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Merge tag 'acpi-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel…
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Pull ACPI updates from Rafael Wysocki:
 "The new feaures here are the support for ACPI overlays (allowing ACPI
  tables to be loaded at any time from EFI variables or via configfs)
  and the LPI (Low-Power Idle) support.  Also notable is the ACPI-based
  NUMA support for ARM64.

  Apart from that we have two new drivers, for the DPTF (Dynamic Power
  and Thermal Framework) power participant device and for the Intel
  Broxton WhiskeyCove PMIC, some more PMIC-related changes, support for
  the Boot Error Record Table (BERT) in APEI and support for
  platform-initiated graceful shutdown.

  Plus two new pieces of documentation and usual assorted fixes and
  cleanups in quite a few places.

  Specifics:

   - Support for ACPI SSDT overlays allowing Secondary System
     Description Tables (SSDTs) to be loaded at any time from EFI
     variables or via configfs (Octavian Purdila, Mika Westerberg).

   - Support for the ACPI LPI (Low-Power Idle) feature introduced in
     ACPI 6.0 and allowing processor idle states to be represented in
     ACPI tables in a hierarchical way (with the help of Processor
     Container objects) and support for ACPI idle states management on
     ARM64, based on LPI (Sudeep Holla).

   - General improvements of ACPI support for NUMA and ARM64 support for
     ACPI-based NUMA (Hanjun Guo, David Daney, Robert Richter).

   - General improvements of the ACPI table upgrade mechanism and ARM64
     support for that feature (Aleksey Makarov, Jon Masters).

   - Support for the Boot Error Record Table (BERT) in APEI and
     improvements of kernel messages printed by the error injection code
     (Huang Ying, Borislav Petkov).

   - New driver for the Intel Broxton WhiskeyCove PMIC operation region
     and support for the REGS operation region on Broxton, PMIC code
     cleanups (Bin Gao, Felipe Balbi, Paul Gortmaker).

   - New driver for the power participant device which is part of the
     Dynamic Power and Thermal Framework (DPTF) and DPTF-related code
     reorganization (Srinivas Pandruvada).

   - Support for the platform-initiated graceful shutdown feature
     introduced in ACPI 6.1 (Prashanth Prakash).

   - ACPI button driver update related to lid input events generated
     automatically on initialization and system resume that have been
     problematic for some time (Lv Zheng).

   - ACPI EC driver cleanups (Lv Zheng).

   - Documentation of the ACPICA release automation process and the
     in-kernel ACPI AML debugger (Lv Zheng).

   - New blacklist entry and two fixes for the ACPI backlight driver
     (Alex Hung, Arvind Yadav, Ralf Gerbig).

   - Cleanups of the ACPI pci_slot driver (Joe Perches, Paul Gortmaker).

   - ACPI CPPC code changes to make it more robust against possible
     defects in ACPI tables and new symbol definitions for PCC (Hoan
     Tran).

   - System reboot code modification to execute the ACPI _PTS (Prepare
     To Sleep) method in addition to _TTS (Ocean He).

   - ACPICA-related change to carry out lock ordering checks in ACPICA
     if ACPICA debug is enabled in the kernel (Lv Zheng).

   - Assorted minor fixes and cleanups (Andy Shevchenko, Baoquan He,
     Bhaktipriya Shridhar, Paul Gortmaker, Rafael Wysocki)"

* tag 'acpi-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (71 commits)
  ACPI: enable ACPI_PROCESSOR_IDLE on ARM64
  arm64: add support for ACPI Low Power Idle(LPI)
  drivers: firmware: psci: initialise idle states using ACPI LPI
  cpuidle: introduce CPU_PM_CPU_IDLE_ENTER macro for ARM{32, 64}
  arm64: cpuidle: drop __init section marker to arm_cpuidle_init
  ACPI / processor_idle: Add support for Low Power Idle(LPI) states
  ACPI / processor_idle: introduce ACPI_PROCESSOR_CSTATE
  ACPI / DPTF: move int340x_thermal.c to the DPTF folder
  ACPI / DPTF: Add DPTF power participant driver
  ACPI / lpat: make it explicitly non-modular
  ACPI / dock: make dock explicitly non-modular
  ACPI / PCI: make pci_slot explicitly non-modular
  ACPI / PMIC: remove modular references from non-modular code
  ACPICA: Linux: Enable ACPI_MUTEX_DEBUG for Linux kernel
  ACPI: Rename configfs.c to acpi_configfs.c to prevent link error
  ACPI / debugger: Add AML debugger documentation
  ACPI: Add documentation describing ACPICA release automation
  ACPI: add support for loading SSDTs via configfs
  ACPI: add support for configfs
  efi / ACPI: load SSTDs from EFI variables
  ...
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36 changes: 36 additions & 0 deletions Documentation/ABI/testing/configfs-acpi
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What: /config/acpi
Date: July 2016
KernelVersion: 4.8
Contact: [email protected]
Description:
This represents the ACPI subsystem entry point directory. It
contains sub-groups corresponding to ACPI configurable options.

