[PATCH v3 6/7] OvmfPkg/VirtNorFlashDxe: Not add memory space if it exists

["Tuan Phan" <tphan@ventanamicro.com>]

The flash base address can be added to GCD before this driver run.
So only add it if it has not been done.

Signed-off-by: Tuan Phan <tphan@ventanamicro.com>
Reviewed-by: Andrei Warkentin <andrei.warkentin@intel.com>
---
 OvmfPkg/VirtNorFlashDxe/VirtNorFlashDxe.c | 25 +++++++++++++++--------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/OvmfPkg/VirtNorFlashDxe/VirtNorFlashDxe.c b/OvmfPkg/VirtNorFlashDxe/VirtNorFlashDxe.c
index 6b9ef261335e..bbd1697a51dd 100644
--- a/OvmfPkg/VirtNorFlashDxe/VirtNorFlashDxe.c
+++ b/OvmfPkg/VirtNorFlashDxe/VirtNorFlashDxe.c
@@ -372,10 +372,11 @@ NorFlashFvbInitialize (
   IN NOR_FLASH_INSTANCE  *Instance
   )
 {
-  EFI_STATUS     Status;
-  UINT32         FvbNumLba;
-  EFI_BOOT_MODE  BootMode;
-  UINTN          RuntimeMmioRegionSize;
+  EFI_STATUS                      Status;
+  UINT32                          FvbNumLba;
+  EFI_BOOT_MODE                   BootMode;
+  UINTN                           RuntimeMmioRegionSize;
+  EFI_GCD_MEMORY_SPACE_DESCRIPTOR Desc;
 
   DEBUG ((DEBUG_BLKIO, "NorFlashFvbInitialize\n"));
   ASSERT ((Instance != NULL));
@@ -390,13 +391,19 @@ NorFlashFvbInitialize (
   //       is written as the base of the flash region (ie: Instance->DeviceBaseAddress)
   RuntimeMmioRegionSize = (Instance->RegionBaseAddress - Instance->DeviceBaseAddress) + Instance->Size;
 
-  Status = gDS->AddMemorySpace (
-                  EfiGcdMemoryTypeMemoryMappedIo,
+  Status = gDS->GetMemorySpaceDescriptor (
                   Instance->DeviceBaseAddress,
-                  RuntimeMmioRegionSize,
-                  EFI_MEMORY_UC | EFI_MEMORY_RUNTIME
+                  &Desc
                   );
-  ASSERT_EFI_ERROR (Status);
+  if (Status == EFI_NOT_FOUND) {
+    Status = gDS->AddMemorySpace (
+                    EfiGcdMemoryTypeMemoryMappedIo,
+                    Instance->DeviceBaseAddress,
+                    RuntimeMmioRegionSize,
+                    EFI_MEMORY_UC | EFI_MEMORY_RUNTIME
+                    );
+    ASSERT_EFI_ERROR (Status);
+  }
 
   Status = gDS->SetMemorySpaceAttributes (
                   Instance->DeviceBaseAddress,
-- 
2.25.1