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PMEVTYPER<n>, Performance Monitors Event Type Registers, n = 0 - 30

The PMEVTYPER<n> characteristics are:

Purpose

Configures event counter n, where n is 0 to 30.

Configuration

AArch32 System register PMEVTYPER<n> bits [31:0] are architecturally mapped to AArch64 System register PMEVTYPER<n>_EL0[31:0] .

AArch32 System register PMEVTYPER<n> bits [31:0] are architecturally mapped to External register PMEVTYPER<n>_EL0[31:0] .

This register is in the Warm reset domain. On a Warm or Cold reset RW fields in this register reset to architecturally UNKNOWN values.

Attributes

PMEVTYPER<n> is a 32-bit register.

Field descriptions

The PMEVTYPER<n> bit assignments are:

313029282726252423222120191817161514131211109876543210
PUNSKNSUNSHRES0MTRES0evtCount[15:10]evtCount[9:0]

P, bit [31]

Privileged filtering bit. Controls counting in EL1. If EL3 is implemented, then counting in Non-secure EL1 is further controlled by the NSK bit. The possible values of this bit are:

PMeaning
0b0

Count events in EL1.

0b1

Do not count events in EL1.

On a Warm reset, this field resets to an architecturally UNKNOWN value.

U, bit [30]

User filtering bit. Controls counting in EL0. If EL3 is implemented, then counting in Non-secure EL0 is further controlled by the NSU bit. The possible values of this bit are:

UMeaning
0b0

Count events in EL0.

0b1

Do not count events in EL0.

On a Warm reset, this field resets to an architecturally UNKNOWN value.

NSK, bit [29]

Non-secure EL1 (kernel) modes filtering bit. Controls counting in Non-secure EL1. If EL3 is not implemented, this bit is RES0.

If the value of this bit is equal to the value of P, events in Non-secure EL1 are counted.

Otherwise, events in Non-secure EL1 are not counted.

On a Warm reset, this field resets to an architecturally UNKNOWN value.

NSU, bit [28]

Non-secure EL0 (Unprivileged) filtering. Controls counting in Non-secure EL0. If EL3 is not implemented, this bit is RES0.

If the value of this bit is equal to the value of U, events in Non-secure EL0 are counted.

Otherwise, events in Non-secure EL0 are not counted.

On a Warm reset, this field resets to an architecturally UNKNOWN value.

NSH, bit [27]

Non-secure EL2 (Hyp mode) filtering bit. Controls counting in Non-secure EL2. If EL2 is not implemented, this bit is RES0.

NSHMeaning
0b0

Do not count events in EL2.

0b1

Count events in EL2.

On a Warm reset, this field resets to an architecturally UNKNOWN value.

Bit [26]

Reserved, RES0.

MT, bit [25]

Multithreading. When the implementation is multi-threaded, the valid values for this bit are:

MTMeaning
0b0

Count events only on controlling PE.

0b1

Count events from any PE with the same affinity at level 1 and above as this PE.

When the implementation is not multi-threaded, this bit is RES0.

Note
  • When the lowest level of affinity consists of logical PEs that are implemented using a multi-threading type approach, an implementation is described as multi-threaded. That is, the performance of PEs at the lowest affinity level is highly interdependent. On such an implementation, when read at the highest implemented Exception level, the value of MPIDR_EL1.MT is 1.
  • Events from a different thread of a multithreaded implementation are not Attributable to the thread counting the event.

On a Warm reset, this field resets to an architecturally UNKNOWN value.

Bits [24:16]

Reserved, RES0.

evtCount[15:10], bits [15:10]

From Armv8.1:

Extension to evtCount[9:0]. See evtCount[9:0] for more details.


Otherwise:

Reserved, RES0.

evtCount[9:0], bits [9:0]

Event to count. The event number of the event that is counted by event counter PMEVCNTR<n>.

Software must program this field with an event that is supported by the PE being programmed.

There are three types of event:

  • Common architectural and microarchitectural events.
  • Arm recommended common architectural and microarchitectural events.
  • IMPLEMENTATION DEFINED events.

The ranges of event numbers allocated to each type of event are shown in Allocation of the PMU event number space.

If evtCount is programmed to an event that is reserved or not supported by the PE, the behavior depends on the event type:

  • For the range 0x000 to 0x03F, no events are counted, and the value returned by a direct or external read of the evtCount field is the value written to the field.
  • For IMPLEMENTATION DEFINED events, it is UNPREDICTABLE what event, if any, is counted, and the value returned by a direct or external read of the evtCount field is UNKNOWN.
Note

UNPREDICTABLE means the event must not expose privileged information.

Arm recommends that the behavior across a family of implementations is defined such that if a given implementation does not include an event from a set of common IMPLEMENTATION DEFINED events, then no event is counted and the value read back on evtCount is the value written.

On a Warm reset, this field resets to an architecturally UNKNOWN value.

Accessing the PMEVTYPER<n>

PMEVTYPER<n> can also be accessed by using PMXEVTYPER with PMSELR.SEL set to n.

