Commit efc499f9 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

Merge branches 'acpi-numa', 'acpi-tables' and 'acpi-osi' 

* acpi-numa:
  ACPI / SRAT: fix SRAT parsing order with both LAPIC and X2APIC present

* acpi-tables:
  ACPI / tables: Fix DSDT override mechanism
  ACPI / tables: Convert initrd table override to table upgrade mechanism
  ACPI / x86: Cleanup initrd related code
  ACPI / tables: Move table override mechanisms to tables.c

* acpi-osi:
  ACPI / osi: Collect _OSI handling into one single file
  ACPI / osi: Cleanup coding style issues before creating a separate OSI source file
  ACPI / osi: Cleanup OSI handling code to use bool
  ACPI / osi: Fix default _OSI(Darwin) support
  ACPI / osi: Add acpi_osi=!! to allow reverting acpi_osi=!
  ACPI / osi: Cleanup _OSI("Linux") related code before introducing new support
  ACPI / osi: Fix an issue that acpi_osi=!* cannot disable ACPICA internal strings

Conflicts:
	drivers/acpi/internal.h
parents a6becfba 702b07fc 74216699 e5f660eb

Documentation/acpi/initrd_table_override.txt

+39 −26
Original line number Diff line number Diff line 
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:

Documentation/kernel-parameters.txt

+2 −0
Original line number Diff line number Diff line
@@ -312,6 +312,8 @@ 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

arch/x86/kernel/setup.c

+9 −3
Original line number Diff line number Diff line
@@ -398,6 +398,11 @@ static void __init reserve_initrd(void) 


	memblock_free(ramdisk_image, ramdisk_end - ramdisk_image);

}



static void __init early_initrd_acpi_init(void)

{

	early_acpi_table_init((void *)initrd_start, initrd_end - initrd_start);

}

#else

static void __init early_reserve_initrd(void)

{
@@ -405,6 +410,9 @@ static void __init early_reserve_initrd(void) 
static void __init reserve_initrd(void)

{

}

static void __init early_initrd_acpi_init(void)

{

}

#endif /* CONFIG_BLK_DEV_INITRD */



static void __init parse_setup_data(void)
@@ -1138,9 +1146,7 @@ void __init setup_arch(char **cmdline_p) 


	reserve_initrd();



#if defined(CONFIG_ACPI) && defined(CONFIG_BLK_DEV_INITRD)

	acpi_initrd_override((void *)initrd_start, initrd_end - initrd_start);

#endif

	early_initrd_acpi_init();



	vsmp_init();

drivers/acpi/Kconfig

+4 −4
Original line number Diff line number Diff line
@@ -311,12 +311,12 @@ config ACPI_CUSTOM_DSDT 
	bool

	default ACPI_CUSTOM_DSDT_FILE != ""



config ACPI_INITRD_TABLE_OVERRIDE

	bool "ACPI tables override via initrd"

config ACPI_TABLE_UPGRADE

	bool "Allow upgrading ACPI tables via initrd"

	depends on BLK_DEV_INITRD && X86

	default n

	default y

	help

	  This option provides functionality to override arbitrary ACPI tables

	  This option provides functionality to upgrade arbitrary ACPI tables

	  via initrd. No functional change if no ACPI tables are passed via

	  initrd, therefore it's safe to say Y.

	  See Documentation/acpi/initrd_table_override.txt for details

drivers/acpi/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -18,7 +18,7 @@ obj-$(CONFIG_ACPI) += acpi.o \ 
					acpica/



# All the builtin files are in the "acpi." module_param namespace.

acpi-y				+= osl.o utils.o reboot.o

acpi-y				+= osi.o osl.o utils.o reboot.o

acpi-y				+= nvs.o



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