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

drivers/acpi/scan.c

@@ -27,6 +27,12 @@ extern struct acpi_device *acpi_root;
 
 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
 
+/*
+ * If set, devices will be hot-removed even if they cannot be put offline
+ * gracefully (from the kernel's standpoint).
+ */
+bool acpi_force_hot_remove;
+
 static const char *dummy_hid = "device";
 
 static LIST_HEAD(acpi_device_list);
@@ -120,12 +126,78 @@ acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, cha
 }
 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
 
+static acpi_status acpi_bus_offline_companions(acpi_handle handle, u32 lvl,
+					       void *data, void **ret_p)
+{
+	struct acpi_device *device = NULL;
+	struct acpi_device_physical_node *pn;
+	bool second_pass = (bool)data;
+	acpi_status status = AE_OK;
+
+	if (acpi_bus_get_device(handle, &device))
+		return AE_OK;
+
+	mutex_lock(&device->physical_node_lock);
+
+	list_for_each_entry(pn, &device->physical_node_list, node) {
+		int ret;
+
+		if (second_pass) {
+			/* Skip devices offlined by the first pass. */
+			if (pn->put_online)
+				continue;
+		} else {
+			pn->put_online = false;
+		}
+		ret = device_offline(pn->dev);
+		if (acpi_force_hot_remove)
+			continue;
+
+		if (ret >= 0) {
+			pn->put_online = !ret;
+		} else {
+			*ret_p = pn->dev;
+			if (second_pass) {
+				status = AE_ERROR;
+				break;
+			}
+		}
+	}
+
+	mutex_unlock(&device->physical_node_lock);
+
+	return status;
+}
+
+static acpi_status acpi_bus_online_companions(acpi_handle handle, u32 lvl,
+					      void *data, void **ret_p)
+{
+	struct acpi_device *device = NULL;
+	struct acpi_device_physical_node *pn;
+
+	if (acpi_bus_get_device(handle, &device))
+		return AE_OK;
+
+	mutex_lock(&device->physical_node_lock);
+
+	list_for_each_entry(pn, &device->physical_node_list, node)
+		if (pn->put_online) {
+			device_online(pn->dev);
+			pn->put_online = false;
+		}
+
+	mutex_unlock(&device->physical_node_lock);
+
+	return AE_OK;
+}
+
 static int acpi_scan_hot_remove(struct acpi_device *device)
 {
 	acpi_handle handle = device->handle;
 	acpi_handle not_used;
 	struct acpi_object_list arg_list;
 	union acpi_object arg;
+	struct device *errdev;
 	acpi_status status;
 	unsigned long long sta;
 
@@ -136,10 +208,53 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
 		return -EINVAL;
 	}
 
+	lock_device_hotplug();
+
+	/*
+	 * Carry out two passes here and ignore errors in the first pass,
+	 * because if the devices in question are memory blocks and
+	 * CONFIG_MEMCG is set, one of the blocks may hold data structures
+	 * that the other blocks depend on, but it is not known in advance which
+	 * block holds them.
+	 *
+	 * If the first pass is successful, the second one isn't needed, though.
+	 */
+	errdev = NULL;
+	acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
+			    NULL, acpi_bus_offline_companions,
+			    (void *)false, (void **)&errdev);
+	acpi_bus_offline_companions(handle, 0, (void *)false, (void **)&errdev);
+	if (errdev) {
+		errdev = NULL;
+		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
+				    NULL, acpi_bus_offline_companions,
+				    (void *)true , (void **)&errdev);
+		if (!errdev || acpi_force_hot_remove)
+			acpi_bus_offline_companions(handle, 0, (void *)true,
+						    (void **)&errdev);
+
+		if (errdev && !acpi_force_hot_remove) {
+			dev_warn(errdev, "Offline failed.\n");
+			acpi_bus_online_companions(handle, 0, NULL, NULL);
+			acpi_walk_namespace(ACPI_TYPE_ANY, handle,
+					    ACPI_UINT32_MAX,
+					    acpi_bus_online_companions, NULL,
+					    NULL, NULL);
+
+			unlock_device_hotplug();
+
+			put_device(&device->dev);
+			return -EBUSY;
+		}
+	}
+
 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 		"Hot-removing device %s...\n", dev_name(&device->dev)));
 
 	acpi_bus_trim(device);
+
+	unlock_device_hotplug();
+
 	/* Device node has been unregistered. */
 	put_device(&device->dev);
 	device = NULL;
@@ -236,6 +351,7 @@ static void acpi_scan_bus_device_check(acpi_handle handle, u32 ost_source)
 	int error;
 
 	mutex_lock(&acpi_scan_lock);
+	lock_device_hotplug();
 
 	acpi_bus_get_device(handle, &device);
 	if (device) {
@@ -259,6 +375,7 @@ static void acpi_scan_bus_device_check(acpi_handle handle, u32 ost_source)
 		kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
 
  out:
+	unlock_device_hotplug();
 	acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL);
 	mutex_unlock(&acpi_scan_lock);
 }
@@ -952,7 +1069,6 @@ int acpi_device_add(struct acpi_device *device,
 		printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
 		       dev_name(&device->dev));
 
-	device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
 	return 0;
 
  err:
@@ -1939,7 +2055,6 @@ static acpi_status acpi_bus_device_detach(acpi_handle handle, u32 lvl_not_used,
 	if (!acpi_bus_get_device(handle, &device)) {
 		struct acpi_scan_handler *dev_handler = device->handler;
 
-		device->removal_type = ACPI_BUS_REMOVAL_EJECT;
 		if (dev_handler) {
 			if (dev_handler->detach)
 				dev_handler->detach(device);
@@ -2038,6 +2153,7 @@ int __init acpi_scan_init(void)
 
 	acpi_pci_root_init();
 	acpi_pci_link_init();
+	acpi_processor_init();
 	acpi_platform_init();
 	acpi_lpss_init();
 	acpi_container_init();