From 01674afdad3460f1c1f5f7a941c4c5895c8c3f86 Mon Sep 17 00:00:00 2001
From: Olivier Martin <olivier.martin@arm.com>
Date: Tue, 3 Jun 2014 16:37:29 +0000
Subject: ArmPkg/ArmLib: Drain Write Buffer before DCache maintenance
 operations.

Cache maintenance operations by Set/Way require that the Write Buffer
be drained before the cache is flushed.  Without that, the flush can
miss the most recent values written as they are still "pipelined".
That has unfortunate consequences, especially where code is being
copied to RAM.
The fix is to add DSB instructions before the affected operations.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15551 6f19259b-4bc3-4df7-8a09-765794883524
---
 ArmPkg/Library/ArmLib/ArmV7/ArmV7Lib.c | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'ArmPkg/Library/ArmLib/ArmV7/ArmV7Lib.c')

diff --git a/ArmPkg/Library/ArmLib/ArmV7/ArmV7Lib.c b/ArmPkg/Library/ArmLib/ArmV7/ArmV7Lib.c
index cc5074bfc2..65709780ed 100644
--- a/ArmPkg/Library/ArmLib/ArmV7/ArmV7Lib.c
+++ b/ArmPkg/Library/ArmLib/ArmV7/ArmV7Lib.c
@@ -1,6 +1,7 @@
 /** @file
 
   Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
+  Copyright (c) 2011 - 2014, 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
@@ -233,6 +234,7 @@ ArmInvalidateDataCache (
   VOID
   )
 {
+  ArmDrainWriteBuffer ();
   ArmV7DataCacheOperation (ArmInvalidateDataCacheEntryBySetWay);
 }
 
@@ -242,6 +244,7 @@ ArmCleanInvalidateDataCache (
   VOID
   )
 {
+  ArmDrainWriteBuffer ();
   ArmV7DataCacheOperation (ArmCleanInvalidateDataCacheEntryBySetWay);
 }
 
@@ -251,6 +254,7 @@ ArmCleanDataCache (
   VOID
   )
 {
+  ArmDrainWriteBuffer ();
   ArmV7DataCacheOperation (ArmCleanDataCacheEntryBySetWay);
 }
 
@@ -260,5 +264,6 @@ ArmCleanDataCacheToPoU (
   VOID
   )
 {
+  ArmDrainWriteBuffer ();
   ArmV7PoUDataCacheOperation (ArmCleanDataCacheEntryBySetWay);
 }
-- 
cgit v1.2.3