2 files changed, 149 insertions, 0 deletions

diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index f12898d53078..e99471d3232b 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -8,6 +8,7 @@ obj-y			+= power/
 obj-$(CONFIG_FW_LOADER) += firmware_class.o
 obj-$(CONFIG_NUMA)      += node.o
 obj-$(CONFIG_MEMORY_HOTPLUG) += memory.o
+obj-$(CONFIG_SMP)       += topology.o
 
 ifeq ($(CONFIG_DEBUG_DRIVER),y)
 EXTRA_CFLAGS += -DDEBUG
diff --git a/drivers/base/topology.c b/drivers/base/topology.c
new file mode 100644
index 000000000000..915810f6237e
--- /dev/null
+++ b/drivers/base/topology.c
@@ -0,0 +1,148 @@
+/*
+ * 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);
+