
294 }
295
296 numa_domain = of_node_numa_domain(cpu);
297
298 if (numa_domain >= num_online_nodes()) {
299 /*
300 * POWER4 LPAR uses 0xffff as invalid node,
301 * dont warn in this case.
302 */
303 if (numa_domain != 0xffff)
304 printk(KERN_ERR "WARNING: cpu %ld "
305 "maps to invalid NUMA node %d\n",
306 lcpu, numa_domain);
307 numa_domain = 0;
308 }
309 out:
310 node_set_online(numa_domain);
311
312 map_cpu_to_node(lcpu, numa_domain);
313
314 of_node_put(cpu);
315
316 return numa_domain;
317 }
318
319 static int cpu_numa_callback(struct notifier_block *nfb,
320 unsigned long action,
321 void *hcpu)
322 {
323 unsigned long lcpu = (unsigned long)hcpu;
324 int ret = NOTIFY_DONE;
325
326 switch (action) {
327 case CPU_UP_PREPARE:
328 if (min_common_depth == -1 || !numa_enabled)
329 map_cpu_to_node(lcpu, 0);
330 else
331 numa_setup_cpu(lcpu);
332 ret = NOTIFY_OK;
333 break;
334 #ifdef CONFIG_HOTPLUG_CPU
335 case CPU_DEAD:
336 case CPU_UP_CANCELED:
337 unmap_cpu_from_node(lcpu);
338 break;
339 ret = NOTIFY_OK;
340 #endif
341 }
342 return ret;
343 }
344
345 /*
346 * Check and possibly modify a memory region to enforce the memory limit.
347 *
348 * Returns the size the region should have to enforce the memory limit.
349 * This will either be the original value of size, a truncated value,
350 * or zero. If the returned value of size is 0 the region should be
351 * discarded as it lies wholy above the memory limit.
352 */
353 static unsigned long __init numa_enforce_memory_limit(unsigned long start,
354 unsigned long size)
355 {
356 /*
357 * We use lmb_end_of_DRAM() in here instead of memory_limit because
358 * we've already adjusted it for the limit and it takes care of
359 * having memory holes below the limit.
360 */
361
362 if (! memory_limit)
363 return size;
364
365 if (start + size <= lmb_end_of_DRAM())
366 return size;
367
368 if (start >= lmb_end_of_DRAM())
369 return 0;
370
371 return lmb_end_of_DRAM() - start;
372 }
373
374 static int __init parse_numa_properties(void)
375 {
376 struct device_node *cpu = NULL;
377 struct device_node *memory = NULL;
378 int max_domain;
379 unsigned long i;
380
381 if (numa_enabled == 0) {
382 printk(KERN_WARNING "NUMA disabled by user\n");
383 return -1;
384 }
385
386 min_common_depth = find_min_common_depth();
387
388 dbg("NUMA associativity depth for CPU/Memory: %d\n", min_common_depth);
389 if (min_common_depth < 0)
390 return min_common_depth;
391
392 max_domain = numa_setup_cpu(boot_cpuid);
393
394 /*
395 * Even though we connect cpus to numa domains later in SMP init,
396 * we need to know the maximum node id now. This is because each
397 * node id must have NODE_DATA etc backing it.
398 * As a result of hotplug we could still have cpus appear later on
399 * with larger node ids. In that case we force the cpu into node 0.
