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Commit c27b2c33 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

ACPI / hotplug: Introduce common hotplug function acpi_device_hotplug() 



Modify the common ACPI device hotplug code to always queue up the
same function, acpi_device_hotplug(), using acpi_hotplug_execute()
and make the PCI host bridge hotplug code use that function too for
device hot removal.

This allows some code duplication to be reduced and a race condition
where the relevant ACPI handle may become invalid between the
notification handler and the function queued up by it via
acpi_hotplug_execute() to be avoided.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
parent 1ceaba05

drivers/acpi/internal.h

+1 −1
Original line number Diff line number Diff line
@@ -89,7 +89,7 @@ void acpi_device_add_finalize(struct acpi_device *device); 
void acpi_free_pnp_ids(struct acpi_device_pnp *pnp);

int acpi_bind_one(struct device *dev, acpi_handle handle);

int acpi_unbind_one(struct device *dev);

void acpi_bus_device_eject(void *data, u32 ost_src);

void acpi_device_hotplug(void *data, u32 ost_src);

bool acpi_device_is_present(struct acpi_device *adev);



/* --------------------------------------------------------------------------

drivers/acpi/pci_root.c

+3 −1
Original line number Diff line number Diff line
@@ -683,11 +683,13 @@ static void hotplug_event_root(void *data, u32 type) 
		if (!root)

			break;



		acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,

					  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);

		get_device(&root->device->dev);



		acpi_scan_lock_release();



		acpi_bus_device_eject(root->device, ACPI_NOTIFY_EJECT_REQUEST);

		acpi_device_hotplug(root->device, ACPI_NOTIFY_EJECT_REQUEST);

		return;

	default:

		acpi_handle_warn(handle,

drivers/acpi/scan.c

+64 −77
Original line number Diff line number Diff line
@@ -206,12 +206,8 @@ static int acpi_scan_hot_remove(struct acpi_device *device) 
	acpi_status status;

	unsigned long long sta;



	/* If there is no handle, the device node has been unregistered. */

	if (!handle) {

		dev_dbg(&device->dev, "ACPI handle missing\n");

		put_device(&device->dev);

		return -EINVAL;

	}

	if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)

		kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);



	/*

	 * Carry out two passes here and ignore errors in the first pass,
@@ -230,7 +226,6 @@ static int acpi_scan_hot_remove(struct acpi_device *device) 
		dev_warn(errdev, "Offline disabled.\n");

		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,

				    acpi_bus_online, NULL, NULL, NULL);

		put_device(&device->dev);

		return -EPERM;

	}

	acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
@@ -249,7 +244,6 @@ static int acpi_scan_hot_remove(struct acpi_device *device) 
			acpi_walk_namespace(ACPI_TYPE_ANY, handle,

					    ACPI_UINT32_MAX, acpi_bus_online,

					    NULL, NULL, NULL);

			put_device(&device->dev);

			return -EBUSY;

		}

	}
@@ -259,9 +253,6 @@ static int acpi_scan_hot_remove(struct acpi_device *device) 


	acpi_bus_trim(device);



	put_device(&device->dev);

	device = NULL;



	acpi_evaluate_lck(handle, 0);

	/*

	 * TBD: _EJD support.
@@ -288,77 +279,74 @@ static int acpi_scan_hot_remove(struct acpi_device *device) 
	return 0;

}



void acpi_bus_device_eject(void *data, u32 ost_src)

static int acpi_scan_device_check(struct acpi_device *adev)

{

	struct acpi_device *device = data;

	acpi_handle handle = device->handle;

	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;

	int error;



	lock_device_hotplug();

	mutex_lock(&acpi_scan_lock);



	if (ost_src == ACPI_NOTIFY_EJECT_REQUEST)

		acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,

					  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);



	if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)

		kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);



	error = acpi_scan_hot_remove(device);

	if (error == -EPERM) {

		goto err_support;

	} else if (error) {

		goto err_out;

	/*

	 * This function is only called for device objects for which matching

	 * scan handlers exist.  The only situation in which the scan handler is

	 * not attached to this device object yet is when the device has just

	 * appeared (either it wasn't present at all before or it was removed

	 * and then added again).

