xref: /openbmc/linux/arch/ia64/kernel/numa.c (revision 293d5b43)
1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License as published by
4  * the Free Software Foundation; either version 2 of the License, or
5  * (at your option) any later version.
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10  * GNU General Public License for more details.
11  *
12  * You should have received a copy of the GNU General Public License
13  * along with this program; if not, write to the Free Software
14  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
15  *
16  * ia64 kernel NUMA specific stuff
17  *
18  * Copyright (C) 2002 Erich Focht <efocht@ess.nec.de>
19  * Copyright (C) 2004 Silicon Graphics, Inc.
20  *   Jesse Barnes <jbarnes@sgi.com>
21  */
22 #include <linux/topology.h>
23 #include <linux/module.h>
24 #include <asm/processor.h>
25 #include <asm/smp.h>
26 
27 u16 cpu_to_node_map[NR_CPUS] __cacheline_aligned;
28 EXPORT_SYMBOL(cpu_to_node_map);
29 
30 cpumask_t node_to_cpu_mask[MAX_NUMNODES] __cacheline_aligned;
31 EXPORT_SYMBOL(node_to_cpu_mask);
32 
33 void map_cpu_to_node(int cpu, int nid)
34 {
35 	int oldnid;
36 	if (nid < 0) { /* just initialize by zero */
37 		cpu_to_node_map[cpu] = 0;
38 		return;
39 	}
40 	/* sanity check first */
41 	oldnid = cpu_to_node_map[cpu];
42 	if (cpumask_test_cpu(cpu, &node_to_cpu_mask[oldnid])) {
43 		return; /* nothing to do */
44 	}
45 	/* we don't have cpu-driven node hot add yet...
46 	   In usual case, node is created from SRAT at boot time. */
47 	if (!node_online(nid))
48 		nid = first_online_node;
49 	cpu_to_node_map[cpu] = nid;
50 	cpumask_set_cpu(cpu, &node_to_cpu_mask[nid]);
51 	return;
52 }
53 
54 void unmap_cpu_from_node(int cpu, int nid)
55 {
56 	WARN_ON(!cpumask_test_cpu(cpu, &node_to_cpu_mask[nid]));
57 	WARN_ON(cpu_to_node_map[cpu] != nid);
58 	cpu_to_node_map[cpu] = 0;
59 	cpumask_clear_cpu(cpu, &node_to_cpu_mask[nid]);
60 }
61 
62 
63 /**
64  * build_cpu_to_node_map - setup cpu to node and node to cpumask arrays
65  *
66  * Build cpu to node mapping and initialize the per node cpu masks using
67  * info from the node_cpuid array handed to us by ACPI.
68  */
69 void __init build_cpu_to_node_map(void)
70 {
71 	int cpu, i, node;
72 
73 	for(node=0; node < MAX_NUMNODES; node++)
74 		cpumask_clear(&node_to_cpu_mask[node]);
75 
76 	for_each_possible_early_cpu(cpu) {
77 		node = -1;
78 		for (i = 0; i < NR_CPUS; ++i)
79 			if (cpu_physical_id(cpu) == node_cpuid[i].phys_id) {
80 				node = node_cpuid[i].nid;
81 				break;
82 			}
83 		map_cpu_to_node(cpu, node);
84 	}
85 }
86