Commit db7d31ac authored by Mahesh Salgaonkar's avatar Mahesh Salgaonkar Committed by Michael Ellerman

powernv/pseries: consolidate code for mce early handling.

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: default avatarMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent c6d15258
......@@ -244,14 +244,13 @@ 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:
......@@ -305,7 +304,9 @@ 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
......@@ -324,7 +325,6 @@ 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
......@@ -332,7 +332,7 @@ 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)
......@@ -345,103 +345,6 @@ 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 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
......@@ -540,6 +443,9 @@ 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
/*
......@@ -563,11 +469,12 @@ 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:
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
BEGIN_FTR_SECTION
/*
* We are coming from kernel context. Check if we are coming from
* guest. if yes, then we can continue. We will fall through
......@@ -576,6 +483,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early)
lbz r11,HSTATE_IN_GUEST(r13)
cmpwi r11,0 /* Check if coming from guest */
bne 9f /* continue if we are. */
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
#endif
/*
* At this point we are not sure about what context we come from.
......@@ -610,6 +518,7 @@ 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
......@@ -618,10 +527,24 @@ 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. */
......@@ -639,29 +562,7 @@ 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 .
......
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