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>
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 987a165..8c2df34 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -679,7 +679,7 @@
  */
 static int cpufreq_add_dev_policy(unsigned int cpu,
 				  struct cpufreq_policy *policy,
-				  struct sys_device *sys_dev)
+				  struct device *dev)
 {
 	int ret = 0;
 #ifdef CONFIG_SMP
@@ -728,7 +728,7 @@
 			spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
 			pr_debug("CPU already managed, adding link\n");
-			ret = sysfs_create_link(&sys_dev->kobj,
+			ret = sysfs_create_link(&dev->kobj,
 						&managed_policy->kobj,
 						"cpufreq");
 			if (ret)
@@ -761,7 +761,7 @@
 
 	for_each_cpu(j, policy->cpus) {
 		struct cpufreq_policy *managed_policy;
-		struct sys_device *cpu_sys_dev;
+		struct device *cpu_dev;
 
 		if (j == cpu)
 			continue;
@@ -770,8 +770,8 @@
 
 		pr_debug("CPU %u already managed, adding link\n", j);
 		managed_policy = cpufreq_cpu_get(cpu);
-		cpu_sys_dev = get_cpu_sysdev(j);
-		ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj,
+		cpu_dev = get_cpu_device(j);
+		ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
 					"cpufreq");
 		if (ret) {
 			cpufreq_cpu_put(managed_policy);
@@ -783,7 +783,7 @@
 
 static int cpufreq_add_dev_interface(unsigned int cpu,
 				     struct cpufreq_policy *policy,
-				     struct sys_device *sys_dev)
+				     struct device *dev)
 {
 	struct cpufreq_policy new_policy;
 	struct freq_attr **drv_attr;
@@ -793,7 +793,7 @@
 
 	/* prepare interface data */
 	ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
-				   &sys_dev->kobj, "cpufreq");
+				   &dev->kobj, "cpufreq");
 	if (ret)
 		return ret;
 
@@ -866,9 +866,9 @@
  * with with cpu hotplugging and all hell will break loose. Tried to clean this
  * mess up, but more thorough testing is needed. - Mathieu
  */
-static int cpufreq_add_dev(struct sys_device *sys_dev)
+static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
 {
-	unsigned int cpu = sys_dev->id;
+	unsigned int cpu = dev->id;
 	int ret = 0, found = 0;
 	struct cpufreq_policy *policy;
 	unsigned long flags;
@@ -947,7 +947,7 @@
 	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
 				     CPUFREQ_START, policy);
 
-	ret = cpufreq_add_dev_policy(cpu, policy, sys_dev);
+	ret = cpufreq_add_dev_policy(cpu, policy, dev);
 	if (ret) {
 		if (ret > 0)
 			/* This is a managed cpu, symlink created,
@@ -956,7 +956,7 @@
 		goto err_unlock_policy;
 	}
 
-	ret = cpufreq_add_dev_interface(cpu, policy, sys_dev);
+	ret = cpufreq_add_dev_interface(cpu, policy, dev);
 	if (ret)
 		goto err_out_unregister;
 
@@ -999,15 +999,15 @@
  * Caller should already have policy_rwsem in write mode for this CPU.
  * This routine frees the rwsem before returning.
  */
-static int __cpufreq_remove_dev(struct sys_device *sys_dev)
+static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
 {
-	unsigned int cpu = sys_dev->id;
+	unsigned int cpu = dev->id;
 	unsigned long flags;
 	struct cpufreq_policy *data;
 	struct kobject *kobj;
 	struct completion *cmp;
 #ifdef CONFIG_SMP
-	struct sys_device *cpu_sys_dev;
+	struct device *cpu_dev;
 	unsigned int j;
 #endif
 
@@ -1032,7 +1032,7 @@
 		pr_debug("removing link\n");
 		cpumask_clear_cpu(cpu, data->cpus);
 		spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
-		kobj = &sys_dev->kobj;
+		kobj = &dev->kobj;
 		cpufreq_cpu_put(data);
 		unlock_policy_rwsem_write(cpu);
 		sysfs_remove_link(kobj, "cpufreq");
@@ -1071,8 +1071,8 @@
 			strncpy(per_cpu(cpufreq_cpu_governor, j),
 				data->governor->name, CPUFREQ_NAME_LEN);
 #endif
-			cpu_sys_dev = get_cpu_sysdev(j);
-			kobj = &cpu_sys_dev->kobj;
+			cpu_dev = get_cpu_device(j);
+			kobj = &cpu_dev->kobj;
 			unlock_policy_rwsem_write(cpu);
 			sysfs_remove_link(kobj, "cpufreq");
 			lock_policy_rwsem_write(cpu);
@@ -1112,11 +1112,11 @@
 	if (unlikely(cpumask_weight(data->cpus) > 1)) {
 		/* first sibling now owns the new sysfs dir */
 		cpumask_clear_cpu(cpu, data->cpus);
-		cpufreq_add_dev(get_cpu_sysdev(cpumask_first(data->cpus)));
+		cpufreq_add_dev(get_cpu_device(cpumask_first(data->cpus)), NULL);
 
