On platforms where the Low Power S0 Idle _DSM interface is used,
on wakeup from suspend-to-idle, when it is known that the ACPI SCI
has triggered while suspended, dispatch the EC GPE in order to catch
all EC events that may have triggered the wakeup before carrying out
the noirq phase of device resume.

That is needed to handle power button wakeup on some platforms where
the EC goes into a low-power mode during suspend-to-idle and while in
that mode it will discard events after a timeout.  If that timeout is
shorter than the time it takes to complete the noirq resume of
devices, looking for EC events after the latter is too late.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reported-by: NZhang Rui <rui.zhang@intel.com>
Tested-by: NWendy Wang <wendy.wang@intel.com>

acpi_ec.gpe is "unsigned long", hence treating it as "u32" would expose
the wrong half on big-endian 64-bit systems.  Fix this by changing its
type to "u32" and removing the cast, as all other code already uses u32
or sometimes even only u8.

Fixes: 1195a098 (ACPI: Provide /sys/kernel/debug/ec/...)
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

On platforms (ASUS X550ZE and possibly all ASUS X series) with valid ECDT
EC but invalid DSDT EC, EC PM ops won't be invoked as ECDT EC is not an
ACPI device. Thus the following commit actually removed post-resume
acpi_ec_enable_event() invocation for such platforms, and triggered a
regression on them that after being resumed, EC (actually should be ECDT)
driver stops handling EC events:

 Commit: c2b46d67
 Subject: ACPI / EC: Add PM operations to improve event handling for resume process

Notice that the root cause actually is "ECDT is not an ACPI device" rather
than "the timing of acpi_ec_enable_event() invocation", this patch fixes
this issue by enumerating ECDT EC as an ACPI device. Due to the existence
of the noirq stage, the ability of tuning the timing of
acpi_ec_enable_event() invocation is still meaningful.

This patch is a little bit different from the posted fix by moving
acpi_config_boot_ec() from acpi_ec_ecdt_start() to acpi_ec_add() to make
sure that EC event handling won't be stopped as long as the ACPI EC driver
is bound. Thus the following sequence shouldn't disable EC event handling:
unbind,suspend,resume,bind.

Fixes: c2b46d67 (ACPI / EC: Add PM operations to improve event handling for resume process)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=196847Reported-by: NLuya Tshimbalanga <luya@fedoraproject.org>
Tested-by: NLuya Tshimbalanga <luya@fedoraproject.org>
Cc: 4.9+ <stable@vger.kernel.org> # 4.9+
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add functionality to read LPIT table, which provides:

 - Sysfs interface to read residency counters via
   /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us
   /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us

Here the count "low_power_idle_cpu_residency_us" shows the time spent
by CPU package in low power state.  This is read via MSR interface,
which points to MSR for PKG C10.

Here the count "low_power_idle_system_residency_us" show the count the
system was in low power state. This is read via MMIO interface. This
is mapped to SLP_S0 residency on modern Intel systems. This residency
is achieved only when CPU is in PKG C10 and all functional blocks are
in low power state.

It is possible that none of the above counters present or anyone of the
counter present or all counters present.

For example: On my Kabylake system both of the above counters present.
After suspend to idle these counts updated and prints:

 6916179
 6998564

This counter can be read by tools like turbostat to display. Or it can
be used to debug, if modern systems are reaching desired low power state.

 - Provides an interface to read residency counter memory address

   This address can be used to get the base address of PMC memory
   mapped IO.  This is utilized by intel_pmc_core driver to print
   more debug information.

In addition, to avoid code duplication to read iomem, removed the read of
iomem from acpi_os_read_memory() in osl.c and made a common function
acpi_os_read_iomem(). This new function is used for reading iomem in
in both osl.c and acpi_lpit.c.

Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdfSigned-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 2a570840 (ACPI / EC: Fix a gap that ECDT EC cannot handle
EC events) introduced acpi_ec_ecdt_start(), but that function is
invoked before acpi_ec_query_init(), which is too early.  This causes
the kernel to crash if an EC event occurs after boot, when ec_query_wq
is not valid:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000102
 ...
 Workqueue: events acpi_ec_event_handler
 task: ffff9f539790dac0 task.stack: ffffb437c0e10000
 RIP: 0010:__queue_work+0x32/0x430

Normally, the DSDT EC should always be valid, so acpi_ec_ecdt_start()
is actually a no-op in the majority of cases.  However, commit
c712bb58 (ACPI / EC: Add support to skip boot stage DSDT probe)
caused the probing of the DSDT EC as the "boot EC" to be skipped when
the ECDT EC is valid and uncovered the bug.

Fix this issue by invoking acpi_ec_ecdt_start() after acpi_ec_query_init()
in acpi_ec_init().

Link: https://jira01.devtools.intel.com/browse/LCK-4348
Fixes: 2a570840 (ACPI / EC: Fix a gap that ECDT EC cannot handle EC events)
Fixes: c712bb58 (ACPI / EC: Add support to skip boot stage DSDT probe)
Reported-by: NWang Wendy <wendy.wang@intel.com>
Tested-by: NFeng Chenzhou <chenzhoux.feng@intel.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
[ rjw: Changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

While the rest of the world has standardized on _DSD as the way to store
device properties in AML (introduced with ACPI 5.1 in 2014), Apple has
been using a custom _DSM to achieve the same for much longer (ever since
they switched from DeviceTree-based PowerPC to Intel in 2005, verified
with MacOS X 10.4.11).

The theory of operation on macOS is as follows:  AppleACPIPlatform.kext
invokes mergeEFIproperties() and mergeDSMproperties() for each device to
merge properties conveyed by EFI drivers as well as properties stored in
AML into the I/O Kit registry from which they can be retrieved by
drivers.  We've been supporting EFI properties since commit 58c5475a
("x86/efi: Retrieve and assign Apple device properties").  The present
commit adds support for _DSM properties, thereby completing our support
for Apple device properties.  The _DSM properties are made available
under the primary fwnode, the EFI properties under the secondary fwnode.
So for devices which possess both property types, they can all be
elegantly accessed with the uniform API in <linux/property.h>.

Until recently we had no need to support _DSM properties, they contained
only uninteresting garbage.  The situation has changed with MacBooks and
MacBook Pros introduced since 2015:  Their keyboard is attached with SPI
instead of USB and the _CRS data which is necessary to initialize the
spi driver only contains valid information if OSPM responds "false" to
_OSI("Darwin").  If OSPM responds "true", _CRS is empty and the spi
driver fails to initialize.  The rationale is very simple, Apple only
cares about macOS and Windows:  On Windows, _CRS contains valid data,
whereas on macOS it is empty.  Instead, macOS gleans the necessary data
from the _DSM properties.

Since Linux deliberately defaults to responding "true" to _OSI("Darwin"),
we need to emulate macOS' behaviour by initializing the spi driver with
data returned by the _DSM.

An out-of-tree driver for the SPI keyboard exists which currently binds
to the ACPI device, invokes the _DSM, parses the returned package and
instantiates an SPI device with the data gleaned from the _DSM:
https://github.com/cb22/macbook12-spi-driver/commit/9a416d699ef4
https://github.com/cb22/macbook12-spi-driver/commit/0c34936ed9a1

By adding support for Apple's _DSM properties in generic ACPI code, the
out-of-tree driver will be able to register as a regular SPI driver,
significantly reducing its amount of code and improving its chances to
be mainlined.

The SPI keyboard will not be the only user of this commit:  E.g. on the
MacBook8,1, the UART-attached Bluetooth device likewise returns empty
_CRS data if OSPM returns "true" to _OSI("Darwin").

The _DSM returns a Package whose format unfortunately deviates slightly
from the _DSD spec:  The properties are marshalled up in a single Package
as alternating key/value elements, unlike _DSD which stores them as a
Package of 2-element Packages.  The present commit therefore converts
the Package to _DSD format and the ACPI core can then treat the data as
if Apple would follow the standard.