400 */
401 for_each_cpu(i) {
402 int numa_domain;
403
404 cpu = find_cpu_node(i);
405
406 if (cpu) {
407 numa_domain = of_node_numa_domain(cpu);
408 of_node_put(cpu);
409
410 if (numa_domain < MAX_NUMNODES &&
411 max_domain < numa_domain)
412 max_domain = numa_domain;
413 }
414 }
415
416 get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells);
417 memory = NULL;
418 while ((memory = of_find_node_by_type(memory, "memory")) != NULL) {
419 unsigned long start;
420 unsigned long size;
421 int numa_domain;
422 int ranges;
423 unsigned int *memcell_buf;
424 unsigned int len;
425
426 memcell_buf = (unsigned int *)get_property(memory,
427 "linux,usable-memory", &len);
428 if (!memcell_buf || len <= 0)
429 memcell_buf =
430 (unsigned int *)get_property(memory, "reg",
431 &len);
432 if (!memcell_buf || len <= 0)
433 continue;
434
435 ranges = memory->n_addrs;
436 new_range:
437 /* these are order-sensitive, and modify the buffer pointer */
438 start = read_n_cells(n_mem_addr_cells, &memcell_buf);
439 size = read_n_cells(n_mem_size_cells, &memcell_buf);
440
441 numa_domain = of_node_numa_domain(memory);
442
443 if (numa_domain >= MAX_NUMNODES) {
444 if (numa_domain != 0xffff)
445 printk(KERN_ERR "WARNING: memory at %lx maps "
446 "to invalid NUMA node %d\n", start,
447 numa_domain);
448 numa_domain = 0;
449 }
450
451 if (max_domain < numa_domain)
452 max_domain = numa_domain;
453
454 if (!(size = numa_enforce_memory_limit(start, size))) {
455 if (--ranges)
456 goto new_range;
457 else
458 continue;
459 }
460
461 add_region(numa_domain, start >> PAGE_SHIFT,
462 size >> PAGE_SHIFT);
463
464 if (--ranges)
465 goto new_range;
466 }
467
468 for (i = 0; i <= max_domain; i++)
469 node_set_online(i);
470
471 return 0;
472 }
473
474 static void __init setup_nonnuma(void)
475 {
476 unsigned long top_of_ram = lmb_end_of_DRAM();
477 unsigned long total_ram = lmb_phys_mem_size();
478 unsigned int i;
479
480 printk(KERN_INFO "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
481 top_of_ram, total_ram);
482 printk(KERN_INFO "Memory hole size: %ldMB\n",
483 (top_of_ram - total_ram) >> 20);
484
485 map_cpu_to_node(boot_cpuid, 0);
486 for (i = 0; i < lmb.memory.cnt; ++i)
487 add_region(0, lmb.memory.region[i].base >> PAGE_SHIFT,
488 lmb_size_pages(&lmb.memory, i));
489 node_set_online(0);
490 }
491
492 void __init dump_numa_cpu_topology(void)
493 {
494 unsigned int node;
495 unsigned int cpu, count;
496
497 if (min_common_depth == -1 || !numa_enabled)
498 return;
499
500 for_each_online_node(node) {
501 printk(KERN_INFO "Node %d CPUs:", node);
502
503 count = 0;
504 /*
505 * If we used a CPU iterator here we would miss printing
506 * the holes in the cpumap.
507 */
508 for (cpu = 0; cpu < NR_CPUS; cpu++) {
509 if (cpu_isset(cpu, numa_cpumask_lookup_table[node])) {
510 if (count == 0)
511 printk(" %u", cpu);
512 ++count;
513 } else {
514 if (count > 1)
515 printk("-%u", cpu - 1);
516 count = 0;
517 }
518 }
519
520 if (count > 1)
521 printk("-%u", NR_CPUS - 1);
522 printk("\n");
523 }
524 }
525
526 static void __init dump_numa_memory_topology(void)
527 {
528 unsigned int node;
529 unsigned int count;
530
531 if (min_common_depth == -1 || !numa_enabled)
532 return;
533
534 for_each_online_node(node) {
535 unsigned long i;
536
537 printk(KERN_INFO "Node %d Memory:", node);
538
539 count = 0;
540
541 for (i = 0; i < lmb_end_of_DRAM();
542 i += (1 << SECTION_SIZE_BITS)) {
543 if (early_pfn_to_nid(i >> PAGE_SHIFT) == node) {
544 if (count == 0)
545 printk(" 0x%lx", i);
546 ++count;
547 } else {
548 if (count > 0)
549 printk("-0x%lx", i);
550 count = 0;
551 }
552 }
553
554 if (count > 0)
555 printk("-0x%lx", i);
556 printk("\n");
557 }
558 }
559
560 /*
561 * Allocate some memory, satisfying the lmb or bootmem allocator where
562 * required. nid is the preferred node and end is the physical address of
563 * the highest address in the node.
564 *
565 * Returns the physical address of the memory.
