Move the LPSS-specific code from acpi_lpss_runtime_suspend()
and acpi_lpss_runtime_resume() into separate functions,
acpi_lpss_suspend() and acpi_lpss_resume(), respectively, and
make acpi_lpss_suspend_late() and acpi_lpss_resume_early() use
them too in order to unify the runtime PM and system sleep
handling in the LPSS driver.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>

On top of a previous change getting rid of the PM QoS flag
PM_QOS_FLAG_REMOTE_WAKEUP, combine two ACPI device suspend routines,
acpi_dev_runtime_suspend() and acpi_dev_suspend_late(), into one,
acpi_dev_suspend(), to eliminate some code duplication.

It also avoids enabling wakeup for devices handled by the ACPI
LPSS middle layer on driver removal.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>

The PM QoS flag PM_QOS_FLAG_REMOTE_WAKEUP is not used consistently
and the vast majority of code simply assumes that remote wakeup
should be enabled for devices in runtime suspend if they can
generate wakeup signals, so drop it.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.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>

Move the code dealing with validation of whether runtime resuming the
device is needed during system suspend.

In this way it becomes more clear for what circumstances ACPI is prevented
from trying the direct_complete path.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 58a1fbbb (PM / PCI / ACPI: Kick devices that might have
been reset by firmware), made PCI's and ACPI's ->complete() callbacks
to be assigned to a new API called pm_complete_with_resume_check(),
which was introduced in the same change.

Later it turned out that using pm_complete_with_resume_check() wasn't
good enough for PCI, as it needed additional PCI specific checks,
before deciding whether runtime resuming the device is needed when
running the ->complete() callback.

This leaves ACPI as the only user of pm_complete_with_resume_check().
Therefore let's restore ACPI's acpi_subsys_complete(), which was
dropped in commit 58a1fbbb (PM / PCI / ACPI: Kick devices that
might have been reset by firmware).

This enables us to remove the pm_complete_with_resume_check() API in
a following change, but it also enables ACPI to add more ACPI
specific checks in acpi_subsys_complete() if that turns out to be
necessary.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Notice that acpi_dev_runtime_resume() and acpi_dev_resume_early() are
actually literally identical after some more-or-less recent changes,
so rename acpi_dev_runtime_resume() to acpi_dev_resume(), use it
everywhere instead of acpi_dev_resume_early() and drop the latter.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>

commit f6810c15 ("iommu/arm-smmu: Clean up early-probing
workarounds") removed kernel code that was allowing to initialize
and probe the SMMU devices early (ie earlier than PCI devices, through
linker script callback entries) in the boot process because it was not
needed any longer in that the SMMU devices/drivers now support deferred
probing.

Since the SMMUs probe routines are also in charge of requesting global
PCI ACS kernel enablement, commit f6810c15 ("iommu/arm-smmu: Clean
up early-probing workarounds") also postponed PCI ACS enablement to
SMMUs devices probe time, which is too late given that PCI devices needs
to detect if PCI ACS is enabled to init the respective capability
through the following call path:

pci_device_add()
 -> pci_init_capabilities()
  -> pci_enable_acs()

Add code in the ACPI IORT SMMU platform devices initialization path
(that is called before ACPI PCI enumeration) to detect if there
exists firmware mappings to map root complexes ids to SMMU ids
and if so enable ACS for the system.

Fixes: f6810c15 ("iommu/arm-smmu: Clean up early-probing workarounds")
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Tested-by: NNate Watterson <nwatters@codeaurora.org>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Zhou Wang <wangzhou1@hisilicon.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Currently we acknowledge errors before clearing the error status.
This could cause a new error to be populated by firmware in-between
the error acknowledgment and the error status clearing which would
cause the second error's status to be cleared without being handled.
So, clear the error status before acknowledging the errors.

Also, make sure to acknowledge the error if the error status read
fails.
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The recently merged patch "ACPI: Prepare for constifying
acpi_get_next_subnode() fwnode argument" was part of a patchset
constifying the fwnode arguments across the fwnode property API. The
purpose of the patch was to allow returning non-const fwnodes from a data
structure the root of which is const.

Unfortunately the patch introduced the functionality, in particular when
starting parsed from an ACPI device node, the hierarchical data extension
nodes would not be enumerated.

Restore the old behaviour while still retaining constness properties of
the patch.

Fixes: 01c1da28 "ACPI: Prepare for constifying acpi_get_next_subnode() fwnode argument"
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Due to commit db3e50f3 (device property: Get rid of struct
fwnode_handle type field), ACPI_HANDLE() inadvertently became
a GPL-only call. The call path that led to that was:

ACPI_HANDLE()
    ACPI_COMPANION()
        to_acpi_device_node()
            is_acpi_device_node()
                acpi_device_fwnode_ops
                    DECLARE_ACPI_FWNODE_OPS(acpi_device_fwnode_ops);

...and the new DECLARE_ACPI_FWNODE_OPS() includes
EXPORT_SYMBOL_GPL, whereas previously it was a static struct.

In order to avoid changing any of that, let's instead provide ever
so slightly better encapsulation of those struct fwnode_operations
instances. Those do not really need to be directly used in
inline function calls in header files. Simply moving two small
functions (is_acpi_device_node and is_acpi_data_node) out of
acpi_bus.h, and into a .c file, does that.

That leaves the internals of struct fwnode_operations as GPL-only
(which I think was the intent all along), but un-breaks any driver
code out there that relies on the ACPI subsystem's being (historically)
an EXPORT_SYMBOL-usable system. By that, I mean, ACPI_HANDLE() and
other basic ACPI calls were non-GPL-protected.

Also, while I'm there, remove a tiny bit of redundancy that was missed
in the earlier commit, by having is_acpi_node() use the other two
routines, instead of checking fwnode directly.

Fixes: db3e50f3 (device property: Get rid of struct fwnode_handle type field)
Signed-off-by: NJohn Hubbard <jhubbard@nvidia.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We copy a local resource structure into a list, but only
initialize some of its members, as pointed out by gcc-4.4:

drivers/acpi/acpi_watchdog.c: In function 'acpi_watchdog_init':
drivers/acpi/acpi_watchdog.c:105: error: 'res.child' may be used uninitialized in this function
drivers/acpi/acpi_watchdog.c:105: error: 'res.sibling' may be used uninitialized in this function
drivers/acpi/acpi_watchdog.c:105: error: 'res.parent' may be used uninitialized in this function
drivers/acpi/acpi_watchdog.c:105: error: 'res.desc' may be used uninitialized in this function
drivers/acpi/acpi_watchdog.c:105: error: 'res.name' may be used uninitialized in this function

Newer compilers can presumably optimize the uninitialized access
away entirely and don't warn at all, but rely on the kzalloc()
to zero the structure first. This adds an explicit initialization
to force consistent behavior.

Fixes: 058dfc76 (ACPI / watchdog: Add support for WDAT hardware watchdog)
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

... and __initconst if applicable.

Based on similar work for an older kernel in the Grsecurity patch.

[JD: fix toshiba-wmi build]
[JD: add htcpen]
[JD: move __initconst where checkscript wants it]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJean Delvare <jdelvare@suse.de>

Delay the check of nd_reserved2 to the actual endpoint (acpi_nfit_ctl)
that uses it, as a prevention of a potential double-fetch bug.

While examining the kernel source code, I found a dangerous operation that
could turn into a double-fetch situation (a race condition bug) where
the same userspace memory region are fetched twice into kernel with sanity
checks after the first fetch while missing checks after the second fetch.

In the case of _IOC_NR(ioctl_cmd) == ND_CMD_CALL:

1. The first fetch happens in line 935 copy_from_user(&pkg, p, sizeof(pkg)

2. subsequently `pkg.nd_reserved2` is asserted to be all zeroes
(line 984 to 986).

3. The second fetch happens in line 1022 copy_from_user(buf, p, buf_len)

4. Given that `p` can be fully controlled in userspace, an attacker can
race condition to override the header part of `p`, say,
`((struct nd_cmd_pkg *)p)->nd_reserved2` to arbitrary value
(say nine 0xFFFFFFFF for `nd_reserved2`) after the first fetch but before the
second fetch. The changed value will be copied to `buf`.

5. There is no checks on the second fetches until the use of it in
line 1034: nd_cmd_clear_to_send(nvdimm_bus, nvdimm, cmd, buf) and
line 1038: nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, &cmd_rc)
which means that the assumed relation, `p->nd_reserved2` are all zeroes might
not hold after the second fetch. And once the control goes to these functions
we lose the context to assert the assumed relation.

6. Based on my manual analysis, `p->nd_reserved2` is not used in function
`nd_cmd_clear_to_send` and potential implementations of `nd_desc->ndctl`
so there is no working exploit against it right now. However, this could
easily turns to an exploitable one if careless developers start to use
`p->nd_reserved2` later and assume that they are all zeroes.

Move the validation of the nd_reserved2 field to the ->ndctl()
implementation where it has a stable buffer to evaluate.
Signed-off-by: NMeng Xu <mengxu.gatech@gmail.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

mmio_flush_range() suffers from a lack of clearly-defined semantics,
and is somewhat ambiguous to port to other architectures where the
scope of the writeback implied by "flush" and ordering might matter,
but MMIO would tend to imply non-cacheable anyway. Per the rationale
in 67a3e8fe ("nd_blk: change aperture mapping from WC to WB"), the
only existing use is actually to invalidate clean cache lines for
ARCH_MEMREMAP_PMEM type mappings *without* writeback. Since the recent
cleanup of the pmem API, that also now happens to be the exact purpose
of arch_invalidate_pmem(), which would be a far more well-defined tool
for the job.

Rather than risk potentially inconsistent implementations of
mmio_flush_range() for the sake of one callsite, streamline things by
removing it entirely and instead move the ARCH_MEMREMAP_PMEM related
definitions up to the libnvdimm level, so they can be shared by NFIT
as well. This allows NFIT to be enabled for arm64.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

When the nfit driver initializes it runs an ARS (Address Range Scrub)
operation across every pmem range. Part of that process involves
determining the ARS capabilities of a given address range. One of the
capabilities that is reported is the 'Clear Uncorrectable Error Range
Length Unit Size' (see: ACPI 6.2 section 9.20.7.4 Function Index 1 -
Query ARS Capabilities). This property is of interest to userspace
software as it indicates the boundary at which the NVDIMM may need to
perform read-modify-write cycles to maintain ECC blocks.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

According to the ACPI specification, firmware is not required to provide
the Hardware Error Source Table (HEST). When HEST is not present, the
following superfluous message is printed to the kernel boot log -

[    3.460067] GHES: HEST is not enabled!

Extend hest_disable variable to track whether the firmware provides this
table and if it is not present skip any log output. The existing
behaviour is preserved in all other cases.
Suggested-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Make the drivers that want to include the polling state into their
states table initialize it explicitly and drop the initialization of
it (which in fact is conditional, but that is not obvious from the
code) from the core.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

On some architectures the first (index 0) idle state is a polling
one and it doesn't really save energy, so there is the
CPUIDLE_DRIVER_STATE_START symbol allowing some pieces of
cpuidle code to avoid using that state.

However, this makes the code rather hard to follow.  It is better
to explicitly avoid the polling state, so add a new cpuidle state
flag CPUIDLE_FLAG_POLLING to mark it and make the relevant code
check that flag for the first state instead of using the
CPUIDLE_DRIVER_STATE_START symbol.

In the ACPI processor driver that cannot always rely on the state
flags (like before the states table has been set up) define
a new internal symbol ACPI_IDLE_STATE_START equivalent to the
CPUIDLE_DRIVER_STATE_START one and drop the latter.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

COMPLETION_INITIALIZER_ONSTACK() is supposed to be used as an initializer,
in other words, it should only be used in assignment expressions or
compound literals. So the usage in drivers/acpi/nfit/core.c:

	COMPLETION_INITIALIZER_ONSTACK(flush.cmp);

... is inappropriate.

Besides, this usage could also break the build for another fix that
reduces stack sizes caused by COMPLETION_INITIALIZER_ONSTACK(), because
that fix changes COMPLETION_INITIALIZER_ONSTACK() from rvalue to lvalue,
and usage as above will report the following error:

	drivers/acpi/nfit/core.c: In function 'acpi_nfit_flush_probe':
	include/linux/completion.h:77:3: error: value computed is not used [-Werror=unused-value]
	  (*({ init_completion(&work); &work; }))

This patch fixes this by replacing COMPLETION_INITIALIZER_ONSTACK()
with init_completion() in acpi_nfit_flush_probe(), which does the
same initialization without any other problems.
Signed-off-by: NBoqun Feng <boqun.feng@gmail.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: walken@google.com
Cc: willy@infradead.org
Link: http://lkml.kernel.org/r/20170824142239.15178-1-boqun.feng@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

ACPI OEM ID / OEM Table ID / Revision can be used to identify
a platform based on ACPI firmware info.  acpi_blacklisted(),
intel_pstate_platform_pwr_mgmt_exists(), and some other funcs,
have been using similar check to detect a list of platforms
that require special handlings.

Move the platform check in acpi_blacklisted() to a new common
utility function, acpi_match_platform_list(), so that other
drivers do not have to implement their own version.

There is no change in functionality.
Signed-off-by: NToshi Kani <toshi.kani@hpe.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI defines a number of instructions to use for triggering errors. However
we are currently removing the address resources from the trigger resources
for only the WRITE_REGISTER_VALUE instruction. This leads to a resource
conflict for any other valid instruction.

Check that the instruction is less than or equal to the
WRITE_REGISTER_VALUE instruction. This allows all valid memory access
instructions and protects against invalid instructions.

Fixes: b4e008dc (ACPI, APEI, EINJ, Refine the fix of resource conflict)
Signed-off-by: NYazen Ghannam <yazen.ghannam@amd.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Make these const as they are only passed as an argument to the function
device_create_file and device_remove_file and the corresponding
arguments are of type const.
Done using Coccinelle
Signed-off-by: NBhumika Goyal <bhumirks@gmail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI sysfs interface provides a way to read each ACPI table from
userspace via entries in /sys/firmware/acpi/tables/

The BERT table simply provides the size and address of the error
record in BIOS reserved memory and users may want access to this
record.

In an earlier age we might have used /dev/mem to retrieve this error
record, but many systems disable /dev/mem for security reasons.

Extend this driver to provide read-only access to the data via a
file in a new directory /sys/firmware/acpi/tables/data/BERT
Acked-by: NPunit Agrawal <punit.agrawal@arm.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

v4: fix typo reported by Punit
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The revision 0x300 generic error data entry is different
from the old version, but currently iterating through the
GHES estatus blocks does not take into account this difference.
This will lead to failure to get the right data entry if GHES
has revision 0x300 error data entry.

Update the GHES estatus iteration macro to properly increment using
acpi_hest_get_next(), and correct the iteration termination condition
because the status block data length only includes error data
length.

Convert the CPER estatus checking and printing iteration logic
to use same macro.
Signed-off-by: NDongjiu Geng <gengdongjiu@huawei.com>
Tested-by: NTyler Baicar <tbaicar@codeaurora.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The function acpi_processor_check_duplicates() is local to the source
and does not need to be in global scope, so make it static.

Cleans up sparse warnings:
symbol 'acpi_processor_check_duplicates' was not declared. Should it
be static?
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

acpi_graph_get_child_prop_value() is intended to find a child node with a
certain property value pair. The check

	if (!fwnode_property_read_u32(fwnode, prop_name, &nr))
		continue;

is faulty: fwnode_property_read_u32() returns zero on success, not on
failure, leading to comparing values only if the searched property was not
found.

Moreover, the check is made against the parent device node instead of
the child one as it should be.

Fixes: 79389a83 (ACPI / property: Add support for remote endpoints)
Reported-by: NHyungwoo Yang <hyungwoo.yang@intel.com>
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Cc: 4.12+ <stable@vger.kernel.org> # 4.12+
[ rjw: Changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 2d2a9543 (ACPICA: Update two error messages to emit
control method name) causes acpi_evaluate_object_typed() to fail
if its pathname argument is NULL, but some callers of that function
in the kernel, particularly acpi_nondev_subnode_data_ok(), pass
NULL as pathname to it and expect it to work.

For this reason, make acpi_evaluate_object_typed() check if its
pathname argument is NULL and fall back to using the pathname of
its handle argument if that is the case.
Reported-by: NSakari Ailus <sakari.ailus@intel.com>
Tested-by: NYang, Hyungwoo <hyungwoo.yang@intel.com>
Fixes: 2d2a9543 (ACPICA: Update two error messages to emit control method name)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

EC_FLAGS_COMMAND_STORM is actually used to mask GPE during IRQ processing.
This patch cleans it up using more readable flag/function names.
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Tested-by: NTomislav Ivek <tomislav.ivek@gmail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Use the observation that the EC command/data register addresses are
sufficient to determine if two EC devices are equivelent to modify
acpi_is_boot_ec().

Then, for the removed comparison factors, EC ID and EC GPE, they need
to be synchronized for the boot_ec:

 1. Before registering the BIOS-provided EC event handlers in
    acpi_ec_register_query_methods(), the namespace node holding
    _Qxx methods should be located.  The real namespace PNP0C09
    device location then is apparently more trustworthy than the
    ECDT EC ID.

 2. Because of the ASUS quirks, the ECDT EC GPE is more trustworthy
    than the namespace PNP0C09 device's _GPE setting.

Use the above observations to synchronize the boot_ec settings in
acpi_ec_add().

Finally, change the order of acpi_ec_ecdt_start() and acpi_ec_add(),
called from acpi_bus_register_driver(), so as to follow the fast path
of determining the location of _Qxx.
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
[ rjw : Changelog & comments ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

For SoC to achieve its lowest power platform idle state a set of hardware
preconditions must be met. These preconditions or constraints can be
obtained by issuing a device specific method (_DSM) with function "1".
Refer to the document provided in the link below.

Here during initialization (from attach() callback of LPS0 device), invoke
function 1 to get the device constraints. Each enabled constraint is
stored in a table.

The devices in this table are used to check whether they were in required
minimum state, while entering suspend. This check is done from platform
freeze wake() callback, only when /sys/power/pm_debug_messages attribute
is non zero.

If any constraint is not met and device is ACPI power managed then it
prints the device information to kernel logs.

Also if debug is enabled in acpi/sleep.c, the constraint table and state
of each device on wake is dumped in kernel logs.

Since pm_debug_messages_on setting is used as condition to check
constraints outside kernel/power/main.c, pm_debug_messages_on is changed
to a global variable.

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>

Add statements to trace invocations of the ACPI PM notify handler
and the work functions called by it.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It sometimes is useful to examine the timing of ACPI events during
certain operations only, like during system suspend/resume, so add
pr_debug() statements for that to acpi_global_event_handler().
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

On some systems the platform firmware expects GPEs to be enabled
before the enumeration of devices and if that expectation is not
met, the systems in question may not boot in some situations.

For this reason, change the initialization ordering of the ACPI
subsystem to make it enable GPEs before scanning the namespace
for the first time in order to enumerate devices.
Reported-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Suggested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NLv Zheng <lv.zheng@intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>

Runtime GPEs have corresponding _Lxx/_Exx methods and are enabled
automatically during the initialization of the ACPI subsystem through
acpi_update_all_gpes() with the assumption that acpi_setup_gpe_for_wake()
will be called in advance for all of the GPEs pointed to by _PRW
objects in the namespace that may be affected by acpi_update_all_gpes().
That is, acpi_ev_initialize_gpe_block() can only be called for a GPE
block after acpi_setup_gpe_for_wake() has been called for all of the
_PRW (wakeup) GPEs in it.

The platform firmware on some systems, however, expects GPEs to be
enabled before the enumeration of devices which is when
acpi_setup_gpe_for_wake() is called and that goes against the above
assumption.

For this reason, introduce a new flag to be set by
acpi_ev_initialize_gpe_block() when automatically enabling a GPE
to indicate to acpi_setup_gpe_for_wake() that it needs to drop the
reference to the GPE coming from acpi_ev_initialize_gpe_block()
and modify acpi_setup_gpe_for_wake() accordingly.  These changes
allow acpi_setup_gpe_for_wake() and acpi_ev_initialize_gpe_block()
to be invoked in any order.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>

In some cases GPEs are already active when they are enabled by
acpi_ev_initialize_gpe_block() and whatever happens next may depend
on the result of handling the events signaled by them, so the
events should not be discarded (which is what happens currently) and
they should be handled as soon as reasonably possible.

For this reason, modify acpi_ev_initialize_gpe_block() to
dispatch GPEs with the status flag set in-band right after
enabling them.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.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>

xgene v1/v2 8250 UARTs don't run at the standard clock rate expected by
the driver and there is no information on clocking available from the
SPCR table. As there has been no progress on relevant vendors updating
DBG2/SPCR specifications to fix this work around this using the previous
xgene quirk handling to avoid setting a baud rate and therefore using
the UART as configured by firmware.
Signed-off-by: NGraeme Gregory <graeme.gregory@linaro.org>
Tested-by: NMark Salter <msalter@redhat.com>
Reviewed-by: NMark Salter <msalter@redhat.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

xgene v1/v2 chips are also used on moonshot cartridges that have
different table headers to the ones on Mustang. Extend the quirk
so it also recognises the Moonshot M400 variant too.
Signed-off-by: NGraeme Gregory <graeme.gregory@linaro.org>
Tested-by: NMark Salter <msalter@redhat.com>
Reviewed-by: NMark Salter <msalter@redhat.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Rename struct platform_freeze_ops to platform_s2idle_ops to make it
clear that the callbacks in it are used during suspend-to-idle
suspend/resume transitions and rename the related functions,
variables and so on accordingly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>