x86: unify 64-bit UMA and NUMA paging_init()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / arch / x86 / mm / numa_64.c
blobfb61d81a656f72629b219fd1e85b92ce7e7f19c5
1 /*
2 * Generic VM initialization for x86-64 NUMA setups.
3 * Copyright 2002,2003 Andi Kleen, SuSE Labs.
4 */
5 #include <linux/kernel.h>
6 #include <linux/mm.h>
7 #include <linux/string.h>
8 #include <linux/init.h>
9 #include <linux/bootmem.h>
10 #include <linux/mmzone.h>
11 #include <linux/ctype.h>
12 #include <linux/module.h>
13 #include <linux/nodemask.h>
14 #include <linux/sched.h>
16 #include <asm/e820.h>
17 #include <asm/proto.h>
18 #include <asm/dma.h>
19 #include <asm/numa.h>
20 #include <asm/acpi.h>
21 #include <asm/k8.h>
23 struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
24 EXPORT_SYMBOL(node_data);
26 struct memnode memnode;
28 s16 apicid_to_node[MAX_LOCAL_APIC] __cpuinitdata = {
29 [0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
32 int numa_off __initdata;
33 static unsigned long __initdata nodemap_addr;
34 static unsigned long __initdata nodemap_size;
36 DEFINE_PER_CPU(int, node_number) = 0;
37 EXPORT_PER_CPU_SYMBOL(node_number);
40 * Map cpu index to node index
42 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
43 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
46 * Given a shift value, try to populate memnodemap[]
47 * Returns :
48 * 1 if OK
49 * 0 if memnodmap[] too small (of shift too small)
50 * -1 if node overlap or lost ram (shift too big)
52 static int __init populate_memnodemap(const struct bootnode *nodes,
53 int numnodes, int shift, int *nodeids)
55 unsigned long addr, end;
56 int i, res = -1;
58 memset(memnodemap, 0xff, sizeof(s16)*memnodemapsize);
59 for (i = 0; i < numnodes; i++) {
60 addr = nodes[i].start;
61 end = nodes[i].end;
62 if (addr >= end)
63 continue;
64 if ((end >> shift) >= memnodemapsize)
65 return 0;
66 do {
67 if (memnodemap[addr >> shift] != NUMA_NO_NODE)
68 return -1;
70 if (!nodeids)
71 memnodemap[addr >> shift] = i;
72 else
73 memnodemap[addr >> shift] = nodeids[i];
75 addr += (1UL << shift);
76 } while (addr < end);
77 res = 1;
79 return res;
82 static int __init allocate_cachealigned_memnodemap(void)
84 unsigned long addr;
86 memnodemap = memnode.embedded_map;
87 if (memnodemapsize <= ARRAY_SIZE(memnode.embedded_map))
88 return 0;
90 addr = 0x8000;
91 nodemap_size = roundup(sizeof(s16) * memnodemapsize, L1_CACHE_BYTES);
92 nodemap_addr = find_e820_area(addr, max_pfn<<PAGE_SHIFT,
93 nodemap_size, L1_CACHE_BYTES);
94 if (nodemap_addr == -1UL) {
95 printk(KERN_ERR
96 "NUMA: Unable to allocate Memory to Node hash map\n");
97 nodemap_addr = nodemap_size = 0;
98 return -1;
100 memnodemap = phys_to_virt(nodemap_addr);
101 reserve_early(nodemap_addr, nodemap_addr + nodemap_size, "MEMNODEMAP");
103 printk(KERN_DEBUG "NUMA: Allocated memnodemap from %lx - %lx\n",
104 nodemap_addr, nodemap_addr + nodemap_size);
105 return 0;
109 * The LSB of all start and end addresses in the node map is the value of the
110 * maximum possible shift.
