x86, apic: Don't use logical-flat mode when CPU hotplug may exceed 8 CPUs
[linux-2.6/mini2440.git] / arch / x86 / mm / numa_64.c
blob459913beac71dc0539a4f0bd11a299df869e5711
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
183 setup_node_bootmem(int nodeid, unsigned long start, unsigned long end)
185 unsigned long start_pfn, last_pfn, bootmap_pages, bootmap_size;
186 const int pgdat_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
187 unsigned long bootmap_start, nodedata_phys;
188 void *bootmap;
189 int nid;
191 if (!end)
192 return;
195 * Don't confuse VM with a node that doesn't have the
196 * minimum amount of memory:
198 if (end && (end - start) < NODE_MIN_SIZE)
199 return;
201 start = roundup(start, ZONE_ALIGN);
203 printk(KERN_INFO "Bootmem setup node %d %016lx-%016lx\n", nodeid,
204 start, end);
206 start_pfn = start >> PAGE_SHIFT;
207 last_pfn = end >> PAGE_SHIFT;
209 node_data[nodeid] = early_node_mem(nodeid, start, end, pgdat_size,
210 SMP_CACHE_BYTES);
211 if (node_data[nodeid] == NULL)
212 return;
213 nodedata_phys = __pa(node_data[nodeid]);
214 printk(KERN_INFO " NODE_DATA [%016lx - %016lx]\n", nodedata_phys,
215 nodedata_phys + pgdat_size - 1);
217 memset(NODE_DATA(nodeid), 0, sizeof(pg_data_t));
218 NODE_DATA(nodeid)->bdata = &bootmem_node_data[nodeid];
219 NODE_DATA(nodeid)->node_start_pfn = start_pfn;
220 NODE_DATA(nodeid)->node_spanned_pages = last_pfn - start_pfn;
223 * Find a place for the bootmem map
224 * nodedata_phys could be on other nodes by alloc_bootmem,
225 * so need to sure bootmap_start not to be small, otherwise
226 * early_node_mem will get that with find_e820_area instead
227 * of alloc_bootmem, that could clash with reserved range
229 bootmap_pages = bootmem_bootmap_pages(last_pfn - start_pfn);
230 nid = phys_to_nid(nodedata_phys);
231 if (nid == nodeid)
232 bootmap_start = roundup(nodedata_phys + pgdat_size, PAGE_SIZE);
233 else
234 bootmap_start = roundup(start, PAGE_SIZE);
236 * SMP_CACHE_BYTES could be enough, but init_bootmem_node like
237 * to use that to align to PAGE_SIZE
239 bootmap = early_node_mem(nodeid, bootmap_start, end,
240 bootmap_pages<<PAGE_SHIFT, PAGE_SIZE);
241 if (bootmap == NULL) {
242 if (nodedata_phys < start || nodedata_phys >= end)
243 free_bootmem(nodedata_phys, pgdat_size);
244 node_data[nodeid] = NULL;
245 return;
247 bootmap_start = __pa(bootmap);
249 bootmap_size = init_bootmem_node(NODE_DATA(nodeid),
250 bootmap_start >> PAGE_SHIFT,
251 start_pfn, last_pfn);
253 printk(KERN_INFO " bootmap [%016lx - %016lx] pages %lx\n",
254 bootmap_start, bootmap_start + bootmap_size - 1,
255 bootmap_pages);
257 free_bootmem_with_active_regions(nodeid, end);
260 * convert early reserve to bootmem reserve earlier
261 * otherwise early_node_mem could use early reserved mem
262 * on previous node
264 early_res_to_bootmem(start, end);
267 * in some case early_node_mem could use alloc_bootmem
268 * to get range on other node, don't reserve that again
270 if (nid != nodeid)
271 printk(KERN_INFO " NODE_DATA(%d) on node %d\n", nodeid, nid);
272 else
273 reserve_bootmem_node(NODE_DATA(nodeid), nodedata_phys,
274 pgdat_size, BOOTMEM_DEFAULT);
275 nid = phys_to_nid(bootmap_start);
276 if (nid != nodeid)
277 printk(KERN_INFO " bootmap(%d) on node %d\n", nodeid, nid);
278 else
279 reserve_bootmem_node(NODE_DATA(nodeid), bootmap_start,
280 bootmap_pages<<PAGE_SHIFT, BOOTMEM_DEFAULT);
282 node_set_online(nodeid);
286 * There are unfortunately some poorly designed mainboards around that
287 * only connect memory to a single CPU. This breaks the 1:1 cpu->node
288 * mapping. To avoid this fill in the mapping for all possible CPUs,
289 * as the number of CPUs is not known yet. We round robin the existing
290 * nodes.
