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| author | Nicholas Piggin <npiggin@gmail.com> | 2017-07-12 14:35:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-12 16:26:02 -0700 |
| commit | 2104180a53698df5aec35aed5f840a26ade0551d (patch) | |
| tree | 72fcbf52fd53a333282de9103197c04576025c54 /arch/powerpc/kernel/exceptions-64s.S | |
| parent | a10a842ff81a7e3810817b3b04e4c432b6191e21 (diff) | |
| download | linux-2104180a53698df5aec35aed5f840a26ade0551d.tar.gz | |
powerpc/64s: implement arch-specific hardlockup watchdog
Implement an arch-speicfic watchdog rather than use the perf-based
hardlockup detector.
The new watchdog takes the soft-NMI directly, rather than going through
perf. Perf interrupts are to be made maskable in future, so that would
prevent the perf detector from working in those regions.
Additionally, implement a SMP based detector where all CPUs watch one
another by pinging a shared cpumask. This is because powerpc Book3S
does not have a true periodic local NMI, but some platforms do implement
a true NMI IPI.
If a CPU is stuck with interrupts hard disabled, the soft-NMI watchdog
does not work, but the SMP watchdog will. Even on platforms without a
true NMI IPI to get a good trace from the stuck CPU, other CPUs will
notice the lockup sufficiently to report it and panic.
[npiggin@gmail.com: honor watchdog disable at boot/hotplug]
Link: http://lkml.kernel.org/r/20170621001346.5bb337c9@roar.ozlabs.ibm.com
[npiggin@gmail.com: fix false positive warning at CPU unplug]
Link: http://lkml.kernel.org/r/20170630080740.20766-1-npiggin@gmail.com
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170616065715.18390-6-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Tested-by: Babu Moger <babu.moger@oracle.com> [sparc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 4c18a5fbb4bb..e6d8354d79ef 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1314,6 +1314,31 @@ EXC_REAL_NONE(0x1800, 0x100) EXC_VIRT_NONE(0x5800, 0x100) #endif +#if defined(CONFIG_HARDLOCKUP_DETECTOR) && defined(CONFIG_HAVE_HARDLOCKUP_DETECTOR_ARCH) + +#define MASKED_DEC_HANDLER_LABEL 3f + +#define MASKED_DEC_HANDLER(_H) \ +3: /* soft-nmi */ \ + std r12,PACA_EXGEN+EX_R12(r13); \ + GET_SCRATCH0(r10); \ + std r10,PACA_EXGEN+EX_R13(r13); \ + EXCEPTION_PROLOG_PSERIES_1(soft_nmi_common, _H) + +EXC_COMMON_BEGIN(soft_nmi_common) + mr r10,r1 + ld r1,PACAEMERGSP(r13) + ld r1,PACA_NMI_EMERG_SP(r13) + subi r1,r1,INT_FRAME_SIZE + EXCEPTION_COMMON_NORET_STACK(PACA_EXGEN, 0x900, + system_reset, soft_nmi_interrupt, + ADD_NVGPRS;ADD_RECONCILE) + b ret_from_except + +#else +#define MASKED_DEC_HANDLER_LABEL 2f /* normal return */ +#define MASKED_DEC_HANDLER(_H) +#endif /* * An interrupt came in while soft-disabled. We set paca->irq_happened, then: @@ -1336,7 +1361,7 @@ masked_##_H##interrupt: \ lis r10,0x7fff; \ ori r10,r10,0xffff; \ mtspr SPRN_DEC,r10; \ - b 2f; \ + b MASKED_DEC_HANDLER_LABEL; \ 1: cmpwi r10,PACA_IRQ_DBELL; \ beq 2f; \ cmpwi r10,PACA_IRQ_HMI; \ @@ -1351,7 +1376,8 @@ masked_##_H##interrupt: \ ld r11,PACA_EXGEN+EX_R11(r13); \ GET_SCRATCH0(r13); \ ##_H##rfid; \ - b . + b .; \ + MASKED_DEC_HANDLER(_H) /* * Real mode exceptions actually use this too, but alternate |