From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8BBDFC433E6 for ; Tue, 1 Sep 2020 03:18:49 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 44B8320719 for ; Tue, 1 Sep 2020 03:18:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 44B8320719 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4BgXN65gzSzDqZC for ; Tue, 1 Sep 2020 13:18:46 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=arm.com (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=anshuman.khandual@arm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=arm.com Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 4BgXJs3Y9yzDqVr for ; Tue, 1 Sep 2020 13:15:57 +1000 (AEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A61C630E; Mon, 31 Aug 2020 20:15:55 -0700 (PDT) Received: from [192.168.0.130] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1AFB03F68F; Mon, 31 Aug 2020 20:15:50 -0700 (PDT) From: Anshuman Khandual Subject: Re: [PATCH v3 03/13] mm/debug_vm_pgtable/ppc64: Avoid setting top bits in radom value To: "Aneesh Kumar K.V" , linux-mm@kvack.org, akpm@linux-foundation.org References: <20200827080438.315345-1-aneesh.kumar@linux.ibm.com> <20200827080438.315345-4-aneesh.kumar@linux.ibm.com> Message-ID: <3a0b0101-e6ec-26c5-e104-5b0bb95c3e51@arm.com> Date: Tue, 1 Sep 2020 08:45:14 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200827080438.315345-4-aneesh.kumar@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Christophe Leroy , x86@kernel.org, Mike Rapoport , Qian Cai , Gerald Schaefer , Vineet Gupta , linux-snps-arc@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 08/27/2020 01:34 PM, Aneesh Kumar K.V wrote: > ppc64 use bit 62 to indicate a pte entry (_PAGE_PTE). Avoid setting that bit in > random value. > > Signed-off-by: Aneesh Kumar K.V > --- > mm/debug_vm_pgtable.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c > index 086309fb9b6f..bbf9df0e64c6 100644 > --- a/mm/debug_vm_pgtable.c > +++ b/mm/debug_vm_pgtable.c > @@ -44,10 +44,17 @@ > * entry type. But these bits might affect the ability to clear entries with > * pxx_clear() because of how dynamic page table folding works on s390. So > * while loading up the entries do not change the lower 4 bits. It does not > - * have affect any other platform. > + * have affect any other platform. Also avoid the 62nd bit on ppc64 that is > + * used to mark a pte entry. > */ > -#define S390_MASK_BITS 4 > -#define RANDOM_ORVALUE GENMASK(BITS_PER_LONG - 1, S390_MASK_BITS) > +#define S390_SKIP_MASK GENMASK(3, 0) > +#ifdef CONFIG_PPC_BOOK3S_64 > +#define PPC64_SKIP_MASK GENMASK(62, 62) > +#else > +#define PPC64_SKIP_MASK 0x0 > +#endif Please drop the #ifdef CONFIG_PPC_BOOK3S_64 here. We already accommodate skip bits for a s390 platform requirement and can also do so for ppc64 as well. As mentioned before, please avoid adding any platform specific constructs in the test. > +#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK) > +#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK) > #define RANDOM_NZVALUE GENMASK(7, 0) Please fix the alignments here. Feel free to consider following changes after this patch. diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 122416464e0f..f969031152bb 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -48,14 +48,11 @@ * have affect any other platform. Also avoid the 62nd bit on ppc64 that is * used to mark a pte entry. */ -#define S390_SKIP_MASK GENMASK(3, 0) -#ifdef CONFIG_PPC_BOOK3S_64 -#define PPC64_SKIP_MASK GENMASK(62, 62) -#else -#define PPC64_SKIP_MASK 0x0 -#endif -#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK) -#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK) +#define S390_SKIP_MASK GENMASK(3, 0) +#define PPC64_SKIP_MASK GENMASK(62, 62) +#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK) +#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK) + #define RANDOM_NZVALUE GENMASK(7, 0) > > static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot) > Besides, there is also one checkpatch.pl warning here. WARNING: Possible unwrapped commit description (prefer a maximum 75 chars per line) #7: ppc64 use bit 62 to indicate a pte entry (_PAGE_PTE). Avoid setting that bit in total: 0 errors, 1 warnings, 20 lines checked