ArmPkg/ArmCpuLib: Replaced complex functions ArmCpuSynchronizeWait & ArmCpuSynchronizeSignal by sev & wfe

Previsouly the synchronization of MpCore was using the SGI (Software
Generated Interrupt) to synchronize MpCore during the early boot.
This commit replaced this mechanism by the more appropriate SEV/WFE
instructions (Send/Wait Event instructions).
That also eases the port to a new cpu/platform.

Signed-off-by: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13249 6f19259b-4bc3-4df7-8a09-765794883524

ArmPkg/Library/ArmLib/Common/ArmLibSupport.S

@@ -1,7 +1,7 @@
 #------------------------------------------------------------------------------ 
 #
 # Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
-# Copyright (c) 2011, ARM Limited. All rights reserved.
+# Copyright (c) 2011-2012, ARM Limited. All rights reserved.
 #
 # This program and the accompanying materials
 # are licensed and made available under the terms and conditions of the BSD License
@@ -40,6 +40,8 @@ GCC_ASM_EXPORT(ArmUpdateTranslationTableEntry)
 GCC_ASM_EXPORT(ArmWriteNsacr)
 GCC_ASM_EXPORT(ArmWriteScr)
 GCC_ASM_EXPORT(ArmWriteVMBar)
+GCC_ASM_EXPORT(ArmCallWFE)
+GCC_ASM_EXPORT(ArmCallSEV)
 
 #------------------------------------------------------------------------------
 
@@ -146,4 +148,12 @@ ASM_PFX(ArmWriteVMBar):
   mcr     p15, 0, r0, c12, c0, 1
   bx      lr
 
+ASM_PFX(ArmCallWFE):
+  wfe
+  bx      lr
+
+ASM_PFX(ArmCallSEV):
+  sev
+  bx      lr
+
 ASM_FUNCTION_REMOVE_IF_UNREFERENCED

ArmPkg/Library/ArmLib/Common/ArmLibSupport.asm

@@ -40,6 +40,8 @@
     EXPORT ArmWriteNsacr
     EXPORT ArmWriteScr
     EXPORT ArmWriteVMBar
+    EXPORT ArmCallWFE
+    EXPORT ArmCallSEV
 
     AREA ArmLibSupport, CODE, READONLY
 
@@ -146,4 +148,12 @@ ArmWriteVMBar
   mcr     p15, 0, r0, c12, c0, 1
   bx      lr
   
+ArmCallWFE
+  wfe
+  blx   lr
+
+ArmCallSEV
+  sev
+  blx   lr
+
   END