2 * linux/include/asm-i386/topology.h
4 * Written by: Matthew Dobson, IBM Corporation
6 * Copyright (C) 2002, IBM Corp.
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
18 * NON INFRINGEMENT. See the GNU General Public License for more
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 * Send feedback to <colpatch@us.ibm.com>
27 #ifndef _ASM_I386_TOPOLOGY_H
28 #define _ASM_I386_TOPOLOGY_H
32 #include <asm/mpspec.h>
34 #include <linux/cpumask.h>
36 /* Mappings between logical cpu number and node number */
37 extern cpumask_t node_2_cpu_mask[];
38 extern int cpu_2_node[];
40 /* Returns the number of the node containing CPU 'cpu' */
41 static inline int cpu_to_node(int cpu)
43 return cpu_2_node[cpu];
46 /* Returns the number of the node containing Node 'node'. This architecture is flat,
47 so it is a pretty simple function! */
48 #define parent_node(node) (node)
50 /* Returns a bitmask of CPUs on Node 'node'. */
51 static inline cpumask_t node_to_cpumask(int node)
53 return node_2_cpu_mask[node];
56 /* Returns the number of the first CPU on Node 'node'. */
57 static inline int node_to_first_cpu(int node)
59 cpumask_t mask = node_to_cpumask(node);
60 return first_cpu(mask);
63 /* Returns the number of the node containing PCI bus 'bus' */
64 static inline cpumask_t pcibus_to_cpumask(int bus)
66 return node_to_cpumask(mp_bus_id_to_node[bus]);
69 /* Node-to-Node distance */
70 #define node_distance(from, to) (from != to)
72 /* Cross-node load balancing interval. */
73 #define NODE_BALANCE_RATE 100
75 #else /* !CONFIG_NUMA */
77 * Other i386 platforms should define their own version of the
81 #include <asm-generic/topology.h>
83 #endif /* CONFIG_NUMA */
85 #endif /* _ASM_I386_TOPOLOGY_H */