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Commit a74599a5 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Benjamin Herrenschmidt
Browse files

powerpc/pseries: PACA save area fix for MCE vs MCE 



MCE must not enable MSR_RI until PACA_EXMC is no longer being used.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 3f3b5dc1

arch/powerpc/kernel/exceptions-64s.S

+20 −1
Original line number Diff line number Diff line
@@ -485,7 +485,23 @@ machine_check_fwnmi: 
	EXCEPTION_PROLOG_0(PACA_EXMC)

machine_check_pSeries_0:

	EXCEPTION_PROLOG_1(PACA_EXMC, KVMTEST, 0x200)

	EXCEPTION_PROLOG_PSERIES_1(machine_check_common, EXC_STD)

	/*

	 * The following is essentially EXCEPTION_PROLOG_PSERIES_1 with the

	 * difference that MSR_RI is not enabled, because PACA_EXMC is being

	 * used, so nested machine check corrupts it. machine_check_common

	 * enables MSR_RI.

	 */

	ld	r12,PACAKBASE(r13)

	ld	r10,PACAKMSR(r13)

	xori	r10,r10,MSR_RI

	mfspr	r11,SPRN_SRR0

	LOAD_HANDLER(r12, machine_check_common)

	mtspr	SPRN_SRR0,r12

	mfspr	r12,SPRN_SRR1

	mtspr	SPRN_SRR1,r10

	rfid

	b	.	/* prevent speculative execution */



	KVM_HANDLER_SKIP(PACA_EXMC, EXC_STD, 0x200)

	KVM_HANDLER_SKIP(PACA_EXGEN, EXC_STD, 0x300)

	KVM_HANDLER_SKIP(PACA_EXSLB, EXC_STD, 0x380)
@@ -977,6 +993,9 @@ machine_check_common: 
	RECONCILE_IRQ_STATE(r10, r11)

	ld	r3,PACA_EXMC+EX_DAR(r13)

	lwz	r4,PACA_EXMC+EX_DSISR(r13)

	/* Enable MSR_RI when finished with PACA_EXMC */

	li	r10,MSR_RI

	mtmsrd 	r10,1

	std	r3,_DAR(r1)

	std	r4,_DSISR(r1)

	bl	save_nvgprs