112 static int __init extract_lsb_from_nodes(const struct bootnode *nodes,
113 int numnodes)
115 int i, nodes_used = 0;
116 unsigned long start, end;
117 unsigned long bitfield = 0, memtop = 0;
119 for (i = 0; i < numnodes; i++) {
120 start = nodes[i].start;
121 end = nodes[i].end;
122 if (start >= end)
123 continue;
124 bitfield |= start;
125 nodes_used++;
126 if (end > memtop)
127 memtop = end;
129 if (nodes_used <= 1)
130 i = 63;
131 else
132 i = find_first_bit(&bitfield, sizeof(unsigned long)*8);
133 memnodemapsize = (memtop >> i)+1;
134 return i;
137 int __init compute_hash_shift(struct bootnode *nodes, int numnodes,
138 int *nodeids)
140 int shift;
142 shift = extract_lsb_from_nodes(nodes, numnodes);
143 if (allocate_cachealigned_memnodemap())
144 return -1;
145 printk(KERN_DEBUG "NUMA: Using %d for the hash shift.\n",
146 shift);
148 if (populate_memnodemap(nodes, numnodes, shift, nodeids) != 1) {
149 printk(KERN_INFO "Your memory is not aligned you need to "
150 "rebuild your kernel with a bigger NODEMAPSIZE "
151 "shift=%d\n", shift);
152 return -1;
154 return shift;
157 int __meminit __early_pfn_to_nid(unsigned long pfn)
159 return phys_to_nid(pfn << PAGE_SHIFT);
162 static void * __init early_node_mem(int nodeid, unsigned long start,
163 unsigned long end, unsigned long size,
164 unsigned long align)
166 unsigned long mem = find_e820_area(start, end, size, align);
167 void *ptr;
169 if (mem != -1L)
170 return __va(mem);
172 ptr = __alloc_bootmem_nopanic(size, align, __pa(MAX_DMA_ADDRESS));
173 if (ptr == NULL) {
174 printk(KERN_ERR "Cannot find %lu bytes in node %d\n",
175 size, nodeid);
176 return NULL;
178 return ptr;
181 /* Initialize bootmem allocator for a node */
182 void __init setup_node_bootmem(int nodeid, unsigned long start,
183 unsigned long end)
185 unsigned long start_pfn, last_pfn, bootmap_pages, bootmap_size;
186 unsigned long bootmap_start, nodedata_phys;
187 void *bootmap;
188 const int pgdat_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
189 int nid;
191 if (!end)
192 return;
194 start = roundup(start, ZONE_ALIGN);
196 printk(KERN_INFO "Bootmem setup node %d %016lx-%016lx\n", nodeid,
197 start, end);
199 start_pfn = start >> PAGE_SHIFT;
200 last_pfn = end >> PAGE_SHIFT;
202 node_data[nodeid] = early_node_mem(nodeid, start, end, pgdat_size,
203 SMP_CACHE_BYTES);
204 if (node_data[nodeid] == NULL)
205 return;
206 nodedata_phys = __pa(node_data[nodeid]);
207 printk(KERN_INFO " NODE_DATA [%016lx - %016lx]\n", nodedata_phys,
208 nodedata_phys + pgdat_size - 1);
210 memset(NODE_DATA(nodeid), 0, sizeof(pg_data_t));
211 NODE_DATA(nodeid)->bdata = &bootmem_node_data[nodeid];
212 NODE_DATA(nodeid)->node_start_pfn = start_pfn;
213 NODE_DATA(nodeid)->node_spanned_pages = last_pfn - start_pfn;
216 * Find a place for the bootmem map
217 * nodedata_phys could be on other nodes by alloc_bootmem,
218 * so need to sure bootmap_start not to be small, otherwise
219 * early_node_mem will get that with find_e820_area instead
220 * of alloc_bootmem, that could clash with reserved range
222 bootmap_pages = bootmem_bootmap_pages(last_pfn - start_pfn);
223 nid = phys_to_nid(nodedata_phys);
224 if (nid == nodeid)
225 bootmap_start = roundup(nodedata_phys + pgdat_size, PAGE_SIZE);
226 else
227 bootmap_start = roundup(start, PAGE_SIZE);
229 * SMP_CACHE_BYTES could be enough, but init_bootmem_node like
230 * to use that to align to PAGE_SIZE
232 bootmap = early_node_mem(nodeid, bootmap_start, end,
233 bootmap_pages<<PAGE_SHIFT, PAGE_SIZE);
