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authorLinus Torvalds <torvalds@linux-foundation.org>2016-05-16 19:41:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-16 19:41:41 -0700
commit46c13450624e36302547a2ac3695f2350fe7ffc3 (patch)
treee0454dae2c92873d193e8f9d8afeb920e3b0576a /Documentation
parentd57d39431924d1628ac9b93a2de7f806fc80680a (diff)
parentfc723957801465c4a911d0a509709f0f8b91aa8a (diff)
downloadlinux-46c13450624e36302547a2ac3695f2350fe7ffc3.tar.bz2
Merge tag 'acpi-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI updates from Rafael Wysocki: "The new features here are ACPI 6.1 support (and some previously missing bits of ACPI 6.0 support) in ACPICA and two new drivers, a driver for the ACPI Generic Event Device (GED) feature introduced by ACPI 6.1 and the INT3406 thermal driver for display thermal management. Also the value returned by the _HRV (hardware revision) ACPI object will be exported to user space via sysfs now. In addition to that, ACPI on ARM64 will not depend on EXPERT any more. The rest is mostly fixes and cleanups and some code reorganization. Specifics: - In-kernel ACPICA code update to the upstream release 20160422 adding support for ACPI 6.1 along with some previously missing bits of ACPI 6.0 support, making a fair amount of fixes and cleanups and reducing divergences between the upstream ACPICA and the in-kernel code (Bob Moore, Lv Zheng, Al Stone, Aleksey Makarov, Will Miles) - ACPI Generic Event Device (GED) support and a fix for it (Sinan Kaya, Paul Gortmaker) - INT3406 thermal driver for display thermal management and ACPI backlight support code reorganization related to it (Aaron Lu, Arnd Bergmann) - Support for exporting the value returned by the _HRV (hardware revision) ACPI object via sysfs (Betty Dall) - Removal of the EXPERT dependency for ACPI on ARM64 (Mark Brown) - Rework of the handling of ACPI _OSI mechanism allowing the _OSI("Darwin") support to be overridden from the kernel command line among other things (Lv Zheng, Chen Yu) - Rework of the ACPI tables override mechanism to prepare it for the introduction of overlays support going forward (Lv Zheng, Rafael Wysocki) - Fixes related to the ECDT support and module-level execution of AML (Lv Zheng) - ACPI PCI interrupts management update to make it work better on ARM64 mostly (Sinan Kaya) - ACPI SRAT handling update to make the code process all entires in the table order regardless of the entry type (Lukasz Anaczkowski) - EFI power off support for full-hardware ACPI platforms that don't support ACPI S5 (Chen Yu) - Fixes and cleanups related to the ACPI core's sysfs interface (Dan Carpenter, Betty Dall) - acpi_dev_present() API rework to reduce possible confusion related to it (Lukas Wunner) - Removal of CLK_IS_ROOT from two ACPI drivers (Stephen Boyd)" * tag 'acpi-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (82 commits) ACPI / video: mark acpi_video_get_levels() inline Thermal / ACPI / video: add INT3406 thermal driver ACPI / GED: make evged.c explicitly non-modular ACPI / tables: Fix DSDT override mechanism ACPI / sysfs: fix error code in get_status() ACPICA: Update version to 20160422 ACPICA: Move all ASCII utilities to a common file ACPICA: ACPI 2.0, Hardware: Add access_width/bit_offset support for acpi_hw_write() ACPICA: ACPI 2.0, Hardware: Add access_width/bit_offset support in acpi_hw_read() ACPICA: Executer: Introduce a set of macros to handle bit width mask generation ACPICA: Hardware: Add optimized access bit width support ACPICA: Utilities: Add ACPI_IS_ALIGNED() macro ACPICA: Renamed some #defined flag constants for clarity ACPICA: ACPI 6.0, tools/iasl: Add support for new resource descriptors ACPICA: ACPI 6.0: Update _BIX support for new package element ACPICA: ACPI 6.1: Support for new PCCT subtable ACPICA: Refactor evaluate_object to reduce nesting ACPICA: Divergence: remove unwanted spaces for typedef ACPI,PCI,IRQ: remove SCI penalize function ACPI,PCI,IRQ: remove redundant code in acpi_irq_penalty_init() ..
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/acpi/initrd_table_override.txt65
-rw-r--r--Documentation/kernel-parameters.txt2
2 files changed, 41 insertions, 26 deletions
diff --git a/Documentation/acpi/initrd_table_override.txt b/Documentation/acpi/initrd_table_override.txt
index 35c3f5415476..eb651a6aa285 100644
--- a/Documentation/acpi/initrd_table_override.txt
+++ b/Documentation/acpi/initrd_table_override.txt
@@ -1,5 +1,5 @@
-Overriding ACPI tables via initrd
-=================================
+Upgrading ACPI tables via initrd
+================================
1) Introduction (What is this about)
2) What is this for
@@ -9,12 +9,14 @@ Overriding ACPI tables via initrd
1) What is this about
---------------------
-If the ACPI_INITRD_TABLE_OVERRIDE compile option is true, it is possible to
-override nearly any ACPI table provided by the BIOS with an instrumented,
-modified one.
+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.
-For a full list of ACPI tables that can be overridden, take a look at
-the char *table_sigs[MAX_ACPI_SIGNATURE]; definition in drivers/acpi/osl.c
+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)
@@ -25,17 +27,20 @@ Both could get implemented as well.
2) What is this for
-------------------
-Please keep in mind that this is a debug option.
-ACPI tables should not get overridden for productive use.
-If BIOS ACPI tables are overridden the kernel will get tainted with the
-TAINT_OVERRIDDEN_ACPI_TABLE flag.
-Complain to your platform/BIOS vendor if you find a bug which is so sever
-that a workaround is not accepted in the Linux kernel.
+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.
-Still, it can and should be enabled in any kernel, because:
- - There is no functional change with not instrumented initrds
- - It provides a powerful feature to easily debug and test ACPI BIOS table
- compatibility with the Linux kernel.
+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.
3) How does it work
@@ -50,23 +55,31 @@ 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.
-# The uncompressed cpio archive must be the first.
-# Other, typically compressed cpio archives, must be
-# concatenated on top of the uncompressed one.
+# 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: #define ACPI_OVERRIDE_TABLES 10
-# tables are currently allowed (see osl.c):
+# 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
-# Create the uncompressed cpio archive and concatenate the original initrd
-# on top:
+# 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:
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 1b322c0c8dff..d3240feef367 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -315,6 +315,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
acpi_osi=!* # remove all strings
acpi_osi=! # disable all built-in OS vendor
strings
+ acpi_osi=!! # enable all built-in OS vendor
+ strings
acpi_osi= # disable all strings
'acpi_osi=!' can be used in combination with single or