LORID_EL1, LORegionID (EL1)

The LORID_EL1 characteristics are:

Purpose

Indicates the number of LORegions and LORegion descriptors supported by the PE.

Configuration

This register is present only when FEAT_LOR is implemented. Otherwise, direct accesses to LORID_EL1 are UNDEFINED.

If no LORegion descriptors are implemented, then the registers LORC_EL1, LORN_EL1, LOREA_EL1, and LORSA_EL1 are RES0.

Attributes

LORID_EL1 is a 64-bit register.

Field descriptions

The LORID_EL1 bit assignments are:

6362616059585756555453525150494847464544434241403938373635343332
RES0
RES0LDRES0LR
313029282726252423222120191817161514131211109876543210

Bits [63:24]

Reserved, RES0.

LD, bits [23:16]

Number of LORegion descriptors supported by the PE. This is an 8-bit binary number.

Bits [15:8]

Reserved, RES0.

LR, bits [7:0]

Number of LORegions supported by the PE. This is an 8-bit binary number.

Note

If LORID_EL1 indicates that no LORegions are implemented, then LoadLOAcquire and StoreLORelease will behave as LoadAcquire and StoreRelease.

Accessing the LORID_EL1

Accesses to this register use the following encodings:

MRS <Xt>, LORID_EL1

op0op1CRnCRmop2
0b110b0000b10100b01000b111

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && SCR_EL3.TLOR == '1' then UNDEFINED; elsif EL2Enabled() && HCR_EL2.TLOR == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGRTR_EL2.LORID_EL1 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.TLOR == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else return LORID_EL1; elsif PSTATE.EL == EL2 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && SCR_EL3.TLOR == '1' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.TLOR == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else return LORID_EL1; elsif PSTATE.EL == EL3 then return LORID_EL1;




30/09/2020 15:07; ccead0cb9f089f9ceec50268e82aec9e71047211

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