234 if (bootmap == NULL) {
235 if (nodedata_phys < start || nodedata_phys >= end)
236 free_bootmem(nodedata_phys, pgdat_size);
237 node_data[nodeid] = NULL;
238 return;
240 bootmap_start = __pa(bootmap);
242 bootmap_size = init_bootmem_node(NODE_DATA(nodeid),
243 bootmap_start >> PAGE_SHIFT,
244 start_pfn, last_pfn);
246 printk(KERN_INFO " bootmap [%016lx - %016lx] pages %lx\n",
247 bootmap_start, bootmap_start + bootmap_size - 1,
248 bootmap_pages);
250 free_bootmem_with_active_regions(nodeid, end);
253 * convert early reserve to bootmem reserve earlier
254 * otherwise early_node_mem could use early reserved mem
255 * on previous node
257 early_res_to_bootmem(start, end);
260 * in some case early_node_mem could use alloc_bootmem
261 * to get range on other node, don't reserve that again
263 if (nid != nodeid)
264 printk(KERN_INFO " NODE_DATA(%d) on node %d\n", nodeid, nid);
265 else
266 reserve_bootmem_node(NODE_DATA(nodeid), nodedata_phys,
267 pgdat_size, BOOTMEM_DEFAULT);
268 nid = phys_to_nid(bootmap_start);
269 if (nid != nodeid)
270 printk(KERN_INFO " bootmap(%d) on node %d\n", nodeid, nid);
271 else
272 reserve_bootmem_node(NODE_DATA(nodeid), bootmap_start,
273 bootmap_pages<<PAGE_SHIFT, BOOTMEM_DEFAULT);
275 #ifdef CONFIG_ACPI_NUMA
276 srat_reserve_add_area(nodeid);
277 #endif
278 node_set_online(nodeid);
282 * There are unfortunately some poorly designed mainboards around that
283 * only connect memory to a single CPU. This breaks the 1:1 cpu->node
284 * mapping. To avoid this fill in the mapping for all possible CPUs,
285 * as the number of CPUs is not known yet. We round robin the existing
286 * nodes.
288 void __init numa_init_array(void)
290 int rr, i;
292 rr = first_node(node_online_map);
293 for (i = 0; i < nr_cpu_ids; i++) {
294 if (early_cpu_to_node(i) != NUMA_NO_NODE)
295 continue;
296 numa_set_node(i, rr);
297 rr = next_node(rr, node_online_map);
298 if (rr == MAX_NUMNODES)
299 rr = first_node(node_online_map);
303 #ifdef CONFIG_NUMA_EMU
304 /* Numa emulation */
305 static char *cmdline __initdata;
308 * Setups up nid to range from addr to addr + size. If the end
309 * boundary is greater than max_addr, then max_addr is used instead.
310 * The return value is 0 if there is additional memory left for
311 * allocation past addr and -1 otherwise. addr is adjusted to be at
312 * the end of the node.
314 static int __init setup_node_range(int nid, struct bootnode *nodes, u64 *addr,
315 u64 size, u64 max_addr)
317 int ret = 0;
319 nodes[nid].start = *addr;
320 *addr += size;
321 if (*addr >= max_addr) {
322 *addr = max_addr;
323 ret = -1;
325 nodes[nid].end = *addr;
326 node_set(nid, node_possible_map);
327 printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n", nid,
328 nodes[nid].start, nodes[nid].end,
329 (nodes[nid].end - nodes[nid].start) >> 20);
330 return ret;
334 * Splits num_nodes nodes up equally starting at node_start. The return value
335 * is the number of nodes split up and addr is adjusted to be at the end of the
336 * last node allocated.
338 static int __init split_nodes_equally(struct bootnode *nodes, u64 *addr,
339 u64 max_addr, int node_start,
340 int num_nodes)
342 unsigned int big;
343 u64 size;
344 int i;
346 if (num_nodes <= 0)
347 return -1;
348 if (num_nodes > MAX_NUMNODES)
349 num_nodes = MAX_NUMNODES;
350 size = (max_addr - *addr - e820_hole_size(*addr, max_addr)) /
351 num_nodes;
353 * Calculate the number of big nodes that can be allocated as a result
354 * of consolidating the leftovers.
