[PATCH v3 06/42] powerpc/64s: Consolidate Machine Check 0x200 interrupt
Michael Ellerman
mpe at ellerman.id.au
Wed Oct 5 11:22:28 AEDT 2016
From: Nicholas Piggin <npiggin at gmail.com>
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
---
arch/powerpc/kernel/exceptions-64s.S | 659 +++++++++++++++++------------------
1 file changed, 329 insertions(+), 330 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index b163e7a62289..afdb2043b1f3 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -218,6 +218,301 @@ FTR_SECTION_ELSE
b machine_check_pSeries_0
ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE)
EXC_REAL_END(machine_check, 0x200, 0x300)
+EXC_VIRT_NONE(0x4200, 0x4300)
+TRAMP_REAL_BEGIN(machine_check_powernv_early)
+BEGIN_FTR_SECTION
+ EXCEPTION_PROLOG_1(PACA_EXMC, NOTEST, 0x200)
+ /*
+ * Register contents:
+ * R13 = PACA
+ * R9 = CR
+ * Original R9 to R13 is saved on PACA_EXMC
+ *
+ * Switch to mc_emergency stack and handle re-entrancy (we limit
+ * the nested MCE upto level 4 to avoid stack overflow).
+ * Save MCE registers srr1, srr0, dar and dsisr and then set ME=1
+ *
+ * We use paca->in_mce to check whether this is the first entry or
+ * nested machine check. We increment paca->in_mce to track nested
+ * machine checks.
+ *
+ * If this is the first entry then set stack pointer to
+ * paca->mc_emergency_sp, otherwise r1 is already pointing to
+ * stack frame on mc_emergency stack.
+ *
+ * NOTE: We are here with MSR_ME=0 (off), which means we risk a
+ * checkstop if we get another machine check exception before we do
+ * rfid with MSR_ME=1.
+ */
+ mr r11,r1 /* Save r1 */
+ lhz r10,PACA_IN_MCE(r13)
+ cmpwi r10,0 /* 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 r10,r10,1 /* increment paca->in_mce */
+ sth r10,PACA_IN_MCE(r13)
+ /* Limit nested MCE to level 4 to avoid stack overflow */
+ cmpwi r10,4
+ bgt 2f /* Check if we hit limit of 4 */
+ std r11,GPR1(r1) /* Save r1 on the stack. */
+ std r11,0(r1) /* make stack chain pointer */
+ mfspr r11,SPRN_SRR0 /* Save SRR0 */
+ std r11,_NIP(r1)
+ mfspr r11,SPRN_SRR1 /* Save SRR1 */
+ std r11,_MSR(r1)
+ mfspr r11,SPRN_DAR /* Save DAR */
+ std r11,_DAR(r1)
+ mfspr r11,SPRN_DSISR /* Save DSISR */
+ std r11,_DSISR(r1)
+ std r9,_CCR(r1) /* Save CR in stackframe */
+ /* Save r9 through r13 from EXMC save area to stack frame. */
+ EXCEPTION_PROLOG_COMMON_2(PACA_EXMC)
+ mfmsr r11 /* get MSR value */
+ ori r11,r11,MSR_ME /* turn on ME bit */
+ ori r11,r11,MSR_RI /* turn on RI bit */
+ LOAD_HANDLER(r12, machine_check_handle_early)
+1: mtspr SPRN_SRR0,r12
+ mtspr SPRN_SRR1,r11
+ rfid
+ b . /* prevent speculative execution */
+2:
+ /* Stack overflow. Stay on emergency stack and panic.
+ * Keep the ME bit off while panic-ing, so that if we hit
+ * another machine check we checkstop.
