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/arch_topology.h>
31 #include <linux/cpumask.h>
32 #include <linux/bitops.h>
33 #include <linux/mmzone.h>
34 #include <linux/smp.h>
35 #include <linux/percpu.h>
36 #include <asm/topology.h>
37
38 #ifndef nr_cpus_node
39 #define nr_cpus_node(node) cpumask_weight(cpumask_of_node(node))
40 #endif
41
42 #define for_each_node_with_cpus(node) \
43 for_each_online_node(node) \
44 if (nr_cpus_node(node))
45
46 int arch_update_cpu_topology(void);
47
48 /* Conform to ACPI 2.0 SLIT distance definitions */
49 #define LOCAL_DISTANCE 10
50 #define REMOTE_DISTANCE 20
51 #define DISTANCE_BITS 8
52 #ifndef node_distance
53 #define node_distance(from,to) ((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
54 #endif
55 #ifndef RECLAIM_DISTANCE
56 /*
57 * If the distance between nodes in a system is larger than RECLAIM_DISTANCE
58 * (in whatever arch specific measurement units returned by node_distance())
59 * and node_reclaim_mode is enabled then the VM will only call node_reclaim()
60 * on nodes within this distance.
61 */
62 #define RECLAIM_DISTANCE 30
63 #endif
64
65 /*
66 * The following tunable allows platforms to override the default node
67 * reclaim distance (RECLAIM_DISTANCE) if remote memory accesses are
68 * sufficiently fast that the default value actually hurts
69 * performance.
70 *
71 * AMD EPYC machines use this because even though the 2-hop distance
72 * is 32 (3.2x slower than a local memory access) performance actually
73 * *improves* if allowed to reclaim memory and load balance tasks
74 * between NUMA nodes 2-hops apart.
75 */
76 extern int __read_mostly node_reclaim_distance;
77
78 #ifndef PENALTY_FOR_NODE_WITH_CPUS
79 #define PENALTY_FOR_NODE_WITH_CPUS (1)
80 #endif
81
82 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
83 DECLARE_PER_CPU(int, numa_node);
84
85 #ifndef numa_node_id
86 /* Returns the number of the current Node. */
numa_node_id(void)87 static inline int numa_node_id(void)
88 {
89 return raw_cpu_read(numa_node);
90 }
91 #endif
92
93 #ifndef cpu_to_node
cpu_to_node(int cpu)94 static inline int cpu_to_node(int cpu)
95 {
96 return per_cpu(numa_node, cpu);
97 }
98 #endif
99
100 #ifndef set_numa_node
set_numa_node(int node)101 static inline void set_numa_node(int node)
102 {
103 this_cpu_write(numa_node, node);
104 }
105 #endif
106
107 #ifndef set_cpu_numa_node
set_cpu_numa_node(int cpu,int node)108 static inline void set_cpu_numa_node(int cpu, int node)
109 {
110 per_cpu(numa_node, cpu) = node;
111 }
112 #endif
113
114 #else /* !CONFIG_USE_PERCPU_NUMA_NODE_ID */
115
116 /* Returns the number of the current Node. */
117 #ifndef numa_node_id
numa_node_id(void)118 static inline int numa_node_id(void)
119 {
120 return cpu_to_node(raw_smp_processor_id());
121 }
122 #endif
123
124 #endif /* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */
125
126 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
127
128 /*
129 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
130 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
131 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem().
132 */
133 DECLARE_PER_CPU(int, _numa_mem_);
134
135 #ifndef set_numa_mem
set_numa_mem(int node)136 static inline void set_numa_mem(int node)
137 {
138 this_cpu_write(_numa_mem_, node);
139 }
140 #endif
141
142 #ifndef numa_mem_id
143 /* Returns the number of the nearest Node with memory */
numa_mem_id(void)144 static inline int numa_mem_id(void)
145 {
146 return raw_cpu_read(_numa_mem_);
147 }
148 #endif
149
150 #ifndef cpu_to_mem
cpu_to_mem(int cpu)151 static inline int cpu_to_mem(int cpu)
152 {
153 return per_cpu(_numa_mem_, cpu);
154 }
155 #endif
156
157 #ifndef set_cpu_numa_mem
set_cpu_numa_mem(int cpu,int node)158 static inline void set_cpu_numa_mem(int cpu, int node)
159 {
160 per_cpu(_numa_mem_, cpu) = node;
161 }
162 #endif
163
164 #else /* !CONFIG_HAVE_MEMORYLESS_NODES */
165
166 #ifndef numa_mem_id
167 /* Returns the number of the nearest Node with memory */
numa_mem_id(void)168 static inline int numa_mem_id(void)
169 {
170 return numa_node_id();
171 }
172 #endif
173
174 #ifndef cpu_to_mem
cpu_to_mem(int cpu)175 static inline int cpu_to_mem(int cpu)
176 {
177 return cpu_to_node(cpu);
178 }
179 #endif
180
181 #endif /* [!]CONFIG_HAVE_MEMORYLESS_NODES */
182
183 #ifndef topology_physical_package_id
184 #define topology_physical_package_id(cpu) ((void)(cpu), -1)
185 #endif
186 #ifndef topology_die_id
187 #define topology_die_id(cpu) ((void)(cpu), -1)
188 #endif
189 #ifndef topology_core_id
190 #define topology_core_id(cpu) ((void)(cpu), 0)
191 #endif
192 #ifndef topology_sibling_cpumask
193 #define topology_sibling_cpumask(cpu) cpumask_of(cpu)
194 #endif
195 #ifndef topology_core_cpumask
196 #define topology_core_cpumask(cpu) cpumask_of(cpu)
197 #endif
198 #ifndef topology_die_cpumask
199 #define topology_die_cpumask(cpu) cpumask_of(cpu)
200 #endif
201
202 #if defined(CONFIG_SCHED_SMT) && !defined(cpu_smt_mask)
cpu_smt_mask(int cpu)203 static inline const struct cpumask *cpu_smt_mask(int cpu)
204 {
205 return topology_sibling_cpumask(cpu);
206 }
207 #endif
208
cpu_cpu_mask(int cpu)209 static inline const struct cpumask *cpu_cpu_mask(int cpu)
210 {
211 return cpumask_of_node(cpu_to_node(cpu));
212 }
213
214
215 #endif /* _LINUX_TOPOLOGY_H */
216