ERRDEVAFF, Device Affinity Register

The ERRDEVAFF characteristics are:

Purpose

For a group of error records that has affinity with a single PE or a group of PEs, ERRDEVAFF is a copy of MPIDR_EL1 or part of MPIDR_EL1:

• If the group of error records has affinity with a single PE, the affinity level is 0, ERRDEVAFF reads the same value as MPIDR_EL1, and ERRDEVAFF.F0V reads-as-one to indicate affinity level 0.
• If the group of error records has affinity with a group of PEs, the affinity level is 1, 2, or 3, parts of ERRDEVAFF reads the same value as parts of MPIDR_EL1, and the rest of ERRDEVAFF indicates the level.

For example, if the group of PEs is a subset of the PEs at affinity level 1 then all of the following are true:

• All the PEs in the group have the same values in MPIDR_EL1.{Aff3,Aff2}, and these values are equal to ERRDEVAFF.{Aff3,Aff2}.
• ERRDEVAFF.Aff1 is nonzero and not 0x80, and ERRDEVAFF.{Aff0,F0V} read-as-zero, to indicate at least affinity level 1. The subset of PEs at level 1 that the group of error records has affinity with is indicated by the least-significant set bit in ERRDEVAFF.Aff1. In this example, if ERRDEVAFF.Aff1[2:0] is 0b100, then the group of error records has affinity with the up-to 8 PEs that have MPIDR_EL1.Aff1[7:3] == ERRDEVAFF.Aff1[7:3].

If RAS System Architecture v1.1 is not implemented, ERRDEVAFF can only describe a group of error records that is affine with a single PE or all the PEs at an affinity level.

Configuration

This register is present only when the group of error records has affinity with a PE or cluster of PEs. Otherwise, direct accesses to ERRDEVAFF are RES0.

ERRDEVAFF is implemented only as part of a memory-mapped group of error records.

Attributes

ERRDEVAFF is a 64-bit register.

Field descriptions

The ERRDEVAFF bit assignments are:

Bits [63:40]

Reserved, RES0.

Aff3, bits [39:32]

PE affinity level 3. The MPIDR_EL1.Aff3 field, viewed from the highest Exception level of the associated PE or PEs.

F0V, bit [31]

Indicates that the ERRDEVAFF.Aff0 field is valid.

U, bit [30]

When ERRDEVAFF.F0V == 1:

Uniprocessor. The MPIDR_EL1.U bit, viewed from the highest Exception level of the associated PE.

Otherwise:

Reserved, UNKNOWN.

Bits [29:25]

Reserved, RES0.

MT, bit [24]

When ERRDEVAFF.F0V == 1:

Multithreaded. The MPIDR_EL1.MT bit, viewed from the highest Exception level of the associated PE.

Otherwise:

Reserved, UNKNOWN.

Aff2, bits [23:16]

When affine with a PE or PEs at affinity level 2 or below:

PE affinity level 2. The MPIDR_EL1.Aff2 field, viewed from the highest Exception level of the associated PE or PEs.

When affine with a sub-set of PEs at affinity level 2:

PE affinity level 2. Defines part of the MPIDR_EL1.Aff2 field, viewed from the highest Exception level of the associated PEs.

Otherwise:

PE affinity level 2. Indicates whether the PE affinity is at level 3.

All other values are reserved.

Aff1, bits [15:8]

When affine with a PE or PEs at affinity level 1 or below:

PE affinity level 1. The MPIDR_EL1.Aff1 field, viewed from the highest Exception level of the associated PE or PEs.

When affine with a sub-set of PEs at affinity level 1:

PE affinity level 1. Defines part of the MPIDR_EL1.Aff1 field, viewed from the highest Exception level of the associated PEs.

Otherwise:

PE affinity level 1. Indicates whether the PE affinity is at level 2.

Aff0, bits [7:0]

When affine with a PE at affinity level 0:

PE affinity level 0. The MPIDR_EL1.Aff0 field, viewed from the highest Exception level of the associated PE.

When affine with a sub-set of PEs at affinity level 0:

PE affinity level 0. Defines part of the MPIDR_EL1.Aff0 field, viewed from the highest Exception level of the associated PEs.

Otherwise:

PE affinity level 0. Indicates whether the PE affinity is at level 1.

Accessing the ERRDEVAFF

ERRDEVAFF can be accessed through the memory-mapped interfaces:

Accesses on this interface are RO.