356 big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * num_nodes) /
357 FAKE_NODE_MIN_SIZE;
359 /* Round down to nearest FAKE_NODE_MIN_SIZE. */
360 size &= FAKE_NODE_MIN_HASH_MASK;
361 if (!size) {
362 printk(KERN_ERR "Not enough memory for each node. "
363 "NUMA emulation disabled.\n");
364 return -1;
367 for (i = node_start; i < num_nodes + node_start; i++) {
368 u64 end = *addr + size;
370 if (i < big)
371 end += FAKE_NODE_MIN_SIZE;
373 * The final node can have the remaining system RAM. Other
374 * nodes receive roughly the same amount of available pages.
376 if (i == num_nodes + node_start - 1)
377 end = max_addr;
378 else
379 while (end - *addr - e820_hole_size(*addr, end) <
380 size) {
381 end += FAKE_NODE_MIN_SIZE;
382 if (end > max_addr) {
383 end = max_addr;
384 break;
387 if (setup_node_range(i, nodes, addr, end - *addr, max_addr) < 0)
388 break;
390 return i - node_start + 1;
394 * Splits the remaining system RAM into chunks of size. The remaining memory is
395 * always assigned to a final node and can be asymmetric. Returns the number of
396 * nodes split.
398 static int __init split_nodes_by_size(struct bootnode *nodes, u64 *addr,
399 u64 max_addr, int node_start, u64 size)
401 int i = node_start;
402 size = (size << 20) & FAKE_NODE_MIN_HASH_MASK;
403 while (!setup_node_range(i++, nodes, addr, size, max_addr))
405 return i - node_start;
409 * Sets up the system RAM area from start_pfn to last_pfn according to the
410 * numa=fake command-line option.
412 static struct bootnode nodes[MAX_NUMNODES] __initdata;
414 static int __init numa_emulation(unsigned long start_pfn, unsigned long last_pfn)
416 u64 size, addr = start_pfn << PAGE_SHIFT;
417 u64 max_addr = last_pfn << PAGE_SHIFT;
418 int num_nodes = 0, num = 0, coeff_flag, coeff = -1, i;
420 memset(&nodes, 0, sizeof(nodes));
422 * If the numa=fake command-line is just a single number N, split the
423 * system RAM into N fake nodes.
425 if (!strchr(cmdline, '*') && !strchr(cmdline, ',')) {
426 long n = simple_strtol(cmdline, NULL, 0);
428 num_nodes = split_nodes_equally(nodes, &addr, max_addr, 0, n);
429 if (num_nodes < 0)
430 return num_nodes;
431 goto out;
434 /* Parse the command line. */
435 for (coeff_flag = 0; ; cmdline++) {
436 if (*cmdline && isdigit(*cmdline)) {
437 num = num * 10 + *cmdline - '0';
438 continue;
440 if (*cmdline == '*') {
441 if (num > 0)
442 coeff = num;
443 coeff_flag = 1;
445 if (!*cmdline || *cmdline == ',') {
446 if (!coeff_flag)
447 coeff = 1;
449 * Round down to the nearest FAKE_NODE_MIN_SIZE.
450 * Command-line coefficients are in megabytes.