Well, except for one small annoyance:  The properties returned by the
_DSM only ever have one of two types, Integer or Buffer.  The former is
retrievable as usual with device_property_read_u64(), but the latter is
not part of the _DSD spec and it is not possible to retrieve Buffer
properties with the device_property_read_*() functions due to the type
checking performed in drivers/acpi/property.c.  It is however possible
to retrieve them with acpi_dev_get_property().  Apple is using the
Buffer type somewhat sloppily to store null-terminated strings but also
integers.  The real data type is not distinguishable by the ACPI core
and the onus is on the caller to use the contents of the Buffer in an
appropriate way.

In case Apple moves to _DSD in the future, this commit first checks for
_DSD and falls back to _DSM only if _DSD is not found.
Tested-by: NRonald Tschalär <ronald@innovation.ch>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit eed4d47e (ACPI / sleep: Ignore spurious SCI wakeups from
suspend-to-idle) introduced acpi_freeze_sync() whose purpose is to
flush all of the processing of possible wakeup events signaled via
the ACPI SCI.  However, it doesn't flush the query workqueue used
by the EC driver, so the events generated by the EC may not be
processed timely which leads to issues (increased overhead at least,
lost events possibly).

To fix that introduce acpi_ec_flush_work() that will flush all of
the outstanding EC work and call it from acpi_freeze_sync().

Fixes: eed4d47e (ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some recent Dell laptops, including the XPS13 model numbers 9360 and
9365, cannot be woken up from suspend-to-idle by pressing the power
button which is unexpected and makes that feature less usable on
those systems.  Moreover, on the 9365 ACPI S3 (suspend-to-RAM) is
not expected to be used at all (the OS these systems ship with never
exercises the ACPI S3 path in the firmware) and suspend-to-idle is
the only viable system suspend mechanism there.

The reason why the power button wakeup from suspend-to-idle doesn't
work on those systems is because their power button events are
signaled by the EC (Embedded Controller), whose GPE (General Purpose
Event) line is disabled during suspend-to-idle transitions in Linux.
That is done on purpose, because in general the EC tends to be noisy
for various reasons (battery and thermal updates and similar, for
example) and all events signaled by it would kick the CPUs out of
deep idle states while in suspend-to-idle, which effectively might
defeat its purpose.

Of course, on the Dell systems in question the EC GPE must be enabled
during suspend-to-idle transitions for the button press events to
be signaled while suspended at all, but fortunately there is a way
out of this puzzle.

First of all, those systems have the ACPI_FADT_LOW_POWER_S0 flag set
in their ACPI tables, which means that the OS is expected to prefer
the "low power S0 idle" system state over ACPI S3 on them.  That
causes the most recent versions of other OSes to simply ignore ACPI
S3 on those systems, so it is reasonable to expect that it should not
be necessary to block GPEs during suspend-to-idle on them.

Second, in addition to that, the systems in question provide a special
firmware interface that can be used to indicate to the platform that
the OS is transitioning into a system-wide low-power state in which
certain types of activity are not desirable or that it is leaving
such a state and that (in principle) should allow the platform to
adjust its operation mode accordingly.

That interface is a special _DSM object under a System Power
Management Controller device (PNP0D80).  The expected way to use it
is to invoke function 0 from it on system initialization, functions
3 and 5 during suspend transitions and functions 4 and 6 during
resume transitions (to reverse the actions carried out by the
former).  In particular, function 5 from the "Low-Power S0" device
_DSM is expected to cause the platform to put itself into a low-power
operation mode which should include making the EC less verbose (so to
speak).  Next, on resume, function 6 switches the platform back to
the "working-state" operation mode.

In accordance with the above, modify the ACPI suspend-to-idle code
to look for the "Low-Power S0" _DSM interface on platforms with the
ACPI_FADT_LOW_POWER_S0 flag set in the ACPI tables.  If it's there,
use it during suspend-to-idle transitions as prescribed and avoid
changing the GPE configuration in that case.  [That should reflect
what the most recent versions of other OSes do.]

Also modify the ACPI EC driver to make it handle events during
suspend-to-idle in the usual way if the "Low-Power S0" _DSM interface
is going to be used to make the power button events work while
suspended on the Dell machines mentioned above

Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdfSigned-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This will be needed in constifying the fwnode API.

The side effects the function had have been moved to the callers.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI SCI (System Control Interrupt) is set up as a wakeup IRQ
during suspend-to-idle transitions and, consequently, any events
signaled through it wake up the system from that state.  However,
on some systems some of the events signaled via the ACPI SCI while
suspended to idle should not cause the system to wake up.  In fact,
quite often they should just be discarded.

Arguably, systems should not resume entirely on such events, but in
order to decide which events really should cause the system to resume
and which are spurious, it is necessary to resume up to the point
when ACPI SCIs are actually handled and processed, which is after
executing dpm_resume_noirq() in the system resume path.

For this reasons, add a loop around freeze_enter() in which the
platforms can process events signaled via multiplexed IRQ lines
like the ACPI SCI and add suspend-to-idle hooks that can be
used for this purpose to struct platform_freeze_ops.

In the ACPI case, the ->wake hook is used for checking if the SCI
has triggered while suspended and deferring the interrupt-induced
system wakeup until the events signaled through it are actually
processed sufficiently to decide whether or not the system should
resume.  In turn, the ->sync hook allows all of the relevant event
queues to be flushed so as to prevent events from being missed due
to race conditions.

In addition to that, some ACPI code processing wakeup events needs
to be modified to use the "hard" version of wakeup triggers, so that
it will cause a system resume to happen on device-induced wakeup
events even if the "soft" mechanism to prevent the system from
suspending is not enabled.  However, to preserve the existing
behavior with respect to suspend-to-RAM, this only is done in
the suspend-to-idle case and only if an SCI has occurred while
suspended.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

/sys/firmware/acpi/hotplug/force_remove was presumably added to support
auto offlining in the past. This is, however, inherently dangerous for
some hotplugable resources like memory. The memory offlining fails when
the memory is still in use and cannot be dropped or migrated. If we
ignore the failure we are basically allowing for subtle memory
corruption or a crash.

We have actually noticed the later while hitting BUG() during the memory
hotremove (remove_memory):
	ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL,
			check_memblock_offlined_cb);
	if (ret)
		BUG();

it took us quite non-trivial time realize that the customer had
force_remove enabled. Even if the BUG was removed here and we could
propagate the error up the call chain it wouldn't help at all because
then we would hit a crash or a memory corruption later and harder to
debug. So force_remove is unfixable for the memory hotremove. We haven't
checked other hotplugable resources to be prone to a similar problems.

Remove the force_remove functionality because it is not fixable currently.
Keep the sysfs file and report an error if somebody tries to enable it.
Encourage users to report about the missing functionality and work with
them with an alternative solution.
Reviewed-by: NLee, Chun-Yi <jlee@suse.com>
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The hot removal of IOAPIC is handling PCI and ACPI removal in one go. That
only works when the PCI drivers released the interrupt resources, but
breaks when a IOAPIC interrupt is still associated to a PCI device.

The new pcibios_release_device() callback allows to solve that problem by
splitting the removal into two steps:

1) PCI removal:

   Release all PCI resources including eventually not yet released IOAPIC
   interrupts via the new pcibios_release_device() callback.

2) ACPI removal:

   After release of all PCI resources the ACPI resources can be released
   without issue.

[ tglx: Rewrote changelog ]
Signed-off-by: NRui Wang <rui.y.wang@intel.com>
Cc: tony.luck@intel.com
Cc: linux-pci@vger.kernel.org
Cc: rjw@rjwysocki.net
Cc: linux-acpi@vger.kernel.org
Cc: fengguang.wu@intel.com
Cc: helgaas@kernel.org
Cc: kbuild-all@01.org
Cc: bhelgaas@google.com
Link: http://lkml.kernel.org/r/1488288869-31290-3-git-send-email-rui.y.wang@intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

When GPE is not enabled, it is not efficient to use the wait polling mode
as it introduces an unexpected scheduler delay.
So before the GPE handler is installed, this patch uses busy polling mode
for all EC(s) and the logic can be applied to non boot EC(s) during the
suspend/resume process.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=191561Tested-by: NJakobus Schurz <jakobus.schurz@gmail.com>
Tested-by: NChen Yu <yu.c.chen@intel.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Sometimes, the users may require a quirk to be provided from ACPI subsystem
core to prevent a GPE from flooding.
Normally, if a GPE cannot be dispatched, ACPICA core automatically prevents
the GPE from firing. But there are cases the GPE is dispatched by _Lxx/_Exx
provided via AML table, and OSPM is lacking of the knowledge to get
_Lxx/_Exx correctly executed to handle the GPE, thus the GPE flooding may
still occur.

The existing quirk mechanism can be enabled/disabled using the following
commands to prevent such kind of GPE flooding during runtime:
 # echo mask > /sys/firmware/acpi/interrupts/gpe00
 # echo unmask > /sys/firmware/acpi/interrupts/gpe00
To avoid GPE flooding during boot, we need a boot stage mechanism.

This patch provides such a boot stage quirk mechanism to stop this kind of
GPE flooding. This patch doesn't fix any feature gap but since the new
feature gaps could be found in the future endlessly, and can disappear if
the feature gaps are filled, providing a boot parameter rather than a DMI
table should suffice.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=53071
Link: https://bugzilla.kernel.org/show_bug.cgi?id=117481
Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/887793Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Starting from Intel Skylake the iTCO watchdog timer registers were moved to
reside in the same register space with SMBus host controller.  Not all
needed registers are available though and we need to unhide P2SB (Primary
to Sideband) device briefly to be able to read status of required NO_REBOOT
bit. The i2c-i801.c SMBus driver used to handle this and creation of the
iTCO watchdog platform device.

Windows, on the other hand, does not use the iTCO watchdog hardware
directly even if it is available. Instead it relies on ACPI Watchdog Action
Table (WDAT) table to describe the watchdog hardware to the OS. This table
contains necessary information about the the hardware and also set of
actions which are executed by a driver as needed.

This patch implements a new watchdog driver that takes advantage of the
ACPI WDAT table. We split the functionality into two parts: first part
enumerates the WDAT table and if found, populates resources and creates
platform device for the actual driver. The second part is the driver
itself.

The reason for the split is that this way we can make the driver itself to
be a module and loaded automatically if the WDAT table is found. Otherwise
the module is not loaded.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It is possible to register _Qxx from namespace and use the ECDT EC to
perform event handling. The reported bug reveals that Windows is using ECDT
in this way in case the namespace EC is not present. This patch facilitates
Linux to support ECDT in this way.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=115021Reported-and-tested-by: NLuya Tshimbalanga <luya@fedoraproject.org>
Tested-by: NJonh Henderson <jw.hendy@gmail.com>
Reviewed-by: NPeter Wu <peter@lekensteyn.nl>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch makes 2 changes:

1. Restore old behavior
Originally, EC driver stops handling both events and transactions in
acpi_ec_block_transactions(), and restarts to handle transactions in
acpi_ec_unblock_transactions_early(), restarts to handle both events and
transactions in acpi_ec_unblock_transactions().
While currently, EC driver still stops handling both events and
transactions in acpi_ec_block_transactions(), but restarts to handle both
events and transactions in acpi_ec_unblock_transactions_early().
This patch tries to restore the old behavior by dropping
__acpi_ec_enable_event() from acpi_unblock_transactions_early().

2. Improve old behavior
However this still cannot fix the real issue as both of the
acpi_ec_unblock_xxx() functions are invoked in the noirq stage. Since the
EC driver actually doesn't implement the event handling in the polling
mode, re-enabling the event handling too early in the noirq stage could
result in the problem that if there is no triggering source causing
advance_transaction() to be invoked, pending SCI_EVT cannot be detected by
the EC driver and _Qxx cannot be triggered.
It actually makes sense to restart the event handling in any point during
resuming after the noirq stage. Just like the boot stage where the event
handling is enabled in .add(), this patch further moves
acpi_ec_enable_event() to .resume(). After doing that, the following 2
functions can be combined:
acpi_ec_unblock_transactions_early()/acpi_ec_unblock_transactions().

