2005-04-17 02:20:36 +04:00
|
|
|
/*
|
2013-03-04 02:05:55 +04:00
|
|
|
* container.c - ACPI Generic Container Driver
|
2005-04-17 02:20:36 +04:00
|
|
|
*
|
|
|
|
|
* Copyright (C) 2004 Anil S Keshavamurthy (anil.s.keshavamurthy@intel.com)
|
|
|
|
|
* Copyright (C) 2004 Keiichiro Tokunaga (tokunaga.keiich@jp.fujitsu.com)
|
|
|
|
|
* Copyright (C) 2004 Motoyuki Ito (motoyuki@soft.fujitsu.com)
|
|
|
|
|
* Copyright (C) 2004 FUJITSU LIMITED
|
2013-03-04 02:05:55 +04:00
|
|
|
* Copyright (C) 2004, 2013 Intel Corp.
|
|
|
|
|
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
2005-04-17 02:20:36 +04:00
|
|
|
*
|
|
|
|
|
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
|
*
|
|
|
|
|
* This program is free software; you can redistribute it and/or modify
|
|
|
|
|
* it under the terms of the GNU General Public License as published by
|
|
|
|
|
* the Free Software Foundation; either version 2 of the License, or (at
|
|
|
|
|
* your option) any later version.
|
|
|
|
|
*
|
|
|
|
|
* This program is distributed in the hope that it will be useful, but
|
|
|
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
|
|
|
* General Public License for more details.
|
|
|
|
|
*
|
|
|
|
|
* You should have received a copy of the GNU General Public License along
|
|
|
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
|
|
|
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
|
|
|
|
|
*
|
|
|
|
|
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
|
*/
|
|
|
|
|
#include <linux/acpi.h>
|
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 <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-29 18:25:48 +04:00
|
|
|
#include <linux/container.h>
|
2005-04-17 02:20:36 +04:00
|
|
|
|
2013-03-11 13:17:07 +04:00
|
|
|
#include "internal.h"
|
|
|
|
|
|
2005-04-17 02:20:36 +04:00
|
|
|
#define _COMPONENT ACPI_CONTAINER_COMPONENT
|
2007-02-13 06:42:12 +03:00
|
|
|
ACPI_MODULE_NAME("container");
|
2005-04-17 02:20:36 +04:00
|
|
|
|
2007-07-23 16:44:41 +04:00
|
|
|
static const struct acpi_device_id container_device_ids[] = {
|
|
|
|
|
{"ACPI0004", 0},
|
|
|
|
|
{"PNP0A05", 0},
|
|
|
|
|
{"PNP0A06", 0},
|
|
|
|
|
{"", 0},
|
|
|
|
|
};
|
|
|
|
|
|
2014-05-30 06:28:20 +04:00
|
|
|
#ifdef CONFIG_ACPI_CONTAINER
|
|
|
|
|
|
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 <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-29 18:25:48 +04:00
|
|
|
static int acpi_container_offline(struct container_dev *cdev)
|
|
|
|
|
{
|
|
|
|
|
struct acpi_device *adev = ACPI_COMPANION(&cdev->dev);
|
|
|
|
|
struct acpi_device *child;
|
|
|
|
|
|
|
|
|
|
/* Check all of the dependent devices' physical companions. */
|
|
|
|
|
list_for_each_entry(child, &adev->children, node)
|
|
|
|
|
if (!acpi_scan_is_offline(child, false))
|
|
|
|
|
return -EBUSY;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void acpi_container_release(struct device *dev)
|
|
|
|
|
{
|
|
|
|
|
kfree(to_container_dev(dev));
|
|
|
|
|
}
|
|
|
|
|
|
2013-11-23 00:55:32 +04:00
|
|
|
static int container_device_attach(struct acpi_device *adev,
|
2013-02-09 02:52:39 +04:00
|
|
|
const struct acpi_device_id *not_used)
|
|
|
|
|
{
|
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 <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-29 18:25:48 +04:00
|
|
|
struct container_dev *cdev;
|
|
|
|
|
struct device *dev;
|
|
|
|
|
int ret;
|
|
|
|
|
|
ACPI / dock: Dispatch dock notifications from the global notify handler
The ACPI dock station code carries out an extra namespace scan
before the main one in order to find and register all of the dock
device objects. Then, it registers a notify handler for each of
them for handling dock events.
However, dock device objects need not be scanned for upfront. They
very well can be enumerated and registered during the first phase
of the main namespace scan, before attaching scan handlers and ACPI
drivers to ACPI device objects. Then, the dependent devices can be
added to the in the second phase. That makes it possible to drop
the extra namespace scan, so do it.
Moreover, it is not necessary to register notify handlers for all
of the dock stations' namespace nodes, becuase notifications may
be dispatched from the global notify handler for them. Do that and
drop two functions used for dock notify handling, acpi_dock_deferred_cb()
and dock_notify_handler(), that aren't necessary any more.
Finally, some dock station objects have _HID objects matching the
ACPI container scan handler which causes it to claim those objects
and try to handle their hotplug, but that is not a good idea,
because those objects have their own special hotplug handling anyway.
For this reason, the hotplug_notify flag should not be set for ACPI
device objects representing dock stations and the container scan
handler should be made ignore those objects, so make that happen.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-16 04:51:01 +04:00
|
|
|
if (adev->flags.is_dock_station)
|
|
|
|
|
return 0;
|
|
|
|
|
|
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 <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-29 18:25:48 +04:00
|
|
|
cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
|
|
|
|
|
if (!cdev)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
|
|
cdev->offline = acpi_container_offline;
|
|
|
|
|
dev = &cdev->dev;
|
|
|
|
|
dev->bus = &container_subsys;
|
|
|
|
|
dev_set_name(dev, "%s", dev_name(&adev->dev));
|
|
|
|
|
ACPI_COMPANION_SET(dev, adev);
|
|
|
|
|
dev->release = acpi_container_release;
|
|
|
|
|
ret = device_register(dev);
|
2014-02-12 03:52:49 +04:00
|
|
|
if (ret) {
|
|
|
|
|
put_device(dev);
|
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 <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-29 18:25:48 +04:00
|
|
|
return ret;
|
2014-02-12 03:52:49 +04:00
|
|
|
}
|
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 <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-29 18:25:48 +04:00
|
|
|
adev->driver_data = dev;
|
2013-02-09 02:52:39 +04:00
|
|
|
return 1;
|
|
|
|
|
}
|
|
|
|
|
|
2013-11-23 00:55:32 +04:00
|
|
|
static void container_device_detach(struct acpi_device *adev)
|
|
|
|
|
{
|
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 <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-29 18:25:48 +04:00
|
|
|
struct device *dev = acpi_driver_data(adev);
|
|
|
|
|
|
|
|
|
|
adev->driver_data = NULL;
|
|
|
|
|
if (dev)
|
|
|
|
|
device_unregister(dev);
|
2013-11-23 00:55:32 +04:00
|
|
|
}
|
|
|
|
|
|
2014-09-21 04:58:18 +04:00
|
|
|
static void container_device_online(struct acpi_device *adev)
|
|
|
|
|
{
|
|
|
|
|
struct device *dev = acpi_driver_data(adev);
|
|
|
|
|
|
|
|
|
|
kobject_uevent(&dev->kobj, KOBJ_ONLINE);
|
|
|
|
|
}
|
|
|
|
|
|
2013-03-04 02:08:45 +04:00
|
|
|
static struct acpi_scan_handler container_handler = {
|
2007-07-23 16:44:41 +04:00
|
|
|
.ids = container_device_ids,
|
2013-02-09 02:52:39 +04:00
|
|
|
.attach = container_device_attach,
|
2013-11-23 00:55:32 +04:00
|
|
|
.detach = container_device_detach,
|
2013-03-04 02:05:55 +04:00
|
|
|
.hotplug = {
|
|
|
|
|
.enabled = true,
|
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 <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-29 18:25:48 +04:00
|
|
|
.demand_offline = true,
|
2014-09-21 04:58:18 +04:00
|
|
|
.notify_online = container_device_online,
|
2013-03-04 02:05:55 +04:00
|
|
|
},
|
2005-04-17 02:20:36 +04:00
|
|
|
};
|
|
|
|
|
|
2014-05-30 06:28:20 +04:00
|
|
|
void __init acpi_container_init(void)
|
|
|
|
|
{
|
|
|
|
|
acpi_scan_add_handler(&container_handler);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#else
|
|
|
|
|
|
|
|
|
|
static struct acpi_scan_handler container_handler = {
|
|
|
|
|
.ids = container_device_ids,
|
|
|
|
|
};
|
|
|
|
|
|
2013-02-09 02:52:39 +04:00
|
|
|
void __init acpi_container_init(void)
|
2005-04-17 02:20:36 +04:00
|
|
|
{
|
2013-03-04 02:08:45 +04:00
|
|
|
acpi_scan_add_handler_with_hotplug(&container_handler, "container");
|
2005-04-17 02:20:36 +04:00
|
|
|
}
|
2014-05-30 06:28:20 +04:00
|
|
|
|
|
|
|
|
#endif /* CONFIG_ACPI_CONTAINER */
|
