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author | Nicholas Piggin <npiggin@gmail.com> | 2016-08-10 10:48:43 (GMT) |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2016-08-22 01:09:33 (GMT) |
commit | a74599a5041979ae83aec7a6d5c8df9131db2ce6 (patch) | |
tree | b6fd23af69287eb9f0f73387169cf7b9a5ae93f9 /arch/powerpc | |
parent | 3f3b5dc14c25254d3fe98115c71b2a1f3ed97798 (diff) | |
download | linux-a74599a5041979ae83aec7a6d5c8df9131db2ce6.tar.xz |
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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 034b7ea..bffec73 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -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 |