drivers/base/topology.c

   1 /*
   2  * driver/base/topology.c - Populate sysfs with cpu topology information
   3  *
   4  * Written by: Zhang Yanmin, Intel Corporation
   5  *
   6  * Copyright (C) 2006, Intel Corp.
   7  *
   8  * All rights reserved.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  18  * NON INFRINGEMENT.  See the GNU General Public License for more
  19  * details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  *
  25  */
  26 #include <linux/mm.h>
  27 #include <linux/cpu.h>
  28 #include <linux/module.h>
  29 #include <linux/hardirq.h>
  30 #include <linux/topology.h>
  31
  32 #define define_id_show_func(name)                               \
  33 static ssize_t name##_show(struct device *dev,                  \
  34                 struct device_attribute *attr, char *buf)       \
  35 {                                                               \
  36         return sprintf(buf, "%d\n", topology_##name(dev->id));  \
  37 }
  38
  39 #define define_siblings_show_map(name, mask)                            \
  40 static ssize_t name##_show(struct device *dev,                          \
  41                            struct device_attribute *attr, char *buf)    \
  42 {                                                                       \
  43         return cpumap_print_to_pagebuf(false, buf, topology_##mask(dev->id));\
  44 }
  45
  46 #define define_siblings_show_list(name, mask)                           \
  47 static ssize_t name##_list_show(struct device *dev,                     \
  48                                 struct device_attribute *attr,          \
  49                                 char *buf)                              \
  50 {                                                                       \
  51         return cpumap_print_to_pagebuf(true, buf, topology_##mask(dev->id));\
  52 }
  53
  54 #define define_siblings_show_func(name, mask)   \
  55         define_siblings_show_map(name, mask);   \
  56         define_siblings_show_list(name, mask)
  57
  58 define_id_show_func(physical_package_id);
  59 static DEVICE_ATTR_RO(physical_package_id);
  60
  61 define_id_show_func(coregroup_id);
  62 static DEVICE_ATTR_RO(coregroup_id);
  63
  64 define_id_show_func(core_id);
  65 static DEVICE_ATTR_RO(core_id);
  66
  67 define_siblings_show_func(thread_siblings, sibling_cpumask);
  68 static DEVICE_ATTR_RO(thread_siblings);
  69 static DEVICE_ATTR_RO(thread_siblings_list);
  70
  71 define_siblings_show_func(core_siblings, core_cpumask);
  72 static DEVICE_ATTR_RO(core_siblings);
  73 static DEVICE_ATTR_RO(core_siblings_list);
  74
  75 define_siblings_show_func(cluster_siblings, cluster_cpumask);
  76 static DEVICE_ATTR_RO(cluster_siblings);
  77 static DEVICE_ATTR_RO(cluster_siblings_list);
  78
  79 #ifdef CONFIG_SCHED_BOOK
  80 define_id_show_func(book_id);
  81 static DEVICE_ATTR_RO(book_id);
  82 define_siblings_show_func(book_siblings, book_cpumask);
  83 static DEVICE_ATTR_RO(book_siblings);
  84 static DEVICE_ATTR_RO(book_siblings_list);
  85 #endif
  86
  87 #ifdef CONFIG_SCHED_DRAWER
  88 define_id_show_func(drawer_id);
  89 static DEVICE_ATTR_RO(drawer_id);
  90 define_siblings_show_func(drawer_siblings, drawer_cpumask);
  91 static DEVICE_ATTR_RO(drawer_siblings);
  92 static DEVICE_ATTR_RO(drawer_siblings_list);
  93 #endif
  94
  95 static struct attribute *default_attrs[] = {
  96         &dev_attr_physical_package_id.attr,
  97         &dev_attr_core_id.attr,
  98         &dev_attr_thread_siblings.attr,
  99         &dev_attr_thread_siblings_list.attr,
 100         &dev_attr_core_siblings.attr,
 101         &dev_attr_core_siblings_list.attr,
 102         &dev_attr_coregroup_id.attr,
 103         &dev_attr_cluster_siblings.attr,
 104         &dev_attr_cluster_siblings_list.attr,
 105 #ifdef CONFIG_SCHED_BOOK
 106         &dev_attr_book_id.attr,
 107         &dev_attr_book_siblings.attr,
 108         &dev_attr_book_siblings_list.attr,
 109 #endif
 110 #ifdef CONFIG_SCHED_DRAWER
 111         &dev_attr_drawer_id.attr,
 112         &dev_attr_drawer_siblings.attr,
 113         &dev_attr_drawer_siblings_list.attr,
 114 #endif
 115         NULL
 116 };
 117
 118 static const struct attribute_group topology_attr_group = {
 119         .attrs = default_attrs,
 120         .name = "topology"
 121 };
 122
 123 static bool cpu_sys_init[NR_CPUS];
 124 /* Add/Remove cpu_topology interface for CPU device */
 125 static int topology_add_dev(unsigned int cpu)
 126 {
 127         struct device *dev = get_cpu_device(cpu);
 128         int ret;
 129
 130         if (cpu_sys_init[cpu])
 131                 return 0;
 132
 133         ret = sysfs_create_group(&dev->kobj, &topology_attr_group);
 134         if (!ret)
 135                 cpu_sys_init[cpu] = true;
 136
 137         return ret;
 138 }
 139
 140 static int topology_remove_dev(unsigned int cpu)
 141 {
 142         struct device *dev;
 143
 144         if (cpu_sys_init[cpu])
 145                 return 0;
 146
 147         dev = get_cpu_device(cpu);
 148         sysfs_remove_group(&dev->kobj, &topology_attr_group);
 149         return 0;
 150 }
 151
 152 static int topology_sysfs_init(void)
 153 {
 154         return cpuhp_setup_state(CPUHP_TOPOLOGY_PREPARE,
 155                                  "base/topology:prepare", topology_add_dev,
 156                                  topology_remove_dev);
 157 }
 158
 159 device_initcall(topology_sysfs_init);