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TLBI VALE2OS, TLB Invalidate by VA, Last level, EL2, Outer Shareable

The TLBI VALE2OS characteristics are:

Purpose

When EL2 is implemented and enabled in the current Security state, invalidates cached copies of translation table entries from TLBs that meet all the following requirements:

  • The entry is a stage 1 translation table entry, from the final level of the translation table walk.

  • The entry would be used to translate the specified VA, and one of the following applies:

    • The entry is a global entry from the final level of lookup.

    • The entry is a non-global entry from the final level of lookup that matches the specified ASID.

  • If HCR_EL2.{E2H, TGE} is not {1, 1}, the entry would be used with the current VMID and would be required to translate the specified VA using the EL2 translation regime.

  • If HCR_EL2.{E2H, TGE} is {1, 1}, the entry would be required to translate the specified VA using the EL2&0 translation regime.

The invalidation only applies to all PEs in the same Outer Shareable shareability domain as the PE that executes this instruction.

Configuration

This instruction is present only when ARMv8.4-TLBI is implemented. Otherwise, direct accesses to TLBI VALE2OS are UNDEFINED.

Attributes

TLBI VALE2OS is a 64-bit System instruction.

Field descriptions

The TLBI VALE2OS input value bit assignments are:

6362616059585756555453525150494847464544434241403938373635343332
ASIDTTLVA[55:12]
VA[55:12]
313029282726252423222120191817161514131211109876543210

ASID, bits [63:48]

ASID value to match. Any TLB entries that match the ASID value and VA value will be affected by this operation.

Global TLB entries that match the VA value will be affected by this operation, regardless of the value of the ASID field.

If the implementation supports 16 bits of ASID, but only 8 bits are being used in the context being invalidated, the upper bits are RES0.

TTL, bits [47:44]

When ARMv8.4-TTL is implemented:

Translation Table Level. Indicates the level of the page table walk that holds the leaf entry for the address being invalidated.

TTLMeaning
0b00xx

No information supplied as to the translation table level. Hardware must assume that the entry can be from any level. In this case, TTL<1:0> is RES0.

0b01xx

The entry comes from a 4KB translation granule. The level of walk for the leaf level 0bxx is encoded as:

0b00 : Reserved. Treat as if TTL<3:2> is 0b00.

0b01 : Level 1.

0b10 : Level 2.

0b11 : Level 3.

0b10xx

The entry comes from a 16KB translation granule. The level of walk for the leaf level 0bxx is encoded as:

0b00 : Reserved. Treat as if TTL<3:2> is 0b00.

0b01 : Reserved. Treat as if TTL<3:2> is 0b00.

0b10 : Level 2.

0b11 : Level 3.

0b11xx

The entry comes from a 64KB translation granule. The level of walk for the leaf level 0bxx is encoded as:

0b00 : Reserved. Treat as if TTL<3:2> is 0b00.

0b01 : Level 1.

0b10 : Level 2.

0b11 : Level 3.

If an incorrect value of the TTL field is specified for the entry being invalidated by the instruction, then no entries are required by the architecture to be invalidated from the TLB.


Otherwise:

Reserved, RES0.

VA[55:12], bits [43:0]

Bits[55:12] of the virtual address to match. Any appropriate TLB entries that match the ASID value (if appropriate) and VA will be affected by this operation.

If the TLB maintenance instructions are targeting a translation regime that is using AArch32, and so has a VA of only 32 bits, then the software must treat bits[55:32] as RES0.

The treatment of the low-order bits of this field depends on the translation granule size, as follows:

  • Where a 4KB translation granule is being used, all bits are valid and used for the invalidation.

  • Where a 16KB translation granule is being used, bits [1:0] of this field are RES0 and ignored when the instruction is executed, because VA[13:12] have no effect on the operation of the instruction.

  • Where a 64KB translation granule is being used, bits [3:0] of this field are RES0 and ignored when the instruction is executed, because VA[15:12] have no effect on the operation of the instruction.

Executing the TLBI VALE2OS instruction

Accesses to this instruction use the following encodings:

TLBI VALE2OS{, <Xt>}

op0CRnop1op2CRm
0b010b10000b1000b1010b0001
if PSTATE.EL == EL0 then
    UNDEFINED;
elsif PSTATE.EL == EL1 then
    if EL2Enabled() && HCR_EL2.NV == '1' then
        AArch64.SystemAccessTrap(EL2, 0x18);
    else
        UNDEFINED;
elsif PSTATE.EL == EL2 then
    TLBI_VALE2OS(X[t]);
elsif PSTATE.EL == EL3 then
    if !EL2Enabled() then
        UNDEFINED;
    else
        TLBI_VALE2OS(X[t]);
              


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