[edk2-staging/UEFI_PCI_ENHANCE-2 PATCH 03/12] PciBusDxe: Separation of the PCI device registration and start

["Javeed, Ashraf" <ashraf.javeed@intel.com>]

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2194

The separation of the PCI device registration phase includes only the
installation of the PCI IO Protocol on the PCI node to acquire the EFI
handles, and loading of its applicable PCI Option ROM.

The separation of the PCI device start phase only includes the code that
enables the PCI Bridge device as a Bus Master.

This code change is made in order to introduce the enabling of the other
PCI features in the PCI Bus driver.

Signed-off-by: Ashraf Javeed <ashraf.javeed@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
---
 MdeModulePkg/Bus/Pci/PciBusDxe/PciDeviceSupport.c | 164 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------
 1 file changed, 130 insertions(+), 34 deletions(-)

diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciDeviceSupport.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciDeviceSupport.c
index 149a120..33a0e94 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciDeviceSupport.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciDeviceSupport.c
@@ -561,7 +561,7 @@ DeRegisterPciDevice (
 }
 
 /**
-  Start to manage the PCI device on the specified root bridge or PCI-PCI Bridge.
+  Start the PCI root Ports or PCI-PCI Bridge only.
 
   @param Controller          The root bridge handle.
   @param RootBridge          A pointer to the PCI_IO_DEVICE.
@@ -576,7 +576,82 @@ DeRegisterPciDevice (
 
 **/
 EFI_STATUS
-StartPciDevicesOnBridge (
+StartPciRootPortsOnBridge (
+  IN EFI_HANDLE                          Controller,
+  IN PCI_IO_DEVICE                       *RootBridge
+  )
+
+{
+  PCI_IO_DEVICE             *PciIoDevice;
+  EFI_STATUS                Status;
+  LIST_ENTRY                *CurrentLink;
+  UINT64                    Supports;
+
+  PciIoDevice = NULL;
+  CurrentLink = RootBridge->ChildList.ForwardLink;
+
+  while (CurrentLink != NULL && CurrentLink != &RootBridge->ChildList) {
+
+    PciIoDevice = PCI_IO_DEVICE_FROM_LINK (CurrentLink);
+
+    //
+    // check if the device has been assigned with required resource
+    // and registered
+    //
+    if (!PciIoDevice->Registered && !PciIoDevice->Allocated) {
+      return EFI_NOT_READY;
+    }
+
+    if (IS_PCI_BRIDGE (&PciIoDevice->Pci)) {
+      Status = StartPciRootPortsOnBridge (
+                 Controller,
+                 PciIoDevice
+                 );
+
+      PciIoDevice->PciIo.Attributes (
+                           &(PciIoDevice->PciIo),
+                           EfiPciIoAttributeOperationSupported,
+                           0,
+                           &Supports
+                         );
+      Supports &= (UINT64)EFI_PCI_DEVICE_ENABLE;
+      PciIoDevice->PciIo.Attributes (
+                           &(PciIoDevice->PciIo),
+                           EfiPciIoAttributeOperationEnable,
+                           Supports,
+                           NULL
+                         );
+
+    }
+
+    CurrentLink = CurrentLink->ForwardLink;
+  }
+
+  if (PciIoDevice == NULL) {
+    return EFI_NOT_FOUND;
+  } else {
+    return EFI_SUCCESS;
+  }
+}
+
+
+/**
+  Register to manage the PCI device on the specified root bridge or PCI-PCI Bridge.
+
+  @param Controller          The root bridge handle.
+  @param RootBridge          A pointer to the PCI_IO_DEVICE.
+  @param RemainingDevicePath A pointer to the EFI_DEVICE_PATH_PROTOCOL.
+  @param NumberOfChildren    Children number.
+  @param ChildHandleBuffer   A pointer to the child handle buffer.
+
+  @retval EFI_NOT_READY   Device is not allocated.
+  @retval EFI_UNSUPPORTED Device only support PCI-PCI bridge.
+  @retval EFI_NOT_FOUND   Can not find the specific device.
+  @retval EFI_SUCCESS     Success to start Pci devices on bridge.
+
+**/
+EFI_STATUS
+RegisterPciDevicesOnBridge (
   IN EFI_HANDLE                          Controller,
   IN PCI_IO_DEVICE                       *RootBridge,
   IN EFI_DEVICE_PATH_PROTOCOL            *RemainingDevicePath,
@@ -590,7 +665,6 @@ StartPciDevicesOnBridge (
   EFI_DEVICE_PATH_PROTOCOL  *CurrentDevicePath;
   EFI_STATUS                Status;
   LIST_ENTRY                *CurrentLink;
-  UINT64                    Supports;
 
