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| -rw-r--r-- | Documentation/arm64/acpi_object_usage.rst (renamed from Documentation/arm64/acpi_object_usage.txt) | 288 |
1 files changed, 202 insertions, 86 deletions
diff --git a/Documentation/arm64/acpi_object_usage.txt b/Documentation/arm64/acpi_object_usage.rst index c77010c5c1f0..d51b69dc624d 100644 --- a/Documentation/arm64/acpi_object_usage.txt +++ b/Documentation/arm64/acpi_object_usage.rst @@ -1,5 +1,7 @@ +=========== ACPI Tables ------------ +=========== + The expectations of individual ACPI tables are discussed in the list that follows. @@ -11,54 +13,71 @@ outside of the UEFI Forum (see Section 5.2.6 of the specification). For ACPI on arm64, tables also fall into the following categories: - -- Required: DSDT, FADT, GTDT, MADT, MCFG, RSDP, SPCR, XSDT + - Required: DSDT, FADT, GTDT, MADT, MCFG, RSDP, SPCR, XSDT - -- Recommended: BERT, EINJ, ERST, HEST, PCCT, SSDT + - Recommended: BERT, EINJ, ERST, HEST, PCCT, SSDT - -- Optional: BGRT, CPEP, CSRT, DBG2, DRTM, ECDT, FACS, FPDT, IORT, + - Optional: BGRT, CPEP, CSRT, DBG2, DRTM, ECDT, FACS, FPDT, IORT, MCHI, MPST, MSCT, NFIT, PMTT, RASF, SBST, SLIT, SPMI, SRAT, STAO, TCPA, TPM2, UEFI, XENV - -- Not supported: BOOT, DBGP, DMAR, ETDT, HPET, IBFT, IVRS, LPIT, + - Not supported: BOOT, DBGP, DMAR, ETDT, HPET, IBFT, IVRS, LPIT, MSDM, OEMx, PSDT, RSDT, SLIC, WAET, WDAT, WDRT, WPBT +====== ======================================================================== Table Usage for ARMv8 Linux ------ ---------------------------------------------------------------- +====== ======================================================================== BERT Section 18.3 (signature == "BERT") - == Boot Error Record Table == + + **Boot Error Record Table** + Must be supplied if RAS support is provided by the platform. It is recommended this table be supplied. BOOT Signature Reserved (signature == "BOOT") - == simple BOOT flag table == + + **simple BOOT flag table** + Microsoft only table, will not be supported. BGRT Section 5.2.22 (signature == "BGRT") - == Boot Graphics Resource Table == + + **Boot Graphics Resource Table** + Optional, not currently supported, with no real use-case for an ARM server. CPEP Section 5.2.18 (signature == "CPEP") - == Corrected Platform Error Polling table == + + **Corrected Platform Error Polling table** + Optional, not currently supported, and not recommended until such time as ARM-compatible hardware is available, and the specification suitably modified. CSRT Signature Reserved (signature == "CSRT") - == Core System Resources Table == + + **Core System Resources Table** + Optional, not currently supported. DBG2 Signature Reserved (signature == "DBG2") - == DeBuG port table 2 == + + **DeBuG port table 2** + License has changed and should be usable. Optional if used instead of earlycon=<device> on the command line. DBGP Signature Reserved (signature == "DBGP") - == DeBuG Port table == + + **DeBuG Port table** + Microsoft only table, will not be supported. DSDT Section 5.2.11.1 (signature == "DSDT") - == Differentiated System Description Table == + + **Differentiated System Description Table** + A DSDT is required; see also SSDT. ACPI tables contain only one DSDT but can contain one or more SSDTs, @@ -66,22 +85,30 @@ DSDT Section 5.2.11.1 (signature == "DSDT") but cannot modify or replace anything in the DSDT. DMAR Signature Reserved (signature == "DMAR") - == DMA Remapping table == + + **DMA Remapping table** + x86 only table, will not be supported. DRTM Signature Reserved (signature == "DRTM") - == Dynamic Root of Trust for Measurement table == + + **Dynamic Root of Trust for Measurement table** + Optional, not currently supported. ECDT Section 5.2.16 (signature == "ECDT") - == Embedded Controller Description Table == + + **Embedded Controller Description Table** + Optional, not currently supported, but could be used on ARM if and only if one uses the GPE_BIT field to represent an IRQ number, since there are no GPE blocks defined in hardware reduced mode. This would need to be modified in the ACPI specification. EINJ Section 18.6 (signature == "EINJ") - == Error Injection table == + + **Error Injection table** + This table is very useful for testing platform response to error conditions; it allows one to inject an error into the system as if it had actually occurred. However, this table should not be @@ -89,27 +116,35 @@ EINJ Section 18.6 (signature == "EINJ") and executed with the ACPICA tools only during testing. ERST Section 18.5 (signature == "ERST") - == Error Record Serialization Table == + + **Error Record Serialization Table** + On a platform supports