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=-8.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,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 84DEFC433E9 for ; Thu, 3 Sep 2020 16:58:00 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 50D5D206A5 for ; Thu, 3 Sep 2020 16:58:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="n1H4y+Gr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 50D5D206A5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=uqjvfLSETi9X8Ffbnd0WTYxiRdDOBjkzTTiwuwlBk7g=; b=n1H4y+GrOJFnKRXS1aFPUCfHd JlltyQwb93DYWcSdJe88Ir6KKsxnGEVHLwSMjRau7l9XJudnyTRQJZ8qamlDo2hOrKOIOV3pce5pc V3xVjZtYgZbFquP19ESB8YIhvb24Zzi90wXzsUbDo5JrKVCN1sxGVvnadYD2D9FPvvSeKIMjyjlZB mbb3HLBiyZnEqdUKYqTXYylnX2i/p2Bthd6CqWMk+1AsEC0/0YxV1eIzkgIyq+URbjgZ3Br0qOxom bbs4hTVVwVHFN/HLr3OgQ6jALRHWwM/v4b1gM4ifl0Z5IhMHmIle258gyulbj1kSLktXHYETsnrEk SB4szz2+A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kDsXR-0005CK-0N; Thu, 03 Sep 2020 16:56:41 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kDsXN-0005BO-GU for linux-arm-kernel@lists.infradead.org; Thu, 03 Sep 2020 16:56:38 +0000 Received: from gaia (unknown [46.69.195.48]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CF3B9206A5; Thu, 3 Sep 2020 16:56:34 +0000 (UTC) Date: Thu, 3 Sep 2020 17:56:32 +0100 From: Catalin Marinas To: Anshuman Khandual Subject: Re: [PATCH 1/2] arm64/mm: Change THP helpers to comply with generic MM semantics Message-ID: <20200903165631.GC31409@gaia> References: <1597655984-15428-1-git-send-email-anshuman.khandual@arm.com> <1597655984-15428-2-git-send-email-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1597655984-15428-2-git-send-email-anshuman.khandual@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200903_125637_609546_DFA0D3B7 X-CRM114-Status: GOOD ( 20.43 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Suzuki Poulose , Marc Zyngier , linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, will@kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Aug 17, 2020 at 02:49:43PM +0530, Anshuman Khandual wrote: > pmd_present() and pmd_trans_huge() are expected to behave in the following > manner during various phases of a given PMD. It is derived from a previous > detailed discussion on this topic [1] and present THP documentation [2]. > > pmd_present(pmd): > > - Returns true if pmd refers to system RAM with a valid pmd_page(pmd) > - Returns false if pmd does not refer to system RAM - Invalid pmd_page(pmd) The second bullet doesn't make much sense. If you have a pmd mapping of some I/O memory, pmd_present() still returns true (as does pte_present()). > diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h > index 4d867c6446c4..28792fdd9627 100644 > --- a/arch/arm64/include/asm/pgtable-prot.h > +++ b/arch/arm64/include/asm/pgtable-prot.h > @@ -19,6 +19,13 @@ > #define PTE_DEVMAP (_AT(pteval_t, 1) << 57) > #define PTE_PROT_NONE (_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */ > > +/* > + * This help indicate that the entry is present i.e pmd_page() Nit: add another . after i.e > + * still points to a valid huge page in memory even if the pmd > + * has been invalidated. > + */ > +#define PMD_PRESENT_INVALID (_AT(pteval_t, 1) << 59) /* only when !PMD_SECT_VALID */ > + > #ifndef __ASSEMBLY__ > > #include > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index d5d3fbe73953..7aa69cace784 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -145,6 +145,18 @@ static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot) > return pte; > } > > +static inline pmd_t clr_pmd_bit(pmd_t pmd, pgprot_t prot) > +{ > + pmd_val(pmd) &= ~pgprot_val(prot); > + return pmd; > +} Could you use clear_pmd_bit (instead of clr) for consistency with clear_pte_bit()? It would be good if the mm folk can do a sanity check on the assumptions about pmd_present/pmdp_invalidate/pmd_trans_huge. The patch looks fine to me otherwise, feel free to add: Reviewed-by: Catalin Marinas -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel