Currently, the implementation of EFI_PCI_IO_PROTOCOL::GetLocation() in NonDiscoverablePciDeviceDxe returns the same set of dummy values for each instance of the NON_DISCOVERABLE_DEVICE protocol that it attaches itself to. However, this turns out to be causing problems in cases where software (such as the ARM Compliance Test Suite [ACS]) attempts to use these values to uniquely identify controllers, since the collisions create ambiguity in this regard.
So let's modify GetLocation() to return an arbitrary bus/device tuple on segment 0xff instead. This is guaranteed not to clash with other non-discoverable PCI devices, and highly unlikely to clash with real PCIe devices. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ard Biesheuvel <[email protected]> Tested-by: Marcin Wojtas <[email protected]> --- v2: add sanity check on id value so we don't exceed 256 buses initialize counter to 0 explicitly - this isn't strictly necessary but clarifies the code MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c | 10 ++++++++++ MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c | 10 +++++++--- MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.h | 6 ++++++ 3 files changed, 23 insertions(+), 3 deletions(-) diff --git a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c index 3e9ff6620d8d..2483c7296912 100644 --- a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c +++ b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c @@ -16,6 +16,9 @@ #include <Protocol/DriverBinding.h> +#define MAX_NON_DISCOVERABLE_PCI_DEVICE_ID (32 * 256) + +STATIC UINTN mUniqueIdCounter = 0; EFI_CPU_ARCH_PROTOCOL *mCpu; // @@ -141,6 +144,11 @@ NonDiscoverablePciDeviceStart ( NON_DISCOVERABLE_PCI_DEVICE *Dev; EFI_STATUS Status; + ASSERT (mUniqueIdCounter < MAX_NON_DISCOVERABLE_PCI_DEVICE_ID); + if (mUniqueIdCounter >= MAX_NON_DISCOVERABLE_PCI_DEVICE_ID) { + return EFI_OUT_OF_RESOURCES; + } + Dev = AllocateZeroPool (sizeof *Dev); if (Dev == NULL) { return EFI_OUT_OF_RESOURCES; @@ -167,6 +175,8 @@ NonDiscoverablePciDeviceStart ( goto CloseProtocol; } + Dev->UniqueId = mUniqueIdCounter++; + return EFI_SUCCESS; CloseProtocol: diff --git a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c index 0e42ae4bf6ec..58cb5d8b1fc5 100644 --- a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c +++ b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c @@ -1181,6 +1181,8 @@ PciIoGetLocation ( OUT UINTN *FunctionNumber ) { + NON_DISCOVERABLE_PCI_DEVICE *Dev; + if (SegmentNumber == NULL || BusNumber == NULL || DeviceNumber == NULL || @@ -1188,9 +1190,11 @@ PciIoGetLocation ( return EFI_INVALID_PARAMETER; } - *SegmentNumber = 0; - *BusNumber = 0xff; - *DeviceNumber = 0; + Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(This); + + *SegmentNumber = 0xff; + *BusNumber = Dev->UniqueId >> 5; + *DeviceNumber = Dev->UniqueId & 0x1f; *FunctionNumber = 0; return EFI_SUCCESS; diff --git a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.h b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.h index e641189267ee..5b4c57fa2a8e 100644 --- a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.h +++ b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.h @@ -100,6 +100,12 @@ typedef struct { // on behalf of this device // LIST_ENTRY UncachedAllocationList; + // + // Unique ID for this device instance: needed so that we can report unique + // segment/bus/device number for each device instance. Note that this number + // may change when disconnecting/reconnecting the driver. + // + UINTN UniqueId; } NON_DISCOVERABLE_PCI_DEVICE; /** -- 2.19.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
