From: Yinghai Lu <yinghai@kernel.org>
Date: Tue, 17 Nov 2009 07:04:56 +0000 (-0800)
Subject: x86: When cleaning MTRRs, do not fold WP into UC
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=508d85c2c6bc8cba53d2a54d9a306ad64a0a80bf;p=linux-beck.git

x86: When cleaning MTRRs, do not fold WP into UC

The current MTRR code treats WP as a form of UC.  This really isn't
desirable behaviour, except possibly in the case of severe MTRR
shortage.  Disable this, to allow legitimate uses of WP to remain
unmolested.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/arch/x86/kernel/cpu/mtrr/cleanup.c b/arch/x86/kernel/cpu/mtrr/cleanup.c
index 315738c74aad..6e49f6f91f31 100644
--- a/arch/x86/kernel/cpu/mtrr/cleanup.c
+++ b/arch/x86/kernel/cpu/mtrr/cleanup.c
@@ -689,8 +689,6 @@ static int __init mtrr_need_cleanup(void)
 			continue;
 		if (!size)
 			type = MTRR_NUM_TYPES;
-		if (type == MTRR_TYPE_WRPROT)
-			type = MTRR_TYPE_UNCACHABLE;
 		num[type]++;
 	}