xref: /linux-6.15/include/linux/topology.h (revision ef264cf0)
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 <[email protected]>
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 node_has_online_mem
38 #define node_has_online_mem(nid) (1)
39 #endif
40 
41 #ifndef nr_cpus_node
42 #define nr_cpus_node(node) cpumask_weight(cpumask_of_node(node))
43 #endif
44 
45 #define for_each_node_with_cpus(node)			\
46 	for_each_online_node(node)			\
47 		if (nr_cpus_node(node))
48 
49 int arch_update_cpu_topology(void);
50 
51 /* Conform to ACPI 2.0 SLIT distance definitions */
52 #define LOCAL_DISTANCE		10
53 #define REMOTE_DISTANCE		20
54 #ifndef node_distance
55 #define node_distance(from,to)	((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
56 #endif
57 #ifndef RECLAIM_DISTANCE
58 /*
59  * If the distance between nodes in a system is larger than RECLAIM_DISTANCE
60  * (in whatever arch specific measurement units returned by node_distance())
61  * and zone_reclaim_mode is enabled then the VM will only call zone_reclaim()
62  * on nodes within this distance.
63  */
64 #define RECLAIM_DISTANCE 30
65 #endif
66 #ifndef PENALTY_FOR_NODE_WITH_CPUS
67 #define PENALTY_FOR_NODE_WITH_CPUS	(1)
68 #endif
69 
70 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
71 DECLARE_PER_CPU(int, numa_node);
72 
73 #ifndef numa_node_id
74 /* Returns the number of the current Node. */
75 static inline int numa_node_id(void)
76 {
77 	return raw_cpu_read(numa_node);
78 }
79 #endif
80 
81 #ifndef cpu_to_node
82 static inline int cpu_to_node(int cpu)
83 {
84 	return per_cpu(numa_node, cpu);
85 }
86 #endif
87 
88 #ifndef set_numa_node
89 static inline void set_numa_node(int node)
90 {
91 	this_cpu_write(numa_node, node);
92 }
93 #endif
94 
95 #ifndef set_cpu_numa_node
96 static inline void set_cpu_numa_node(int cpu, int node)
97 {
98 	per_cpu(numa_node, cpu) = node;
99 }
100 #endif
101 
102 #else	/* !CONFIG_USE_PERCPU_NUMA_NODE_ID */
103 
104 /* Returns the number of the current Node. */
105 #ifndef numa_node_id
106 static inline int numa_node_id(void)
107 {
108 	return cpu_to_node(raw_smp_processor_id());
109 }
110 #endif
111 
112 #endif	/* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */
113 
114 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
115 
116 /*
117  * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
118  * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
119  * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem().
120  */
121 DECLARE_PER_CPU(int, _numa_mem_);
122 
123 #ifndef set_numa_mem
124 static inline void set_numa_mem(int node)
125 {
126 	this_cpu_write(_numa_mem_, node);
127 }
128 #endif
129 
130 #ifndef numa_mem_id
131 /* Returns the number of the nearest Node with memory */
132 static inline int numa_mem_id(void)
133 {
134 	return raw_cpu_read(_numa_mem_);
135 }
136 #endif
137 
138 #ifndef cpu_to_mem
139 static inline int cpu_to_mem(int cpu)
140 {
141 	return per_cpu(_numa_mem_, cpu);
142 }
143 #endif
144 
145 #ifndef set_cpu_numa_mem
146 static inline void set_cpu_numa_mem(int cpu, int node)
147 {
148 	per_cpu(_numa_mem_, cpu) = node;
149 }
150 #endif
151 
152 #else	/* !CONFIG_HAVE_MEMORYLESS_NODES */
153 
154 #ifndef numa_mem_id
155 /* Returns the number of the nearest Node with memory */
156 static inline int numa_mem_id(void)
157 {
158 	return numa_node_id();
159 }
160 #endif
161 
162 #ifndef cpu_to_mem
163 static inline int cpu_to_mem(int cpu)
164 {
165 	return cpu_to_node(cpu);
166 }
167 #endif
168 
169 #endif	/* [!]CONFIG_HAVE_MEMORYLESS_NODES */
170 
171 #ifndef topology_physical_package_id
172 #define topology_physical_package_id(cpu)	((void)(cpu), -1)
173 #endif
174 #ifndef topology_core_id
175 #define topology_core_id(cpu)			((void)(cpu), 0)
176 #endif
177 #ifndef topology_thread_cpumask
178 #define topology_thread_cpumask(cpu)		cpumask_of(cpu)
179 #endif
180 #ifndef topology_core_cpumask
181 #define topology_core_cpumask(cpu)		cpumask_of(cpu)
182 #endif
183 
184 #ifdef CONFIG_SCHED_SMT
185 static inline const struct cpumask *cpu_smt_mask(int cpu)
186 {
187 	return topology_thread_cpumask(cpu);
188 }
189 #endif
190 
191 static inline const struct cpumask *cpu_cpu_mask(int cpu)
192 {
193 	return cpumask_of_node(cpu_to_node(cpu));
194 }
195 
196 
197 #endif /* _LINUX_TOPOLOGY_H */
198