+ */
+ addi r1,r1,INT_FRAME_SIZE /* go back to previous stack frame */
+ ld r11,PACAKMSR(r13)
+ LOAD_HANDLER(r12, unrecover_mce)
+ li r10,MSR_ME
+ 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
+machine_check_fwnmi:
+ SET_SCRATCH0(r13) /* save r13 */
+ EXCEPTION_PROLOG_0(PACA_EXMC)
+machine_check_pSeries_0:
+ EXCEPTION_PROLOG_1(PACA_EXMC, KVMTEST_PR, 0x200)
+ /*
+ * 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 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 */
+
+TRAMP_KVM_SKIP(PACA_EXMC, 0x200)
+
+EXC_COMMON_BEGIN(machine_check_common)
+ /*
+ * Machine check is different because we use a different
+ * save area: PACA_EXMC instead of PACA_EXGEN.
+ */
+ mfspr r10,SPRN_DAR
+ std r10,PACA_EXMC+EX_DAR(r13)
+ mfspr r10,SPRN_DSISR
+ stw r10,PACA_EXMC+EX_DSISR(r13)
+ EXCEPTION_PROLOG_COMMON(0x200, PACA_EXMC)
+ FINISH_NAP
+ 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
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ bl machine_check_exception
+ b ret_from_except
+
+#define MACHINE_CHECK_HANDLER_WINDUP \
+ /* Clear MSR_RI before setting SRR0 and SRR1. */\
+ li r0,MSR_RI; \
+ mfmsr r9; /* get MSR value */ \
+ andc r9,r9,r0; \
+ mtmsrd r9,1; /* Clear MSR_RI */ \
+ /* Move original SRR0 and SRR1 into the respective regs */ \
+ 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)
+
+ /*
+ * Handle machine check early in real mode. We come here with
+ * ME=1, MMU (IR=0 and DR=0) off and using MC emergency stack.
+ */
+EXC_COMMON_BEGIN(machine_check_handle_early)
+ std r0,GPR0(r1) /* Save r0 */
+ EXCEPTION_PROLOG_COMMON_3(0x200)
+ bl save_nvgprs
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ bl machine_check_early
+ std r3,RESULT(r1) /* Save result */
+ ld r12,_MSR(r1)
+#ifdef CONFIG_PPC_P7_NAP
+ /*
+ * Check if thread was in power saving mode. We come here when any
+ * of the following is true:
+ * a. thread wasn't in power saving mode
+ * b. thread was in power saving mode with no state loss,
+ * supervisor state loss or hypervisor state loss.
+ *
+ * Go back to nap/sleep/winkle mode again if (b) is true.
+ */
+ rlwinm. r11,r12,47-31,30,31 /* Was it in power saving mode? */
+ beq 4f /* No, it wasn;t */
+ /* Thread was in power saving mode. Go back to nap again. */
+ cmpwi r11,2
+ blt 3f
+ /* Supervisor/Hypervisor state loss */
+ li r0,1
+ stb r0,PACA_NAPSTATELOST(r13)
+3: bl machine_check_queue_event
+ MACHINE_CHECK_HANDLER_WINDUP
+ GET_PACA(r13)
+ ld r1,PACAR1(r13)
+ /*
+ * Check what idle state this CPU was in and go back to same mode
+ * again.
+ */
+ lbz r3,PACA_THREAD_IDLE_STATE(r13)
+ cmpwi r3,PNV_THREAD_NAP
+ bgt 10f
+ IDLE_STATE_ENTER_SEQ(PPC_NAP)
+ /* No return */
+10:
+ cmpwi r3,PNV_THREAD_SLEEP
+ bgt 2f
+ IDLE_STATE_ENTER_SEQ(PPC_SLEEP)
+ /* No return */
+
+2:
+ /*
+ * Go back to winkle. Please note that this thread was woken up in
+ * machine check from winkle and have not restored the per-subcore
+ * state. Hence before going back to winkle, set last bit of HSPGR0
+ * to 1. This will make sure that if this thread gets woken up
+ * again at reset vector 0x100 then it will get chance to restore
+ * the subcore state.
+ */
+ ori r13,r13,1
+ SET_PACA(r13)
+ IDLE_STATE_ENTER_SEQ(PPC_WINKLE)
+ /* No return */
+4:
+#endif
+ /*
+ * Check if we are coming from hypervisor userspace. If yes then we
+ * continue in host kernel in V mode to deliver the MC event.
+ */
+ 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. */
+ bne 9f /* continue in V mode if we are. */
+
+5:
+#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
+ /*
+ * We are coming from kernel context. Check if we are coming from
+ * guest. if yes, then we can continue. We will fall through
+ * do_kvm_200->kvmppc_interrupt to deliver the MC event to guest.
+ */
+ lbz r11,HSTATE_IN_GUEST(r13)
+ cmpwi r11,0 /* Check if coming from guest */
+ bne 9f /* continue if we are. */
+#endif
+ /*
+ * At this point we are not sure about what context we come from.
+ * Queue up the MCE event 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
+ bne 2f
+1: mfspr r11,SPRN_SRR0
+ 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, system will checkstop
+ * and hypervisor will get restarted cleanly by SP.
+ */
+ li r3,MSR_ME
+ andc r10,r10,r3 /* Turn off MSR_ME */
+ mtspr SPRN_SRR1,r10
+ rfid
+ b .
+2:
+ /*
+ * Check if we have successfully handled/recovered from error, if not
+ * then stay on emergency stack and panic.
+ */
+ ld r3,RESULT(r1) /* Load result */
+ cmpdi r3,0 /* see if we handled MCE successfully */
+
+ beq 1b /* if !handled then panic */
+ /*
+ * Return from MC interrupt.
+ * Queue up the MCE event so that we can log it later, while
+ * returning from kernel or opal call.
+ */
+ bl machine_check_queue_event
+ MACHINE_CHECK_HANDLER_WINDUP
+ rfid
+9:
+ /* Deliver the machine check to host kernel in V mode. */
+ MACHINE_CHECK_HANDLER_WINDUP
+ b machine_check_pSeries
+
+EXC_COMMON_BEGIN(unrecover_mce)
+ /* Invoke machine_check_exception to print MCE event and panic. */
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ bl machine_check_exception
+ /*
+ * We will not reach here. Even if we did, there is no way out. Call
+ * unrecoverable_exception and die.
+ */
+1: addi r3,r1,STACK_FRAME_OVERHEAD
+ bl unrecoverable_exception
+ b 1b
+
EXC_REAL(data_access, 0x300, 0x380)
@@ -388,140 +683,43 @@ EXC_REAL_BEGIN(denorm_exception_hv, 0x1500, 0x1600)
#ifdef CONFIG_PPC_DENORMALISATION
mfspr r10,SPRN_HSRR1
mfspr r11,SPRN_HSRR0 /* save HSRR0 */
- andis. r10,r10,(HSRR1_DENORM)@h /* denorm? */
- addi r11,r11,-4 /* HSRR0 is next instruction */
- bne+ denorm_assist
-#endif
-
- KVMTEST_PR(0x1500)
- EXCEPTION_PROLOG_PSERIES_1(denorm_common, EXC_HV)
-EXC_REAL_END(denorm_exception_hv, 0x1500, 0x1600)
-
-TRAMP_KVM_SKIP(PACA_EXGEN, 0x1500)
-
-#ifdef CONFIG_CBE_RAS
-EXC_REAL_HV(cbe_maintenance, 0x1600, 0x1700)
-
-TRAMP_KVM_HV_SKIP(PACA_EXGEN, 0x1600)
-
-#else /* CONFIG_CBE_RAS */
-EXC_REAL_NONE(0x1600, 0x1700)
-#endif
-
-EXC_REAL(altivec_assist, 0x1700, 0x1800)
-
-TRAMP_KVM(PACA_EXGEN, 0x1700)
-
-#ifdef CONFIG_CBE_RAS
-EXC_REAL_HV(cbe_thermal, 0x1800, 0x1900)
-
-TRAMP_KVM_HV_SKIP(PACA_EXGEN, 0x1800)
-
-#else /* CONFIG_CBE_RAS */
-EXC_REAL_NONE(0x1800, 0x1900)
-#endif
-
-
-/*** Out of line interrupts support ***/
-
- /* moved from 0x200 */
-TRAMP_REAL_BEGIN(machine_check_powernv_early)
-BEGIN_FTR_SECTION
- EXCEPTION_PROLOG_1(PACA_EXMC, NOTEST, 0x200)
- /*
- * Register contents:
- * R13 = PACA
- * R9 = CR
- * Original R9 to R13 is saved on PACA_EXMC
- *
- * Switch to mc_emergency stack and handle re-entrancy (we limit
- * the nested MCE upto level 4 to avoid stack overflow).
- * Save MCE registers srr1, srr0, dar and dsisr and then set ME=1
- *
- * We use paca->in_mce to check whether this is the first entry or
- * nested machine check. We increment paca->in_mce to track nested
- * machine checks.
- *
- * If this is the first entry then set stack pointer to
- * paca->mc_emergency_sp, otherwise r1 is already pointing to
- * stack frame on mc_emergency stack.
- *
- * NOTE: We are here with MSR_ME=0 (off), which means we risk a
- * checkstop if we get another machine check exception before we do
- * rfid with MSR_ME=1.
- */
- mr r11,r1 /* Save r1 */
- lhz r10,PACA_IN_MCE(r13)
- cmpwi r10,0 /* 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 r10,r10,1 /* increment paca->in_mce */
- sth r10,PACA_IN_MCE(r13)
- /* Limit nested MCE to level 4 to avoid stack overflow */
- cmpwi r10,4
- bgt 2f /* Check if we hit limit of 4 */
- std r11,GPR1(r1) /* Save r1 on the stack. */
- std r11,0(r1) /* make stack chain pointer */
- mfspr r11,SPRN_SRR0 /* Save SRR0 */
- std r11,_NIP(r1)
- mfspr r11,SPRN_SRR1 /* Save SRR1 */
- std r11,_MSR(r1)
- mfspr r11,SPRN_DAR /* Save DAR */
- std r11,_DAR(r1)
- mfspr r11,SPRN_DSISR /* Save DSISR */
- std r11,_DSISR(r1)
- std r9,_CCR(r1) /* Save CR in stackframe */
- /* Save r9 through r13 from EXMC save area to stack frame. */
- EXCEPTION_PROLOG_COMMON_2(PACA_EXMC)
- mfmsr r11 /* get MSR value */
- ori r11,r11,MSR_ME /* turn on ME bit */
- ori r11,r11,MSR_RI /* turn on RI bit */
- LOAD_HANDLER(r12, machine_check_handle_early)
-1: mtspr SPRN_SRR0,r12
- mtspr SPRN_SRR1,r11
- rfid
- b . /* prevent speculative execution */
-2:
- /* Stack overflow. Stay on emergency stack and panic.
- * Keep the ME bit off while panic-ing, so that if we hit
- * another machine check we checkstop.
