The CP15DMB characteristics are:
Performs a Data Memory Barrier.
Arm deprecates any use of this System instruction, and strongly recommends that software use the DMB instruction instead.
This instruction is present only when AArch32 is supported at any Exception level. Otherwise, direct accesses to CP15DMB are UNKNOWN.
CP15DMB is a 32-bit System instruction.
CP15DMB ignores the value in the register specified by the instruction encoding. Software does not have to write a value to the register before issuing this instruction.
Accesses to this instruction use the following encodings:
coproc | opc1 | CRn | CRm | opc2 |
---|---|---|---|---|
0b1111 | 0b000 | 0b0111 | 0b1010 | 0b101 |
if PSTATE.EL == EL0 then if !ELUsingAArch32(EL1) && !(EL2Enabled() && HCR_EL2.<E2H,TGE> == '11') && SCTLR_EL1.CP15BEN == '0' then UNDEFINED; elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.<E2H,TGE> == '11' && SCTLR_EL2.CP15BEN == '0' then UNDEFINED; elsif ELUsingAArch32(EL1) && SCTLR.CP15BEN == '0' then UNDEFINED; elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.<E2H,TGE> != '11' && HSTR_EL2.T7 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T7 == '1' then AArch32.TakeHypTrapException(0x03); else CP15DMB(); elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T7 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T7 == '1' then AArch32.TakeHypTrapException(0x03); elsif ELUsingAArch32(EL1) && SCTLR.CP15BEN == '0' then UNDEFINED; else CP15DMB(); elsif PSTATE.EL == EL2 then if HSCTLR.CP15BEN == '0' then UNDEFINED; else CP15DMB(); elsif PSTATE.EL == EL3 then CP15DMB();
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