MdeModulePkg/Gcd: Filter gCpu->SetMemoryAttributes() calls

[mirror_edk2.git] / MdeModulePkg / Core / Dxe / Gcd / Gcd.c

diff --git a/MdeModulePkg/Core/Dxe/Gcd/Gcd.c b/MdeModulePkg/Core/Dxe/Gcd/Gcd.c
index 907245a3f512c2eeb5424cdf166744b57c1df2ce..31ddf9c3bb516e7dd34b92813f408d993c36aa7a 100644 (file)
--- a/MdeModulePkg/Core/Dxe/Gcd/Gcd.c
+++ b/MdeModulePkg/Core/Dxe/Gcd/Gcd.c
@@ -48,8 +48,6 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #define NONEXCLUSIVE_MEMORY_ATTRIBUTES (EFI_MEMORY_XP | EFI_MEMORY_RP | \\r
                                         EFI_MEMORY_RO)\r
 \r
-#define INVALID_CPU_ARCH_ATTRIBUTES   0xffffffff\r
-\r
 //\r
 // Module Variables\r
 //\r
@@ -873,7 +871,21 @@ CoreConvertSpace (
     // Call CPU Arch Protocol to attempt to set attributes on the range\r
     //\r
     CpuArchAttributes = ConverToCpuArchAttributes (Attributes);\r
-    if (CpuArchAttributes != INVALID_CPU_ARCH_ATTRIBUTES) {\r
+    //\r
+    // CPU arch attributes include page attributes and cache attributes. \r
+    // Only page attributes supports to be cleared, but not cache attributes.\r
+    // Caller is expected to use GetMemorySpaceDescriptor() to get the current\r
+    // attributes, AND/OR attributes, and then calls SetMemorySpaceAttributes()\r
+    // to set the new attributes.\r
+    // So 0 CPU arch attributes should not happen as memory should always have\r
+    // a cache attribute (no matter UC or WB, etc). \r
+    //\r
+    // Here, 0 CPU arch attributes will be filtered to be compatible with the\r
+    // case that caller just calls SetMemorySpaceAttributes() with none CPU\r
+    // arch attributes (for example, RUNTIME) as the purpose of the case is not\r
+    // to clear CPU arch attributes.\r
+    //\r
+    if (CpuArchAttributes != 0) {\r
       if (gCpu == NULL) {\r
         Status = EFI_NOT_AVAILABLE_YET;\r
       } else {\r
@@ -936,6 +948,13 @@ CoreConvertSpace (
     // Set attributes operation\r
     //\r
     case GCD_SET_ATTRIBUTES_MEMORY_OPERATION:\r
+      if (CpuArchAttributes == 0) {\r
+        //\r
+        // Keep original CPU arch attributes when caller just calls\r
+        // SetMemorySpaceAttributes() with none CPU arch attributes (for example, RUNTIME).\r
+        //\r
+        Attributes |= (Entry->Attributes & (EXCLUSIVE_MEMORY_ATTRIBUTES | NONEXCLUSIVE_MEMORY_ATTRIBUTES));\r
+      }\r
       Entry->Attributes = Attributes;\r
       break;\r
     //\r