EFI_INCOMPATIBLE_PCI_DEVICE_SUPPORT_PROTOCOL returns ACPI address
descriptors describing PCI resource requirements. When both _MIF (BIT2)
and _MAF (BIT3) are set in the descriptor's GenFlag, the descriptor
represents a fixed address range.
Extend PCI_BAR with FixedBaseAddress and update the PCI bus driver to
preserve and use this information:
* UpdatePciInfo() detects _MIF|_MAF, records AddrRangeMin as
FixedBaseAddress, and marks the BAR as fixed.
* ProgramBar() programs FixedBaseAddress into the BAR register instead
of the resource allocator selected address for fixed BARs.
No functional change occurs unless a platform driver supplies fixed BAR
descriptors through EFI_INCOMPATIBLE_PCI_DEVICE_SUPPORT_PROTOCOL.
Signed-off-by: Tushar Dave <[email protected]>
---
MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h | 1 +
.../Bus/Pci/PciBusDxe/PciEnumeratorSupport.c | 12 ++++++++++++
MdeModulePkg/Bus/Pci/PciBusDxe/PciResourceSupport.c | 13 +++++++++++++
3 files changed, 26 insertions(+)
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
index 01bce28b1b..4edf45119f 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
@@ -96,6 +96,7 @@ struct _PCI_BAR {
UINT64 Alignment;
PCI_BAR_TYPE BarType;
BOOLEAN BarTypeFixed;
+ UINT64 FixedBaseAddress;
UINT16 Offset;
};
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
index ae94462f60..da16355d9f 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
@@ -1638,6 +1638,18 @@ UpdatePciInfo (
if (Ptr->AddrLen != 0) {
PciIoDevice->PciBar[BarIndex].Length = Ptr->AddrLen;
}
+
+ //
+ // When both _MIF (BIT2) and _MAF (BIT3) are set in GenFlag the
+ // descriptor carries a fixed base address in AddrRangeMin.
+ //
+ if ((Ptr->GenFlag & (BIT2 | BIT3)) == (BIT2 | BIT3)) {
+ PciIoDevice->PciBar[BarIndex].BarTypeFixed = TRUE;
+ PciIoDevice->PciBar[BarIndex].FixedBaseAddress = Ptr->AddrRangeMin;
+ DEBUG ((DEBUG_INFO,
+ "PciBus: UpdatePciInfo BAR[%u] fixed address=0x%016Lx\n",
+ (UINT32)BarIndex, Ptr->AddrRangeMin));
+ }
}
}
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciResourceSupport.c
b/MdeModulePkg/Bus/Pci/PciBusDxe/PciResourceSupport.c
index 8f3cff3eaa..5cc3ae797d 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciResourceSupport.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciResourceSupport.c
@@ -1276,6 +1276,19 @@ ProgramBar (
Address = Base + Node->Offset;
+ //
+ // If EFI_INCOMPATIBLE_PCI_DEVICE_SUPPORT_PROTOCOL supplied a fixed
+ // base address (_MIF|_MAF in the ACPI descriptor), use it directly.
+ //
+ if (Node->PciDev->PciBar[Node->Bar].BarTypeFixed &&
+ (Node->PciDev->PciBar[Node->Bar].FixedBaseAddress != 0))
+ {
+ Address = Node->PciDev->PciBar[Node->Bar].FixedBaseAddress;
+ DEBUG ((DEBUG_INFO,
+ "PciBus: BAR[%d] fixed address 0x%016Lx (GCD 0x%016Lx)\n",
+ Node->Bar, Address, Base + Node->Offset));
+ }
+
//
// Indicate pci bus driver has allocated
// resource for this device
--
2.34.1
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