Merge branch 'acpi-hotplug'

* acpi-hotplug:
  ACPI: Do not use CONFIG_ACPI_HOTPLUG_MEMORY_MODULE
  ACPI / cpufreq: Add ACPI processor device IDs to acpi-cpufreq
  Memory hotplug: Move alternative function definitions to header
  ACPI / processor: Fix potential NULL pointer dereference in acpi_processor_add()
  Memory hotplug / ACPI: Simplify memory removal
  ACPI / scan: Add second pass of companion offlining to hot-remove code
  Driver core / MM: Drop offline_memory_block()
  ACPI / processor: Pass processor object handle to acpi_bind_one()
  ACPI: Drop removal_type field from struct acpi_device
  Driver core / memory: Simplify __memory_block_change_state()
  ACPI / processor: Initialize per_cpu(processors, pr->id) properly
  CPU: Fix sysfs cpu/online of offlined CPUs
  Driver core: Introduce offline/online callbacks for memory blocks
  ACPI / memhotplug: Bind removable memory blocks to ACPI device nodes
  ACPI / processor: Use common hotplug infrastructure
  ACPI / hotplug: Use device offline/online for graceful hot-removal
  Driver core: Use generic offline/online for CPU offline/online
  Driver core: Add offline/online device operations

3 files changed, 248 insertions, 97 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 2499cef..2166f34 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -403,6 +403,36 @@ static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
 static struct device_attribute uevent_attr =
 	__ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
 
+static ssize_t show_online(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	bool val;
+
+	lock_device_hotplug();
+	val = !dev->offline;
+	unlock_device_hotplug();
+	return sprintf(buf, "%u\n", val);
+}
+
+static ssize_t store_online(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	bool val;
+	int ret;
+
+	ret = strtobool(buf, &val);
+	if (ret < 0)
+		return ret;
+
+	lock_device_hotplug();
+	ret = val ? device_online(dev) : device_offline(dev);
+	unlock_device_hotplug();
+	return ret < 0 ? ret : count;
+}
+
+static struct device_attribute online_attr =
+	__ATTR(online, S_IRUGO | S_IWUSR, show_online, store_online);
+
 static int device_add_attributes(struct device *dev,
 				 struct device_attribute *attrs)
 {
@@ -516,6 +546,12 @@ static int device_add_attrs(struct device *dev)
 	if (error)
 		goto err_remove_type_groups;
 
+	if (device_supports_offline(dev) && !dev->offline_disabled) {
+		error = device_create_file(dev, &online_attr);
+		if (error)
+			goto err_remove_type_groups;
+	}
+
 	return 0;
 
  err_remove_type_groups:
@@ -536,6 +572,7 @@ static void device_remove_attrs(struct device *dev)
 	struct class *class = dev->class;
 	const struct device_type *type = dev->type;
 
+	device_remove_file(dev, &online_attr);
 	device_remove_groups(dev, dev->groups);
 
 	if (type)
@@ -1433,6 +1470,99 @@ EXPORT_SYMBOL_GPL(put_device);
 EXPORT_SYMBOL_GPL(device_create_file);
 EXPORT_SYMBOL_GPL(device_remove_file);
 
