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=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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=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 0529DC433B4 for ; Thu, 15 Apr 2021 09:32:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C078C61153 for ; Thu, 15 Apr 2021 09:32:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231842AbhDOJcW (ORCPT ); Thu, 15 Apr 2021 05:32:22 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:47833 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230474AbhDOJb6 (ORCPT ); Thu, 15 Apr 2021 05:31:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618479091; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=phkRKYasHy2ON2Zd+AYnzw9m/3bL2pWoEajZ+S+eLjE=; b=UHVBgssU6AtMt7bHKsoNjGWZmLb2dNLpL302eS/pWSek+cSANzQYV+T5IF5/6J8TY3XYK9 oGUUZTiXJVLBmXGkoT9uyfn2IYP61rhRDkv/FkfDp4d7J8WZKq9kOSpPzEBM/YRFhSEhTM UCRPfAOEIqko7TFJbvhXa55fXK1c8DU= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-12-6VbZ0yRqOay4S7RceM_prw-1; Thu, 15 Apr 2021 05:31:29 -0400 X-MC-Unique: 6VbZ0yRqOay4S7RceM_prw-1 Received: by mail-wr1-f72.google.com with SMTP id t14-20020adff04e0000b0290103307c23e1so2465906wro.8 for ; Thu, 15 Apr 2021 02:31:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:organization :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=phkRKYasHy2ON2Zd+AYnzw9m/3bL2pWoEajZ+S+eLjE=; b=SDpTCX12bYHwLDP5RxzOR9eT9wUDnhDSFdFPZ+8jZ41M714+nltKQI/YVgftphoThd 6xEUlbqKF9LK3GfHppxHoloxhDKecK5M9qjGOF8QMrsVUL7WmN/qef/0wM+qeKQucaoi 2E4ivmAGUePR3GI6K7YFnPaGwqApo62Qd3h0BvGgGBUj+twPsvrdsWJM+H6UWqb9H/kW hdrw8AIctYk0iqvHvYMfqtiqfQV9JqCxAutHvarNyECAWTGF4qg6UI18m2M87KMfotJT AQ5SrySWjm51Vw6lfu4hT+4rLugPc2HoPoIbbfrhW5N6fUhhP1qDQgjvI+fNNxZaOPs+ w4LA== X-Gm-Message-State: AOAM533O3uIybgMWwSk5Qn97ddiCFJBzzdLDH9eXsg7laq/yN8y15P4K mnERsRjDhQK2j5fBkDdkicIX4YvWM0gFczWHcQ6K8yoA+h7f9q8ekPpRO6x2QYxZZ8Xy0lgD86O xjp+dMgDHX9okmZJEQJviMQkX X-Received: by 2002:adf:8b45:: with SMTP id v5mr2406839wra.398.1618479088756; Thu, 15 Apr 2021 02:31:28 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxfQSnAXznxI2JGkIgFlRINBs/MudcZie1Vu3F7EQtZ3n7ewfaKl4lNqKpS1JUJMayw6nDijQ== X-Received: by 2002:adf:8b45:: with SMTP id v5mr2406812wra.398.1618479088514; Thu, 15 Apr 2021 02:31:28 -0700 (PDT) Received: from [192.168.3.132] (p5b0c6392.dip0.t-ipconnect.de. [91.12.99.146]) by smtp.gmail.com with ESMTPSA id t19sm1746813wmq.14.2021.04.15.02.31.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 15 Apr 2021 02:31:27 -0700 (PDT) Subject: Re: [RFC/RFT PATCH 2/3] arm64: decouple check whether pfn is normal memory from pfn_valid() To: Mike Rapoport 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 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> From: David Hildenbrand Organization: Red Hat Message-ID: <62161846-4f03-e4b1-ae0b-fdf96f78d97c@redhat.com> Date: Thu, 15 Apr 2021 11:31:26 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14.04.21 22:29, Mike Rapoport wrote: > 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 :) And even that is moot. It doesn't tell you if a PFN is *actually* mapped (hello secretmem). I'd suggest to just use memblock_is_map_memory() in arch specific code. Then it's clear what we are querying exactly and what the semantics might be. -- Thanks, David / dhildenb 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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 4CAF7C433B4 for ; Thu, 15 Apr 2021 09:31:37 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id BB26161158 for ; Thu, 15 Apr 2021 09:31:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BB26161158 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 26C754B63A; Thu, 15 Apr 2021 05:31:36 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@redhat.com Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 2ITYUSqM6SVa; Thu, 15 Apr 2021 05:31:34 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id AA7EB4B646; Thu, 15 Apr 2021 05:31:34 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id ECBA54B626 for ; Thu, 15 Apr 2021 05:31:32 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id v17ypZHRkVb0 for ; Thu, 15 Apr 2021 05:31:31 -0400 (EDT) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by mm01.cs.columbia.edu (Postfix) with ESMTP id B3A254B455 for ; Thu, 15 Apr 2021 05:31:31 