UefiCpuPkg/MtrrLib: Add comments to recommend to use batch-set API

[mirror_edk2.git] / UefiCpuPkg / Library / MtrrLib / MtrrLib.c

diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
index 30b0df030b5618ed7e4663263fd3abb1675f0f88..dfce9a996b3b80ae2a1494fabc2aa6e0389ea215 100644 (file)
--- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
+++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
@@ -2513,7 +2513,14 @@ Exit:
                                     BaseAddress and Length cannot be modified.\r
   @retval RETURN_OUT_OF_RESOURCES   There are not enough system resources to modify the attributes of\r
                                     the memory resource range.\r
-  @retval RETURN_BUFFER_TOO_SMALL   The scratch buffer is too small for MTRR calculation.\r
+                                    Multiple memory range attributes setting by calling this API multiple\r
+                                    times may fail with status RETURN_OUT_OF_RESOURCES. It may not mean\r
+                                    the number of CPU MTRRs are too small to set such memory attributes.\r
+                                    Pass the multiple memory range attributes to one call of\r
+                                    MtrrSetMemoryAttributesInMtrrSettings() may succeed.\r
+  @retval RETURN_BUFFER_TOO_SMALL   The fixed internal scratch buffer is too small for MTRR calculation.\r
+                                    Caller should use MtrrSetMemoryAttributesInMtrrSettings() to specify\r
+                                    external scratch buffer.\r
 **/\r
 RETURN_STATUS\r
 EFIAPI\r
@@ -2559,7 +2566,14 @@ MtrrSetMemoryAttributeInMtrrSettings (
   @retval RETURN_OUT_OF_RESOURCES   There are not enough system resources to\r
                                     modify the attributes of the memory\r
                                     resource range.\r
-  @retval RETURN_BUFFER_TOO_SMALL   The scratch buffer is too small for MTRR calculation.\r
+                                    Multiple memory range attributes setting by calling this API multiple\r
+                                    times may fail with status RETURN_OUT_OF_RESOURCES. It may not mean\r
+                                    the number of CPU MTRRs are too small to set such memory attributes.\r
+                                    Pass the multiple memory range attributes to one call of\r
+                                    MtrrSetMemoryAttributesInMtrrSettings() may succeed.\r
+  @retval RETURN_BUFFER_TOO_SMALL   The fixed internal scratch buffer is too small for MTRR calculation.\r
+                                    Caller should use MtrrSetMemoryAttributesInMtrrSettings() to specify\r
+                                    external scratch buffer.\r
 **/\r
 RETURN_STATUS\r
 EFIAPI\r