DCCISW, Data Cache line Clean and Invalidate by Set/Way

The DCCISW characteristics are:

Purpose

Clean and Invalidate data or unified cache line by set/way.

Configuration

AArch32 System instruction DCCISW performs the same function as AArch64 System instruction DC CISW.

Attributes

DCCISW is a 32-bit System instruction.

Field descriptions

The DCCISW input value bit assignments are:

313029282726252423222120191817161514131211109876543210
SetWayLevel0

SetWay, bits [31:4]

Contains two fields:

Bits[L-1:4] are RES0.

A = Log2(ASSOCIATIVITY), L = Log2(LINELEN), B = (L + S), S = Log2(NSETS).

ASSOCIATIVITY, LINELEN (line length, in bytes), and NSETS (number of sets) have their usual meanings and are the values for the cache level being operated on. The values of A and S are rounded up to the next integer.

Level, bits [3:1]

Cache level to operate on, minus 1. For example, this field is 0 for operations on L1 cache, or 1 for operations on L2 cache.

Bit [0]

Reserved, RES0.

Executing the DCCISW instruction

If this instruction is executed with a set, way or level argument that is larger than the value supported by the implementation then the behavior is CONSTRAINED UNPREDICTABLE and one of the following occurs:

Accesses to this instruction use the following encodings:

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

opc1opc2CRncoprocCRm
0b0000b0100b01110b11110b1110

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T7 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T7 == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TSW == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR.TSW == '1' then AArch32.TakeHypTrapException(0x03); else DCCISW(R[t]); elsif PSTATE.EL == EL2 then DCCISW(R[t]); elsif PSTATE.EL == EL3 then DCCISW(R[t]);




13/12/2018 16:42; 6379d01c197f1d40720d32d0f84c419c9187c009

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