With the introduction of ACPI scan handlers, ACPI device objects
with an ACPI scan handler attached to them must not be bound to
by ACPI drivers any more.  Unfortunately, however, the ACPI video
driver attempts to do just that if there is a _ROM ACPI control
method defined under a device object with an ACPI scan handler.

Prevent that from happening by making the video driver's "add"
routine check if the device object already has an ACPI scan handler
attached to it and return an error code in that case.

That is not sufficient, though, because acpi_bus_driver_init() would
then clear the device object's driver_data that may be set by its
scan handler, so for the fix to work acpi_bus_driver_init() has to be
modified to leave driver_data as is on errors.

References: https://bugzilla.kernel.org/show_bug.cgi?id=58091Bisected-and-tested-by: NDmitry S. Demin <dmitryy.demin@gmail.com>
Reported-and-tested-by: NJason Cassell <bluesloth600@gmail.com>
Tracked-down-by: NAaron Lu <aaron.lu@intel.com>
Cc: 3.9+ <stable@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NAaron Lu <aaron.lu@intel.com>

Commit 9f29ab11 ("ACPI / scan: do not match drivers against objects
having scan handlers") introduced a boot regression on Tony's ia64 HP
rx2600.  Tony says:

  "It panics with the message:

   Kernel panic - not syncing: Unable to find SBA IOMMU: Try a generic or DIG kernel

   [...] my problem comes from arch/ia64/hp/common/sba_iommu.c
   where the code in sba_init() says:

        acpi_bus_register_driver(&acpi_sba_ioc_driver);
        if (!ioc_list) {

   but because of this change we never managed to call ioc_init()
   so ioc_list doesn't get set up, and we die."

Revert it to avoid this breakage and we'll fix the problem it attempted
to address later.
Reported-by: NTony Luck <tony.luck@gmail.com>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the introduction of ACPI scan handlers, an ACPI device object
with an ACPI scan handler attached to it must not be bound to an ACPI
driver any more.  Therefore it doesn't make sense to match those
ACPI device objects against a newly registered ACPI driver in
acpi_bus_match(), so make that function return 0 if the device
object passed to it has an ACPI scan handler attached.

This also addresses a regression related to a broken ACPI table in
the BIOS, where it has defined a _ROM method under the PCI root
bridge object.  This causes the video module to treat that object
as a display controller device (since only display devices are
supposed to have a _ROM method defined according to the ACPI spec).
As a result, the ACPI video driver binds to the PCI root bridge
object and overwrites the previously assigned driver_data field of
it, causing subsequent calls to acpi_get_pci_dev() to fail.

[rjw: Subject and changelog]
References: https://bugzilla.kernel.org/show_bug.cgi?id=58091Reported-by: NJason Cassell <bluesloth600@gmail.com>
Reported-and-bisected-by: NDmitry S. Demin <dmitryy.demin@gmail.com>
Cc: 3.9+ <stable@kernel.org>
Signed-off-by: NAaron Lu <aaron.lu@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Following commit 6b772e8f (ACPI: Update PNPID match handling for
notify), the acpi_scan_init_hotplug() calls acpi_set_pnp_ids() which
allocates acpi_hardware_id and copies a few strings (kstrdup). If the
devices does not have hardware_id set, the function exits without
freeing the previously allocated ids (and kmemleak complains). This
patch calls simply changes 'return' on error to a 'goto out' which
calls acpi_free_pnp_ids().
Reported-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NToshi Kani <toshi.kani@hp.com>
Tested-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since we have CSRT only to get additional DMA controller resources, let's get
rid of drivers/acpi/csrt.c and move its logic inside ACPI DMA helpers code.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Currently the pci_slot driver doesn't update PCI slot devices when PCI
device hotplug event happens, which may cause memory leak and returning
stale information to user.

Now the pci_slot driver has been changed as built-in driver, so invoke
PCI slot enumeration and destroy routines directly from the PCI core.
And remove ACPI PCI sub-driver related code because it isn't needed
any more.

[bhelgas: removed "extern" from function declarations]
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Toshi Kani <toshi.kani@hp.com>

ACPI spec states that the OS evaluates _STA after calling _EJ0
in order to verify if eject was successful.  Added a check to
verify if the enabled bit of the status value is cleared after
_EJ0.

