[RFC v4 2/3] MdeModulePkg/PciBus: convert host address to device address

[Heyi Guo <heyi.guo@linaro.org>]

According to UEFI spec 2.7, PciRootBridgeIo->Configuration() should
return host address (CPU view ddress) rather than device address
(PCI view address), so in function GetMmioAddressTranslationOffset we
need to convert the range to device address before comparing.

And device address = host address + translation offset.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Heyi Guo <heyi.guo@linaro.org>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
---
 MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c
index 190f4b0dc7ed..fef3eceb7f62 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c
@@ -1812,10 +1812,14 @@ GetMmioAddressTranslationOffset (
     return (UINT64) -1;
   }
 
+  // According to UEFI 2.7, EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL::Configuration()
+  // returns host address instead of device address, while AddrTranslationOffset
+  // is not zero, and device address = host address + AddrTranslationOffset, so
+  // we convert host address to device address for range compare.
   while (Configuration->Desc == ACPI_ADDRESS_SPACE_DESCRIPTOR) {
     if ((Configuration->ResType == ACPI_ADDRESS_SPACE_TYPE_MEM) &&
-        (Configuration->AddrRangeMin <= AddrRangeMin) &&
-        (Configuration->AddrRangeMin + Configuration->AddrLen >= AddrRangeMin + AddrLen)
+        (Configuration->AddrRangeMin + Configuration->AddrTranslationOffset <= AddrRangeMin) &&
+        (Configuration->AddrRangeMin + Configuration->AddrLen + Configuration->AddrTranslationOffset >= AddrRangeMin + AddrLen)
         ) {
       return Configuration->AddrTranslationOffset;
     }
-- 
2.7.4