The PCI host bridge scan handler installs its own notify handler,
handle_hotplug_event_root(), by itself. Nevertheless, the ACPI
hotplug framework also installs the common notify handler,
acpi_hotplug_notify_cb(), for PCI root bridges. This causes
acpi_hotplug_notify_cb() to call _OST method with unsupported
error as hotplug.enabled is not set.
To address this issue, introduce hotplug.ignore flag, which
indicates that the scan handler installs its own notify handler by
itself. The ACPI hotplug framework does not install the common
notify handler when this flag is set.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
[rjw: Changed the name of the new flag]
Cc: 3.9+ <stable@vger.kernel.org> # 3.9+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Before commit 6931007cc9 (ACPI / scan: Start matching drivers
after trying scan handlers) the match_driver flag for all devices
was set in acpi_add_single_object(), but now it is set by
acpi_bus_device_attach() which is not called for the "fixed"
devices added by acpi_bus_scan_fixed(). This means that
flags.match_driver is never set for those devices now, so make
acpi_bus_scan_fixed() set it before calling device_attach().
Fixes: 6931007cc9 (ACPI / scan: Start matching drivers after trying scan handlers)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since the PCI host bridge scan handler does not set hotplug.enabled,
the check of it in acpi_bus_device_eject() effectively prevents the
root bridge hot removal from working after commit a3b1b1ef78
(ACPI / hotplug: Merge device hot-removal routines). However, that
check is not necessary, because the other acpi_bus_device_eject()
users, acpi_hotplug_notify_cb and acpi_eject_store(), do the same
check by themselves before executing that function.
For this reason, remove the scan handler check from
acpi_bus_device_eject() to make PCI hot bridge hot removal work
again.
Fixes: a3b1b1ef78 (ACPI / hotplug: Merge device hot-removal routines)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Since acpi_bus_get_device() returns a plain int and not acpi_status,
ACPI_FAILURE() should not be used for checking its return value. Fix
that.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
There are two different interfaces for queuing up work items on the
ACPI hotplug workqueue, alloc_acpi_hp_work() used by PCI and PCI host
bridge hotplug code and acpi_os_hotplug_execute() used by the common
ACPI hotplug code and docking stations. They both are somewhat
cumbersome to use and work slightly differently.
The users of alloc_acpi_hp_work() have to submit a work function that
will extract the necessary data items from a struct acpi_hp_work
object allocated by alloc_acpi_hp_work() and then will free that
object, while it would be more straightforward to simply use a work
function with one more argument and let the interface take care of
the execution details.
The users of acpi_os_hotplug_execute() also have to deal with the
fact that it takes only one argument in addition to the work function
pointer, although acpi_os_execute_deferred() actually takes care of
the allocation and freeing of memory, so it would have been able to
pass more arguments to the work function if it hadn't been
constrained by the connection with acpi_os_execute().
Moreover, while alloc_acpi_hp_work() makes GFP_KERNEL memory
allocations, which is correct, because hotplug work items are
always queued up from process context, acpi_os_hotplug_execute()
uses GFP_ATOMIC, as that is needed by acpi_os_execute(). Also,
acpi_os_execute_deferred() queued up by it waits for the ACPI event
workqueues to flush before executing the work function, whereas
alloc_acpi_hp_work() can't do anything similar. That leads to
somewhat arbitrary differences in behavior between various ACPI
hotplug code paths and has to be straightened up.
For this reason, replace both alloc_acpi_hp_work() and
acpi_os_hotplug_execute() with a single interface,
acpi_hotplug_execute(), combining their behavior and being more
friendly to its users than any of the two.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
According to the ACPI spec (5.0, Section 6.3.5), the "Device
insertion in progress (pending)" (0x80) _OST status code is
reserved for the "Insertion Processing" (0x200) source event
which is "a result of an OSPM action". Specifically, it is not
a notification, so that status code should not be used during
notification processing, which unfortunately is done by
acpi_scan_bus_device_check().
For this reason, drop the ACPI_OST_SC_INSERT_IN_PROGRESS _OST
status evaluation from there (it was a mistake to put it in there
in the first place).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Since _handle_hotplug_event_root() is run from the ACPI hotplug
workqueue, it doesn't need to queue up a work item to eject a PCI
host bridge on the same workqueue. Instead, it can just carry out
the eject by calling acpi_bus_device_eject() directly, so make that
happen.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is no real reasn why acpi_bus_device_eject() and
acpi_bus_hot_remove_device() should work differently, so rework
acpi_bus_device_eject() so that it can be called internally by
both acpi_bus_hot_remove_device() and acpi_eject_store_work().
