Mark Brown | f6e763b | 2014-03-04 07:51:17 +0000 | [diff] [blame] | 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> |
Mark Brown | ebdc944 | 2014-05-02 21:38:29 +0100 | [diff] [blame] | 20 | #include <linux/of.h> |
Mark Brown | f6e763b | 2014-03-04 07:51:17 +0000 | [diff] [blame] | 21 | #include <linux/sched.h> |
| 22 | |
Zi Shen Lim | 4e6f708 | 2014-06-07 01:55:27 +0100 | [diff] [blame] | 23 | #include <asm/cputype.h> |
Mark Brown | f6e763b | 2014-03-04 07:51:17 +0000 | [diff] [blame] | 24 | #include <asm/topology.h> |
| 25 | |
Mark Brown | ebdc944 | 2014-05-02 21:38:29 +0100 | [diff] [blame] | 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 | */ |
Zi Shen Lim | 4e6f708 | 2014-06-07 01:55:27 +0100 | [diff] [blame] | 192 | for_each_possible_cpu(cpu) |
| 193 | if (cpu_topology[cpu].cluster_id == -1) |
Mark Brown | ebdc944 | 2014-05-02 21:38:29 +0100 | [diff] [blame] | 194 | ret = -EINVAL; |
Mark Brown | ebdc944 | 2014-05-02 21:38:29 +0100 | [diff] [blame] | 195 | |
| 196 | out_map: |
| 197 | of_node_put(map); |
| 198 | out: |
| 199 | of_node_put(cn); |
| 200 | return ret; |
| 201 | } |
| 202 | |
Mark Brown | f6e763b | 2014-03-04 07:51:17 +0000 | [diff] [blame] | 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 | |
Mark Brown | f6e763b | 2014-03-04 07:51:17 +0000 | [diff] [blame] | 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 | { |
Zi Shen Lim | 4e6f708 | 2014-06-07 01:55:27 +0100 | [diff] [blame] | 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); |
Mark Brown | 1cefdae | 2014-11-21 00:36:49 +0000 | [diff] [blame] | 258 | cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 2) | |
| 259 | MPIDR_AFFINITY_LEVEL(mpidr, 3) << 8; |
Zi Shen Lim | 4e6f708 | 2014-06-07 01:55:27 +0100 | [diff] [blame] | 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); |
Mark Brown | 1cefdae | 2014-11-21 00:36:49 +0000 | [diff] [blame] | 264 | cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 1) | |
| 265 | MPIDR_AFFINITY_LEVEL(mpidr, 2) << 8 | |
| 266 | MPIDR_AFFINITY_LEVEL(mpidr, 3) << 16; |
Zi Shen Lim | 4e6f708 | 2014-06-07 01:55:27 +0100 | [diff] [blame] | 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: |
Mark Brown | f6e763b | 2014-03-04 07:51:17 +0000 | [diff] [blame] | 274 | update_siblings_masks(cpuid); |
| 275 | } |
| 276 | |
Mark Brown | ebdc944 | 2014-05-02 21:38:29 +0100 | [diff] [blame] | 277 | static void __init reset_cpu_topology(void) |
Mark Brown | f6e763b | 2014-03-04 07:51:17 +0000 | [diff] [blame] | 278 | { |
| 279 | unsigned int cpu; |
| 280 | |
Mark Brown | f6e763b | 2014-03-04 07:51:17 +0000 | [diff] [blame] | 281 | for_each_possible_cpu(cpu) { |
| 282 | struct cpu_topology *cpu_topo = &cpu_topology[cpu]; |
| 283 | |
| 284 | cpu_topo->thread_id = -1; |
Mark Brown | c31bf04 | 2014-05-02 21:38:28 +0100 | [diff] [blame] | 285 | cpu_topo->core_id = 0; |
Mark Brown | f6e763b | 2014-03-04 07:51:17 +0000 | [diff] [blame] | 286 | cpu_topo->cluster_id = -1; |
Mark Brown | c31bf04 | 2014-05-02 21:38:28 +0100 | [diff] [blame] | 287 | |
Mark Brown | f6e763b | 2014-03-04 07:51:17 +0000 | [diff] [blame] | 288 | cpumask_clear(&cpu_topo->core_sibling); |
Mark Brown | c31bf04 | 2014-05-02 21:38:28 +0100 | [diff] [blame] | 289 | cpumask_set_cpu(cpu, &cpu_topo->core_sibling); |
Mark Brown | f6e763b | 2014-03-04 07:51:17 +0000 | [diff] [blame] | 290 | cpumask_clear(&cpu_topo->thread_sibling); |
Mark Brown | c31bf04 | 2014-05-02 21:38:28 +0100 | [diff] [blame] | 291 | cpumask_set_cpu(cpu, &cpu_topo->thread_sibling); |
Mark Brown | f6e763b | 2014-03-04 07:51:17 +0000 | [diff] [blame] | 292 | } |
| 293 | } |
Mark Brown | ebdc944 | 2014-05-02 21:38:29 +0100 | [diff] [blame] | 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 | */ |
Sudeep Holla | e094d44 | 2015-07-23 18:28:26 +0100 | [diff] [blame] | 303 | if (of_have_populated_dt() && parse_dt_topology()) |
Mark Brown | ebdc944 | 2014-05-02 21:38:29 +0100 | [diff] [blame] | 304 | reset_cpu_topology(); |
| 305 | } |