452 size = ((u64)num << 20) & FAKE_NODE_MIN_HASH_MASK;
453 if (size)
454 for (i = 0; i < coeff; i++, num_nodes++)
455 if (setup_node_range(num_nodes, nodes,
456 &addr, size, max_addr) < 0)
457 goto done;
458 if (!*cmdline)
459 break;
460 coeff_flag = 0;
461 coeff = -1;
463 num = 0;
465 done:
466 if (!num_nodes)
467 return -1;
468 /* Fill remainder of system RAM, if appropriate. */
469 if (addr < max_addr) {
470 if (coeff_flag && coeff < 0) {
471 /* Split remaining nodes into num-sized chunks */
472 num_nodes += split_nodes_by_size(nodes, &addr, max_addr,
473 num_nodes, num);
474 goto out;
476 switch (*(cmdline - 1)) {
477 case '*':
478 /* Split remaining nodes into coeff chunks */
479 if (coeff <= 0)
480 break;
481 num_nodes += split_nodes_equally(nodes, &addr, max_addr,
482 num_nodes, coeff);
483 break;
484 case ',':
485 /* Do not allocate remaining system RAM */
486 break;
487 default:
488 /* Give one final node */
489 setup_node_range(num_nodes, nodes, &addr,
490 max_addr - addr, max_addr);
491 num_nodes++;
494 out:
495 memnode_shift = compute_hash_shift(nodes, num_nodes, NULL);
496 if (memnode_shift < 0) {
497 memnode_shift = 0;
498 printk(KERN_ERR "No NUMA hash function found. NUMA emulation "
499 "disabled.\n");
500 return -1;
504 * We need to vacate all active ranges that may have been registered by
505 * SRAT and set acpi_numa to -1 so that srat_disabled() always returns
506 * true. NUMA emulation has succeeded so we will not scan ACPI nodes.
508 remove_all_active_ranges();
509 #ifdef CONFIG_ACPI_NUMA
510 acpi_numa = -1;
511 #endif
512 for_each_node_mask(i, node_possible_map) {
513 e820_register_active_regions(i, nodes[i].start >> PAGE_SHIFT,
514 nodes[i].end >> PAGE_SHIFT);
515 setup_node_bootmem(i, nodes[i].start, nodes[i].end);
517 acpi_fake_nodes(nodes, num_nodes);
518 numa_init_array();
519 return 0;
521 #endif /* CONFIG_NUMA_EMU */
523 void __init initmem_init(unsigned long start_pfn, unsigned long last_pfn)
525 int i;
527 nodes_clear(node_possible_map);
528 nodes_clear(node_online_map);
530 #ifdef CONFIG_NUMA_EMU
531 if (cmdline && !numa_emulation(start_pfn, last_pfn))
532 return;
533 nodes_clear(node_possible_map);
534 nodes_clear(node_online_map);
535 #endif
537 #ifdef CONFIG_ACPI_NUMA
538 if (!numa_off && !acpi_scan_nodes(start_pfn << PAGE_SHIFT,
539 last_pfn << PAGE_SHIFT))
540 return;
541 nodes_clear(node_possible_map);
542 nodes_clear(node_online_map);
543 #endif
545 #ifdef CONFIG_K8_NUMA
546 if (!numa_off && !k8_scan_nodes(start_pfn<<PAGE_SHIFT,
547 last_pfn<<PAGE_SHIFT))
548 return;
549 nodes_clear(node_possible_map);
550 nodes_clear(node_online_map);
551 #endif
552 printk(KERN_INFO "%s\n",
553 numa_off ? "NUMA turned off" : "No NUMA configuration found");
555 printk(KERN_INFO "Faking a node at %016lx-%016lx\n",
556 start_pfn << PAGE_SHIFT,
557 last_pfn << PAGE_SHIFT);
558 /* setup dummy node covering all memory */
559 memnode_shift = 63;
560 memnodemap = memnode.embedded_map;
561 memnodemap[0] = 0;
562 node_set_online(0);
563 node_set(0, node_possible_map);
564 for (i = 0; i < nr_cpu_ids; i++)
565 numa_set_node(i, 0);
566 e820_register_active_regions(0, start_pfn, last_pfn);
567 setup_node_bootmem(0, start_pfn << PAGE_SHIFT, last_pfn << PAGE_SHIFT);
570 unsigned long __init numa_free_all_bootmem(void)
572 unsigned long pages = 0;
573 int i;
575 for_each_online_node(i)
576 pages += free_all_bootmem_node(NODE_DATA(i));
578 return pages;
581 static __init int numa_setup(char *opt)
583 if (!opt)
584 return -EINVAL;
585 if (!strncmp(opt, "off", 3))
586 numa_off = 1;
587 #ifdef CONFIG_NUMA_EMU
588 if (!strncmp(opt, "fake=", 5))
589 cmdline = opt + 5;
590 #endif
591 #ifdef CONFIG_ACPI_NUMA
592 if (!strncmp(opt, "noacpi", 6))
593 acpi_numa = -1;
594 if (!strncmp(opt, "hotadd=", 7))
595 hotadd_percent = simple_strtoul(opt+7, NULL, 10);
596 #endif
597 return 0;
599 early_param("numa", numa_setup);
601 #ifdef CONFIG_NUMA
603 * Setup early cpu_to_node.
