MdePkg/BaseLib: Support IA32 processors without CLFLUSH

[mirror_edk2.git] / MdePkg / Library / BaseLib / Ia32 / FlushCacheLine.asm

diff --git a/MdePkg/Library/BaseLib/Ia32/FlushCacheLine.asm b/MdePkg/Library/BaseLib/Ia32/FlushCacheLine.asm
index 124d7610609da78c88ab02a1a2654b2cf2970d7b..a64f96bf7e5b75fdcd7f7b58009b39049241231b 100644 (file)
--- a/MdePkg/Library/BaseLib/Ia32/FlushCacheLine.asm
+++ b/MdePkg/Library/BaseLib/Ia32/FlushCacheLine.asm
@@ -1,6 +1,6 @@
 ;------------------------------------------------------------------------------\r
 ;\r
-; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>\r
+; Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>\r
 ; This program and the accompanying materials\r
 ; are licensed and made available under the terms and conditions of the BSD License\r
 ; which accompanies this distribution.  The full text of the license may be found at\r
@@ -34,9 +34,20 @@
 ;   );\r
 ;------------------------------------------------------------------------------\r
 AsmFlushCacheLine   PROC\r
+    ;\r
+    ; If the CPU does not support CLFLUSH instruction, \r
+    ; then promote flush range to flush entire cache.\r
+    ;\r
+    mov     eax, 1\r
+    cpuid\r
     mov     eax, [esp + 4]\r
+    test    edx, BIT19\r
+    jz      @F\r
     clflush [eax]\r
     ret\r
+@@:\r
+    wbinvd\r
+    ret\r
 AsmFlushCacheLine   ENDP\r
 \r
     END\r