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# MPAMIDR_EL1, MPAM ID Register (EL1)

The MPAMIDR_EL1 characteristics are:

## Purpose

MPAMIDR_EL1 indicates the presence and maximum PARTID and PMG values supported in the implementation. It also indicates whether the implementation supports MPAM virtualization.

## Configuration

This register is present only when MPAM is implemented. Otherwise, direct accesses to MPAMIDR_EL1 are UNDEFINED.

## Attributes

MPAMIDR_EL1 is a 64-bit register.

## Field descriptions

The MPAMIDR_EL1 bit assignments are:

63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 38 | 37 | 36 | 35 | 34 | 33 | 32
RES0 | PMG_MAX
RES0 | VPMR_MAX | HAS_HCR | RES0 | PARTID_MAX
31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0

MPAMIDR_EL1 indicates the MPAM implementation parameters of the PE.

#### Bits [63:40]

Reserved, RES0.

#### PMG_MAX, bits [39:32]

The largest value of PMG that the implementation can generate. The PMG_I and PMG_D fields of every MPAMn_ELx must implement at least enough bits to represent PMG_MAX.

#### Bits [31:21]

Reserved, RES0.

#### VPMR_MAX, bits [20:18]

If HAS_HCR == 0, VPMR_MAX must be 0b000. Otherwise, it indicates the maximum register index n for the MPAMVPM<n>_EL2 registers.

#### HAS_HCR, bit [17]

HAS_HCR indicates that the PE implementation supports MPAM virtualization, including MPAMHCR_EL2, MPAMVPMV_EL2 and MPAMVPM<n>_EL2 with n in the range 0 to VPMR_MAX. Must be 0 if EL2 is not implemented in either security state.

HAS_HCR | Meaning
--- | ---
0b0 | MPAM virtualization is not supported.
0b1 | MPAM virtualization is supported.

#### Bit [16]

Reserved, RES0.

#### PARTID_MAX, bits [15:0]

The largest value of PMG that the implementation can generate. The PARTED_I and PARTID_D fields of every MPAMn_ELx must implement at least enough bits to represent PARTID_MAX.

## Accessing the MPAMIDR_EL1

Accesses to this register use the following encodings:

#### MRS <Xt>, MPAMIDR_EL1

op0 | op1 | CRn | CRm | op2
--- | --- | --- | --- | ---
0b11 | 0b000 | 0b1010 | 0b0100 | 0b100

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && !ELUsingAArch32(EL3) && MPAM3_EL3.TRAPLOWER == '1' then AArch64.SystemAccessTrap(EL3, 0x18); elsif EL2Enabled() && !ELUsingAArch32(EL2) && MPAMIDR_EL1.HAS_HCR == '1' && MPAMHCR_EL2.TRAP_MPAMIDR_EL1 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else return MPAMIDR_EL1; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && MPAM3_EL3.TRAPLOWER == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else return MPAMIDR_EL1; elsif PSTATE.EL == EL3 then return MPAMIDR_EL1;

AArch32 Registers | AArch64 Registers | AArch32 Instructions | AArch64 Instructions | Index by Encoding | External Registers | External Registers by Offset | Registers by Functional Group | Proprietary Notice

15/04/2019 16:47; 8c23526ba8a13a72aada4137daf3e3977b49036e

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