605 * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
606 * and apicid_to_node[] tables have valid entries for a CPU.
607 * This means we skip cpu_to_node[] initialisation for NUMA
608 * emulation and faking node case (when running a kernel compiled
609 * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
610 * is already initialized in a round robin manner at numa_init_array,
611 * prior to this call, and this initialization is good enough
612 * for the fake NUMA cases.
614 * Called before the per_cpu areas are setup.
616 void __init init_cpu_to_node(void)
618 int cpu;
619 u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
621 BUG_ON(cpu_to_apicid == NULL);
623 for_each_possible_cpu(cpu) {
624 int node;
625 u16 apicid = cpu_to_apicid[cpu];
627 if (apicid == BAD_APICID)
628 continue;
629 node = apicid_to_node[apicid];
630 if (node == NUMA_NO_NODE)
631 continue;
632 if (!node_online(node))
633 continue;
634 numa_set_node(cpu, node);
637 #endif
640 void __cpuinit numa_set_node(int cpu, int node)
642 int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
644 /* early setting, no percpu area yet */
645 if (cpu_to_node_map) {
646 cpu_to_node_map[cpu] = node;
647 return;
650 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
651 if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
652 printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
653 dump_stack();
654 return;
656 #endif
657 per_cpu(x86_cpu_to_node_map, cpu) = node;
659 if (node != NUMA_NO_NODE)
660 per_cpu(node_number, cpu) = node;
663 void __cpuinit numa_clear_node(int cpu)
665 numa_set_node(cpu, NUMA_NO_NODE);
668 #ifndef CONFIG_DEBUG_PER_CPU_MAPS
670 void __cpuinit numa_add_cpu(int cpu)
672 cpumask_set_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
675 void __cpuinit numa_remove_cpu(int cpu)
677 cpumask_clear_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
680 #else /* CONFIG_DEBUG_PER_CPU_MAPS */
683 * --------- debug versions of the numa functions ---------
685 static void __cpuinit numa_set_cpumask(int cpu, int enable)
687 int node = early_cpu_to_node(cpu);
688 struct cpumask *mask;
689 char buf[64];
691 mask = node_to_cpumask_map[node];
692 if (mask == NULL) {
693 printk(KERN_ERR "node_to_cpumask_map[%i] NULL\n", node);
694 dump_stack();
695 return;
698 if (enable)
699 cpumask_set_cpu(cpu, mask);
700 else
701 cpumask_clear_cpu(cpu, mask);
703 cpulist_scnprintf(buf, sizeof(buf), mask);
704 printk(KERN_DEBUG "%s cpu %d node %d: mask now %s\n",
705 enable ? "numa_add_cpu" : "numa_remove_cpu", cpu, node, buf);
708 void __cpuinit numa_add_cpu(int cpu)
710 numa_set_cpumask(cpu, 1);
713 void __cpuinit numa_remove_cpu(int cpu)
715 numa_set_cpumask(cpu, 0);
718 int cpu_to_node(int cpu)
720 if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
721 printk(KERN_WARNING
722 "cpu_to_node(%d): usage too early!\n", cpu);
723 dump_stack();
724 return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
726 return per_cpu(x86_cpu_to_node_map, cpu);
728 EXPORT_SYMBOL(cpu_to_node);
731 * Same function as cpu_to_node() but used if called before the
732 * per_cpu areas are setup.
734 int early_cpu_to_node(int cpu)
736 if (early_per_cpu_ptr(x86_cpu_to_node_map))
737 return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
739 if (!cpu_possible(cpu)) {
740 printk(KERN_WARNING
741 "early_cpu_to_node(%d): no per_cpu area!\n", cpu);
742 dump_stack();
743 return NUMA_NO_NODE;
745 return per_cpu(x86_cpu_to_node_map, cpu);
749 * --------- end of debug versions of the numa functions ---------
752 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */