From 9c5ad36d987a1b06f6b0b9dc7bc61a45d277455d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 28 Nov 2013 23:58:28 +0100 Subject: ACPI / bind: Redefine acpi_preset_companion() Modify acpi_preset_companion() to take a struct acpi_device pointer instead of an ACPI handle as its second argument and redefine it as a static inline wrapper around ACPI_COMPANION_SET() passing the return value of acpi_find_child_device() directly as the second argument to it. Update its users to pass struct acpi_device pointers instead of ACPI handles to it. This allows some unnecessary acpi_bus_get_device() calls to be avoided. Signed-off-by: Rafael J. Wysocki Reviewed-by: Aaron Lu Tested-by: Aaron Lu # for ATA binding --- include/linux/acpi.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/acpi.h b/include/linux/acpi.h index d9099b15b472..115c610324d1 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -53,6 +53,12 @@ static inline acpi_handle acpi_device_handle(struct acpi_device *adev) #define ACPI_COMPANION_SET(dev, adev) ACPI_COMPANION(dev) = (adev) #define ACPI_HANDLE(dev) acpi_device_handle(ACPI_COMPANION(dev)) +static inline void acpi_preset_companion(struct device *dev, + struct acpi_device *parent, u64 addr) +{ + ACPI_COMPANION_SET(dev, acpi_find_child_device(parent, addr, NULL)); +} + static inline const char *acpi_dev_name(struct acpi_device *adev) { return dev_name(&adev->dev); -- cgit v1.2.3 From caa73ea158de9419f08e456f2716c71d1f06012a Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 29 Dec 2013 15:25:48 +0100 Subject: ACPI / hotplug / driver core: Handle containers in a special way ACPI container devices require special hotplug handling, at least on some systems, since generally user space needs to carry out system-specific cleanup before it makes sense to offline devices in the container. However, the current ACPI hotplug code for containers first attempts to offline devices in the container and only then it notifies user space of the container offline. Moreover, after commit 202317a573b2 (ACPI / scan: Add acpi_device objects for all device nodes in the namespace), ACPI device objects representing containers are present as long as the ACPI namespace nodes corresponding to them are present, which may be forever, even if the container devices are physically detached from the system (the return values of the corresponding _STA methods change in those cases, but generally the namespace nodes themselves are still there). Thus it is useful to introduce entities representing containers that will go away during container hot-unplug. The goal of this change is to address both the above issues. The idea is to create a "companion" container system device for each of the ACPI container device objects during the initial namespace scan or on a hotplug event making the container present. That system device will be unregistered on container removal. A new bus type for container devices is added for this purpose, because device offline and online operations need to be defined for them. The online operation is a trivial function that is always successful and the offline uses a callback pointed to by the container device's offline member. For ACPI containers that callback simply walks the list of ACPI device objects right below the container object (its children) and checks if all of their physical companion devices are offline. If that's not the case, it returns -EBUSY and the container system devivce cannot be put offline. Consequently, to put the container system device offline, it is necessary to put all of the physical devices depending on its ACPI companion object offline beforehand. Container system devices created for ACPI container objects are initially online. They are created by the container ACPI scan handler whose hotplug.demand_offline flag is set. That causes acpi_scan_hot_remove() to check if the companion container system device is offline before attempting to remove an ACPI container or any devices below it. If the check fails, a KOBJ_CHANGE uevent is emitted for the container system device in question and user space is expected to offline all devices below the container and the container itself in response to it. Then, user space can finalize the removal of the container with the help of its ACPI device object's eject attribute in sysfs. Tested-by: Yasuaki Ishimatsu Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman --- include/linux/container.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 include/linux/container.h (limited to 'include/linux') diff --git a/include/linux/container.h b/include/linux/container.h new file mode 100644 index 000000000000..3c03e6fd2035 --- /dev/null +++ b/include/linux/container.h @@ -0,0 +1,25 @@ +/* + * Definitions for container bus type. + * + * Copyright (C) 2013, Intel Corporation + * Author: Rafael J. Wysocki + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include + +/* drivers/base/power/container.c */ +extern struct bus_type container_subsys; + +struct container_dev { + struct device dev; + int (*offline)(struct container_dev *cdev); +}; + +static inline struct container_dev *to_container_dev(struct device *dev) +{ + return container_of(dev, struct container_dev, dev); +} -- cgit v1.2.3