[PATCH 0/5] x86: Cleanups around slow_down_io()
From: Juergen Gross
Date: Wed Nov 26 2025 - 11:20:22 EST
While looking at paravirt cleanups I stumbled over slow_down_io() and
the related REALLY_SLOW_IO define.
Especially REALLY_SLOW_IO is a mess, which is proven by 2 completely
wrong use cases.
Do several cleanups, resulting in a deletion of REALLY_SLOW_IO and the
io_delay() paravirt function hook.
Patches 2 and 3 are not changing any functionality, but maybe they
should? As the potential bug has been present for more than a decade
now, I went with just deleting the useless "#define REALLY_SLOW_IO".
The alternative would be to do something similar as in patch 5.
Juergen Gross (5):
x86/paravirt: Replace io_delay() hook with a bool
hwmon/lm78: Drop REALLY_SLOW_IO setting
hwmon/w83781d: Drop REALLY_SLOW_IO setting
block/floppy: Don't use REALLY_SLOW_IO for delays
x86/io: Remove REALLY_SLOW_IO handling
arch/x86/include/asm/floppy.h | 27 ++++++++++++++++++++++-----
arch/x86/include/asm/io.h | 12 +++++-------
arch/x86/include/asm/paravirt.h | 11 +----------
arch/x86/include/asm/paravirt_types.h | 3 +--
arch/x86/kernel/cpu/vmware.c | 2 +-
arch/x86/kernel/kvm.c | 8 +-------
arch/x86/kernel/paravirt.c | 3 +--
arch/x86/xen/enlighten_pv.c | 6 +-----
drivers/block/floppy.c | 2 --
drivers/hwmon/lm78.c | 5 +++--
drivers/hwmon/w83781d.c | 5 +++--
11 files changed, 39 insertions(+), 45 deletions(-)
--
2.51.0