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) \ 35static SYSDEV_ATTR(_name, 0444, _func, NULL) 36 37#define define_one_ro(_name) \ 38static SYSDEV_ATTR(_name, 0444, show_##_name, NULL) 39 40#define define_id_show_func(name) \ 41static 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) 49static 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#ifdef arch_provides_topology_pointers 66#define define_siblings_show_map(name) \ 67static ssize_t show_##name(struct sys_device *dev, \ 68 struct sysdev_attribute *attr, char *buf) \ 69{ \ 70 unsigned int cpu = dev->id; \ 71 return show_cpumap(0, topology_##name(cpu), buf); \ 72} 73 74#define define_siblings_show_list(name) \ 75static ssize_t show_##name##_list(struct sys_device *dev, \ 76 struct sysdev_attribute *attr, \ 77 char *buf) \ 78{ \ 79 unsigned int cpu = dev->id; \ 80 return show_cpumap(1, topology_##name(cpu), buf); \ 81} 82 83#else 84#define define_siblings_show_map(name) \ 85static ssize_t show_##name(struct sys_device *dev, \ 86 struct sysdev_attribute *attr, char *buf) \ 87{ \ 88 return show_cpumap(0, topology_##name(dev->id), buf); \ 89} 90 91#define define_siblings_show_list(name) \ 92static ssize_t show_##name##_list(struct sys_device *dev, \ 93 struct sysdev_attribute *attr, \ 94 char *buf) \ 95{ \ 96 return show_cpumap(1, topology_##name(dev->id), buf); \ 97} 98#endif 99 100#define define_siblings_show_func(name) \ 101 define_siblings_show_map(name); define_siblings_show_list(name) 102 103define_id_show_func(physical_package_id); 104define_one_ro(physical_package_id); 105 106define_id_show_func(core_id); 107define_one_ro(core_id); 108 109define_siblings_show_func(thread_cpumask); 110define_one_ro_named(thread_siblings, show_thread_cpumask); 111define_one_ro_named(thread_siblings_list, show_thread_cpumask_list); 112 113define_siblings_show_func(core_cpumask); 114define_one_ro_named(core_siblings, show_core_cpumask); 115define_one_ro_named(core_siblings_list, show_core_cpumask_list); 116 117static struct attribute *default_attrs[] = { 118 &attr_physical_package_id.attr, 119 &attr_core_id.attr, 120 &attr_thread_siblings.attr, 121 &attr_thread_siblings_list.attr, 122 &attr_core_siblings.attr, 123 &attr_core_siblings_list.attr, 124 NULL 125}; 126 127static struct attribute_group topology_attr_group = { 128 .attrs = default_attrs, 129 .name = "topology" 130}; 131 132/* Add/Remove cpu_topology interface for CPU device */ 133static int __cpuinit topology_add_dev(unsigned int cpu) 134{ 135 struct sys_device *sys_dev = get_cpu_sysdev(cpu); 136 137 return sysfs_create_group(&sys_dev->kobj, &topology_attr_group); 138} 139 140static void __cpuinit topology_remove_dev(unsigned int cpu) 141{ 142 struct sys_device *sys_dev = get_cpu_sysdev(cpu); 143 144 sysfs_remove_group(&sys_dev->kobj, &topology_attr_group); 145} 146 147static int __cpuinit topology_cpu_callback(struct notifier_block *nfb, 148 unsigned long action, void *hcpu) 149{ 150 unsigned int cpu = (unsigned long)hcpu; 151 int rc = 0; 152 153 switch (action) { 154 case CPU_UP_PREPARE: 155 case CPU_UP_PREPARE_FROZEN: 156 rc = topology_add_dev(cpu); 157 break; 158 case CPU_UP_CANCELED: 159 case CPU_UP_CANCELED_FROZEN: 160 case CPU_DEAD: 161 case CPU_DEAD_FROZEN: 162 topology_remove_dev(cpu); 163 break; 164 } 165 return notifier_from_errno(rc); 166} 167 168static int __cpuinit topology_sysfs_init(void) 169{ 170 int cpu; 171 int rc; 172 173 for_each_online_cpu(cpu) { 174 rc = topology_add_dev(cpu); 175 if (rc) 176 return rc; 177 } 178 hotcpu_notifier(topology_cpu_callback, 0); 179 180 return 0; 181} 182 183device_initcall(topology_sysfs_init); 184