566 */
567 static void __init *careful_allocation(int nid, unsigned long size,
568 unsigned long align,
569 unsigned long end_pfn)
570 {
571 int new_nid;
572 unsigned long ret = lmb_alloc_base(size, align, end_pfn << PAGE_SHIFT);
573
574 /* retry over all memory */
575 if (!ret)
576 ret = lmb_alloc_base(size, align, lmb_end_of_DRAM());
577
578 if (!ret)
579 panic("numa.c: cannot allocate %lu bytes on node %d",
580 size, nid);
581
582 /*
583 * If the memory came from a previously allocated node, we must
584 * retry with the bootmem allocator.
585 */
586 new_nid = early_pfn_to_nid(ret >> PAGE_SHIFT);
587 if (new_nid < nid) {
588 ret = (unsigned long)__alloc_bootmem_node(NODE_DATA(new_nid),
589 size, align, 0);
590
591 if (!ret)
592 panic("numa.c: cannot allocate %lu bytes on node %d",
593 size, new_nid);
594
595 ret = __pa(ret);
596
597 dbg("alloc_bootmem %lx %lx\n", ret, size);
598 }
599
600 return (void *)ret;
601 }
602
603 void __init do_init_bootmem(void)
604 {
605 int nid;
606 unsigned int i;
607 static struct notifier_block ppc64_numa_nb = {
608 .notifier_call = cpu_numa_callback,
609 .priority = 1 /* Must run before sched domains notifier. */
610 };
611
612 min_low_pfn = 0;
613 max_low_pfn = lmb_end_of_DRAM() >> PAGE_SHIFT;
614 max_pfn = max_low_pfn;
615
616 if (parse_numa_properties())
617 setup_nonnuma();
618 else
619 dump_numa_memory_topology();
620
621 register_cpu_notifier(&ppc64_numa_nb);
622
623 for_each_online_node(nid) {
624 unsigned long start_pfn, end_pfn, pages_present;
625 unsigned long bootmem_paddr;
626 unsigned long bootmap_pages;
627
628 get_region(nid, &start_pfn, &end_pfn, &pages_present);
629
630 /* Allocate the node structure node local if possible */
631 NODE_DATA(nid) = careful_allocation(nid,
632 sizeof(struct pglist_data),
633 SMP_CACHE_BYTES, end_pfn);
634 NODE_DATA(nid) = __va(NODE_DATA(nid));
635 memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));
636
637 dbg("node %d\n", nid);
638 dbg("NODE_DATA() = %p\n", NODE_DATA(nid));
639
640 NODE_DATA(nid)->bdata = &plat_node_bdata[nid];
641 NODE_DATA(nid)->node_start_pfn = start_pfn;
642 NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
643
644 if (NODE_DATA(nid)->node_spanned_pages == 0)
645 continue;
646
647 dbg("start_paddr = %lx\n", start_pfn << PAGE_SHIFT);
648 dbg("end_paddr = %lx\n", end_pfn << PAGE_SHIFT);
649
650 bootmap_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
651 bootmem_paddr = (unsigned long)careful_allocation(nid,
652 bootmap_pages << PAGE_SHIFT,
653 PAGE_SIZE, end_pfn);
654 memset(__va(bootmem_paddr), 0, bootmap_pages << PAGE_SHIFT);
655
656 dbg("bootmap_paddr = %lx\n", bootmem_paddr);
657
658 init_bootmem_node(NODE_DATA(nid), bootmem_paddr >> PAGE_SHIFT,
659 start_pfn, end_pfn);
660
661 /* Add free regions on this node */
662 for (i = 0; init_node_data[i].end_pfn; i++) {
663 unsigned long start, end;
664
665 if (init_node_data[i].nid != nid)
666 continue;
667
668 start = init_node_data[i].start_pfn << PAGE_SHIFT;
669 end = init_node_data[i].end_pfn << PAGE_SHIFT;
670
671 dbg("free_bootmem %lx %lx\n", start, end - start);
672 free_bootmem_node(NODE_DATA(nid), start, end - start);
673 }
674
675 /* Mark reserved regions on this node */
676 for (i = 0; i < lmb.reserved.cnt; i++) {
677 unsigned long physbase = lmb.reserved.region[i].base;
678 unsigned long size = lmb.reserved.region[i].size;