Accordingly, rework acpi_hotplug_notify_cb() to queue up the
execution of acpi_bus_hot_remove_device() through
acpi_os_hotplug_execute() on eject request notifications.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Notice that handle_root_bridge_removal() is the only user of
acpi_bus_hot_remove_device(), so it doesn't have to be exported
any more and can be made internal to the ACPI core.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Simplify handle_root_bridge_removal() and acpi_eject_store() by
getting rid of struct acpi_eject_event and passing device objects
directly to async routines executed via acpi_os_hotplug_execute().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
In theory, an ACPI device object may be the parent of another
device object whose hotplug is disabled by user space through its
scan handler. In that case, the eject operation targeting the
parent should fail as though the parent's own hotplug was disabled,
but currently this is not the case, because acpi_scan_hot_remove()
doesn't check the disable/enable hotplug status of the children
of the top-most object passed to it.
To fix this, modify acpi_bus_offline_companions() to return an
error code if hotplug is disabled for the given device object.
[Also change the name of the function to acpi_bus_offline(),
because it is not only about companions any more, and change
the name of acpi_bus_online_companions() accordingly.] Make
acpi_scan_hot_remove() propagate that error to its callers.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
ACPI scan handlers should always be attached to struct acpi_device
objects before any ACPI drivers, but there is a window during which
a driver may be attached to a struct acpi_device before checking if
there is a matching scan handler. Namely, that will happen if an
ACPI driver module is loaded during acpi_bus_scan() right after
the first namespace walk is complete and before the given device
is processed by the second namespace walk.
To prevent that from happening, set the match_driver flags of
struct acpi_device objects right before running device_attach()
for them in acpi_bus_device_attach().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Two functions defined in device_pm.c, acpi_dev_pm_add_dependent()
and acpi_dev_pm_remove_dependent(), have no callers and may be
dropped, so drop them.
Moreover, they are the only functions adding entries to and removing
entries from the power_dependent list in struct acpi_device, so drop
that list too.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit caf5c03f (ACPI: Move acpi_bus_get_device() from bus.c to
scan.c) caused acpi_bus_get_device() to be exported using
EXPORT_SYMBOL_GPL(), but that broke some binary drivers in
existence, so revert that change.
Reported-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Change the ordering of device hotplug locks in scan.c so that
acpi_scan_lock is always acquired after device_hotplug_lock.
This will make it possible to use device_hotplug_lock around some
code paths that acquire acpi_scan_lock safely (most importantly
system suspend and hibernation). Apart from that, acpi_scan_lock
is platform-specific and device_hotplug_lock is general, so the
new ordering appears to be more appropriate from the overall
design viewpoint.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
The current protocol for handling hot remove of containers is very
fragile and causes acpi_eject_store() to acquire acpi_scan_lock
which may deadlock with the removal of the device that it is called
for (the reason is that device sysfs attributes cannot be removed
while their callbacks are being executed and ACPI device objects
are removed under acpi_scan_lock).
The problem is related to the fact that containers are handled by
acpi_bus_device_eject() in a special way, which is to emit an
offline uevent instead of just removing the container. Then, user
space is expected to handle that uevent and use the container's
"eject" attribute to actually remove it. That is fragile, because
user space may fail to complete the ejection (for example, by not
using the container's "eject" attribute at all) leaving the BIOS
kind of in a limbo. Moreover, if the eject event is not signaled
for a container itself, but for its parent device object (or
generally, for an ancestor above it in the ACPI namespace), the
container will be removed straight away without doing that whole
dance.
For this reason, modify acpi_bus_device_eject() to remove containers
synchronously like any other objects (user space will get its uevent
anyway in case it does some other things in response to it) and
remove the eject_pending ACPI device flag that is not used any more.
This way acpi_eject_store() doesn't have a reason to acquire
acpi_scan_lock any more and one possible deadlock scenario goes
away (plus the code is simplified a bit).
Reported-and-tested-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>
* acpi-pm:
ACPI / PM: Add state information to error message in acpi_device_set_power()
ACPI / PM: Remove redundant power manageable check from acpi_bus_set_power()
ACPI / PM: Use ACPI_STATE_D3_COLD instead of ACPI_STATE_D3 everywhere
ACPI / PM: Make messages in acpi_device_set_power() print device names
ACPI / PM: Only set power states of devices that are power manageable
* acpi-cleanup: (21 commits)
ACPI / dock: fix error return code in dock_add()
ACPI / dock: Drop unnecessary local variable from dock_add()
ACPI / dock / PCI: Drop ACPI dock notifier chain
ACPI / dock: Do not check CONFIG_ACPI_DOCK_MODULE
ACPI / dock: Do not leak memory on falilures to add a dock station
ACPI: Drop ACPI bus notifier call chain
ACPI / dock: Rework the handling of notifications
ACPI / dock: Simplify dock_init_hotplug() and dock_release_hotplug()
ACPI / dock: Walk list in reverse order during removal of devices
ACPI / dock: Rework and simplify find_dock_devices()
ACPI / dock: Drop the hp_lock mutex from struct dock_station
ACPI: simplify acpiphp driver with new helper functions
ACPI: simplify dock driver with new helper functions
ACPI: Export acpi_(bay)|(dock)_match() from scan.c
ACPI: introduce two helper functions for _EJ0 and _LCK
ACPI: introduce helper function acpi_execute_simple_method()
ACPI: introduce helper function acpi_has_method()
ACPI / dock: simplify dock_create_acpi_device()
ACPI / dock: mark initialization functions with __init
ACPI / dock: drop redundant spin lock in dock station object
...