+static DEFINE_MUTEX(device_hotplug_lock);
+
+void lock_device_hotplug(void)
+{
+	mutex_lock(&device_hotplug_lock);
+}
+
+void unlock_device_hotplug(void)
+{
+	mutex_unlock(&device_hotplug_lock);
+}
+
+static int device_check_offline(struct device *dev, void *not_used)
+{
+	int ret;
+
+	ret = device_for_each_child(dev, NULL, device_check_offline);
+	if (ret)
+		return ret;
+
+	return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
+}
+
+/**
+ * device_offline - Prepare the device for hot-removal.
+ * @dev: Device to be put offline.
+ *
+ * Execute the device bus type's .offline() callback, if present, to prepare
+ * the device for a subsequent hot-removal.  If that succeeds, the device must
+ * not be used until either it is removed or its bus type's .online() callback
+ * is executed.
+ *
+ * Call under device_hotplug_lock.
+ */
+int device_offline(struct device *dev)
+{
+	int ret;
+
+	if (dev->offline_disabled)
+		return -EPERM;
+
+	ret = device_for_each_child(dev, NULL, device_check_offline);
+	if (ret)
+		return ret;
+
+	device_lock(dev);
+	if (device_supports_offline(dev)) {
+		if (dev->offline) {
+			ret = 1;
+		} else {
+			ret = dev->bus->offline(dev);
+			if (!ret) {
+				kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
+				dev->offline = true;
+			}
+		}
+	}
+	device_unlock(dev);
+
+	return ret;
+}
+
+/**
+ * device_online - Put the device back online after successful device_offline().
+ * @dev: Device to be put back online.
+ *
+ * If device_offline() has been successfully executed for @dev, but the device
+ * has not been removed subsequently, execute its bus type's .online() callback
+ * to indicate that the device can be used again.
+ *
+ * Call under device_hotplug_lock.
+ */
+int device_online(struct device *dev)
+{
+	int ret = 0;
+
+	device_lock(dev);
+	if (device_supports_offline(dev)) {
+		if (dev->offline) {
+			ret = dev->bus->online(dev);
+			if (!ret) {
+				kobject_uevent(&dev->kobj, KOBJ_ONLINE);
+				dev->offline = false;
+			}
+		} else {
+			ret = 1;
+		}
+	}
+	device_unlock(dev);
+
+	return ret;
+}
+
 struct root_device {
 	struct device dev;
 	struct module *owner;
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 3d48fc8..1d110dc6 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -13,17 +13,21 @@
 #include <linux/gfp.h>
 #include <linux/slab.h>
 #include <linux/percpu.h>
+#include <linux/acpi.h>
 
 #include "base.h"
 
-struct bus_type cpu_subsys = {
-	.name = "cpu",
-	.dev_name = "cpu",
-};
-EXPORT_SYMBOL_GPL(cpu_subsys);
-
 static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
 
+static int cpu_subsys_match(struct device *dev, struct device_driver *drv)
+{
+	/* ACPI style match is the only one that may succeed. */
+	if (acpi_driver_match_device(dev, drv))
+		return 1;
+
+	return 0;
+}
+
 #ifdef CONFIG_HOTPLUG_CPU
 static void change_cpu_under_node(struct cpu *cpu,
 			unsigned int from_nid, unsigned int to_nid)
@@ -34,69 +38,45 @@ static void change_cpu_under_node(struct cpu *cpu,
 	cpu->node_id = to_nid;
 }
 
-static ssize_t show_online(struct device *dev,
-			   struct device_attribute *attr,
-			   char *buf)
+static int __ref cpu_subsys_online(struct device *dev)
 {
 	struct cpu *cpu = container_of(dev, struct cpu, dev);
+	int cpuid = dev->id;
+	int from_nid, to_nid;
+	int ret;
 
-	return sprintf(buf, "%u\n", !!cpu_online(cpu->dev.id));
+	cpu_hotplug_driver_lock();
+
+	from_nid = cpu_to_node(cpuid);
+	ret = cpu_up(cpuid);
+	/*
+	 * When hot adding memory to memoryless node and enabling a cpu
+	 * on the node, node number of the cpu may internally change.
+	 */
+	to_nid = cpu_to_node(cpuid);
+	if (from_nid != to_nid)
+		change_cpu_under_node(cpu, from_nid, to_nid);
+
+	cpu_hotplug_driver_unlock();
+	return ret;
 }
 
-static ssize_t __ref store_online(struct device *dev,
-				  struct device_attribute *attr,
-				  const char *buf, size_t count)
+static int cpu_subsys_offline(struct device *dev)
 {
-	struct cpu *cpu = container_of(dev, struct cpu, dev);
-	int cpuid = cpu->dev.id;
-	int from_nid, to_nid;
-	ssize_t ret;
+	int ret;
 
 	cpu_hotplug_driver_lock();
-	switch (buf[0]) {
-	case '0':
-		ret = cpu_down(cpuid);
-		if (!ret)
-			kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
-		break;
-	case '1':
-		from_nid = cpu_to_node(cpuid);
-		ret = cpu_up(cpuid);
-
-		/*
-		 * When hot adding memory to memoryless node and enabling a cpu
-		 * on the node, node number of the cpu may internally change.
-		 */
-		to_nid = cpu_to_node(cpuid);
-		if (from_nid != to_nid)
-			change_cpu_under_node(cpu, from_nid, to_nid);
-
-		if (!ret)
-			kobject_uevent(&dev->kobj, KOBJ_ONLINE);
-		break;
-	default:
-		ret = -EINVAL;
-	}
+	ret = cpu_down(dev->id);
 	cpu_hotplug_driver_unlock();
-
-	if (ret >= 0)
-		ret = count;
 	return ret;
 }
-static DEVICE_ATTR(online, 0644, show_online, store_online);
 
