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/topology.h> 32 33 #define define_one_ro(_name) \ 34 static SYSDEV_ATTR(_name, 0444, show_##_name, NULL) 35 36 #define define_id_show_func(name) \ 37 static ssize_t show_##name(struct sys_device *dev, \ 38 struct sysdev_attribute *attr, char *buf) \ 39 { \ 40 unsigned int cpu = dev->id; \ 41 return sprintf(buf, "%d\n", topology_##name(cpu)); \ 42 } 43 44 #if defined(topology_thread_siblings) || defined(topology_core_siblings) 45 static ssize_t show_cpumap(int type, cpumask_t *mask, char *buf) 46 { 47 ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf; 48 int n = 0; 49 50 if (len > 1) { 51 n = type? 52 cpulist_scnprintf(buf, len-2, *mask): 53 cpumask_scnprintf(buf, len-2, *mask); 54 buf[n++] = '\n'; 55 buf[n] = '\0'; 56 } 57 return n; 58 } 59 #endif 60 61 #ifdef arch_provides_topology_pointers 62 #define define_siblings_show_map(name) \ 63 static ssize_t show_##name(struct sys_device *dev, \ 64 struct sysdev_attribute *attr, char *buf) \ 65 { \ 66 unsigned int cpu = dev->id; \ 67 return show_cpumap(0, &(topology_##name(cpu)), buf); \ 68 } 69 70 #define define_siblings_show_list(name) \ 71 static ssize_t show_##name##_list(struct sys_device *dev, \ 72 struct sysdev_attribute *attr, \ 73 char *buf) \ 74 { \ 75 unsigned int cpu = dev->id; \ 76 return show_cpumap(1, &(topology_##name(cpu)), buf); \ 77 } 78 79 #else 80 #define define_siblings_show_map(name) \ 81 static ssize_t show_##name(struct sys_device *dev, \ 82 struct sysdev_attribute *attr, char *buf) \ 83 { \ 84 unsigned int cpu = dev->id; \ 85 cpumask_t mask = topology_##name(cpu); \ 86 return show_cpumap(0, &mask, buf); \ 87 } 88 89 #define define_siblings_show_list(name) \ 90 static ssize_t show_##name##_list(struct sys_device *dev, \ 91 struct sysdev_attribute *attr, \ 92 char *buf) \ 93 { \ 94 unsigned int cpu = dev->id; \ 95 cpumask_t mask = topology_##name(cpu); \ 96 return show_cpumap(1, &mask, buf); \ 97 } 98 #endif 99 100 #define define_siblings_show_func(name) \ 101 define_siblings_show_map(name); define_siblings_show_list(name) 102 103 define_id_show_func(physical_package_id); 104 define_one_ro(physical_package_id); 105 106 define_id_show_func(core_id); 107 define_one_ro(core_id); 108 109 define_siblings_show_func(thread_siblings); 110 define_one_ro(thread_siblings); 111 define_one_ro(thread_siblings_list); 112 113 define_siblings_show_func(core_siblings); 114 define_one_ro(core_siblings); 115 define_one_ro(core_siblings_list); 116 117 static 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 }; 126 127 static struct attribute_group topology_attr_group = { 128 .attrs = default_attrs, 129 .name = "topology" 130 }; 131 132 /* Add/Remove cpu_topology interface for CPU device */ 133 static 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 } 139 140 static 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 } 146 147 static 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 rc ? NOTIFY_BAD : NOTIFY_OK; 166 } 167 168 static 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 } 182 183 device_initcall(topology_sysfs_init); 184