1 files changed, 24 insertions, 0 deletions
diff --git a/MdePkg/Include/Library/PciExpressLib.h b/MdePkg/Include/Library/PciExpressLib.h
index 68d17901f6..098f815510 100644
--- a/MdePkg/Include/Library/PciExpressLib.h
+++ b/MdePkg/Include/Library/PciExpressLib.h
@@ -39,6 +39,30 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
   (((Offset) & 0xfff) | (((Function) & 0x07) << 12) | (((Device) & 0x1f) << 15) | (((Bus) & 0xff) << 20))
 
 /**
+  Register a PCI device so PCI configuration registers may be accessed after 
+  SetVirtualAddressMap().
+  
+  If Address > 0x0FFFFFFF, then ASSERT().
+
+  @param  Address Address that encodes the PCI Bus, Device, Function and
+                  Register.
+  
+  @retval RETURN_SUCCESS           The PCI device was registered for runtime access.
+  @retval RETURN_UNSUPPORTED       An attempt was made to call this function 
+                                   after ExitBootServices().
+  @retval RETURN_UNSUPPORTED       The resources required to access the PCI device
+                                   at runtime could not be mapped.
+  @retval RETURN_OUT_OF_RESOURCES  There are not enough resources available to
+                                   complete the registration.
+
+**/
+RETURN_STATUS
+EFIAPI
+PciExpressRegisterForRuntimeAccess (
+  IN UINTN  Address
+  );
+
+/**
   Reads an 8-bit PCI configuration register.
 
   Reads and returns the 8-bit PCI configuration register specified by Address.