Re: [edk2-devel] [edk2-staging/UEFI_PCI_ENHANCE-2 PATCH 05/12] PciBusDxe: Setup sub-phases for PCI feature enumeration

["Ni, Ray" <ray.ni@intel.com>]

Please check comments below.
I may have more comments regarding to the four phases after I finish review of further patches.

Besides the comments below, I have a general comments to the debug message: can you please
review the existing debug message in the PciBus driver and make sure your newly added debug message
aligns to existing style. And try to use less lines of debug messages with still enough debug information.

> > +PRIMARY_ROOT_PORT_NODE                      *mPrimaryRootPortList;
> > +
> > +/**
> > +  A global pointer to PCI_FEATURE_CONFIGURATION_COMPLETION_LIST,
> > which
> > +stores all
> > +  the PCI Root Bridge instances that are enumerated for the other PCI
> > +features,
> > +  like MaxPayloadSize & MaxReadReqSize; during the the Start()
> > +interface of the
> > +  driver binding protocol. The records pointed by this pointer would be
> > +destroyed
> > +  when the DXE core invokes the Stop() interface.
> > +**/
> > +PCI_FEATURE_CONFIGURATION_COMPLETION_LIST
> > *mPciFeaturesConfigurationCompletionList = NULL;

1. Please follow existing linked list usage style. The first node in the list is an empty header node.

LIST_ENTRY   mPrimaryRootPortList;
LIST_ENTRY   mPciFeaturesConfigurationCompletionList;

> > +BOOLEAN
> > +CheckPciFeatureConfigurationRecordExist (
> > +  IN  PCI_IO_DEVICE                             *RootBridge,
> > +  OUT PCI_FEATURE_CONFIGURATION_COMPLETION_LIST
> > +**PciFeatureConfigRecord
> > +  )

2. Is this function to check whether the PCIE features under a root bridge
is already initialized?
Can you use the existing variable gFullEnumeration?
The variable is set to TRUE when the enumeration is done to a host bridge in the first time.
By using gFullEnumeration, the entire function is not needed.

> > +EFI_STATUS AddRootBridgeInPciFeaturesConfigCompletionList (
> > +  IN PCI_IO_DEVICE          *RootBridge,
> > +  IN BOOLEAN                ReEnumerationRequired
> > +  )

3. Same question as #2. I think by using gFullEnumeration, this function is not needed.


> > +BOOLEAN
> > +IsPciRootPortEmpty (
> > +  IN  PCI_IO_DEVICE                           *PciDevice
> > +  )

4. Please use IsListEmpty() directly from callers and remove this function.

> > +**/
> > +EFI_STATUS
> > +EnumerateOtherPciFeatures (

5. Can it be "EnumeratePcieFeatures"?

> > +  IN PCI_IO_DEVICE          *RootBridge
> > +  )
> > +{
> > +  EFI_STATUS            Status;
> > +  UINTN                 OtherPciFeatureConfigPhase;
> > +
> > +  //
> > +  // check on PCI features configuration is complete and re-enumeration
> > + is required  //  if (!CheckPciFeaturesConfigurationRequired
> > + (RootBridge)) {
> > +    return EFI_ALREADY_STARTED;
> > +  }
> > +
 > > +  CHAR16                *Str;
> > +  Str = ConvertDevicePathToText (
> > +          DevicePathFromHandle (RootBridge->Handle),
> > +          FALSE,
> > +          FALSE
> > +        );
> > +  DEBUG ((DEBUG_INFO, "Enumerating PCI features for Root Bridge %s\n",
> > + Str != NULL ? Str : L""));

6. Please use DEBUG_CODE macro to include ConvertDevicePathToText() and DEBUG().
Please remember to call FreePool().

> > +
> > +  for ( OtherPciFeatureConfigPhase = PciFeatureRootBridgeScan
> > +      ; OtherPciFeatureConfigPhase <= PciFeatureConfigurationComplete
> > +      ; OtherPciFeatureConfigPhase++
> > +      ) {
> > +    switch (OtherPciFeatureConfigPhase){
> > +      case  PciFeatureRootBridgeScan:
> > +        SetupPciFeaturesConfigurationDefaults ();
> > +        //
> > +        //first scan the entire root bridge heirarchy for the primary PCI root
> ports
> > +        //
> > +        RecordPciRootPortBridges (RootBridge);

7. How about "RecordPciRootPorts (RootBridge)"? The "Bridges" suffix is a bit confusing.

> > +      case  PciFeatureGetDevicePolicy:
> > +      case  PciFeatureSetupPhase:

8. In SetupPciFeatures(), why do you need to call DeviceExist()?
Did you see any case that a device is detected in the beginning of PciBus scan but
is hidden when calling SetupPciFeatures()?

9. In GetPciFeaturesConfigurationTable() when checking whether a PCI device
belongs to a root port, we can use below simpler logic:
  SizeOfPciDevicePath = GetDevicePathSize (PciDevicePath);
  SizeOfRootPortDevicePath = GetDevicePathSize (RootPortPath);
  if ((SizeOfRootPortDevicePath < SizeOfPciDevicePath) &&
      CompareMem (PciDevicePath, RootPortPath, SizeOfRootPortDevicePath - END_DEVICE_PATH_LENGTH) == 0)) {
    // PCI device belongs to the root port.
  }

> > +        Status = ProgramPciFeatures (RootBridge);
10. ProgramPcieFeatures()?

> > +
> > +  if (Str != NULL) {
> > +    FreePool (Str);
> > +  }

11. OK the Str is freed here because Str is needed for other debug messages inside the function.

> > +  //
> > +  // mark this root bridge as PCI features configuration complete, and
> > +no new
> > +  // enumeration is required
> > +  //
> > +  AddRootBridgeInPciFeaturesConfigCompletionList (RootBridge, FALSE);

12. Not needed.

> > +_PRIMARY_ROOT_PORT_NODE {

> > +  //
> > +  // Signature header
> > +  //
> > +  UINT32                                    Signature;
> > +  //
> > +  // linked list pointers to next node
> > +  //
> > +  LIST_ENTRY                                NeighborRootPort;
> > +  //
> > +  // pointer to PCI_IO_DEVICE of the primary PCI Controller device
> > +  //
> > +  EFI_DEVICE_PATH_PROTOCOL                  *RootPortDevicePath;
> > +  //
> > +  // pointer to the corresponding PCI feature configuration Table node
> > +  // all the child PCI devices of the controller are aligned based on
> > +this table
> > +  //
> > +  OTHER_PCI_FEATURES_CONFIGURATION_TABLE
> > *OtherPciFeaturesConfigurationTable;
> > +};

13. Can you add the OTHER_PCI_FEATURES_CONFIGURATION_TABLE field to PCI_IO_DEVICE structure?
So this structure PRIMARY_ROOT_PORT_NODE is not needed.

> > +struct _PCI_FEATURE_CONFIGURATION_COMPLETION_LIST {
14. This structure is not needed if using gFullEnumeration.