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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 F03CFC433ED for ; Wed, 21 Apr 2021 13:12:49 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 68A4361440 for ; Wed, 21 Apr 2021 13:12:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 68A4361440 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AAD9C6B006C; Wed, 21 Apr 2021 09:12:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A83446B006E; Wed, 21 Apr 2021 09:12:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9AC186B0070; Wed, 21 Apr 2021 09:12:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0087.hostedemail.com [216.40.44.87]) by kanga.kvack.org (Postfix) with ESMTP id 7E4F96B006C for ; Wed, 21 Apr 2021 09:12:48 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 3987B82499B9 for ; Wed, 21 Apr 2021 13:12:48 +0000 (UTC) X-FDA: 78056414016.01.68F986C Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf26.hostedemail.com (Postfix) with ESMTP id 6439840002C1 for ; Wed, 21 Apr 2021 13:12:41 +0000 (UTC) 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 2AA4F11B3; Wed, 21 Apr 2021 06:12:45 -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 6693B3F774; Wed, 21 Apr 2021 06:12:41 -0700 (PDT) Subject: Re: [PATCH v2 3/4] arm64: decouple check whether pfn is in linear map from pfn_valid() To: Mike Rapoport Cc: linux-arm-kernel@lists.infradead.org, Andrew Morton , Ard Biesheuvel , Catalin Marinas , David Hildenbrand , Marc Zyngier , Mark Rutland , Mike Rapoport , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20210421065108.1987-1-rppt@kernel.org> <20210421065108.1987-4-rppt@kernel.org> <0a7cc0d4-5d3d-7d6d-f4c3-bb2965b810e6@arm.com> From: Anshuman Khandual Message-ID: <2f9fb38c-0125-feca-4e15-3d443f3635e4@arm.com> Date: Wed, 21 Apr 2021 18:43:28 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Stat-Signature: fc4jqwd83q4gu4693subjztwz8pjspah X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 6439840002C1 Received-SPF: none (arm.com>: No applicable sender policy available) receiver=imf26; identity=mailfrom; envelope-from=""; helo=foss.arm.com; client-ip=217.140.110.172 X-HE-DKIM-Result: none/none X-HE-Tag: 1619010761-379999 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 4/21/21 5:49 PM, Mike Rapoport wrote: > On Wed, Apr 21, 2021 at 04:29:48PM +0530, Anshuman Khandual wrote: >> >> On 4/21/21 12:21 PM, Mike Rapoport wrote: >>> From: Mike Rapoport >>> >>> The intended semantics of pfn_valid() is to verify whether there is a >>> struct page for the pfn in question and nothing else. >>> >>> Yet, on arm64 it is used to distinguish memory areas that are mapped in the >>> linear map vs those that require ioremap() to access them. >>> >>> Introduce a dedicated pfn_is_map_memory() wrapper for >>> memblock_is_map_memory() to perform such check and use it where >>> appropriate. >>> >>> Using a wrapper allows to avoid cyclic include dependencies. >>> >>> Signed-off-by: Mike Rapoport >>> --- >>> arch/arm64/include/asm/memory.h | 2 +- >>> arch/arm64/include/asm/page.h | 1 + >>> arch/arm64/kvm/mmu.c | 2 +- >>> arch/arm64/mm/init.c | 11 +++++++++++ >>> arch/arm64/mm/ioremap.c | 4 ++-- >>> arch/arm64/mm/mmu.c | 2 +- >>> 6 files changed, 17 insertions(+), 5 deletions(-) >>> >>> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h >>> index 0aabc3be9a75..194f9f993d30 100644 >>> --- a/arch/arm64/include/asm/memory.h >>> +++ b/arch/arm64/include/asm/memory.h >>> @@ -351,7 +351,7 @@ static inline void *phys_to_virt(phys_addr_t x) >>> >>> #define virt_addr_valid(addr) ({ \ >>> __typeof__(addr) __addr = __tag_reset(addr); \ >>> - __is_lm_address(__addr) && pfn_valid(virt_to_pfn(__addr)); \ >>> + __is_lm_address(__addr) && pfn_is_map_memory(virt_to_pfn(__addr)); \ >>> }) >>> >>> void dump_mem_limit(void); >>> diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h >>> index 012cffc574e8..99a6da91f870 100644 >>> --- a/arch/arm64/include/asm/page.h >>> +++ b/arch/arm64/include/asm/page.h >>> @@ -38,6 +38,7 @@ void copy_highpage(struct page *to, struct page *from); >>> typedef struct page *pgtable_t; >>> >>> extern int pfn_valid(unsigned long); >>> +extern int pfn_is_map_memory(unsigned long); >> >> Check patch is complaining about this. >> >> WARNING: function definition argument 'unsigned long' should also have an identifier name >> #50: FILE: arch/arm64/include/asm/page.h:41: >> +extern int pfn_is_map_memory(unsigned long); >> >> >>> >>> #include >>> >>> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c >>> index 8711894db8c2..23dd99e29b23 100644 >>> --- a/arch/arm64/kvm/mmu.c >>> +++ b/arch/arm64/kvm/mmu.c >>> @@ -85,7 +85,7 @@ void kvm_flush_remote_tlbs(struct kvm *kvm) >>> >>> static bool kvm_is_device_pfn(unsigned long pfn) >>> { >>> - return !pfn_valid(pfn); >>> + return !pfn_is_map_memory(pfn); >>> } >>> >>> /* >>> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c >>> index 3685e12aba9b..dc03bdc12c0f 100644 >>> --- a/arch/arm64/mm/init.c >>> +++ b/arch/arm64/mm/init.c >>> @@ -258,6 +258,17 @@ int pfn_valid(unsigned long pfn) >>> } >>> EXPORT_SYMBOL(pfn_valid); >>> >>> +int pfn_is_map_memory(unsigned long pfn) >>> +{ >>> + phys_addr_t addr = PFN_PHYS(pfn); >>> + >> >> Should also bring with it, the comment regarding upper bits in >> the pfn from arm64 pfn_valid(). > > I think a reference to the comment in pfn_valid() will suffice. Okay. > > BTW, I wonder how is that other architectures do not need this check? Trying to move that into generic pfn_valid() in mmzone.h, will resend the RFC patch after this series. https://patchwork.kernel.org/project/linux-mm/patch/1615174073-10520-1-git-send-email-anshuman.khandual@arm.com/ > >>> + if (PHYS_PFN(addr) != pfn) >>> + return 0; >>> + >> >> ^^^^^ trailing spaces here. >> >> ERROR: trailing whitespace >> #81: FILE: arch/arm64/mm/init.c:263: >> +^I$ > > Oops :) > >>> + return memblock_is_map_memory(addr); >>> +} >>> +EXPORT_SYMBOL(pfn_is_map_memory); >>> + >> >> Is the EXPORT_SYMBOL() required to build drivers which will use >> pfn_is_map_memory() but currently use pfn_valid() ? > > Yes, this is required for virt_addr_valid() that is used by modules. > There will be two adjacent EXPORT_SYMBOLS(), one for pfn_valid() and one for pfn_is_map_memory(). But its okay I guess, cant help it.