xref: /linux/arch/x86/mm/numa.c (revision 6ee738610f41b59733f63718f0bdbcba7d3a3f12)
1 /* Common code for 32 and 64-bit NUMA */
2 #include <linux/topology.h>
3 #include <linux/module.h>
4 #include <linux/bootmem.h>
5 
6 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
7 # define DBG(x...) printk(KERN_DEBUG x)
8 #else
9 # define DBG(x...)
10 #endif
11 
12 /*
13  * Which logical CPUs are on which nodes
14  */
15 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
16 EXPORT_SYMBOL(node_to_cpumask_map);
17 
18 /*
19  * Allocate node_to_cpumask_map based on number of available nodes
20  * Requires node_possible_map to be valid.
21  *
22  * Note: node_to_cpumask() is not valid until after this is done.
23  * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
24  */
25 void __init setup_node_to_cpumask_map(void)
26 {
27 	unsigned int node, num = 0;
28 
29 	/* setup nr_node_ids if not done yet */
30 	if (nr_node_ids == MAX_NUMNODES) {
31 		for_each_node_mask(node, node_possible_map)
32 			num = node;
33 		nr_node_ids = num + 1;
34 	}
35 
36 	/* allocate the map */
37 	for (node = 0; node < nr_node_ids; node++)
38 		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
39 
40 	/* cpumask_of_node() will now work */
41 	pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
42 }
43 
44 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
45 /*
46  * Returns a pointer to the bitmask of CPUs on Node 'node'.
47  */
48 const struct cpumask *cpumask_of_node(int node)
49 {
50 	if (node >= nr_node_ids) {
51 		printk(KERN_WARNING
52 			"cpumask_of_node(%d): node > nr_node_ids(%d)\n",
53 			node, nr_node_ids);
54 		dump_stack();
55 		return cpu_none_mask;
56 	}
57 	if (node_to_cpumask_map[node] == NULL) {
58 		printk(KERN_WARNING
59 			"cpumask_of_node(%d): no node_to_cpumask_map!\n",
60 			node);
61 		dump_stack();
62 		return cpu_online_mask;
63 	}
64 	return node_to_cpumask_map[node];
65 }
66 EXPORT_SYMBOL(cpumask_of_node);
67 #endif
68