GITS_TYPER, ITS Type Register

The GITS_TYPER characteristics are:

Purpose

Specifies the features that an ITS supports.

This register is part of the GIC ITS registers functional group.

Usage constraints

This register is accessible as follows:

Security disabledSecureNon-secure
RORORO

Configuration

There are no configuration notes.

Attributes

GITS_TYPER is a 64-bit register.

Field descriptions

The GITS_TYPER bit assignments are:

6362616059585756555453525150494847464544434241403938373635343332
00000000000000000000000000VMOVPCILCIDbits
HCC0000PTASEISDevbitsID_bitsITT_entry_sizeIMPLEMENTATION DEFINEDCCTVirtualPhysical
313029282726252423222120191817161514131211109876543210

Bits [63:38]

Reserved, RES0.

VMOVP, bit [37]

Indicates the form of the VMOVP command.

VMOVPMeaning
0

When moving a vPE, software must issue a VMOVP on all ITSs that have mappings for that vPE. The ITSList and Sequence Number fields in the VMOVP command must ensure synchronization, otherwise behavior is UNPREDICTABLE.

1

When moving a vPE, software must only issue a VMOVP on one of the ITSs that has a mapping for that vPE. The ITSList and Sequence Number fields in the VMOVP command are RES0.

CIL, bit [36]

Collection ID Limit.

CILMeaning
0

ITS supports 16-bit Collection ID, GITS_TYPER.CIDbits is RES0.

1

GITS_TYPER.CIDbits indicates supported Collection ID size

In implementations that do not support Collections in external memory, this bit is RES0 and the number of Collections supported is reported by GITS_TYPER.HCC.

CIDbits, bits [35:32]

Number of Collection ID bits.

HCC, bits [31:24]

Hardware Collection Count. The number of interrupt collections supported by the ITS without provisioning of external memory.

Note

Collections held in hardware are unmapped at reset.

Bits [23:20]

Reserved, RES0.

PTA, bit [19]

Physical Target Addresses. Indicates the format of the target address:

PTAMeaning
0

The target address corresponds to the PE number specified by GICR_TYPER.Processor_Number.

1

The target address corresponds to the base physical address of the required Redistributor.

See Target addresses for more information.

SEIS, bit [18]

SEI support. Indicates whether the virtual CPU interface supports generation of SEIs:

SEISMeaning
0

The ITS does not support local generation of SEIs.

1

The ITS supports local generation of SEIs.

Devbits, bits [17:13]

The number of DeviceID bits implemented, minus one.

ID_bits, bits [12:8]

The number of EventID bits implemented, minus one.

ITT_entry_size, bits [7:4]

Read-only. Indicates the number of bytes per translation table entry, minus one.

See the ITS command 'MAPD' for more information.

IMPLEMENTATION DEFINED, bit [3]

IMPLEMENTATION DEFINED.

CCT, bit [2]

Cumulative Collection Tables.

CCTMeaning
0

The total number of supported collections is determined by the number of collections held in memory only.

1

The total number of supported collections is determined by number of collections that are held in memory and the number indicated by GITS_TYPER.HCC.

If GITS_TYPER.HCC==0, or if memory backed collections are not supported (all GITS_BASER<n>.Type != 100), this bit is RES0.

Virtual, bit [1]

Indicates whether the ITS supports virtual LPIs and direct injection of virtual LPIs:

VirtualMeaning
0

The ITS does not support virtual LPIs or direct injection of virtual LPIs.

1

The ITS supports virtual LPIs and direct injection of virtual LPIs.

This field is RES0 in GICv3 implementations.

Physical, bit [0]

Indicates whether the ITS supports physical LPIs:

PhysicalMeaning
0

The ITS does not support physical LPIs.

1

The ITS supports physical LPIs.

This field is RES1, indicating that the ITS supports physical LPIs.

Accessing the GITS_TYPER

GITS_TYPER can be accessed through its memory-mapped interface:

ComponentOffset
GIC ITS control0x0008-0x000C



18/04/2017 17:00

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