You copied the Doc URL to your clipboard.

PMSCR_EL2, Statistical Profiling Control Register (EL2)

The PMSCR_EL2 characteristics are:

Purpose

Provides EL2 controls for Statistical Profiling

Configuration

This register is present only when SPE is implemented. Otherwise, direct accesses to PMSCR_EL2 are UNDEFINED.

RW fields in this register reset to architecturally UNKNOWN values.

Attributes

PMSCR_EL2 is a 64-bit register.

Field descriptions

The PMSCR_EL2 bit assignments are:

6362616059585756555453525150494847464544434241403938373635343332
RES0
RES0PCTTSPACXRES0E2SPEE0HSPE
313029282726252423222120191817161514131211109876543210

Bits [63:8]

Reserved, RES0.

PCT, bits [7:6]

Physical Timestamp. If timestamp sampling is enabled, determines which counter is collected. The behavior depends on the Profiling Buffer owning Exception level.

If ARMv8.6-ECV is implemented, this is a two bit field as shown. Otherwise, bit[7] is RES0.

PCTMeaningApplies when
0b00

Virtual counter, CNTVCT_EL0, is collected.

0b01

If the Profiling Buffer owning Exception level is EL2: Physical counter, CNTPCT_EL0, is collected.

If the Profiling Buffer owning Exception level is EL1: Timestamp value is selected by PMSCR_EL1.PCT.

0b11

If the Profiling Buffer owning Exception level is EL2: Physical counter, CNTPCT_EL0, minus CNTPOFF_EL2 is collected.

If the Profiling Buffer owning Exception level is EL1: If PMSCR_EL1.PCT == 0b00, the virtual counter, CNTVCT_EL0 is collected. Otherwise, the physical counter, CNTPCT_EL0, minus CNTPOFF_EL2 is collected.

When ARMv8.6-ECV is implemented

When EL2 is implemented and enabled in the current Security state, the physical counter uses a fixed physical offset of zero if either of the following are true:

If EL2 is not implemented or EL2 is disabled in the current Security state, the PE behaves as if this field is set to 0b01, other than for a direct read of the register.

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

TS, bit [5]

Timestamp Enable.

TSMeaning
0b0

Timestamp sampling disabled.

0b1

Timestamp sampling enabled.

This bit is ignored by the PE when any of the following are true:

  • The Profiling Buffer owning Exception level is EL1.

  • In Secure state, and either ARMv8.4-SecEL2 is not implemented or Secure EL2 is disabled.

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

PA, bit [4]

Physical Address Sample Enable.

PAMeaning
0b0

Physical addresses are not collected.

0b1

Physical addresses are collected.

If the Profiling Buffer owning Exception level is EL1, and EL2 is enabled in the current Security state, this bit is combined with PMSCR_EL1.PA to determine which address is collected.

If EL2 is not implemented or EL2 is disabled in the current Security state, the PE ignores the value of this bit and behaves as if this bit is set to 1, other than for a direct read of the register.

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

CX, bit [3]

CONTEXTIDR_EL2 Sample Enable.

CXMeaning
0b0

CONTEXTIDR_EL2 is not collected.

0b1

CONTEXTIDR_EL2 is collected.

If EL2 is not implemented or EL2 is disabled in the current Security state, the PE ignores the value of this bit.

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

Bit [2]

Reserved, RES0.

E2SPE, bit [1]

EL2 Statistical Profiling Enable.

E2SPEMeaning
0b0

Sampling disabled at EL2.

0b1

Sampling enabled at EL2.

This bit is RES0 if MDCR_EL2.E2PB != 0b00.

If EL2 is disabled in the current Security state, this bit is ignored by the PE.

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

E0HSPE, bit [0]

EL0 Statistical Profiling Enable.

E0HSPEMeaning
0b0

Sampling disabled at EL0.

0b1

Sampling enabled at EL0.

If MDCR_EL2.E2PB != 0b00, this bit is RES0.

If EL2 is implemented and enabled in the current Security state, this bit is ignored by the PE when HCR_EL2.TGE == 0.

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

Accessing the PMSCR_EL2

Accesses to this register use the following encodings:

MRS <Xt>, PMSCR_EL2

op0op1CRnCRmop2
0b110b1000b10010b10010b000
if PSTATE.EL == EL0 then
    UNDEFINED;
elsif PSTATE.EL == EL1 then
    if EL2Enabled() && HCR_EL2.NV == '1' then
        AArch64.SystemAccessTrap(EL2, 0x18);
    else
        UNDEFINED;
elsif PSTATE.EL == EL2 then
    if HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.NS == '0' && MDCR_EL3.NSPB != '01' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.NS == '1' && MDCR_EL3.NSPB != '11' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    else
        return PMSCR_EL2;
elsif PSTATE.EL == EL3 then
    return PMSCR_EL2;
              

MSR PMSCR_EL2, <Xt>

op0op1CRnCRmop2
0b110b1000b10010b10010b000
if PSTATE.EL == EL0 then
    UNDEFINED;
elsif PSTATE.EL == EL1 then
    if EL2Enabled() && HCR_EL2.NV == '1' then
        AArch64.SystemAccessTrap(EL2, 0x18);
    else
        UNDEFINED;
elsif PSTATE.EL == EL2 then
    if HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.NS == '0' && MDCR_EL3.NSPB != '01' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.NS == '1' && MDCR_EL3.NSPB != '11' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    else
        PMSCR_EL2 = X[t];
elsif PSTATE.EL == EL3 then
    PMSCR_EL2 = X[t];
              

MRS <Xt>, PMSCR_EL1

op0op1CRnCRmop2
0b110b0000b10010b10010b000
if PSTATE.EL == EL0 then
    UNDEFINED;
elsif PSTATE.EL == EL1 then
    if EL2Enabled() && !ELUsingAArch32(EL2) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGRTR_EL2.PMSCR_EL1 == '1' then
        AArch64.SystemAccessTrap(EL2, 0x18);
    elsif EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.TPMS == '1' then
        AArch64.SystemAccessTrap(EL2, 0x18);
    elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.NS == '0' && MDCR_EL3.NSPB != '01' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.NS == '1' && MDCR_EL3.NSPB != '11' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.<NV2,NV1,NV> == '111' then
        return NVMem[0x828];
    else
        return PMSCR_EL1;
elsif PSTATE.EL == EL2 then
    if HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.NS == '0' && MDCR_EL3.NSPB != '01' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.NS == '1' && MDCR_EL3.NSPB != '11' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    elsif HCR_EL2.E2H == '1' then
        return PMSCR_EL2;
    else
        return PMSCR_EL1;
elsif PSTATE.EL == EL3 then
    return PMSCR_EL1;
              

MSR PMSCR_EL1, <Xt>

op0op1CRnCRmop2
0b110b0000b10010b10010b000
if PSTATE.EL == EL0 then
    UNDEFINED;
elsif PSTATE.EL == EL1 then
    if EL2Enabled() && !ELUsingAArch32(EL2) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGWTR_EL2.PMSCR_EL1 == '1' then
        AArch64.SystemAccessTrap(EL2, 0x18);
    elsif EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.TPMS == '1' then
        AArch64.SystemAccessTrap(EL2, 0x18);
    elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.NS == '0' && MDCR_EL3.NSPB != '01' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.NS == '1' && MDCR_EL3.NSPB != '11' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.<NV2,NV1,NV> == '111' then
        NVMem[0x828] = X[t];
    else
        PMSCR_EL1 = X[t];
elsif PSTATE.EL == EL2 then
    if HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.NS == '0' && MDCR_EL3.NSPB != '01' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.NS == '1' && MDCR_EL3.NSPB != '11' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    elsif HCR_EL2.E2H == '1' then
        PMSCR_EL2 = X[t];
    else
        PMSCR_EL1 = X[t];
elsif PSTATE.EL == EL3 then
    PMSCR_EL1 = X[t];
              


Was this page helpful? Yes No