- */
- addi r1,r1,INT_FRAME_SIZE /* go back to previous stack frame */
- ld r11,PACAKMSR(r13)
- LOAD_HANDLER(r12, unrecover_mce)
- li r10,MSR_ME
- andc r11,r11,r10 /* Turn off MSR_ME */
- b 1b
- b . /* prevent speculative execution */
-END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
+ andis. r10,r10,(HSRR1_DENORM)@h /* denorm? */
+ addi r11,r11,-4 /* HSRR0 is next instruction */
+ bne+ denorm_assist
+#endif
-TRAMP_REAL_BEGIN(machine_check_pSeries)
- .globl machine_check_fwnmi
-machine_check_fwnmi:
- SET_SCRATCH0(r13) /* save r13 */
- EXCEPTION_PROLOG_0(PACA_EXMC)
-machine_check_pSeries_0:
- EXCEPTION_PROLOG_1(PACA_EXMC, KVMTEST_PR, 0x200)
- /*
- * 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 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 */
+ KVMTEST_PR(0x1500)
+ EXCEPTION_PROLOG_PSERIES_1(denorm_common, EXC_HV)
+EXC_REAL_END(denorm_exception_hv, 0x1500, 0x1600)
+TRAMP_KVM_SKIP(PACA_EXGEN, 0x1500)
-TRAMP_KVM_SKIP(PACA_EXMC, 0x200)
+#ifdef CONFIG_CBE_RAS
+EXC_REAL_HV(cbe_maintenance, 0x1600, 0x1700)
+
+TRAMP_KVM_HV_SKIP(PACA_EXGEN, 0x1600)
+
+#else /* CONFIG_CBE_RAS */
+EXC_REAL_NONE(0x1600, 0x1700)
+#endif
+
+EXC_REAL(altivec_assist, 0x1700, 0x1800)
+
+TRAMP_KVM(PACA_EXGEN, 0x1700)
+
+#ifdef CONFIG_CBE_RAS
+EXC_REAL_HV(cbe_thermal, 0x1800, 0x1900)
+
+TRAMP_KVM_HV_SKIP(PACA_EXGEN, 0x1800)
+
+#else /* CONFIG_CBE_RAS */
+EXC_REAL_NONE(0x1800, 0x1900)
+#endif
+
+
+/*** Out of line interrupts support ***/
+
+ /* moved from 0x200 */
TRAMP_KVM_SKIP(PACA_EXGEN, 0x300)
TRAMP_KVM_SKIP(PACA_EXSLB, 0x380)
TRAMP_KVM(PACA_EXGEN, 0x400)
@@ -791,7 +989,6 @@ EXC_COMMON(altivec_assist_common, 0x1700, unknown_exception)
* only has extra guff for STAB-based processors -- which never
* come here.
*/
-EXC_VIRT_NONE(0x4200, 0x4300)
EXC_VIRT(data_access, 0x4300, 0x4380, 0x300)
@@ -971,30 +1168,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
EXC_COMMON(h_instr_storage_common, 0xe20, unknown_exception)
- /*
- * Machine check is different because we use a different
- * save area: PACA_EXMC instead of PACA_EXGEN.
- */
-EXC_COMMON_BEGIN(machine_check_common)
- mfspr r10,SPRN_DAR
- std r10,PACA_EXMC+EX_DAR(r13)
- mfspr r10,SPRN_DSISR
- stw r10,PACA_EXMC+EX_DSISR(r13)
- EXCEPTION_PROLOG_COMMON(0x200, PACA_EXMC)
- FINISH_NAP
- 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
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl machine_check_exception
- b ret_from_except
-
EXC_COMMON_BEGIN(alignment_common)
mfspr r10,SPRN_DAR
std r10,PACA_EXGEN+EX_DAR(r13)
@@ -1195,180 +1368,6 @@ hmi_exception_after_realmode:
EXCEPTION_PROLOG_0(PACA_EXGEN)
b tramp_real_hmi_exception
-
-#define MACHINE_CHECK_HANDLER_WINDUP \
- /* Clear MSR_RI before setting SRR0 and SRR1. */\
- li r0,MSR_RI; \
- mfmsr r9; /* get MSR value */ \
- andc r9,r9,r0; \
- mtmsrd r9,1; /* Clear MSR_RI */ \
- /* Move original SRR0 and SRR1 into the respective regs */ \
- 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)
-
- /*
- * Handle machine check early in real mode. We come here with
- * ME=1, MMU (IR=0 and DR=0) off and using MC emergency stack.
- */
-EXC_COMMON_BEGIN(machine_check_handle_early)
- std r0,GPR0(r1) /* Save r0 */
- EXCEPTION_PROLOG_COMMON_3(0x200)
- bl save_nvgprs
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl machine_check_early
- std r3,RESULT(r1) /* Save result */
- ld r12,_MSR(r1)
-#ifdef CONFIG_PPC_P7_NAP
- /*
- * Check if thread was in power saving mode. We come here when any
- * of the following is true:
- * a. thread wasn't in power saving mode
- * b. thread was in power saving mode with no state loss,
- * supervisor state loss or hypervisor state loss.
- *
- * Go back to nap/sleep/winkle mode again if (b) is true.
- */
- rlwinm. r11,r12,47-31,30,31 /* Was it in power saving mode? */
- beq 4f /* No, it wasn;t */
- /* Thread was in power saving mode. Go back to nap again. */
- cmpwi r11,2
- blt 3f
- /* Supervisor/Hypervisor state loss */
- li r0,1
- stb r0,PACA_NAPSTATELOST(r13)
-3: bl machine_check_queue_event
- MACHINE_CHECK_HANDLER_WINDUP
- GET_PACA(r13)
- ld r1,PACAR1(r13)
- /*
- * Check what idle state this CPU was in and go back to same mode
- * again.
- */
- lbz r3,PACA_THREAD_IDLE_STATE(r13)
- cmpwi r3,PNV_THREAD_NAP
- bgt 10f
- IDLE_STATE_ENTER_SEQ(PPC_NAP)
- /* No return */
-10:
- cmpwi r3,PNV_THREAD_SLEEP
- bgt 2f
- IDLE_STATE_ENTER_SEQ(PPC_SLEEP)
- /* No return */
-
-2:
- /*
- * Go back to winkle. Please note that this thread was woken up in
- * machine check from winkle and have not restored the per-subcore
- * state. Hence before going back to winkle, set last bit of HSPGR0
- * to 1. This will make sure that if this thread gets woken up
- * again at reset vector 0x100 then it will get chance to restore
- * the subcore state.
- */
- ori r13,r13,1
- SET_PACA(r13)
- IDLE_STATE_ENTER_SEQ(PPC_WINKLE)
- /* No return */
-4:
-#endif
- /*
- * Check if we are coming from hypervisor userspace. If yes then we
- * continue in host kernel in V mode to deliver the MC event.
- */
- 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. */
- bne 9f /* continue in V mode if we are. */
-
-5:
-#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
- /*
- * We are coming from kernel context. Check if we are coming from
- * guest. if yes, then we can continue. We will fall through
- * do_kvm_200->kvmppc_interrupt to deliver the MC event to guest.
- */
- lbz r11,HSTATE_IN_GUEST(r13)
- cmpwi r11,0 /* Check if coming from guest */
- bne 9f /* continue if we are. */
-#endif
- /*
- * At this point we are not sure about what context we come from.
- * Queue up the MCE event 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
- bne 2f
-1: mfspr r11,SPRN_SRR0
- 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, system will checkstop
- * and hypervisor will get restarted cleanly by SP.
- */
- li r3,MSR_ME
- andc r10,r10,r3 /* Turn off MSR_ME */
- mtspr SPRN_SRR1,r10
- rfid
- b .
-2:
- /*
- * Check if we have successfully handled/recovered from error, if not
- * then stay on emergency stack and panic.
- */
- ld r3,RESULT(r1) /* Load result */
- cmpdi r3,0 /* see if we handled MCE successfully */
-
- beq 1b /* if !handled then panic */
- /*
- * Return from MC interrupt.
- * Queue up the MCE event so that we can log it later, while
- * returning from kernel or opal call.
- */
- bl machine_check_queue_event
- MACHINE_CHECK_HANDLER_WINDUP
- rfid
-9:
- /* Deliver the machine check to host kernel in V mode. */
- MACHINE_CHECK_HANDLER_WINDUP
- b machine_check_pSeries
-
-EXC_COMMON_BEGIN(unrecover_mce)
- /* Invoke machine_check_exception to print MCE event and panic. */
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl machine_check_exception
- /*
- * We will not reach here. Even if we did, there is no way out. Call
- * unrecoverable_exception and die.
- */
-1: addi r3,r1,STACK_FRAME_OVERHEAD
- bl unrecoverable_exception
- b 1b
-
/*
* r13 points to the PACA, r9 contains the saved CR,
* r12 contain the saved SRR1, SRR0 is still ready for return
--
2.7.4
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