292 void __init numa_init_array(void)
294 int rr, i;
296 rr = first_node(node_online_map);
297 for (i = 0; i < nr_cpu_ids; i++) {
298 if (early_cpu_to_node(i) != NUMA_NO_NODE)
299 continue;
300 numa_set_node(i, rr);
301 rr = next_node(rr, node_online_map);
302 if (rr == MAX_NUMNODES)
303 rr = first_node(node_online_map);
307 #ifdef CONFIG_NUMA_EMU
308 /* Numa emulation */
309 static char *cmdline __initdata;
312 * Setups up nid to range from addr to addr + size. If the end
313 * boundary is greater than max_addr, then max_addr is used instead.
314 * The return value is 0 if there is additional memory left for
315 * allocation past addr and -1 otherwise. addr is adjusted to be at
316 * the end of the node.
318 static int __init setup_node_range(int nid, struct bootnode *nodes, u64 *addr,
319 u64 size, u64 max_addr)
321 int ret = 0;
323 nodes[nid].start = *addr;
324 *addr += size;
325 if (*addr >= max_addr) {
326 *addr = max_addr;
327 ret = -1;
329 nodes[nid].end = *addr;
330 node_set(nid, node_possible_map);
331 printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n", nid,
332 nodes[nid].start, nodes[nid].end,
333 (nodes[nid].end - nodes[nid].start) >> 20);
334 return ret;
338 * Splits num_nodes nodes up equally starting at node_start. The return value
339 * is the number of nodes split up and addr is adjusted to be at the end of the
340 * last node allocated.
342 static int __init split_nodes_equally(struct bootnode *nodes, u64 *addr,
343 u64 max_addr, int node_start,
344 int num_nodes)
346 unsigned int big;
347 u64 size;
348 int i;
350 if (num_nodes <= 0)
351 return -1;
352 if (num_nodes > MAX_NUMNODES)
353 num_nodes = MAX_NUMNODES;
354 size = (max_addr - *addr - e820_hole_size(*addr, max_addr)) /
355 num_nodes;
357 * Calculate the number of big nodes that can be allocated as a result
358 * of consolidating the leftovers.
360 big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * num_nodes) /
361 FAKE_NODE_MIN_SIZE;
363 /* Round down to nearest FAKE_NODE_MIN_SIZE. */
364 size &= FAKE_NODE_MIN_HASH_MASK;
365 if (!size) {
366 printk(KERN_ERR "Not enough memory for each node. "
367 "NUMA emulation disabled.\n");
368 return -1;
371 for (i = node_start; i < num_nodes + node_start; i++) {
372 u64 end = *addr + size;
374 if (i < big)
375 end += FAKE_NODE_MIN_SIZE;
377 * The final node can have the remaining system RAM. Other
378 * nodes receive roughly the same amount of available pages.
380 if (i == num_nodes + node_start - 1)
381 end = max_addr;
382 else
383 while (end - *addr - e820_hole_size(*addr, end) <
384 size) {
385 end += FAKE_NODE_MIN_SIZE;
386 if (end > max_addr) {
387 end = max_addr;
388 break;
391 if (setup_node_range(i, nodes, addr, end - *addr, max_addr) < 0)
392 break;
394 return i - node_start + 1;
398 * Splits the remaining system RAM into chunks of size. The remaining memory is
399 * always assigned to a final node and can be asymmetric. Returns the number of
400 * nodes split.
402 static int __init split_nodes_by_size(struct bootnode *nodes, u64 *addr,
403 u64 max_addr, int node_start, u64 size)
405 int i = node_start;
406 size = (size << 20) & FAKE_NODE_MIN_HASH_MASK;
407 while (!setup_node_range(i++, nodes, addr, size, max_addr))
409 return i - node_start;
413 * Sets up the system RAM area from start_pfn to last_pfn according to the
414 * numa=fake command-line option.
416 static struct bootnode nodes[MAX_NUMNODES] __initdata;
418 static int __init numa_emulation(unsigned long start_pfn, unsigned long last_pfn)
420 u64 size, addr = start_pfn << PAGE_SHIFT;
421 u64 max_addr = last_pfn << PAGE_SHIFT;
422 int num_nodes = 0, num = 0, coeff_flag, coeff = -1, i;
424 memset(&nodes, 0, sizeof(nodes));
426 * If the numa=fake command-line is just a single number N, split the
427 * system RAM into N fake nodes.
