Silicon/SynQuacer: tweak PCI I/O windows for ACPI/Linux support

The ACPI/Linux code does not cope very well with I/O BAR windows that
involve type translation and address translation. In particular, the
secondary I/O window we implement on SynQuacer:

   I/O  0x10000 ... 0x1ffff -> 0x77f00000

is misinterpreted by Linux, and results in the MMIO range starting at
0x77f10000 to be mapped for I/O port access to this range.

This can be mitigated by using the same bus range for I/O port access
on both RCs., i.e., [0x0 ... 0xffff]. This configuration can be represented
using both DT and ACPI, and will work as expected in Linux.

Now that the generic PCI host bridge driver has gained support for address
translation, we can actually support this configuration seamlessly in UEFI
as well, by applying an offset to the second I/O window to make it appear
adjacent to the first one in the CPU view of the I/O space.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

0 files changed, 0 insertions, 0 deletions