What: /config/acpi/table
Date: July 2016
KernelVersion: 4.8
Description:

This group contains the configuration for user defined ACPI
tables. The attributes of a user define table are:

aml - a binary attribute that the user can use to
fill in the ACPI aml definitions. Once the aml
data is written to this file and the file is
closed the table will be loaded and ACPI devices
will be enumerated. To check if the operation is
successful the user must check the error code
for close(). If the operation is successful,
subsequent writes to this attribute will fail.

The rest of the attributes are read-only and are valid only
after the table has been loaded by filling the aml entry:

signature - ASCII table signature
length - length of table in bytes, including the header
revision - ACPI Specification minor version number
oem_id - ASCII OEM identification
oem_table_id - ASCII OEM table identification
oem_revision - OEM revision number
asl_compiler_id - ASCII ASL compiler vendor ID
asl_compiler_revision - ASL compiler version
66 changes: 66 additions & 0 deletions Documentation/acpi/aml-debugger.txt
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The AML Debugger

Copyright (C) 2016, Intel Corporation
Author: Lv Zheng <[email protected]>


This document describes the usage of the AML debugger embedded in the Linux
kernel.

1. Build the debugger

The following kernel configuration items are required to enable the AML
debugger interface from the Linux kernel:

CONFIG_ACPI_DEBUGGER=y
CONFIG_ACPI_DEBUGGER_USER=m

The userspace utlities can be built from the kernel source tree using
the following commands:

$ cd tools
$ make acpi

The resultant userspace tool binary is then located at:

tools/acpi/power/acpi/acpidbg/acpidbg

It can be installed to system directories by running "make install" (as a
sufficiently privileged user).

2. Start the userspace debugger interface

After booting the kernel with the debugger built-in, the debugger can be
started by using the following commands:

# mount -t debugfs none /sys/kernel/debug
# modprobe acpi_dbg
# tools/acpi/power/acpi/acpidbg/acpidbg

That spawns the interactive AML debugger environment where you can execute
debugger commands.

The commands are documented in the "ACPICA Overview and Programmer Reference"
that can be downloaded from

https://acpica.org/documentation

The detailed debugger commands reference is located in Chapter 12 "ACPICA
Debugger Reference". The "help" command can be used for a quick reference.

3. Stop the userspace debugger interface

The interactive debugger interface can be closed by pressing Ctrl+C or using
the "quit" or "exit" commands. When finished, unload the module with:

# rmmod acpi_dbg

The module unloading may fail if there is an acpidbg instance running.

4. Run the debugger in a script

It may be useful to run the AML debugger in a test script. "acpidbg" supports
this in a special "batch" mode. For example, the following command outputs
the entire ACPI namespace:

# acpidbg -b "namespace"
262 changes: 262 additions & 0 deletions Documentation/acpi/linuxized-acpica.txt
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Linuxized ACPICA - Introduction to ACPICA Release Automation

Copyright (C) 2013-2016, Intel Corporation
Author: Lv Zheng <[email protected]>


Abstract:

This document describes the ACPICA project and the relationship between
ACPICA and Linux. It also describes how ACPICA code in drivers/acpi/acpica,
include/acpi and tools/power/acpi is automatically updated to follow the
upstream.


1. ACPICA Project

The ACPI Component Architecture (ACPICA) project provides an operating
system (OS)-independent reference implementation of the Advanced
Configuration and Power Interface Specification (ACPI). It has been
adapted by various host OSes. By directly integrating ACPICA, Linux can
also benefit from the application experiences of ACPICA from other host
OSes.

The homepage of ACPICA project is: www.acpica.org, it is maintained and
supported by Intel Corporation.

