Currently we allocate IO BARs bottom-up in the EfiPciHostBridgeAllocateResources phase of the enumeration.
> GCD:AddIoSpace(Base=0000000000000000,Length=0000000000010000) > GcdIoType = I/O > Status = Success > GCDIoType Range > ========== ================================= > I/O 0000000000000000-000000000000FFFF Because the IO aperture is based at zero, the first allocation happens to get the zero address. However, a zero address for a PCI BAR is considered unmapped; see eg.: - <http://www.pcisig.com/reflector/msg00459.html>, - the (new_addr == 0) part in QEMU, pci_bar_address() [hw/pci/pci.c]: new_addr = pci_get_long(d->config + bar) & ~(size - 1); last_addr = new_addr + size - 1; /* Check if 32 bit BAR wraps around explicitly. * TODO: make priorities correct and remove this work around. */ if (last_addr <= new_addr || new_addr == 0 || last_addr >= UINT32_MAX) { return PCI_BAR_UNMAPPED; } We can avoid this problem by allocating top-down in the IO aperture. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek <[email protected]> Reviewed-by: Olivier Martin <[email protected]> --- ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c index 0aa72a6..558786a 100644 --- a/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c +++ b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c @@ -382,8 +382,9 @@ NotifyPhase( BitsOfAlignment = 0; } + BaseAddress = mResAperture[0][0].IoLimit; Status = gDS->AllocateIoSpace ( - EfiGcdAllocateAnySearchBottomUp, + EfiGcdAllocateMaxAddressSearchTopDown, EfiGcdIoTypeIo, BitsOfAlignment, AddrLen, -- 1.8.3.1 ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=190641631&iu=/4140/ostg.clktrk _______________________________________________ edk2-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/edk2-devel