RAS, this table must be supplied if it is not UEFI-based; if it is UEFI-based, this table may be supplied. When this table is not present, UEFI run time service will be utilized to save and retrieve hardware error information to and from a persistent store. ETDT Signature Reserved (signature == "ETDT") - == Event Timer Description Table == + + **Event Timer Description Table** + Obsolete table, will not be supported. FACS Section 5.2.10 (signature == "FACS") - == Firmware ACPI Control Structure == + + **Firmware ACPI Control Structure** + It is unlikely that this table will be terribly useful. If it is provided, the Global Lock will NOT be used since it is not part of the hardware reduced profile, and only 64-bit address fields will be considered valid. FADT Section 5.2.9 (signature == "FACP") - == Fixed ACPI Description Table == + + **Fixed ACPI Description Table** Required for arm64. + The HW_REDUCED_ACPI flag must be set. All of the fields that are to be ignored when HW_REDUCED_ACPI is set are expected to be set to zero. @@ -118,22 +153,28 @@ FADT Section 5.2.9 (signature == "FACP") used, not FIRMWARE_CTRL. If PSCI is used (as is recommended), make sure that ARM_BOOT_ARCH is - filled in properly -- that the PSCI_COMPLIANT flag is set and that + filled in properly - that the PSCI_COMPLIANT flag is set and that PSCI_USE_HVC is set or unset as needed (see table 5-37). For the DSDT that is also required, the X_DSDT field is to be used, not the DSDT field. FPDT Section 5.2.23 (signature == "FPDT") - == Firmware Performance Data Table == + + **Firmware Performance Data Table** + Optional, not currently supported. GTDT Section 5.2.24 (signature == "GTDT") - == Generic Timer Description Table == + + **Generic Timer Description Table** + Required for arm64. HEST Section 18.3.2 (signature == "HEST") - == Hardware Error Source Table == + + **Hardware Error Source Table** + ARM-specific error sources have been defined; please use those or the PCI types such as type 6 (AER Root Port), 7 (AER Endpoint), or 8 (AER Bridge), or use type 9 (Generic Hardware Error Source). Firmware first @@ -144,122 +185,174 @@ HEST Section 18.3.2 (signature == "HEST") is recommended this table be supplied. HPET Signature Reserved (signature == "HPET") - == High Precision Event timer Table == + + **High Precision Event timer Table** + x86 only table, will not be supported. IBFT Signature Reserved (signature == "IBFT") - == iSCSI Boot Firmware Table == + + **iSCSI Boot Firmware Table** + Microsoft defined table, support TBD. IORT Signature Reserved (signature == "IORT") - == Input Output Remapping Table == + + **Input Output Remapping Table** + arm64 only table, required in order to describe IO topology, SMMUs, and GIC ITSs, and how those various components are connected together, such as identifying which components are behind which SMMUs/ITSs. This table will only be required on certain SBSA platforms (e.g., - when using GICv3-ITS and an SMMU); on SBSA Level 0 platforms, it + when using GICv3-ITS and an SMMU); on SBSA Level 0 platforms, it remains optional. IVRS Signature Reserved (signature == "IVRS") - == I/O Virtualization Reporting Structure == + + **I/O Virtualization Reporting Structure** + x86_64 (AMD) only table, will not be supported. LPIT Signature Reserved (signature == "LPIT") - == Low Power Idle Table == + + **Low Power Idle Table** + x86 only table as of ACPI 5.1; starting with ACPI 6.0, processor descriptions and power states on ARM platforms should use the DSDT and define processor container devices (_HID ACPI0010, Section 8.4, and more specifically 8.4.3 and and 8.4.4). MADT Section 5.2.12 (signature == "APIC") - == Multiple APIC Description Table == + + **Multiple APIC Description Table** + Required for arm64. Only the GIC interrupt controller structures should be used (types 0xA - 0xF). MCFG Signature Reserved (signature == "MCFG") - == Memory-mapped ConFiGuration space == + + **Memory-mapped ConFiGuration space** + If the platform supports PCI/PCIe, an MCFG table is required. MCHI Signature Reserved (signature == "MCHI") - == Management Controller Host Interface table == + + **Management Controller Host Interface table** + Optional, not currently supported. MPST Section 5.2.21 (signature == "MPST") - == Memory Power State Table == + + **Memory Power State Table** + Optional, not currently supported. MSCT Section 5.2.19 (signature == "MSCT") - == Maximum System Characteristic Table == + + **Maximum System Characteristic Table** + Optional, not currently supported. MSDM Signature Reserved (signature == "MSDM") - == Microsoft Data Management table == + + **Microsoft Data Management