Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752109AbbGVSHW (ORCPT ); Wed, 22 Jul 2015 14:07:22 -0400 Received: from g2t2354.austin.hp.com ([15.217.128.53]:40396 "EHLO g2t2354.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751820AbbGVSHV (ORCPT ); Wed, 22 Jul 2015 14:07:21 -0400 From: Toshi Kani To: mingo@kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, bp@suse.de, jbeulich@suse.com, x86@kernel.org, linux-kernel@vger.kernel.org, Toshi Kani Subject: [PATCH] x86, pat: Add comments to cachemode translation tables Date: Wed, 22 Jul 2015 12:06:11 -0600 Message-Id: <1437588371-28223-1-git-send-email-toshi.kani@hp.com> X-Mailer: git-send-email 2.4.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1689 Lines: 41 Add comments to the cachemode translation tables to clarify that the default values are set as minimal supported mode, which are necessary to handle WC and WT fallback to UC- when they are not enabled. Signed-off-by: Toshi Kani Cc: Jan Beulich Cc: Borislav Petkov Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Thomas Gleixner --- Ingo, please replace the patch below with this patch. https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg937806.html --- arch/x86/mm/init.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 8533b46..1d8a83d 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -30,8 +30,11 @@ /* * Tables translating between page_cache_type_t and pte encoding. * - * Minimal supported modes are defined statically, they are modified - * during bootup if more supported cache modes are available. + * The default values are defined statically as minimal supported mode; + * WC and WT fall back to UC-. pat_init() updates these values to support + * more cache modes, WC and WT, when it is safe to do so. See pat_init() + * for the details. Note, __early_ioremap() used during early boot-time + * takes pgprot_t (pte encoding) and does not use these tables. * * Index into __cachemode2pte_tbl[] is the cachemode. * -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/