-static void __cpuinit register_cpu_control(struct cpu *cpu)
-{
-	device_create_file(&cpu->dev, &dev_attr_online);
-}
 void unregister_cpu(struct cpu *cpu)
 {
 	int logical_cpu = cpu->dev.id;
 
 	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
 
-	device_remove_file(&cpu->dev, &dev_attr_online);
-
 	device_unregister(&cpu->dev);
 	per_cpu(cpu_sys_devices, logical_cpu) = NULL;
 	return;
@@ -123,12 +103,19 @@ 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 */
-static inline void register_cpu_control(struct cpu *cpu)
-{
-}
 #endif /* CONFIG_HOTPLUG_CPU */
 
+struct bus_type cpu_subsys = {
+	.name = "cpu",
+	.dev_name = "cpu",
+	.match = cpu_subsys_match,
+#ifdef CONFIG_HOTPLUG_CPU
+	.online = cpu_subsys_online,
+	.offline = cpu_subsys_offline,
+#endif
+};
+EXPORT_SYMBOL_GPL(cpu_subsys);
+
 #ifdef CONFIG_KEXEC
 #include <linux/kexec.h>
 
@@ -277,12 +264,12 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
 	cpu->dev.id = num;
 	cpu->dev.bus = &cpu_subsys;
 	cpu->dev.release = cpu_device_release;
+	cpu->dev.offline_disabled = !cpu->hotpluggable;
+	cpu->dev.offline = !cpu_online(num);
 #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
 	cpu->dev.bus->uevent = arch_cpu_uevent;
 #endif
 	error = device_register(&cpu->dev);
-	if (!error && cpu->hotpluggable)
-		register_cpu_control(cpu);
 	if (!error)
 		per_cpu(cpu_sys_devices, num) = &cpu->dev;
 	if (!error)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 14f8a69..4ebf97f 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -37,9 +37,14 @@ static inline int base_memory_block_id(int section_nr)
 	return section_nr / sections_per_block;
 }
 
+static int memory_subsys_online(struct device *dev);
+static int memory_subsys_offline(struct device *dev);
+
 static struct bus_type memory_subsys = {
 	.name = MEMORY_CLASS_NAME,
 	.dev_name = MEMORY_CLASS_NAME,
+	.online = memory_subsys_online,
+	.offline = memory_subsys_offline,
 };
 
 static BLOCKING_NOTIFIER_HEAD(memory_chain);
@@ -88,6 +93,7 @@ int register_memory(struct memory_block *memory)
 	memory->dev.bus = &memory_subsys;
 	memory->dev.id = memory->start_section_nr / sections_per_block;
 	memory->dev.release = memory_block_release;
+	memory->dev.offline = memory->state == MEM_OFFLINE;
 
 	error = device_register(&memory->dev);
 	return error;
@@ -278,33 +284,64 @@ static int __memory_block_change_state(struct memory_block *mem,
 {
 	int ret = 0;
 
-	if (mem->state != from_state_req) {
-		ret = -EINVAL;
-		goto out;
-	}
+	if (mem->state != from_state_req)
+		return -EINVAL;
 
 	if (to_state == MEM_OFFLINE)
 		mem->state = MEM_GOING_OFFLINE;
 
 	ret = memory_block_action(mem->start_section_nr, to_state, online_type);
+	mem->state = ret ? from_state_req : to_state;
+	return ret;
+}
 
-	if (ret) {
-		mem->state = from_state_req;
-		goto out;
-	}
+static int memory_subsys_online(struct device *dev)
+{
+	struct memory_block *mem = container_of(dev, struct memory_block, dev);
+	int ret;
 
