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=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 A075CC433B4 for ; Thu, 15 Apr 2021 09:31:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3C7F46113B for ; Thu, 15 Apr 2021 09:31:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C7F46113B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CDA686B0036; Thu, 15 Apr 2021 05:31:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CB0106B006C; Thu, 15 Apr 2021 05:31:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B29B56B0070; Thu, 15 Apr 2021 05:31:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0091.hostedemail.com [216.40.44.91]) by kanga.kvack.org (Postfix) with ESMTP id 9554C6B0036 for ; Thu, 15 Apr 2021 05:31:32 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 5B32E12E6 for ; Thu, 15 Apr 2021 09:31:32 +0000 (UTC) X-FDA: 78034083624.29.29F10E3 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf14.hostedemail.com (Postfix) with ESMTP id 79C90C0007F2 for ; Thu, 15 Apr 2021 09:31:23 +0000 (UTC) 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-519-158Xmqg2OTGr7s5Kx-lY_g-1; Thu, 15 Apr 2021 05:31:30 -0400 X-MC-Unique: 158Xmqg2OTGr7s5Kx-lY_g-1 Received: by mail-wr1-f72.google.com with SMTP id s9-20020a5d51090000b02901028ea30da6so2457247wrt.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=au1jISdRbEBxLPGPwZJBnNswx3a0JiMJhKMHp2X6UHCzyNDLejfYbyLqFDDNzF/3Xn a1M681Z442yqISKuSv1hcmLDkVWfyck17cJeXWLsIZM6YaKdFZDT7Mo2b5VIA3GhcJlI cHMwWcNNv03HfV6cHL+h0p2C/AXOj9abA0dNocVgVvSHn5EGckTRSXFS7ghHocfSRJBi ixF+Rvu7TfZG6ad/LxEX+QtQFyP7lUO3p2AFtd2dVEJbdXaEzDEZrANwsSBuXhjiCP6r fGM3QM4+xV37ZfcffKLqSiEHrJmwvHyxZ1RkTO7ssdr2Z28UsAMZfvK3nDT4wFBWIWBE s4ig== X-Gm-Message-State: AOAM533pNcXxxdyDFL0Hr1ekmjOehEjjxP2zAl64GztYYumsxUqIcOBF VTK3gGqU8XbO0uJHF1px/A+L0IURa+2cNnxaTdkr4/wJ6SeCJYckZMwzxZ7XfF4KZ6gPy66ooBr NCCWM4qeLT/N88AzSeH+TVqN54LXl8+jcb4y9pul45HR2DA6ja4np5od970w= X-Received: by 2002:adf:8b45:: with SMTP id v5mr2406843wra.398.1618479088789; 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: 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-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Stat-Signature: 8kgfjrfpajujqzt56edaqmqmmg7jrssp X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 79C90C0007F2 Received-SPF: none (redhat.com>: No applicable sender policy available) receiver=imf14; identity=mailfrom; envelope-from=""; helo=us-smtp-delivery-124.mimecast.com; client-ip=216.205.24.124 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1618479083-115522 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 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