diff options
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index ea04dfb8c092..b36e11d73702 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -331,6 +331,9 @@ TRAMP_REAL_BEGIN(machine_check_pSeries) machine_check_fwnmi: SET_SCRATCH0(r13) /* save r13 */ EXCEPTION_PROLOG_0(PACA_EXMC) +BEGIN_FTR_SECTION + b machine_check_pSeries_early +END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE) machine_check_pSeries_0: EXCEPTION_PROLOG_1(PACA_EXMC, KVMTEST_PR, 0x200) /* @@ -342,6 +345,103 @@ machine_check_pSeries_0: TRAMP_KVM_SKIP(PACA_EXMC, 0x200) +TRAMP_REAL_BEGIN(machine_check_pSeries_early) +BEGIN_FTR_SECTION + EXCEPTION_PROLOG_1(PACA_EXMC, NOTEST, 0x200) + mr r10,r1 /* Save r1 */ + lhz r11,PACA_IN_MCE(r13) + cmpwi r11,0 /* Are we in nested machine check */ + bne 0f /* Yes, we are. */ + /* First machine check entry */ + ld r1,PACAMCEMERGSP(r13) /* Use MC emergency stack */ +0: subi r1,r1,INT_FRAME_SIZE /* alloc stack frame */ + addi r11,r11,1 /* increment paca->in_mce */ + sth r11,PACA_IN_MCE(r13) + /* Limit nested MCE to level 4 to avoid stack overflow */ + cmpwi r11,MAX_MCE_DEPTH + bgt 1f /* Check if we hit limit of 4 */ + mfspr r11,SPRN_SRR0 /* Save SRR0 */ + mfspr r12,SPRN_SRR1 /* Save SRR1 */ + EXCEPTION_PROLOG_COMMON_1() + EXCEPTION_PROLOG_COMMON_2(PACA_EXMC) + EXCEPTION_PROLOG_COMMON_3(0x200) + addi r3,r1,STACK_FRAME_OVERHEAD + BRANCH_LINK_TO_FAR(machine_check_early) /* Function call ABI */ + ld r12,_MSR(r1) + andi. r11,r12,MSR_PR /* See if coming from user. */ + bne 2f /* continue in V mode if we are. */ + + /* + * At this point we are not sure about what context we come from. + * We may be in the middle of switching stack. r1 may not be valid. + * Hence stay on emergency stack, call machine_check_exception and + * return from the interrupt. + * But before that, check if this is an un-recoverable exception. + * If yes, then stay on emergency stack and panic. + */ + andi. r11,r12,MSR_RI + beq 1f + + /* + * Check if we have successfully handled/recovered from error, if not + * then stay on emergency stack and panic. + */ + cmpdi r3,0 /* see if we handled MCE successfully */ + beq 1f /* if !handled then panic */ + + /* Stay on emergency stack and return from interrupt. */ + LOAD_HANDLER(r10,mce_return) + mtspr SPRN_SRR0,r10 + ld r10,PACAKMSR(r13) + mtspr SPRN_SRR1,r10 + RFI_TO_KERNEL + b . + +1: LOAD_HANDLER(r10,unrecover_mce) + mtspr SPRN_SRR0,r10 + ld r10,PACAKMSR(r13) + /* + * We are going down. But there are chances that we might get hit by + * another MCE during panic path and we may run into unstable state + * with no way out. Hence, turn ME bit off while going down, so that + * when another MCE is hit during panic path, hypervisor will + * power cycle the lpar, instead of getting into MCE loop. + */ + li r3,MSR_ME + andc r10,r10,r3 /* Turn off MSR_ME */ + mtspr SPRN_SRR1,r10 + RFI_TO_KERNEL + b . + + /* Move original SRR0 and SRR1 into the respective regs */ +2: ld r9,_MSR(r1) + mtspr SPRN_SRR1,r9 + ld r3,_NIP(r1) + mtspr SPRN_SRR0,r3 + ld r9,_CTR(r1) + mtctr r9 + ld r9,_XER(r1) + mtxer r9 + ld r9,_LINK(r1) + mtlr r9 + REST_GPR(0, r1) + REST_8GPRS(2, r1) + REST_GPR(10, r1) + ld r11,_CCR(r1) + mtcr r11 + /* Decrement paca->in_mce. */ + lhz r12,PACA_IN_MCE(r13) + subi r12,r12,1 + sth r12,PACA_IN_MCE(r13) + REST_GPR(11, r1) + REST_2GPRS(12, r1) + /* restore original r1. */ + ld r1,GPR1(r1) + SET_SCRATCH0(r13) /* save r13 */ + EXCEPTION_PROLOG_0(PACA_EXMC) + b machine_check_pSeries_0 +END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE) + EXC_COMMON_BEGIN(machine_check_common) /* * Machine check is different because we use a different @@ -535,6 +635,35 @@ EXC_COMMON_BEGIN(unrecover_mce) bl unrecoverable_exception b 1b +EXC_COMMON_BEGIN(mce_return) + /* Invoke machine_check_exception to print MCE event and return. */ + addi r3,r1,STACK_FRAME_OVERHEAD + bl machine_check_exception + ld r9,_MSR(r1) + mtspr SPRN_SRR1,r9 + ld r3,_NIP(r1) + mtspr SPRN_SRR0,r3 + ld r9,_CTR(r1) + mtctr r9 + ld r9,_XER(r1) + mtxer r9 + ld r9,_LINK(r1) + mtlr r9 + REST_GPR(0, r1) + REST_8GPRS(2, r1) + REST_GPR(10, r1) + ld r11,_CCR(r1) + mtcr r11 + /* Decrement paca->in_mce. */ + lhz r12,PACA_IN_MCE(r13) + subi r12,r12,1 + sth r12,PACA_IN_MCE(r13) + REST_GPR(11, r1) + REST_2GPRS(12, r1) + /* restore original r1. */ + ld r1,GPR1(r1) + RFI_TO_KERNEL + b . EXC_REAL(data_access, 0x300, 0x80) EXC_VIRT(data_access, 0x4300, 0x80, 0x300) |