CP15DMB

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CP15DMB, Data Memory Barrier System instruction

Purpose

Arm deprecates any use of this System instruction, and strongly recommends that software use the DMB instruction instead.

Configuration

This instruction is present only when FEAT_AA32 is implemented. Otherwise, direct accesses to CP15DMB are UNDEFINED.

Attributes

Field descriptions

Executing CP15DMB

Accesses to this instruction use the following encodings in the System instruction encoding space:

MCR{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}

coproc	opc1	CRn	CRm	opc2
0b1111	0b000	0b0111	0b1010	0b101

if !IsFeatureImplemented(FEAT_AA32) then Undefined(); elsif PSTATE.EL == EL0 then if IsFeatureImplemented(FEAT_AA64EL1) && !ELUsingAArch32(EL1) && !ELIsInHost(EL0) && SCTLR_EL1().CP15BEN == '0' then Undefined(); elsif ELIsInHost(EL0) && SCTLR_EL2().CP15BEN == '0' then Undefined(); elsif IsFeatureImplemented(FEAT_AA32EL1) && ELUsingAArch32(EL1) && SCTLR().CP15BEN == '0' then Undefined(); elsif EL2Enabled() && (IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2)) && !ELIsInHost(EL0) && HSTR_EL2().T7 == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && (IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2)) && HSTR().T7 == '1' then AArch32_TakeHypTrapException(0x03); else CP15DMB(); end; elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && HSTR_EL2().T7 == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HSTR().T7 == '1' then AArch32_TakeHypTrapException(0x03); elsif SCTLR().CP15BEN == '0' then Undefined(); else CP15DMB(); end; elsif PSTATE.EL == EL2 then if HSCTLR().CP15BEN == '0' then Undefined(); else CP15DMB(); end; elsif PSTATE.EL == EL3 then if SCTLR().CP15BEN == '0' then Undefined(); else CP15DMB(); end; end;