linux/arch/powerpc
Nicholas Piggin 2104180a53 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>
2017-07-12 16:26:02 -07:00
..
boot powerpc updates for 4.13 2017-07-07 13:55:45 -07:00
configs powerpc/44x/fsp2: Add defconfig for FSP2 board 2017-05-30 14:59:51 +10:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-05-02 15:53:46 -07:00
include powerpc/64s: implement arch-specific hardlockup watchdog 2017-07-12 16:26:02 -07:00
kernel powerpc/64s: implement arch-specific hardlockup watchdog 2017-07-12 16:26:02 -07:00
kvm powerpc updates for 4.13 2017-07-07 13:55:45 -07:00
lib powerpc/lib/code-patching: Use alternate map for patch_instruction() 2017-07-03 23:12:19 +10:00
math-emu
mm powerpc updates for 4.13 2017-07-07 13:55:45 -07:00
net bpf: Add jited_len to struct bpf_prog 2017-06-06 15:41:24 -04:00
oprofile
perf Merge branch 'fixes' into next 2017-07-03 23:05:43 +10:00
platforms powerpc updates for 4.13 2017-07-07 13:55:45 -07:00
purgatory kexec, x86/purgatory: Unbreak it and clean it up 2017-03-10 20:55:09 +01:00
sysdev powerpc updates for 4.13 2017-07-07 13:55:45 -07:00
tools powerpc/64: Tool to check head sections location sanity 2017-05-30 14:59:51 +10:00
xmon powerpc/xmon: Add patch_instruction() support for xmon 2017-07-03 23:12:19 +10:00
Kconfig powerpc/64s: implement arch-specific hardlockup watchdog 2017-07-12 16:26:02 -07:00
Kconfig.debug
Makefile powerpc: Link warning for orphan sections 2017-05-30 14:59:51 +10:00
Makefile.postlink powerpc/64: Tool to check head sections location sanity 2017-05-30 14:59:51 +10:00