table** + Microsoft only table, will not be supported. NFIT Section 5.2.25 (signature == "NFIT") - == NVDIMM Firmware Interface Table == + + **NVDIMM Firmware Interface Table** + Optional, not currently supported. OEMx Signature of "OEMx" only - == OEM Specific Tables == + + **OEM Specific Tables** + All tables starting with a signature of "OEM" are reserved for OEM use. Since these are not meant to be of general use but are limited to very specific end users, they are not recommended for use and are not supported by the kernel for arm64. PCCT Section 14.1 (signature == "PCCT) - == Platform Communications Channel Table == + + **Platform Communications Channel Table** + Recommend for use on arm64; use of PCC is recommended when using CPPC to control performance and power for platform processors. PMTT Section 5.2.21.12 (signature == "PMTT") - == Platform Memory Topology Table == + + **Platform Memory Topology Table** + Optional, not currently supported. PSDT Section 5.2.11.3 (signature == "PSDT") - == Persistent System Description Table == + + **Persistent System Description Table** + Obsolete table, will not be supported. RASF Section 5.2.20 (signature == "RASF") - == RAS Feature table == + + **RAS Feature table** + Optional, not currently supported. RSDP Section 5.2.5 (signature == "RSD PTR") - == Root System Description PoinTeR == + + **Root System Description PoinTeR** + Required for arm64. RSDT Section 5.2.7 (signature == "RSDT") - == Root System Description Table == + + **Root System Description Table** + Since this table can only provide 32-bit addresses, it is deprecated on arm64, and will not be used. If provided, it will be ignored. SBST Section 5.2.14 (signature == "SBST") - == Smart Battery Subsystem Table == + + **Smart Battery Subsystem Table** + Optional, not currently supported. SLIC Signature Reserved (signature == "SLIC") - == Software LIcensing table == + + **Software LIcensing table** + Microsoft only table, will not be supported. SLIT Section 5.2.17 (signature == "SLIT") - == System Locality distance Information Table == + + **System Locality distance Information Table** + Optional in general, but required for NUMA systems. SPCR Signature Reserved (signature == "SPCR") - == Serial Port Console Redirection table == + + **Serial Port Console Redirection table** + Required for arm64. SPMI Signature Reserved (signature == "SPMI") - == Server Platform Management Interface table == + + **Server Platform Management Interface table** + Optional, not currently supported. SRAT Section 5.2.16 (signature == "SRAT") - == System Resource Affinity Table == + + **System Resource Affinity Table** + Optional, but if used, only the GICC Affinity structures are read. To support arm64 NUMA, this table is required. SSDT Section 5.2.11.2 (signature == "SSDT") - == Secondary System Description Table == + + **Secondary System Description Table** + These tables are a continuation of the DSDT; these are recommended for use with devices that can be added to a running system, but can also serve the purpose of dividing up device descriptions into more @@ -272,49 +365,69 @@ SSDT Section 5.2.11.2 (signature == "SSDT") one DSDT but can contain many SSDTs. STAO Signature Reserved (signature == "STAO") - == _STA Override table == + + **_STA Override table** + Optional, but only necessary in virtualized environments in order to hide devices from guest OSs. TCPA Signature Reserved (signature == "TCPA") - == Trusted Computing Platform Alliance table == + + **Trusted Computing Platform Alliance table** + Optional, not currently supported, and may need changes to fully interoperate with arm64. TPM2 Signature Reserved (signature == "TPM2") - == Trusted Platform Module 2 table == + + **Trusted Platform Module 2 table** + Optional, not currently supported, and may need changes to fully interoperate with arm64. UEFI Signature Reserved (signature == "UEFI") - == UEFI ACPI data table == + + **UEFI ACPI data table** + Optional, not currently supported. No known use case for arm64, at present. WAET Signature Reserved (signature == "WAET") - == Windows ACPI Emulated devices Table == + + **Windows ACPI Emulated devices Table** + Microsoft only table, will not be supported. WDAT Signature Reserved (signature == "WDAT") - == Watch Dog Action Table == + + **Watch Dog Action Table** + Microsoft only table, will not be supported. WDRT Signature Reserved (signature == "WDRT") - == Watch Dog Resource Table == + + **Watch Dog Resource Table** + Microsoft only table, will not be supported. WPBT Signature Reserved (signature == "WPBT") - == Windows Platform Binary Table == + + **Windows Platform Binary