Note, the present bit is not checked since some FW implementations
do not clear the present bit until the hardware is physically
removed.
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When the kernel calls _OSC with OSC_SB_HOTPLUG_OST_SUPPORT bit
set at boot-time, the OS is responsible for calling _OST for
ACPI hotplug events.  However, when hotplug.enabled attribute
is unset for ACPI scan drivers, their notify handlers are removed
and _OST is not called for ACPI hotplug events as a result.

This patch keeps the notify handler of ACPI scan drivers,
acpi_hotplug_notify_cb(), installed regardless of the state of
hotplug.enabled.  The notify handler then checks if hotplug.enabled
is set for the associated scan handler.  If unset, the notify
handler calls _OST with a proper error code.  The patch also
eliminates ACPI namespace walk when hotplug.enabled is changed
via sysfs.
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When installing/removing a notify handler to/from an ACPI device
object, ACPI core tries to match its associated scan handler to
see if it supports hotplug.  However, the matching logic of the
notify handler is different from the matching logic of attaching
a scan handler to an ACPI device object.  This patch updates the
matching logic of the notify handlers to be consistent with the
attach handling.
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch introduces acpi_set_pnp_ids() and acpi_free_pnp_ids(),
which are updated from acpi_device_set_id() and acpi_free_ids(),
to setup and free acpi_device_pnp for a given acpi_handle.  They
can be called without acpi_device.
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch updates the internal operations of acpi_device_set_id()
to setup acpi_device_pnp without using acpi_device.  There is no
functional change to acpi_device_set_id() in this patch.

acpi_pnp_type is added to acpi_device_pnp, so that PNPID type is
self-contained within acpi_device_pnp.  acpi_add_id(), acpi_bay_match(),
acpi_dock_match(), acpi_ibm_smbus_match() and acpi_is_video_device()
are changed to take acpi_handle as an argument, instead of acpi_device.
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Devices on the Intel Lynxpoint Low Power Subsystem (LPSS) have some
common features that aren't shared with any other platform devices,
including the clock and LTR (Latency Tolerance Reporting) registers.
It is better to handle those features in common code than to bother
device drivers with doing that (I/O functionality-wise the LPSS
devices are generally compatible with other devices that don't
have those special registers and may be handled by the same drivers).

The clock registers of the LPSS devices are now taken care of by
the special clk-x86-lpss driver, but the MMIO mappings used for
accessing those registers can also be used for accessing the LTR
registers on those devices (LTR support for the Lynxpoint LPSS is
going to be added by a subsequent patch).  Thus it is convenient
to add a special ACPI scan handler for the Lynxpoint LPSS devices
that will create the MMIO mappings for accessing the clock (and
LTR in the future) registers and will register the LPSS devices'
clocks, so the clk-x86-lpss driver will only need to take care of
the main Lynxpoint LPSS clock.

Introduce a special ACPI scan handler for Intel Lynxpoint LPSS
devices as described above.  This also reduces overhead related to
browsing the ACPI namespace in search of the LPSS devices before the
registration of their clocks, removes some LPSS-specific (and
somewhat ugly) code from acpi_platform.c and shrinks the overall code
size slightly.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NMike Turquette <mturquette@linaro.org>

Make the ACPI memory hotplug driver use struct acpi_scan_handler
for representing the object used to set up ACPI memory hotplug
functionality and to remove hotplug memory ranges and data
structures used by the driver before unregistering ACPI device
nodes representing memory.  Register the new struct acpi_scan_handler
object with the help of acpi_scan_add_handler_with_hotplug() to allow
user space to manipulate the attributes of the memory hotplug
profile.

This results in a significant reduction of the drvier's code size
and removes some ACPI hotplug code duplication.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>
Tested-by: NToshi Kani <toshi.kani@hp.com>

Introduce user space interface for manipulating hotplug profiles
associated with ACPI scan handlers.

The interface consists of sysfs directories under
/sys/firmware/acpi/hotplug/, one for each hotplug profile, containing
an attribute allowing user space to manipulate the enabled field of
the corresponding profile.  Namely, switching the enabled attribute
from '0' to '1' will cause the common hotplug notify handler to be
installed for all ACPI namespace objects representing devices matching
the scan handler associated with the given hotplug profile (and
analogously for the converse switch).

