cpu: convert 'cpu' and 'machinecheck' sysdev_class to a regular subsystem

This moves the 'cpu sysdev_class' over to a regular 'cpu' subsystem
and converts the devices to regular devices. The sysdev drivers are
implemented as subsystem interfaces now.

After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.

Userspace relies on events and generic sysfs subsystem infrastructure
from sysdev devices, which are made available with this conversion.

Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@amd64.org>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Len Brown <lenb@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 77 insertions, 69 deletions

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 251acea..5bb0298 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -1,8 +1,7 @@
 /*
- * drivers/base/cpu.c - basic CPU class support
+ * CPU subsystem support
  */
 
-#include <linux/sysdev.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/sched.h>
@@ -14,40 +13,40 @@
 
 #include "base.h"
 
-static struct sysdev_class_attribute *cpu_sysdev_class_attrs[];
-
-struct sysdev_class cpu_sysdev_class = {
+struct bus_type cpu_subsys = {
 	.name = "cpu",
-	.attrs = cpu_sysdev_class_attrs,
+	.dev_name = "cpu",
 };
-EXPORT_SYMBOL(cpu_sysdev_class);
+EXPORT_SYMBOL_GPL(cpu_subsys);
 
-static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices);
+static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
 
 #ifdef CONFIG_HOTPLUG_CPU
-static ssize_t show_online(struct sys_device *dev, struct sysdev_attribute *attr,
+static ssize_t show_online(struct device *dev,
+			   struct device_attribute *attr,
 			   char *buf)
 {
-	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
+	struct cpu *cpu = container_of(dev, struct cpu, dev);
 
-	return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id));
+	return sprintf(buf, "%u\n", !!cpu_online(cpu->dev.id));
 }
 
-static ssize_t __ref store_online(struct sys_device *dev, struct sysdev_attribute *attr,
-				 const char *buf, size_t count)
+static ssize_t __ref store_online(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
 {
-	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
+	struct cpu *cpu = container_of(dev, struct cpu, dev);
 	ssize_t ret;
 
 	cpu_hotplug_driver_lock();
 	switch (buf[0]) {
 	case '0':
-		ret = cpu_down(cpu->sysdev.id);
+		ret = cpu_down(cpu->dev.id);
 		if (!ret)
 			kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
 		break;
 	case '1':
-		ret = cpu_up(cpu->sysdev.id);
+		ret = cpu_up(cpu->dev.id);
 		if (!ret)
 			kobject_uevent(&dev->kobj, KOBJ_ONLINE);
 		break;
@@ -60,44 +59,44 @@ static ssize_t __ref store_online(struct sys_device *dev, struct sysdev_attribut
 		ret = count;
 	return ret;
 }
-static SYSDEV_ATTR(online, 0644, show_online, store_online);
+static DEVICE_ATTR(online, 0644, show_online, store_online);
 
 static void __cpuinit register_cpu_control(struct cpu *cpu)
 {
-	sysdev_create_file(&cpu->sysdev, &attr_online);
+	device_create_file(&cpu->dev, &dev_attr_online);
 }
 void unregister_cpu(struct cpu *cpu)
 {
-	int logical_cpu = cpu->sysdev.id;
+	int logical_cpu = cpu->dev.id;
 
 	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
 
-	sysdev_remove_file(&cpu->sysdev, &attr_online);
+	device_remove_file(&cpu->dev, &dev_attr_online);
 
-	sysdev_unregister(&cpu->sysdev);
+	device_unregister(&cpu->dev);
 	per_cpu(cpu_sys_devices, logical_cpu) = NULL;
 	return;
 }
 
 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
-static ssize_t cpu_probe_store(struct sysdev_class *class,
-			       struct sysdev_class_attribute *attr,
+static ssize_t cpu_probe_store(struct device *dev,
+			       struct device_attribute *attr,
 			       const char *buf,
 			       size_t count)
 {
 	return arch_cpu_probe(buf, count);
 }
 
-static ssize_t cpu_release_store(struct sysdev_class *class,
-				 struct sysdev_class_attribute *attr,
+static ssize_t cpu_release_store(struct device *dev,
+				 struct device_attribute *attr,
 				 const char *buf,
 				 size_t count)
 {
 	return arch_cpu_release(buf, count);
 }
 
-static SYSDEV_CLASS_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
-static SYSDEV_CLASS_ATTR(release, S_IWUSR, NULL, cpu_release_store);
+static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
+static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store);
 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
 
 #else /* ... !CONFIG_HOTPLUG_CPU */
@@ -109,15 +108,15 @@ static inline void register_cpu_control(struct cpu *cpu)
 #ifdef CONFIG_KEXEC
 #include <linux/kexec.h>
 
-static ssize_t show_crash_notes(struct sys_device *dev, struct sysdev_attribute *attr,
+static ssize_t show_crash_notes(struct device *dev, struct device_attribute *attr,
 				char *buf)
 {
-	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
+	struct cpu *cpu = container_of(dev, struct cpu, dev);
 	ssize_t rc;
 	unsigned long long addr;
 	int cpunum;
 
-	cpunum = cpu->sysdev.id;
+	cpunum = cpu->dev.id;
 
 	/*
 	 * Might be reading other cpu's data based on which cpu read thread
@@ -129,7 +128,7 @@ static ssize_t show_crash_notes(struct sys_device *dev, struct sysdev_attribute
 	rc = sprintf(buf, "%Lx\n", addr);
 	return rc;
 }
-static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
+static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL);
 #endif
 
