drivers/base/topology.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * driver/base/topology.c - Populate sysfs with cpu topology information
   4  *
   5  * Written by: Zhang Yanmin, Intel Corporation
   6  *
   7  * Copyright (C) 2006, Intel Corp.
   8  *
   9  * All rights reserved.
  10  */
  11 #include <linux/mm.h>
  12 #include <linux/cpu.h>
  13 #include <linux/module.h>
  14 #include <linux/hardirq.h>
  15 #include <linux/topology.h>
  16
  17 #define define_id_show_func(name, fmt)                                  \
  18 static ssize_t name##_show(struct device *dev,                          \
  19                            struct device_attribute *attr, char *buf)    \
  20 {                                                                       \
  21         return sysfs_emit(buf, fmt "\n", topology_##name(dev->id));     \
  22 }
  23
  24 #define define_siblings_read_func(name, mask)                                   \
  25 static ssize_t name##_read(struct file *file, struct kobject *kobj,             \
  26                            const struct bin_attribute *attr, char *buf,         \
  27                            loff_t off, size_t count)                            \
  28 {                                                                               \
  29         struct device *dev = kobj_to_dev(kobj);                                 \
  30         cpumask_var_t mask;                                                     \
  31         ssize_t n;                                                              \
  32                                                                                 \
  33         if (!alloc_cpumask_var(&mask, GFP_KERNEL))                              \
  34                 return -ENOMEM;                                                 \
  35                                                                                 \
  36         cpumask_copy(mask, topology_##mask(dev->id));                           \
  37         n = cpumap_print_bitmask_to_buf(buf, mask, off, count);                 \
  38         free_cpumask_var(mask);                                                 \
  39                                                                                 \
  40         return n;                                                               \
  41 }                                                                               \
  42                                                                                 \
  43 static ssize_t name##_list_read(struct file *file, struct kobject *kobj,        \
  44                                 const struct bin_attribute *attr, char *buf,    \
  45                                 loff_t off, size_t count)                       \
  46 {                                                                               \
  47         struct device *dev = kobj_to_dev(kobj);                                 \
  48         cpumask_var_t mask;                                                     \
  49         ssize_t n;                                                              \
  50                                                                                 \
  51         if (!alloc_cpumask_var(&mask, GFP_KERNEL))                              \
  52                 return -ENOMEM;                                                 \
  53                                                                                 \
  54         cpumask_copy(mask, topology_##mask(dev->id));                           \
  55         n = cpumap_print_list_to_buf(buf, mask, off, count);                    \
  56         free_cpumask_var(mask);                                                 \
  57                                                                                 \
  58         return n;                                                               \
  59 }
  60
  61 define_id_show_func(physical_package_id, "%d");
  62 static DEVICE_ATTR_RO(physical_package_id);
  63
  64 #ifdef TOPOLOGY_DIE_SYSFS
  65 define_id_show_func(die_id, "%d");
  66 static DEVICE_ATTR_RO(die_id);
  67 #endif
  68
  69 #ifdef TOPOLOGY_CLUSTER_SYSFS
  70 define_id_show_func(cluster_id, "%d");
  71 static DEVICE_ATTR_RO(cluster_id);
  72 #endif
  73
  74 define_id_show_func(core_id, "%d");
  75 static DEVICE_ATTR_RO(core_id);
  76
  77 define_id_show_func(ppin, "0x%llx");
  78 static DEVICE_ATTR_ADMIN_RO(ppin);
  79
  80 define_siblings_read_func(thread_siblings, sibling_cpumask);
  81 static const BIN_ATTR_RO(thread_siblings, CPUMAP_FILE_MAX_BYTES);
  82 static const BIN_ATTR_RO(thread_siblings_list, CPULIST_FILE_MAX_BYTES);
  83
  84 define_siblings_read_func(core_cpus, sibling_cpumask);
  85 static const BIN_ATTR_RO(core_cpus, CPUMAP_FILE_MAX_BYTES);
  86 static const BIN_ATTR_RO(core_cpus_list, CPULIST_FILE_MAX_BYTES);
  87
  88 define_siblings_read_func(core_siblings, core_cpumask);
  89 static const BIN_ATTR_RO(core_siblings, CPUMAP_FILE_MAX_BYTES);
  90 static const BIN_ATTR_RO(core_siblings_list, CPULIST_FILE_MAX_BYTES);
  91
  92 #ifdef TOPOLOGY_CLUSTER_SYSFS
  93 define_siblings_read_func(cluster_cpus, cluster_cpumask);
  94 static const BIN_ATTR_RO(cluster_cpus, CPUMAP_FILE_MAX_BYTES);
  95 static const BIN_ATTR_RO(cluster_cpus_list, CPULIST_FILE_MAX_BYTES);
  96 #endif
  97
  98 #ifdef TOPOLOGY_DIE_SYSFS
  99 define_siblings_read_func(die_cpus, die_cpumask);
