On 03/01/16 08:16, Jordan Justen wrote:
> 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?
No, that's the one we should use. I wasn't aware of its existence in
"MdePkg/Include/IndustryStandard/Pci22.h".
Thanks
Laszlo
>
> -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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