679 unsigned long start_paddr = start_pfn << PAGE_SHIFT;
680 unsigned long end_paddr = end_pfn << PAGE_SHIFT;
681
682 if (early_pfn_to_nid(physbase >> PAGE_SHIFT) != nid &&
683 early_pfn_to_nid((physbase+size-1) >> PAGE_SHIFT) != nid)
684 continue;
685
686 if (physbase < end_paddr &&
687 (physbase+size) > start_paddr) {
688 /* overlaps */
689 if (physbase < start_paddr) {
690 size -= start_paddr - physbase;
691 physbase = start_paddr;
692 }
693
694 if (size > end_paddr - physbase)
695 size = end_paddr - physbase;
696
697 dbg("reserve_bootmem %lx %lx\n", physbase,
698 size);
699 reserve_bootmem_node(NODE_DATA(nid), physbase,
700 size);
701 }
702 }
703
704 /* Add regions into sparsemem */
705 for (i = 0; init_node_data[i].end_pfn; i++) {
706 unsigned long start, end;
707
708 if (init_node_data[i].nid != nid)
709 continue;
710
711 start = init_node_data[i].start_pfn;
712 end = init_node_data[i].end_pfn;
713
714 memory_present(nid, start, end);
715 }
716 }
717 }
718
719 void __init paging_init(void)
720 {
721 unsigned long zones_size[MAX_NR_ZONES];
722 unsigned long zholes_size[MAX_NR_ZONES];
723 int nid;
724
725 memset(zones_size, 0, sizeof(zones_size));
726 memset(zholes_size, 0, sizeof(zholes_size));
727
728 for_each_online_node(nid) {
729 unsigned long start_pfn, end_pfn, pages_present;
730
731 get_region(nid, &start_pfn, &end_pfn, &pages_present);
732
733 zones_size[ZONE_DMA] = end_pfn - start_pfn;
734 zholes_size[ZONE_DMA] = zones_size[ZONE_DMA] - pages_present;
735
736 dbg("free_area_init node %d %lx %lx (hole: %lx)\n", nid,
737 zones_size[ZONE_DMA], start_pfn, zholes_size[ZONE_DMA]);
738
739 free_area_init_node(nid, NODE_DATA(nid), zones_size, start_pfn,
740 zholes_size);
741 }
742 }
743
744 static int __init early_numa(char *p)
745 {
746 if (!p)
747 return 0;
748
749 if (strstr(p, "off"))
750 numa_enabled = 0;
751
752 if (strstr(p, "debug"))
753 numa_debug = 1;
754
755 return 0;
756 }
757 early_param("numa", early_numa);
758
759 #ifdef CONFIG_MEMORY_HOTPLUG
760 /*
761 * Find the node associated with a hot added memory section. Section
762 * corresponds to a SPARSEMEM section, not an LMB. It is assumed that
763 * sections are fully contained within a single LMB.
764 */
765 int hot_add_scn_to_nid(unsigned long scn_addr)
766 {
767 struct device_node *memory = NULL;
768
769 if (!numa_enabled || (min_common_depth < 0))
770 return 0;
771
772 while ((memory = of_find_node_by_type(memory, "memory")) != NULL) {
773 unsigned long start, size;
774 int numa_domain, ranges;
775 unsigned int *memcell_buf;
776 unsigned int len;
777
778 memcell_buf = (unsigned int *)get_property(memory, "reg", &len);
779 if (!memcell_buf || len <= 0)
780 continue;
781
782 ranges = memory->n_addrs; /* ranges in cell */
783 ha_new_range:
784 start = read_n_cells(n_mem_addr_cells, &memcell_buf);
785 size = read_n_cells(n_mem_size_cells, &memcell_buf);
786 numa_domain = of_node_numa_domain(memory);
787
788 /* Domains not present at boot default to 0 */
789 if (!node_online(numa_domain))
790 numa_domain = any_online_node(NODE_MASK_ALL);
791
792 if ((scn_addr >= start) && (scn_addr < (start + size))) {
793 of_node_put(memory);
794 return numa_domain;
795 }
796
797 if (--ranges) /* process all ranges in cell */
798 goto ha_new_range;
799 }
800
801 BUG(); /* section address should be found above */
802 return 0;
803 }
804 #endif /* CONFIG_MEMORY_HOTPLUG */