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author | Nicholas Piggin <npiggin@gmail.com> | 2019-08-02 12:56:35 +0200 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-08-30 02:32:35 +0200 |
commit | 272f636445cf556498c8840dc63ad1218e94391b (patch) | |
tree | ecc87836a3b5e6c0ea70cf3529a351d8539c3210 /arch/powerpc/kernel/exceptions-64s.S | |
parent | powerpc/64s/pseries: machine check convert to use common event code (diff) | |
download | linux-272f636445cf556498c8840dc63ad1218e94391b.tar.xz linux-272f636445cf556498c8840dc63ad1218e94391b.zip |
powerpc/64s/exception: machine check pseries should skip the late handler for kernel MCEs
The powernv machine check handler copes with taking a MCE from one of
three contexts, guest, kernel, and user. In each case the early
handler runs first on a special stack, then:
- The guest case branches to the KVM interrupt handler (via standard
interrupt macros).
- The user case will run the "late" handler which is like a normal
interrupt that runs in virtual mode and uses the regular kernel
stack.
- The kernel case queues the event and schedules it for processing
with irq work.
The last case is important, it must not enable virtual memory because
the MMU state may not be set up to deal with that (e.g., SLB might be
clear), it must not use the regular kernel stack for similar reasons
(e.g., might be in OPAL with OPAL stack in r1), and the kernel does
not expect anything to touch its stack if interrupts are disabled.
The pseries handler does not do this queueing, but instead it always
runs the late handler for host MCEs, which has some of the same
problems.
Now that pseries is using machine_check_events, change it to do the
same as powernv and queue events for kernel MCEs.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802105709.27696-11-npiggin@gmail.com
Diffstat (limited to '')
-rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 22 |
1 files changed, 2 insertions, 20 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index b7c4149cb91c..aa3720c0b8fe 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1163,7 +1163,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206) 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 @@ -1172,18 +1172,7 @@ BEGIN_FTR_SECTION bl machine_check_queue_event MACHINE_CHECK_HANDLER_WINDUP RFI_TO_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. */ BEGIN_FTR_SECTION @@ -1212,13 +1201,6 @@ 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 - MACHINE_CHECK_HANDLER_WINDUP - RFI_TO_KERNEL - b . EXC_REAL_BEGIN(data_access, 0x300, 0x80) EXCEPTION_PROLOG_0 PACA_EXGEN |