If <n> is greater or equal to the number of accessible counters, reads and writes of PMEVTYPER<n> 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.
  • If EL2 is implemented and enabled in the current Security state, and <n> is less than the number of implemented counters, accesses from EL1 or permitted accesses from EL0 are trapped to EL2.
Note

In EL0, an access is permitted if it is enabled by PMUSERENR.EN or PMUSERENR_EL0.EN.

If EL2 is implemented and enabled in the current Security state, at EL0 and EL1:

  • If EL2 is using AArch32, HDCR.HPMN identifies the number of accessible counters.
  • If EL2 is using AArch64, MDCR_EL2.HPMN identifies the number of accessible counters.

Otherwise, the number of accessible counters is the number of implemented counters. See HDCR.HPMN and MDCR_EL2.HPMN for more details.

Accesses to this register use the following encodings:

MRC{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}

coprocopc1CRnCRmopc2
0b11110b0000b11100b11[n:4:3]0b[n:2:0]
if PSTATE.EL == EL0 then
    if !ELUsingAArch32(EL1) && PMUSERENR_EL0.EN == '0' then
        if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TGE == '1' then
            AArch64.AArch32SystemAccessTrap(EL2, 0x03);
        else
            AArch64.AArch32SystemAccessTrap(EL1, 0x03);
    elsif ELUsingAArch32(EL1) && PMUSERENR.EN == '0' then
        if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TGE == '1' then
            AArch64.AArch32SystemAccessTrap(EL2, 0x03);
        elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.TGE == '1' then
            AArch32.TakeHypTrapException(0x00);
        else
            UNDEFINED;
    elsif EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.TPM == '1' then
        AArch64.AArch32SystemAccessTrap(EL2, 0x03);
    elsif EL2Enabled() && ELUsingAArch32(EL2) && HDCR.TPM == '1' then
        AArch32.TakeHypTrapException(0x03);
    elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then
        AArch64.AArch32SystemAccessTrap(EL3, 0x03);
    else
        return PMEVTYPER[UInt(CRm<1:0>:opc2<2:0>)];
elsif PSTATE.EL == EL1 then
    if EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.TPM == '1' then
        AArch64.AArch32SystemAccessTrap(EL2, 0x03);
    elsif EL2Enabled() && ELUsingAArch32(EL2) && HDCR.TPM == '1' then
        AArch32.TakeHypTrapException(0x03);
    elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then
        AArch64.AArch32SystemAccessTrap(EL3, 0x03);
    else
        return PMEVTYPER[UInt(CRm<1:0>:opc2<2:0>)];
elsif PSTATE.EL == EL2 then
    if HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then
        AArch64.AArch32SystemAccessTrap(EL3, 0x03);
    else
        return PMEVTYPER[UInt(CRm<1:0>:opc2<2:0>)];
elsif PSTATE.EL == EL3 then
    return PMEVTYPER[UInt(CRm<1:0>:opc2<2:0>)];
              

MCR{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}

coprocopc1CRnCRmopc2
0b11110b0000b11100b11[n:4:3]0b[n:2:0]
if PSTATE.EL == EL0 then
    if !ELUsingAArch32(EL1) && PMUSERENR_EL0.EN == '0' then
        if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TGE == '1' then
            AArch64.AArch32SystemAccessTrap(EL2, 0x03);
        else
            AArch64.AArch32SystemAccessTrap(EL1, 0x03);
    elsif ELUsingAArch32(EL1) && PMUSERENR.EN == '0' then
        if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TGE == '1' then
            AArch64.AArch32SystemAccessTrap(EL2, 0x03);
        elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.TGE == '1' then
            AArch32.TakeHypTrapException(0x00);
        else
            UNDEFINED;
    elsif EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.TPM == '1' then
        AArch64.AArch32SystemAccessTrap(EL2, 0x03);
    elsif EL2Enabled() && ELUsingAArch32(EL2) && HDCR.TPM == '1' then
        AArch32.TakeHypTrapException(0x03);
    elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then
        AArch64.AArch32SystemAccessTrap(EL3, 0x03);
    else
        PMEVTYPER[UInt(CRm<1:0>:opc2<2:0>)] = R[t];
elsif PSTATE.EL == EL1 then
    if EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.TPM == '1' then
        AArch64.AArch32SystemAccessTrap(EL2, 0x03);
    elsif EL2Enabled() && ELUsingAArch32(EL2) && HDCR.TPM == '1' then
        AArch32.TakeHypTrapException(0x03);
    elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then
        AArch64.AArch32SystemAccessTrap(EL3, 0x03);
    else
        PMEVTYPER[UInt(CRm<1:0>:opc2<2:0>)] = R[t];
elsif PSTATE.EL == EL2 then
    if HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then
        AArch64.AArch32SystemAccessTrap(EL3, 0x03);
    else
        PMEVTYPER[UInt(CRm<1:0>:opc2<2:0>)] = R[t];
elsif PSTATE.EL == EL3 then
    PMEVTYPER[UInt(CRm<1:0>:opc2<2:0>)] = R[t];
              


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