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/acpi.h>
15 #include <linux/arch_topology.h>
16 #include <linux/cacheinfo.h>
17 #include <linux/cpu.h>
18 #include <linux/cpumask.h>
19 #include <linux/init.h>
20 #include <linux/percpu.h>
21 #include <linux/node.h>
22 #include <linux/nodemask.h>
23 #include <linux/of.h>
24 #include <linux/sched.h>
25 #include <linux/sched/topology.h>
26 #include <linux/slab.h>
27 #include <linux/smp.h>
28 #include <linux/string.h>
29
30 #include <asm/cpu.h>
31 #include <asm/cputype.h>
32 #include <asm/topology.h>
33
get_cpu_for_node(struct device_node * node)34 static int __init get_cpu_for_node(struct device_node *node)
35 {
36 struct device_node *cpu_node;
37 int cpu;
38
39 cpu_node = of_parse_phandle(node, "cpu", 0);
40 if (!cpu_node)
41 return -1;
42
43 cpu = of_cpu_node_to_id(cpu_node);
44 if (cpu >= 0)
45 topology_parse_cpu_capacity(cpu_node, cpu);
46 else
47 pr_crit("Unable to find CPU node for %pOF\n", cpu_node);
48
49 of_node_put(cpu_node);
50 return cpu;
51 }
52
parse_core(struct device_node * core,int package_id,int core_id)53 static int __init parse_core(struct device_node *core, int package_id,
54 int core_id)
55 {
56 char name[10];
57 bool leaf = true;
58 int i = 0;
59 int cpu;
60 struct device_node *t;
61
62 do {
63 snprintf(name, sizeof(name), "thread%d", i);
64 t = of_get_child_by_name(core, name);
65 if (t) {
66 leaf = false;
67 cpu = get_cpu_for_node(t);
68 if (cpu >= 0) {
69 cpu_topology[cpu].package_id = package_id;
70 cpu_topology[cpu].core_id = core_id;
71 cpu_topology[cpu].thread_id = i;
72 } else {
73 pr_err("%pOF: Can't get CPU for thread\n",
74 t);
75 of_node_put(t);
76 return -EINVAL;
77 }
78 of_node_put(t);
79 }
80 i++;
81 } while (t);
82
83 cpu = get_cpu_for_node(core);
84 if (cpu >= 0) {
85 if (!leaf) {
86 pr_err("%pOF: Core has both threads and CPU\n",
87 core);
88 return -EINVAL;
89 }
90
91 cpu_topology[cpu].package_id = package_id;
92 cpu_topology[cpu].core_id = core_id;
93 } else if (leaf) {
94 pr_err("%pOF: Can't get CPU for leaf core\n", core);
95 return -EINVAL;
96 }
97
98 return 0;
99 }
100
parse_cluster(struct device_node * cluster,int depth)101 static int __init parse_cluster(struct device_node *cluster, int depth)
102 {
103 char name[10];
104 bool leaf = true;
105 bool has_cores = false;
106 struct device_node *c;
107 static int package_id __initdata;
108 int core_id = 0;
109 int i, ret;
110
111 /*
112 * First check for child clusters; we currently ignore any
113 * information about the nesting of clusters and present the
114 * scheduler with a flat list of them.
115 */
116 i = 0;
117 do {
118 snprintf(name, sizeof(name), "cluster%d", i);
119 c = of_get_child_by_name(cluster, name);
120 if (c) {
121 leaf = false;
122 ret = parse_cluster(c, depth + 1);
123 of_node_put(c);
124 if (ret != 0)
125 return ret;
126 }
127 i++;
128 } while (c);
129
130 /* Now check for cores */
131 i = 0;
132 do {
133 snprintf(name, sizeof(name), "core%d", i);
134 c = of_get_child_by_name(cluster, name);
135 if (c) {
136 has_cores = true;
137
138 if (depth == 0) {
139 pr_err("%pOF: cpu-map children should be clusters\n",
140 c);
141 of_node_put(c);
142 return -EINVAL;
143 }
144
145 if (leaf) {
146 ret = parse_core(c, package_id, core_id++);
147 } else {
148 pr_err("%pOF: Non-leaf cluster with core %s\n",
149 cluster, name);
150 ret = -EINVAL;
151 }
152
153 of_node_put(c);
154 if (ret != 0)
155 return ret;
156 }
157 i++;
158 } while (c);
159
160 if (leaf && !has_cores)
161 pr_warn("%pOF: empty cluster\n", cluster);
162
163 if (leaf)
164 package_id++;
165
166 return 0;
167 }
168
parse_dt_topology(void)169 static int __init parse_dt_topology(void)
170 {
171 struct device_node *cn, *map;
172 int ret = 0;
173 int cpu;
174
175 cn = of_find_node_by_path("/cpus");
176 if (!cn) {
177 pr_err("No CPU information found in DT\n");
178 return 0;
179 }
180
181 /*
182 * When topology is provided cpu-map is essentially a root
183 * cluster with restricted subnodes.
