On Thu, May 21, 2020 at 13:10:28 +0200, Ard Biesheuvel wrote:
> The way EDK2 invokes the UEFI driver model assumes that PCI I/O
> protocol instances exist for all PCI I/O controllers in the system.
>
> For instance, UefiBootManagerLib connects the short-form USB device
> path of the console input by looking for PCI I/O controllers that
> have the 'USB host controller' class code, and passing each one to
> ConnectController(), using the device path as the 'RemainingDevicePath'
> argument.
>
> For true PCI I/O protocol instances produced by the PCI root bridge
> driver, this works fine, since it always enumerates the PCIe hierarchy
> exhaustively. However, for platform devices that are wired to PCI class
> drivers using the non-discoverable PCIe driver, this breaks down, due
> to the fact that the PCI I/O protocol instance does not exist unless the
> non-discoverable device protocol handle is connected first.
>
> So let's connect these handles non-recursively as soon as they appear.
>
> Cc: Hao A Wu <hao.a...@intel.com>
> Cc: Ray Ni <ray...@intel.com>
> Signed-off-by: Ard Biesheuvel <ard.biesheu...@arm.com>
Acked-by: Leif Lindholm <l...@nuviainc.com>
> ---
>
> MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c
> | 43 ++++++++++++++++++++
> 1 file changed, 43 insertions(+)
>
> diff --git
> a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c
>
> b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c
> index 5c93e2a7663c..a14c06e7f4e1 100644
> ---
> a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c
> +++
> b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c
> @@ -15,6 +15,8 @@
> STATIC UINTN mUniqueIdCounter = 0;
> EFI_CPU_ARCH_PROTOCOL *mCpu;
>
> +STATIC VOID *mProtocolNotifyRegistration;
> +
> //
> // We only support the following device types
> //
> @@ -250,6 +252,43 @@ STATIC EFI_DRIVER_BINDING_PROTOCOL gDriverBinding = {
> NULL
> };
>
> +STATIC
> +VOID
> +EFIAPI
> +NonDiscoverablePciDeviceProtocolNotify (
> + IN EFI_EVENT Event,
> + IN VOID *Context
> + )
> +{
> + EFI_STATUS Status;
> + EFI_HANDLE *Handles;
> + UINTN HandleCount;
> + UINTN Index;
> +
> + Status = gBS->LocateHandleBuffer (ByRegisterNotify, NULL,
> + mProtocolNotifyRegistration, &HandleCount, &Handles);
> + if (EFI_ERROR (Status)) {
> + if (Status != EFI_NOT_FOUND) {
> + DEBUG ((DEBUG_WARN, "%a: LocateHandleBuffer() failed - %r\n",
> + __FUNCTION__, Status));
> + }
> + return;
> + }
> +
> + for (Index = 0; Index < HandleCount; Index++) {
> + //
> + // Connect each newly registered gEdkiiNonDiscoverableDeviceProtocolGuid
> + // instance non-recursively to this driver specifically. This ensures
> that
> + // PCI I/O instances exist for each, regardless of whether ConnectAll()
> is
> + // used at any point.
> + //
> + Status = gBS->ConnectController (Handles[Index], gImageHandle, NULL,
> FALSE);
> + DEBUG ((DEBUG_VERBOSE, "%a: ConnectController () returned %r\n",
> + __FUNCTION__, Status));
> + }
> + gBS->FreePool (Handles);
> +}
> +
> /**
> Entry point of this driver.
>
> @@ -272,6 +311,10 @@ NonDiscoverablePciDeviceDxeEntryPoint (
> Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID
> **)&mCpu);
> ASSERT_EFI_ERROR(Status);
>
> + EfiCreateProtocolNotifyEvent (&gEdkiiNonDiscoverableDeviceProtocolGuid,
> + TPL_CALLBACK, NonDiscoverablePciDeviceProtocolNotify, NULL,
> + &mProtocolNotifyRegistration);
> +
> return EfiLibInstallDriverBindingComponentName2 (
> ImageHandle,
> SystemTable,
> --
> 2.17.1
>
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