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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 3D37FC433ED for ; Wed, 14 Apr 2021 20:29:55 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B399761158 for ; Wed, 14 Apr 2021 20:29:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B399761158 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3EBB36B007B; Wed, 14 Apr 2021 16:29:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3C4AC6B007D; Wed, 14 Apr 2021 16:29:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 23D976B007E; Wed, 14 Apr 2021 16:29:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0107.hostedemail.com [216.40.44.107]) by kanga.kvack.org (Postfix) with ESMTP id 05F806B007B for ; Wed, 14 Apr 2021 16:29:53 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id AA3C6824805A for ; Wed, 14 Apr 2021 20:29:53 +0000 (UTC) X-FDA: 78032113866.29.450E6C7 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf01.hostedemail.com (Postfix) with ESMTP id 48DBA5001528 for ; Wed, 14 Apr 2021 20:29:52 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id EB62F61090; Wed, 14 Apr 2021 20:29:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618432191; bh=0/g8QgxcPByWv4b4UdJd4FLad687IHnLM2vVf0ZWjRY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bqtXXI6cAJ95seHOi/o4nAFhJ6cmvJJ3iQYMhPzjIWkExHdlx8qW3SiuEYaM0ZbZI SqlG/khazIjpgkFsNZeYJE0YqMrUJBpSpOb/xeXncRBxBxvk8HcF5jTAdCcBeYu7UA dqeZ3w4s4t1e9PzpKaAW9T5x3oV5xw05JxqA4W/nk8pXWO/6lnOH4YGoyD3Y5hOxOK OLkp3g6pY7ZhKS3tdc02Vjmlo9GL43D5mcxMnU+nN507gzFgo8NFsOTj8RiIGfH3EY 3jGFfEVngjqnmqUHYKFS/ghGTuTXbRfPGslgr+/4hS6QkesNPAlwppYYSbuFF52+4J /QjLAfgysF3YQ== Date: Wed, 14 Apr 2021 23:29:42 +0300 From: Mike Rapoport To: David Hildenbrand Cc: Anshuman Khandual , linux-arm-kernel@lists.infradead.org, Ard Biesheuvel , Catalin Marinas , Marc Zyngier , Mark Rutland , Mike Rapoport , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC/RFT PATCH 2/3] arm64: decouple check whether pfn is normal memory from pfn_valid() Message-ID: References: <20210407172607.8812-1-rppt@kernel.org> <20210407172607.8812-3-rppt@kernel.org> <4a788546-b854-fd35-644a-f1d9075a9a78@arm.com> <9c0956f0-494e-5c6b-bdc2-d4213afd5e2f@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9c0956f0-494e-5c6b-bdc2-d4213afd5e2f@redhat.com> X-Stat-Signature: znqgjc41mx43d4fxnzkuj3oz8qjhm4h8 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 48DBA5001528 Received-SPF: none (kernel.org>: No applicable sender policy available) receiver=imf01; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1618432192-556009 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 Wed, Apr 14, 2021 at 05:58:26PM +0200, David Hildenbrand wrote: > On 08.04.21 07:14, Anshuman Khandual wrote: > > > > On 4/7/21 10:56 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. > > > > Should there be a comment affirming this semantics interpretation, above the > > generic pfn_valid() in include/linux/mmzone.h ? > > > > > > > > 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_memory() to perform such check and use it > > > where appropriate. > > > > > > 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 | 6 ++++++ > > > arch/arm64/mm/ioremap.c | 4 ++-- > > > arch/arm64/mm/mmu.c | 2 +- > > > 6 files changed, 12 insertions(+), 5 deletions(-) > > > > > > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h > > > index 0aabc3be9a75..7e77fdf71b9d 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_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..32b485bcc6ff 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_memory(unsigned long); > > > #include > > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > > > index 8711894db8c2..ad2ea65a3937 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_memory(pfn); > > > } > > > /* > > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > > > index 3685e12aba9b..258b1905ed4a 100644 > > > --- a/arch/arm64/mm/init.c > > > +++ b/arch/arm64/mm/init.c > > > @@ -258,6 +258,12 @@ int pfn_valid(unsigned long pfn) > > > } > > > EXPORT_SYMBOL(pfn_valid); > > > +int pfn_is_memory(unsigned long pfn) > > > +{ > > > + return memblock_is_map_memory(PFN_PHYS(pfn)); > > > +} > > > +EXPORT_SYMBOL(pfn_is_memory);> + > > > > Should not this be generic though ? There is nothing platform or arm64 > > specific in here. Wondering as pfn_is_memory() just indicates that the > > pfn is linear mapped, should not it be renamed as pfn_is_linear_memory() > > instead ? Regardless, it's fine either way. > > TBH, I dislike (generic) pfn_is_memory(). It feels like we're mixing > concepts. Yeah, at the moment NOMAP is very much arm specific so I'd keep it this way for now. > NOMAP memory vs !NOMAP memory; even NOMAP is some kind of memory > after all. pfn_is_map_memory() would be more expressive, although still > sub-optimal. > > We'd actually want some kind of arm64-specific pfn_is_system_memory() or the > inverse pfn_is_device_memory() -- to be improved. In my current version (to be posted soon) I've started with pfn_lineary_mapped() but then ended up with pfn_mapped() to make it "upward" compatible with architectures that use direct rather than linear map :) -- Sincerely yours, Mike.