Write a value to the Allocation Tags of a naturally aligned block of N bytes, where the size of N is identified in DCZID_EL0. The Allocation Tag used is determined by the input address.
This instruction is present only when FEAT_MTE is implemented. Otherwise, direct accesses to DC GVA are UNDEFINED.
DC GVA is a 64-bit System instruction.
| 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 |
| 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 |
| VA | |||||||||||||||||||||||||||||||
| VA | |||||||||||||||||||||||||||||||
Virtual address to use. There is no alignment restriction on the address within the block of N bytes that is used.
When this instruction is executed, it can generate memory faults or watchpoints which are prioritized in the same way as other memory-related faults or watchpoints. If a synchronous Data Abort fault or a watchpoint is generated, the CM bit in the ESR_ELx.ISS field is not set.
A DC GVA instruction to any type of Device memory is CONSTRAINED UNPREDICTABLE between:
This instruction applies to Normal memory regardless of cacheability attributes.
This instruction behaves as a set of stores to each Allocation Tag within the block being accessed, and so it:
Accesses to this instruction use the following encodings in the System instruction encoding space:
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b01 | 0b011 | 0b0111 | 0b0100 | 0b011 |
if !IsFeatureImplemented(FEAT_MTE) then UNDEFINED; elsif PSTATE.EL == EL0 then if !ELIsInHost(EL0) && SCTLR_EL1.DZE == '0' then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && !ELIsInHost(EL0) && HCR_EL2.TDZ == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && !ELIsInHost(EL0) && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGITR_EL2.DCZVA == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif ELIsInHost(EL0) && SCTLR_EL2.DZE == '0' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.MemZero(X[t, 64], CacheType_Tag); elsif PSTATE.EL == EL1 then if EL2Enabled() && HCR_EL2.TDZ == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGITR_EL2.DCZVA == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.MemZero(X[t, 64], CacheType_Tag); elsif PSTATE.EL == EL2 then AArch64.MemZero(X[t, 64], CacheType_Tag); elsif PSTATE.EL == EL3 then AArch64.MemZero(X[t, 64], CacheType_Tag);