From a8cfbf3e93e333b0a9e3839a4b99aa7f1d335cd3 Mon Sep 17 00:00:00 2001
From: Stefan Lankes <lankes@lfbs.rwth-aachen.de>
Date: Mon, 29 Aug 2011 01:49:19 -0700
Subject: [PATCH] disable MPE flag (=> using L2 cache) for readonly regions

---
 arch/x86/mm/page.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/page.c b/arch/x86/mm/page.c
index dad71657..cecbab61 100644
--- a/arch/x86/mm/page.c
+++ b/arch/x86/mm/page.c
@@ -413,10 +413,19 @@ int change_page_permissions(size_t start, size_t end, uint32_t flags)
 					newflags &= ~PG_PRESENT;
 
 				// update flags
-				if (!(flags & VMA_WRITE))
+				if (!(flags & VMA_WRITE)) {
 					newflags &= ~PG_RW;
-				else
+#ifdef CONFIG_ROCKCREEK
+					if (newflags & (PG_SVM_STRONG|PG_SVM_LAZYRELEASE))
+						newflags &= ~PG_MPE;
+#endif
+				} else  {
 					newflags |= PG_RW;
+#ifdef CONFIG_ROCKCREEK
+					if (newflags & (PG_SVM_STRONG|PG_SVM_LAZYRELEASE))
+						newflags |= PG_MPE;
+#endif
+				}
 
 				pgt->entries[index2] = (newflags & 0xFFF) | (phyaddr & 0xFFFFF000);