1 /*
2  * include/linux/topology.h
3  *
4  * Written by: Matthew Dobson, IBM Corporation
5  *
6  * Copyright (C) 2002, IBM Corp.
7  *
8  * All rights reserved.
9  *
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.
14  *
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
19  * details.
20  *
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.
24  *
25  * Send feedback to <colpatch@us.ibm.com>
26  */
27 #ifndef _LINUX_TOPOLOGY_H
28 #define _LINUX_TOPOLOGY_H
29 
30 #include <linux/cpumask.h>
31 #include <linux/bitops.h>
32 #include <linux/mmzone.h>
33 #include <linux/smp.h>
34 #include <linux/percpu.h>
35 #include <asm/topology.h>
36 
37 #ifndef nr_cpus_node
38 #define nr_cpus_node(node) cpumask_weight(cpumask_of_node(node))
39 #endif
40 
41 #define for_each_node_with_cpus(node)			\
42 	for_each_online_node(node)			\
43 		if (nr_cpus_node(node))
44 
45 int arch_update_cpu_topology(void);
46 
47 /* Conform to ACPI 2.0 SLIT distance definitions */
48 #define LOCAL_DISTANCE		10
49 #define REMOTE_DISTANCE		20
50 #define DISTANCE_BITS           8
51 #ifndef node_distance
52 #define node_distance(from,to)	((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
53 #endif
54 #ifndef RECLAIM_DISTANCE
55 /*
56  * If the distance between nodes in a system is larger than RECLAIM_DISTANCE
57  * (in whatever arch specific measurement units returned by node_distance())
58  * and node_reclaim_mode is enabled then the VM will only call node_reclaim()
59  * on nodes within this distance.
60  */
61 #define RECLAIM_DISTANCE 30
62 #endif
63 #ifndef PENALTY_FOR_NODE_WITH_CPUS
64 #define PENALTY_FOR_NODE_WITH_CPUS	(1)
65 #endif
66 
67 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
68 DECLARE_PER_CPU(int, numa_node);
69 
70 #ifndef numa_node_id
71 /* Returns the number of the current Node. */
numa_node_id(void)72 static inline int numa_node_id(void)
73 {
74 	return raw_cpu_read(numa_node);
75 }
76 #endif
77 
78 #ifndef cpu_to_node
cpu_to_node(int cpu)79 static inline int cpu_to_node(int cpu)
80 {
81 	return per_cpu(numa_node, cpu);
82 }
83 #endif
84 
85 #ifndef set_numa_node
set_numa_node(int node)86 static inline void set_numa_node(int node)
87 {
88 	this_cpu_write(numa_node, node);
89 }
90 #endif
91 
92 #ifndef set_cpu_numa_node
set_cpu_numa_node(int cpu,int node)93 static inline void set_cpu_numa_node(int cpu, int node)
94 {
95 	per_cpu(numa_node, cpu) = node;
96 }
97 #endif
98 
99 #else	/* !CONFIG_USE_PERCPU_NUMA_NODE_ID */
100 
101 /* Returns the number of the current Node. */
102 #ifndef numa_node_id
numa_node_id(void)103 static inline int numa_node_id(void)
104 {
105 	return cpu_to_node(raw_smp_processor_id());
106 }
107 #endif
108 
109 #endif	/* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */
110 
111 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
112 
113 /*
114  * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
115  * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
116  * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem().
117  */
118 DECLARE_PER_CPU(int, _numa_mem_);
119 extern int _node_numa_mem_[MAX_NUMNODES];
120 
121 #ifndef set_numa_mem
set_numa_mem(int node)122 static inline void set_numa_mem(int node)
123 {
124 	this_cpu_write(_numa_mem_, node);
125 	_node_numa_mem_[numa_node_id()] = node;
126 }
127 #endif
128 
129 #ifndef node_to_mem_node
node_to_mem_node(int node)130 static inline int node_to_mem_node(int node)
131 {
132 	return _node_numa_mem_[node];
133 }
134 #endif
135 
136 #ifndef numa_mem_id
137 /* Returns the number of the nearest Node with memory */
numa_mem_id(void)138 static inline int numa_mem_id(void)
139 {
140 	return raw_cpu_read(_numa_mem_);
141 }
142 #endif
143 
144 #ifndef cpu_to_mem
cpu_to_mem(int cpu)145 static inline int cpu_to_mem(int cpu)
146 {
147 	return per_cpu(_numa_mem_, cpu);
148 }
149 #endif
150 
151 #ifndef set_cpu_numa_mem
set_cpu_numa_mem(int cpu,int node)152 static inline void set_cpu_numa_mem(int cpu, int node)
153 {
154 	per_cpu(_numa_mem_, cpu) = node;
155 	_node_numa_mem_[cpu_to_node(cpu)] = node;
156 }
157 #endif
158 
159 #else	/* !CONFIG_HAVE_MEMORYLESS_NODES */
160 
161 #ifndef numa_mem_id
162 /* Returns the number of the nearest Node with memory */
numa_mem_id(void)163 static inline int numa_mem_id(void)
164 {
165 	return numa_node_id();
166 }
167 #endif
168 
169 #ifndef node_to_mem_node
node_to_mem_node(int node)170 static inline int node_to_mem_node(int node)
171 {
172 	return node;
173 }
174 #endif
175 
176 #ifndef cpu_to_mem
cpu_to_mem(int cpu)177 static inline int cpu_to_mem(int cpu)
178 {
179 	return cpu_to_node(cpu);
180 }
181 #endif
182 
183 #endif	/* [!]CONFIG_HAVE_MEMORYLESS_NODES */
184 
185 #ifndef topology_physical_package_id
186 #define topology_physical_package_id(cpu)	((void)(cpu), -1)
187 #endif
188 #ifndef topology_core_id
189 #define topology_core_id(cpu)			((void)(cpu), 0)
190 #endif
191 #ifndef topology_sibling_cpumask
192 #define topology_sibling_cpumask(cpu)		cpumask_of(cpu)
193 #endif
194 #ifndef topology_core_cpumask
195 #define topology_core_cpumask(cpu)		cpumask_of(cpu)
196 #endif
197 
198 #ifdef CONFIG_SCHED_SMT
cpu_smt_mask(int cpu)199 static inline const struct cpumask *cpu_smt_mask(int cpu)
200 {
201 	return topology_sibling_cpumask(cpu);
202 }
203 #endif
204 
cpu_cpu_mask(int cpu)205 static inline const struct cpumask *cpu_cpu_mask(int cpu)
206 {
207 	return cpumask_of_node(cpu_to_node(cpu));
208 }
209 
210 
211 #endif /* _LINUX_TOPOLOGY_H */
212