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Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/acpi/aml-debugger.txt | 66 | ||||
| -rw-r--r-- | Documentation/acpi/linuxized-acpica.txt | 262 |
2 files changed, 328 insertions, 0 deletions
diff --git a/Documentation/acpi/aml-debugger.txt b/Documentation/acpi/aml-debugger.txt new file mode 100644 index 000000000000..5f62aa4a493b --- /dev/null +++ b/Documentation/acpi/aml-debugger.txt @@ -0,0 +1,66 @@ +The AML Debugger + +Copyright (C) 2016, Intel Corporation +Author: Lv Zheng <lv.zheng@intel.com> + + +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" diff --git a/Documentation/acpi/linuxized-acpica.txt b/Documentation/acpi/linuxized-acpica.txt new file mode 100644 index 000000000000..defe2eec5331 --- /dev/null +++ b/Documentation/acpi/linuxized-acpica.txt @@ -0,0 +1,262 @@ +Linuxized ACPICA - Introduction to ACPICA Release Automation + +Copyright (C) 2013-2016, Intel Corporation +Author: Lv Zheng <lv.zheng@intel.com> + + +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 |