MdeModulePkg/PciBusDxe: Enumerator to check for RCiEP before looking for RP

Before trying to access parent root port to check ARI capabilities,
enumerator should see if Endpoint device is not Root Complex integrated
to avoid undefined parent register accesses.

Signed-off-by: Damian Bassa <damian.bassa@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>

diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
index ed7f2d4ac66d614e78020dfed820fdd59f5980af..9251388bc26836f6422656cf7b5a4b32bb3001e0 100644 (file)
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
@@ -2115,6 +2115,27 @@ AuthenticatePciDevice (
   return EFI_SUCCESS;\r
 }\r
 \r
+/**\r
+  Checks if PCI device is Root Bridge.\r
+\r
+  @param PciIoDevice       Instance of PCI device\r
+\r
+  @retval TRUE             Device is Root Bridge\r
+  @retval FALSE            Device is not Root Bridge\r
+\r
+**/\r
+BOOLEAN\r
+IsRootBridge (\r
+  IN PCI_IO_DEVICE  *PciIoDevice\r
+  )\r
+{\r
+  if (PciIoDevice->Parent == NULL) {\r
+    return TRUE;\r
+  } else {\r
+    return FALSE;\r
+  }\r
+}\r
+\r
 /**\r
   Create and initialize general PCI I/O device instance for\r
   PCI device/bridge device/hotplug bridge device.\r
@@ -2217,7 +2238,10 @@ CreatePciIoDevice (
     return NULL;\r
   }\r
 \r
-  if (PcdGetBool (PcdAriSupport)) {\r
+  //\r
+  // Check if device's parent is not Root Bridge\r
+  //\r
+  if (PcdGetBool (PcdAriSupport) && !IsRootBridge (Bridge)) {\r
     //\r
     // Check if the device is an ARI device.\r
     //\r