ICC_DIR_EL1

Access Instructions

There are two cases when writing to ICC_DIR_EL1 that were UNPREDICTABLE for a corresponding GICv2 write to GICC_DIR:

• When EOImode == 0. GICv3 implementations must ignore such writes. In systems supporting system error generation, an implementation might generate an SEI.
• When EOImode == 1 but no EOI has been issued. The interrupt will be deactivated by the Distributor, however the active priority in the CPU interface for the interrupt will remain set (because no EOI was issued).

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

(op0 = 0b11, op1 = 0b000, CRn = 0b1100, CRm = 0b1011, op2 = 0b001)

if !((IsFeatureImplemented(FEAT_GICv3) || IsFeatureImplemented(FEAT_GCIE_LEGACY)) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif HaveEL(EL3) && !(EffectivelyAtEL0InHost() || EffectivelyAtEL0NotInHost() || PSTATE.EL == EL3) && EL3SDDUndefPriority() && SCR_EL3().[IRQ,FIQ] == '11' then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if IsFeatureImplemented(FEAT_GCIE_LEGACY) && (ICH_VCTLR_EL2().V3 == '0' || !EL2Enabled() || !(ICH_HCR_EL2().TDIR == '1' || ICH_HCR_EL2().TC == '1' || HCR_EL2().FMO == '1' || HCR_EL2().IMO == '1')) then Undefined(); elsif ICC_SRE_EL1().SRE == '0' then AArch64_SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && ICH_HCR_EL2().TDIR == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && ICH_HCR_EL2().TC == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && HCR_EL2().FMO == '1' then ICV_DIR_EL1() = X{64}(t); elsif EL2Enabled() && HCR_EL2().IMO == '1' then ICV_DIR_EL1() = X{64}(t); elsif HaveEL(EL3) && SCR_EL3().[IRQ,FIQ] == '11' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else ICC_DIR_EL1() = X{64}(t); end; elsif PSTATE.EL == EL2 then if IsFeatureImplemented(FEAT_GCIE_LEGACY) then Undefined(); elsif ICC_SRE_EL2().SRE == '0' then AArch64_SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3().[IRQ,FIQ] == '11' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else ICC_DIR_EL1() = X{64}(t); end; elsif PSTATE.EL == EL3 then if IsFeatureImplemented(FEAT_GCIE_LEGACY) then Undefined(); elsif ICC_SRE_EL3().SRE == '0' then AArch64_SystemAccessTrap(EL3, 0x18); else ICC_DIR_EL1() = X{64}(t); end; end;