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(_name) \ 35 static SYSDEV_ATTR(_name, 0444, show_##_name, NULL) 36 37 #define define_id_show_func(name) \ 38 static ssize_t show_##name(struct sys_device *dev, \ 39 struct sysdev_attribute *attr, char *buf) \ 40 { \ 41 unsigned int cpu = dev->id; \ 42 return sprintf(buf, "%d\n", topology_##name(cpu)); \ 43 } 44 45 #if defined(topology_thread_siblings) || defined(topology_core_siblings) 46 static ssize_t show_cpumap(int type, cpumask_t *mask, char *buf) 47 { 48 ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf; 49 int n = 0; 50 51 if (len > 1) { 52 n = type? 53 cpulist_scnprintf(buf, len-2, mask) : 54 cpumask_scnprintf(buf, len-2, mask); 55 buf[n++] = '\n'; 56 buf[n] = '\0'; 57 } 58 return n; 59 } 60 #endif 61 62 #ifdef arch_provides_topology_pointers 63 #define define_siblings_show_map(name) \ 64 static ssize_t show_##name(struct sys_device *dev, \ 65 struct sysdev_attribute *attr, char *buf) \ 66 { \ 67 unsigned int cpu = dev->id; \ 68 return show_cpumap(0, &(topology_##name(cpu)), buf); \ 69 } 70 71 #define define_siblings_show_list(name) \ 72 static ssize_t show_##name##_list(struct sys_device *dev, \ 73 struct sysdev_attribute *attr, \ 74 char *buf) \ 75 { \ 76 unsigned int cpu = dev->id; \ 77 return show_cpumap(1, &(topology_##name(cpu)), buf); \ 78 } 79 80 #else 81 #define define_siblings_show_map(name) \ 82 static ssize_t show_##name(struct sys_device *dev, \ 83 struct sysdev_attribute *attr, char *buf) \ 84 { \ 85 unsigned int cpu = dev->id; \ 86 cpumask_t mask = topology_##name(cpu); \ 87 return show_cpumap(0, &mask, buf); \ 88 } 89 90 #define define_siblings_show_list(name) \ 91 static ssize_t show_##name##_list(struct sys_device *dev, \ 92 struct sysdev_attribute *attr, \ 93 char *buf) \ 94 { \ 95 unsigned int cpu = dev->id; \ 96 cpumask_t mask = topology_##name(cpu); \ 97 return show_cpumap(1, &mask, 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_siblings); 111 define_one_ro(thread_siblings); 112 define_one_ro(thread_siblings_list); 113 114 define_siblings_show_func(core_siblings); 115 define_one_ro(core_siblings); 116 define_one_ro(core_siblings_list); 117 118 static struct attribute *default_attrs[] = { 119 &attr_physical_package_id.attr, 120 &attr_core_id.attr, 121 &attr_thread_siblings.attr, 122 &attr_thread_siblings_list.attr, 123 &attr_core_siblings.attr, 124 &attr_core_siblings_list.attr, 125 NULL 126 }; 127 128 static struct attribute_group topology_attr_group = { 129 .attrs = default_attrs, 130 .name = "topology" 131 }; 132 133 /* Add/Remove cpu_topology interface for CPU device */ 134 static int __cpuinit topology_add_dev(unsigned int cpu) 135 { 136 struct sys_device *sys_dev = get_cpu_sysdev(cpu); 137 138 return sysfs_create_group(&sys_dev->kobj, &topology_attr_group); 139 } 140 141 static void __cpuinit topology_remove_dev(unsigned int cpu) 142 { 143 struct sys_device *sys_dev = get_cpu_sysdev(cpu); 144 145 sysfs_remove_group(&sys_dev->kobj, &topology_attr_group); 146 } 147 148 static int __cpuinit topology_cpu_callback(struct notifier_block *nfb, 149 unsigned long action, void *hcpu) 150 { 151 unsigned int cpu = (unsigned long)hcpu; 152 int rc = 0; 153 154 switch (action) { 155 case CPU_UP_PREPARE: 156 case CPU_UP_PREPARE_FROZEN: 157 rc = topology_add_dev(cpu); 158 break; 159 case CPU_UP_CANCELED: 160 case CPU_UP_CANCELED_FROZEN: 161 case CPU_DEAD: 162 case CPU_DEAD_FROZEN: 163 topology_remove_dev(cpu); 164 break; 165 } 166 return rc ? NOTIFY_BAD : NOTIFY_OK; 167 } 168 169 static int __cpuinit topology_sysfs_init(void) 170 { 171 int cpu; 172 int rc; 173 174 for_each_online_cpu(cpu) { 175 rc = topology_add_dev(cpu); 176 if (rc) 177 return rc; 178 } 179 hotcpu_notifier(topology_cpu_callback, 0); 180 181 return 0; 182 } 183 184 device_initcall(topology_sysfs_init); 185