[CHERRY-PICK][REBASE & FF] Revert Mu Commits In Favor of edk2 Commits

EmbeddedPkg/Library/NonCoherentDmaLib/NonCoherentDmaLib.c

@@ -500,10 +500,12 @@ DmaAllocateAlignedBuffer (
 {
   EFI_GCD_MEMORY_SPACE_DESCRIPTOR  GcdDescriptor;
   VOID                             *Allocation;
-  UINT64                           MemType;
+  UINT64                           Attributes;
   UNCACHED_ALLOCATION              *Alloc;
   EFI_STATUS                       Status;
 
+  Attributes = EFI_MEMORY_XP;
+
   if (Alignment == 0) {
     Alignment = EFI_PAGE_SIZE;
   }
@@ -534,9 +536,9 @@ DmaAllocateAlignedBuffer (
 
   // Choose a suitable uncached memory type that is supported by the region
   if (GcdDescriptor.Capabilities & EFI_MEMORY_WC) {
-    MemType = EFI_MEMORY_WC;
+    Attributes |= EFI_MEMORY_WC;
   } else if (GcdDescriptor.Capabilities & EFI_MEMORY_UC) {
-    MemType = EFI_MEMORY_UC;
+    Attributes |= EFI_MEMORY_UC;
   } else {
     Status = EFI_UNSUPPORTED;
     goto FreeBuffer;
@@ -553,11 +555,37 @@ DmaAllocateAlignedBuffer (
 
   InsertHeadList (&UncachedAllocationList, &Alloc->Link);
 
-  // Remap the region with the new attributes
+  // Ensure that EFI_MEMORY_XP is in the capability set
+  if ((GcdDescriptor.Capabilities & EFI_MEMORY_XP) != EFI_MEMORY_XP) {
+    Status = gDS->SetMemorySpaceCapabilities (
+                    (PHYSICAL_ADDRESS)(UINTN)Allocation,
+                    EFI_PAGES_TO_SIZE (Pages),
+                    GcdDescriptor.Capabilities | EFI_MEMORY_XP
+                    );
+
+    // if we were to fail setting the capability, this would indicate an internal failure of the GCD code. We should
+    // assert here to let a platform know something went crazy, but for a release build we can let the allocation occur
+    // without the EFI_MEMORY_XP bit set, as that was the existing behavior
+    if (EFI_ERROR (Status)) {
+      DEBUG ((
+        DEBUG_ERROR,
+        "%a failed to set EFI_MEMORY_XP capability on 0x%llx for length 0x%llx. Attempting to allocate without XP set.\n",
+        __func__,
+        Allocation,
+        EFI_PAGES_TO_SIZE (Pages)
+        ));
+
+      ASSERT_EFI_ERROR (Status);
+
+      Attributes &= ~EFI_MEMORY_XP;
+    }
+  }
+
+  // Remap the region with the new attributes and mark it non-executable
   Status = gDS->SetMemorySpaceAttributes (
                   (PHYSICAL_ADDRESS)(UINTN)Allocation,
                   EFI_PAGES_TO_SIZE (Pages),
-                  MemType | EFI_MEMORY_XP // MU_CHANGE: Allocate DMA memory XP by default
+                  Attributes
                   );
   if (EFI_ERROR (Status)) {
     goto FreeAlloc;

FmpDevicePkg/FmpDxe/FmpDxe.c

@@ -181,10 +181,12 @@ GetImageTypeIdGuid (
     if (ImageTypeIdGuidSize == sizeof (EFI_GUID)) {
       FmpDeviceLibGuid = (EFI_GUID *)PcdGetPtr (PcdFmpDeviceImageTypeIdGuid);
     } else {
-      // MU_CHANGE start - this is a misconfiguration error, we should assert
-      DEBUG ((DEBUG_ERROR, "FmpDxe(%s): Fall back to ImageTypeIdGuid of gEfiCallerIdGuid. FmpDxe error: misconfiguration\n", mImageIdName));
+      DEBUG ((
+        DEBUG_ERROR,
+        "FmpDxe(%s): Fall back to ImageTypeIdGuid of gEfiCallerIdGuid. FmpDxe error: misconfiguration\n",
+        mImageIdName
+        ));
       ASSERT (FALSE);
-      // MU_CHANGE end
       FmpDeviceLibGuid = &gEfiCallerIdGuid;
     }
   }

PrmPkg/PrmConfigDxe/PrmConfigDxe.c

@@ -152,17 +152,15 @@ SetRuntimeMemoryRangeAttributes (
       continue;
     }
 
+    // The memory space descriptor access attributes are not accurate. Don't pass
+    // in access attributes so SetMemorySpaceAttributes() doesn't update them.
+    // EFI_MEMORY_RUNTIME is not a CPU arch attribute, so calling
+    // SetMemorySpaceAttributes() with only it set will not clear existing page table
+    // attributes for this region, such as EFI_MEMORY_XP
     Status = gDS->SetMemorySpaceAttributes (
                     RuntimeMmioRanges->Range[Index].PhysicalBaseAddress,
                     (UINT64)RuntimeMmioRanges->Range[Index].Length,
-                    // MU_CHANGE START: The memory space descriptor access attributes are not accurate. Don't pass
-                    //                  in access attributes so SetMemorySpaceAttributes() doesn't update them.
-                    //                  EFI_MEMORY_RUNTIME is not a CPU arch attribute, so calling
-                    //                  SetMemorySpaceAttributes() with only it set will not clear existing page table
-                    //                  attributes for this region, such as EFI_MEMORY_XP
-                    // Descriptor.Attributes | EFI_MEMORY_RUNTIME
                     EFI_MEMORY_RUNTIME
-                    // MU_CHANGE END
                     );
     ASSERT_EFI_ERROR (Status);
     if (EFI_ERROR (Status)) {