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SPMSCR_EL1: System Performance Monitors Secure Control Register

Purpose

Controls observability of Secure events by System PMU <s>, and optionally controls Secure attributes for message signaled interrupts and Non-secure access to the performance monitor registers.

Configuration

This register is present only when Secure EL1 is implemented and FEAT_SPMU is implemented. Otherwise, direct accesses to SPMSCR_EL1 are UNDEFINED.

Attributes

SPMSCR_EL1 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
IMPLEMENTATION DEFINED
RAORES0NAORES0SO

IMPLEMENTATION DEFINED, bits [63:32]

IMPLEMENTATION DEFINED observation controls. Additional IMPLEMENTATION DEFINED bits to control certain types of filter or events by System PMU <s>.

The reset behavior of this field is:

Bit [31]

Reserved, RAO.

Indicates SPMSCR_EL1 is implemented by System PMU <s>.

This field reads-as-one.

Bits [30:5]

Reserved, RES0.

NAO, bit [4]

When System PMU <s> can count or monitor non-attributable events:

Non-attributable Observation. Controls whether events or monitorable characteristics not attributable with any source can be monitored by System PMU <s>.

NAOMeaning
0b0

Events not attributable with any event source are not counted by System PMU <s>, unless overridden by SPMSCR_EL1.SO.

0b1

Counting non-attributable events by System PMU <s> is not prevented by this mechanism.

When both SPMROOTCR_EL3 and SPMSCR_EL1 are implemented, non-attributable events are counted only if both SPMROOTCR_EL3.NAO is 1 and SPMSCR_EL1.{NAO, SO} is nonzero.

SPMSCR_EL1.NAO has the opposite reset polarity to SPMROOTCR_EL3.NAO.

This field is optional if Root and Realm states are not implemented. When this field is not implemented, System PMU <s> behaves as if SPMSCR_EL1.NAO is 0, and whether events or monitorable characteristics not attributable with any source can be monitored is controlled by SPMSCR_EL1.SO.

The reset behavior of this field is:



Otherwise:

Reserved, RES0.

Bits [3:1]

Reserved, RES0.

SO, bit [0]

Secure Observation. Controls whether events or monitorable characteristics attributable to a Secure event source can be monitored by System PMU <s>.

SOMeaning
0b0

Events attributable to a Secure event source are not counted by System PMU <s>.

0b1

Counting events by System PMU <s> that are attributable to a Secure event source is not prevented by this mechanism.

Also controls whether events or monitorable characteristics not attributable with any source can be monitored by System PMU <s>. See SPMSCR_EL1.NAO.

The reset behavior of this field is:

Accessing SPMSCR_EL1

To access SPMSCR_EL1 for System PMU <s>, set SPMSELR_EL0.SYSPMUSEL to s.

SPMSCR_EL1 reads-as-zero and ignores writes if any of the following are true:

SPMSCR_EL1 is UNDEFINED if accessed in Non-secure or Realm state.

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

MRS <Xt>, SPMSCR_EL1

op0op1CRnCRmop2
0b100b1110b10010b11100b111

if IsCurrentSecurityState(SS_NonSecure) || (IsFeatureImplemented(FEAT_RME) && IsCurrentSecurityState(SS_Realm)) then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.EnPM2 == '0' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && SPMACCESSR_EL3<(UInt(SPMSELR_EL0.SYSPMUSEL) * 2) + 1:UInt(SPMSELR_EL0.SYSPMUSEL) * 2> == '00' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT2) && ((HaveEL(EL3) && SCR_EL3.FGTEn2 == '0') || HDFGRTR2_EL2.nSPMSCR_EL1 == '0') then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2.EnSPM == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && SPMACCESSR_EL2<(UInt(SPMSELR_EL0.SYSPMUSEL) * 2) + 1:UInt(SPMSELR_EL0.SYSPMUSEL) * 2> == '00' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3.EnPM2 == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif HaveEL(EL3) && SPMACCESSR_EL3<(UInt(SPMSELR_EL0.SYSPMUSEL) * 2) + 1:UInt(SPMSELR_EL0.SYSPMUSEL) * 2> == '00' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = SPMSCR_EL1[UInt(SPMSELR_EL0.SYSPMUSEL)]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.EnPM2 == '0' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && SPMACCESSR_EL3<(UInt(SPMSELR_EL0.SYSPMUSEL) * 2) + 1:UInt(SPMSELR_EL0.SYSPMUSEL) * 2> == '00' then UNDEFINED; elsif HaveEL(EL3) && MDCR_EL3.EnPM2 == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif HaveEL(EL3) && SPMACCESSR_EL3<(UInt(SPMSELR_EL0.SYSPMUSEL) * 2) + 1:UInt(SPMSELR_EL0.SYSPMUSEL) * 2> == '00' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = SPMSCR_EL1[UInt(SPMSELR_EL0.SYSPMUSEL)]; elsif PSTATE.EL == EL3 then X[t, 64] = SPMSCR_EL1[UInt(SPMSELR_EL0.SYSPMUSEL)];

MSR SPMSCR_EL1, <Xt>

op0op1CRnCRmop2
0b100b1110b10010b11100b111

if IsCurrentSecurityState(SS_NonSecure) || (IsFeatureImplemented(FEAT_RME) && IsCurrentSecurityState(SS_Realm)) then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.EnPM2 == '0' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && SPMACCESSR_EL3<(UInt(SPMSELR_EL0.SYSPMUSEL) * 2) + 1:UInt(SPMSELR_EL0.SYSPMUSEL) * 2> != '11' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT2) && ((HaveEL(EL3) && SCR_EL3.FGTEn2 == '0') || HDFGWTR2_EL2.nSPMSCR_EL1 == '0') then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2.EnSPM == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && SPMACCESSR_EL2<(UInt(SPMSELR_EL0.SYSPMUSEL) * 2) + 1:UInt(SPMSELR_EL0.SYSPMUSEL) * 2> != '11' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3.EnPM2 == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif HaveEL(EL3) && SPMACCESSR_EL3<(UInt(SPMSELR_EL0.SYSPMUSEL) * 2) + 1:UInt(SPMSELR_EL0.SYSPMUSEL) * 2> != '11' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else SPMSCR_EL1[UInt(SPMSELR_EL0.SYSPMUSEL)] = X[t, 64]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.EnPM2 == '0' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && SPMACCESSR_EL3<(UInt(SPMSELR_EL0.SYSPMUSEL) * 2) + 1:UInt(SPMSELR_EL0.SYSPMUSEL) * 2> != '11' then UNDEFINED; elsif HaveEL(EL3) && MDCR_EL3.EnPM2 == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif HaveEL(EL3) && SPMACCESSR_EL3<(UInt(SPMSELR_EL0.SYSPMUSEL) * 2) + 1:UInt(SPMSELR_EL0.SYSPMUSEL) * 2> != '11' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else SPMSCR_EL1[UInt(SPMSELR_EL0.SYSPMUSEL)] = X[t, 64]; elsif PSTATE.EL == EL3 then SPMSCR_EL1[UInt(SPMSELR_EL0.SYSPMUSEL)] = X[t, 64];