Merge tag 'acpi-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI updates from Rafael Wysocki:
 "These rearrange the ACPI documentation by converting it to the .rst
  format and splitting it into clear categories (admin guide, driver
  API, firmware guide), switch over multiple users of a problematic
  library function to a new better one, update the ACPICA code in the
  kernel to a new upstream release, fix a few issues, improve power
  device management diagnostics and do some cleanups.

  Specifics:

   - Convert the ACPI documentation in the kernel source tree to the
     .rst format and split it into the admin guide, driver API and
     firmware guide parts (Changbin Du).

   - Add a PRP0001 usage example to the ACPI documentation (Thomas
     Preston).

   - Switch over the users of the acpi_dev_get_first_match_name()
     library function which turned out to be problematic to a new,
     better one called acpi_dev_get_first_match_dev() (Andy Shevchenko,
     YueHaibing).

   - Update the ACPICA code in the kernel to upstream release 20190405
     including:
       * Null pointer dereference check in acpi_ns_delete_node() (Erik
         Schmauss).
       * Multiple macro and function name changes (Bob Moore).
       * Predefined operation region name fix (Erik Schmauss).

   - Fix hibernation issue on systems using the Baytrail and Cherrytrail
     Intel SoCs introduced during the 4.20 development cycle (Hans de
     Goede).

   - Add Sony VPCEH3U1E to the backlight quirk list (Zhang Rui).

   - Fix button handling during system resume (Zhang Rui).

   - Add a device PM diagnostic message (Rafael Wysocki).

   - Clean up the code, comments and white space in multiple places
     (Bjorn Helgaas, Gustavo Silva, Kefeng Wang)"

* tag 'acpi-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (53 commits)
  Documentation: ACPI: move video_extension.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move ssdt-overlays.txt to admin-guide/acpi and convert to reST
  Documentation: ACPI: move lpit.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move cppc_sysfs.txt to admin-guide/acpi and convert to reST
  Documentation: ACPI: move apei/einj.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move apei/output_format.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move aml-debugger.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move method-tracing.txt to firmware-guide/acpi and convert to rsST
  Documentation: ACPI: move debug.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move dsd/data-node-references.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move dsd/graph.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move acpi-lid.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move i2c-muxes.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move dsdt-override.txt to admin-guide/acpi and convert to reST
  Documentation: ACPI: move initrd_table_override.txt to admin-guide/acpi and convert to reST
  Documentation: ACPI: move method-customizing.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move gpio-properties.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move DSD-properties-rules.txt to firmware-guide/acpi and covert to reST
  Documentation: ACPI: move scan_handlers.txt to driver-api/acpi and convert to reST
  Documentation: ACPI: move linuxized-acpica.txt to driver-api/acpi and convert to reST
  ...

