| Message ID | 153469851942.21878.15396539991879060950.stgit@jupiter.in.ibm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | powerpc/pseries: Machine check handler improvements. | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | warning | next/apply_patch Patch failed to apply |
| snowpatch_ozlabs/apply_patch | fail | Failed to apply to any branch |
On Sun, 19 Aug 2018 22:38:39 +0530 Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com> wrote: > From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> > > Now that other platforms also implements real mode mce handler, > lets consolidate the code by sharing existing powernv machine check > early code. Rename machine_check_powernv_early to > machine_check_common_early and reuse the code. > > Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> > --- > arch/powerpc/kernel/exceptions-64s.S | 155 ++++++---------------------------- > 1 file changed, 28 insertions(+), 127 deletions(-) > > diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S > index 12f056179112..2f85a7baf026 100644 > --- a/arch/powerpc/kernel/exceptions-64s.S > +++ b/arch/powerpc/kernel/exceptions-64s.S > @@ -243,14 +243,13 @@ EXC_REAL_BEGIN(machine_check, 0x200, 0x100) > SET_SCRATCH0(r13) /* save r13 */ > EXCEPTION_PROLOG_0(PACA_EXMC) > BEGIN_FTR_SECTION > - b machine_check_powernv_early > + b machine_check_common_early > FTR_SECTION_ELSE > b machine_check_pSeries_0 > ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) > EXC_REAL_END(machine_check, 0x200, 0x100) > EXC_VIRT_NONE(0x4200, 0x100) > -TRAMP_REAL_BEGIN(machine_check_powernv_early) > -BEGIN_FTR_SECTION > +TRAMP_REAL_BEGIN(machine_check_common_early) > EXCEPTION_PROLOG_1(PACA_EXMC, NOTEST, 0x200) > /* > * Register contents: > @@ -306,7 +305,9 @@ BEGIN_FTR_SECTION > /* Save r9 through r13 from EXMC save area to stack frame. */ > EXCEPTION_PROLOG_COMMON_2(PACA_EXMC) > mfmsr r11 /* get MSR value */ > +BEGIN_FTR_SECTION > ori r11,r11,MSR_ME /* turn on ME bit */ > +END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) > ori r11,r11,MSR_RI /* turn on RI bit */ > LOAD_HANDLER(r12, machine_check_handle_early) > 1: mtspr SPRN_SRR0,r12 > @@ -325,7 +326,6 @@ BEGIN_FTR_SECTION > andc r11,r11,r10 /* Turn off MSR_ME */ > b 1b > b . /* prevent speculative execution */ > -END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) > > TRAMP_REAL_BEGIN(machine_check_pSeries) > .globl machine_check_fwnmi > @@ -333,7 +333,7 @@ machine_check_fwnmi: > SET_SCRATCH0(r13) /* save r13 */ > EXCEPTION_PROLOG_0(PACA_EXMC) > BEGIN_FTR_SECTION > - b machine_check_pSeries_early > + b machine_check_common_early > END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE) > machine_check_pSeries_0: > EXCEPTION_PROLOG_1(PACA_EXMC, KVMTEST_PR, 0x200) > @@ -346,103 +346,6 @@ 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 swithing 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 > @@ -541,6 +444,9 @@ EXC_COMMON_BEGIN(machine_check_handle_early) > bl machine_check_early > std r3,RESULT(r1) /* Save result */ > ld r12,_MSR(r1) > +BEGIN_FTR_SECTION > + b 4f > +END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE) > > #ifdef CONFIG_PPC_P7_NAP > /* > @@ -564,10 +470,11 @@ EXC_COMMON_BEGIN(machine_check_handle_early) > */ > rldicl. r11,r12,4,63 /* See if MC hit while in HV mode. */ > beq 5f > - andi. r11,r12,MSR_PR /* See if coming from user. */ > +4: andi. r11,r12,MSR_PR /* See if coming from user. */ > bne 9f /* continue in V mode if we are. */ > > 5: > +BEGIN_FTR_SECTION > #ifdef CONFIG_KVM_BOOK3S_64_HANDLER > /* > * We are coming from kernel context. Check if we are coming from > @@ -578,6 +485,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early) > cmpwi r11,0 /* Check if coming from guest */ > bne 9f /* continue if we are. */ > #endif > +END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) Put these inside the ifdef? > /* > * At this point we are not sure about what context we come from. > * Queue up the MCE event and return from the interrupt. > @@ -611,6 +519,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early) > cmpdi r3,0 /* see if we handled MCE successfully */ > > beq 1b /* if !handled then panic */ > +BEGIN_FTR_SECTION > /* > * Return from MC interrupt. > * Queue up the MCE event so that we can log it later, while > @@ -619,10 +528,24 @@ EXC_COMMON_BEGIN(machine_check_handle_early) > bl machine_check_queue_event > MACHINE_CHECK_HANDLER_WINDUP > RFI_TO_USER_OR_KERNEL > +FTR_SECTION_ELSE > + /* > + * pSeries: Return from MC interrupt. Before that stay on emergency > + * stack and call machine_check_exception to log the MCE event. > + */ > + LOAD_HANDLER(r10,mce_return) > + mtspr SPRN_SRR0,r10 > + ld r10,PACAKMSR(r13) > + mtspr SPRN_SRR1,r10 > + RFI_TO_KERNEL > + b . > +ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) Do you still need mce_return? Why can't you consolidate it as well? ... Hmm, okay so now I look back at patch 2, I don't think you should call machine_check_exception there. You're supposed to call machine_check_queue_event here and it will be handled by irq work. I think when you do that more of this code should fall out and be consolidated. Sorry for not picking that up earlier. Thanks, Nick
On 08/20/2018 05:04 PM, Nicholas Piggin wrote: > On Sun, 19 Aug 2018 22:38:39 +0530 > Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com> wrote: > >> From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> >> >> Now that other platforms also implements real mode mce handler, >> lets consolidate the code by sharing existing powernv machine check >> early code. Rename machine_check_powernv_early to >> machine_check_common_early and reuse the code. >> >> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> >> --- >> arch/powerpc/kernel/exceptions-64s.S | 155 ++++++---------------------------- >> 1 file changed, 28 insertions(+), 127 deletions(-) >> >> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S >> index 12f056179112..2f85a7baf026 100644 >> --- a/arch/powerpc/kernel/exceptions-64s.S >> +++ b/arch/powerpc/kernel/exceptions-64s.S >> @@ -243,14 +243,13 @@ EXC_REAL_BEGIN(machine_check, 0x200, 0x100) >> SET_SCRATCH0(r13) /* save r13 */ >> EXCEPTION_PROLOG_0(PACA_EXMC) >> BEGIN_FTR_SECTION >> - b machine_check_powernv_early >> + b machine_check_common_early >> FTR_SECTION_ELSE >> b machine_check_pSeries_0 >> ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) >> EXC_REAL_END(machine_check, 0x200, 0x100) >> EXC_VIRT_NONE(0x4200, 0x100) >> -TRAMP_REAL_BEGIN(machine_check_powernv_early) >> -BEGIN_FTR_SECTION >> +TRAMP_REAL_BEGIN(machine_check_common_early) >> EXCEPTION_PROLOG_1(PACA_EXMC, NOTEST, 0x200) >> /* >> * Register contents: >> @@ -306,7 +305,9 @@ BEGIN_FTR_SECTION >> /* Save r9 through r13 from EXMC save area to stack frame. */ >> EXCEPTION_PROLOG_COMMON_2(PACA_EXMC) >> mfmsr