The differences of the event handling availability between the old behavior
(this patch isn't applied) and the new behavior (this patch is applied) are
as follows:
                        !Applied        Applied
before suspend          Y               Y
suspend before EC       Y               Y
suspend after EC        Y               Y
suspend_late            Y               Y
suspend_noirq           Y (actually N)  Y (actually N)
resume_noirq            Y (actually N)  Y (actually N)
resume_late             Y (actually N)  Y (actually N)
resume before EC        Y (actually N)  Y (actually N)
resume after EC         Y (actually N)  Y
after resume            Y (actually N)  Y
Where "actually N" means if there is no triggering source, the EC driver
is actually not able to notice the pending SCI_EVT occurred in the noirq
stage. So we can clearly see that this patch has improved the situation.
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Tested-by: NTodd E Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Following the fwnode of a device is currently a one-way road: We provide
ACPI_COMPANION() to obtain the fwnode but there's no (public) method to
do the reverse. Granted, there may be multiple physical_nodes, but often
the first one in the list is sufficient.

A handy function to obtain it was introduced with commit 3b95bd16
("ACPI: introduce a function to find the first physical device"), but
currently it's only available internally.

We're about to add an EFI Device Path parser which needs this function.
Consider the following device path: ACPI(PNP0A03,0)/PCI(28,2)/PCI(0,0)
The PCI root is encoded as an ACPI device in the path, so the parser
has to find the corresponding ACPI device, then find its physical node,
find the PCI bridge in slot 1c (decimal 28), function 2 below it and
finally find the PCI device in slot 0, function 0.

To this end, make acpi_get_first_physical_node() public.
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Change the argument of acpi_ioapic_add() to a generic ACPI handle, and
move its prototype from drivers/acpi/internal.h to include/linux/acpi.h
so that it can be called from outside the pci_root driver.
Signed-off-by: NRui Wang <rui.y.wang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bhelgaas@google.com
Cc: helgaas@kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: rjw@rjwysocki.net
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1471420837-31003-2-git-send-email-rui.y.wang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

It is reported that on some platforms, resume speed is not fast. The cause
is: in noirq stage, EC driver is working in polling mode, and each state
machine advancement requires a context switch.

The context switch is not necessary to the EC driver's polling mode. This
patch implements PM hooks to automatically switch the driver to/from the
busy polling mode to eliminate the overhead caused by the context switch.

This finally contributes to the tuning result: acpi_pm_finish() execution
time is improved from 192ms to 6ms.
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Reported-and-tested-by: NTodd E Brandt <todd.e.brandt@linux.intel.com>
[ rjw: Subject ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add support for ACPI reconfiguration notifiers to allow subsystems
to react to changes in the ACPI tables that happen after the initial
enumeration. This is similar with the way dynamic device tree
notifications work.

The reconfigure notifications supported for now are device add and
device remove.

Since ACPICA allows only one table notification handler, this patch
makes the table notifier function generic and moves it out of the
sysfs specific code.
Signed-off-by: NOctavian Purdila <octavian.purdila@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

According to the Windows probing result, during the table loading, the EC
device described in the ECDT should be used. And the ECDT EC is also
effective during the period the namespace objects are initialized (we can
see a separate process executing _STA/_INI on Windows before executing
other device specific control methods, for example, EC._REG). During the
device enumration, the EC device described in the DSDT should be used. But
there are differences between Linux and Windows around the device probing
order. Thus in Linux, we should enable the DSDT EC as early as possible
before enumerating devices in order not to trigger issues related to the
device enumeration order differences.

This patch thus converts acpi_boot_ec_enable() into acpi_ec_dsdt_probe() to
fix the gap. This also fixes a user reported regression triggered after we
switched the "table loading"/"ECDT support" to be ACPI spec 2.0 compliant.

