/* * driver/base/topology.c - Populate sysfs with cpu topology information * * Written by: Zhang Yanmin, Intel Corporation * * Copyright (C) 2006, Intel Corp. * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or * NON INFRINGEMENT. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include <linux/sysdev.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/cpu.h> #include <linux/module.h> #include <linux/topology.h> #define define_one_ro(_name) \ static SYSDEV_ATTR(_name, 0444, show_##_name, NULL) #define define_id_show_func(name) \ static ssize_t show_##name(struct sys_device *dev, char *buf) \ { \ unsigned int cpu = dev->id; \ return sprintf(buf, "%d\n", topology_##name(cpu)); \ } #define define_siblings_show_func(name) \ static ssize_t show_##name(struct sys_device *dev, char *buf) \ { \ ssize_t len = -1; \ unsigned int cpu = dev->id; \ len = cpumask_scnprintf(buf, NR_CPUS+1, topology_##name(cpu)); \ return (len + sprintf(buf + len, "\n")); \ } #ifdef topology_physical_package_id define_id_show_func(physical_package_id); define_one_ro(physical_package_id); #define ref_physical_package_id_attr &attr_physical_package_id.attr, #else #define ref_physical_package_id_attr #endif #ifdef topology_core_id define_id_show_func(core_id); define_one_ro(core_id); #define ref_core_id_attr &attr_core_id.attr, #else #define ref_core_id_attr #endif #ifdef topology_thread_siblings define_siblings_show_func(thread_siblings); define_one_ro(thread_siblings); #define ref_thread_siblings_attr &attr_thread_siblings.attr, #else #define ref_thread_siblings_attr #endif #ifdef topology_core_siblings define_siblings_show_func(core_siblings); define_one_ro(core_siblings); #define ref_core_siblings_attr &attr_core_siblings.attr, #else #define ref_core_siblings_attr #endif static struct attribute *default_attrs[] = { ref_physical_package_id_attr ref_core_id_attr ref_thread_siblings_attr ref_core_siblings_attr NULL }; static struct attribute_group topology_attr_group = { .attrs = default_attrs, .name = "topology" }; static cpumask_t topology_dev_map = CPU_MASK_NONE; /* Add/Remove cpu_topology interface for CPU device */ static int __cpuinit topology_add_dev(unsigned int cpu) { int rc; struct sys_device *sys_dev = get_cpu_sysdev(cpu); rc = sysfs_create_group(&sys_dev->kobj, &topology_attr_group); if (!rc) cpu_set(cpu, topology_dev_map); return rc; } static void __cpuinit topology_remove_dev(unsigned int cpu) { struct sys_device *sys_dev = get_cpu_sysdev(cpu); if (!cpu_isset(cpu, topology_dev_map)) return; cpu_clear(cpu, topology_dev_map); sysfs_remove_group(&sys_dev->kobj, &topology_attr_group); } static int __cpuinit topology_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) { unsigned int cpu = (unsigned long)hcpu; int rc = 0; switch (action) { case CPU_UP_PREPARE: rc = topology_add_dev(cpu); break; case CPU_UP_CANCELED: case CPU_DEAD: topology_remove_dev(cpu); break; } return rc ? NOTIFY_BAD : NOTIFY_OK; } static int __cpuinit topology_sysfs_init(void) { int cpu; int rc; for_each_online_cpu(cpu) { rc = topology_add_dev(cpu); if (rc) return rc; } hotcpu_notifier(topology_cpu_callback, 0); return 0; } device_initcall(topology_sysfs_init);