Move acpi_bus_get_device() from bus.c to scan.c which allows
acpi_bus_data_handler() to become static and clean up the latter.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are several places in the tree where ACPI_STATE_D3 is used
instead of ACPI_STATE_D3_COLD which should be used instead for
clarity. Modify them all to use ACPI_STATE_D3_COLD as appropriate.
[The definition of ACPI_STATE_D3 itself cannot go away at this point
as it is part of ACPICA.]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Functions acpi_dock_match() and acpi_bay_match() in scan.c can be
shared with dock.c to reduce code duplication, so export them as
global functions.
Also add a new function acpi_ata_match() to check whether an ACPI
device object represents an ATA device.
[rjw: Changelog]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Introduce two helper functions, acpi_evaluate_ej0() and
acpi_evaluate_lck(), that will execute the _EJ0 and _LCK ACPI
control methods, respectively, and use them to simplify the
ACPI scan code.
[rjw: Changelog]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Introduce helper function acpi_has_method() and use it in a number
of places to simplify code.
[rjw: Changelog]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
An ACPI_NOTIFY_BUS_CHECK notification means that we should scan the
entire namespace starting from the given handle even if the device
represented by that handle is present (other devices below it may
just have appeared).
For this reason, modify acpi_scan_bus_device_check() to always run
acpi_bus_scan() if the notification being handled is of type
ACPI_NOTIFY_BUS_CHECK.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Cc: 3.10+ <stable@vger.kernel.org>
In acpi_bus_device_attach(), if there is an ACPI device object
for the given handle and that device object has a scan handler
attached to it already, there's nothing more to do for that handle.
Moreover, if acpi_scan_attach_handler() is called then, it may
execute the .attach() callback of the ACPI scan handler already
attached to the device object and that may lead to interesting
breakage.
For this reason, make acpi_bus_device_attach() return success
immediately when the handle's device object has a scan handler
attached to it.
Reported-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Cc: 3.10+ <stable@vger.kernel.org>
The acpi_device_list list is not used, so removed it.
[rjw: Changelog]
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* acpi-assorted:
ACPI / EC: Add HP Folio 13 to ec_dmi_table in order to skip DSDT scan
ACPI: Add CMOS RTC Operation Region handler support
ACPI: Remove unused flags in acpi_device_flags
ACPI: Remove useless initializers
ACPI / battery: Make sure all spaces are in correct places
ACPI: add _STA evaluation at do_acpi_find_child()
ACPI / EC: access user space with get_user()/put_user()
On HP Folio 13-2000, the BIOS defines a CMOS RTC Operation Region and
the EC's _REG methord accesses that region. Thus an appropriate
address space handler must be registered for that region before the
EC driver is loaded.
Introduce a mechanism for adding CMOS RTC address space handlers.
Register an ACPI scan handler for CMOS RTC devices such that, when
a device of that kind is detected during an ACPI namespace scan, a
common CMOS RTC operation region address space handler will be
installed for it.
References: https://bugzilla.kernel.org/show_bug.cgi?id=54621
Reported-and-tested-by: Stefan Nagy <public@stefan-nagy.at>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit 3b63aaa70e (PCI: acpiphp: Do not use ACPI PCI subdriver
mechanism) introduced an ACPI dock support regression, because it
changed the relative initialization order of the ACPI dock subsystem
and the ACPI-based PCI hotplug (acpiphp).
Namely, the ACPI dock subsystem has to be initialized before
acpiphp_enumerate_slots() is first run, which after commit
3b63aaa70e happens during the initial enumeration of the PCI
hierarchy triggered by the initial ACPI namespace scan in
acpi_scan_init(). For this reason, the dock subsystem has to be
initialized before the initial ACPI namespace scan in
acpi_scan_init().
To make that happen, modify the ACPI dock subsystem to be
non-modular and add the invocation of its initialization routine,
acpi_dock_init(), to acpi_scan_init() directly before the initial
namespace scan.
[rjw: Changelog, removal of dock_exit().]