r11 /* get MSR value */ >> +BEGIN_FTR_SECTION >> ori r11,r11,MSR_ME /* turn on ME bit */ >> +END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) >> ori r11,r11,MSR_RI /* turn on RI bit */ >> LOAD_HANDLER(r12, machine_check_handle_early) >> 1: mtspr SPRN_SRR0,r12 >> @@ -325,7 +326,6 @@ BEGIN_FTR_SECTION >> andc r11,r11,r10 /* Turn off MSR_ME */ >> b 1b >> b . /* prevent speculative execution */ >> -END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) >> >> TRAMP_REAL_BEGIN(machine_check_pSeries) >> .globl machine_check_fwnmi >> @@ -333,7 +333,7 @@ machine_check_fwnmi: >> SET_SCRATCH0(r13) /* save r13 */ >> EXCEPTION_PROLOG_0(PACA_EXMC) >> BEGIN_FTR_SECTION >> - b machine_check_pSeries_early >> + b machine_check_common_early >> END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE) >> machine_check_pSeries_0: >> EXCEPTION_PROLOG_1(PACA_EXMC, KVMTEST_PR, 0x200) >> @@ -346,103 +346,6 @@ 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 swithing 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 >> @@ -541,6 +444,9 @@ EXC_COMMON_BEGIN(machine_check_handle_early) >> bl machine_check_early >> std r3,RESULT(r1) /* Save result */ >> ld r12,_MSR(r1) >> +BEGIN_FTR_SECTION >> + b 4f >> +END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE) >> >> #ifdef CONFIG_PPC_P7_NAP >> /* >> @@ -564,10 +470,11 @@ EXC_COMMON_BEGIN(machine_check_handle_early) >> */ >> rldicl. r11,r12,4,63 /* See if MC hit while in HV mode. */ >> beq 5f >> - andi. r11,r12,MSR_PR /* See if coming from user. */ >> +4: andi. r11,r12,MSR_PR /* See if coming from user. */ >> bne 9f /* continue in V mode if we are. */ >> >> 5: >> +BEGIN_FTR_SECTION >> #ifdef CONFIG_KVM_BOOK3S_64_HANDLER >> /* >> * We are coming from kernel context. Check if we are coming from >> @@ -578,6 +485,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early) >> cmpwi r11,0 /* Check if coming from guest */ >> bne 9f /* continue if we are. */ >> #endif >> +END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) > > Put these inside the ifdef? > > >> /* >> * At this point we are not sure about what context we come from. >> * Queue up the MCE event and return from the interrupt. >> @@ -611,6 +519,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early) >> cmpdi r3,0 /* see if we handled MCE successfully */ >> >> beq 1b /* if !handled then panic */ >> +BEGIN_FTR_SECTION >> /* >> * Return from MC interrupt. >> * Queue up the MCE event so that we can log it later, while >> @@ -619,10 +528,24 @@ EXC_COMMON_BEGIN(machine_check_handle_early) >> bl machine_check_queue_event >> MACHINE_CHECK_HANDLER_WINDUP >> RFI_TO_USER_OR_KERNEL >> +FTR_SECTION_ELSE >> + /* >> + * pSeries: Return from MC interrupt. Before that stay on emergency >> + * stack and call machine_check_exception to log the MCE event. >> + */ >> + LOAD_HANDLER(r10,mce_return) >> + mtspr SPRN_SRR0,r10 >> + ld r10,PACAKMSR(r13) >> + mtspr SPRN_SRR1,r10 >> + RFI_TO_KERNEL >> + b . >> +ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) > > Do you still need mce_return? Why can't you consolidate it as well? ... > Hmm, okay so now I look back at patch 2, I don't think you should call > machine_check_exception there. You're supposed to call > machine_check_queue_event here and it will be handled by irq work. machine_check_queue_event does not handle RTAS mce event. Also, we need to call fwnmi_release_errinfo() as early as possible which is why I am calling machine_check_exception() in mce_return path for pSeries. Otherwise if we get another MCE before calling fwnmi_release_errinfo() then lpar will get rebooted without any logs getting printed. Thanks, -Mahesh.
On Thu, 23 Aug 2018 14:13:13 +0530 Mahesh Jagannath Salgaonkar <mahesh@linux.vnet.ibm.com> wrote: > On 08/20/2018 05:04 PM, Nicholas Piggin wrote: > > On Sun, 19 Aug 2018 22:38:39 +0530 > > Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com> wrote: > > > >> From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> > >> > >> Now that other platforms also implements real mode mce handler, > >> lets consolidate the code by sharing existing powernv machine check > >> early code. Rename machine_check_powernv_early to > >> machine_check_common_early and reuse the code. > >> > >> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> > >> --- > >> arch/powerpc/kernel/exceptions-64s.S | 155 ++++++---------------------------- > >> 1 file changed, 28 insertions(+), 127 deletions(-) > >> > >> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S > >> index 12f056179112..2f85a7baf026 100644 > >> --- a/arch/powerpc/kernel/exceptions-64s.S > >> +++ b/arch/powerpc/kernel/exceptions-64s.S > >> @@ -243,14 +243,13 @@ EXC_REAL_BEGIN(machine_check, 0x200, 0x100) > >> SET_SCRATCH0(r13) /* save r13 */ > >> EXCEPTION_PROLOG_0(PACA_EXMC) > >> BEGIN_FTR_SECTION > >> - b machine_check_powernv_early > >> + b machine_check_common_early > >> FTR_SECTION_ELSE > >> b machine_check_pSeries_0 > >> ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) > >> EXC_REAL_END(machine_check, 0x200, 0x100) > >> EXC_VIRT_NONE(0x4200, 0x100) > >> -TRAMP_REAL_BEGIN(machine_check_powernv_early) > >> -BEGIN_FTR_SECTION > >> +TRAMP_REAL_BEGIN(machine_check_common_early) > >> EXCEPTION_PROLOG_1(PACA_EXMC, NOTEST, 0x200) > >> /* > >> * Register contents: > >> @@ -306,7 +305,9 @@ BEGIN_FTR_SECTION > >> /* Save r9 through r13 from EXMC save area to stack frame. */ > >> EXCEPTION_PROLOG_COMMON_2(PACA_EXMC) > >> mfmsr r11 /* get MSR value */ > >> +BEGIN_FTR_SECTION > >> ori r11,r11,MSR_ME /* turn on ME bit */ > >> +END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) > >> ori r11,r11,MSR_RI /* turn on RI bit */ > >> LOAD_HANDLER(r12, machine_check_handle_early) > >> 1: mtspr SPRN_SRR0,r12 > >> @@ -325,7 +326,6 @@ BEGIN_FTR_SECTION > >> andc r11,r11,r10 /* Turn off MSR_ME */ > >> b 1b > >> b . /* prevent speculative execution */ > >> -END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) > >> > >> TRAMP_REAL_BEGIN(machine_check_pSeries) > >> .globl machine_check_fwnmi > >> @@ -333,7 +333,7 @@ machine_check_fwnmi: > >> SET_SCRATCH0(r13) /* save r13 */ > >> EXCEPTION_PROLOG_0(PACA_EXMC) > >> BEGIN_FTR_SECTION > >> - b machine_check_pSeries_early > >> + b machine_check_common_early > >> END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE) > >> machine_check_pSeries_0: > >> EXCEPTION_PROLOG_1(PACA_EXMC, KVMTEST_PR, 0x200) > >> @@ -346,103 +346,6 @@ 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 swithing 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 > >> @@ -541,6 +444,9 @@ EXC_COMMON_BEGIN(machine_check_handle_early) > >> bl machine_check_early > >> std r3,RESULT(r1) /* Save result */ > >> ld r12,_MSR(r1) > >> +BEGIN_FTR_SECTION > >> + b 4f > >> +END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE) > >> > >> #ifdef CONFIG_PPC_P7_NAP > >> /* > >> @@ -564,10 +470,11 @@ EXC_COMMON_BEGIN(machine_check_handle_early) > >> */ > >> rldicl. r11,r12,4,63 /* See if MC hit while in HV mode. */ > >> beq 5f > >> - andi. r11,r12,MSR_PR /* See if coming from user. */ > >> +4: andi. r11,r12,MSR_PR /* See if coming from user. */ > >> bne 9f /* continue in V mode if we are. */ > >> > >> 5: > >> +BEGIN_FTR_SECTION > >> #ifdef CONFIG_KVM_BOOK3S_64_HANDLER > >> /* > >> * We are coming from kernel context. Check if we are coming from > >> @@ -578,6 +485,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early) > >> cmpwi r11,0 /* Check if coming from guest */ > >> bne 9f /* continue if we are. */ > >> #endif > >> +END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) > > > > Put these inside the ifdef? > > > > > >> /* > >> * At this point we are not sure about what context we come from. > >> * Queue up the MCE event and return from the interrupt. > >> @@ -611,6 +519,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early) > >> cmpdi r3,0 /* see if we handled MCE successfully */ > >> > >> beq 1b /* if !handled then panic */ > >> +BEGIN_FTR_SECTION > >> /* > >> * Return from MC interrupt. > >> * Queue up the MCE event so that we can log it later, while > >> @@ -619,10 +528,24 @@ EXC_COMMON_BEGIN(machine_check_handle_early) > >> bl machine_check_queue_event > >> MACHINE_CHECK_HANDLER_WINDUP > >> RFI_TO_USER_OR_KERNEL > >> +FTR_SECTION_ELSE > >> + /* > >> + * pSeries: Return from MC interrupt. Before that stay on emergency > >> + * stack and call machine_check_exception to log the MCE event. > >> + */ > >> + LOAD_HANDLER(r10,mce_return) > >> + mtspr SPRN_SRR0,r10 > >> + ld r10,PACAKMSR(r13) > >> + mtspr SPRN_SRR1,r10 > >> + RFI_TO_KERNEL > >> + b . > >> +ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) > > > > Do you still need mce_return? Why can't you consolidate it as well? ... > > Hmm, okay so now I look back at patch 2, I don't think you should call > > machine_check_exception there. You're supposed to call > > machine_check_queue_event here and it will be handled by irq work. > > machine_check_queue_event does not handle RTAS mce event. Yes it would need a bit of work. > Also, we need > to call fwnmi_release_errinfo() as early as possible which is why I am > calling machine_check_exception() in mce_return path for pSeries. > Otherwise if we get another MCE before calling fwnmi_release_errinfo() > then lpar will get rebooted without any logs getting printed. I think you can call that in your early handler, but then defer the printing to the irq work. Although hmm, maybe that's less of a problem now we do nmi_enter in machine check exception so I think printk will use an NMI safe buffer. We have to be careful actually of soft irq state if we take a machine check in an un-reconciled state or in the middle of the irq replay code I'm not actually sure we do the right thing, but that would be a bug in existing code too. And we definitely have MSR[RI] vs DAR/DSISR bugs in existing code, sigh. I don't know... maybe just push what you have and we'll try to do some more fixes and cleanups on top of that. Thanks, Nick
On 08/23/2018 02:32 PM, Nicholas Piggin wrote: > On Thu, 23 Aug 2018 14:13:13 +0530 > Mahesh Jagannath Salgaonkar <mahesh@linux.vnet.ibm.com> wrote: > >> On 08/20/2018 05:04 PM, Nicholas Piggin wrote: >>> On Sun, 19 Aug 2018 22:38:39 +0530 >>> Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com> wrote: >>> >>>> From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> >>>> >>>> Now that other platforms also implements real mode mce handler, >>>> lets consolidate the code by sharing existing powernv machine check >>>> early code. Rename machine_check_powernv_early to >>>> machine_check_common_early and reuse the code. >>>> >>>> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> >>>> --- >>>> arch/powerpc/kernel/exceptions-64s.S | 155 ++++++---------------------------- >>>> 1 file changed, 28 insertions(+), 127 deletions(-) >>>> >>>> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S >>>> index 12f056179112..2f85a7baf026 100644 >>>> --- a/arch/powerpc/kernel/exceptions-64s.S >>>> +++ b/arch/powerpc/kernel/exceptions-64s.S >>>> @@ -243,14 +243,13 @@ EXC_REAL_BEGIN(machine_check, 0x200, 0x100) >>>> SET_SCRATCH0(r13) /* save r13 */ >>>> EXCEPTION_PROLOG_0(PACA_EXMC) >>>> BEGIN_FTR_SECTION >>>> - b machine_check_powernv_early >>>> + b machine_check_common_early >>>> FTR_SECTION_ELSE >>>> b machine_check_pSeries_0 >>>> ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) >>>> EXC_REAL_END(machine_check, 0x200, 0x100) >>>> EXC_VIRT_NONE(0x4200, 0x100) >>>> -TRAMP_REAL_BEGIN(machine_check_powernv_early) >>>> -BEGIN_FTR_SECTION >>>> +TRAMP_REAL_BEGIN(machine_check_common_early) >>>> EXCEPTION_PROLOG_1(PACA_EXMC, NOTEST, 0x200) >>>> /* >>>> * Register contents: >>>> @@ -306,7 +305,9 @@ BEGIN_FTR_SECTION >>>> /* Save r9 through r13 from EXMC save area to stack frame. */ >>>> EXCEPTION_PROLOG_COMMON_2(PACA_EXMC) >>>> mfmsr r11 /* get MSR value */ >>>> +BEGIN_FTR_SECTION >>>> ori r11,r11,MSR_ME /* turn on ME bit */ >>>> +END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) >>>> ori r11,r11,MSR_RI /* turn on RI bit */ >>>> LOAD_HANDLER(r12, machine_check_handle_early) >>>> 1: mtspr SPRN_SRR0,r12 >>>> @@ -325,7 +326,6 @@ BEGIN_FTR_SECTION >>>> andc r11,r11,r10 /* Turn off MSR_ME */ >>>> b 1b >>>> b . /* prevent speculative execution */ >>>> -END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) >>>> >>>> TRAMP_REAL_BEGIN(machine_check_pSeries) >>>> .globl machine_check_fwnmi >>>> @@ -333,7 +333,7 @@ machine_check_fwnmi: >>>> SET_SCRATCH0(r13) /* save r13 */ >>>> EXCEPTION_PROLOG_0(PACA_EXMC) >>>> BEGIN_FTR_SECTION >>>> - b machine_check_pSeries_early >>>> + b machine_check_common_early >>>> END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE) >>>> machine_check_pSeries_0: >>>> EXCEPTION_PROLOG_1(PACA_EXMC, KVMTEST_PR, 0x200) >>>> @@ -346,103 +346,6 @@ 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 swithing 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 >>>> @@ -541,6 +444,9 @@ EXC_COMMON_BEGIN(machine_check_handle_early) >>>> bl machine_check_early >>>> std r3,RESULT(r1) /* Save result */ >>>> ld r12,_MSR(r1) >>>> +BEGIN_FTR_SECTION >>>> + b 4f >>>> +END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE) >>>> >>>> #ifdef CONFIG_PPC_P7_NAP >>>> /* >>>> @@ -564,10 +470,11 @@ EXC_COMMON_BEGIN(machine_check_handle_early) >>>> */ >>>> rldicl. r11,r12,4,63 /* See if MC hit while in HV mode. */ >>>> beq 5f >>>> - andi. r11,r12,MSR_PR /* See if coming from user. */ >>>> +4: andi. r11,r12,MSR_PR /* See if coming from user. */ >>>> bne 9f /* continue in V mode if we are. */ >>>> >>>> 5: >>>> +BEGIN_FTR_SECTION >>>> #ifdef CONFIG_KVM_BOOK3S_64_HANDLER >>>> /* >>>> * We are coming from kernel context. Check if we are coming from >>>> @@ -578,6 +485,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early) >>>> cmpwi r11,0 /* Check if coming from guest */ >>>> bne 9f /* continue if we are. */ >>>> #endif >>>> +END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) >>> >>> Put these inside the ifdef? >>> >>> >>>> /* >>>> * At this point we are not sure about what context we come from. >>>> * Queue up the MCE event and return from the interrupt. >>>> @@ -611,6 +519,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early) >>>> cmpdi r3,0 /* see if we handled MCE successfully */ >>>> >>>> beq 1b /* if !handled then panic */ >>>> +BEGIN_FTR_SECTION >>>> /* >>>> * Return from MC interrupt. >>>> * Queue up the MCE event so that we can log it later, while >>>> @@ -619,10 +528,24 @@ EXC_COMMON_BEGIN(machine_check_handle_early) >>>> bl machine_check_queue_event >>>> MACHINE_CHECK_HANDLER_WINDUP >>>> RFI_TO_USER_OR_KERNEL >>>> +FTR_SECTION_ELSE >>>> + /* >>>> + * pSeries: Return from MC interrupt. Before that stay on emergency >>>> + * stack and call machine_check_exception to log the MCE event. >>>> + */ >>>> + LOAD_HANDLER(r10,mce_return) >>>> + mtspr SPRN_SRR0,r10 >>>> + ld r10,PACAKMSR(r13) >>>> + mtspr SPRN_SRR1,r10 >>>> + RFI_TO_KERNEL >>>> + b . >>>> +ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) >>> >>> Do you still need mce_return? Why can't you consolidate it as well? ... >>> Hmm, okay so now I look back at patch 2, I don't think you should call >>> machine_check_exception there. You're supposed to call >>> machine_check_queue_event here and it will be handled by irq work. >> >> machine_check_queue_event does not handle RTAS mce event. > > Yes it would need a bit of work. > >> Also, we need >> to call fwnmi_release_errinfo() as early as possible which is why I am >> calling machine_check_exception() in mce_return path for pSeries. >> Otherwise if we get another MCE before calling fwnmi_release_errinfo() >> then lpar will get rebooted without any logs getting printed. > > I think you can call that in your early handler, but then defer > the printing to the irq work. > > Although hmm, maybe that's less of a problem now we do nmi_enter > in machine check exception so I think printk will use an NMI safe > buffer. > > We have to be careful actually of soft irq state if we take a > machine check in an un-reconciled state or in the middle of > the irq replay code I'm not actually sure we do the right thing, > but that would be a bug in existing code too. And we definitely > have MSR[RI] vs DAR/DSISR bugs in existing code, sigh. > > I don't know... maybe just push what you have and we'll try to do > some more fixes and cleanups on top of that. Sure. I will respin the next version addressing your other minor comments. Will work on more improvements as separate change. Thanks, -Mahesh.
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 12f056179112..2f85a7baf026 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -243,14 +243,13 @@ EXC_REAL_BEGIN(machine_check, 0x200, 0x100) SET_SCRATCH0(r13) /* save r13 */ EXCEPTION_PROLOG_0(PACA_EXMC) BEGIN_FTR_SECTION - b machine_check_powernv_early + b machine_check_common_early FTR_SECTION_ELSE b machine_check_pSeries_0 ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) EXC_REAL_END(machine_check, 0x200, 0x100) EXC_VIRT_NONE(0x4200, 0x100) -TRAMP_REAL_BEGIN(machine_check_powernv_early) -BEGIN_FTR_SECTION +TRAMP_REAL_BEGIN(machine_check_common_early) EXCEPTION_PROLOG_1(PACA_EXMC, NOTEST, 0x200) /* * Register contents: @@ -306,7 +305,9 @@ BEGIN_FTR_SECTION /* Save r9 through r13 from EXMC save area to stack frame. */ EXCEPTION_PROLOG_COMMON_2(PACA_EXMC) mfmsr r11 /* get MSR value */ +BEGIN_FTR_SECTION ori r11,r11,MSR_ME /* turn on ME bit */ +END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) ori r11,r11,MSR_RI /* turn on RI bit */ LOAD_HANDLER(r12, machine_check_handle_early) 1: mtspr SPRN_SRR0,r12 @@ -325,7 +326,6 @@ BEGIN_FTR_SECTION andc r11,r11,r10 /* Turn off MSR_ME */ b 1b b . /* prevent speculative execution */ -END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) TRAMP_REAL_BEGIN(machine_check_pSeries) .globl machine_check_fwnmi @@ -333,7 +333,7 @@ machine_check_fwnmi: SET_SCRATCH0(r13) /* save r13 */ EXCEPTION_PROLOG_0(PACA_EXMC) BEGIN_FTR_SECTION - b machine_check_pSeries_early + b machine_check_common_early END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE) machine_check_pSeries_0: EXCEPTION_PROLOG_1(PACA_EXMC, KVMTEST_PR, 0x200) @@ -346,103 +346,6 @@ 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 swithing 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 @@ -541,6 +444,9 @@ EXC_COMMON_BEGIN(machine_check_handle_early) bl machine_check_early std r3,RESULT(r1) /* Save result */ ld r12,_MSR(r1) +BEGIN_FTR_SECTION + b 4f +END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE) #ifdef CONFIG_PPC_P7_NAP /* @@ -564,10 +470,11 @@ EXC_COMMON_BEGIN(machine_check_handle_early) */ rldicl. r11,r12,4,63 /* See if MC hit while in HV mode. */ beq 5f - andi. r11,r12,MSR_PR /* See if coming from user. */ +4: andi. r11,r12,MSR_PR /* See if coming from user. */ bne 9f /* continue in V mode if we are. */ 5: +BEGIN_FTR_SECTION #ifdef CONFIG_KVM_BOOK3S_64_HANDLER /* * We are coming from kernel context. Check if we are coming from @@ -578,6 +485,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early) cmpwi r11,0 /* Check if coming from guest */ bne 9f /* continue if we are. */ #endif +END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) /* * At this point we are not sure about what context we come from. * Queue up the MCE event and return from the interrupt. @@ -611,6 +519,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early) cmpdi r3,0 /* see if we handled MCE successfully */ beq 1b /* if !handled then panic */ +BEGIN_FTR_SECTION /* * Return from MC interrupt. * Queue up the MCE event so that we can log it later, while @@ -619,10 +528,24 @@ EXC_COMMON_BEGIN(machine_check_handle_early) bl machine_check_queue_event MACHINE_CHECK_HANDLER_WINDUP RFI_TO_USER_OR_KERNEL +FTR_SECTION_ELSE + /* + * pSeries: Return from MC interrupt. Before that stay on emergency + * stack and call machine_check_exception to log the MCE event. + */ + LOAD_HANDLER(r10,mce_return) + mtspr SPRN_SRR0,r10 + ld r10,PACAKMSR(r13) + mtspr SPRN_SRR1,r10 + RFI_TO_KERNEL + b . +ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) 9: /* Deliver the machine check to host kernel in V mode. */ MACHINE_CHECK_HANDLER_WINDUP - b machine_check_pSeries + SET_SCRATCH0(r13) /* save r13 */ + EXCEPTION_PROLOG_0(PACA_EXMC) + b machine_check_pSeries_0 EXC_COMMON_BEGIN(unrecover_mce) /* Invoke machine_check_exception to print MCE event and panic. */ @@ -640,29 +563,7 @@ 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) + MACHINE_CHECK_HANDLER_WINDUP RFI_TO_KERNEL b .