tree c571511c7fa0a720ecfbcd821bd71676253c2374
parent 9bc7e2ce343ec1d6b33f53d828410b7b930aa559
author Andre Przywara <andre.przywara@arm.com> 1615822412 +0000
committer Will Deacon <will@kernel.org> 1616060685 +0000

mmio: Extend handling to include ioport emulation

In their core functionality MMIO and I/O port traps are not really
different, yet we still have two totally separate code paths for
handling them. Devices need to decide on one conduit or need to provide
different handler functions for each of them.

Extend the existing MMIO emulation to also cover ioport handlers.
This just adds another RB tree root for holding the I/O port handlers,
but otherwise uses the same tree population and lookup code.
"ioport" or "mmio" just become a flag in the registration function.
Provide wrappers to not break existing users, and allow an easy
transition for the existing ioport handlers.

This also means that ioport handlers now can use the same emulation
callback prototype as MMIO handlers, which means we have to migrate them
over. To allow a smooth transition, we hook up the new I/O emulate
function to the end of the existing ioport emulation code.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210315153350.19988-5-andre.przywara@arm.com
Signed-off-by: Will Deacon <will@kernel.org>