Table** + Microsoft only table, will not be supported. XENV Signature Reserved (signature == "XENV") - == Xen project table == + + **Xen project table** + Optional, used only by Xen at present. XSDT Section 5.2.8 (signature == "XSDT") - == eXtended System Description Table == - Required for arm64. + **eXtended System Description Table** + + Required for arm64. +====== ======================================================================== ACPI Objects ------------ @@ -323,10 +436,11 @@ shown in the list that follows; any object not explicitly mentioned below should be used as needed for a particular platform or particular subsystem, such as power management or PCI. +===== ================ ======================================================== Name Section Usage for ARMv8 Linux ----- ------------ ------------------------------------------------- +===== ================ ======================================================== _CCA 6.2.17 This method must be defined for all bus masters - on arm64 -- there are no assumptions made about + on arm64 - there are no assumptions made about whether such devices are cache coherent or not. The _CCA value is inherited by all descendants of these devices so it does not need to be repeated. @@ -422,8 +536,8 @@ _OSC 6.2.11 This method can be a global method in ACPI (i.e., by the kernel community, then register it with the UEFI Forum. -\_OSI 5.7.2 Deprecated on ARM64. As far as ACPI firmware is - concerned, _OSI is not to be used to determine what +\_OSI 5.7.2 Deprecated on ARM64. As far as ACPI firmware is + concerned, _OSI is not to be used to determine what sort of system is being used or what functionality is provided. The _OSC method is to be used instead. @@ -447,7 +561,7 @@ _PSx 7.3.2-5 Use as needed; power management specific. If _PS0 is usage, change them in these methods. _RDI 8.4.4.4 Recommended for use with processor definitions (_HID - ACPI0010) on arm64. This should only be used in + ACPI0010) on arm64. This should only be used in conjunction with _LPI. \_REV 5.7.4 Always returns the latest version of ACPI supported. @@ -476,6 +590,7 @@ _SWS 7.4.3 Use as needed; power management specific; this may _UID 6.1.12 Recommended for distinguishing devices of the same class; define it if at all possible. +===== ================ ======================================================== @@ -488,7 +603,7 @@ platforms, ACPI events must be signaled differently. There are two options: GPIO-signaled interrupts (Section 5.6.5), and interrupt-signaled events (Section 5.6.9). Interrupt-signaled events are a -new feature in the ACPI 6.1 specification. Either -- or both -- can be used +new feature in the ACPI 6.1 specification. Either - or both - can be used on a given platform, and which to use may be dependent of limitations in any given SoC. If possible, interrupt-signaled events are recommended. @@ -564,39 +679,40 @@ supported. The following classes of objects are not supported: - -- Section 9.2: ambient light sensor devices + - Section 9.2: ambient light sensor devices - -- Section 9.3: battery devices + - Section 9.3: battery devices - -- Section 9.4: lids (e.g., laptop lids) + - Section 9.4: lids (e.g., laptop lids) - -- Section 9.8.2: IDE controllers + - Section 9.8.2: IDE controllers - -- Section 9.9: floppy controllers + - Section 9.9: floppy controllers - -- Section 9.10: GPE block devices + - Section 9.10: GPE block devices - -- Section 9.15: PC/AT RTC/CMOS devices + - Section 9.15: PC/AT RTC/CMOS devices - -- Section 9.16: user presence detection devices + - Section 9.16: user presence detection devices - -- Section 9.17: I/O APIC devices; all GICs must be enumerable via MADT + - Section 9.17: I/O APIC devices; all GICs must be enumerable via MADT - -- Section 9.18: time and alarm devices (see 9.15) + - Section 9.18: time and alarm devices (see 9.15) - -- Section 10: power source and power meter devices + - Section 10: power source and power meter devices - -- Section 11: thermal management + - Section 11: thermal management - -- Section 12: embedded controllers interface + - Section 12: embedded controllers interface - -- Section 13: SMBus interfaces + - Section 13: SMBus interfaces This also means that there is no support for the following objects: +==== =========================== ==== ========== Name Section Name Section ----- ------------ ---- ------------ +==== =========================== ==== ========== _ALC 9.3.4 _FDM 9.10.3 _ALI 9.3.2 _FIX 6.2.7 _ALP 9.3.6 _GAI 10.4.5 @@ -619,4 +735,4 @@ _DCK 6.5.2 _UPD 9.16.1 _EC 12.12 _UPP 9.16.2 _FDE 9.10.1 _WPC 10.5.2 _FDI 9.10.2 _WPP 10.5.3 - +==== =========================== ==== ========== |