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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 6E4CBC4360F for ; Thu, 14 Feb 2019 17:11:17 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 3EAAF222DA for ; Thu, 14 Feb 2019 17:11:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="am3jgWa9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3EAAF222DA 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+infradead-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=bombadil.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=lX8LG05LOAPgHgsQUzo9JPsJHPTiSfpTOVOTBkXA0iw=; b=am3jgWa9EVDclo t2NpxRZmf4o4vd3DSzlswTQRRYQCFAiTdTe1qTYQMl65DNWm4NYAgg/f6Uaeg0G48Q/eD3KhM5MYi xEkn2STHnw7zaqyABJsMTpm/J/wIJ2CpMGp+rPTKSWW1Om2INrMUR2psMYhpJz2j+YHyWsSdrfVRZ MZky/0tJXrJpB+SaMpraVU3zeUndIBlXnp2NfElZwaDPMrvw6rWciyC1eIv6LysNiUmrEVP90hagr pU+MHyPjIzx1K9OF/PSpyxAr3XiI3eMuCzar7fllzpCr8iM/Hq1mz3jjQNPMuhgzJoys5QYlKkxax Yy3fseKfaLsHw8nsi57Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1guKXX-0004QY-ED; Thu, 14 Feb 2019 17:11:11 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1guKXT-0004Jl-2B for linux-arm-kernel@lists.infradead.org; Thu, 14 Feb 2019 17:11:09 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id F0579EBD; Thu, 14 Feb 2019 09:11:04 -0800 (PST) Received: from fuggles.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7691E3F589; Thu, 14 Feb 2019 09:11:03 -0800 (PST) Date: Thu, 14 Feb 2019 17:11:01 +0000 From: Will Deacon To: Anshuman Khandual Subject: Re: [PATCH 3/6] arm64/mm: Make pgd_pgtable_alloc() call pte_alloc_one() always Message-ID: <20190214171101.GD2475@fuggles.cambridge.arm.com> References: <1548307220-19756-1-git-send-email-anshuman.khandual@arm.com> <1548307220-19756-4-git-send-email-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1548307220-19756-4-git-send-email-anshuman.khandual@arm.com> User-Agent: Mutt/1.11.1+86 (6f28e57d73f2) () X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190214_091107_315373_F7D85916 X-CRM114-Status: GOOD ( 20.37 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, Steve.Capper@arm.com, marc.zyngier@arm.com, Catalin.Marinas@arm.com, suzuki.poulose@arm.com, james.morse@arm.com, 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+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jan 24, 2019 at 10:50:17AM +0530, Anshuman Khandual wrote: > pgd_pgtable_alloc() provides page allocation function while creating all > levels of page table (e.g PGD, PUD, CONT PMD) for various kernel mappings. > It calls __get_free_page() and initializes page with pagetable_page_ctor(). > pte_alloc_one() already provides a standard interface for allocating a page > table page and initializes it with pagetable_page_ctor(). This removes the > redundancy and instead make it call pte_alloc_one() directly. > > Signed-off-by: Anshuman Khandual > --- > arch/arm64/mm/mmu.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index b6f5aa5..2dbd723 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -372,13 +372,22 @@ static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys, > > static phys_addr_t pgd_pgtable_alloc(void) > { > - void *ptr = (void *)__get_free_page(PGALLOC_GFP); > - if (!ptr || !pgtable_page_ctor(virt_to_page(ptr))) > - BUG(); > + > + pgtable_t ptr; > + > + /* > + * pgd_pgtable_alloc() is called while creating kernel mappings > + * through __create_pgd_mapping() might not install it through > + * swapper_pg_dir (&init_mm). Even then init_mm is passed here > + * just to indicate that the allocation is kernel specific not > + * for the user space page tables. > + */ > + ptr = pte_alloc_one(&init_mm); > + BUG_ON(!ptr); > > /* Ensure the zeroed page is visible to the page table walker */ > dsb(ishst); > - return __pa(ptr); > + return page_to_phys(ptr); Are you sure this is safe? afaict, this code is used to set up the linear mapping which happens before the mem_map is initialised. I don't think page_to_phys() can be used at this point. What am I missing? Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel