According to Intel VT-d specification, _DSM method to support DMAR
hotplug should exist directly under corresponding ACPI object
representing PCI host bridge. But some BIOSes doesn't conform to
this, so search for _DSM method in the subtree starting from the
ACPI object representing the PCI host bridge.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Reviewed-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

On Intel platforms, an IO Hub (PCI/PCIe host bridge) may contain DMAR
units, so we need to support DMAR hotplug when supporting PCI host
bridge hotplug on Intel platforms.

According to Section 8.8 "Remapping Hardware Unit Hot Plug" in "Intel
Virtualization Technology for Directed IO Architecture Specification
Rev 2.2", ACPI BIOS should implement ACPI _DSM method under the ACPI
object for the PCI host bridge to support DMAR hotplug.

This patch introduces interfaces to parse ACPI _DSM method for
DMAR unit hotplug. It also implements state machines for DMAR unit
hot-addition and hot-removal.

The PCI host bridge hotplug driver should call dmar_hotplug_hotplug()
before scanning PCI devices connected for hot-addition and after
destroying all PCI devices for hot-removal.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Reviewed-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Introduce functions to support dynamic IOMMU seq_id allocating and
releasing, which will be used to support DMAR hotplug.

Also rename IOMMU_UNITS_SUPPORTED as DMAR_UNITS_SUPPORTED.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Reviewed-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Introduce helper function dmar_walk_resources to walk resource entries
in DMAR table and ACPI buffer object returned by ACPI _DSM method
for IOMMU hot-plug.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Conflicts:
	drivers/iommu/arm-smmu.c

The VT-d specification states that an RMRR entry in the DMAR
table needs to specify the full path to the device. This is
also how newer Linux kernels implement it.

Unfortunatly older drivers just match for the target device
and not the full path to the device, so that BIOS vendors
implement that behavior into their BIOSes to make them work
with older Linux kernels. But those RMRR entries break on
newer Linux kernels.

Work around this issue by adding a fall-back into the RMRR
matching code to match those old RMRR entries too.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

This will be used later to match broken RMRR entries.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

Checking adev == NULL is not sufficient as
acpi_bus_get_device() might not touch the value of this
parameter in an error case, so check the return value
directly.

Fixes: ed40356b5fcf1ce28e026ab39c5b2b6939068b50
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>

The use of "rcu_assign_pointer()" is NULLing out the pointer.
According to RCU_INIT_POINTER()'s block comment:
"1.   This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.

The following Coccinelle semantic patch was used:
@@
@@

- rcu_assign_pointer
+ RCU_INIT_POINTER
  (..., NULL)

Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Pull ACPI and power management updates from Rafael Wysocki:
 "Again, ACPICA leads the pack (47 commits), followed by cpufreq (18
  commits) and system suspend/hibernation (9 commits).

  From the new code perspective, the ACPICA update brings ACPI 5.1 to
  the table, including a new device configuration object called _DSD
  (Device Specific Data) that will hopefully help us to operate device
  properties like Device Trees do (at least to some extent) and changes
  related to supporting ACPI on ARM.

  Apart from that we have hibernation changes making it use radix trees
  to store memory bitmaps which should speed up some operations carried
  out by it quite significantly.  We also have some power management
  changes related to suspend-to-idle (the "freeze" sleep state) support
  and more preliminary changes needed to support ACPI on ARM (outside of
  ACPICA).

  The rest is fixes and cleanups pretty much everywhere.

  Specifics:

   - ACPICA update to upstream version 20140724.  That includes ACPI 5.1
     material (support for the _CCA and _DSD predefined names, changes
     related to the DMAR and PCCT tables and ARM support among other
     things) and cleanups related to using ACPICA's header files.  A
     major part of it is related to acpidump and the core code used by
     that utility.  Changes from Bob Moore, David E Box, Lv Zheng,
     Sascha Wildner, Tomasz Nowicki, Hanjun Guo.

   - Radix trees for memory bitmaps used by the hibernation core from
     Joerg Roedel.

   - Support for waking up the system from suspend-to-idle (also known
     as the "freeze" sleep state) using ACPI-based PCI wakeup signaling
     (Rafael J Wysocki).

   - Fixes for issues related to ACPI button events (Rafael J Wysocki).

   - New device ID for an ACPI-enumerated device included into the
     Wildcat Point PCH from Jie Yang.

   - ACPI video updates related to backlight handling from Hans de Goede
     and Linus Torvalds.

   - Preliminary changes needed to support ACPI on ARM from Hanjun Guo
     and Graeme Gregory.

   - ACPI PNP core cleanups from Arjun Sreedharan and Zhang Rui.

   - Cleanups related to ACPI_COMPANION() and ACPI_HANDLE() macros
     (Rafael J Wysocki).

   - ACPI-based device hotplug cleanups from Wei Yongjun and Rafael J
     Wysocki.

   - Cleanups and improvements related to system suspend from Lan
     Tianyu, Randy Dunlap and Rafael J Wysocki.

   - ACPI battery cleanup from Wei Yongjun.

   - cpufreq core fixes from Viresh Kumar.

   - Elimination of a deadband effect from the cpufreq ondemand governor
     and intel_pstate driver cleanups from Stratos Karafotis.

   - 350MHz CPU support for the powernow-k6 cpufreq driver from Mikulas
     Patocka.

   - Fix for the imx6 cpufreq driver from Anson Huang.

   - cpuidle core and governor cleanups from Daniel Lezcano, Sandeep
     Tripathy and Mohammad Merajul Islam Molla.

   - Build fix for the big_little cpuidle driver from Sachin Kamat.

   - Configuration fix for the Operation Performance Points (OPP)
     framework from Mark Brown.

   - APM cleanup from Jean Delvare.

   - cpupower utility fixes and cleanups from Peter Senna Tschudin,
     Andrey Utkin, Himangi Saraogi, Rickard Strandqvist, Thomas
     Renninger"

* tag 'pm+acpi-3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (118 commits)
  ACPI / LPSS: add LPSS device for Wildcat Point PCH
  ACPI / PNP: Replace faulty is_hex_digit() by isxdigit()
  ACPICA: Update version to 20140724.
  ACPICA: ACPI 5.1: Update for PCCT table changes.
  ACPICA/ARM: ACPI 5.1: Update for GTDT table changes.
  ACPICA/ARM: ACPI 5.1: Update for MADT changes.
  ACPICA/ARM: ACPI 5.1: Update for FADT changes.
  ACPICA: ACPI 5.1: Support for the _CCA predifined name.
  ACPICA: ACPI 5.1: New notify value for System Affinity Update.
  ACPICA: ACPI 5.1: Support for the _DSD predefined name.
  ACPICA: Debug object: Add current value of Timer() to debug line prefix.
  ACPICA: acpihelp: Add UUID support, restructure some existing files.
  ACPICA: Utilities: Fix local printf issue.
  ACPICA: Tables: Update for DMAR table changes.
  ACPICA: Remove some extraneous printf arguments.
  ACPICA: Update for comments/formatting. No functional changes.
  ACPICA: Disassembler: Add support for the ToUUID opererator (macro).
  ACPICA: Remove a redundant cast to acpi_size for ACPI_OFFSET() macro.
  ACPICA: Work around an ancient GCC bug.
  ACPI / processor: Make it possible to get local x2apic id via _MAT
  ...