 100 static const BIN_ATTR_RO(die_cpus, CPUMAP_FILE_MAX_BYTES);
 101 static const BIN_ATTR_RO(die_cpus_list, CPULIST_FILE_MAX_BYTES);
 102 #endif
 103
 104 define_siblings_read_func(package_cpus, core_cpumask);
 105 static const BIN_ATTR_RO(package_cpus, CPUMAP_FILE_MAX_BYTES);
 106 static const BIN_ATTR_RO(package_cpus_list, CPULIST_FILE_MAX_BYTES);
 107
 108 #ifdef TOPOLOGY_BOOK_SYSFS
 109 define_id_show_func(book_id, "%d");
 110 static DEVICE_ATTR_RO(book_id);
 111 define_siblings_read_func(book_siblings, book_cpumask);
 112 static const BIN_ATTR_RO(book_siblings, CPUMAP_FILE_MAX_BYTES);
 113 static const BIN_ATTR_RO(book_siblings_list, CPULIST_FILE_MAX_BYTES);
 114 #endif
 115
 116 #ifdef TOPOLOGY_DRAWER_SYSFS
 117 define_id_show_func(drawer_id, "%d");
 118 static DEVICE_ATTR_RO(drawer_id);
 119 define_siblings_read_func(drawer_siblings, drawer_cpumask);
 120 static const BIN_ATTR_RO(drawer_siblings, CPUMAP_FILE_MAX_BYTES);
 121 static const BIN_ATTR_RO(drawer_siblings_list, CPULIST_FILE_MAX_BYTES);
 122 #endif
 123
 124 static const struct bin_attribute *const bin_attrs[] = {
 125         &bin_attr_core_cpus,
 126         &bin_attr_core_cpus_list,
 127         &bin_attr_thread_siblings,
 128         &bin_attr_thread_siblings_list,
 129         &bin_attr_core_siblings,
 130         &bin_attr_core_siblings_list,
 131 #ifdef TOPOLOGY_CLUSTER_SYSFS
 132         &bin_attr_cluster_cpus,
 133         &bin_attr_cluster_cpus_list,
 134 #endif
 135 #ifdef TOPOLOGY_DIE_SYSFS
 136         &bin_attr_die_cpus,
 137         &bin_attr_die_cpus_list,
 138 #endif
 139         &bin_attr_package_cpus,
 140         &bin_attr_package_cpus_list,
 141 #ifdef TOPOLOGY_BOOK_SYSFS
 142         &bin_attr_book_siblings,
 143         &bin_attr_book_siblings_list,
 144 #endif
 145 #ifdef TOPOLOGY_DRAWER_SYSFS
 146         &bin_attr_drawer_siblings,
 147         &bin_attr_drawer_siblings_list,
 148 #endif
 149         NULL
 150 };
 151
 152 static struct attribute *default_attrs[] = {
 153         &dev_attr_physical_package_id.attr,
 154 #ifdef TOPOLOGY_DIE_SYSFS
 155         &dev_attr_die_id.attr,
 156 #endif
 157 #ifdef TOPOLOGY_CLUSTER_SYSFS
 158         &dev_attr_cluster_id.attr,
 159 #endif
 160         &dev_attr_core_id.attr,
 161 #ifdef TOPOLOGY_BOOK_SYSFS
 162         &dev_attr_book_id.attr,
 163 #endif
 164 #ifdef TOPOLOGY_DRAWER_SYSFS
 165         &dev_attr_drawer_id.attr,
 166 #endif
 167         &dev_attr_ppin.attr,
 168         NULL
 169 };
 170
 171 static umode_t topology_is_visible(struct kobject *kobj,
 172                                    struct attribute *attr, int unused)
 173 {
 174         if (attr == &dev_attr_ppin.attr && !topology_ppin(kobj_to_dev(kobj)->id))
 175                 return 0;
 176
 177         return attr->mode;
 178 }
 179
 180 static const struct attribute_group topology_attr_group = {
 181         .attrs = default_attrs,
 182         .bin_attrs_new = bin_attrs,
 183         .is_visible = topology_is_visible,
 184         .name = "topology"
 185 };
 186
 187 /* Add/Remove cpu_topology interface for CPU device */
 188 static int topology_add_dev(unsigned int cpu)
 189 {
 190         struct device *dev = get_cpu_device(cpu);
 191
 192         return sysfs_create_group(&dev->kobj, &topology_attr_group);
 193 }
 194
 195 static int topology_remove_dev(unsigned int cpu)
 196 {
 197         struct device *dev = get_cpu_device(cpu);
 198
 199         sysfs_remove_group(&dev->kobj, &topology_attr_group);
 200         return 0;
 201 }
 202
 203 static int __init topology_sysfs_init(void)
 204 {
 205         return cpuhp_setup_state(CPUHP_TOPOLOGY_PREPARE,
 206                                  "base/topology:prepare", topology_add_dev,
 207                                  topology_remove_dev);
 208 }
 209
 210 device_initcall(topology_sysfs_init);
 211
 212 DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
 213 EXPORT_PER_CPU_SYMBOL_GPL(cpu_scale);
 214
 215 void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
 216 {
 217         per_cpu(cpu_scale, cpu) = capacity;
 218 }
 219
 220 static ssize_t cpu_capacity_show(struct device *dev,
 221                                  struct device_attribute *attr,
 222                                  char *buf)
 223 {
 224         struct cpu *cpu = container_of(dev, struct cpu, dev);
 225
 226         return sysfs_emit(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
 227 }
 228
 229 static DEVICE_ATTR_RO(cpu_capacity);
 230
 231 static int cpu_capacity_sysctl_add(unsigned int cpu)
 232 {
 233         struct device *cpu_dev = get_cpu_device(cpu);
 234
 235         if (!cpu_dev)
 236                 return -ENOENT;
 237
 238         device_create_file(cpu_dev, &dev_attr_cpu_capacity);
 239
 240         return 0;
 241 }
 242
 243 static int cpu_capacity_sysctl_remove(unsigned int cpu)
 244 {
 245         struct device *cpu_dev = get_cpu_device(cpu);
 246
 247         if (!cpu_dev)
 248                 return -ENOENT;
 249
 250         device_remove_file(cpu_dev, &dev_attr_cpu_capacity);
 251
 252         return 0;
 253 }
 254
 255 static int register_cpu_capacity_sysctl(void)
 256 {
 257         cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "topology/cpu-capacity",
 258                           cpu_capacity_sysctl_add, cpu_capacity_sysctl_remove);
 259
 260         return 0;
 261 }
 262 subsys_initcall(register_cpu_capacity_sysctl);