The following figure depicts the Linux ACPI subystem where the ACPICA
adaptation is included:

+---------------------------------------------------------+
| |
| +---------------------------------------------------+ |
| | +------------------+ | |
| | | Table Management | | |
| | +------------------+ | |
| | +----------------------+ | |
| | | Namespace Management | | |
| | +----------------------+ | |
| | +------------------+ ACPICA Components | |
| | | Event Management | | |
| | +------------------+ | |
| | +---------------------+ | |
| | | Resource Management | | |
| | +---------------------+ | |
| | +---------------------+ | |
| | | Hardware Management | | |
| | +---------------------+ | |
| +---------------------------------------------------+ | |
| | | +------------------+ | | |
| | | | OS Service Layer | | | |
| | | +------------------+ | | |
| | +-------------------------------------------------|-+ |
| | +--------------------+ | |
| | | Device Enumeration | | |
| | +--------------------+ | |
| | +------------------+ | |
| | | Power Management | | |
| | +------------------+ Linux/ACPI Components | |
| | +--------------------+ | |
| | | Thermal Management | | |
| | +--------------------+ | |
| | +--------------------------+ | |
| | | Drivers for ACPI Devices | | |
| | +--------------------------+ | |
| | +--------+ | |
| | | ...... | | |
| | +--------+ | |
| +---------------------------------------------------+ |
| |
+---------------------------------------------------------+

Figure 1. Linux ACPI Software Components

NOTE:
A. OS Service Layer - Provided by Linux to offer OS dependent
implementation of the predefined ACPICA interfaces (acpi_os_*).
include/acpi/acpiosxf.h
drivers/acpi/osl.c
include/acpi/platform
include/asm/acenv.h
B. ACPICA Functionality - Released from ACPICA code base to offer
OS independent implementation of the ACPICA interfaces (acpi_*).
drivers/acpi/acpica
include/acpi/ac*.h
tools/power/acpi
C. Linux/ACPI Functionality - Providing Linux specific ACPI
functionality to the other Linux kernel subsystems and user space
programs.
drivers/acpi
include/linux/acpi.h
include/linux/acpi*.h
include/acpi
tools/power/acpi
D. Architecture Specific ACPICA/ACPI Functionalities - Provided by the
ACPI subsystem to offer architecture specific implementation of the
ACPI interfaces. They are Linux specific components and are out of
the scope of this document.
include/asm/acpi.h
include/asm/acpi*.h
arch/*/acpi

2. ACPICA Release

The ACPICA project maintains its code base at the following repository URL:
https://github.com/acpica/acpica.git. As a rule, a release is made every
month.

As the coding style adopted by the ACPICA project is not acceptable by
Linux, there is a release process to convert the ACPICA git commits into
Linux patches. The patches generated by this process are referred to as
"linuxized ACPICA patches". The release process is carried out on a local
copy the ACPICA git repository. Each commit in the monthly release is
converted into a linuxized ACPICA patch. Together, they form the montly
ACPICA release patchset for the Linux ACPI community. This process is
illustrated in the following figure:

+-----------------------------+
| acpica / master (-) commits |
+-----------------------------+
/|\ |
| \|/
| /---------------------\ +----------------------+
| < Linuxize repo Utility >-->| old linuxized acpica |--+
| \---------------------/ +----------------------+ |
| |
/---------\ |
< git reset > \
\---------/ \
/|\ /+-+
| / |
+-----------------------------+ | |
| acpica / master (+) commits | | |
+-----------------------------+ | |
| | |
\|/ | |
/-----------------------\ +----------------------+ | |
< Linuxize repo Utilities >-->| new linuxized acpica |--+ |
\-----------------------/ +----------------------+ |
\|/
+--------------------------+ /----------------------\
| Linuxized ACPICA Patches |<----------------< Linuxize patch Utility >
+--------------------------+ \----------------------/
|
\|/
/---------------------------\
< Linux ACPI Community Review >
\---------------------------/
|
\|/
+-----------------------+ /------------------\ +----------------+
| linux-pm / linux-next |-->< Linux Merge Window >-->| linux / master |
+-----------------------+ \------------------/ +----------------+

Figure 2. ACPICA -> Linux Upstream Process

NOTE:
A. Linuxize Utilities - Provided by the ACPICA repository, including a
utility located in source/tools/acpisrc folder and a number of
scripts located in generate/linux folder.
B. acpica / master - "master" branch of the git repository at
<https://github.com/acpica/acpica.git>.
C. linux-pm / linux-next - "linux-next" branch of the git repository at
<http://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git>.
D. linux / master - "master" branch of the git repository at
<http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git>.

