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/sysdev.h>
  27 #include <linux/init.h>
  28 #include <linux/mm.h>
  29 #include <linux/cpu.h>
  30 #include <linux/module.h>
  31 #include <linux/hardirq.h>
  32 #include <linux/topology.h>
  33
  34 #define define_one_ro_named(_name, _func)                               \
  35 static SYSDEV_ATTR(_name, 0444, _func, NULL)
  36
  37 #define define_one_ro(_name)                            \
  38 static SYSDEV_ATTR(_name, 0444, show_##_name, NULL)
  39
  40 #define define_id_show_func(name)                               \
  41 static ssize_t show_##name(struct sys_device *dev,              \
  42                 struct sysdev_attribute *attr, char *buf)       \
  43 {                                                               \
  44         unsigned int cpu = dev->id;                             \
  45         return sprintf(buf, "%d\n", topology_##name(cpu));      \
  46 }
  47
  48 #if defined(topology_thread_cpumask) || defined(topology_core_cpumask) || \
  49     defined(topology_book_cpumask)
  50 static ssize_t show_cpumap(int type, const struct cpumask *mask, char *buf)
  51 {
  52         ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
  53         int n = 0;
  54
  55         if (len > 1) {
  56                 n = type?
  57                         cpulist_scnprintf(buf, len-2, mask) :
  58                         cpumask_scnprintf(buf, len-2, mask);
  59                 buf[n++] = '\n';
  60                 buf[n] = '\0';
  61         }
  62         return n;
  63 }
  64 #endif
  65
  66 #ifdef arch_provides_topology_pointers
  67 #define define_siblings_show_map(name)                                  \
  68 static ssize_t show_##name(struct sys_device *dev,                      \
  69                            struct sysdev_attribute *attr, char *buf)    \
  70 {                                                                       \
  71         unsigned int cpu = dev->id;                                     \
  72         return show_cpumap(0, topology_##name(cpu), buf);               \
  73 }
  74
  75 #define define_siblings_show_list(name)                                 \
  76 static ssize_t show_##name##_list(struct sys_device *dev,               \
  77                                   struct sysdev_attribute *attr,        \
  78                                   char *buf)                            \
  79 {                                                                       \
  80         unsigned int cpu = dev->id;                                     \
  81         return show_cpumap(1, topology_##name(cpu), buf);               \
  82 }
  83
  84 #else
  85 #define define_siblings_show_map(name)                                  \
  86 static ssize_t show_##name(struct sys_device *dev,                      \
  87                            struct sysdev_attribute *attr, char *buf)    \
  88 {                                                                       \
  89         return show_cpumap(0, topology_##name(dev->id), buf);           \
  90 }
  91
  92 #define define_siblings_show_list(name)                                 \
  93 static ssize_t show_##name##_list(struct sys_device *dev,               \
  94                                   struct sysdev_attribute *attr,        \
  95                                   char *buf)                            \
  96 {                                                                       \
  97         return show_cpumap(1, topology_##name(dev->id), buf);           \
  98 }
  99 #endif
 100
 101 #define define_siblings_show_func(name)         \
 102         define_siblings_show_map(name); define_siblings_show_list(name)
 103
 104 define_id_show_func(physical_package_id);
 105 define_one_ro(physical_package_id);
 106
 107 define_id_show_func(core_id);
 108 define_one_ro(core_id);
 109
 110 define_siblings_show_func(thread_cpumask);
 111 define_one_ro_named(thread_siblings, show_thread_cpumask);
 112 define_one_ro_named(thread_siblings_list, show_thread_cpumask_list);
 113
 114 define_siblings_show_func(core_cpumask);
 115 define_one_ro_named(core_siblings, show_core_cpumask);
 116 define_one_ro_named(core_siblings_list, show_core_cpumask_list);
 117
 118 #ifdef CONFIG_SCHED_BOOK
 119 define_id_show_func(book_id);
 120 define_one_ro(book_id);
 121 define_siblings_show_func(book_cpumask);
 122 define_one_ro_named(book_siblings, show_book_cpumask);
 123 define_one_ro_named(book_siblings_list, show_book_cpumask_list);
 124 #endif
 125
 126 static struct attribute *default_attrs[] = {
 127         &attr_physical_package_id.attr,
 128         &attr_core_id.attr,
 129         &attr_thread_siblings.attr,
 130         &attr_thread_siblings_list.attr,
 131         &attr_core_siblings.attr,
 132         &attr_core_siblings_list.attr,
 133 #ifdef CONFIG_SCHED_BOOK
 134         &attr_book_id.attr,
 135         &attr_book_siblings.attr,
 136         &attr_book_siblings_list.attr,
 137 #endif
 138         NULL
 139 };
 140
 141 static struct attribute_group topology_attr_group = {
 142         .attrs = default_attrs,
 143         .name = "topology"
 144 };
 145
 146 /* Add/Remove cpu_topology interface for CPU device */
 147 static int __cpuinit topology_add_dev(unsigned int cpu)
 148 {
 149         struct sys_device *sys_dev = get_cpu_sysdev(cpu);
 150
 151         return sysfs_create_group(&sys_dev->kobj, &topology_attr_group);
 152 }
 153
 154 static void __cpuinit topology_remove_dev(unsigned int cpu)
 155 {
 156         struct sys_device *sys_dev = get_cpu_sysdev(cpu);
 157
 158         sysfs_remove_group(&sys_dev->kobj, &topology_attr_group);
 159 }
 160
 161 static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
 162                                            unsigned long action, void *hcpu)
 163 {
 164         unsigned int cpu = (unsigned long)hcpu;
 165         int rc = 0;
 166
 167         switch (action) {
 168         case CPU_UP_PREPARE:
 169         case CPU_UP_PREPARE_FROZEN:
 170                 rc = topology_add_dev(cpu);
 171                 break;
 172         case CPU_UP_CANCELED:
 173         case CPU_UP_CANCELED_FROZEN:
 174         case CPU_DEAD:
 175         case CPU_DEAD_FROZEN:
 176                 topology_remove_dev(cpu);
 177                 break;
 178         }
 179         return notifier_from_errno(rc);
 180 }
 181
 182 static int __cpuinit topology_sysfs_init(void)
 183 {
 184         int cpu;
 185         int rc;
 186
 187         for_each_online_cpu(cpu) {
 188                 rc = topology_add_dev(cpu);
 189                 if (rc)
 190                         return rc;
 191         }
 192         hotcpu_notifier(topology_cpu_callback, 0);
 193
 194         return 0;
 195 }
 196
 197 device_initcall(topology_sysfs_init);