Drivers willing to use the new user space interface should add their
ACPI scan handlers with the help of new funtion
acpi_scan_add_handler_with_hotplug().
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>
Tested-by: NToshi Kani <toshi.kani@hp.com>

Introduce new helper routine acpi_scan_handler_matching() for
checking if the given ACPI scan handler matches a given device ID
and rework acpi_scan_match_handler() to use the new routine (that
routine will also be useful for other purposes in the future).
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>
Tested-by: NToshi Kani <toshi.kani@hp.com>

Multiple drivers handling hotplug-capable ACPI device nodes install
notify handlers covering the same types of events in a very similar
way.  Moreover, those handlers are installed in separate namespace
walks, although that really should be done during namespace scans
carried out by acpi_bus_scan().  This leads to substantial code
duplication, unnecessary overhead and behavior that is hard to
follow.

For this reason, introduce common code in drivers/acpi/scan.c for
handling hotplug-related notification and carrying out device
insertion and eject operations in a generic fashion, such that it
may be used by all of the relevant drivers in the future.  To cover
the existing differences between those drivers introduce struct
acpi_hotplug_profile for representing collections of hotplug
settings associated with different ACPI scan handlers that can be
used by the drivers to make the common code reflect their current
behavior.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>
Tested-by: NToshi Kani <toshi.kani@hp.com>

Introduce helper routine acpi_scan_match_handler() that will find the
ACPI scan handler matching a given device ID, if there is one, and
rework acpi_scan_attach_handler() to use the new routine (that
routine will also be useful for other purposes going forward).
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>
Tested-by: NToshi Kani <toshi.kani@hp.com>

Commit d2e5f0c1 (ACPI / PCI: Rework the setup and cleanup of device
wakeup) moved the initial disabling of system wakeup for PCI devices
into a place where it can actually work and that exposed a hidden old
issue with crap^Wunusual system designs where the same power
resources are used for both wakeup power and device power control at
run time.

Namely, say there is one power resource such that the ACPI power
state D0 of a PCI device depends on that power resource (i.e. the
device is in D0 when that power resource is "on") and it is used
as a wakeup power resource for the same device.  Then, calling
acpi_pci_sleep_wake(pci_dev, false) for the device in question will
cause the reference counter of that power resource to drop to 0,
which in turn will cause it to be turned off.  As a result, the
device will go into D3cold at that point, although it should have
stayed in D0.

As it turns out, that happens to USB controllers on some laptops
and USB becomes unusable on those machines as a result, which is
a major regression from v3.8.

To fix this problem, (1) increment the reference counters of wakup
power resources during their initialization if they are "on"
initially, (2) prevent acpi_disable_wakeup_device_power() from
decrementing the reference counters of wakeup power resources that
were not enabled for wakeup power previously, and (3) prevent
acpi_enable_wakeup_device_power() from incrementing the reference
counters of wakeup power resources that already are enabled for
wakeup power.

In addition to that, if it is impossible to determine the initial
states of wakeup power resources, avoid enabling wakeup for devices
whose wakeup power depends on those power resources.
Reported-by: NDave Jones <davej@redhat.com>
Reported-by: NFabio Baltieri <fabio.baltieri@linaro.org>
Tested-by: NFabio Baltieri <fabio.baltieri@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

As discussed in thread at https://patchwork.kernel.org/patch/1946851/,
there's no value in supporting CONFIG_ACPI_PCI_SLOT=m any more.
So change Kconfig and code to only support building pci_slot as
built-in driver.
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

This changeset is aimed at fixing a few different but related
problems in the ACPI hotplug infrastructure.

First of all, since notify handlers may be run in parallel with
acpi_bus_scan(), acpi_bus_trim() and acpi_bus_hot_remove_device()
and some of them are installed for ACPI handles that have no struct
acpi_device objects attached (i.e. before those objects are created),
those notify handlers have to take acpi_scan_lock to prevent races
from taking place (e.g. a struct acpi_device is found to be present
for the given ACPI handle, but right after that it is removed by
acpi_bus_trim() running in parallel to the given notify handler).
Moreover, since some of them call acpi_bus_scan() and
acpi_bus_trim(), this leads to the conclusion that acpi_scan_lock
should be acquired by the callers of these two funtions rather by
these functions themselves.

For these reasons, make all notify handlers that can handle device
addition and eject events take acpi_scan_lock and remove the
acpi_scan_lock locking from acpi_bus_scan() and acpi_bus_trim().
Accordingly, update all of their users to make sure that they
are always called under acpi_scan_lock.

Furthermore, since eject operations are carried out asynchronously
with respect to the notify events that trigger them, with the help
of acpi_bus_hot_remove_device(), even if notify handlers take the
ACPI scan lock, it still is possible that, for example,
acpi_bus_trim() will run between acpi_bus_hot_remove_device() and
the notify handler that scheduled its execution and that
acpi_bus_trim() will remove the device node passed to
acpi_bus_hot_remove_device() for ejection.  In that case, the struct
acpi_device object obtained by acpi_bus_hot_remove_device() will be
invalid and not-so-funny things will ensue.  To protect agaist that,
make the users of acpi_bus_hot_remove_device() run get_device() on
ACPI device node objects that are about to be passed to it and make
acpi_bus_hot_remove_device() run put_device() on them and check if
their ACPI handles are not NULL (make acpi_device_unregister() clear
the device nodes' ACPI handles for that check to work).

Finally, observe that acpi_os_hotplug_execute() actually can fail,
in which case its caller ought to free memory allocated for the
context object to prevent leaks from happening.  It also needs to
run put_device() on the device node that it ran get_device() on
previously in that case.  Modify the code accordingly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>

In order to drop reference counts of all power resources used by an
ACPI device node being removed, acpi_device_unregister() calls
acpi_power_transition(device, ACPI_STATE_D3_COLD), which effectively
transitions the device node into D3cold if it uses any power
resources.  However, for some device nodes it may not be appropriate
to remove power from them entirely before putting them into D3hot
before.  On the other hand, executing _PS3 for devices that don't
use power resources before removing them shouldn't really hurt.
In fact, that is done by acpi_bus_hot_remove_device(), but this is
not the right place to do it, because the bus trimming may have
caused power to be removed from the device node in question already
before.

For these reasons, make acpi_device_unregister() carry out full
power-off transition for all device nodes supporting that and remove
the direct evaluation of _PS3 from acpi_bus_hot_remove_device().
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI scan lock has been introduced to prevent acpi_bus_scan()
and acpi_bus_trim() from running in parallel with each other for
overlapping ACPI namespace scopes.  However, it is not sufficient
to do that, because if acpi_bus_scan() is run (for an overlapping
namespace scope) right after the acpi_bus_trim() in
acpi_bus_hot_remove_device(), the subsequent eject will remove
devices without removing the corresponding struct acpi_device
objects (and possibly companion "physical" device objects).
Therefore acpi_bus_hot_remove_device() has to acquire the scan
lock before carrying out the bus trimming and hold it through
the evaluation of _EJ0, so make that happen.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>

Make the ACPI container driver use struct acpi_scan_handler for
representing the object used to initialize ACPI containers and remove
the ACPI driver structure used previously and the data structures
created by it, since in fact they were not used for any purpose.

This simplifies the code and reduces the kernel's memory footprint by
avoiding the registration of a struct device_driver object with the
driver core and creation of its sysfs directory which is unnecessary.

In addition to that, make the namespace walk callback used for
installing the notify handlers for ACPI containers more
straightforward.

This change includes fixes from Toshi Kani.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Tested-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: NToshi Kani <toshi.kani@hp.com>
Tested-by: NToshi Kani <toshi.kani@hp.com>

Since the FORCE_EJECT symbol is never defined, the
#ifndef FORCE_EJECT in acpi_eject_store() is always true, so drop it.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Tested-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: NToshi Kani <toshi.kani@hp.com>
Tested-by: NToshi Kani <toshi.kani@hp.com>

When acpi_device_install_notify_handler() failed in acpi_device_probe(),
it calls acpi_drv->ops.remove() and fails the probe.  However, the ACPI
driver is left bound to the acpi_device.  Fix it by clearing the driver
and driver_data fields.
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Changed sysfs eject, acpi_eject_store(), so that it doesn't return
error codes for devices nodes with ACPI scan handlers attached and
no ACPI drivers.

[rjw: Changelog]
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The IDs of ACPI device nodes stored in their pnp.ids member arrays
are sorted by decreasing priority (i.e. the highest-priority ID is
the first entry).  This means that when matching scan handlers to
device nodes, the namespace scanning code should walk the list of
scan handlers for each device node ID instead of walking the list
of device node IDs for each handler (the latter causes the first
handler matching any of the device node IDs to be chosen, although
there may be another handler matching an ID of a higher priority
which should be preferred).  Make the code follow this observation.

This change has been suggested and justified by Toshi Kani.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>

In general, for ACPI device power management to work, the initial
power states of devices must be known (otherwise, we wouldn't be able
to keep track of power resources, for example).  Hence, if it is
impossible to determine the initial ACPI power states of some
devices, they can't be regarded as power-manageable using ACPI.

