[PATCH v7 9/9] powernv/pseries: consolidate code for mce early handling.
Mahesh J Salgaonkar
mahesh at linux.vnet.ibm.com
Wed Aug 8 00:18:04 AEST 2018
From: Mahesh Salgaonkar <mahesh at 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 at linux.vnet.ibm.com>
---
arch/powerpc/kernel/exceptions-64s.S | 138 +++++++---------------------------
1 file changed, 28 insertions(+), 110 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index cb06f219570a..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)
@@ -346,90 +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 */
- ld r1,PACAMCEMERGSP(r13) /* Use MC emergency stack */
- subi r1,r1,INT_FRAME_SIZE /* alloc stack frame */
- 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
- bne 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 */
- bne 1f /* if handled then return from interrupt */
-
- 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 .
-
- /* Stay on emergency stack and return from interrupt. */
-1: LOAD_HANDLER(r10,mce_return)
- mtspr SPRN_SRR0,r10
- ld r10,PACAKMSR(r13)
- 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
- 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
@@ -528,6 +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
/*
@@ -551,10 +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
@@ -565,6 +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.
@@ -598,6 +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
@@ -606,10 +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. */
@@ -627,25 +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
- REST_GPR(11, r1)
- REST_2GPRS(12, r1)
- /* restore original r1. */
- ld r1,GPR1(r1)
+ MACHINE_CHECK_HANDLER_WINDUP
RFI_TO_KERNEL
b .
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