The DC GVA characteristics are:
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 ARMv8.5-MemTag is implemented. Otherwise, direct accesses to DC GVA are UNDEFINED.
DC GVA is a 64-bit System instruction.
The DC GVA input value 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 |
Virtual address to use | |||||||||||||||||||||||||||||||
Virtual address to use | |||||||||||||||||||||||||||||||
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 |
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.
If the memory region being zeroed is any type of Device memory, this instruction can give an alignment fault which is prioritized in the same way as other alignment faults that are determined by the memory type.
This instruction applies to Normal memory regardless of cacheability attributes.
This instruction behaves as a set of Stores to each byte within the block being accessed, and so it:
Accesses to this instruction use the following encodings:
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b01 | 0b011 | 0b0111 | 0b0100 | 0b011 |
if PSTATE.EL == EL0 then if !ELUsingAArch32(EL1) && !(EL2Enabled() && HCR_EL2.<E2H,TGE> == '11') && SCTLR_EL1.DZE == '0' then if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.<E2H,TGE> != '11' && HCR_EL2.TDZ == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.<E2H,TGE> == '11' && SCTLR_EL2.DZE == '0' then AArch64.SystemAccessTrap(EL2, 0x18); else DC_GVA(X[t]); elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TDZ == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else DC_GVA(X[t]); elsif PSTATE.EL == EL2 then DC_GVA(X[t]); elsif PSTATE.EL == EL3 then DC_GVA(X[t]);
27/03/2019 21:59; e5e4db499bf9867a4b93324c4dbac985d3da9376
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