[PATCH 0/6 V2] x86, nmi: Various fixes and cleanups

[Don Zickus <dzickus@redhat.com>]

I started this patch by fixing a performance problem with the GHES
NMI handler and then things evolved to more patches as I was poking
around in the code.

The main focus was moving the GHES NMI driver to its own NMI subtype
to avoid slowing down perf handling.  Then I decided to move the
default external NMI handler to its own routine.  Then finally, I
needed to see which NMI handlers were registered so I hacked up
/proc/interrupts to show me.

Tested mostly on HP boxes that have GHES enabled and having the iLO
send NMIs to panic the box (using hpwdt driver).  Ran perf on other
GHES enabled boxes to test performance results.

V2: adding irq_work items to handled possible lost NMIs (new patch 1)
    modified output of /proc/interrupts based on feedback (patch 6)

Don Zickus (5):
  x86, nmi:  Add new nmi type 'external'
  x86, nmi: Add boot line option 'panic_on_unrecovered_nmi' and
    'panic_on_io_nmi'
  x86, nmi: Remove 'reason' value from unknown nmi output
  x86, nmi: Move default external NMI handler to its own routine
  x86, nmi: Add better NMI stats to /proc/interrupts and show handlers

 Documentation/kernel-parameters.txt |    9 ++
 arch/x86/include/asm/nmi.h          |    5 +
 arch/x86/kernel/irq.c               |    3 +
 arch/x86/kernel/nmi.c               |  199 ++++++++++++++++++++++++++--------
 drivers/acpi/apei/ghes.c            |    4 +-
 drivers/watchdog/hpwdt.c            |   24 +++--
 6 files changed, 187 insertions(+), 57 deletions(-)

*** BLURB HERE ***

Don Zickus (6):
  x86, nmi:  Implement delayed irq_work mechanism to handle lost NMIs
  x86, nmi:  Add new nmi type 'external'
  x86, nmi: Add boot line option 'panic_on_unrecovered_nmi' and
    'panic_on_io_nmi'
  x86, nmi: Remove 'reason' value from unknown nmi output
  x86, nmi: Move default external NMI handler to its own routine
  x86, nmi: Add better NMI stats to /proc/interrupts and show handlers

 Documentation/kernel-parameters.txt |    9 +
 arch/x86/include/asm/nmi.h          |    5 +
 arch/x86/kernel/irq.c               |    3 +
 arch/x86/kernel/nmi.c               |  302 +++++++++++++++++++++++++++++-----
 drivers/acpi/apei/ghes.c            |    4 +-
 drivers/watchdog/hpwdt.c            |   24 ++-
 6 files changed, 292 insertions(+), 55 deletions(-)