~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/arm64/kernel/topology.c

Version: ~ [ linux-5.16-rc1 ] ~ [ linux-5.15.2 ] ~ [ linux-5.14.18 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.79 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.159 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.217 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.255 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.290 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.292 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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>
 20 #include <linux/of.h>
 21 #include <linux/sched.h>
 22 
 23 #include <asm/cputype.h>
 24 #include <asm/topology.h>
 25 
 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          */
192         for_each_possible_cpu(cpu)
193                 if (cpu_topology[cpu].cluster_id == -1)
194                         ret = -EINVAL;
195 
196 out_map:
197         of_node_put(map);
198 out:
199         of_node_put(cn);
200         return ret;
201 }
202 
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 
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 {
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);
258                 cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 2) |
259                                          MPIDR_AFFINITY_LEVEL(mpidr, 3) << 8;
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);
264                 cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 1) |
265                                          MPIDR_AFFINITY_LEVEL(mpidr, 2) << 8 |
266                                          MPIDR_AFFINITY_LEVEL(mpidr, 3) << 16;
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:
274         update_siblings_masks(cpuid);
275 }
276 
277 static void __init reset_cpu_topology(void)
278 {
279         unsigned int cpu;
280 
281         for_each_possible_cpu(cpu) {
282                 struct cpu_topology *cpu_topo = &cpu_topology[cpu];
283 
284                 cpu_topo->thread_id = -1;
285                 cpu_topo->core_id = 0;
286                 cpu_topo->cluster_id = -1;
287 
288                 cpumask_clear(&cpu_topo->core_sibling);
289                 cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
290                 cpumask_clear(&cpu_topo->thread_sibling);
291                 cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
292         }
293 }
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          */
303         if (of_have_populated_dt() && parse_dt_topology())
304                 reset_cpu_topology();
305 }
306 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp