On 2015-07-07 08:09:22, Laszlo Ersek wrote:
> In this patch we assume that root bus number 0 is always there (same as
> before), and scan the rest of the extra root buses, up to and including
> 255. When an extra root bus is found, we install the PCI root bridge IO
> protocol for the previous root bus (which might be bus 0 or just the
> previous extra root bus).
>
> The root bridge protocol created thus will report the available bus number
> range
>
> [own bus number, next extra root bus number - 1]
>
> The LHS of this interval will be used for the root bus's own number, and
> the rest of the interval (which might encompass 0 additional elements too)
> can be used by the PCI bus driver to assign subordinate bus numbers from.
>
> (Subordinate buses are provided by PCI bridges that hang off the root bus
> in question.)
>
> For MMIO and IO space allocation, all the root buses share the original
> [0x8000_0000, 0xFFFF_FFFF] and [0x0, 0xFFFF] ranges, respectively.
>
> Cc: Jordan Justen <jordan.l.jus...@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Laszlo Ersek <ler...@redhat.com>
> Regression-tested-by: Gabriel Somlo <so...@cmu.edu>
> ---
> OvmfPkg/PciHostBridgeDxe/PciHostBridge.c | 95 +++++++++++++++-----
> 1 file changed, 71 insertions(+), 24 deletions(-)
>
> diff --git a/OvmfPkg/PciHostBridgeDxe/PciHostBridge.c
> b/OvmfPkg/PciHostBridgeDxe/PciHostBridge.c
> index 7dda75f..3486644 100644
> --- a/OvmfPkg/PciHostBridgeDxe/PciHostBridge.c
> +++ b/OvmfPkg/PciHostBridgeDxe/PciHostBridge.c
> @@ -43,14 +43,6 @@ EFI_PCI_ROOT_BRIDGE_DEVICE_PATH
> mRootBridgeDevicePathTemplate = {
> }
> };
>
> -//
> -// Hard code: Root Bridge's resource aperture
> -//
> -
> -PCI_ROOT_BRIDGE_RESOURCE_APERTURE mResAperture[1] = {
> - {0, 0xff, 0x80000000, 0xffffffff, 0, 0xffff}
> -};
> -
> EFI_HANDLE mDriverImageHandle;
>
> PCI_HOST_BRIDGE_INSTANCE mPciHostBridgeInstanceTemplate = {
> @@ -80,8 +72,15 @@ PCI_HOST_BRIDGE_INSTANCE mPciHostBridgeInstanceTemplate = {
>
> param[in] RootBusNumber The bus number of the root bus (root bridge)
> to
> create.
> - RootBusNumber is expected to fall into the
> valid
> - offset range of mResAperture.
> +
> + param[in] MaxSubBusNumber The inclusive maximum bus number that can be
> + assigned to any subordinate bus found behind
> any
> + PCI bridge hanging off this root bus.
> +
> + The caller is repsonsible for ensuring that
> + RootBusNumber <= MaxSubBusNumber. If
> + RootBusNumber equals MaxSubBusNumber, then the
> + root bus has no room for subordinate buses.
>
> param[in] HostBridgeHandle The EFI_HANDLE corresponding to the host
> bridge
> that is the parent of the root bridge to
> create.
> @@ -108,12 +107,16 @@ STATIC
> EFI_STATUS
> InitRootBridge (
> IN UINT8 RootBusNumber,
> + IN UINT8 MaxSubBusNumber,
> IN EFI_HANDLE HostBridgeHandle,
> OUT PCI_ROOT_BRIDGE_INSTANCE **RootBus
> )
> {
> - PCI_ROOT_BRIDGE_INSTANCE *PrivateData;
> - EFI_STATUS Status;
> + PCI_ROOT_BRIDGE_INSTANCE *PrivateData;
> + PCI_ROOT_BRIDGE_RESOURCE_APERTURE ResAperture;
> + EFI_STATUS Status;
> +
> + ASSERT (RootBusNumber <= MaxSubBusNumber);
>
> PrivateData = AllocateZeroPool (sizeof *PrivateData);
> if (PrivateData == NULL) {
> @@ -126,13 +129,18 @@ InitRootBridge (
> sizeof mRootBridgeDevicePathTemplate);
> PrivateData->DevicePath.AcpiDevicePath.UID = RootBusNumber;
>
> + ResAperture.BusBase = RootBusNumber;
> + ResAperture.BusLimit = MaxSubBusNumber;
> + ResAperture.MemBase = BASE_2GB;
> + ResAperture.MemLimit = BASE_4GB - 1;
> + ResAperture.IoBase = 0;
> + ResAperture.IoLimit = MAX_UINT16;
> //
> // The function call below allocates no resources and performs no actions
> // that have to be rolled back on later failure. It always succeeds.