References: https://bugzilla.kernel.org/show_bug.cgi?id=59501
Reported-and-tested-by: Alexander E. Patrakov <patrakov@gmail.com>
Tested-by: Illya Klymov <xanf@xanf.me>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI drivers must not be bound to device objects having scan handlers
attatched to them, so make acpi_device_probe() fail with -EINVAL if the
device object being probed has an ACPI scan handler.
After this change the analogous check introduced into the ACPI video
driver by commit 8c9b7a7 (ACPI / video: Do not bind to device objects
with a scan handler) is not necessary any more and may be dropped, so
drop it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Tony Luck <tony.luck@gmail.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
There is no particular reason why acpi_bus_driver_init() needs to be
a separate function and its location with respect to its only caller,
acpi_device_probe(), makes the code a bit difficult to follow.
Besides, it doesn't really make sense to check if 'device' is not
NULL in acpi_bus_driver_init(), because we've already dereferenced
dev->driver in acpi_device_probe() at that point and, moreover,
'device' cannot be NULL then, because acpi_device_probe() is called
via really_probe() (which also sets dev->driver for that matter).
For these reasons, drop acpi_bus_driver_init() altogether and move
the remaining code from it directly into acpi_device_probe().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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=58091
Bisected-and-tested-by: Dmitry S. Demin <dmitryy.demin@gmail.com>
Reported-and-tested-by: Jason Cassell <bluesloth600@gmail.com>
Tracked-down-by: Aaron Lu <aaron.lu@intel.com>
Cc: 3.9+ <stable@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Commit 9f29ab11dd ("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: Tony Luck <tony.luck@gmail.com>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus 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=58091
Reported-by: Jason Cassell <bluesloth600@gmail.com>
Reported-and-bisected-by: Dmitry S. Demin <dmitryy.demin@gmail.com>
Cc: 3.9+ <stable@kernel.org>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
As indicated by comments in mm/memory_hotplug.c:remove_memory(),
if CONFIG_MEMCG is set, it may not be possible to offline all of the
memory blocks held by one module (FRU) in one pass (because one of
them may be used by the others to store page cgroup in that case
and that block has to be offlined before the other ones).
To handle that arguably corner case, add a second pass of companion
device offlining to acpi_scan_hot_remove() and make it ignore errors
returned in the first pass (and make it skip the second pass if the
first one is successful).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
The ACPI processor driver was the only user of the removal_type
field in struct acpi_device, but it doesn't use that field any more
after recent changes. Thus, removal_type has no more users, so drop
it along with the associated data type.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Pull slave-dma fixes from Vinod Koul:
"We have two patches from Andy & Rafael fixing the Lynxpoint dma"
* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
ACPI / LPSS: register clock device for Lynxpoint DMA properly
dma: acpi-dma: parse CSRT to extract additional resources
Following commit 6b772e8f9 (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: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Rafael 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: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Split the ACPI processor driver into two parts, one that is
non-modular, resides in the ACPI core and handles the enumeration
and hotplug of processors and one that implements the rest of the
existing processor driver functionality.
The non-modular part uses an ACPI scan handler object to enumerate
processors on the basis of information provided by the ACPI namespace
and to hook up with the common ACPI hotplug infrastructure. It also
populates the ACPI handle of each processor device having a
corresponding object in the ACPI namespace, which allows the driver
proper to bind to those devices, and makes the driver bind to them
if it is readily available (i.e. loaded) when the scan handler's
.attach() routine is running.
There are a few reasons to make this change.
First, switching the ACPI processor driver to using the common ACPI
hotplug infrastructure reduces code duplication and size considerably,
even though a new file is created along with a header comment etc.
Second, since the common hotplug code attempts to offline devices
before starting the (non-reversible) removal procedure, it will abort
(and possibly roll back) hot-remove operations involving processors
if cpu_down() returns an error code for one of them instead of
continuing them blindly (if /sys/firmware/acpi/hotplug/force_remove
is unset). That is a more desirable behavior than what the current
code does.
Finally, the separation of the scan/hotplug part from the driver
proper makes it possible to simplify the driver's .remove() routine,
because it doesn't need to worry about the possible cleanup related
to processor removal any more (the scan/hotplug part is responsible
for that now) and can handle device removal and driver removal
symmetricaly (i.e. as appropriate).
Some user-visible changes in sysfs are made (for example, the
'sysdev' link from the ACPI device node to the processor device's
directory is gone and a 'physical_node' link is present instead
and a corresponding 'firmware_node' is present in the processor
device's directory, the processor driver is now visible under
/sys/bus/cpu/drivers/ and bound to the processor device), but
that shouldn't affect the functionality that users care about
(frequency scaling, C-states and thermal management).
Tested on my venerable Toshiba Portege R500.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