 		/* finally remove our own symlink */
 		lock_policy_rwsem_write(cpu);
-		__cpufreq_remove_dev(sys_dev);
+		__cpufreq_remove_dev(dev, sif);
 	}
 #endif
 
@@ -1128,9 +1128,9 @@
 }
 
 
-static int cpufreq_remove_dev(struct sys_device *sys_dev)
+static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
 {
-	unsigned int cpu = sys_dev->id;
+	unsigned int cpu = dev->id;
 	int retval;
 
 	if (cpu_is_offline(cpu))
@@ -1139,7 +1139,7 @@
 	if (unlikely(lock_policy_rwsem_write(cpu)))
 		BUG();
 
-	retval = __cpufreq_remove_dev(sys_dev);
+	retval = __cpufreq_remove_dev(dev, sif);
 	return retval;
 }
 
@@ -1271,9 +1271,11 @@
 }
 EXPORT_SYMBOL(cpufreq_get);
 
-static struct sysdev_driver cpufreq_sysdev_driver = {
-	.add		= cpufreq_add_dev,
-	.remove		= cpufreq_remove_dev,
+static struct subsys_interface cpufreq_interface = {
+	.name		= "cpufreq",
+	.subsys		= &cpu_subsys,
+	.add_dev	= cpufreq_add_dev,
+	.remove_dev	= cpufreq_remove_dev,
 };
 
 
@@ -1765,25 +1767,25 @@
 					unsigned long action, void *hcpu)
 {
 	unsigned int cpu = (unsigned long)hcpu;
-	struct sys_device *sys_dev;
+	struct device *dev;
 
-	sys_dev = get_cpu_sysdev(cpu);
-	if (sys_dev) {
+	dev = get_cpu_device(cpu);
+	if (dev) {
 		switch (action) {
 		case CPU_ONLINE:
 		case CPU_ONLINE_FROZEN:
-			cpufreq_add_dev(sys_dev);
+			cpufreq_add_dev(dev, NULL);
 			break;
 		case CPU_DOWN_PREPARE:
 		case CPU_DOWN_PREPARE_FROZEN:
 			if (unlikely(lock_policy_rwsem_write(cpu)))
 				BUG();
 
-			__cpufreq_remove_dev(sys_dev);
+			__cpufreq_remove_dev(dev, NULL);
 			break;
 		case CPU_DOWN_FAILED:
 		case CPU_DOWN_FAILED_FROZEN:
-			cpufreq_add_dev(sys_dev);
+			cpufreq_add_dev(dev, NULL);
 			break;
 		}
 	}
@@ -1830,8 +1832,7 @@
 	cpufreq_driver = driver_data;
 	spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
-	ret = sysdev_driver_register(&cpu_sysdev_class,
-					&cpufreq_sysdev_driver);
+	ret = subsys_interface_register(&cpufreq_interface);
 	if (ret)
 		goto err_null_driver;
 
@@ -1850,7 +1851,7 @@
 		if (ret) {
 			pr_debug("no CPU initialized for driver %s\n",
 							driver_data->name);
-			goto err_sysdev_unreg;
+			goto err_if_unreg;
 		}
 	}
 
@@ -1858,9 +1859,8 @@
 	pr_debug("driver %s up and running\n", driver_data->name);
 
 	return 0;
-err_sysdev_unreg:
-	sysdev_driver_unregister(&cpu_sysdev_class,
-			&cpufreq_sysdev_driver);
+err_if_unreg:
+	subsys_interface_unregister(&cpufreq_interface);
 err_null_driver:
 	spin_lock_irqsave(&cpufreq_driver_lock, flags);
 	cpufreq_driver = NULL;
@@ -1887,7 +1887,7 @@
 
 	pr_debug("unregistering driver %s\n", driver->name);
 
-	sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver);
+	subsys_interface_unregister(&cpufreq_interface);
 	unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
 
 	spin_lock_irqsave(&cpufreq_driver_lock, flags);
@@ -1907,8 +1907,7 @@
 		init_rwsem(&per_cpu(cpu_policy_rwsem, cpu));
 	}
 
-	cpufreq_global_kobject = kobject_create_and_add("cpufreq",
-						&cpu_sysdev_class.kset.kobj);
+	cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
 	BUG_ON(!cpufreq_global_kobject);
 	register_syscore_ops(&cpufreq_syscore_ops);