6 files changed, 399 insertions, 0 deletions

diff --git a/Documentation/admin-guide/acpi/cppc_sysfs.rst b/Documentation/admin-guide/acpi/cppc_sysfs.rst
new file mode 100644
index 000000000000..a4b99afbe331
--- /dev/null
+++ b/Documentation/admin-guide/acpi/cppc_sysfs.rst
@@ -0,0 +1,76 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==================================================
+Collaborative Processor Performance Control (CPPC)
+==================================================
+
+CPPC
+====
+
+CPPC defined in the ACPI spec describes a mechanism for the OS to manage the
+performance of a logical processor on a contigious and abstract performance
+scale. CPPC exposes a set of registers to describe abstract performance scale,
+to request performance levels and to measure per-cpu delivered performance.
+
+For more details on CPPC please refer to the ACPI specification at:
+
+http://uefi.org/specifications
+
+Some of the CPPC registers are exposed via sysfs under::
+
+  /sys/devices/system/cpu/cpuX/acpi_cppc/
+
+for each cpu X::
+
+  $ ls -lR  /sys/devices/system/cpu/cpu0/acpi_cppc/
+  /sys/devices/system/cpu/cpu0/acpi_cppc/:
+  total 0
+  -r--r--r-- 1 root root 65536 Mar  5 19:38 feedback_ctrs
+  -r--r--r-- 1 root root 65536 Mar  5 19:38 highest_perf
+  -r--r--r-- 1 root root 65536 Mar  5 19:38 lowest_freq
+  -r--r--r-- 1 root root 65536 Mar  5 19:38 lowest_nonlinear_perf
+  -r--r--r-- 1 root root 65536 Mar  5 19:38 lowest_perf
+  -r--r--r-- 1 root root 65536 Mar  5 19:38 nominal_freq
+  -r--r--r-- 1 root root 65536 Mar  5 19:38 nominal_perf
+  -r--r--r-- 1 root root 65536 Mar  5 19:38 reference_perf
+  -r--r--r-- 1 root root 65536 Mar  5 19:38 wraparound_time
+
+* highest_perf : Highest performance of this processor (abstract scale).
+* nominal_perf : Highest sustained performance of this processor
+  (abstract scale).
+* lowest_nonlinear_perf : Lowest performance of this processor with nonlinear
+  power savings (abstract scale).
+* lowest_perf : Lowest performance of this processor (abstract scale).
+
+* lowest_freq : CPU frequency corresponding to lowest_perf (in MHz).
+* nominal_freq : CPU frequency corresponding to nominal_perf (in MHz).
+  The above frequencies should only be used to report processor performance in
+  freqency instead of abstract scale. These values should not be used for any
+  functional decisions.
+
+* feedback_ctrs : Includes both Reference and delivered performance counter.
+  Reference counter ticks up proportional to processor's reference performance.
+  Delivered counter ticks up proportional to processor's delivered performance.
+* wraparound_time: Minimum time for the feedback counters to wraparound
+  (seconds).
+* reference_perf : Performance level at which reference performance counter
+  accumulates (abstract scale).
+
+
+Computing Average Delivered Performance
+=======================================
+
+Below describes the steps to compute the average performance delivered by
+taking two different snapshots of feedback counters at time T1 and T2.
+
+  T1: Read feedback_ctrs as fbc_t1
+      Wait or run some workload
+
+  T2: Read feedback_ctrs as fbc_t2
+
+::
+
+  delivered_counter_delta = fbc_t2[del] - fbc_t1[del]
+  reference_counter_delta = fbc_t2[ref] - fbc_t1[ref]
+
+  delivered_perf = (refernce_perf x delivered_counter_delta) / reference_counter_delta
diff --git a/Documentation/admin-guide/acpi/dsdt-override.rst b/Documentation/admin-guide/acpi/dsdt-override.rst
new file mode 100644
index 000000000000..50bd7f194bf4
--- /dev/null
+++ b/Documentation/admin-guide/acpi/dsdt-override.rst
@@ -0,0 +1,13 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===============
+Overriding DSDT
+===============
+
+Linux supports a method of overriding the BIOS DSDT:
+
+CONFIG_ACPI_CUSTOM_DSDT - builds the image into the kernel.
+
+When to use this method is described in detail on the
+Linux/ACPI home page:
+https://01.org/linux-acpi/documentation/overriding-dsdt
diff --git a/Documentation/admin-guide/acpi/index.rst b/Documentation/admin-guide/acpi/index.rst
new file mode 100644
index 000000000000..4d13eeea1eca
--- /dev/null
+++ b/Documentation/admin-guide/acpi/index.rst
@@ -0,0 +1,14 @@
+============
