2 * Generic VM initialization for x86-64 NUMA setups.
3 * Copyright 2002,2003 Andi Kleen, SuSE Labs.
5 #include <linux/kernel.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>
17 #include <asm/proto.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;
37 * Map cpu index to node index
39 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
40 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
43 * Given a shift value, try to populate memnodemap[]
46 * 0 if memnodmap[] too small (of shift too small)
47 * -1 if node overlap or lost ram (shift too big)
49 static int __init populate_memnodemap(const struct bootnode *nodes,
50 int numnodes, int shift, int *nodeids)
52 unsigned long addr, end;
55 memset(memnodemap, 0xff, sizeof(s16)*memnodemapsize);
56 for (i = 0; i < numnodes; i++) {
57 addr = nodes[i].start;
61 if ((end >> shift) >= memnodemapsize)
64 if (memnodemap[addr >> shift] != NUMA_NO_NODE)
68 memnodemap[addr >> shift] = i;
70 memnodemap[addr >> shift] = nodeids[i];
72 addr += (1UL << shift);
79 static int __init allocate_cachealigned_memnodemap(void)
83 memnodemap = memnode.embedded_map;
84 if (memnodemapsize <= ARRAY_SIZE(memnode.embedded_map))
88 nodemap_size = roundup(sizeof(s16) * memnodemapsize, L1_CACHE_BYTES);
89 nodemap_addr = find_e820_area(addr, max_pfn<<PAGE_SHIFT,
90 nodemap_size, L1_CACHE_BYTES);
91 if (nodemap_addr == -1UL) {
93 "NUMA: Unable to allocate Memory to Node hash map\n");
94 nodemap_addr = nodemap_size = 0;
97 memnodemap = phys_to_virt(nodemap_addr);
98 reserve_early(nodemap_addr, nodemap_addr + nodemap_size, "MEMNODEMAP");
100 printk(KERN_DEBUG "NUMA: Allocated memnodemap from %lx - %lx\n",
101 nodemap_addr, nodemap_addr + nodemap_size);
106 * The LSB of all start and end addresses in the node map is the value of the
107 * maximum possible shift.
109 static int __init extract_lsb_from_nodes(const struct bootnode *nodes,
112 int i, nodes_used = 0;
113 unsigned long start, end;
114 unsigned long bitfield = 0, memtop = 0;
116 for (i = 0; i < numnodes; i++) {
117 start = nodes[i].start;
129 i = find_first_bit(&bitfield, sizeof(unsigned long)*8);
130 memnodemapsize = (memtop >> i)+1;
134 int __init compute_hash_shift(struct bootnode *nodes, int numnodes,
139 shift = extract_lsb_from_nodes(nodes, numnodes);
140 if (allocate_cachealigned_memnodemap())
142 printk(KERN_DEBUG "NUMA: Using %d for the hash shift.\n",
145 if (populate_memnodemap(nodes, numnodes, shift, nodeids) != 1) {
146 printk(KERN_INFO "Your memory is not aligned you need to "
147 "rebuild your kernel with a bigger NODEMAPSIZE "
148 "shift=%d\n", shift);
154 int __meminit __early_pfn_to_nid(unsigned long pfn)
156 return phys_to_nid(pfn << PAGE_SHIFT);
159 static void * __init early_node_mem(int nodeid, unsigned long start,
160 unsigned long end, unsigned long size,
166 * put it on high as possible
167 * something will go with NODE_DATA
169 if (start < (MAX_DMA_PFN<<PAGE_SHIFT))
170 start = MAX_DMA_PFN<<PAGE_SHIFT;
171 if (start < (MAX_DMA32_PFN<<PAGE_SHIFT) &&
172 end > (MAX_DMA32_PFN<<PAGE_SHIFT))
173 start = MAX_DMA32_PFN<<PAGE_SHIFT;
174 mem = find_e820_area(start, end, size, align);
178 /* extend the search scope */
179 end = max_pfn_mapped << PAGE_SHIFT;
180 if (end > (MAX_DMA32_PFN<<PAGE_SHIFT))
181 start = MAX_DMA32_PFN<<PAGE_SHIFT;
183 start = MAX_DMA_PFN<<PAGE_SHIFT;
184 mem = find_e820_area(start, end, size, align);
188 printk(KERN_ERR "Cannot find %lu bytes in node %d\n",
194 /* Initialize bootmem allocator for a node */
196 setup_node_bootmem(int nodeid, unsigned long start, unsigned long end)
198 unsigned long start_pfn, last_pfn, nodedata_phys;
199 const int pgdat_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
201 #ifndef CONFIG_NO_BOOTMEM
202 unsigned long bootmap_start, bootmap_pages, bootmap_size;
210 * Don't confuse VM with a node that doesn't have the
211 * minimum amount of memory:
213 if (end && (end - start) < NODE_MIN_SIZE)
216 start = roundup(start, ZONE_ALIGN);
218 printk(KERN_INFO "Initmem setup node %d %016lx-%016lx\n", nodeid,
221 start_pfn = start >> PAGE_SHIFT;
222 last_pfn = end >> PAGE_SHIFT;
224 node_data[nodeid] = early_node_mem(nodeid, start, end, pgdat_size,
226 if (node_data[nodeid] == NULL)
228 nodedata_phys = __pa(node_data[nodeid]);
229 reserve_early(nodedata_phys, nodedata_phys + pgdat_size, "NODE_DATA");
230 printk(KERN_INFO " NODE_DATA [%016lx - %016lx]\n", nodedata_phys,
231 nodedata_phys + pgdat_size - 1);
232 nid = phys_to_nid(nodedata_phys);
234 printk(KERN_INFO " NODE_DATA(%d) on node %d\n", nodeid, nid);
236 memset(NODE_DATA(nodeid), 0, sizeof(pg_data_t));
237 NODE_DATA(nodeid)->node_id = nodeid;
238 NODE_DATA(nodeid)->node_start_pfn = start_pfn;
239 NODE_DATA(nodeid)->node_spanned_pages = last_pfn - start_pfn;
241 #ifndef CONFIG_NO_BOOTMEM
242 NODE_DATA(nodeid)->bdata = &bootmem_node_data[nodeid];
245 * Find a place for the bootmem map
246 * nodedata_phys could be on other nodes by alloc_bootmem,
247 * so need to sure bootmap_start not to be small, otherwise
248 * early_node_mem will get that with find_e820_area instead
249 * of alloc_bootmem, that could clash with reserved range
251 bootmap_pages = bootmem_bootmap_pages(last_pfn - start_pfn);
252 bootmap_start = roundup(nodedata_phys + pgdat_size, PAGE_SIZE);
254 * SMP_CACHE_BYTES could be enough, but init_bootmem_node like
255 * to use that to align to PAGE_SIZE
257 bootmap = early_node_mem(nodeid, bootmap_start, end,
258 bootmap_pages<<PAGE_SHIFT, PAGE_SIZE);
259 if (bootmap == NULL) {
260 free_early(nodedata_phys, nodedata_phys + pgdat_size);
261 node_data[nodeid] = NULL;
264 bootmap_start = __pa(bootmap);
265 reserve_early(bootmap_start, bootmap_start+(bootmap_pages<<PAGE_SHIFT),
268 bootmap_size = init_bootmem_node(NODE_DATA(nodeid),
269 bootmap_start >> PAGE_SHIFT,
270 start_pfn, last_pfn);
272 printk(KERN_INFO " bootmap [%016lx - %016lx] pages %lx\n",
273 bootmap_start, bootmap_start + bootmap_size - 1,
275 nid = phys_to_nid(bootmap_start);
277 printk(KERN_INFO " bootmap(%d) on node %d\n", nodeid, nid);
279 free_bootmem_with_active_regions(nodeid, end);
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
292 void __init numa_init_array(void)
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)
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
309 static struct bootnode nodes[MAX_NUMNODES] __initdata;
310 static struct bootnode physnodes[MAX_NUMNODES] __initdata;
311 static char *cmdline __initdata;
313 static int __init setup_physnodes(unsigned long start, unsigned long end,
320 #ifdef CONFIG_ACPI_NUMA
322 nr_nodes = acpi_get_nodes(physnodes);
324 #ifdef CONFIG_K8_NUMA
326 nr_nodes = k8_get_nodes(physnodes);
329 * Basic sanity checking on the physical node map: there may be errors
330 * if the SRAT or K8 incorrectly reported the topology or the mem=
331 * kernel parameter is used.
333 for (i = 0; i < nr_nodes; i++) {
334 if (physnodes[i].start == physnodes[i].end)
336 if (physnodes[i].start > end) {
337 physnodes[i].end = physnodes[i].start;
340 if (physnodes[i].end < start) {
341 physnodes[i].start = physnodes[i].end;
344 if (physnodes[i].start < start)
345 physnodes[i].start = start;
346 if (physnodes[i].end > end)
347 physnodes[i].end = end;
351 * Remove all nodes that have no memory or were truncated because of the
352 * limited address range.
354 for (i = 0; i < nr_nodes; i++) {
355 if (physnodes[i].start == physnodes[i].end)
357 physnodes[ret].start = physnodes[i].start;
358 physnodes[ret].end = physnodes[i].end;
363 * If no physical topology was detected, a single node is faked to cover
364 * the entire address space.
367 physnodes[ret].start = start;
368 physnodes[ret].end = end;
375 * Setups up nid to range from addr to addr + size. If the end
376 * boundary is greater than max_addr, then max_addr is used instead.
377 * The return value is 0 if there is additional memory left for
378 * allocation past addr and -1 otherwise. addr is adjusted to be at
379 * the end of the node.
381 static int __init setup_node_range(int nid, u64 *addr, u64 size, u64 max_addr)
384 nodes[nid].start = *addr;
386 if (*addr >= max_addr) {
390 nodes[nid].end = *addr;
391 node_set(nid, node_possible_map);
392 printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n", nid,
393 nodes[nid].start, nodes[nid].end,
394 (nodes[nid].end - nodes[nid].start) >> 20);
399 * Sets up nr_nodes fake nodes interleaved over physical nodes ranging from addr
400 * to max_addr. The return value is the number of nodes allocated.
402 static int __init split_nodes_interleave(u64 addr, u64 max_addr,
403 int nr_phys_nodes, int nr_nodes)
405 nodemask_t physnode_mask = NODE_MASK_NONE;
413 if (nr_nodes > MAX_NUMNODES) {
414 pr_info("numa=fake=%d too large, reducing to %d\n",
415 nr_nodes, MAX_NUMNODES);
416 nr_nodes = MAX_NUMNODES;
419 size = (max_addr - addr - e820_hole_size(addr, max_addr)) / nr_nodes;
421 * Calculate the number of big nodes that can be allocated as a result
422 * of consolidating the remainder.
424 big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * nr_nodes) /
427 size &= FAKE_NODE_MIN_HASH_MASK;
429 pr_err("Not enough memory for each node. "
430 "NUMA emulation disabled.\n");
434 for (i = 0; i < nr_phys_nodes; i++)
435 if (physnodes[i].start != physnodes[i].end)
436 node_set(i, physnode_mask);
439 * Continue to fill physical nodes with fake nodes until there is no
440 * memory left on any of them.
442 while (nodes_weight(physnode_mask)) {
443 for_each_node_mask(i, physnode_mask) {
444 u64 end = physnodes[i].start + size;
445 u64 dma32_end = PFN_PHYS(MAX_DMA32_PFN);
448 end += FAKE_NODE_MIN_SIZE;
451 * Continue to add memory to this fake node if its
452 * non-reserved memory is less than the per-node size.
454 while (end - physnodes[i].start -
455 e820_hole_size(physnodes[i].start, end) < size) {
456 end += FAKE_NODE_MIN_SIZE;
457 if (end > physnodes[i].end) {
458 end = physnodes[i].end;
464 * If there won't be at least FAKE_NODE_MIN_SIZE of
465 * non-reserved memory in ZONE_DMA32 for the next node,
466 * this one must extend to the boundary.
468 if (end < dma32_end && dma32_end - end -
469 e820_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE)
473 * If there won't be enough non-reserved memory for the
474 * next node, this one must extend to the end of the
477 if (physnodes[i].end - end -
478 e820_hole_size(end, physnodes[i].end) < size)
479 end = physnodes[i].end;
482 * Avoid allocating more nodes than requested, which can
483 * happen as a result of rounding down each node's size
484 * to FAKE_NODE_MIN_SIZE.
486 if (nodes_weight(physnode_mask) + ret >= nr_nodes)
487 end = physnodes[i].end;
489 if (setup_node_range(ret++, &physnodes[i].start,
490 end - physnodes[i].start,
491 physnodes[i].end) < 0)
492 node_clear(i, physnode_mask);
499 * Returns the end address of a node so that there is at least `size' amount of
500 * non-reserved memory or `max_addr' is reached.
502 static u64 __init find_end_of_node(u64 start, u64 max_addr, u64 size)
504 u64 end = start + size;
506 while (end - start - e820_hole_size(start, end) < size) {
507 end += FAKE_NODE_MIN_SIZE;
508 if (end > max_addr) {
517 * Sets up fake nodes of `size' interleaved over physical nodes ranging from
518 * `addr' to `max_addr'. The return value is the number of nodes allocated.
520 static int __init split_nodes_size_interleave(u64 addr, u64 max_addr, u64 size)
522 nodemask_t physnode_mask = NODE_MASK_NONE;
530 * The limit on emulated nodes is MAX_NUMNODES, so the size per node is
531 * increased accordingly if the requested size is too small. This
532 * creates a uniform distribution of node sizes across the entire
533 * machine (but not necessarily over physical nodes).
535 min_size = (max_addr - addr - e820_hole_size(addr, max_addr)) /
537 min_size = max(min_size, FAKE_NODE_MIN_SIZE);
538 if ((min_size & FAKE_NODE_MIN_HASH_MASK) < min_size)
539 min_size = (min_size + FAKE_NODE_MIN_SIZE) &
540 FAKE_NODE_MIN_HASH_MASK;
541 if (size < min_size) {
542 pr_err("Fake node size %LuMB too small, increasing to %LuMB\n",
543 size >> 20, min_size >> 20);
546 size &= FAKE_NODE_MIN_HASH_MASK;
548 for (i = 0; i < MAX_NUMNODES; i++)
549 if (physnodes[i].start != physnodes[i].end)
550 node_set(i, physnode_mask);
552 * Fill physical nodes with fake nodes of size until there is no memory
553 * left on any of them.
555 while (nodes_weight(physnode_mask)) {
556 for_each_node_mask(i, physnode_mask) {
557 u64 dma32_end = MAX_DMA32_PFN << PAGE_SHIFT;
560 end = find_end_of_node(physnodes[i].start,
561 physnodes[i].end, size);
563 * If there won't be at least FAKE_NODE_MIN_SIZE of
564 * non-reserved memory in ZONE_DMA32 for the next node,
565 * this one must extend to the boundary.
567 if (end < dma32_end && dma32_end - end -
568 e820_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE)
572 * If there won't be enough non-reserved memory for the
573 * next node, this one must extend to the end of the
576 if (physnodes[i].end - end -
577 e820_hole_size(end, physnodes[i].end) < size)
578 end = physnodes[i].end;
581 * Setup the fake node that will be allocated as bootmem
582 * later. If setup_node_range() returns non-zero, there
583 * is no more memory available on this physical node.
585 if (setup_node_range(ret++, &physnodes[i].start,
586 end - physnodes[i].start,
587 physnodes[i].end) < 0)
588 node_clear(i, physnode_mask);
595 * Sets up the system RAM area from start_pfn to last_pfn according to the
596 * numa=fake command-line option.
598 static int __init numa_emulation(unsigned long start_pfn,
599 unsigned long last_pfn, int acpi, int k8)
601 u64 addr = start_pfn << PAGE_SHIFT;
602 u64 max_addr = last_pfn << PAGE_SHIFT;
607 num_phys_nodes = setup_physnodes(addr, max_addr, acpi, k8);
609 * If the numa=fake command-line contains a 'M' or 'G', it represents
610 * the fixed node size. Otherwise, if it is just a single number N,
611 * split the system RAM into N fake nodes.
613 if (strchr(cmdline, 'M') || strchr(cmdline, 'G')) {
616 size = memparse(cmdline, &cmdline);
617 num_nodes = split_nodes_size_interleave(addr, max_addr, size);
621 n = simple_strtoul(cmdline, NULL, 0);
622 num_nodes = split_nodes_interleave(addr, max_addr, num_phys_nodes, n);
627 memnode_shift = compute_hash_shift(nodes, num_nodes, NULL);
628 if (memnode_shift < 0) {
630 printk(KERN_ERR "No NUMA hash function found. NUMA emulation "
636 * We need to vacate all active ranges that may have been registered for
637 * the e820 memory map.
639 remove_all_active_ranges();
640 for_each_node_mask(i, node_possible_map) {
641 e820_register_active_regions(i, nodes[i].start >> PAGE_SHIFT,
642 nodes[i].end >> PAGE_SHIFT);
643 setup_node_bootmem(i, nodes[i].start, nodes[i].end);
645 acpi_fake_nodes(nodes, num_nodes);
649 #endif /* CONFIG_NUMA_EMU */
651 void __init initmem_init(unsigned long start_pfn, unsigned long last_pfn,
656 nodes_clear(node_possible_map);
657 nodes_clear(node_online_map);
659 #ifdef CONFIG_NUMA_EMU
660 if (cmdline && !numa_emulation(start_pfn, last_pfn, acpi, k8))
662 nodes_clear(node_possible_map);
663 nodes_clear(node_online_map);
666 #ifdef CONFIG_ACPI_NUMA
667 if (!numa_off && acpi && !acpi_scan_nodes(start_pfn << PAGE_SHIFT,
668 last_pfn << PAGE_SHIFT))
670 nodes_clear(node_possible_map);
671 nodes_clear(node_online_map);
674 #ifdef CONFIG_K8_NUMA
675 if (!numa_off && k8 && !k8_scan_nodes())
677 nodes_clear(node_possible_map);
678 nodes_clear(node_online_map);
680 printk(KERN_INFO "%s\n",
681 numa_off ? "NUMA turned off" : "No NUMA configuration found");
683 printk(KERN_INFO "Faking a node at %016lx-%016lx\n",
684 start_pfn << PAGE_SHIFT,
685 last_pfn << PAGE_SHIFT);
686 /* setup dummy node covering all memory */
688 memnodemap = memnode.embedded_map;
691 node_set(0, node_possible_map);
692 for (i = 0; i < nr_cpu_ids; i++)
694 e820_register_active_regions(0, start_pfn, last_pfn);
695 setup_node_bootmem(0, start_pfn << PAGE_SHIFT, last_pfn << PAGE_SHIFT);
698 unsigned long __init numa_free_all_bootmem(void)
700 unsigned long pages = 0;
703 for_each_online_node(i)
704 pages += free_all_bootmem_node(NODE_DATA(i));
706 #ifdef CONFIG_NO_BOOTMEM
707 pages += free_all_memory_core_early(MAX_NUMNODES);
713 static __init int numa_setup(char *opt)
717 if (!strncmp(opt, "off", 3))
719 #ifdef CONFIG_NUMA_EMU
720 if (!strncmp(opt, "fake=", 5))
723 #ifdef CONFIG_ACPI_NUMA
724 if (!strncmp(opt, "noacpi", 6))
729 early_param("numa", numa_setup);
733 static __init int find_near_online_node(int node)
736 int min_val = INT_MAX;
739 for_each_online_node(n) {
740 val = node_distance(node, n);
752 * Setup early cpu_to_node.