 /*
@@ -137,12 +136,12 @@ static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
  */
 
 struct cpu_attr {
-	struct sysdev_class_attribute attr;
+	struct device_attribute attr;
 	const struct cpumask *const * const map;
 };
 
-static ssize_t show_cpus_attr(struct sysdev_class *class,
-			      struct sysdev_class_attribute *attr,
+static ssize_t show_cpus_attr(struct device *dev,
+			      struct device_attribute *attr,
 			      char *buf)
 {
 	struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr);
@@ -153,10 +152,10 @@ static ssize_t show_cpus_attr(struct sysdev_class *class,
 	return n;
 }
 
-#define _CPU_ATTR(name, map)						\
-	{ _SYSDEV_CLASS_ATTR(name, 0444, show_cpus_attr, NULL), map }
+#define _CPU_ATTR(name, map) \
+	{ __ATTR(name, 0444, show_cpus_attr, NULL), map }
 
-/* Keep in sync with cpu_sysdev_class_attrs */
+/* Keep in sync with cpu_subsys_attrs */
 static struct cpu_attr cpu_attrs[] = {
 	_CPU_ATTR(online, &cpu_online_mask),
 	_CPU_ATTR(possible, &cpu_possible_mask),
@@ -166,19 +165,19 @@ static struct cpu_attr cpu_attrs[] = {
 /*
  * Print values for NR_CPUS and offlined cpus
  */
-static ssize_t print_cpus_kernel_max(struct sysdev_class *class,
-				     struct sysdev_class_attribute *attr, char *buf)
+static ssize_t print_cpus_kernel_max(struct device *dev,
+				     struct device_attribute *attr, char *buf)
 {
 	int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
 	return n;
 }
-static SYSDEV_CLASS_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
+static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
 
 /* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
 unsigned int total_cpus;
 
-static ssize_t print_cpus_offline(struct sysdev_class *class,
-				  struct sysdev_class_attribute *attr, char *buf)
+static ssize_t print_cpus_offline(struct device *dev,
+				  struct device_attribute *attr, char *buf)
 {
 	int n = 0, len = PAGE_SIZE-2;
 	cpumask_var_t offline;
@@ -205,7 +204,7 @@ static ssize_t print_cpus_offline(struct sysdev_class *class,
 	n += snprintf(&buf[n], len - n, "\n");
 	return n;
 }
-static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL);
+static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);
 
 /*
  * register_cpu - Setup a sysfs device for a CPU.
@@ -218,57 +217,66 @@ static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL);
 int __cpuinit register_cpu(struct cpu *cpu, int num)
 {
 	int error;
-	cpu->node_id = cpu_to_node(num);
-	cpu->sysdev.id = num;
-	cpu->sysdev.cls = &cpu_sysdev_class;
-
-	error = sysdev_register(&cpu->sysdev);
 
+	cpu->node_id = cpu_to_node(num);
+	cpu->dev.id = num;
+	cpu->dev.bus = &cpu_subsys;
+	error = device_register(&cpu->dev);
 	if (!error && cpu->hotpluggable)
 		register_cpu_control(cpu);
 	if (!error)
-		per_cpu(cpu_sys_devices, num) = &cpu->sysdev;
+		per_cpu(cpu_sys_devices, num) = &cpu->dev;
 	if (!error)
 		register_cpu_under_node(num, cpu_to_node(num));
 
 #ifdef CONFIG_KEXEC
 	if (!error)
-		error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes);
+		error = device_create_file(&cpu->dev, &dev_attr_crash_notes);
 #endif
 	return error;
 }
 
-struct sys_device *get_cpu_sysdev(unsigned cpu)
+struct device *get_cpu_device(unsigned cpu)
 {
 	if (cpu < nr_cpu_ids && cpu_possible(cpu))
 		return per_cpu(cpu_sys_devices, cpu);
 	else
 		return NULL;
 }
-EXPORT_SYMBOL_GPL(get_cpu_sysdev);
+EXPORT_SYMBOL_GPL(get_cpu_device);
+
+static struct attribute *cpu_root_attrs[] = {
+#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
+	&dev_attr_probe.attr,
+	&dev_attr_release.attr,
+#endif
+	&cpu_attrs[0].attr.attr,
+	&cpu_attrs[1].attr.attr,
+	&cpu_attrs[2].attr.attr,
+	&dev_attr_kernel_max.attr,
+	&dev_attr_offline.attr,
+	NULL
+};
+
+static struct attribute_group cpu_root_attr_group = {
+	.attrs = cpu_root_attrs,
+};
+
+static const struct attribute_group *cpu_root_attr_groups[] = {
+	&cpu_root_attr_group,
+	NULL,
+};
 
 int __init cpu_dev_init(void)
 {
 	int err;
 
-	err = sysdev_class_register(&cpu_sysdev_class);
+	err = subsys_system_register(&cpu_subsys, cpu_root_attr_groups);
+	if (err)
+		return err;
+
 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
-	if (!err)
-		err = sched_create_sysfs_power_savings_entries(&cpu_sysdev_class);
+	err = sched_create_sysfs_power_savings_entries(cpu_subsys.dev_root);
 #endif
-
 	return err;
 }
-
-static struct sysdev_class_attribute *cpu_sysdev_class_attrs[] = {
-#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
-	&attr_probe,
-	&attr_release,
-#endif
-	&cpu_attrs[0].attr,
-	&cpu_attrs[1].attr,
-	&cpu_attrs[2].attr,
-	&attr_kernel_max,
-	&attr_offline,
-	NULL
-};