	 */

	if (adev->handler) {

		dev_warn(&adev->dev, "Already enumerated\n");

		return -EBUSY;

	}



 out:

	mutex_unlock(&acpi_scan_lock);

	unlock_device_hotplug();

	return;



 err_support:

	ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;

 err_out:

	acpi_evaluate_hotplug_ost(handle, ost_src, ost_code, NULL);

	goto out;

	error = acpi_bus_scan(adev->handle);

	if (error) {

		dev_warn(&adev->dev, "Namespace scan failure\n");

		return error;

	}

	if (adev->handler) {

		if (adev->handler->hotplug.mode == AHM_CONTAINER)

			kobject_uevent(&adev->dev.kobj, KOBJ_ONLINE);

	} else {

		dev_warn(&adev->dev, "Enumeration failure\n");

		return -ENODEV;

	}

	return 0;

}



static void acpi_scan_bus_device_check(void *data, u32 ost_source)

void acpi_device_hotplug(void *data, u32 src)

{

	acpi_handle handle = data;

	struct acpi_device *device;

	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;

	struct acpi_device *adev = data;

	int error;



	lock_device_hotplug();

	mutex_lock(&acpi_scan_lock);



	if (ost_source != ACPI_NOTIFY_BUS_CHECK) {

		device = NULL;

		acpi_bus_get_device(handle, &device);

		if (acpi_device_enumerated(device)) {

			dev_warn(&device->dev, "Attempt to re-insert\n");

			goto out;

		}

	}

	error = acpi_bus_scan(handle);

	if (error) {

		acpi_handle_warn(handle, "Namespace scan failure\n");

		goto out;

	}

	device = NULL;

	acpi_bus_get_device(handle, &device);

	if (!acpi_device_enumerated(device)) {

		acpi_handle_warn(handle, "Device not enumerated\n");

	/*

	 * The device object's ACPI handle cannot become invalid as long as we

	 * are holding acpi_scan_lock, but it may have become invalid before

	 * that lock was acquired.

	 */

	if (adev->handle == INVALID_ACPI_HANDLE)

		goto out;



	switch (src) {

	case ACPI_NOTIFY_BUS_CHECK:

		error = acpi_bus_scan(adev->handle);

		break;

	case ACPI_NOTIFY_DEVICE_CHECK:

		error = acpi_scan_device_check(adev);

		break;

	case ACPI_NOTIFY_EJECT_REQUEST:

	case ACPI_OST_EC_OSPM_EJECT:

		error = acpi_scan_hot_remove(adev);

		break;

	default:

		error = -EINVAL;

		break;

	}

	if (!error)

		ost_code = ACPI_OST_SC_SUCCESS;

	if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)

		kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);



 out:

	acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL);

	acpi_evaluate_hotplug_ost(adev->handle, src, ost_code, NULL);

	put_device(&adev->dev);

	mutex_unlock(&acpi_scan_lock);

	unlock_device_hotplug();

}
@@ -370,6 +358,9 @@ static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data) 
	struct acpi_device *adev;

	acpi_status status;



	if (acpi_bus_get_device(handle, &adev))

		goto err_out;



	switch (type) {

	case ACPI_NOTIFY_BUS_CHECK:

		acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
@@ -384,24 +375,20 @@ static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data) 
			ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;

			goto err_out;

		}

		if (acpi_bus_get_device(handle, &adev))

			goto err_out;



		get_device(&adev->dev);

		status = acpi_hotplug_execute(acpi_bus_device_eject, adev, type);

		if (ACPI_SUCCESS(status))

			return;



		put_device(&adev->dev);

		goto err_out;

		acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,

					  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);

		break;

	default:

		/* non-hotplug event; possibly handled by other handler */

		return;

	}

	status = acpi_hotplug_execute(acpi_scan_bus_device_check, handle, type);

	get_device(&adev->dev);

	status = acpi_hotplug_execute(acpi_device_hotplug, adev, type);

	if (ACPI_SUCCESS(status))

		return;



	put_device(&adev->dev);



 err_out:

	acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);

}
@@ -454,7 +441,7 @@ acpi_eject_store(struct device *d, struct device_attribute *attr, 
	acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,

				  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);

	get_device(&acpi_device->dev);

	status = acpi_hotplug_execute(acpi_bus_device_eject, acpi_device,

	status = acpi_hotplug_execute(acpi_device_hotplug, acpi_device,

				      ACPI_OST_EC_OSPM_EJECT);

	if (ACPI_SUCCESS(status))

		return count;