184 */
185 map = of_get_child_by_name(cn, "cpu-map");
186 if (!map)
187 goto out;
188
189 ret = parse_cluster(map, 0);
190 if (ret != 0)
191 goto out_map;
192
193 topology_normalize_cpu_scale();
194
195 /*
196 * Check that all cores are in the topology; the SMP code will
197 * only mark cores described in the DT as possible.
198 */
199 for_each_possible_cpu(cpu)
200 if (cpu_topology[cpu].package_id == -1)
201 ret = -EINVAL;
202
203 out_map:
204 of_node_put(map);
205 out:
206 of_node_put(cn);
207 return ret;
208 }
209
210 /*
211 * cpu topology table
212 */
213 struct cpu_topology cpu_topology[NR_CPUS];
214 EXPORT_SYMBOL_GPL(cpu_topology);
215
cpu_coregroup_mask(int cpu)216 const struct cpumask *cpu_coregroup_mask(int cpu)
217 {
218 const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu));
219
220 /* Find the smaller of NUMA, core or LLC siblings */
221 if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) {
222 /* not numa in package, lets use the package siblings */
223 core_mask = &cpu_topology[cpu].core_sibling;
224 }
225 if (cpu_topology[cpu].llc_id != -1) {
226 if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask))
227 core_mask = &cpu_topology[cpu].llc_sibling;
228 }
229
230 return core_mask;
231 }
232
update_siblings_masks(unsigned int cpuid)233 static void update_siblings_masks(unsigned int cpuid)
234 {
235 struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
236 int cpu;
237
238 /* update core and thread sibling masks */
239 for_each_online_cpu(cpu) {
240 cpu_topo = &cpu_topology[cpu];
241
242 if (cpuid_topo->llc_id == cpu_topo->llc_id) {
243 cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
244 cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
245 }
246
247 if (cpuid_topo->package_id != cpu_topo->package_id)
248 continue;
249
250 cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
251 cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
252
253 if (cpuid_topo->core_id != cpu_topo->core_id)
254 continue;
255
256 cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
257 cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
258 }
259 }
260
store_cpu_topology(unsigned int cpuid)261 void store_cpu_topology(unsigned int cpuid)
262 {
263 struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];
264 u64 mpidr;
265
266 if (cpuid_topo->package_id != -1)
267 goto topology_populated;
268
269 mpidr = read_cpuid_mpidr();
270
271 /* Uniprocessor systems can rely on default topology values */
272 if (mpidr & MPIDR_UP_BITMASK)
273 return;
274
275 /* Create cpu topology mapping based on MPIDR. */
276 if (mpidr & MPIDR_MT_BITMASK) {
277 /* Multiprocessor system : Multi-threads per core */
278 cpuid_topo->thread_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
279 cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
280 cpuid_topo->package_id = MPIDR_AFFINITY_LEVEL(mpidr, 2) |
281 MPIDR_AFFINITY_LEVEL(mpidr, 3) << 8;
282 } else {
283 /* Multiprocessor system : Single-thread per core */
284 cpuid_topo->thread_id = -1;
285 cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
286 cpuid_topo->package_id = MPIDR_AFFINITY_LEVEL(mpidr, 1) |
287 MPIDR_AFFINITY_LEVEL(mpidr, 2) << 8 |
288 MPIDR_AFFINITY_LEVEL(mpidr, 3) << 16;
289 }
290
