From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753577Ab0IKBQN (ORCPT ); Fri, 10 Sep 2010 21:16:13 -0400 Received: from smtp-out.google.com ([74.125.121.35]:63059 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750974Ab0IKBQB (ORCPT ); Fri, 10 Sep 2010 21:16:01 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to: references:x-system-of-record; b=Blh+1ZWaTSYGMwwgGsP2GWPK2FmX/ouvCCSfMWKxmWRxyCFrdxUQrfp5aGh9eHeZq ic7L6S4m8fruZX2YGjMwg== From: Venkatesh Pallipadi To: Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner , Yinghai Lu Cc: Suresh Siddha , Mark Langsdorf , linux-kernel@vger.kernel.org, Venkatesh Pallipadi Subject: [PATCH 1/2] x86: refactor MTRR type overlap check code Date: Fri, 10 Sep 2010 18:15:32 -0700 Message-Id: <1284167733-2683-2-git-send-email-venki@google.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1284167733-2683-1-git-send-email-venki@google.com> References: <1284167733-2683-1-git-send-email-venki@google.com> X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Move the MTRR type overlap check into a new function. No functional change in this patch. Just making it easier to add multiple region overlap check in the following patch. Signed-off-by: Venkatesh Pallipadi Reviewed-by: Suresh Siddha --- arch/x86/kernel/cpu/mtrr/generic.c | 44 +++++++++++++++++++++++------------ 1 files changed, 29 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index 7d28d7d..14f4f0c 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -65,6 +65,33 @@ static inline void k8_check_syscfg_dram_mod_en(void) } /* + * Check and return the effective type for MTRR-MTRR type overlap. + * Returns 1 if the effective type is UNCACHEABLE, else returns 0 + */ +static int check_type_overlap(u8 *prev, u8 *curr) +{ + if (*prev == MTRR_TYPE_UNCACHABLE || *curr == MTRR_TYPE_UNCACHABLE) { + *prev = MTRR_TYPE_UNCACHABLE; + *curr = MTRR_TYPE_UNCACHABLE; + return 1; + } + + if ((*prev == MTRR_TYPE_WRBACK && *curr == MTRR_TYPE_WRTHROUGH) || + (*prev == MTRR_TYPE_WRTHROUGH && *curr == MTRR_TYPE_WRBACK)) { + *prev = MTRR_TYPE_WRTHROUGH; + *curr = MTRR_TYPE_WRTHROUGH; + } + + if (*prev != *curr) { + *prev = MTRR_TYPE_UNCACHABLE; + *curr = MTRR_TYPE_UNCACHABLE; + return 1; + } + + return 0; +} + +/* * Returns the effective MTRR type for the region * Error returns: * - 0xFE - when the range is "not entirely covered" by _any_ var range MTRR @@ -138,21 +165,8 @@ u8 mtrr_type_lookup(u64 start, u64 end) continue; } - if (prev_match == MTRR_TYPE_UNCACHABLE || - curr_match == MTRR_TYPE_UNCACHABLE) { - return MTRR_TYPE_UNCACHABLE; - } - - if ((prev_match == MTRR_TYPE_WRBACK && - curr_match == MTRR_TYPE_WRTHROUGH) || - (prev_match == MTRR_TYPE_WRTHROUGH && - curr_match == MTRR_TYPE_WRBACK)) { - prev_match = MTRR_TYPE_WRTHROUGH; - curr_match = MTRR_TYPE_WRTHROUGH; - } - - if (prev_match != curr_match) - return MTRR_TYPE_UNCACHABLE; + if (check_type_overlap(&prev_match, &curr_match)) + return curr_match; } if (mtrr_tom2) { -- 1.7.1