429 if (!strchr(cmdline, '*') && !strchr(cmdline, ',')) {
430 long n = simple_strtol(cmdline, NULL, 0);
432 num_nodes = split_nodes_equally(nodes, &addr, max_addr, 0, n);
433 if (num_nodes < 0)
434 return num_nodes;
435 goto out;
438 /* Parse the command line. */
439 for (coeff_flag = 0; ; cmdline++) {
440 if (*cmdline && isdigit(*cmdline)) {
441 num = num * 10 + *cmdline - '0';
442 continue;
444 if (*cmdline == '*') {
445 if (num > 0)
446 coeff = num;
447 coeff_flag = 1;
449 if (!*cmdline || *cmdline == ',') {
450 if (!coeff_flag)
451 coeff = 1;
453 * Round down to the nearest FAKE_NODE_MIN_SIZE.
454 * Command-line coefficients are in megabytes.
456 size = ((u64)num << 20) & FAKE_NODE_MIN_HASH_MASK;
457 if (size)
458 for (i = 0; i < coeff; i++, num_nodes++)
459 if (setup_node_range(num_nodes, nodes,
460 &addr, size, max_addr) < 0)
461 goto done;
462 if (!*cmdline)
463 break;
464 coeff_flag = 0;
465 coeff = -1;
467 num = 0;
469 done:
470 if (!num_nodes)
471 return -1;
472 /* Fill remainder of system RAM, if appropriate. */
473 if (addr < max_addr) {
474 if (coeff_flag && coeff < 0) {
475 /* Split remaining nodes into num-sized chunks */
476 num_nodes += split_nodes_by_size(nodes, &addr, max_addr,
477 num_nodes, num);
478 goto out;
480 switch (*(cmdline - 1)) {
481 case '*':
482 /* Split remaining nodes into coeff chunks */
483 if (coeff <= 0)
484 break;
485 num_nodes += split_nodes_equally(nodes, &addr, max_addr,
486 num_nodes, coeff);
487 break;
488 case ',':
489 /* Do not allocate remaining system RAM */
490 break;
491 default:
492 /* Give one final node */
493 setup_node_range(num_nodes, nodes, &addr,
494 max_addr - addr, max_addr);
495 num_nodes++;
498 out:
499 memnode_shift = compute_hash_shift(nodes, num_nodes, NULL);
500 if (memnode_shift < 0) {
501 memnode_shift = 0;
502 printk(KERN_ERR "No NUMA hash function found. NUMA emulation "
503 "disabled.\n");
504 return -1;
508 * We need to vacate all active ranges that may have been registered by
509 * SRAT and set acpi_numa to -1 so that srat_disabled() always returns
510 * true. NUMA emulation has succeeded so we will not scan ACPI nodes.
512 remove_all_active_ranges();
513 #ifdef CONFIG_ACPI_NUMA
514 acpi_numa = -1;
515 #endif
516 for_each_node_mask(i, node_possible_map) {
517 e820_register_active_regions(i, nodes[i].start >> PAGE_SHIFT,
518 nodes[i].end >> PAGE_SHIFT);
519 setup_node_bootmem(i, nodes[i].start, nodes[i].end);
521 acpi_fake_nodes(nodes, num_nodes);
522 numa_init_array();
523 return 0;
525 #endif /* CONFIG_NUMA_EMU */
527 void __init initmem_init(unsigned long start_pfn, unsigned long last_pfn)
529 int i;
531 nodes_clear(node_possible_map);
532 nodes_clear(node_online_map);
534 #ifdef CONFIG_NUMA_EMU
535 if (cmdline && !numa_emulation(start_pfn, last_pfn))
536 return;
537 nodes_clear(node_possible_map);
538 nodes_clear(node_online_map);
539 #endif
541 #ifdef CONFIG_ACPI_NUMA
542 if (!numa_off && !acpi_scan_nodes(start_pfn << PAGE_SHIFT,
543 last_pfn << PAGE_SHIFT))
544 return;
545 nodes_clear(node_possible_map);
546 nodes_clear(node_online_map);
547 #endif
549 #ifdef CONFIG_K8_NUMA
550 if (!numa_off && !k8_scan_nodes(start_pfn<<PAGE_SHIFT,
551 last_pfn<<PAGE_SHIFT))
552 return;
553 nodes_clear(node_possible_map);
554 nodes_clear(node_online_map);
555 #endif
556 printk(KERN_INFO "%s\n",
557 numa_off ? "NUMA turned off" : "No NUMA configuration found");
559 printk(KERN_INFO "Faking a node at %016lx-%016lx\n",
560 start_pfn << PAGE_SHIFT,
561 last_pfn << PAGE_SHIFT);
562 /* setup dummy node covering all memory */
563 memnode_shift = 63;
564 memnodemap = memnode.embedded_map;
565 memnodemap[0] = 0;
566 node_set_online(0);
567 node_set(0, node_possible_map);
568 for (i = 0; i < nr_cpu_ids; i++)
569 numa_set_node(i, 0);
570 e820_register_active_regions(0, start_pfn, last_pfn);
571 setup_node_bootmem(0, start_pfn << PAGE_SHIFT, last_pfn << PAGE_SHIFT);
574 unsigned long __init numa_free_all_bootmem(void)
576 unsigned long pages = 0;
577 int i;
579 for_each_online_node(i)
580 pages += free_all_bootmem_node(NODE_DATA(i));
582 return pages;
585 static __init int numa_setup(char *opt)
587 if (!opt)
588 return -EINVAL;
589 if (!strncmp(opt, "off", 3))
590 numa_off = 1;
591 #ifdef CONFIG_NUMA_EMU
592 if (!strncmp(opt, "fake=", 5))
593 cmdline = opt + 5;
594 #endif
595 #ifdef CONFIG_ACPI_NUMA
596 if (!strncmp(opt, "noacpi", 6))
597 acpi_numa = -1;
598 #endif
599 return 0;
601 early_param("numa", numa_setup);
603 #ifdef CONFIG_NUMA
605 * Setup early cpu_to_node.
