On 2016-02-26 16:23:26, Laszlo Ersek wrote:
> In this patch we import the scan for extra root buses from the
> InitializePciHostBridge() function, in file
> "OvmfPkg/PciHostBridgeDxe/PciHostBridge.c".
>
> For the time being, the InitRootBridge() and UninitRootBridge() functions
> are just placeholders.
>
> The PciHostBridgeGetRootBridges() API expects us to return the
> PCI_ROOT_BRIDGE structures in a contiguous array, instead of a linked
> list. Therefore the following bits have to be converted manually:
>
> (1) The array is allocated in advance, in a single step.
>
> (2) The calculation of the array size depends on an explicit
> multiplication, which we must check against overflow. Since more than
> 255 extra root bridges make no sense anyway, we use (1 + 255) as the
> limit on the main plus all extra root bridges. This also ensures that
> the UINTN multiplication doesn't overflow.
>
> (3) The PciHostBridgeDxe code decrements "ExtraRootBridgesLeft" to
> terminate the scanning early. Here we need track the increasing count
> of used array elements as well, so we employ "ExtraRootBridges" as a
> constant limit, and increment the new local variable "Initialized".
>
> (4) The prototypes of InitRootBridge() and UninitRootBridge() reflect that
> the PCI_ROOT_BRIDGE structure is allocated by the caller; only
> in-place initialization is necessary.
>
> Additionally, MAX_PCI_DEVICE_NUMBER is open coded as 31 (decimal) form
> "OvmfPkg/PciHostBridgeDxe/PciHostBridge.h".
>
Do we need a different macro than PCI_MAX_DEVICE?
-Jordan
> Cc: Jordan Justen <jordan.l.jus...@intel.com>
> Cc: Ruiyu Ni <ruiyu...@intel.com>
> Cc: Marcel Apfelbaum <mar...@redhat.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Laszlo Ersek <ler...@redhat.com>
> ---
> OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.inf | 9 +-
> OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c | 165
> +++++++++++++++++++-
> 2 files changed, 172 insertions(+), 2 deletions(-)
>
> diff --git a/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.inf
> b/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.inf
> index 1f3930195a1d..b83693191261 100644
> --- a/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.inf
> +++ b/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.inf
> @@ -34,5 +34,12 @@ [Sources]
> PciHostBridgeLib.c
>
> [Packages]
> - MdePkg/MdePkg.dec
> MdeModulePkg/MdeModulePkg.dec
> + MdePkg/MdePkg.dec
> + OvmfPkg/OvmfPkg.dec
> +
> +[LibraryClasses]
> + DebugLib
> + MemoryAllocationLib
> + PciLib
> + QemuFwCfgLib
> diff --git a/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c
> b/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c
> index 3752993f65aa..b1f7e50ce781 100644
> --- a/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c
> +++ b/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c
> @@ -14,14 +14,77 @@
>
> **/
> #include <PiDxe.h>
> -#include <Library/PciHostBridgeLib.h>
> +
> +#include <IndustryStandard/Pci.h>
> +
> #include <Library/DebugLib.h>
> +#include <Library/MemoryAllocationLib.h>
> +#include <Library/PciHostBridgeLib.h>
> +#include <Library/PciLib.h>
> +#include <Library/QemuFwCfgLib.h>
> +
> +#define MAX_PCI_DEVICE_NUMBER 31
> +
>
> GLOBAL_REMOVE_IF_UNREFERENCED
> CHAR16 *mPciHostBridgeLibAcpiAddressSpaceTypeStr[] = {
> L"Mem", L"I/O", L"Bus"
> };
>
> +
> +/**
> + Initialize a PCI_ROOT_BRIDGE structure.
> +
> + param[in] RootBusNumber The bus number to store in RootBus.
> +
> + 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[out] RootBus The PCI_ROOT_BRIDGE structure (allocated by
> the
> + caller) that should be filled in by this
> + function.
> +
> + @retval EFI_SUCCESS Initialization successful. A device path
> + consisting of an ACPI device path node, with
> + UID = RootBusNumber, has been allocated and
> + linked into RootBus.
> +
> + @retval EFI_OUT_OF_RESOURCES Memory allocation failed.