Before the linuxized ACPICA patches are sent to the Linux ACPI community
for review, there is a quality ensurance build test process to reduce
porting issues. Currently this build process only takes care of the
following kernel configuration options:
CONFIG_ACPI/CONFIG_ACPI_DEBUG/CONFIG_ACPI_DEBUGGER

3. ACPICA Divergences

Ideally, all of the ACPICA commits should be converted into Linux patches
automatically without manual modifications, the "linux / master" tree should
contain the ACPICA code that exactly corresponds to the ACPICA code
contained in "new linuxized acpica" tree and it should be possible to run
the release process fully automatically.

As a matter of fact, however, there are source code differences between
the ACPICA code in Linux and the upstream ACPICA code, referred to as
"ACPICA Divergences".

The various sources of ACPICA divergences include:
1. Legacy divergences - Before the current ACPICA release process was
established, there already had been divergences between Linux and
ACPICA. Over the past several years those divergences have been greatly
reduced, but there still are several ones and it takes time to figure
out the underlying reasons for their existence.
2. Manual modifications - Any manual modification (eg. coding style fixes)
made directly in the Linux sources obviously hurts the ACPICA release
automation. Thus it is recommended to fix such issues in the ACPICA
upstream source code and generate the linuxized fix using the ACPICA
release utilities (please refer to Section 4 below for the details).
3. Linux specific features - Sometimes it's impossible to use the
current ACPICA APIs to implement features required by the Linux kernel,
so Linux developers occasionaly have to change ACPICA code directly.
Those changes may not be acceptable by ACPICA upstream and in such cases
they are left as committed ACPICA divergences unless the ACPICA side can
implement new mechanisms as replacements for them.
4. ACPICA release fixups - ACPICA only tests commits using a set of the
user space simulation utilies, thus the linuxized ACPICA patches may
break the Linux kernel, leaving us build/boot failures. In order to
avoid breaking Linux bisection, fixes are applied directly to the
linuxized ACPICA patches during the release process. When the release
fixups are backported to the upstream ACPICA sources, they must follow
the upstream ACPICA rules and so further modifications may appear.
That may result in the appearance of new divergences.
5. Fast tracking of ACPICA commits - Some ACPICA commits are regression
fixes or stable-candidate material, so they are applied in advance with
respect to the ACPICA release process. If such commits are reverted or
rebased on the ACPICA side in order to offer better solutions, new ACPICA
divergences are generated.

4. ACPICA Development

This paragraph guides Linux developers to use the ACPICA upstream release
utilities to obtain Linux patches corresponding to upstream ACPICA commits
before they become available from the ACPICA release process.

1. Cherry-pick an ACPICA commit

First you need to git clone the ACPICA repository and the ACPICA change
you want to cherry pick must be committed into the local repository.

Then the gen-patch.sh command can help to cherry-pick an ACPICA commit
from the ACPICA local repository:

$ git clone https://github.com/acpica/acpica
$ cd acpica
$ generate/linux/gen-patch.sh -u [commit ID]

Here the commit ID is the ACPICA local repository commit ID you want to
cherry pick. It can be omitted if the commit is "HEAD".

2. Cherry-pick recent ACPICA commits

Sometimes you need to rebase your code on top of the most recent ACPICA
changes that haven't been applied to Linux yet.

You can generate the ACPICA release series yourself and rebase your code on
top of the generated ACPICA release patches:

$ git clone https://github.com/acpica/acpica
$ cd acpica
$ generate/linux/make-patches.sh -u [commit ID]

The commit ID should be the last ACPICA commit accepted by Linux. Usually,
it is the commit modifying ACPI_CA_VERSION. It can be found by executing
"git blame source/include/acpixf.h" and referencing the line that contains
"ACPI_CA_VERSION".

3. Inspect the current divergences

If you have local copies of both Linux and upstream ACPICA, you can generate
a diff file indicating the state of the current divergences:

# git clone https://github.com/acpica/acpica
# git clone http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
# cd acpica
# generate/linux/divergences.sh -s ../linux
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