607 * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
608 * and apicid_to_node[] tables have valid entries for a CPU.
609 * This means we skip cpu_to_node[] initialisation for NUMA
610 * emulation and faking node case (when running a kernel compiled
611 * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
612 * is already initialized in a round robin manner at numa_init_array,
613 * prior to this call, and this initialization is good enough
614 * for the fake NUMA cases.
616 * Called before the per_cpu areas are setup.
618 void __init init_cpu_to_node(void)
620 int cpu;
621 u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
623 BUG_ON(cpu_to_apicid == NULL);
625 for_each_possible_cpu(cpu) {
626 int node;
627 u16 apicid = cpu_to_apicid[cpu];
629 if (apicid == BAD_APICID)
630 continue;
631 node = apicid_to_node[apicid];
632 if (node == NUMA_NO_NODE)
633 continue;
634 if (!node_online(node))
635 continue;
636 numa_set_node(cpu, node);
639 #endif
642 void __cpuinit numa_set_node(int cpu, int node)
644 int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
646 /* early setting, no percpu area yet */
647 if (cpu_to_node_map) {
648 cpu_to_node_map[cpu] = node;
649 return;
652 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
653 if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
654 printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
655 dump_stack();
656 return;
658 #endif
659 per_cpu(x86_cpu_to_node_map, cpu) = node;
661 if (node != NUMA_NO_NODE)
662 per_cpu(node_number, cpu) = node;
665 void __cpuinit numa_clear_node(int cpu)
667 numa_set_node(cpu, NUMA_NO_NODE);
670 #ifndef CONFIG_DEBUG_PER_CPU_MAPS
672 void __cpuinit numa_add_cpu(int cpu)
674 cpumask_set_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
677 void __cpuinit numa_remove_cpu(int cpu)
679 cpumask_clear_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
682 #else /* CONFIG_DEBUG_PER_CPU_MAPS */
685 * --------- debug versions of the numa functions ---------
687 static void __cpuinit numa_set_cpumask(int cpu, int enable)
689 int node = early_cpu_to_node(cpu);
690 struct cpumask *mask;
691 char buf[64];
693 mask = node_to_cpumask_map[node];
694 if (mask == NULL) {
695 printk(KERN_ERR "node_to_cpumask_map[%i] NULL\n", node);
696 dump_stack();
697 return;
700 if (enable)
701 cpumask_set_cpu(cpu, mask);
702 else
703 cpumask_clear_cpu(cpu, mask);
705 cpulist_scnprintf(buf, sizeof(buf), mask);
706 printk(KERN_DEBUG "%s cpu %d node %d: mask now %s\n",
707 enable ? "numa_add_cpu" : "numa_remove_cpu", cpu, node, buf);
710 void __cpuinit numa_add_cpu(int cpu)
712 numa_set_cpumask(cpu, 1);
715 void __cpuinit numa_remove_cpu(int cpu)
717 numa_set_cpumask(cpu, 0);
720 int cpu_to_node(int cpu)
722 if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
723 printk(KERN_WARNING
724 "cpu_to_node(%d): usage too early!\n", cpu);
725 dump_stack();
726 return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
728 return per_cpu(x86_cpu_to_node_map, cpu);
730 EXPORT_SYMBOL(cpu_to_node);
733 * Same function as cpu_to_node() but used if called before the
734 * per_cpu areas are setup.
736 int early_cpu_to_node(int cpu)
738 if (early_per_cpu_ptr(x86_cpu_to_node_map))
739 return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
741 if (!cpu_possible(cpu)) {
742 printk(KERN_WARNING
743 "early_cpu_to_node(%d): no per_cpu area!\n", cpu);
744 dump_stack();
745 return NUMA_NO_NODE;
747 return per_cpu(x86_cpu_to_node_map, cpu);
751 * --------- end of debug versions of the numa functions ---------
754 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */