ICH_EISR_EL2: Interrupt Controller End of Interrupt Status Register

Purpose

Indicates which List registers have outstanding EOI maintenance interrupts.

Configuration

AArch64 System register ICH_EISR_EL2 bits [31:0] are architecturally mapped to AArch32 System register ICH_EISR[31:0].

This register is present only when GICv3 is implemented, (EL2 is implemented or EL3 is implemented), and FEAT_AA64 is implemented. Otherwise, direct accesses to ICH_EISR_EL2 are UNDEFINED.

If EL2 is not implemented, this register is RES0 from EL3.

Attributes

ICH_EISR_EL2 is a 64-bit register.

Field descriptions

63	62	61	60	59	58	57	56	55	54	53	52	51	50	49	48	47	46	45	44	43	42	41	40	39	38	37	36	35	34	33	32
31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
RES0
RES0																Status15	Status14	Status13	Status12	Status11	Status10	Status9	Status8	Status7	Status6	Status5	Status4	Status3	Status2	Status1	Status0

Bits [63:16]

Reserved, RES0.

Status<n>, bit [n], for n = 15 to 0

EOI maintenance interrupt status bit for List register <n>:

Status<n>	Meaning
0b0	List register <n>, ICH_LR<n>_EL2, does not have an EOI maintenance interrupt.
0b1	List register <n>, ICH_LR<n>_EL2, has an EOI maintenance interrupt that has not been handled.

For any ICH_LR<n>_EL2, the corresponding status bit is set to 1 if all of the following are true:

ICH_LR<n>_EL2.State is 0b00.
ICH_LR<n>_EL2.HW is 0.
ICH_LR<n>_EL2.EOI (bit [41]) is 1, indicating that when the interrupt corresponding to that List register is deactivated, a maintenance interrupt is asserted.

Otherwise the status bit takes the value 0.

Accessing ICH_EISR_EL2

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

MRS <Xt>, ICH_EISR_EL2

op0	op1	CRn	CRm	op2
0b11	0b100	0b1100	0b1011	0b011

if !(IsFeatureImplemented(FEAT_GICv3) && (HaveEL(EL2) || HaveEL(EL3)) && IsFeatureImplemented(FEAT_AA64)) then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if ICC_SRE_EL2.SRE == '0' then AArch64.SystemAccessTrap(EL2, 0x18); else X[t, 64] = ICH_EISR_EL2; elsif PSTATE.EL == EL3 then if ICC_SRE_EL3.SRE == '0' then AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = ICH_EISR_EL2;