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); 198