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