Fixes: 59f0aa94 (ACPI 2.0 / ECDT: Remove early namespace reference from EC)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=119261Reported-and-tested-by: NGabriele Mazzotta <gabriele.mzt@gmail.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

_OSI handling code grows giant and it's time to move them into one file.

This patch collects all _OSI handling code into one single file.
So that we only have the following functions to be used externally:

 early_acpi_osi_init(): Used by DMI detections;
 acpi_osi_init(): Used to initialize OSI command line settings and install
                  Linux specific _OSI handler;
 acpi_osi_setup(): The API that should be used by the external quirks.
 acpi_osi_is_win8(): The API is used by the external drivers to determine
                     if BIOS supports Win8.

CONFIG_DMI is not useful as stub dmi_check_system() can make everything
stub because of strip.

No functional changes.
Tested-by: NLukas Wunner <lukas@wunner.de>
Tested-by: NChen Yu <yu.c.chen@intel.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch moves acpi_os_table_override() and
acpi_os_physical_table_override() to tables.c.

Along with the mechanisms, acpi_initrd_initialize_tables() is also moved to
tables.c to form a static function. The following functions are renamed
according to this change:
 1. acpi_initrd_override() -> renamed to early_acpi_table_init(), which
    invokes acpi_table_initrd_init()
 2. acpi_os_physical_table_override() -> which invokes
    acpi_table_initrd_override()
 3. acpi_initialize_initrd_tables() -> renamed to acpi_table_initrd_scan()
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There are several reports of freeze on enabling HWP (Hardware PStates)
feature on Skylake-based systems by the Intel P-states driver. The root
cause is identified as the HWP interrupts causing BIOS code to freeze.

HWP interrupts use the thermal LVT which can be handled by Linux
natively, but on the affected Skylake-based systems SMM will respond
to it by default.  This is a problem for several reasons:
 - On the affected systems the SMM thermal LVT handler is broken (it
   will crash when invoked) and a BIOS update is necessary to fix it.
 - With thermal interrupt handled in SMM we lose all of the reporting
   features of the arch/x86/kernel/cpu/mcheck/therm_throt driver.
 - Some thermal drivers like x86-package-temp depend on the thermal
   threshold interrupts signaled via the thermal LVT.
 - The HWP interrupts are useful for debugging and tuning
   performance (if the kernel can handle them).
The native handling of thermal interrupts needs to be enabled
because of that.

This requires some way to tell SMM that the OS can handle thermal
interrupts.  That can be done by using _OSC/_PDC in processor
scope very early during ACPI initialization.

The meaning of _OSC/_PDC bit 12 in processor scope is whether or
not the OS supports native handling of interrupts for Collaborative
Processor Performance Control (CPPC) notifications.  Since on
HWP-capable systems CPPC is a firmware interface to HWP, setting
this bit effectively tells the firmware that the OS will handle
thermal interrupts natively going forward.

For details on _OSC/_PDC refer to:
http://www.intel.com/content/www/us/en/standards/processor-vendor-specific-acpi-specification.html

To implement the _OSC/_PDC handshake as described, introduce a new
function, acpi_early_processor_osc(), that walks the ACPI
namespace looking for ACPI processor objects and invokes _OSC for
them with bit 12 in the capabilities buffer set and terminates the
namespace walk on the first success.

Also modify intel_thermal_interrupt() to clear HWP status bits in
the HWP_STATUS MSR to acknowledge HWP interrupts (which prevents
them from firing continuously).
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Subject & changelog, function rename ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch adds support to install tables from initrd.

If a table in the initrd wasn't used by the override mechanism,
the table would be installed after initializing all RSDT/XSDT
tables.

Link: https://lkml.org/lkml/2014/2/28/368Reported-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

On ARM64 some devices use the AMBA device and not the platform bus for
probing so add support for this. Uses a dummy clock for apb_pclk as ACPI
does not have a suitable clock representation and to keep the core
AMBA bus code unchanged between probing methods.
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NGraeme Gregory <graeme.gregory@linaro.org>
Signed-off-by: NAleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Factor out the code that finds the first physical device
of a given ACPI device.  It is used in several places.
Signed-off-by: NAleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add a missing space in the definition of struct acpi_device_bus_id.
Signed-off-by: NLukas Wunner <lukas@wunner.de>
[ rjw: Subject and changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There's an idiom in use by 7 Linux drivers to detect the presence of a
particular ACPI HID by walking the namespace with acpi_get_devices().
The callback passed to acpi_get_devices() is mostly identical across
the drivers, leading to lots of duplicate code.

Add acpi_dev_present(), the ACPI equivalent to pci_dev_present(),
allowing us to deduplicate all that boilerplate in the drivers.
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Reviewed-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Its a bit odd that debugfs_create_bool() takes 'u32 *' as an argument,
when all it needs is a boolean pointer.

It would be better to update this API to make it accept 'bool *'
instead, as that will make it more consistent and often more convenient.
Over that bool takes just a byte.

That required updates to all user sites as well, in the same commit
updating the API. regmap core was also using
debugfs_{read|write}_file_bool(), directly and variable types were
updated for that to be bool as well.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NMark Brown <broonie@kernel.org>
Acked-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

global_lock is defined as an unsigned long and accessing only its lower
32 bits from sysfs is incorrect, as we need to consider other 32 bits
for big endian 64-bit systems. There are no such platforms yet, but the
code needs to be robust for such a case.

Fix that by changing type of 'global_lock' to u32.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch changes the type of the return value of the acpi_sleep_proc_init()
method to be void, as this method never fails and its return value is never
used.

Signed-off-by: Rami Rosen <ramirose@gmail.com>\
[ rjw : Fixed up the static inline stub ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch changes the type of the return value of the init_acpi_device_notify()
method to be void, as this method never fails and its return value is never
used.
Signed-off-by: NRami Rosen <ramirose@gmail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

acpi_debugfs_init function is declared with return type int in
drivers/acpi/internal.h when CONFIG_DEBUG_FS is enabled, but its
definition in drivers/acpi/debugfs.c has return type void. This is due
to commit aecad432 ("ACPI: Cleanup custom_method debug stuff"),
which changed the return type from int to void without updating the
declaration.

Fix this inconsistency by updating acpi_debugfs_init prototype.  While
at it, include internal.h in debugfs.c so that the compiler can check
that the declaration and definition remain compatible.
Signed-off-by: NNicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some devices, like MFD subdevices, share a single ACPI companion device so
that they are able to access their resources and children. However,
currently all these subdevices are attached to the ACPI power domain and
this might cause that the power methods for the companion device get called
more than once.

In order to solve this we attach the ACPI power domain only to the first
physical device that is bound to the ACPI companion device. In case of MFD
devices, this is the parent MFD device itself.
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

To reduce the size of scan.c and improve the readability of it, move
all code related to device sysfs, modalias creation etc. to a new
file called device_sysfs.c.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is no need to carry potentially outdated Free Software Foundation
mailing address in file headers since the COPYING file includes it.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The platform firmware on some systems expects Linux to return "5" as
the supported ACPI revision which makes it expose system configuration
information in a special way.

For example, based on what ACPI exports as the supported revision,
Dell XPS 13 (2015) configures its audio device to either work in HDA
mode or in I2S mode, where the former is supposed to be used on Linux
until the latter is fully supported (in the kernel as well as in user
space).

Since ACPI 6 mandates that _REV should return "2" if ACPI 2 or later
is supported by the OS, a subsequent change will make that happen, so
make it possible to override that on systems where "5" is expected to
be returned for Linux to work correctly one them (such as the Dell
machine mentioned above).
Original-by: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

acpi_osi_is_win8 needs access to acpi_gbl_osi_data which is not exported,
so move it to osl.c. Alternatively we could export acpi_gbl_osi_data but
that seems undesirable.

This allows video_detect.c to be build as a module, besides that
acpi_osi_is_win8() is something which does not really belong in
video_detect.c in the first place.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Acked-by: NDarren Hart <dvhart@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>