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1 | /* |
2 | * arch/arm64/kernel/topology.c | |
3 | * | |
4 | * Copyright (C) 2011,2013,2014 Linaro Limited. | |
5 | * | |
6 | * Based on the arm32 version written by Vincent Guittot in turn based on | |
7 | * arch/sh/kernel/topology.c | |
8 | * | |
9 | * This file is subject to the terms and conditions of the GNU General Public | |
10 | * License. See the file "COPYING" in the main directory of this archive | |
11 | * for more details. | |
12 | */ | |
13 | ||
14 | #include <linux/cpu.h> | |
15 | #include <linux/cpumask.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/percpu.h> | |
18 | #include <linux/node.h> | |
19 | #include <linux/nodemask.h> | |
ebdc9447 | 20 | #include <linux/of.h> |
f6e763b9 MB |
21 | #include <linux/sched.h> |
22 | ||
4e6f7084 | 23 | #include <asm/cputype.h> |
f6e763b9 MB |
24 | #include <asm/topology.h> |
25 | ||
ebdc9447 MB |
26 | static int __init get_cpu_for_node(struct device_node *node) |
27 | { | |
28 | struct device_node *cpu_node; | |
29 | int cpu; | |
30 | ||
31 | cpu_node = of_parse_phandle(node, "cpu", 0); | |
32 | if (!cpu_node) | |
33 | return -1; | |
34 | ||
35 | for_each_possible_cpu(cpu) { | |
36 | if (of_get_cpu_node(cpu, NULL) == cpu_node) { | |
37 | of_node_put(cpu_node); | |
38 | return cpu; | |
39 | } | |
40 | } | |
41 | ||
42 | pr_crit("Unable to find CPU node for %s\n", cpu_node->full_name); | |
43 | ||
44 | of_node_put(cpu_node); | |
45 | return -1; | |
46 | } | |
47 | ||
48 | static int __init parse_core(struct device_node *core, int cluster_id, | |
49 | int core_id) | |
50 | { | |
51 | char name[10]; | |
52 | bool leaf = true; | |
53 | int i = 0; | |
54 | int cpu; | |
55 | struct device_node *t; | |
56 | ||
57 | do { | |
58 | snprintf(name, sizeof(name), "thread%d", i); | |
59 | t = of_get_child_by_name(core, name); | |
60 | if (t) { | |
61 | leaf = false; | |
62 | cpu = get_cpu_for_node(t); | |
63 | if (cpu >= 0) { | |
64 | cpu_topology[cpu].cluster_id = cluster_id; | |
65 | cpu_topology[cpu].core_id = core_id; | |
66 | cpu_topology[cpu].thread_id = i; | |
67 | } else { | |
68 | pr_err("%s: Can't get CPU for thread\n", | |
69 | t->full_name); | |
70 | of_node_put(t); | |
71 | return -EINVAL; | |
72 | } | |
73 | of_node_put(t); | |
74 | } | |
75 | i++; | |
76 | } while (t); | |
77 | ||
78 | cpu = get_cpu_for_node(core); | |
79 | if (cpu >= 0) { | |
80 | if (!leaf) { | |
81 | pr_err("%s: Core has both threads and CPU\n", | |
82 | core->full_name); | |
83 | return -EINVAL; | |
84 | } | |
85 | ||
86 | cpu_topology[cpu].cluster_id = cluster_id; | |
87 | cpu_topology[cpu].core_id = core_id; | |
88 | } else if (leaf) { | |
89 | pr_err("%s: Can't get CPU for leaf core\n", core->full_name); | |
90 | return -EINVAL; | |
91 | } | |
92 | ||
93 | return 0; | |
94 | } | |
95 | ||
96 | static int __init parse_cluster(struct device_node *cluster, int depth) | |
97 | { | |
98 | char name[10]; | |
99 | bool leaf = true; | |
100 | bool has_cores = false; | |
101 | struct device_node *c; | |
102 | static int cluster_id __initdata; | |
103 | int core_id = 0; | |
104 | int i, ret; | |
105 | ||
106 | /* | |
107 | * First check for child clusters; we currently ignore any | |
