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Commit 25474279 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

Merge branches 'acpi-bus', 'acpi-pci', 'acpica' and 'acpi-doc'

* acpi-bus:
  ACPI / bus: Support for platform initiated graceful shutdown
  ACPI / bus: Correct the comments about acpi_subsystem_init()
  ACPI / bus: Use acpi_handle_debug() in acpi_print_osc_error()

* acpi-pci:
  ACPI / PCI: make pci_slot explicitly non-modular
  ACPI / PCI: pci_slot: Use generic pr_debug utility
  ACPI / PCI: pci_slot: Use more common logging style

* acpica:
  ACPICA: Linux: Enable ACPI_MUTEX_DEBUG for Linux kernel

* acpi-doc:
  ACPI / debugger: Add AML debugger documentation
  ACPI: Add documentation describing ACPICA release automation
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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"
+262 −0
Original line number Diff line number Diff line
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
+62 −14
Original line number Diff line number Diff line
@@ -30,6 +30,9 @@
#include <linux/acpi.h>
#include <linux/slab.h>
#include <linux/regulator/machine.h>
#include <linux/workqueue.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#ifdef CONFIG_X86
#include <asm/mpspec.h>
#endif
@@ -176,20 +179,15 @@ EXPORT_SYMBOL_GPL(acpi_bus_detach_private_data);
static void acpi_print_osc_error(acpi_handle handle,
				 struct acpi_osc_context *context, char *error)
{
	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
	int i;

	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer)))
		printk(KERN_DEBUG "%s: %s\n", context->uuid_str, error);
	else {
		printk(KERN_DEBUG "%s (%s): %s\n",
		       (char *)buffer.pointer, context->uuid_str, error);
		kfree(buffer.pointer);
	}
	printk(KERN_DEBUG "_OSC request data:");
	acpi_handle_debug(handle, "(%s): %s\n", context->uuid_str, error);

	pr_debug("_OSC request data:");
	for (i = 0; i < context->cap.length; i += sizeof(u32))
		printk(" %x", *((u32 *)(context->cap.pointer + i)));
	printk("\n");
		pr_debug(" %x", *((u32 *)(context->cap.pointer + i)));

	pr_debug("\n");
}

acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
@@ -475,6 +473,56 @@ static void acpi_device_remove_notify_handler(struct acpi_device *device)
					   acpi_device_notify);
}

/* Handle events targeting \_SB device (at present only graceful shutdown) */

#define ACPI_SB_NOTIFY_SHUTDOWN_REQUEST 0x81
#define ACPI_SB_INDICATE_INTERVAL	10000

static void sb_notify_work(struct work_struct *dummy)
{
	acpi_handle sb_handle;

	orderly_poweroff(true);

	/*
	 * After initiating graceful shutdown, the ACPI spec requires OSPM
	 * to evaluate _OST method once every 10seconds to indicate that
	 * the shutdown is in progress
	 */
	acpi_get_handle(NULL, "\\_SB", &sb_handle);
	while (1) {
		pr_info("Graceful shutdown in progress.\n");
		acpi_evaluate_ost(sb_handle, ACPI_OST_EC_OSPM_SHUTDOWN,
				ACPI_OST_SC_OS_SHUTDOWN_IN_PROGRESS, NULL);
		msleep(ACPI_SB_INDICATE_INTERVAL);
	}
}

static void acpi_sb_notify(acpi_handle handle, u32 event, void *data)
{
	static DECLARE_WORK(acpi_sb_work, sb_notify_work);

	if (event == ACPI_SB_NOTIFY_SHUTDOWN_REQUEST) {
		if (!work_busy(&acpi_sb_work))
			schedule_work(&acpi_sb_work);
	} else
		pr_warn("event %x is not supported by \\_SB device\n", event);
}

static int __init acpi_setup_sb_notify_handler(void)
{
	acpi_handle sb_handle;