-	mem->state = to_state;
-	switch (mem->state) {
-	case MEM_OFFLINE:
-		kobject_uevent(&mem->dev.kobj, KOBJ_OFFLINE);
-		break;
-	case MEM_ONLINE:
-		kobject_uevent(&mem->dev.kobj, KOBJ_ONLINE);
-		break;
-	default:
-		break;
+	mutex_lock(&mem->state_mutex);
+
+	ret = mem->state == MEM_ONLINE ? 0 :
+		__memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE,
+					    ONLINE_KEEP);
+
+	mutex_unlock(&mem->state_mutex);
+	return ret;
+}
+
+static int memory_subsys_offline(struct device *dev)
+{
+	struct memory_block *mem = container_of(dev, struct memory_block, dev);
+	int ret;
+
+	mutex_lock(&mem->state_mutex);
+
+	ret = mem->state == MEM_OFFLINE ? 0 :
+		__memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE, -1);
+
+	mutex_unlock(&mem->state_mutex);
+	return ret;
+}
+
+static int __memory_block_change_state_uevent(struct memory_block *mem,
+		unsigned long to_state, unsigned long from_state_req,
+		int online_type)
+{
+	int ret = __memory_block_change_state(mem, to_state, from_state_req,
+					      online_type);
+	if (!ret) {
+		switch (mem->state) {
+		case MEM_OFFLINE:
+			kobject_uevent(&mem->dev.kobj, KOBJ_OFFLINE);
+			break;
+		case MEM_ONLINE:
+			kobject_uevent(&mem->dev.kobj, KOBJ_ONLINE);
+			break;
+		default:
+			break;
+		}
 	}
-out:
 	return ret;
 }
 
@@ -315,8 +352,8 @@ static int memory_block_change_state(struct memory_block *mem,
 	int ret;
 
 	mutex_lock(&mem->state_mutex);
-	ret = __memory_block_change_state(mem, to_state, from_state_req,
-					  online_type);
+	ret = __memory_block_change_state_uevent(mem, to_state, from_state_req,
+						 online_type);
 	mutex_unlock(&mem->state_mutex);
 
 	return ret;
@@ -326,22 +363,34 @@ store_mem_state(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct memory_block *mem;
+	bool offline;
 	int ret = -EINVAL;
 
 	mem = container_of(dev, struct memory_block, dev);
 
-	if (!strncmp(buf, "online_kernel", min_t(int, count, 13)))
+	lock_device_hotplug();
+
+	if (!strncmp(buf, "online_kernel", min_t(int, count, 13))) {
+		offline = false;
 		ret = memory_block_change_state(mem, MEM_ONLINE,
 						MEM_OFFLINE, ONLINE_KERNEL);
-	else if (!strncmp(buf, "online_movable", min_t(int, count, 14)))
+	} else if (!strncmp(buf, "online_movable", min_t(int, count, 14))) {
+		offline = false;
 		ret = memory_block_change_state(mem, MEM_ONLINE,
 						MEM_OFFLINE, ONLINE_MOVABLE);
-	else if (!strncmp(buf, "online", min_t(int, count, 6)))
+	} else if (!strncmp(buf, "online", min_t(int, count, 6))) {
+		offline = false;
 		ret = memory_block_change_state(mem, MEM_ONLINE,
 						MEM_OFFLINE, ONLINE_KEEP);
-	else if(!strncmp(buf, "offline", min_t(int, count, 7)))
+	} else if(!strncmp(buf, "offline", min_t(int, count, 7))) {
+		offline = true;
 		ret = memory_block_change_state(mem, MEM_OFFLINE,
 						MEM_ONLINE, -1);
+	}
+	if (!ret)
+		dev->offline = offline;
+
+	unlock_device_hotplug();
 
 	if (ret)
 		return ret;
@@ -679,21 +728,6 @@ int unregister_memory_section(struct mem_section *section)
 }
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 
-/*
- * offline one memory block. If the memory block has been offlined, do nothing.
- */
-int offline_memory_block(struct memory_block *mem)
-{
-	int ret = 0;
-
-	mutex_lock(&mem->state_mutex);
-	if (mem->state != MEM_OFFLINE)
-		ret = __memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE, -1);
-	mutex_unlock(&mem->state_mutex);
-
-	return ret;
-}
-
 /* return true if the memory block is offlined, otherwise, return false */
 bool is_memblock_offlined(struct memory_block *mem)
 {