ACTLRMASK_EL1, Auxiliary Control Masking Register (EL1)

The ACTLRMASK_EL1 characteristics are:

Purpose

Mask register to prevent updates of fields in ACTLR_EL1 on writes to ACTLR_EL1 or ACTLRALIAS_EL1.

Configuration

This register is present only when FEAT_SRMASK is implemented. Otherwise, direct accesses to ACTLRMASK_EL1 are UNDEFINED.

Attributes

ACTLRMASK_EL1 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
IMPLEMENTATION DEFINED
IMPLEMENTATION DEFINED

IMPLEMENTATION DEFINED, bits [63:0]

IMPLEMENTATION DEFINED.

Accessing ACTLRMASK_EL1

When the Effective value of HCR_EL2.E2H is 1, without explicit synchronization, accesses from EL3 using the accessor name ACTLRMASK_EL1 or ACTLRMASK_EL12 are not guaranteed to be ordered with respect to accesses using the other accessor name.

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

MRS <Xt>, ACTLRMASK_EL1

op0op1CRnCRmop2
0b110b0000b00010b01000b001

if !IsFeatureImplemented(FEAT_SRMASK) then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.SRMASKEn == '0' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT2) && ((HaveEL(EL3) && SCR_EL3.FGTEn2 == '0') || HFGRTR2_EL2.nACTLRMASK_EL1 == '0') then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && (!IsHCRXEL2Enabled() || HCRX_EL2.SRMASKEn == '0') then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.SRMASKEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif EffectiveHCR_EL2_NVx() IN {'1x1'} && (!boolean IMPLEMENTATION_DEFINED "IMPLEMENTED_ACTLR_ELx accessor behavior" || EffectiveHCR_EL2_NVx() == '111') then X[t, 64] = NVMem[0x340]; else X[t, 64] = ACTLRMASK_EL1; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.SRMASKEn == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.SRMASKEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif boolean IMPLEMENTATION_DEFINED "IMPLEMENTED_ACTLR_ELx accessor behavior" && ELIsInHost(EL2) then X[t, 64] = ACTLRMASK_EL2; else X[t, 64] = ACTLRMASK_EL1; elsif PSTATE.EL == EL3 then X[t, 64] = ACTLRMASK_EL1;

MSR ACTLRMASK_EL1, <Xt>

op0op1CRnCRmop2
0b110b0000b00010b01000b001

if !IsFeatureImplemented(FEAT_SRMASK) then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.SRMASKEn == '0' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT2) && ((HaveEL(EL3) && SCR_EL3.FGTEn2 == '0') || HFGWTR2_EL2.nACTLRMASK_EL1 == '0') then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && (!IsHCRXEL2Enabled() || HCRX_EL2.SRMASKEn == '0') then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.SRMASKEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif EffectiveHCR_EL2_NVx() IN {'1x1'} && (!boolean IMPLEMENTATION_DEFINED "IMPLEMENTED_ACTLR_ELx accessor behavior" || EffectiveHCR_EL2_NVx() == '111') then X[t, 64] = NVMem[0x340]; elsif !IsZero(EffectiveACTLRMASK_EL1()) then UNDEFINED; else ACTLRMASK_EL1 = X[t, 64]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.SRMASKEn == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.SRMASKEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif boolean IMPLEMENTATION_DEFINED "IMPLEMENTED_ACTLR_ELx accessor behavior" && ELIsInHost(EL2) then if !IsZero(EffectiveACTLRMASK_EL2()) then UNDEFINED; else ACTLRMASK_EL2 = X[t, 64]; else ACTLRMASK_EL1 = X[t, 64]; elsif PSTATE.EL == EL3 then ACTLRMASK_EL1 = X[t, 64];

When an implementation implements ACTLR_ELx accessor behavior

MRS <Xt>, ACTLRMASK_EL12

op0op1CRnCRmop2
0b110b1010b00010b01000b001

if !IsFeatureImplemented(FEAT_SRMASK) then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() == '101' then X[t, 64] = NVMem[0x340]; elsif EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if ELIsInHost(EL2) then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.SRMASKEn == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.SRMASKEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = ACTLRMASK_EL1; else UNDEFINED; elsif PSTATE.EL == EL3 then if ELIsInHost(EL2) then X[t, 64] = ACTLRMASK_EL1; else UNDEFINED;

When an implementation implements ACTLR_ELx accessor behavior

MSR ACTLRMASK_EL12, <Xt>

op0op1CRnCRmop2
0b110b1010b00010b01000b001

if !IsFeatureImplemented(FEAT_SRMASK) then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() == '101' then NVMem[0x340] = X[t, 64]; elsif EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if ELIsInHost(EL2) then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.SRMASKEn == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.SRMASKEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else ACTLRMASK_EL1 = X[t, 64]; else UNDEFINED; elsif PSTATE.EL == EL3 then if ELIsInHost(EL2) then ACTLRMASK_EL1 = X[t, 64]; else UNDEFINED;


15/12/2024 22:27; 5e0a212688c6bd7aee92394b6f5e491b4d0fee1d

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