PMXEVCNTR_EL0

Access Instructions

If FEAT_FGT is implemented and PMSELR_EL0.SEL is greater than or equal to the number of accessible event counters, then the behavior of permitted reads and writes of PMXEVCNTR_EL0 is as follows:

• If PMSELR_EL0.SEL is greater than or equal to the Effective value of PMCCR.EPMN, the access is UNDEFINED.
• Otherwise, the access is trapped to EL2.

If FEAT_FGT is not implemented and PMSELR_EL0.SEL is greater than or equal to the number of accessible event counters, then reads and writes of PMXEVCNTR_EL0 are CONSTRAINED UNPREDICTABLE, and the following behaviors are permitted:

• Accesses to the register are UNDEFINED.
• Accesses to the register behave as RAZ/WI.
• Accesses to the register execute as a NOP
• Accesses to the register behave as if PMSELR_EL0.SEL has an UNKNOWN value less than the number of counters accessible at the current Exception level and Security state.
• If EL2 is implemented and enabled in the current Security state, and PMSELR_EL0.SEL is less than the number of implemented event counters, accesses from EL1 or permitted accesses from EL0 are trapped to EL2.

Permitted reads and writes of PMXEVCNTR_EL0 are RAZ/WI if all of the following are true:

• FEAT_PMUv3p9 is implemented.
• EL0 is the current Exception level.
• PMUSERENR_EL0.UEN is 1.
• PMUACR_EL1.P<UInt(PMSELR_EL0.SEL)> is 0.

Permitted writes of PMXEVCNTR_EL0 are ignored if all of the following are true:

• FEAT_PMUv3p9 is implemented.
• EL0 is the current Exception level.
• PMUSERENR_EL0.{UEN,ER} is {1,1}.

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

(op0 = 0b11, op1 = 0b011, CRn = 0b1001, CRm = 0b1101, op2 = 0b010)

if !(IsFeatureImplemented(FEAT_PMUv3) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif UInt(PMSELR_EL0().SEL) >= GetNumEventCountersSelfHosted() then if IsFeatureImplemented(FEAT_FGT) then Undefined(); else ConstrainUnpredictableProcedure(Unpredictable_PMUEVENTCOUNTER); end; elsif HaveEL(EL3) && PSTATE.EL != EL3 && EL3SDDUndefPriority() && MDCR_EL3().TPM == '1' then Undefined(); elsif PSTATE.EL == EL0 then if (IsFeatureImplemented(FEAT_PMUv3p9) && PMUSERENR_EL0().[UEN,ER,EN] == '000') || (!IsFeatureImplemented(FEAT_PMUv3p9) && PMUSERENR_EL0().[ER,EN] == '00') then AArch64_SystemAccessTraptoEL1orEL2(0x18); elsif EL2Enabled() && EffectivelyAtEL0NotInHost() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3().FGTEn == '1') && HDFGRTR_EL2().PMEVCNTRn_EL0 == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2().TPM == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && UInt(PMSELR_EL0().SEL) >= GetNumEventCountersAccessible() then if !IsFeatureImplemented(FEAT_FGT) then ConstrainUnpredictableProcedure(Unpredictable_PMUEVENTCOUNTER); else AArch64_SystemAccessTrap(EL2, 0x18); end; elsif HaveEL(EL3) && MDCR_EL3().TPM == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif IsFeatureImplemented(FEAT_PMUv3p9) && PMUSERENR_EL0().UEN == '1' && PMUACR_EL1()[UInt(PMSELR_EL0().SEL)] == '0' then X{64}(t) = Zeros{64}; else X{64}(t) = PMEVCNTR_EL0(UInt(PMSELR_EL0().SEL)); end; elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3().FGTEn == '1') && HDFGRTR_EL2().PMEVCNTRn_EL0 == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2().TPM == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && UInt(PMSELR_EL0().SEL) >= GetNumEventCountersAccessible() then if !IsFeatureImplemented(FEAT_FGT) then ConstrainUnpredictableProcedure(Unpredictable_PMUEVENTCOUNTER); else AArch64_SystemAccessTrap(EL2, 0x18); end; elsif HaveEL(EL3) && MDCR_EL3().TPM == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else X{64}(t) = PMEVCNTR_EL0(UInt(PMSELR_EL0().SEL)); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && MDCR_EL3().TPM == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else X{64}(t) = PMEVCNTR_EL0(UInt(PMSELR_EL0().SEL)); end; elsif PSTATE.EL == EL3 then X{64}(t) = PMEVCNTR_EL0(UInt(PMSELR_EL0().SEL)); end;

(op0 = 0b11, op1 = 0b011, CRn = 0b1001, CRm = 0b1101, op2 = 0b010)

if !(IsFeatureImplemented(FEAT_PMUv3) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif UInt(PMSELR_EL0().SEL) >= GetNumEventCountersSelfHosted() then if IsFeatureImplemented(FEAT_FGT) then Undefined(); else ConstrainUnpredictableProcedure(Unpredictable_PMUEVENTCOUNTER); end; elsif HaveEL(EL3) && PSTATE.EL != EL3 && EL3SDDUndefPriority() && MDCR_EL3().TPM == '1' then Undefined(); elsif PSTATE.EL == EL0 then if PMUSERENR_EL0().EN == '0' && (!IsFeatureImplemented(FEAT_PMUv3p9) || PMUSERENR_EL0().UEN == '0') then AArch64_SystemAccessTraptoEL1orEL2(0x18); elsif EL2Enabled() && EffectivelyAtEL0NotInHost() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3().FGTEn == '1') && HDFGWTR_EL2().PMEVCNTRn_EL0 == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2().TPM == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && UInt(PMSELR_EL0().SEL) >= GetNumEventCountersAccessible() then if !IsFeatureImplemented(FEAT_FGT) then ConstrainUnpredictableProcedure(Unpredictable_PMUEVENTCOUNTER); else AArch64_SystemAccessTrap(EL2, 0x18); end; elsif HaveEL(EL3) && MDCR_EL3().TPM == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif IsFeatureImplemented(FEAT_PMUv3p9) && PMUSERENR_EL0().UEN == '1' && (PMUACR_EL1()[UInt(PMSELR_EL0().SEL)] == '0' || PMUSERENR_EL0().ER == '1') then return; else PMEVCNTR_EL0(UInt(PMSELR_EL0().SEL)) = X{64}(t); end; elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3().FGTEn == '1') && HDFGWTR_EL2().PMEVCNTRn_EL0 == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2().TPM == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && UInt(PMSELR_EL0().SEL) >= GetNumEventCountersAccessible() then if !IsFeatureImplemented(FEAT_FGT) then ConstrainUnpredictableProcedure(Unpredictable_PMUEVENTCOUNTER); else AArch64_SystemAccessTrap(EL2, 0x18); end; elsif HaveEL(EL3) && MDCR_EL3().TPM == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else PMEVCNTR_EL0(UInt(PMSELR_EL0().SEL)) = X{64}(t); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && MDCR_EL3().TPM == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else PMEVCNTR_EL0(UInt(PMSELR_EL0().SEL)) = X{64}(t); end; elsif PSTATE.EL == EL3 then PMEVCNTR_EL0(UInt(PMSELR_EL0().SEL)) = X{64}(t); end;