> +**/
> +STATIC
> +EFI_STATUS
> +InitRootBridge (
> + IN UINT8 RootBusNumber,
> + IN UINT8 MaxSubBusNumber,
> + OUT PCI_ROOT_BRIDGE *RootBus
> + )
> +{
> + return EFI_OUT_OF_RESOURCES;
> +}
> +
> +
> +/**
> + Uninitialize a PCI_ROOT_BRIDGE structure set up with InitRootBridge().
> +
> + param[in] RootBus The PCI_ROOT_BRIDGE structure, allocated by the caller
> and
> + initialized with InitRootBridge(), that should be
> + uninitialized. This function doesn't free RootBus.
> +**/
> +STATIC
> +VOID
> +UninitRootBridge (
> + IN PCI_ROOT_BRIDGE *RootBus
> + )
> +{
> +}
> +
> +
> /**
> Return all the root bridge instances in an array.
>
> @@ -37,10 +100,109 @@ PciHostBridgeGetRootBridges (
> UINTN *Count
> )
> {
> + EFI_STATUS Status;
> + FIRMWARE_CONFIG_ITEM FwCfgItem;
> + UINTN FwCfgSize;
> + UINT64 ExtraRootBridges;
> + PCI_ROOT_BRIDGE *Bridges;
> + UINTN Initialized;
> + UINTN LastRootBridgeNumber;
> + UINTN RootBridgeNumber;
> +
> *Count = 0;
> +
> + //
> + // QEMU provides the number of extra root buses, shortening the exhaustive
> + // search below. If there is no hint, the feature is missing.
> + //
> + Status = QemuFwCfgFindFile ("etc/extra-pci-roots", &FwCfgItem, &FwCfgSize);
> + if (EFI_ERROR (Status) || FwCfgSize != sizeof ExtraRootBridges) {
> + ExtraRootBridges = 0;
> + } else {
> + QemuFwCfgSelectItem (FwCfgItem);
> + QemuFwCfgReadBytes (FwCfgSize, &ExtraRootBridges);
> +
> + if (ExtraRootBridges > 255) {
> + DEBUG ((EFI_D_ERROR, "%a: invalid count of extra root buses (%Lu) "
> + "reported by QEMU\n", __FUNCTION__, ExtraRootBridges));
> + return NULL;
> + }
> + DEBUG ((EFI_D_INFO, "%a: %Lu extra root buses reported by QEMU\n",
> + __FUNCTION__, ExtraRootBridges));
> + }
> +
> + //
> + // Allocate the "main" root bridge, and any extra root bridges.
> + //
> + Bridges = AllocatePool ((1 + (UINTN)ExtraRootBridges) * sizeof *Bridges);
> + if (Bridges == NULL) {
> + DEBUG ((EFI_D_ERROR, "%a: %r\n", __FUNCTION__, EFI_OUT_OF_RESOURCES));
> + return NULL;
> + }
> + Initialized = 0;
> +
> + //
> + // 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 && Initialized < ExtraRootBridges;
> + ++RootBridgeNumber) {
> + UINTN Device;
> +
> + for (Device = 0; Device <= MAX_PCI_DEVICE_NUMBER; ++Device) {
> + if (PciRead16 (PCI_LIB_ADDRESS (RootBridgeNumber, Device, 0,
> + PCI_VENDOR_ID_OFFSET)) != MAX_UINT16) {
> + break;
> + }
> + }
> + 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), &Bridges[Initialized]);
> + if (EFI_ERROR (Status)) {
> + goto FreeBridges;
> + }
> + ++Initialized;
> + 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,
> + &Bridges[Initialized]);
> + if (EFI_ERROR (Status)) {
> + goto FreeBridges;
> + }
> + ++Initialized;
> +
> + *Count = Initialized;
> + return Bridges;
> +
> +FreeBridges:
> + while (Initialized > 0) {
> + --Initialized;
> + UninitRootBridge (&Bridges[Initialized]);
> + }
> +
> + FreePool (Bridges);
> return NULL;
> }
>
> +
> /**
> Free the root bridge instances array returned from
> PciHostBridgeGetRootBridges().
> @@ -58,6 +220,7 @@ PciHostBridgeFreeRootBridges (
> return;
> }
>
> +
> /**
> Inform the platform that the resource conflict happens.
>
> --
> 1.8.3.1
>
>
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