> //
> Status = RootBridgeConstructor (&PrivateData->Io, HostBridgeHandle,
> - EFI_PCI_HOST_BRIDGE_COMBINE_MEM_PMEM,
> - &mResAperture[RootBusNumber]);
> + EFI_PCI_HOST_BRIDGE_COMBINE_MEM_PMEM, &ResAperture);
> ASSERT_EFI_ERROR (Status);
>
> Status = gBS->InstallMultipleProtocolInterfaces (&PrivateData->Handle,
> @@ -143,6 +151,9 @@ InitRootBridge (
> goto FreePrivateData;
> }
>
> + DEBUG ((EFI_D_INFO,
> + "%a: installed root bus %d, with room for %d subordinate bus(es)\n",
> + __FUNCTION__, RootBusNumber, MaxSubBusNumber - RootBusNumber));
> *RootBus = PrivateData;
> return EFI_SUCCESS;
>
> @@ -196,6 +207,7 @@ InitializePciHostBridge (
> )
> {
> EFI_STATUS Status;
> + UINTN LastRootBridgeNumber;
> UINTN RootBridgeNumber;
> PCI_HOST_BRIDGE_INSTANCE *HostBridge;
> PCI_ROOT_BRIDGE_INSTANCE *RootBus;
> @@ -224,19 +236,54 @@ InitializePciHostBridge (
> goto FreeHostBridge;
> }
>
> - for (RootBridgeNumber = 0;
> - RootBridgeNumber < 1;
> + //
> + // The "main" root bus is always there.
> + //
> + LastRootBridgeNumber = 0;
> +
> + //
> + // Scan all other root buses. If function 0 of any device on a bus returns
> a
> + // VendorId register value different from all-bits-one, then that bus is
> + // alive.
> + //
> + for (RootBridgeNumber = 1;
> + RootBridgeNumber < 256;
Do we want to scan all these buses on Xen?
> ++RootBridgeNumber) {
> - Status = InitRootBridge (
> - (UINT8)RootBridgeNumber,
> - HostBridge->HostBridgeHandle,
> - &RootBus
> - );
> - if (EFI_ERROR (Status)) {
> - goto RollbackProtocols;
> + UINTN Device;
> +
> + for (Device = 0; Device <= MAX_PCI_DEVICE_NUMBER; ++Device) {
I guess there's no guarantee that device 0 will be present on these
buses?
-Jordan
> + if (PciRead16 (PCI_LIB_ADDRESS (RootBridgeNumber, Device, 0,
> + PCI_VENDOR_ID_OFFSET)) != MAX_UINT16) {
> + break;
> + }
> }
> - InsertTailList (&HostBridge->Head, &RootBus->Link);
> + if (Device <= MAX_PCI_DEVICE_NUMBER) {
> + //
> + // Found the next root bus. We can now install the *previous* one,
> + // because now we know how big a bus number range *that* one has, for
> any
> + // subordinate buses that might exist behind PCI bridges hanging off
> it.
> + //
> + Status = InitRootBridge ((UINT8)LastRootBridgeNumber,
> + (UINT8)(RootBridgeNumber - 1), HostBridge->HostBridgeHandle,
> + &RootBus);
> + if (EFI_ERROR (Status)) {
> + goto RollbackProtocols;
> + }
> + InsertTailList (&HostBridge->Head, &RootBus->Link);
> + LastRootBridgeNumber = RootBridgeNumber;
> + }
> + }
> +
> + //
> + // Install the last root bus (which might be the only, ie. main, root bus,
> if
> + // we've found no extra root buses).
> + //
> + Status = InitRootBridge ((UINT8)LastRootBridgeNumber, 255,
> + HostBridge->HostBridgeHandle, &RootBus);
> + if (EFI_ERROR (Status)) {
> + goto RollbackProtocols;
> }
> + InsertTailList (&HostBridge->Head, &RootBus->Link);
>
> return EFI_SUCCESS;
>
> --
> 1.8.3.1
>
>
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