291 pr_debug("CPU%u: cluster %d core %d thread %d mpidr %#016llx\n",
292 cpuid, cpuid_topo->package_id, cpuid_topo->core_id,
293 cpuid_topo->thread_id, mpidr);
294
295 topology_populated:
296 update_siblings_masks(cpuid);
297 }
298
clear_cpu_topology(int cpu)299 static void clear_cpu_topology(int cpu)
300 {
301 struct cpu_topology *cpu_topo = &cpu_topology[cpu];
302
303 cpumask_clear(&cpu_topo->llc_sibling);
304 cpumask_set_cpu(cpu, &cpu_topo->llc_sibling);
305
306 cpumask_clear(&cpu_topo->core_sibling);
307 cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
308 cpumask_clear(&cpu_topo->thread_sibling);
309 cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
310 }
311
reset_cpu_topology(void)312 static void __init reset_cpu_topology(void)
313 {
314 unsigned int cpu;
315
316 for_each_possible_cpu(cpu) {
317 struct cpu_topology *cpu_topo = &cpu_topology[cpu];
318
319 cpu_topo->thread_id = -1;
320 cpu_topo->core_id = 0;
321 cpu_topo->package_id = -1;
322 cpu_topo->llc_id = -1;
323
324 clear_cpu_topology(cpu);
325 }
326 }
327
remove_cpu_topology(unsigned int cpu)328 void remove_cpu_topology(unsigned int cpu)
329 {
330 int sibling;
331
332 for_each_cpu(sibling, topology_core_cpumask(cpu))
333 cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
334 for_each_cpu(sibling, topology_sibling_cpumask(cpu))
335 cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
336 for_each_cpu(sibling, topology_llc_cpumask(cpu))
337 cpumask_clear_cpu(cpu, topology_llc_cpumask(sibling));
338
339 clear_cpu_topology(cpu);
340 }
341
342 #ifdef CONFIG_ACPI
343 /*
344 * Propagate the topology information of the processor_topology_node tree to the
345 * cpu_topology array.
346 */
parse_acpi_topology(void)347 static int __init parse_acpi_topology(void)
348 {
349 bool is_threaded;
350 int cpu, topology_id;
351
352 is_threaded = read_cpuid_mpidr() & MPIDR_MT_BITMASK;
353
354 for_each_possible_cpu(cpu) {
355 int i, cache_id;
356
357 topology_id = find_acpi_cpu_topology(cpu, 0);
358 if (topology_id < 0)
359 return topology_id;
360
361 if (is_threaded) {
362 cpu_topology[cpu].thread_id = topology_id;
363 topology_id = find_acpi_cpu_topology(cpu, 1);
364 cpu_topology[cpu].core_id = topology_id;
365 } else {
366 cpu_topology[cpu].thread_id = -1;
367 cpu_topology[cpu].core_id = topology_id;
368 }
369 topology_id = find_acpi_cpu_topology_package(cpu);
370 cpu_topology[cpu].package_id = topology_id;
371
372 i = acpi_find_last_cache_level(cpu);
373
374 if (i > 0) {
375 /*
376 * this is the only part of cpu_topology that has
377 * a direct relationship with the cache topology
378 */
379 cache_id = find_acpi_cpu_cache_topology(cpu, i);
380 if (cache_id > 0)
381 cpu_topology[cpu].llc_id = cache_id;
382 }
383 }
384
385 return 0;
386 }
387
388 #else
parse_acpi_topology(void)389 static inline int __init parse_acpi_topology(void)
390 {
391 return -EINVAL;
392 }
393 #endif
394
init_cpu_topology(void)395 void __init init_cpu_topology(void)
396 {
397 reset_cpu_topology();
398
399 /*
400 * Discard anything that was parsed if we hit an error so we
401 * don't use partial information.
402 */
403 if (!acpi_disabled && parse_acpi_topology())
404 reset_cpu_topology();
405 else if (of_have_populated_dt() && parse_dt_topology())
406 reset_cpu_topology();
407 }
408