+ACPI Support
+============
+
+Here we document in detail how to interact with various mechanisms in
+the Linux ACPI support.
+
+.. toctree::
+   :maxdepth: 1
+
+   initrd_table_override
+   dsdt-override
+   ssdt-overlays
+   cppc_sysfs
diff --git a/Documentation/admin-guide/acpi/initrd_table_override.rst b/Documentation/admin-guide/acpi/initrd_table_override.rst
new file mode 100644
index 000000000000..cbd768207631
--- /dev/null
+++ b/Documentation/admin-guide/acpi/initrd_table_override.rst
@@ -0,0 +1,115 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+================================
+Upgrading ACPI tables via initrd
+================================
+
+What is this about
+==================
+
+If the ACPI_TABLE_UPGRADE compile option is true, it is possible to
+upgrade the ACPI execution environment that is defined by the ACPI tables
+via upgrading the ACPI tables provided by the BIOS with an instrumented,
+modified, more recent version one, or installing brand new ACPI tables.
+
+When building initrd with kernel in a single image, option
+ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD should also be true for this
+feature to work.
+
+For a full list of ACPI tables that can be upgraded/installed, take a look
+at the char `*table_sigs[MAX_ACPI_SIGNATURE];` definition in
+drivers/acpi/tables.c.
+
+All ACPI tables iasl (Intel's ACPI compiler and disassembler) knows should
+be overridable, except:
+
+  - ACPI_SIG_RSDP (has a signature of 6 bytes)
+  - ACPI_SIG_FACS (does not have an ordinary ACPI table header)
+
+Both could get implemented as well.
+
+
+What is this for
+================
+
+Complain to your platform/BIOS vendor if you find a bug which is so severe
+that a workaround is not accepted in the Linux kernel. And this facility
+allows you to upgrade the buggy tables before your platform/BIOS vendor
+releases an upgraded BIOS binary.
+
+This facility can be used by platform/BIOS vendors to provide a Linux
+compatible environment without modifying the underlying platform firmware.
+
+This facility also provides a powerful feature to easily debug and test
+ACPI BIOS table compatibility with the Linux kernel by modifying old
+platform provided ACPI tables or inserting new ACPI tables.
+
+It can and should be enabled in any kernel because there is no functional
+change with not instrumented initrds.
+
+
+How does it work
+================
+::
+
+  # Extract the machine's ACPI tables:
+  cd /tmp
+  acpidump >acpidump
+  acpixtract -a acpidump
+  # Disassemble, modify and recompile them:
+  iasl -d *.dat
+  # For example add this statement into a _PRT (PCI Routing Table) function
+  # of the DSDT:
+  Store("HELLO WORLD", debug)
+  # And increase the OEM Revision. For example, before modification:
+  DefinitionBlock ("DSDT.aml", "DSDT", 2, "INTEL ", "TEMPLATE", 0x00000000)
+  # After modification:
+  DefinitionBlock ("DSDT.aml", "DSDT", 2, "INTEL ", "TEMPLATE", 0x00000001)
+  iasl -sa dsdt.dsl
+  # Add the raw ACPI tables to an uncompressed cpio archive.
+  # They must be put into a /kernel/firmware/acpi directory inside the cpio
+  # archive. Note that if the table put here matches a platform table
+  # (similar Table Signature, and similar OEMID, and similar OEM Table ID)
+  # with a more recent OEM Revision, the platform table will be upgraded by
+  # this table. If the table put here doesn't match a platform table
+  # (dissimilar Table Signature, or dissimilar OEMID, or dissimilar OEM Table
+  # ID), this table will be appended.
+  mkdir -p kernel/firmware/acpi
+  cp dsdt.aml kernel/firmware/acpi
+  # A maximum of "NR_ACPI_INITRD_TABLES (64)" tables are currently allowed
+  # (see osl.c):
+  iasl -sa facp.dsl
+  iasl -sa ssdt1.dsl
+  cp facp.aml kernel/firmware/acpi
+  cp ssdt1.aml kernel/firmware/acpi
+  # The uncompressed cpio archive must be the first. Other, typically
+  # compressed cpio archives, must be concatenated on top of the uncompressed
+  # one. Following command creates the uncompressed cpio archive and
+  # concatenates the original initrd on top:
+  find kernel | cpio -H newc --create > /boot/instrumented_initrd
+  cat /boot/initrd >>/boot/instrumented_initrd
+  # reboot with increased acpi debug level, e.g. boot params:
+  acpi.debug_level=0x2 acpi.debug_layer=0xFFFFFFFF
+  # and check your syslog:
+  [    1.268089] ACPI: PCI Interrupt Routing Table [\_SB_.PCI0._PRT]
+  [    1.272091] [ACPI Debug]  String [0x0B] "HELLO WORLD"
+
+iasl is able to disassemble and recompile quite a lot different,
+also static ACPI tables.
+
+
+Where to retrieve userspace tools
+=================================
+
+iasl and acpixtract are part of Intel's ACPICA project:
+http://acpica.org/
+
+and should be packaged by distributions (for example in the acpica package
+on SUSE).
+
+acpidump can be found in Len Browns pmtools:
+ftp://kernel.org/pub/linux/kernel/people/lenb/acpi/utils/pmtools/acpidump
+
+This tool is also part of the acpica package on SUSE.
+Alternatively, used ACPI tables can be retrieved via sysfs in latest kernels:
+/sys/firmware/acpi/tables
diff --git a/Documentation/admin-guide/acpi/ssdt-overlays.rst b/Documentation/admin-guide/acpi/ssdt-overlays.rst
new file mode 100644
index 000000000000..da37455f96c9
--- /dev/null
+++ b/Documentation/admin-guide/acpi/ssdt-overlays.rst
@@ -0,0 +1,180 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=============
+SSDT Overlays
+=============
+
+In order to support ACPI open-ended hardware configurations (e.g. development
+boards) we need a way to augment the ACPI configuration provided by the firmware
+image. A common example is connecting sensors on I2C / SPI buses on development
+boards.
+
+Although this can be accomplished by creating a kernel platform driver or
+recompiling the firmware image with updated ACPI tables, neither is practical:
+the former proliferates board specific kernel code while the latter requires
+access to firmware tools which are often not publicly available.
+
+Because ACPI supports external references in AML code a more practical
+way to augment firmware ACPI configuration is by dynamically loading
+user defined SSDT tables that contain the board specific information.
+
+For example, to enumerate a Bosch BMA222E accelerometer on the I2C bus of the
+Minnowboard MAX development board exposed via the LSE connector [1], the
+following ASL code can be used::
+
+    DefinitionBlock ("minnowmax.aml", "SSDT", 1, "Vendor", "Accel", 0x00000003)
+    {
+        External (\_SB.I2C6, DeviceObj)
+
+        Scope (\_SB.I2C6)
+        {
+            Device (STAC)
+            {
+                Name (_ADR, Zero)
+                Name (_HID, "BMA222E")
+
+                Method (_CRS, 0, Serialized)
+                {
+                    Name (RBUF, ResourceTemplate ()
+                    {
+                        I2cSerialBus (0x0018, ControllerInitiated, 0x00061A80,
+                                    AddressingMode7Bit, "\\_SB.I2C6", 0x00,
+                                    ResourceConsumer, ,)
+                        GpioInt (Edge, ActiveHigh, Exclusive, PullDown, 0x0000,
+                                "\\_SB.GPO2", 0x00, ResourceConsumer, , )
+                        { // Pin list
+                            0
+                        }
+                    })
+                    Return (RBUF)
+                }
+            }
+        }
+    }
+
+which can then be compiled to AML binary format::
+
+    $ iasl minnowmax.asl
+
+    Intel ACPI Component Architecture
+    ASL Optimizing Compiler version 20140214-64 [Mar 29 2014]
+    Copyright (c) 2000 - 2014 Intel Corporation
+
+    ASL Input:     minnomax.asl - 30 lines, 614 bytes, 7 keywords
+    AML Output:    minnowmax.aml - 165 bytes, 6 named objects, 1 executable opcodes
+
+[1] http://wiki.minnowboard.org/MinnowBoard_MAX#Low_Speed_Expansion_Connector_.28Top.29
+
+The resulting AML code can then be loaded by the kernel using one of the methods
+below.
+
+Loading ACPI SSDTs from initrd
+==============================
+
+This option allows loading of user defined SSDTs from initrd and it is useful
+when the system does not support EFI or when there is not enough EFI storage.
+
+It works in a similar way with initrd based ACPI tables override/upgrade: SSDT
+aml code must be placed in the first, uncompressed, initrd under the
+"kernel/firmware/acpi" path. Multiple files can be used and this will translate
+in loading multiple tables. Only SSDT and OEM tables are allowed. See
+initrd_table_override.txt for more details.
+
+Here is an example::
+
+    # Add the raw ACPI tables to an uncompressed cpio archive.
+    # They must be put into a /kernel/firmware/acpi directory inside the
+    # cpio archive.
+    # The uncompressed cpio archive must be the first.
+    # Other, typically compressed cpio archives, must be
+    # concatenated on top of the uncompressed one.
+    mkdir -p kernel/firmware/acpi
+    cp ssdt.aml kernel/firmware/acpi
+
+    # Create the uncompressed cpio archive and concatenate the original initrd
+    # on top:
+    find kernel | cpio -H newc --create > /boot/instrumented_initrd
+    cat /boot/initrd >>/boot/instrumented_initrd
+
+Loading ACPI SSDTs from EFI variables
+=====================================
+
+This is the preferred method, when EFI is supported on the platform, because it
+allows a persistent, OS independent way of storing the user defined SSDTs. There
+is also work underway to implement EFI support for loading user defined SSDTs
+and using this method will make it easier to convert to the EFI loading
+mechanism when that will arrive.
+
+In order to load SSDTs from an EFI variable the efivar_ssdt kernel command line
+parameter can be used. The argument for the option is the variable name to
+use. If there are multiple variables with the same name but with different
+vendor GUIDs, all of them will be loaded.
+
+In order to store the AML code in an EFI variable the efivarfs filesystem can be
+used. It is enabled and mounted by default in /sys/firmware/efi/efivars in all
+recent distribution.
+
+Creating a new file in /sys/firmware/efi/efivars will automatically create a new
+EFI variable. Updating a file in /sys/firmware/efi/efivars will update the EFI
+variable. Please note that the file name needs to be specially formatted as
+"Name-GUID" and that the first 4 bytes in the file (little-endian format)
+represent the attributes of the EFI variable (see EFI_VARIABLE_MASK in
+include/linux/efi.h). Writing to the file must also be done with one write
+operation.
+
+For example, you can use the following bash script to create/update an EFI
+variable with the content from a given file::
+
+    #!/bin/sh -e
+
+    while ! [ -z "$1" ]; do
+            case "$1" in
+            "-f") filename="$2"; shift;;
+            "-g") guid="$2"; shift;;
+            *) name="$1";;
+            esac
+            shift
+    done
+
+    usage()
+    {
+            echo "Syntax: ${0##*/} -f filename [ -g guid ] name"
+            exit 1
+    }
+
+    [ -n "$name" -a -f "$filename" ] || usage
+
+    EFIVARFS="/sys/firmware/efi/efivars"
+
+    [ -d "$EFIVARFS" ] || exit 2
+
+    if stat -tf $EFIVARFS | grep -q -v de5e81e4; then
+            mount -t efivarfs none $EFIVARFS
+    fi
+
+    # try to pick up an existing GUID
+    [ -n "$guid" ] || guid=$(find "$EFIVARFS" -name "$name-*" | head -n1 | cut -f2- -d-)
+
+    # use a randomly generated GUID
+    [ -n "$guid" ] || guid="$(cat /proc/sys/kernel/random/uuid)"
+
+    # efivarfs expects all of the data in one write
+    tmp=$(mktemp)
+    /bin/echo -ne "\007\000\000\000" | cat - $filename > $tmp
+    dd if=$tmp of="$EFIVARFS/$name-$guid" bs=$(stat -c %s $tmp)
+    rm $tmp
+
+Loading ACPI SSDTs from configfs
+================================
+
+This option allows loading of user defined SSDTs from userspace via the configfs
+interface. The CONFIG_ACPI_CONFIGFS option must be select and configfs must be
+mounted. In the following examples, we assume that configfs has been mounted in
+/config.
+
+New tables can be loading by creating new directories in /config/acpi/table/ and
+writing the SSDT aml code in the aml attribute::
+
+    cd /config/acpi/table
+    mkdir my_ssdt
+    cat ~/ssdt.aml > my_ssdt/aml
diff --git a/Documentation/admin-guide/index.rst b/Documentation/admin-guide/index.rst
index 0a491676685e..5b8286fdd91b 100644
--- a/Documentation/admin-guide/index.rst
+++ b/Documentation/admin-guide/index.rst
@@ -77,6 +77,7 @@ configure specific aspects of kernel behavior to your liking.
    LSM/index
    mm/index
    perf-security
+   acpi/index
 
 .. only::  subproject and html