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 <[email protected]> Reviewed-by: Ray Ni <[email protected]>
seuzht · Dec 29, 2021 · c095122 · c095122
1 parent 7935be0
commit c095122
Showing 1 changed file with 25 additions and 1 deletion.
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
@@ -2115,6 +2115,27 @@ AuthenticatePciDevice (
   return EFI_SUCCESS;
 }
 
+/**
+  Checks if PCI device is Root Bridge.
+
+  @param PciIoDevice       Instance of PCI device
+
+  @retval TRUE             Device is Root Bridge
+  @retval FALSE            Device is not Root Bridge
+
+**/
+BOOLEAN
+IsRootBridge (
+  IN PCI_IO_DEVICE  *PciIoDevice
+  )
+{
+  if (PciIoDevice->Parent == NULL) {
+    return TRUE;
+  } else {
+    return FALSE;
+  }
+}
+
 /**
   Create and initialize general PCI I/O device instance for
   PCI device/bridge device/hotplug bridge device.
@@ -2217,7 +2238,10 @@ CreatePciIoDevice (
     return NULL;
   }
 
-  if (PcdGetBool (PcdAriSupport)) {
+  //
+  // Check if device's parent is not Root Bridge
+  //
+  if (PcdGetBool (PcdAriSupport) && !IsRootBridge (Bridge)) {
     //
     // Check if the device is an ARI device.
     //