   PciIoDevice = NULL;
   CurrentLink = RootBridge->ChildList.ForwardLink;
@@ -645,7 +719,7 @@ StartPciDevicesOnBridge (
       // If it is a PPB
       //
       if (IS_PCI_BRIDGE (&PciIoDevice->Pci)) {
-        Status = StartPciDevicesOnBridge (
+        Status = RegisterPciDevicesOnBridge (
                    Controller,
                    PciIoDevice,
                    CurrentDevicePath,
@@ -653,20 +727,6 @@ StartPciDevicesOnBridge (
                    ChildHandleBuffer
                    );
 
-        PciIoDevice->PciIo.Attributes (
-                             &(PciIoDevice->PciIo),
-                             EfiPciIoAttributeOperationSupported,
-                             0,
-                             &Supports
-                             );
-        Supports &= (UINT64)EFI_PCI_DEVICE_ENABLE;
-        PciIoDevice->PciIo.Attributes (
-                             &(PciIoDevice->PciIo),
-                             EfiPciIoAttributeOperationEnable,
-                             Supports,
-                             NULL
-                             );
-
         return Status;
       } else {
 
@@ -697,28 +757,13 @@ StartPciDevicesOnBridge (
       }
 
       if (IS_PCI_BRIDGE (&PciIoDevice->Pci)) {
-        Status = StartPciDevicesOnBridge (
+        Status = RegisterPciDevicesOnBridge (
                    Controller,
                    PciIoDevice,
                    RemainingDevicePath,
                    NumberOfChildren,
                    ChildHandleBuffer
                    );
-
-        PciIoDevice->PciIo.Attributes (
-                             &(PciIoDevice->PciIo),
-                             EfiPciIoAttributeOperationSupported,
-                             0,
-                             &Supports
-                             );
-        Supports &= (UINT64)EFI_PCI_DEVICE_ENABLE;
-        PciIoDevice->PciIo.Attributes (
-                             &(PciIoDevice->PciIo),
-                             EfiPciIoAttributeOperationEnable,
-                             Supports,
-                             NULL
-                             );
-
       }
 
       CurrentLink = CurrentLink->ForwardLink;
@@ -732,6 +777,57 @@ StartPciDevicesOnBridge (
   }
 }
 
+/**
+  Start to manage the PCI device on the specified root bridge or PCI-PCI Bridge.
+
+  @param Controller          The root bridge handle.
+  @param RootBridge          A pointer to the PCI_IO_DEVICE.
+  @param RemainingDevicePath A pointer to the EFI_DEVICE_PATH_PROTOCOL.
+  @param NumberOfChildren    Children number.
+  @param ChildHandleBuffer   A pointer to the child handle buffer.
+
+  @retval EFI_NOT_READY   Device is not allocated.
+  @retval EFI_UNSUPPORTED Device only support PCI-PCI bridge.
+  @retval EFI_NOT_FOUND   Can not find the specific device.
+  @retval EFI_SUCCESS     Success to start Pci devices on bridge.
+
+**/
+EFI_STATUS
+StartPciDevicesOnBridge (
+  IN EFI_HANDLE                          Controller,
+  IN PCI_IO_DEVICE                       *RootBridge,
+  IN EFI_DEVICE_PATH_PROTOCOL            *RemainingDevicePath,
+  IN OUT UINT8                           *NumberOfChildren,
+  IN OUT EFI_HANDLE                      *ChildHandleBuffer
+  )
+
+{
+  EFI_STATUS                Status;
+
+  //
+  // first register all the PCI devices
+  //
+  Status = RegisterPciDevicesOnBridge (
+             Controller,
+             RootBridge,
+             RemainingDevicePath,
+             NumberOfChildren,
+             ChildHandleBuffer
+             );
+
+  if (EFI_ERROR (Status) == EFI_NOT_FOUND) {
+    return Status;
+  } else {
+    //
+    // finally start those PCI bridge port devices only
+    //
+    return StartPciRootPortsOnBridge (
+            Controller,
+            RootBridge
+            );
+  }
+}
+
 /**
   Start to manage all the PCI devices it found previously under
   the entire host bridge.
-- 
2.21.0.windows.1