From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f171.google.com (mail-ob0-f171.google.com [209.85.214.171]) by kanga.kvack.org (Postfix) with ESMTP id 7C0056B0032 for ; Thu, 7 May 2015 10:04:12 -0400 (EDT) Received: by obfe9 with SMTP id e9so32051005obf.1 for ; Thu, 07 May 2015 07:04:12 -0700 (PDT) Received: from g2t2354.austin.hp.com (g2t2354.austin.hp.com. [15.217.128.53]) by mx.google.com with ESMTPS id i8si1306261obe.19.2015.05.07.07.04.11 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 07 May 2015 07:04:11 -0700 (PDT) Message-ID: <1431006304.23761.349.camel@misato.fc.hp.com> Subject: Re: [PATCH v4 6/7] mtrr, x86: Clean up mtrr_type_lookup() From: Toshi Kani Date: Thu, 07 May 2015 07:45:04 -0600 In-Reply-To: <20150507075210.GA6859@pd.tnic> References: <1427234921-19737-1-git-send-email-toshi.kani@hp.com> <1427234921-19737-7-git-send-email-toshi.kani@hp.com> <20150506134127.GE22949@pd.tnic> <1430928030.23761.328.camel@misato.fc.hp.com> <20150506224931.GL22949@pd.tnic> <1430955730.23761.348.camel@misato.fc.hp.com> <20150507075210.GA6859@pd.tnic> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Borislav Petkov Cc: akpm@linux-foundation.org, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, linux-mm@kvack.org, x86@kernel.org, linux-kernel@vger.kernel.org, dave.hansen@intel.com, Elliott@hp.com, pebolle@tiscali.nl On Thu, 2015-05-07 at 09:52 +0200, Borislav Petkov wrote: > On Wed, May 06, 2015 at 05:42:10PM -0600, Toshi Kani wrote: > > Well, creating mtrr_type_lookup_fixed() is one of the comments I had in > > the previous code review. Anyway, let me make sure if I understand your > > comment correctly. Do the following changes look right to you? > > > > 1) Change the caller responsible for the condition checks. > > > > if ((start < 0x100000) && > > (mtrr_state.have_fixed) && > > (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) > > return mtrr_type_lookup_fixed(start, end); > > > > 2) Delete the checks with mtrr_state in mtrr_type_lookup_fixed() as they > > are done by the caller. Keep the check with '(start >= 0x100000)' to > > assure that the code handles the range [0xC0000 - 0xFFFFF] correctly. > > That is a good defensive measure. > > > static u8 mtrr_type_lookup_fixed(u64 start, u64 end) > > { > > int idx; > > > > if (start >= 0x100000) > > return MTRR_TYPE_INVALID; > > > > - if (!(mtrr_state.have_fixed) || > > - !(mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) > > - return MTRR_TYPE_INVALID; > > Yeah, that's what I mean. Thanks for the clarification! Will change accordingly. -Toshi -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org