	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &sb_handle)))
		return -ENXIO;

	if (ACPI_FAILURE(acpi_install_notify_handler(sb_handle, ACPI_DEVICE_NOTIFY,
						acpi_sb_notify, NULL)))
		return -EINVAL;

	return 0;
}

/* --------------------------------------------------------------------------
                             Device Matching
   -------------------------------------------------------------------------- */
@@ -961,8 +1009,7 @@ void __init acpi_early_init(void)
/**
 * acpi_subsystem_init - Finalize the early initialization of ACPI.
 *
 * Switch over the platform to the ACPI mode (if possible), initialize the
 * handling of ACPI events, install the interrupt and global lock handlers.
 * Switch over the platform to the ACPI mode (if possible).
 *
 * Doing this too early is generally unsafe, but at the same time it needs to be
 * done before all things that really depend on ACPI.  The right spot appears to
@@ -1133,6 +1180,7 @@ static int __init acpi_init(void)
	acpi_sleep_proc_init();
	acpi_wakeup_device_init();
	acpi_debugger_init();
	acpi_setup_sb_notify_handler();
	return 0;
}

+13 −30
Original line number Diff line number Diff line
@@ -22,8 +22,9 @@
 *  General Public License for more details.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
@@ -33,30 +34,11 @@
#include <linux/dmi.h>
#include <linux/pci-acpi.h>

static bool debug;
static int check_sta_before_sun;

#define DRIVER_VERSION 	"0.1"
#define DRIVER_AUTHOR	"Alex Chiang <achiang@hp.com>"
#define DRIVER_DESC	"ACPI PCI Slot Detection Driver"
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
module_param(debug, bool, 0644);

#define _COMPONENT		ACPI_PCI_COMPONENT
ACPI_MODULE_NAME("pci_slot");

#define MY_NAME "pci_slot"
#define err(format, arg...) pr_err("%s: " format , MY_NAME , ## arg)
#define info(format, arg...) pr_info("%s: " format , MY_NAME , ## arg)
#define dbg(format, arg...)					\
	do {							\
		if (debug)					\
			pr_debug("%s: " format,	MY_NAME , ## arg); \
	} while (0)

#define SLOT_NAME_SIZE 21		/* Inspired by #define in acpiphp.h */

struct acpi_pci_slot {
@@ -76,7 +58,7 @@ check_slot(acpi_handle handle, unsigned long long *sun)
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
	dbg("Checking slot on path: %s\n", (char *)buffer.pointer);
	pr_debug("Checking slot on path: %s\n", (char *)buffer.pointer);

	if (check_sta_before_sun) {
		/* If SxFy doesn't have _STA, we just assume it's there */
@@ -87,14 +69,16 @@ check_slot(acpi_handle handle, unsigned long long *sun)

	status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
	if (ACPI_FAILURE(status)) {
		dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer);
		pr_debug("_ADR returned %d on %s\n",
			 status, (char *)buffer.pointer);
		goto out;
	}

	/* No _SUN == not a slot == bail */
	status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
	if (ACPI_FAILURE(status)) {
		dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer);
		pr_debug("_SUN returned %d on %s\n",
			 status, (char *)buffer.pointer);
		goto out;
	}

@@ -132,15 +116,13 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
	}

	slot = kmalloc(sizeof(*slot), GFP_KERNEL);
	if (!slot) {
		err("%s: cannot allocate memory\n", __func__);
	if (!slot)
		return AE_OK;
	}

	snprintf(name, sizeof(name), "%llu", sun);
	pci_slot = pci_create_slot(pci_bus, device, name, NULL);
	if (IS_ERR(pci_slot)) {
		err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
		pr_err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
		kfree(slot);
		return AE_OK;
	}
@@ -150,7 +132,7 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)

	get_device(&pci_bus->dev);

	dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n",
	pr_debug("%p, pci_bus: %x, device: %d, name: %s\n",
		 pci_slot, pci_bus->number, device, name);

	return AE_OK;
@@ -186,7 +168,8 @@ void acpi_pci_slot_remove(struct pci_bus *bus)

static int do_sta_before_sun(const struct dmi_system_id *d)
{
	info("%s detected: will evaluate _STA before calling _SUN\n", d->ident);
	pr_info("%s detected: will evaluate _STA before calling _SUN\n",
		d->ident);
	check_sta_before_sun = 1;
	return 0;
}
+4 −0
Original line number Diff line number Diff line
@@ -73,6 +73,10 @@
#define ACPI_DEBUGGER
#endif

#ifdef CONFIG_ACPI_DEBUG
#define ACPI_MUTEX_DEBUG
#endif

#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/ctype.h>