108 | * information about the nesting of clusters and present the | |
109 | * scheduler with a flat list of them. | |
110 | */ | |
111 | i = 0; | |
112 | do { | |
113 | snprintf(name, sizeof(name), "cluster%d", i); | |
114 | c = of_get_child_by_name(cluster, name); | |
115 | if (c) { | |
116 | leaf = false; | |
117 | ret = parse_cluster(c, depth + 1); | |
118 | of_node_put(c); | |
119 | if (ret != 0) | |
120 | return ret; | |
121 | } | |
122 | i++; | |
123 | } while (c); | |
124 | ||
125 | /* Now check for cores */ | |
126 | i = 0; | |
127 | do { | |
128 | snprintf(name, sizeof(name), "core%d", i); | |
129 | c = of_get_child_by_name(cluster, name); | |
130 | if (c) { | |
131 | has_cores = true; | |
132 | ||
133 | if (depth == 0) { | |
134 | pr_err("%s: cpu-map children should be clusters\n", | |
135 | c->full_name); | |
136 | of_node_put(c); | |
137 | return -EINVAL; | |
138 | } | |
139 | ||
140 | if (leaf) { | |
141 | ret = parse_core(c, cluster_id, core_id++); | |
142 | } else { | |
143 | pr_err("%s: Non-leaf cluster with core %s\n", | |
144 | cluster->full_name, name); | |
145 | ret = -EINVAL; | |
146 | } | |
147 | ||
148 | of_node_put(c); | |
149 | if (ret != 0) | |
150 | return ret; | |
151 | } | |
152 | i++; | |
153 | } while (c); | |
154 | ||
155 | if (leaf && !has_cores) | |
156 | pr_warn("%s: empty cluster\n", cluster->full_name); | |
157 | ||
158 | if (leaf) | |
159 | cluster_id++; | |
160 | ||
161 | return 0; | |
162 | } | |
163 | ||
164 | static int __init parse_dt_topology(void) | |
165 | { | |
166 | struct device_node *cn, *map; | |
167 | int ret = 0; | |
168 | int cpu; | |
169 | ||
170 | cn = of_find_node_by_path("/cpus"); | |
171 | if (!cn) { | |
172 | pr_err("No CPU information found in DT\n"); | |
173 | return 0; | |
174 | } | |
175 | ||
176 | /* | |
177 | * When topology is provided cpu-map is essentially a root | |
178 | * cluster with restricted subnodes. | |
179 | */ | |
180 | map = of_get_child_by_name(cn, "cpu-map"); | |
181 | if (!map) | |
182 | goto out; | |
183 | ||
184 | ret = parse_cluster(map, 0); | |
185 | if (ret != 0) | |
186 | goto out_map; | |
187 | ||
188 | /* | |
189 | * Check that all cores are in the topology; the SMP code will | |
190 | * only mark cores described in the DT as possible. | |
191 | */ | |
4e6f7084 ZSL |
192 | for_each_possible_cpu(cpu) |
193 | if (cpu_topology[cpu].cluster_id == -1) | |
ebdc9447 | 194 | ret = -EINVAL; |
ebdc9447 MB |
195 | |
196 | out_map: | |
197 | of_node_put(map); | |
198 | out: | |
199 | of_node_put(cn); | |
200 | return ret; | |
201 | } | |
202 | ||
f6e763b9 MB |
203 | /* |
204 | * cpu topology table | |
205 | */ | |
206 | struct cpu_topology cpu_topology[NR_CPUS]; | |
207 | EXPORT_SYMBOL_GPL(cpu_topology); | |
208 | ||
209 | const struct cpumask *cpu_coregroup_mask(int cpu) | |
210 | { | |
211 | return &cpu_topology[cpu].core_sibling; | |
212 | } | |
213 | ||
214 | static void update_siblings_masks(unsigned int cpuid) | |
215 | { | |
216 | struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid]; | |
217 | int cpu; | |
218 | ||
f6e763b9 MB |
219 | /* update core and thread sibling masks */ |
220 | for_each_possible_cpu(cpu) { | |
221 | cpu_topo = &cpu_topology[cpu]; | |
