--- /dev/null
+
+Export cpu topology info by sysfs. Items (attributes) are similar
+to /proc/cpuinfo.
+
+1) /sys/devices/system/cpu/cpuX/topology/physical_package_id:
+represent the physical package id of cpu X;
+2) /sys/devices/system/cpu/cpuX/topology/core_id:
+represent the cpu core id to cpu X;
+3) /sys/devices/system/cpu/cpuX/topology/thread_siblings:
+represent the thread siblings to cpu X in the same core;
+4) /sys/devices/system/cpu/cpuX/topology/core_siblings:
+represent the thread siblings to cpu X in the same physical package;
+
+To implement it in an architecture-neutral way, a new source file,
+driver/base/topology.c, is to export the 5 attributes.
+
+If one architecture wants to support this feature, it just needs to
+implement 4 defines, typically in file include/asm-XXX/topology.h.
+The 4 defines are:
+#define topology_physical_package_id(cpu)
+#define topology_core_id(cpu)
+#define topology_thread_siblings(cpu)
+#define topology_core_siblings(cpu)
+
+The type of **_id is int.
+The type of siblings is cpumask_t.
+
+To be consistent on all architectures, the 4 attributes should have
+deafult values if their values are unavailable. Below is the rule.
+1) physical_package_id: If cpu has no physical package id, -1 is the
+default value.
+2) core_id: If cpu doesn't support multi-core, its core id is 0.
+3) thread_siblings: Just include itself, if the cpu doesn't support
+HT/multi-thread.
+4) core_siblings: Just include itself, if the cpu doesn't support
+multi-core and HT/Multi-thread.
+
+So be careful when declaring the 4 defines in include/asm-XXX/topology.h.
+
+If an attribute isn't defined on an architecture, it won't be exported.
+
int i, err = 0;
#ifdef CONFIG_NUMA
- sysfs_nodes = kmalloc(sizeof(struct node) * MAX_NUMNODES, GFP_KERNEL);
+ sysfs_nodes = kzalloc(sizeof(struct node) * MAX_NUMNODES, GFP_KERNEL);
if (!sysfs_nodes) {
err = -ENOMEM;
goto out;
}
- memset(sysfs_nodes, 0, sizeof(struct node) * MAX_NUMNODES);
- /* MCD - Do we want to register all ONLINE nodes, or all POSSIBLE nodes? */
- for_each_online_node(i)
+ /*
+ * MCD - Do we want to register all ONLINE nodes, or all POSSIBLE nodes?
+ */
+ for_each_online_node(i) {
if ((err = register_node(&sysfs_nodes[i], i, 0)))
goto out;
+ }
#endif
- sysfs_cpus = kmalloc(sizeof(struct ia64_cpu) * NR_CPUS, GFP_KERNEL);
+ sysfs_cpus = kzalloc(sizeof(struct ia64_cpu) * NR_CPUS, GFP_KERNEL);
if (!sysfs_cpus) {
err = -ENOMEM;
goto out;
}
- memset(sysfs_cpus, 0, sizeof(struct ia64_cpu) * NR_CPUS);
- for_each_present_cpu(i)
+ for_each_present_cpu(i) {
if((err = arch_register_cpu(i)))
goto out;
+ }
out:
return err;
}
-__initcall(topology_init);
+subsys_initcall(topology_init);
--- /dev/null
+/*
+ * 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"
+};
+
+/* Add/Remove cpu_topology interface for CPU device */
+static int __cpuinit topology_add_dev(struct sys_device * sys_dev)
+{
+ sysfs_create_group(&sys_dev->kobj, &topology_attr_group);
+ return 0;
+}
+
+static int __cpuinit topology_remove_dev(struct sys_device * sys_dev)
+{
+ sysfs_remove_group(&sys_dev->kobj, &topology_attr_group);
+ return 0;
+}
+
+static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+ struct sys_device *sys_dev;
+
+ sys_dev = get_cpu_sysdev(cpu);
+ switch (action) {
+ case CPU_ONLINE:
+ topology_add_dev(sys_dev);
+ break;
+ case CPU_DEAD:
+ topology_remove_dev(sys_dev);
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block topology_cpu_notifier =
+{
+ .notifier_call = topology_cpu_callback,
+};
+
+static int __cpuinit topology_sysfs_init(void)
+{
+ int i;
+
+ for_each_online_cpu(i) {
+ topology_cpu_callback(&topology_cpu_notifier, CPU_ONLINE,
+ (void *)(long)i);
+ }
+
+ register_cpu_notifier(&topology_cpu_notifier);
+
+ return 0;
+}
+
+device_initcall(topology_sysfs_init);
+
projects / linux-2.6 / commitdiff