For this reason, modify acpi_bus_get_power_flags() to clear the
power_manageable flag if acpi_bus_init_power() fails and add some
extra fallback code to acpi_bus_init_power() to cover broken
BIOSes that provide _PS0/_PS3 without _PSC for some devices.

Verified to work on my HP nx6325 that has this problem.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NPeter Wu <lekensteyn@gmail.com>

Make acpi_bus_get_parent() more straightforward and remove an
unnecessary local variable ret from it.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>

Since acpi_bus_get_device() returns int and not acpi_status, change
acpi_match_device() so that it doesn't apply ACPI_FAILURE() to the
return value of acpi_bus_get_device().
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>

Currently, the ACPI namespace scanning code creates platform device
objects for ACPI device nodes whose IDs match the contents of the
acpi_platform_device_ids[] table.  However, this adds a superfluous
special case into acpi_bus_device_attach() and makes it more
difficult to follow than it has to be.  It also will make it more
difficult to implement removal code for those platform device objects
in the future.

For the above reasons, introduce a struct acpi_scan_handler object
for creating platform devices and move the code related to that from
acpi_bus_device_attach() to the .attach() callback of that object.
Also move the acpi_platform_device_ids[] table to acpi_platform.c.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>

Make the ACPI PCI IRQ link driver use struct acpi_scan_handler
for representing the object used to set up ACPI interrupt links and
to remove data structures used for this purpose before unregistering
the corresponding ACPI device nodes.

This simplifies the code slightly and reduces the kernel's memory
footprint by avoiding the registration of a struct device_driver
object with the driver core and creation of its sysfs directory
which is unnecessary.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NToshi Kani <toshi.kani@hp.com>

Introduce struct acpi_scan_handler for representing objects that
will do configuration tasks depending on ACPI device nodes'
hardware IDs (HIDs).

Currently, those tasks are done either directly by the ACPI namespace
scanning code or by ACPI device drivers designed specifically for
this purpose.  None of the above is desirable, however, because
doing that directly in the namespace scanning code makes that code
overly complicated and difficult to follow and doing that in
"special" device drivers leads to a great deal of confusion about
their role and to confusing interactions with the driver core (for
example, sysfs directories are created for those drivers, but they
are completely unnecessary and only increase the kernel's memory
footprint in vain).
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>

Make acpi_bus_scan_fixed() use device_attach() directly to attach
drivers, if any, to the fixed devices in analogy with how
acpi_bus_scan() works, which allows the last argument of
acpi_add_single_object() to be dropped and the manipulation of the
flags.match_driver bit to be moved to acpi_init_device_object()
and acpi_device_add_finalize().

After these changes all of the functions for the initialization
and registration of struct acpi_device objects work in the same
way for all of them.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>

There is no guarantee that acpi_bus_scan() and acpi_bus_trim() will
not be run in parallel for the same scope of the ACPI namespace,
which may lead to a great deal of confusion, so introduce a new mutex
to prevent that from happening.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>

The second argument of ACPI driver .remove() operation is only used
by the ACPI processor driver and the value passed to that driver
through it is always available from the given struct acpi_device
object's removal_type field.  For this reason, the second ACPI driver
.remove() argument is in fact useless, so drop it.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NJiang Liu <jiang.liu@huawei.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>

Since acpi_bus_trim() cannot fail, change its definition to a void
function, so that its callers don't check the return value in vain
and update the callers.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>

The acpiphp driver is confusing because it contains partial support for PCI
host bridge hotplug as well as support for hotplug of PCI devices.

This patch moves the host bridge hot-add support to pci_root.c and adds
hot-remove support in pci_root.c.

How to test it: if sci_emu patch is applied, find out root bus number to
ACPI root name mapping from dmesg or /sys.  To remove root bus:

  echo "\_SB.PCIB 3" > /sys/kernel/debug/acpi/sci_notify

To add back root bus:

  echo "\_SB.PCIB 1" > /sys/kernel/debug/acpi/sci_notify
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since ACPI power resources are going to be used more extensively on
new hardware platforms, it becomes necessary for user space (powertop
in particular) to observe some properties of those resources for
diagnostics purposes.

For this reason, expose the current status of each ACPI power
resource to user space via sysfs by adding a new resource_in_use
attribute to the sysfs directory representing the given power
resource.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make it possible to retrieve the current power state of a device with
ACPI power management from user space via sysfs by adding two new
attributes, power_state and real_power_state, to the sysfs directory
associated with the struct acpi_device object representing the
device's ACPI node.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>