222 | ||
223 | if (cpuid_topo->cluster_id != cpu_topo->cluster_id) | |
224 | continue; | |
225 | ||
226 | cpumask_set_cpu(cpuid, &cpu_topo->core_sibling); | |
227 | if (cpu != cpuid) | |
228 | cpumask_set_cpu(cpu, &cpuid_topo->core_sibling); | |
229 | ||
230 | if (cpuid_topo->core_id != cpu_topo->core_id) | |
231 | continue; | |
232 | ||
233 | cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling); | |
234 | if (cpu != cpuid) | |
235 | cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling); | |
236 | } | |
237 | } | |
238 | ||
239 | void store_cpu_topology(unsigned int cpuid) | |
240 | { | |
4e6f7084 ZSL |
241 | struct cpu_topology *cpuid_topo = &cpu_topology[cpuid]; |
242 | u64 mpidr; | |
243 | ||
244 | if (cpuid_topo->cluster_id != -1) | |
245 | goto topology_populated; | |
246 | ||
247 | mpidr = read_cpuid_mpidr(); | |
248 | ||
249 | /* Uniprocessor systems can rely on default topology values */ | |
250 | if (mpidr & MPIDR_UP_BITMASK) | |
251 | return; | |
252 | ||
253 | /* Create cpu topology mapping based on MPIDR. */ | |
254 | if (mpidr & MPIDR_MT_BITMASK) { | |
255 | /* Multiprocessor system : Multi-threads per core */ | |
256 | cpuid_topo->thread_id = MPIDR_AFFINITY_LEVEL(mpidr, 0); | |
257 | cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 1); | |
1cefdaea MB |
258 | cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 2) | |
259 | MPIDR_AFFINITY_LEVEL(mpidr, 3) << 8; | |
4e6f7084 ZSL |
260 | } else { |
261 | /* Multiprocessor system : Single-thread per core */ | |
262 | cpuid_topo->thread_id = -1; | |
263 | cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0); | |
1cefdaea MB |
264 | cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 1) | |
265 | MPIDR_AFFINITY_LEVEL(mpidr, 2) << 8 | | |
266 | MPIDR_AFFINITY_LEVEL(mpidr, 3) << 16; | |
4e6f7084 ZSL |
267 | } |
268 | ||
269 | pr_debug("CPU%u: cluster %d core %d thread %d mpidr %#016llx\n", | |
270 | cpuid, cpuid_topo->cluster_id, cpuid_topo->core_id, | |
271 | cpuid_topo->thread_id, mpidr); | |
272 | ||
273 | topology_populated: | |
f6e763b9 MB |
274 | update_siblings_masks(cpuid); |
275 | } | |
276 | ||
ebdc9447 | 277 | static void __init reset_cpu_topology(void) |
f6e763b9 MB |
278 | { |
279 | unsigned int cpu; | |
280 | ||
f6e763b9 MB |
281 | for_each_possible_cpu(cpu) { |
282 | struct cpu_topology *cpu_topo = &cpu_topology[cpu]; | |
283 | ||
284 | cpu_topo->thread_id = -1; | |
c31bf048 | 285 | cpu_topo->core_id = 0; |
f6e763b9 | 286 | cpu_topo->cluster_id = -1; |
c31bf048 | 287 | |
f6e763b9 | 288 | cpumask_clear(&cpu_topo->core_sibling); |
c31bf048 | 289 | cpumask_set_cpu(cpu, &cpu_topo->core_sibling); |
f6e763b9 | 290 | cpumask_clear(&cpu_topo->thread_sibling); |
c31bf048 | 291 | cpumask_set_cpu(cpu, &cpu_topo->thread_sibling); |
f6e763b9 MB |
292 | } |
293 | } | |
ebdc9447 MB |
294 | |
295 | void __init init_cpu_topology(void) | |
296 | { | |
297 | reset_cpu_topology(); | |
298 | ||
299 | /* | |
300 | * Discard anything that was parsed if we hit an error so we | |
301 | * don't use partial information. | |
302 | */ | |
e094d445 | 303 | if (of_have_populated_dt() && parse_dt_topology()) |
ebdc9447 MB |
304 | reset_cpu_topology(); |
305 | } |