754 * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
755 * and apicid_to_node[] tables have valid entries for a CPU.
756 * This means we skip cpu_to_node[] initialisation for NUMA
757 * emulation and faking node case (when running a kernel compiled
758 * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
759 * is already initialized in a round robin manner at numa_init_array,
760 * prior to this call, and this initialization is good enough
761 * for the fake NUMA cases.
763 * Called before the per_cpu areas are setup.
765 void __init init_cpu_to_node(void)
768 u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
770 BUG_ON(cpu_to_apicid == NULL);
772 for_each_possible_cpu(cpu) {
774 u16 apicid = cpu_to_apicid[cpu];
776 if (apicid == BAD_APICID)
778 node = apicid_to_node[apicid];
779 if (node == NUMA_NO_NODE)
781 if (!node_online(node))
782 node = find_near_online_node(node);
783 numa_set_node(cpu, node);
789 void __cpuinit numa_set_node(int cpu, int node)
791 int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
793 /* early setting, no percpu area yet */
794 if (cpu_to_node_map) {
795 cpu_to_node_map[cpu] = node;
799 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
800 if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
801 printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
806 per_cpu(x86_cpu_to_node_map, cpu) = node;
808 if (node != NUMA_NO_NODE)
809 set_cpu_numa_node(cpu, node);
812 void __cpuinit numa_clear_node(int cpu)
814 numa_set_node(cpu, NUMA_NO_NODE);
817 #ifndef CONFIG_DEBUG_PER_CPU_MAPS
819 void __cpuinit numa_add_cpu(int cpu)
821 cpumask_set_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
824 void __cpuinit numa_remove_cpu(int cpu)
826 cpumask_clear_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
829 #else /* CONFIG_DEBUG_PER_CPU_MAPS */
832 * --------- debug versions of the numa functions ---------
834 static void __cpuinit numa_set_cpumask(int cpu, int enable)
836 int node = early_cpu_to_node(cpu);
837 struct cpumask *mask;
840 mask = node_to_cpumask_map[node];
842 printk(KERN_ERR "node_to_cpumask_map[%i] NULL\n", node);
848 cpumask_set_cpu(cpu, mask);
850 cpumask_clear_cpu(cpu, mask);
852 cpulist_scnprintf(buf, sizeof(buf), mask);
853 printk(KERN_DEBUG "%s cpu %d node %d: mask now %s\n",
854 enable ? "numa_add_cpu" : "numa_remove_cpu", cpu, node, buf);
857 void __cpuinit numa_add_cpu(int cpu)
859 numa_set_cpumask(cpu, 1);
862 void __cpuinit numa_remove_cpu(int cpu)
864 numa_set_cpumask(cpu, 0);
867 int __cpu_to_node(int cpu)
869 if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
871 "cpu_to_node(%d): usage too early!\n", cpu);
873 return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
875 return per_cpu(x86_cpu_to_node_map, cpu);
877 EXPORT_SYMBOL(__cpu_to_node);
880 * Same function as cpu_to_node() but used if called before the
881 * per_cpu areas are setup.
883 int early_cpu_to_node(int cpu)
885 if (early_per_cpu_ptr(x86_cpu_to_node_map))
886 return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
888 if (!cpu_possible(cpu)) {
890 "early_cpu_to_node(%d): no per_cpu area!\n", cpu);
894 return per_cpu(x86_cpu_to_node_map, cpu);
898 * --------- end of debug versions of the numa functions ---------
901 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */