[PATCH v4 0/6] x86: Cleanups around slow_down_io()

[Juergen Gross <jgross@suse.com>]

While looking at paravirt cleanups I stumbled over slow_down_io() and
the related REALLY_SLOW_IO define.

Do several cleanups, resulting in a deletion of REALLY_SLOW_IO and the
io_delay() paravirt function hook.

Patch 4 is removing the config options for selecting the default delay
mechanism and sets the default to "no delay". This is in preparation of
removing the io_delay() functionality completely, as suggested by Ingo
Molnar.

Patch 5 is adding an additional config option allowing to avoid
building io_delay.c (default is still to build it).

Changes in V2:
- patches 2 and 3 of V1 have been applied
- new patches 4 and 5

Changes in V3:
- rebase to tip/master kernel branch

Changes in V4:
- add patch 1 as prereq patch to the series

Juergen Gross (6):
  x86/irqflags: Fix build failure
  x86/paravirt: Replace io_delay() hook with a bool
  block/floppy: Don't use REALLY_SLOW_IO for delays
  x86/io: Remove REALLY_SLOW_IO handling
  x86/io_delay: Switch io_delay() default mechanism to "none"
  x86/io_delay: Add config option for controlling build of io_delay.

 arch/x86/Kconfig                      |  8 +++
 arch/x86/Kconfig.debug                | 30 ----------
 arch/x86/include/asm/floppy.h         | 31 ++++++++--
 arch/x86/include/asm/io.h             | 19 ++++---
 arch/x86/include/asm/irqflags.h       |  6 +-
 arch/x86/include/asm/paravirt-base.h  |  6 ++
 arch/x86/include/asm/paravirt.h       | 11 ----
 arch/x86/include/asm/paravirt_types.h |  2 -
 arch/x86/kernel/Makefile              |  3 +-
 arch/x86/kernel/cpu/vmware.c          |  2 +-
 arch/x86/kernel/io_delay.c            | 81 +--------------------------
 arch/x86/kernel/kvm.c                 |  8 +--
 arch/x86/kernel/paravirt.c            |  3 +-
 arch/x86/kernel/setup.c               |  4 +-
 arch/x86/xen/enlighten_pv.c           |  6 +-
 drivers/block/floppy.c                |  2 -
 16 files changed, 63 insertions(+), 159 deletions(-)

-- 
2.52.0