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618479091; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=phkRKYasHy2ON2Zd+AYnzw9m/3bL2pWoEajZ+S+eLjE=; b=UHVBgssU6AtMt7bHKsoNjGWZmLb2dNLpL302eS/pWSek+cSANzQYV+T5IF5/6J8TY3XYK9 oGUUZTiXJVLBmXGkoT9uyfn2IYP61rhRDkv/FkfDp4d7J8WZKq9kOSpPzEBM/YRFhSEhTM UCRPfAOEIqko7TFJbvhXa55fXK1c8DU= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-519-We74jQ1HNMadSc7uBlTm7w-1; Thu, 15 Apr 2021 05:31:30 -0400 X-MC-Unique: We74jQ1HNMadSc7uBlTm7w-1 Received: by mail-wm1-f70.google.com with SMTP id i5-20020a05600c3545b029010c8bb11782so2685381wmq.7 for ; Thu, 15 Apr 2021 02:31:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:organization :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=phkRKYasHy2ON2Zd+AYnzw9m/3bL2pWoEajZ+S+eLjE=; b=eAP7E7n+sNOOhkLTjRFYKKRJgMYOt6XGLe/z8K+Ks/lSycDTAfp8IRa6JNd/LeZlb1 TbXnQw3rnT1LQryDeWn/4c3mecylFZYv79LRi0Din3GOEvBPkc5c73rl3KvksBW8D6vu rft9A9TT8W99fodSa29fxuSOS1aRamlY5f7VqEGIB8tWN+oGWtQiHQFH6B7OkvWj4XE3 F5Regt4G12tkDFigqF0GOyNekcJCVj8BGTzsViAHS1Z+N1KvsL+zhbveMsALrrhpkepV fuc6rezPTRzGCMGXzc3NyiK7eJ0UMkHUYx1x9yUurR4zaKds3chvovYxr6G8Vo6E23GK lcmw== X-Gm-Message-State: AOAM530+ZP8IoiqvNS2ZBMaucTPVOThZaQ6jvm77Oe2hSlCziz5vV6Eu 0mFYvD4mf2kyV+gxbKSB1FHCUCct26HqgUvCj54iLpTZdpmGQpTEs0nd97zxSRi/He8O2nnbhzy TqC+DwcX4bENkIWFou//udpAL X-Received: by 2002:adf:8b45:: with SMTP id v5mr2406844wra.398.1618479088794; Thu, 15 Apr 2021 02:31:28 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxfQSnAXznxI2JGkIgFlRINBs/MudcZie1Vu3F7EQtZ3n7ewfaKl4lNqKpS1JUJMayw6nDijQ== X-Received: by 2002:adf:8b45:: with SMTP id v5mr2406812wra.398.1618479088514; Thu, 15 Apr 2021 02:31:28 -0700 (PDT) Received: from [192.168.3.132] (p5b0c6392.dip0.t-ipconnect.de. [91.12.99.146]) by smtp.gmail.com with ESMTPSA id t19sm1746813wmq.14.2021.04.15.02.31.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 15 Apr 2021 02:31:27 -0700 (PDT) Subject: Re: [RFC/RFT PATCH 2/3] arm64: decouple check whether pfn is normal memory from pfn_valid() To: Mike Rapoport 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> From: David Hildenbrand Organization: Red Hat Message-ID: <62161846-4f03-e4b1-ae0b-fdf96f78d97c@redhat.com> Date: Thu, 15 Apr 2021 11:31:26 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=david@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Cc: Anshuman Khandual , Catalin Marinas , linux-kernel@vger.kernel.org, Mike Rapoport , linux-mm@kvack.org, kvmarm@lists.cs.columbia.edu, Marc Zyngier , Will Deacon , linux-arm-kernel@lists.infradead.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On 14.04.21 22:29, Mike Rapoport wrote: > 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 :) And even that is moot. It doesn't tell you if a PFN is *actually* mapped (hello secretmem). I'd suggest to just use memblock_is_map_memory() in arch specific code. Then it's clear what we are querying exactly and what the semantics might be. -- Thanks, David / dhildenb _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm 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,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,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 CD883C433B4 for ; Thu, 15 Apr 2021 09:33:12 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 3EF4461153 for ; 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[91.12.99.146]) by smtp.gmail.com with ESMTPSA id t19sm1746813wmq.14.2021.04.15.02.31.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 15 Apr 2021 02:31:27 -0700 (PDT) Subject: Re: [RFC/RFT PATCH 2/3] arm64: decouple check whether pfn is normal memory from pfn_valid() To: Mike Rapoport 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 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> From: David Hildenbrand Organization: Red Hat Message-ID: <62161846-4f03-e4b1-ae0b-fdf96f78d97c@redhat.com> Date: Thu, 15 Apr 2021 11:31:26 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=david@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210415_023133_283384_C07F1CE4 X-CRM114-Status: GOOD ( 25.24 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 14.04.21 22:29, Mike Rapoport wrote: > 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 :) And even that is moot. It doesn't tell you if a PFN is *actually* mapped (hello secretmem). I'd suggest to just use memblock_is_map_memory() in arch specific code. Then it's clear what we are querying exactly and what the semantics might be. -- Thanks, David / dhildenb _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel